cgroup: hold cgroup_mutex before calling css_offline()

cpuset no longer nests cgroup_mutex inside cpu_hotplug lock, so
we don't have to release cgroup_mutex before calling css_offline().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2013-03-12 15:35:59 -07:00 коммит произвёл Tejun Heo
Родитель 6dc01181ea
Коммит d7eeac1913
2 изменённых файлов: 2 добавлений и 10 удалений

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@ -580,6 +580,7 @@ propagation along the hierarchy. See the comment on
cgroup_for_each_descendant_pre() for details.
void css_offline(struct cgroup *cgrp);
(cgroup_mutex held by caller)
This is the counterpart of css_online() and called iff css_online()
has succeeded on @cgrp. This signifies the beginning of the end of

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@ -4169,17 +4169,8 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
if (!(css->flags & CSS_ONLINE))
return;
/*
* css_offline() should be called with cgroup_mutex unlocked. See
* 3fa59dfbc3 ("cgroup: fix potential deadlock in pre_destroy") for
* details. This temporary unlocking should go away once
* cgroup_mutex is unexported from controllers.
*/
if (ss->css_offline) {
mutex_unlock(&cgroup_mutex);
if (ss->css_offline)
ss->css_offline(cgrp);
mutex_lock(&cgroup_mutex);
}
cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE;
}