[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>

2 files changed, 5 insertions, 2 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index d5f0340ddcd9..5fe9af38aa20 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -590,8 +590,10 @@ linvfs_sync_super(
         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;
diff --git a/fs/xfs/linux-2.6/xfs_vfs.h b/fs/xfs/linux-2.6/xfs_vfs.h
index 76493991578f..7ee1f714e9ba 100644
--- a/fs/xfs/linux-2.6/xfs_vfs.h
+++ b/fs/xfs/linux-2.6/xfs_vfs.h
@@ -107,6 +107,7 @@ typedef enum {
 #define SYNC_FSDATA             0x0020  /* flush fs data (e.g. superblocks) */
 #define SYNC_REFCACHE           0x0040  /* prune some of the nfs ref cache */
 #define SYNC_REMOUNT            0x0080  /* remount readonly, no dummy LRs */
+#define SYNC_QUIESCE            0x0100  /* quiesce fileystem for a snapshot */
 
 typedef int     (*vfs_mount_t)(bhv_desc_t *,
                                 struct xfs_mount_args *, struct cred *);