diff options
Diffstat (limited to 'kernel/fs/gfs2/file.c')
| -rw-r--r-- | kernel/fs/gfs2/file.c | 1159 |
1 files changed, 1159 insertions, 0 deletions
diff --git a/kernel/fs/gfs2/file.c b/kernel/fs/gfs2/file.c new file mode 100644 index 000000000..31892871e --- /dev/null +++ b/kernel/fs/gfs2/file.c @@ -0,0 +1,1159 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License version 2. + */ + +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/pagemap.h> +#include <linux/uio.h> +#include <linux/blkdev.h> +#include <linux/mm.h> +#include <linux/mount.h> +#include <linux/fs.h> +#include <linux/gfs2_ondisk.h> +#include <linux/falloc.h> +#include <linux/swap.h> +#include <linux/crc32.h> +#include <linux/writeback.h> +#include <asm/uaccess.h> +#include <linux/dlm.h> +#include <linux/dlm_plock.h> +#include <linux/delay.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.h" +#include "dir.h" +#include "glock.h" +#include "glops.h" +#include "inode.h" +#include "log.h" +#include "meta_io.h" +#include "quota.h" +#include "rgrp.h" +#include "trans.h" +#include "util.h" + +/** + * gfs2_llseek - seek to a location in a file + * @file: the file + * @offset: the offset + * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END) + * + * SEEK_END requires the glock for the file because it references the + * file's size. + * + * Returns: The new offset, or errno + */ + +static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence) +{ + struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); + struct gfs2_holder i_gh; + loff_t error; + + switch (whence) { + case SEEK_END: /* These reference inode->i_size */ + case SEEK_DATA: + case SEEK_HOLE: + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (!error) { + error = generic_file_llseek(file, offset, whence); + gfs2_glock_dq_uninit(&i_gh); + } + break; + case SEEK_CUR: + case SEEK_SET: + error = generic_file_llseek(file, offset, whence); + break; + default: + error = -EINVAL; + } + + return error; +} + +/** + * gfs2_readdir - Iterator for a directory + * @file: The directory to read from + * @ctx: What to feed directory entries to + * + * Returns: errno + */ + +static int gfs2_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *dir = file->f_mapping->host; + struct gfs2_inode *dip = GFS2_I(dir); + struct gfs2_holder d_gh; + int error; + + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); + if (error) + return error; + + error = gfs2_dir_read(dir, ctx, &file->f_ra); + + gfs2_glock_dq_uninit(&d_gh); + + return error; +} + +/** + * fsflags_cvt + * @table: A table of 32 u32 flags + * @val: a 32 bit value to convert + * + * This function can be used to convert between fsflags values and + * GFS2's own flags values. + * + * Returns: the converted flags + */ +static u32 fsflags_cvt(const u32 *table, u32 val) +{ + u32 res = 0; + while(val) { + if (val & 1) + res |= *table; + table++; + val >>= 1; + } + return res; +} + +static const u32 fsflags_to_gfs2[32] = { + [3] = GFS2_DIF_SYNC, + [4] = GFS2_DIF_IMMUTABLE, + [5] = GFS2_DIF_APPENDONLY, + [7] = GFS2_DIF_NOATIME, + [12] = GFS2_DIF_EXHASH, + [14] = GFS2_DIF_INHERIT_JDATA, + [17] = GFS2_DIF_TOPDIR, +}; + +static const u32 gfs2_to_fsflags[32] = { + [gfs2fl_Sync] = FS_SYNC_FL, + [gfs2fl_Immutable] = FS_IMMUTABLE_FL, + [gfs2fl_AppendOnly] = FS_APPEND_FL, + [gfs2fl_NoAtime] = FS_NOATIME_FL, + [gfs2fl_ExHash] = FS_INDEX_FL, + [gfs2fl_TopLevel] = FS_TOPDIR_FL, + [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL, +}; + +static int gfs2_get_flags(struct file *filp, u32 __user *ptr) +{ + struct inode *inode = file_inode(filp); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + int error; + u32 fsflags; + + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + error = gfs2_glock_nq(&gh); + if (error) + return error; + + fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags); + if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA) + fsflags |= FS_JOURNAL_DATA_FL; + if (put_user(fsflags, ptr)) + error = -EFAULT; + + gfs2_glock_dq(&gh); + gfs2_holder_uninit(&gh); + return error; +} + +void gfs2_set_inode_flags(struct inode *inode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + unsigned int flags = inode->i_flags; + + flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC); + if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode)) + inode->i_flags |= S_NOSEC; + if (ip->i_diskflags & GFS2_DIF_IMMUTABLE) + flags |= S_IMMUTABLE; + if (ip->i_diskflags & GFS2_DIF_APPENDONLY) + flags |= S_APPEND; + if (ip->i_diskflags & GFS2_DIF_NOATIME) + flags |= S_NOATIME; + if (ip->i_diskflags & GFS2_DIF_SYNC) + flags |= S_SYNC; + inode->i_flags = flags; +} + +/* Flags that can be set by user space */ +#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \ + GFS2_DIF_IMMUTABLE| \ + GFS2_DIF_APPENDONLY| \ + GFS2_DIF_NOATIME| \ + GFS2_DIF_SYNC| \ + GFS2_DIF_SYSTEM| \ + GFS2_DIF_TOPDIR| \ + GFS2_DIF_INHERIT_JDATA) + +/** + * do_gfs2_set_flags - set flags on an inode + * @filp: file pointer + * @reqflags: The flags to set + * @mask: Indicates which flags are valid + * + */ +static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask) +{ + struct inode *inode = file_inode(filp); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct buffer_head *bh; + struct gfs2_holder gh; + int error; + u32 new_flags, flags; + + error = mnt_want_write_file(filp); + if (error) + return error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + if (error) + goto out_drop_write; + + error = -EACCES; + if (!inode_owner_or_capable(inode)) + goto out; + + error = 0; + flags = ip->i_diskflags; + new_flags = (flags & ~mask) | (reqflags & mask); + if ((new_flags ^ flags) == 0) + goto out; + + error = -EINVAL; + if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET) + goto out; + + error = -EPERM; + if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE)) + goto out; + if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY)) + goto out; + if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) && + !capable(CAP_LINUX_IMMUTABLE)) + goto out; + if (!IS_IMMUTABLE(inode)) { + error = gfs2_permission(inode, MAY_WRITE); + if (error) + goto out; + } + if ((flags ^ new_flags) & GFS2_DIF_JDATA) { + if (flags & GFS2_DIF_JDATA) + gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH); + error = filemap_fdatawrite(inode->i_mapping); + if (error) + goto out; + error = filemap_fdatawait(inode->i_mapping); + if (error) + goto out; + } + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + goto out; + error = gfs2_meta_inode_buffer(ip, &bh); + if (error) + goto out_trans_end; + gfs2_trans_add_meta(ip->i_gl, bh); + ip->i_diskflags = new_flags; + gfs2_dinode_out(ip, bh->b_data); + brelse(bh); + gfs2_set_inode_flags(inode); + gfs2_set_aops(inode); +out_trans_end: + gfs2_trans_end(sdp); +out: + gfs2_glock_dq_uninit(&gh); +out_drop_write: + mnt_drop_write_file(filp); + return error; +} + +static int gfs2_set_flags(struct file *filp, u32 __user *ptr) +{ + struct inode *inode = file_inode(filp); + u32 fsflags, gfsflags; + + if (get_user(fsflags, ptr)) + return -EFAULT; + + gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags); + if (!S_ISDIR(inode->i_mode)) { + gfsflags &= ~GFS2_DIF_TOPDIR; + if (gfsflags & GFS2_DIF_INHERIT_JDATA) + gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA); + return do_gfs2_set_flags(filp, gfsflags, ~0); + } + return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA); +} + +static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + switch(cmd) { + case FS_IOC_GETFLAGS: + return gfs2_get_flags(filp, (u32 __user *)arg); + case FS_IOC_SETFLAGS: + return gfs2_set_flags(filp, (u32 __user *)arg); + case FITRIM: + return gfs2_fitrim(filp, (void __user *)arg); + } + return -ENOTTY; +} + +/** + * gfs2_size_hint - Give a hint to the size of a write request + * @filep: The struct file + * @offset: The file offset of the write + * @size: The length of the write + * + * When we are about to do a write, this function records the total + * write size in order to provide a suitable hint to the lower layers + * about how many blocks will be required. + * + */ + +static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size) +{ + struct inode *inode = file_inode(filep); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_inode *ip = GFS2_I(inode); + size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift; + int hint = min_t(size_t, INT_MAX, blks); + + if (hint > atomic_read(&ip->i_res->rs_sizehint)) + atomic_set(&ip->i_res->rs_sizehint, hint); +} + +/** + * gfs2_allocate_page_backing - Use bmap to allocate blocks + * @page: The (locked) page to allocate backing for + * + * We try to allocate all the blocks required for the page in + * one go. This might fail for various reasons, so we keep + * trying until all the blocks to back this page are allocated. + * If some of the blocks are already allocated, thats ok too. + */ + +static int gfs2_allocate_page_backing(struct page *page) +{ + struct inode *inode = page->mapping->host; + struct buffer_head bh; + unsigned long size = PAGE_CACHE_SIZE; + u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + + do { + bh.b_state = 0; + bh.b_size = size; + gfs2_block_map(inode, lblock, &bh, 1); + if (!buffer_mapped(&bh)) + return -EIO; + size -= bh.b_size; + lblock += (bh.b_size >> inode->i_blkbits); + } while(size > 0); + return 0; +} + +/** + * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable + * @vma: The virtual memory area + * @vmf: The virtual memory fault containing the page to become writable + * + * When the page becomes writable, we need to ensure that we have + * blocks allocated on disk to back that page. + */ + +static int gfs2_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 gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_alloc_parms ap = { .aflags = 0, }; + unsigned long last_index; + u64 pos = page->index << PAGE_CACHE_SHIFT; + unsigned int data_blocks, ind_blocks, rblocks; + struct gfs2_holder gh; + loff_t size; + int ret; + + sb_start_pagefault(inode->i_sb); + + /* Update file times before taking page lock */ + file_update_time(vma->vm_file); + + ret = get_write_access(inode); + if (ret) + goto out; + + ret = gfs2_rs_alloc(ip); + if (ret) + goto out_write_access; + + gfs2_size_hint(vma->vm_file, pos, PAGE_CACHE_SIZE); + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + ret = gfs2_glock_nq(&gh); + if (ret) + goto out_uninit; + + set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); + set_bit(GIF_SW_PAGED, &ip->i_flags); + + if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) { + lock_page(page); + if (!PageUptodate(page) || page->mapping != inode->i_mapping) { + ret = -EAGAIN; + unlock_page(page); + } + goto out_unlock; + } + + ret = gfs2_rindex_update(sdp); + if (ret) + goto out_unlock; + + gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks); + ap.target = data_blocks + ind_blocks; + ret = gfs2_quota_lock_check(ip, &ap); + if (ret) + goto out_unlock; + ret = gfs2_inplace_reserve(ip, &ap); + if (ret) + goto out_quota_unlock; + + rblocks = RES_DINODE + ind_blocks; + if (gfs2_is_jdata(ip)) + rblocks += data_blocks ? data_blocks : 1; + if (ind_blocks || data_blocks) { + rblocks += RES_STATFS + RES_QUOTA; + rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); + } + ret = gfs2_trans_begin(sdp, rblocks, 0); + if (ret) + goto out_trans_fail; + + lock_page(page); + ret = -EINVAL; + size = i_size_read(inode); + last_index = (size - 1) >> PAGE_CACHE_SHIFT; + /* Check page index against inode size */ + if (size == 0 || (page->index > last_index)) + goto out_trans_end; + + ret = -EAGAIN; + /* If truncated, we must retry the operation, we may have raced + * with the glock demotion code. + */ + if (!PageUptodate(page) || page->mapping != inode->i_mapping) + goto out_trans_end; + + /* Unstuff, if required, and allocate backing blocks for page */ + ret = 0; + if (gfs2_is_stuffed(ip)) + ret = gfs2_unstuff_dinode(ip, page); + if (ret == 0) + ret = gfs2_allocate_page_backing(page); + +out_trans_end: + if (ret) + unlock_page(page); + gfs2_trans_end(sdp); +out_trans_fail: + gfs2_inplace_release(ip); +out_quota_unlock: + gfs2_quota_unlock(ip); +out_unlock: + gfs2_glock_dq(&gh); +out_uninit: + gfs2_holder_uninit(&gh); + if (ret == 0) { + set_page_dirty(page); + wait_for_stable_page(page); + } +out_write_access: + put_write_access(inode); +out: + sb_end_pagefault(inode->i_sb); + return block_page_mkwrite_return(ret); +} + +static const struct vm_operations_struct gfs2_vm_ops = { + .fault = filemap_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = gfs2_page_mkwrite, +}; + +/** + * gfs2_mmap - + * @file: The file to map + * @vma: The VMA which described the mapping + * + * There is no need to get a lock here unless we should be updating + * atime. We ignore any locking errors since the only consequence is + * a missed atime update (which will just be deferred until later). + * + * Returns: 0 + */ + +static int gfs2_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); + + if (!