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From:   Chengguang Xu <cgxu519@mykernel.net>
To:     miklos@szeredi.hu, jack@suse.cz, amir73il@gmail.com
Cc:     linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org,
        linux-kernel@vger.kernel.org, Chengguang Xu <cgxu519@mykernel.net>
Message-ID: <20210923130814.140814-7-cgxu519@mykernel.net>
Subject: [RFC PATCH v5 06/10] ovl: implement overlayfs' ->write_inode operation
Date:   Thu, 23 Sep 2021 21:08:10 +0800
In-Reply-To: <20210923130814.140814-1-cgxu519@mykernel.net>
References: <20210923130814.140814-1-cgxu519@mykernel.net>
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Implement overlayfs' ->write_inode to sync dirty data
and redirty overlayfs' inode if necessary.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
---
 fs/overlayfs/super.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 2ab77adf7256..cddae3ca2fa5 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -412,12 +412,42 @@ static void ovl_evict_inode(struct inode *inode)
 =09clear_inode(inode);
 }
=20
+static int ovl_write_inode(struct inode *inode,
+=09=09=09   struct writeback_control *wbc)
+{
+=09struct ovl_fs *ofs =3D inode->i_sb->s_fs_info;
+=09struct inode *upper =3D ovl_inode_upper(inode);
+=09unsigned long iflag =3D 0;
+=09int ret =3D 0;
+
+=09if (!upper)
+=09=09return 0;
+
+=09if (!ovl_should_sync(ofs))
+=09=09return 0;
+
+=09if (upper->i_sb->s_op->write_inode)
+=09=09ret =3D upper->i_sb->s_op->write_inode(inode, wbc);
+
+=09if (mapping_writably_mapped(upper->i_mapping) ||
+=09    mapping_tagged(upper->i_mapping, PAGECACHE_TAG_WRITEBACK))
+=09=09iflag |=3D I_DIRTY_PAGES;
+
+=09iflag |=3D upper->i_state & I_DIRTY_ALL;
+
+=09if (iflag)
+=09=09ovl_mark_inode_dirty(inode);
+
+=09return ret;
+}
+
 static const struct super_operations ovl_super_operations =3D {
 =09.alloc_inode=09=3D ovl_alloc_inode,
 =09.free_inode=09=3D ovl_free_inode,
 =09.destroy_inode=09=3D ovl_destroy_inode,
 =09.drop_inode=09=3D generic_delete_inode,
 =09.evict_inode=09=3D ovl_evict_inode,
+=09.write_inode=09=3D ovl_write_inode,
 =09.put_super=09=3D ovl_put_super,
 =09.sync_fs=09=3D ovl_sync_fs,
 =09.statfs=09=09=3D ovl_statfs,
--=20
2.27.0