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| author | Miao Xie <miaox@cn.fujitsu.com> | 2011-09-11 10:52:24 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2011-09-11 10:52:24 -0400 |
| commit | 0c1a98c81413e00a6c379d898e06a09350d31926 (patch) | |
| tree | 6f92bcd7954fc8131197ccca25b94a3a88dbb368 /fs/btrfs | |
| parent | 5b397377e97d436fc2ed872fc53f85395bb984e0 (diff) | |
| download | lwn-0c1a98c81413e00a6c379d898e06a09350d31926.tar.gz lwn-0c1a98c81413e00a6c379d898e06a09350d31926.zip | |
Btrfs: fix the file extent gap when doing direct IO
When we write some data to the place that is beyond the end of the file
in direct I/O mode, a data hole will be created. And Btrfs should insert
a file extent item that point to this hole into the fs tree. But unfortunately
Btrfs forgets doing it.
The following is a simple way to reproduce it:
# mkfs.btrfs /dev/sdc2
# mount /dev/sdc2 /test4
# touch /test4/a
# dd if=/dev/zero of=/test4/a seek=8 count=1 bs=4K oflag=direct conv=nocreat,notrunc
# umount /test4
# btrfsck /dev/sdc2
root 5 inode 257 errors 100
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/file.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 15e5a1cd8764..98d95bb5f253 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1075,12 +1075,6 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file, start_pos = pos & ~((u64)root->sectorsize - 1); last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; - if (start_pos > inode->i_size) { - err = btrfs_cont_expand(inode, i_size_read(inode), start_pos); - if (err) - return err; - } - again: for (i = 0; i < num_pages; i++) { pages[i] = find_or_create_page(inode->i_mapping, index + i, @@ -1338,6 +1332,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, struct inode *inode = fdentry(file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; loff_t *ppos = &iocb->ki_pos; + u64 start_pos; ssize_t num_written = 0; ssize_t err = 0; size_t count, ocount; @@ -1386,6 +1381,15 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, file_update_time(file); BTRFS_I(inode)->sequence++; + start_pos = round_down(pos, root->sectorsize); + if (start_pos > i_size_read(inode)) { + err = btrfs_cont_expand(inode, i_size_read(inode), start_pos); + if (err) { + mutex_unlock(&inode->i_mutex); + goto out; + } + } + if (unlikely(file->f_flags & O_DIRECT)) { num_written = __btrfs_direct_write(iocb, iov, nr_segs, pos, ppos, count, ocount); |