diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ab5c9a5a0596..ea87340af871 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -705,6 +705,8 @@ static void put_css_set_locked(struct css_set *cset) list_for_each_entry_safe(link, tmp_link, &cset->cgrp_links, cgrp_link) { list_del(&link->cset_link); list_del(&link->cgrp_link); + if (cgroup_parent(link->cgrp)) + cgroup_put(link->cgrp); kfree(link); } @@ -919,6 +921,9 @@ static void link_css_set(struct list_head *tmp_links, struct css_set *cset, * is sorted by order of hierarchy creation */ list_add_tail(&link->cgrp_link, &cset->cgrp_links); + + if (cgroup_parent(cgrp)) + cgroup_get(cgrp); } /** @@ -4998,10 +5003,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) lockdep_assert_held(&cgroup_mutex); - /* - * css_set_rwsem synchronizes access to ->cset_links and prevents - * @cgrp from being removed while put_css_set() is in progress. - */ + /* css_set_rwsem synchronizes access to ->cset_links */ down_read(&css_set_rwsem); empty = list_empty(&cgrp->cset_links); up_read(&css_set_rwsem);