diff --git a/[refs] b/[refs]
index 8a11b98ee24d..821ee6c95703 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 01c4a4283137d24c9cc3785f1f312e895a18f273
+refs/heads/master: cfebe563bd0a3ff97e1bc167123120d59c7a84db
diff --git a/trunk/include/linux/cgroup.h b/trunk/include/linux/cgroup.h
index e4e8e117d27d..499900d0cee7 100644
--- a/trunk/include/linux/cgroup.h
+++ b/trunk/include/linux/cgroup.h
@@ -378,6 +378,7 @@ struct cgroup_subsys {
 	 * - initiating hotplug events
 	 */
 	struct mutex hierarchy_mutex;
+	struct lock_class_key subsys_key;
 
 	/*
 	 * Link to parent, and list entry in parent's children.
diff --git a/trunk/kernel/cgroup.c b/trunk/kernel/cgroup.c
index 5a54ff42874e..e14db9c089b9 100644
--- a/trunk/kernel/cgroup.c
+++ b/trunk/kernel/cgroup.c
@@ -2351,7 +2351,7 @@ static void cgroup_lock_hierarchy(struct cgroupfs_root *root)
 	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 		struct cgroup_subsys *ss = subsys[i];
 		if (ss->root == root)
-			mutex_lock_nested(&ss->hierarchy_mutex, i);
+			mutex_lock(&ss->hierarchy_mutex);
 	}
 }
 
@@ -2637,6 +2637,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
 	BUG_ON(!list_empty(&init_task.tasks));
 
 	mutex_init(&ss->hierarchy_mutex);
+	lockdep_set_class(&ss->hierarchy_mutex, &ss->subsys_key);
 	ss->active = 1;
 }