Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

26 files changed, 18933 insertions, 0 deletions

diff --git a/kernel/fs/f2fs/Kconfig b/kernel/fs/f2fs/Kconfig
new file mode 100644
index 000000000..05f0f663f
--- /dev/null
+++ b/kernel/fs/f2fs/Kconfig
@@ -0,0 +1,83 @@
+config F2FS_FS
+	tristate "F2FS filesystem support"
+	depends on BLOCK
+	help
+	  F2FS is based on Log-structured File System (LFS), which supports
+	  versatile "flash-friendly" features. The design has been focused on
+	  addressing the fundamental issues in LFS, which are snowball effect
+	  of wandering tree and high cleaning overhead.
+
+	  Since flash-based storages show different characteristics according to
+	  the internal geometry or flash memory management schemes aka FTL, F2FS
+	  and tools support various parameters not only for configuring on-disk
+	  layout, but also for selecting allocation and cleaning algorithms.
+
+	  If unsure, say N.
+
+config F2FS_STAT_FS
+	bool "F2FS Status Information"
+	depends on F2FS_FS && DEBUG_FS
+	default y
+	help
+	  /sys/kernel/debug/f2fs/ contains information about all the partitions
+	  mounted as f2fs. Each file shows the whole f2fs information.
+
+	  /sys/kernel/debug/f2fs/status includes:
+	    - major filesystem information managed by f2fs currently
+	    - average SIT information about whole segments
+	    - current memory footprint consumed by f2fs.
+
+config F2FS_FS_XATTR
+	bool "F2FS extended attributes"
+	depends on F2FS_FS
+	default y
+	help
+	  Extended attributes are name:value pairs associated with inodes by
+	  the kernel or by users (see the attr(5) manual page, or visit
+	  <http://acl.bestbits.at/> for details).
+
+	  If unsure, say N.
+
+config F2FS_FS_POSIX_ACL
+	bool "F2FS Access Control Lists"
+	depends on F2FS_FS_XATTR
+	select FS_POSIX_ACL
+	default y
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  gourps beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N
+
+config F2FS_FS_SECURITY
+	bool "F2FS Security Labels"
+	depends on F2FS_FS_XATTR
+	help
+	  Security labels provide an access control facility to support Linux
+	  Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
+	  Linux. This option enables an extended attribute handler for file
+	  security labels in the f2fs filesystem, so that it requires enabling
+	  the extended attribute support in advance.
+
+	  If you are not using a security module, say N.
+
+config F2FS_CHECK_FS
+	bool "F2FS consistency checking feature"
+	depends on F2FS_FS
+	help
+	  Enables BUG_ONs which check the filesystem consistency in runtime.
+
+	  If you want to improve the performance, say N.
+
+config F2FS_IO_TRACE
+	bool "F2FS IO tracer"
+	depends on F2FS_FS
+	depends on FUNCTION_TRACER
+	help
+	  F2FS IO trace is based on a function trace, which gathers process
+	  information and block IO patterns in the filesystem level.
+
+	  If unsure, say N.
diff --git a/kernel/fs/f2fs/Makefile b/kernel/fs/f2fs/Makefile
new file mode 100644
index 000000000..d92397731
--- /dev/null
+++ b/kernel/fs/f2fs/Makefile
@@ -0,0 +1,8 @@
+obj-$(CONFIG_F2FS_FS) += f2fs.o
+
+f2fs-y		:= dir.o file.o inode.o namei.o hash.o super.o inline.o
+f2fs-y		+= checkpoint.o gc.o data.o node.o segment.o recovery.o
+f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
+f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
+f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o
+f2fs-$(CONFIG_F2FS_IO_TRACE) += trace.o
diff --git a/kernel/fs/f2fs/acl.c b/kernel/fs/f2fs/acl.c
new file mode 100644
index 000000000..4320ffab3
--- /dev/null
+++ b/kernel/fs/f2fs/acl.c
@@ -0,0 +1,410 @@
+/*
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+static inline size_t f2fs_acl_size(int count)
+{
+	if (count <= 4) {
+		return sizeof(struct f2fs_acl_header) +
+			count * sizeof(struct f2fs_acl_entry_short);
+	} else {
+		return sizeof(struct f2fs_acl_header) +
+			4 * sizeof(struct f2fs_acl_entry_short) +
+			(count - 4) * sizeof(struct f2fs_acl_entry);
+	}
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+	ssize_t s;
+	size -= sizeof(struct f2fs_acl_header);
+	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+	if (s < 0) {
+		if (size % sizeof(struct f2fs_acl_entry_short))
+			return -1;
+		return size / sizeof(struct f2fs_acl_entry_short);
+	} else {
+		if (s % sizeof(struct f2fs_acl_entry))
+			return -1;
+		return s / sizeof(struct f2fs_acl_entry) + 4;
+	}
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+	int i, count;
+	struct posix_acl *acl;
+	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+	const char *end = value + size;
+
+	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+		return ERR_PTR(-EINVAL);
+
+	count = f2fs_acl_count(size);
+	if (count < 0)
+		return ERR_PTR(-EINVAL);
+	if (count == 0)
+		return NULL;
+
+	acl = posix_acl_alloc(count, GFP_NOFS);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < count; i++) {
+
+		if ((char *)entry > end)
+			goto fail;
+
+		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
+		acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+
+		case ACL_USER:
+			acl->a_entries[i].e_uid =
+				make_kuid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			acl->a_entries[i].e_gid =
+				make_kgid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	if ((char *)entry != end)
+		goto fail;
+	return acl;
+fail:
+	posix_acl_release(acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+	struct f2fs_acl_header *f2fs_acl;
+	struct f2fs_acl_entry *entry;
+	int i;
+
+	f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
+			sizeof(struct f2fs_acl_entry), GFP_NOFS);
+	if (!f2fs_acl)
+		return ERR_PTR(-ENOMEM);
+
+	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+	for (i = 0; i < acl->a_count; i++) {
+
+		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
+		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER:
+			entry->e_id = cpu_to_le32(
+					from_kuid(&init_user_ns,
+						acl->a_entries[i].e_uid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			entry->e_id = cpu_to_le32(
+					from_kgid(&init_user_ns,
+						acl->a_entries[i].e_gid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	*size = f2fs_acl_size(acl->a_count);
+	return (void *)f2fs_acl;
+
+fail:
+	kfree(f2fs_acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
+						struct page *dpage)
+{
+	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+	void *value = NULL;
+	struct posix_acl *acl;
+	int retval;
+
+	if (type == ACL_TYPE_ACCESS)
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+	retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
+	if (retval > 0) {
+		value = kmalloc(retval, GFP_F2FS_ZERO);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		retval = f2fs_getxattr(inode, name_index, "", value,
+							retval, dpage);
+	}
+
+	if (retval > 0)
+		acl = f2fs_acl_from_disk(value, retval);
+	else if (retval == -ENODATA)
+		acl = NULL;
+	else
+		acl = ERR_PTR(retval);
+	kfree(value);
+
+	if (!IS_ERR(acl))
+		set_cached_acl(inode, type, acl);
+
+	return acl;
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+	return __f2fs_get_acl(inode, type, NULL);
+}
+
+static int __f2fs_set_acl(struct inode *inode, int type,
+			struct posix_acl *acl, struct page *ipage)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	int name_index;
+	void *value = NULL;
+	size_t size = 0;
+	int error;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+		if (acl) {
+			error = posix_acl_equiv_mode(acl, &inode->i_mode);
+			if (error < 0)
+				return error;
+			set_acl_inode(fi, inode->i_mode);
+			if (error == 0)
+				acl = NULL;
+		}
+		break;
+
+	case ACL_TYPE_DEFAULT:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (acl) {
+		value = f2fs_acl_to_disk(acl, &size);
+		if (IS_ERR(value)) {
+			clear_inode_flag(fi, FI_ACL_MODE);
+			return (int)PTR_ERR(value);
+		}
+	}
+
+	error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
+
+	kfree(value);
+	if (!error)
+		set_cached_acl(inode, type, acl);
+
+	clear_inode_flag(fi, FI_ACL_MODE);
+	return error;
+}
+
+int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	return __f2fs_set_acl(inode, type, acl, NULL);
+}
+
+/*
+ * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
+ * are copied from posix_acl.c
+ */
+static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
+							gfp_t flags)
+{
+	struct posix_acl *clone = NULL;
+
+	if (acl) {
+		int size = sizeof(struct posix_acl) + acl->a_count *
+				sizeof(struct posix_acl_entry);
+		clone = kmemdup(acl, size, flags);
+		if (clone)
+			atomic_set(&clone->a_refcount, 1);
+	}
+	return clone;
+}
+
+static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
+{
+	struct posix_acl_entry *pa, *pe;
+	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+	umode_t mode = *mode_p;
+	int not_equiv = 0;
+
+	/* assert(atomic_read(acl->a_refcount) == 1); */
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch(pa->e_tag) {
+		case ACL_USER_OBJ:
+			pa->e_perm &= (mode >> 6) | ~S_IRWXO;
+			mode &= (pa->e_perm << 6) | ~S_IRWXU;
+			break;
+
+		case ACL_USER:
+		case ACL_GROUP:
+			not_equiv = 1;
+			break;
+
+		case ACL_GROUP_OBJ:
+			group_obj = pa;
+			break;
+
+		case ACL_OTHER:
+			pa->e_perm &= mode | ~S_IRWXO;
+			mode &= pa->e_perm | ~S_IRWXO;
+			break;
+
+		case ACL_MASK:
+			mask_obj = pa;
+			not_equiv = 1;
+			break;
+
+		default:
+			return -EIO;
+		}
+	}
+
+	if (mask_obj) {
+		mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
+	} else {
+		if (!group_obj)
+			return -EIO;
+		group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
+	}
+
+	*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+        return not_equiv;
+}
+
+static int f2fs_acl_create(struct inode *dir, umode_t *mode,
+		struct posix_acl **default_acl, struct posix_acl **acl,
+		struct page *dpage)
+{
+	struct posix_acl *p;
+	int ret;
+
+	if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
+		goto no_acl;
+
+	p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
+	if (IS_ERR(p)) {
+		if (p == ERR_PTR(-EOPNOTSUPP))
+			goto apply_umask;
+		return PTR_ERR(p);
+	}
+
+	if (!p)
+		goto apply_umask;
+
+	*acl = f2fs_acl_clone(p, GFP_NOFS);
+	if (!*acl)
+		goto no_mem;
+
+	ret = f2fs_acl_create_masq(*acl, mode);
+	if (ret < 0)
+		goto no_mem_clone;
+
+	if (ret == 0) {
+		posix_acl_release(*acl);
+		*acl = NULL;
+	}
+
+	if (!S_ISDIR(*mode)) {
+		posix_acl_release(p);
+		*default_acl = NULL;
+	} else {
+		*default_acl = p;
+	}
+	return 0;
+
+apply_umask:
+	*mode &= ~current_umask();
+no_acl:
+	*default_acl = NULL;
+	*acl = NULL;
+	return 0;
+
+no_mem_clone:
+	posix_acl_release(*acl);
+no_mem:
+	posix_acl_release(p);
+	return -ENOMEM;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
+							struct page *dpage)
+{
+	struct posix_acl *default_acl = NULL, *acl = NULL;
+	int error = 0;
+
+	error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
+	if (error)
+		return error;
+
+	if (default_acl) {
+		error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
+				       ipage);
+		posix_acl_release(default_acl);
+	}
+	if (acl) {
+		if (!error)
+			error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
+					       ipage);
+		posix_acl_release(acl);
+	}
+
+	return error;
+}
diff --git a/kernel/fs/f2fs/acl.h b/kernel/fs/f2fs/acl.h
new file mode 100644
index 000000000..997ca8edb
--- /dev/null
+++ b/kernel/fs/f2fs/acl.h
@@ -0,0 +1,54 @@
+/*
+ * fs/f2fs/acl.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.h
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_ACL_H__
+#define __F2FS_ACL_H__
+
+#include <linux/posix_acl_xattr.h>
+
+#define F2FS_ACL_VERSION	0x0001
+
+struct f2fs_acl_entry {
+	__le16 e_tag;
+	__le16 e_perm;
+	__le32 e_id;
+};
+
+struct f2fs_acl_entry_short {
+	__le16 e_tag;
+	__le16 e_perm;
+};
+
+struct f2fs_acl_header {
+	__le32 a_version;
+};
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+
+extern struct posix_acl *f2fs_get_acl(struct inode *, int);
+extern int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
+							struct page *);
+#else
+#define f2fs_check_acl	NULL
+#define f2fs_get_acl	NULL
+#define f2fs_set_acl	NULL
+
+static inline int f2fs_init_acl(struct inode *inode, struct inode *dir,
+				struct page *ipage, struct page *dpage)
+{
+	return 0;
+}
+#endif
+#endif /* __F2FS_ACL_H__ */
diff --git a/kernel/fs/f2fs/checkpoint.c b/kernel/fs/f2fs/checkpoint.c
new file mode 100644
index 000000000..a5e17a2a0
--- /dev/null
+++ b/kernel/fs/f2fs/checkpoint.c
@@ -0,0 +1,1135 @@
+/*
+ * fs/f2fs/checkpoint.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/bio.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static struct kmem_cache *ino_entry_slab;
+struct kmem_cache *inode_entry_slab;
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	struct page *page = NULL;
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+	f2fs_wait_on_page_writeback(page, META);
+	SetPageUptodate(page);
+	return page;
+}
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	struct page *page;
+	struct f2fs_io_info fio = {
+		.type = META,
+		.rw = READ_SYNC | REQ_META | REQ_PRIO,
+		.blk_addr = index,
+	};
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+	if (PageUptodate(page))
+		goto out;
+
+	if (f2fs_submit_page_bio(sbi, page, &fio))
+		goto repeat;
+
+	lock_page(page);
+	if (unlikely(page->mapping != mapping)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+out:
+	return page;
+}
+
+static inline bool is_valid_blkaddr(struct f2fs_sb_info *sbi,
+						block_t blkaddr, int type)
+{
+	switch (type) {
+	case META_NAT:
+		break;
+	case META_SIT:
+		if (unlikely(blkaddr >= SIT_BLK_CNT(sbi)))
+			return false;
+		break;
+	case META_SSA:
+		if (unlikely(blkaddr >= MAIN_BLKADDR(sbi) ||
+			blkaddr < SM_I(sbi)->ssa_blkaddr))
+			return false;
+		break;
+	case META_CP:
+		if (unlikely(blkaddr >= SIT_I(sbi)->sit_base_addr ||
+			blkaddr < __start_cp_addr(sbi)))
+			return false;
+		break;
+	case META_POR:
+		if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
+			blkaddr < MAIN_BLKADDR(sbi)))
+			return false;
+		break;
+	default:
+		BUG();
+	}
+
+	return true;
+}
+
+/*
+ * Readahead CP/NAT/SIT/SSA pages
+ */
+int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages, int type)
+{
+	block_t prev_blk_addr = 0;
+	struct page *page;
+	block_t blkno = start;
+	struct f2fs_io_info fio = {
+		.type = META,
+		.rw = READ_SYNC | REQ_META | REQ_PRIO
+	};
+
+	for (; nrpages-- > 0; blkno++) {
+
+		if (!is_valid_blkaddr(sbi, blkno, type))
+			goto out;
+
+		switch (type) {
+		case META_NAT:
+			if (unlikely(blkno >=
+					NAT_BLOCK_OFFSET(NM_I(sbi)->max_nid)))
+				blkno = 0;
+			/* get nat block addr */
+			fio.blk_addr = current_nat_addr(sbi,
+					blkno * NAT_ENTRY_PER_BLOCK);
+			break;
+		case META_SIT:
+			/* get sit block addr */
+			fio.blk_addr = current_sit_addr(sbi,
+					blkno * SIT_ENTRY_PER_BLOCK);
+			if (blkno != start && prev_blk_addr + 1 != fio.blk_addr)
+				goto out;
+			prev_blk_addr = fio.blk_addr;
+			break;
+		case META_SSA:
+		case META_CP:
+		case META_POR:
+			fio.blk_addr = blkno;
+			break;
+		default:
+			BUG();
+		}
+
+		page = grab_cache_page(META_MAPPING(sbi), fio.blk_addr);
+		if (!page)
+			continue;
+		if (PageUptodate(page)) {
+			f2fs_put_page(page, 1);
+			continue;
+		}
+
+		f2fs_submit_page_mbio(sbi, page, &fio);
+		f2fs_put_page(page, 0);
+	}
+out:
+	f2fs_submit_merged_bio(sbi, META, READ);
+	return blkno - start;
+}
+
+void ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct page *page;
+	bool readahead = false;
+
+	page = find_get_page(META_MAPPING(sbi), index);
+	if (!page || (page && !PageUptodate(page)))
+		readahead = true;
+	f2fs_put_page(page, 0);
+
+	if (readahead)
+		ra_meta_pages(sbi, index, MAX_BIO_BLOCKS(sbi), META_POR);
+}
+
+static int f2fs_write_meta_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+
+	trace_f2fs_writepage(page, META);
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+	if (wbc->for_reclaim && page->index < GET_SUM_BLOCK(sbi, 0))
+		goto redirty_out;
+	if (unlikely(f2fs_cp_error(sbi)))
+		goto redirty_out;
+
+	f2fs_wait_on_page_writeback(page, META);
+	write_meta_page(sbi, page);
+	dec_page_count(sbi, F2FS_DIRTY_META);
+	unlock_page(page);
+
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_bio(sbi, META, WRITE);
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+static int f2fs_write_meta_pages(struct address_space *mapping,
+				struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+	long diff, written;
+
+	trace_f2fs_writepages(mapping->host, wbc, META);
+
+	/* collect a number of dirty meta pages and write together */
+	if (wbc->for_kupdate ||
+		get_pages(sbi, F2FS_DIRTY_META) < nr_pages_to_skip(sbi, META))
+		goto skip_write;
+
+	/* if mounting is failed, skip writing node pages */
+	mutex_lock(&sbi->cp_mutex);
+	diff = nr_pages_to_write(sbi, META, wbc);
+	written = sync_meta_pages(sbi, META, wbc->nr_to_write);
+	mutex_unlock(&sbi->cp_mutex);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_META);
+	return 0;
+}
+
+long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
+						long nr_to_write)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	pgoff_t index = 0, end = LONG_MAX;
+	struct pagevec pvec;
+	long nwritten = 0;
+	struct writeback_control wbc = {
+		.for_reclaim = 0,
+	};
+
+	pagevec_init(&pvec, 0);
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (unlikely(nr_pages == 0))
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != mapping)) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			if (mapping->a_ops->writepage(page, &wbc)) {
+				unlock_page(page);
+				break;
+			}
+			nwritten++;
+			if (unlikely(nwritten >= nr_to_write))
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+
+	if (nwritten)
+		f2fs_submit_merged_bio(sbi, type, WRITE);
+
+	return nwritten;
+}
+
+static int f2fs_set_meta_page_dirty(struct page *page)
+{
+	trace_f2fs_set_page_dirty(page, META);
+
+	SetPageUptodate(page);
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_META);
+		SetPagePrivate(page);
+		f2fs_trace_pid(page);
+		return 1;
+	}
+	return 0;
+}
+
+const struct address_space_operations f2fs_meta_aops = {
+	.writepage	= f2fs_write_meta_page,
+	.writepages	= f2fs_write_meta_pages,
+	.set_page_dirty	= f2fs_set_meta_page_dirty,
+	.invalidatepage = f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+};
+
+static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	struct inode_management *im = &sbi->im[type];
+	struct ino_entry *e;
+retry:
+	if (radix_tree_preload(GFP_NOFS)) {
+		cond_resched();
+		goto retry;
+	}
+
+	spin_lock(&im->ino_lock);
+
+	e = radix_tree_lookup(&im->ino_root, ino);
+	if (!e) {
+		e = kmem_cache_alloc(ino_entry_slab, GFP_ATOMIC);
+		if (!e) {
+			spin_unlock(&im->ino_lock);
+			radix_tree_preload_end();
+			goto retry;
+		}
+		if (radix_tree_insert(&im->ino_root, ino, e)) {
+			spin_unlock(&im->ino_lock);
+			kmem_cache_free(ino_entry_slab, e);
+			radix_tree_preload_end();
+			goto retry;
+		}
+		memset(e, 0, sizeof(struct ino_entry));
+		e->ino = ino;
+
+		list_add_tail(&e->list, &im->ino_list);
+		if (type != ORPHAN_INO)
+			im->ino_num++;
+	}
+	spin_unlock(&im->ino_lock);
+	radix_tree_preload_end();
+}
+
+static void __remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	struct inode_management *im = &sbi->im[type];
+	struct ino_entry *e;
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	if (e) {
+		list_del(&e->list);
+		radix_tree_delete(&im->ino_root, ino);
+		im->ino_num--;
+		spin_unlock(&im->ino_lock);
+		kmem_cache_free(ino_entry_slab, e);
+		return;
+	}
+	spin_unlock(&im->ino_lock);
+}
+
+void add_dirty_inode(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	/* add new dirty ino entry into list */
+	__add_ino_entry(sbi, ino, type);
+}
+
+void remove_dirty_inode(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	/* remove dirty ino entry from list */
+	__remove_ino_entry(sbi, ino, type);
+}
+
+/* mode should be APPEND_INO or UPDATE_INO */
+bool exist_written_data(struct f2fs_sb_info *sbi, nid_t ino, int mode)
+{
+	struct inode_management *im = &sbi->im[mode];
+	struct ino_entry *e;
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	spin_unlock(&im->ino_lock);
+	return e ? true : false;
+}
+
+void release_dirty_inode(struct f2fs_sb_info *sbi)
+{
+	struct ino_entry *e, *tmp;
+	int i;
+
+	for (i = APPEND_INO; i <= UPDATE_INO; i++) {
+		struct inode_management *im = &sbi->im[i];
+
+		spin_lock(&im->ino_lock);
+		list_for_each_entry_safe(e, tmp, &im->ino_list, list) {
+			list_del(&e->list);
+			radix_tree_delete(&im->ino_root, e->ino);
+			kmem_cache_free(ino_entry_slab, e);
+			im->ino_num--;
+		}
+		spin_unlock(&im->ino_lock);
+	}
+}
+
+int acquire_orphan_inode(struct f2fs_sb_info *sbi)
+{
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+	int err = 0;
+
+	spin_lock(&im->ino_lock);
+	if (unlikely(im->ino_num >= sbi->max_orphans))
+		err = -ENOSPC;
+	else
+		im->ino_num++;
+	spin_unlock(&im->ino_lock);
+
+	return err;
+}
+
+void release_orphan_inode(struct f2fs_sb_info *sbi)
+{
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+
+	spin_lock(&im->ino_lock);
+	f2fs_bug_on(sbi, im->ino_num == 0);
+	im->ino_num--;
+	spin_unlock(&im->ino_lock);
+}
+
+void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	/* add new orphan ino entry into list */
+	__add_ino_entry(sbi, ino, ORPHAN_INO);
+}
+
+void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	/* remove orphan entry from orphan list */
+	__remove_ino_entry(sbi, ino, ORPHAN_INO);
+}
+
+static void recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode = f2fs_iget(sbi->sb, ino);
+	f2fs_bug_on(sbi, IS_ERR(inode));
+	clear_nlink(inode);
+
+	/* truncate all the data during iput */
+	iput(inode);
+}
+
+void recover_orphan_inodes(struct f2fs_sb_info *sbi)
+{
+	block_t start_blk, orphan_blocks, i, j;
+
+	if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
+		return;
+
+	set_sbi_flag(sbi, SBI_POR_DOING);
+
+	start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
+	orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi);
+
+	ra_meta_pages(sbi, start_blk, orphan_blocks, META_CP);
+
+	for (i = 0; i < orphan_blocks; i++) {
+		struct page *page = get_meta_page(sbi, start_blk + i);
+		struct f2fs_orphan_block *orphan_blk;
+
+		orphan_blk = (struct f2fs_orphan_block *)page_address(page);
+		for (j = 0; j < le32_to_cpu(orphan_blk->entry_count); j++) {
+			nid_t ino = le32_to_cpu(orphan_blk->ino[j]);
+			recover_orphan_inode(sbi, ino);
+		}
+		f2fs_put_page(page, 1);
+	}
+	/* clear Orphan Flag */
+	clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+	return;
+}
+
+static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	struct list_head *head;
+	struct f2fs_orphan_block *orphan_blk = NULL;
+	unsigned int nentries = 0;
+	unsigned short index;
+	unsigned short orphan_blocks;
+	struct page *page = NULL;
+	struct ino_entry *orphan = NULL;
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+
+	orphan_blocks = GET_ORPHAN_BLOCKS(im->ino_num);
+
+	for (index = 0; index < orphan_blocks; index++)
+		grab_meta_page(sbi, start_blk + index);
+
+	index = 1;
+	spin_lock(&im->ino_lock);
+	head = &im->ino_list;
+
+	/* loop for each orphan inode entry and write them in Jornal block */
+	list_for_each_entry(orphan, head, list) {
+		if (!page) {
+			page = find_get_page(META_MAPPING(sbi), start_blk++);
+			f2fs_bug_on(sbi, !page);
+			orphan_blk =
+				(struct f2fs_orphan_block *)page_address(page);
+			memset(orphan_blk, 0, sizeof(*orphan_blk));
+			f2fs_put_page(page, 0);
+		}
+
+		orphan_blk->ino[nentries++] = cpu_to_le32(orphan->ino);
+
+		if (nentries == F2FS_ORPHANS_PER_BLOCK) {
+			/*
+			 * an orphan block is full of 1020 entries,
+			 * then we need to flush current orphan blocks
+			 * and bring another one in memory
+			 */
+			orphan_blk->blk_addr = cpu_to_le16(index);
+			orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+			orphan_blk->entry_count = cpu_to_le32(nentries);
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+			index++;
+			nentries = 0;
+			page = NULL;
+		}
+	}
+
+	if (page) {
+		orphan_blk->blk_addr = cpu_to_le16(index);
+		orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+		orphan_blk->entry_count = cpu_to_le32(nentries);
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+
+	spin_unlock(&im->ino_lock);
+}
+
+static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
+				block_t cp_addr, unsigned long long *version)
+{
+	struct page *cp_page_1, *cp_page_2 = NULL;
+	unsigned long blk_size = sbi->blocksize;
+	struct f2fs_checkpoint *cp_block;
+	unsigned long long cur_version = 0, pre_version = 0;
+	size_t crc_offset;
+	__u32 crc = 0;
+
+	/* Read the 1st cp block in this CP pack */
+	cp_page_1 = get_meta_page(sbi, cp_addr);
+
+	/* get the version number */
+	cp_block = (struct f2fs_checkpoint *)page_address(cp_page_1);
+	crc_offset = le32_to_cpu(cp_block->checksum_offset);
+	if (crc_offset >= blk_size)
+		goto invalid_cp1;
+
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)cp_block + crc_offset)));
+	if (!f2fs_crc_valid(crc, cp_block, crc_offset))
+		goto invalid_cp1;
+
+	pre_version = cur_cp_version(cp_block);
+
+	/* Read the 2nd cp block in this CP pack */
+	cp_addr += le32_to_cpu(cp_block->cp_pack_total_block_count) - 1;
+	cp_page_2 = get_meta_page(sbi, cp_addr);
+
+	cp_block = (struct f2fs_checkpoint *)page_address(cp_page_2);
+	crc_offset = le32_to_cpu(cp_block->checksum_offset);
+	if (crc_offset >= blk_size)
+		goto invalid_cp2;
+
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)cp_block + crc_offset)));
+	if (!f2fs_crc_valid(crc, cp_block, crc_offset))
+		goto invalid_cp2;
+
+	cur_version = cur_cp_version(cp_block);
+
+	if (cur_version == pre_version) {
+		*version = cur_version;
+		f2fs_put_page(cp_page_2, 1);
+		return cp_page_1;
+	}
+invalid_cp2:
+	f2fs_put_page(cp_page_2, 1);
+invalid_cp1:
+	f2fs_put_page(cp_page_1, 1);
+	return NULL;
+}
+
+int get_valid_checkpoint(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *cp_block;
+	struct f2fs_super_block *fsb = sbi->raw_super;
+	struct page *cp1, *cp2, *cur_page;
+	unsigned long blk_size = sbi->blocksize;
+	unsigned long long cp1_version = 0, cp2_version = 0;
+	unsigned long long cp_start_blk_no;
+	unsigned int cp_blks = 1 + __cp_payload(sbi);
+	block_t cp_blk_no;
+	int i;
+
+	sbi->ckpt = kzalloc(cp_blks * blk_size, GFP_KERNEL);
+	if (!sbi->ckpt)
+		return -ENOMEM;
+	/*
+	 * Finding out valid cp block involves read both
+	 * sets( cp pack1 and cp pack 2)
+	 */
+	cp_start_blk_no = le32_to_cpu(fsb->cp_blkaddr);
+	cp1 = validate_checkpoint(sbi, cp_start_blk_no, &cp1_version);
+
+	/* The second checkpoint pack should start at the next segment */
+	cp_start_blk_no += ((unsigned long long)1) <<
+				le32_to_cpu(fsb->log_blocks_per_seg);
+	cp2 = validate_checkpoint(sbi, cp_start_blk_no, &cp2_version);
+
+	if (cp1 && cp2) {
+		if (ver_after(cp2_version, cp1_version))
+			cur_page = cp2;
+		else
+			cur_page = cp1;
+	} else if (cp1) {
+		cur_page = cp1;
+	} else if (cp2) {
+		cur_page = cp2;
+	} else {
+		goto fail_no_cp;
+	}
+
+	cp_block = (struct f2fs_checkpoint *)page_address(cur_page);
+	memcpy(sbi->ckpt, cp_block, blk_size);
+
+	if (cp_blks <= 1)
+		goto done;
+
+	cp_blk_no = le32_to_cpu(fsb->cp_blkaddr);
+	if (cur_page == cp2)
+		cp_blk_no += 1 << le32_to_cpu(fsb->log_blocks_per_seg);
+
+	for (i = 1; i < cp_blks; i++) {
+		void *sit_bitmap_ptr;
+		unsigned char *ckpt = (unsigned char *)sbi->ckpt;
+
+		cur_page = get_meta_page(sbi, cp_blk_no + i);
+		sit_bitmap_ptr = page_address(cur_page);
+		memcpy(ckpt + i * blk_size, sit_bitmap_ptr, blk_size);
+		f2fs_put_page(cur_page, 1);
+	}
+done:
+	f2fs_put_page(cp1, 1);
+	f2fs_put_page(cp2, 1);
+	return 0;
+
+fail_no_cp:
+	kfree(sbi->ckpt);
+	return -EINVAL;
+}
+
+static int __add_dirty_inode(struct inode *inode, struct inode_entry *new)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (is_inode_flag_set(F2FS_I(inode), FI_DIRTY_DIR))
+		return -EEXIST;
+
+	set_inode_flag(F2FS_I(inode), FI_DIRTY_DIR);
+	F2FS_I(inode)->dirty_dir = new;
+	list_add_tail(&new->list, &sbi->dir_inode_list);
+	stat_inc_dirty_dir(sbi);
+	return 0;
+}
+
+void update_dirty_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct inode_entry *new;
+	int ret = 0;
+
+	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode))
+		return;
+
+	if (!S_ISDIR(inode->i_mode)) {
+		inode_inc_dirty_pages(inode);
+		goto out;
+	}
+
+	new = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	new->inode = inode;
+	INIT_LIST_HEAD(&new->list);
+
+	spin_lock(&sbi->dir_inode_lock);
+	ret = __add_dirty_inode(inode, new);
+	inode_inc_dirty_pages(inode);
+	spin_unlock(&sbi->dir_inode_lock);
+
+	if (ret)
+		kmem_cache_free(inode_entry_slab, new);
+out:
+	SetPagePrivate(page);
+	f2fs_trace_pid(page);
+}
+
+void add_dirty_dir_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct inode_entry *new =
+			f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	int ret = 0;
+
+	new->inode = inode;
+	INIT_LIST_HEAD(&new->list);
+
+	spin_lock(&sbi->dir_inode_lock);
+	ret = __add_dirty_inode(inode, new);
+	spin_unlock(&sbi->dir_inode_lock);
+
+	if (ret)
+		kmem_cache_free(inode_entry_slab, new);
+}
+
+void remove_dirty_dir_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct inode_entry *entry;
+
+	if (!S_ISDIR(inode->i_mode))
+		return;
+
+	spin_lock(&sbi->dir_inode_lock);
+	if (get_dirty_pages(inode) ||
+			!is_inode_flag_set(F2FS_I(inode), FI_DIRTY_DIR)) {
+		spin_unlock(&sbi->dir_inode_lock);
+		return;
+	}
+
+	entry = F2FS_I(inode)->dirty_dir;
+	list_del(&entry->list);
+	F2FS_I(inode)->dirty_dir = NULL;
+	clear_inode_flag(F2FS_I(inode), FI_DIRTY_DIR);
+	stat_dec_dirty_dir(sbi);
+	spin_unlock(&sbi->dir_inode_lock);
+	kmem_cache_free(inode_entry_slab, entry);
+
+	/* Only from the recovery routine */
+	if (is_inode_flag_set(F2FS_I(inode), FI_DELAY_IPUT)) {
+		clear_inode_flag(F2FS_I(inode), FI_DELAY_IPUT);
+		iput(inode);
+	}
+}
+
+void sync_dirty_dir_inodes(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head;
+	struct inode_entry *entry;
+	struct inode *inode;
+retry:
+	if (unlikely(f2fs_cp_error(sbi)))
+		return;
+
+	spin_lock(&sbi->dir_inode_lock);
+
+	head = &sbi->dir_inode_list;
+	if (list_empty(head)) {
+		spin_unlock(&sbi->dir_inode_lock);
+		return;
+	}
+	entry = list_entry(head->next, struct inode_entry, list);
+	inode = igrab(entry->inode);
+	spin_unlock(&sbi->dir_inode_lock);
+	if (inode) {
+		filemap_fdatawrite(inode->i_mapping);
+		iput(inode);
+	} else {
+		/*
+		 * We should submit bio, since it exists several
+		 * wribacking dentry pages in the freeing inode.
+		 */
+		f2fs_submit_merged_bio(sbi, DATA, WRITE);
+		cond_resched();
+	}
+	goto retry;
+}
+
+/*
+ * Freeze all the FS-operations for checkpoint.
+ */
+static int block_operations(struct f2fs_sb_info *sbi)
+{
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = LONG_MAX,
+		.for_reclaim = 0,
+	};
+	struct blk_plug plug;
+	int err = 0;
+
+	blk_start_plug(&plug);
+
+retry_flush_dents:
+	f2fs_lock_all(sbi);
+	/* write all the dirty dentry pages */
+	if (get_pages(sbi, F2FS_DIRTY_DENTS)) {
+		f2fs_unlock_all(sbi);
+		sync_dirty_dir_inodes(sbi);
+		if (unlikely(f2fs_cp_error(sbi))) {
+			err = -EIO;
+			goto out;
+		}
+		goto retry_flush_dents;
+	}
+
+	/*
+	 * POR: we should ensure that there are no dirty node pages
+	 * until finishing nat/sit flush.
+	 */
+retry_flush_nodes:
+	down_write(&sbi->node_write);
+
+	if (get_pages(sbi, F2FS_DIRTY_NODES)) {
+		up_write(&sbi->node_write);
+		sync_node_pages(sbi, 0, &wbc);
+		if (unlikely(f2fs_cp_error(sbi))) {
+			f2fs_unlock_all(sbi);
+			err = -EIO;
+			goto out;
+		}
+		goto retry_flush_nodes;
+	}
+out:
+	blk_finish_plug(&plug);
+	return err;
+}
+
+static void unblock_operations(struct f2fs_sb_info *sbi)
+{
+	up_write(&sbi->node_write);
+	f2fs_unlock_all(sbi);
+}
+
+static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
+{
+	DEFINE_WAIT(wait);
+
+	for (;;) {
+		prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
+
+		if (!get_pages(sbi, F2FS_WRITEBACK))
+			break;
+
+		io_schedule();
+	}
+	finish_wait(&sbi->cp_wait, &wait);
+}
+
+static void do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
+	nid_t last_nid = nm_i->next_scan_nid;
+	block_t start_blk;
+	struct page *cp_page;
+	unsigned int data_sum_blocks, orphan_blocks;
+	__u32 crc32 = 0;
+	void *kaddr;
+	int i;
+	int cp_payload_blks = __cp_payload(sbi);
+
+	/*
+	 * This avoids to conduct wrong roll-forward operations and uses
+	 * metapages, so should be called prior to sync_meta_pages below.
+	 */
+	discard_next_dnode(sbi, NEXT_FREE_BLKADDR(sbi, curseg));
+
+	/* Flush all the NAT/SIT pages */
+	while (get_pages(sbi, F2FS_DIRTY_META)) {
+		sync_meta_pages(sbi, META, LONG_MAX);
+		if (unlikely(f2fs_cp_error(sbi)))
+			return;
+	}
+
+	next_free_nid(sbi, &last_nid);
+
+	/*
+	 * modify checkpoint
+	 * version number is already updated
+	 */
+	ckpt->elapsed_time = cpu_to_le64(get_mtime(sbi));
+	ckpt->valid_block_count = cpu_to_le64(valid_user_blocks(sbi));
+	ckpt->free_segment_count = cpu_to_le32(free_segments(sbi));
+	for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+		ckpt->cur_node_segno[i] =
+			cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_NODE));
+		ckpt->cur_node_blkoff[i] =
+			cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_NODE));
+		ckpt->alloc_type[i + CURSEG_HOT_NODE] =
+				curseg_alloc_type(sbi, i + CURSEG_HOT_NODE);
+	}
+	for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
+		ckpt->cur_data_segno[i] =
+			cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_DATA));
+		ckpt->cur_data_blkoff[i] =
+			cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_DATA));
+		ckpt->alloc_type[i + CURSEG_HOT_DATA] =
+				curseg_alloc_type(sbi, i + CURSEG_HOT_DATA);
+	}
+
+	ckpt->valid_node_count = cpu_to_le32(valid_node_count(sbi));
+	ckpt->valid_inode_count = cpu_to_le32(valid_inode_count(sbi));
+	ckpt->next_free_nid = cpu_to_le32(last_nid);
+
+	/* 2 cp  + n data seg summary + orphan inode blocks */
+	data_sum_blocks = npages_for_summary_flush(sbi, false);
+	if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
+		set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+	else
+		clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+
+	orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num);
+	ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
+			orphan_blocks);
+
+	if (__remain_node_summaries(cpc->reason))
+		ckpt->cp_pack_total_block_count = cpu_to_le32(F2FS_CP_PACKS+
+				cp_payload_blks + data_sum_blocks +
+				orphan_blocks + NR_CURSEG_NODE_TYPE);
+	else
+		ckpt->cp_pack_total_block_count = cpu_to_le32(F2FS_CP_PACKS +
+				cp_payload_blks + data_sum_blocks +
+				orphan_blocks);
+
+	if (cpc->reason == CP_UMOUNT)
+		set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+	else
+		clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+
+	if (cpc->reason == CP_FASTBOOT)
+		set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+	else
+		clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+
+	if (orphan_num)
+		set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+	else
+		clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+
+	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
+		set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+
+	/* update SIT/NAT bitmap */
+	get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
+	get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
+
+	crc32 = f2fs_crc32(ckpt, le32_to_cpu(ckpt->checksum_offset));
+	*((__le32 *)((unsigned char *)ckpt +
+				le32_to_cpu(ckpt->checksum_offset)))
+				= cpu_to_le32(crc32);
+
+	start_blk = __start_cp_addr(sbi);
+
+	/* write out checkpoint buffer at block 0 */
+	cp_page = grab_meta_page(sbi, start_blk++);
+	kaddr = page_address(cp_page);
+	memcpy(kaddr, ckpt, F2FS_BLKSIZE);
+	set_page_dirty(cp_page);
+	f2fs_put_page(cp_page, 1);
+
+	for (i = 1; i < 1 + cp_payload_blks; i++) {
+		cp_page = grab_meta_page(sbi, start_blk++);
+		kaddr = page_address(cp_page);
+		memcpy(kaddr, (char *)ckpt + i * F2FS_BLKSIZE, F2FS_BLKSIZE);
+		set_page_dirty(cp_page);
+		f2fs_put_page(cp_page, 1);
+	}
+
+	if (orphan_num) {
+		write_orphan_inodes(sbi, start_blk);
+		start_blk += orphan_blocks;
+	}
+
+	write_data_summaries(sbi, start_blk);
+	start_blk += data_sum_blocks;
+	if (__remain_node_summaries(cpc->reason)) {
+		write_node_summaries(sbi, start_blk);
+		start_blk += NR_CURSEG_NODE_TYPE;
+	}
+
+	/* writeout checkpoint block */
+	cp_page = grab_meta_page(sbi, start_blk);
+	kaddr = page_address(cp_page);
+	memcpy(kaddr, ckpt, F2FS_BLKSIZE);
+	set_page_dirty(cp_page);
+	f2fs_put_page(cp_page, 1);
+
+	/* wait for previous submitted node/meta pages writeback */
+	wait_on_all_pages_writeback(sbi);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return;
+
+	filemap_fdatawait_range(NODE_MAPPING(sbi), 0, LONG_MAX);
+	filemap_fdatawait_range(META_MAPPING(sbi), 0, LONG_MAX);
+
+	/* update user_block_counts */
+	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	sbi->alloc_valid_block_count = 0;
+
+	/* Here, we only have one bio having CP pack */
+	sync_meta_pages(sbi, META_FLUSH, LONG_MAX);
+
+	/* wait for previous submitted meta pages writeback */
+	wait_on_all_pages_writeback(sbi);
+
+	release_dirty_inode(sbi);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return;
+
+	clear_prefree_segments(sbi);
+	clear_sbi_flag(sbi, SBI_IS_DIRTY);
+}
+
+/*
+ * We guarantee that this checkpoint procedure will not fail.
+ */
+void write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned long long ckpt_ver;
+
+	mutex_lock(&sbi->cp_mutex);
+
+	if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) &&
+		(cpc->reason == CP_FASTBOOT || cpc->reason == CP_SYNC))
+		goto out;
+	if (unlikely(f2fs_cp_error(sbi)))
+		goto out;
+	if (f2fs_readonly(sbi->sb))
+		goto out;
+
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "start block_ops");
+
+	if (block_operations(sbi))
+		goto out;
+
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish block_ops");
+
+	f2fs_submit_merged_bio(sbi, DATA, WRITE);
+	f2fs_submit_merged_bio(sbi, NODE, WRITE);
+	f2fs_submit_merged_bio(sbi, META, WRITE);
+
+	/*
+	 * update checkpoint pack index
+	 * Increase the version number so that
+	 * SIT entries and seg summaries are written at correct place
+	 */
+	ckpt_ver = cur_cp_version(ckpt);
+	ckpt->checkpoint_ver = cpu_to_le64(++ckpt_ver);
+
+	/* write cached NAT/SIT entries to NAT/SIT area */
+	flush_nat_entries(sbi);
+	flush_sit_entries(sbi, cpc);
+
+	/* unlock all the fs_lock[] in do_checkpoint() */
+	do_checkpoint(sbi, cpc);
+
+	unblock_operations(sbi);
+	stat_inc_cp_count(sbi->stat_info);
+
+	if (cpc->reason == CP_RECOVERY)
+		f2fs_msg(sbi->sb, KERN_NOTICE,
+			"checkpoint: version = %llx", ckpt_ver);
+out:
+	mutex_unlock(&sbi->cp_mutex);
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");
+}
+
+void init_ino_entry_info(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	for (i = 0; i < MAX_INO_ENTRY; i++) {
+		struct inode_management *im = &sbi->im[i];
+
+		INIT_RADIX_TREE(&im->ino_root, GFP_ATOMIC);
+		spin_lock_init(&im->ino_lock);
+		INIT_LIST_HEAD(&im->ino_list);
+		im->ino_num = 0;
+	}
+
+	sbi->max_orphans = (sbi->blocks_per_seg - F2FS_CP_PACKS -
+			NR_CURSEG_TYPE - __cp_payload(sbi)) *
+				F2FS_ORPHANS_PER_BLOCK;
+}
+
+int __init create_checkpoint_caches(void)
+{
+	ino_entry_slab = f2fs_kmem_cache_create("f2fs_ino_entry",
+			sizeof(struct ino_entry));
+	if (!ino_entry_slab)
+		return -ENOMEM;
+	inode_entry_slab = f2fs_kmem_cache_create("f2fs_inode_entry",
+			sizeof(struct inode_entry));
+	if (!inode_entry_slab) {
+		kmem_cache_destroy(ino_entry_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void destroy_checkpoint_caches(void)
+{
+	kmem_cache_destroy(ino_entry_slab);
+	kmem_cache_destroy(inode_entry_slab);
+}
diff --git a/kernel/fs/f2fs/data.c b/kernel/fs/f2fs/data.c
new file mode 100644
index 000000000..1e1aae669
--- /dev/null
+++ b/kernel/fs/f2fs/data.c
@@ -0,0 +1,1864 @@
+/*
+ * fs/f2fs/data.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/prefetch.h>
+#include <linux/uio.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static struct kmem_cache *extent_tree_slab;
+static struct kmem_cache *extent_node_slab;
+
+static void f2fs_read_end_io(struct bio *bio, int err)
+{
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		if (!err) {
+			SetPageUptodate(page);
+		} else {
+			ClearPageUptodate(page);
+			SetPageError(page);
+		}
+		unlock_page(page);
+	}
+	bio_put(bio);
+}
+
+static void f2fs_write_end_io(struct bio *bio, int err)
+{
+	struct f2fs_sb_info *sbi = bio->bi_private;
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		if (unlikely(err)) {
+			set_page_dirty(page);
+			set_bit(AS_EIO, &page->mapping->flags);
+			f2fs_stop_checkpoint(sbi);
+		}
+		end_page_writeback(page);
+		dec_page_count(sbi, F2FS_WRITEBACK);
+	}
+
+	if (!get_pages(sbi, F2FS_WRITEBACK) &&
+			!list_empty(&sbi->cp_wait.task_list))
+		wake_up(&sbi->cp_wait);
+
+	bio_put(bio);
+}
+
+/*
+ * Low-level block read/write IO operations.
+ */
+static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
+				int npages, bool is_read)
+{
+	struct bio *bio;
+
+	/* No failure on bio allocation */
+	bio = bio_alloc(GFP_NOIO, npages);
+
+	bio->bi_bdev = sbi->sb->s_bdev;
+	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
+	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
+	bio->bi_private = sbi;
+
+	return bio;
+}
+
+static void __submit_merged_bio(struct f2fs_bio_info *io)
+{
+	struct f2fs_io_info *fio = &io->fio;
+
+	if (!io->bio)
+		return;
+
+	if (is_read_io(fio->rw))
+		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
+	else
+		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
+
+	submit_bio(fio->rw, io->bio);
+	io->bio = NULL;
+}
+
+void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
+				enum page_type type, int rw)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	struct f2fs_bio_info *io;
+
+	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
+
+	down_write(&io->io_rwsem);
+
+	/* change META to META_FLUSH in the checkpoint procedure */
+	if (type >= META_FLUSH) {
+		io->fio.type = META_FLUSH;
+		if (test_opt(sbi, NOBARRIER))
+			io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
+		else
+			io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
+	}
+	__submit_merged_bio(io);
+	up_write(&io->io_rwsem);
+}
+
+/*
+ * Fill the locked page with data located in the block address.
+ * Return unlocked page.
+ */
+int f2fs_submit_page_bio(struct f2fs_sb_info *sbi, struct page *page,
+					struct f2fs_io_info *fio)
+{
+	struct bio *bio;
+
+	trace_f2fs_submit_page_bio(page, fio);
+	f2fs_trace_ios(page, fio, 0);
+
+	/* Allocate a new bio */
+	bio = __bio_alloc(sbi, fio->blk_addr, 1, is_read_io(fio->rw));
+
+	if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
+		bio_put(bio);
+		f2fs_put_page(page, 1);
+		return -EFAULT;
+	}
+
+	submit_bio(fio->rw, bio);
+	return 0;
+}
+
+void f2fs_submit_page_mbio(struct f2fs_sb_info *sbi, struct page *page,
+					struct f2fs_io_info *fio)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
+	struct f2fs_bio_info *io;
+	bool is_read = is_read_io(fio->rw);
+
+	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
+
+	verify_block_addr(sbi, fio->blk_addr);
+
+	down_write(&io->io_rwsem);
+
+	if (!is_read)
+		inc_page_count(sbi, F2FS_WRITEBACK);
+
+	if (io->bio && (io->last_block_in_bio != fio->blk_addr - 1 ||
+						io->fio.rw != fio->rw))
+		__submit_merged_bio(io);
+alloc_new:
+	if (io->bio == NULL) {
+		int bio_blocks = MAX_BIO_BLOCKS(sbi);
+
+		io->bio = __bio_alloc(sbi, fio->blk_addr, bio_blocks, is_read);
+		io->fio = *fio;
+	}
+
+	if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) <
+							PAGE_CACHE_SIZE) {
+		__submit_merged_bio(io);
+		goto alloc_new;
+	}
+
+	io->last_block_in_bio = fio->blk_addr;
+	f2fs_trace_ios(page, fio, 0);
+
+	up_write(&io->io_rwsem);
+	trace_f2fs_submit_page_mbio(page, fio);
+}
+
+/*
+ * Lock ordering for the change of data block address:
+ * ->data_page
+ *  ->node_page
+ *    update block addresses in the node page
+ */
+void set_data_blkaddr(struct dnode_of_data *dn)
+{
+	struct f2fs_node *rn;
+	__le32 *addr_array;
+	struct page *node_page = dn->node_page;
+	unsigned int ofs_in_node = dn->ofs_in_node;
+
+	f2fs_wait_on_page_writeback(node_page, NODE);
+
+	rn = F2FS_NODE(node_page);
+
+	/* Get physical address of data block */
+	addr_array = blkaddr_in_node(rn);
+	addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
+	set_page_dirty(node_page);
+}
+
+int reserve_new_block(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+
+	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
+		return -EPERM;
+	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
+		return -ENOSPC;
+
+	trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
+
+	dn->data_blkaddr = NEW_ADDR;
+	set_data_blkaddr(dn);
+	mark_inode_dirty(dn->inode);
+	sync_inode_page(dn);
+	return 0;
+}
+
+int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
+{
+	bool need_put = dn->inode_page ? false : true;
+	int err;
+
+	err = get_dnode_of_data(dn, index, ALLOC_NODE);
+	if (err)
+		return err;
+
+	if (dn->data_blkaddr == NULL_ADDR)
+		err = reserve_new_block(dn);
+	if (err || need_put)
+		f2fs_put_dnode(dn);
+	return err;
+}
+
+static void f2fs_map_bh(struct super_block *sb, pgoff_t pgofs,
+			struct extent_info *ei, struct buffer_head *bh_result)
+{
+	unsigned int blkbits = sb->s_blocksize_bits;
+	size_t max_size = bh_result->b_size;
+	size_t mapped_size;
+
+	clear_buffer_new(bh_result);
+	map_bh(bh_result, sb, ei->blk + pgofs - ei->fofs);
+	mapped_size = (ei->fofs + ei->len - pgofs) << blkbits;
+	bh_result->b_size = min(max_size, mapped_size);
+}
+
+static bool lookup_extent_info(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	pgoff_t start_fofs, end_fofs;
+	block_t start_blkaddr;
+
+	read_lock(&fi->ext_lock);
+	if (fi->ext.len == 0) {
+		read_unlock(&fi->ext_lock);
+		return false;
+	}
+
+	stat_inc_total_hit(inode->i_sb);
+
+	start_fofs = fi->ext.fofs;
+	end_fofs = fi->ext.fofs + fi->ext.len - 1;
+	start_blkaddr = fi->ext.blk;
+
+	if (pgofs >= start_fofs && pgofs <= end_fofs) {
+		*ei = fi->ext;
+		stat_inc_read_hit(inode->i_sb);
+		read_unlock(&fi->ext_lock);
+		return true;
+	}
+	read_unlock(&fi->ext_lock);
+	return false;
+}
+
+static bool update_extent_info(struct inode *inode, pgoff_t fofs,
+								block_t blkaddr)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	pgoff_t start_fofs, end_fofs;
+	block_t start_blkaddr, end_blkaddr;
+	int need_update = true;
+
+	write_lock(&fi->ext_lock);
+
+	start_fofs = fi->ext.fofs;
+	end_fofs = fi->ext.fofs + fi->ext.len - 1;
+	start_blkaddr = fi->ext.blk;
+	end_blkaddr = fi->ext.blk + fi->ext.len - 1;
+
+	/* Drop and initialize the matched extent */
+	if (fi->ext.len == 1 && fofs == start_fofs)
+		fi->ext.len = 0;
+
+	/* Initial extent */
+	if (fi->ext.len == 0) {
+		if (blkaddr != NULL_ADDR) {
+			fi->ext.fofs = fofs;
+			fi->ext.blk = blkaddr;
+			fi->ext.len = 1;
+		}
+		goto end_update;
+	}
+
+	/* Front merge */
+	if (fofs == start_fofs - 1 && blkaddr == start_blkaddr - 1) {
+		fi->ext.fofs--;
+		fi->ext.blk--;
+		fi->ext.len++;
+		goto end_update;
+	}
+
+	/* Back merge */
+	if (fofs == end_fofs + 1 && blkaddr == end_blkaddr + 1) {
+		fi->ext.len++;
+		goto end_update;
+	}
+
+	/* Split the existing extent */
+	if (fi->ext.len > 1 &&
+		fofs >= start_fofs && fofs <= end_fofs) {
+		if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
+			fi->ext.len = fofs - start_fofs;
+		} else {
+			fi->ext.fofs = fofs + 1;
+			fi->ext.blk = start_blkaddr + fofs - start_fofs + 1;
+			fi->ext.len -= fofs - start_fofs + 1;
+		}
+	} else {
+		need_update = false;
+	}
+
+	/* Finally, if the extent is very fragmented, let's drop the cache. */
+	if (fi->ext.len < F2FS_MIN_EXTENT_LEN) {
+		fi->ext.len = 0;
+		set_inode_flag(fi, FI_NO_EXTENT);
+		need_update = true;
+	}
+end_update:
+	write_unlock(&fi->ext_lock);
+	return need_update;
+}
+
+static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node *parent, struct rb_node **p)
+{
+	struct extent_node *en;
+
+	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
+	if (!en)
+		return NULL;
+
+	en->ei = *ei;
+	INIT_LIST_HEAD(&en->list);
+
+	rb_link_node(&en->rb_node, parent, p);
+	rb_insert_color(&en->rb_node, &et->root);
+	et->count++;
+	atomic_inc(&sbi->total_ext_node);
+	return en;
+}
+
+static void __detach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	rb_erase(&en->rb_node, &et->root);
+	et->count--;
+	atomic_dec(&sbi->total_ext_node);
+
+	if (et->cached_en == en)
+		et->cached_en = NULL;
+}
+
+static struct extent_tree *__find_extent_tree(struct f2fs_sb_info *sbi,
+							nid_t ino)
+{
+	struct extent_tree *et;
+
+	down_read(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		up_read(&sbi->extent_tree_lock);
+		return NULL;
+	}
+	atomic_inc(&et->refcount);
+	up_read(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_tree *__grab_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	nid_t ino = inode->i_ino;
+
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
+		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
+		memset(et, 0, sizeof(struct extent_tree));
+		et->ino = ino;
+		et->root = RB_ROOT;
+		et->cached_en = NULL;
+		rwlock_init(&et->lock);
+		atomic_set(&et->refcount, 0);
+		et->count = 0;
+		sbi->total_ext_tree++;
+	}
+	atomic_inc(&et->refcount);
+	up_write(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_node *__lookup_extent_tree(struct extent_tree *et,
+							unsigned int fofs)
+{
+	struct rb_node *node = et->root.rb_node;
+	struct extent_node *en;
+
+	if (et->cached_en) {
+		struct extent_info *cei = &et->cached_en->ei;
+
+		if (cei->fofs <= fofs && cei->fofs + cei->len > fofs)
+			return et->cached_en;
+	}
+
+	while (node) {
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (fofs < en->ei.fofs) {
+			node = node->rb_left;
+		} else if (fofs >= en->ei.fofs + en->ei.len) {
+			node = node->rb_right;
+		} else {
+			et->cached_en = en;
+			return en;
+		}
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_back_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *prev;
+	struct rb_node *node;
+
+	node = rb_prev(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	prev = rb_entry(node, struct extent_node, rb_node);
+	if (__is_back_mergeable(&en->ei, &prev->ei)) {
+		en->ei.fofs = prev->ei.fofs;
+		en->ei.blk = prev->ei.blk;
+		en->ei.len += prev->ei.len;
+		__detach_extent_node(sbi, et, prev);
+		return prev;
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_front_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *next;
+	struct rb_node *node;
+
+	node = rb_next(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	next = rb_entry(node, struct extent_node, rb_node);
+	if (__is_front_mergeable(&en->ei, &next->ei)) {
+		en->ei.len += next->ei.len;
+		__detach_extent_node(sbi, et, next);
+		return next;
+	}
+	return NULL;
+}
+
+static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct extent_node **den)
+{
+	struct rb_node **p = &et->root.rb_node;
+	struct rb_node *parent = NULL;
+	struct extent_node *en;
+
+	while (*p) {
+		parent = *p;
+		en = rb_entry(parent, struct extent_node, rb_node);
+
+		if (ei->fofs < en->ei.fofs) {
+			if (__is_front_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.fofs = ei->fofs;
+				en->ei.blk = ei->blk;
+				en->ei.len += ei->len;
+				*den = __try_back_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_left;
+		} else if (ei->fofs >= en->ei.fofs + en->ei.len) {
+			if (__is_back_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.len += ei->len;
+				*den = __try_front_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_right;
+		} else {
+			f2fs_bug_on(sbi, 1);
+		}
+	}
+
+	return __attach_extent_node(sbi, et, ei, parent, p);
+}
+
+static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
+					struct extent_tree *et, bool free_all)
+{
+	struct rb_node *node, *next;
+	struct extent_node *en;
+	unsigned int count = et->count;
+
+	node = rb_first(&et->root);
+	while (node) {
+		next = rb_next(node);
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (free_all) {
+			spin_lock(&sbi->extent_lock);
+			if (!list_empty(&en->list))
+				list_del_init(&en->list);
+			spin_unlock(&sbi->extent_lock);
+		}
+
+		if (free_all || list_empty(&en->list)) {
+			__detach_extent_node(sbi, et, en);
+			kmem_cache_free(extent_node_slab, en);
+		}
+		node = next;
+	}
+
+	return count - et->count;
+}
+
+static void f2fs_init_extent_tree(struct inode *inode,
+						struct f2fs_extent *i_ext)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+	struct extent_info ei;
+
+	if (le32_to_cpu(i_ext->len) < F2FS_MIN_EXTENT_LEN)
+		return;
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+	if (et->count)
+		goto out;
+
+	set_extent_info(&ei, le32_to_cpu(i_ext->fofs),
+		le32_to_cpu(i_ext->blk), le32_to_cpu(i_ext->len));
+
+	en = __insert_extent_tree(sbi, et, &ei, NULL);
+	if (en) {
+		et->cached_en = en;
+
+		spin_lock(&sbi->extent_lock);
+		list_add_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+	}
+out:
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+
+	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		return false;
+
+	read_lock(&et->lock);
+	en = __lookup_extent_tree(et, pgofs);
+	if (en) {
+		*ei = en->ei;
+		spin_lock(&sbi->extent_lock);
+		if (!list_empty(&en->list))
+			list_move_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+		stat_inc_read_hit(sbi->sb);
+	}
+	stat_inc_total_hit(sbi->sb);
+	read_unlock(&et->lock);
+
+	trace_f2fs_lookup_extent_tree_end(inode, pgofs, en);
+
+	atomic_dec(&et->refcount);
+	return en ? true : false;
+}
+
+static void f2fs_update_extent_tree(struct inode *inode, pgoff_t fofs,
+							block_t blkaddr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en = NULL, *en1 = NULL, *en2 = NULL, *en3 = NULL;
+	struct extent_node *den = NULL;
+	struct extent_info ei, dei;
+	unsigned int endofs;
+
+	trace_f2fs_update_extent_tree(inode, fofs, blkaddr);
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+
+	/* 1. lookup and remove existing extent info in cache */
+	en = __lookup_extent_tree(et, fofs);
+	if (!en)
+		goto update_extent;
+
+	dei = en->ei;
+	__detach_extent_node(sbi, et, en);
+
+	/* 2. if extent can be split more, split and insert the left part */
+	if (dei.len > 1) {
+		/*  insert left part of split extent into cache */
+		if (fofs - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, dei.fofs, dei.blk,
+							fofs - dei.fofs);
+			en1 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+
+		/* insert right part of split extent into cache */
+		endofs = dei.fofs + dei.len - 1;
+		if (endofs - fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, fofs + 1,
+				fofs - dei.fofs + dei.blk, endofs - fofs);
+			en2 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+	}
+
+update_extent:
+	/* 3. update extent in extent cache */
+	if (blkaddr) {
+		set_extent_info(&ei, fofs, blkaddr, 1);
+		en3 = __insert_extent_tree(sbi, et, &ei, &den);
+	}
+
+	/* 4. update in global extent list */
+	spin_lock(&sbi->extent_lock);
+	if (en && !list_empty(&en->list))
+		list_del(&en->list);
+	/*
+	 * en1 and en2 split from en, they will become more and more smaller
+	 * fragments after splitting several times. So if the length is smaller
+	 * than F2FS_MIN_EXTENT_LEN, we will not add them into extent tree.
+	 */
+	if (en1)
+		list_add_tail(&en1->list, &sbi->extent_list);
+	if (en2)
+		list_add_tail(&en2->list, &sbi->extent_list);
+	if (en3) {
+		if (list_empty(&en3->list))
+			list_add_tail(&en3->list, &sbi->extent_list);
+		else
+			list_move_tail(&en3->list, &sbi->extent_list);
+	}
+	if (den && !list_empty(&den->list))
+		list_del(&den->list);
+	spin_unlock(&sbi->extent_lock);
+
+	/* 5. release extent node */
+	if (en)
+		kmem_cache_free(extent_node_slab, en);
+	if (den)
+		kmem_cache_free(extent_node_slab, den);
+
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+void f2fs_preserve_extent_tree(struct inode *inode)
+{
+	struct extent_tree *et;
+	struct extent_info *ext = &F2FS_I(inode)->ext;
+	bool sync = false;
+
+	if (!test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(F2FS_I_SB(inode), inode->i_ino);
+	if (!et) {
+		if (ext->len) {
+			ext->len = 0;
+			update_inode_page(inode);
+		}
+		return;
+	}
+
+	read_lock(&et->lock);
+	if (et->count) {
+		struct extent_node *en;
+
+		if (et->cached_en) {
+			en = et->cached_en;
+		} else {
+			struct rb_node *node = rb_first(&et->root);
+
+			if (!node)
+				node = rb_last(&et->root);
+			en = rb_entry(node, struct extent_node, rb_node);
+		}
+
+		if (__is_extent_same(ext, &en->ei))
+			goto out;
+
+		*ext = en->ei;
+		sync = true;
+	} else if (ext->len) {
+		ext->len = 0;
+		sync = true;
+	}
+out:
+	read_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+
+	if (sync)
+		update_inode_page(inode);
+}
+
+void f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct extent_tree *treevec[EXT_TREE_VEC_SIZE];
+	struct extent_node *en, *tmp;
+	unsigned long ino = F2FS_ROOT_INO(sbi);
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int found;
+	unsigned int node_cnt = 0, tree_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	if (available_free_memory(sbi, EXTENT_CACHE))
+		return;
+
+	spin_lock(&sbi->extent_lock);
+	list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
+		if (!nr_shrink--)
+			break;
+		list_del_init(&en->list);
+	}
+	spin_unlock(&sbi->extent_lock);
+
+	down_read(&sbi->extent_tree_lock);
+	while ((found = radix_tree_gang_lookup(&sbi->extent_tree_root,
+				(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
+		unsigned i;
+
+		ino = treevec[found - 1]->ino + 1;
+		for (i = 0; i < found; i++) {
+			struct extent_tree *et = treevec[i];
+
+			atomic_inc(&et->refcount);
+			write_lock(&et->lock);
+			node_cnt += __free_extent_tree(sbi, et, false);
+			write_unlock(&et->lock);
+			atomic_dec(&et->refcount);
+		}
+	}
+	up_read(&sbi->extent_tree_lock);
+
+	down_write(&sbi->extent_tree_lock);
+	radix_tree_for_each_slot(slot, &sbi->extent_tree_root, &iter,
+							F2FS_ROOT_INO(sbi)) {
+		struct extent_tree *et = (struct extent_tree *)*slot;
+
+		if (!atomic_read(&et->refcount) && !et->count) {
+			radix_tree_delete(&sbi->extent_tree_root, et->ino);
+			kmem_cache_free(extent_tree_slab, et);
+			sbi->total_ext_tree--;
+			tree_cnt++;
+		}
+	}
+	up_write(&sbi->extent_tree_lock);
+
+	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
+}
+
+void f2fs_destroy_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	unsigned int node_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		goto out;
+
+	/* free all extent info belong to this extent tree */
+	write_lock(&et->lock);
+	node_cnt = __free_extent_tree(sbi, et, true);
+	write_unlock(&et->lock);
+
+	atomic_dec(&et->refcount);
+
+	/* try to find and delete extent tree entry in radix tree */
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, inode->i_ino);
+	if (!et) {
+		up_write(&sbi->extent_tree_lock);
+		goto out;
+	}
+	f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count);
+	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
+	kmem_cache_free(extent_tree_slab, et);
+	sbi->total_ext_tree--;
+	up_write(&sbi->extent_tree_lock);
+out:
+	trace_f2fs_destroy_extent_tree(inode, node_cnt);
+	return;
+}
+
+void f2fs_init_extent_cache(struct inode *inode, struct f2fs_extent *i_ext)
+{
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		f2fs_init_extent_tree(inode, i_ext);
+
+	write_lock(&F2FS_I(inode)->ext_lock);
+	get_extent_info(&F2FS_I(inode)->ext, *i_ext);
+	write_unlock(&F2FS_I(inode)->ext_lock);
+}
+
+static bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	if (is_inode_flag_set(F2FS_I(inode), FI_NO_EXTENT))
+		return false;
+
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return f2fs_lookup_extent_tree(inode, pgofs, ei);
+
+	return lookup_extent_info(inode, pgofs, ei);
+}
+
+void f2fs_update_extent_cache(struct dnode_of_data *dn)
+{
+	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+	pgoff_t fofs;
+
+	f2fs_bug_on(F2FS_I_SB(dn->inode), dn->data_blkaddr == NEW_ADDR);
+
+	if (is_inode_flag_set(fi, FI_NO_EXTENT))
+		return;
+
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
+							dn->ofs_in_node;
+
+	if (test_opt(F2FS_I_SB(dn->inode), EXTENT_CACHE))
+		return f2fs_update_extent_tree(dn->inode, fofs,
+							dn->data_blkaddr);
+
+	if (update_extent_info(dn->inode, fofs, dn->data_blkaddr))
+		sync_inode_page(dn);
+}
+
+struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct dnode_of_data dn;
+	struct page *page;
+	struct extent_info ei;
+	int err;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = sync ? READ_SYNC : READA,
+	};
+
+	/*
+	 * If sync is false, it needs to check its block allocation.
