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>

1 files changed, 1537 insertions, 0 deletions

diff --git a/kernel/fs/9p/vfs_inode.c b/kernel/fs/9p/vfs_inode.c
new file mode 100644
index 000000000..703342e30
--- /dev/null
+++ b/kernel/fs/9p/vfs_inode.c
@@ -0,0 +1,1537 @@
+/*
+ *  linux/fs/9p/vfs_inode.c
+ *
+ * This file contains vfs inode ops for the 9P2000 protocol.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/namei.h>
+#include <linux/idr.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+#include "cache.h"
+#include "xattr.h"
+#include "acl.h"
+
+static const struct inode_operations v9fs_dir_inode_operations;
+static const struct inode_operations v9fs_dir_inode_operations_dotu;
+static const struct inode_operations v9fs_file_inode_operations;
+static const struct inode_operations v9fs_symlink_inode_operations;
+
+/**
+ * unixmode2p9mode - convert unix mode bits to plan 9
+ * @v9ses: v9fs session information
+ * @mode: mode to convert
+ *
+ */
+
+static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
+{
+	int res;
+	res = mode & 0777;
+	if (S_ISDIR(mode))
+		res |= P9_DMDIR;
+	if (v9fs_proto_dotu(v9ses)) {
+		if (v9ses->nodev == 0) {
+			if (S_ISSOCK(mode))
+				res |= P9_DMSOCKET;
+			if (S_ISFIFO(mode))
+				res |= P9_DMNAMEDPIPE;
+			if (S_ISBLK(mode))
+				res |= P9_DMDEVICE;
+			if (S_ISCHR(mode))
+				res |= P9_DMDEVICE;
+		}
+
+		if ((mode & S_ISUID) == S_ISUID)
+			res |= P9_DMSETUID;
+		if ((mode & S_ISGID) == S_ISGID)
+			res |= P9_DMSETGID;
+		if ((mode & S_ISVTX) == S_ISVTX)
+			res |= P9_DMSETVTX;
+	}
+	return res;
+}
+
+/**
+ * p9mode2perm- convert plan9 mode bits to unix permission bits
+ * @v9ses: v9fs session information
+ * @stat: p9_wstat from which mode need to be derived
+ *
+ */
+static int p9mode2perm(struct v9fs_session_info *v9ses,
+		       struct p9_wstat *stat)
+{
+	int res;
+	int mode = stat->mode;
+
+	res = mode & S_IALLUGO;
+	if (v9fs_proto_dotu(v9ses)) {
+		if ((mode & P9_DMSETUID) == P9_DMSETUID)
+			res |= S_ISUID;
+
+		if ((mode & P9_DMSETGID) == P9_DMSETGID)
+			res |= S_ISGID;
+
+		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
+			res |= S_ISVTX;
+	}
+	return res;
+}
+
+/**
+ * p9mode2unixmode- convert plan9 mode bits to unix mode bits
+ * @v9ses: v9fs session information
+ * @stat: p9_wstat from which mode need to be derived
+ * @rdev: major number, minor number in case of device files.
+ *
+ */
+static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
+			       struct p9_wstat *stat, dev_t *rdev)
+{
+	int res;
+	u32 mode = stat->mode;
+
+	*rdev = 0;
+	res = p9mode2perm(v9ses, stat);
+
+	if ((mode & P9_DMDIR) == P9_DMDIR)
+		res |= S_IFDIR;
+	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
+		res |= S_IFLNK;
+	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
+		 && (v9ses->nodev == 0))
+		res |= S_IFSOCK;
+	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
+		 && (v9ses->nodev == 0))
+		res |= S_IFIFO;
+	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
+		 && (v9ses->nodev == 0)) {
+		char type = 0, ext[32];
+		int major = -1, minor = -1;
+
+		strlcpy(ext, stat->extension, sizeof(ext));
+		sscanf(ext, "%c %i %i", &type, &major, &minor);
+		switch (type) {
+		case 'c':
+			res |= S_IFCHR;
+			break;
+		case 'b':
+			res |= S_IFBLK;
+			break;
+		default:
+			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
+				 type, stat->extension);
+		};
+		*rdev = MKDEV(major, minor);
+	} else
+		res |= S_IFREG;
+
+	return res;
+}
+
+/**
+ * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
+ * @uflags: flags to convert
+ * @extended: if .u extensions are active
+ */
+
+int v9fs_uflags2omode(int uflags, int extended)
+{
+	int ret;
+
+	ret = 0;
+	switch (uflags&3) {
+	default:
+	case O_RDONLY:
+		ret = P9_OREAD;
+		break;
+
+	case O_WRONLY:
+		ret = P9_OWRITE;
+		break;
+
+	case O_RDWR:
+		ret = P9_ORDWR;
+		break;
+	}
+
+	if (extended) {
+		if (uflags & O_EXCL)
+			ret |= P9_OEXCL;
+
+		if (uflags & O_APPEND)
+			ret |= P9_OAPPEND;
+	}
+
+	return ret;
+}
+
+/**
