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, 1 deletions

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index ddfc40887848..d90b1652f2af 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1634,7 +1634,7 @@ hfsc_dequeue(struct Qdisc *sch)
                 }
         }
 
-        skb = cl->qdisc->dequeue(cl->qdisc);
+        skb = qdisc_dequeue_peeked(cl->qdisc);
         if (skb == NULL) {
                 if (net_ratelimit())
                         printk("HFSC: Non-work-conserving qdisc ?\n");
@@ -1727,6 +1727,7 @@ static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
         .dump           = hfsc_dump_qdisc,
         .enqueue        = hfsc_enqueue,
         .dequeue        = hfsc_dequeue,
+        .peek           = qdisc_peek_dequeued,
         .requeue        = hfsc_requeue,
         .drop           = hfsc_drop,
         .cl_ops         = &hfsc_class_ops,