diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2019-01-09 17:09:43 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-01-15 20:12:00 -0800 |
| commit | 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea (patch) | |
| tree | 29e8d6fccf9da0a9c19129f477a0ef0ae244464d | |
| parent | f6bab199315b70fd83fe3ee0947bc84c7a35f3d4 (diff) | |
| download | linux-37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea.tar.gz | |
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>
| -rw-r--r-- | net/sched/sch_drr.c | 4 | ||||
| -rw-r--r-- | net/sched/sch_hfsc.c | 4 | ||||
| -rw-r--r-- | net/sched/sch_qfq.c | 4 |
3 files changed, 9 insertions, 3 deletions
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index feaf47178653..09b800991065 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -354,6 +354,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct drr_sched *q = qdisc_priv(sch); struct drr_class *cl; int err = 0; + bool first; cl = drr_classify(skb, sch, &err); if (cl == NULL) { @@ -363,6 +364,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, return err; } + first = !cl->qdisc->q.qlen; err = qdisc_enqueue(skb, cl->qdisc, to_free); if (unlikely(err != NET_XMIT_SUCCESS)) { if (net_xmit_drop_count(err)) { @@ -372,7 +374,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, return err; } - if (cl->qdisc->q.qlen == 1) { + if (first) { list_add_tail(&cl->alist, &q->active); cl->deficit = cl->quantum; } diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 6bb8f73a8473..24cc220a3218 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1542,6 +1542,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) unsigned int len = qdisc_pkt_len(skb); struct hfsc_class *cl; int uninitialized_var(err); + bool first; cl = hfsc_classify(skb, sch, &err); if (cl == NULL) { @@ -1551,6 +1552,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) return err; } + first = !cl->qdisc->q.qlen; err = qdisc_enqueue(skb, cl->qdisc, to_free); if (unlikely(err != NET_XMIT_SUCCESS)) { if (net_xmit_drop_count(err)) { @@ -1560,7 +1562,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) return err; } - if (cl->qdisc->q.qlen == 1) { + if (first) { if (cl->cl_flags & HFSC_RSC) init_ed(cl, len); if (cl->cl_flags & HFSC_FSC) 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) |