From: Patrick McHardy Date: Thu, 30 Nov 2006 01:37:42 +0000 (-0800) Subject: [NET_SCHED]: Fix endless loops (part 5): netem/tbf/hfsc ->requeue failures X-Git-Tag: v2.6.20-rc1~34^2~40^2~77 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e488eafcc50be296f0d1e1fd67c6b5d865183011;p=linux-2.6 [NET_SCHED]: Fix endless loops (part 5): netem/tbf/hfsc ->requeue failures When peeking at the next packet in a child qdisc by calling dequeue/requeue, the upper qdisc qlen counter may get out of sync in case the requeue fails. The qdisc and the child qdisc both have their counter decremented, but since no packet is given to the upper qdisc it won't decrement its counter itself. requeue should not fail, so this is mostly for "correctness". Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 2d437447e0..6eefa69957 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -946,6 +946,7 @@ qdisc_peek_len(struct Qdisc *sch) if (unlikely(sch->ops->requeue(skb, sch) != NET_XMIT_SUCCESS)) { if (net_ratelimit()) printk("qdisc_peek_len: failed to requeue\n"); + qdisc_tree_decrease_qlen(sch, 1); return 0; } return len; diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 672c354457..79542af9da 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -287,13 +287,10 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now); if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) { + qdisc_tree_decrease_qlen(q->qdisc, 1); sch->qstats.drops++; - - /* After this qlen is confused */ printk(KERN_ERR "netem: queue discpline %s could not requeue\n", q->qdisc->ops->id); - - sch->q.qlen--; } mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay)); diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 23b7624354..ed9b6d9385 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -250,7 +250,7 @@ static struct sk_buff *tbf_dequeue(struct Qdisc* sch) if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) { /* When requeue fails skb is dropped */ - sch->q.qlen--; + qdisc_tree_decrease_qlen(q->qdisc, 1); sch->qstats.drops++; }