Re: [PATCH] f2fs: Prevent s_writer rw_sem count mismatch in f2fs_evict_inode

[Chao Yu]

On 2024/3/22 12:16, Yeongjin Gil wrote:
> If f2fs_evict_inode is called between freeze_super and thaw_super, the
> s_writer rwsem count may become negative, resulting in hang.
>
> CPU1 CPU2
>
> f2fs_resize_fs()           f2fs_evict_inode()
>    f2fs_freeze
>      set SBI_IS_FREEZING
>                               skip sb_start_intwrite
>    f2fs_unfreeze
>      clear SBI_IS_FREEZING
>                               sb_end_intwrite
>
> To solve this problem, the call to sb_end_write is determined by whether
> sb_start_intwrite is called, rather than the current freezing status.
>
> Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
> Reviewed-by: Sunmin Jeong <s_min.jeong@xxxxxxxxxxx>
> Signed-off-by: Yeongjin Gil <youngjin.gil@xxxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,