+	 * This is need and triggered by two flows:
+	 *   gc and truncate_partial_data_page.
+	 */
+	if (!sync)
+		goto search;
+
+	page = find_get_page(mapping, index);
+	if (page && PageUptodate(page))
+		return page;
+	f2fs_put_page(page, 0);
+search:
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+	if (err)
+		return ERR_PTR(err);
+	f2fs_put_dnode(&dn);
+
+	if (dn.data_blkaddr == NULL_ADDR)
+		return ERR_PTR(-ENOENT);
+
+	/* By fallocate(), there is no cached page, but with NEW_ADDR */
+	if (unlikely(dn.data_blkaddr == NEW_ADDR))
+		return ERR_PTR(-EINVAL);
+
+got_it:
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (PageUptodate(page)) {
+		unlock_page(page);
+		return page;
+	}
+
+	fio.blk_addr = dn.data_blkaddr;
+	err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+	if (err)
+		return ERR_PTR(err);
+
+	if (sync) {
+		wait_on_page_locked(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 0);
+			return ERR_PTR(-EIO);
+		}
+	}
+	return page;
+}
+
+/*
+ * If it tries to access a hole, return an error.
+ * Because, the callers, functions in dir.c and GC, should be able to know
+ * whether this page exists or not.
+ */
+struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct dnode_of_data dn;
+	struct page *page;
+	struct extent_info ei;
+	int err;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = READ_SYNC,
+	};
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+	if (err) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	}
+	f2fs_put_dnode(&dn);
+
+	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-ENOENT);
+	}
+
+got_it:
+	if (PageUptodate(page))
+		return page;
+
+	/*
+	 * A new dentry page is allocated but not able to be written, since its
+	 * new inode page couldn't be allocated due to -ENOSPC.
+	 * In such the case, its blkaddr can be remained as NEW_ADDR.
+	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
+	 */
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
+		return page;
+	}
+
+	fio.blk_addr = dn.data_blkaddr;
+	err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+	if (err)
+		return ERR_PTR(err);
+
+	lock_page(page);
+	if (unlikely(!PageUptodate(page))) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	if (unlikely(page->mapping != mapping)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+	return page;
+}
+
+/*
+ * Caller ensures that this data page is never allocated.
+ * A new zero-filled data page is allocated in the page cache.
+ *
+ * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ * Note that, ipage is set only by make_empty_dir.
+ */
+struct page *get_new_data_page(struct inode *inode,
+		struct page *ipage, pgoff_t index, bool new_i_size)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+	struct dnode_of_data dn;
+	int err;
+
+	set_new_dnode(&dn, inode, ipage, NULL, 0);
+	err = f2fs_reserve_block(&dn, index);
+	if (err)
+		return ERR_PTR(err);
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		err = -ENOMEM;
+		goto put_err;
+	}
+
+	if (PageUptodate(page))
+		return page;
+
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
+	} else {
+		struct f2fs_io_info fio = {
+			.type = DATA,
+			.rw = READ_SYNC,
+			.blk_addr = dn.data_blkaddr,
+		};
+		err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+		if (err)
+			goto put_err;
+
+		lock_page(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 1);
+			err = -EIO;
+			goto put_err;
+		}
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+	}
+
+	if (new_i_size &&
+		i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
+		i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
+		/* Only the directory inode sets new_i_size */
+		set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
+	}
+	return page;
+
+put_err:
+	f2fs_put_dnode(&dn);
+	return ERR_PTR(err);
+}
+
+static int __allocate_data_block(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+	struct f2fs_summary sum;
+	struct node_info ni;
+	int seg = CURSEG_WARM_DATA;
+	pgoff_t fofs;
+
+	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
+		return -EPERM;
+
+	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
+	if (dn->data_blkaddr == NEW_ADDR)
+		goto alloc;
+
+	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
+		return -ENOSPC;
+
+alloc:
+	get_node_info(sbi, dn->nid, &ni);
+	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+
+	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
+		seg = CURSEG_DIRECT_IO;
+
+	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
+								&sum, seg);
+
+	/* direct IO doesn't use extent cache to maximize the performance */
+	set_data_blkaddr(dn);
+
+	/* update i_size */
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
+							dn->ofs_in_node;
+	if (i_size_read(dn->inode) < ((fofs + 1) << PAGE_CACHE_SHIFT))
+		i_size_write(dn->inode, ((fofs + 1) << PAGE_CACHE_SHIFT));
+
+	return 0;
+}
+
+static void __allocate_data_blocks(struct inode *inode, loff_t offset,
+							size_t count)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	u64 start = F2FS_BYTES_TO_BLK(offset);
+	u64 len = F2FS_BYTES_TO_BLK(count);
+	bool allocated;
+	u64 end_offset;
+
+	while (len) {
+		f2fs_balance_fs(sbi);
+		f2fs_lock_op(sbi);
+
+		/* When reading holes, we need its node page */
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		if (get_dnode_of_data(&dn, start, ALLOC_NODE))
+			goto out;
+
+		allocated = false;
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+		while (dn.ofs_in_node < end_offset && len) {
+			block_t blkaddr;
+
+			blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+			if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
+				if (__allocate_data_block(&dn))
+					goto sync_out;
+				allocated = true;
+			}
+			len--;
+			start++;
+			dn.ofs_in_node++;
+		}
+
+		if (allocated)
+			sync_inode_page(&dn);
+
+		f2fs_put_dnode(&dn);
+		f2fs_unlock_op(sbi);
+	}
+	return;
+
+sync_out:
+	if (allocated)
+		sync_inode_page(&dn);
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_unlock_op(sbi);
+	return;
+}
+
+/*
+ * get_data_block() now supported readahead/bmap/rw direct_IO with mapped bh.
+ * If original data blocks are allocated, then give them to blockdev.
+ * Otherwise,
+ *     a. preallocate requested block addresses
+ *     b. do not use extent cache for better performance
+ *     c. give the block addresses to blockdev
+ */
+static int __get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create, bool fiemap)
+{
+	unsigned int blkbits = inode->i_sb->s_blocksize_bits;
+	unsigned maxblocks = bh_result->b_size >> blkbits;
+	struct dnode_of_data dn;
+	int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
+	pgoff_t pgofs, end_offset;
+	int err = 0, ofs = 1;
+	struct extent_info ei;
+	bool allocated = false;
+
+	/* Get the page offset from the block offset(iblock) */
+	pgofs =	(pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
+
+	if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
+		f2fs_map_bh(inode->i_sb, pgofs, &ei, bh_result);
+		goto out;
+	}
+
+	if (create)
+		f2fs_lock_op(F2FS_I_SB(inode));
+
+	/* When reading holes, we need its node page */
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, pgofs, mode);
+	if (err) {
+		if (err == -ENOENT)
+			err = 0;
+		goto unlock_out;
+	}
+	if (dn.data_blkaddr == NEW_ADDR && !fiemap)
+		goto put_out;
+
+	if (dn.data_blkaddr != NULL_ADDR) {
+		clear_buffer_new(bh_result);
+		map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
+	} else if (create) {
+		err = __allocate_data_block(&dn);
+		if (err)
+			goto put_out;
+		allocated = true;
+		set_buffer_new(bh_result);
+		map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
+	} else {
+		goto put_out;
+	}
+
+	end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+	bh_result->b_size = (((size_t)1) << blkbits);
+	dn.ofs_in_node++;
+	pgofs++;
+
+get_next:
+	if (dn.ofs_in_node >= end_offset) {
+		if (allocated)
+			sync_inode_page(&dn);
+		allocated = false;
+		f2fs_put_dnode(&dn);
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, pgofs, mode);
+		if (err) {
+			if (err == -ENOENT)
+				err = 0;
+			goto unlock_out;
+		}
+		if (dn.data_blkaddr == NEW_ADDR && !fiemap)
+			goto put_out;
+
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+	}
+
+	if (maxblocks > (bh_result->b_size >> blkbits)) {
+		block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+		if (blkaddr == NULL_ADDR && create) {
+			err = __allocate_data_block(&dn);
+			if (err)
+				goto sync_out;
+			allocated = true;
+			set_buffer_new(bh_result);
+			blkaddr = dn.data_blkaddr;
+		}
+		/* Give more consecutive addresses for the readahead */
+		if (blkaddr == (bh_result->b_blocknr + ofs)) {
+			ofs++;
+			dn.ofs_in_node++;
+			pgofs++;
+			bh_result->b_size += (((size_t)1) << blkbits);
+			goto get_next;
+		}
+	}
+sync_out:
+	if (allocated)
+		sync_inode_page(&dn);
+put_out:
+	f2fs_put_dnode(&dn);
+unlock_out:
+	if (create)
+		f2fs_unlock_op(F2FS_I_SB(inode));
+out:
+	trace_f2fs_get_data_block(inode, iblock, bh_result, err);
+	return err;
+}
+
+static int get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, false);
+}
+
+static int get_data_block_fiemap(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, true);
+}
+
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 len)
+{
+	return generic_block_fiemap(inode, fieinfo,
+				start, len, get_data_block_fiemap);
+}
+
+static int f2fs_read_data_page(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	int ret = -EAGAIN;
+
+	trace_f2fs_readpage(page, DATA);
+
+	/* If the file has inline data, try to read it directly */
+	if (f2fs_has_inline_data(inode))
+		ret = f2fs_read_inline_data(inode, page);
+	if (ret == -EAGAIN)
+		ret = mpage_readpage(page, get_data_block);
+
+	return ret;
+}
+
+static int f2fs_read_data_pages(struct file *file,
+			struct address_space *mapping,
+			struct list_head *pages, unsigned nr_pages)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	/* If the file has inline data, skip readpages */
+	if (f2fs_has_inline_data(inode))
+		return 0;
+
+	return mpage_readpages(mapping, pages, nr_pages, get_data_block);
+}
+
+int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
+{
+	struct inode *inode = page->mapping->host;
+	struct dnode_of_data dn;
+	int err = 0;
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	fio->blk_addr = dn.data_blkaddr;
+
+	/* This page is already truncated */
+	if (fio->blk_addr == NULL_ADDR) {
+		ClearPageUptodate(page);
+		goto out_writepage;
+	}
+
+	set_page_writeback(page);
+
+	/*
+	 * If current allocation needs SSR,
+	 * it had better in-place writes for updated data.
+	 */
+	if (unlikely(fio->blk_addr != NEW_ADDR &&
+			!is_cold_data(page) &&
+			need_inplace_update(inode))) {
+		rewrite_data_page(page, fio);
+		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
+		trace_f2fs_do_write_data_page(page, IPU);
+	} else {
+		write_data_page(page, &dn, fio);
+		set_data_blkaddr(&dn);
+		f2fs_update_extent_cache(&dn);
+		trace_f2fs_do_write_data_page(page, OPU);
+		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
+		if (page->index == 0)
+			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+	}
+out_writepage:
+	f2fs_put_dnode(&dn);
+	return err;
+}
+
+static int f2fs_write_data_page(struct page *page,
+					struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	loff_t i_size = i_size_read(inode);
+	const pgoff_t end_index = ((unsigned long long) i_size)
+							>> PAGE_CACHE_SHIFT;
+	unsigned offset = 0;
+	bool need_balance_fs = false;
+	int err = 0;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
+	};
+
+	trace_f2fs_writepage(page, DATA);
+
+	if (page->index < end_index)
+		goto write;
+
+	/*
+	 * If the offset is out-of-range of file size,
+	 * this page does not have to be written to disk.
+	 */
+	offset = i_size & (PAGE_CACHE_SIZE - 1);
+	if ((page->index >= end_index + 1) || !offset)
+		goto out;
+
+	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+write:
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+	if (f2fs_is_drop_cache(inode))
+		goto out;
+	if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
+			available_free_memory(sbi, BASE_CHECK))
+		goto redirty_out;
+
+	/* Dentry blocks are controlled by checkpoint */
+	if (S_ISDIR(inode->i_mode)) {
+		if (unlikely(f2fs_cp_error(sbi)))
+			goto redirty_out;
+		err = do_write_data_page(page, &fio);
+		goto done;
+	}
+
+	/* we should bypass data pages to proceed the kworkder jobs */
+	if (unlikely(f2fs_cp_error(sbi))) {
+		SetPageError(page);
+		goto out;
+	}
+
+	if (!wbc->for_reclaim)
+		need_balance_fs = true;
+	else if (has_not_enough_free_secs(sbi, 0))
+		goto redirty_out;
+
+	err = -EAGAIN;
+	f2fs_lock_op(sbi);
+	if (f2fs_has_inline_data(inode))
+		err = f2fs_write_inline_data(inode, page);
+	if (err == -EAGAIN)
+		err = do_write_data_page(page, &fio);
+	f2fs_unlock_op(sbi);
+done:
+	if (err && err != -ENOENT)
+		goto redirty_out;
+
+	clear_cold_data(page);
+out:
+	inode_dec_dirty_pages(inode);
+	if (err)
+		ClearPageUptodate(page);
+	unlock_page(page);
+	if (need_balance_fs)
+		f2fs_balance_fs(sbi);
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_bio(sbi, DATA, WRITE);
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
+			void *data)
+{
+	struct address_space *mapping = data;
+	int ret = mapping->a_ops->writepage(page, wbc);
+	mapping_set_error(mapping, ret);
+	return ret;
+}
+
+static int f2fs_write_data_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	bool locked = false;
+	int ret;
+	long diff;
+
+	trace_f2fs_writepages(mapping->host, wbc, DATA);
+
+	/* deal with chardevs and other special file */
+	if (!mapping->a_ops->writepage)
+		return 0;
+
+	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
+			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
+			available_free_memory(sbi, DIRTY_DENTS))
+		goto skip_write;
+
+	/* during POR, we don't need to trigger writepage at all. */
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	diff = nr_pages_to_write(sbi, DATA, wbc);
+
+	if (!S_ISDIR(inode->i_mode)) {
+		mutex_lock(&sbi->writepages);
+		locked = true;
+	}
+	ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
+	if (locked)
+		mutex_unlock(&sbi->writepages);
+
+	f2fs_submit_merged_bio(sbi, DATA, WRITE);
+
+	remove_dirty_dir_inode(inode);
+
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+	return ret;
+
+skip_write:
+	wbc->pages_skipped += get_dirty_pages(inode);
+	return 0;
+}
+
+static void f2fs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		truncate_blocks(inode, inode->i_size, true);
+	}
+}
+
+static int f2fs_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page, *ipage;
+	pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
+	struct dnode_of_data dn;
+	int err = 0;
+
+	trace_f2fs_write_begin(inode, pos, len, flags);
+
+	f2fs_balance_fs(sbi);
+
+	/*
+	 * We should check this at this moment to avoid deadlock on inode page
+	 * and #0 page. The locking rule for inline_data conversion should be:
+	 * lock_page(page #0) -> lock_page(inode_page)
+	 */
+	if (index != 0) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			goto fail;
+	}
+repeat:
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	*pagep = page;
+
+	f2fs_lock_op(sbi);
+
+	/* check inline_data */
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto unlock_fail;
+	}
+
+	set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+	if (f2fs_has_inline_data(inode)) {
+		if (pos + len <= MAX_INLINE_DATA) {
+			read_inline_data(page, ipage);
+			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+			sync_inode_page(&dn);
+			goto put_next;
+		}
+		err = f2fs_convert_inline_page(&dn, page);
+		if (err)
+			goto put_fail;
+	}
+	err = f2fs_reserve_block(&dn, index);
+	if (err)
+		goto put_fail;
+put_next:
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+
+	if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
+		return 0;
+
+	f2fs_wait_on_page_writeback(page, DATA);
+
+	if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
+		unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+		unsigned end = start + len;
+
+		/* Reading beyond i_size is simple: memset to zero */
+		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
+		goto out;
+	}
+
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+	} else {
+		struct f2fs_io_info fio = {
+			.type = DATA,
+			.rw = READ_SYNC,
+			.blk_addr = dn.data_blkaddr,
+		};
+		err = f2fs_submit_page_bio(sbi, page, &fio);
+		if (err)
+			goto fail;
+
+		lock_page(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 1);
+			err = -EIO;
+			goto fail;
+		}
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+	}
+out:
+	SetPageUptodate(page);
+	clear_cold_data(page);
+	return 0;
+
+put_fail:
+	f2fs_put_dnode(&dn);
+unlock_fail:
+	f2fs_unlock_op(sbi);
+	f2fs_put_page(page, 1);
+fail:
+	f2fs_write_failed(mapping, pos + len);
+	return err;
+}
+
+static int f2fs_write_end(struct file *file,
+			struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	struct inode *inode = page->mapping->host;
+
+	trace_f2fs_write_end(inode, pos, len, copied);
+
+	set_page_dirty(page);
+
+	if (pos + copied > i_size_read(inode)) {
+		i_size_write(inode, pos + copied);
+		mark_inode_dirty(inode);
+		update_inode_page(inode);
+	}
+
+	f2fs_put_page(page, 1);
+	return copied;
+}
+
+static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
+			   loff_t offset)
+{
+	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
+
+	if (iov_iter_rw(iter) == READ)
+		return 0;
+
+	if (offset & blocksize_mask)
+		return -EINVAL;
+
+	if (iov_iter_alignment(iter) & blocksize_mask)
+		return -EINVAL;
+
+	return 0;
+}
+
+static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+			      loff_t offset)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
+	int err;
+
+	/* we don't need to use inline_data strictly */
+	if (f2fs_has_inline_data(inode)) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+
+	if (check_direct_IO(inode, iter, offset))
+		return 0;
+
+	trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
+
+	if (iov_iter_rw(iter) == WRITE)
+		__allocate_data_blocks(inode, offset, count);
+
+	err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block);
+	if (err < 0 && iov_iter_rw(iter) == WRITE)
+		f2fs_write_failed(mapping, offset + count);
+
+	trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
+
+	return err;
+}
+
+void f2fs_invalidate_page(struct page *page, unsigned int offset,
+							unsigned int length)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
+		(offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
+		return;
+
+	if (PageDirty(page)) {
+		if (inode->i_ino == F2FS_META_INO(sbi))
+			dec_page_count(sbi, F2FS_DIRTY_META);
+		else if (inode->i_ino == F2FS_NODE_INO(sbi))
+			dec_page_count(sbi, F2FS_DIRTY_NODES);
+		else
+			inode_dec_dirty_pages(inode);
+	}
+	ClearPagePrivate(page);
+}
+
+int f2fs_release_page(struct page *page, gfp_t wait)
+{
+	/* If this is dirty page, keep PagePrivate */
+	if (PageDirty(page))
+		return 0;
+
+	ClearPagePrivate(page);
+	return 1;
+}
+
+static int f2fs_set_data_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+
+	trace_f2fs_set_page_dirty(page, DATA);
+
+	SetPageUptodate(page);
+
+	if (f2fs_is_atomic_file(inode)) {
+		register_inmem_page(inode, page);
+		return 1;
+	}
+
+	mark_inode_dirty(inode);
+
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		update_dirty_page(inode, page);
+		return 1;
+	}
+	return 0;
+}
+
+static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *inode = mapping->host;
+
+	/* we don't need to use inline_data strictly */
+	if (f2fs_has_inline_data(inode)) {
+		int err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+	return generic_block_bmap(mapping, block, get_data_block);
+}
+
+void init_extent_cache_info(struct f2fs_sb_info *sbi)
+{
+	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
+	init_rwsem(&sbi->extent_tree_lock);
+	INIT_LIST_HEAD(&sbi->extent_list);
+	spin_lock_init(&sbi->extent_lock);
+	sbi->total_ext_tree = 0;
+	atomic_set(&sbi->total_ext_node, 0);
+}
+
+int __init create_extent_cache(void)
+{
+	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
+			sizeof(struct extent_tree));
+	if (!extent_tree_slab)
+		return -ENOMEM;
+	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
+			sizeof(struct extent_node));
+	if (!extent_node_slab) {
+		kmem_cache_destroy(extent_tree_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void destroy_extent_cache(void)
+{
+	kmem_cache_destroy(extent_node_slab);
+	kmem_cache_destroy(extent_tree_slab);
+}
+
+const struct address_space_operations f2fs_dblock_aops = {
+	.readpage	= f2fs_read_data_page,
+	.readpages	= f2fs_read_data_pages,
+	.writepage	= f2fs_write_data_page,
+	.writepages	= f2fs_write_data_pages,
+	.write_begin	= f2fs_write_begin,
+	.write_end	= f2fs_write_end,
+	.set_page_dirty	= f2fs_set_data_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+	.direct_IO	= f2fs_direct_IO,
+	.bmap		= f2fs_bmap,
+};
diff --git a/kernel/fs/f2fs/debug.c b/kernel/fs/f2fs/debug.c
new file mode 100644
index 000000000..f5388f372
--- /dev/null
+++ b/kernel/fs/f2fs/debug.c
@@ -0,0 +1,413 @@
+/*
+ * f2fs debugging statistics
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ * Copyright (c) 2012 Linux Foundation
+ * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/backing-dev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/blkdev.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "gc.h"
+
+static LIST_HEAD(f2fs_stat_list);
+static struct dentry *f2fs_debugfs_root;
+static DEFINE_MUTEX(f2fs_stat_mutex);
+
+static void update_general_status(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	int i;
+
+	/* validation check of the segment numbers */
+	si->hit_ext = sbi->read_hit_ext;
+	si->total_ext = sbi->total_hit_ext;
+	si->ext_tree = sbi->total_ext_tree;
+	si->ext_node = atomic_read(&sbi->total_ext_node);
+	si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
+	si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
+	si->ndirty_dirs = sbi->n_dirty_dirs;
+	si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META);
+	si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES);
+	si->wb_pages = get_pages(sbi, F2FS_WRITEBACK);
+	si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
+	si->rsvd_segs = reserved_segments(sbi);
+	si->overp_segs = overprovision_segments(sbi);
+	si->valid_count = valid_user_blocks(sbi);
+	si->valid_node_count = valid_node_count(sbi);
+	si->valid_inode_count = valid_inode_count(sbi);
+	si->inline_inode = atomic_read(&sbi->inline_inode);
+	si->inline_dir = atomic_read(&sbi->inline_dir);
+	si->utilization = utilization(sbi);
+
+	si->free_segs = free_segments(sbi);
+	si->free_secs = free_sections(sbi);
+	si->prefree_count = prefree_segments(sbi);
+	si->dirty_count = dirty_segments(sbi);
+	si->node_pages = NODE_MAPPING(sbi)->nrpages;
+	si->meta_pages = META_MAPPING(sbi)->nrpages;
+	si->nats = NM_I(sbi)->nat_cnt;
+	si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
+	si->sits = MAIN_SEGS(sbi);
+	si->dirty_sits = SIT_I(sbi)->dirty_sentries;
+	si->fnids = NM_I(sbi)->fcnt;
+	si->bg_gc = sbi->bg_gc;
+	si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_valid = (int)(written_block_count(sbi) >>
+						sbi->log_blocks_per_seg)
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_invalid = 50 - si->util_free - si->util_valid;
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+		si->curseg[i] = curseg->segno;
+		si->cursec[i] = curseg->segno / sbi->segs_per_sec;
+		si->curzone[i] = si->cursec[i] / sbi->secs_per_zone;
+	}
+
+	for (i = 0; i < 2; i++) {
+		si->segment_count[i] = sbi->segment_count[i];
+		si->block_count[i] = sbi->block_count[i];
+	}
+
+	si->inplace_count = atomic_read(&sbi->inplace_count);
+}
+
+/*
+ * This function calculates BDF of every segments
+ */
+static void update_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned int blks_per_sec, hblks_per_sec, total_vblocks, bimodal, dist;
+	unsigned int segno, vblocks;
+	int ndirty = 0;
+
+	bimodal = 0;
+	total_vblocks = 0;
+	blks_per_sec = sbi->segs_per_sec * (1 << sbi->log_blocks_per_seg);
+	hblks_per_sec = blks_per_sec / 2;
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
+		vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
+		dist = abs(vblocks - hblks_per_sec);
+		bimodal += dist * dist;
+
+		if (vblocks > 0 && vblocks < blks_per_sec) {
+			total_vblocks += vblocks;
+			ndirty++;
+		}
+	}
+	dist = MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec / 100;
+	si->bimodal = bimodal / dist;
+	if (si->dirty_count)
+		si->avg_vblocks = total_vblocks / ndirty;
+	else
+		si->avg_vblocks = 0;
+}
+
+/*
+ * This function calculates memory footprint.
+ */
+static void update_mem_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned npages;
+	int i;
+
+	if (si->base_mem)
+		goto get_cache;
+
+	si->base_mem = sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
+	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
+	si->base_mem += sizeof(*sbi->ckpt);
+
+	/* build sm */
+	si->base_mem += sizeof(struct f2fs_sm_info);
+
+	/* build sit */
+	si->base_mem += sizeof(struct sit_info);
+	si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
+	si->base_mem += SIT_VBLOCK_MAP_SIZE;
+	if (sbi->segs_per_sec > 1)
+		si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry);
+	si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
+
+	/* build free segmap */
+	si->base_mem += sizeof(struct free_segmap_info);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build curseg */
+	si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
+	si->base_mem += PAGE_CACHE_SIZE * NR_CURSEG_TYPE;
+
+	/* build dirty segmap */
+	si->base_mem += sizeof(struct dirty_seglist_info);
+	si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build nm */
+	si->base_mem += sizeof(struct f2fs_nm_info);
+	si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
+
+get_cache:
+	si->cache_mem = 0;
+
+	/* build gc */
+	if (sbi->gc_thread)
+		si->cache_mem += sizeof(struct f2fs_gc_kthread);
+
+	/* build merge flush thread */
+	if (SM_I(sbi)->cmd_control_info)
+		si->cache_mem += sizeof(struct flush_cmd_control);
+
+	/* free nids */
+	si->cache_mem += NM_I(sbi)->fcnt * sizeof(struct free_nid);
+	si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry);
+	si->cache_mem += NM_I(sbi)->dirty_nat_cnt *
+					sizeof(struct nat_entry_set);
+	si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages);
+	si->cache_mem += sbi->n_dirty_dirs * sizeof(struct inode_entry);
+	for (i = 0; i <= UPDATE_INO; i++)
+		si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
+	si->cache_mem += sbi->total_ext_tree * sizeof(struct extent_tree);
+	si->cache_mem += atomic_read(&sbi->total_ext_node) *
+						sizeof(struct extent_node);
+
+	si->page_mem = 0;
+	npages = NODE_MAPPING(sbi)->nrpages;
+	si->page_mem += npages << PAGE_CACHE_SHIFT;
+	npages = META_MAPPING(sbi)->nrpages;
+	si->page_mem += npages << PAGE_CACHE_SHIFT;
+}
+
+static int stat_show(struct seq_file *s, void *v)
+{
+	struct f2fs_stat_info *si;
+	int i = 0;
+	int j;
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_for_each_entry(si, &f2fs_stat_list, stat_list) {
+		char devname[BDEVNAME_SIZE];
+
+		update_general_status(si->sbi);
+
+		seq_printf(s, "\n=====[ partition info(%s). #%d ]=====\n",
+			bdevname(si->sbi->sb->s_bdev, devname), i++);
+		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
+			   si->sit_area_segs, si->nat_area_segs);
+		seq_printf(s, "[SSA: %d] [MAIN: %d",
+			   si->ssa_area_segs, si->main_area_segs);
+		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
+			   si->overp_segs, si->rsvd_segs);
+		seq_printf(s, "Utilization: %d%% (%d valid blocks)\n",
+			   si->utilization, si->valid_count);
+		seq_printf(s, "  - Node: %u (Inode: %u, ",
+			   si->valid_node_count, si->valid_inode_count);
+		seq_printf(s, "Other: %u)\n  - Data: %u\n",
+			   si->valid_node_count - si->valid_inode_count,
+			   si->valid_count - si->valid_node_count);
+		seq_printf(s, "  - Inline_data Inode: %u\n",
+			   si->inline_inode);
+		seq_printf(s, "  - Inline_dentry Inode: %u\n",
+			   si->inline_dir);
+		seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
+			   si->main_area_segs, si->main_area_sections,
+			   si->main_area_zones);
+		seq_printf(s, "  - COLD  data: %d, %d, %d\n",
+			   si->curseg[CURSEG_COLD_DATA],
+			   si->cursec[CURSEG_COLD_DATA],
+			   si->curzone[CURSEG_COLD_DATA]);
+		seq_printf(s, "  - WARM  data: %d, %d, %d\n",
+			   si->curseg[CURSEG_WARM_DATA],
+			   si->cursec[CURSEG_WARM_DATA],
+			   si->curzone[CURSEG_WARM_DATA]);
+		seq_printf(s, "  - HOT   data: %d, %d, %d\n",
+			   si->curseg[CURSEG_HOT_DATA],
+			   si->cursec[CURSEG_HOT_DATA],
+			   si->curzone[CURSEG_HOT_DATA]);
+		seq_printf(s, "  - Dir   dnode: %d, %d, %d\n",
+			   si->curseg[CURSEG_HOT_NODE],
+			   si->cursec[CURSEG_HOT_NODE],
+			   si->curzone[CURSEG_HOT_NODE]);
+		seq_printf(s, "  - File   dnode: %d, %d, %d\n",
+			   si->curseg[CURSEG_WARM_NODE],
+			   si->cursec[CURSEG_WARM_NODE],
+			   si->curzone[CURSEG_WARM_NODE]);
+		seq_printf(s, "  - Indir nodes: %d, %d, %d\n",
+			   si->curseg[CURSEG_COLD_NODE],
+			   si->cursec[CURSEG_COLD_NODE],
+			   si->curzone[CURSEG_COLD_NODE]);
+		seq_printf(s, "\n  - Valid: %d\n  - Dirty: %d\n",
+			   si->main_area_segs - si->dirty_count -
+			   si->prefree_count - si->free_segs,
+			   si->dirty_count);
+		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
+			   si->prefree_count, si->free_segs, si->free_secs);
+		seq_printf(s, "CP calls: %d\n", si->cp_count);
+		seq_printf(s, "GC calls: %d (BG: %d)\n",
+			   si->call_count, si->bg_gc);
+		seq_printf(s, "  - data segments : %d (%d)\n",
+				si->data_segs, si->bg_data_segs);
+		seq_printf(s, "  - node segments : %d (%d)\n",
+				si->node_segs, si->bg_node_segs);
+		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
+				si->bg_data_blks + si->bg_node_blks);
+		seq_printf(s, "  - data blocks : %d (%d)\n", si->data_blks,
+				si->bg_data_blks);
+		seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
+				si->bg_node_blks);
+		seq_printf(s, "\nExtent Hit Ratio: %d / %d\n",
+			   si->hit_ext, si->total_ext);
+		seq_printf(s, "\nExtent Tree Count: %d\n", si->ext_tree);
+		seq_printf(s, "\nExtent Node Count: %d\n", si->ext_node);
+		seq_puts(s, "\nBalancing F2FS Async:\n");
+		seq_printf(s, "  - inmem: %4d, wb: %4d\n",
+			   si->inmem_pages, si->wb_pages);
+		seq_printf(s, "  - nodes: %4d in %4d\n",
+			   si->ndirty_node, si->node_pages);
+		seq_printf(s, "  - dents: %4d in dirs:%4d\n",
+			   si->ndirty_dent, si->ndirty_dirs);
+		seq_printf(s, "  - meta: %4d in %4d\n",
+			   si->ndirty_meta, si->meta_pages);
+		seq_printf(s, "  - NATs: %9d/%9d\n  - SITs: %9d/%9d\n",
+			   si->dirty_nats, si->nats, si->dirty_sits, si->sits);
+		seq_printf(s, "  - free_nids: %9d\n",
+			   si->fnids);
+		seq_puts(s, "\nDistribution of User Blocks:");
+		seq_puts(s, " [ valid | invalid | free ]\n");
+		seq_puts(s, "  [");
+
+		for (j = 0; j < si->util_valid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_invalid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_free; j++)
+			seq_putc(s, '-');
+		seq_puts(s, "]\n\n");
+		seq_printf(s, "IPU: %u blocks\n", si->inplace_count);
+		seq_printf(s, "SSR: %u blocks in %u segments\n",
+			   si->block_count[SSR], si->segment_count[SSR]);
+		seq_printf(s, "LFS: %u blocks in %u segments\n",
+			   si->block_count[LFS], si->segment_count[LFS]);
+
+		/* segment usage info */
+		update_sit_info(si->sbi);
+		seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
+			   si->bimodal, si->avg_vblocks);
+
+		/* memory footprint */
+		update_mem_info(si->sbi);
+		seq_printf(s, "\nMemory: %u KB\n",
+			(si->base_mem + si->cache_mem + si->page_mem) >> 10);
+		seq_printf(s, "  - static: %u KB\n",
+				si->base_mem >> 10);
+		seq_printf(s, "  - cached: %u KB\n",
+				si->cache_mem >> 10);
+		seq_printf(s, "  - paged : %u KB\n",
+				si->page_mem >> 10);
+	}
+	mutex_unlock(&f2fs_stat_mutex);
+	return 0;
+}
+
+static int stat_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, stat_show, inode->i_private);
+}
+
+static const struct file_operations stat_fops = {
+	.open = stat_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+int f2fs_build_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_stat_info *si;
+
+	si = kzalloc(sizeof(struct f2fs_stat_info), GFP_KERNEL);
+	if (!si)
+		return -ENOMEM;
+
+	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
+	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
+	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
+	si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
+	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
+	si->main_area_sections = le32_to_cpu(raw_super->section_count);
+	si->main_area_zones = si->main_area_sections /
+				le32_to_cpu(raw_super->secs_per_zone);
+	si->sbi = sbi;
+	sbi->stat_info = si;
+
+	atomic_set(&sbi->inline_inode, 0);
+	atomic_set(&sbi->inline_dir, 0);
+	atomic_set(&sbi->inplace_count, 0);
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_add_tail(&si->stat_list, &f2fs_stat_list);
+	mutex_unlock(&f2fs_stat_mutex);
+
+	return 0;
+}
+
+void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_del(&si->stat_list);
+	mutex_unlock(&f2fs_stat_mutex);
+
+	kfree(si);
+}
+
+void __init f2fs_create_root_stats(void)
+{
+	struct dentry *file;
+
+	f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
+	if (!f2fs_debugfs_root)
+		return;
+
+	file = debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root,
+			NULL, &stat_fops);
+	if (!file) {
+		debugfs_remove(f2fs_debugfs_root);
+		f2fs_debugfs_root = NULL;
+	}
+}
+
+void f2fs_destroy_root_stats(void)
+{
+	if (!f2fs_debugfs_root)
+		return;
+
+	debugfs_remove_recursive(f2fs_debugfs_root);
+	f2fs_debugfs_root = NULL;
+}
diff --git a/kernel/fs/f2fs/dir.c b/kernel/fs/f2fs/dir.c
new file mode 100644
index 000000000..3a3302ab7
--- /dev/null
+++ b/kernel/fs/f2fs/dir.c
@@ -0,0 +1,811 @@
+/*
+ * fs/f2fs/dir.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "node.h"
+#include "acl.h"
+#include "xattr.h"
+
+static unsigned long dir_blocks(struct inode *inode)
+{
+	return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
+							>> PAGE_CACHE_SHIFT;
+}
+
+static unsigned int dir_buckets(unsigned int level, int dir_level)
+{
+	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
+		return 1 << (level + dir_level);
+	else
+		return MAX_DIR_BUCKETS;
+}
+
+static unsigned int bucket_blocks(unsigned int level)
+{
+	if (level < MAX_DIR_HASH_DEPTH / 2)
+		return 2;
+	else
+		return 4;
+}
+
+unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
+	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
+	[F2FS_FT_REG_FILE]	= DT_REG,
+	[F2FS_FT_DIR]		= DT_DIR,
+	[F2FS_FT_CHRDEV]	= DT_CHR,
+	[F2FS_FT_BLKDEV]	= DT_BLK,
+	[F2FS_FT_FIFO]		= DT_FIFO,
+	[F2FS_FT_SOCK]		= DT_SOCK,
+	[F2FS_FT_SYMLINK]	= DT_LNK,
+};
+
+#define S_SHIFT 12
+static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
+	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
+	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
+	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
+	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
+	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
+	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
+	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
+};
+
+void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
+{
+	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
+}
+
+static unsigned long dir_block_index(unsigned int level,
+				int dir_level, unsigned int idx)
+{
+	unsigned long i;
+	unsigned long bidx = 0;
+
+	for (i = 0; i < level; i++)
+		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
+	bidx += idx * bucket_blocks(level);
+	return bidx;
+}
+
+static bool early_match_name(size_t namelen, f2fs_hash_t namehash,
+				struct f2fs_dir_entry *de)
+{
+	if (le16_to_cpu(de->name_len) != namelen)
+		return false;
+
+	if (de->hash_code != namehash)
+		return false;
+
+	return true;
+}
+
+static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
+				struct qstr *name, int *max_slots,
+				struct page **res_page)
+{
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_ptr d;
+
+	dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
+
+	make_dentry_ptr(&d, (void *)dentry_blk, 1);
+	de = find_target_dentry(name, max_slots, &d);
+
+	if (de)
+		*res_page = dentry_page;
+	else
+		kunmap(dentry_page);
+
+	/*
+	 * For the most part, it should be a bug when name_len is zero.
+	 * We stop here for figuring out where the bugs has occurred.
+	 */
+	f2fs_bug_on(F2FS_P_SB(dentry_page), d.max < 0);
+	return de;
+}
+
+struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
+						struct f2fs_dentry_ptr *d)
+{
+	struct f2fs_dir_entry *de;
+	unsigned long bit_pos = 0;
+	f2fs_hash_t namehash = f2fs_dentry_hash(name);
+	int max_len = 0;
+
+	if (max_slots)
+		*max_slots = 0;
+	while (bit_pos < d->max) {
+		if (!test_bit_le(bit_pos, d->bitmap)) {
+			bit_pos++;
+			max_len++;
+			continue;
+		}
+
+		de = &d->dentry[bit_pos];
+		if (early_match_name(name->len, namehash, de) &&
+			!memcmp(d->filename[bit_pos], name->name, name->len))
+			goto found;
+
+		if (max_slots && max_len > *max_slots)
+			*max_slots = max_len;
+		max_len = 0;
+
+		/* remain bug on condition */
+		if (unlikely(!de->name_len))
+			d->max = -1;
+
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+	}
+
+	de = NULL;
+found:
+	if (max_slots && max_len > *max_slots)
+		*max_slots = max_len;
+	return de;
+}
+
+static struct f2fs_dir_entry *find_in_level(struct inode *dir,
+			unsigned int level, struct qstr *name,
+			f2fs_hash_t namehash, struct page **res_page)
+{
+	int s = GET_DENTRY_SLOTS(name->len);
+	unsigned int nbucket, nblock;
+	unsigned int bidx, end_block;
+	struct page *dentry_page;
+	struct f2fs_dir_entry *de = NULL;
+	bool room = false;
+	int max_slots;
+
+	f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+					le32_to_cpu(namehash) % nbucket);
+	end_block = bidx + nblock;
+
+	for (; bidx < end_block; bidx++) {
+		/* no need to allocate new dentry pages to all the indices */
+		dentry_page = find_data_page(dir, bidx, true);
+		if (IS_ERR(dentry_page)) {
+			room = true;
+			continue;
+		}
+
+		de = find_in_block(dentry_page, name, &max_slots, res_page);
+		if (de)
+			break;
+
+		if (max_slots >= s)
+			room = true;
+		f2fs_put_page(dentry_page, 0);
+	}
+
+	if (!de && room && F2FS_I(dir)->chash != namehash) {
+		F2FS_I(dir)->chash = namehash;
+		F2FS_I(dir)->clevel = level;
+	}
+
+	return de;
+}
+
+/*
+ * Find an entry in the specified directory with the wanted name.
+ * It returns the page where the entry was found (as a parameter - res_page),
+ * and the entry itself. Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
+			struct qstr *child, struct page **res_page)
+{
+	unsigned long npages = dir_blocks(dir);
+	struct f2fs_dir_entry *de = NULL;
+	f2fs_hash_t name_hash;
+	unsigned int max_depth;
+	unsigned int level;
+
+	*res_page = NULL;
+
+	if (f2fs_has_inline_dentry(dir))
+		return find_in_inline_dir(dir, child, res_page);
+
+	if (npages == 0)
+		return NULL;
+
+	name_hash = f2fs_dentry_hash(child);
+	max_depth = F2FS_I(dir)->i_current_depth;
+
+	for (level = 0; level < max_depth; level++) {
+		de = find_in_level(dir, level, child, name_hash, res_page);
+		if (de)
+			break;
+	}
+	if (!de && F2FS_I(dir)->chash != name_hash) {
+		F2FS_I(dir)->chash = name_hash;
+		F2FS_I(dir)->clevel = level - 1;
+	}
+	return de;
+}
+
+struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
+{
+	struct page *page;
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_block *dentry_blk;
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_parent_inline_dir(dir, p);
+
+	page = get_lock_data_page(dir, 0);
+	if (IS_ERR(page))
+		return NULL;
+
+	dentry_blk = kmap(page);
+	de = &dentry_blk->dentry[1];
+	*p = page;
+	unlock_page(page);
+	return de;
+}
+
+ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
+{
+	ino_t res = 0;
+	struct f2fs_dir_entry *de;
+	struct page *page;
+
+	de = f2fs_find_entry(dir, qstr, &page);
+	if (de) {
+		res = le32_to_cpu(de->ino);
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+	}
+
+	return res;
+}
+
+void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
+		struct page *page, struct inode *inode)
+{
+	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, type);
+	de->ino = cpu_to_le32(inode->i_ino);
+	set_de_type(de, inode->i_mode);
+	f2fs_dentry_kunmap(dir, page);
+	set_page_dirty(page);
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(dir);
+
+	f2fs_put_page(page, 1);
+}
+
+static void init_dent_inode(const struct qstr *name, struct page *ipage)
+{
+	struct f2fs_inode *ri;
+
+	f2fs_wait_on_page_writeback(ipage, NODE);
+
+	/* copy name info. to this inode page */
+	ri = F2FS_INODE(ipage);
+	ri->i_namelen = cpu_to_le32(name->len);
+	memcpy(ri->i_name, name->name, name->len);
+	set_page_dirty(ipage);
+}
+
+int update_dent_inode(struct inode *inode, const struct qstr *name)
+{
+	struct page *page;
+
+	page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	init_dent_inode(name, page);
+	f2fs_put_page(page, 1);
+
+	return 0;
+}
+
+void do_make_empty_dir(struct inode *inode, struct inode *parent,
+					struct f2fs_dentry_ptr *d)
+{
+	struct f2fs_dir_entry *de;
+
+	de = &d->dentry[0];
+	de->name_len = cpu_to_le16(1);
+	de->hash_code = 0;
+	de->ino = cpu_to_le32(inode->i_ino);
+	memcpy(d->filename[0], ".", 1);
+	set_de_type(de, inode->i_mode);
+
+	de = &d->dentry[1];
+	de->hash_code = 0;
+	de->name_len = cpu_to_le16(2);
+	de->ino = cpu_to_le32(parent->i_ino);
+	memcpy(d->filename[1], "..", 2);
+	set_de_type(de, parent->i_mode);
+
+	test_and_set_bit_le(0, (void *)d->bitmap);
+	test_and_set_bit_le(1, (void *)d->bitmap);
+}
+
+static int make_empty_dir(struct inode *inode,
+		struct inode *parent, struct page *page)
+{
+	struct page *dentry_page;
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dentry_ptr d;
+
+	if (f2fs_has_inline_dentry(inode))
+		return make_empty_inline_dir(inode, parent, page);
+
+	dentry_page = get_new_data_page(inode, page, 0, true);
+	if (IS_ERR(dentry_page))
+		return PTR_ERR(dentry_page);
+
+	dentry_blk = kmap_atomic(dentry_page);
+
+	make_dentry_ptr(&d, (void *)dentry_blk, 1);
+	do_make_empty_dir(inode, parent, &d);
+
+	kunmap_atomic(dentry_blk);
+
+	set_page_dirty(dentry_page);
+	f2fs_put_page(dentry_page, 1);
+	return 0;
+}
+
+struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
+			const struct qstr *name, struct page *dpage)
+{
+	struct page *page;
+	int err;
+
+	if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
+		page = new_inode_page(inode);
+		if (IS_ERR(page))
+			return page;
+
+		if (S_ISDIR(inode->i_mode)) {
+			err = make_empty_dir(inode, dir, page);
+			if (err)
+				goto error;
+		}
+
+		err = f2fs_init_acl(inode, dir, page, dpage);
+		if (err)
+			goto put_error;
+
+		err = f2fs_init_security(inode, dir, name, page);
+		if (err)
+			goto put_error;
+	} else {
+		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
+		if (IS_ERR(page))
+			return page;
+
+		set_cold_node(inode, page);
+	}
+
+	if (name)
+		init_dent_inode(name, page);
+
+	/*
+	 * This file should be checkpointed during fsync.
+	 * We lost i_pino from now on.
+	 */
+	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
+		file_lost_pino(inode);
+		/*
+		 * If link the tmpfile to alias through linkat path,
+		 * we should remove this inode from orphan list.
+		 */
+		if (inode->i_nlink == 0)
+			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
+		inc_nlink(inode);
+	}
+	return page;
+
+put_error:
+	f2fs_put_page(page, 1);
+error:
+	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
+	truncate_inode_pages(&inode->i_data, 0);
+	truncate_blocks(inode, 0, false);
+	remove_dirty_dir_inode(inode);
+	remove_inode_page(inode);
+	return ERR_PTR(err);
+}
+
+void update_parent_metadata(struct inode *dir, struct inode *inode,
+						unsigned int current_depth)
+{
+	if (inode && is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
+		if (S_ISDIR(inode->i_mode)) {
+			inc_nlink(dir);
+			set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+		}
+		clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
+	}
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(dir);
+
+	if (F2FS_I(dir)->i_current_depth != current_depth) {
+		F2FS_I(dir)->i_current_depth = current_depth;
+		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
+
+	if (inode && is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
+		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
+}
+
+int room_for_filename(const void *bitmap, int slots, int max_slots)
+{
+	int bit_start = 0;
+	int zero_start, zero_end;
+next:
+	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
+	if (zero_start >= max_slots)
+		return max_slots;
+
+	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
+	if (zero_end - zero_start >= slots)
+		return zero_start;
+
+	bit_start = zero_end + 1;
+
+	if (zero_end + 1 >= max_slots)
+		return max_slots;
+	goto next;
+}
+
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
+				const struct qstr *name, f2fs_hash_t name_hash,
+				unsigned int bit_pos)
+{
+	struct f2fs_dir_entry *de;
+	int slots = GET_DENTRY_SLOTS(name->len);
+	int i;
+
+	de = &d->dentry[bit_pos];
+	de->hash_code = name_hash;
+	de->name_len = cpu_to_le16(name->len);
+	memcpy(d->filename[bit_pos], name->name, name->len);
+	de->ino = cpu_to_le32(ino);
+	set_de_type(de, mode);
+	for (i = 0; i < slots; i++)
+		test_and_set_bit_le(bit_pos + i, (void *)d->bitmap);
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+int __f2fs_add_link(struct inode *dir, const struct qstr *name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	unsigned int bit_pos;
+	unsigned int level;
+	unsigned int current_depth;
+	unsigned long bidx, block;
+	f2fs_hash_t dentry_hash;
+	unsigned int nbucket, nblock;
+	size_t namelen = name->len;
+	struct page *dentry_page = NULL;
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
+	int slots = GET_DENTRY_SLOTS(namelen);
+	struct page *page = NULL;
+	int err = 0;
+
+	if (f2fs_has_inline_dentry(dir)) {
+		err = f2fs_add_inline_entry(dir, name, inode, ino, mode);
+		if (!err || err != -EAGAIN)
+			return err;
+		else
+			err = 0;
+	}
+
+	dentry_hash = f2fs_dentry_hash(name);
+	level = 0;
+	current_depth = F2FS_I(dir)->i_current_depth;
+	if (F2FS_I(dir)->chash == dentry_hash) {
+		level = F2FS_I(dir)->clevel;
+		F2FS_I(dir)->chash = 0;
+	}
+
+start:
+	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
+		return -ENOSPC;
+
+	/* Increase the depth, if required */
+	if (level == current_depth)
+		++current_depth;
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+				(le32_to_cpu(dentry_hash) % nbucket));
+
+	for (block = bidx; block <= (bidx + nblock - 1); block++) {
+		dentry_page = get_new_data_page(dir, NULL, block, true);
+		if (IS_ERR(dentry_page))
+			return PTR_ERR(dentry_page);
+
+		dentry_blk = kmap(dentry_page);
+		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
+						slots, NR_DENTRY_IN_BLOCK);
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			goto add_dentry;
+
+		kunmap(dentry_page);
+		f2fs_put_page(dentry_page, 1);
+	}
+
+	/* Move to next level to find the empty slot for new dentry */
+	++level;
+	goto start;
+add_dentry:
+	f2fs_wait_on_page_writeback(dentry_page, DATA);
+
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, name, NULL);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
+	}
+
+	make_dentry_ptr(&d, (void *)dentry_blk, 1);
+	f2fs_update_dentry(ino, mode, &d, name, dentry_hash, bit_pos);
+
+	set_page_dirty(dentry_page);
+
+	if (inode) {
+		/* we don't need to mark_inode_dirty now */
+		F2FS_I(inode)->i_pino = dir->i_ino;
+		update_inode(inode, page);
+		f2fs_put_page(page, 1);
+	}
+
+	update_parent_metadata(dir, inode, current_depth);
+fail:
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
+
+	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
+		update_inode_page(dir);
+		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
+	kunmap(dentry_page);
+	f2fs_put_page(dentry_page, 1);
+	return err;
+}
+
+int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
+{
+	struct page *page;
+	int err = 0;
+
+	down_write(&F2FS_I(inode)->i_sem);
+	page = init_inode_metadata(inode, dir, NULL, NULL);
+	if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+		goto fail;
+	}
+	/* we don't need to mark_inode_dirty now */
+	update_inode(inode, page);
+	f2fs_put_page(page, 1);
+
+	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
+fail:
+	up_write(&F2FS_I(inode)->i_sem);
+	return err;
+}
+
+void f2fs_drop_nlink(struct inode *dir, struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+
+	down_write(&F2FS_I(inode)->i_sem);
+
+	if (S_ISDIR(inode->i_mode)) {
+		drop_nlink(dir);
+		if (page)
+			update_inode(dir, page);
+		else
+			update_inode_page(dir);
+	}
+	inode->i_ctime = CURRENT_TIME;
+
+	drop_nlink(inode);
+	if (S_ISDIR(inode->i_mode)) {
+		drop_nlink(inode);
+		i_size_write(inode, 0);
+	}
+	up_write(&F2FS_I(inode)->i_sem);
+	update_inode_page(inode);
+
+	if (inode->i_nlink == 0)
+		add_orphan_inode(sbi, inode->i_ino);
+	else
+		release_orphan_inode(sbi);
+}
+
+/*
+ * It only removes the dentry from the dentry page, corresponding name
+ * entry in name page does not need to be touched during deletion.
+ */
+void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
+					struct inode *dir, struct inode *inode)
+{
+	struct	f2fs_dentry_block *dentry_blk;
+	unsigned int bit_pos;
+	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
+	int i;
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_delete_inline_entry(dentry, page, dir, inode);
+
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, DATA);
+
+	dentry_blk = page_address(page);
+	bit_pos = dentry - dentry_blk->dentry;
+	for (i = 0; i < slots; i++)
+		clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
+
+	/* Let's check and deallocate this dentry page */
+	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+			NR_DENTRY_IN_BLOCK,
+			0);
+	kunmap(page); /* kunmap - pair of f2fs_find_entry */
+	set_page_dirty(page);
+
+	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+
+	if (inode)
+		f2fs_drop_nlink(dir, inode, NULL);
+
+	if (bit_pos == NR_DENTRY_IN_BLOCK) {
+		truncate_hole(dir, page->index, page->index + 1);
+		clear_page_dirty_for_io(page);
+		ClearPagePrivate(page);
+		ClearPageUptodate(page);
+		inode_dec_dirty_pages(dir);
+	}
+	f2fs_put_page(page, 1);
+}
+
+bool f2fs_empty_dir(struct inode *dir)
+{
+	unsigned long bidx;
+	struct page *dentry_page;
+	unsigned int bit_pos;
+	struct f2fs_dentry_block *dentry_blk;
+	unsigned long nblock = dir_blocks(dir);
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_empty_inline_dir(dir);
+
+	for (bidx = 0; bidx < nblock; bidx++) {
+		dentry_page = get_lock_data_page(dir, bidx);
+		if (IS_ERR(dentry_page)) {
+			if (PTR_ERR(dentry_page) == -ENOENT)
+				continue;
+			else
+				return false;
+		}
+
+		dentry_blk = kmap_atomic(dentry_page);
+		if (bidx == 0)
+			bit_pos = 2;
+		else
+			bit_pos = 0;
+		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+						NR_DENTRY_IN_BLOCK,
+						bit_pos);
+		kunmap_atomic(dentry_blk);
+
+		f2fs_put_page(dentry_page, 1);
+
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			return false;
+	}
+	return true;
+}
+
+bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
+						unsigned int start_pos)
+{
+	unsigned char d_type = DT_UNKNOWN;
+	unsigned int bit_pos;
+	struct f2fs_dir_entry *de = NULL;
+
+	bit_pos = ((unsigned long)ctx->pos % d->max);
+
+	while (bit_pos < d->max) {
+		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
+		if (bit_pos >= d->max)
+			break;
+
+		de = &d->dentry[bit_pos];
+		if (de->file_type < F2FS_FT_MAX)
+			d_type = f2fs_filetype_table[de->file_type];
+		else
+			d_type = DT_UNKNOWN;
+		if (!dir_emit(ctx, d->filename[bit_pos],
+					le16_to_cpu(de->name_len),
+					le32_to_cpu(de->ino), d_type))
+			return true;
+
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+		ctx->pos = start_pos + bit_pos;
+	}
+	return false;
+}
+
+static int f2fs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	unsigned long npages = dir_blocks(inode);
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct page *dentry_page = NULL;
+	struct file_ra_state *ra = &file->f_ra;
+	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
+	struct f2fs_dentry_ptr d;
+
+	if (f2fs_has_inline_dentry(inode))
+		return f2fs_read_inline_dir(file, ctx);
+
+	/* readahead for multi pages of dir */
+	if (npages - n > 1 && !ra_has_index(ra, n))
+		page_cache_sync_readahead(inode->i_mapping, ra, file, n,
+				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
+
+	for (; n < npages; n++) {
+		dentry_page = get_lock_data_page(inode, n);
+		if (IS_ERR(dentry_page))
+			continue;
+
+		dentry_blk = kmap(dentry_page);
+
+		make_dentry_ptr(&d, (void *)dentry_blk, 1);
+
+		if (f2fs_fill_dentries(ctx, &d, n * NR_DENTRY_IN_BLOCK))
+			goto stop;
+
+		ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
+		kunmap(dentry_page);
+		f2fs_put_page(dentry_page, 1);
+		dentry_page = NULL;
+	}
+stop:
+	if (dentry_page && !IS_ERR(dentry_page)) {
+		kunmap(dentry_page);
+		f2fs_put_page(dentry_page, 1);
+	}
+
+	return 0;
+}
+
+const struct file_operations f2fs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate	= f2fs_readdir,
+	.fsync		= f2fs_sync_file,
+	.unlocked_ioctl	= f2fs_ioctl,
+};
diff --git a/kernel/fs/f2fs/f2fs.h b/kernel/fs/f2fs/f2fs.h
new file mode 100644
index 000000000..8de34ab6d
--- /dev/null
+++ b/kernel/fs/f2fs/f2fs.h
@@ -0,0 +1,1814 @@
+/*
+ * fs/f2fs/f2fs.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef _LINUX_F2FS_H
+#define _LINUX_F2FS_H
+
+#include <linux/types.h>
+#include <linux/page-flags.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/magic.h>
+#include <linux/kobject.h>
+#include <linux/sched.h>
+
+#ifdef CONFIG_F2FS_CHECK_FS
+#define f2fs_bug_on(sbi, condition)	BUG_ON(condition)
+#define f2fs_down_write(x, y)	down_write_nest_lock(x, y)
+#else
+#define f2fs_bug_on(sbi, condition)					\
+	do {								\
+		if (unlikely(condition)) {				\
+			WARN_ON(1);					\
+			set_sbi_flag(sbi, SBI_NEED_FSCK);		\
+		}							\
+	} while (0)
+#define f2fs_down_write(x, y)	down_write(x)
+#endif
+
+/*
+ * For mount options
+ */
+#define F2FS_MOUNT_BG_GC		0x00000001
+#define F2FS_MOUNT_DISABLE_ROLL_FORWARD	0x00000002
+#define F2FS_MOUNT_DISCARD		0x00000004
+#define F2FS_MOUNT_NOHEAP		0x00000008
+#define F2FS_MOUNT_XATTR_USER		0x00000010
+#define F2FS_MOUNT_POSIX_ACL		0x00000020
+#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY	0x00000040
+#define F2FS_MOUNT_INLINE_XATTR		0x00000080
+#define F2FS_MOUNT_INLINE_DATA		0x00000100
+#define F2FS_MOUNT_INLINE_DENTRY	0x00000200
+#define F2FS_MOUNT_FLUSH_MERGE		0x00000400
+#define F2FS_MOUNT_NOBARRIER		0x00000800
+#define F2FS_MOUNT_FASTBOOT		0x00001000
+#define F2FS_MOUNT_EXTENT_CACHE		0x00002000
+
+#define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
+#define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
+#define test_opt(sbi, option)	(sbi->mount_opt.opt & F2FS_MOUNT_##option)
+
+#define ver_after(a, b)	(typecheck(unsigned long long, a) &&		\
+		typecheck(unsigned long long, b) &&			\
+		((long long)((a) - (b)) > 0))
+
+typedef u32 block_t;	/*
+			 * should not change u32, since it is the on-disk block
+			 * address format, __le32.
+			 */
+typedef u32 nid_t;
+
+struct f2fs_mount_info {
+	unsigned int	opt;
+};
+
+#define CRCPOLY_LE 0xedb88320
+
+static inline __u32 f2fs_crc32(void *buf, size_t len)
+{
+	unsigned char *p = (unsigned char *)buf;
+	__u32 crc = F2FS_SUPER_MAGIC;
+	int i;
+
+	while (len--) {
+		crc ^= *p++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+	}
+	return crc;
+}
+
+static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
+{
+	return f2fs_crc32(buf, buf_size) == blk_crc;
+}
+
+/*
+ * For checkpoint manager
+ */
+enum {
+	NAT_BITMAP,
+	SIT_BITMAP
+};
+
+enum {
+	CP_UMOUNT,
+	CP_FASTBOOT,
+	CP_SYNC,
+	CP_RECOVERY,
+	CP_DISCARD,
+};
+
+#define DEF_BATCHED_TRIM_SECTIONS	32
+#define BATCHED_TRIM_SEGMENTS(sbi)	\
+		(SM_I(sbi)->trim_sections * (sbi)->segs_per_sec)
+
+struct cp_control {
+	int reason;
+	__u64 trim_start;
+	__u64 trim_end;
+	__u64 trim_minlen;
+	__u64 trimmed;
+};
+
+/*
+ * For CP/NAT/SIT/SSA readahead
+ */
+enum {
+	META_CP,
+	META_NAT,
+	META_SIT,
+	META_SSA,
+	META_POR,
+};
+
+/* for the list of ino */
+enum {
+	ORPHAN_INO,		/* for orphan ino list */
+	APPEND_INO,		/* for append ino list */
+	UPDATE_INO,		/* for update ino list */
+	MAX_INO_ENTRY,		/* max. list */
+};
+
+struct ino_entry {
+	struct list_head list;	/* list head */
+	nid_t ino;		/* inode number */
+};
+
+/*
+ * for the list of directory inodes or gc inodes.
+ * NOTE: there are two slab users for this structure, if we add/modify/delete
+ * fields in structure for one of slab users, it may affect fields or size of
+ * other one, in this condition, it's better to split both of slab and related
+ * data structure.
+ */
+struct inode_entry {
+	struct list_head list;	/* list head */
+	struct inode *inode;	/* vfs inode pointer */
+};
+
+/* for the list of blockaddresses to be discarded */
+struct discard_entry {
+	struct list_head list;	/* list head */
+	block_t blkaddr;	/* block address to be discarded */
+	int len;		/* # of consecutive blocks of the discard */
+};
+
+/* for the list of fsync inodes, used only during recovery */
+struct fsync_inode_entry {
+	struct list_head list;	/* list head */
+	struct inode *inode;	/* vfs inode pointer */
+	block_t blkaddr;	/* block address locating the last fsync */
+	block_t last_dentry;	/* block address locating the last dentry */
+	block_t last_inode;	/* block address locating the last inode */
+};
+
+#define nats_in_cursum(sum)		(le16_to_cpu(sum->n_nats))
+#define sits_in_cursum(sum)		(le16_to_cpu(sum->n_sits))
+
+#define nat_in_journal(sum, i)		(sum->nat_j.entries[i].ne)
+#define nid_in_journal(sum, i)		(sum->nat_j.entries[i].nid)
+#define sit_in_journal(sum, i)		(sum->sit_j.entries[i].se)
+#define segno_in_journal(sum, i)	(sum->sit_j.entries[i].segno)
+
+#define MAX_NAT_JENTRIES(sum)	(NAT_JOURNAL_ENTRIES - nats_in_cursum(sum))
+#define MAX_SIT_JENTRIES(sum)	(SIT_JOURNAL_ENTRIES - sits_in_cursum(sum))
+
+static inline int update_nats_in_cursum(struct f2fs_summary_block *rs, int i)
+{
+	int before = nats_in_cursum(rs);
+	rs->n_nats = cpu_to_le16(before + i);
+	return before;
+}
+
+static inline int update_sits_in_cursum(struct f2fs_summary_block *rs, int i)
+{
+	int before = sits_in_cursum(rs);
+	rs->n_sits = cpu_to_le16(before + i);
+	return before;
+}
+
+static inline bool __has_cursum_space(struct f2fs_summary_block *sum, int size,
+								int type)
+{
+	if (type == NAT_JOURNAL)
+		return size <= MAX_NAT_JENTRIES(sum);
+	return size <= MAX_SIT_JENTRIES(sum);
+}
+
+/*
+ * ioctl commands
+ */
+#define F2FS_IOC_GETFLAGS		FS_IOC_GETFLAGS
+#define F2FS_IOC_SETFLAGS		FS_IOC_SETFLAGS
+#define F2FS_IOC_GETVERSION		FS_IOC_GETVERSION
+
+#define F2FS_IOCTL_MAGIC		0xf5
+#define F2FS_IOC_START_ATOMIC_WRITE	_IO(F2FS_IOCTL_MAGIC, 1)
+#define F2FS_IOC_COMMIT_ATOMIC_WRITE	_IO(F2FS_IOCTL_MAGIC, 2)
+#define F2FS_IOC_START_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 3)
+#define F2FS_IOC_RELEASE_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 4)
+#define F2FS_IOC_ABORT_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 5)
+
+/*
+ * should be same as XFS_IOC_GOINGDOWN.
