1 files changed, 53 insertions, 40 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7973b5221fb8..0f711c213d2e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -811,10 +811,12 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 	 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
 	 * hierarchy(even if use_hierarchy is disabled in "mem").
 	 */
+	rcu_read_lock();
 	if (mem->use_hierarchy)
 		ret = css_is_ancestor(&curr->css, &mem->css);
 	else
 		ret = (curr == mem);
+	rcu_read_unlock();
 	css_put(&curr->css);
 	return ret;
 }
@@ -1359,16 +1361,19 @@ void mem_cgroup_update_file_mapped(struct page *page, int val)
 
 	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 +1806,13 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
 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]);
@@ -2312,7 +2314,9 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
 
 	/* record memcg information */
 	if (do_swap_account && swapout && memcg) {
+		rcu_read_lock();
 		swap_cgroup_record(ent, css_id(&memcg->css));
+		rcu_read_unlock();
 		mem_cgroup_get(memcg);
 	}
 	if (swapout && memcg)
@@ -2369,8 +2373,10 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
 {
 	unsigned short old_id, new_id;
 
+	rcu_read_lock();
 	old_id = css_id(&from->css);
 	new_id = css_id(&to->css);
+	rcu_read_unlock();
 
 	if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
 		mem_cgroup_swap_statistics(from, false);
@@ -2429,11 +2435,11 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
 	}
 	unlock_page_cgroup(pc);
 
+	*ptr = mem;
 	if (mem) {
-		ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
+		ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false);
 		css_put(&mem->css);
 	}
-	*ptr = mem;
 	return ret;
 }
 
@@ -3691,8 +3697,10 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 	else
 		mem = vmalloc(size);
 
-	if (mem)
-		memset(mem, 0, size);
+	if (!mem)
+		return NULL;
+
+	memset(mem, 0, size);
 	mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
 	if (!mem->stat) {
 		if (size < PAGE_SIZE)
@@ -3946,28 +3954,6 @@ one_by_one:
 	}
 	return ret;
 }
-#else	/* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
-				struct cgroup *cgroup,
-				struct task_struct *p,
-				bool threadgroup)
-{
-	return 0;
-}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
-				struct cgroup *cgroup,
-				struct task_struct *p,
-				bool threadgroup)
-{
-}
-static void mem_cgroup_move_task(struct cgroup_subsys *ss,
-				struct cgroup *cont,
-				struct cgroup *old_cont,
-				struct task_struct *p,
-				bool threadgroup)
-{
-}
-#endif
 
 /**
  * is_target_pte_for_mc - check a pte whether it is valid for move charge
@@ -4058,11 +4044,16 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
 			put_page(page);
 	}
 	/* throught */
-	if (ent.val && do_swap_account && !ret &&
-			css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
-		ret = MC_TARGET_SWAP;
-		if (target)
-			target->ent = ent;
+	if (ent.val && do_swap_account && !ret) {
+		unsigned short id;
+		rcu_read_lock();
+		id = css_id(&mc.from->css);
+		rcu_read_unlock();
+		if (id == lookup_swap_cgroup(ent)) {
+			ret = MC_TARGET_SWAP;
+			if (target)
+				target->ent = ent;
+		}
 	}
 	return ret;
 }
@@ -4330,6 +4321,28 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
 	}
 	mem_cgroup_clear_mc();
 }
+#else	/* !CONFIG_MMU */
+static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
+				struct cgroup *cgroup,
+				struct task_struct *p,
+				bool threadgroup)
+{
+	return 0;
+}
+static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
+				struct cgroup *cgroup,
+				struct task_struct *p,
+				bool threadgroup)
+{
+}
+static void mem_cgroup_move_task(struct cgroup_subsys *ss,
+				struct cgroup *cont,
+				struct cgroup *old_cont,
+				struct task_struct *p,
+				bool threadgroup)
+{
+}
+#endif
 
 struct cgroup_subsys mem_cgroup_subsys = {
 	.name = "memory",