From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH v6 3/5] memcg: fail to create cgroup if the cgroup id is too big Date: Mon, 23 Sep 2013 16:56:29 +0800 Message-ID: <5240023D.6040606@huawei.com> References: <524001F8.6070205@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <524001F8.6070205-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: Tejun Heo , Michal Hocko , KAMEZAWA Hiroyuki , Johannes Weiner , LKML , cgroups , "linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org" memcg requires the cgroup id to be smaller than 65536. This is a preparation to kill css id. Signed-off-by: Li Zefan Acked-by: Michal Hocko --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6719e2c..4e40ebe 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -498,6 +498,12 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) return (memcg == root_mem_cgroup); } +/* + * We restrict the id in the range of [1, 65535], so it can fit into + * an unsigned short. + */ +#define MEM_CGROUP_ID_MAX USHRT_MAX + static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) { /* @@ -6312,6 +6318,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css)); int error = 0; + if (css->cgroup->id > MEM_CGROUP_ID_MAX) + return -ENOSPC; + if (!parent) return 0; -- 1.8.0.2