pkt_sched: Add peek emulation for non-work-conserving qdiscs.

This patch adds qdisc_peek_dequeued() wrapper to emulate peek method
with qdisc->dequeue() and storing "peeked" skb in qdisc->gso_skb until
dequeuing. This is mainly for compatibility reasons not to break some
strange configs because peeking is expected for non-work-conserving
parent qdiscs to query work-conserving child qdiscs.

This implementation requires using qdisc_dequeue_peeked() wrapper
instead of directly calling qdisc->dequeue() for all qdiscs ever
querried with qdisc->ops->peek() or qdisc_peek_dequeued().

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 2ee0c1a8efa9..6eb9a650b63d 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -484,7 +484,7 @@ static void sch_atm_dequeue(unsigned long data)
                         if (!atm_may_send(flow->vcc, skb->truesize))
                                 break;
 
-                        skb = flow->q->dequeue(flow->q);
+                        skb = qdisc_dequeue_peeked(flow->q);
                         if (unlikely(!skb))
                                 break;
 
@@ -519,7 +519,7 @@ static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
 
         pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
         tasklet_schedule(&p->task);
-        skb = p->link.q->dequeue(p->link.q);
+        skb = qdisc_dequeue_peeked(p->link.q);
         if (skb)
                 sch->q.qlen--;
         return skb;