(file->f_flags & O_NOATIME) && + !IS_NOATIME(&ip->i_inode)) { + struct gfs2_holder i_gh; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (error) + return error; + /* grab lock to update inode */ + gfs2_glock_dq_uninit(&i_gh); + file_accessed(file); + } + vma->vm_ops = &gfs2_vm_ops; + + return 0; +} + +/** + * gfs2_open_common - This is common to open and atomic_open + * @inode: The inode being opened + * @file: The file being opened + * + * This maybe called under a glock or not depending upon how it has + * been called. We must always be called under a glock for regular + * files, however. For other file types, it does not matter whether + * we hold the glock or not. + * + * Returns: Error code or 0 for success + */ + +int gfs2_open_common(struct inode *inode, struct file *file) +{ + struct gfs2_file *fp; + int ret; + + if (S_ISREG(inode->i_mode)) { + ret = generic_file_open(inode, file); + if (ret) + return ret; + } + + fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS); + if (!fp) + return -ENOMEM; + + mutex_init(&fp->f_fl_mutex); + + gfs2_assert_warn(GFS2_SB(inode), !file->private_data); + file->private_data = fp; + return 0; +} + +/** + * gfs2_open - open a file + * @inode: the inode to open + * @file: the struct file for this opening + * + * After atomic_open, this function is only used for opening files + * which are already cached. We must still get the glock for regular + * files to ensure that we have the file size uptodate for the large + * file check which is in the common code. That is only an issue for + * regular files though. + * + * Returns: errno + */ + +static int gfs2_open(struct inode *inode, struct file *file) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder i_gh; + int error; + bool need_unlock = false; + + if (S_ISREG(ip->i_inode.i_mode)) { + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (error) + return error; + need_unlock = true; + } + + error = gfs2_open_common(inode, file); + + if (need_unlock) + gfs2_glock_dq_uninit(&i_gh); + + return error; +} + +/** + * gfs2_release - called to close a struct file + * @inode: the inode the struct file belongs to + * @file: the struct file being closed + * + * Returns: errno + */ + +static int gfs2_release(struct inode *inode, struct file *file) +{ + struct gfs2_inode *ip = GFS2_I(inode); + + kfree(file->private_data); + file->private_data = NULL; + + if (!(file->f_mode & FMODE_WRITE)) + return 0; + + gfs2_rs_delete(ip, &inode->i_writecount); + return 0; +} + +/** + * gfs2_fsync - sync the dirty data for a file (across the cluster) + * @file: the file that points to the dentry + * @start: the start position in the file to sync + * @end: the end position in the file to sync + * @datasync: set if we can ignore timestamp changes + * + * We split the data flushing here so that we don't wait for the data + * until after we've also sent the metadata to disk. Note that for + * data=ordered, we will write & wait for the data at the log flush + * stage anyway, so this is unlikely to make much of a difference + * except in the data=writeback case. + * + * If the fdatawrite fails due to any reason except -EIO, we will + * continue the remainder of the fsync, although we'll still report + * the error at the end. This is to match filemap_write_and_wait_range() + * behaviour. + * + * Returns: errno + */ + +static int gfs2_fsync(struct file *file, loff_t start, loff_t end, + int datasync) +{ + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + int sync_state = inode->i_state & I_DIRTY_ALL; + struct gfs2_inode *ip = GFS2_I(inode); + int ret = 0, ret1 = 0; + + if (mapping->nrpages) { + ret1 = filemap_fdatawrite_range(mapping, start, end); + if (ret1 == -EIO) + return ret1; + } + + if (!gfs2_is_jdata(ip)) + sync_state &= ~I_DIRTY_PAGES; + if (datasync) + sync_state &= ~(I_DIRTY_SYNC | I_DIRTY_TIME); + + if (sync_state) { + ret = sync_inode_metadata(inode, 1); + if (ret) + return ret; + if (gfs2_is_jdata(ip)) + filemap_write_and_wait(mapping); + gfs2_ail_flush(ip->i_gl, 1); + } + + if (mapping->nrpages) + ret = filemap_fdatawait_range(mapping, start, end); + + return ret ? ret : ret1; +} + +/** + * gfs2_file_write_iter - Perform a write to a file + * @iocb: The io context + * @iov: The data to write + * @nr_segs: Number of @iov segments + * @pos: The file position + * + * We have to do a lock/unlock here to refresh the inode size for + * O_APPEND writes, otherwise we can land up writing at the wrong + * offset. There is still a race, but provided the app is using its + * own file locking, this will make O_APPEND work as expected. + * + */ + +static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct gfs2_inode *ip = GFS2_I(file_inode(file)); + int ret; + + ret = gfs2_rs_alloc(ip); + if (ret) + return ret; + + gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from)); + + if (iocb->ki_flags & IOCB_APPEND) { + struct gfs2_holder gh; + + ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + if (ret) + return ret; + gfs2_glock_dq_uninit(&gh); + } + + return generic_file_write_iter(iocb, from); +} + +static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, + int mode) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct buffer_head *dibh; + int error; + unsigned int nr_blks; + sector_t lblock = offset >> inode->i_blkbits; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (unlikely(error)) + return error; + + gfs2_trans_add_meta(ip->i_gl, dibh); + + if (gfs2_is_stuffed(ip)) { + error = gfs2_unstuff_dinode(ip, NULL); + if (unlikely(error)) + goto out; + } + + while (len) { + struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 }; + bh_map.b_size = len; + set_buffer_zeronew(&bh_map); + + error = gfs2_block_map(inode, lblock, &bh_map, 1); + if (unlikely(error)) + goto out; + len -= bh_map.b_size; + nr_blks = bh_map.b_size >> inode->i_blkbits; + lblock += nr_blks; + if (!buffer_new(&bh_map)) + continue; + if (unlikely(!buffer_zeronew(&bh_map))) { + error = -EIO; + goto out; + } + } +out: + brelse(dibh); + return error; +} +/** + * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of + * blocks, determine how many bytes can be written. + * @ip: The inode in question. + * @len: Max cap of bytes. What we return in *len must be <= this. + * @data_blocks: Compute and return the number of data blocks needed + * @ind_blocks: Compute and return the number of indirect blocks needed + * @max_blocks: The total blocks available to work with. + * + * Returns: void, but @len, @data_blocks and @ind_blocks are filled in. + */ +static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len, + unsigned int *data_blocks, unsigned int *ind_blocks, + unsigned int max_blocks) +{ + loff_t max = *len; + const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1); + + for (tmp = max_data; tmp > sdp->sd_diptrs;) { + tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs); + max_data -= tmp; + } + + *data_blocks = max_data; + *ind_blocks = max_blocks - max_data; + *len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift; + if (*len > max) { + *len = max; + gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks); + } +} + +static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) +{ + struct inode *inode = file_inode(file); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_alloc_parms ap = { .aflags = 0, }; + unsigned int data_blocks = 0, ind_blocks = 0, rblocks; + loff_t bytes, max_bytes, max_blks = UINT_MAX; + int error; + const loff_t pos = offset; + const loff_t count = len; + loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1); + loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift; + loff_t max_chunk_size = UINT_MAX & bsize_mask; + + next = (next + 1) << sdp->sd_sb.sb_bsize_shift; + + offset &= bsize_mask; + + len = next - offset; + bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2; + if (!bytes) + bytes = UINT_MAX; + bytes &= bsize_mask; + if (bytes == 0) + bytes = sdp->sd_sb.sb_bsize; + + gfs2_size_hint(file, offset, len); + + gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks); + ap.min_target = data_blocks + ind_blocks; + + while (len > 0) { + if (len < bytes) + bytes = len; + if (!gfs2_write_alloc_required(ip, offset, bytes)) { + len -= bytes; + offset += bytes; + continue; + } + + /* We need to determine how many bytes we can actually + * fallocate without exceeding quota or going over the + * end of the fs. We start off optimistically by assuming + * we can write max_bytes */ + max_bytes = (len > max_chunk_size) ? max_chunk_size : len; + + /* Since max_bytes is most likely a theoretical max, we + * calculate a more realistic 'bytes' to serve as a good + * starting point for the number of bytes we may be able + * to write */ + gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks); + ap.target = data_blocks + ind_blocks; + + error = gfs2_quota_lock_check(ip, &ap); + if (error) + return error; + /* ap.allowed tells us how many blocks quota will allow + * us to write. Check if this reduces max_blks */ + if (ap.allowed && ap.allowed < max_blks) + max_blks = ap.allowed; + + error = gfs2_inplace_reserve(ip, &ap); + if (error) + goto out_qunlock; + + /* check if the selected rgrp limits our max_blks further */ + if (ap.allowed && ap.allowed < max_blks) + max_blks = ap.allowed; + + /* Almost done. Calculate bytes that can be written using + * max_blks. We also recompute max_bytes, data_blocks and + * ind_blocks */ + calc_max_reserv(ip, &max_bytes, &data_blocks, + &ind_blocks, max_blks); + + rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA + + RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks); + if (gfs2_is_jdata(ip)) + rblocks += data_blocks ? data_blocks : 1; + + error = gfs2_trans_begin(sdp, rblocks, + PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize); + if (error) + goto out_trans_fail; + + error = fallocate_chunk(inode, offset, max_bytes, mode); + gfs2_trans_end(sdp); + + if (error) + goto out_trans_fail; + + len -= max_bytes; + offset += max_bytes; + gfs2_inplace_release(ip); + gfs2_quota_unlock(ip); + } + + if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size) { + i_size_write(inode, pos + count); + /* Marks the inode as dirty */ + file_update_time(file); + } + + return generic_write_sync(file, pos, count); + +out_trans_fail: + gfs2_inplace_release(ip); +out_qunlock: + gfs2_quota_unlock(ip); + return error; +} + +static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) +{ + struct inode *inode = file_inode(file); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + int ret; + + if (mode & ~FALLOC_FL_KEEP_SIZE) + return -EOPNOTSUPP; + + mutex_lock(&inode->i_mutex); + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); + ret = gfs2_glock_nq(&gh); + if (ret) + goto out_uninit; + + if (!(mode & FALLOC_FL_KEEP_SIZE) && + (offset + len) > inode->i_size) { + ret = inode_newsize_ok(inode, offset + len); + if (ret) + goto out_unlock; + } + + ret = get_write_access(inode); + if (ret) + goto out_unlock; + + ret = gfs2_rs_alloc(ip); + if (ret) + goto out_putw; + + ret = __gfs2_fallocate(file, mode, offset, len); + if (ret) + gfs2_rs_deltree(ip->i_res); +out_putw: + put_write_access(inode); +out_unlock: + gfs2_glock_dq(&gh); +out_uninit: + gfs2_holder_uninit(&gh); + mutex_unlock(&inode->i_mutex); + return ret; +} + +static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe, + struct file *out, loff_t *ppos, + size_t len, unsigned int flags) +{ + int error; + struct gfs2_inode *ip = GFS2_I(out->f_mapping->host); + + error = gfs2_rs_alloc(ip); + if (error) + return (ssize_t)error; + + gfs2_size_hint(out, *ppos, len); + + return iter_file_splice_write(pipe, out, ppos, len, flags); +} + +#ifdef CONFIG_GFS2_FS_LOCKING_DLM + +/** + * gfs2_lock - acquire/release a posix lock on a file + * @file: the file pointer + * @cmd: either modify or retrieve lock state, possibly wait + * @fl: type and range of lock + * + * Returns: errno + */ + +static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl) +{ + struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); + struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host); + struct lm_lockstruct *ls = &sdp->sd_lockstruct; + + if (!