+ * Flags for going down operation used by FS_IOC_GOINGDOWN
+ */
+#define F2FS_IOC_SHUTDOWN	_IOR('X', 125, __u32)	/* Shutdown */
+#define F2FS_GOING_DOWN_FULLSYNC	0x0	/* going down with full sync */
+#define F2FS_GOING_DOWN_METASYNC	0x1	/* going down with metadata */
+#define F2FS_GOING_DOWN_NOSYNC		0x2	/* going down */
+
+#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
+/*
+ * ioctl commands in 32 bit emulation
+ */
+#define F2FS_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
+#define F2FS_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
+#endif
+
+/*
+ * For INODE and NODE manager
+ */
+/* for directory operations */
+struct f2fs_dentry_ptr {
+	const void *bitmap;
+	struct f2fs_dir_entry *dentry;
+	__u8 (*filename)[F2FS_SLOT_LEN];
+	int max;
+};
+
+static inline void make_dentry_ptr(struct f2fs_dentry_ptr *d,
+					void *src, int type)
+{
+	if (type == 1) {
+		struct f2fs_dentry_block *t = (struct f2fs_dentry_block *)src;
+		d->max = NR_DENTRY_IN_BLOCK;
+		d->bitmap = &t->dentry_bitmap;
+		d->dentry = t->dentry;
+		d->filename = t->filename;
+	} else {
+		struct f2fs_inline_dentry *t = (struct f2fs_inline_dentry *)src;
+		d->max = NR_INLINE_DENTRY;
+		d->bitmap = &t->dentry_bitmap;
+		d->dentry = t->dentry;
+		d->filename = t->filename;
+	}
+}
+
+/*
+ * XATTR_NODE_OFFSET stores xattrs to one node block per file keeping -1
+ * as its node offset to distinguish from index node blocks.
+ * But some bits are used to mark the node block.
+ */
+#define XATTR_NODE_OFFSET	((((unsigned int)-1) << OFFSET_BIT_SHIFT) \
+				>> OFFSET_BIT_SHIFT)
+enum {
+	ALLOC_NODE,			/* allocate a new node page if needed */
+	LOOKUP_NODE,			/* look up a node without readahead */
+	LOOKUP_NODE_RA,			/*
+					 * look up a node with readahead called
+					 * by get_data_block.
+					 */
+};
+
+#define F2FS_LINK_MAX		32000	/* maximum link count per file */
+
+#define MAX_DIR_RA_PAGES	4	/* maximum ra pages of dir */
+
+/* vector size for gang look-up from extent cache that consists of radix tree */
+#define EXT_TREE_VEC_SIZE	64
+
+/* for in-memory extent cache entry */
+#define F2FS_MIN_EXTENT_LEN	64	/* minimum extent length */
+
+/* number of extent info in extent cache we try to shrink */
+#define EXTENT_CACHE_SHRINK_NUMBER	128
+
+struct extent_info {
+	unsigned int fofs;		/* start offset in a file */
+	u32 blk;			/* start block address of the extent */
+	unsigned int len;		/* length of the extent */
+};
+
+struct extent_node {
+	struct rb_node rb_node;		/* rb node located in rb-tree */
+	struct list_head list;		/* node in global extent list of sbi */
+	struct extent_info ei;		/* extent info */
+};
+
+struct extent_tree {
+	nid_t ino;			/* inode number */
+	struct rb_root root;		/* root of extent info rb-tree */
+	struct extent_node *cached_en;	/* recently accessed extent node */
+	rwlock_t lock;			/* protect extent info rb-tree */
+	atomic_t refcount;		/* reference count of rb-tree */
+	unsigned int count;		/* # of extent node in rb-tree*/
+};
+
+/*
+ * i_advise uses FADVISE_XXX_BIT. We can add additional hints later.
+ */
+#define FADVISE_COLD_BIT	0x01
+#define FADVISE_LOST_PINO_BIT	0x02
+
+#define DEF_DIR_LEVEL		0
+
+struct f2fs_inode_info {
+	struct inode vfs_inode;		/* serve a vfs inode */
+	unsigned long i_flags;		/* keep an inode flags for ioctl */
+	unsigned char i_advise;		/* use to give file attribute hints */
+	unsigned char i_dir_level;	/* use for dentry level for large dir */
+	unsigned int i_current_depth;	/* use only in directory structure */
+	unsigned int i_pino;		/* parent inode number */
+	umode_t i_acl_mode;		/* keep file acl mode temporarily */
+
+	/* Use below internally in f2fs*/
+	unsigned long flags;		/* use to pass per-file flags */
+	struct rw_semaphore i_sem;	/* protect fi info */
+	atomic_t dirty_pages;		/* # of dirty pages */
+	f2fs_hash_t chash;		/* hash value of given file name */
+	unsigned int clevel;		/* maximum level of given file name */
+	nid_t i_xattr_nid;		/* node id that contains xattrs */
+	unsigned long long xattr_ver;	/* cp version of xattr modification */
+	struct extent_info ext;		/* in-memory extent cache entry */
+	rwlock_t ext_lock;		/* rwlock for single extent cache */
+	struct inode_entry *dirty_dir;	/* the pointer of dirty dir */
+
+	struct radix_tree_root inmem_root;	/* radix tree for inmem pages */
+	struct list_head inmem_pages;	/* inmemory pages managed by f2fs */
+	struct mutex inmem_lock;	/* lock for inmemory pages */
+};
+
+static inline void get_extent_info(struct extent_info *ext,
+					struct f2fs_extent i_ext)
+{
+	ext->fofs = le32_to_cpu(i_ext.fofs);
+	ext->blk = le32_to_cpu(i_ext.blk);
+	ext->len = le32_to_cpu(i_ext.len);
+}
+
+static inline void set_raw_extent(struct extent_info *ext,
+					struct f2fs_extent *i_ext)
+{
+	i_ext->fofs = cpu_to_le32(ext->fofs);
+	i_ext->blk = cpu_to_le32(ext->blk);
+	i_ext->len = cpu_to_le32(ext->len);
+}
+
+static inline void set_extent_info(struct extent_info *ei, unsigned int fofs,
+						u32 blk, unsigned int len)
+{
+	ei->fofs = fofs;
+	ei->blk = blk;
+	ei->len = len;
+}
+
+static inline bool __is_extent_same(struct extent_info *ei1,
+						struct extent_info *ei2)
+{
+	return (ei1->fofs == ei2->fofs && ei1->blk == ei2->blk &&
+						ei1->len == ei2->len);
+}
+
+static inline bool __is_extent_mergeable(struct extent_info *back,
+						struct extent_info *front)
+{
+	return (back->fofs + back->len == front->fofs &&
+			back->blk + back->len == front->blk);
+}
+
+static inline bool __is_back_mergeable(struct extent_info *cur,
+						struct extent_info *back)
+{
+	return __is_extent_mergeable(back, cur);
+}
+
+static inline bool __is_front_mergeable(struct extent_info *cur,
+						struct extent_info *front)
+{
+	return __is_extent_mergeable(cur, front);
+}
+
+struct f2fs_nm_info {
+	block_t nat_blkaddr;		/* base disk address of NAT */
+	nid_t max_nid;			/* maximum possible node ids */
+	nid_t available_nids;		/* maximum available node ids */
+	nid_t next_scan_nid;		/* the next nid to be scanned */
+	unsigned int ram_thresh;	/* control the memory footprint */
+
+	/* NAT cache management */
+	struct radix_tree_root nat_root;/* root of the nat entry cache */
+	struct radix_tree_root nat_set_root;/* root of the nat set cache */
+	struct rw_semaphore nat_tree_lock;	/* protect nat_tree_lock */
+	struct list_head nat_entries;	/* cached nat entry list (clean) */
+	unsigned int nat_cnt;		/* the # of cached nat entries */
+	unsigned int dirty_nat_cnt;	/* total num of nat entries in set */
+
+	/* free node ids management */
+	struct radix_tree_root free_nid_root;/* root of the free_nid cache */
+	struct list_head free_nid_list;	/* a list for free nids */
+	spinlock_t free_nid_list_lock;	/* protect free nid list */
+	unsigned int fcnt;		/* the number of free node id */
+	struct mutex build_lock;	/* lock for build free nids */
+
+	/* for checkpoint */
+	char *nat_bitmap;		/* NAT bitmap pointer */
+	int bitmap_size;		/* bitmap size */
+};
+
+/*
+ * this structure is used as one of function parameters.
+ * all the information are dedicated to a given direct node block determined
+ * by the data offset in a file.
+ */
+struct dnode_of_data {
+	struct inode *inode;		/* vfs inode pointer */
+	struct page *inode_page;	/* its inode page, NULL is possible */
+	struct page *node_page;		/* cached direct node page */
+	nid_t nid;			/* node id of the direct node block */
+	unsigned int ofs_in_node;	/* data offset in the node page */
+	bool inode_page_locked;		/* inode page is locked or not */
+	block_t	data_blkaddr;		/* block address of the node block */
+};
+
+static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
+		struct page *ipage, struct page *npage, nid_t nid)
+{
+	memset(dn, 0, sizeof(*dn));
+	dn->inode = inode;
+	dn->inode_page = ipage;
+	dn->node_page = npage;
+	dn->nid = nid;
+}
+
+/*
+ * For SIT manager
+ *
+ * By default, there are 6 active log areas across the whole main area.
+ * When considering hot and cold data separation to reduce cleaning overhead,
+ * we split 3 for data logs and 3 for node logs as hot, warm, and cold types,
+ * respectively.
+ * In the current design, you should not change the numbers intentionally.
+ * Instead, as a mount option such as active_logs=x, you can use 2, 4, and 6
+ * logs individually according to the underlying devices. (default: 6)
+ * Just in case, on-disk layout covers maximum 16 logs that consist of 8 for
+ * data and 8 for node logs.
+ */
+#define	NR_CURSEG_DATA_TYPE	(3)
+#define NR_CURSEG_NODE_TYPE	(3)
+#define NR_CURSEG_TYPE	(NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)
+
+enum {
+	CURSEG_HOT_DATA	= 0,	/* directory entry blocks */
+	CURSEG_WARM_DATA,	/* data blocks */
+	CURSEG_COLD_DATA,	/* multimedia or GCed data blocks */
+	CURSEG_HOT_NODE,	/* direct node blocks of directory files */
+	CURSEG_WARM_NODE,	/* direct node blocks of normal files */
+	CURSEG_COLD_NODE,	/* indirect node blocks */
+	NO_CHECK_TYPE,
+	CURSEG_DIRECT_IO,	/* to use for the direct IO path */
+};
+
+struct flush_cmd {
+	struct completion wait;
+	struct llist_node llnode;
+	int ret;
+};
+
+struct flush_cmd_control {
+	struct task_struct *f2fs_issue_flush;	/* flush thread */
+	wait_queue_head_t flush_wait_queue;	/* waiting queue for wake-up */
+	struct llist_head issue_list;		/* list for command issue */
+	struct llist_node *dispatch_list;	/* list for command dispatch */
+};
+
+struct f2fs_sm_info {
+	struct sit_info *sit_info;		/* whole segment information */
+	struct free_segmap_info *free_info;	/* free segment information */
+	struct dirty_seglist_info *dirty_info;	/* dirty segment information */
+	struct curseg_info *curseg_array;	/* active segment information */
+
+	block_t seg0_blkaddr;		/* block address of 0'th segment */
+	block_t main_blkaddr;		/* start block address of main area */
+	block_t ssa_blkaddr;		/* start block address of SSA area */
+
+	unsigned int segment_count;	/* total # of segments */
+	unsigned int main_segments;	/* # of segments in main area */
+	unsigned int reserved_segments;	/* # of reserved segments */
+	unsigned int ovp_segments;	/* # of overprovision segments */
+
+	/* a threshold to reclaim prefree segments */
+	unsigned int rec_prefree_segments;
+
+	/* for small discard management */
+	struct list_head discard_list;		/* 4KB discard list */
+	int nr_discards;			/* # of discards in the list */
+	int max_discards;			/* max. discards to be issued */
+
+	/* for batched trimming */
+	unsigned int trim_sections;		/* # of sections to trim */
+
+	struct list_head sit_entry_set;	/* sit entry set list */
+
+	unsigned int ipu_policy;	/* in-place-update policy */
+	unsigned int min_ipu_util;	/* in-place-update threshold */
+	unsigned int min_fsync_blocks;	/* threshold for fsync */
+
+	/* for flush command control */
+	struct flush_cmd_control *cmd_control_info;
+
+};
+
+/*
+ * For superblock
+ */
+/*
+ * COUNT_TYPE for monitoring
+ *
+ * f2fs monitors the number of several block types such as on-writeback,
+ * dirty dentry blocks, dirty node blocks, and dirty meta blocks.
+ */
+enum count_type {
+	F2FS_WRITEBACK,
+	F2FS_DIRTY_DENTS,
+	F2FS_DIRTY_NODES,
+	F2FS_DIRTY_META,
+	F2FS_INMEM_PAGES,
+	NR_COUNT_TYPE,
+};
+
+/*
+ * The below are the page types of bios used in submit_bio().
+ * The available types are:
+ * DATA			User data pages. It operates as async mode.
+ * NODE			Node pages. It operates as async mode.
+ * META			FS metadata pages such as SIT, NAT, CP.
+ * NR_PAGE_TYPE		The number of page types.
+ * META_FLUSH		Make sure the previous pages are written
+ *			with waiting the bio's completion
+ * ...			Only can be used with META.
+ */
+#define PAGE_TYPE_OF_BIO(type)	((type) > META ? META : (type))
+enum page_type {
+	DATA,
+	NODE,
+	META,
+	NR_PAGE_TYPE,
+	META_FLUSH,
+	INMEM,		/* the below types are used by tracepoints only. */
+	INMEM_DROP,
+	IPU,
+	OPU,
+};
+
+struct f2fs_io_info {
+	enum page_type type;	/* contains DATA/NODE/META/META_FLUSH */
+	int rw;			/* contains R/RS/W/WS with REQ_META/REQ_PRIO */
+	block_t blk_addr;	/* block address to be written */
+};
+
+#define is_read_io(rw)	(((rw) & 1) == READ)
+struct f2fs_bio_info {
+	struct f2fs_sb_info *sbi;	/* f2fs superblock */
+	struct bio *bio;		/* bios to merge */
+	sector_t last_block_in_bio;	/* last block number */
+	struct f2fs_io_info fio;	/* store buffered io info. */
+	struct rw_semaphore io_rwsem;	/* blocking op for bio */
+};
+
+/* for inner inode cache management */
+struct inode_management {
+	struct radix_tree_root ino_root;	/* ino entry array */
+	spinlock_t ino_lock;			/* for ino entry lock */
+	struct list_head ino_list;		/* inode list head */
+	unsigned long ino_num;			/* number of entries */
+};
+
+/* For s_flag in struct f2fs_sb_info */
+enum {
+	SBI_IS_DIRTY,				/* dirty flag for checkpoint */
+	SBI_IS_CLOSE,				/* specify unmounting */
+	SBI_NEED_FSCK,				/* need fsck.f2fs to fix */
+	SBI_POR_DOING,				/* recovery is doing or not */
+};
+
+struct f2fs_sb_info {
+	struct super_block *sb;			/* pointer to VFS super block */
+	struct proc_dir_entry *s_proc;		/* proc entry */
+	struct buffer_head *raw_super_buf;	/* buffer head of raw sb */
+	struct f2fs_super_block *raw_super;	/* raw super block pointer */
+	int s_flag;				/* flags for sbi */
+
+	/* for node-related operations */
+	struct f2fs_nm_info *nm_info;		/* node manager */
+	struct inode *node_inode;		/* cache node blocks */
+
+	/* for segment-related operations */
+	struct f2fs_sm_info *sm_info;		/* segment manager */
+
+	/* for bio operations */
+	struct f2fs_bio_info read_io;			/* for read bios */
+	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
+
+	/* for checkpoint */
+	struct f2fs_checkpoint *ckpt;		/* raw checkpoint pointer */
+	struct inode *meta_inode;		/* cache meta blocks */
+	struct mutex cp_mutex;			/* checkpoint procedure lock */
+	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
+	struct rw_semaphore node_write;		/* locking node writes */
+	struct mutex writepages;		/* mutex for writepages() */
+	wait_queue_head_t cp_wait;
+
+	struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
+
+	/* for orphan inode, use 0'th array */
+	unsigned int max_orphans;		/* max orphan inodes */
+
+	/* for directory inode management */
+	struct list_head dir_inode_list;	/* dir inode list */
+	spinlock_t dir_inode_lock;		/* for dir inode list lock */
+
+	/* for extent tree cache */
+	struct radix_tree_root extent_tree_root;/* cache extent cache entries */
+	struct rw_semaphore extent_tree_lock;	/* locking extent radix tree */
+	struct list_head extent_list;		/* lru list for shrinker */
+	spinlock_t extent_lock;			/* locking extent lru list */
+	int total_ext_tree;			/* extent tree count */
+	atomic_t total_ext_node;		/* extent info count */
+
+	/* basic filesystem units */
+	unsigned int log_sectors_per_block;	/* log2 sectors per block */
+	unsigned int log_blocksize;		/* log2 block size */
+	unsigned int blocksize;			/* block size */
+	unsigned int root_ino_num;		/* root inode number*/
+	unsigned int node_ino_num;		/* node inode number*/
+	unsigned int meta_ino_num;		/* meta inode number*/
+	unsigned int log_blocks_per_seg;	/* log2 blocks per segment */
+	unsigned int blocks_per_seg;		/* blocks per segment */
+	unsigned int segs_per_sec;		/* segments per section */
+	unsigned int secs_per_zone;		/* sections per zone */
+	unsigned int total_sections;		/* total section count */
+	unsigned int total_node_count;		/* total node block count */
+	unsigned int total_valid_node_count;	/* valid node block count */
+	unsigned int total_valid_inode_count;	/* valid inode count */
+	int active_logs;			/* # of active logs */
+	int dir_level;				/* directory level */
+
+	block_t user_block_count;		/* # of user blocks */
+	block_t total_valid_block_count;	/* # of valid blocks */
+	block_t alloc_valid_block_count;	/* # of allocated blocks */
+	block_t last_valid_block_count;		/* for recovery */
+	u32 s_next_generation;			/* for NFS support */
+	atomic_t nr_pages[NR_COUNT_TYPE];	/* # of pages, see count_type */
+
+	struct f2fs_mount_info mount_opt;	/* mount options */
+
+	/* for cleaning operations */
+	struct mutex gc_mutex;			/* mutex for GC */
+	struct f2fs_gc_kthread	*gc_thread;	/* GC thread */
+	unsigned int cur_victim_sec;		/* current victim section num */
+
+	/* maximum # of trials to find a victim segment for SSR and GC */
+	unsigned int max_victim_search;
+
+	/*
+	 * for stat information.
+	 * one is for the LFS mode, and the other is for the SSR mode.
+	 */
+#ifdef CONFIG_F2FS_STAT_FS
+	struct f2fs_stat_info *stat_info;	/* FS status information */
+	unsigned int segment_count[2];		/* # of allocated segments */
+	unsigned int block_count[2];		/* # of allocated blocks */
+	atomic_t inplace_count;		/* # of inplace update */
+	int total_hit_ext, read_hit_ext;	/* extent cache hit ratio */
+	atomic_t inline_inode;			/* # of inline_data inodes */
+	atomic_t inline_dir;			/* # of inline_dentry inodes */
+	int bg_gc;				/* background gc calls */
+	unsigned int n_dirty_dirs;		/* # of dir inodes */
+#endif
+	unsigned int last_victim[2];		/* last victim segment # */
+	spinlock_t stat_lock;			/* lock for stat operations */
+
+	/* For sysfs suppport */
+	struct kobject s_kobj;
+	struct completion s_kobj_unregister;
+};
+
+/*
+ * Inline functions
+ */
+static inline struct f2fs_inode_info *F2FS_I(struct inode *inode)
+{
+	return container_of(inode, struct f2fs_inode_info, vfs_inode);
+}
+
+static inline struct f2fs_sb_info *F2FS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct f2fs_sb_info *F2FS_I_SB(struct inode *inode)
+{
+	return F2FS_SB(inode->i_sb);
+}
+
+static inline struct f2fs_sb_info *F2FS_M_SB(struct address_space *mapping)
+{
+	return F2FS_I_SB(mapping->host);
+}
+
+static inline struct f2fs_sb_info *F2FS_P_SB(struct page *page)
+{
+	return F2FS_M_SB(page->mapping);
+}
+
+static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_super_block *)(sbi->raw_super);
+}
+
+static inline struct f2fs_checkpoint *F2FS_CKPT(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_checkpoint *)(sbi->ckpt);
+}
+
+static inline struct f2fs_node *F2FS_NODE(struct page *page)
+{
+	return (struct f2fs_node *)page_address(page);
+}
+
+static inline struct f2fs_inode *F2FS_INODE(struct page *page)
+{
+	return &((struct f2fs_node *)page_address(page))->i;
+}
+
+static inline struct f2fs_nm_info *NM_I(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_nm_info *)(sbi->nm_info);
+}
+
+static inline struct f2fs_sm_info *SM_I(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_sm_info *)(sbi->sm_info);
+}
+
+static inline struct sit_info *SIT_I(struct f2fs_sb_info *sbi)
+{
+	return (struct sit_info *)(SM_I(sbi)->sit_info);
+}
+
+static inline struct free_segmap_info *FREE_I(struct f2fs_sb_info *sbi)
+{
+	return (struct free_segmap_info *)(SM_I(sbi)->free_info);
+}
+
+static inline struct dirty_seglist_info *DIRTY_I(struct f2fs_sb_info *sbi)
+{
+	return (struct dirty_seglist_info *)(SM_I(sbi)->dirty_info);
+}
+
+static inline struct address_space *META_MAPPING(struct f2fs_sb_info *sbi)
+{
+	return sbi->meta_inode->i_mapping;
+}
+
+static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi)
+{
+	return sbi->node_inode->i_mapping;
+}
+
+static inline bool is_sbi_flag_set(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	return sbi->s_flag & (0x01 << type);
+}
+
+static inline void set_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	sbi->s_flag |= (0x01 << type);
+}
+
+static inline void clear_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	sbi->s_flag &= ~(0x01 << type);
+}
+
+static inline unsigned long long cur_cp_version(struct f2fs_checkpoint *cp)
+{
+	return le64_to_cpu(cp->checkpoint_ver);
+}
+
+static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+	return ckpt_flags & f;
+}
+
+static inline void set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+	ckpt_flags |= f;
+	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
+}
+
+static inline void clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+	ckpt_flags &= (~f);
+	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
+}
+
+static inline void f2fs_lock_op(struct f2fs_sb_info *sbi)
+{
+	down_read(&sbi->cp_rwsem);
+}
+
+static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
+{
+	up_read(&sbi->cp_rwsem);
+}
+
+static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
+{
+	f2fs_down_write(&sbi->cp_rwsem, &sbi->cp_mutex);
+}
+
+static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)
+{
+	up_write(&sbi->cp_rwsem);
+}
+
+static inline int __get_cp_reason(struct f2fs_sb_info *sbi)
+{
+	int reason = CP_SYNC;
+
+	if (test_opt(sbi, FASTBOOT))
+		reason = CP_FASTBOOT;
+	if (is_sbi_flag_set(sbi, SBI_IS_CLOSE))
+		reason = CP_UMOUNT;
+	return reason;
+}
+
+static inline bool __remain_node_summaries(int reason)
+{
+	return (reason == CP_UMOUNT || reason == CP_FASTBOOT);
+}
+
+static inline bool __exist_node_summaries(struct f2fs_sb_info *sbi)
+{
+	return (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG) ||
+			is_set_ckpt_flags(F2FS_CKPT(sbi), CP_FASTBOOT_FLAG));
+}
+
+/*
+ * Check whether the given nid is within node id range.
+ */
+static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	if (unlikely(nid < F2FS_ROOT_INO(sbi)))
+		return -EINVAL;
+	if (unlikely(nid >= NM_I(sbi)->max_nid))
+		return -EINVAL;
+	return 0;
+}
+
+#define F2FS_DEFAULT_ALLOCATED_BLOCKS	1
+
+/*
+ * Check whether the inode has blocks or not
+ */
+static inline int F2FS_HAS_BLOCKS(struct inode *inode)
+{
+	if (F2FS_I(inode)->i_xattr_nid)
+		return inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS + 1;
+	else
+		return inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS;
+}
+
+static inline bool f2fs_has_xattr_block(unsigned int ofs)
+{
+	return ofs == XATTR_NODE_OFFSET;
+}
+
+static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
+				 struct inode *inode, blkcnt_t count)
+{
+	block_t	valid_block_count;
+
+	spin_lock(&sbi->stat_lock);
+	valid_block_count =
+		sbi->total_valid_block_count + (block_t)count;
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
+		spin_unlock(&sbi->stat_lock);
+		return false;
+	}
+	inode->i_blocks += count;
+	sbi->total_valid_block_count = valid_block_count;
+	sbi->alloc_valid_block_count += (block_t)count;
+	spin_unlock(&sbi->stat_lock);
+	return true;
+}
+
+static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
+						struct inode *inode,
+						blkcnt_t count)
+{
+	spin_lock(&sbi->stat_lock);
+	f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count);
+	f2fs_bug_on(sbi, inode->i_blocks < count);
+	inode->i_blocks -= count;
+	sbi->total_valid_block_count -= (block_t)count;
+	spin_unlock(&sbi->stat_lock);
+}
+
+static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
+{
+	atomic_inc(&sbi->nr_pages[count_type]);
+	set_sbi_flag(sbi, SBI_IS_DIRTY);
+}
+
+static inline void inode_inc_dirty_pages(struct inode *inode)
+{
+	atomic_inc(&F2FS_I(inode)->dirty_pages);
+	if (S_ISDIR(inode->i_mode))
+		inc_page_count(F2FS_I_SB(inode), F2FS_DIRTY_DENTS);
+}
+
+static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
+{
+	atomic_dec(&sbi->nr_pages[count_type]);
+}
+
+static inline void inode_dec_dirty_pages(struct inode *inode)
+{
+	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode))
+		return;
+
+	atomic_dec(&F2FS_I(inode)->dirty_pages);
+
+	if (S_ISDIR(inode->i_mode))
+		dec_page_count(F2FS_I_SB(inode), F2FS_DIRTY_DENTS);
+}
+
+static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
+{
+	return atomic_read(&sbi->nr_pages[count_type]);
+}
+
+static inline int get_dirty_pages(struct inode *inode)
+{
+	return atomic_read(&F2FS_I(inode)->dirty_pages);
+}
+
+static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
+{
+	unsigned int pages_per_sec = sbi->segs_per_sec *
+					(1 << sbi->log_blocks_per_seg);
+	return ((get_pages(sbi, block_type) + pages_per_sec - 1)
+			>> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
+}
+
+static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_valid_block_count;
+}
+
+static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+
+	/* return NAT or SIT bitmap */
+	if (flag == NAT_BITMAP)
+		return le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
+	else if (flag == SIT_BITMAP)
+		return le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
+
+	return 0;
+}
+
+static inline block_t __cp_payload(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+}
+
+static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	int offset;
+
+	if (__cp_payload(sbi) > 0) {
+		if (flag == NAT_BITMAP)
+			return &ckpt->sit_nat_version_bitmap;
+		else
+			return (unsigned char *)ckpt + F2FS_BLKSIZE;
+	} else {
+		offset = (flag == NAT_BITMAP) ?
+			le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
+		return &ckpt->sit_nat_version_bitmap + offset;
+	}
+}
+
+static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
+{
+	block_t start_addr;
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned long long ckpt_version = cur_cp_version(ckpt);
+
+	start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);
+
+	/*
+	 * odd numbered checkpoint should at cp segment 0
+	 * and even segment must be at cp segment 1
+	 */
+	if (!(ckpt_version & 1))
+		start_addr += sbi->blocks_per_seg;
+
+	return start_addr;
+}
+
+static inline block_t __start_sum_addr(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
+}
+
+static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
+						struct inode *inode)
+{
+	block_t	valid_block_count;
+	unsigned int valid_node_count;
+
+	spin_lock(&sbi->stat_lock);
+
+	valid_block_count = sbi->total_valid_block_count + 1;
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
+		spin_unlock(&sbi->stat_lock);
+		return false;
+	}
+
+	valid_node_count = sbi->total_valid_node_count + 1;
+	if (unlikely(valid_node_count > sbi->total_node_count)) {
+		spin_unlock(&sbi->stat_lock);
+		return false;
+	}
+
+	if (inode)
+		inode->i_blocks++;
+
+	sbi->alloc_valid_block_count++;
+	sbi->total_valid_node_count++;
+	sbi->total_valid_block_count++;
+	spin_unlock(&sbi->stat_lock);
+
+	return true;
+}
+
+static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
+						struct inode *inode)
+{
+	spin_lock(&sbi->stat_lock);
+
+	f2fs_bug_on(sbi, !sbi->total_valid_block_count);
+	f2fs_bug_on(sbi, !sbi->total_valid_node_count);
+	f2fs_bug_on(sbi, !inode->i_blocks);
+
+	inode->i_blocks--;
+	sbi->total_valid_node_count--;
+	sbi->total_valid_block_count--;
+
+	spin_unlock(&sbi->stat_lock);
+}
+
+static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_valid_node_count;
+}
+
+static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	spin_lock(&sbi->stat_lock);
+	f2fs_bug_on(sbi, sbi->total_valid_inode_count == sbi->total_node_count);
+	sbi->total_valid_inode_count++;
+	spin_unlock(&sbi->stat_lock);
+}
+
+static inline void dec_valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	spin_lock(&sbi->stat_lock);
+	f2fs_bug_on(sbi, !sbi->total_valid_inode_count);
+	sbi->total_valid_inode_count--;
+	spin_unlock(&sbi->stat_lock);
+}
+
+static inline unsigned int valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_valid_inode_count;
+}
+
+static inline void f2fs_put_page(struct page *page, int unlock)
+{
+	if (!page)
+		return;
+
+	if (unlock) {
+		f2fs_bug_on(F2FS_P_SB(page), !PageLocked(page));
+		unlock_page(page);
+	}
+	page_cache_release(page);
+}
+
+static inline void f2fs_put_dnode(struct dnode_of_data *dn)
+{
+	if (dn->node_page)
+		f2fs_put_page(dn->node_page, 1);
+	if (dn->inode_page && dn->node_page != dn->inode_page)
+		f2fs_put_page(dn->inode_page, 0);
+	dn->node_page = NULL;
+	dn->inode_page = NULL;
+}
+
+static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
+					size_t size)
+{
+	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, NULL);
+}
+
+static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
+						gfp_t flags)
+{
+	void *entry;
+retry:
+	entry = kmem_cache_alloc(cachep, flags);
+	if (!entry) {
+		cond_resched();
+		goto retry;
+	}
+
+	return entry;
+}
+
+static inline void f2fs_radix_tree_insert(struct radix_tree_root *root,
+				unsigned long index, void *item)
+{
+	while (radix_tree_insert(root, index, item))
+		cond_resched();
+}
+
+#define RAW_IS_INODE(p)	((p)->footer.nid == (p)->footer.ino)
+
+static inline bool IS_INODE(struct page *page)
+{
+	struct f2fs_node *p = F2FS_NODE(page);
+	return RAW_IS_INODE(p);
+}
+
+static inline __le32 *blkaddr_in_node(struct f2fs_node *node)
+{
+	return RAW_IS_INODE(node) ? node->i.i_addr : node->dn.addr;
+}
+
+static inline block_t datablock_addr(struct page *node_page,
+		unsigned int offset)
+{
+	struct f2fs_node *raw_node;
+	__le32 *addr_array;
+	raw_node = F2FS_NODE(node_page);
+	addr_array = blkaddr_in_node(raw_node);
+	return le32_to_cpu(addr_array[offset]);
+}
+
+static inline int f2fs_test_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	return mask & *addr;
+}
+
+static inline int f2fs_test_and_set_bit(unsigned int nr, char *addr)
+{
+	int mask;
+	int ret;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	ret = mask & *addr;
+	*addr |= mask;
+	return ret;
+}
+
+static inline int f2fs_test_and_clear_bit(unsigned int nr, char *addr)
+{
+	int mask;
+	int ret;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	ret = mask & *addr;
+	*addr &= ~mask;
+	return ret;
+}
+
+static inline void f2fs_change_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	*addr ^= mask;
+}
+
+/* used for f2fs_inode_info->flags */
+enum {
+	FI_NEW_INODE,		/* indicate newly allocated inode */
+	FI_DIRTY_INODE,		/* indicate inode is dirty or not */
+	FI_DIRTY_DIR,		/* indicate directory has dirty pages */
+	FI_INC_LINK,		/* need to increment i_nlink */
+	FI_ACL_MODE,		/* indicate acl mode */
+	FI_NO_ALLOC,		/* should not allocate any blocks */
+	FI_UPDATE_DIR,		/* should update inode block for consistency */
+	FI_DELAY_IPUT,		/* used for the recovery */
+	FI_NO_EXTENT,		/* not to use the extent cache */
+	FI_INLINE_XATTR,	/* used for inline xattr */
+	FI_INLINE_DATA,		/* used for inline data*/
+	FI_INLINE_DENTRY,	/* used for inline dentry */
+	FI_APPEND_WRITE,	/* inode has appended data */
+	FI_UPDATE_WRITE,	/* inode has in-place-update data */
+	FI_NEED_IPU,		/* used for ipu per file */
+	FI_ATOMIC_FILE,		/* indicate atomic file */
+	FI_VOLATILE_FILE,	/* indicate volatile file */
+	FI_FIRST_BLOCK_WRITTEN,	/* indicate #0 data block was written */
+	FI_DROP_CACHE,		/* drop dirty page cache */
+	FI_DATA_EXIST,		/* indicate data exists */
+	FI_INLINE_DOTS,		/* indicate inline dot dentries */
+};
+
+static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
+{
+	if (!test_bit(flag, &fi->flags))
+		set_bit(flag, &fi->flags);
+}
+
+static inline int is_inode_flag_set(struct f2fs_inode_info *fi, int flag)
+{
+	return test_bit(flag, &fi->flags);
+}
+
+static inline void clear_inode_flag(struct f2fs_inode_info *fi, int flag)
+{
+	if (test_bit(flag, &fi->flags))
+		clear_bit(flag, &fi->flags);
+}
+
+static inline void set_acl_inode(struct f2fs_inode_info *fi, umode_t mode)
+{
+	fi->i_acl_mode = mode;
+	set_inode_flag(fi, FI_ACL_MODE);
+}
+
+static inline void get_inline_info(struct f2fs_inode_info *fi,
+					struct f2fs_inode *ri)
+{
+	if (ri->i_inline & F2FS_INLINE_XATTR)
+		set_inode_flag(fi, FI_INLINE_XATTR);
+	if (ri->i_inline & F2FS_INLINE_DATA)
+		set_inode_flag(fi, FI_INLINE_DATA);
+	if (ri->i_inline & F2FS_INLINE_DENTRY)
+		set_inode_flag(fi, FI_INLINE_DENTRY);
+	if (ri->i_inline & F2FS_DATA_EXIST)
+		set_inode_flag(fi, FI_DATA_EXIST);
+	if (ri->i_inline & F2FS_INLINE_DOTS)
+		set_inode_flag(fi, FI_INLINE_DOTS);
+}
+
+static inline void set_raw_inline(struct f2fs_inode_info *fi,
+					struct f2fs_inode *ri)
+{
+	ri->i_inline = 0;
+
+	if (is_inode_flag_set(fi, FI_INLINE_XATTR))
+		ri->i_inline |= F2FS_INLINE_XATTR;
+	if (is_inode_flag_set(fi, FI_INLINE_DATA))
+		ri->i_inline |= F2FS_INLINE_DATA;
+	if (is_inode_flag_set(fi, FI_INLINE_DENTRY))
+		ri->i_inline |= F2FS_INLINE_DENTRY;
+	if (is_inode_flag_set(fi, FI_DATA_EXIST))
+		ri->i_inline |= F2FS_DATA_EXIST;
+	if (is_inode_flag_set(fi, FI_INLINE_DOTS))
+		ri->i_inline |= F2FS_INLINE_DOTS;
+}
+
+static inline int f2fs_has_inline_xattr(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_XATTR);
+}
+
+static inline unsigned int addrs_per_inode(struct f2fs_inode_info *fi)
+{
+	if (f2fs_has_inline_xattr(&fi->vfs_inode))
+		return DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS;
+	return DEF_ADDRS_PER_INODE;
+}
+
+static inline void *inline_xattr_addr(struct page *page)
+{
+	struct f2fs_inode *ri = F2FS_INODE(page);
+	return (void *)&(ri->i_addr[DEF_ADDRS_PER_INODE -
+					F2FS_INLINE_XATTR_ADDRS]);
+}
+
+static inline int inline_xattr_size(struct inode *inode)
+{
+	if (f2fs_has_inline_xattr(inode))
+		return F2FS_INLINE_XATTR_ADDRS << 2;
+	else
+		return 0;
+}
+
+static inline int f2fs_has_inline_data(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DATA);
+}
+
+static inline void f2fs_clear_inline_inode(struct inode *inode)
+{
+	clear_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+	clear_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+}
+
+static inline int f2fs_exist_data(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_DATA_EXIST);
+}
+
+static inline int f2fs_has_inline_dots(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DOTS);
+}
+
+static inline bool f2fs_is_atomic_file(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_ATOMIC_FILE);
+}
+
+static inline bool f2fs_is_volatile_file(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_VOLATILE_FILE);
+}
+
+static inline bool f2fs_is_first_block_written(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+}
+
+static inline bool f2fs_is_drop_cache(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_DROP_CACHE);
+}
+
+static inline void *inline_data_addr(struct page *page)
+{
+	struct f2fs_inode *ri = F2FS_INODE(page);
+	return (void *)&(ri->i_addr[1]);
+}
+
+static inline int f2fs_has_inline_dentry(struct inode *inode)
+{
+	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DENTRY);
+}
+
+static inline void f2fs_dentry_kunmap(struct inode *dir, struct page *page)
+{
+	if (!f2fs_has_inline_dentry(dir))
+		kunmap(page);
+}
+
+static inline int f2fs_readonly(struct super_block *sb)
+{
+	return sb->s_flags & MS_RDONLY;
+}
+
+static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
+{
+	return is_set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+}
+
+static inline void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi)
+{
+	set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+	sbi->sb->s_flags |= MS_RDONLY;
+}
+
+#define get_inode_mode(i) \
+	((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
+	 (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
+
+/* get offset of first page in next direct node */
+#define PGOFS_OF_NEXT_DNODE(pgofs, fi)				\
+	((pgofs < ADDRS_PER_INODE(fi)) ? ADDRS_PER_INODE(fi) :	\
+	(pgofs - ADDRS_PER_INODE(fi) + ADDRS_PER_BLOCK) /	\
+	ADDRS_PER_BLOCK * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi))
+
+/*
+ * file.c
+ */
+int f2fs_sync_file(struct file *, loff_t, loff_t, int);
+void truncate_data_blocks(struct dnode_of_data *);
+int truncate_blocks(struct inode *, u64, bool);
+void f2fs_truncate(struct inode *);
+int f2fs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+int f2fs_setattr(struct dentry *, struct iattr *);
+int truncate_hole(struct inode *, pgoff_t, pgoff_t);
+int truncate_data_blocks_range(struct dnode_of_data *, int);
+long f2fs_ioctl(struct file *, unsigned int, unsigned long);
+long f2fs_compat_ioctl(struct file *, unsigned int, unsigned long);
+
+/*
+ * inode.c
+ */
+void f2fs_set_inode_flags(struct inode *);
+struct inode *f2fs_iget(struct super_block *, unsigned long);
+int try_to_free_nats(struct f2fs_sb_info *, int);
+void update_inode(struct inode *, struct page *);
+void update_inode_page(struct inode *);
+int f2fs_write_inode(struct inode *, struct writeback_control *);
+void f2fs_evict_inode(struct inode *);
+void handle_failed_inode(struct inode *);
+
+/*
+ * namei.c
+ */
+struct dentry *f2fs_get_parent(struct dentry *child);
+
+/*
+ * dir.c
+ */
+extern unsigned char f2fs_filetype_table[F2FS_FT_MAX];
+void set_de_type(struct f2fs_dir_entry *, umode_t);
+struct f2fs_dir_entry *find_target_dentry(struct qstr *, int *,
+			struct f2fs_dentry_ptr *);
+bool f2fs_fill_dentries(struct dir_context *, struct f2fs_dentry_ptr *,
+			unsigned int);
+void do_make_empty_dir(struct inode *, struct inode *,
+			struct f2fs_dentry_ptr *);
+struct page *init_inode_metadata(struct inode *, struct inode *,
+			const struct qstr *, struct page *);
+void update_parent_metadata(struct inode *, struct inode *, unsigned int);
+int room_for_filename(const void *, int, int);
+void f2fs_drop_nlink(struct inode *, struct inode *, struct page *);
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *, struct qstr *,
+							struct page **);
+struct f2fs_dir_entry *f2fs_parent_dir(struct inode *, struct page **);
+ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
+void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
+				struct page *, struct inode *);
+int update_dent_inode(struct inode *, const struct qstr *);
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *,
+			const struct qstr *, f2fs_hash_t , unsigned int);
+int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *, nid_t,
+			umode_t);
+void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *,
+							struct inode *);
+int f2fs_do_tmpfile(struct inode *, struct inode *);
+int f2fs_make_empty(struct inode *, struct inode *);
+bool f2fs_empty_dir(struct inode *);
+
+static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
+{
+	return __f2fs_add_link(d_inode(dentry->d_parent), &dentry->d_name,
+				inode, inode->i_ino, inode->i_mode);
+}
+
+/*
+ * super.c
+ */
+int f2fs_sync_fs(struct super_block *, int);
+extern __printf(3, 4)
+void f2fs_msg(struct super_block *, const char *, const char *, ...);
+
+/*
+ * hash.c
+ */
+f2fs_hash_t f2fs_dentry_hash(const struct qstr *);
+
+/*
+ * node.c
+ */
+struct dnode_of_data;
+struct node_info;
+
+bool available_free_memory(struct f2fs_sb_info *, int);
+bool is_checkpointed_node(struct f2fs_sb_info *, nid_t);
+bool has_fsynced_inode(struct f2fs_sb_info *, nid_t);
+bool need_inode_block_update(struct f2fs_sb_info *, nid_t);
+void get_node_info(struct f2fs_sb_info *, nid_t, struct node_info *);
+int get_dnode_of_data(struct dnode_of_data *, pgoff_t, int);
+int truncate_inode_blocks(struct inode *, pgoff_t);
+int truncate_xattr_node(struct inode *, struct page *);
+int wait_on_node_pages_writeback(struct f2fs_sb_info *, nid_t);
+void remove_inode_page(struct inode *);
+struct page *new_inode_page(struct inode *);
+struct page *new_node_page(struct dnode_of_data *, unsigned int, struct page *);
+void ra_node_page(struct f2fs_sb_info *, nid_t);
+struct page *get_node_page(struct f2fs_sb_info *, pgoff_t);
+struct page *get_node_page_ra(struct page *, int);
+void sync_inode_page(struct dnode_of_data *);
+int sync_node_pages(struct f2fs_sb_info *, nid_t, struct writeback_control *);
+bool alloc_nid(struct f2fs_sb_info *, nid_t *);
+void alloc_nid_done(struct f2fs_sb_info *, nid_t);
+void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
+void recover_inline_xattr(struct inode *, struct page *);
+void recover_xattr_data(struct inode *, struct page *, block_t);
+int recover_inode_page(struct f2fs_sb_info *, struct page *);
+int restore_node_summary(struct f2fs_sb_info *, unsigned int,
+				struct f2fs_summary_block *);
+void flush_nat_entries(struct f2fs_sb_info *);
+int build_node_manager(struct f2fs_sb_info *);
+void destroy_node_manager(struct f2fs_sb_info *);
+int __init create_node_manager_caches(void);
+void destroy_node_manager_caches(void);
+
+/*
+ * segment.c
+ */
+void register_inmem_page(struct inode *, struct page *);
+void commit_inmem_pages(struct inode *, bool);
+void f2fs_balance_fs(struct f2fs_sb_info *);
+void f2fs_balance_fs_bg(struct f2fs_sb_info *);
+int f2fs_issue_flush(struct f2fs_sb_info *);
+int create_flush_cmd_control(struct f2fs_sb_info *);
+void destroy_flush_cmd_control(struct f2fs_sb_info *);
+void invalidate_blocks(struct f2fs_sb_info *, block_t);
+void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
+void clear_prefree_segments(struct f2fs_sb_info *);
+void release_discard_addrs(struct f2fs_sb_info *);
+void discard_next_dnode(struct f2fs_sb_info *, block_t);
+int npages_for_summary_flush(struct f2fs_sb_info *, bool);
+void allocate_new_segments(struct f2fs_sb_info *);
+int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
+struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
+void write_meta_page(struct f2fs_sb_info *, struct page *);
+void write_node_page(struct f2fs_sb_info *, struct page *,
+				unsigned int, struct f2fs_io_info *);
+void write_data_page(struct page *, struct dnode_of_data *,
+			struct f2fs_io_info *);
+void rewrite_data_page(struct page *, struct f2fs_io_info *);
+void recover_data_page(struct f2fs_sb_info *, struct page *,
+				struct f2fs_summary *, block_t, block_t);
+void allocate_data_block(struct f2fs_sb_info *, struct page *,
+		block_t, block_t *, struct f2fs_summary *, int);
+void f2fs_wait_on_page_writeback(struct page *, enum page_type);
+void write_data_summaries(struct f2fs_sb_info *, block_t);
+void write_node_summaries(struct f2fs_sb_info *, block_t);
+int lookup_journal_in_cursum(struct f2fs_summary_block *,
+					int, unsigned int, int);
+void flush_sit_entries(struct f2fs_sb_info *, struct cp_control *);
+int build_segment_manager(struct f2fs_sb_info *);
+void destroy_segment_manager(struct f2fs_sb_info *);
+int __init create_segment_manager_caches(void);
+void destroy_segment_manager_caches(void);
+
+/*
+ * checkpoint.c
+ */
+struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
+struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
+int ra_meta_pages(struct f2fs_sb_info *, block_t, int, int);
+void ra_meta_pages_cond(struct f2fs_sb_info *, pgoff_t);
+long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
+void add_dirty_inode(struct f2fs_sb_info *, nid_t, int type);
+void remove_dirty_inode(struct f2fs_sb_info *, nid_t, int type);
+void release_dirty_inode(struct f2fs_sb_info *);
+bool exist_written_data(struct f2fs_sb_info *, nid_t, int);
+int acquire_orphan_inode(struct f2fs_sb_info *);
+void release_orphan_inode(struct f2fs_sb_info *);
+void add_orphan_inode(struct f2fs_sb_info *, nid_t);
+void remove_orphan_inode(struct f2fs_sb_info *, nid_t);
+void recover_orphan_inodes(struct f2fs_sb_info *);
+int get_valid_checkpoint(struct f2fs_sb_info *);
+void update_dirty_page(struct inode *, struct page *);
+void add_dirty_dir_inode(struct inode *);
+void remove_dirty_dir_inode(struct inode *);
+void sync_dirty_dir_inodes(struct f2fs_sb_info *);
+void write_checkpoint(struct f2fs_sb_info *, struct cp_control *);
+void init_ino_entry_info(struct f2fs_sb_info *);
+int __init create_checkpoint_caches(void);
+void destroy_checkpoint_caches(void);
+
+/*
+ * data.c
+ */
+void f2fs_submit_merged_bio(struct f2fs_sb_info *, enum page_type, int);
+int f2fs_submit_page_bio(struct f2fs_sb_info *, struct page *,
+						struct f2fs_io_info *);
+void f2fs_submit_page_mbio(struct f2fs_sb_info *, struct page *,
+						struct f2fs_io_info *);
+void set_data_blkaddr(struct dnode_of_data *);
+int reserve_new_block(struct dnode_of_data *);
+int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
+void f2fs_shrink_extent_tree(struct f2fs_sb_info *, int);
+void f2fs_destroy_extent_tree(struct inode *);
+void f2fs_init_extent_cache(struct inode *, struct f2fs_extent *);
+void f2fs_update_extent_cache(struct dnode_of_data *);
+void f2fs_preserve_extent_tree(struct inode *);
+struct page *find_data_page(struct inode *, pgoff_t, bool);
+struct page *get_lock_data_page(struct inode *, pgoff_t);
+struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool);
+int do_write_data_page(struct page *, struct f2fs_io_info *);
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *, u64, u64);
+void init_extent_cache_info(struct f2fs_sb_info *);
+int __init create_extent_cache(void);
+void destroy_extent_cache(void);
+void f2fs_invalidate_page(struct page *, unsigned int, unsigned int);
+int f2fs_release_page(struct page *, gfp_t);
+
+/*
+ * gc.c
+ */
+int start_gc_thread(struct f2fs_sb_info *);
+void stop_gc_thread(struct f2fs_sb_info *);
+block_t start_bidx_of_node(unsigned int, struct f2fs_inode_info *);
+int f2fs_gc(struct f2fs_sb_info *);
+void build_gc_manager(struct f2fs_sb_info *);
+
+/*
+ * recovery.c
+ */
+int recover_fsync_data(struct f2fs_sb_info *);
+bool space_for_roll_forward(struct f2fs_sb_info *);
+
+/*
+ * debug.c
+ */
+#ifdef CONFIG_F2FS_STAT_FS
+struct f2fs_stat_info {
+	struct list_head stat_list;
+	struct f2fs_sb_info *sbi;
+	int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
+	int main_area_segs, main_area_sections, main_area_zones;
+	int hit_ext, total_ext, ext_tree, ext_node;
+	int ndirty_node, ndirty_dent, ndirty_dirs, ndirty_meta;
+	int nats, dirty_nats, sits, dirty_sits, fnids;
+	int total_count, utilization;
+	int bg_gc, inline_inode, inline_dir, inmem_pages, wb_pages;
+	unsigned int valid_count, valid_node_count, valid_inode_count;
+	unsigned int bimodal, avg_vblocks;
+	int util_free, util_valid, util_invalid;
+	int rsvd_segs, overp_segs;
+	int dirty_count, node_pages, meta_pages;
+	int prefree_count, call_count, cp_count;
+	int tot_segs, node_segs, data_segs, free_segs, free_secs;
+	int bg_node_segs, bg_data_segs;
+	int tot_blks, data_blks, node_blks;
+	int bg_data_blks, bg_node_blks;
+	int curseg[NR_CURSEG_TYPE];
+	int cursec[NR_CURSEG_TYPE];
+	int curzone[NR_CURSEG_TYPE];
+
+	unsigned int segment_count[2];
+	unsigned int block_count[2];
+	unsigned int inplace_count;
+	unsigned base_mem, cache_mem, page_mem;
+};
+
+static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_stat_info *)sbi->stat_info;
+}
+
+#define stat_inc_cp_count(si)		((si)->cp_count++)
+#define stat_inc_call_count(si)		((si)->call_count++)
+#define stat_inc_bggc_count(sbi)	((sbi)->bg_gc++)
+#define stat_inc_dirty_dir(sbi)		((sbi)->n_dirty_dirs++)
+#define stat_dec_dirty_dir(sbi)		((sbi)->n_dirty_dirs--)
+#define stat_inc_total_hit(sb)		((F2FS_SB(sb))->total_hit_ext++)
+#define stat_inc_read_hit(sb)		((F2FS_SB(sb))->read_hit_ext++)
+#define stat_inc_inline_inode(inode)					\
+	do {								\
+		if (f2fs_has_inline_data(inode))			\
+			(atomic_inc(&F2FS_I_SB(inode)->inline_inode));	\
+	} while (0)
+#define stat_dec_inline_inode(inode)					\
+	do {								\
+		if (f2fs_has_inline_data(inode))			\
+			(atomic_dec(&F2FS_I_SB(inode)->inline_inode));	\
+	} while (0)
+#define stat_inc_inline_dir(inode)					\
+	do {								\
+		if (f2fs_has_inline_dentry(inode))			\
+			(atomic_inc(&F2FS_I_SB(inode)->inline_dir));	\
+	} while (0)
+#define stat_dec_inline_dir(inode)					\
+	do {								\
+		if (f2fs_has_inline_dentry(inode))			\
+			(atomic_dec(&F2FS_I_SB(inode)->inline_dir));	\
+	} while (0)
+#define stat_inc_seg_type(sbi, curseg)					\
+		((sbi)->segment_count[(curseg)->alloc_type]++)
+#define stat_inc_block_count(sbi, curseg)				\
+		((sbi)->block_count[(curseg)->alloc_type]++)
+#define stat_inc_inplace_blocks(sbi)					\
+		(atomic_inc(&(sbi)->inplace_count))
+#define stat_inc_seg_count(sbi, type, gc_type)				\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		(si)->tot_segs++;					\
+		if (type == SUM_TYPE_DATA) {				\
+			si->data_segs++;				\
+			si->bg_data_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		} else {						\
+			si->node_segs++;				\
+			si->bg_node_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		}							\
+	} while (0)
+
+#define stat_inc_tot_blk_count(si, blks)				\
+	(si->tot_blks += (blks))
+
+#define stat_inc_data_blk_count(sbi, blks, gc_type)			\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		stat_inc_tot_blk_count(si, blks);			\
+		si->data_blks += (blks);				\
+		si->bg_data_blks += (gc_type == BG_GC) ? (blks) : 0;	\
+	} while (0)
+
+#define stat_inc_node_blk_count(sbi, blks, gc_type)			\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		stat_inc_tot_blk_count(si, blks);			\
+		si->node_blks += (blks);				\
+		si->bg_node_blks += (gc_type == BG_GC) ? (blks) : 0;	\
+	} while (0)
+
+int f2fs_build_stats(struct f2fs_sb_info *);
+void f2fs_destroy_stats(struct f2fs_sb_info *);
+void __init f2fs_create_root_stats(void);
+void f2fs_destroy_root_stats(void);
+#else
+#define stat_inc_cp_count(si)
+#define stat_inc_call_count(si)
+#define stat_inc_bggc_count(si)
+#define stat_inc_dirty_dir(sbi)
+#define stat_dec_dirty_dir(sbi)
+#define stat_inc_total_hit(sb)
+#define stat_inc_read_hit(sb)
+#define stat_inc_inline_inode(inode)
+#define stat_dec_inline_inode(inode)
+#define stat_inc_inline_dir(inode)
+#define stat_dec_inline_dir(inode)
+#define stat_inc_seg_type(sbi, curseg)
+#define stat_inc_block_count(sbi, curseg)
+#define stat_inc_inplace_blocks(sbi)
+#define stat_inc_seg_count(sbi, type, gc_type)
+#define stat_inc_tot_blk_count(si, blks)
+#define stat_inc_data_blk_count(sbi, blks, gc_type)
+#define stat_inc_node_blk_count(sbi, blks, gc_type)
+
+static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
+static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
+static inline void __init f2fs_create_root_stats(void) { }
+static inline void f2fs_destroy_root_stats(void) { }
+#endif
+
+extern const struct file_operations f2fs_dir_operations;
+extern const struct file_operations f2fs_file_operations;
+extern const struct inode_operations f2fs_file_inode_operations;
+extern const struct address_space_operations f2fs_dblock_aops;
+extern const struct address_space_operations f2fs_node_aops;
+extern const struct address_space_operations f2fs_meta_aops;
+extern const struct inode_operations f2fs_dir_inode_operations;
+extern const struct inode_operations f2fs_symlink_inode_operations;
+extern const struct inode_operations f2fs_special_inode_operations;
+extern struct kmem_cache *inode_entry_slab;
+
+/*
+ * inline.c
+ */
+bool f2fs_may_inline(struct inode *);
+void read_inline_data(struct page *, struct page *);
+bool truncate_inline_inode(struct page *, u64);
+int f2fs_read_inline_data(struct inode *, struct page *);
+int f2fs_convert_inline_page(struct dnode_of_data *, struct page *);
+int f2fs_convert_inline_inode(struct inode *);
+int f2fs_write_inline_data(struct inode *, struct page *);
+bool recover_inline_data(struct inode *, struct page *);
+struct f2fs_dir_entry *find_in_inline_dir(struct inode *, struct qstr *,
+							struct page **);
+struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *, struct page **);
+int make_empty_inline_dir(struct inode *inode, struct inode *, struct page *);
+int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *,
+						nid_t, umode_t);
+void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *,
+						struct inode *, struct inode *);
+bool f2fs_empty_inline_dir(struct inode *);
+int f2fs_read_inline_dir(struct file *, struct dir_context *);
+#endif
diff --git a/kernel/fs/f2fs/file.c b/kernel/fs/f2fs/file.c
new file mode 100644
index 000000000..2b52e48d7
--- /dev/null
+++ b/kernel/fs/f2fs/file.c
@@ -0,0 +1,1172 @@
+/*
+ * fs/f2fs/file.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/stat.h>
+#include <linux/buffer_head.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/falloc.h>
+#include <linux/types.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/mount.h>
+#include <linux/pagevec.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "acl.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
+						struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	struct inode *inode = file_inode(vma->vm_file);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	int err;
+
+	f2fs_balance_fs(sbi);
+
+	sb_start_pagefault(inode->i_sb);
+
+	f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
+
+	/* block allocation */
+	f2fs_lock_op(sbi);
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = f2fs_reserve_block(&dn, page->index);
+	if (err) {
+		f2fs_unlock_op(sbi);
+		goto out;
+	}
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+
+	file_update_time(vma->vm_file);
+	lock_page(page);
+	if (unlikely(page->mapping != inode->i_mapping ||
+			page_offset(page) > i_size_read(inode) ||
+			!PageUptodate(page))) {
+		unlock_page(page);
+		err = -EFAULT;
+		goto out;
+	}
+
+	/*
+	 * check to see if the page is mapped already (no holes)
+	 */
+	if (PageMappedToDisk(page))
+		goto mapped;
+
+	/* page is wholly or partially inside EOF */
+	if (((page->index + 1) << PAGE_CACHE_SHIFT) > i_size_read(inode)) {
+		unsigned offset;
+		offset = i_size_read(inode) & ~PAGE_CACHE_MASK;
+		zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+	}
+	set_page_dirty(page);
+	SetPageUptodate(page);
+
+	trace_f2fs_vm_page_mkwrite(page, DATA);
+mapped:
+	/* fill the page */
+	f2fs_wait_on_page_writeback(page, DATA);
+out:
+	sb_end_pagefault(inode->i_sb);
+	return block_page_mkwrite_return(err);
+}
+
+static const struct vm_operations_struct f2fs_file_vm_ops = {
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= f2fs_vm_page_mkwrite,
+};
+
+static int get_parent_ino(struct inode *inode, nid_t *pino)
+{
+	struct dentry *dentry;
+
+	inode = igrab(inode);
+	dentry = d_find_any_alias(inode);
+	iput(inode);
+	if (!dentry)
+		return 0;
+
+	if (update_dent_inode(inode, &dentry->d_name)) {
+		dput(dentry);
+		return 0;
+	}
+
+	*pino = parent_ino(dentry);
+	dput(dentry);
+	return 1;
+}
+
+static inline bool need_do_checkpoint(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	bool need_cp = false;
+
+	if (!S_ISREG(inode->i_mode) || inode->i_nlink != 1)
+		need_cp = true;
+	else if (file_wrong_pino(inode))
+		need_cp = true;
+	else if (!space_for_roll_forward(sbi))
+		need_cp = true;
+	else if (!is_checkpointed_node(sbi, F2FS_I(inode)->i_pino))
+		need_cp = true;
+	else if (F2FS_I(inode)->xattr_ver == cur_cp_version(F2FS_CKPT(sbi)))
+		need_cp = true;
+	else if (test_opt(sbi, FASTBOOT))
+		need_cp = true;
+	else if (sbi->active_logs == 2)
+		need_cp = true;
+
+	return need_cp;
+}
+
+static bool need_inode_page_update(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct page *i = find_get_page(NODE_MAPPING(sbi), ino);
+	bool ret = false;
+	/* But we need to avoid that there are some inode updates */
+	if ((i && PageDirty(i)) || need_inode_block_update(sbi, ino))
+		ret = true;
+	f2fs_put_page(i, 0);
+	return ret;
+}
+
+static void try_to_fix_pino(struct inode *inode)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	nid_t pino;
+
+	down_write(&fi->i_sem);
+	fi->xattr_ver = 0;
+	if (file_wrong_pino(inode) && inode->i_nlink == 1 &&
+			get_parent_ino(inode, &pino)) {
+		fi->i_pino = pino;
+		file_got_pino(inode);
+		up_write(&fi->i_sem);
+
+		mark_inode_dirty_sync(inode);
+		f2fs_write_inode(inode, NULL);
+	} else {
+		up_write(&fi->i_sem);
+	}
+}
+
+int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t ino = inode->i_ino;
+	int ret = 0;
+	bool need_cp = false;
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = LONG_MAX,
+		.for_reclaim = 0,
+	};
+
+	if (unlikely(f2fs_readonly(inode->i_sb)))
+		return 0;
+
+	trace_f2fs_sync_file_enter(inode);
+
+	/* if fdatasync is triggered, let's do in-place-update */
+	if (get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
+		set_inode_flag(fi, FI_NEED_IPU);
+	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	clear_inode_flag(fi, FI_NEED_IPU);
+
+	if (ret) {
+		trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
+		return ret;
+	}
+
+	/* if the inode is dirty, let's recover all the time */
+	if (!datasync && is_inode_flag_set(fi, FI_DIRTY_INODE)) {
+		update_inode_page(inode);
+		goto go_write;
+	}
+
+	/*
+	 * if there is no written data, don't waste time to write recovery info.
+	 */
+	if (!is_inode_flag_set(fi, FI_APPEND_WRITE) &&
+			!exist_written_data(sbi, ino, APPEND_INO)) {
+
+		/* it may call write_inode just prior to fsync */
+		if (need_inode_page_update(sbi, ino))
+			goto go_write;
+
+		if (is_inode_flag_set(fi, FI_UPDATE_WRITE) ||
+				exist_written_data(sbi, ino, UPDATE_INO))
+			goto flush_out;
+		goto out;
+	}
+go_write:
+	/* guarantee free sections for fsync */
+	f2fs_balance_fs(sbi);
+
+	/*
+	 * Both of fdatasync() and fsync() are able to be recovered from
+	 * sudden-power-off.
+	 */
+	down_read(&fi->i_sem);
+	need_cp = need_do_checkpoint(inode);
+	up_read(&fi->i_sem);
+
+	if (need_cp) {
+		/* all the dirty node pages should be flushed for POR */
+		ret = f2fs_sync_fs(inode->i_sb, 1);
+
+		/*
+		 * We've secured consistency through sync_fs. Following pino
+		 * will be used only for fsynced inodes after checkpoint.
