From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755963Ab3LUPyP (ORCPT ); Sat, 21 Dec 2013 10:54:15 -0500 Received: from relay.parallels.com ([195.214.232.42]:38776 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754428Ab3LUPyL (ORCPT ); Sat, 21 Dec 2013 10:54:11 -0500 From: Vladimir Davydov To: CC: , , , , , , Johannes Weiner , Christoph Lameter Subject: [PATCH 01/11] slab: cleanup kmem_cache_create_memcg() error handling Date: Sat, 21 Dec 2013 19:53:52 +0400 Message-ID: X-Mailer: git-send-email 1.7.10.4 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.24.25.198] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently kmem_cache_create_memcg() backoffs on failure inside conditionals, without using gotos. This results in the rollback code duplication, which makes the function look cumbersome even though on error we should only free the allocated cache. Since in the next patch I am going to add yet another rollback function call on error path there, let's employ labels instead of conditionals for undoing any changes on failure to keep things clean. Signed-off-by: Vladimir Davydov Reviewed-by: Pekka Enberg Cc: Michal Hocko Cc: Glauber Costa Cc: Johannes Weiner Cc: Christoph Lameter Cc: Andrew Morton --- mm/slab_common.c | 65 ++++++++++++++++++++++++++---------------------------- 1 file changed, 31 insertions(+), 34 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 0b7bb39..f70df3e 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -171,13 +171,14 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size, struct kmem_cache *parent_cache) { struct kmem_cache *s = NULL; - int err = 0; + int err; get_online_cpus(); mutex_lock(&slab_mutex); - if (!kmem_cache_sanity_check(memcg, name, size) == 0) - goto out_locked; + err = kmem_cache_sanity_check(memcg, name, size); + if (err) + goto out_unlock; /* * Some allocators will constraint the set of valid flags to a subset @@ -189,45 +190,38 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size, s = __kmem_cache_alias(memcg, name, size, align, flags, ctor); if (s) - goto out_locked; + goto out_unlock; + err = -ENOMEM; s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); - if (s) { - s->object_size = s->size = size; - s->align = calculate_alignment(flags, align, size); - s->ctor = ctor; + if (!s) + goto out_unlock; - if (memcg_register_cache(memcg, s, parent_cache)) { - kmem_cache_free(kmem_cache, s); - err = -ENOMEM; - goto out_locked; - } + s->object_size = s->size = size; + s->align = calculate_alignment(flags, align, size); + s->ctor = ctor; - s->name = kstrdup(name, GFP_KERNEL); - if (!s->name) { - kmem_cache_free(kmem_cache, s); - err = -ENOMEM; - goto out_locked; - } + s->name = kstrdup(name, GFP_KERNEL); + if (!s->name) + goto out_free_cache; - err = __kmem_cache_create(s, flags); - if (!err) { - s->refcount = 1; - list_add(&s->list, &slab_caches); - memcg_cache_list_add(memcg, s); - } else { - kfree(s->name); - kmem_cache_free(kmem_cache, s); - } - } else - err = -ENOMEM; + err = memcg_register_cache(memcg, s, parent_cache); + if (err) + goto out_free_cache; + + err = __kmem_cache_create(s, flags); + if (err) + goto out_free_cache; + + s->refcount = 1; + list_add(&s->list, &slab_caches); + memcg_cache_list_add(memcg, s); -out_locked: +out_unlock: mutex_unlock(&slab_mutex); put_online_cpus(); if (err) { - if (flags & SLAB_PANIC) panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", name, err); @@ -236,11 +230,14 @@ out_locked: name, err); dump_stack(); } - return NULL; } - return s; + +out_free_cache: + kfree(s->name); + kmem_cache_free(kmem_cache, s); + goto out_unlock; } struct kmem_cache * -- 1.7.10.4