pkt_sched: move the sanity test in qdisc_list_add()
The WARN_ON(root == &noop_qdisc)) added in qdisc_list_add()
can trigger in normal conditions when devices are not up.
It should be done only right before the list_add_tail() call.
Fixes: e57a784d8cae4 ("pkt_sched: set root qdisc before change() in attach_default_qdiscs()")
Reported-by: Valdis Kletnieks <[email protected]>
Tested-by: Mirco Tischler <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 1313145..a07d55e 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -273,11 +273,12 @@
void qdisc_list_add(struct Qdisc *q)
{
- struct Qdisc *root = qdisc_dev(q)->qdisc;
+ if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
+ struct Qdisc *root = qdisc_dev(q)->qdisc;
- WARN_ON_ONCE(root == &noop_qdisc);
- if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
+ WARN_ON_ONCE(root == &noop_qdisc);
list_add_tail(&q->list, &root->list);
+ }
}
EXPORT_SYMBOL(qdisc_list_add);
