1 files changed, 103 insertions, 124 deletions

diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 8302717ea303..9b6d79bd8737 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * net/sched/sch_drr.c         Deficit Round Robin scheduler
  *
  * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
  */
 
 #include <linux/module.h>
@@ -20,12 +17,10 @@
 
 struct drr_class {
 	struct Qdisc_class_common	common;
-	unsigned int			refcnt;
-	unsigned int			filter_cnt;
 
-	struct gnet_stats_basic_packed		bstats;
+	struct gnet_stats_basic_sync		bstats;
 	struct gnet_stats_queue		qstats;
-	struct gnet_stats_rate_est64	rate_est;
+	struct net_rate_estimator __rcu *rate_est;
 	struct list_head		alist;
 	struct Qdisc			*qdisc;
 
@@ -35,10 +30,16 @@ struct drr_class {
 
 struct drr_sched {
 	struct list_head		active;
-	struct tcf_proto		*filter_list;
+	struct tcf_proto __rcu		*filter_list;
+	struct tcf_block		*block;
 	struct Qdisc_class_hash		clhash;
 };
 
+static bool cl_is_active(struct drr_class *cl)
+{
+	return !list_empty(&cl->alist);
+}
+
 static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
 {
 	struct drr_sched *q = qdisc_priv(sch);
@@ -50,20 +51,13 @@ static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
 	return container_of(clc, struct drr_class, common);
 }
 
-static void drr_purge_queue(struct drr_class *cl)
-{
-	unsigned int len = cl->qdisc->q.qlen;
-
-	qdisc_reset(cl->qdisc);
-	qdisc_tree_decrease_qlen(cl->qdisc, len);
-}
-
 static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
 	[TCA_DRR_QUANTUM]	= { .type = NLA_U32 },
 };
 
 static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
-			    struct nlattr **tca, unsigned long *arg)
+			    struct nlattr **tca, unsigned long *arg,
+			    struct netlink_ext_ack *extack)
 {
 	struct drr_sched *q = qdisc_priv(sch);
 	struct drr_class *cl = (struct drr_class *)*arg;
@@ -72,27 +66,35 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	u32 quantum;
 	int err;
 
-	if (!opt)
+	if (!opt) {
+		NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
 		return -EINVAL;
+	}
 
-	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
+	err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
+					  extack);
 	if (err < 0)
 		return err;
 
 	if (tb[TCA_DRR_QUANTUM]) {
 		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
-		if (quantum == 0)
+		if (quantum == 0) {
+			NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
 			return -EINVAL;
+		}
 	} else
 		quantum = psched_mtu(qdisc_dev(sch));
 
 	if (cl != NULL) {
 		if (tca[TCA_RATE]) {
-			err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
-						    qdisc_root_sleeping_lock(sch),
+			err = gen_replace_estimator(&cl->bstats, NULL,
+						    &cl->rate_est,
+						    NULL, true,
 						    tca[TCA_RATE]);
-			if (err)
+			if (err) {
+				NL_SET_ERR_MSG(extack, "Failed to replace estimator");
 				return err;
+			}
 		}
 
 		sch_tree_lock(sch);
@@ -107,20 +109,24 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	if (cl == NULL)
 		return -ENOBUFS;
 
-	cl->refcnt	   = 1;
+	gnet_stats_basic_sync_init(&cl->bstats);
+	INIT_LIST_HEAD(&cl->alist);
 	cl->common.classid = classid;
 	cl->quantum	   = quantum;
 	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
-					       &pfifo_qdisc_ops, classid);
+					       &pfifo_qdisc_ops, classid,
+					       NULL);
 	if (cl->qdisc == NULL)
 		cl->qdisc = &noop_qdisc;
+	else
+		qdisc_hash_add(cl->qdisc, true);
 
 	if (tca[TCA_RATE]) {
-		err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
-					    qdisc_root_sleeping_lock(sch),
-					    tca[TCA_RATE]);
+		err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
+					    NULL, true, tca[TCA_RATE]);
 		if (err) {
-			qdisc_destroy(cl->qdisc);
+			NL_SET_ERR_MSG(extack, "Failed to replace estimator");
+			qdisc_put(cl->qdisc);
 			kfree(cl);
 			return err;
 		}
@@ -138,60 +144,49 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
 {
-	gen_kill_estimator(&cl->bstats, &cl->rate_est);
-	qdisc_destroy(cl->qdisc);
+	gen_kill_estimator(&cl->rate_est);
+	qdisc_put(cl->qdisc);
 	kfree(cl);
 }
 
-static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
+static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
+			    struct netlink_ext_ack *extack)
 {
 	struct drr_sched *q = qdisc_priv(sch);
 	struct drr_class *cl = (struct drr_class *)arg;
 
-	if (cl->filter_cnt > 0)
+	if (qdisc_class_in_use(&cl->common)) {
+		NL_SET_ERR_MSG(extack, "DRR class is in use");
 		return -EBUSY;
+	}
 
 	sch_tree_lock(sch);
 
