From d5aa8a74f0a044cf7a64f99f9b9351ebe92be475 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 8 Mar 2014 08:01:19 -0800 Subject: 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 Tested-by: Mirco Tischler Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_api.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 4df817499..066211a84 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -221,11 +221,12 @@ static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) static 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); + } } void qdisc_list_del(struct Qdisc *q) -- cgit v1.2.3