+ * v9fs_blank_wstat - helper function to setup a 9P stat structure
+ * @wstat: structure to initialize
+ *
+ */
+
+void
+v9fs_blank_wstat(struct p9_wstat *wstat)
+{
+	wstat->type = ~0;
+	wstat->dev = ~0;
+	wstat->qid.type = ~0;
+	wstat->qid.version = ~0;
+	*((long long *)&wstat->qid.path) = ~0;
+	wstat->mode = ~0;
+	wstat->atime = ~0;
+	wstat->mtime = ~0;
+	wstat->length = ~0;
+	wstat->name = NULL;
+	wstat->uid = NULL;
+	wstat->gid = NULL;
+	wstat->muid = NULL;
+	wstat->n_uid = INVALID_UID;
+	wstat->n_gid = INVALID_GID;
+	wstat->n_muid = INVALID_UID;
+	wstat->extension = NULL;
+}
+
+/**
+ * v9fs_alloc_inode - helper function to allocate an inode
+ *
+ */
+struct inode *v9fs_alloc_inode(struct super_block *sb)
+{
+	struct v9fs_inode *v9inode;
+	v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
+							GFP_KERNEL);
+	if (!v9inode)
+		return NULL;
+#ifdef CONFIG_9P_FSCACHE
+	v9inode->fscache = NULL;
+	spin_lock_init(&v9inode->fscache_lock);
+#endif
+	v9inode->writeback_fid = NULL;
+	v9inode->cache_validity = 0;
+	mutex_init(&v9inode->v_mutex);
+	return &v9inode->vfs_inode;
+}
+
+/**
+ * v9fs_destroy_inode - destroy an inode
+ *
+ */
+
+static void v9fs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
+}
+
+void v9fs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, v9fs_i_callback);
+}
+
+int v9fs_init_inode(struct v9fs_session_info *v9ses,
+		    struct inode *inode, umode_t mode, dev_t rdev)
+{
+	int err = 0;
+
+	inode_init_owner(inode, NULL, mode);
+	inode->i_blocks = 0;
+	inode->i_rdev = rdev;
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	inode->i_mapping->a_ops = &v9fs_addr_operations;
+
+	switch (mode & S_IFMT) {
+	case S_IFIFO:
+	case S_IFBLK:
+	case S_IFCHR:
+	case S_IFSOCK:
+		if (v9fs_proto_dotl(v9ses)) {
+			inode->i_op = &v9fs_file_inode_operations_dotl;
+		} else if (v9fs_proto_dotu(v9ses)) {
+			inode->i_op = &v9fs_file_inode_operations;
+		} else {
+			p9_debug(P9_DEBUG_ERROR,
+				 "special files without extended mode\n");
+			err = -EINVAL;
+			goto error;
+		}
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+		break;
+	case S_IFREG:
+		if (v9fs_proto_dotl(v9ses)) {
+			inode->i_op = &v9fs_file_inode_operations_dotl;
+			if (v9ses->cache == CACHE_LOOSE ||
+			    v9ses->cache == CACHE_FSCACHE)
+				inode->i_fop =
+					&v9fs_cached_file_operations_dotl;
+			else if (v9ses->cache == CACHE_MMAP)
+				inode->i_fop = &v9fs_mmap_file_operations_dotl;
+			else
+				inode->i_fop = &v9fs_file_operations_dotl;
+		} else {
+			inode->i_op = &v9fs_file_inode_operations;
+			if (v9ses->cache == CACHE_LOOSE ||
+			    v9ses->cache == CACHE_FSCACHE)
+				inode->i_fop =
+					&v9fs_cached_file_operations;
+			else if (v9ses->cache == CACHE_MMAP)
+				inode->i_fop = &v9fs_mmap_file_operations;
+			else
+				inode->i_fop = &v9fs_file_operations;
+		}
+
+		break;
+	case S_IFLNK:
+		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
+			p9_debug(P9_DEBUG_ERROR,
+				 "extended modes used with legacy protocol\n");
+			err = -EINVAL;
+			goto error;
+		}
+
+		if (v9fs_proto_dotl(v9ses))
+			inode->i_op = &v9fs_symlink_inode_operations_dotl;
+		else
+			inode->i_op = &v9fs_symlink_inode_operations;
+
+		break;
+	case S_IFDIR:
+		inc_nlink(inode);
+		if (v9fs_proto_dotl(v9ses))
+			inode->i_op = &v9fs_dir_inode_operations_dotl;
+		else if (v9fs_proto_dotu(v9ses))
+			inode->i_op = &v9fs_dir_inode_operations_dotu;
+		else
+			inode->i_op = &v9fs_dir_inode_operations;
+
+		if (v9fs_proto_dotl(v9ses))
+			inode->i_fop = &v9fs_dir_operations_dotl;
+		else
+			inode->i_fop = &v9fs_dir_operations;
+
+		break;
+	default:
+		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
+			 mode, mode & S_IFMT);
+		err = -EINVAL;
+		goto error;
+	}
+error:
+	return err;
+
+}
+
+/**
+ * v9fs_get_inode - helper function to setup an inode
+ * @sb: superblock
+ * @mode: mode to setup inode with
+ *
+ */
+
+struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
+{
+	int err;
+	struct inode *inode;
+	struct v9fs_session_info *v9ses = sb->s_fs_info;
+
+	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
