From 648bb56d076bde31113f09a7d24d95bc8d4155ac Mon Sep 17 00:00:00 2001 From: Tejun Heo <tj@kernel.org> Date: Mon, 19 Nov 2012 08:13:36 -0800 Subject: [PATCH] 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> --- kernel/cgroup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 6cc693b91c4a51..09751657abdc17 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -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); -- GitLab