[PATCH -next] cgroup: don't call cgroup1_pidlist_destroy_all() for v2

[Xiu Jianfeng]

From: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>

Currently cgroup1_pidlist_destroy_all() will be called when releasing
cgroup even if the cgroup is on default hierarchy, however it doesn't
make any sense for v2 to destroy pidlist of v1.

Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
---
 kernel/cgroup/cgroup-v1.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 520a11cb12f4..46d89157d558 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -197,6 +197,8 @@ void cgroup1_pidlist_destroy_all(struct cgroup *cgrp)
 {
 	struct cgroup_pidlist *l, *tmp_l;
 
+	if (cgroup_on_dfl(cgrp))
+		return;
 	mutex_lock(&cgrp->pidlist_mutex);
 	list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
 		mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
-- 
2.34.1