+
+	inode = new_inode(sb);
+	if (!inode) {
+		pr_warn("%s (%d): Problem allocating inode\n",
+			__func__, task_pid_nr(current));
+		return ERR_PTR(-ENOMEM);
+	}
+	err = v9fs_init_inode(v9ses, inode, mode, rdev);
+	if (err) {
+		iput(inode);
+		return ERR_PTR(err);
+	}
+	return inode;
+}
+
+/*
+static struct v9fs_fid*
+v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
+{
+	int err;
+	int nfid;
+	struct v9fs_fid *ret;
+	struct v9fs_fcall *fcall;
+
+	nfid = v9fs_get_idpool(&v9ses->fidpool);
+	if (nfid < 0) {
+		eprintk(KERN_WARNING, "no free fids available\n");
+		return ERR_PTR(-ENOSPC);
+	}
+
+	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
+		&fcall);
+
+	if (err < 0) {
+		if (fcall && fcall->id == RWALK)
+			goto clunk_fid;
+
+		PRINT_FCALL_ERROR("walk error", fcall);
+		v9fs_put_idpool(nfid, &v9ses->fidpool);
+		goto error;
+	}
+
+	kfree(fcall);
+	fcall = NULL;
+	ret = v9fs_fid_create(v9ses, nfid);
+	if (!ret) {
+		err = -ENOMEM;
+		goto clunk_fid;
+	}
+
+	err = v9fs_fid_insert(ret, dentry);
+	if (err < 0) {
+		v9fs_fid_destroy(ret);
+		goto clunk_fid;
+	}
+
+	return ret;
+
+clunk_fid:
+	v9fs_t_clunk(v9ses, nfid);
+
+error:
+	kfree(fcall);
+	return ERR_PTR(err);
+}
+*/
+
+
+/**
+ * v9fs_clear_inode - release an inode
+ * @inode: inode to release
+ *
+ */
+void v9fs_evict_inode(struct inode *inode)
+{
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+
+	truncate_inode_pages_final(inode->i_mapping);
+	clear_inode(inode);
+	filemap_fdatawrite(inode->i_mapping);
+
+	v9fs_cache_inode_put_cookie(inode);
+	/* clunk the fid stashed in writeback_fid */
+	if (v9inode->writeback_fid) {
+		p9_client_clunk(v9inode->writeback_fid);
+		v9inode->writeback_fid = NULL;
+	}
+}
+
+static int v9fs_test_inode(struct inode *inode, void *data)
+{
+	int umode;
+	dev_t rdev;
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+	struct p9_wstat *st = (struct p9_wstat *)data;
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
+
+	umode = p9mode2unixmode(v9ses, st, &rdev);
+	/* don't match inode of different type */
+	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
+		return 0;
+
+	/* compare qid details */
+	if (memcmp(&v9inode->qid.version,
+		   &st->qid.version, sizeof(v9inode->qid.version)))
+		return 0;
+
+	if (v9inode->qid.type != st->qid.type)
+		return 0;
+	return 1;
+}
+
+static int v9fs_test_new_inode(struct inode *inode, void *data)
+{
+	return 0;
+}
+
+static int v9fs_set_inode(struct inode *inode,  void *data)
+{
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+	struct p9_wstat *st = (struct p9_wstat *)data;
+
+	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
+	return 0;
+}
+
+static struct inode *v9fs_qid_iget(struct super_block *sb,
+				   struct p9_qid *qid,
+				   struct p9_wstat *st,
+				   int new)
+{
+	dev_t rdev;
+	int retval;
+	umode_t umode;
+	unsigned long i_ino;
+	struct inode *inode;
+	struct v9fs_session_info *v9ses = sb->s_fs_info;
+	int (*test)(struct inode *, void *);
+
+	if (new)
+		test = v9fs_test_new_inode;
+	else
+		test = v9fs_test_inode;
+
+	i_ino = v9fs_qid2ino(qid);
+	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+	/*
+	 * initialize the inode with the stat info
+	 * FIXME!! we may need support for stale inodes
+	 * later.
+	 */
+	inode->i_ino = i_ino;
+	umode = p9mode2unixmode(v9ses, st, &rdev);
+	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
+	if (retval)
+		goto error;
+
+	v9fs_stat2inode(st, inode, sb);
+	v9fs_cache_inode_get_cookie(inode);
+	unlock_new_inode(inode);
+	return inode;
+error:
+	unlock_new_inode(inode);
+	iput(inode);
+	return ERR_PTR(retval);
+
+}
+
+struct inode *
+v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
+		    struct super_block *sb, int new)
+{
+	struct p9_wstat *st;
+	struct inode *inode = NULL;
+
+	st = p9_client_stat(fid);
+	if (IS_ERR(st))
+		return ERR_CAST(st);
+
+	inode = v9fs_qid_iget(sb, &st->qid, st, new);
+	p9stat_free(st);
+	kfree(st);
+	return inode;
+}
+
+/**
+ * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
+ * plan 9 AT flag.
