We got follow bug_on when run fsstress with injecting IO fault:
[130747.323114] kernel BUG at fs/ext4/extents_status.c:762!
[130747.323117] Internal error: Oops - BUG: 0 [#1] SMP
......
[130747.334329] Call trace:
[130747.334553] ext4_es_cache_extent+0x150/0x168 [ext4]
[130747.334975] ext4_cache_extents+0x64/0xe8 [ext4]
[130747.335368] ext4_find_extent+0x300/0x330 [ext4]
[130747.335759] ext4_ext_map_blocks+0x74/0x1178 [ext4]
[130747.336179] ext4_map_blocks+0x2f4/0x5f0 [ext4]
[130747.336567] ext4_mpage_readpages+0x4a8/0x7a8 [ext4]
[130747.336995] ext4_readpage+0x54/0x100 [ext4]
[130747.337359] generic_file_buffered_read+0x410/0xae8
[130747.337767] generic_file_read_iter+0x114/0x190
[130747.338152] ext4_file_read_iter+0x5c/0x140 [ext4]
[130747.338556] __vfs_read+0x11c/0x188
[130747.338851] vfs_read+0x94/0x150
[130747.339110] ksys_read+0x74/0xf0
If call ext4_ext_insert_extent failed but new extent already inserted, we just
update "ex->ee_len = orig_ex.ee_len", this will lead to extent overlap, then
cause bug on when cache extent.
If call ext4_ext_insert_extent failed don't update ex->ee_len with old value.
Maybe there will lead to block leak, but it can be fixed by fsck later.
Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
---
fs/ext4/extents.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 77c84d6f1af6..6161db9c17c9 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3245,8 +3245,11 @@ static int ext4_split_extent_at(handle_t *handle,
err = ext4_zeroout_es(inode, &zero_ex);
goto out;
- } else if (err)
+ } else if (err == -EROFS) {
+ return err;
+ } else {
goto fix_extent_len;
+ }
out:
ext4_ext_show_leaf(inode, path);
--
2.25.4
