[PATCH 3.16 031/204] net_sched: always reset qdisc backlog in qdisc_reset()

From: Ben Hutchings
Date: Thu Dec 28 2017 - 13:03:08 EST


3.16.52-rc1 review patch. If anyone has any objections, please let me know.

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

From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>

commit c8e1812960eeae42e2183154927028511c4bc566 upstream.

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@xxxxxxxxxxxxxx>
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/sched/sch_generic.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -621,6 +621,7 @@ void qdisc_reset(struct Qdisc *qdisc)
qdisc->gso_skb = NULL;
qdisc->q.qlen = 0;
}
+ qdisc->qstats.backlog = 0;
}
EXPORT_SYMBOL(qdisc_reset);