[PATCH 4.9 07/84] net_sched: remove warning from qdisc_hash_add

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>


[ Upstream commit c90e95147c27b1780e76c6e8fea1b5c78d7d387f ]

It was added in commit e57a784d8cae ("pkt_sched: set root qdisc
before change() in attach_default_qdiscs()") to hide duplicates
from "tc qdisc show" for incative deivices.

After 59cc1f61f ("net: sched: convert qdisc linked list to hashtable")
it triggered when classful qdisc is added to inactive device because
default qdiscs are added before switching root qdisc.

Anyway after commit ea3274695353 ("net: sched: avoid duplicates in
qdisc dump") duplicates are filtered right in dumper.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/sched/sch_api.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -277,9 +277,6 @@ static struct Qdisc *qdisc_match_from_ro
 void qdisc_hash_add(struct Qdisc *q)
 {
 	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
-		struct Qdisc *root = qdisc_dev(q)->qdisc;
-
-		WARN_ON_ONCE(root == &noop_qdisc);
 		ASSERT_RTNL();
 		hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
 	}