Patch "net_sched: remove warning from qdisc_hash_add" has been added to the 4.12-stable tree

Patch "net_sched: remove warning from qdisc_hash_add" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    net_sched: remove warning from qdisc_hash_add

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net_sched-remove-warning-from-qdisc_hash_add.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Aug 24 17:43:45 PDT 2017
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Date: Tue, 15 Aug 2017 16:39:05 +0300
Subject: net_sched: remove warning from qdisc_hash_add

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>


[ 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@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/sched/sch_api.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -286,9 +286,6 @@ static struct Qdisc *qdisc_match_from_ro
 void qdisc_hash_add(struct Qdisc *q, bool invisible)
 {
 	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);
 		if (invisible)


Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are

queue-4.12/net_sched-remove-warning-from-qdisc_hash_add.patch
queue-4.12/net_sched-fix-order-of-queue-length-updates-in-qdisc_replace.patch
queue-4.12/net_sched-sfq-update-hierarchical-backlog-when-drop-packet.patch