[PATCH v7 REBASED 09/17] list_lru: Add memcg argument to list_lru_from_kmem()

[Kirill Tkhai <ktkhai@virtuozzo.com>]

This is just refactoring to allow next patches to have
memcg pointer in list_lru_from_kmem().

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
---
 mm/list_lru.c |   25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 077956f8d58f..55a76465f7a2 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -65,18 +65,24 @@ static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
+list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+		   struct mem_cgroup **memcg_ptr)
 {
-	struct mem_cgroup *memcg;
+	struct list_lru_one *l = &nlru->lru;
+	struct mem_cgroup *memcg = NULL;
 
 	if (!nlru->memcg_lrus)
-		return &nlru->lru;
+		goto out;
 
 	memcg = mem_cgroup_from_kmem(ptr);
 	if (!memcg)
-		return &nlru->lru;
+		goto out;
 
-	return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+	l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+out:
+	if (memcg_ptr)
+		*memcg_ptr = memcg;
+	return l;
 }
 #else
 static void list_lru_register(struct list_lru *lru)
@@ -99,8 +105,11 @@ list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
+list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+		   struct mem_cgroup **memcg_ptr)
 {
+	if (memcg_ptr)
+		*memcg_ptr = NULL;
 	return &nlru->lru;
 }
 #endif /* CONFIG_MEMCG_KMEM */
@@ -113,7 +122,7 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
 
 	spin_lock(&nlru->lock);
 	if (list_empty(item)) {
-		l = list_lru_from_kmem(nlru, item);
+		l = list_lru_from_kmem(nlru, item, NULL);
 		list_add_tail(item, &l->list);
 		l->nr_items++;
 		nlru->nr_items++;
@@ -133,7 +142,7 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item)
 
 	spin_lock(&nlru->lock);
 	if (!list_empty(item)) {
-		l = list_lru_from_kmem(nlru, item);
+		l = list_lru_from_kmem(nlru, item, NULL);
 		list_del_init(item);
 		l->nr_items--;
 		nlru->nr_items--;