diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index f4fc32356e287..e138812ffcc89 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -770,15 +770,12 @@ static u32 qdisc_alloc_handle(struct net_device *dev) void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) { - bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; const struct Qdisc_class_ops *cops; unsigned long cl; u32 parentid; bool notify; int drops; - if (n == 0 && len == 0) - return; drops = max_t(int, n, 0); rcu_read_lock(); while ((parentid = sch->parent)) { @@ -787,17 +784,8 @@ void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) if (sch->flags & TCQ_F_NOPARENT) break; - /* Notify parent qdisc only if child qdisc becomes empty. - * - * If child was empty even before update then backlog - * counter is screwed and we skip notification because - * parent class is already passive. - * - * If the original child was offloaded then it is allowed - * to be seem as empty, so the parent is notified anyway. - */ - notify = !sch->q.qlen && !WARN_ON_ONCE(!n && - !qdisc_is_offloaded); + /* Notify parent qdisc only if child qdisc becomes empty. */ + notify = !sch->q.qlen; /* TODO: perform the search on a per txq basis */ sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid)); if (sch == NULL) { @@ -806,6 +794,9 @@ void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) } cops = sch->ops->cl_ops; if (notify && cops->qlen_notify) { + /* Note that qlen_notify must be idempotent as it may get called + * multiple times. + */ cl = cops->find(sch, parentid); cops->qlen_notify(sch, cl); } diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c index d733934935533..2a36b11c31b76 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -291,7 +291,7 @@ static void ets_class_qlen_notify(struct Qdisc *sch, unsigned long arg) * to remove them. */ if (!ets_class_is_strict(q, cl) && sch->q.qlen) - list_del(&cl->alist); + list_del_init(&cl->alist); } static int ets_class_dump(struct Qdisc *sch, unsigned long arg, @@ -493,7 +493,7 @@ static struct sk_buff *ets_qdisc_dequeue(struct Qdisc *sch) if (unlikely(!skb)) goto out; if (cl->qdisc->q.qlen == 0) - list_del(&cl->alist); + list_del_init(&cl->alist); return ets_qdisc_dequeue_skb(sch, skb); } @@ -658,23 +658,24 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, sch_tree_lock(sch); - q->nbands = nbands; + for (i = nbands; i < oldbands; i++) { + if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) + list_del_init(&q->classes[i].alist); + qdisc_purge_queue(q->classes[i].qdisc); + } + + WRITE_ONCE(q->nbands, nbands); for (i = nstrict; i < q->nstrict; i++) { if (q->classes[i].qdisc->q.qlen) { list_add_tail(&q->classes[i].alist, &q->active); q->classes[i].deficit = quanta[i]; } } - for (i = q->nbands; i < oldbands; i++) { - if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) - list_del(&q->classes[i].alist); - qdisc_tree_flush_backlog(q->classes[i].qdisc); - } - q->nstrict = nstrict; + WRITE_ONCE(q->nstrict, nstrict); memcpy(q->prio2band, priomap, sizeof(priomap)); for (i = 0; i < q->nbands; i++) - q->classes[i].quantum = quanta[i]; + WRITE_ONCE(q->classes[i].quantum, quanta[i]); for (i = oldbands; i < q->nbands; i++) { q->classes[i].qdisc = queues[i]; @@ -688,7 +689,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, for (i = q->nbands; i < oldbands; i++) { qdisc_put(q->classes[i].qdisc); q->classes[i].qdisc = NULL; - q->classes[i].quantum = 0; + WRITE_ONCE(q->classes[i].quantum, 0); q->classes[i].deficit = 0; gnet_stats_basic_sync_init(&q->classes[i].bstats); memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats)); @@ -723,7 +724,7 @@ static void ets_qdisc_reset(struct Qdisc *sch) for (band = q->nstrict; band < q->nbands; band++) { if (q->classes[band].qdisc->q.qlen) - list_del(&q->classes[band].alist); + list_del_init(&q->classes[band].alist); } for (band = 0; band < q->nbands; band++) qdisc_reset(q->classes[band].qdisc); @@ -747,6 +748,7 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) struct ets_sched *q = qdisc_priv(sch); struct nlattr *opts; struct nlattr *nest; + u8 nbands, nstrict; int band; int prio; int err; @@ -759,21 +761,22 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) if (!opts) goto nla_err; - if (nla_put_u8(skb, TCA_ETS_NBANDS, q->nbands)) + nbands = READ_ONCE(q->nbands); + if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands)) goto nla_err; - if (q->nstrict && - nla_put_u8(skb, TCA_ETS_NSTRICT, q->nstrict)) + nstrict = READ_ONCE(q->nstrict); + if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict)) goto nla_err; - if (q->nbands > q->nstrict) { + if (nbands > nstrict) { nest = nla_nest_start(skb, TCA_ETS_QUANTA); if (!nest) goto nla_err; - for (band = q->nstrict; band < q->nbands; band++) { + for (band = nstrict; band < nbands; band++) { if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND, - q->classes[band].quantum)) + READ_ONCE(q->classes[band].quantum))) goto nla_err; } @@ -785,7 +788,8 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_err; for (prio = 0; prio <= TC_PRIO_MAX; prio++) { - if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, q->prio2band[prio])) + if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, + READ_ONCE(q->prio2band[prio]))) goto nla_err; } diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index f61a8cec81595..3013932683fc5 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1584,6 +1584,9 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) return err; } + sch->qstats.backlog += len; + sch->q.qlen++; + if (first && !cl_in_el_or_vttree(cl)) { if (cl->cl_flags & HFSC_RSC) init_ed(cl, len); @@ -1599,9 +1602,6 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) } - sch->qstats.backlog += len; - sch->q.qlen++; - return NET_XMIT_SUCCESS; }