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| author | Ye Bin <yebin10@huawei.com> | 2022-12-08 06:34:24 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2022-12-09 08:58:04 +0300 |
| commit | 1da18e38cb97e9521e93d63034521a9649524f64 (patch) | |
| tree | 239a08aa598e0252fe0caa49e12a0da2c36aff3f /fs/ext4 | |
| parent | e4db04f7d3dbbe16680e0ded27ea2a65b10f766a (diff) | |
| download | linux-1da18e38cb97e9521e93d63034521a9649524f64.tar.xz | |
ext4: fix reserved cluster accounting in __es_remove_extent()
When bigalloc is enabled, reserved cluster accounting for delayed
allocation is handled in extent_status.c. With a corrupted file
system, it's possible for this accounting to be incorrect,
dsicovered by Syzbot:
EXT4-fs error (device loop0): ext4_validate_block_bitmap:398: comm rep:
bg 0: block 5: invalid block bitmap
EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical
offset 0 with max blocks 32 with error 28
EXT4-fs (loop0): This should not happen!! Data will be lost
EXT4-fs (loop0): Total free blocks count 0
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=0
EXT4-fs (loop0): dirty_blocks=32
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=2
EXT4-fs (loop0): Inode 18 (00000000845cd634):
i_reserved_data_blocks (1) not cleared!
Above issue happens as follows:
Assume:
sbi->s_cluster_ratio = 16
Step1:
Insert delay block [0, 31] -> ei->i_reserved_data_blocks=2
Step2:
ext4_writepages
mpage_map_and_submit_extent -> return failed
mpage_release_unused_pages -> to release [0, 30]
ext4_es_remove_extent -> remove lblk=0 end=30
__es_remove_extent -> len1=0 len2=31-30=1
__es_remove_extent:
...
if (len2 > 0) {
...
if (len1 > 0) {
...
} else {
es->es_lblk = end + 1;
es->es_len = len2;
...
}
if (count_reserved)
count_rsvd(inode, lblk, ...);
goto out; -> will return but didn't calculate 'reserved'
...
Step3:
ext4_destroy_inode -> trigger "i_reserved_data_blocks (1) not cleared!"
To solve above issue if 'len2>0' call 'get_rsvd()' before goto out.
Reported-by: syzbot+05a0f0ccab4a25626e38@syzkaller.appspotmail.com
Fixes: 8fcc3a580651 ("ext4: rework reserved cluster accounting when invalidating pages")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Eric Whitney <enwlinux@gmail.com>
Link: https://lore.kernel.org/r/20221208033426.1832460-2-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/extents_status.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 97eccc0028a1..7bc221038c6c 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -1369,7 +1369,7 @@ retry: if (count_reserved) count_rsvd(inode, lblk, orig_es.es_len - len1 - len2, &orig_es, &rc); - goto out; + goto out_get_reserved; } if (len1 > 0) { @@ -1411,6 +1411,7 @@ retry: } } +out_get_reserved: if (count_reserved) *reserved = get_rsvd(inode, end, es, &rc); out: |