+		 */
+		try_to_fix_pino(inode);
+		clear_inode_flag(fi, FI_APPEND_WRITE);
+		clear_inode_flag(fi, FI_UPDATE_WRITE);
+		goto out;
+	}
+sync_nodes:
+	sync_node_pages(sbi, ino, &wbc);
+
+	/* if cp_error was enabled, we should avoid infinite loop */
+	if (unlikely(f2fs_cp_error(sbi)))
+		goto out;
+
+	if (need_inode_block_update(sbi, ino)) {
+		mark_inode_dirty_sync(inode);
+		f2fs_write_inode(inode, NULL);
+		goto sync_nodes;
+	}
+
+	ret = wait_on_node_pages_writeback(sbi, ino);
+	if (ret)
+		goto out;
+
+	/* once recovery info is written, don't need to tack this */
+	remove_dirty_inode(sbi, ino, APPEND_INO);
+	clear_inode_flag(fi, FI_APPEND_WRITE);
+flush_out:
+	remove_dirty_inode(sbi, ino, UPDATE_INO);
+	clear_inode_flag(fi, FI_UPDATE_WRITE);
+	ret = f2fs_issue_flush(sbi);
+out:
+	trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
+	f2fs_trace_ios(NULL, NULL, 1);
+	return ret;
+}
+
+static pgoff_t __get_first_dirty_index(struct address_space *mapping,
+						pgoff_t pgofs, int whence)
+{
+	struct pagevec pvec;
+	int nr_pages;
+
+	if (whence != SEEK_DATA)
+		return 0;
+
+	/* find first dirty page index */
+	pagevec_init(&pvec, 0);
+	nr_pages = pagevec_lookup_tag(&pvec, mapping, &pgofs,
+					PAGECACHE_TAG_DIRTY, 1);
+	pgofs = nr_pages ? pvec.pages[0]->index : LONG_MAX;
+	pagevec_release(&pvec);
+	return pgofs;
+}
+
+static bool __found_offset(block_t blkaddr, pgoff_t dirty, pgoff_t pgofs,
+							int whence)
+{
+	switch (whence) {
+	case SEEK_DATA:
+		if ((blkaddr == NEW_ADDR && dirty == pgofs) ||
+			(blkaddr != NEW_ADDR && blkaddr != NULL_ADDR))
+			return true;
+		break;
+	case SEEK_HOLE:
+		if (blkaddr == NULL_ADDR)
+			return true;
+		break;
+	}
+	return false;
+}
+
+static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t maxbytes = inode->i_sb->s_maxbytes;
+	struct dnode_of_data dn;
+	pgoff_t pgofs, end_offset, dirty;
+	loff_t data_ofs = offset;
+	loff_t isize;
+	int err = 0;
+
+	mutex_lock(&inode->i_mutex);
+
+	isize = i_size_read(inode);
+	if (offset >= isize)
+		goto fail;
+
+	/* handle inline data case */
+	if (f2fs_has_inline_data(inode) || f2fs_has_inline_dentry(inode)) {
+		if (whence == SEEK_HOLE)
+			data_ofs = isize;
+		goto found;
+	}
+
+	pgofs = (pgoff_t)(offset >> PAGE_CACHE_SHIFT);
+
+	dirty = __get_first_dirty_index(inode->i_mapping, pgofs, whence);
+
+	for (; data_ofs < isize; data_ofs = pgofs << PAGE_CACHE_SHIFT) {
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
+		if (err && err != -ENOENT) {
+			goto fail;
+		} else if (err == -ENOENT) {
+			/* direct node does not exists */
+			if (whence == SEEK_DATA) {
+				pgofs = PGOFS_OF_NEXT_DNODE(pgofs,
+							F2FS_I(inode));
+				continue;
+			} else {
+				goto found;
+			}
+		}
+
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+		/* find data/hole in dnode block */
+		for (; dn.ofs_in_node < end_offset;
+				dn.ofs_in_node++, pgofs++,
+				data_ofs = (loff_t)pgofs << PAGE_CACHE_SHIFT) {
+			block_t blkaddr;
+			blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+
+			if (__found_offset(blkaddr, dirty, pgofs, whence)) {
+				f2fs_put_dnode(&dn);
+				goto found;
+			}
+		}
+		f2fs_put_dnode(&dn);
+	}
+
+	if (whence == SEEK_DATA)
+		goto fail;
+found:
+	if (whence == SEEK_HOLE && data_ofs > isize)
+		data_ofs = isize;
+	mutex_unlock(&inode->i_mutex);
+	return vfs_setpos(file, data_ofs, maxbytes);
+fail:
+	mutex_unlock(&inode->i_mutex);
+	return -ENXIO;
+}
+
+static loff_t f2fs_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t maxbytes = inode->i_sb->s_maxbytes;
+
+	switch (whence) {
+	case SEEK_SET:
+	case SEEK_CUR:
+	case SEEK_END:
+		return generic_file_llseek_size(file, offset, whence,
+						maxbytes, i_size_read(inode));
+	case SEEK_DATA:
+	case SEEK_HOLE:
+		if (offset < 0)
+			return -ENXIO;
+		return f2fs_seek_block(file, offset, whence);
+	}
+
+	return -EINVAL;
+}
+
+static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct inode *inode = file_inode(file);
+
+	/* we don't need to use inline_data strictly */
+	if (f2fs_has_inline_data(inode)) {
+		int err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+
+	file_accessed(file);
+	vma->vm_ops = &f2fs_file_vm_ops;
+	return 0;
+}
+
+int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
+{
+	int nr_free = 0, ofs = dn->ofs_in_node;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_node *raw_node;
+	__le32 *addr;
+
+	raw_node = F2FS_NODE(dn->node_page);
+	addr = blkaddr_in_node(raw_node) + ofs;
+
+	for (; count > 0; count--, addr++, dn->ofs_in_node++) {
+		block_t blkaddr = le32_to_cpu(*addr);
+		if (blkaddr == NULL_ADDR)
+			continue;
+
+		dn->data_blkaddr = NULL_ADDR;
+		set_data_blkaddr(dn);
+		f2fs_update_extent_cache(dn);
+		invalidate_blocks(sbi, blkaddr);
+		if (dn->ofs_in_node == 0 && IS_INODE(dn->node_page))
+			clear_inode_flag(F2FS_I(dn->inode),
+						FI_FIRST_BLOCK_WRITTEN);
+		nr_free++;
+	}
+	if (nr_free) {
+		dec_valid_block_count(sbi, dn->inode, nr_free);
+		set_page_dirty(dn->node_page);
+		sync_inode_page(dn);
+	}
+	dn->ofs_in_node = ofs;
+
+	trace_f2fs_truncate_data_blocks_range(dn->inode, dn->nid,
+					 dn->ofs_in_node, nr_free);
+	return nr_free;
+}
+
+void truncate_data_blocks(struct dnode_of_data *dn)
+{
+	truncate_data_blocks_range(dn, ADDRS_PER_BLOCK);
+}
+
+static int truncate_partial_data_page(struct inode *inode, u64 from,
+								bool force)
+{
+	unsigned offset = from & (PAGE_CACHE_SIZE - 1);
+	struct page *page;
+
+	if (!offset && !force)
+		return 0;
+
+	page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, force);
+	if (IS_ERR(page))
+		return 0;
+
+	lock_page(page);
+	if (unlikely(!PageUptodate(page) ||
+			page->mapping != inode->i_mapping))
+		goto out;
+
+	f2fs_wait_on_page_writeback(page, DATA);
+	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
+	if (!force)
+		set_page_dirty(page);
+out:
+	f2fs_put_page(page, 1);
+	return 0;
+}
+
+int truncate_blocks(struct inode *inode, u64 from, bool lock)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	unsigned int blocksize = inode->i_sb->s_blocksize;
+	struct dnode_of_data dn;
+	pgoff_t free_from;
+	int count = 0, err = 0;
+	struct page *ipage;
+	bool truncate_page = false;
+
+	trace_f2fs_truncate_blocks_enter(inode, from);
+
+	free_from = (pgoff_t)F2FS_BYTES_TO_BLK(from + blocksize - 1);
+
+	if (lock)
+		f2fs_lock_op(sbi);
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto out;
+	}
+
+	if (f2fs_has_inline_data(inode)) {
+		if (truncate_inline_inode(ipage, from))
+			set_page_dirty(ipage);
+		f2fs_put_page(ipage, 1);
+		truncate_page = true;
+		goto out;
+	}
+
+	set_new_dnode(&dn, inode, ipage, NULL, 0);
+	err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE);
+	if (err) {
+		if (err == -ENOENT)
+			goto free_next;
+		goto out;
+	}
+
+	count = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+	count -= dn.ofs_in_node;
+	f2fs_bug_on(sbi, count < 0);
+
+	if (dn.ofs_in_node || IS_INODE(dn.node_page)) {
+		truncate_data_blocks_range(&dn, count);
+		free_from += count;
+	}
+
+	f2fs_put_dnode(&dn);
+free_next:
+	err = truncate_inode_blocks(inode, free_from);
+out:
+	if (lock)
+		f2fs_unlock_op(sbi);
+
+	/* lastly zero out the first data page */
+	if (!err)
+		err = truncate_partial_data_page(inode, from, truncate_page);
+
+	trace_f2fs_truncate_blocks_exit(inode, err);
+	return err;
+}
+
+void f2fs_truncate(struct inode *inode)
+{
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+				S_ISLNK(inode->i_mode)))
+		return;
+
+	trace_f2fs_truncate(inode);
+
+	/* we should check inline_data size */
+	if (f2fs_has_inline_data(inode) && !f2fs_may_inline(inode)) {
+		if (f2fs_convert_inline_inode(inode))
+			return;
+	}
+
+	if (!truncate_blocks(inode, i_size_read(inode), true)) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		mark_inode_dirty(inode);
+	}
+}
+
+int f2fs_getattr(struct vfsmount *mnt,
+			 struct dentry *dentry, struct kstat *stat)
+{
+	struct inode *inode = d_inode(dentry);
+	generic_fillattr(inode, stat);
+	stat->blocks <<= 3;
+	return 0;
+}
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+static void __setattr_copy(struct inode *inode, const struct iattr *attr)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int ia_valid = attr->ia_valid;
+
+	if (ia_valid & ATTR_UID)
+		inode->i_uid = attr->ia_uid;
+	if (ia_valid & ATTR_GID)
+		inode->i_gid = attr->ia_gid;
+	if (ia_valid & ATTR_ATIME)
+		inode->i_atime = timespec_trunc(attr->ia_atime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MTIME)
+		inode->i_mtime = timespec_trunc(attr->ia_mtime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_CTIME)
+		inode->i_ctime = timespec_trunc(attr->ia_ctime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MODE) {
+		umode_t mode = attr->ia_mode;
+
+		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+			mode &= ~S_ISGID;
+		set_acl_inode(fi, mode);
+	}
+}
+#else
+#define __setattr_copy setattr_copy
+#endif
+
+int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	int err;
+
+	err = inode_change_ok(inode, attr);
+	if (err)
+		return err;
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		if (attr->ia_size != i_size_read(inode)) {
+			truncate_setsize(inode, attr->ia_size);
+			f2fs_truncate(inode);
+			f2fs_balance_fs(F2FS_I_SB(inode));
+		} else {
+			/*
+			 * giving a chance to truncate blocks past EOF which
+			 * are fallocated with FALLOC_FL_KEEP_SIZE.
+			 */
+			f2fs_truncate(inode);
+		}
+	}
+
+	__setattr_copy(inode, attr);
+
+	if (attr->ia_valid & ATTR_MODE) {
+		err = posix_acl_chmod(inode, get_inode_mode(inode));
+		if (err || is_inode_flag_set(fi, FI_ACL_MODE)) {
+			inode->i_mode = fi->i_acl_mode;
+			clear_inode_flag(fi, FI_ACL_MODE);
+		}
+	}
+
+	mark_inode_dirty(inode);
+	return err;
+}
+
+const struct inode_operations f2fs_file_inode_operations = {
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= f2fs_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+	.fiemap		= f2fs_fiemap,
+};
+
+static void fill_zero(struct inode *inode, pgoff_t index,
+					loff_t start, loff_t len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page;
+
+	if (!len)
+		return;
+
+	f2fs_balance_fs(sbi);
+
+	f2fs_lock_op(sbi);
+	page = get_new_data_page(inode, NULL, index, false);
+	f2fs_unlock_op(sbi);
+
+	if (!IS_ERR(page)) {
+		f2fs_wait_on_page_writeback(page, DATA);
+		zero_user(page, start, len);
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+}
+
+int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
+{
+	pgoff_t index;
+	int err;
+
+	for (index = pg_start; index < pg_end; index++) {
+		struct dnode_of_data dn;
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+		if (err) {
+			if (err == -ENOENT)
+				continue;
+			return err;
+		}
+
+		if (dn.data_blkaddr != NULL_ADDR)
+			truncate_data_blocks_range(&dn, 1);
+		f2fs_put_dnode(&dn);
+	}
+	return 0;
+}
+
+static int punch_hole(struct inode *inode, loff_t offset, loff_t len)
+{
+	pgoff_t pg_start, pg_end;
+	loff_t off_start, off_end;
+	int ret = 0;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	/* skip punching hole beyond i_size */
+	if (offset >= inode->i_size)
+		return ret;
+
+	if (f2fs_has_inline_data(inode)) {
+		ret = f2fs_convert_inline_inode(inode);
+		if (ret)
+			return ret;
+	}
+
+	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
+	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;
+
+	off_start = offset & (PAGE_CACHE_SIZE - 1);
+	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);
+
+	if (pg_start == pg_end) {
+		fill_zero(inode, pg_start, off_start,
+						off_end - off_start);
+	} else {
+		if (off_start)
+			fill_zero(inode, pg_start++, off_start,
+					PAGE_CACHE_SIZE - off_start);
+		if (off_end)
+			fill_zero(inode, pg_end, 0, off_end);
+
+		if (pg_start < pg_end) {
+			struct address_space *mapping = inode->i_mapping;
+			loff_t blk_start, blk_end;
+			struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+			f2fs_balance_fs(sbi);
+
+			blk_start = pg_start << PAGE_CACHE_SHIFT;
+			blk_end = pg_end << PAGE_CACHE_SHIFT;
+			truncate_inode_pages_range(mapping, blk_start,
+					blk_end - 1);
+
+			f2fs_lock_op(sbi);
+			ret = truncate_hole(inode, pg_start, pg_end);
+			f2fs_unlock_op(sbi);
+		}
+	}
+
+	return ret;
+}
+
+static int expand_inode_data(struct inode *inode, loff_t offset,
+					loff_t len, int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	pgoff_t index, pg_start, pg_end;
+	loff_t new_size = i_size_read(inode);
+	loff_t off_start, off_end;
+	int ret = 0;
+
+	f2fs_balance_fs(sbi);
+
+	ret = inode_newsize_ok(inode, (len + offset));
+	if (ret)
+		return ret;
+
+	if (f2fs_has_inline_data(inode)) {
+		ret = f2fs_convert_inline_inode(inode);
+		if (ret)
+			return ret;
+	}
+
+	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
+	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;
+
+	off_start = offset & (PAGE_CACHE_SIZE - 1);
+	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);
+
+	f2fs_lock_op(sbi);
+
+	for (index = pg_start; index <= pg_end; index++) {
+		struct dnode_of_data dn;
+
+		if (index == pg_end && !off_end)
+			goto noalloc;
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		ret = f2fs_reserve_block(&dn, index);
+		if (ret)
+			break;
+noalloc:
+		if (pg_start == pg_end)
+			new_size = offset + len;
+		else if (index == pg_start && off_start)
+			new_size = (index + 1) << PAGE_CACHE_SHIFT;
+		else if (index == pg_end)
+			new_size = (index << PAGE_CACHE_SHIFT) + off_end;
+		else
+			new_size += PAGE_CACHE_SIZE;
+	}
+
+	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+		i_size_read(inode) < new_size) {
+		i_size_write(inode, new_size);
+		mark_inode_dirty(inode);
+		update_inode_page(inode);
+	}
+	f2fs_unlock_op(sbi);
+
+	return ret;
+}
+
+static long f2fs_fallocate(struct file *file, int mode,
+				loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(file);
+	long ret;
+
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+		return -EOPNOTSUPP;
+
+	mutex_lock(&inode->i_mutex);
+
+	if (mode & FALLOC_FL_PUNCH_HOLE)
+		ret = punch_hole(inode, offset, len);
+	else
+		ret = expand_inode_data(inode, offset, len, mode);
+
+	if (!ret) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		mark_inode_dirty(inode);
+	}
+
+	mutex_unlock(&inode->i_mutex);
+
+	trace_f2fs_fallocate(inode, mode, offset, len, ret);
+	return ret;
+}
+
+static int f2fs_release_file(struct inode *inode, struct file *filp)
+{
+	/* some remained atomic pages should discarded */
+	if (f2fs_is_atomic_file(inode))
+		commit_inmem_pages(inode, true);
+	if (f2fs_is_volatile_file(inode)) {
+		set_inode_flag(F2FS_I(inode), FI_DROP_CACHE);
+		filemap_fdatawrite(inode->i_mapping);
+		clear_inode_flag(F2FS_I(inode), FI_DROP_CACHE);
+	}
+	return 0;
+}
+
+#define F2FS_REG_FLMASK		(~(FS_DIRSYNC_FL | FS_TOPDIR_FL))
+#define F2FS_OTHER_FLMASK	(FS_NODUMP_FL | FS_NOATIME_FL)
+
+static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
+{
+	if (S_ISDIR(mode))
+		return flags;
+	else if (S_ISREG(mode))
+		return flags & F2FS_REG_FLMASK;
+	else
+		return flags & F2FS_OTHER_FLMASK;
+}
+
+static int f2fs_ioc_getflags(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int flags = fi->i_flags & FS_FL_USER_VISIBLE;
+	return put_user(flags, (int __user *)arg);
+}
+
+static int f2fs_ioc_setflags(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int flags = fi->i_flags & FS_FL_USER_VISIBLE;
+	unsigned int oldflags;
+	int ret;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	if (!inode_owner_or_capable(inode)) {
+		ret = -EACCES;
+		goto out;
+	}
+
+	if (get_user(flags, (int __user *)arg)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	flags = f2fs_mask_flags(inode->i_mode, flags);
+
+	mutex_lock(&inode->i_mutex);
+
+	oldflags = fi->i_flags;
+
+	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
+		if (!capable(CAP_LINUX_IMMUTABLE)) {
+			mutex_unlock(&inode->i_mutex);
+			ret = -EPERM;
+			goto out;
+		}
+	}
+
+	flags = flags & FS_FL_USER_MODIFIABLE;
+	flags |= oldflags & ~FS_FL_USER_MODIFIABLE;
+	fi->i_flags = flags;
+	mutex_unlock(&inode->i_mutex);
+
+	f2fs_set_inode_flags(inode);
+	inode->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(inode);
+out:
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_getversion(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+
+	return put_user(inode->i_generation, (int __user *)arg);
+}
+
+static int f2fs_ioc_start_atomic_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	f2fs_balance_fs(F2FS_I_SB(inode));
+
+	if (f2fs_is_atomic_file(inode))
+		return 0;
+
+	set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+
+	return f2fs_convert_inline_inode(inode);
+}
+
+static int f2fs_ioc_commit_atomic_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (f2fs_is_volatile_file(inode))
+		return 0;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	if (f2fs_is_atomic_file(inode))
+		commit_inmem_pages(inode, false);
+
+	ret = f2fs_sync_file(filp, 0, LONG_MAX, 0);
+	mnt_drop_write_file(filp);
+	clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+	return ret;
+}
+
+static int f2fs_ioc_start_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (f2fs_is_volatile_file(inode))
+		return 0;
+
+	set_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
+
+	return f2fs_convert_inline_inode(inode);
+}
+
+static int f2fs_ioc_release_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (!f2fs_is_volatile_file(inode))
+		return 0;
+
+	if (!f2fs_is_first_block_written(inode))
+		return truncate_partial_data_page(inode, 0, true);
+
+	punch_hole(inode, 0, F2FS_BLKSIZE);
+	return 0;
+}
+
+static int f2fs_ioc_abort_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	f2fs_balance_fs(F2FS_I_SB(inode));
+
+	if (f2fs_is_atomic_file(inode)) {
+		commit_inmem_pages(inode, false);
+		clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+	}
+
+	if (f2fs_is_volatile_file(inode)) {
+		clear_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
+		filemap_fdatawrite(inode->i_mapping);
+		set_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
+	}
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct super_block *sb = sbi->sb;
+	__u32 in;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(in, (__u32 __user *)arg))
+		return -EFAULT;
+
+	switch (in) {
+	case F2FS_GOING_DOWN_FULLSYNC:
+		sb = freeze_bdev(sb->s_bdev);
+		if (sb && !IS_ERR(sb)) {
+			f2fs_stop_checkpoint(sbi);
+			thaw_bdev(sb->s_bdev, sb);
+		}
+		break;
+	case F2FS_GOING_DOWN_METASYNC:
+		/* do checkpoint only */
+		f2fs_sync_fs(sb, 1);
+		f2fs_stop_checkpoint(sbi);
+		break;
+	case F2FS_GOING_DOWN_NOSYNC:
+		f2fs_stop_checkpoint(sbi);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	struct request_queue *q = bdev_get_queue(sb->s_bdev);
+	struct fstrim_range range;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!blk_queue_discard(q))
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
+				sizeof(range)))
+		return -EFAULT;
+
+	range.minlen = max((unsigned int)range.minlen,
+				q->limits.discard_granularity);
+	ret = f2fs_trim_fs(F2FS_SB(sb), &range);
+	if (ret < 0)
+		return ret;
+
+	if (copy_to_user((struct fstrim_range __user *)arg, &range,
+				sizeof(range)))
+		return -EFAULT;
+	return 0;
+}
+
+long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case F2FS_IOC_GETFLAGS:
+		return f2fs_ioc_getflags(filp, arg);
+	case F2FS_IOC_SETFLAGS:
+		return f2fs_ioc_setflags(filp, arg);
+	case F2FS_IOC_GETVERSION:
+		return f2fs_ioc_getversion(filp, arg);
+	case F2FS_IOC_START_ATOMIC_WRITE:
+		return f2fs_ioc_start_atomic_write(filp);
+	case F2FS_IOC_COMMIT_ATOMIC_WRITE:
+		return f2fs_ioc_commit_atomic_write(filp);
+	case F2FS_IOC_START_VOLATILE_WRITE:
+		return f2fs_ioc_start_volatile_write(filp);
+	case F2FS_IOC_RELEASE_VOLATILE_WRITE:
+		return f2fs_ioc_release_volatile_write(filp);
+	case F2FS_IOC_ABORT_VOLATILE_WRITE:
+		return f2fs_ioc_abort_volatile_write(filp);
+	case F2FS_IOC_SHUTDOWN:
+		return f2fs_ioc_shutdown(filp, arg);
+	case FITRIM:
+		return f2fs_ioc_fitrim(filp, arg);
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case F2FS_IOC32_GETFLAGS:
+		cmd = F2FS_IOC_GETFLAGS;
+		break;
+	case F2FS_IOC32_SETFLAGS:
+		cmd = F2FS_IOC_SETFLAGS;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
+
+const struct file_operations f2fs_file_operations = {
+	.llseek		= f2fs_llseek,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
+	.open		= generic_file_open,
+	.release	= f2fs_release_file,
+	.mmap		= f2fs_file_mmap,
+	.fsync		= f2fs_sync_file,
+	.fallocate	= f2fs_fallocate,
+	.unlocked_ioctl	= f2fs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= f2fs_compat_ioctl,
+#endif
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+};
diff --git a/kernel/fs/f2fs/gc.c b/kernel/fs/f2fs/gc.c
new file mode 100644
index 000000000..ed58211fe
--- /dev/null
+++ b/kernel/fs/f2fs/gc.c
@@ -0,0 +1,746 @@
+/*
+ * fs/f2fs/gc.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/init.h>
+#include <linux/f2fs_fs.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/blkdev.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "gc.h"
+#include <trace/events/f2fs.h>
+
+static int gc_thread_func(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
+	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
+	long wait_ms;
+
+	wait_ms = gc_th->min_sleep_time;
+
+	do {
+		if (try_to_freeze())
+			continue;
+		else
+			wait_event_interruptible_timeout(*wq,
+						kthread_should_stop(),
+						msecs_to_jiffies(wait_ms));
+		if (kthread_should_stop())
+			break;
+
+		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
+			increase_sleep_time(gc_th, &wait_ms);
+			continue;
+		}
+
+		/*
+		 * [GC triggering condition]
+		 * 0. GC is not conducted currently.
+		 * 1. There are enough dirty segments.
+		 * 2. IO subsystem is idle by checking the # of writeback pages.
+		 * 3. IO subsystem is idle by checking the # of requests in
+		 *    bdev's request list.
+		 *
+		 * Note) We have to avoid triggering GCs frequently.
+		 * Because it is possible that some segments can be
+		 * invalidated soon after by user update or deletion.
+		 * So, I'd like to wait some time to collect dirty segments.
+		 */
+		if (!mutex_trylock(&sbi->gc_mutex))
+			continue;
+
+		if (!is_idle(sbi)) {
+			increase_sleep_time(gc_th, &wait_ms);
+			mutex_unlock(&sbi->gc_mutex);
+			continue;
+		}
+
+		if (has_enough_invalid_blocks(sbi))
+			decrease_sleep_time(gc_th, &wait_ms);
+		else
+			increase_sleep_time(gc_th, &wait_ms);
+
+		stat_inc_bggc_count(sbi);
+
+		/* if return value is not zero, no victim was selected */
+		if (f2fs_gc(sbi))
+			wait_ms = gc_th->no_gc_sleep_time;
+
+		/* balancing f2fs's metadata periodically */
+		f2fs_balance_fs_bg(sbi);
+
+	} while (!kthread_should_stop());
+	return 0;
+}
+
+int start_gc_thread(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_gc_kthread *gc_th;
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	int err = 0;
+
+	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
+	if (!gc_th) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
+	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
+	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
+
+	gc_th->gc_idle = 0;
+
+	sbi->gc_thread = gc_th;
+	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
+	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
+			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(gc_th->f2fs_gc_task)) {
+		err = PTR_ERR(gc_th->f2fs_gc_task);
+		kfree(gc_th);
+		sbi->gc_thread = NULL;
+	}
+out:
+	return err;
+}
+
+void stop_gc_thread(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
+	if (!gc_th)
+		return;
+	kthread_stop(gc_th->f2fs_gc_task);
+	kfree(gc_th);
+	sbi->gc_thread = NULL;
+}
+
+static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
+{
+	int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
+
+	if (gc_th && gc_th->gc_idle) {
+		if (gc_th->gc_idle == 1)
+			gc_mode = GC_CB;
+		else if (gc_th->gc_idle == 2)
+			gc_mode = GC_GREEDY;
+	}
+	return gc_mode;
+}
+
+static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
+			int type, struct victim_sel_policy *p)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	if (p->alloc_mode == SSR) {
+		p->gc_mode = GC_GREEDY;
+		p->dirty_segmap = dirty_i->dirty_segmap[type];
+		p->max_search = dirty_i->nr_dirty[type];
+		p->ofs_unit = 1;
+	} else {
+		p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
+		p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
+		p->max_search = dirty_i->nr_dirty[DIRTY];
+		p->ofs_unit = sbi->segs_per_sec;
+	}
+
+	if (p->max_search > sbi->max_victim_search)
+		p->max_search = sbi->max_victim_search;
+
+	p->offset = sbi->last_victim[p->gc_mode];
+}
+
+static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
+				struct victim_sel_policy *p)
+{
+	/* SSR allocates in a segment unit */
+	if (p->alloc_mode == SSR)
+		return 1 << sbi->log_blocks_per_seg;
+	if (p->gc_mode == GC_GREEDY)
+		return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
+	else if (p->gc_mode == GC_CB)
+		return UINT_MAX;
+	else /* No other gc_mode */
+		return 0;
+}
+
+static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int secno;
+
+	/*
+	 * If the gc_type is FG_GC, we can select victim segments
+	 * selected by background GC before.
+	 * Those segments guarantee they have small valid blocks.
+	 */
+	for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
+		if (sec_usage_check(sbi, secno))
+			continue;
+		clear_bit(secno, dirty_i->victim_secmap);
+		return secno * sbi->segs_per_sec;
+	}
+	return NULL_SEGNO;
+}
+
+static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int secno = GET_SECNO(sbi, segno);
+	unsigned int start = secno * sbi->segs_per_sec;
+	unsigned long long mtime = 0;
+	unsigned int vblocks;
+	unsigned char age = 0;
+	unsigned char u;
+	unsigned int i;
+
+	for (i = 0; i < sbi->segs_per_sec; i++)
+		mtime += get_seg_entry(sbi, start + i)->mtime;
+	vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
+
+	mtime = div_u64(mtime, sbi->segs_per_sec);
+	vblocks = div_u64(vblocks, sbi->segs_per_sec);
+
+	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
+
+	/* Handle if the system time has changed by the user */
+	if (mtime < sit_i->min_mtime)
+		sit_i->min_mtime = mtime;
+	if (mtime > sit_i->max_mtime)
+		sit_i->max_mtime = mtime;
+	if (sit_i->max_mtime != sit_i->min_mtime)
+		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
+				sit_i->max_mtime - sit_i->min_mtime);
+
+	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
+}
+
+static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct victim_sel_policy *p)
+{
+	if (p->alloc_mode == SSR)
+		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
+
+	/* alloc_mode == LFS */
+	if (p->gc_mode == GC_GREEDY)
+		return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
+	else
+		return get_cb_cost(sbi, segno);
+}
+
+/*
+ * This function is called from two paths.
+ * One is garbage collection and the other is SSR segment selection.
+ * When it is called during GC, it just gets a victim segment
+ * and it does not remove it from dirty seglist.
+ * When it is called from SSR segment selection, it finds a segment
+ * which has minimum valid blocks and removes it from dirty seglist.
+ */
+static int get_victim_by_default(struct f2fs_sb_info *sbi,
+		unsigned int *result, int gc_type, int type, char alloc_mode)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct victim_sel_policy p;
+	unsigned int secno, max_cost;
+	int nsearched = 0;
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	p.alloc_mode = alloc_mode;
+	select_policy(sbi, gc_type, type, &p);
+
+	p.min_segno = NULL_SEGNO;
+	p.min_cost = max_cost = get_max_cost(sbi, &p);
+
+	if (p.alloc_mode == LFS && gc_type == FG_GC) {
+		p.min_segno = check_bg_victims(sbi);
+		if (p.min_segno != NULL_SEGNO)
+			goto got_it;
+	}
+
+	while (1) {
+		unsigned long cost;
+		unsigned int segno;
+
+		segno = find_next_bit(p.dirty_segmap, MAIN_SEGS(sbi), p.offset);
+		if (segno >= MAIN_SEGS(sbi)) {
+			if (sbi->last_victim[p.gc_mode]) {
+				sbi->last_victim[p.gc_mode] = 0;
+				p.offset = 0;
+				continue;
+			}
+			break;
+		}
+
+		p.offset = segno + p.ofs_unit;
+		if (p.ofs_unit > 1)
+			p.offset -= segno % p.ofs_unit;
+
+		secno = GET_SECNO(sbi, segno);
+
+		if (sec_usage_check(sbi, secno))
+			continue;
+		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
+			continue;
+
+		cost = get_gc_cost(sbi, segno, &p);
+
+		if (p.min_cost > cost) {
+			p.min_segno = segno;
+			p.min_cost = cost;
+		} else if (unlikely(cost == max_cost)) {
+			continue;
+		}
+
+		if (nsearched++ >= p.max_search) {
+			sbi->last_victim[p.gc_mode] = segno;
+			break;
+		}
+	}
+	if (p.min_segno != NULL_SEGNO) {
+got_it:
+		if (p.alloc_mode == LFS) {
+			secno = GET_SECNO(sbi, p.min_segno);
+			if (gc_type == FG_GC)
+				sbi->cur_victim_sec = secno;
+			else
+				set_bit(secno, dirty_i->victim_secmap);
+		}
+		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
+
+		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
+				sbi->cur_victim_sec,
+				prefree_segments(sbi), free_segments(sbi));
+	}
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	return (p.min_segno == NULL_SEGNO) ? 0 : 1;
+}
+
+static const struct victim_selection default_v_ops = {
+	.get_victim = get_victim_by_default,
+};
+
+static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
+{
+	struct inode_entry *ie;
+
+	ie = radix_tree_lookup(&gc_list->iroot, ino);
+	if (ie)
+		return ie->inode;
+	return NULL;
+}
+
+static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
+{
+	struct inode_entry *new_ie;
+
+	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
+		iput(inode);
+		return;
+	}
+	new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	new_ie->inode = inode;
+
+	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
+	list_add_tail(&new_ie->list, &gc_list->ilist);
+}
+
+static void put_gc_inode(struct gc_inode_list *gc_list)
+{
+	struct inode_entry *ie, *next_ie;
+	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
+		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
+		iput(ie->inode);
+		list_del(&ie->list);
+		kmem_cache_free(inode_entry_slab, ie);
+	}
+}
+
+static int check_valid_map(struct f2fs_sb_info *sbi,
+				unsigned int segno, int offset)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct seg_entry *sentry;
+	int ret;
+
+	mutex_lock(&sit_i->sentry_lock);
+	sentry = get_seg_entry(sbi, segno);
+	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
+	mutex_unlock(&sit_i->sentry_lock);
+	return ret;
+}
+
+/*
+ * This function compares node address got in summary with that in NAT.
+ * On validity, copy that node with cold status, otherwise (invalid node)
+ * ignore that.
+ */
+static void gc_node_segment(struct f2fs_sb_info *sbi,
+		struct f2fs_summary *sum, unsigned int segno, int gc_type)
+{
+	bool initial = true;
+	struct f2fs_summary *entry;
+	int off;
+
+next_step:
+	entry = sum;
+
+	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
+		nid_t nid = le32_to_cpu(entry->nid);
+		struct page *node_page;
+
+		/* stop BG_GC if there is not enough free sections. */
+		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
+			return;
+
+		if (check_valid_map(sbi, segno, off) == 0)
+			continue;
+
+		if (initial) {
+			ra_node_page(sbi, nid);
+			continue;
+		}
+		node_page = get_node_page(sbi, nid);
+		if (IS_ERR(node_page))
+			continue;
+
+		/* block may become invalid during get_node_page */
+		if (check_valid_map(sbi, segno, off) == 0) {
+			f2fs_put_page(node_page, 1);
+			continue;
+		}
+
+		/* set page dirty and write it */
+		if (gc_type == FG_GC) {
+			f2fs_wait_on_page_writeback(node_page, NODE);
+			set_page_dirty(node_page);
+		} else {
+			if (!PageWriteback(node_page))
+				set_page_dirty(node_page);
+		}
+		f2fs_put_page(node_page, 1);
+		stat_inc_node_blk_count(sbi, 1, gc_type);
+	}
+
+	if (initial) {
+		initial = false;
+		goto next_step;
+	}
+
+	if (gc_type == FG_GC) {
+		struct writeback_control wbc = {
+			.sync_mode = WB_SYNC_ALL,
+			.nr_to_write = LONG_MAX,
+			.for_reclaim = 0,
+		};
+		sync_node_pages(sbi, 0, &wbc);
+
+		/*
+		 * In the case of FG_GC, it'd be better to reclaim this victim
+		 * completely.
+		 */
+		if (get_valid_blocks(sbi, segno, 1) != 0)
+			goto next_step;
+	}
+}
+
+/*
+ * Calculate start block index indicating the given node offset.
+ * Be careful, caller should give this node offset only indicating direct node
+ * blocks. If any node offsets, which point the other types of node blocks such
+ * as indirect or double indirect node blocks, are given, it must be a caller's
+ * bug.
+ */
+block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi)
+{
+	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
+	unsigned int bidx;
+
+	if (node_ofs == 0)
+		return 0;
+
+	if (node_ofs <= 2) {
+		bidx = node_ofs - 1;
+	} else if (node_ofs <= indirect_blks) {
+		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
+		bidx = node_ofs - 2 - dec;
+	} else {
+		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
+		bidx = node_ofs - 5 - dec;
+	}
+	return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi);
+}
+
+static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
+{
+	struct page *node_page;
+	nid_t nid;
+	unsigned int ofs_in_node;
+	block_t source_blkaddr;
+
+	nid = le32_to_cpu(sum->nid);
+	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
+
+	node_page = get_node_page(sbi, nid);
+	if (IS_ERR(node_page))
+		return 0;
+
+	get_node_info(sbi, nid, dni);
+
+	if (sum->version != dni->version) {
+		f2fs_put_page(node_page, 1);
+		return 0;
+	}
+
+	*nofs = ofs_of_node(node_page);
+	source_blkaddr = datablock_addr(node_page, ofs_in_node);
+	f2fs_put_page(node_page, 1);
+
+	if (source_blkaddr != blkaddr)
+		return 0;
+	return 1;
+}
+
+static void move_data_page(struct inode *inode, struct page *page, int gc_type)
+{
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = WRITE_SYNC,
+	};
+
+	if (gc_type == BG_GC) {
+		if (PageWriteback(page))
+			goto out;
+		set_page_dirty(page);
+		set_cold_data(page);
+	} else {
+		f2fs_wait_on_page_writeback(page, DATA);
+
+		if (clear_page_dirty_for_io(page))
+			inode_dec_dirty_pages(inode);
+		set_cold_data(page);
+		do_write_data_page(page, &fio);
+		clear_cold_data(page);
+	}
+out:
+	f2fs_put_page(page, 1);
+}
+
+/*
+ * This function tries to get parent node of victim data block, and identifies
+ * data block validity. If the block is valid, copy that with cold status and
+ * modify parent node.
+ * If the parent node is not valid or the data block address is different,
+ * the victim data block is ignored.
+ */
+static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+		struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
+{
+	struct super_block *sb = sbi->sb;
+	struct f2fs_summary *entry;
+	block_t start_addr;
+	int off;
+	int phase = 0;
+
+	start_addr = START_BLOCK(sbi, segno);
+
+next_step:
+	entry = sum;
+
+	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
+		struct page *data_page;
+		struct inode *inode;
+		struct node_info dni; /* dnode info for the data */
+		unsigned int ofs_in_node, nofs;
+		block_t start_bidx;
+
+		/* stop BG_GC if there is not enough free sections. */
+		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
+			return;
+
+		if (check_valid_map(sbi, segno, off) == 0)
+			continue;
+
+		if (phase == 0) {
+			ra_node_page(sbi, le32_to_cpu(entry->nid));
+			continue;
+		}
+
+		/* Get an inode by ino with checking validity */
+		if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
+			continue;
+
+		if (phase == 1) {
+			ra_node_page(sbi, dni.ino);
+			continue;
+		}
+
+		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
+
+		if (phase == 2) {
+			inode = f2fs_iget(sb, dni.ino);
+			if (IS_ERR(inode) || is_bad_inode(inode))
+				continue;
+
+			start_bidx = start_bidx_of_node(nofs, F2FS_I(inode));
+
+			data_page = find_data_page(inode,
+					start_bidx + ofs_in_node, false);
+			if (IS_ERR(data_page)) {
+				iput(inode);
+				continue;
+			}
+
+			f2fs_put_page(data_page, 0);
+			add_gc_inode(gc_list, inode);
+			continue;
+		}
+
+		/* phase 3 */
+		inode = find_gc_inode(gc_list, dni.ino);
+		if (inode) {
+			start_bidx = start_bidx_of_node(nofs, F2FS_I(inode));
+			data_page = get_lock_data_page(inode,
+						start_bidx + ofs_in_node);
+			if (IS_ERR(data_page))
+				continue;
+			move_data_page(inode, data_page, gc_type);
+			stat_inc_data_blk_count(sbi, 1, gc_type);
+		}
+	}
+
+	if (++phase < 4)
+		goto next_step;
+
+	if (gc_type == FG_GC) {
+		f2fs_submit_merged_bio(sbi, DATA, WRITE);
+
+		/*
+		 * In the case of FG_GC, it'd be better to reclaim this victim
+		 * completely.
+		 */
+		if (get_valid_blocks(sbi, segno, 1) != 0) {
+			phase = 2;
+			goto next_step;
+		}
+	}
+}
+
+static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
+			int gc_type)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	int ret;
+
+	mutex_lock(&sit_i->sentry_lock);
+	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
+					      NO_CHECK_TYPE, LFS);
+	mutex_unlock(&sit_i->sentry_lock);
+	return ret;
+}
+
+static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
+				struct gc_inode_list *gc_list, int gc_type)
+{
+	struct page *sum_page;
+	struct f2fs_summary_block *sum;
+	struct blk_plug plug;
+
+	/* read segment summary of victim */
+	sum_page = get_sum_page(sbi, segno);
+
+	blk_start_plug(&plug);
+
+	sum = page_address(sum_page);
+
+	switch (GET_SUM_TYPE((&sum->footer))) {
+	case SUM_TYPE_NODE:
+		gc_node_segment(sbi, sum->entries, segno, gc_type);
+		break;
+	case SUM_TYPE_DATA:
+		gc_data_segment(sbi, sum->entries, gc_list, segno, gc_type);
+		break;
+	}
+	blk_finish_plug(&plug);
+
+	stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type);
+	stat_inc_call_count(sbi->stat_info);
+
+	f2fs_put_page(sum_page, 1);
+}
+
+int f2fs_gc(struct f2fs_sb_info *sbi)
+{
+	unsigned int segno, i;
+	int gc_type = BG_GC;
+	int nfree = 0;
+	int ret = -1;
+	struct cp_control cpc;
+	struct gc_inode_list gc_list = {
+		.ilist = LIST_HEAD_INIT(gc_list.ilist),
+		.iroot = RADIX_TREE_INIT(GFP_NOFS),
+	};
+
+	cpc.reason = __get_cp_reason(sbi);
+gc_more:
+	if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE)))
+		goto stop;
+	if (unlikely(f2fs_cp_error(sbi)))
+		goto stop;
+
+	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
+		gc_type = FG_GC;
+		write_checkpoint(sbi, &cpc);
+	}
+
+	if (!__get_victim(sbi, &segno, gc_type))
+		goto stop;
+	ret = 0;
+
+	/* readahead multi ssa blocks those have contiguous address */
+	if (sbi->segs_per_sec > 1)
+		ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec,
+								META_SSA);
+
+	for (i = 0; i < sbi->segs_per_sec; i++)
+		do_garbage_collect(sbi, segno + i, &gc_list, gc_type);
+
+	if (gc_type == FG_GC) {
+		sbi->cur_victim_sec = NULL_SEGNO;
+		nfree++;
+		WARN_ON(get_valid_blocks(sbi, segno, sbi->segs_per_sec));
+	}
+
+	if (has_not_enough_free_secs(sbi, nfree))
+		goto gc_more;
+
+	if (gc_type == FG_GC)
+		write_checkpoint(sbi, &cpc);
+stop:
+	mutex_unlock(&sbi->gc_mutex);
+
+	put_gc_inode(&gc_list);
+	return ret;
+}
+
+void build_gc_manager(struct f2fs_sb_info *sbi)
+{
+	DIRTY_I(sbi)->v_ops = &default_v_ops;
+}
diff --git a/kernel/fs/f2fs/gc.h b/kernel/fs/f2fs/gc.h
new file mode 100644
index 000000000..b4a65be9f
--- /dev/null
+++ b/kernel/fs/f2fs/gc.h
@@ -0,0 +1,110 @@
+/*
+ * fs/f2fs/gc.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#define GC_THREAD_MIN_WB_PAGES		1	/*
+						 * a threshold to determine
+						 * whether IO subsystem is idle
+						 * or not
+						 */
+#define DEF_GC_THREAD_MIN_SLEEP_TIME	30000	/* milliseconds */
+#define DEF_GC_THREAD_MAX_SLEEP_TIME	60000
+#define DEF_GC_THREAD_NOGC_SLEEP_TIME	300000	/* wait 5 min */
+#define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
+#define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
+
+/* Search max. number of dirty segments to select a victim segment */
+#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
+
+struct f2fs_gc_kthread {
+	struct task_struct *f2fs_gc_task;
+	wait_queue_head_t gc_wait_queue_head;
+
+	/* for gc sleep time */
+	unsigned int min_sleep_time;
+	unsigned int max_sleep_time;
+	unsigned int no_gc_sleep_time;
+
+	/* for changing gc mode */
+	unsigned int gc_idle;
+};
+
+struct gc_inode_list {
+	struct list_head ilist;
+	struct radix_tree_root iroot;
+};
+
+/*
+ * inline functions
+ */
+static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
+{
+	if (free_segments(sbi) < overprovision_segments(sbi))
+		return 0;
+	else
+		return (free_segments(sbi) - overprovision_segments(sbi))
+			<< sbi->log_blocks_per_seg;
+}
+
+static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
+{
+	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
+}
+
+static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
+{
+	block_t reclaimable_user_blocks = sbi->user_block_count -
+		written_block_count(sbi);
+	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
+}
+
+static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
+								long *wait)
+{
+	if (*wait == gc_th->no_gc_sleep_time)
+		return;
+
+	*wait += gc_th->min_sleep_time;
+	if (*wait > gc_th->max_sleep_time)
+		*wait = gc_th->max_sleep_time;
+}
+
+static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
+								long *wait)
+{
+	if (*wait == gc_th->no_gc_sleep_time)
+		*wait = gc_th->max_sleep_time;
+
+	*wait -= gc_th->min_sleep_time;
+	if (*wait <= gc_th->min_sleep_time)
+		*wait = gc_th->min_sleep_time;
+}
+
+static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
+{
+	block_t invalid_user_blocks = sbi->user_block_count -
+					written_block_count(sbi);
+	/*
+	 * Background GC is triggered with the following conditions.
+	 * 1. There are a number of invalid blocks.
+	 * 2. There is not enough free space.
+	 */
+	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
+			free_user_blocks(sbi) < limit_free_user_blocks(sbi))
+		return true;
+	return false;
+}
+
+static inline int is_idle(struct f2fs_sb_info *sbi)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
+	struct request_list *rl = &q->root_rl;
+	return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
+}
diff --git a/kernel/fs/f2fs/hash.c b/kernel/fs/f2fs/hash.c
new file mode 100644
index 000000000..a844fcfb9
--- /dev/null
+++ b/kernel/fs/f2fs/hash.c
@@ -0,0 +1,104 @@
+/*
+ * fs/f2fs/hash.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext3/hash.c
+ *
+ * Copyright (C) 2002 by Theodore Ts'o
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/cryptohash.h>
+#include <linux/pagemap.h>
+
+#include "f2fs.h"
+
+/*
+ * Hashing code copied from ext3
+ */
+#define DELTA 0x9E3779B9
+
+static void TEA_transform(unsigned int buf[4], unsigned int const in[])
+{
+	__u32 sum = 0;
+	__u32 b0 = buf[0], b1 = buf[1];
+	__u32 a = in[0], b = in[1], c = in[2], d = in[3];
+	int n = 16;
+
+	do {
+		sum += DELTA;
+		b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
+		b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
+	} while (--n);
+
+	buf[0] += b0;
+	buf[1] += b1;
+}
+
+static void str2hashbuf(const unsigned char *msg, size_t len,
+				unsigned int *buf, int num)
+{
+	unsigned pad, val;
+	int i;
+
+	pad = (__u32)len | ((__u32)len << 8);
+	pad |= pad << 16;
+
+	val = pad;
+	if (len > num * 4)
+		len = num * 4;
+	for (i = 0; i < len; i++) {
+		if ((i % 4) == 0)
+			val = pad;
+		val = msg[i] + (val << 8);
+		if ((i % 4) == 3) {
+			*buf++ = val;
+			val = pad;
+			num--;
+		}
+	}
+	if (--num >= 0)
+		*buf++ = val;
+	while (--num >= 0)
+		*buf++ = pad;
+}
+
+f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info)
+{
+	__u32 hash;
+	f2fs_hash_t f2fs_hash;
+	const unsigned char *p;
+	__u32 in[8], buf[4];
+	const unsigned char *name = name_info->name;
+	size_t len = name_info->len;
+
+	if ((len <= 2) && (name[0] == '.') &&
+		(name[1] == '.' || name[1] == '\0'))
+		return 0;
+
+	/* Initialize the default seed for the hash checksum functions */
+	buf[0] = 0x67452301;
+	buf[1] = 0xefcdab89;
+	buf[2] = 0x98badcfe;
+	buf[3] = 0x10325476;
+
+	p = name;
+	while (1) {
+		str2hashbuf(p, len, in, 4);
+		TEA_transform(buf, in);
+		p += 16;
+		if (len <= 16)
+			break;
+		len -= 16;
+	}
+	hash = buf[0];
+	f2fs_hash = cpu_to_le32(hash & ~F2FS_HASH_COL_BIT);
+	return f2fs_hash;
+}
diff --git a/kernel/fs/f2fs/inline.c b/kernel/fs/f2fs/inline.c
new file mode 100644
index 000000000..8140e4f0e
--- /dev/null
+++ b/kernel/fs/f2fs/inline.c
@@ -0,0 +1,532 @@
+/*
+ * fs/f2fs/inline.c
+ * Copyright (c) 2013, Intel Corporation
+ * Authors: Huajun Li <huajun.li@intel.com>
+ *          Haicheng Li <haicheng.li@intel.com>
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+
+bool f2fs_may_inline(struct inode *inode)
+{
+	if (!test_opt(F2FS_I_SB(inode), INLINE_DATA))
+		return false;
+
+	if (f2fs_is_atomic_file(inode))
+		return false;
+
+	if (!S_ISREG(inode->i_mode) && !S_ISLNK(inode->i_mode))
+		return false;
+
+	if (i_size_read(inode) > MAX_INLINE_DATA)
+		return false;
+
+	return true;
+}
+
+void read_inline_data(struct page *page, struct page *ipage)
+{
+	void *src_addr, *dst_addr;
+
+	if (PageUptodate(page))
+		return;
+
+	f2fs_bug_on(F2FS_P_SB(page), page->index);
+
+	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
+
+	/* Copy the whole inline data block */
+	src_addr = inline_data_addr(ipage);
+	dst_addr = kmap_atomic(page);
+	memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
+	flush_dcache_page(page);
+	kunmap_atomic(dst_addr);
+	SetPageUptodate(page);
+}
+
+bool truncate_inline_inode(struct page *ipage, u64 from)
+{
+	void *addr;
+
+	if (from >= MAX_INLINE_DATA)
+		return false;
+
+	addr = inline_data_addr(ipage);
+
+	f2fs_wait_on_page_writeback(ipage, NODE);
+	memset(addr + from, 0, MAX_INLINE_DATA - from);
+
+	return true;
+}
+
+int f2fs_read_inline_data(struct inode *inode, struct page *page)
+{
+	struct page *ipage;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage)) {
+		unlock_page(page);
+		return PTR_ERR(ipage);
+	}
+
+	if (!f2fs_has_inline_data(inode)) {
+		f2fs_put_page(ipage, 1);
+		return -EAGAIN;
+	}
+
+	if (page->index)
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+	else
+		read_inline_data(page, ipage);
+
+	SetPageUptodate(page);
+	f2fs_put_page(ipage, 1);
+	unlock_page(page);
+	return 0;
+}
+
+int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = WRITE_SYNC | REQ_PRIO,
+	};
+	int dirty, err;
+
+	f2fs_bug_on(F2FS_I_SB(dn->inode), page->index);
+
+	if (!f2fs_exist_data(dn->inode))
+		goto clear_out;
+
+	err = f2fs_reserve_block(dn, 0);
+	if (err)
+		return err;
+
+	f2fs_wait_on_page_writeback(page, DATA);
+
+	if (PageUptodate(page))
+		goto no_update;
+
+	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
+
+	/* Copy the whole inline data block */
+	src_addr = inline_data_addr(dn->inode_page);
+	dst_addr = kmap_atomic(page);
+	memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
+	flush_dcache_page(page);
+	kunmap_atomic(dst_addr);
+	SetPageUptodate(page);
+no_update:
+	/* clear dirty state */
+	dirty = clear_page_dirty_for_io(page);
+
+	/* write data page to try to make data consistent */
+	set_page_writeback(page);
+	fio.blk_addr = dn->data_blkaddr;
+	write_data_page(page, dn, &fio);
+	set_data_blkaddr(dn);
+	f2fs_update_extent_cache(dn);
+	f2fs_wait_on_page_writeback(page, DATA);
+	if (dirty)
+		inode_dec_dirty_pages(dn->inode);
+
+	/* this converted inline_data should be recovered. */
+	set_inode_flag(F2FS_I(dn->inode), FI_APPEND_WRITE);
+
+	/* clear inline data and flag after data writeback */
+	truncate_inline_inode(dn->inode_page, 0);
+clear_out:
+	stat_dec_inline_inode(dn->inode);
+	f2fs_clear_inline_inode(dn->inode);
+	sync_inode_page(dn);
+	f2fs_put_dnode(dn);
+	return 0;
+}
+
+int f2fs_convert_inline_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	struct page *ipage, *page;
+	int err = 0;
+
+	page = grab_cache_page(inode->i_mapping, 0);
+	if (!page)
+		return -ENOMEM;
+
+	f2fs_lock_op(sbi);
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto out;
+	}
+
+	set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+	if (f2fs_has_inline_data(inode))
+		err = f2fs_convert_inline_page(&dn, page);
+
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_unlock_op(sbi);
+
+	f2fs_put_page(page, 1);
+	return err;
+}
+
+int f2fs_write_inline_data(struct inode *inode, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	struct dnode_of_data dn;
+	int err;
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, 0, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	if (!f2fs_has_inline_data(inode)) {
+		f2fs_put_dnode(&dn);
+		return -EAGAIN;
+	}
+
+	f2fs_bug_on(F2FS_I_SB(inode), page->index);
+
+	f2fs_wait_on_page_writeback(dn.inode_page, NODE);
+	src_addr = kmap_atomic(page);
+	dst_addr = inline_data_addr(dn.inode_page);
+	memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
+	kunmap_atomic(src_addr);
+
+	set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
+	set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+
+	sync_inode_page(&dn);
+	f2fs_put_dnode(&dn);
+	return 0;
+}
+
+bool recover_inline_data(struct inode *inode, struct page *npage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode *ri = NULL;
+	void *src_addr, *dst_addr;
+	struct page *ipage;
+
+	/*
+	 * The inline_data recovery policy is as follows.
+	 * [prev.] [next] of inline_data flag
+	 *    o       o  -> recover inline_data
+	 *    o       x  -> remove inline_data, and then recover data blocks
+	 *    x       o  -> remove inline_data, and then recover inline_data
+	 *    x       x  -> recover data blocks
+	 */
+	if (IS_INODE(npage))
+		ri = F2FS_INODE(npage);
+
+	if (f2fs_has_inline_data(inode) &&
+			ri && (ri->i_inline & F2FS_INLINE_DATA)) {
+process_inline:
+		ipage = get_node_page(sbi, inode->i_ino);
+		f2fs_bug_on(sbi, IS_ERR(ipage));
+
+		f2fs_wait_on_page_writeback(ipage, NODE);
+
+		src_addr = inline_data_addr(npage);
+		dst_addr = inline_data_addr(ipage);
+		memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
+
+		set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+		set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+
+		update_inode(inode, ipage);
+		f2fs_put_page(ipage, 1);
+		return true;
+	}
+
+	if (f2fs_has_inline_data(inode)) {
+		ipage = get_node_page(sbi, inode->i_ino);
+		f2fs_bug_on(sbi, IS_ERR(ipage));
+		truncate_inline_inode(ipage, 0);
+		f2fs_clear_inline_inode(inode);
+		update_inode(inode, ipage);
+		f2fs_put_page(ipage, 1);
+	} else if (ri && (ri->i_inline & F2FS_INLINE_DATA)) {
+		truncate_blocks(inode, 0, false);
+		goto process_inline;
+	}
+	return false;
+}
+
+struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir,
+				struct qstr *name, struct page **res_page)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+	struct f2fs_inline_dentry *inline_dentry;
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_ptr d;
+	struct page *ipage;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return NULL;
+
+	inline_dentry = inline_data_addr(ipage);
+
+	make_dentry_ptr(&d, (void *)inline_dentry, 2);
+	de = find_target_dentry(name, NULL, &d);
+
+	unlock_page(ipage);
+	if (de)
+		*res_page = ipage;
+	else
+		f2fs_put_page(ipage, 0);
+
+	/*
+	 * For the most part, it should be a bug when name_len is zero.
+	 * We stop here for figuring out where the bugs has occurred.
+	 */
+	f2fs_bug_on(sbi, d.max < 0);
+	return de;
+}
+
+struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *dir,
+							struct page **p)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct page *ipage;
+	struct f2fs_dir_entry *de;
+	struct f2fs_inline_dentry *dentry_blk;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return NULL;
+
+	dentry_blk = inline_data_addr(ipage);
+	de = &dentry_blk->dentry[1];
+	*p = ipage;
+	unlock_page(ipage);
+	return de;
+}
+
+int make_empty_inline_dir(struct inode *inode, struct inode *parent,
+							struct page *ipage)
+{
+	struct f2fs_inline_dentry *dentry_blk;
+	struct f2fs_dentry_ptr d;
+
+	dentry_blk = inline_data_addr(ipage);
+
+	make_dentry_ptr(&d, (void *)dentry_blk, 2);
+	do_make_empty_dir(inode, parent, &d);
+
+	set_page_dirty(ipage);
+
+	/* update i_size to MAX_INLINE_DATA */
+	if (i_size_read(inode) < MAX_INLINE_DATA) {
+		i_size_write(inode, MAX_INLINE_DATA);
+		set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
+	}
+	return 0;
+}
+
+static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
+				struct f2fs_inline_dentry *inline_dentry)
+{
+	struct page *page;
+	struct dnode_of_data dn;
+	struct f2fs_dentry_block *dentry_blk;
+	int err;
+
+	page = grab_cache_page(dir->i_mapping, 0);
+	if (!page)
+		return -ENOMEM;
+
+	set_new_dnode(&dn, dir, ipage, NULL, 0);
+	err = f2fs_reserve_block(&dn, 0);
+	if (err)
+		goto out;
+
+	f2fs_wait_on_page_writeback(page, DATA);
+	zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+
+	dentry_blk = kmap_atomic(page);
+
+	/* copy data from inline dentry block to new dentry block */
+	memcpy(dentry_blk->dentry_bitmap, inline_dentry->dentry_bitmap,
+					INLINE_DENTRY_BITMAP_SIZE);
+	memcpy(dentry_blk->dentry, inline_dentry->dentry,
+			sizeof(struct f2fs_dir_entry) * NR_INLINE_DENTRY);
+	memcpy(dentry_blk->filename, inline_dentry->filename,
+					NR_INLINE_DENTRY * F2FS_SLOT_LEN);
+
+	kunmap_atomic(dentry_blk);
+	SetPageUptodate(page);
+	set_page_dirty(page);
+
+	/* clear inline dir and flag after data writeback */
+	truncate_inline_inode(ipage, 0);
+
+	stat_dec_inline_dir(dir);
+	clear_inode_flag(F2FS_I(dir), FI_INLINE_DENTRY);
+
+	if (i_size_read(dir) < PAGE_CACHE_SIZE) {
+		i_size_write(dir, PAGE_CACHE_SIZE);
+		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
+
+	sync_inode_page(&dn);
+out:
+	f2fs_put_page(page, 1);
+	return err;
+}
+
+int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
+			struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct page *ipage;
+	unsigned int bit_pos;
+	f2fs_hash_t name_hash;
+	size_t namelen = name->len;
+	struct f2fs_inline_dentry *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
+	int slots = GET_DENTRY_SLOTS(namelen);
+	struct page *page = NULL;
+	int err = 0;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	dentry_blk = inline_data_addr(ipage);
+	bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
+						slots, NR_INLINE_DENTRY);
+	if (bit_pos >= NR_INLINE_DENTRY) {
+		err = f2fs_convert_inline_dir(dir, ipage, dentry_blk);
+		if (!err)
+			err = -EAGAIN;
+		goto out;
+	}
+
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, name, ipage);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
+	}
+
+	f2fs_wait_on_page_writeback(ipage, NODE);
+
+	name_hash = f2fs_dentry_hash(name);
+	make_dentry_ptr(&d, (void *)dentry_blk, 2);
+	f2fs_update_dentry(ino, mode, &d, name, name_hash, bit_pos);
+
+	set_page_dirty(ipage);
+
+	/* we don't need to mark_inode_dirty now */
+	if (inode) {
+		F2FS_I(inode)->i_pino = dir->i_ino;
+		update_inode(inode, page);
+		f2fs_put_page(page, 1);
+	}
+
+	update_parent_metadata(dir, inode, 0);
+fail:
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
+
+	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
+		update_inode(dir, ipage);
+		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
+out:
+	f2fs_put_page(ipage, 1);
+	return err;
+}
+
+void f2fs_delete_inline_entry(struct f2fs_dir_entry *dentry, struct page *page,
+					struct inode *dir, struct inode *inode)
+{
+	struct f2fs_inline_dentry *inline_dentry;
+	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
+	unsigned int bit_pos;
+	int i;
+
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, NODE);
+
+	inline_dentry = inline_data_addr(page);
+	bit_pos = dentry - inline_dentry->dentry;
+	for (i = 0; i < slots; i++)
+		test_and_clear_bit_le(bit_pos + i,
+				&inline_dentry->dentry_bitmap);
+
+	set_page_dirty(page);
+
+	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+
+	if (inode)
+		f2fs_drop_nlink(dir, inode, page);
+
+	f2fs_put_page(page, 1);
+}
+
+bool f2fs_empty_inline_dir(struct inode *dir)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct page *ipage;
+	unsigned int bit_pos = 2;
+	struct f2fs_inline_dentry *dentry_blk;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return false;
+
+	dentry_blk = inline_data_addr(ipage);
+	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+					NR_INLINE_DENTRY,
+					bit_pos);
+
+	f2fs_put_page(ipage, 1);
+
+	if (bit_pos < NR_INLINE_DENTRY)
+		return false;
+
+	return true;
+}
+
+int f2fs_read_inline_dir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct f2fs_inline_dentry *inline_dentry = NULL;
+	struct page *ipage = NULL;
+	struct f2fs_dentry_ptr d;
+
+	if (ctx->pos == NR_INLINE_DENTRY)
+		return 0;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	inline_dentry = inline_data_addr(ipage);
+
+	make_dentry_ptr(&d, (void *)inline_dentry, 2);
+
+	if (!f2fs_fill_dentries(ctx, &d, 0))
+		ctx->pos = NR_INLINE_DENTRY;
+
+	f2fs_put_page(ipage, 1);
+	return 0;
+}
diff --git a/kernel/fs/f2fs/inode.c b/kernel/fs/f2fs/inode.c
new file mode 100644
index 000000000..e622ec954
--- /dev/null
+++ b/kernel/fs/f2fs/inode.c
@@ -0,0 +1,387 @@
+/*
+ * fs/f2fs/inode.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/writeback.h>
+#include <linux/bitops.h>
+
+#include "f2fs.h"
+#include "node.h"
+
+#include <trace/events/f2fs.h>
+
+void f2fs_set_inode_flags(struct inode *inode)
+{
+	unsigned int flags = F2FS_I(inode)->i_flags;
+	unsigned int new_fl = 0;
+
+	if (flags & FS_SYNC_FL)
+		new_fl |= S_SYNC;
+	if (flags & FS_APPEND_FL)
+		new_fl |= S_APPEND;
+	if (flags & FS_IMMUTABLE_FL)
+		new_fl |= S_IMMUTABLE;
+	if (flags & FS_NOATIME_FL)
+		new_fl |= S_NOATIME;
+	if (flags & FS_DIRSYNC_FL)
+		new_fl |= S_DIRSYNC;
+	set_mask_bits(&inode->i_flags,
+			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC, new_fl);
+}
+
+static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
+{
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+		if (ri->i_addr[0])
+			inode->i_rdev =
+				old_decode_dev(le32_to_cpu(ri->i_addr[0]));
+		else
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(ri->i_addr[1]));
+	}
+}
+
+static bool __written_first_block(struct f2fs_inode *ri)
+{
+	block_t addr = le32_to_cpu(ri->i_addr[0]);
+
+	if (addr != NEW_ADDR && addr != NULL_ADDR)
+		return true;
+	return false;
+}
+
+static void __set_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
+{
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (old_valid_dev(inode->i_rdev)) {
+			ri->i_addr[0] =
+				cpu_to_le32(old_encode_dev(inode->i_rdev));
+			ri->i_addr[1] = 0;
+		} else {
+			ri->i_addr[0] = 0;
+			ri->i_addr[1] =
+				cpu_to_le32(new_encode_dev(inode->i_rdev));
+			ri->i_addr[2] = 0;
+		}
+	}
+}
+
+static void __recover_inline_status(struct inode *inode, struct page *ipage)
+{
+	void *inline_data = inline_data_addr(ipage);
+	__le32 *start = inline_data;
+	__le32 *end = start + MAX_INLINE_DATA / sizeof(__le32);
+
+	while (start < end) {
+		if (*start++) {
+			f2fs_wait_on_page_writeback(ipage, NODE);
+
+			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+			set_raw_inline(F2FS_I(inode), F2FS_INODE(ipage));
+			set_page_dirty(ipage);
+			return;
+		}
+	}
+	return;
+}
+
+static int do_read_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct page *node_page;
+	struct f2fs_inode *ri;
+
+	/* Check if ino is within scope */
+	if (check_nid_range(sbi, inode->i_ino)) {
+		f2fs_msg(inode->i_sb, KERN_ERR, "bad inode number: %lu",
+			 (unsigned long) inode->i_ino);
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	node_page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(node_page))
+		return PTR_ERR(node_page);
+
+	ri = F2FS_INODE(node_page);
+
+	inode->i_mode = le16_to_cpu(ri->i_mode);
+	i_uid_write(inode, le32_to_cpu(ri->i_uid));
+	i_gid_write(inode, le32_to_cpu(ri->i_gid));
+	set_nlink(inode, le32_to_cpu(ri->i_links));
+	inode->i_size = le64_to_cpu(ri->i_size);
+	inode->i_blocks = le64_to_cpu(ri->i_blocks);
+
+	inode->i_atime.tv_sec = le64_to_cpu(ri->i_atime);
+	inode->i_ctime.tv_sec = le64_to_cpu(ri->i_ctime);
+	inode->i_mtime.tv_sec = le64_to_cpu(ri->i_mtime);
+	inode->i_atime.tv_nsec = le32_to_cpu(ri->i_atime_nsec);
+	inode->i_ctime.tv_nsec = le32_to_cpu(ri->i_ctime_nsec);
+	inode->i_mtime.tv_nsec = le32_to_cpu(ri->i_mtime_nsec);
+	inode->i_generation = le32_to_cpu(ri->i_generation);
+
+	fi->i_current_depth = le32_to_cpu(ri->i_current_depth);
+	fi->i_xattr_nid = le32_to_cpu(ri->i_xattr_nid);
+	fi->i_flags = le32_to_cpu(ri->i_flags);
+	fi->flags = 0;
+	fi->i_advise = ri->i_advise;
+	fi->i_pino = le32_to_cpu(ri->i_pino);
+	fi->i_dir_level = ri->i_dir_level;
+
+	f2fs_init_extent_cache(inode, &ri->i_ext);
+
+	get_inline_info(fi, ri);
+
+	/* check data exist */
+	if (f2fs_has_inline_data(inode) && !f2fs_exist_data(inode))
+		__recover_inline_status(inode, node_page);
+
+	/* get rdev by using inline_info */
+	__get_inode_rdev(inode, ri);
+
+	if (__written_first_block(ri))
+		set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+
+	f2fs_put_page(node_page, 1);
+
+	stat_inc_inline_inode(inode);
+	stat_inc_inline_dir(inode);
+
+	return 0;
+}
+
+struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct inode *inode;
+	int ret = 0;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (!(inode->i_state & I_NEW)) {
+		trace_f2fs_iget(inode);
+		return inode;
+	}
+	if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
+		goto make_now;
+
+	ret = do_read_inode(inode);
+	if (ret)
+		goto bad_inode;
+make_now:
+	if (ino == F2FS_NODE_INO(sbi)) {
+		inode->i_mapping->a_ops = &f2fs_node_aops;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
+	} else if (ino == F2FS_META_INO(sbi)) {
+		inode->i_mapping->a_ops = &f2fs_meta_aops;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
+	} else if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &f2fs_file_inode_operations;
+		inode->i_fop = &f2fs_file_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &f2fs_dir_inode_operations;
+		inode->i_fop = &f2fs_dir_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
+	} else if (S_ISLNK(inode->i_mode)) {
+		inode->i_op = &f2fs_symlink_inode_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+		inode->i_op = &f2fs_special_inode_operations;
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+	} else {
+		ret = -EIO;
+		goto bad_inode;
+	}
+	unlock_new_inode(inode);
+	trace_f2fs_iget(inode);
+	return inode;
+
+bad_inode:
+	iget_failed(inode);
+	trace_f2fs_iget_exit(inode, ret);
+	return ERR_PTR(ret);
+}
+
+void update_inode(struct inode *inode, struct page *node_page)
+{
+	struct f2fs_inode *ri;
+
+	f2fs_wait_on_page_writeback(node_page, NODE);
+
+	ri = F2FS_INODE(node_page);
+
+	ri->i_mode = cpu_to_le16(inode->i_mode);
+	ri->i_advise = F2FS_I(inode)->i_advise;
+	ri->i_uid = cpu_to_le32(i_uid_read(inode));
+	ri->i_gid = cpu_to_le32(i_gid_read(inode));
+	ri->i_links = cpu_to_le32(inode->i_nlink);
+	ri->i_size = cpu_to_le64(i_size_read(inode));
+	ri->i_blocks = cpu_to_le64(inode->i_blocks);
+
+	read_lock(&F2FS_I(inode)->ext_lock);
+	set_raw_extent(&F2FS_I(inode)->ext, &ri->i_ext);
+	read_unlock(&F2FS_I(inode)->ext_lock);
+
+	set_raw_inline(F2FS_I(inode), ri);
+
+	ri->i_atime = cpu_to_le64(inode->i_atime.tv_sec);
+	ri->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
+	ri->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
+	ri->i_atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
+	ri->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+	ri->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
+	ri->i_current_depth = cpu_to_le32(F2FS_I(inode)->i_current_depth);
+	ri->i_xattr_nid = cpu_to_le32(F2FS_I(inode)->i_xattr_nid);
+	ri->i_flags = cpu_to_le32(F2FS_I(inode)->i_flags);
+	ri->i_pino = cpu_to_le32(F2FS_I(inode)->i_pino);
+	ri->i_generation = cpu_to_le32(inode->i_generation);
+	ri->i_dir_level = F2FS_I(inode)->i_dir_level;
+
+	__set_inode_rdev(inode, ri);
+	set_cold_node(inode, node_page);
+	set_page_dirty(node_page);
+
+	clear_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
+}
+
+void update_inode_page(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *node_page;
+retry:
+	node_page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(node_page)) {
+		int err = PTR_ERR(node_page);
+		if (err == -ENOMEM) {
+			cond_resched();
+			goto retry;
+		} else if (err != -ENOENT) {
+			f2fs_stop_checkpoint(sbi);
+		}
+		return;
+	}
+	update_inode(inode, node_page);
+	f2fs_put_page(node_page, 1);
+}
+
+int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
+			inode->i_ino == F2FS_META_INO(sbi))
+		return 0;
+
+	if (!is_inode_flag_set(F2FS_I(inode), FI_DIRTY_INODE))
+		return 0;
+
+	/*
+	 * We need to lock here to prevent from producing dirty node pages
+	 * during the urgent cleaning time when runing out of free sections.
