cgroup: lock cgroup_mutex in cgroup_init_subsys()

Make cgroup_init_subsys() grab cgroup_mutex while initializing a
subsystem so that all helpers and callbacks are called under the
context they expect.  This isn't strictly necessary as
cgroup_init_subsys() doesn't race with anybody but will allow adding
lockdep assertions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2012-11-19 08:13:36 -08:00
parent b48c6a80a0
commit 648bb56d07

View File

@ -4317,6 +4317,8 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
printk(KERN_INFO "Initializing cgroup subsys %s\n", ss->name);
mutex_lock(&cgroup_mutex);
/* init base cftset */
cgroup_init_cftsets(ss);
@ -4346,6 +4348,8 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
if (ss->post_create)
ss->post_create(dummytop);
mutex_unlock(&cgroup_mutex);
/* this function shouldn't be used with modular subsystems, since they
* need to register a subsys_id, among other things */
BUG_ON(ss->module);