-	drr_purge_queue(cl);
+	qdisc_purge_queue(cl->qdisc);
 	qdisc_class_hash_remove(&q->clhash, &cl->common);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
 	sch_tree_unlock(sch);
-	return 0;
-}
 
-static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
-{
-	struct drr_class *cl = drr_find_class(sch, classid);
-
-	if (cl != NULL)
-		cl->refcnt++;
-
-	return (unsigned long)cl;
+	drr_destroy_class(sch, cl);
+	return 0;
 }
 
-static void drr_put_class(struct Qdisc *sch, unsigned long arg)
+static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
 {
-	struct drr_class *cl = (struct drr_class *)arg;
-
-	if (--cl->refcnt == 0)
-		drr_destroy_class(sch, cl);
+	return (unsigned long)drr_find_class(sch, classid);
 }
 
-static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
+static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
+				       struct netlink_ext_ack *extack)
 {
 	struct drr_sched *q = qdisc_priv(sch);
 
-	if (cl)
+	if (cl) {
+		NL_SET_ERR_MSG(extack, "DRR classid must be zero");
 		return NULL;
+	}
 
-	return &q->filter_list;
+	return q->block;
 }
 
 static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
@@ -199,8 +194,8 @@ static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
 {
 	struct drr_class *cl = drr_find_class(sch, classid);
 
-	if (cl != NULL)
-		cl->filter_cnt++;
+	if (cl)
+		qdisc_class_get(&cl->common);
 
 	return (unsigned long)cl;
 }
@@ -209,26 +204,23 @@ static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
 {
 	struct drr_class *cl = (struct drr_class *)arg;
 
-	cl->filter_cnt--;
+	qdisc_class_put(&cl->common);
 }
 
 static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
-			   struct Qdisc *new, struct Qdisc **old)
+			   struct Qdisc *new, struct Qdisc **old,
+			   struct netlink_ext_ack *extack)
 {
 	struct drr_class *cl = (struct drr_class *)arg;
 
 	if (new == NULL) {
-		new = qdisc_create_dflt(sch->dev_queue,
-					&pfifo_qdisc_ops, cl->common.classid);
+		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					cl->common.classid, NULL);
 		if (new == NULL)
 			new = &noop_qdisc;
 	}
 
-	sch_tree_lock(sch);
-	drr_purge_queue(cl);
-	*old = cl->qdisc;
-	cl->qdisc = new;
-	sch_tree_unlock(sch);
+	*old = qdisc_replace(sch, new, &cl->qdisc);
 	return 0;
 }
 
@@ -243,8 +235,7 @@ static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
 {
 	struct drr_class *cl = (struct drr_class *)arg;
 
-	if (cl->qdisc->q.qlen == 0)
-		list_del(&cl->alist);
+	list_del_init(&cl->alist);
 }
 
 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
@@ -257,7 +248,7 @@ static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
 	tcm->tcm_handle	= cl->common.classid;
 	tcm->tcm_info	= cl->qdisc->handle;
 
-	nest = nla_nest_start(skb, TCA_OPTIONS);
+	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 	if (nest == NULL)
 		goto nla_put_failure;
 	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
@@ -273,17 +264,17 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 				struct gnet_dump *d)
 {
 	struct drr_class *cl = (struct drr_class *)arg;
+	__u32 qlen = qdisc_qlen_sum(cl->qdisc);
+	struct Qdisc *cl_q = cl->qdisc;
 	struct tc_drr_stats xstats;
 
 	memset(&xstats, 0, sizeof(xstats));
-	if (cl->qdisc->q.qlen) {
+	if (qlen)
 		xstats.deficit = cl->deficit;
-		cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
-	}
 
-	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
-	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
-	    gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
+	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
+	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
+	    gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
 		return -1;
 
 	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
@@ -300,15 +291,8 @@ static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
-			if (arg->count < arg->skip) {
-				arg->count++;
-				continue;
-			}
-			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
-				arg->stop = 1;
+			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
 				return;
-			}
-			arg->count++;
 		}
 	}
 }
@@ -319,6 +303,7 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
 	struct drr_sched *q = qdisc_priv(sch);
 	struct drr_class *cl;
 	struct tcf_result res;
+	struct tcf_proto *fl;
 	int result;
 
 	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
@@ -328,13 +313,16 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
 	}
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	result = tc_classify(skb, q->filter_list, &res);
+	fl = rcu_dereference_bh(q->filter_list);
+	result = tcf_classify(skb, NULL, fl, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
 		case TC_ACT_QUEUED:
 		case TC_ACT_STOLEN:
+		case TC_ACT_TRAP:
 			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+			fallthrough;
 		case TC_ACT_SHOT:
 			return NULL;
 		}
@@ -347,8 +335,10 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
 	return NULL;
 }
 
-static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+		       struct sk_buff **to_free)
 {
+	unsigned int len = qdisc_pkt_len(skb);
 	struct drr_sched *q = qdisc_priv(sch);
 	struct drr_class *cl;
 	int err = 0;
@@ -356,25 +346,26 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 	cl = drr_classify(skb, sch, &err);
 	if (cl == NULL) {
 		if (err & __NET_XMIT_BYPASS)
-			sch->qstats.drops++;
-		kfree_skb(skb);
+			qdisc_qstats_drop(sch);
+		__qdisc_drop(skb, to_free);
 		return err;
 	}
 
-	err = qdisc_enqueue(skb, cl->qdisc);
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
 	if (unlikely(err != NET_XMIT_SUCCESS)) {
 		if (net_xmit_drop_count(err)) {
 			cl->qstats.drops++;
-			sch->qstats.drops++;
+			qdisc_qstats_drop(sch);
 		}
 		return err;
 	}
 
-	if (cl->qdisc->q.qlen == 1) {
+	if (!cl_is_active(cl)) {
 		list_add_tail(&cl->alist, &q->active);
 		cl->deficit = cl->quantum;
 	}
 
+	sch->qstats.backlog += len;
 	sch->q.qlen++;
 	return err;
 }
@@ -391,18 +382,23 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch)
 	while (1) {
 		cl = list_first_entry(&q->active, struct drr_class, alist);
 		skb = cl->qdisc->ops->peek(cl->qdisc);
-		if (skb == NULL)
+		if (skb == NULL) {
+			qdisc_warn_nonwc(__func__, cl->qdisc);
 			goto out;
+		}
 
 		len = qdisc_pkt_len(skb);
 		if (len <= cl->deficit) {
 			cl->deficit -= len;
 			skb = qdisc_dequeue_peeked(cl->qdisc);
+			if (unlikely(skb == NULL))
+				goto out;
 			if (cl->qdisc->q.qlen == 0)
-				list_del(&cl->alist);
+				list_del_init(&cl->alist);
 
 			bstats_update(&cl->bstats, skb);
 			qdisc_bstats_update(sch, skb);
+			qdisc_qstats_backlog_dec(sch, skb);
 			sch->q.qlen--;
 			return skb;
 		}
@@ -414,31 +410,15 @@ out:
 	return NULL;
 }
 
-static unsigned int drr_drop(struct Qdisc *sch)
-{
-	struct drr_sched *q = qdisc_priv(sch);
-	struct drr_class *cl;
-	unsigned int len;
-
-	list_for_each_entry(cl, &q->active, alist) {
-		if (cl->qdisc->ops->drop) {
-			len = cl->qdisc->ops->drop(cl->qdisc);
-			if (len > 0) {
-				sch->q.qlen--;
-				if (cl->qdisc->q.qlen == 0)
-					list_del(&cl->alist);
-				return len;
-			}
-		}
-	}
-	return 0;
-}
-
-static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
+static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
+			  struct netlink_ext_ack *extack)
 {
 	struct drr_sched *q = qdisc_priv(sch);
 	int err;
 
+	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+	if (err)
+		return err;
 	err = qdisc_class_hash_init(&q->clhash);
 	if (err < 0)
 		return err;
@@ -455,11 +435,10 @@ static void drr_reset_qdisc(struct Qdisc *sch)
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
 			if (cl->qdisc->q.qlen)
-				list_del(&cl->alist);
+				list_del_init(&cl->alist);
 			qdisc_reset(cl->qdisc);
 		}
 	}
-	sch->q.qlen = 0;
 }
 
 static void drr_destroy_qdisc(struct Qdisc *sch)
@@ -469,7 +448,7 @@ static void drr_destroy_qdisc(struct Qdisc *sch)
 	struct hlist_node *next;
 	unsigned int i;
 
-	tcf_destroy_chain(&q->filter_list);
+	tcf_block_put(q->block);
 
 	for (i = 0; i < q->clhash.hashsize; i++) {
 		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
@@ -482,9 +461,8 @@ static void drr_destroy_qdisc(struct Qdisc *sch)
 static const struct Qdisc_class_ops drr_class_ops = {
 	.change		= drr_change_class,
 	.delete		= drr_delete_class,
-	.get		= drr_get_class,
-	.put		= drr_put_class,
-	.tcf_chain	= drr_tcf_chain,
+	.find		= drr_search_class,
+	.tcf_block	= drr_tcf_block,
 	.bind_tcf	= drr_bind_tcf,
 	.unbind_tcf	= drr_unbind_tcf,
 	.graft		= drr_graft_class,
@@ -502,12 +480,12 @@ static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
 	.enqueue	= drr_enqueue,
 	.dequeue	= drr_dequeue,
 	.peek		= qdisc_peek_dequeued,
-	.drop		= drr_drop,
 	.init		= drr_init_qdisc,
 	.reset		= drr_reset_qdisc,
 	.destroy	= drr_destroy_qdisc,
 	.owner		= THIS_MODULE,
 };
+MODULE_ALIAS_NET_SCH("drr");
 
 static int __init drr_init(void)
 {
@@ -522,3 +500,4 @@ static void __exit drr_exit(void)
 module_init(drr_init);
 module_exit(drr_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Deficit Round Robin scheduler");