netem: fix dequeue

commit 50612537e9 (netem: fix classful handling) added two errors in
netem_dequeue()

1) After checking skb at the head of tfifo queue for time constraints,
   it dequeues tail skb, thus adding unwanted reordering.

2) qdisc stats are updated twice per packet
   (one when packet dequeued from tfifo, once when delivered)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index e83d61ca78cab71c7a54c22b7d09cc94611726a8..5da548fa7ae9d46de78f5b75152e1a84b99ca9a7 100644 (file)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -501,9 +501,8 @@ tfifo_dequeue:
 
                /* if more time remaining? */
                if (cb->time_to_send <= psched_get_time()) {
-                       skb = qdisc_dequeue_tail(sch);
-                       if (unlikely(!skb))
-                               goto qdisc_dequeue;
+                       __skb_unlink(skb, &sch->q);
+                       sch->qstats.backlog -= qdisc_pkt_len(skb);
 
 #ifdef CONFIG_NET_CLS_ACT
                        /*
@@ -539,7 +538,6 @@ deliver:
                qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send);
        }
 
-qdisc_dequeue:
        if (q->qdisc) {
                skb = q->qdisc->ops->dequeue(q->qdisc);
                if (skb)