On Fri, Nov 13, 2020 at 7:57 AM Chengguang Xu <cgxu519@xxxxxxxxxxxx> wrote:
>
> Now overlayfs can only sync dirty inode during syncfs,
> so remove unnecessary sync_filesystem() on upper file
> system.
>
> Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
> ---
> fs/overlayfs/super.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index 982b3954b47c..58507f1cd583 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -15,6 +15,8 @@
> #include <linux/seq_file.h>
> #include <linux/posix_acl_xattr.h>
> #include <linux/exportfs.h>
> +#include <linux/blkdev.h>
> +#include <linux/writeback.h>
> #include "overlayfs.h"
>
> MODULE_AUTHOR("Miklos Szeredi <miklos@xxxxxxxxxx>");
> @@ -270,8 +272,7 @@ 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
> + * if this is a syncfs(2) call, it will be enough we do it when being
> * called with wait == 1.
> */
> if (!wait)
> @@ -280,7 +281,11 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
> upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
>
> down_read(&upper_sb->s_umount);
> - ret = sync_filesystem(upper_sb);
> + wait_sb_inodes(upper_sb);
> + if (upper_sb->s_op->sync_fs)
> + ret = upper_sb->s_op->sync_fs(upper_sb, wait);
> + if (!ret)
> + ret = sync_blockdev(upper_sb->s_bdev);
Should this instead be __sync_blockdev(..., wait)?
Thanks,
Miklos
