From cbc125efada6d8c2555dd35e938694eb9b7cd791 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 14 May 2014 09:15:01 -0400 Subject: [PATCH] cgroup: separate out cgroup_has_live_children() from cgroup_destroy_locked() We're expecting another user. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- kernel/cgroup.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index b57a949ae4bc..3f5f48130b6b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3295,6 +3295,21 @@ css_next_descendant_post(struct cgroup_subsys_state *pos, return css_parent(pos); } +static bool cgroup_has_live_children(struct cgroup *cgrp) +{ + struct cgroup *child; + + rcu_read_lock(); + list_for_each_entry_rcu(child, &cgrp->children, sibling) { + if (!cgroup_is_dead(child)) { + rcu_read_unlock(); + return true; + } + } + rcu_read_unlock(); + return false; +} + /** * css_advance_task_iter - advance a task itererator to the next css_set * @it: the iterator to advance @@ -4465,7 +4480,6 @@ static void kill_css(struct cgroup_subsys_state *css) static int cgroup_destroy_locked(struct cgroup *cgrp) __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { - struct cgroup *child; struct cgroup_subsys_state *css; bool empty; int ssid; @@ -4487,15 +4501,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) * emptiness as dead children linger on it while being destroyed; * otherwise, "rmdir parent/child parent" may fail with -EBUSY. */ - empty = true; - rcu_read_lock(); - list_for_each_entry_rcu(child, &cgrp->children, sibling) { - empty = cgroup_is_dead(child); - if (!empty) - break; - } - rcu_read_unlock(); - if (!empty) + if (cgroup_has_live_children(cgrp)) return -EBUSY; /* -- 2.34.1