+	 */
+	f2fs_lock_op(sbi);
+	update_inode_page(inode);
+	f2fs_unlock_op(sbi);
+
+	if (wbc)
+		f2fs_balance_fs(sbi);
+
+	return 0;
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero
+ */
+void f2fs_evict_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+
+	/* some remained atomic pages should discarded */
+	if (f2fs_is_atomic_file(inode))
+		commit_inmem_pages(inode, true);
+
+	trace_f2fs_evict_inode(inode);
+	truncate_inode_pages_final(&inode->i_data);
+
+	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
+			inode->i_ino == F2FS_META_INO(sbi))
+		goto out_clear;
+
+	f2fs_bug_on(sbi, get_dirty_pages(inode));
+	remove_dirty_dir_inode(inode);
+
+	if (inode->i_nlink || is_bad_inode(inode))
+		goto no_delete;
+
+	sb_start_intwrite(inode->i_sb);
+	set_inode_flag(F2FS_I(inode), FI_NO_ALLOC);
+	i_size_write(inode, 0);
+
+	if (F2FS_HAS_BLOCKS(inode))
+		f2fs_truncate(inode);
+
+	f2fs_lock_op(sbi);
+	remove_inode_page(inode);
+	f2fs_unlock_op(sbi);
+
+	sb_end_intwrite(inode->i_sb);
+no_delete:
+	stat_dec_inline_dir(inode);
+	stat_dec_inline_inode(inode);
+
+	/* update extent info in inode */
+	if (inode->i_nlink)
+		f2fs_preserve_extent_tree(inode);
+	f2fs_destroy_extent_tree(inode);
+
+	invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino);
+	if (xnid)
+		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
+	if (is_inode_flag_set(F2FS_I(inode), FI_APPEND_WRITE))
+		add_dirty_inode(sbi, inode->i_ino, APPEND_INO);
+	if (is_inode_flag_set(F2FS_I(inode), FI_UPDATE_WRITE))
+		add_dirty_inode(sbi, inode->i_ino, UPDATE_INO);
+out_clear:
+	clear_inode(inode);
+}
+
+/* caller should call f2fs_lock_op() */
+void handle_failed_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	clear_nlink(inode);
+	make_bad_inode(inode);
+	unlock_new_inode(inode);
+
+	i_size_write(inode, 0);
+	if (F2FS_HAS_BLOCKS(inode))
+		f2fs_truncate(inode);
+
+	remove_inode_page(inode);
+
+	clear_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+	clear_inode_flag(F2FS_I(inode), FI_INLINE_DENTRY);
+	alloc_nid_failed(sbi, inode->i_ino);
+	f2fs_unlock_op(sbi);
+
+	/* iput will drop the inode object */
+	iput(inode);
+}
diff --git a/kernel/fs/f2fs/namei.c b/kernel/fs/f2fs/namei.c
new file mode 100644
index 000000000..658e8079a
--- /dev/null
+++ b/kernel/fs/f2fs/namei.c
@@ -0,0 +1,832 @@
+/*
+ * fs/f2fs/namei.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/ctype.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "xattr.h"
+#include "acl.h"
+#include <trace/events/f2fs.h>
+
+static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	nid_t ino;
+	struct inode *inode;
+	bool nid_free = false;
+	int err;
+
+	inode = new_inode(dir->i_sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	f2fs_lock_op(sbi);
+	if (!alloc_nid(sbi, &ino)) {
+		f2fs_unlock_op(sbi);
+		err = -ENOSPC;
+		goto fail;
+	}
+	f2fs_unlock_op(sbi);
+
+	inode_init_owner(inode, dir, mode);
+
+	inode->i_ino = ino;
+	inode->i_blocks = 0;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	inode->i_generation = sbi->s_next_generation++;
+
+	err = insert_inode_locked(inode);
+	if (err) {
+		err = -EINVAL;
+		nid_free = true;
+		goto out;
+	}
+
+	if (f2fs_may_inline(inode))
+		set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+	if (test_opt(sbi, INLINE_DENTRY) && S_ISDIR(inode->i_mode))
+		set_inode_flag(F2FS_I(inode), FI_INLINE_DENTRY);
+
+	trace_f2fs_new_inode(inode, 0);
+	mark_inode_dirty(inode);
+	return inode;
+
+out:
+	clear_nlink(inode);
+	unlock_new_inode(inode);
+fail:
+	trace_f2fs_new_inode(inode, err);
+	make_bad_inode(inode);
+	iput(inode);
+	if (nid_free)
+		alloc_nid_failed(sbi, ino);
+	return ERR_PTR(err);
+}
+
+static int is_multimedia_file(const unsigned char *s, const char *sub)
+{
+	size_t slen = strlen(s);
+	size_t sublen = strlen(sub);
+
+	if (sublen > slen)
+		return 0;
+
+	return !strncasecmp(s + slen - sublen, sub, sublen);
+}
+
+/*
+ * Set multimedia files as cold files for hot/cold data separation
+ */
+static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
+		const unsigned char *name)
+{
+	int i;
+	__u8 (*extlist)[8] = sbi->raw_super->extension_list;
+
+	int count = le32_to_cpu(sbi->raw_super->extension_count);
+	for (i = 0; i < count; i++) {
+		if (is_multimedia_file(name, extlist[i])) {
+			file_set_cold(inode);
+			break;
+		}
+	}
+}
+
+static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+						bool excl)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	nid_t ino = 0;
+	int err;
+
+	f2fs_balance_fs(sbi);
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
+		set_cold_files(sbi, inode, dentry->d_name.name);
+
+	inode->i_op = &f2fs_file_inode_operations;
+	inode->i_fop = &f2fs_file_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	ino = inode->i_ino;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, ino);
+
+	stat_inc_inline_inode(inode);
+	d_instantiate(dentry, inode);
+	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
+		struct dentry *dentry)
+{
+	struct inode *inode = d_inode(old_dentry);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	int err;
+
+	f2fs_balance_fs(sbi);
+
+	inode->i_ctime = CURRENT_TIME;
+	ihold(inode);
+
+	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	d_instantiate(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out:
+	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
+	iput(inode);
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
+struct dentry *f2fs_get_parent(struct dentry *child)
+{
+	struct qstr dotdot = QSTR_INIT("..", 2);
+	unsigned long ino = f2fs_inode_by_name(d_inode(child), &dotdot);
+	if (!ino)
+		return ERR_PTR(-ENOENT);
+	return d_obtain_alias(f2fs_iget(d_inode(child)->i_sb, ino));
+}
+
+static int __recover_dot_dentries(struct inode *dir, nid_t pino)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct qstr dot = QSTR_INIT(".", 1);
+	struct qstr dotdot = QSTR_INIT("..", 2);
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	int err = 0;
+
+	f2fs_lock_op(sbi);
+
+	de = f2fs_find_entry(dir, &dot, &page);
+	if (de) {
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+	} else {
+		err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
+		if (err)
+			goto out;
+	}
+
+	de = f2fs_find_entry(dir, &dotdot, &page);
+	if (de) {
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+	} else {
+		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
+	}
+out:
+	if (!err) {
+		clear_inode_flag(F2FS_I(dir), FI_INLINE_DOTS);
+		mark_inode_dirty(dir);
+	}
+
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
+static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
+		unsigned int flags)
+{
+	struct inode *inode = NULL;
+	struct f2fs_dir_entry *de;
+	struct page *page;
+
+	if (dentry->d_name.len > F2FS_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	de = f2fs_find_entry(dir, &dentry->d_name, &page);
+	if (de) {
+		nid_t ino = le32_to_cpu(de->ino);
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+
+		inode = f2fs_iget(dir->i_sb, ino);
+		if (IS_ERR(inode))
+			return ERR_CAST(inode);
+
+		if (f2fs_has_inline_dots(inode)) {
+			int err;
+
+			err = __recover_dot_dentries(inode, dir->i_ino);
+			if (err) {
+				iget_failed(inode);
+				return ERR_PTR(err);
+			}
+		}
+	}
+
+	return d_splice_alias(inode, dentry);
+}
+
+static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode = d_inode(dentry);
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	int err = -ENOENT;
+
+	trace_f2fs_unlink_enter(dir, dentry);
+	f2fs_balance_fs(sbi);
+
+	de = f2fs_find_entry(dir, &dentry->d_name, &page);
+	if (!de)
+		goto fail;
+
+	f2fs_lock_op(sbi);
+	err = acquire_orphan_inode(sbi);
+	if (err) {
+		f2fs_unlock_op(sbi);
+		f2fs_dentry_kunmap(dir, page);
+		f2fs_put_page(page, 0);
+		goto fail;
+	}
+	f2fs_delete_entry(de, page, dir, inode);
+	f2fs_unlock_op(sbi);
+
+	/* In order to evict this inode, we set it dirty */
+	mark_inode_dirty(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+fail:
+	trace_f2fs_unlink_exit(inode, err);
+	return err;
+}
+
+static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct page *page = page_follow_link_light(dentry, nd);
+
+	if (IS_ERR_OR_NULL(page))
+		return page;
+
+	/* this is broken symlink case */
+	if (*nd_get_link(nd) == 0) {
+		page_put_link(dentry, nd, page);
+		return ERR_PTR(-ENOENT);
+	}
+	return page;
+}
+
+static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
+					const char *symname)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	size_t symlen = strlen(symname) + 1;
+	int err;
+
+	f2fs_balance_fs(sbi);
+
+	inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = &f2fs_symlink_inode_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	err = page_symlink(inode, symname, symlen);
+	alloc_nid_done(sbi, inode->i_ino);
+
+	d_instantiate(dentry, inode);
+	unlock_new_inode(inode);
+
+	/*
+	 * Let's flush symlink data in order to avoid broken symlink as much as
+	 * possible. Nevertheless, fsyncing is the best way, but there is no
+	 * way to get a file descriptor in order to flush that.
+	 *
+	 * Note that, it needs to do dir->fsync to make this recoverable.
+	 * If the symlink path is stored into inline_data, there is no
+	 * performance regression.
+	 */
+	filemap_write_and_wait_range(inode->i_mapping, 0, symlen - 1);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return err;
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err;
+
+	f2fs_balance_fs(sbi);
+
+	inode = f2fs_new_inode(dir, S_IFDIR | mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = &f2fs_dir_inode_operations;
+	inode->i_fop = &f2fs_dir_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
+
+	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out_fail;
+	f2fs_unlock_op(sbi);
+
+	stat_inc_inline_dir(inode);
+	alloc_nid_done(sbi, inode->i_ino);
+
+	d_instantiate(dentry, inode);
+	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+
+out_fail:
+	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+	if (f2fs_empty_dir(inode))
+		return f2fs_unlink(dir, dentry);
+	return -ENOTEMPTY;
+}
+
+static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
+				umode_t mode, dev_t rdev)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err = 0;
+
+	if (!new_valid_dev(rdev))
+		return -EINVAL;
+
+	f2fs_balance_fs(sbi);
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	init_special_inode(inode, inode->i_mode, rdev);
+	inode->i_op = &f2fs_special_inode_operations;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, inode->i_ino);
+
+	d_instantiate(dentry, inode);
+	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct page *old_dir_page;
+	struct page *old_page, *new_page;
+	struct f2fs_dir_entry *old_dir_entry = NULL;
+	struct f2fs_dir_entry *old_entry;
+	struct f2fs_dir_entry *new_entry;
+	int err = -ENOENT;
+
+	f2fs_balance_fs(sbi);
+
+	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
+	if (!old_entry)
+		goto out;
+
+	if (S_ISDIR(old_inode->i_mode)) {
+		err = -EIO;
+		old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
+		if (!old_dir_entry)
+			goto out_old;
+	}
+
+	if (new_inode) {
+
+		err = -ENOTEMPTY;
+		if (old_dir_entry && !f2fs_empty_dir(new_inode))
+			goto out_dir;
+
+		err = -ENOENT;
+		new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
+						&new_page);
+		if (!new_entry)
+			goto out_dir;
+
+		f2fs_lock_op(sbi);
+
+		err = acquire_orphan_inode(sbi);
+		if (err)
+			goto put_out_dir;
+
+		if (update_dent_inode(old_inode, &new_dentry->d_name)) {
+			release_orphan_inode(sbi);
+			goto put_out_dir;
+		}
+
+		f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+
+		new_inode->i_ctime = CURRENT_TIME;
+		down_write(&F2FS_I(new_inode)->i_sem);
+		if (old_dir_entry)
+			drop_nlink(new_inode);
+		drop_nlink(new_inode);
+		up_write(&F2FS_I(new_inode)->i_sem);
+
+		mark_inode_dirty(new_inode);
+
+		if (!new_inode->i_nlink)
+			add_orphan_inode(sbi, new_inode->i_ino);
+		else
+			release_orphan_inode(sbi);
+
+		update_inode_page(old_inode);
+		update_inode_page(new_inode);
+	} else {
+		f2fs_lock_op(sbi);
+
+		err = f2fs_add_link(new_dentry, old_inode);
+		if (err) {
+			f2fs_unlock_op(sbi);
+			goto out_dir;
+		}
+
+		if (old_dir_entry) {
+			inc_nlink(new_dir);
+			update_inode_page(new_dir);
+		}
+	}
+
+	down_write(&F2FS_I(old_inode)->i_sem);
+	file_lost_pino(old_inode);
+	up_write(&F2FS_I(old_inode)->i_sem);
+
+	old_inode->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(old_inode);
+
+	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);
+
+	if (old_dir_entry) {
+		if (old_dir != new_dir) {
+			f2fs_set_link(old_inode, old_dir_entry,
+						old_dir_page, new_dir);
+			update_inode_page(old_inode);
+		} else {
+			f2fs_dentry_kunmap(old_inode, old_dir_page);
+			f2fs_put_page(old_dir_page, 0);
+		}
+		drop_nlink(old_dir);
+		mark_inode_dirty(old_dir);
+		update_inode_page(old_dir);
+	}
+
+	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+
+put_out_dir:
+	f2fs_unlock_op(sbi);
+	f2fs_dentry_kunmap(new_dir, new_page);
+	f2fs_put_page(new_page, 0);
+out_dir:
+	if (old_dir_entry) {
+		f2fs_dentry_kunmap(old_inode, old_dir_page);
+		f2fs_put_page(old_dir_page, 0);
+	}
+out_old:
+	f2fs_dentry_kunmap(old_dir, old_page);
+	f2fs_put_page(old_page, 0);
+out:
+	return err;
+}
+
+static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
+			     struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct page *old_dir_page, *new_dir_page;
+	struct page *old_page, *new_page;
+	struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
+	struct f2fs_dir_entry *old_entry, *new_entry;
+	int old_nlink = 0, new_nlink = 0;
+	int err = -ENOENT;
+
+	f2fs_balance_fs(sbi);
+
+	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
+	if (!old_entry)
+		goto out;
+
+	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
+	if (!new_entry)
+		goto out_old;
+
+	/* prepare for updating ".." directory entry info later */
+	if (old_dir != new_dir) {
+		if (S_ISDIR(old_inode->i_mode)) {
+			err = -EIO;
+			old_dir_entry = f2fs_parent_dir(old_inode,
+							&old_dir_page);
+			if (!old_dir_entry)
+				goto out_new;
+		}
+
+		if (S_ISDIR(new_inode->i_mode)) {
+			err = -EIO;
+			new_dir_entry = f2fs_parent_dir(new_inode,
+							&new_dir_page);
+			if (!new_dir_entry)
+				goto out_old_dir;
+		}
+	}
+
+	/*
+	 * If cross rename between file and directory those are not
+	 * in the same directory, we will inc nlink of file's parent
+	 * later, so we should check upper boundary of its nlink.
+	 */
+	if ((!old_dir_entry || !new_dir_entry) &&
+				old_dir_entry != new_dir_entry) {
+		old_nlink = old_dir_entry ? -1 : 1;
+		new_nlink = -old_nlink;
+		err = -EMLINK;
+		if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) ||
+			(new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
+			goto out_new_dir;
+	}
+
+	f2fs_lock_op(sbi);
+
+	err = update_dent_inode(old_inode, &new_dentry->d_name);
+	if (err)
+		goto out_unlock;
+
+	err = update_dent_inode(new_inode, &old_dentry->d_name);
+	if (err)
+		goto out_undo;
+
+	/* update ".." directory entry info of old dentry */
+	if (old_dir_entry)
+		f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);
+
+	/* update ".." directory entry info of new dentry */
+	if (new_dir_entry)
+		f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);
+
+	/* update directory entry info of old dir inode */
+	f2fs_set_link(old_dir, old_entry, old_page, new_inode);
+
+	down_write(&F2FS_I(old_inode)->i_sem);
+	file_lost_pino(old_inode);
+	up_write(&F2FS_I(old_inode)->i_sem);
+
+	update_inode_page(old_inode);
+
+	old_dir->i_ctime = CURRENT_TIME;
+	if (old_nlink) {
+		down_write(&F2FS_I(old_dir)->i_sem);
+		if (old_nlink < 0)
+			drop_nlink(old_dir);
+		else
+			inc_nlink(old_dir);
+		up_write(&F2FS_I(old_dir)->i_sem);
+	}
+	mark_inode_dirty(old_dir);
+	update_inode_page(old_dir);
+
+	/* update directory entry info of new dir inode */
+	f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+
+	down_write(&F2FS_I(new_inode)->i_sem);
+	file_lost_pino(new_inode);
+	up_write(&F2FS_I(new_inode)->i_sem);
+
+	update_inode_page(new_inode);
+
+	new_dir->i_ctime = CURRENT_TIME;
+	if (new_nlink) {
+		down_write(&F2FS_I(new_dir)->i_sem);
+		if (new_nlink < 0)
+			drop_nlink(new_dir);
+		else
+			inc_nlink(new_dir);
+		up_write(&F2FS_I(new_dir)->i_sem);
+	}
+	mark_inode_dirty(new_dir);
+	update_inode_page(new_dir);
+
+	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out_undo:
+	/* Still we may fail to recover name info of f2fs_inode here */
+	update_dent_inode(old_inode, &old_dentry->d_name);
+out_unlock:
+	f2fs_unlock_op(sbi);
+out_new_dir:
+	if (new_dir_entry) {
+		f2fs_dentry_kunmap(new_inode, new_dir_page);
+		f2fs_put_page(new_dir_page, 0);
+	}
+out_old_dir:
+	if (old_dir_entry) {
+		f2fs_dentry_kunmap(old_inode, old_dir_page);
+		f2fs_put_page(old_dir_page, 0);
+	}
+out_new:
+	f2fs_dentry_kunmap(new_dir, new_page);
+	f2fs_put_page(new_page, 0);
+out_old:
+	f2fs_dentry_kunmap(old_dir, old_page);
+	f2fs_put_page(old_page, 0);
+out:
+	return err;
+}
+
+static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	if (flags & RENAME_EXCHANGE) {
+		return f2fs_cross_rename(old_dir, old_dentry,
+					 new_dir, new_dentry);
+	}
+	/*
+	 * VFS has already handled the new dentry existence case,
+	 * here, we just deal with "RENAME_NOREPLACE" as regular rename.
+	 */
+	return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err;
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = &f2fs_file_inode_operations;
+	inode->i_fop = &f2fs_file_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+
+	f2fs_lock_op(sbi);
+	err = acquire_orphan_inode(sbi);
+	if (err)
+		goto out;
+
+	err = f2fs_do_tmpfile(inode, dir);
+	if (err)
+		goto release_out;
+
+	/*
+	 * add this non-linked tmpfile to orphan list, in this way we could
+	 * remove all unused data of tmpfile after abnormal power-off.
+	 */
+	add_orphan_inode(sbi, inode->i_ino);
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, inode->i_ino);
+
+	stat_inc_inline_inode(inode);
+	d_tmpfile(dentry, inode);
+	unlock_new_inode(inode);
+	return 0;
+
+release_out:
+	release_orphan_inode(sbi);
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+const struct inode_operations f2fs_dir_inode_operations = {
+	.create		= f2fs_create,
+	.lookup		= f2fs_lookup,
+	.link		= f2fs_link,
+	.unlink		= f2fs_unlink,
+	.symlink	= f2fs_symlink,
+	.mkdir		= f2fs_mkdir,
+	.rmdir		= f2fs_rmdir,
+	.mknod		= f2fs_mknod,
+	.rename2	= f2fs_rename2,
+	.tmpfile	= f2fs_tmpfile,
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= f2fs_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+};
+
+const struct inode_operations f2fs_symlink_inode_operations = {
+	.readlink       = generic_readlink,
+	.follow_link    = f2fs_follow_link,
+	.put_link       = page_put_link,
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= f2fs_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+};
+
+const struct inode_operations f2fs_special_inode_operations = {
+	.getattr	= f2fs_getattr,
+	.setattr        = f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.setxattr       = generic_setxattr,
+	.getxattr       = generic_getxattr,
+	.listxattr	= f2fs_listxattr,
+	.removexattr    = generic_removexattr,
+#endif
+};
diff --git a/kernel/fs/f2fs/node.c b/kernel/fs/f2fs/node.c
new file mode 100644
index 000000000..8ab0cf193
--- /dev/null
+++ b/kernel/fs/f2fs/node.c
@@ -0,0 +1,2084 @@
+/*
+ * fs/f2fs/node.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/mpage.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+#define on_build_free_nids(nmi) mutex_is_locked(&nm_i->build_lock)
+
+static struct kmem_cache *nat_entry_slab;
+static struct kmem_cache *free_nid_slab;
+static struct kmem_cache *nat_entry_set_slab;
+
+bool available_free_memory(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct sysinfo val;
+	unsigned long avail_ram;
+	unsigned long mem_size = 0;
+	bool res = false;
+
+	si_meminfo(&val);
+
+	/* only uses low memory */
+	avail_ram = val.totalram - val.totalhigh;
+
+	/*
+	 * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
+	 */
+	if (type == FREE_NIDS) {
+		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >>
+							PAGE_CACHE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+	} else if (type == NAT_ENTRIES) {
+		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
+							PAGE_CACHE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+	} else if (type == DIRTY_DENTS) {
+		if (sbi->sb->s_bdi->dirty_exceeded)
+			return false;
+		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == INO_ENTRIES) {
+		int i;
+
+		for (i = 0; i <= UPDATE_INO; i++)
+			mem_size += (sbi->im[i].ino_num *
+				sizeof(struct ino_entry)) >> PAGE_CACHE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == EXTENT_CACHE) {
+		mem_size = (sbi->total_ext_tree * sizeof(struct extent_tree) +
+				atomic_read(&sbi->total_ext_node) *
+				sizeof(struct extent_node)) >> PAGE_CACHE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else {
+		if (sbi->sb->s_bdi->dirty_exceeded)
+			return false;
+	}
+	return res;
+}
+
+static void clear_node_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	unsigned int long flags;
+
+	if (PageDirty(page)) {
+		spin_lock_irqsave(&mapping->tree_lock, flags);
+		radix_tree_tag_clear(&mapping->page_tree,
+				page_index(page),
+				PAGECACHE_TAG_DIRTY);
+		spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+		clear_page_dirty_for_io(page);
+		dec_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_NODES);
+	}
+	ClearPageUptodate(page);
+}
+
+static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	pgoff_t index = current_nat_addr(sbi, nid);
+	return get_meta_page(sbi, index);
+}
+
+static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *src_page;
+	struct page *dst_page;
+	pgoff_t src_off;
+	pgoff_t dst_off;
+	void *src_addr;
+	void *dst_addr;
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	src_off = current_nat_addr(sbi, nid);
+	dst_off = next_nat_addr(sbi, src_off);
+
+	/* get current nat block page with lock */
+	src_page = get_meta_page(sbi, src_off);
+	dst_page = grab_meta_page(sbi, dst_off);
+	f2fs_bug_on(sbi, PageDirty(src_page));
+
+	src_addr = page_address(src_page);
+	dst_addr = page_address(dst_page);
+	memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
+	set_page_dirty(dst_page);
+	f2fs_put_page(src_page, 1);
+
+	set_to_next_nat(nm_i, nid);
+
+	return dst_page;
+}
+
+static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
+{
+	return radix_tree_lookup(&nm_i->nat_root, n);
+}
+
+static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
+}
+
+static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
+{
+	list_del(&e->list);
+	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
+	nm_i->nat_cnt--;
+	kmem_cache_free(nat_entry_slab, e);
+}
+
+static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+						struct nat_entry *ne)
+{
+	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
+	struct nat_entry_set *head;
+
+	if (get_nat_flag(ne, IS_DIRTY))
+		return;
+
+	head = radix_tree_lookup(&nm_i->nat_set_root, set);
+	if (!head) {
+		head = f2fs_kmem_cache_alloc(nat_entry_set_slab, GFP_ATOMIC);
+
+		INIT_LIST_HEAD(&head->entry_list);
+		INIT_LIST_HEAD(&head->set_list);
+		head->set = set;
+		head->entry_cnt = 0;
+		f2fs_radix_tree_insert(&nm_i->nat_set_root, set, head);
+	}
+	list_move_tail(&ne->list, &head->entry_list);
+	nm_i->dirty_nat_cnt++;
+	head->entry_cnt++;
+	set_nat_flag(ne, IS_DIRTY, true);
+}
+
+static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+						struct nat_entry *ne)
+{
+	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
+	struct nat_entry_set *head;
+
+	head = radix_tree_lookup(&nm_i->nat_set_root, set);
+	if (head) {
+		list_move_tail(&ne->list, &nm_i->nat_entries);
+		set_nat_flag(ne, IS_DIRTY, false);
+		head->entry_cnt--;
+		nm_i->dirty_nat_cnt--;
+	}
+}
+
+static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry_set **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_set_root, (void **)ep,
+							start, nr);
+}
+
+bool is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool is_cp = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
+		is_cp = false;
+	up_read(&nm_i->nat_tree_lock);
+	return is_cp;
+}
+
+bool has_fsynced_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool fsynced = false;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_FSYNCED_INODE))
+		fsynced = true;
+	up_read(&nm_i->nat_tree_lock);
+	return fsynced;
+}
+
+bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool need_update = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
+			(get_nat_flag(e, IS_CHECKPOINTED) ||
+			 get_nat_flag(e, HAS_FSYNCED_INODE)))
+		need_update = false;
+	up_read(&nm_i->nat_tree_lock);
+	return need_update;
+}
+
+static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
+{
+	struct nat_entry *new;
+
+	new = f2fs_kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
+	f2fs_radix_tree_insert(&nm_i->nat_root, nid, new);
+	memset(new, 0, sizeof(struct nat_entry));
+	nat_set_nid(new, nid);
+	nat_reset_flag(new);
+	list_add_tail(&new->list, &nm_i->nat_entries);
+	nm_i->nat_cnt++;
+	return new;
+}
+
+static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
+						struct f2fs_nat_entry *ne)
+{
+	struct nat_entry *e;
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (!e) {
+		e = grab_nat_entry(nm_i, nid);
+		node_info_from_raw_nat(&e->ni, ne);
+	}
+	up_write(&nm_i->nat_tree_lock);
+}
+
+static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
+			block_t new_blkaddr, bool fsync_done)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ni->nid);
+	if (!e) {
+		e = grab_nat_entry(nm_i, ni->nid);
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
+	} else if (new_blkaddr == NEW_ADDR) {
+		/*
+		 * when nid is reallocated,
+		 * previous nat entry can be remained in nat cache.
+		 * So, reinitialize it with new information.
+		 */
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
+	}
+
+	/* sanity check */
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NULL_ADDR &&
+			new_blkaddr == NULL_ADDR);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NEW_ADDR &&
+			new_blkaddr == NEW_ADDR);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) != NEW_ADDR &&
+			nat_get_blkaddr(e) != NULL_ADDR &&
+			new_blkaddr == NEW_ADDR);
+
+	/* increment version no as node is removed */
+	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
+		unsigned char version = nat_get_version(e);
+		nat_set_version(e, inc_node_version(version));
+	}
+
+	/* change address */
+	nat_set_blkaddr(e, new_blkaddr);
+	if (new_blkaddr == NEW_ADDR || new_blkaddr == NULL_ADDR)
+		set_nat_flag(e, IS_CHECKPOINTED, false);
+	__set_nat_cache_dirty(nm_i, e);
+
+	/* update fsync_mark if its inode nat entry is still alive */
+	e = __lookup_nat_cache(nm_i, ni->ino);
+	if (e) {
+		if (fsync_done && ni->nid == ni->ino)
+			set_nat_flag(e, HAS_FSYNCED_INODE, true);
+		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
+	}
+	up_write(&nm_i->nat_tree_lock);
+}
+
+int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	if (available_free_memory(sbi, NAT_ENTRIES))
+		return 0;
+
+	down_write(&nm_i->nat_tree_lock);
+	while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
+		struct nat_entry *ne;
+		ne = list_first_entry(&nm_i->nat_entries,
+					struct nat_entry, list);
+		__del_from_nat_cache(nm_i, ne);
+		nr_shrink--;
+	}
+	up_write(&nm_i->nat_tree_lock);
+	return nr_shrink;
+}
+
+/*
+ * This function always returns success
+ */
+void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	nid_t start_nid = START_NID(nid);
+	struct f2fs_nat_block *nat_blk;
+	struct page *page = NULL;
+	struct f2fs_nat_entry ne;
+	struct nat_entry *e;
+	int i;
+
+	ni->nid = nid;
+
+	/* Check nat cache */
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e) {
+		ni->ino = nat_get_ino(e);
+		ni->blk_addr = nat_get_blkaddr(e);
+		ni->version = nat_get_version(e);
+	}
+	up_read(&nm_i->nat_tree_lock);
+	if (e)
+		return;
+
+	memset(&ne, 0, sizeof(struct f2fs_nat_entry));
+
+	/* Check current segment summary */
+	mutex_lock(&curseg->curseg_mutex);
+	i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
+	if (i >= 0) {
+		ne = nat_in_journal(sum, i);
+		node_info_from_raw_nat(ni, &ne);
+	}
+	mutex_unlock(&curseg->curseg_mutex);
+	if (i >= 0)
+		goto cache;
+
+	/* Fill node_info from nat page */
+	page = get_current_nat_page(sbi, start_nid);
+	nat_blk = (struct f2fs_nat_block *)page_address(page);
+	ne = nat_blk->entries[nid - start_nid];
+	node_info_from_raw_nat(ni, &ne);
+	f2fs_put_page(page, 1);
+cache:
+	/* cache nat entry */
+	cache_nat_entry(NM_I(sbi), nid, &ne);
+}
+
+/*
+ * The maximum depth is four.
+ * Offset[0] will have raw inode offset.
+ */
+static int get_node_path(struct f2fs_inode_info *fi, long block,
+				int offset[4], unsigned int noffset[4])
+{
+	const long direct_index = ADDRS_PER_INODE(fi);
+	const long direct_blks = ADDRS_PER_BLOCK;
+	const long dptrs_per_blk = NIDS_PER_BLOCK;
+	const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
+	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
+	int n = 0;
+	int level = 0;
+
+	noffset[0] = 0;
+
+	if (block < direct_index) {
+		offset[n] = block;
+		goto got;
+	}
+	block -= direct_index;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR1_BLOCK;
+		noffset[n] = 1;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR2_BLOCK;
+		noffset[n] = 2;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND1_BLOCK;
+		noffset[n] = 3;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 4 + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND2_BLOCK;
+		noffset[n] = 4 + dptrs_per_blk;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < dindirect_blks) {
+		offset[n++] = NODE_DIND_BLOCK;
+		noffset[n] = 5 + (dptrs_per_blk * 2);
+		offset[n++] = block / indirect_blks;
+		noffset[n] = 6 + (dptrs_per_blk * 2) +
+			      offset[n - 1] * (dptrs_per_blk + 1);
+		offset[n++] = (block / direct_blks) % dptrs_per_blk;
+		noffset[n] = 7 + (dptrs_per_blk * 2) +
+			      offset[n - 2] * (dptrs_per_blk + 1) +
+			      offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 3;
+		goto got;
+	} else {
+		BUG();
+	}
+got:
+	return level;
+}
+
+/*
+ * Caller should call f2fs_put_dnode(dn).
+ * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op() only if ro is not set RDONLY_NODE.
+ * In the case of RDONLY_NODE, we don't need to care about mutex.
+ */
+int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct page *npage[4];
+	struct page *parent = NULL;
+	int offset[4];
+	unsigned int noffset[4];
+	nid_t nids[4];
+	int level, i;
+	int err = 0;
+
+	level = get_node_path(F2FS_I(dn->inode), index, offset, noffset);
+
+	nids[0] = dn->inode->i_ino;
+	npage[0] = dn->inode_page;
+
+	if (!npage[0]) {
+		npage[0] = get_node_page(sbi, nids[0]);
+		if (IS_ERR(npage[0]))
+			return PTR_ERR(npage[0]);
+	}
+
+	/* if inline_data is set, should not report any block indices */
+	if (f2fs_has_inline_data(dn->inode) && index) {
+		err = -ENOENT;
+		f2fs_put_page(npage[0], 1);
+		goto release_out;
+	}
+
+	parent = npage[0];
+	if (level != 0)
+		nids[1] = get_nid(parent, offset[0], true);
+	dn->inode_page = npage[0];
+	dn->inode_page_locked = true;
+
+	/* get indirect or direct nodes */
+	for (i = 1; i <= level; i++) {
+		bool done = false;
+
+		if (!nids[i] && mode == ALLOC_NODE) {
+			/* alloc new node */
+			if (!alloc_nid(sbi, &(nids[i]))) {
+				err = -ENOSPC;
+				goto release_pages;
+			}
+
+			dn->nid = nids[i];
+			npage[i] = new_node_page(dn, noffset[i], NULL);
+			if (IS_ERR(npage[i])) {
+				alloc_nid_failed(sbi, nids[i]);
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+
+			set_nid(parent, offset[i - 1], nids[i], i == 1);
+			alloc_nid_done(sbi, nids[i]);
+			done = true;
+		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
+			npage[i] = get_node_page_ra(parent, offset[i - 1]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+			done = true;
+		}
+		if (i == 1) {
+			dn->inode_page_locked = false;
+			unlock_page(parent);
+		} else {
+			f2fs_put_page(parent, 1);
+		}
+
+		if (!done) {
+			npage[i] = get_node_page(sbi, nids[i]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				f2fs_put_page(npage[0], 0);
+				goto release_out;
+			}
+		}
+		if (i < level) {
+			parent = npage[i];
+			nids[i + 1] = get_nid(parent, offset[i], false);
+		}
+	}
+	dn->nid = nids[level];
+	dn->ofs_in_node = offset[level];
+	dn->node_page = npage[level];
+	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
+	return 0;
+
+release_pages:
+	f2fs_put_page(parent, 1);
+	if (i > 1)
+		f2fs_put_page(npage[0], 0);
+release_out:
+	dn->inode_page = NULL;
+	dn->node_page = NULL;
+	return err;
+}
+
+static void truncate_node(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info ni;
+
+	get_node_info(sbi, dn->nid, &ni);
+	if (dn->inode->i_blocks == 0) {
+		f2fs_bug_on(sbi, ni.blk_addr != NULL_ADDR);
+		goto invalidate;
+	}
+	f2fs_bug_on(sbi, ni.blk_addr == NULL_ADDR);
+
+	/* Deallocate node address */
+	invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, dn->inode);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+	if (dn->nid == dn->inode->i_ino) {
+		remove_orphan_inode(sbi, dn->nid);
+		dec_valid_inode_count(sbi);
+	} else {
+		sync_inode_page(dn);
+	}
+invalidate:
+	clear_node_page_dirty(dn->node_page);
+	set_sbi_flag(sbi, SBI_IS_DIRTY);
+
+	f2fs_put_page(dn->node_page, 1);
+
+	invalidate_mapping_pages(NODE_MAPPING(sbi),
+			dn->node_page->index, dn->node_page->index);
+
+	dn->node_page = NULL;
+	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
+}
+
+static int truncate_dnode(struct dnode_of_data *dn)
+{
+	struct page *page;
+
+	if (dn->nid == 0)
+		return 1;
+
+	/* get direct node */
+	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
+		return 1;
+	else if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	/* Make dnode_of_data for parameter */
+	dn->node_page = page;
+	dn->ofs_in_node = 0;
+	truncate_data_blocks(dn);
+	truncate_node(dn);
+	return 1;
+}
+
+static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
+						int ofs, int depth)
+{
+	struct dnode_of_data rdn = *dn;
+	struct page *page;
+	struct f2fs_node *rn;
+	nid_t child_nid;
+	unsigned int child_nofs;
+	int freed = 0;
+	int i, ret;
+
+	if (dn->nid == 0)
+		return NIDS_PER_BLOCK + 1;
+
+	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
+
+	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	rn = F2FS_NODE(page);
+	if (depth < 3) {
+		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0)
+				continue;
+			rdn.nid = child_nid;
+			ret = truncate_dnode(&rdn);
+			if (ret < 0)
+				goto out_err;
+			set_nid(page, i, 0, false);
+		}
+	} else {
+		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
+		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0) {
+				child_nofs += NIDS_PER_BLOCK + 1;
+				continue;
+			}
+			rdn.nid = child_nid;
+			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
+			if (ret == (NIDS_PER_BLOCK + 1)) {
+				set_nid(page, i, 0, false);
+				child_nofs += ret;
+			} else if (ret < 0 && ret != -ENOENT) {
+				goto out_err;
+			}
+		}
+		freed = child_nofs;
+	}
+
+	if (!ofs) {
+		/* remove current indirect node */
+		dn->node_page = page;
+		truncate_node(dn);
+		freed++;
+	} else {
+		f2fs_put_page(page, 1);
+	}
+	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
+	return freed;
+
+out_err:
+	f2fs_put_page(page, 1);
+	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
+	return ret;
+}
+
+static int truncate_partial_nodes(struct dnode_of_data *dn,
+			struct f2fs_inode *ri, int *offset, int depth)
+{
+	struct page *pages[2];
+	nid_t nid[3];
+	nid_t child_nid;
+	int err = 0;
+	int i;
+	int idx = depth - 2;
+
+	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+	if (!nid[0])
+		return 0;
+
+	/* get indirect nodes in the path */
+	for (i = 0; i < idx + 1; i++) {
+		/* reference count'll be increased */
+		pages[i] = get_node_page(F2FS_I_SB(dn->inode), nid[i]);
+		if (IS_ERR(pages[i])) {
+			err = PTR_ERR(pages[i]);
+			idx = i - 1;
+			goto fail;
+		}
+		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
+	}
+
+	/* free direct nodes linked to a partial indirect node */
+	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
+		child_nid = get_nid(pages[idx], i, false);
+		if (!child_nid)
+			continue;
+		dn->nid = child_nid;
+		err = truncate_dnode(dn);
+		if (err < 0)
+			goto fail;
+		set_nid(pages[idx], i, 0, false);
+	}
+
+	if (offset[idx + 1] == 0) {
+		dn->node_page = pages[idx];
+		dn->nid = nid[idx];
+		truncate_node(dn);
+	} else {
+		f2fs_put_page(pages[idx], 1);
+	}
+	offset[idx]++;
+	offset[idx + 1] = 0;
+	idx--;
+fail:
+	for (i = idx; i >= 0; i--)
+		f2fs_put_page(pages[i], 1);
+
+	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
+
+	return err;
+}
+
+/*
+ * All the block addresses of data and nodes should be nullified.
+ */
+int truncate_inode_blocks(struct inode *inode, pgoff_t from)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err = 0, cont = 1;
+	int level, offset[4], noffset[4];
+	unsigned int nofs = 0;
+	struct f2fs_inode *ri;
+	struct dnode_of_data dn;
+	struct page *page;
+
+	trace_f2fs_truncate_inode_blocks_enter(inode, from);
+
+	level = get_node_path(F2FS_I(inode), from, offset, noffset);
+restart:
+	page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	set_new_dnode(&dn, inode, page, NULL, 0);
+	unlock_page(page);
+
+	ri = F2FS_INODE(page);
+	switch (level) {
+	case 0:
+	case 1:
+		nofs = noffset[1];
+		break;
+	case 2:
+		nofs = noffset[1];
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		nofs += 1 + NIDS_PER_BLOCK;
+		break;
+	case 3:
+		nofs = 5 + 2 * NIDS_PER_BLOCK;
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		break;
+	default:
+		BUG();
+	}
+
+skip_partial:
+	while (cont) {
+		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+		switch (offset[0]) {
+		case NODE_DIR1_BLOCK:
+		case NODE_DIR2_BLOCK:
+			err = truncate_dnode(&dn);
+			break;
+
+		case NODE_IND1_BLOCK:
+		case NODE_IND2_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 2);
+			break;
+
+		case NODE_DIND_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 3);
+			cont = 0;
+			break;
+
+		default:
+			BUG();
+		}
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		if (offset[1] == 0 &&
+				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
+			lock_page(page);
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+				f2fs_put_page(page, 1);
+				goto restart;
+			}
+			f2fs_wait_on_page_writeback(page, NODE);
+			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
+			set_page_dirty(page);
+			unlock_page(page);
+		}
+		offset[1] = 0;
+		offset[0]++;
+		nofs += err;
+	}
+fail:
+	f2fs_put_page(page, 0);
+	trace_f2fs_truncate_inode_blocks_exit(inode, err);
+	return err > 0 ? 0 : err;
+}
+
+int truncate_xattr_node(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t nid = F2FS_I(inode)->i_xattr_nid;
+	struct dnode_of_data dn;
+	struct page *npage;
+
+	if (!nid)
+		return 0;
+
+	npage = get_node_page(sbi, nid);
+	if (IS_ERR(npage))
+		return PTR_ERR(npage);
+
+	F2FS_I(inode)->i_xattr_nid = 0;
+
+	/* need to do checkpoint during fsync */
+	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
+
+	set_new_dnode(&dn, inode, page, npage, nid);
+
+	if (page)
+		dn.inode_page_locked = true;
+	truncate_node(&dn);
+	return 0;
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+void remove_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+	if (get_dnode_of_data(&dn, 0, LOOKUP_NODE))
+		return;
+
+	if (truncate_xattr_node(inode, dn.inode_page)) {
+		f2fs_put_dnode(&dn);
+		return;
+	}
+
+	/* remove potential inline_data blocks */
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+				S_ISLNK(inode->i_mode))
+		truncate_data_blocks_range(&dn, 1);
+
+	/* 0 is possible, after f2fs_new_inode() has failed */
+	f2fs_bug_on(F2FS_I_SB(inode),
+			inode->i_blocks != 0 && inode->i_blocks != 1);
+
+	/* will put inode & node pages */
+	truncate_node(&dn);
+}
+
+struct page *new_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+
+	/* allocate inode page for new inode */
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+
+	/* caller should f2fs_put_page(page, 1); */
+	return new_node_page(&dn, 0, NULL);
+}
+
+struct page *new_node_page(struct dnode_of_data *dn,
+				unsigned int ofs, struct page *ipage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info old_ni, new_ni;
+	struct page *page;
+	int err;
+
+	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
+		return ERR_PTR(-EPERM);
+
+	page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
+		err = -ENOSPC;
+		goto fail;
+	}
+
+	get_node_info(sbi, dn->nid, &old_ni);
+
+	/* Reinitialize old_ni with new node page */
+	f2fs_bug_on(sbi, old_ni.blk_addr != NULL_ADDR);
+	new_ni = old_ni;
+	new_ni.ino = dn->inode->i_ino;
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+
+	f2fs_wait_on_page_writeback(page, NODE);
+	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
+	set_cold_node(dn->inode, page);
+	SetPageUptodate(page);
+	set_page_dirty(page);
+
+	if (f2fs_has_xattr_block(ofs))
+		F2FS_I(dn->inode)->i_xattr_nid = dn->nid;
+
+	dn->node_page = page;
+	if (ipage)
+		update_inode(dn->inode, ipage);
+	else
+		sync_inode_page(dn);
+	if (ofs == 0)
+		inc_valid_inode_count(sbi);
+
+	return page;
+
+fail:
+	clear_node_page_dirty(page);
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+/*
+ * Caller should do after getting the following values.
+ * 0: f2fs_put_page(page, 0)
+ * LOCKED_PAGE: f2fs_put_page(page, 1)
+ * error: nothing
+ */
+static int read_node_page(struct page *page, int rw)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.type = NODE,
+		.rw = rw,
+	};
+
+	get_node_info(sbi, page->index, &ni);
+
+	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		f2fs_put_page(page, 1);
+		return -ENOENT;
+	}
+
+	if (PageUptodate(page))
+		return LOCKED_PAGE;
+
+	fio.blk_addr = ni.blk_addr;
+	return f2fs_submit_page_bio(sbi, page, &fio);
+}
+
+/*
+ * Readahead a node page
+ */
+void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *apage;
+	int err;
+
+	apage = find_get_page(NODE_MAPPING(sbi), nid);
+	if (apage && PageUptodate(apage)) {
+		f2fs_put_page(apage, 0);
+		return;
+	}
+	f2fs_put_page(apage, 0);
+
+	apage = grab_cache_page(NODE_MAPPING(sbi), nid);
+	if (!apage)
+		return;
+
+	err = read_node_page(apage, READA);
+	if (err == 0)
+		f2fs_put_page(apage, 0);
+	else if (err == LOCKED_PAGE)
+		f2fs_put_page(apage, 1);
+}
+
+struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
+{
+	struct page *page;
+	int err;
+repeat:
+	page = grab_cache_page(NODE_MAPPING(sbi), nid);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	err = read_node_page(page, READ_SYNC);
+	if (err < 0)
+		return ERR_PTR(err);
+	else if (err != LOCKED_PAGE)
+		lock_page(page);
+
+	if (unlikely(!PageUptodate(page) || nid != nid_of_node(page))) {
+		ClearPageUptodate(page);
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+	return page;
+}
+
+/*
+ * Return a locked page for the desired node page.
+ * And, readahead MAX_RA_NODE number of node pages.
+ */
+struct page *get_node_page_ra(struct page *parent, int start)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+	struct blk_plug plug;
+	struct page *page;
+	int err, i, end;
+	nid_t nid;
+
+	/* First, try getting the desired direct node. */
+	nid = get_nid(parent, start, false);
+	if (!nid)
+		return ERR_PTR(-ENOENT);
+repeat:
+	page = grab_cache_page(NODE_MAPPING(sbi), nid);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	err = read_node_page(page, READ_SYNC);
+	if (err < 0)
+		return ERR_PTR(err);
+	else if (err == LOCKED_PAGE)
+		goto page_hit;
+
+	blk_start_plug(&plug);
+
+	/* Then, try readahead for siblings of the desired node */
+	end = start + MAX_RA_NODE;
+	end = min(end, NIDS_PER_BLOCK);
+	for (i = start + 1; i < end; i++) {
+		nid = get_nid(parent, i, false);
+		if (!nid)
+			continue;
+		ra_node_page(sbi, nid);
+	}
+
+	blk_finish_plug(&plug);
+
+	lock_page(page);
+	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+page_hit:
+	if (unlikely(!PageUptodate(page))) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	return page;
+}
+
+void sync_inode_page(struct dnode_of_data *dn)
+{
+	if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
+		update_inode(dn->inode, dn->node_page);
+	} else if (dn->inode_page) {
+		if (!dn->inode_page_locked)
+			lock_page(dn->inode_page);
+		update_inode(dn->inode, dn->inode_page);
+		if (!dn->inode_page_locked)
+			unlock_page(dn->inode_page);
+	} else {
+		update_inode_page(dn->inode);
+	}
+}
+
+int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
+					struct writeback_control *wbc)
+{
+	pgoff_t index, end;
+	struct pagevec pvec;
+	int step = ino ? 2 : 0;
+	int nwritten = 0, wrote = 0;
+
+	pagevec_init(&pvec, 0);
+
+next_step:
+	index = 0;
+	end = LONG_MAX;
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			/*
+			 * flushing sequence with step:
+			 * 0. indirect nodes
+			 * 1. dentry dnodes
+			 * 2. file dnodes
+			 */
+			if (step == 0 && IS_DNODE(page))
+				continue;
+			if (step == 1 && (!IS_DNODE(page) ||
+						is_cold_node(page)))
+				continue;
+			if (step == 2 && (!IS_DNODE(page) ||
+						!is_cold_node(page)))
+				continue;
+
+			/*
+			 * If an fsync mode,
+			 * we should not skip writing node pages.
+			 */
+			if (ino && ino_of_node(page) == ino)
+				lock_page(page);
+			else if (!trylock_page(page))
+				continue;
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (ino && ino_of_node(page) != ino)
+				goto continue_unlock;
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			/* called by fsync() */
+			if (ino && IS_DNODE(page)) {
+				set_fsync_mark(page, 1);
+				if (IS_INODE(page)) {
+					if (!is_checkpointed_node(sbi, ino) &&
+						!has_fsynced_inode(sbi, ino))
+						set_dentry_mark(page, 1);
+					else
+						set_dentry_mark(page, 0);
+				}
+				nwritten++;
+			} else {
+				set_fsync_mark(page, 0);
+				set_dentry_mark(page, 0);
+			}
+
+			if (NODE_MAPPING(sbi)->a_ops->writepage(page, wbc))
+				unlock_page(page);
+			else
+				wrote++;
+
+			if (--wbc->nr_to_write == 0)
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+
+		if (wbc->nr_to_write == 0) {
+			step = 2;
+			break;
+		}
+	}
+
+	if (step < 2) {
+		step++;
+		goto next_step;
+	}
+
+	if (wrote)
+		f2fs_submit_merged_bio(sbi, NODE, WRITE);
+	return nwritten;
+}
+
+int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	pgoff_t index = 0, end = LONG_MAX;
+	struct pagevec pvec;
+	int ret2 = 0, ret = 0;
+
+	pagevec_init(&pvec, 0);
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_WRITEBACK,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			/* until radix tree lookup accepts end_index */
+			if (unlikely(page->index > end))
+				continue;
+
+			if (ino && ino_of_node(page) == ino) {
+				f2fs_wait_on_page_writeback(page, NODE);
+				if (TestClearPageError(page))
+					ret = -EIO;
+			}
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+
+	if (unlikely(test_and_clear_bit(AS_ENOSPC, &NODE_MAPPING(sbi)->flags)))
+		ret2 = -ENOSPC;
+	if (unlikely(test_and_clear_bit(AS_EIO, &NODE_MAPPING(sbi)->flags)))
+		ret2 = -EIO;
+	if (!ret)
+		ret = ret2;
+	return ret;
+}
+
+static int f2fs_write_node_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	nid_t nid;
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.type = NODE,
+		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
+	};
+
+	trace_f2fs_writepage(page, NODE);
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+	if (unlikely(f2fs_cp_error(sbi)))
+		goto redirty_out;
+
+	f2fs_wait_on_page_writeback(page, NODE);
+
+	/* get old block addr of this node page */
+	nid = nid_of_node(page);
+	f2fs_bug_on(sbi, page->index != nid);
+
+	get_node_info(sbi, nid, &ni);
+
+	/* This page is already truncated */
+	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		dec_page_count(sbi, F2FS_DIRTY_NODES);
+		unlock_page(page);
+		return 0;
+	}
+
+	if (wbc->for_reclaim) {
+		if (!down_read_trylock(&sbi->node_write))
+			goto redirty_out;
+	} else {
+		down_read(&sbi->node_write);
+	}
+
+	set_page_writeback(page);
+	fio.blk_addr = ni.blk_addr;
+	write_node_page(sbi, page, nid, &fio);
+	set_node_addr(sbi, &ni, fio.blk_addr, is_fsync_dnode(page));
+	dec_page_count(sbi, F2FS_DIRTY_NODES);
+	up_read(&sbi->node_write);
+	unlock_page(page);
+
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_bio(sbi, NODE, WRITE);
+
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+static int f2fs_write_node_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+	long diff;
+
+	trace_f2fs_writepages(mapping->host, wbc, NODE);
+
+	/* balancing f2fs's metadata in background */
+	f2fs_balance_fs_bg(sbi);
+
+	/* collect a number of dirty node pages and write together */
+	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
+		goto skip_write;
+
+	diff = nr_pages_to_write(sbi, NODE, wbc);
+	wbc->sync_mode = WB_SYNC_NONE;
+	sync_node_pages(sbi, 0, wbc);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
+	return 0;
+}
+
+static int f2fs_set_node_page_dirty(struct page *page)
+{
+	trace_f2fs_set_page_dirty(page, NODE);
+
+	SetPageUptodate(page);
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
+		SetPagePrivate(page);
+		f2fs_trace_pid(page);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Structure of the f2fs node operations
+ */
+const struct address_space_operations f2fs_node_aops = {
+	.writepage	= f2fs_write_node_page,
+	.writepages	= f2fs_write_node_pages,
+	.set_page_dirty	= f2fs_set_node_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+};
+
+static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
+						nid_t n)
+{
+	return radix_tree_lookup(&nm_i->free_nid_root, n);
+}
+
+static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
+						struct free_nid *i)
+{
+	list_del(&i->list);
+	radix_tree_delete(&nm_i->free_nid_root, i->nid);
+}
+
+static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	struct nat_entry *ne;
+	bool allocated = false;
+
+	if (!available_free_memory(sbi, FREE_NIDS))
+		return -1;
+
+	/* 0 nid should not be used */
+	if (unlikely(nid == 0))
+		return 0;
+
+	if (build) {
+		/* do not add allocated nids */
+		down_read(&nm_i->nat_tree_lock);
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (ne &&
+			(!get_nat_flag(ne, IS_CHECKPOINTED) ||
+				nat_get_blkaddr(ne) != NULL_ADDR))
+			allocated = true;
+		up_read(&nm_i->nat_tree_lock);
+		if (allocated)
+			return 0;
+	}
+
+	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
+	i->nid = nid;
+	i->state = NID_NEW;
+
+	if (radix_tree_preload(GFP_NOFS)) {
+		kmem_cache_free(free_nid_slab, i);
+		return 0;
+	}
+
+	spin_lock(&nm_i->free_nid_list_lock);
+	if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
+		spin_unlock(&nm_i->free_nid_list_lock);
+		radix_tree_preload_end();
+		kmem_cache_free(free_nid_slab, i);
+		return 0;
+	}
+	list_add_tail(&i->list, &nm_i->free_nid_list);
+	nm_i->fcnt++;
+	spin_unlock(&nm_i->free_nid_list_lock);
+	radix_tree_preload_end();
+	return 1;
+}
+
+static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
+{
+	struct free_nid *i;
+	bool need_free = false;
+
+	spin_lock(&nm_i->free_nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	if (i && i->state == NID_NEW) {
+		__del_from_free_nid_list(nm_i, i);
+		nm_i->fcnt--;
+		need_free = true;
+	}
+	spin_unlock(&nm_i->free_nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+static void scan_nat_page(struct f2fs_sb_info *sbi,
+			struct page *nat_page, nid_t start_nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct f2fs_nat_block *nat_blk = page_address(nat_page);
+	block_t blk_addr;
+	int i;
+
+	i = start_nid % NAT_ENTRY_PER_BLOCK;
+
+	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
+
+		if (unlikely(start_nid >= nm_i->max_nid))
+			break;
+
+		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
+		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
+		if (blk_addr == NULL_ADDR) {
+			if (add_free_nid(sbi, start_nid, true) < 0)
+				break;
+		}
+	}
+}
+
+static void build_free_nids(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	int i = 0;
+	nid_t nid = nm_i->next_scan_nid;
+
+	/* Enough entries */
+	if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
+		return;
+
+	/* readahead nat pages to be scanned */
+	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
+
+	while (1) {
+		struct page *page = get_current_nat_page(sbi, nid);
+
+		scan_nat_page(sbi, page, nid);
+		f2fs_put_page(page, 1);
+
+		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
+		if (unlikely(nid >= nm_i->max_nid))
+			nid = 0;
+
+		if (i++ == FREE_NID_PAGES)
+			break;
+	}
+
+	/* go to the next free nat pages to find free nids abundantly */
+	nm_i->next_scan_nid = nid;
+
+	/* find free nids from current sum_pages */
+	mutex_lock(&curseg->curseg_mutex);
+	for (i = 0; i < nats_in_cursum(sum); i++) {
+		block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
+		nid = le32_to_cpu(nid_in_journal(sum, i));
+		if (addr == NULL_ADDR)
+			add_free_nid(sbi, nid, true);
+		else
+			remove_free_nid(nm_i, nid);
+	}
+	mutex_unlock(&curseg->curseg_mutex);
+}
+
+/*
+ * If this function returns success, caller can obtain a new nid
+ * from second parameter of this function.
+ * The returned nid could be used ino as well as nid when inode is created.
+ */
+bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i = NULL;
+retry:
+	if (unlikely(sbi->total_valid_node_count + 1 > nm_i->available_nids))
+		return false;
+
+	spin_lock(&nm_i->free_nid_list_lock);
+
+	/* We should not use stale free nids created by build_free_nids */
+	if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
+		f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
+		list_for_each_entry(i, &nm_i->free_nid_list, list)
+			if (i->state == NID_NEW)
+				break;
+
+		f2fs_bug_on(sbi, i->state != NID_NEW);
+		*nid = i->nid;
+		i->state = NID_ALLOC;
+		nm_i->fcnt--;
+		spin_unlock(&nm_i->free_nid_list_lock);
+		return true;
+	}
+	spin_unlock(&nm_i->free_nid_list_lock);
+
+	/* Let's scan nat pages and its caches to get free nids */
+	mutex_lock(&nm_i->build_lock);
+	build_free_nids(sbi);
+	mutex_unlock(&nm_i->build_lock);
+	goto retry;
+}
+
+/*
+ * alloc_nid() should be called prior to this function.
+ */
+void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+
+	spin_lock(&nm_i->free_nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i || i->state != NID_ALLOC);
+	__del_from_free_nid_list(nm_i, i);
+	spin_unlock(&nm_i->free_nid_list_lock);
+
+	kmem_cache_free(free_nid_slab, i);
+}
+
+/*
+ * alloc_nid() should be called prior to this function.
