1 files changed, 115 insertions, 44 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index aa3ca5bb01b5..9c217255ac49 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -22,6 +22,53 @@
 enum slab_state slab_state;
 LIST_HEAD(slab_caches);
 DEFINE_MUTEX(slab_mutex);
+struct kmem_cache *kmem_cache;
+
+#ifdef CONFIG_DEBUG_VM
+static int kmem_cache_sanity_check(const char *name, size_t size)
+{
+	struct kmem_cache *s = NULL;
+
+	if (!name || in_interrupt() || size < sizeof(void *) ||
+		size > KMALLOC_MAX_SIZE) {
+		pr_err("kmem_cache_create(%s) integrity check failed\n", name);
+		return -EINVAL;
+	}
+
+	list_for_each_entry(s, &slab_caches, list) {
+		char tmp;
+		int res;
+
+		/*
+		 * This happens when the module gets unloaded and doesn't
+		 * destroy its slab cache and no-one else reuses the vmalloc
+		 * area of the module.  Print a warning.
+		 */
+		res = probe_kernel_address(s->name, tmp);
+		if (res) {
+			pr_err("Slab cache with size %d has lost its name\n",
+			       s->object_size);
+			continue;
+		}
+
+		if (!strcmp(s->name, name)) {
+			pr_err("%s (%s): Cache name already exists.\n",
+			       __func__, name);
+			dump_stack();
+			s = NULL;
+			return -EINVAL;
+		}
+	}
+
+	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
+	return 0;
+}
+#else
+static inline int kmem_cache_sanity_check(const char *name, size_t size)
+{
+	return 0;
+}
+#endif
 
 /*
  * kmem_cache_create - Create a cache.
@@ -52,68 +99,92 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align
 		unsigned long flags, void (*ctor)(void *))
 {
 	struct kmem_cache *s = NULL;
-
-#ifdef CONFIG_DEBUG_VM
-	if (!name || in_interrupt() || size < sizeof(void *) ||
-		size > KMALLOC_MAX_SIZE) {
-		printk(KERN_ERR "kmem_cache_create(%s) integrity check"
-			" failed\n", name);
-		goto out;
-	}
-#endif
+	int err = 0;
 
 	get_online_cpus();
 	mutex_lock(&slab_mutex);
 
-#ifdef CONFIG_DEBUG_VM
-	list_for_each_entry(s, &slab_caches, list) {
-		char tmp;
-		int res;
+	if (!kmem_cache_sanity_check(name, size) == 0)
+		goto out_locked;
 
-		/*
-		 * This happens when the module gets unloaded and doesn't
-		 * destroy its slab cache and no-one else reuses the vmalloc
-		 * area of the module.  Print a warning.
-		 */
-		res = probe_kernel_address(s->name, tmp);
-		if (res) {
-			printk(KERN_ERR
-			       "Slab cache with size %d has lost its name\n",
-			       s->object_size);
-			continue;
-		}
 
-		if (!strcmp(s->name, name)) {
-			printk(KERN_ERR "kmem_cache_create(%s): Cache name"
-				" already exists.\n",
-				name);
-			dump_stack();
-			s = NULL;
-			goto oops;
+	s = __kmem_cache_alias(name, size, align, flags, ctor);
+	if (s)
+		goto out_locked;
+
+	s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
+	if (s) {
+		s->object_size = s->size = size;
+		s->align = align;
+		s->ctor = ctor;
+		s->name = kstrdup(name, GFP_KERNEL);
+		if (!s->name) {
+			kmem_cache_free(kmem_cache, s);
+			err = -ENOMEM;
+			goto out_locked;
 		}
-	}
 
-	WARN_ON(strchr(name, ' '));	/* It confuses parsers */
-#endif
+		err = __kmem_cache_create(s, flags);
+		if (!err) {
 
-	s = __kmem_cache_create(name, size, align, flags, ctor);
+			s->refcount = 1;
+			list_add(&s->list, &slab_caches);
 
-#ifdef CONFIG_DEBUG_VM
-oops:
-#endif
+		} else {
+			kfree(s->name);
+			kmem_cache_free(kmem_cache, s);
+		}
+	} else
+		err = -ENOMEM;
+
+out_locked:
 	mutex_unlock(&slab_mutex);
 	put_online_cpus();
 
-#ifdef CONFIG_DEBUG_VM
-out:
-#endif
-	if (!s && (flags & SLAB_PANIC))
-		panic("kmem_cache_create: Failed to create slab '%s'\n", name);
+	if (err) {
+
+		if (flags & SLAB_PANIC)
+			panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
+				name, err);
+		else {
+			printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
+				name, err);
+			dump_stack();
+		}
+
+		return NULL;
+	}
 
 	return s;
 }
 EXPORT_SYMBOL(kmem_cache_create);
 
+void kmem_cache_destroy(struct kmem_cache *s)
+{
+	get_online_cpus();
+	mutex_lock(&slab_mutex);
+	s->refcount--;
+	if (!s->refcount) {
+		list_del(&s->list);
+
+		if (!__kmem_cache_shutdown(s)) {
+			if (s->flags & SLAB_DESTROY_BY_RCU)
+				rcu_barrier();
+
+			kfree(s->name);
+			kmem_cache_free(kmem_cache, s);
+		} else {
+			list_add(&s->list, &slab_caches);
+			printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n",
+				s->name);
+			dump_stack();
+		}
+	}
+	mutex_unlock(&slab_mutex);
+	put_online_cpus();
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
 int slab_is_available(void)
 {
 	return slab_state >= UP;