xfs: remove explicit xfs_sync_data/xfs_sync_attr calls on umount

On the final put of a superblock the VFS already calls sync_filesystem
for us to write out all data and wait for it.  No need to start another
asynchronous writeback inside ->put_super.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/linux-2.6/xfs_super.c

@@ -1146,18 +1146,6 @@ xfs_fs_put_super(
 
 	xfs_syncd_stop(mp);
 
-	if (!(sb->s_flags & MS_RDONLY)) {
-		/*
-		 * XXX(hch): this should be SYNC_WAIT.
-		 *
-		 * Or more likely not needed at all because the VFS is already
-		 * calling ->sync_fs after shutting down all filestem
-		 * operations and just before calling ->put_super.
-		 */
-		xfs_sync_data(mp, 0);
-		xfs_sync_attr(mp, 0);
-	}
-
 	/*
 	 * Blow away any referenced inode in the filestreams cache.
 	 * This can and will cause log traffic as inodes go inactive

fs/xfs/linux-2.6/xfs_sync.c

@@ -308,7 +308,7 @@ xfs_sync_inode_attr(
 /*
  * Write out pagecache data for the whole filesystem.
  */
-int
+STATIC int
 xfs_sync_data(
 	struct xfs_mount	*mp,
 	int			flags)
@@ -329,7 +329,7 @@ xfs_sync_data(
 /*
  * Write out inode metadata (attributes) for the whole filesystem.
  */
-int
+STATIC int
 xfs_sync_attr(
 	struct xfs_mount	*mp,
 	int			flags)

fs/xfs/linux-2.6/xfs_sync.h

@@ -35,9 +35,6 @@ typedef struct xfs_sync_work {
 int xfs_syncd_init(struct xfs_mount *mp);
 void xfs_syncd_stop(struct xfs_mount *mp);
 
-int xfs_sync_attr(struct xfs_mount *mp, int flags);
-int xfs_sync_data(struct xfs_mount *mp, int flags);
-
 int xfs_quiesce_data(struct xfs_mount *mp);
 void xfs_quiesce_attr(struct xfs_mount *mp);