cbq: remove TCA_CBQ_OVL_STRATEGY support

since initial revision of cbq in 2004 iproute 2 has never implemented
support for TCA_CBQ_OVL_STRATEGY, which is what needs to be set to
activate the class->drop() call (TC_CBQ_OVL_DROP strategy must be
set by userspace value must be set by userspace).

David Miller says:
   It seems really safe to kill this thing off, flag an error if someone
   tries to set the attribute, and therefore kill off all of the
   non-default cbq_ovl_*() functions.

A followup commit can then remove all .drop qdisc methods since this
removed the only caller.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 1b8128fb845d49462c13a2c826abacff96d62450..fdca45e342307ffd179a3601a210a8a8afba5c53 100644 (file)
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -80,7 +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 */
-       unsigned char           ovl_strategy;
 #ifdef CONFIG_NET_CLS_ACT
        unsigned char           police;
 #endif
@@ -94,10 +93,6 @@ struct cbq_class {
        u32                     avpkt;
        struct qdisc_rate_table *R_tab;
 
-       /* Overlimit strategy parameters */
-       void                    (*overlimit)(struct cbq_class *cl);
-       psched_tdiff_t          penalty;
-
        /* General scheduler (WRR) parameters */
        long                    allot;
        long                    quantum;        /* Allotment per WRR round */
@@ -402,11 +397,8 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        return ret;
 }
 
-/* Overlimit actions */
-
-/* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
-
-static void cbq_ovl_classic(struct cbq_class *cl)
+/* Overlimit action: penalize leaf class by adding offtime */
+static void cbq_overlimit(struct cbq_class *cl)
 {
        struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
        psched_tdiff_t delay = cl->undertime - q->now;
@@ -456,99 +448,6 @@ static void cbq_ovl_classic(struct cbq_class *cl)
        }
 }
 
-/* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
- * they go overlimit
- */
-
-static void cbq_ovl_rclassic(struct cbq_class *cl)
-{
-       struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
-       struct cbq_class *this = cl;
-
-       do {
-               if (cl->level > q->toplevel) {
-                       cl = NULL;
-                       break;
-               }
-       } while ((cl = cl->borrow) != NULL);
-
-       if (cl == NULL)
-               cl = this;
-       cbq_ovl_classic(cl);
-}
-
-/* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
-
-static void cbq_ovl_delay(struct cbq_class *cl)
-{
-       struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
-       psched_tdiff_t delay = cl->undertime - q->now;
-
-       if (test_bit(__QDISC_STATE_DEACTIVATED,
-                    &qdisc_root_sleeping(cl->qdisc)->state))
-               return;
-
-       if (!cl->delayed) {
-               psched_time_t sched = q->now;
-               ktime_t expires;
-
-               delay += cl->offtime;
-               if (cl->avgidle < 0)
-                       delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
-               if (cl->avgidle < cl->minidle)
-                       cl->avgidle = cl->minidle;
-               cl->undertime = q->now + delay;
-
-               if (delay > 0) {
-                       sched += delay + cl->penalty;
-                       cl->penalized = sched;
-                       cl->cpriority = TC_CBQ_MAXPRIO;
-                       q->pmask |= (1<<TC_CBQ_MAXPRIO);
-
-                       expires = ns_to_ktime(PSCHED_TICKS2NS(sched));
-                       if (hrtimer_try_to_cancel(&q->delay_timer) &&
-                           ktime_to_ns(ktime_sub(
-                                       hrtimer_get_expires(&q->delay_timer),
-                                       expires)) > 0)
-                               hrtimer_set_expires(&q->delay_timer, expires);
-                       hrtimer_restart(&q->delay_timer);
-                       cl->delayed = 1;
-                       cl->xstats.overactions++;
-                       return;
-               }
-               delay = 1;
-       }
-       if (q->wd_expires == 0 || q->wd_expires > delay)
-               q->wd_expires = delay;
-}
-
-/* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
-
-static void cbq_ovl_lowprio(struct cbq_class *cl)
-{
-       struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
-
-       cl->penalized = q->now + cl->penalty;
-
-       if (cl->cpriority != cl->priority2) {
-               cl->cpriority = cl->priority2;
-               q->pmask |= (1<<cl->cpriority);
-               cl->xstats.overactions++;
-       }
-       cbq_ovl_classic(cl);
-}
-
-/* TC_CBQ_OVL_DROP: penalize class by dropping */
-
-static void cbq_ovl_drop(struct cbq_class *cl)
-{
-       if (cl->q->ops->drop)
-               if (cl->q->ops->drop(cl->q))
-                       cl->qdisc->q.qlen--;
-       cl->xstats.overactions++;
-       cbq_ovl_classic(cl);
-}
-
 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
                                       psched_time_t now)
 {
@@ -807,7 +706,7 @@ cbq_under_limit(struct cbq_class *cl)
                cl = cl->borrow;
                if (!cl) {
                        this_cl->qstats.overlimits++;
-                       this_cl->overlimit(this_cl);
+                       cbq_overlimit(this_cl);
                        return NULL;
                }
                if (cl->level > q->toplevel)
@@ -1280,35 +1179,6 @@ static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
        return 0;
 }
 