+ */
+void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	bool need_free = false;
+
+	if (!nid)
+		return;
+
+	spin_lock(&nm_i->free_nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i || i->state != NID_ALLOC);
+	if (!available_free_memory(sbi, FREE_NIDS)) {
+		__del_from_free_nid_list(nm_i, i);
+		need_free = true;
+	} else {
+		i->state = NID_NEW;
+		nm_i->fcnt++;
+	}
+	spin_unlock(&nm_i->free_nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+void recover_inline_xattr(struct inode *inode, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	size_t inline_size;
+	struct page *ipage;
+	struct f2fs_inode *ri;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	f2fs_bug_on(F2FS_I_SB(inode), IS_ERR(ipage));
+
+	ri = F2FS_INODE(page);
+	if (!(ri->i_inline & F2FS_INLINE_XATTR)) {
+		clear_inode_flag(F2FS_I(inode), FI_INLINE_XATTR);
+		goto update_inode;
+	}
+
+	dst_addr = inline_xattr_addr(ipage);
+	src_addr = inline_xattr_addr(page);
+	inline_size = inline_xattr_size(inode);
+
+	f2fs_wait_on_page_writeback(ipage, NODE);
+	memcpy(dst_addr, src_addr, inline_size);
+update_inode:
+	update_inode(inode, ipage);
+	f2fs_put_page(ipage, 1);
+}
+
+void recover_xattr_data(struct inode *inode, struct page *page, block_t blkaddr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
+	nid_t new_xnid = nid_of_node(page);
+	struct node_info ni;
+
+	/* 1: invalidate the previous xattr nid */
+	if (!prev_xnid)
+		goto recover_xnid;
+
+	/* Deallocate node address */
+	get_node_info(sbi, prev_xnid, &ni);
+	f2fs_bug_on(sbi, ni.blk_addr == NULL_ADDR);
+	invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, inode);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+recover_xnid:
+	/* 2: allocate new xattr nid */
+	if (unlikely(!inc_valid_node_count(sbi, inode)))
+		f2fs_bug_on(sbi, 1);
+
+	remove_free_nid(NM_I(sbi), new_xnid);
+	get_node_info(sbi, new_xnid, &ni);
+	ni.ino = inode->i_ino;
+	set_node_addr(sbi, &ni, NEW_ADDR, false);
+	F2FS_I(inode)->i_xattr_nid = new_xnid;
+
+	/* 3: update xattr blkaddr */
+	refresh_sit_entry(sbi, NEW_ADDR, blkaddr);
+	set_node_addr(sbi, &ni, blkaddr, false);
+
+	update_inode_page(inode);
+}
+
+int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *src, *dst;
+	nid_t ino = ino_of_node(page);
+	struct node_info old_ni, new_ni;
+	struct page *ipage;
+
+	get_node_info(sbi, ino, &old_ni);
+
+	if (unlikely(old_ni.blk_addr != NULL_ADDR))
+		return -EINVAL;
+
+	ipage = grab_cache_page(NODE_MAPPING(sbi), ino);
+	if (!ipage)
+		return -ENOMEM;
+
+	/* Should not use this inode from free nid list */
+	remove_free_nid(NM_I(sbi), ino);
+
+	SetPageUptodate(ipage);
+	fill_node_footer(ipage, ino, ino, 0, true);
+
+	src = F2FS_INODE(page);
+	dst = F2FS_INODE(ipage);
+
+	memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
+	dst->i_size = 0;
+	dst->i_blocks = cpu_to_le64(1);
+	dst->i_links = cpu_to_le32(1);
+	dst->i_xattr_nid = 0;
+	dst->i_inline = src->i_inline & F2FS_INLINE_XATTR;
+
+	new_ni = old_ni;
+	new_ni.ino = ino;
+
+	if (unlikely(!inc_valid_node_count(sbi, NULL)))
+		WARN_ON(1);
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+	inc_valid_inode_count(sbi);
+	set_page_dirty(ipage);
+	f2fs_put_page(ipage, 1);
+	return 0;
+}
+
+int restore_node_summary(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct f2fs_summary_block *sum)
+{
+	struct f2fs_node *rn;
+	struct f2fs_summary *sum_entry;
+	block_t addr;
+	int bio_blocks = MAX_BIO_BLOCKS(sbi);
+	int i, idx, last_offset, nrpages;
+
+	/* scan the node segment */
+	last_offset = sbi->blocks_per_seg;
+	addr = START_BLOCK(sbi, segno);
+	sum_entry = &sum->entries[0];
+
+	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
+		nrpages = min(last_offset - i, bio_blocks);
+
+		/* readahead node pages */
+		ra_meta_pages(sbi, addr, nrpages, META_POR);
+
+		for (idx = addr; idx < addr + nrpages; idx++) {
+			struct page *page = get_meta_page(sbi, idx);
+
+			rn = F2FS_NODE(page);
+			sum_entry->nid = rn->footer.nid;
+			sum_entry->version = 0;
+			sum_entry->ofs_in_node = 0;
+			sum_entry++;
+			f2fs_put_page(page, 1);
+		}
+
+		invalidate_mapping_pages(META_MAPPING(sbi), addr,
+							addr + nrpages);
+	}
+	return 0;
+}
+
+static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	int i;
+
+	mutex_lock(&curseg->curseg_mutex);
+	for (i = 0; i < nats_in_cursum(sum); i++) {
+		struct nat_entry *ne;
+		struct f2fs_nat_entry raw_ne;
+		nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
+
+		raw_ne = nat_in_journal(sum, i);
+
+		down_write(&nm_i->nat_tree_lock);
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (!ne) {
+			ne = grab_nat_entry(nm_i, nid);
+			node_info_from_raw_nat(&ne->ni, &raw_ne);
+		}
+		__set_nat_cache_dirty(nm_i, ne);
+		up_write(&nm_i->nat_tree_lock);
+	}
+	update_nats_in_cursum(sum, -i);
+	mutex_unlock(&curseg->curseg_mutex);
+}
+
+static void __adjust_nat_entry_set(struct nat_entry_set *nes,
+						struct list_head *head, int max)
+{
+	struct nat_entry_set *cur;
+
+	if (nes->entry_cnt >= max)
+		goto add_out;
+
+	list_for_each_entry(cur, head, set_list) {
+		if (cur->entry_cnt >= nes->entry_cnt) {
+			list_add(&nes->set_list, cur->set_list.prev);
+			return;
+		}
+	}
+add_out:
+	list_add_tail(&nes->set_list, head);
+}
+
+static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
+					struct nat_entry_set *set)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	nid_t start_nid = set->set * NAT_ENTRY_PER_BLOCK;
+	bool to_journal = true;
+	struct f2fs_nat_block *nat_blk;
+	struct nat_entry *ne, *cur;
+	struct page *page = NULL;
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	/*
+	 * there are two steps to flush nat entries:
+	 * #1, flush nat entries to journal in current hot data summary block.
+	 * #2, flush nat entries to nat page.
+	 */
+	if (!__has_cursum_space(sum, set->entry_cnt, NAT_JOURNAL))
+		to_journal = false;
+
+	if (to_journal) {
+		mutex_lock(&curseg->curseg_mutex);
+	} else {
+		page = get_next_nat_page(sbi, start_nid);
+		nat_blk = page_address(page);
+		f2fs_bug_on(sbi, !nat_blk);
+	}
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(ne, cur, &set->entry_list, list) {
+		struct f2fs_nat_entry *raw_ne;
+		nid_t nid = nat_get_nid(ne);
+		int offset;
+
+		if (nat_get_blkaddr(ne) == NEW_ADDR)
+			continue;
+
+		if (to_journal) {
+			offset = lookup_journal_in_cursum(sum,
+							NAT_JOURNAL, nid, 1);
+			f2fs_bug_on(sbi, offset < 0);
+			raw_ne = &nat_in_journal(sum, offset);
+			nid_in_journal(sum, offset) = cpu_to_le32(nid);
+		} else {
+			raw_ne = &nat_blk->entries[nid - start_nid];
+		}
+		raw_nat_from_node_info(raw_ne, &ne->ni);
+
+		down_write(&NM_I(sbi)->nat_tree_lock);
+		nat_reset_flag(ne);
+		__clear_nat_cache_dirty(NM_I(sbi), ne);
+		up_write(&NM_I(sbi)->nat_tree_lock);
+
+		if (nat_get_blkaddr(ne) == NULL_ADDR)
+			add_free_nid(sbi, nid, false);
+	}
+
+	if (to_journal)
+		mutex_unlock(&curseg->curseg_mutex);
+	else
+		f2fs_put_page(page, 1);
+
+	f2fs_bug_on(sbi, set->entry_cnt);
+
+	down_write(&nm_i->nat_tree_lock);
+	radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
+	up_write(&nm_i->nat_tree_lock);
+	kmem_cache_free(nat_entry_set_slab, set);
+}
+
+/*
+ * This function is called during the checkpointing process.
+ */
+void flush_nat_entries(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	struct nat_entry_set *set, *tmp;
+	unsigned int found;
+	nid_t set_idx = 0;
+	LIST_HEAD(sets);
+
+	if (!nm_i->dirty_nat_cnt)
+		return;
+	/*
+	 * if there are no enough space in journal to store dirty nat
+	 * entries, remove all entries from journal and merge them
+	 * into nat entry set.
+	 */
+	if (!__has_cursum_space(sum, nm_i->dirty_nat_cnt, NAT_JOURNAL))
+		remove_nats_in_journal(sbi);
+
+	down_write(&nm_i->nat_tree_lock);
+	while ((found = __gang_lookup_nat_set(nm_i,
+					set_idx, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+		set_idx = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++)
+			__adjust_nat_entry_set(setvec[idx], &sets,
+							MAX_NAT_JENTRIES(sum));
+	}
+	up_write(&nm_i->nat_tree_lock);
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(set, tmp, &sets, set_list)
+		__flush_nat_entry_set(sbi, set);
+
+	f2fs_bug_on(sbi, nm_i->dirty_nat_cnt);
+}
+
+static int init_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned char *version_bitmap;
+	unsigned int nat_segs, nat_blocks;
+
+	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
+
+	/* segment_count_nat includes pair segment so divide to 2. */
+	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
+	nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
+
+	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
+
+	/* not used nids: 0, node, meta, (and root counted as valid node) */
+	nm_i->available_nids = nm_i->max_nid - F2FS_RESERVED_NODE_NUM;
+	nm_i->fcnt = 0;
+	nm_i->nat_cnt = 0;
+	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
+
+	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
+	INIT_LIST_HEAD(&nm_i->free_nid_list);
+	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);
+	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
+	INIT_LIST_HEAD(&nm_i->nat_entries);
+
+	mutex_init(&nm_i->build_lock);
+	spin_lock_init(&nm_i->free_nid_list_lock);
+	init_rwsem(&nm_i->nat_tree_lock);
+
+	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
+	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
+	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
+	if (!version_bitmap)
+		return -EFAULT;
+
+	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
+					GFP_KERNEL);
+	if (!nm_i->nat_bitmap)
+		return -ENOMEM;
+	return 0;
+}
+
+int build_node_manager(struct f2fs_sb_info *sbi)
+{
+	int err;
+
+	sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
+	if (!sbi->nm_info)
+		return -ENOMEM;
+
+	err = init_node_manager(sbi);
+	if (err)
+		return err;
+
+	build_free_nids(sbi);
+	return 0;
+}
+
+void destroy_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *next_i;
+	struct nat_entry *natvec[NATVEC_SIZE];
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	nid_t nid = 0;
+	unsigned int found;
+
+	if (!nm_i)
+		return;
+
+	/* destroy free nid list */
+	spin_lock(&nm_i->free_nid_list_lock);
+	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
+		f2fs_bug_on(sbi, i->state == NID_ALLOC);
+		__del_from_free_nid_list(nm_i, i);
+		nm_i->fcnt--;
+		spin_unlock(&nm_i->free_nid_list_lock);
+		kmem_cache_free(free_nid_slab, i);
+		spin_lock(&nm_i->free_nid_list_lock);
+	}
+	f2fs_bug_on(sbi, nm_i->fcnt);
+	spin_unlock(&nm_i->free_nid_list_lock);
+
+	/* destroy nat cache */
+	down_write(&nm_i->nat_tree_lock);
+	while ((found = __gang_lookup_nat_cache(nm_i,
+					nid, NATVEC_SIZE, natvec))) {
+		unsigned idx;
+
+		nid = nat_get_nid(natvec[found - 1]) + 1;
+		for (idx = 0; idx < found; idx++)
+			__del_from_nat_cache(nm_i, natvec[idx]);
+	}
+	f2fs_bug_on(sbi, nm_i->nat_cnt);
+
+	/* destroy nat set cache */
+	nid = 0;
+	while ((found = __gang_lookup_nat_set(nm_i,
+					nid, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+
+		nid = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++) {
+			/* entry_cnt is not zero, when cp_error was occurred */
+			f2fs_bug_on(sbi, !list_empty(&setvec[idx]->entry_list));
+			radix_tree_delete(&nm_i->nat_set_root, setvec[idx]->set);
+			kmem_cache_free(nat_entry_set_slab, setvec[idx]);
+		}
+	}
+	up_write(&nm_i->nat_tree_lock);
+
+	kfree(nm_i->nat_bitmap);
+	sbi->nm_info = NULL;
+	kfree(nm_i);
+}
+
+int __init create_node_manager_caches(void)
+{
+	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
+			sizeof(struct nat_entry));
+	if (!nat_entry_slab)
+		goto fail;
+
+	free_nid_slab = f2fs_kmem_cache_create("free_nid",
+			sizeof(struct free_nid));
+	if (!free_nid_slab)
+		goto destroy_nat_entry;
+
+	nat_entry_set_slab = f2fs_kmem_cache_create("nat_entry_set",
+			sizeof(struct nat_entry_set));
+	if (!nat_entry_set_slab)
+		goto destroy_free_nid;
+	return 0;
+
+destroy_free_nid:
+	kmem_cache_destroy(free_nid_slab);
+destroy_nat_entry:
+	kmem_cache_destroy(nat_entry_slab);
+fail:
+	return -ENOMEM;
+}
+
+void destroy_node_manager_caches(void)
+{
+	kmem_cache_destroy(nat_entry_set_slab);
+	kmem_cache_destroy(free_nid_slab);
+	kmem_cache_destroy(nat_entry_slab);
+}
diff --git a/kernel/fs/f2fs/node.h b/kernel/fs/f2fs/node.h
new file mode 100644
index 000000000..c56026f17
--- /dev/null
+++ b/kernel/fs/f2fs/node.h
@@ -0,0 +1,416 @@
+/*
+ * fs/f2fs/node.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+/* start node id of a node block dedicated to the given node id */
+#define	START_NID(nid) ((nid / NAT_ENTRY_PER_BLOCK) * NAT_ENTRY_PER_BLOCK)
+
+/* node block offset on the NAT area dedicated to the given start node id */
+#define	NAT_BLOCK_OFFSET(start_nid) (start_nid / NAT_ENTRY_PER_BLOCK)
+
+/* # of pages to perform readahead before building free nids */
+#define FREE_NID_PAGES 4
+
+/* maximum readahead size for node during getting data blocks */
+#define MAX_RA_NODE		128
+
+/* control the memory footprint threshold (10MB per 1GB ram) */
+#define DEF_RAM_THRESHOLD	10
+
+/* vector size for gang look-up from nat cache that consists of radix tree */
+#define NATVEC_SIZE	64
+#define SETVEC_SIZE	32
+
+/* return value for read_node_page */
+#define LOCKED_PAGE	1
+
+/* For flag in struct node_info */
+enum {
+	IS_CHECKPOINTED,	/* is it checkpointed before? */
+	HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
+	HAS_LAST_FSYNC,		/* has the latest node fsync mark? */
+	IS_DIRTY,		/* this nat entry is dirty? */
+};
+
+/*
+ * For node information
+ */
+struct node_info {
+	nid_t nid;		/* node id */
+	nid_t ino;		/* inode number of the node's owner */
+	block_t	blk_addr;	/* block address of the node */
+	unsigned char version;	/* version of the node */
+	unsigned char flag;	/* for node information bits */
+};
+
+struct nat_entry {
+	struct list_head list;	/* for clean or dirty nat list */
+	struct node_info ni;	/* in-memory node information */
+};
+
+#define nat_get_nid(nat)		(nat->ni.nid)
+#define nat_set_nid(nat, n)		(nat->ni.nid = n)
+#define nat_get_blkaddr(nat)		(nat->ni.blk_addr)
+#define nat_set_blkaddr(nat, b)		(nat->ni.blk_addr = b)
+#define nat_get_ino(nat)		(nat->ni.ino)
+#define nat_set_ino(nat, i)		(nat->ni.ino = i)
+#define nat_get_version(nat)		(nat->ni.version)
+#define nat_set_version(nat, v)		(nat->ni.version = v)
+
+#define inc_node_version(version)	(++version)
+
+static inline void copy_node_info(struct node_info *dst,
+						struct node_info *src)
+{
+	dst->nid = src->nid;
+	dst->ino = src->ino;
+	dst->blk_addr = src->blk_addr;
+	dst->version = src->version;
+	/* should not copy flag here */
+}
+
+static inline void set_nat_flag(struct nat_entry *ne,
+				unsigned int type, bool set)
+{
+	unsigned char mask = 0x01 << type;
+	if (set)
+		ne->ni.flag |= mask;
+	else
+		ne->ni.flag &= ~mask;
+}
+
+static inline bool get_nat_flag(struct nat_entry *ne, unsigned int type)
+{
+	unsigned char mask = 0x01 << type;
+	return ne->ni.flag & mask;
+}
+
+static inline void nat_reset_flag(struct nat_entry *ne)
+{
+	/* these states can be set only after checkpoint was done */
+	set_nat_flag(ne, IS_CHECKPOINTED, true);
+	set_nat_flag(ne, HAS_FSYNCED_INODE, false);
+	set_nat_flag(ne, HAS_LAST_FSYNC, true);
+}
+
+static inline void node_info_from_raw_nat(struct node_info *ni,
+						struct f2fs_nat_entry *raw_ne)
+{
+	ni->ino = le32_to_cpu(raw_ne->ino);
+	ni->blk_addr = le32_to_cpu(raw_ne->block_addr);
+	ni->version = raw_ne->version;
+}
+
+static inline void raw_nat_from_node_info(struct f2fs_nat_entry *raw_ne,
+						struct node_info *ni)
+{
+	raw_ne->ino = cpu_to_le32(ni->ino);
+	raw_ne->block_addr = cpu_to_le32(ni->blk_addr);
+	raw_ne->version = ni->version;
+}
+
+enum mem_type {
+	FREE_NIDS,	/* indicates the free nid list */
+	NAT_ENTRIES,	/* indicates the cached nat entry */
+	DIRTY_DENTS,	/* indicates dirty dentry pages */
+	INO_ENTRIES,	/* indicates inode entries */
+	EXTENT_CACHE,	/* indicates extent cache */
+	BASE_CHECK,	/* check kernel status */
+};
+
+struct nat_entry_set {
+	struct list_head set_list;	/* link with other nat sets */
+	struct list_head entry_list;	/* link with dirty nat entries */
+	nid_t set;			/* set number*/
+	unsigned int entry_cnt;		/* the # of nat entries in set */
+};
+
+/*
+ * For free nid mangement
+ */
+enum nid_state {
+	NID_NEW,	/* newly added to free nid list */
+	NID_ALLOC	/* it is allocated */
+};
+
+struct free_nid {
+	struct list_head list;	/* for free node id list */
+	nid_t nid;		/* node id */
+	int state;		/* in use or not: NID_NEW or NID_ALLOC */
+};
+
+static inline void next_free_nid(struct f2fs_sb_info *sbi, nid_t *nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *fnid;
+
+	spin_lock(&nm_i->free_nid_list_lock);
+	if (nm_i->fcnt <= 0) {
+		spin_unlock(&nm_i->free_nid_list_lock);
+		return;
+	}
+	fnid = list_entry(nm_i->free_nid_list.next, struct free_nid, list);
+	*nid = fnid->nid;
+	spin_unlock(&nm_i->free_nid_list_lock);
+}
+
+/*
+ * inline functions
+ */
+static inline void get_nat_bitmap(struct f2fs_sb_info *sbi, void *addr)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	memcpy(addr, nm_i->nat_bitmap, nm_i->bitmap_size);
+}
+
+static inline pgoff_t current_nat_addr(struct f2fs_sb_info *sbi, nid_t start)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	pgoff_t block_off;
+	pgoff_t block_addr;
+	int seg_off;
+
+	block_off = NAT_BLOCK_OFFSET(start);
+	seg_off = block_off >> sbi->log_blocks_per_seg;
+
+	block_addr = (pgoff_t)(nm_i->nat_blkaddr +
+		(seg_off << sbi->log_blocks_per_seg << 1) +
+		(block_off & ((1 << sbi->log_blocks_per_seg) - 1)));
+
+	if (f2fs_test_bit(block_off, nm_i->nat_bitmap))
+		block_addr += sbi->blocks_per_seg;
+
+	return block_addr;
+}
+
+static inline pgoff_t next_nat_addr(struct f2fs_sb_info *sbi,
+						pgoff_t block_addr)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	block_addr -= nm_i->nat_blkaddr;
+	if ((block_addr >> sbi->log_blocks_per_seg) % 2)
+		block_addr -= sbi->blocks_per_seg;
+	else
+		block_addr += sbi->blocks_per_seg;
+
+	return block_addr + nm_i->nat_blkaddr;
+}
+
+static inline void set_to_next_nat(struct f2fs_nm_info *nm_i, nid_t start_nid)
+{
+	unsigned int block_off = NAT_BLOCK_OFFSET(start_nid);
+
+	f2fs_change_bit(block_off, nm_i->nat_bitmap);
+}
+
+static inline void fill_node_footer(struct page *page, nid_t nid,
+				nid_t ino, unsigned int ofs, bool reset)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int old_flag = 0;
+
+	if (reset)
+		memset(rn, 0, sizeof(*rn));
+	else
+		old_flag = le32_to_cpu(rn->footer.flag);
+
+	rn->footer.nid = cpu_to_le32(nid);
+	rn->footer.ino = cpu_to_le32(ino);
+
+	/* should remain old flag bits such as COLD_BIT_SHIFT */
+	rn->footer.flag = cpu_to_le32((ofs << OFFSET_BIT_SHIFT) |
+					(old_flag & OFFSET_BIT_MASK));
+}
+
+static inline void copy_node_footer(struct page *dst, struct page *src)
+{
+	struct f2fs_node *src_rn = F2FS_NODE(src);
+	struct f2fs_node *dst_rn = F2FS_NODE(dst);
+	memcpy(&dst_rn->footer, &src_rn->footer, sizeof(struct node_footer));
+}
+
+static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	struct f2fs_node *rn = F2FS_NODE(page);
+
+	rn->footer.cp_ver = ckpt->checkpoint_ver;
+	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
+}
+
+static inline nid_t ino_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.ino);
+}
+
+static inline nid_t nid_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.nid);
+}
+
+static inline unsigned int ofs_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	unsigned flag = le32_to_cpu(rn->footer.flag);
+	return flag >> OFFSET_BIT_SHIFT;
+}
+
+static inline unsigned long long cpver_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le64_to_cpu(rn->footer.cp_ver);
+}
+
+static inline block_t next_blkaddr_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.next_blkaddr);
+}
+
+/*
+ * f2fs assigns the following node offsets described as (num).
+ * N = NIDS_PER_BLOCK
+ *
+ *  Inode block (0)
+ *    |- direct node (1)
+ *    |- direct node (2)
+ *    |- indirect node (3)
+ *    |            `- direct node (4 => 4 + N - 1)
+ *    |- indirect node (4 + N)
+ *    |            `- direct node (5 + N => 5 + 2N - 1)
+ *    `- double indirect node (5 + 2N)
+ *                 `- indirect node (6 + 2N)
+ *                       `- direct node
+ *                 ......
+ *                 `- indirect node ((6 + 2N) + x(N + 1))
+ *                       `- direct node
+ *                 ......
+ *                 `- indirect node ((6 + 2N) + (N - 1)(N + 1))
+ *                       `- direct node
+ */
+static inline bool IS_DNODE(struct page *node_page)
+{
+	unsigned int ofs = ofs_of_node(node_page);
+
+	if (f2fs_has_xattr_block(ofs))
+		return false;
+
+	if (ofs == 3 || ofs == 4 + NIDS_PER_BLOCK ||
+			ofs == 5 + 2 * NIDS_PER_BLOCK)
+		return false;
+	if (ofs >= 6 + 2 * NIDS_PER_BLOCK) {
+		ofs -= 6 + 2 * NIDS_PER_BLOCK;
+		if (!((long int)ofs % (NIDS_PER_BLOCK + 1)))
+			return false;
+	}
+	return true;
+}
+
+static inline void set_nid(struct page *p, int off, nid_t nid, bool i)
+{
+	struct f2fs_node *rn = F2FS_NODE(p);
+
+	f2fs_wait_on_page_writeback(p, NODE);
+
+	if (i)
+		rn->i.i_nid[off - NODE_DIR1_BLOCK] = cpu_to_le32(nid);
+	else
+		rn->in.nid[off] = cpu_to_le32(nid);
+	set_page_dirty(p);
+}
+
+static inline nid_t get_nid(struct page *p, int off, bool i)
+{
+	struct f2fs_node *rn = F2FS_NODE(p);
+
+	if (i)
+		return le32_to_cpu(rn->i.i_nid[off - NODE_DIR1_BLOCK]);
+	return le32_to_cpu(rn->in.nid[off]);
+}
+
+/*
+ * Coldness identification:
+ *  - Mark cold files in f2fs_inode_info
+ *  - Mark cold node blocks in their node footer
+ *  - Mark cold data pages in page cache
+ */
+static inline int is_file(struct inode *inode, int type)
+{
+	return F2FS_I(inode)->i_advise & type;
+}
+
+static inline void set_file(struct inode *inode, int type)
+{
+	F2FS_I(inode)->i_advise |= type;
+}
+
+static inline void clear_file(struct inode *inode, int type)
+{
+	F2FS_I(inode)->i_advise &= ~type;
+}
+
+#define file_is_cold(inode)	is_file(inode, FADVISE_COLD_BIT)
+#define file_wrong_pino(inode)	is_file(inode, FADVISE_LOST_PINO_BIT)
+#define file_set_cold(inode)	set_file(inode, FADVISE_COLD_BIT)
+#define file_lost_pino(inode)	set_file(inode, FADVISE_LOST_PINO_BIT)
+#define file_clear_cold(inode)	clear_file(inode, FADVISE_COLD_BIT)
+#define file_got_pino(inode)	clear_file(inode, FADVISE_LOST_PINO_BIT)
+
+static inline int is_cold_data(struct page *page)
+{
+	return PageChecked(page);
+}
+
+static inline void set_cold_data(struct page *page)
+{
+	SetPageChecked(page);
+}
+
+static inline void clear_cold_data(struct page *page)
+{
+	ClearPageChecked(page);
+}
+
+static inline int is_node(struct page *page, int type)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	return le32_to_cpu(rn->footer.flag) & (1 << type);
+}
+
+#define is_cold_node(page)	is_node(page, COLD_BIT_SHIFT)
+#define is_fsync_dnode(page)	is_node(page, FSYNC_BIT_SHIFT)
+#define is_dent_dnode(page)	is_node(page, DENT_BIT_SHIFT)
+
+static inline void set_cold_node(struct inode *inode, struct page *page)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int flag = le32_to_cpu(rn->footer.flag);
+
+	if (S_ISDIR(inode->i_mode))
+		flag &= ~(0x1 << COLD_BIT_SHIFT);
+	else
+		flag |= (0x1 << COLD_BIT_SHIFT);
+	rn->footer.flag = cpu_to_le32(flag);
+}
+
+static inline void set_mark(struct page *page, int mark, int type)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int flag = le32_to_cpu(rn->footer.flag);
+	if (mark)
+		flag |= (0x1 << type);
+	else
+		flag &= ~(0x1 << type);
+	rn->footer.flag = cpu_to_le32(flag);
+}
+#define set_dentry_mark(page, mark)	set_mark(page, mark, DENT_BIT_SHIFT)
+#define set_fsync_mark(page, mark)	set_mark(page, mark, FSYNC_BIT_SHIFT)
diff --git a/kernel/fs/f2fs/recovery.c b/kernel/fs/f2fs/recovery.c
new file mode 100644
index 000000000..8d8ea99f2
--- /dev/null
+++ b/kernel/fs/f2fs/recovery.c
@@ -0,0 +1,575 @@
+/*
+ * fs/f2fs/recovery.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+/*
+ * Roll forward recovery scenarios.
+ *
+ * [Term] F: fsync_mark, D: dentry_mark
+ *
+ * 1. inode(x) | CP | inode(x) | dnode(F)
+ * -> Update the latest inode(x).
+ *
+ * 2. inode(x) | CP | inode(F) | dnode(F)
+ * -> No problem.
+ *
+ * 3. inode(x) | CP | dnode(F) | inode(x)
+ * -> Recover to the latest dnode(F), and drop the last inode(x)
+ *
+ * 4. inode(x) | CP | dnode(F) | inode(F)
+ * -> No problem.
+ *
+ * 5. CP | inode(x) | dnode(F)
+ * -> The inode(DF) was missing. Should drop this dnode(F).
+ *
+ * 6. CP | inode(DF) | dnode(F)
+ * -> No problem.
+ *
+ * 7. CP | dnode(F) | inode(DF)
+ * -> If f2fs_iget fails, then goto next to find inode(DF).
+ *
+ * 8. CP | dnode(F) | inode(x)
+ * -> If f2fs_iget fails, then goto next to find inode(DF).
+ *    But it will fail due to no inode(DF).
+ */
+
+static struct kmem_cache *fsync_entry_slab;
+
+bool space_for_roll_forward(struct f2fs_sb_info *sbi)
+{
+	if (sbi->last_valid_block_count + sbi->alloc_valid_block_count
+			> sbi->user_block_count)
+		return false;
+	return true;
+}
+
+static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
+								nid_t ino)
+{
+	struct fsync_inode_entry *entry;
+
+	list_for_each_entry(entry, head, list)
+		if (entry->inode->i_ino == ino)
+			return entry;
+
+	return NULL;
+}
+
+static int recover_dentry(struct inode *inode, struct page *ipage)
+{
+	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
+	nid_t pino = le32_to_cpu(raw_inode->i_pino);
+	struct f2fs_dir_entry *de;
+	struct qstr name;
+	struct page *page;
+	struct inode *dir, *einode;
+	int err = 0;
+
+	dir = f2fs_iget(inode->i_sb, pino);
+	if (IS_ERR(dir)) {
+		err = PTR_ERR(dir);
+		goto out;
+	}
+
+	name.len = le32_to_cpu(raw_inode->i_namelen);
+	name.name = raw_inode->i_name;
+
+	if (unlikely(name.len > F2FS_NAME_LEN)) {
+		WARN_ON(1);
+		err = -ENAMETOOLONG;
+		goto out_err;
+	}
+retry:
+	de = f2fs_find_entry(dir, &name, &page);
+	if (de && inode->i_ino == le32_to_cpu(de->ino))
+		goto out_unmap_put;
+
+	if (de) {
+		einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
+		if (IS_ERR(einode)) {
+			WARN_ON(1);
+			err = PTR_ERR(einode);
+			if (err == -ENOENT)
+				err = -EEXIST;
+			goto out_unmap_put;
+		}
+		err = acquire_orphan_inode(F2FS_I_SB(inode));
+		if (err) {
+			iput(einode);
+			goto out_unmap_put;
+		}
+		f2fs_delete_entry(de, page, dir, einode);
+		iput(einode);
+		goto retry;
+	}
+	err = __f2fs_add_link(dir, &name, inode, inode->i_ino, inode->i_mode);
+	if (err)
+		goto out_err;
+
+	if (is_inode_flag_set(F2FS_I(dir), FI_DELAY_IPUT)) {
+		iput(dir);
+	} else {
+		add_dirty_dir_inode(dir);
+		set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
+	}
+
+	goto out;
+
+out_unmap_put:
+	f2fs_dentry_kunmap(dir, page);
+	f2fs_put_page(page, 0);
+out_err:
+	iput(dir);
+out:
+	f2fs_msg(inode->i_sb, KERN_NOTICE,
+			"%s: ino = %x, name = %s, dir = %lx, err = %d",
+			__func__, ino_of_node(ipage), raw_inode->i_name,
+			IS_ERR(dir) ? 0 : dir->i_ino, err);
+	return err;
+}
+
+static void recover_inode(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode *raw = F2FS_INODE(page);
+
+	inode->i_mode = le16_to_cpu(raw->i_mode);
+	i_size_write(inode, le64_to_cpu(raw->i_size));
+	inode->i_atime.tv_sec = le64_to_cpu(raw->i_mtime);
+	inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
+	inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
+	inode->i_atime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
+	inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
+	inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
+
+	f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
+			ino_of_node(page), F2FS_INODE(page)->i_name);
+}
+
+static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
+{
+	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
+	struct curseg_info *curseg;
+	struct page *page = NULL;
+	block_t blkaddr;
+	int err = 0;
+
+	/* get node pages in the current segment */
+	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	ra_meta_pages(sbi, blkaddr, 1, META_POR);
+
+	while (1) {
+		struct fsync_inode_entry *entry;
+
+		if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
+			return 0;
+
+		page = get_meta_page(sbi, blkaddr);
+
+		if (cp_ver != cpver_of_node(page))
+			break;
+
+		if (!is_fsync_dnode(page))
+			goto next;
+
+		entry = get_fsync_inode(head, ino_of_node(page));
+		if (!entry) {
+			if (IS_INODE(page) && is_dent_dnode(page)) {
+				err = recover_inode_page(sbi, page);
+				if (err)
+					break;
+			}
+
+			/* add this fsync inode to the list */
+			entry = kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
+			if (!entry) {
+				err = -ENOMEM;
+				break;
+			}
+			/*
+			 * CP | dnode(F) | inode(DF)
+			 * For this case, we should not give up now.
+			 */
+			entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
+			if (IS_ERR(entry->inode)) {
+				err = PTR_ERR(entry->inode);
+				kmem_cache_free(fsync_entry_slab, entry);
+				if (err == -ENOENT) {
+					err = 0;
+					goto next;
+				}
+				break;
+			}
+			list_add_tail(&entry->list, head);
+		}
+		entry->blkaddr = blkaddr;
+
+		if (IS_INODE(page)) {
+			entry->last_inode = blkaddr;
+			if (is_dent_dnode(page))
+				entry->last_dentry = blkaddr;
+		}
+next:
+		/* check next segment */
+		blkaddr = next_blkaddr_of_node(page);
+		f2fs_put_page(page, 1);
+
+		ra_meta_pages_cond(sbi, blkaddr);
+	}
+	f2fs_put_page(page, 1);
+	return err;
+}
+
+static void destroy_fsync_dnodes(struct list_head *head)
+{
+	struct fsync_inode_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, head, list) {
+		iput(entry->inode);
+		list_del(&entry->list);
+		kmem_cache_free(fsync_entry_slab, entry);
+	}
+}
+
+static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
+			block_t blkaddr, struct dnode_of_data *dn)
+{
+	struct seg_entry *sentry;
+	unsigned int segno = GET_SEGNO(sbi, blkaddr);
+	unsigned short blkoff = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+	struct f2fs_summary_block *sum_node;
+	struct f2fs_summary sum;
+	struct page *sum_page, *node_page;
+	struct dnode_of_data tdn = *dn;
+	nid_t ino, nid;
+	struct inode *inode;
+	unsigned int offset;
+	block_t bidx;
+	int i;
+
+	sentry = get_seg_entry(sbi, segno);
+	if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
+		return 0;
+
+	/* Get the previous summary */
+	for (i = CURSEG_WARM_DATA; i <= CURSEG_COLD_DATA; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+		if (curseg->segno == segno) {
+			sum = curseg->sum_blk->entries[blkoff];
+			goto got_it;
+		}
+	}
+
+	sum_page = get_sum_page(sbi, segno);
+	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
+	sum = sum_node->entries[blkoff];
+	f2fs_put_page(sum_page, 1);
+got_it:
+	/* Use the locked dnode page and inode */
+	nid = le32_to_cpu(sum.nid);
+	if (dn->inode->i_ino == nid) {
+		tdn.nid = nid;
+		if (!dn->inode_page_locked)
+			lock_page(dn->inode_page);
+		tdn.node_page = dn->inode_page;
+		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		goto truncate_out;
+	} else if (dn->nid == nid) {
+		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		goto truncate_out;
+	}
+
+	/* Get the node page */
+	node_page = get_node_page(sbi, nid);
+	if (IS_ERR(node_page))
+		return PTR_ERR(node_page);
+
+	offset = ofs_of_node(node_page);
+	ino = ino_of_node(node_page);
+	f2fs_put_page(node_page, 1);
+
+	if (ino != dn->inode->i_ino) {
+		/* Deallocate previous index in the node page */
+		inode = f2fs_iget(sbi->sb, ino);
+		if (IS_ERR(inode))
+			return PTR_ERR(inode);
+	} else {
+		inode = dn->inode;
+	}
+
+	bidx = start_bidx_of_node(offset, F2FS_I(inode)) +
+			le16_to_cpu(sum.ofs_in_node);
+
+	/*
+	 * if inode page is locked, unlock temporarily, but its reference
+	 * count keeps alive.
+	 */
+	if (ino == dn->inode->i_ino && dn->inode_page_locked)
+		unlock_page(dn->inode_page);
+
+	set_new_dnode(&tdn, inode, NULL, NULL, 0);
+	if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
+		goto out;
+
+	if (tdn.data_blkaddr == blkaddr)
+		truncate_data_blocks_range(&tdn, 1);
+
+	f2fs_put_dnode(&tdn);
+out:
+	if (ino != dn->inode->i_ino)
+		iput(inode);
+	else if (dn->inode_page_locked)
+		lock_page(dn->inode_page);
+	return 0;
+
+truncate_out:
+	if (datablock_addr(tdn.node_page, tdn.ofs_in_node) == blkaddr)
+		truncate_data_blocks_range(&tdn, 1);
+	if (dn->inode->i_ino == nid && !dn->inode_page_locked)
+		unlock_page(dn->inode_page);
+	return 0;
+}
+
+static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
+					struct page *page, block_t blkaddr)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int start, end;
+	struct dnode_of_data dn;
+	struct f2fs_summary sum;
+	struct node_info ni;
+	int err = 0, recovered = 0;
+
+	/* step 1: recover xattr */
+	if (IS_INODE(page)) {
+		recover_inline_xattr(inode, page);
+	} else if (f2fs_has_xattr_block(ofs_of_node(page))) {
+		/*
+		 * Deprecated; xattr blocks should be found from cold log.
+		 * But, we should remain this for backward compatibility.
+		 */
+		recover_xattr_data(inode, page, blkaddr);
+		goto out;
+	}
+
+	/* step 2: recover inline data */
+	if (recover_inline_data(inode, page))
+		goto out;
+
+	/* step 3: recover data indices */
+	start = start_bidx_of_node(ofs_of_node(page), fi);
+	end = start + ADDRS_PER_PAGE(page, fi);
+
+	f2fs_lock_op(sbi);
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+
+	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
+	if (err) {
+		f2fs_unlock_op(sbi);
+		goto out;
+	}
+
+	f2fs_wait_on_page_writeback(dn.node_page, NODE);
+
+	get_node_info(sbi, dn.nid, &ni);
+	f2fs_bug_on(sbi, ni.ino != ino_of_node(page));
+	f2fs_bug_on(sbi, ofs_of_node(dn.node_page) != ofs_of_node(page));
+
+	for (; start < end; start++) {
+		block_t src, dest;
+
+		src = datablock_addr(dn.node_page, dn.ofs_in_node);
+		dest = datablock_addr(page, dn.ofs_in_node);
+
+		if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR &&
+			dest >= MAIN_BLKADDR(sbi) && dest < MAX_BLKADDR(sbi)) {
+
+			if (src == NULL_ADDR) {
+				err = reserve_new_block(&dn);
+				/* We should not get -ENOSPC */
+				f2fs_bug_on(sbi, err);
+			}
+
+			/* Check the previous node page having this index */
+			err = check_index_in_prev_nodes(sbi, dest, &dn);
+			if (err)
+				goto err;
+
+			set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
+
+			/* write dummy data page */
+			recover_data_page(sbi, NULL, &sum, src, dest);
+			dn.data_blkaddr = dest;
+			set_data_blkaddr(&dn);
+			f2fs_update_extent_cache(&dn);
+			recovered++;
+		}
+		dn.ofs_in_node++;
+	}
+
+	if (IS_INODE(dn.node_page))
+		sync_inode_page(&dn);
+
+	copy_node_footer(dn.node_page, page);
+	fill_node_footer(dn.node_page, dn.nid, ni.ino,
+					ofs_of_node(page), false);
+	set_page_dirty(dn.node_page);
+err:
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+out:
+	f2fs_msg(sbi->sb, KERN_NOTICE,
+		"recover_data: ino = %lx, recovered = %d blocks, err = %d",
+		inode->i_ino, recovered, err);
+	return err;
+}
+
+static int recover_data(struct f2fs_sb_info *sbi,
+				struct list_head *head, int type)
+{
+	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
+	struct curseg_info *curseg;
+	struct page *page = NULL;
+	int err = 0;
+	block_t blkaddr;
+
+	/* get node pages in the current segment */
+	curseg = CURSEG_I(sbi, type);
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	while (1) {
+		struct fsync_inode_entry *entry;
+
+		if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
+			break;
+
+		ra_meta_pages_cond(sbi, blkaddr);
+
+		page = get_meta_page(sbi, blkaddr);
+
+		if (cp_ver != cpver_of_node(page)) {
+			f2fs_put_page(page, 1);
+			break;
+		}
+
+		entry = get_fsync_inode(head, ino_of_node(page));
+		if (!entry)
+			goto next;
+		/*
+		 * inode(x) | CP | inode(x) | dnode(F)
+		 * In this case, we can lose the latest inode(x).
+		 * So, call recover_inode for the inode update.
+		 */
+		if (entry->last_inode == blkaddr)
+			recover_inode(entry->inode, page);
+		if (entry->last_dentry == blkaddr) {
+			err = recover_dentry(entry->inode, page);
+			if (err) {
+				f2fs_put_page(page, 1);
+				break;
+			}
+		}
+		err = do_recover_data(sbi, entry->inode, page, blkaddr);
+		if (err) {
+			f2fs_put_page(page, 1);
+			break;
+		}
+
+		if (entry->blkaddr == blkaddr) {
+			iput(entry->inode);
+			list_del(&entry->list);
+			kmem_cache_free(fsync_entry_slab, entry);
+		}
+next:
+		/* check next segment */
+		blkaddr = next_blkaddr_of_node(page);
+		f2fs_put_page(page, 1);
+	}
+	if (!err)
+		allocate_new_segments(sbi);
+	return err;
+}
+
+int recover_fsync_data(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+	struct list_head inode_list;
+	block_t blkaddr;
+	int err;
+	bool need_writecp = false;
+
+	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
+			sizeof(struct fsync_inode_entry));
+	if (!fsync_entry_slab)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&inode_list);
+
+	/* step #1: find fsynced inode numbers */
+	set_sbi_flag(sbi, SBI_POR_DOING);
+
+	/* prevent checkpoint */
+	mutex_lock(&sbi->cp_mutex);
+
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	err = find_fsync_dnodes(sbi, &inode_list);
+	if (err)
+		goto out;
+
+	if (list_empty(&inode_list))
+		goto out;
+
+	need_writecp = true;
+
+	/* step #2: recover data */
+	err = recover_data(sbi, &inode_list, CURSEG_WARM_NODE);
+	if (!err)
+		f2fs_bug_on(sbi, !list_empty(&inode_list));
+out:
+	destroy_fsync_dnodes(&inode_list);
+	kmem_cache_destroy(fsync_entry_slab);
+
+	/* truncate meta pages to be used by the recovery */
+	truncate_inode_pages_range(META_MAPPING(sbi),
+			MAIN_BLKADDR(sbi) << PAGE_CACHE_SHIFT, -1);
+
+	if (err) {
+		truncate_inode_pages_final(NODE_MAPPING(sbi));
+		truncate_inode_pages_final(META_MAPPING(sbi));
+	}
+
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+	if (err) {
+		discard_next_dnode(sbi, blkaddr);
+
+		/* Flush all the NAT/SIT pages */
+		while (get_pages(sbi, F2FS_DIRTY_META))
+			sync_meta_pages(sbi, META, LONG_MAX);
+		set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+		mutex_unlock(&sbi->cp_mutex);
+	} else if (need_writecp) {
+		struct cp_control cpc = {
+			.reason = CP_RECOVERY,
+		};
+		mutex_unlock(&sbi->cp_mutex);
+		write_checkpoint(sbi, &cpc);
+	} else {
+		mutex_unlock(&sbi->cp_mutex);
+	}
+	return err;
+}
diff --git a/kernel/fs/f2fs/segment.c b/kernel/fs/f2fs/segment.c
new file mode 100644
index 000000000..f93966094
--- /dev/null
+++ b/kernel/fs/f2fs/segment.c
@@ -0,0 +1,2307 @@
+/*
+ * fs/f2fs/segment.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/prefetch.h>
+#include <linux/kthread.h>
+#include <linux/vmalloc.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "segment.h"
+#include "node.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+#define __reverse_ffz(x) __reverse_ffs(~(x))
+
+static struct kmem_cache *discard_entry_slab;
+static struct kmem_cache *sit_entry_set_slab;
+static struct kmem_cache *inmem_entry_slab;
+
+/*
+ * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
+ * MSB and LSB are reversed in a byte by f2fs_set_bit.
+ */
+static inline unsigned long __reverse_ffs(unsigned long word)
+{
+	int num = 0;
+
+#if BITS_PER_LONG == 64
+	if ((word & 0xffffffff) == 0) {
+		num += 32;
+		word >>= 32;
+	}
+#endif
+	if ((word & 0xffff) == 0) {
+		num += 16;
+		word >>= 16;
+	}
+	if ((word & 0xff) == 0) {
+		num += 8;
+		word >>= 8;
+	}
+	if ((word & 0xf0) == 0)
+		num += 4;
+	else
+		word >>= 4;
+	if ((word & 0xc) == 0)
+		num += 2;
+	else
+		word >>= 2;
+	if ((word & 0x2) == 0)
+		num += 1;
+	return num;
+}
+
+/*
+ * __find_rev_next(_zero)_bit is copied from lib/find_next_bit.c because
+ * f2fs_set_bit makes MSB and LSB reversed in a byte.
+ * Example:
+ *                             LSB <--> MSB
+ *   f2fs_set_bit(0, bitmap) => 0000 0001
+ *   f2fs_set_bit(7, bitmap) => 1000 0000
+ */
+static unsigned long __find_rev_next_bit(const unsigned long *addr,
+			unsigned long size, unsigned long offset)
+{
+	const unsigned long *p = addr + BIT_WORD(offset);
+	unsigned long result = offset & ~(BITS_PER_LONG - 1);
+	unsigned long tmp;
+	unsigned long mask, submask;
+	unsigned long quot, rest;
+
+	if (offset >= size)
+		return size;
+
+	size -= result;
+	offset %= BITS_PER_LONG;
+	if (!offset)
+		goto aligned;
+
+	tmp = *(p++);
+	quot = (offset >> 3) << 3;
+	rest = offset & 0x7;
+	mask = ~0UL << quot;
+	submask = (unsigned char)(0xff << rest) >> rest;
+	submask <<= quot;
+	mask &= submask;
+	tmp &= mask;
+	if (size < BITS_PER_LONG)
+		goto found_first;
+	if (tmp)
+		goto found_middle;
+
+	size -= BITS_PER_LONG;
+	result += BITS_PER_LONG;
+aligned:
+	while (size & ~(BITS_PER_LONG-1)) {
+		tmp = *(p++);
+		if (tmp)
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+found_first:
+	tmp &= (~0UL >> (BITS_PER_LONG - size));
+	if (tmp == 0UL)		/* Are any bits set? */
+		return result + size;   /* Nope. */
+found_middle:
+	return result + __reverse_ffs(tmp);
+}
+
+static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
+			unsigned long size, unsigned long offset)
+{
+	const unsigned long *p = addr + BIT_WORD(offset);
+	unsigned long result = offset & ~(BITS_PER_LONG - 1);
+	unsigned long tmp;
+	unsigned long mask, submask;
+	unsigned long quot, rest;
+
+	if (offset >= size)
+		return size;
+
+	size -= result;
+	offset %= BITS_PER_LONG;
+	if (!offset)
+		goto aligned;
+
+	tmp = *(p++);
+	quot = (offset >> 3) << 3;
+	rest = offset & 0x7;
+	mask = ~(~0UL << quot);
+	submask = (unsigned char)~((unsigned char)(0xff << rest) >> rest);
+	submask <<= quot;
+	mask += submask;
+	tmp |= mask;
+	if (size < BITS_PER_LONG)
+		goto found_first;
+	if (~tmp)
+		goto found_middle;
+
+	size -= BITS_PER_LONG;
+	result += BITS_PER_LONG;
+aligned:
+	while (size & ~(BITS_PER_LONG - 1)) {
+		tmp = *(p++);
+		if (~tmp)
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+
+found_first:
+	tmp |= ~0UL << size;
+	if (tmp == ~0UL)        /* Are any bits zero? */
+		return result + size;   /* Nope. */
+found_middle:
+	return result + __reverse_ffz(tmp);
+}
+
+void register_inmem_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *new;
+	int err;
+
+	SetPagePrivate(page);
+	f2fs_trace_pid(page);
+
+	new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
+
+	/* add atomic page indices to the list */
+	new->page = page;
+	INIT_LIST_HEAD(&new->list);
+retry:
+	/* increase reference count with clean state */
+	mutex_lock(&fi->inmem_lock);
+	err = radix_tree_insert(&fi->inmem_root, page->index, new);
+	if (err == -EEXIST) {
+		mutex_unlock(&fi->inmem_lock);
+		kmem_cache_free(inmem_entry_slab, new);
+		return;
+	} else if (err) {
+		mutex_unlock(&fi->inmem_lock);
+		goto retry;
+	}
+	get_page(page);
+	list_add_tail(&new->list, &fi->inmem_pages);
+	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	mutex_unlock(&fi->inmem_lock);
+
+	trace_f2fs_register_inmem_page(page, INMEM);
+}
+
+void commit_inmem_pages(struct inode *inode, bool abort)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *cur, *tmp;
+	bool submit_bio = false;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = WRITE_SYNC | REQ_PRIO,
+	};
+
+	/*
+	 * The abort is true only when f2fs_evict_inode is called.
+	 * Basically, the f2fs_evict_inode doesn't produce any data writes, so
+	 * that we don't need to call f2fs_balance_fs.
+	 * Otherwise, f2fs_gc in f2fs_balance_fs can wait forever until this
+	 * inode becomes free by iget_locked in f2fs_iget.
+	 */
+	if (!abort) {
+		f2fs_balance_fs(sbi);
+		f2fs_lock_op(sbi);
+	}
+
+	mutex_lock(&fi->inmem_lock);
+	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
+		if (!abort) {
+			lock_page(cur->page);
+			if (cur->page->mapping == inode->i_mapping) {
+				f2fs_wait_on_page_writeback(cur->page, DATA);
+				if (clear_page_dirty_for_io(cur->page))
+					inode_dec_dirty_pages(inode);
+				trace_f2fs_commit_inmem_page(cur->page, INMEM);
+				do_write_data_page(cur->page, &fio);
+				submit_bio = true;
+			}
+			f2fs_put_page(cur->page, 1);
+		} else {
+			trace_f2fs_commit_inmem_page(cur->page, INMEM_DROP);
+			put_page(cur->page);
+		}
+		radix_tree_delete(&fi->inmem_root, cur->page->index);
+		list_del(&cur->list);
+		kmem_cache_free(inmem_entry_slab, cur);
+		dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	}
+	mutex_unlock(&fi->inmem_lock);
+
+	if (!abort) {
+		f2fs_unlock_op(sbi);
+		if (submit_bio)
+			f2fs_submit_merged_bio(sbi, DATA, WRITE);
+	}
+}
+
+/*
+ * This function balances dirty node and dentry pages.
+ * In addition, it controls garbage collection.
+ */
+void f2fs_balance_fs(struct f2fs_sb_info *sbi)
+{
+	/*
+	 * We should do GC or end up with checkpoint, if there are so many dirty
+	 * dir/node pages without enough free segments.
+	 */
+	if (has_not_enough_free_secs(sbi, 0)) {
+		mutex_lock(&sbi->gc_mutex);
+		f2fs_gc(sbi);
+	}
+}
+
+void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
+{
+	/* try to shrink extent cache when there is no enough memory */
+	f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
+
+	/* check the # of cached NAT entries and prefree segments */
+	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
+			excess_prefree_segs(sbi) ||
+			!available_free_memory(sbi, INO_ENTRIES))
+		f2fs_sync_fs(sbi->sb, true);
+}
+
+static int issue_flush_thread(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+	wait_queue_head_t *q = &fcc->flush_wait_queue;
+repeat:
+	if (kthread_should_stop())
+		return 0;
+
+	if (!llist_empty(&fcc->issue_list)) {
+		struct bio *bio = bio_alloc(GFP_NOIO, 0);
+		struct flush_cmd *cmd, *next;
+		int ret;
+
+		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
+		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
+
+		bio->bi_bdev = sbi->sb->s_bdev;
+		ret = submit_bio_wait(WRITE_FLUSH, bio);
+
+		llist_for_each_entry_safe(cmd, next,
+					  fcc->dispatch_list, llnode) {
+			cmd->ret = ret;
+			complete(&cmd->wait);
+		}
+		bio_put(bio);
+		fcc->dispatch_list = NULL;
+	}
+
+	wait_event_interruptible(*q,
+		kthread_should_stop() || !llist_empty(&fcc->issue_list));
+	goto repeat;
+}
+
+int f2fs_issue_flush(struct f2fs_sb_info *sbi)
+{
+	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+	struct flush_cmd cmd;
+
+	trace_f2fs_issue_flush(sbi->sb, test_opt(sbi, NOBARRIER),
+					test_opt(sbi, FLUSH_MERGE));
+
+	if (test_opt(sbi, NOBARRIER))
+		return 0;
+
+	if (!test_opt(sbi, FLUSH_MERGE))
+		return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
+
+	init_completion(&cmd.wait);
+
+	llist_add(&cmd.llnode, &fcc->issue_list);
+
+	if (!fcc->dispatch_list)
+		wake_up(&fcc->flush_wait_queue);
+
+	wait_for_completion(&cmd.wait);
+
+	return cmd.ret;
+}
+
+int create_flush_cmd_control(struct f2fs_sb_info *sbi)
+{
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	struct flush_cmd_control *fcc;
+	int err = 0;
+
+	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
+	if (!fcc)
+		return -ENOMEM;
+	init_waitqueue_head(&fcc->flush_wait_queue);
+	init_llist_head(&fcc->issue_list);
+	SM_I(sbi)->cmd_control_info = fcc;
+	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
+				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(fcc->f2fs_issue_flush)) {
+		err = PTR_ERR(fcc->f2fs_issue_flush);
+		kfree(fcc);
+		SM_I(sbi)->cmd_control_info = NULL;
+		return err;
+	}
+
+	return err;
+}
+
+void destroy_flush_cmd_control(struct f2fs_sb_info *sbi)
+{
+	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+
+	if (fcc && fcc->f2fs_issue_flush)
+		kthread_stop(fcc->f2fs_issue_flush);
+	kfree(fcc);
+	SM_I(sbi)->cmd_control_info = NULL;
+}
+
+static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	/* need not be added */
+	if (IS_CURSEG(sbi, segno))
+		return;
+
+	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
+		dirty_i->nr_dirty[dirty_type]++;
+
+	if (dirty_type == DIRTY) {
+		struct seg_entry *sentry = get_seg_entry(sbi, segno);
+		enum dirty_type t = sentry->type;
+
+		if (unlikely(t >= DIRTY)) {
+			f2fs_bug_on(sbi, 1);
+			return;
+		}
+		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]++;
+	}
+}
+
+static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
+		dirty_i->nr_dirty[dirty_type]--;
+
+	if (dirty_type == DIRTY) {
+		struct seg_entry *sentry = get_seg_entry(sbi, segno);
+		enum dirty_type t = sentry->type;
+
+		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]--;
+
+		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
+			clear_bit(GET_SECNO(sbi, segno),
+						dirty_i->victim_secmap);
+	}
+}
+
+/*
+ * Should not occur error such as -ENOMEM.
+ * Adding dirty entry into seglist is not critical operation.
+ * If a given segment is one of current working segments, it won't be added.
+ */
+static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned short valid_blocks;
+
+	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
+		return;
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	valid_blocks = get_valid_blocks(sbi, segno, 0);
+
+	if (valid_blocks == 0) {
+		__locate_dirty_segment(sbi, segno, PRE);
+		__remove_dirty_segment(sbi, segno, DIRTY);
+	} else if (valid_blocks < sbi->blocks_per_seg) {
+		__locate_dirty_segment(sbi, segno, DIRTY);
+	} else {
+		/* Recovery routine with SSR needs this */
+		__remove_dirty_segment(sbi, segno, DIRTY);
+	}
+
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
+				block_t blkstart, block_t blklen)
+{
+	sector_t start = SECTOR_FROM_BLOCK(blkstart);
+	sector_t len = SECTOR_FROM_BLOCK(blklen);
+	trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
+	return blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
+}
+
+void discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	if (f2fs_issue_discard(sbi, blkaddr, 1)) {
+		struct page *page = grab_meta_page(sbi, blkaddr);
+		/* zero-filled page */
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+}
+
+static void __add_discard_entry(struct f2fs_sb_info *sbi,
+		struct cp_control *cpc, unsigned int start, unsigned int end)
+{
+	struct list_head *head = &SM_I(sbi)->discard_list;
+	struct discard_entry *new, *last;
+
+	if (!list_empty(head)) {
+		last = list_last_entry(head, struct discard_entry, list);
+		if (START_BLOCK(sbi, cpc->trim_start) + start ==
+						last->blkaddr + last->len) {
+			last->len += end - start;
+			goto done;
+		}
+	}
+
+	new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
+	INIT_LIST_HEAD(&new->list);
+	new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
+	new->len = end - start;
+	list_add_tail(&new->list, head);
+done:
+	SM_I(sbi)->nr_discards += end - start;
+	cpc->trimmed += end - start;
+}
+
+static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
+	int max_blocks = sbi->blocks_per_seg;
+	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
+	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
+	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
+	unsigned long *dmap = SIT_I(sbi)->tmp_map;
+	unsigned int start = 0, end = -1;
+	bool force = (cpc->reason == CP_DISCARD);
+	int i;
+
+	if (!force && (!test_opt(sbi, DISCARD) ||
+			SM_I(sbi)->nr_discards >= SM_I(sbi)->max_discards))
+		return;
+
+	if (force && !se->valid_blocks) {
+		struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+		/*
+		 * if this segment is registered in the prefree list, then
+		 * we should skip adding a discard candidate, and let the
+		 * checkpoint do that later.
+		 */
+		mutex_lock(&dirty_i->seglist_lock);
+		if (test_bit(cpc->trim_start, dirty_i->dirty_segmap[PRE])) {
+			mutex_unlock(&dirty_i->seglist_lock);
+			cpc->trimmed += sbi->blocks_per_seg;
+			return;
+		}
+		mutex_unlock(&dirty_i->seglist_lock);
+
+		__add_discard_entry(sbi, cpc, 0, sbi->blocks_per_seg);
+		return;
+	}
+
+	/* zero block will be discarded through the prefree list */
+	if (!se->valid_blocks || se->valid_blocks == max_blocks)
+		return;
+
+	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
+	for (i = 0; i < entries; i++)
+		dmap[i] = force ? ~ckpt_map[i] :
+				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
+
+	while (force || SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
+		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
+		if (start >= max_blocks)
+			break;
+
+		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
+
+		if (force && end - start < cpc->trim_minlen)
+			continue;
+
+		__add_discard_entry(sbi, cpc, start, end);
+	}
+}
+
+void release_discard_addrs(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &(SM_I(sbi)->discard_list);
+	struct discard_entry *entry, *this;
+
+	/* drop caches */
+	list_for_each_entry_safe(entry, this, head, list) {
+		list_del(&entry->list);
+		kmem_cache_free(discard_entry_slab, entry);
+	}
+}
+
+/*
+ * Should call clear_prefree_segments after checkpoint is done.
