• Ye Bin's avatar
    ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed · 082cd4ec
    Ye Bin authored
    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
    
    This patch's modification is according to Jan Kara's suggestion in:
    https://patchwork.ozlabs.org/project/linux-ext4/patch/20210428085158.3728201-1-yebin10@huawei.com/
    "I see. Now I understand your patch. Honestly, seeing how fragile is trying
    to fix extent tree after split has failed in the middle, I would probably
    go even further and make sure we fix the tree properly in case of ENOSPC
    and EDQUOT (those are easily user triggerable).  Anything else indicates a
    HW problem or fs corruption so I'd rather leave the extent tree as is and
    don't try to fix it (which also means we will not create overlapping
    extents)."
    
    Cc: stable@kernel.org
    Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
    Reviewed-by: default avatarJan Kara <jack@suse.cz>
    Link: https://lore.kernel.org/r/20210506141042.3298679-1-yebin10@huawei.comSigned-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    082cd4ec
extents.c 164 KB