pkt_sched: set root qdisc before change() in attach_default_qdiscs()
After commit 95dc19299f74 ("pkt_sched: give visibility to mq slave
qdiscs") we call disc_list_add() while the device qdisc might be
the noop_qdisc one.
This shows up as duplicates in "tc qdisc show", as all inactive devices
point to noop_qdisc.
Fix this by setting dev->qdisc to the new qdisc before calling
ops->change() in attach_default_qdiscs()
Add a WARN_ON_ONCE() to catch any future similar problem.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 6a91d7d..32bb942 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -718,8 +718,8 @@
} else {
qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
if (qdisc) {
- qdisc->ops->attach(qdisc);
dev->qdisc = qdisc;
+ qdisc->ops->attach(qdisc);
}
}
}