+ * @flags: flags to convert
+ */
+static int v9fs_at_to_dotl_flags(int flags)
+{
+	int rflags = 0;
+	if (flags & AT_REMOVEDIR)
+		rflags |= P9_DOTL_AT_REMOVEDIR;
+	return rflags;
+}
+
+/**
+ * v9fs_remove - helper function to remove files and directories
+ * @dir: directory inode that is being deleted
+ * @dentry:  dentry that is being deleted
+ * @flags: removing a directory
+ *
+ */
+
+static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
+{
+	struct inode *inode;
+	int retval = -EOPNOTSUPP;
+	struct p9_fid *v9fid, *dfid;
+	struct v9fs_session_info *v9ses;
+
+	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
+		 dir, dentry, flags);
+
+	v9ses = v9fs_inode2v9ses(dir);
+	inode = d_inode(dentry);
+	dfid = v9fs_fid_lookup(dentry->d_parent);
+	if (IS_ERR(dfid)) {
+		retval = PTR_ERR(dfid);
+		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
+		return retval;
+	}
+	if (v9fs_proto_dotl(v9ses))
+		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
+					    v9fs_at_to_dotl_flags(flags));
+	if (retval == -EOPNOTSUPP) {
+		/* Try the one based on path */
+		v9fid = v9fs_fid_clone(dentry);
+		if (IS_ERR(v9fid))
+			return PTR_ERR(v9fid);
+		retval = p9_client_remove(v9fid);
+	}
+	if (!retval) {
+		/*
+		 * directories on unlink should have zero
+		 * link count
+		 */
+		if (flags & AT_REMOVEDIR) {
+			clear_nlink(inode);
+			drop_nlink(dir);
+		} else
+			drop_nlink(inode);
+
+		v9fs_invalidate_inode_attr(inode);
+		v9fs_invalidate_inode_attr(dir);
+	}
+	return retval;
+}
+
+/**
+ * v9fs_create - Create a file
+ * @v9ses: session information
+ * @dir: directory that dentry is being created in
+ * @dentry:  dentry that is being created
+ * @extension: 9p2000.u extension string to support devices, etc.
+ * @perm: create permissions
+ * @mode: open mode
+ *
+ */
+static struct p9_fid *
+v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
+		struct dentry *dentry, char *extension, u32 perm, u8 mode)
+{
+	int err;
+	char *name;
+	struct p9_fid *dfid, *ofid, *fid;
+	struct inode *inode;
+
+	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
+
+	err = 0;
+	ofid = NULL;
+	fid = NULL;
+	name = (char *) dentry->d_name.name;
+	dfid = v9fs_fid_lookup(dentry->d_parent);
+	if (IS_ERR(dfid)) {
+		err = PTR_ERR(dfid);
+		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
+		return ERR_PTR(err);
+	}
+
+	/* clone a fid to use for creation */
+	ofid = p9_client_walk(dfid, 0, NULL, 1);
+	if (IS_ERR(ofid)) {
+		err = PTR_ERR(ofid);
+		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
+		return ERR_PTR(err);
+	}
+
+	err = p9_client_fcreate(ofid, name, perm, mode, extension);
+	if (err < 0) {
+		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
+		goto error;
+	}
+
+	if (!(perm & P9_DMLINK)) {
+		/* now walk from the parent so we can get unopened fid */
+		fid = p9_client_walk(dfid, 1, &name, 1);
+		if (IS_ERR(fid)) {
+			err = PTR_ERR(fid);
+			p9_debug(P9_DEBUG_VFS,
+				   "p9_client_walk failed %d\n", err);
+			fid = NULL;
+			goto error;
+		}
+		/*
+		 * instantiate inode and assign the unopened fid to the dentry
+		 */
+		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
+		if (IS_ERR(inode)) {
+			err = PTR_ERR(inode);
+			p9_debug(P9_DEBUG_VFS,
+				   "inode creation failed %d\n", err);
+			goto error;
+		}
+		v9fs_fid_add(dentry, fid);
+		d_instantiate(dentry, inode);
+	}
+	return ofid;
+error:
+	if (ofid)
+		p9_client_clunk(ofid);
+
+	if (fid)
+		p9_client_clunk(fid);
+
+	return ERR_PTR(err);
+}
+
+/**
+ * v9fs_vfs_create - VFS hook to create a regular file
+ *
+ * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
+ * for mknod(2).
+ *
+ * @dir: directory inode that is being created
+ * @dentry:  dentry that is being deleted
+ * @mode: create permissions
+ *
+ */
+
+static int
+v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+		bool excl)
+{
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
+	u32 perm = unixmode2p9mode(v9ses, mode);
+	struct p9_fid *fid;
+
+	/* P9_OEXCL? */
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
+
+	v9fs_invalidate_inode_attr(dir);
+	p9_client_clunk(fid);
+
+	return 0;
+}
+
+/**
+ * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
+ * @dir:  inode that is being unlinked
+ * @dentry: dentry that is being unlinked
+ * @mode: mode for new directory
+ *
+ */
+
+static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	int err;
+	u32 perm;
+	struct p9_fid *fid;
+	struct v9fs_session_info *v9ses;
+
+	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
+	err = 0;
+	v9ses = v9fs_inode2v9ses(dir);
+	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
+	if (IS_ERR(fid)) {
+		err = PTR_ERR(fid);
+		fid = NULL;
+	} else {
+		inc_nlink(dir);
+		v9fs_invalidate_inode_attr(dir);
+	}
+
+	if (fid)
+		p9_client_clunk(fid);
+
+	return err;
+}
+
+/**
+ * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
+ * @dir:  inode that is being walked from
+ * @dentry: dentry that is being walked to?
