diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index fc9bae82ac4..2c30a1116d8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -81,6 +81,8 @@ int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
 	return cgroup == mem;
 }
 
+extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem);
+
 extern int
 mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr);
 extern void mem_cgroup_end_migration(struct mem_cgroup *mem,
@@ -206,6 +208,11 @@ static inline int task_in_mem_cgroup(struct task_struct *task,
 	return 1;
 }
 
+static inline struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+	return NULL;
+}
+
 static inline int
 mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
 {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b5ac61ce734..9eee80d6d49 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -282,6 +282,11 @@ mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
 	return &mem->info.nodeinfo[nid]->zoneinfo[zid];
 }
 
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem)
+{
+	return &mem->css;
+}
+
 static struct mem_cgroup_per_zone *
 page_cgroup_zoneinfo(struct page_cgroup *pc)
 {