memcg: fail to create cgroup if the cgroup id is too big

memcg requires the cgroup id to be smaller than 65536.

This is a preparation to kill css id.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2013-09-23 16:56:29 +08:00 committed by Tejun Heo
parent 34c00c319c
commit 4219b2da20
1 changed files with 9 additions and 0 deletions

View File

@ -488,6 +488,12 @@ 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)
{
/*
@ -6059,6 +6065,9 @@ 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;