+ */
+static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int segno;
+
+	mutex_lock(&dirty_i->seglist_lock);
+	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
+		__set_test_and_free(sbi, segno);
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+void clear_prefree_segments(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &(SM_I(sbi)->discard_list);
+	struct discard_entry *entry, *this;
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
+	unsigned int start = 0, end = -1;
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	while (1) {
+		int i;
+		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
+		if (start >= MAIN_SEGS(sbi))
+			break;
+		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
+								start + 1);
+
+		for (i = start; i < end; i++)
+			clear_bit(i, prefree_map);
+
+		dirty_i->nr_dirty[PRE] -= end - start;
+
+		if (!test_opt(sbi, DISCARD))
+			continue;
+
+		f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
+				(end - start) << sbi->log_blocks_per_seg);
+	}
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	/* send small discards */
+	list_for_each_entry_safe(entry, this, head, list) {
+		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
+		list_del(&entry->list);
+		SM_I(sbi)->nr_discards -= entry->len;
+		kmem_cache_free(discard_entry_slab, entry);
+	}
+}
+
+static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+
+	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
+		sit_i->dirty_sentries++;
+		return false;
+	}
+
+	return true;
+}
+
+static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
+					unsigned int segno, int modified)
+{
+	struct seg_entry *se = get_seg_entry(sbi, segno);
+	se->type = type;
+	if (modified)
+		__mark_sit_entry_dirty(sbi, segno);
+}
+
+static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
+{
+	struct seg_entry *se;
+	unsigned int segno, offset;
+	long int new_vblocks;
+
+	segno = GET_SEGNO(sbi, blkaddr);
+
+	se = get_seg_entry(sbi, segno);
+	new_vblocks = se->valid_blocks + del;
+	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+
+	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
+				(new_vblocks > sbi->blocks_per_seg)));
+
+	se->valid_blocks = new_vblocks;
+	se->mtime = get_mtime(sbi);
+	SIT_I(sbi)->max_mtime = se->mtime;
+
+	/* Update valid block bitmap */
+	if (del > 0) {
+		if (f2fs_test_and_set_bit(offset, se->cur_valid_map))
+			f2fs_bug_on(sbi, 1);
+	} else {
+		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map))
+			f2fs_bug_on(sbi, 1);
+	}
+	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
+		se->ckpt_valid_blocks += del;
+
+	__mark_sit_entry_dirty(sbi, segno);
+
+	/* update total number of valid blocks to be written in ckpt area */
+	SIT_I(sbi)->written_valid_blocks += del;
+
+	if (sbi->segs_per_sec > 1)
+		get_sec_entry(sbi, segno)->valid_blocks += del;
+}
+
+void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
+{
+	update_sit_entry(sbi, new, 1);
+	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
+		update_sit_entry(sbi, old, -1);
+
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
+}
+
+void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
+{
+	unsigned int segno = GET_SEGNO(sbi, addr);
+	struct sit_info *sit_i = SIT_I(sbi);
+
+	f2fs_bug_on(sbi, addr == NULL_ADDR);
+	if (addr == NEW_ADDR)
+		return;
+
+	/* add it into sit main buffer */
+	mutex_lock(&sit_i->sentry_lock);
+
+	update_sit_entry(sbi, addr, -1);
+
+	/* add it into dirty seglist */
+	locate_dirty_segment(sbi, segno);
+
+	mutex_unlock(&sit_i->sentry_lock);
+}
+
+/*
+ * This function should be resided under the curseg_mutex lock
+ */
+static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
+					struct f2fs_summary *sum)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	void *addr = curseg->sum_blk;
+	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
+	memcpy(addr, sum, sizeof(struct f2fs_summary));
+}
+
+/*
+ * Calculate the number of current summary pages for writing
+ */
+int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
+{
+	int valid_sum_count = 0;
+	int i, sum_in_page;
+
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		if (sbi->ckpt->alloc_type[i] == SSR)
+			valid_sum_count += sbi->blocks_per_seg;
+		else {
+			if (for_ra)
+				valid_sum_count += le16_to_cpu(
+					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
+			else
+				valid_sum_count += curseg_blkoff(sbi, i);
+		}
+	}
+
+	sum_in_page = (PAGE_CACHE_SIZE - 2 * SUM_JOURNAL_SIZE -
+			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
+	if (valid_sum_count <= sum_in_page)
+		return 1;
+	else if ((valid_sum_count - sum_in_page) <=
+		(PAGE_CACHE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
+		return 2;
+	return 3;
+}
+
+/*
+ * Caller should put this summary page
+ */
+struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
+}
+
+static void write_sum_page(struct f2fs_sb_info *sbi,
+			struct f2fs_summary_block *sum_blk, block_t blk_addr)
+{
+	struct page *page = grab_meta_page(sbi, blk_addr);
+	void *kaddr = page_address(page);
+	memcpy(kaddr, sum_blk, PAGE_CACHE_SIZE);
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+}
+
+static int is_next_segment_free(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int segno = curseg->segno + 1;
+	struct free_segmap_info *free_i = FREE_I(sbi);
+
+	if (segno < MAIN_SEGS(sbi) && segno % sbi->segs_per_sec)
+		return !test_bit(segno, free_i->free_segmap);
+	return 0;
+}
+
+/*
+ * Find a new segment from the free segments bitmap to right order
+ * This function should be returned with success, otherwise BUG
+ */
+static void get_new_segment(struct f2fs_sb_info *sbi,
+			unsigned int *newseg, bool new_sec, int dir)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int segno, secno, zoneno;
+	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
+	unsigned int hint = *newseg / sbi->segs_per_sec;
+	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
+	unsigned int left_start = hint;
+	bool init = true;
+	int go_left = 0;
+	int i;
+
+	spin_lock(&free_i->segmap_lock);
+
+	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
+		segno = find_next_zero_bit(free_i->free_segmap,
+					MAIN_SEGS(sbi), *newseg + 1);
+		if (segno - *newseg < sbi->segs_per_sec -
+					(*newseg % sbi->segs_per_sec))
+			goto got_it;
+	}
+find_other_zone:
+	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
+	if (secno >= MAIN_SECS(sbi)) {
+		if (dir == ALLOC_RIGHT) {
+			secno = find_next_zero_bit(free_i->free_secmap,
+							MAIN_SECS(sbi), 0);
+			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
+		} else {
+			go_left = 1;
+			left_start = hint - 1;
+		}
+	}
+	if (go_left == 0)
+		goto skip_left;
+
+	while (test_bit(left_start, free_i->free_secmap)) {
+		if (left_start > 0) {
+			left_start--;
+			continue;
+		}
+		left_start = find_next_zero_bit(free_i->free_secmap,
+							MAIN_SECS(sbi), 0);
+		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
+		break;
+	}
+	secno = left_start;
+skip_left:
+	hint = secno;
+	segno = secno * sbi->segs_per_sec;
+	zoneno = secno / sbi->secs_per_zone;
+
+	/* give up on finding another zone */
+	if (!init)
+		goto got_it;
+	if (sbi->secs_per_zone == 1)
+		goto got_it;
+	if (zoneno == old_zoneno)
+		goto got_it;
+	if (dir == ALLOC_LEFT) {
+		if (!go_left && zoneno + 1 >= total_zones)
+			goto got_it;
+		if (go_left && zoneno == 0)
+			goto got_it;
+	}
+	for (i = 0; i < NR_CURSEG_TYPE; i++)
+		if (CURSEG_I(sbi, i)->zone == zoneno)
+			break;
+
+	if (i < NR_CURSEG_TYPE) {
+		/* zone is in user, try another */
+		if (go_left)
+			hint = zoneno * sbi->secs_per_zone - 1;
+		else if (zoneno + 1 >= total_zones)
+			hint = 0;
+		else
+			hint = (zoneno + 1) * sbi->secs_per_zone;
+		init = false;
+		goto find_other_zone;
+	}
+got_it:
+	/* set it as dirty segment in free segmap */
+	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
+	__set_inuse(sbi, segno);
+	*newseg = segno;
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	struct summary_footer *sum_footer;
+
+	curseg->segno = curseg->next_segno;
+	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
+	curseg->next_blkoff = 0;
+	curseg->next_segno = NULL_SEGNO;
+
+	sum_footer = &(curseg->sum_blk->footer);
+	memset(sum_footer, 0, sizeof(struct summary_footer));
+	if (IS_DATASEG(type))
+		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
+	if (IS_NODESEG(type))
+		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
+	__set_sit_entry_type(sbi, type, curseg->segno, modified);
+}
+
+/*
+ * Allocate a current working segment.
+ * This function always allocates a free segment in LFS manner.
+ */
+static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int segno = curseg->segno;
+	int dir = ALLOC_LEFT;
+
+	write_sum_page(sbi, curseg->sum_blk,
+				GET_SUM_BLOCK(sbi, segno));
+	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
+		dir = ALLOC_RIGHT;
+
+	if (test_opt(sbi, NOHEAP))
+		dir = ALLOC_RIGHT;
+
+	get_new_segment(sbi, &segno, new_sec, dir);
+	curseg->next_segno = segno;
+	reset_curseg(sbi, type, 1);
+	curseg->alloc_type = LFS;
+}
+
+static void __next_free_blkoff(struct f2fs_sb_info *sbi,
+			struct curseg_info *seg, block_t start)
+{
+	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
+	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
+	unsigned long *target_map = SIT_I(sbi)->tmp_map;
+	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
+	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
+	int i, pos;
+
+	for (i = 0; i < entries; i++)
+		target_map[i] = ckpt_map[i] | cur_map[i];
+
+	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
+
+	seg->next_blkoff = pos;
+}
+
+/*
+ * If a segment is written by LFS manner, next block offset is just obtained
+ * by increasing the current block offset. However, if a segment is written by
+ * SSR manner, next block offset obtained by calling __next_free_blkoff
+ */
+static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
+				struct curseg_info *seg)
+{
+	if (seg->alloc_type == SSR)
+		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
+	else
+		seg->next_blkoff++;
+}
+
+/*
+ * This function always allocates a used segment(from dirty seglist) by SSR
+ * manner, so it should recover the existing segment information of valid blocks
+ */
+static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int new_segno = curseg->next_segno;
+	struct f2fs_summary_block *sum_node;
+	struct page *sum_page;
+
+	write_sum_page(sbi, curseg->sum_blk,
+				GET_SUM_BLOCK(sbi, curseg->segno));
+	__set_test_and_inuse(sbi, new_segno);
+
+	mutex_lock(&dirty_i->seglist_lock);
+	__remove_dirty_segment(sbi, new_segno, PRE);
+	__remove_dirty_segment(sbi, new_segno, DIRTY);
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	reset_curseg(sbi, type, 1);
+	curseg->alloc_type = SSR;
+	__next_free_blkoff(sbi, curseg, 0);
+
+	if (reuse) {
+		sum_page = get_sum_page(sbi, new_segno);
+		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
+		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
+		f2fs_put_page(sum_page, 1);
+	}
+}
+
+static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
+
+	if (IS_NODESEG(type) || !has_not_enough_free_secs(sbi, 0))
+		return v_ops->get_victim(sbi,
+				&(curseg)->next_segno, BG_GC, type, SSR);
+
+	/* For data segments, let's do SSR more intensively */
+	for (; type >= CURSEG_HOT_DATA; type--)
+		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
+						BG_GC, type, SSR))
+			return 1;
+	return 0;
+}
+
+/*
+ * flush out current segment and replace it with new segment
+ * This function should be returned with success, otherwise BUG
+ */
+static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
+						int type, bool force)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+
+	if (force)
+		new_curseg(sbi, type, true);
+	else if (type == CURSEG_WARM_NODE)
+		new_curseg(sbi, type, false);
+	else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
+		new_curseg(sbi, type, false);
+	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
+		change_curseg(sbi, type, true);
+	else
+		new_curseg(sbi, type, false);
+
+	stat_inc_seg_type(sbi, curseg);
+}
+
+static void __allocate_new_segments(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int old_segno;
+
+	old_segno = curseg->segno;
+	SIT_I(sbi)->s_ops->allocate_segment(sbi, type, true);
+	locate_dirty_segment(sbi, old_segno);
+}
+
+void allocate_new_segments(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
+		__allocate_new_segments(sbi, i);
+}
+
+static const struct segment_allocation default_salloc_ops = {
+	.allocate_segment = allocate_segment_by_default,
+};
+
+int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
+{
+	__u64 start = F2FS_BYTES_TO_BLK(range->start);
+	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
+	unsigned int start_segno, end_segno;
+	struct cp_control cpc;
+
+	if (range->minlen > SEGMENT_SIZE(sbi) || start >= MAX_BLKADDR(sbi) ||
+						range->len < sbi->blocksize)
+		return -EINVAL;
+
+	cpc.trimmed = 0;
+	if (end <= MAIN_BLKADDR(sbi))
+		goto out;
+
+	/* start/end segment number in main_area */
+	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
+	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
+						GET_SEGNO(sbi, end);
+	cpc.reason = CP_DISCARD;
+	cpc.trim_minlen = F2FS_BYTES_TO_BLK(range->minlen);
+
+	/* do checkpoint to issue discard commands safely */
+	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
+		cpc.trim_start = start_segno;
+		cpc.trim_end = min_t(unsigned int, rounddown(start_segno +
+				BATCHED_TRIM_SEGMENTS(sbi),
+				sbi->segs_per_sec) - 1, end_segno);
+
+		mutex_lock(&sbi->gc_mutex);
+		write_checkpoint(sbi, &cpc);
+		mutex_unlock(&sbi->gc_mutex);
+	}
+out:
+	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
+	return 0;
+}
+
+static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	if (curseg->next_blkoff < sbi->blocks_per_seg)
+		return true;
+	return false;
+}
+
+static int __get_segment_type_2(struct page *page, enum page_type p_type)
+{
+	if (p_type == DATA)
+		return CURSEG_HOT_DATA;
+	else
+		return CURSEG_HOT_NODE;
+}
+
+static int __get_segment_type_4(struct page *page, enum page_type p_type)
+{
+	if (p_type == DATA) {
+		struct inode *inode = page->mapping->host;
+
+		if (S_ISDIR(inode->i_mode))
+			return CURSEG_HOT_DATA;
+		else
+			return CURSEG_COLD_DATA;
+	} else {
+		if (IS_DNODE(page) && is_cold_node(page))
+			return CURSEG_WARM_NODE;
+		else
+			return CURSEG_COLD_NODE;
+	}
+}
+
+static int __get_segment_type_6(struct page *page, enum page_type p_type)
+{
+	if (p_type == DATA) {
+		struct inode *inode = page->mapping->host;
+
+		if (S_ISDIR(inode->i_mode))
+			return CURSEG_HOT_DATA;
+		else if (is_cold_data(page) || file_is_cold(inode))
+			return CURSEG_COLD_DATA;
+		else
+			return CURSEG_WARM_DATA;
+	} else {
+		if (IS_DNODE(page))
+			return is_cold_node(page) ? CURSEG_WARM_NODE :
+						CURSEG_HOT_NODE;
+		else
+			return CURSEG_COLD_NODE;
+	}
+}
+
+static int __get_segment_type(struct page *page, enum page_type p_type)
+{
+	switch (F2FS_P_SB(page)->active_logs) {
+	case 2:
+		return __get_segment_type_2(page, p_type);
+	case 4:
+		return __get_segment_type_4(page, p_type);
+	}
+	/* NR_CURSEG_TYPE(6) logs by default */
+	f2fs_bug_on(F2FS_P_SB(page),
+		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
+	return __get_segment_type_6(page, p_type);
+}
+
+void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+		block_t old_blkaddr, block_t *new_blkaddr,
+		struct f2fs_summary *sum, int type)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg;
+	bool direct_io = (type == CURSEG_DIRECT_IO);
+
+	type = direct_io ? CURSEG_WARM_DATA : type;
+
+	curseg = CURSEG_I(sbi, type);
+
+	mutex_lock(&curseg->curseg_mutex);
+	mutex_lock(&sit_i->sentry_lock);
+
+	/* direct_io'ed data is aligned to the segment for better performance */
+	if (direct_io && curseg->next_blkoff)
+		__allocate_new_segments(sbi, type);
+
+	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	/*
+	 * __add_sum_entry should be resided under the curseg_mutex
+	 * because, this function updates a summary entry in the
+	 * current summary block.
+	 */
+	__add_sum_entry(sbi, type, sum);
+
+	__refresh_next_blkoff(sbi, curseg);
+
+	stat_inc_block_count(sbi, curseg);
+
+	if (!__has_curseg_space(sbi, type))
+		sit_i->s_ops->allocate_segment(sbi, type, false);
+	/*
+	 * SIT information should be updated before segment allocation,
+	 * since SSR needs latest valid block information.
+	 */
+	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
+
+	mutex_unlock(&sit_i->sentry_lock);
+
+	if (page && IS_NODESEG(type))
+		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
+
+	mutex_unlock(&curseg->curseg_mutex);
+}
+
+static void do_write_page(struct f2fs_sb_info *sbi, struct page *page,
+			struct f2fs_summary *sum,
+			struct f2fs_io_info *fio)
+{
+	int type = __get_segment_type(page, fio->type);
+
+	allocate_data_block(sbi, page, fio->blk_addr, &fio->blk_addr, sum, type);
+
+	/* writeout dirty page into bdev */
+	f2fs_submit_page_mbio(sbi, page, fio);
+}
+
+void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_io_info fio = {
+		.type = META,
+		.rw = WRITE_SYNC | REQ_META | REQ_PRIO,
+		.blk_addr = page->index,
+	};
+
+	set_page_writeback(page);
+	f2fs_submit_page_mbio(sbi, page, &fio);
+}
+
+void write_node_page(struct f2fs_sb_info *sbi, struct page *page,
+			unsigned int nid, struct f2fs_io_info *fio)
+{
+	struct f2fs_summary sum;
+	set_summary(&sum, nid, 0, 0);
+	do_write_page(sbi, page, &sum, fio);
+}
+
+void write_data_page(struct page *page, struct dnode_of_data *dn,
+				struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_summary sum;
+	struct node_info ni;
+
+	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
+	get_node_info(sbi, dn->nid, &ni);
+	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+	do_write_page(sbi, page, &sum, fio);
+	dn->data_blkaddr = fio->blk_addr;
+}
+
+void rewrite_data_page(struct page *page, struct f2fs_io_info *fio)
+{
+	stat_inc_inplace_blocks(F2FS_P_SB(page));
+	f2fs_submit_page_mbio(F2FS_P_SB(page), page, fio);
+}
+
+void recover_data_page(struct f2fs_sb_info *sbi,
+			struct page *page, struct f2fs_summary *sum,
+			block_t old_blkaddr, block_t new_blkaddr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg;
+	unsigned int segno, old_cursegno;
+	struct seg_entry *se;
+	int type;
+
+	segno = GET_SEGNO(sbi, new_blkaddr);
+	se = get_seg_entry(sbi, segno);
+	type = se->type;
+
+	if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
+		if (old_blkaddr == NULL_ADDR)
+			type = CURSEG_COLD_DATA;
+		else
+			type = CURSEG_WARM_DATA;
+	}
+	curseg = CURSEG_I(sbi, type);
+
+	mutex_lock(&curseg->curseg_mutex);
+	mutex_lock(&sit_i->sentry_lock);
+
+	old_cursegno = curseg->segno;
+
+	/* change the current segment */
+	if (segno != curseg->segno) {
+		curseg->next_segno = segno;
+		change_curseg(sbi, type, true);
+	}
+
+	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
+	__add_sum_entry(sbi, type, sum);
+
+	refresh_sit_entry(sbi, old_blkaddr, new_blkaddr);
+	locate_dirty_segment(sbi, old_cursegno);
+
+	mutex_unlock(&sit_i->sentry_lock);
+	mutex_unlock(&curseg->curseg_mutex);
+}
+
+static inline bool is_merged_page(struct f2fs_sb_info *sbi,
+					struct page *page, enum page_type type)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	struct f2fs_bio_info *io = &sbi->write_io[btype];
+	struct bio_vec *bvec;
+	int i;
+
+	down_read(&io->io_rwsem);
+	if (!io->bio)
+		goto out;
+
+	bio_for_each_segment_all(bvec, io->bio, i) {
+		if (page == bvec->bv_page) {
+			up_read(&io->io_rwsem);
+			return true;
+		}
+	}
+
+out:
+	up_read(&io->io_rwsem);
+	return false;
+}
+
+void f2fs_wait_on_page_writeback(struct page *page,
+				enum page_type type)
+{
+	if (PageWriteback(page)) {
+		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+
+		if (is_merged_page(sbi, page, type))
+			f2fs_submit_merged_bio(sbi, type, WRITE);
+		wait_on_page_writeback(page);
+	}
+}
+
+static int read_compacted_summaries(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct curseg_info *seg_i;
+	unsigned char *kaddr;
+	struct page *page;
+	block_t start;
+	int i, j, offset;
+
+	start = start_sum_block(sbi);
+
+	page = get_meta_page(sbi, start++);
+	kaddr = (unsigned char *)page_address(page);
+
+	/* Step 1: restore nat cache */
+	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	memcpy(&seg_i->sum_blk->n_nats, kaddr, SUM_JOURNAL_SIZE);
+
+	/* Step 2: restore sit cache */
+	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	memcpy(&seg_i->sum_blk->n_sits, kaddr + SUM_JOURNAL_SIZE,
+						SUM_JOURNAL_SIZE);
+	offset = 2 * SUM_JOURNAL_SIZE;
+
+	/* Step 3: restore summary entries */
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		unsigned short blk_off;
+		unsigned int segno;
+
+		seg_i = CURSEG_I(sbi, i);
+		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
+		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
+		seg_i->next_segno = segno;
+		reset_curseg(sbi, i, 0);
+		seg_i->alloc_type = ckpt->alloc_type[i];
+		seg_i->next_blkoff = blk_off;
+
+		if (seg_i->alloc_type == SSR)
+			blk_off = sbi->blocks_per_seg;
+
+		for (j = 0; j < blk_off; j++) {
+			struct f2fs_summary *s;
+			s = (struct f2fs_summary *)(kaddr + offset);
+			seg_i->sum_blk->entries[j] = *s;
+			offset += SUMMARY_SIZE;
+			if (offset + SUMMARY_SIZE <= PAGE_CACHE_SIZE -
+						SUM_FOOTER_SIZE)
+				continue;
+
+			f2fs_put_page(page, 1);
+			page = NULL;
+
+			page = get_meta_page(sbi, start++);
+			kaddr = (unsigned char *)page_address(page);
+			offset = 0;
+		}
+	}
+	f2fs_put_page(page, 1);
+	return 0;
+}
+
+static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_summary_block *sum;
+	struct curseg_info *curseg;
+	struct page *new;
+	unsigned short blk_off;
+	unsigned int segno = 0;
+	block_t blk_addr = 0;
+
+	/* get segment number and block addr */
+	if (IS_DATASEG(type)) {
+		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
+		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
+							CURSEG_HOT_DATA]);
+		if (__exist_node_summaries(sbi))
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
+		else
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
+	} else {
+		segno = le32_to_cpu(ckpt->cur_node_segno[type -
+							CURSEG_HOT_NODE]);
+		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
+							CURSEG_HOT_NODE]);
+		if (__exist_node_summaries(sbi))
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
+							type - CURSEG_HOT_NODE);
+		else
+			blk_addr = GET_SUM_BLOCK(sbi, segno);
+	}
+
+	new = get_meta_page(sbi, blk_addr);
+	sum = (struct f2fs_summary_block *)page_address(new);
+
+	if (IS_NODESEG(type)) {
+		if (__exist_node_summaries(sbi)) {
+			struct f2fs_summary *ns = &sum->entries[0];
+			int i;
+			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
+				ns->version = 0;
+				ns->ofs_in_node = 0;
+			}
+		} else {
+			int err;
+
+			err = restore_node_summary(sbi, segno, sum);
+			if (err) {
+				f2fs_put_page(new, 1);
+				return err;
+			}
+		}
+	}
+
+	/* set uncompleted segment to curseg */
+	curseg = CURSEG_I(sbi, type);
+	mutex_lock(&curseg->curseg_mutex);
+	memcpy(curseg->sum_blk, sum, PAGE_CACHE_SIZE);
+	curseg->next_segno = segno;
+	reset_curseg(sbi, type, 0);
+	curseg->alloc_type = ckpt->alloc_type[type];
+	curseg->next_blkoff = blk_off;
+	mutex_unlock(&curseg->curseg_mutex);
+	f2fs_put_page(new, 1);
+	return 0;
+}
+
+static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
+{
+	int type = CURSEG_HOT_DATA;
+	int err;
+
+	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
+		int npages = npages_for_summary_flush(sbi, true);
+
+		if (npages >= 2)
+			ra_meta_pages(sbi, start_sum_block(sbi), npages,
+								META_CP);
+
+		/* restore for compacted data summary */
+		if (read_compacted_summaries(sbi))
+			return -EINVAL;
+		type = CURSEG_HOT_NODE;
+	}
+
+	if (__exist_node_summaries(sbi))
+		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
+					NR_CURSEG_TYPE - type, META_CP);
+
+	for (; type <= CURSEG_COLD_NODE; type++) {
+		err = read_normal_summaries(sbi, type);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct page *page;
+	unsigned char *kaddr;
+	struct f2fs_summary *summary;
+	struct curseg_info *seg_i;
+	int written_size = 0;
+	int i, j;
+
+	page = grab_meta_page(sbi, blkaddr++);
+	kaddr = (unsigned char *)page_address(page);
+
+	/* Step 1: write nat cache */
+	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	memcpy(kaddr, &seg_i->sum_blk->n_nats, SUM_JOURNAL_SIZE);
+	written_size += SUM_JOURNAL_SIZE;
+
+	/* Step 2: write sit cache */
+	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	memcpy(kaddr + written_size, &seg_i->sum_blk->n_sits,
+						SUM_JOURNAL_SIZE);
+	written_size += SUM_JOURNAL_SIZE;
+
+	/* Step 3: write summary entries */
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		unsigned short blkoff;
+		seg_i = CURSEG_I(sbi, i);
+		if (sbi->ckpt->alloc_type[i] == SSR)
+			blkoff = sbi->blocks_per_seg;
+		else
+			blkoff = curseg_blkoff(sbi, i);
+
+		for (j = 0; j < blkoff; j++) {
+			if (!page) {
+				page = grab_meta_page(sbi, blkaddr++);
+				kaddr = (unsigned char *)page_address(page);
+				written_size = 0;
+			}
+			summary = (struct f2fs_summary *)(kaddr + written_size);
+			*summary = seg_i->sum_blk->entries[j];
+			written_size += SUMMARY_SIZE;
+
+			if (written_size + SUMMARY_SIZE <= PAGE_CACHE_SIZE -
+							SUM_FOOTER_SIZE)
+				continue;
+
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+			page = NULL;
+		}
+	}
+	if (page) {
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+}
+
+static void write_normal_summaries(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type)
+{
+	int i, end;
+	if (IS_DATASEG(type))
+		end = type + NR_CURSEG_DATA_TYPE;
+	else
+		end = type + NR_CURSEG_NODE_TYPE;
+
+	for (i = type; i < end; i++) {
+		struct curseg_info *sum = CURSEG_I(sbi, i);
+		mutex_lock(&sum->curseg_mutex);
+		write_sum_page(sbi, sum->sum_blk, blkaddr + (i - type));
+		mutex_unlock(&sum->curseg_mutex);
+	}
+}
+
+void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG))
+		write_compacted_summaries(sbi, start_blk);
+	else
+		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
+}
+
+void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
+}
+
+int lookup_journal_in_cursum(struct f2fs_summary_block *sum, int type,
+					unsigned int val, int alloc)
+{
+	int i;
+
+	if (type == NAT_JOURNAL) {
+		for (i = 0; i < nats_in_cursum(sum); i++) {
+			if (le32_to_cpu(nid_in_journal(sum, i)) == val)
+				return i;
+		}
+		if (alloc && nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES)
+			return update_nats_in_cursum(sum, 1);
+	} else if (type == SIT_JOURNAL) {
+		for (i = 0; i < sits_in_cursum(sum); i++)
+			if (le32_to_cpu(segno_in_journal(sum, i)) == val)
+				return i;
+		if (alloc && sits_in_cursum(sum) < SIT_JOURNAL_ENTRIES)
+			return update_sits_in_cursum(sum, 1);
+	}
+	return -1;
+}
+
+static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
+					unsigned int segno)
+{
+	return get_meta_page(sbi, current_sit_addr(sbi, segno));
+}
+
+static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
+					unsigned int start)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct page *src_page, *dst_page;
+	pgoff_t src_off, dst_off;
+	void *src_addr, *dst_addr;
+
+	src_off = current_sit_addr(sbi, start);
+	dst_off = next_sit_addr(sbi, src_off);
+
+	/* get current sit block page without lock */
+	src_page = get_meta_page(sbi, src_off);
+	dst_page = grab_meta_page(sbi, dst_off);
+	f2fs_bug_on(sbi, PageDirty(src_page));
+
+	src_addr = page_address(src_page);
+	dst_addr = page_address(dst_page);
+	memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
+
+	set_page_dirty(dst_page);
+	f2fs_put_page(src_page, 1);
+
+	set_to_next_sit(sit_i, start);
+
+	return dst_page;
+}
+
+static struct sit_entry_set *grab_sit_entry_set(void)
+{
+	struct sit_entry_set *ses =
+			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_ATOMIC);
+
+	ses->entry_cnt = 0;
+	INIT_LIST_HEAD(&ses->set_list);
+	return ses;
+}
+
+static void release_sit_entry_set(struct sit_entry_set *ses)
+{
+	list_del(&ses->set_list);
+	kmem_cache_free(sit_entry_set_slab, ses);
+}
+
+static void adjust_sit_entry_set(struct sit_entry_set *ses,
+						struct list_head *head)
+{
+	struct sit_entry_set *next = ses;
+
+	if (list_is_last(&ses->set_list, head))
+		return;
+
+	list_for_each_entry_continue(next, head, set_list)
+		if (ses->entry_cnt <= next->entry_cnt)
+			break;
+
+	list_move_tail(&ses->set_list, &next->set_list);
+}
+
+static void add_sit_entry(unsigned int segno, struct list_head *head)
+{
+	struct sit_entry_set *ses;
+	unsigned int start_segno = START_SEGNO(segno);
+
+	list_for_each_entry(ses, head, set_list) {
+		if (ses->start_segno == start_segno) {
+			ses->entry_cnt++;
+			adjust_sit_entry_set(ses, head);
+			return;
+		}
+	}
+
+	ses = grab_sit_entry_set();
+
+	ses->start_segno = start_segno;
+	ses->entry_cnt++;
+	list_add(&ses->set_list, head);
+}
+
+static void add_sits_in_set(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_info = SM_I(sbi);
+	struct list_head *set_list = &sm_info->sit_entry_set;
+	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
+	unsigned int segno;
+
+	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
+		add_sit_entry(segno, set_list);
+}
+
+static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	int i;
+
+	for (i = sits_in_cursum(sum) - 1; i >= 0; i--) {
+		unsigned int segno;
+		bool dirtied;
+
+		segno = le32_to_cpu(segno_in_journal(sum, i));
+		dirtied = __mark_sit_entry_dirty(sbi, segno);
+
+		if (!dirtied)
+			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
+	}
+	update_sits_in_cursum(sum, -sits_in_cursum(sum));
+}
+
+/*
+ * CP calls this function, which flushes SIT entries including sit_journal,
+ * and moves prefree segs to free segs.
+ */
+void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	struct sit_entry_set *ses, *tmp;
+	struct list_head *head = &SM_I(sbi)->sit_entry_set;
+	bool to_journal = true;
+	struct seg_entry *se;
+
+	mutex_lock(&curseg->curseg_mutex);
+	mutex_lock(&sit_i->sentry_lock);
+
+	if (!sit_i->dirty_sentries)
+		goto out;
+
+	/*
+	 * add and account sit entries of dirty bitmap in sit entry
+	 * set temporarily
+	 */
+	add_sits_in_set(sbi);
+
+	/*
+	 * if there are no enough space in journal to store dirty sit
+	 * entries, remove all entries from journal and add and account
+	 * them in sit entry set.
+	 */
+	if (!__has_cursum_space(sum, sit_i->dirty_sentries, SIT_JOURNAL))
+		remove_sits_in_journal(sbi);
+
+	/*
+	 * there are two steps to flush sit entries:
+	 * #1, flush sit entries to journal in current cold data summary block.
+	 * #2, flush sit entries to sit page.
+	 */
+	list_for_each_entry_safe(ses, tmp, head, set_list) {
+		struct page *page = NULL;
+		struct f2fs_sit_block *raw_sit = NULL;
+		unsigned int start_segno = ses->start_segno;
+		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
+						(unsigned long)MAIN_SEGS(sbi));
+		unsigned int segno = start_segno;
+
+		if (to_journal &&
+			!__has_cursum_space(sum, ses->entry_cnt, SIT_JOURNAL))
+			to_journal = false;
+
+		if (!to_journal) {
+			page = get_next_sit_page(sbi, start_segno);
+			raw_sit = page_address(page);
+		}
+
+		/* flush dirty sit entries in region of current sit set */
+		for_each_set_bit_from(segno, bitmap, end) {
+			int offset, sit_offset;
+
+			se = get_seg_entry(sbi, segno);
+
+			/* add discard candidates */
+			if (cpc->reason != CP_DISCARD) {
+				cpc->trim_start = segno;
+				add_discard_addrs(sbi, cpc);
+			}
+
+			if (to_journal) {
+				offset = lookup_journal_in_cursum(sum,
+							SIT_JOURNAL, segno, 1);
+				f2fs_bug_on(sbi, offset < 0);
+				segno_in_journal(sum, offset) =
+							cpu_to_le32(segno);
+				seg_info_to_raw_sit(se,
+						&sit_in_journal(sum, offset));
+			} else {
+				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
+				seg_info_to_raw_sit(se,
+						&raw_sit->entries[sit_offset]);
+			}
+
+			__clear_bit(segno, bitmap);
+			sit_i->dirty_sentries--;
+			ses->entry_cnt--;
+		}
+
+		if (!to_journal)
+			f2fs_put_page(page, 1);
+
+		f2fs_bug_on(sbi, ses->entry_cnt);
+		release_sit_entry_set(ses);
+	}
+
+	f2fs_bug_on(sbi, !list_empty(head));
+	f2fs_bug_on(sbi, sit_i->dirty_sentries);
+out:
+	if (cpc->reason == CP_DISCARD) {
+		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
+			add_discard_addrs(sbi, cpc);
+	}
+	mutex_unlock(&sit_i->sentry_lock);
+	mutex_unlock(&curseg->curseg_mutex);
+
+	set_prefree_as_free_segments(sbi);
+}
+
+static int build_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct sit_info *sit_i;
+	unsigned int sit_segs, start;
+	char *src_bitmap, *dst_bitmap;
+	unsigned int bitmap_size;
+
+	/* allocate memory for SIT information */
+	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
+	if (!sit_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->sit_info = sit_i;
+
+	sit_i->sentries = vzalloc(MAIN_SEGS(sbi) * sizeof(struct seg_entry));
+	if (!sit_i->sentries)
+		return -ENOMEM;
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+	sit_i->dirty_sentries_bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!sit_i->dirty_sentries_bitmap)
+		return -ENOMEM;
+
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
+		sit_i->sentries[start].cur_valid_map
+			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		sit_i->sentries[start].ckpt_valid_map
+			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		if (!sit_i->sentries[start].cur_valid_map
+				|| !sit_i->sentries[start].ckpt_valid_map)
+			return -ENOMEM;
+	}
+
+	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+	if (!sit_i->tmp_map)
+		return -ENOMEM;
+
+	if (sbi->segs_per_sec > 1) {
+		sit_i->sec_entries = vzalloc(MAIN_SECS(sbi) *
+					sizeof(struct sec_entry));
+		if (!sit_i->sec_entries)
+			return -ENOMEM;
+	}
+
+	/* get information related with SIT */
+	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
+
+	/* setup SIT bitmap from ckeckpoint pack */
+	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
+	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
+
+	dst_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	if (!dst_bitmap)
+		return -ENOMEM;
+
+	/* init SIT information */
+	sit_i->s_ops = &default_salloc_ops;
+
+	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
+	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
+	sit_i->written_valid_blocks = le64_to_cpu(ckpt->valid_block_count);
+	sit_i->sit_bitmap = dst_bitmap;
+	sit_i->bitmap_size = bitmap_size;
+	sit_i->dirty_sentries = 0;
+	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
+	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
+	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
+	mutex_init(&sit_i->sentry_lock);
+	return 0;
+}
+
+static int build_free_segmap(struct f2fs_sb_info *sbi)
+{
+	struct free_segmap_info *free_i;
+	unsigned int bitmap_size, sec_bitmap_size;
+
+	/* allocate memory for free segmap information */
+	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
+	if (!free_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->free_info = free_i;
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+	free_i->free_segmap = kmalloc(bitmap_size, GFP_KERNEL);
+	if (!free_i->free_segmap)
+		return -ENOMEM;
+
+	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
+	free_i->free_secmap = kmalloc(sec_bitmap_size, GFP_KERNEL);
+	if (!free_i->free_secmap)
+		return -ENOMEM;
+
+	/* set all segments as dirty temporarily */
+	memset(free_i->free_segmap, 0xff, bitmap_size);
+	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
+
+	/* init free segmap information */
+	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
+	free_i->free_segments = 0;
+	free_i->free_sections = 0;
+	spin_lock_init(&free_i->segmap_lock);
+	return 0;
+}
+
+static int build_curseg(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *array;
+	int i;
+
+	array = kcalloc(NR_CURSEG_TYPE, sizeof(*array), GFP_KERNEL);
+	if (!array)
+		return -ENOMEM;
+
+	SM_I(sbi)->curseg_array = array;
+
+	for (i = 0; i < NR_CURSEG_TYPE; i++) {
+		mutex_init(&array[i].curseg_mutex);
+		array[i].sum_blk = kzalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+		if (!array[i].sum_blk)
+			return -ENOMEM;
+		array[i].segno = NULL_SEGNO;
+		array[i].next_blkoff = 0;
+	}
+	return restore_curseg_summaries(sbi);
+}
+
+static void build_sit_entries(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_summary_block *sum = curseg->sum_blk;
+	int sit_blk_cnt = SIT_BLK_CNT(sbi);
+	unsigned int i, start, end;
+	unsigned int readed, start_blk = 0;
+	int nrpages = MAX_BIO_BLOCKS(sbi);
+
+	do {
+		readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);
+
+		start = start_blk * sit_i->sents_per_block;
+		end = (start_blk + readed) * sit_i->sents_per_block;
+
+		for (; start < end && start < MAIN_SEGS(sbi); start++) {
+			struct seg_entry *se = &sit_i->sentries[start];
+			struct f2fs_sit_block *sit_blk;
+			struct f2fs_sit_entry sit;
+			struct page *page;
+
+			mutex_lock(&curseg->curseg_mutex);
+			for (i = 0; i < sits_in_cursum(sum); i++) {
+				if (le32_to_cpu(segno_in_journal(sum, i))
+								== start) {
+					sit = sit_in_journal(sum, i);
+					mutex_unlock(&curseg->curseg_mutex);
+					goto got_it;
+				}
+			}
+			mutex_unlock(&curseg->curseg_mutex);
+
+			page = get_current_sit_page(sbi, start);
+			sit_blk = (struct f2fs_sit_block *)page_address(page);
+			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
+			f2fs_put_page(page, 1);
+got_it:
+			check_block_count(sbi, start, &sit);
+			seg_info_from_raw_sit(se, &sit);
+			if (sbi->segs_per_sec > 1) {
+				struct sec_entry *e = get_sec_entry(sbi, start);
+				e->valid_blocks += se->valid_blocks;
+			}
+		}
+		start_blk += readed;
+	} while (start_blk < sit_blk_cnt);
+}
+
+static void init_free_segmap(struct f2fs_sb_info *sbi)
+{
+	unsigned int start;
+	int type;
+
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
+		struct seg_entry *sentry = get_seg_entry(sbi, start);
+		if (!sentry->valid_blocks)
+			__set_free(sbi, start);
+	}
+
+	/* set use the current segments */
+	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
+		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
+		__set_test_and_inuse(sbi, curseg_t->segno);
+	}
+}
+
+static void init_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int segno = 0, offset = 0;
+	unsigned short valid_blocks;
+
+	while (1) {
+		/* find dirty segment based on free segmap */
+		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
+		if (segno >= MAIN_SEGS(sbi))
+			break;
+		offset = segno + 1;
+		valid_blocks = get_valid_blocks(sbi, segno, 0);
+		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
+			continue;
+		if (valid_blocks > sbi->blocks_per_seg) {
+			f2fs_bug_on(sbi, 1);
+			continue;
+		}
+		mutex_lock(&dirty_i->seglist_lock);
+		__locate_dirty_segment(sbi, segno, DIRTY);
+		mutex_unlock(&dirty_i->seglist_lock);
+	}
+}
+
+static int init_victim_secmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	dirty_i->victim_secmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!dirty_i->victim_secmap)
+		return -ENOMEM;
+	return 0;
+}
+
+static int build_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i;
+	unsigned int bitmap_size, i;
+
+	/* allocate memory for dirty segments list information */
+	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
+	if (!dirty_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->dirty_info = dirty_i;
+	mutex_init(&dirty_i->seglist_lock);
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+
+	for (i = 0; i < NR_DIRTY_TYPE; i++) {
+		dirty_i->dirty_segmap[i] = kzalloc(bitmap_size, GFP_KERNEL);
+		if (!dirty_i->dirty_segmap[i])
+			return -ENOMEM;
+	}
+
+	init_dirty_segmap(sbi);
+	return init_victim_secmap(sbi);
+}
+
+/*
+ * Update min, max modified time for cost-benefit GC algorithm
+ */
+static void init_min_max_mtime(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int segno;
+
+	mutex_lock(&sit_i->sentry_lock);
+
+	sit_i->min_mtime = LLONG_MAX;
+
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
+		unsigned int i;
+		unsigned long long mtime = 0;
+
+		for (i = 0; i < sbi->segs_per_sec; i++)
+			mtime += get_seg_entry(sbi, segno + i)->mtime;
+
+		mtime = div_u64(mtime, sbi->segs_per_sec);
+
+		if (sit_i->min_mtime > mtime)
+			sit_i->min_mtime = mtime;
+	}
+	sit_i->max_mtime = get_mtime(sbi);
+	mutex_unlock(&sit_i->sentry_lock);
+}
+
+int build_segment_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_sm_info *sm_info;
+	int err;
+
+	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
+	if (!sm_info)
+		return -ENOMEM;
+
+	/* init sm info */
+	sbi->sm_info = sm_info;
+	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
+	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
+	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
+	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
+	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
+	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
+	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
+	sm_info->rec_prefree_segments = sm_info->main_segments *
+					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
+	sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
+	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
+	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
+
+	INIT_LIST_HEAD(&sm_info->discard_list);
+	sm_info->nr_discards = 0;
+	sm_info->max_discards = 0;
+
+	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
+
+	INIT_LIST_HEAD(&sm_info->sit_entry_set);
+
+	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
+		err = create_flush_cmd_control(sbi);
+		if (err)
+			return err;
+	}
+
+	err = build_sit_info(sbi);
+	if (err)
+		return err;
+	err = build_free_segmap(sbi);
+	if (err)
+		return err;
+	err = build_curseg(sbi);
+	if (err)
+		return err;
+
+	/* reinit free segmap based on SIT */
+	build_sit_entries(sbi);
+
+	init_free_segmap(sbi);
+	err = build_dirty_segmap(sbi);
+	if (err)
+		return err;
+
+	init_min_max_mtime(sbi);
+	return 0;
+}
+
+static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	mutex_lock(&dirty_i->seglist_lock);
+	kfree(dirty_i->dirty_segmap[dirty_type]);
+	dirty_i->nr_dirty[dirty_type] = 0;
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	kfree(dirty_i->victim_secmap);
+}
+
+static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	int i;
+
+	if (!dirty_i)
+		return;
+
+	/* discard pre-free/dirty segments list */
+	for (i = 0; i < NR_DIRTY_TYPE; i++)
+		discard_dirty_segmap(sbi, i);
+
+	destroy_victim_secmap(sbi);
+	SM_I(sbi)->dirty_info = NULL;
+	kfree(dirty_i);
+}
+
+static void destroy_curseg(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *array = SM_I(sbi)->curseg_array;
+	int i;
+
+	if (!array)
+		return;
+	SM_I(sbi)->curseg_array = NULL;
+	for (i = 0; i < NR_CURSEG_TYPE; i++)
+		kfree(array[i].sum_blk);
+	kfree(array);
+}
+
+static void destroy_free_segmap(struct f2fs_sb_info *sbi)
+{
+	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
+	if (!free_i)
+		return;
+	SM_I(sbi)->free_info = NULL;
+	kfree(free_i->free_segmap);
+	kfree(free_i->free_secmap);
+	kfree(free_i);
+}
+
+static void destroy_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int start;
+
+	if (!sit_i)
+		return;
+
+	if (sit_i->sentries) {
+		for (start = 0; start < MAIN_SEGS(sbi); start++) {
+			kfree(sit_i->sentries[start].cur_valid_map);
+			kfree(sit_i->sentries[start].ckpt_valid_map);
+		}
+	}
+	kfree(sit_i->tmp_map);
+
+	vfree(sit_i->sentries);
+	vfree(sit_i->sec_entries);
+	kfree(sit_i->dirty_sentries_bitmap);
+
+	SM_I(sbi)->sit_info = NULL;
+	kfree(sit_i->sit_bitmap);
+	kfree(sit_i);
+}
+
+void destroy_segment_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_info = SM_I(sbi);
+
+	if (!sm_info)
+		return;
+	destroy_flush_cmd_control(sbi);
+	destroy_dirty_segmap(sbi);
+	destroy_curseg(sbi);
+	destroy_free_segmap(sbi);
+	destroy_sit_info(sbi);
+	sbi->sm_info = NULL;
+	kfree(sm_info);
+}
+
+int __init create_segment_manager_caches(void)
+{
+	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
+			sizeof(struct discard_entry));
+	if (!discard_entry_slab)
+		goto fail;
+
+	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
+			sizeof(struct sit_entry_set));
+	if (!sit_entry_set_slab)
+		goto destory_discard_entry;
+
+	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
+			sizeof(struct inmem_pages));
+	if (!inmem_entry_slab)
+		goto destroy_sit_entry_set;
+	return 0;
+
+destroy_sit_entry_set:
+	kmem_cache_destroy(sit_entry_set_slab);
+destory_discard_entry:
+	kmem_cache_destroy(discard_entry_slab);
+fail:
+	return -ENOMEM;
+}
+
+void destroy_segment_manager_caches(void)
+{
+	kmem_cache_destroy(sit_entry_set_slab);
+	kmem_cache_destroy(discard_entry_slab);
+	kmem_cache_destroy(inmem_entry_slab);
+}
diff --git a/kernel/fs/f2fs/segment.h b/kernel/fs/f2fs/segment.h
new file mode 100644
index 000000000..85d7fa751
--- /dev/null
+++ b/kernel/fs/f2fs/segment.h
@@ -0,0 +1,751 @@
+/*
+ * fs/f2fs/segment.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/blkdev.h>
+
+/* constant macro */
+#define NULL_SEGNO			((unsigned int)(~0))
+#define NULL_SECNO			((unsigned int)(~0))
+
+#define DEF_RECLAIM_PREFREE_SEGMENTS	5	/* 5% over total segments */
+
+/* L: Logical segment # in volume, R: Relative segment # in main area */
+#define GET_L2R_SEGNO(free_i, segno)	(segno - free_i->start_segno)
+#define GET_R2L_SEGNO(free_i, segno)	(segno + free_i->start_segno)
+
+#define IS_DATASEG(t)	(t <= CURSEG_COLD_DATA)
+#define IS_NODESEG(t)	(t >= CURSEG_HOT_NODE)
+
+#define IS_CURSEG(sbi, seg)						\
+	((seg == CURSEG_I(sbi, CURSEG_HOT_DATA)->segno) ||	\
+	 (seg == CURSEG_I(sbi, CURSEG_WARM_DATA)->segno) ||	\
+	 (seg == CURSEG_I(sbi, CURSEG_COLD_DATA)->segno) ||	\
+	 (seg == CURSEG_I(sbi, CURSEG_HOT_NODE)->segno) ||	\
+	 (seg == CURSEG_I(sbi, CURSEG_WARM_NODE)->segno) ||	\
+	 (seg == CURSEG_I(sbi, CURSEG_COLD_NODE)->segno))
+
+#define IS_CURSEC(sbi, secno)						\
+	((secno == CURSEG_I(sbi, CURSEG_HOT_DATA)->segno /		\
+	  sbi->segs_per_sec) ||	\
+	 (secno == CURSEG_I(sbi, CURSEG_WARM_DATA)->segno /		\
+	  sbi->segs_per_sec) ||	\
+	 (secno == CURSEG_I(sbi, CURSEG_COLD_DATA)->segno /		\
+	  sbi->segs_per_sec) ||	\
+	 (secno == CURSEG_I(sbi, CURSEG_HOT_NODE)->segno /		\
+	  sbi->segs_per_sec) ||	\
+	 (secno == CURSEG_I(sbi, CURSEG_WARM_NODE)->segno /		\
+	  sbi->segs_per_sec) ||	\
+	 (secno == CURSEG_I(sbi, CURSEG_COLD_NODE)->segno /		\
+	  sbi->segs_per_sec))	\
+
+#define MAIN_BLKADDR(sbi)	(SM_I(sbi)->main_blkaddr)
+#define SEG0_BLKADDR(sbi)	(SM_I(sbi)->seg0_blkaddr)
+
+#define MAIN_SEGS(sbi)	(SM_I(sbi)->main_segments)
+#define MAIN_SECS(sbi)	(sbi->total_sections)
+
+#define TOTAL_SEGS(sbi)	(SM_I(sbi)->segment_count)
+#define TOTAL_BLKS(sbi)	(TOTAL_SEGS(sbi) << sbi->log_blocks_per_seg)
+
+#define MAX_BLKADDR(sbi)	(SEG0_BLKADDR(sbi) + TOTAL_BLKS(sbi))
+#define SEGMENT_SIZE(sbi)	(1ULL << (sbi->log_blocksize +		\
+					sbi->log_blocks_per_seg))
+
+#define START_BLOCK(sbi, segno)	(SEG0_BLKADDR(sbi) +			\
+	 (GET_R2L_SEGNO(FREE_I(sbi), segno) << sbi->log_blocks_per_seg))
+
+#define NEXT_FREE_BLKADDR(sbi, curseg)					\
+	(START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff)
+
+#define GET_SEGOFF_FROM_SEG0(sbi, blk_addr)	((blk_addr) - SEG0_BLKADDR(sbi))
+#define GET_SEGNO_FROM_SEG0(sbi, blk_addr)				\
+	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) >> sbi->log_blocks_per_seg)
+#define GET_BLKOFF_FROM_SEG0(sbi, blk_addr)				\
+	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) & (sbi->blocks_per_seg - 1))
+
+#define GET_SEGNO(sbi, blk_addr)					\
+	(((blk_addr == NULL_ADDR) || (blk_addr == NEW_ADDR)) ?		\
+	NULL_SEGNO : GET_L2R_SEGNO(FREE_I(sbi),			\
+		GET_SEGNO_FROM_SEG0(sbi, blk_addr)))
+#define GET_SECNO(sbi, segno)					\
+	((segno) / sbi->segs_per_sec)
+#define GET_ZONENO_FROM_SEGNO(sbi, segno)				\
+	((segno / sbi->segs_per_sec) / sbi->secs_per_zone)
+
+#define GET_SUM_BLOCK(sbi, segno)				\
+	((sbi->sm_info->ssa_blkaddr) + segno)
+
+#define GET_SUM_TYPE(footer) ((footer)->entry_type)
+#define SET_SUM_TYPE(footer, type) ((footer)->entry_type = type)
+
+#define SIT_ENTRY_OFFSET(sit_i, segno)					\
+	(segno % sit_i->sents_per_block)
+#define SIT_BLOCK_OFFSET(segno)					\
+	(segno / SIT_ENTRY_PER_BLOCK)
+#define	START_SEGNO(segno)		\
+	(SIT_BLOCK_OFFSET(segno) * SIT_ENTRY_PER_BLOCK)
+#define SIT_BLK_CNT(sbi)			\
+	((MAIN_SEGS(sbi) + SIT_ENTRY_PER_BLOCK - 1) / SIT_ENTRY_PER_BLOCK)
+#define f2fs_bitmap_size(nr)			\
+	(BITS_TO_LONGS(nr) * sizeof(unsigned long))
+
+#define SECTOR_FROM_BLOCK(blk_addr)					\
+	(((sector_t)blk_addr) << F2FS_LOG_SECTORS_PER_BLOCK)
+#define SECTOR_TO_BLOCK(sectors)					\
+	(sectors >> F2FS_LOG_SECTORS_PER_BLOCK)
+#define MAX_BIO_BLOCKS(sbi)						\
+	((int)min((int)max_hw_blocks(sbi), BIO_MAX_PAGES))
+
+/*
+ * indicate a block allocation direction: RIGHT and LEFT.
+ * RIGHT means allocating new sections towards the end of volume.
+ * LEFT means the opposite direction.
+ */
+enum {
+	ALLOC_RIGHT = 0,
+	ALLOC_LEFT
+};
+
+/*
+ * In the victim_sel_policy->alloc_mode, there are two block allocation modes.
+ * LFS writes data sequentially with cleaning operations.
+ * SSR (Slack Space Recycle) reuses obsolete space without cleaning operations.
+ */
+enum {
+	LFS = 0,
+	SSR
+};
+
+/*
+ * In the victim_sel_policy->gc_mode, there are two gc, aka cleaning, modes.
+ * GC_CB is based on cost-benefit algorithm.
+ * GC_GREEDY is based on greedy algorithm.
+ */
+enum {
+	GC_CB = 0,
+	GC_GREEDY
+};
+
+/*
+ * BG_GC means the background cleaning job.
+ * FG_GC means the on-demand cleaning job.
+ */
+enum {
+	BG_GC = 0,
+	FG_GC
+};
+
+/* for a function parameter to select a victim segment */
+struct victim_sel_policy {
+	int alloc_mode;			/* LFS or SSR */
+	int gc_mode;			/* GC_CB or GC_GREEDY */
+	unsigned long *dirty_segmap;	/* dirty segment bitmap */
+	unsigned int max_search;	/* maximum # of segments to search */
+	unsigned int offset;		/* last scanned bitmap offset */
+	unsigned int ofs_unit;		/* bitmap search unit */
+	unsigned int min_cost;		/* minimum cost */
+	unsigned int min_segno;		/* segment # having min. cost */
+};
+
+struct seg_entry {
+	unsigned short valid_blocks;	/* # of valid blocks */
+	unsigned char *cur_valid_map;	/* validity bitmap of blocks */
+	/*
+	 * # of valid blocks and the validity bitmap stored in the the last
+	 * checkpoint pack. This information is used by the SSR mode.
+	 */
+	unsigned short ckpt_valid_blocks;
+	unsigned char *ckpt_valid_map;
+	unsigned char type;		/* segment type like CURSEG_XXX_TYPE */
+	unsigned long long mtime;	/* modification time of the segment */
+};
+
+struct sec_entry {
+	unsigned int valid_blocks;	/* # of valid blocks in a section */
+};
+
+struct segment_allocation {
+	void (*allocate_segment)(struct f2fs_sb_info *, int, bool);
+};
+
+struct inmem_pages {
+	struct list_head list;
+	struct page *page;
+};
+
+struct sit_info {
+	const struct segment_allocation *s_ops;
+
+	block_t sit_base_addr;		/* start block address of SIT area */
+	block_t sit_blocks;		/* # of blocks used by SIT area */
+	block_t written_valid_blocks;	/* # of valid blocks in main area */
+	char *sit_bitmap;		/* SIT bitmap pointer */
+	unsigned int bitmap_size;	/* SIT bitmap size */
+
+	unsigned long *tmp_map;			/* bitmap for temporal use */
+	unsigned long *dirty_sentries_bitmap;	/* bitmap for dirty sentries */
+	unsigned int dirty_sentries;		/* # of dirty sentries */
+	unsigned int sents_per_block;		/* # of SIT entries per block */
+	struct mutex sentry_lock;		/* to protect SIT cache */
+	struct seg_entry *sentries;		/* SIT segment-level cache */
+	struct sec_entry *sec_entries;		/* SIT section-level cache */
+
+	/* for cost-benefit algorithm in cleaning procedure */
+	unsigned long long elapsed_time;	/* elapsed time after mount */
+	unsigned long long mounted_time;	/* mount time */
+	unsigned long long min_mtime;		/* min. modification time */
+	unsigned long long max_mtime;		/* max. modification time */
+};
+
+struct free_segmap_info {
+	unsigned int start_segno;	/* start segment number logically */
+	unsigned int free_segments;	/* # of free segments */
+	unsigned int free_sections;	/* # of free sections */
+	spinlock_t segmap_lock;		/* free segmap lock */
+	unsigned long *free_segmap;	/* free segment bitmap */
+	unsigned long *free_secmap;	/* free section bitmap */
+};
+
+/* Notice: The order of dirty type is same with CURSEG_XXX in f2fs.h */
+enum dirty_type {
+	DIRTY_HOT_DATA,		/* dirty segments assigned as hot data logs */
+	DIRTY_WARM_DATA,	/* dirty segments assigned as warm data logs */
+	DIRTY_COLD_DATA,	/* dirty segments assigned as cold data logs */
+	DIRTY_HOT_NODE,		/* dirty segments assigned as hot node logs */
+	DIRTY_WARM_NODE,	/* dirty segments assigned as warm node logs */
+	DIRTY_COLD_NODE,	/* dirty segments assigned as cold node logs */
+	DIRTY,			/* to count # of dirty segments */
+	PRE,			/* to count # of entirely obsolete segments */
+	NR_DIRTY_TYPE
+};
+
+struct dirty_seglist_info {
+	const struct victim_selection *v_ops;	/* victim selction operation */
+	unsigned long *dirty_segmap[NR_DIRTY_TYPE];
+	struct mutex seglist_lock;		/* lock for segment bitmaps */
+	int nr_dirty[NR_DIRTY_TYPE];		/* # of dirty segments */
+	unsigned long *victim_secmap;		/* background GC victims */
+};
+
+/* victim selection function for cleaning and SSR */
+struct victim_selection {
+	int (*get_victim)(struct f2fs_sb_info *, unsigned int *,
+							int, int, char);
+};
+
+/* for active log information */
+struct curseg_info {
+	struct mutex curseg_mutex;		/* lock for consistency */
+	struct f2fs_summary_block *sum_blk;	/* cached summary block */
+	unsigned char alloc_type;		/* current allocation type */
+	unsigned int segno;			/* current segment number */
+	unsigned short next_blkoff;		/* next block offset to write */
+	unsigned int zone;			/* current zone number */
+	unsigned int next_segno;		/* preallocated segment */
+};
+
+struct sit_entry_set {
+	struct list_head set_list;	/* link with all sit sets */
+	unsigned int start_segno;	/* start segno of sits in set */
+	unsigned int entry_cnt;		/* the # of sit entries in set */
+};
+
+/*
+ * inline functions
+ */
+static inline struct curseg_info *CURSEG_I(struct f2fs_sb_info *sbi, int type)
+{
+	return (struct curseg_info *)(SM_I(sbi)->curseg_array + type);
+}
+
+static inline struct seg_entry *get_seg_entry(struct f2fs_sb_info *sbi,
+						unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	return &sit_i->sentries[segno];
+}
+
+static inline struct sec_entry *get_sec_entry(struct f2fs_sb_info *sbi,
+						unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	return &sit_i->sec_entries[GET_SECNO(sbi, segno)];
+}
+
+static inline unsigned int get_valid_blocks(struct f2fs_sb_info *sbi,
+				unsigned int segno, int section)
+{
+	/*
+	 * In order to get # of valid blocks in a section instantly from many
+	 * segments, f2fs manages two counting structures separately.
+	 */
+	if (section > 1)
+		return get_sec_entry(sbi, segno)->valid_blocks;
+	else
+		return get_seg_entry(sbi, segno)->valid_blocks;
+}
+
+static inline void seg_info_from_raw_sit(struct seg_entry *se,
+					struct f2fs_sit_entry *rs)
+{
+	se->valid_blocks = GET_SIT_VBLOCKS(rs);
+	se->ckpt_valid_blocks = GET_SIT_VBLOCKS(rs);
+	memcpy(se->cur_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+	memcpy(se->ckpt_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+	se->type = GET_SIT_TYPE(rs);
+	se->mtime = le64_to_cpu(rs->mtime);
+}
+
+static inline void seg_info_to_raw_sit(struct seg_entry *se,
+					struct f2fs_sit_entry *rs)
+{
+	unsigned short raw_vblocks = (se->type << SIT_VBLOCKS_SHIFT) |
+					se->valid_blocks;
+	rs->vblocks = cpu_to_le16(raw_vblocks);
+	memcpy(rs->valid_map, se->cur_valid_map, SIT_VBLOCK_MAP_SIZE);
+	memcpy(se->ckpt_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+	se->ckpt_valid_blocks = se->valid_blocks;
+	rs->mtime = cpu_to_le64(se->mtime);
+}
+
+static inline unsigned int find_next_inuse(struct free_segmap_info *free_i,
+		unsigned int max, unsigned int segno)
+{
+	unsigned int ret;
+	spin_lock(&free_i->segmap_lock);
+	ret = find_next_bit(free_i->free_segmap, max, segno);
+	spin_unlock(&free_i->segmap_lock);
+	return ret;
+}
+
+static inline void __set_free(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = segno / sbi->segs_per_sec;
+	unsigned int start_segno = secno * sbi->segs_per_sec;
+	unsigned int next;
+
+	spin_lock(&free_i->segmap_lock);
+	clear_bit(segno, free_i->free_segmap);
+	free_i->free_segments++;
+
+	next = find_next_bit(free_i->free_segmap,
+			start_segno + sbi->segs_per_sec, start_segno);
+	if (next >= start_segno + sbi->segs_per_sec) {
+		clear_bit(secno, free_i->free_secmap);
+		free_i->free_sections++;
+	}
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void __set_inuse(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = segno / sbi->segs_per_sec;
+	set_bit(segno, free_i->free_segmap);
+	free_i->free_segments--;
+	if (!test_and_set_bit(secno, free_i->free_secmap))
+		free_i->free_sections--;
+}
+
+static inline void __set_test_and_free(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = segno / sbi->segs_per_sec;
+	unsigned int start_segno = secno * sbi->segs_per_sec;
+	unsigned int next;
+
+	spin_lock(&free_i->segmap_lock);
+	if (test_and_clear_bit(segno, free_i->free_segmap)) {
+		free_i->free_segments++;
+
+		next = find_next_bit(free_i->free_segmap,
+				start_segno + sbi->segs_per_sec, start_segno);
+		if (next >= start_segno + sbi->segs_per_sec) {
+			if (test_and_clear_bit(secno, free_i->free_secmap))
+				free_i->free_sections++;
+		}
+	}
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void __set_test_and_inuse(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = segno / sbi->segs_per_sec;
+	spin_lock(&free_i->segmap_lock);
+	if (!test_and_set_bit(segno, free_i->free_segmap)) {
+		free_i->free_segments--;
+		if (!test_and_set_bit(secno, free_i->free_secmap))
+			free_i->free_sections--;
+	}
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void get_sit_bitmap(struct f2fs_sb_info *sbi,
+		void *dst_addr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	memcpy(dst_addr, sit_i->sit_bitmap, sit_i->bitmap_size);
+}
+
+static inline block_t written_block_count(struct f2fs_sb_info *sbi)
+{
+	return SIT_I(sbi)->written_valid_blocks;
+}
+
+static inline unsigned int free_segments(struct f2fs_sb_info *sbi)
+{
+	return FREE_I(sbi)->free_segments;
+}
+
+static inline int reserved_segments(struct f2fs_sb_info *sbi)
+{
+	return SM_I(sbi)->reserved_segments;
+}
+
+static inline unsigned int free_sections(struct f2fs_sb_info *sbi)
+{
+	return FREE_I(sbi)->free_sections;
+}
+
+static inline unsigned int prefree_segments(struct f2fs_sb_info *sbi)
+{
+	return DIRTY_I(sbi)->nr_dirty[PRE];
+}
+
+static inline unsigned int dirty_segments(struct f2fs_sb_info *sbi)
+{
+	return DIRTY_I(sbi)->nr_dirty[DIRTY_HOT_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_WARM_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_COLD_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_HOT_NODE] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_WARM_NODE] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_COLD_NODE];
+}
+
+static inline int overprovision_segments(struct f2fs_sb_info *sbi)
+{
+	return SM_I(sbi)->ovp_segments;
+}
+
+static inline int overprovision_sections(struct f2fs_sb_info *sbi)
+{
+	return ((unsigned int) overprovision_segments(sbi)) / sbi->segs_per_sec;
+}
+
+static inline int reserved_sections(struct f2fs_sb_info *sbi)
+{
+	return ((unsigned int) reserved_segments(sbi)) / sbi->segs_per_sec;
+}
+
+static inline bool need_SSR(struct f2fs_sb_info *sbi)
+{
+	int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
+	int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
+	return free_sections(sbi) <= (node_secs + 2 * dent_secs +
+						reserved_sections(sbi) + 1);
+}
+
+static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
+{
+	int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
+	int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		return false;
+
+	return (free_sections(sbi) + freed) <= (node_secs + 2 * dent_secs +
+						reserved_sections(sbi));
+}
+
+static inline bool excess_prefree_segs(struct f2fs_sb_info *sbi)
+{
+	return prefree_segments(sbi) > SM_I(sbi)->rec_prefree_segments;
+}
+
+static inline int utilization(struct f2fs_sb_info *sbi)
+{
+	return div_u64((u64)valid_user_blocks(sbi) * 100,
+					sbi->user_block_count);
+}
+
+/*
+ * Sometimes f2fs may be better to drop out-of-place update policy.
+ * And, users can control the policy through sysfs entries.
+ * There are five policies with triggering conditions as follows.
+ * F2FS_IPU_FORCE - all the time,
+ * F2FS_IPU_SSR - if SSR mode is activated,
+ * F2FS_IPU_UTIL - if FS utilization is over threashold,
+ * F2FS_IPU_SSR_UTIL - if SSR mode is activated and FS utilization is over
+ *                     threashold,
+ * F2FS_IPU_FSYNC - activated in fsync path only for high performance flash
+ *                     storages. IPU will be triggered only if the # of dirty
+ *                     pages over min_fsync_blocks.
