diff options
| author | Filipe Manana | 2022-12-23 18:28:53 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-01-12 12:01:56 +0100 |
| commit | 427a36cf819b38d37756291b77ed9c0c6e74daf6 (patch) | |
| tree | 840d0a4c36188ea0f8cd4aac2d67d273421f9833 /fs | |
| parent | acbf70d7f9cd416718ec701dfa945d5da0486fa5 (diff) | |
btrfs: fix off-by-one in delalloc search during lseek
commit 2f2e84ca60660402bd81d0859703567c59556e6a upstream.
During lseek, when searching for delalloc in a range that represents a
hole and that range has a length of 1 byte, we end up not doing the actual
delalloc search in the inode's io tree, resulting in not correctly
reporting the offset with data or a hole. This actually only happens when
the start offset is 0 because with any other start offset we round it down
by sector size.
Reproducer:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt/sdc
$ xfs_io -f -c "pwrite -q 0 1" /mnt/sdc/foo
$ xfs_io -c "seek -d 0" /mnt/sdc/foo
Whence Result
DATA EOF
It should have reported an offset of 0 instead of EOF.
Fix this by updating btrfs_find_delalloc_in_range() and count_range_bits()
to deal with inclusive ranges properly. These functions are already
supposed to work with inclusive end offsets, they just got it wrong in a
couple places due to off-by-one mistakes.
A test case for fstests will be added later.
Reported-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/20221223020509.457113-1-joanbrugueram@gmail.com/
Fixes: b6e833567ea1 ("btrfs: make hole and data seeking a lot more efficient")
CC: stable@vger.kernel.org # 6.1
Tested-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent-io-tree.c | 2 | ||||
| -rw-r--r-- | fs/btrfs/file.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 7b93719a486c..09ae0e73e680 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -1507,7 +1507,7 @@ u64 count_range_bits(struct extent_io_tree *tree, u64 last = 0; int found = 0; - if (WARN_ON(search_end <= cur_start)) + if (WARN_ON(search_end < cur_start)) return 0; spin_lock(&tree->lock); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed4e1c3705d0..9bef8eaa074a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3671,7 +3671,7 @@ bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end, u64 prev_delalloc_end = 0; bool ret = false; - while (cur_offset < end) { + while (cur_offset <= end) { u64 delalloc_start; u64 delalloc_end; bool delalloc; |