+ * @flags: lookup flags (unused)
+ *
+ */
+
+struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
+				      unsigned int flags)
+{
+	struct dentry *res;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *dfid, *fid;
+	struct inode *inode;
+	char *name;
+
+	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
+		 dir, dentry, dentry, flags);
+
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	v9ses = v9fs_inode2v9ses(dir);
+	/* We can walk d_parent because we hold the dir->i_mutex */
+	dfid = v9fs_fid_lookup(dentry->d_parent);
+	if (IS_ERR(dfid))
+		return ERR_CAST(dfid);
+
+	name = (char *) dentry->d_name.name;
+	fid = p9_client_walk(dfid, 1, &name, 1);
+	if (IS_ERR(fid)) {
+		if (fid == ERR_PTR(-ENOENT)) {
+			d_add(dentry, NULL);
+			return NULL;
+		}
+		return ERR_CAST(fid);
+	}
+	/*
+	 * Make sure we don't use a wrong inode due to parallel
+	 * unlink. For cached mode create calls request for new
+	 * inode. But with cache disabled, lookup should do this.
+	 */
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
+	else
+		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
+	if (IS_ERR(inode)) {
+		p9_client_clunk(fid);
+		return ERR_CAST(inode);
+	}
+	/*
+	 * If we had a rename on the server and a parallel lookup
+	 * for the new name, then make sure we instantiate with
+	 * the new name. ie look up for a/b, while on server somebody
+	 * moved b under k and client parallely did a lookup for
+	 * k/b.
+	 */
+	res = d_splice_alias(inode, dentry);
+	if (!res)
+		v9fs_fid_add(dentry, fid);
+	else if (!IS_ERR(res))
+		v9fs_fid_add(res, fid);
+	else
+		p9_client_clunk(fid);
+	return res;
+}
+
+static int
+v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
+		     struct file *file, unsigned flags, umode_t mode,
+		     int *opened)
+{
+	int err;
+	u32 perm;
+	struct v9fs_inode *v9inode;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid, *inode_fid;
+	struct dentry *res = NULL;
+
+	if (d_unhashed(dentry)) {
+		res = v9fs_vfs_lookup(dir, dentry, 0);
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
+		return finish_no_open(file, res);
+
+	err = 0;
+
+	v9ses = v9fs_inode2v9ses(dir);
+	perm = unixmode2p9mode(v9ses, mode);
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
+				v9fs_uflags2omode(flags,
+						v9fs_proto_dotu(v9ses)));
+	if (IS_ERR(fid)) {
+		err = PTR_ERR(fid);
+		fid = NULL;
+		goto error;
+	}
+
+	v9fs_invalidate_inode_attr(dir);
+	v9inode = V9FS_I(d_inode(dentry));
+	mutex_lock(&v9inode->v_mutex);
+	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
+	    !v9inode->writeback_fid &&
+	    ((flags & O_ACCMODE) != O_RDONLY)) {
+		/*
+		 * clone a fid and add it to writeback_fid
+		 * we do it during open time instead of
+		 * page dirty time via write_begin/page_mkwrite
+		 * because we want write after unlink usecase
+		 * to work.
+		 */
+		inode_fid = v9fs_writeback_fid(dentry);
+		if (IS_ERR(inode_fid)) {
+			err = PTR_ERR(inode_fid);
+			mutex_unlock(&v9inode->v_mutex);
+			goto error;
+		}
+		v9inode->writeback_fid = (void *) inode_fid;
+	}
+	mutex_unlock(&v9inode->v_mutex);
+	err = finish_open(file, dentry, generic_file_open, opened);
+	if (err)
+		goto error;
+
+	file->private_data = fid;
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		v9fs_cache_inode_set_cookie(d_inode(dentry), file);
+
+	*opened |= FILE_CREATED;
+out:
+	dput(res);
+	return err;
+
+error:
+	if (fid)
+		p9_client_clunk(fid);
+	goto out;
+}
+
+/**
+ * v9fs_vfs_unlink - VFS unlink hook to delete an inode
+ * @i:  inode that is being unlinked
+ * @d: dentry that is being unlinked
+ *
+ */
+
+int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
+{
+	return v9fs_remove(i, d, 0);
+}
+
+/**
+ * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
+ * @i:  inode that is being unlinked
+ * @d: dentry that is being unlinked
+ *
+ */
+
+int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
+{
+	return v9fs_remove(i, d, AT_REMOVEDIR);
+}
+
+/**
+ * v9fs_vfs_rename - VFS hook to rename an inode
+ * @old_dir:  old dir inode
+ * @old_dentry: old dentry
+ * @new_dir: new dir inode
+ * @new_dentry: new dentry
+ *
+ */
+
+int
+v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+		struct inode *new_dir, struct dentry *new_dentry)
+{
+	int retval;
+	struct inode *old_inode;
+	struct inode *new_inode;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *oldfid;
+	struct p9_fid *olddirfid;
+	struct p9_fid *newdirfid;
