diff --git a/[refs] b/[refs]
index ed510a0f3ead..46c15d47dfad 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 71bce256bf2e2aaddf54a2f4ac216329c74be3ad
+refs/heads/master: de20614b351e4d4d23af0a105baa8fd2d7cd4f26
diff --git a/trunk/fs/xfs/xfs_mount.c b/trunk/fs/xfs/xfs_mount.c
index b57423caef9b..2ec967d93e5a 100644
--- a/trunk/fs/xfs/xfs_mount.c
+++ b/trunk/fs/xfs/xfs_mount.c
@@ -300,6 +300,15 @@ xfs_mount_validate_sb(
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 
+	/*
+	 * 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.
 	 */