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| author | Qu Wenruo <wqu@suse.com> | 2024-08-12 02:22:44 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2024-08-13 14:42:26 +0300 |
| commit | 31723c9542dba1681cc3720571fdf12ffe0eddd9 (patch) | |
| tree | 359ec1f61cbfac5e845e9d1febfe35db4b6a202a | |
| parent | 42fac187b5c746227c92d024f1caf33bc1d337e4 (diff) | |
| download | linux-31723c9542dba1681cc3720571fdf12ffe0eddd9.tar.xz | |
btrfs: tree-checker: reject BTRFS_FT_UNKNOWN dir type
[REPORT]
There is a bug report that kernel is rejecting a mismatching inode mode
and its dir item:
[ 1881.553937] BTRFS critical (device dm-0): inode mode mismatch with
dir: inode mode=040700 btrfs type=2 dir type=0
[CAUSE]
It looks like the inode mode is correct, while the dir item type
0 is BTRFS_FT_UNKNOWN, which should not be generated by btrfs at all.
This may be caused by a memory bit flip.
[ENHANCEMENT]
Although tree-checker is not able to do any cross-leaf verification, for
this particular case we can at least reject any dir type with
BTRFS_FT_UNKNOWN.
So here we enhance the dir type check from [0, BTRFS_FT_MAX), to
(0, BTRFS_FT_MAX).
Although the existing corruption can not be fixed just by such enhanced
checking, it should prevent the same 0x2->0x0 bitflip for dir type to
reach disk in the future.
Reported-by: Kota <nospam@kota.moe>
Link: https://lore.kernel.org/linux-btrfs/CACsxjPYnQF9ZF-0OhH16dAx50=BXXOcP74MxBc3BG+xae4vTTw@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/tree-checker.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index a825fa598e3c..6f1e2f2215d9 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -569,9 +569,10 @@ static int check_dir_item(struct extent_buffer *leaf, /* dir type check */ dir_type = btrfs_dir_ftype(leaf, di); - if (unlikely(dir_type >= BTRFS_FT_MAX)) { + if (unlikely(dir_type <= BTRFS_FT_UNKNOWN || + dir_type >= BTRFS_FT_MAX)) { dir_item_err(leaf, slot, - "invalid dir item type, have %u expect [0, %u)", + "invalid dir item type, have %u expect (0, %u)", dir_type, BTRFS_FT_MAX); return -EUCLEAN; } |