[XFS] Block mount attempts for filesystems with version 1 directories.

SGI Modid: xfs-linux:xfs-kern:21937a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Christoph Hellwig <hch@sgi.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index b57423c..2ec967d 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -301,6 +301,15 @@
 	}
 
 	/*
+	 * Version 1 directory format has never worked on Linux.
+	 */
+	if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) {
+		cmn_err(CE_WARN,
+	"XFS: Attempted to mount file system using version 1 directory format");
+		return XFS_ERROR(ENOSYS);
+	}
+
+	/*
 	 * Until this is fixed only page-sized or smaller data blocks work.
 	 */
 	if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {