net_sched: always reset qdisc backlog in qdisc_reset()

[ Upstream commit c8e1812960eeae42e2183154927028511c4bc566 ]

SKB stored in qdisc->gso_skb also counted into backlog.

Some qdiscs don't reset backlog to zero in ->reset(),
for example sfq just dequeue and free all queued skb.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 6cfb6e9..9016c8b 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -681,6 +681,7 @@ void qdisc_reset(struct Qdisc *qdisc)
                qdisc->gso_skb = NULL;
        }
        qdisc->q.qlen = 0;
+       qdisc->qstats.backlog = 0;
 }
 EXPORT_SYMBOL(qdisc_reset);