[XFS] quiesce the filesystem proper when freezing

SGI-PV: 936977
SGI-Modid: xfs-linux:xfs-kern:193840a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index d5f0340..5fe9af3 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -590,8 +590,10 @@
 	int		error;
 	int		flags = SYNC_FSDATA;
 
-	if (wait)
-		flags |= SYNC_WAIT;
+	if (unlikely(sb->s_frozen == SB_FREEZE_WRITE))
+		flags = SYNC_QUIESCE;
+	else
+		flags = SYNC_FSDATA | (wait ? SYNC_WAIT : 0);
 
 	VFS_SYNC(vfsp, flags, NULL, error);
 	sb->s_dirt = 0;