Re: [PATCH] f2fs: fix to avoid atomicity corruption of atomic file

[Chao Yu <chao@kernel.org>]

On 3/14/25 20:06, Yeongjin Gil wrote:
> In the case of the following call stack for an atomic file,
> FI_DIRTY_INODE is set, but FI_ATOMIC_DIRTIED is not subsequently set.
> 
> f2fs_file_write_iter
>   f2fs_map_blocks
>     f2fs_reserve_new_blocks
>       inc_valid_block_count
>         __mark_inode_dirty(dquot)
>           f2fs_dirty_inode
> 
> If FI_ATOMIC_DIRTIED is not set, atomic file can encounter corruption
> due to a mismatch between old file size and new data.
> 
> To resolve this issue, I changed to set FI_ATOMIC_DIRTIED when
> FI_DIRTY_INODE is set. This ensures that FI_DIRTY_INODE, which was
> previously cleared by the Writeback thread during the commit atomic, is
> set and i_size is updated.

I guess we need to add a regression testcase to cover this issue.

> 
> Fixes: fccaa81de87e ("f2fs: prevent atomic file from being dirtied before commit")
> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
> Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com>
> Signed-off-by: Yeongjin Gil <youngjin.gil@samsung.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,