slub: adjust memcg caches when creating cache alias

Otherwise, kzalloc() called from a memcg won't clear the whole object.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/slub.c b/mm/slub.c
index 7d81afb27048283222febd6755a1edbadabbb3f6..33939e72bc372a0d4b312d444c5f2bad7eede9f2 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3748,7 +3748,11 @@ __kmem_cache_alias(const char *name, size_t size, size_t align,
 
        s = find_mergeable(size, align, flags, name, ctor);
        if (s) {
+               int i;
+               struct kmem_cache *c;
+
                s->refcount++;
+
                /*
                 * Adjust the object sizes so that we clear
                 * the complete object on kzalloc.
@@ -3756,6 +3760,15 @@ __kmem_cache_alias(const char *name, size_t size, size_t align,
                s->object_size = max(s->object_size, (int)size);
                s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
 
+               for_each_memcg_cache_index(i) {
+                       c = cache_from_memcg_idx(s, i);
+                       if (!c)
+                               continue;
+                       c->object_size = s->object_size;
+                       c->inuse = max_t(int, c->inuse,
+                                        ALIGN(size, sizeof(void *)));
+               }
+
                if (sysfs_slab_alias(s, name)) {
                        s->refcount--;
                        s = NULL;