[net-next PATCH v2] net_sched: dsmark: use qdisc_dequeue_peeked()

[Kyeong Yoo]

This fix is for dsmark similar to commit 3557619f0f6f7496ed453d4825e249
("net_sched: prio: use qdisc_dequeue_peeked")
and makes use of qdisc_dequeue_peeked() instead of direct dequeue() call.

First time, wrr peeks dsmark, which will then peek into sfq.
sfq dequeues an skb and it's stored in sch->gso_skb.
Next time, wrr tries to dequeue from dsmark, which will call sfq dequeue
directly. This results skipping the previously peeked skb.

So changed dsmark dequeue to call qdisc_dequeue_peeked() instead to use
peeked skb if exists.

Signed-off-by: Kyeong Yoo <kyeong....@alliedtelesis.co.nz>

diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index f357f34..b204472 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -281,7 +281,7 @@ static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 
        pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
 
-       skb = p->q->ops->dequeue(p->q);
+       skb = qdisc_dequeue_peeked(p->q);
        if (skb == NULL)
                return NULL;