memcg, slab: kmem_cache_create_memcg(): fix memleak on fail path

We do not free the cache's memcg_params if __kmem_cache_create fails.
Fix this.

Plus, rename memcg_register_cache() to memcg_alloc_cache_params(),
because it actually does not register the cache anywhere, but simply
initialize kmem_cache::memcg_params.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b3e7a667e03c24ca5c3d1c54c0db5c7b0bdde052..284daff507fbb8062351fedf4540c6a63a32e21a 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -497,8 +497,9 @@ void __memcg_kmem_commit_charge(struct page *page,
 void __memcg_kmem_uncharge_pages(struct page *page, int order);
 
 int memcg_cache_id(struct mem_cgroup *memcg);
-int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
-                        struct kmem_cache *root_cache);
+int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,
+                            struct kmem_cache *root_cache);
+void memcg_free_cache_params(struct kmem_cache *s);
 void memcg_release_cache(struct kmem_cache *cachep);
 void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep);
 
@@ -640,13 +641,16 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
        return -1;
 }
 
-static inline int
-memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
-                    struct kmem_cache *root_cache)
+static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
+               struct kmem_cache *s, struct kmem_cache *root_cache)
 {
        return 0;
 }
 
+static inline void memcg_free_cache_params(struct kmem_cache *s)
+{
+}
+
 static inline void memcg_release_cache(struct kmem_cache *cachep)
 {
 }

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 72f2d90e7ef628685e214c8b6f2af89540e6347c..b8ebe71f872d7ad2715e24f922b287e430c22323 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3231,8 +3231,8 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
        return 0;
 }
 
-int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
-                        struct kmem_cache *root_cache)
+int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,
+                            struct kmem_cache *root_cache)
 {
        size_t size;
 
@@ -3260,6 +3260,11 @@ int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
        return 0;
 }
 
+void memcg_free_cache_params(struct kmem_cache *s)
+{
+       kfree(s->memcg_params);
+}
+
 void memcg_release_cache(struct kmem_cache *s)
 {
        struct kmem_cache *root;
@@ -3288,7 +3293,7 @@ void memcg_release_cache(struct kmem_cache *s)
 
        css_put(&memcg->css);
 out:
-       kfree(s->memcg_params);
+       memcg_free_cache_params(s);
 }
 
 /*

diff --git a/mm/slab_common.c b/mm/slab_common.c
index f70df3ef6f1a1075e4ccc55d3bd84e4fd079ab45..70f9e249ac30c13d4f730fbeba323c8c545d1341 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -205,7 +205,7 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
        if (!s->name)
                goto out_free_cache;
 
-       err = memcg_register_cache(memcg, s, parent_cache);
+       err = memcg_alloc_cache_params(memcg, s, parent_cache);
        if (err)
                goto out_free_cache;
 
@@ -235,6 +235,7 @@ out_unlock:
        return s;
 
 out_free_cache:
+       memcg_free_cache_params(s);
        kfree(s->name);
        kmem_cache_free(kmem_cache, s);
        goto out_unlock;