From:   Chengguang Xu <cgxu519@mykernel.net>
To:     miklos@szeredi.hu, jack@suse.cz, amir73il@gmail.com
Cc:     linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Chengguang Xu <charliecgxu@tencent.com>
Message-ID: <20211122030038.1938875-8-cgxu519@mykernel.net>
Subject: [RFC PATCH V6 7/7] ovl: implement containerized syncfs for overlayfs
Date:   Mon, 22 Nov 2021 11:00:38 +0800
In-Reply-To: <20211122030038.1938875-1-cgxu519@mykernel.net>
References: <20211122030038.1938875-1-cgxu519@mykernel.net>
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From: Chengguang Xu <charliecgxu@tencent.com>

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@tencent.com>
---
 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 wa=
it)
 =09/*
 =09 * Not called for sync(2) call or an emergency sync (SB_I_SKIP_SYNC).
 =09 * All the super blocks will be iterated, including upper_sb.
-=09 *
-=09 * If this is a syncfs(2) call, then we do need to call
-=09 * sync_filesystem() on upper_sb, but enough if we do it when being
-=09 * called with wait =3D=3D 1.
 =09 */
-=09if (!wait)
-=09=09return 0;
-
 =09upper_sb =3D ovl_upper_mnt(ofs)->mnt_sb;
-
 =09down_read(&upper_sb->s_umount);
-=09ret =3D sync_filesystem(upper_sb);
+=09if (wait)
+=09=09wait_sb_inodes(upper_sb);
+=09if (upper_sb->s_op->sync_fs)
+=09=09upper_sb->s_op->sync_fs(upper_sb, wait);
+=09ret =3D ovl_sync_upper_blockdev(upper_sb, wait);
 =09up_read(&upper_sb->s_umount);
=20
 =09return ret;
--=20
2.27.0