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| author | Filipe Manana <fdmanana@suse.com> | 2022-12-23 18:28:53 +0000 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-01-03 15:53:18 +0100 |
| commit | 2f2e84ca60660402bd81d0859703567c59556e6a (patch) | |
| tree | 4da98c4a48464bbc6242aaada3a31f4773321753 | |
| parent | 1d854e4fbabb0cb12ca4a7fcd784eb67a65de5f8 (diff) | |
| download | pci-2f2e84ca60660402bd81d0859703567c59556e6a.tar.gz | |
btrfs: fix off-by-one in delalloc search during lseek
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>
| -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 9ae9cd1e70352a..3c7766dfaa694a 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -1551,7 +1551,7 @@ 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 91b00eb2440e7d..834bbcb91102fd 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3354,7 +3354,7 @@ bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end, bool search_io_tree = true; bool ret = false; - while (cur_offset < end) { + while (cur_offset <= end) { u64 delalloc_start; u64 delalloc_end; bool delalloc; |