diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9ed760d..f4ede99 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1359,16 +1359,19 @@
 
 	lock_page_cgroup(pc);
 	mem = pc->mem_cgroup;
-	if (!mem)
-		goto done;
-
-	if (!PageCgroupUsed(pc))
+	if (!mem || !PageCgroupUsed(pc))
 		goto done;
 
 	/*
 	 * Preemption is already disabled. We can use __this_cpu_xxx
 	 */
-	__this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], val);
+	if (val > 0) {
+		__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+		SetPageCgroupFileMapped(pc);
+	} else {
+		__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+		ClearPageCgroupFileMapped(pc);
+	}
 
 done:
 	unlock_page_cgroup(pc);
@@ -1801,16 +1804,13 @@
 static void __mem_cgroup_move_account(struct page_cgroup *pc,
 	struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
 {
-	struct page *page;
-
 	VM_BUG_ON(from == to);
 	VM_BUG_ON(PageLRU(pc->page));
 	VM_BUG_ON(!PageCgroupLocked(pc));
 	VM_BUG_ON(!PageCgroupUsed(pc));
 	VM_BUG_ON(pc->mem_cgroup != from);
 
-	page = pc->page;
-	if (page_mapped(page) && !PageAnon(page)) {
+	if (PageCgroupFileMapped(pc)) {
 		/* Update mapped_file data for mem_cgroup */
 		preempt_disable();
 		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);