Re: [f2fs-dev] [PATCH] f2fs: fix to avoid inconsistent quota data

[Chao Yu]

On 2021/1/28 17:02, Chao Yu wrote:
> From: Yi Chen <chenyi77@xxxxxxxxxx>
>
> Occasionally, quota data may be corrupted detected by fsck:
>
> Info: checkpoint state = 45 :  crc compacted_summary unmount
> [QUOTA WARNING] Usage inconsistent for ID 0:actual (1543036928, 762) != expected (1543032832, 762)
> [ASSERT] (fsck_chk_quota_files:1986)  --> Quota file is missing or invalid quota file content found.
> [QUOTA WARNING] Usage inconsistent for ID 0:actual (1352478720, 344) != expected (1352474624, 344)
> [ASSERT] (fsck_chk_quota_files:1986)  --> Quota file is missing or invalid quota file content found.
>
> [FSCK] Unreachable nat entries                        [Ok..] [0x0]
> [FSCK] SIT valid block bitmap checking                [Ok..]
> [FSCK] Hard link checking for regular file            [Ok..] [0x0]
> [FSCK] valid_block_count matching with CP             [Ok..] [0xdf299]
> [FSCK] valid_node_count matcing with CP (de lookup)   [Ok..] [0x2b01]
> [FSCK] valid_node_count matcing with CP (nat lookup)  [Ok..] [0x2b01]
> [FSCK] valid_inode_count matched with CP              [Ok..] [0x2665]
> [FSCK] free segment_count matched with CP             [Ok..] [0xcb04]
> [FSCK] next block offset is free                      [Ok..]
> [FSCK] fixing SIT types
> [FSCK] other corrupted bugs                           [Fail]
>
> The root cause is:
> If we open file w/ readonly flag, disk quota info won't be initialized
> for this file, however, following mmap() will force to convert inline
> inode via f2fs_convert_inline_inode(), which may increase block usage
> for this inode w/o updating quota data, it causes inconsistent disk quota
> info.
>
> The issue will happen in following stack:
> open(file, O_RDONLY)
> mmap(file)
> - f2fs_convert_inline_inode
>   - f2fs_convert_inline_page
>    - f2fs_reserve_block
>     - f2fs_reserve_new_block
>      - f2fs_reserve_new_blocks
>       - f2fs_i_blocks_write
>        - dquot_claim_block
> inode->i_blocks increase, but the dqb_curspace keep the size for the dquots
> is NULL.
>
> To fix this issue, let's call dquot_initialize() anyway in both
> f2fs_truncate() and f2fs_convert_inline_inode() functions to avoid potential
> inconsistent quota data issue.
>
> Fixes: 0abd675e97e6 ("f2fs: support plain user/group quota")
> Signed-off-by: Daiyue Zhang <zhangdaiyue1@xxxxxxxxxx>
> Signed-off-by: Dehe Gu <gudehe@xxxxxxxxxx>
> Signed-off-by: Junchao Jiang <jiangjunchao1@xxxxxxxxxx>
> Signed-off-by: Ge Qiu <qiuge@xxxxxxxxxx>
> Signed-off-by: Yi Chen <chenyi77@xxxxxxxxxx>

[Chao Yu: clean up commit message a bit]
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>

Thanks,