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 <lar...@axis.com>
---
v3: After a discussion with Eric and Cong I went back to v1 and added the
likely() for the common path.
---
net/sched/sch_generic.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index f18c350..80742ed 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);
--
2.1.4