+	struct p9_wstat wstat;
+
+	p9_debug(P9_DEBUG_VFS, "\n");
+	retval = 0;
+	old_inode = d_inode(old_dentry);
+	new_inode = d_inode(new_dentry);
+	v9ses = v9fs_inode2v9ses(old_inode);
+	oldfid = v9fs_fid_lookup(old_dentry);
+	if (IS_ERR(oldfid))
+		return PTR_ERR(oldfid);
+
+	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
+	if (IS_ERR(olddirfid)) {
+		retval = PTR_ERR(olddirfid);
+		goto done;
+	}
+
+	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
+	if (IS_ERR(newdirfid)) {
+		retval = PTR_ERR(newdirfid);
+		goto clunk_olddir;
+	}
+
+	down_write(&v9ses->rename_sem);
+	if (v9fs_proto_dotl(v9ses)) {
+		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
+					    newdirfid, new_dentry->d_name.name);
+		if (retval == -EOPNOTSUPP)
+			retval = p9_client_rename(oldfid, newdirfid,
+						  new_dentry->d_name.name);
+		if (retval != -EOPNOTSUPP)
+			goto clunk_newdir;
+	}
+	if (old_dentry->d_parent != new_dentry->d_parent) {
+		/*
+		 * 9P .u can only handle file rename in the same directory
+		 */
+
+		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
+		retval = -EXDEV;
+		goto clunk_newdir;
+	}
+	v9fs_blank_wstat(&wstat);
+	wstat.muid = v9ses->uname;
+	wstat.name = (char *) new_dentry->d_name.name;
+	retval = p9_client_wstat(oldfid, &wstat);
+
+clunk_newdir:
+	if (!retval) {
+		if (new_inode) {
+			if (S_ISDIR(new_inode->i_mode))
+				clear_nlink(new_inode);
+			else
+				drop_nlink(new_inode);
+		}
+		if (S_ISDIR(old_inode->i_mode)) {
+			if (!new_inode)
+				inc_nlink(new_dir);
+			drop_nlink(old_dir);
+		}
+		v9fs_invalidate_inode_attr(old_inode);
+		v9fs_invalidate_inode_attr(old_dir);
+		v9fs_invalidate_inode_attr(new_dir);
+
+		/* successful rename */
+		d_move(old_dentry, new_dentry);
+	}
+	up_write(&v9ses->rename_sem);
+	p9_client_clunk(newdirfid);
+
+clunk_olddir:
+	p9_client_clunk(olddirfid);
+
+done:
+	return retval;
+}
+
+/**
+ * v9fs_vfs_getattr - retrieve file metadata
+ * @mnt: mount information
+ * @dentry: file to get attributes on
+ * @stat: metadata structure to populate
+ *
+ */
+
+static int
+v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+		 struct kstat *stat)
+{
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid;
+	struct p9_wstat *st;
+
+	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
+	v9ses = v9fs_dentry2v9ses(dentry);
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+		generic_fillattr(d_inode(dentry), stat);
+		return 0;
+	}
+	fid = v9fs_fid_lookup(dentry);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
+
+	st = p9_client_stat(fid);
+	if (IS_ERR(st))
+		return PTR_ERR(st);
+
+	v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb);
+	generic_fillattr(d_inode(dentry), stat);
+
+	p9stat_free(st);
+	kfree(st);
+	return 0;
+}
+
+/**
+ * v9fs_vfs_setattr - set file metadata
+ * @dentry: file whose metadata to set
+ * @iattr: metadata assignment structure
+ *
+ */
+
+static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	int retval;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid;
+	struct p9_wstat wstat;
+
+	p9_debug(P9_DEBUG_VFS, "\n");
+	retval = inode_change_ok(d_inode(dentry), iattr);
+	if (retval)
+		return retval;
+
+	retval = -EPERM;
+	v9ses = v9fs_dentry2v9ses(dentry);
+	fid = v9fs_fid_lookup(dentry);
+	if(IS_ERR(fid))
+		return PTR_ERR(fid);
+
+	v9fs_blank_wstat(&wstat);
+	if (iattr->ia_valid & ATTR_MODE)
+		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
+
+	if (iattr->ia_valid & ATTR_MTIME)
+		wstat.mtime = iattr->ia_mtime.tv_sec;
+
+	if (iattr->ia_valid & ATTR_ATIME)
+		wstat.atime = iattr->ia_atime.tv_sec;
+
+	if (iattr->ia_valid & ATTR_SIZE)
+		wstat.length = iattr->ia_size;
+
+	if (v9fs_proto_dotu(v9ses)) {
+		if (iattr->ia_valid & ATTR_UID)
+			wstat.n_uid = iattr->ia_uid;
+
+		if (iattr->ia_valid & ATTR_GID)
+			wstat.n_gid = iattr->ia_gid;
+	}
+
+	/* Write all dirty data */
+	if (d_is_reg(dentry))
+		filemap_write_and_wait(d_inode(dentry)->i_mapping);
+
+	retval = p9_client_wstat(fid, &wstat);
+	if (retval < 0)
+		return retval;
+
+	if ((iattr->ia_valid & ATTR_SIZE) &&
+	    iattr->ia_size != i_size_read(d_inode(dentry)))
+		truncate_setsize(d_inode(dentry), iattr->ia_size);
+
+	v9fs_invalidate_inode_attr(d_inode(dentry));
+
+	setattr_copy(d_inode(dentry), iattr);
+	mark_inode_dirty(d_inode(dentry));
+	return 0;
+}
+
+/**
+ * v9fs_stat2inode - populate an inode structure with mistat info
+ * @stat: Plan 9 metadata (mistat) structure
