Commit 4219b2da authored by Li Zefan's avatar Li Zefan Committed by Tejun Heo
Browse files

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: default avatarLi Zefan <lizefan@huawei.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 34c00c31

mm/memcontrol.c

+9 −0
Original line number Diff line number Diff line
@@ -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;