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authorToke Høiland-Jørgensen <toke@redhat.com>2019-01-09 17:09:43 +0100
committerDavid S. Miller <davem@davemloft.net>2019-01-15 20:12:00 -0800
commit37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea (patch)
tree29e8d6fccf9da0a9c19129f477a0ef0ae244464d /net/sched/sch_qfq.c
parentf6bab199315b70fd83fe3ee0947bc84c7a35f3d4 (diff)
sched: Fix detection of empty queues in child qdiscs
Several qdiscs check on enqueue whether the packet was enqueued to a class with an empty queue, in which case the class is activated. This is done by checking if the qlen is exactly 1 after enqueue. However, if GSO splitting is enabled in the child qdisc, a single packet can result in a qlen longer than 1. This means the activation check fails, leading to a stalled queue. Fix this by checking if the queue is empty *before* enqueue, and running the activation logic if this was the case. Reported-by: Pete Heist <pete@heistp.net> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_qfq.c')
-rw-r--r--net/sched/sch_qfq.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 8d5e55d5bed2..29f5c4a24688 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -1215,6 +1215,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct qfq_class *cl;
struct qfq_aggregate *agg;
int err = 0;
+ bool first;
cl = qfq_classify(skb, sch, &err);
if (cl == NULL) {
@@ -1236,6 +1237,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
}
gso_segs = skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1;
+ first = !cl->qdisc->q.qlen;
err = qdisc_enqueue(skb, cl->qdisc, to_free);
if (unlikely(err != NET_XMIT_SUCCESS)) {
pr_debug("qfq_enqueue: enqueue failed %d\n", err);
@@ -1253,7 +1255,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
agg = cl->agg;
/* if the queue was not empty, then done here */
- if (cl->qdisc->q.qlen != 1) {
+ if (!first) {
if (unlikely(skb == cl->qdisc->ops->peek(cl->qdisc)) &&
list_first_entry(&agg->active, struct qfq_class, alist)
== cl && cl->deficit < len)