-static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
-{
-       switch (ovl->strategy) {
-       case TC_CBQ_OVL_CLASSIC:
-               cl->overlimit = cbq_ovl_classic;
-               break;
-       case TC_CBQ_OVL_DELAY:
-               cl->overlimit = cbq_ovl_delay;
-               break;
-       case TC_CBQ_OVL_LOWPRIO:
-               if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO ||
-                   ovl->priority2 - 1 <= cl->priority)
-                       return -EINVAL;
-               cl->priority2 = ovl->priority2 - 1;
-               cl->overlimit = cbq_ovl_lowprio;
-               break;
-       case TC_CBQ_OVL_DROP:
-               cl->overlimit = cbq_ovl_drop;
-               break;
-       case TC_CBQ_OVL_RCLASSIC:
-               cl->overlimit = cbq_ovl_rclassic;
-               break;
-       default:
-               return -EINVAL;
-       }
-       cl->penalty = ovl->penalty;
-       return 0;
-}
-
 #ifdef CONFIG_NET_CLS_ACT
 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
 {
@@ -1375,8 +1245,6 @@ static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
        q->link.priority = TC_CBQ_MAXPRIO - 1;
        q->link.priority2 = TC_CBQ_MAXPRIO - 1;
        q->link.cpriority = TC_CBQ_MAXPRIO - 1;
-       q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
-       q->link.overlimit = cbq_ovl_classic;
        q->link.allot = psched_mtu(qdisc_dev(sch));
        q->link.quantum = q->link.allot;
        q->link.weight = q->link.R_tab->rate.rate;
@@ -1463,24 +1331,6 @@ nla_put_failure:
        return -1;
 }
 
-static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
-{
-       unsigned char *b = skb_tail_pointer(skb);
-       struct tc_cbq_ovl opt;
-
-       opt.strategy = cl->ovl_strategy;
-       opt.priority2 = cl->priority2 + 1;
-       opt.pad = 0;
-       opt.penalty = cl->penalty;
-       if (nla_put(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt))
-               goto nla_put_failure;
-       return skb->len;
-
-nla_put_failure:
-       nlmsg_trim(skb, b);
-       return -1;
-}
-
 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
 {
        unsigned char *b = skb_tail_pointer(skb);
@@ -1526,7 +1376,6 @@ 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 ||
-           cbq_dump_ovl(skb, cl) < 0 ||
 #ifdef CONFIG_NET_CLS_ACT
            cbq_dump_police(skb, cl) < 0 ||
 #endif
@@ -1736,6 +1585,9 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
        if (err < 0)
                return err;
 
+       if (tb[TCA_CBQ_OVL_STRATEGY])
+               return -EOPNOTSUPP;
+
        if (cl) {
                /* Check parent */
                if (parentid) {
@@ -1784,9 +1636,6 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
                        cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
                }
 
-               if (tb[TCA_CBQ_OVL_STRATEGY])
-                       cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
-
 #ifdef CONFIG_NET_CLS_ACT
                if (tb[TCA_CBQ_POLICE])
                        cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
@@ -1887,9 +1736,6 @@ 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;
-       cl->overlimit = cbq_ovl_classic;
-       if (tb[TCA_CBQ_OVL_STRATEGY])
-               cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
 #ifdef CONFIG_NET_CLS_ACT
        if (tb[TCA_CBQ_POLICE])
                cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));