(fl->fl_flags & FL_POSIX)) + return -ENOLCK; + if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK) + return -ENOLCK; + + if (cmd == F_CANCELLK) { + /* Hack: */ + cmd = F_SETLK; + fl->fl_type = F_UNLCK; + } + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { + if (fl->fl_type == F_UNLCK) + posix_lock_file_wait(file, fl); + return -EIO; + } + if (IS_GETLK(cmd)) + return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl); + else if (fl->fl_type == F_UNLCK) + return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl); + else + return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl); +} + +static int do_flock(struct file *file, int cmd, struct file_lock *fl) +{ + struct gfs2_file *fp = file->private_data; + struct gfs2_holder *fl_gh = &fp->f_fl_gh; + struct gfs2_inode *ip = GFS2_I(file_inode(file)); + struct gfs2_glock *gl; + unsigned int state; + int flags; + int error = 0; + int sleeptime; + + state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; + flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT; + + mutex_lock(&fp->f_fl_mutex); + + gl = fl_gh->gh_gl; + if (gl) { + if (fl_gh->gh_state == state) + goto out; + flock_lock_file_wait(file, + &(struct file_lock){.fl_type = F_UNLCK}); + gfs2_glock_dq(fl_gh); + gfs2_holder_reinit(state, flags, fl_gh); + } else { + error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr, + &gfs2_flock_glops, CREATE, &gl); + if (error) + goto out; + gfs2_holder_init(gl, state, flags, fl_gh); + gfs2_glock_put(gl); + } + for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) { + error = gfs2_glock_nq(fl_gh); + if (error != GLR_TRYFAILED) + break; + fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT; + fl_gh->gh_error = 0; + msleep(sleeptime); + } + if (error) { + gfs2_holder_uninit(fl_gh); + if (error == GLR_TRYFAILED) + error = -EAGAIN; + } else { + error = flock_lock_file_wait(file, fl); + gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error); + } + +out: + mutex_unlock(&fp->f_fl_mutex); + return error; +} + +static void do_unflock(struct file *file, struct file_lock *fl) +{ + struct gfs2_file *fp = file->private_data; + struct gfs2_holder *fl_gh = &fp->f_fl_gh; + + mutex_lock(&fp->f_fl_mutex); + flock_lock_file_wait(file, fl); + if (fl_gh->gh_gl) { + gfs2_glock_dq(fl_gh); + gfs2_holder_uninit(fl_gh); + } + mutex_unlock(&fp->f_fl_mutex); +} + +/** + * gfs2_flock - acquire/release a flock lock on a file + * @file: the file pointer + * @cmd: either modify or retrieve lock state, possibly wait + * @fl: type and range of lock + * + * Returns: errno + */ + +static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl) +{ + if (!(fl->fl_flags & FL_FLOCK)) + return -ENOLCK; + if (fl->fl_type & LOCK_MAND) + return -EOPNOTSUPP; + + if (fl->fl_type == F_UNLCK) { + do_unflock(file, fl); + return 0; + } else { + return do_flock(file, cmd, fl); + } +} + +const struct file_operations gfs2_file_fops = { + .llseek = gfs2_llseek, + .read_iter = generic_file_read_iter, + .write_iter = gfs2_file_write_iter, + .unlocked_ioctl = gfs2_ioctl, + .mmap = gfs2_mmap, + .open = gfs2_open, + .release = gfs2_release, + .fsync = gfs2_fsync, + .lock = gfs2_lock, + .flock = gfs2_flock, + .splice_read = generic_file_splice_read, + .splice_write = gfs2_file_splice_write, + .setlease = simple_nosetlease, + .fallocate = gfs2_fallocate, +}; + +const struct file_operations gfs2_dir_fops = { + .iterate = gfs2_readdir, + .unlocked_ioctl = gfs2_ioctl, + .open = gfs2_open, + .release = gfs2_release, + .fsync = gfs2_fsync, + .lock = gfs2_lock, + .flock = gfs2_flock, + .llseek = default_llseek, +}; + +#endif /* CONFIG_GFS2_FS_LOCKING_DLM */ + +const struct file_operations gfs2_file_fops_nolock = { + .llseek = gfs2_llseek, + .read_iter = generic_file_read_iter, + .write_iter = gfs2_file_write_iter, + .unlocked_ioctl = gfs2_ioctl, + .mmap = gfs2_mmap, + .open = gfs2_open, + .release = gfs2_release, + .fsync = gfs2_fsync, + .splice_read = generic_file_splice_read, + .splice_write = gfs2_file_splice_write, + .setlease = generic_setlease, + .fallocate = gfs2_fallocate, +}; + +const struct file_operations gfs2_dir_fops_nolock = { + .iterate = gfs2_readdir, + .unlocked_ioctl = gfs2_ioctl, + .open = gfs2_open, + .release = gfs2_release, + .fsync = gfs2_fsync, + .llseek = default_llseek, +}; + |