Re: netfilter: active obj WARN when cleaning up

@@ -98,4 +98,8 @@ struct kmem_cache {
 	struct kmem_cache_node *node[MAX_NUMNODES];
 };

+#ifdef CONFIG_SYSFS
+#define SLAB_SUPPORTS_SYSFS
+#endif
+
 #endif /* _LINUX_SLUB_DEF_H */

@@ -57,6 +57,7 @@ struct mem_cgroup;
 struct kmem_cache *
 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
 		   size_t align, unsigned long flags, void (*ctor)(void *));
+void sysfs_slab_remove(struct kmem_cache *);
 #else
 static inline struct kmem_cache *
 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,

@@ -91,6 +92,7 @@ __kmem_cache_alias(struct mem_cgroup *me
 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)

 int __kmem_cache_shutdown(struct kmem_cache *);
+void slab_kmem_cache_release(struct kmem_cache *);

 struct seq_file;
 struct file;

@@ -251,6 +251,12 @@ kmem_cache_create(const char *name, size
 }
 EXPORT_SYMBOL(kmem_cache_create);

+void slab_kmem_cache_release(struct kmem_cache *s)
+{
+	kfree(s->name);
+	kmem_cache_free(kmem_cache, s);
+}
+
 void kmem_cache_destroy(struct kmem_cache *s)
 {
 	/* Destroy all the children caches if we aren't a memcg cache */

@@ -268,8 +274,12 @@ void kmem_cache_destroy(struct kmem_cach
 				rcu_barrier();

 			memcg_release_cache(s);
-			kfree(s->name);
-			kmem_cache_free(kmem_cache, s);
+#ifdef SLAB_SUPPORTS_SYSFS
+			sysfs_slab_remove(s);
+#else
+			slab_kmem_cache_release();
+
+#endif
 		} else {
 			list_add(&s->list, &slab_caches);
 			mutex_unlock(&slab_mutex);

@@ -210,7 +210,6 @@ enum track_item { TRACK_ALLOC, TRACK_FRE
 #ifdef CONFIG_SYSFS
 static int sysfs_slab_add(struct kmem_cache *);
 static int sysfs_slab_alias(struct kmem_cache *, const char *);
-static void sysfs_slab_remove(struct kmem_cache *);
 static void memcg_propagate_slab_attrs(struct kmem_cache *s);
 #else
 static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }

@@ -3208,23 +3207,7 @@ static inline int kmem_cache_close(struc

 int __kmem_cache_shutdown(struct kmem_cache *s)
 {
-	int rc = kmem_cache_close(s);
-
-	if (!rc) {
-		/*
-		 * We do the same lock strategy around sysfs_slab_add, see
-		 * __kmem_cache_create. Because this is pretty much the last
-		 * operation we do and the lock will be released shortly after
-		 * that in slab_common.c, we could just move sysfs_slab_remove
-		 * to a later point in common code. We should do that when we
-		 * have a common sysfs framework for all allocators.
-		 */
-		mutex_unlock(&slab_mutex);
-		sysfs_slab_remove(s);
-		mutex_lock(&slab_mutex);
-	}
-
-	return rc;
+	return kmem_cache_close(s);
 }

 /********************************************************************

@@ -5073,6 +5056,11 @@ static void memcg_propagate_slab_attrs(s
 #endif
 }

+static void kmem_cache_release(struct kobject *k)
+{
+	slab_kmem_cache_release(to_slab(k));
+}
+
 static const struct sysfs_ops slab_sysfs_ops = {
 	.show = slab_attr_show,
 	.store = slab_attr_store,

@@ -5080,6 +5068,7 @@ static const struct sysfs_ops slab_sysfs

 static struct kobj_type slab_ktype = {
 	.sysfs_ops = &slab_sysfs_ops,
+	.release = kmem_cache_release,
 };

 static int uevent_filter(struct kset *kset, struct kobject *kobj)

@@ -5184,7 +5173,7 @@ static int sysfs_slab_add(struct kmem_ca
 	return 0;
 }

-static void sysfs_slab_remove(struct kmem_cache *s)
+void sysfs_slab_remove(struct kmem_cache *s)
 {
 	if (slab_state < FULL)
 		/*

--