diff options
| author | Qu Wenruo <wqu@suse.com> | 2023-03-02 09:54:12 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-03-15 20:51:05 +0100 |
| commit | 1c3ab6dfa0692c3626580a508cf84e794201b357 (patch) | |
| tree | 6469490346f90c90aafea80c5a5b97d0fddae517 /fs | |
| parent | 675dfe1223a69e270b3d52cb0211c8a501455cec (diff) | |
btrfs: handle missing chunk mapping more gracefully
[BUG]
During my scrub rework, I did a stupid thing like this:
bio->bi_iter.bi_sector = stripe->logical;
btrfs_submit_bio(fs_info, bio, stripe->mirror_num);
Above bi_sector assignment is using logical address directly, which
lacks ">> SECTOR_SHIFT".
This results a read on a range which has no chunk mapping.
This results the following crash:
BTRFS critical (device dm-1): unable to find logical 11274289152 length 65536
assertion failed: !IS_ERR(em), in fs/btrfs/volumes.c:6387
Sure this is all my fault, but this shows a possible problem in real
world, that some bit flip in file extents/tree block can point to
unmapped ranges, and trigger above ASSERT(), or if CONFIG_BTRFS_ASSERT
is not configured, cause invalid pointer access.
[PROBLEMS]
In the above call chain, we just don't handle the possible error from
btrfs_get_chunk_map() inside __btrfs_map_block().
[FIX]
The fix is straightforward, replace the ASSERT() with proper error
handling (callers handle errors already).
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/volumes.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7823168c08a6..6d0124b6e79e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6363,7 +6363,8 @@ int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, ASSERT(op != BTRFS_MAP_DISCARD); em = btrfs_get_chunk_map(fs_info, logical, *length); - ASSERT(!IS_ERR(em)); + if (IS_ERR(em)) + return PTR_ERR(em); map = em->map_lookup; data_stripes = nr_data_stripes(map); |