Re: [RFC PATCH V6 7/7] ovl: implement containerized syncfs for overlayfs
From: Jan Kara
Date: Fri Nov 26 2021 - 04:27:12 EST
On Mon 22-11-21 11:00:38, Chengguang Xu wrote:
> From: Chengguang Xu <charliecgxu@xxxxxxxxxxx>
>
> Now overlayfs can only sync own dirty inodes during syncfs,
> so remove unnecessary sync_filesystem() on upper file system.
>
> Signed-off-by: Chengguang Xu <charliecgxu@xxxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/overlayfs/super.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index ccffcd96491d..213b795a6a86 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -292,18 +292,14 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
> /*
> * Not called for sync(2) call or an emergency sync (SB_I_SKIP_SYNC).
> * All the super blocks will be iterated, including upper_sb.
> - *
> - * If this is a syncfs(2) call, then we do need to call
> - * sync_filesystem() on upper_sb, but enough if we do it when being
> - * called with wait == 1.
> */
> - if (!wait)
> - return 0;
> -
> upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
> -
> down_read(&upper_sb->s_umount);
> - ret = sync_filesystem(upper_sb);
> + if (wait)
> + wait_sb_inodes(upper_sb);
> + if (upper_sb->s_op->sync_fs)
> + upper_sb->s_op->sync_fs(upper_sb, wait);
> + ret = ovl_sync_upper_blockdev(upper_sb, wait);
> up_read(&upper_sb->s_umount);
>
> return ret;
> --
> 2.27.0
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR