From 3dcd493fbebfd631913df6e2773cc295d3bf7d22 Mon Sep 17 00:00:00 2001 From: Lars Persson Date: Tue, 12 Apr 2016 08:45:52 +0200 Subject: net: sched: do not requeue a NULL skb A failure in validate_xmit_skb_list() triggered an unconditional call to dev_requeue_skb with skb=NULL. This slowly grows the queue discipline's qlen count until all traffic through the queue stops. We take the optimistic approach and continue running the queue after a failure since it is unknown if later packets also will fail in the validate path. Fixes: 55a93b3ea780 ("qdisc: validate skb without holding lock") Signed-off-by: Lars Persson Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_generic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/sched') diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index f18c35024207..80742edea96f 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -159,12 +159,15 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, if (validate) skb = validate_xmit_skb_list(skb, dev); - if (skb) { + if (likely(skb)) { HARD_TX_LOCK(dev, txq, smp_processor_id()); if (!netif_xmit_frozen_or_stopped(txq)) skb = dev_hard_start_xmit(skb, dev, txq, &ret); HARD_TX_UNLOCK(dev, txq); + } else { + spin_lock(root_lock); + return qdisc_qlen(q); } spin_lock(root_lock); -- cgit v1.2.3-55-g7522