+ * @inode: inode to populate
+ * @sb: superblock of filesystem
+ *
+ */
+
+void
+v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
+	struct super_block *sb)
+{
+	umode_t mode;
+	char ext[32];
+	char tag_name[14];
+	unsigned int i_nlink;
+	struct v9fs_session_info *v9ses = sb->s_fs_info;
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+
+	set_nlink(inode, 1);
+
+	inode->i_atime.tv_sec = stat->atime;
+	inode->i_mtime.tv_sec = stat->mtime;
+	inode->i_ctime.tv_sec = stat->mtime;
+
+	inode->i_uid = v9ses->dfltuid;
+	inode->i_gid = v9ses->dfltgid;
+
+	if (v9fs_proto_dotu(v9ses)) {
+		inode->i_uid = stat->n_uid;
+		inode->i_gid = stat->n_gid;
+	}
+	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
+		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
+			/*
+			 * Hadlink support got added later to
+			 * to the .u extension. So there can be
+			 * server out there that doesn't support
+			 * this even with .u extension. So check
+			 * for non NULL stat->extension
+			 */
+			strlcpy(ext, stat->extension, sizeof(ext));
+			/* HARDLINKCOUNT %u */
+			sscanf(ext, "%13s %u", tag_name, &i_nlink);
+			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
+				set_nlink(inode, i_nlink);
+		}
+	}
+	mode = p9mode2perm(v9ses, stat);
+	mode |= inode->i_mode & ~S_IALLUGO;
+	inode->i_mode = mode;
+	i_size_write(inode, stat->length);
+
+	/* not real number of blocks, but 512 byte ones ... */
+	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
+	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
+}
+
+/**
+ * v9fs_qid2ino - convert qid into inode number
+ * @qid: qid to hash
+ *
+ * BUG: potential for inode number collisions?
+ */
+
+ino_t v9fs_qid2ino(struct p9_qid *qid)
+{
+	u64 path = qid->path + 2;
+	ino_t i = 0;
+
+	if (sizeof(ino_t) == sizeof(path))
+		memcpy(&i, &path, sizeof(ino_t));
+	else
+		i = (ino_t) (path ^ (path >> 32));
+
+	return i;
+}
+
+/**
+ * v9fs_readlink - read a symlink's location (internal version)
+ * @dentry: dentry for symlink
+ * @buffer: buffer to load symlink location into
+ * @buflen: length of buffer
+ *
+ */
+
+static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
+{
+	int retval;
+
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid;
+	struct p9_wstat *st;
+
+	p9_debug(P9_DEBUG_VFS, " %pd\n", dentry);
+	retval = -EPERM;
+	v9ses = v9fs_dentry2v9ses(dentry);
+	fid = v9fs_fid_lookup(dentry);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
+
+	if (!v9fs_proto_dotu(v9ses))
+		return -EBADF;
+
+	st = p9_client_stat(fid);
+	if (IS_ERR(st))
+		return PTR_ERR(st);
+
+	if (!(st->mode & P9_DMSYMLINK)) {
+		retval = -EINVAL;
+		goto done;
+	}
+
+	/* copy extension buffer into buffer */
+	retval = min(strlen(st->extension)+1, (size_t)buflen);
+	memcpy(buffer, st->extension, retval);
+
+	p9_debug(P9_DEBUG_VFS, "%pd -> %s (%.*s)\n",
+		 dentry, st->extension, buflen, buffer);
+
+done:
+	p9stat_free(st);
+	kfree(st);
+	return retval;
+}
+
+/**
+ * v9fs_vfs_follow_link - follow a symlink path
+ * @dentry: dentry for symlink
+ * @nd: nameidata
+ *
+ */
+
+static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	int len = 0;
+	char *link = __getname();
+
+	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
+
+	if (!link)
+		link = ERR_PTR(-ENOMEM);
+	else {
+		len = v9fs_readlink(dentry, link, PATH_MAX);
+
+		if (len < 0) {
+			__putname(link);
+			link = ERR_PTR(len);
+		} else
+			link[min(len, PATH_MAX-1)] = 0;
+	}
+	nd_set_link(nd, link);
+
+	return NULL;
+}
+
+/**
+ * v9fs_vfs_put_link - release a symlink path
+ * @dentry: dentry for symlink
+ * @nd: nameidata
+ * @p: unused
+ *
+ */
+
+void
+v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
+{
+	char *s = nd_get_link(nd);
+
+	p9_debug(P9_DEBUG_VFS, " %pd %s\n",
+		 dentry, IS_ERR(s) ? "<error>" : s);
+	if (!IS_ERR(s))
+		__putname(s);
+}
+
+/**
+ * v9fs_vfs_mkspecial - create a special file
+ * @dir: inode to create special file in
+ * @dentry: dentry to create
+ * @perm: mode to create special file
+ * @extension: 9p2000.u format extension string representing special file
+ *
+ */
+
+static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
+	u32 perm, const char *extension)
+{
+	struct p9_fid *fid;
+	struct v9fs_session_info *v9ses;
+
+	v9ses = v9fs_inode2v9ses(dir);
+	if (!v9fs_proto_dotu(v9ses)) {
+		p9_debug(P9_DEBUG_ERROR, "not extended\n");
+		return -EPERM;
+	}
+
+	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