+ * F2FS_IPUT_DISABLE - disable IPU. (=default option)
+ */
+#define DEF_MIN_IPU_UTIL	70
+#define DEF_MIN_FSYNC_BLOCKS	8
+
+enum {
+	F2FS_IPU_FORCE,
+	F2FS_IPU_SSR,
+	F2FS_IPU_UTIL,
+	F2FS_IPU_SSR_UTIL,
+	F2FS_IPU_FSYNC,
+};
+
+static inline bool need_inplace_update(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	unsigned int policy = SM_I(sbi)->ipu_policy;
+
+	/* IPU can be done only for the user data */
+	if (S_ISDIR(inode->i_mode) || f2fs_is_atomic_file(inode))
+		return false;
+
+	if (policy & (0x1 << F2FS_IPU_FORCE))
+		return true;
+	if (policy & (0x1 << F2FS_IPU_SSR) && need_SSR(sbi))
+		return true;
+	if (policy & (0x1 << F2FS_IPU_UTIL) &&
+			utilization(sbi) > SM_I(sbi)->min_ipu_util)
+		return true;
+	if (policy & (0x1 << F2FS_IPU_SSR_UTIL) && need_SSR(sbi) &&
+			utilization(sbi) > SM_I(sbi)->min_ipu_util)
+		return true;
+
+	/* this is only set during fdatasync */
+	if (policy & (0x1 << F2FS_IPU_FSYNC) &&
+			is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU))
+		return true;
+
+	return false;
+}
+
+static inline unsigned int curseg_segno(struct f2fs_sb_info *sbi,
+		int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->segno;
+}
+
+static inline unsigned char curseg_alloc_type(struct f2fs_sb_info *sbi,
+		int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->alloc_type;
+}
+
+static inline unsigned short curseg_blkoff(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->next_blkoff;
+}
+
+#ifdef CONFIG_F2FS_CHECK_FS
+static inline void check_seg_range(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	BUG_ON(segno > TOTAL_SEGS(sbi) - 1);
+}
+
+static inline void verify_block_addr(struct f2fs_sb_info *sbi, block_t blk_addr)
+{
+	BUG_ON(blk_addr < SEG0_BLKADDR(sbi));
+	BUG_ON(blk_addr >= MAX_BLKADDR(sbi));
+}
+
+/*
+ * Summary block is always treated as an invalid block
+ */
+static inline void check_block_count(struct f2fs_sb_info *sbi,
+		int segno, struct f2fs_sit_entry *raw_sit)
+{
+	bool is_valid  = test_bit_le(0, raw_sit->valid_map) ? true : false;
+	int valid_blocks = 0;
+	int cur_pos = 0, next_pos;
+
+	/* check segment usage */
+	BUG_ON(GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg);
+
+	/* check boundary of a given segment number */
+	BUG_ON(segno > TOTAL_SEGS(sbi) - 1);
+
+	/* check bitmap with valid block count */
+	do {
+		if (is_valid) {
+			next_pos = find_next_zero_bit_le(&raw_sit->valid_map,
+					sbi->blocks_per_seg,
+					cur_pos);
+			valid_blocks += next_pos - cur_pos;
+		} else
+			next_pos = find_next_bit_le(&raw_sit->valid_map,
+					sbi->blocks_per_seg,
+					cur_pos);
+		cur_pos = next_pos;
+		is_valid = !is_valid;
+	} while (cur_pos < sbi->blocks_per_seg);
+	BUG_ON(GET_SIT_VBLOCKS(raw_sit) != valid_blocks);
+}
+#else
+static inline void check_seg_range(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	if (segno > TOTAL_SEGS(sbi) - 1)
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+}
+
+static inline void verify_block_addr(struct f2fs_sb_info *sbi, block_t blk_addr)
+{
+	if (blk_addr < SEG0_BLKADDR(sbi) || blk_addr >= MAX_BLKADDR(sbi))
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+}
+
+/*
+ * Summary block is always treated as an invalid block
+ */
+static inline void check_block_count(struct f2fs_sb_info *sbi,
+		int segno, struct f2fs_sit_entry *raw_sit)
+{
+	/* check segment usage */
+	if (GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg)
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+
+	/* check boundary of a given segment number */
+	if (segno > TOTAL_SEGS(sbi) - 1)
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+}
+#endif
+
+static inline pgoff_t current_sit_addr(struct f2fs_sb_info *sbi,
+						unsigned int start)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int offset = SIT_BLOCK_OFFSET(start);
+	block_t blk_addr = sit_i->sit_base_addr + offset;
+
+	check_seg_range(sbi, start);
+
+	/* calculate sit block address */
+	if (f2fs_test_bit(offset, sit_i->sit_bitmap))
+		blk_addr += sit_i->sit_blocks;
+
+	return blk_addr;
+}
+
+static inline pgoff_t next_sit_addr(struct f2fs_sb_info *sbi,
+						pgoff_t block_addr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	block_addr -= sit_i->sit_base_addr;
+	if (block_addr < sit_i->sit_blocks)
+		block_addr += sit_i->sit_blocks;
+	else
+		block_addr -= sit_i->sit_blocks;
+
+	return block_addr + sit_i->sit_base_addr;
+}
+
+static inline void set_to_next_sit(struct sit_info *sit_i, unsigned int start)
+{
+	unsigned int block_off = SIT_BLOCK_OFFSET(start);
+
+	f2fs_change_bit(block_off, sit_i->sit_bitmap);
+}
+
+static inline unsigned long long get_mtime(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	return sit_i->elapsed_time + CURRENT_TIME_SEC.tv_sec -
+						sit_i->mounted_time;
+}
+
+static inline void set_summary(struct f2fs_summary *sum, nid_t nid,
+			unsigned int ofs_in_node, unsigned char version)
+{
+	sum->nid = cpu_to_le32(nid);
+	sum->ofs_in_node = cpu_to_le16(ofs_in_node);
+	sum->version = version;
+}
+
+static inline block_t start_sum_block(struct f2fs_sb_info *sbi)
+{
+	return __start_cp_addr(sbi) +
+		le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
+}
+
+static inline block_t sum_blk_addr(struct f2fs_sb_info *sbi, int base, int type)
+{
+	return __start_cp_addr(sbi) +
+		le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_total_block_count)
+				- (base + 1) + type;
+}
+
+static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno)
+{
+	if (IS_CURSEC(sbi, secno) || (sbi->cur_victim_sec == secno))
+		return true;
+	return false;
+}
+
+static inline unsigned int max_hw_blocks(struct f2fs_sb_info *sbi)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
+	return SECTOR_TO_BLOCK(queue_max_sectors(q));
+}
+
+/*
+ * It is very important to gather dirty pages and write at once, so that we can
+ * submit a big bio without interfering other data writes.
+ * By default, 512 pages for directory data,
+ * 512 pages (2MB) * 3 for three types of nodes, and
+ * max_bio_blocks for meta are set.
+ */
+static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
+{
+	if (sbi->sb->s_bdi->dirty_exceeded)
+		return 0;
+
+	if (type == DATA)
+		return sbi->blocks_per_seg;
+	else if (type == NODE)
+		return 3 * sbi->blocks_per_seg;
+	else if (type == META)
+		return MAX_BIO_BLOCKS(sbi);
+	else
+		return 0;
+}
+
+/*
+ * When writing pages, it'd better align nr_to_write for segment size.
+ */
+static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,
+					struct writeback_control *wbc)
+{
+	long nr_to_write, desired;
+
+	if (wbc->sync_mode != WB_SYNC_NONE)
+		return 0;
+
+	nr_to_write = wbc->nr_to_write;
+
+	if (type == DATA)
+		desired = 4096;
+	else if (type == NODE)
+		desired = 3 * max_hw_blocks(sbi);
+	else
+		desired = MAX_BIO_BLOCKS(sbi);
+
+	wbc->nr_to_write = desired;
+	return desired - nr_to_write;
+}
diff --git a/kernel/fs/f2fs/super.c b/kernel/fs/f2fs/super.c
new file mode 100644
index 000000000..b2dd1b01f
--- /dev/null
+++ b/kernel/fs/f2fs/super.c
@@ -0,0 +1,1350 @@
+/*
+ * fs/f2fs/super.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/statfs.h>
+#include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/random.h>
+#include <linux/exportfs.h>
+#include <linux/blkdev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sysfs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "gc.h"
+#include "trace.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/f2fs.h>
+
+static struct proc_dir_entry *f2fs_proc_root;
+static struct kmem_cache *f2fs_inode_cachep;
+static struct kset *f2fs_kset;
+
+enum {
+	Opt_gc_background,
+	Opt_disable_roll_forward,
+	Opt_norecovery,
+	Opt_discard,
+	Opt_noheap,
+	Opt_user_xattr,
+	Opt_nouser_xattr,
+	Opt_acl,
+	Opt_noacl,
+	Opt_active_logs,
+	Opt_disable_ext_identify,
+	Opt_inline_xattr,
+	Opt_inline_data,
+	Opt_inline_dentry,
+	Opt_flush_merge,
+	Opt_nobarrier,
+	Opt_fastboot,
+	Opt_extent_cache,
+	Opt_noinline_data,
+	Opt_err,
+};
+
+static match_table_t f2fs_tokens = {
+	{Opt_gc_background, "background_gc=%s"},
+	{Opt_disable_roll_forward, "disable_roll_forward"},
+	{Opt_norecovery, "norecovery"},
+	{Opt_discard, "discard"},
+	{Opt_noheap, "no_heap"},
+	{Opt_user_xattr, "user_xattr"},
+	{Opt_nouser_xattr, "nouser_xattr"},
+	{Opt_acl, "acl"},
+	{Opt_noacl, "noacl"},
+	{Opt_active_logs, "active_logs=%u"},
+	{Opt_disable_ext_identify, "disable_ext_identify"},
+	{Opt_inline_xattr, "inline_xattr"},
+	{Opt_inline_data, "inline_data"},
+	{Opt_inline_dentry, "inline_dentry"},
+	{Opt_flush_merge, "flush_merge"},
+	{Opt_nobarrier, "nobarrier"},
+	{Opt_fastboot, "fastboot"},
+	{Opt_extent_cache, "extent_cache"},
+	{Opt_noinline_data, "noinline_data"},
+	{Opt_err, NULL},
+};
+
+/* Sysfs support for f2fs */
+enum {
+	GC_THREAD,	/* struct f2fs_gc_thread */
+	SM_INFO,	/* struct f2fs_sm_info */
+	NM_INFO,	/* struct f2fs_nm_info */
+	F2FS_SBI,	/* struct f2fs_sb_info */
+};
+
+struct f2fs_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
+	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
+			 const char *, size_t);
+	int struct_type;
+	int offset;
+};
+
+static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
+{
+	if (struct_type == GC_THREAD)
+		return (unsigned char *)sbi->gc_thread;
+	else if (struct_type == SM_INFO)
+		return (unsigned char *)SM_I(sbi);
+	else if (struct_type == NM_INFO)
+		return (unsigned char *)NM_I(sbi);
+	else if (struct_type == F2FS_SBI)
+		return (unsigned char *)sbi;
+	return NULL;
+}
+
+static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi, char *buf)
+{
+	unsigned char *ptr = NULL;
+	unsigned int *ui;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
+}
+
+static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi,
+			const char *buf, size_t count)
+{
+	unsigned char *ptr;
+	unsigned long t;
+	unsigned int *ui;
+	ssize_t ret;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	ret = kstrtoul(skip_spaces(buf), 0, &t);
+	if (ret < 0)
+		return ret;
+	*ui = t;
+	return count;
+}
+
+static ssize_t f2fs_attr_show(struct kobject *kobj,
+				struct attribute *attr, char *buf)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->show ? a->show(a, sbi, buf) : 0;
+}
+
+static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
+						const char *buf, size_t len)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+									s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->store ? a->store(a, sbi, buf, len) : 0;
+}
+
+static void f2fs_sb_release(struct kobject *kobj)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	complete(&sbi->s_kobj_unregister);
+}
+
+#define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
+static struct f2fs_attr f2fs_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.show	= _show,					\
+	.store	= _store,					\
+	.struct_type = _struct_type,				\
+	.offset = _offset					\
+}
+
+#define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
+	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
+		f2fs_sbi_show, f2fs_sbi_store,			\
+		offsetof(struct struct_name, elname))
+
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
+
+#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
+static struct attribute *f2fs_attrs[] = {
+	ATTR_LIST(gc_min_sleep_time),
+	ATTR_LIST(gc_max_sleep_time),
+	ATTR_LIST(gc_no_gc_sleep_time),
+	ATTR_LIST(gc_idle),
+	ATTR_LIST(reclaim_segments),
+	ATTR_LIST(max_small_discards),
+	ATTR_LIST(batched_trim_sections),
+	ATTR_LIST(ipu_policy),
+	ATTR_LIST(min_ipu_util),
+	ATTR_LIST(min_fsync_blocks),
+	ATTR_LIST(max_victim_search),
+	ATTR_LIST(dir_level),
+	ATTR_LIST(ram_thresh),
+	NULL,
+};
+
+static const struct sysfs_ops f2fs_attr_ops = {
+	.show	= f2fs_attr_show,
+	.store	= f2fs_attr_store,
+};
+
+static struct kobj_type f2fs_ktype = {
+	.default_attrs	= f2fs_attrs,
+	.sysfs_ops	= &f2fs_attr_ops,
+	.release	= f2fs_sb_release,
+};
+
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
+static void init_once(void *foo)
+{
+	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
+
+	inode_init_once(&fi->vfs_inode);
+}
+
+static int parse_options(struct super_block *sb, char *options)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	substring_t args[MAX_OPT_ARGS];
+	char *p, *name;
+	int arg = 0;
+
+	if (!options)
+		return 0;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		/*
+		 * Initialize args struct so we know whether arg was
+		 * found; some options take optional arguments.
+		 */
+		args[0].to = args[0].from = NULL;
+		token = match_token(p, f2fs_tokens, args);
+
+		switch (token) {
+		case Opt_gc_background:
+			name = match_strdup(&args[0]);
+
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 2 && !strncmp(name, "on", 2))
+				set_opt(sbi, BG_GC);
+			else if (strlen(name) == 3 && !strncmp(name, "off", 3))
+				clear_opt(sbi, BG_GC);
+			else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_disable_roll_forward:
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			break;
+		case Opt_norecovery:
+			/* this option mounts f2fs with ro */
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			if (!f2fs_readonly(sb))
+				return -EINVAL;
+			break;
+		case Opt_discard:
+			set_opt(sbi, DISCARD);
+			break;
+		case Opt_noheap:
+			set_opt(sbi, NOHEAP);
+			break;
+#ifdef CONFIG_F2FS_FS_XATTR
+		case Opt_user_xattr:
+			set_opt(sbi, XATTR_USER);
+			break;
+		case Opt_nouser_xattr:
+			clear_opt(sbi, XATTR_USER);
+			break;
+		case Opt_inline_xattr:
+			set_opt(sbi, INLINE_XATTR);
+			break;
+#else
+		case Opt_user_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"user_xattr options not supported");
+			break;
+		case Opt_nouser_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"nouser_xattr options not supported");
+			break;
+		case Opt_inline_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"inline_xattr options not supported");
+			break;
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+		case Opt_acl:
+			set_opt(sbi, POSIX_ACL);
+			break;
+		case Opt_noacl:
+			clear_opt(sbi, POSIX_ACL);
+			break;
+#else
+		case Opt_acl:
+			f2fs_msg(sb, KERN_INFO, "acl options not supported");
+			break;
+		case Opt_noacl:
+			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
+			break;
+#endif
+		case Opt_active_logs:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
+				return -EINVAL;
+			sbi->active_logs = arg;
+			break;
+		case Opt_disable_ext_identify:
+			set_opt(sbi, DISABLE_EXT_IDENTIFY);
+			break;
+		case Opt_inline_data:
+			set_opt(sbi, INLINE_DATA);
+			break;
+		case Opt_inline_dentry:
+			set_opt(sbi, INLINE_DENTRY);
+			break;
+		case Opt_flush_merge:
+			set_opt(sbi, FLUSH_MERGE);
+			break;
+		case Opt_nobarrier:
+			set_opt(sbi, NOBARRIER);
+			break;
+		case Opt_fastboot:
+			set_opt(sbi, FASTBOOT);
+			break;
+		case Opt_extent_cache:
+			set_opt(sbi, EXTENT_CACHE);
+			break;
+		case Opt_noinline_data:
+			clear_opt(sbi, INLINE_DATA);
+			break;
+		default:
+			f2fs_msg(sb, KERN_ERR,
+				"Unrecognized mount option \"%s\" or missing value",
+				p);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static struct inode *f2fs_alloc_inode(struct super_block *sb)
+{
+	struct f2fs_inode_info *fi;
+
+	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
+	if (!fi)
+		return NULL;
+
+	init_once((void *) fi);
+
+	/* Initialize f2fs-specific inode info */
+	fi->vfs_inode.i_version = 1;
+	atomic_set(&fi->dirty_pages, 0);
+	fi->i_current_depth = 1;
+	fi->i_advise = 0;
+	rwlock_init(&fi->ext_lock);
+	init_rwsem(&fi->i_sem);
+	INIT_RADIX_TREE(&fi->inmem_root, GFP_NOFS);
+	INIT_LIST_HEAD(&fi->inmem_pages);
+	mutex_init(&fi->inmem_lock);
+
+	set_inode_flag(fi, FI_NEW_INODE);
+
+	if (test_opt(F2FS_SB(sb), INLINE_XATTR))
+		set_inode_flag(fi, FI_INLINE_XATTR);
+
+	/* Will be used by directory only */
+	fi->i_dir_level = F2FS_SB(sb)->dir_level;
+
+	return &fi->vfs_inode;
+}
+
+static int f2fs_drop_inode(struct inode *inode)
+{
+	/*
+	 * This is to avoid a deadlock condition like below.
+	 * writeback_single_inode(inode)
+	 *  - f2fs_write_data_page
+	 *    - f2fs_gc -> iput -> evict
+	 *       - inode_wait_for_writeback(inode)
+	 */
+	if (!inode_unhashed(inode) && inode->i_state & I_SYNC)
+		return 0;
+	return generic_drop_inode(inode);
+}
+
+/*
+ * f2fs_dirty_inode() is called from __mark_inode_dirty()
+ *
+ * We should call set_dirty_inode to write the dirty inode through write_inode.
+ */
+static void f2fs_dirty_inode(struct inode *inode, int flags)
+{
+	set_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
+}
+
+static void f2fs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
+}
+
+static void f2fs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, f2fs_i_callback);
+}
+
+static void f2fs_put_super(struct super_block *sb)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (sbi->s_proc) {
+		remove_proc_entry("segment_info", sbi->s_proc);
+		remove_proc_entry(sb->s_id, f2fs_proc_root);
+	}
+	kobject_del(&sbi->s_kobj);
+
+	f2fs_destroy_stats(sbi);
+	stop_gc_thread(sbi);
+
+	/*
+	 * We don't need to do checkpoint when superblock is clean.
+	 * But, the previous checkpoint was not done by umount, it needs to do
+	 * clean checkpoint again.
+	 */
+	if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
+			!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG)) {
+		struct cp_control cpc = {
+			.reason = CP_UMOUNT,
+		};
+		write_checkpoint(sbi, &cpc);
+	}
+
+	/*
+	 * normally superblock is clean, so we need to release this.
+	 * In addition, EIO will skip do checkpoint, we need this as well.
+	 */
+	release_dirty_inode(sbi);
+	release_discard_addrs(sbi);
+
+	iput(sbi->node_inode);
+	iput(sbi->meta_inode);
+
+	/* destroy f2fs internal modules */
+	destroy_node_manager(sbi);
+	destroy_segment_manager(sbi);
+
+	kfree(sbi->ckpt);
+	kobject_put(&sbi->s_kobj);
+	wait_for_completion(&sbi->s_kobj_unregister);
+
+	sb->s_fs_info = NULL;
+	brelse(sbi->raw_super_buf);
+	kfree(sbi);
+}
+
+int f2fs_sync_fs(struct super_block *sb, int sync)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	trace_f2fs_sync_fs(sb, sync);
+
+	if (sync) {
+		struct cp_control cpc;
+
+		cpc.reason = __get_cp_reason(sbi);
+
+		mutex_lock(&sbi->gc_mutex);
+		write_checkpoint(sbi, &cpc);
+		mutex_unlock(&sbi->gc_mutex);
+	} else {
+		f2fs_balance_fs(sbi);
+	}
+	f2fs_trace_ios(NULL, NULL, 1);
+
+	return 0;
+}
+
+static int f2fs_freeze(struct super_block *sb)
+{
+	int err;
+
+	if (f2fs_readonly(sb))
+		return 0;
+
+	err = f2fs_sync_fs(sb, 1);
+	return err;
+}
+
+static int f2fs_unfreeze(struct super_block *sb)
+{
+	return 0;
+}
+
+static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+	block_t total_count, user_block_count, start_count, ovp_count;
+
+	total_count = le64_to_cpu(sbi->raw_super->block_count);
+	user_block_count = sbi->user_block_count;
+	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
+	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
+	buf->f_type = F2FS_SUPER_MAGIC;
+	buf->f_bsize = sbi->blocksize;
+
+	buf->f_blocks = total_count - start_count;
+	buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
+	buf->f_bavail = user_block_count - valid_user_blocks(sbi);
+
+	buf->f_files = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
+	buf->f_ffree = buf->f_files - valid_inode_count(sbi);
+
+	buf->f_namelen = F2FS_NAME_LEN;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+
+	return 0;
+}
+
+static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
+
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, BG_GC))
+		seq_printf(seq, ",background_gc=%s", "on");
+	else
+		seq_printf(seq, ",background_gc=%s", "off");
+	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
+		seq_puts(seq, ",disable_roll_forward");
+	if (test_opt(sbi, DISCARD))
+		seq_puts(seq, ",discard");
+	if (test_opt(sbi, NOHEAP))
+		seq_puts(seq, ",no_heap_alloc");
+#ifdef CONFIG_F2FS_FS_XATTR
+	if (test_opt(sbi, XATTR_USER))
+		seq_puts(seq, ",user_xattr");
+	else
+		seq_puts(seq, ",nouser_xattr");
+	if (test_opt(sbi, INLINE_XATTR))
+		seq_puts(seq, ",inline_xattr");
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	if (test_opt(sbi, POSIX_ACL))
+		seq_puts(seq, ",acl");
+	else
+		seq_puts(seq, ",noacl");
+#endif
+	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
+		seq_puts(seq, ",disable_ext_identify");
+	if (test_opt(sbi, INLINE_DATA))
+		seq_puts(seq, ",inline_data");
+	else
+		seq_puts(seq, ",noinline_data");
+	if (test_opt(sbi, INLINE_DENTRY))
+		seq_puts(seq, ",inline_dentry");
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
+		seq_puts(seq, ",flush_merge");
+	if (test_opt(sbi, NOBARRIER))
+		seq_puts(seq, ",nobarrier");
+	if (test_opt(sbi, FASTBOOT))
+		seq_puts(seq, ",fastboot");
+	if (test_opt(sbi, EXTENT_CACHE))
+		seq_puts(seq, ",extent_cache");
+	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+
+	return 0;
+}
+
+static int segment_info_seq_show(struct seq_file *seq, void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	unsigned int total_segs =
+			le32_to_cpu(sbi->raw_super->segment_count_main);
+	int i;
+
+	seq_puts(seq, "format: segment_type|valid_blocks\n"
+		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
+
+	for (i = 0; i < total_segs; i++) {
+		struct seg_entry *se = get_seg_entry(sbi, i);
+
+		if ((i % 10) == 0)
+			seq_printf(seq, "%-5d", i);
+		seq_printf(seq, "%d|%-3u", se->type,
+					get_valid_blocks(sbi, i, 1));
+		if ((i % 10) == 9 || i == (total_segs - 1))
+			seq_putc(seq, '\n');
+		else
+			seq_putc(seq, ' ');
+	}
+
+	return 0;
+}
+
+static int segment_info_open_fs(struct inode *inode, struct file *file)
+{
+	return single_open(file, segment_info_seq_show, PDE_DATA(inode));
+}
+
+static const struct file_operations f2fs_seq_segment_info_fops = {
+	.owner = THIS_MODULE,
+	.open = segment_info_open_fs,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int f2fs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct f2fs_mount_info org_mount_opt;
+	int err, active_logs;
+	bool need_restart_gc = false;
+	bool need_stop_gc = false;
+
+	sync_filesystem(sb);
+
+	/*
+	 * Save the old mount options in case we
+	 * need to restore them.
+	 */
+	org_mount_opt = sbi->mount_opt;
+	active_logs = sbi->active_logs;
+
+	sbi->mount_opt.opt = 0;
+	sbi->active_logs = NR_CURSEG_TYPE;
+
+	/* parse mount options */
+	err = parse_options(sb, data);
+	if (err)
+		goto restore_opts;
+
+	/*
+	 * Previous and new state of filesystem is RO,
+	 * so skip checking GC and FLUSH_MERGE conditions.
+	 */
+	if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
+		goto skip;
+
+	/*
+	 * We stop the GC thread if FS is mounted as RO
+	 * or if background_gc = off is passed in mount
+	 * option. Also sync the filesystem.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
+		if (sbi->gc_thread) {
+			stop_gc_thread(sbi);
+			f2fs_sync_fs(sb, 1);
+			need_restart_gc = true;
+		}
+	} else if (!sbi->gc_thread) {
+		err = start_gc_thread(sbi);
+		if (err)
+			goto restore_opts;
+		need_stop_gc = true;
+	}
+
+	/*
+	 * We stop issue flush thread if FS is mounted as RO
+	 * or if flush_merge is not passed in mount option.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
+		destroy_flush_cmd_control(sbi);
+	} else if (!SM_I(sbi)->cmd_control_info) {
+		err = create_flush_cmd_control(sbi);
+		if (err)
+			goto restore_gc;
+	}
+skip:
+	/* Update the POSIXACL Flag */
+	 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+	return 0;
+restore_gc:
+	if (need_restart_gc) {
+		if (start_gc_thread(sbi))
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"background gc thread has stopped");
+	} else if (need_stop_gc) {
+		stop_gc_thread(sbi);
+	}
+restore_opts:
+	sbi->mount_opt = org_mount_opt;
+	sbi->active_logs = active_logs;
+	return err;
+}
+
+static struct super_operations f2fs_sops = {
+	.alloc_inode	= f2fs_alloc_inode,
+	.drop_inode	= f2fs_drop_inode,
+	.destroy_inode	= f2fs_destroy_inode,
+	.write_inode	= f2fs_write_inode,
+	.dirty_inode	= f2fs_dirty_inode,
+	.show_options	= f2fs_show_options,
+	.evict_inode	= f2fs_evict_inode,
+	.put_super	= f2fs_put_super,
+	.sync_fs	= f2fs_sync_fs,
+	.freeze_fs	= f2fs_freeze,
+	.unfreeze_fs	= f2fs_unfreeze,
+	.statfs		= f2fs_statfs,
+	.remount_fs	= f2fs_remount,
+};
+
+static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
+		u64 ino, u32 generation)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct inode *inode;
+
+	if (check_nid_range(sbi, ino))
+		return ERR_PTR(-ESTALE);
+
+	/*
+	 * f2fs_iget isn't quite right if the inode is currently unallocated!
+	 * However f2fs_iget currently does appropriate checks to handle stale
+	 * inodes so everything is OK.
+	 */
+	inode = f2fs_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (unlikely(generation && inode->i_generation != generation)) {
+		/* we didn't find the right inode.. */
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return inode;
+}
+
+static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static const struct export_operations f2fs_export_ops = {
+	.fh_to_dentry = f2fs_fh_to_dentry,
+	.fh_to_parent = f2fs_fh_to_parent,
+	.get_parent = f2fs_get_parent,
+};
+
+static loff_t max_file_size(unsigned bits)
+{
+	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
+	loff_t leaf_count = ADDRS_PER_BLOCK;
+
+	/* two direct node blocks */
+	result += (leaf_count * 2);
+
+	/* two indirect node blocks */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += (leaf_count * 2);
+
+	/* one double indirect node block */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += leaf_count;
+
+	result <<= bits;
+	return result;
+}
+
+static int sanity_check_raw_super(struct super_block *sb,
+			struct f2fs_super_block *raw_super)
+{
+	unsigned int blocksize;
+
+	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Magic Mismatch, valid(0x%x) - read(0x%x)",
+			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
+		return 1;
+	}
+
+	/* Currently, support only 4KB page cache size */
+	if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid page_cache_size (%lu), supports only 4KB\n",
+			PAGE_CACHE_SIZE);
+		return 1;
+	}
+
+	/* Currently, support only 4KB block size */
+	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
+	if (blocksize != F2FS_BLKSIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid blocksize (%u), supports only 4KB\n",
+			blocksize);
+		return 1;
+	}
+
+	/* Currently, support 512/1024/2048/4096 bytes sector size */
+	if (le32_to_cpu(raw_super->log_sectorsize) >
+				F2FS_MAX_LOG_SECTOR_SIZE ||
+		le32_to_cpu(raw_super->log_sectorsize) <
+				F2FS_MIN_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize (%u)",
+			le32_to_cpu(raw_super->log_sectorsize));
+		return 1;
+	}
+	if (le32_to_cpu(raw_super->log_sectors_per_block) +
+		le32_to_cpu(raw_super->log_sectorsize) !=
+			F2FS_MAX_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid log sectors per block(%u) log sectorsize(%u)",
+			le32_to_cpu(raw_super->log_sectors_per_block),
+			le32_to_cpu(raw_super->log_sectorsize));
+		return 1;
+	}
+	return 0;
+}
+
+static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
+{
+	unsigned int total, fsmeta;
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+
+	total = le32_to_cpu(raw_super->segment_count);
+	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
+	fsmeta += le32_to_cpu(raw_super->segment_count_sit);
+	fsmeta += le32_to_cpu(raw_super->segment_count_nat);
+	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
+	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
+
+	if (unlikely(fsmeta >= total))
+		return 1;
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
+		return 1;
+	}
+	return 0;
+}
+
+static void init_sb_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = sbi->raw_super;
+	int i;
+
+	sbi->log_sectors_per_block =
+		le32_to_cpu(raw_super->log_sectors_per_block);
+	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
+	sbi->blocksize = 1 << sbi->log_blocksize;
+	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
+	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
+	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
+	sbi->total_sections = le32_to_cpu(raw_super->section_count);
+	sbi->total_node_count =
+		(le32_to_cpu(raw_super->segment_count_nat) / 2)
+			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
+	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
+	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
+	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
+	sbi->cur_victim_sec = NULL_SECNO;
+	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
+
+	for (i = 0; i < NR_COUNT_TYPE; i++)
+		atomic_set(&sbi->nr_pages[i], 0);
+
+	sbi->dir_level = DEF_DIR_LEVEL;
+	clear_sbi_flag(sbi, SBI_NEED_FSCK);
+}
+
+/*
+ * Read f2fs raw super block.
+ * Because we have two copies of super block, so read the first one at first,
+ * if the first one is invalid, move to read the second one.
+ */
+static int read_raw_super_block(struct super_block *sb,
+			struct f2fs_super_block **raw_super,
+			struct buffer_head **raw_super_buf)
+{
+	int block = 0;
+
+retry:
+	*raw_super_buf = sb_bread(sb, block);
+	if (!*raw_super_buf) {
+		f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
+				block + 1);
+		if (block == 0) {
+			block++;
+			goto retry;
+		} else {
+			return -EIO;
+		}
+	}
+
+	*raw_super = (struct f2fs_super_block *)
+		((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
+
+	/* sanity checking of raw super */
+	if (sanity_check_raw_super(sb, *raw_super)) {
+		brelse(*raw_super_buf);
+		f2fs_msg(sb, KERN_ERR,
+			"Can't find valid F2FS filesystem in %dth superblock",
+								block + 1);
+		if (block == 0) {
+			block++;
+			goto retry;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct f2fs_sb_info *sbi;
+	struct f2fs_super_block *raw_super = NULL;
+	struct buffer_head *raw_super_buf;
+	struct inode *root;
+	long err = -EINVAL;
+	bool retry = true, need_fsck = false;
+	char *options = NULL;
+	int i;
+
+try_onemore:
+	/* allocate memory for f2fs-specific super block info */
+	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	/* set a block size */
+	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
+		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
+		goto free_sbi;
+	}
+
+	err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
+	if (err)
+		goto free_sbi;
+
+	sb->s_fs_info = sbi;
+	/* init some FS parameters */
+	sbi->active_logs = NR_CURSEG_TYPE;
+
+	set_opt(sbi, BG_GC);
+	set_opt(sbi, INLINE_DATA);
+
+#ifdef CONFIG_F2FS_FS_XATTR
+	set_opt(sbi, XATTR_USER);
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	set_opt(sbi, POSIX_ACL);
+#endif
+	/* parse mount options */
+	options = kstrdup((const char *)data, GFP_KERNEL);
+	if (data && !options) {
+		err = -ENOMEM;
+		goto free_sb_buf;
+	}
+
+	err = parse_options(sb, options);
+	if (err)
+		goto free_options;
+
+	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
+	sb->s_max_links = F2FS_LINK_MAX;
+	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+
+	sb->s_op = &f2fs_sops;
+	sb->s_xattr = f2fs_xattr_handlers;
+	sb->s_export_op = &f2fs_export_ops;
+	sb->s_magic = F2FS_SUPER_MAGIC;
+	sb->s_time_gran = 1;
+	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+	memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+
+	/* init f2fs-specific super block info */
+	sbi->sb = sb;
+	sbi->raw_super = raw_super;
+	sbi->raw_super_buf = raw_super_buf;
+	mutex_init(&sbi->gc_mutex);
+	mutex_init(&sbi->writepages);
+	mutex_init(&sbi->cp_mutex);
+	init_rwsem(&sbi->node_write);
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+	spin_lock_init(&sbi->stat_lock);
+
+	init_rwsem(&sbi->read_io.io_rwsem);
+	sbi->read_io.sbi = sbi;
+	sbi->read_io.bio = NULL;
+	for (i = 0; i < NR_PAGE_TYPE; i++) {
+		init_rwsem(&sbi->write_io[i].io_rwsem);
+		sbi->write_io[i].sbi = sbi;
+		sbi->write_io[i].bio = NULL;
+	}
+
+	init_rwsem(&sbi->cp_rwsem);
+	init_waitqueue_head(&sbi->cp_wait);
+	init_sb_info(sbi);
+
+	/* get an inode for meta space */
+	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
+	if (IS_ERR(sbi->meta_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
+		err = PTR_ERR(sbi->meta_inode);
+		goto free_options;
+	}
+
+	err = get_valid_checkpoint(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
+		goto free_meta_inode;
+	}
+
+	/* sanity checking of checkpoint */
+	err = -EINVAL;
+	if (sanity_check_ckpt(sbi)) {
+		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
+		goto free_cp;
+	}
+
+	sbi->total_valid_node_count =
+				le32_to_cpu(sbi->ckpt->valid_node_count);
+	sbi->total_valid_inode_count =
+				le32_to_cpu(sbi->ckpt->valid_inode_count);
+	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
+	sbi->total_valid_block_count =
+				le64_to_cpu(sbi->ckpt->valid_block_count);
+	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	sbi->alloc_valid_block_count = 0;
+	INIT_LIST_HEAD(&sbi->dir_inode_list);
+	spin_lock_init(&sbi->dir_inode_lock);
+
+	init_extent_cache_info(sbi);
+
+	init_ino_entry_info(sbi);
+
+	/* setup f2fs internal modules */
+	err = build_segment_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS segment manager");
+		goto free_sm;
+	}
+	err = build_node_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS node manager");
+		goto free_nm;
+	}
+
+	build_gc_manager(sbi);
+
+	/* get an inode for node space */
+	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
+	if (IS_ERR(sbi->node_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
+		err = PTR_ERR(sbi->node_inode);
+		goto free_nm;
+	}
+
+	/* if there are nt orphan nodes free them */
+	recover_orphan_inodes(sbi);
+
+	/* read root inode and dentry */
+	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
+	if (IS_ERR(root)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
+		err = PTR_ERR(root);
+		goto free_node_inode;
+	}
+	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+		iput(root);
+		err = -EINVAL;
+		goto free_node_inode;
+	}
+
+	sb->s_root = d_make_root(root); /* allocate root dentry */
+	if (!sb->s_root) {
+		err = -ENOMEM;
+		goto free_root_inode;
+	}
+
+	err = f2fs_build_stats(sbi);
+	if (err)
+		goto free_root_inode;
+
+	if (f2fs_proc_root)
+		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+
+	if (sbi->s_proc)
+		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
+				 &f2fs_seq_segment_info_fops, sb);
+
+	if (test_opt(sbi, DISCARD)) {
+		struct request_queue *q = bdev_get_queue(sb->s_bdev);
+		if (!blk_queue_discard(q))
+			f2fs_msg(sb, KERN_WARNING,
+					"mounting with \"discard\" option, but "
+					"the device does not support discard");
+	}
+
+	sbi->s_kobj.kset = f2fs_kset;
+	init_completion(&sbi->s_kobj_unregister);
+	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
+							"%s", sb->s_id);
+	if (err)
+		goto free_proc;
+
+	/* recover fsynced data */
+	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
+		/*
+		 * mount should be failed, when device has readonly mode, and
+		 * previous checkpoint was not done by clean system shutdown.
+		 */
+		if (bdev_read_only(sb->s_bdev) &&
+				!is_set_ckpt_flags(sbi->ckpt, CP_UMOUNT_FLAG)) {
+			err = -EROFS;
+			goto free_kobj;
+		}
+
+		if (need_fsck)
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+
+		err = recover_fsync_data(sbi);
+		if (err) {
+			need_fsck = true;
+			f2fs_msg(sb, KERN_ERR,
+				"Cannot recover all fsync data errno=%ld", err);
+			goto free_kobj;
+		}
+	}
+
+	/*
+	 * If filesystem is not mounted as read-only then
+	 * do start the gc_thread.
+	 */
+	if (test_opt(sbi, BG_GC) && !f2fs_readonly(sb)) {
+		/* After POR, we can run background GC thread.*/
+		err = start_gc_thread(sbi);
+		if (err)
+			goto free_kobj;
+	}
+	kfree(options);
+	return 0;
+
+free_kobj:
+	kobject_del(&sbi->s_kobj);
+free_proc:
+	if (sbi->s_proc) {
+		remove_proc_entry("segment_info", sbi->s_proc);
+		remove_proc_entry(sb->s_id, f2fs_proc_root);
+	}
+	f2fs_destroy_stats(sbi);
+free_root_inode:
+	dput(sb->s_root);
+	sb->s_root = NULL;
+free_node_inode:
+	iput(sbi->node_inode);
+free_nm:
+	destroy_node_manager(sbi);
+free_sm:
+	destroy_segment_manager(sbi);
+free_cp:
+	kfree(sbi->ckpt);
+free_meta_inode:
+	make_bad_inode(sbi->meta_inode);
+	iput(sbi->meta_inode);
+free_options:
+	kfree(options);
+free_sb_buf:
+	brelse(raw_super_buf);
+free_sbi:
+	kfree(sbi);
+
+	/* give only one another chance */
+	if (retry) {
+		retry = false;
+		shrink_dcache_sb(sb);
+		goto try_onemore;
+	}
+	return err;
+}
+
+static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
+}
+
+static void kill_f2fs_super(struct super_block *sb)
+{
+	if (sb->s_root)
+		set_sbi_flag(F2FS_SB(sb), SBI_IS_CLOSE);
+	kill_block_super(sb);
+}
+
+static struct file_system_type f2fs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "f2fs",
+	.mount		= f2fs_mount,
+	.kill_sb	= kill_f2fs_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("f2fs");
+
+static int __init init_inodecache(void)
+{
+	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
+			sizeof(struct f2fs_inode_info));
+	if (!f2fs_inode_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(f2fs_inode_cachep);
+}
+
+static int __init init_f2fs_fs(void)
+{
+	int err;
+
+	f2fs_build_trace_ios();
+
+	err = init_inodecache();
+	if (err)
+		goto fail;
+	err = create_node_manager_caches();
+	if (err)
+		goto free_inodecache;
+	err = create_segment_manager_caches();
+	if (err)
+		goto free_node_manager_caches;
+	err = create_checkpoint_caches();
+	if (err)
+		goto free_segment_manager_caches;
+	err = create_extent_cache();
+	if (err)
+		goto free_checkpoint_caches;
+	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
+	if (!f2fs_kset) {
+		err = -ENOMEM;
+		goto free_extent_cache;
+	}
+	err = register_filesystem(&f2fs_fs_type);
+	if (err)
+		goto free_kset;
+	f2fs_create_root_stats();
+	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+	return 0;
+
+free_kset:
+	kset_unregister(f2fs_kset);
+free_extent_cache:
+	destroy_extent_cache();
+free_checkpoint_caches:
+	destroy_checkpoint_caches();
+free_segment_manager_caches:
+	destroy_segment_manager_caches();
+free_node_manager_caches:
+	destroy_node_manager_caches();
+free_inodecache:
+	destroy_inodecache();
+fail:
+	return err;
+}
+
+static void __exit exit_f2fs_fs(void)
+{
+	remove_proc_entry("fs/f2fs", NULL);
+	f2fs_destroy_root_stats();
+	unregister_filesystem(&f2fs_fs_type);
+	destroy_extent_cache();
+	destroy_checkpoint_caches();
+	destroy_segment_manager_caches();
+	destroy_node_manager_caches();
+	destroy_inodecache();
+	kset_unregister(f2fs_kset);
+	f2fs_destroy_trace_ios();
+}
+
+module_init(init_f2fs_fs)
+module_exit(exit_f2fs_fs)
+
+MODULE_AUTHOR("Samsung Electronics's Praesto Team");
+MODULE_DESCRIPTION("Flash Friendly File System");
+MODULE_LICENSE("GPL");
diff --git a/kernel/fs/f2fs/trace.c b/kernel/fs/f2fs/trace.c
new file mode 100644
index 000000000..875aa8179
--- /dev/null
+++ b/kernel/fs/f2fs/trace.c
@@ -0,0 +1,159 @@
+/*
+ * f2fs IO tracer
+ *
+ * Copyright (c) 2014 Motorola Mobility
+ * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sched.h>
+#include <linux/radix-tree.h>
+
+#include "f2fs.h"
+#include "trace.h"
+
+static RADIX_TREE(pids, GFP_ATOMIC);
+static spinlock_t pids_lock;
+static struct last_io_info last_io;
+
+static inline void __print_last_io(void)
+{
+	if (!last_io.len)
+		return;
+
+	trace_printk("%3x:%3x %4x %-16s %2x %5x %12x %4x\n",
+			last_io.major, last_io.minor,
+			last_io.pid, "----------------",
+			last_io.type,
+			last_io.fio.rw, last_io.fio.blk_addr,
+			last_io.len);
+	memset(&last_io, 0, sizeof(last_io));
+}
+
+static int __file_type(struct inode *inode, pid_t pid)
+{
+	if (f2fs_is_atomic_file(inode))
+		return __ATOMIC_FILE;
+	else if (f2fs_is_volatile_file(inode))
+		return __VOLATILE_FILE;
+	else if (S_ISDIR(inode->i_mode))
+		return __DIR_FILE;
+	else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
+		return __NODE_FILE;
+	else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
+		return __META_FILE;
+	else if (pid)
+		return __NORMAL_FILE;
+	else
+		return __MISC_FILE;
+}
+
+void f2fs_trace_pid(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	pid_t pid = task_pid_nr(current);
+	void *p;
+
+	page->private = pid;
+
+	if (radix_tree_preload(GFP_NOFS))
+		return;
+
+	spin_lock(&pids_lock);
+	p = radix_tree_lookup(&pids, pid);
+	if (p == current)
+		goto out;
+	if (p)
+		radix_tree_delete(&pids, pid);
+
+	f2fs_radix_tree_insert(&pids, pid, current);
+
+	trace_printk("%3x:%3x %4x %-16s\n",
+			MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
+			pid, current->comm);
+out:
+	spin_unlock(&pids_lock);
+	radix_tree_preload_end();
+}
+
+void f2fs_trace_ios(struct page *page, struct f2fs_io_info *fio, int flush)
+{
+	struct inode *inode;
+	pid_t pid;
+	int major, minor;
+
+	if (flush) {
+		__print_last_io();
+		return;
+	}
+
+	inode = page->mapping->host;
+	pid = page_private(page);
+
+	major = MAJOR(inode->i_sb->s_dev);
+	minor = MINOR(inode->i_sb->s_dev);
+
+	if (last_io.major == major && last_io.minor == minor &&
+			last_io.pid == pid &&
+			last_io.type == __file_type(inode, pid) &&
+			last_io.fio.rw == fio->rw &&
+			last_io.fio.blk_addr + last_io.len == fio->blk_addr) {
+		last_io.len++;
+		return;
+	}
+
+	__print_last_io();
+
+	last_io.major = major;
+	last_io.minor = minor;
+	last_io.pid = pid;
+	last_io.type = __file_type(inode, pid);
+	last_io.fio = *fio;
+	last_io.len = 1;
+	return;
+}
+
+void f2fs_build_trace_ios(void)
+{
+	spin_lock_init(&pids_lock);
+}
+
+#define PIDVEC_SIZE	128
+static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
+							unsigned int max_items)
+{
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int ret = 0;
+
+	if (unlikely(!max_items))
+		return 0;
+
+	radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
+		results[ret] = iter.index;
+		if (++ret == PIDVEC_SIZE)
+			break;
+	}
+	return ret;
+}
+
+void f2fs_destroy_trace_ios(void)
+{
+	pid_t pid[PIDVEC_SIZE];
+	pid_t next_pid = 0;
+	unsigned int found;
+
+	spin_lock(&pids_lock);
+	while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
+		unsigned idx;
+
+		next_pid = pid[found - 1] + 1;
+		for (idx = 0; idx < found; idx++)
+			radix_tree_delete(&pids, pid[idx]);
+	}
+	spin_unlock(&pids_lock);
+}
diff --git a/kernel/fs/f2fs/trace.h b/kernel/fs/f2fs/trace.h
new file mode 100644
index 000000000..1041dbeb5
--- /dev/null
+++ b/kernel/fs/f2fs/trace.h
@@ -0,0 +1,46 @@
+/*
+ * f2fs IO tracer
+ *
+ * Copyright (c) 2014 Motorola Mobility
+ * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_TRACE_H__
+#define __F2FS_TRACE_H__
+
+#ifdef CONFIG_F2FS_IO_TRACE
+#include <trace/events/f2fs.h>
+
+enum file_type {
+	__NORMAL_FILE,
+	__DIR_FILE,
+	__NODE_FILE,
+	__META_FILE,
+	__ATOMIC_FILE,
+	__VOLATILE_FILE,
+	__MISC_FILE,
+};
+
+struct last_io_info {
+	int major, minor;
+	pid_t pid;
+	enum file_type type;
+	struct f2fs_io_info fio;
+	block_t len;
+};
+
+extern void f2fs_trace_pid(struct page *);
+extern void f2fs_trace_ios(struct page *, struct f2fs_io_info *, int);
+extern void f2fs_build_trace_ios(void);
+extern void f2fs_destroy_trace_ios(void);
+#else
+#define f2fs_trace_pid(p)
+#define f2fs_trace_ios(p, i, n)
+#define f2fs_build_trace_ios()
+#define f2fs_destroy_trace_ios()
+
+#endif
+#endif /* __F2FS_TRACE_H__ */
diff --git a/kernel/fs/f2fs/xattr.c b/kernel/fs/f2fs/xattr.c
new file mode 100644
index 000000000..9757f65a0
--- /dev/null
+++ b/kernel/fs/f2fs/xattr.c
@@ -0,0 +1,618 @@
+/*
+ * fs/f2fs/xattr.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Extended attributes for symlinks and special files added per
+ *  suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ *  Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/rwsem.h>
+#include <linux/f2fs_fs.h>
+#include <linux/security.h>
+#include <linux/posix_acl_xattr.h>
+#include "f2fs.h"
+#include "xattr.h"
+
+static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
+		size_t list_size, const char *name, size_t len, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	int total_len, prefix_len = 0;
+	const char *prefix = NULL;
+
+	switch (type) {
+	case F2FS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		prefix = XATTR_USER_PREFIX;
+		prefix_len = XATTR_USER_PREFIX_LEN;
+		break;
+	case F2FS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		prefix = XATTR_TRUSTED_PREFIX;
+		prefix_len = XATTR_TRUSTED_PREFIX_LEN;
+		break;
+	case F2FS_XATTR_INDEX_SECURITY:
+		prefix = XATTR_SECURITY_PREFIX;
+		prefix_len = XATTR_SECURITY_PREFIX_LEN;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	total_len = prefix_len + len + 1;
+	if (list && total_len <= list_size) {
+		memcpy(list, prefix, prefix_len);
+		memcpy(list + prefix_len, name, len);
+		list[prefix_len + len] = '\0';
+	}
+	return total_len;
+}
+
+static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
+		void *buffer, size_t size, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+	switch (type) {
+	case F2FS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		break;
+	case F2FS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		break;
+	case F2FS_XATTR_INDEX_SECURITY:
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return f2fs_getxattr(d_inode(dentry), type, name, buffer, size, NULL);
+}
+
+static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+	switch (type) {
+	case F2FS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		break;
+	case F2FS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		break;
+	case F2FS_XATTR_INDEX_SECURITY:
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+
+	return f2fs_setxattr(d_inode(dentry), type, name,
+					value, size, NULL, flags);
+}
+
+static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
+		size_t list_size, const char *name, size_t len, int type)
+{
+	const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
+	size_t size;
+
+	if (type != F2FS_XATTR_INDEX_ADVISE)
+		return 0;
+
+	size = strlen(xname) + 1;
+	if (list && size <= list_size)
+		memcpy(list, xname, size);
+	return size;
+}
+
+static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
+		void *buffer, size_t size, int type)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+
+	if (buffer)
+		*((char *)buffer) = F2FS_I(inode)->i_advise;
+	return sizeof(char);
+}
+
+static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	if (!inode_owner_or_capable(inode))
+		return -EPERM;
+	if (value == NULL)
+		return -EINVAL;
+
+	F2FS_I(inode)->i_advise |= *(char *)value;
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+#ifdef CONFIG_F2FS_FS_SECURITY
+static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		void *page)
+{
+	const struct xattr *xattr;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
+				xattr->name, xattr->value,
+				xattr->value_len, (struct page *)page, 0);
+		if (err < 0)
+			break;
+	}
+	return err;
+}
+
+int f2fs_init_security(struct inode *inode, struct inode *dir,
+				const struct qstr *qstr, struct page *ipage)
+{
+	return security_inode_init_security(inode, dir, qstr,
+				&f2fs_initxattrs, ipage);
+}
+#endif
+
+const struct xattr_handler f2fs_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_USER,
+	.list	= f2fs_xattr_generic_list,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+const struct xattr_handler f2fs_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_TRUSTED,
+	.list	= f2fs_xattr_generic_list,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+const struct xattr_handler f2fs_xattr_advise_handler = {
+	.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_ADVISE,
+	.list   = f2fs_xattr_advise_list,
+	.get    = f2fs_xattr_advise_get,
+	.set    = f2fs_xattr_advise_set,
+};
+
+const struct xattr_handler f2fs_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_SECURITY,
+	.list	= f2fs_xattr_generic_list,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+static const struct xattr_handler *f2fs_xattr_handler_map[] = {
+	[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
+	[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+	[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+	[F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
+#endif
+	[F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
+};
+
+const struct xattr_handler *f2fs_xattr_handlers[] = {
+	&f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+#endif
+	&f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+	&f2fs_xattr_security_handler,
+#endif
+	&f2fs_xattr_advise_handler,
+	NULL,
+};
+
+static inline const struct xattr_handler *f2fs_xattr_handler(int index)
+{
+	const struct xattr_handler *handler = NULL;
+
+	if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
+		handler = f2fs_xattr_handler_map[index];
+	return handler;
+}
+
+static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index,
+					size_t len, const char *name)
+{
+	struct f2fs_xattr_entry *entry;
+
+	list_for_each_xattr(entry, base_addr) {
+		if (entry->e_name_index != index)
+			continue;
+		if (entry->e_name_len != len)
+			continue;
+		if (!memcmp(entry->e_name, name, len))
+			break;
+	}
+	return entry;
+}
+
+static void *read_all_xattrs(struct inode *inode, struct page *ipage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_xattr_header *header;
+	size_t size = PAGE_SIZE, inline_size = 0;
+	void *txattr_addr;
+
+	inline_size = inline_xattr_size(inode);
+
+	txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
+	if (!txattr_addr)
+		return NULL;
+
+	/* read from inline xattr */
+	if (inline_size) {
+		struct page *page = NULL;
+		void *inline_addr;
+
+		if (ipage) {
+			inline_addr = inline_xattr_addr(ipage);
+		} else {
+			page = get_node_page(sbi, inode->i_ino);
+			if (IS_ERR(page))
+				goto fail;
+			inline_addr = inline_xattr_addr(page);
+		}
+		memcpy(txattr_addr, inline_addr, inline_size);
+		f2fs_put_page(page, 1);
+	}
+
+	/* read from xattr node block */
+	if (F2FS_I(inode)->i_xattr_nid) {
+		struct page *xpage;
+		void *xattr_addr;
+
+		/* The inode already has an extended attribute block. */
+		xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
+		if (IS_ERR(xpage))
+			goto fail;
+
+		xattr_addr = page_address(xpage);
+		memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
+		f2fs_put_page(xpage, 1);
+	}
+
+	header = XATTR_HDR(txattr_addr);
+
+	/* never been allocated xattrs */
+	if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
+		header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
+		header->h_refcount = cpu_to_le32(1);
+	}
+	return txattr_addr;
+fail:
+	kzfree(txattr_addr);
+	return NULL;
+}
+
+static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
+				void *txattr_addr, struct page *ipage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	size_t inline_size = 0;
+	void *xattr_addr;
+	struct page *xpage;
+	nid_t new_nid = 0;
+	int err;
+
+	inline_size = inline_xattr_size(inode);
+
+	if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
+		if (!alloc_nid(sbi, &new_nid))
+			return -ENOSPC;
+
+	/* write to inline xattr */
+	if (inline_size) {
+		struct page *page = NULL;
+		void *inline_addr;
+
+		if (ipage) {
+			inline_addr = inline_xattr_addr(ipage);
+			f2fs_wait_on_page_writeback(ipage, NODE);
+		} else {
+			page = get_node_page(sbi, inode->i_ino);
+			if (IS_ERR(page)) {
+				alloc_nid_failed(sbi, new_nid);
+				return PTR_ERR(page);
+			}
+			inline_addr = inline_xattr_addr(page);
+			f2fs_wait_on_page_writeback(page, NODE);
+		}
+		memcpy(inline_addr, txattr_addr, inline_size);
+		f2fs_put_page(page, 1);
+
+		/* no need to use xattr node block */
+		if (hsize <= inline_size) {
+			err = truncate_xattr_node(inode, ipage);
+			alloc_nid_failed(sbi, new_nid);
+			return err;
+		}
+	}
+
+	/* write to xattr node block */
+	if (F2FS_I(inode)->i_xattr_nid) {
+		xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
+		if (IS_ERR(xpage)) {
+			alloc_nid_failed(sbi, new_nid);
+			return PTR_ERR(xpage);
+		}
+		f2fs_bug_on(sbi, new_nid);
+		f2fs_wait_on_page_writeback(xpage, NODE);
+	} else {
+		struct dnode_of_data dn;
+		set_new_dnode(&dn, inode, NULL, NULL, new_nid);
+		xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
+		if (IS_ERR(xpage)) {
+			alloc_nid_failed(sbi, new_nid);
+			return PTR_ERR(xpage);
+		}
+		alloc_nid_done(sbi, new_nid);
+	}
+
+	xattr_addr = page_address(xpage);
+	memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
+						sizeof(struct node_footer));
+	set_page_dirty(xpage);
+	f2fs_put_page(xpage, 1);
+
+	/* need to checkpoint during fsync */
+	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
+	return 0;
+}
+
+int f2fs_getxattr(struct inode *inode, int index, const char *name,
+		void *buffer, size_t buffer_size, struct page *ipage)
+{
+	struct f2fs_xattr_entry *entry;
+	void *base_addr;
+	int error = 0;
+	size_t size, len;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	len = strlen(name);
+	if (len > F2FS_NAME_LEN)
+		return -ERANGE;
+
+	base_addr = read_all_xattrs(inode, ipage);
+	if (!base_addr)
+		return -ENOMEM;
+
+	entry = __find_xattr(base_addr, index, len, name);
+	if (IS_XATTR_LAST_ENTRY(entry)) {
+		error = -ENODATA;
+		goto cleanup;
+	}
+
+	size = le16_to_cpu(entry->e_value_size);
+
+	if (buffer && size > buffer_size) {
+		error = -ERANGE;
+		goto cleanup;
+	}
+
+	if (buffer) {
+		char *pval = entry->e_name + entry->e_name_len;
+		memcpy(buffer, pval, size);
+	}
+	error = size;
+
+cleanup:
+	kzfree(base_addr);
+	return error;
+}
+
+ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	struct inode *inode = d_inode(dentry);
+	struct f2fs_xattr_entry *entry;
+	void *base_addr;
+	int error = 0;
+	size_t rest = buffer_size;
+
+	base_addr = read_all_xattrs(inode, NULL);
+	if (!base_addr)
+		return -ENOMEM;
+
+	list_for_each_xattr(entry, base_addr) {
+		const struct xattr_handler *handler =
+			f2fs_xattr_handler(entry->e_name_index);
+		size_t size;
+
+		if (!handler)
+			continue;
+
+		size = handler->list(dentry, buffer, rest, entry->e_name,
+				entry->e_name_len, handler->flags);
+		if (buffer && size > rest) {
+			error = -ERANGE;
+			goto cleanup;
+		}
+
+		if (buffer)
+			buffer += size;
+		rest -= size;
+	}
+	error = buffer_size - rest;
+cleanup:
+	kzfree(base_addr);
+	return error;
+}
+
+static int __f2fs_setxattr(struct inode *inode, int index,
+			const char *name, const void *value, size_t size,
+			struct page *ipage, int flags)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_xattr_entry *here, *last;
+	void *base_addr;
+	int found, newsize;
+	size_t len;
+	__u32 new_hsize;
+	int error = -ENOMEM;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	if (value == NULL)
+		size = 0;
+
+	len = strlen(name);
+
+	if (len > F2FS_NAME_LEN || size > MAX_VALUE_LEN(inode))
+		return -ERANGE;
+
+	base_addr = read_all_xattrs(inode, ipage);
+	if (!base_addr)
+		goto exit;
+
+	/* find entry with wanted name. */
+	here = __find_xattr(base_addr, index, len, name);
+
+	found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
+
+	if ((flags & XATTR_REPLACE) && !found) {
+		error = -ENODATA;
+		goto exit;
+	} else if ((flags & XATTR_CREATE) && found) {
+		error = -EEXIST;
+		goto exit;
+	}
+
+	last = here;
+	while (!IS_XATTR_LAST_ENTRY(last))
+		last = XATTR_NEXT_ENTRY(last);
+
+	newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
+
+	/* 1. Check space */
+	if (value) {
+		int free;
+		/*
+		 * If value is NULL, it is remove operation.
+		 * In case of update operation, we calculate free.
+		 */
+		free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
+		if (found)
+			free = free + ENTRY_SIZE(here);
+
+		if (unlikely(free < newsize)) {
+			error = -ENOSPC;
+			goto exit;
+		}
+	}
+
+	/* 2. Remove old entry */
+	if (found) {
+		/*
+		 * If entry is found, remove old entry.
+		 * If not found, remove operation is not needed.
+		 */
+		struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
+		int oldsize = ENTRY_SIZE(here);
+
+		memmove(here, next, (char *)last - (char *)next);
+		last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
+		memset(last, 0, oldsize);
+	}
+
+	new_hsize = (char *)last - (char *)base_addr;
+
+	/* 3. Write new entry */
+	if (value) {
+		char *pval;
+		/*
+		 * Before we come here, old entry is removed.
+		 * We just write new entry.
+		 */
+		memset(last, 0, newsize);
+		last->e_name_index = index;
+		last->e_name_len = len;
+		memcpy(last->e_name, name, len);
+		pval = last->e_name + len;
+		memcpy(pval, value, size);
+		last->e_value_size = cpu_to_le16(size);
+		new_hsize += newsize;
+	}
+
+	error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
+	if (error)
+		goto exit;
+
+	if (is_inode_flag_set(fi, FI_ACL_MODE)) {
+		inode->i_mode = fi->i_acl_mode;
+		inode->i_ctime = CURRENT_TIME;
+		clear_inode_flag(fi, FI_ACL_MODE);
+	}
+
+	if (ipage)
+		update_inode(inode, ipage);
+	else
+		update_inode_page(inode);
+exit:
+	kzfree(base_addr);
+	return error;
+}
+
+int f2fs_setxattr(struct inode *inode, int index, const char *name,
+				const void *value, size_t size,
+				struct page *ipage, int flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err;
+
+	/* this case is only from init_inode_metadata */
+	if (ipage)
+		return __f2fs_setxattr(inode, index, name, value,
+						size, ipage, flags);
+	f2fs_balance_fs(sbi);
+
+	f2fs_lock_op(sbi);
+	/* protect xattr_ver */
+	down_write(&F2FS_I(inode)->i_sem);
+	err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
+	up_write(&F2FS_I(inode)->i_sem);
+	f2fs_unlock_op(sbi);
+
+	return err;
+}
diff --git a/kernel/fs/f2fs/xattr.h b/kernel/fs/f2fs/xattr.h
new file mode 100644
index 000000000..969d792ca
--- /dev/null
+++ b/kernel/fs/f2fs/xattr.h
@@ -0,0 +1,152 @@
+/*
+ * fs/f2fs/xattr.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.h
+ *
+ * On-disk format of extended attributes for the ext2 filesystem.
+ *
+ * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_XATTR_H__
+#define __F2FS_XATTR_H__
+
+#include <linux/init.h>
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define F2FS_XATTR_MAGIC                0xF2F52011
+
+/* Maximum number of references to one attribute block */
+#define F2FS_XATTR_REFCOUNT_MAX         1024
+
+/* Name indexes */
+#define F2FS_SYSTEM_ADVISE_PREFIX		"system.advise"
+#define F2FS_XATTR_INDEX_USER			1
+#define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
+#define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3
+#define F2FS_XATTR_INDEX_TRUSTED		4
+#define F2FS_XATTR_INDEX_LUSTRE			5
+#define F2FS_XATTR_INDEX_SECURITY		6
+#define F2FS_XATTR_INDEX_ADVISE			7
+
+struct f2fs_xattr_header {
+	__le32  h_magic;        /* magic number for identification */
+	__le32  h_refcount;     /* reference count */
+	__u32   h_reserved[4];  /* zero right now */
+};
+
+struct f2fs_xattr_entry {
+	__u8    e_name_index;
+	__u8    e_name_len;
+	__le16  e_value_size;   /* size of attribute value */
+	char    e_name[0];      /* attribute name */
+};
+
+#define XATTR_HDR(ptr)		((struct f2fs_xattr_header *)(ptr))
+#define XATTR_ENTRY(ptr)	((struct f2fs_xattr_entry *)(ptr))
+#define XATTR_FIRST_ENTRY(ptr)	(XATTR_ENTRY(XATTR_HDR(ptr) + 1))
+#define XATTR_ROUND		(3)
+
+#define XATTR_ALIGN(size)	((size + XATTR_ROUND) & ~XATTR_ROUND)
+
+#define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
+			entry->e_name_len + le16_to_cpu(entry->e_value_size)))
+
+#define XATTR_NEXT_ENTRY(entry)	((struct f2fs_xattr_entry *)((char *)(entry) +\
+			ENTRY_SIZE(entry)))
+
+#define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define list_for_each_xattr(entry, addr) \
+		for (entry = XATTR_FIRST_ENTRY(addr);\
+				!IS_XATTR_LAST_ENTRY(entry);\
+				entry = XATTR_NEXT_ENTRY(entry))
+
+#define MIN_OFFSET(i)	XATTR_ALIGN(inline_xattr_size(i) + PAGE_SIZE -	\
+				sizeof(struct node_footer) - sizeof(__u32))
+
+#define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
+				sizeof(struct f2fs_xattr_header) -	\
+				sizeof(struct f2fs_xattr_entry))
+
+/*
+ * On-disk structure of f2fs_xattr
+ * We use inline xattrs space + 1 block for xattr.
+ *
+ * +--------------------+
+ * | f2fs_xattr_header  |
+ * |                    |
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 1  |
+ * | .e_name_len = 3    |
+ * | .e_value_size = 14 |
+ * | .e_name = "foo"    |
+ * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 4  |
+ * | .e_name = "bar"    |
+ * +--------------------+
+ * |                    |
+ * |        Free        |
+ * |                    |
+ * +--------------------+<- MIN_OFFSET
+ * |   node_footer      |
+ * | (nid, ino, offset) |
+ * +--------------------+
+ *
+ **/
+
+#ifdef CONFIG_F2FS_FS_XATTR
+extern const struct xattr_handler f2fs_xattr_user_handler;
+extern const struct xattr_handler f2fs_xattr_trusted_handler;
+extern const struct xattr_handler f2fs_xattr_advise_handler;
+extern const struct xattr_handler f2fs_xattr_security_handler;
+
+extern const struct xattr_handler *f2fs_xattr_handlers[];
+
+extern int f2fs_setxattr(struct inode *, int, const char *,
+				const void *, size_t, struct page *, int);
+extern int f2fs_getxattr(struct inode *, int, const char *, void *,
+						size_t, struct page *);
+extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
+#else
+
+#define f2fs_xattr_handlers	NULL
+static inline int f2fs_setxattr(struct inode *inode, int index,
+		const char *name, const void *value, size_t size, int flags)
+{
+	return -EOPNOTSUPP;
+}
+static inline int f2fs_getxattr(struct inode *inode, int index,
+			const char *name, void *buffer,
+			size_t buffer_size, struct page *dpage)
+{
+	return -EOPNOTSUPP;
+}
+static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
+		size_t buffer_size)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_F2FS_FS_SECURITY
+extern int f2fs_init_security(struct inode *, struct inode *,
+				const struct qstr *, struct page *);
+#else
+static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
+				const struct qstr *qstr, struct page *ipage)
+{
+	return 0;
+}
+#endif
+#endif /* __F2FS_XATTR_H__ */