From dd47c1fa776cda48531b651c88341e951140b0a7 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 9 Jun 2016 00:27:40 +0200 Subject: [PATCH] cbq: remove TCA_CBQ_POLICE support iproute2 doesn't implement any cbq option that results in this attribute being sent to kernel. To make use of it, user would have to - patch iproute2 - add a class - attach a qdisc to the class (default pfifo doesn't work as q->handle is 0 and cbq_set_police() is a no-op in this case) - re-'add' the same class (tc class change ...) again - user must also specifiy a defmap (e.g. 'split 1:0 defmap 3f'), since this 'police' feature relies on its presence - the added qdisc must be one of bfifo, pfifo or netem If all of these conditions are met and _some_ leaf qdiscs, namely p/bfifo, netem, plug or tbf would drop a packet, kernel calls back into cbq, which will attempt to re-queue the skb into a different class as indicated by the parents' defmap entry for TC_PRIO_BESTEFFORT. [ i.e. we behave as if tc_classify returned TC_ACT_RECLASSIFY ]. This feature, which isn't documented or implemented in iproute2, and isn't implemented consistently (most qdiscs like sfq, codel, etc drop right away instead of attempting this reclassification) is the sole reason for the reshape_fail and __parent member in Qdisc struct. So remove TCA_CBQ_POLICE support from the kernel, reject it via EOPNOTSUPP so userspace knows we don't support it, and then remove no-longer needed infrastructure in followup commit. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- include/net/sch_generic.h | 4 -- net/sched/sch_cbq.c | 95 +-------------------------------------- 2 files changed, 1 insertion(+), 98 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index c4f5749342ec..c069ac1dd75d 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -68,10 +68,6 @@ struct Qdisc { void *u32_node; - /* This field is deprecated, but it is still used by CBQ - * and it will live until better solution will be invented. - */ - struct Qdisc *__parent; struct netdev_queue *dev_queue; struct gnet_stats_rate_est64 rate_est; diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c index fdca45e34230..7f4d6c5a0efe 100644 --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -80,9 +80,6 @@ struct cbq_class { unsigned char priority; /* class priority */ unsigned char priority2; /* priority to be used after overlimit */ unsigned char ewma_log; /* time constant for idle time calculation */ -#ifdef CONFIG_NET_CLS_ACT - unsigned char police; -#endif u32 defmap; @@ -377,9 +374,6 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch) return ret; } -#ifdef CONFIG_NET_CLS_ACT - cl->q->__parent = sch; -#endif ret = qdisc_enqueue(skb, cl->q); if (ret == NET_XMIT_SUCCESS) { sch->q.qlen++; @@ -524,40 +518,6 @@ static enum hrtimer_restart cbq_undelay(struct hrtimer *timer) return HRTIMER_NORESTART; } -#ifdef CONFIG_NET_CLS_ACT -static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child) -{ - struct Qdisc *sch = child->__parent; - struct cbq_sched_data *q = qdisc_priv(sch); - struct cbq_class *cl = q->rx_class; - - q->rx_class = NULL; - - if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) { - int ret; - - cbq_mark_toplevel(q, cl); - - q->rx_class = cl; - cl->q->__parent = sch; - - ret = qdisc_enqueue(skb, cl->q); - if (ret == NET_XMIT_SUCCESS) { - sch->q.qlen++; - if (!cl->next_alive) - cbq_activate_class(cl); - return 0; - } - if (net_xmit_drop_count(ret)) - qdisc_qstats_drop(sch); - return 0; - } - - qdisc_qstats_drop(sch); - return -1; -} -#endif - /* * It is mission critical procedure. * @@ -1179,21 +1139,6 @@ static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr) return 0; } -#ifdef CONFIG_NET_CLS_ACT -static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p) -{ - cl->police = p->police; - - if (cl->q->handle) { - if (p->police == TC_POLICE_RECLASSIFY) - cl->q->reshape_fail = cbq_reshape_fail; - else - cl->q->reshape_fail = NULL; - } - return 0; -} -#endif - static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt) { cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange); @@ -1350,35 +1295,11 @@ nla_put_failure: return -1; } -#ifdef CONFIG_NET_CLS_ACT -static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl) -{ - unsigned char *b = skb_tail_pointer(skb); - struct tc_cbq_police opt; - - if (cl->police) { - opt.police = cl->police; - opt.__res1 = 0; - opt.__res2 = 0; - if (nla_put(skb, TCA_CBQ_POLICE, sizeof(opt), &opt)) - goto nla_put_failure; - } - return skb->len; - -nla_put_failure: - nlmsg_trim(skb, b); - return -1; -} -#endif - static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl) { if (cbq_dump_lss(skb, cl) < 0 || cbq_dump_rate(skb, cl) < 0 || cbq_dump_wrr(skb, cl) < 0 || -#ifdef CONFIG_NET_CLS_ACT - cbq_dump_police(skb, cl) < 0 || -#endif cbq_dump_fopt(skb, cl) < 0) return -1; return 0; @@ -1468,11 +1389,6 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, &pfifo_qdisc_ops, cl->common.classid); if (new == NULL) return -ENOBUFS; - } else { -#ifdef CONFIG_NET_CLS_ACT - if (cl->police == TC_POLICE_RECLASSIFY) - new->reshape_fail = cbq_reshape_fail; -#endif } *old = qdisc_replace(sch, new, &cl->q); @@ -1585,7 +1501,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t if (err < 0) return err; - if (tb[TCA_CBQ_OVL_STRATEGY]) + if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE]) return -EOPNOTSUPP; if (cl) { @@ -1636,11 +1552,6 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT])); } -#ifdef CONFIG_NET_CLS_ACT - if (tb[TCA_CBQ_POLICE]) - cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE])); -#endif - if (tb[TCA_CBQ_FOPT]) cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT])); @@ -1736,10 +1647,6 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t cl->maxidle = q->link.maxidle; if (cl->avpkt == 0) cl->avpkt = q->link.avpkt; -#ifdef CONFIG_NET_CLS_ACT - if (tb[TCA_CBQ_POLICE]) - cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE])); -#endif if (tb[TCA_CBQ_FOPT]) cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT])); sch_tree_unlock(sch); -- 2.30.2