+								P9_OREAD);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
+
+	v9fs_invalidate_inode_attr(dir);
+	p9_client_clunk(fid);
+	return 0;
+}
+
+/**
+ * v9fs_vfs_symlink - helper function to create symlinks
+ * @dir: directory inode containing symlink
+ * @dentry: dentry for symlink
+ * @symname: symlink data
+ *
+ * See Also: 9P2000.u RFC for more information
+ *
+ */
+
+static int
+v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
+		 dir->i_ino, dentry, symname);
+
+	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
+}
+
+/**
+ * v9fs_vfs_link - create a hardlink
+ * @old_dentry: dentry for file to link to
+ * @dir: inode destination for new link
+ * @dentry: dentry for link
+ *
+ */
+
+static int
+v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
+	      struct dentry *dentry)
+{
+	int retval;
+	char *name;
+	struct p9_fid *oldfid;
+
+	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
+		 dir->i_ino, dentry, old_dentry);
+
+	oldfid = v9fs_fid_clone(old_dentry);
+	if (IS_ERR(oldfid))
+		return PTR_ERR(oldfid);
+
+	name = __getname();
+	if (unlikely(!name)) {
+		retval = -ENOMEM;
+		goto clunk_fid;
+	}
+
+	sprintf(name, "%d\n", oldfid->fid);
+	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
+	__putname(name);
+	if (!retval) {
+		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
+		v9fs_invalidate_inode_attr(dir);
+	}
+clunk_fid:
+	p9_client_clunk(oldfid);
+	return retval;
+}
+
+/**
+ * v9fs_vfs_mknod - create a special file
+ * @dir: inode destination for new link
+ * @dentry: dentry for file
+ * @mode: mode for creation
+ * @rdev: device associated with special file
+ *
+ */
+
+static int
+v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
+	int retval;
+	char *name;
+	u32 perm;
+
+	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
+		 dir->i_ino, dentry, mode,
+		 MAJOR(rdev), MINOR(rdev));
+
+	if (!new_valid_dev(rdev))
+		return -EINVAL;
+
+	name = __getname();
+	if (!name)
+		return -ENOMEM;
+	/* build extension */
+	if (S_ISBLK(mode))
+		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
+	else if (S_ISCHR(mode))
+		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
+	else if (S_ISFIFO(mode))
+		*name = 0;
+	else if (S_ISSOCK(mode))
+		*name = 0;
+	else {
+		__putname(name);
+		return -EINVAL;
+	}
+
+	perm = unixmode2p9mode(v9ses, mode);
+	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
+	__putname(name);
+
+	return retval;
+}
+
+int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
+{
+	int umode;
+	dev_t rdev;
+	loff_t i_size;
+	struct p9_wstat *st;
+	struct v9fs_session_info *v9ses;
+
+	v9ses = v9fs_inode2v9ses(inode);
+	st = p9_client_stat(fid);
+	if (IS_ERR(st))
+		return PTR_ERR(st);
+	/*
+	 * Don't update inode if the file type is different
+	 */
+	umode = p9mode2unixmode(v9ses, st, &rdev);
+	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
+		goto out;
+
+	spin_lock(&inode->i_lock);
+	/*
+	 * We don't want to refresh inode->i_size,
+	 * because we may have cached data
+	 */
+	i_size = inode->i_size;
+	v9fs_stat2inode(st, inode, inode->i_sb);
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		inode->i_size = i_size;
+	spin_unlock(&inode->i_lock);
+out:
+	p9stat_free(st);
+	kfree(st);
+	return 0;
+}
+
+static const struct inode_operations v9fs_dir_inode_operations_dotu = {
+	.create = v9fs_vfs_create,
+	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
+	.symlink = v9fs_vfs_symlink,
+	.link = v9fs_vfs_link,
+	.unlink = v9fs_vfs_unlink,
+	.mkdir = v9fs_vfs_mkdir,
+	.rmdir = v9fs_vfs_rmdir,
+	.mknod = v9fs_vfs_mknod,
+	.rename = v9fs_vfs_rename,
+	.getattr = v9fs_vfs_getattr,
+	.setattr = v9fs_vfs_setattr,
+};
+
+static const struct inode_operations v9fs_dir_inode_operations = {
+	.create = v9fs_vfs_create,
+	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
+	.unlink = v9fs_vfs_unlink,
+	.mkdir = v9fs_vfs_mkdir,
+	.rmdir = v9fs_vfs_rmdir,
+	.mknod = v9fs_vfs_mknod,
+	.rename = v9fs_vfs_rename,
+	.getattr = v9fs_vfs_getattr,
+	.setattr = v9fs_vfs_setattr,
+};
+
+static const struct inode_operations v9fs_file_inode_operations = {
+	.getattr = v9fs_vfs_getattr,
+	.setattr = v9fs_vfs_setattr,
+};
+
+static const struct inode_operations v9fs_symlink_inode_operations = {
+	.readlink = generic_readlink,
+	.follow_link = v9fs_vfs_follow_link,
+	.put_link = v9fs_vfs_put_link,
+	.getattr = v9fs_vfs_getattr,
+	.setattr = v9fs_vfs_setattr,
+};
+