[linux-block.git] / net / sched / sch_drr.c

/*
 * 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>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/pkt_sched.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

struct drr_class {
	struct Qdisc_class_common	common;
	unsigned int			refcnt;
	unsigned int			filter_cnt;

	struct gnet_stats_basic		bstats;
	struct gnet_stats_queue		qstats;
	struct gnet_stats_rate_est	rate_est;
	struct list_head		alist;
	struct Qdisc			*qdisc;

	u32				quantum;
	u32				deficit;
};

struct drr_sched {
	struct list_head		active;
	struct tcf_proto		*filter_list;
	struct Qdisc_class_hash		clhash;
};

static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct Qdisc_class_common *clc;

	clc = qdisc_class_find(&q->clhash, classid);
	if (clc == NULL)
		return NULL;
	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 drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)*arg;
	struct nlattr *tb[TCA_DRR_MAX + 1];
	u32 quantum;
	int err;

	err = nla_parse_nested(tb, TCA_DRR_MAX, tca[TCA_OPTIONS], drr_policy);
	if (err < 0)
		return err;

	if (tb[TCA_DRR_QUANTUM]) {
		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
		if (quantum == 0)
			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),
						    tca[TCA_RATE]);
			if (err)
				return err;
		}

		sch_tree_lock(sch);
		if (tb[TCA_DRR_QUANTUM])
			cl->quantum = quantum;
		sch_tree_unlock(sch);

		return 0;
	}

	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	if (cl == NULL)
		return -ENOBUFS;

	cl->refcnt	   = 1;
	cl->common.classid = classid;
	cl->quantum	   = quantum;
	cl->qdisc	   = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
					       &pfifo_qdisc_ops, classid);
	if (cl->qdisc == NULL)
		cl->qdisc = &noop_qdisc;

	if (tca[TCA_RATE]) {
		err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
					    qdisc_root_sleeping_lock(sch),
					    tca[TCA_RATE]);
		if (err) {
			qdisc_destroy(cl->qdisc);
			kfree(cl);
			return err;
		}
	}

	sch_tree_lock(sch);
	qdisc_class_hash_insert(&q->clhash, &cl->common);
	sch_tree_unlock(sch);

	qdisc_class_hash_grow(sch, &q->clhash);

	*arg = (unsigned long)cl;
	return 0;
}

static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
{
	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	qdisc_destroy(cl->qdisc);
	kfree(cl);
}

static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)arg;

	if (cl->filter_cnt > 0)
		return -EBUSY;

	sch_tree_lock(sch);

	drr_purge_queue(cl);
	qdisc_class_hash_remove(&q->clhash, &cl->common);

	if (--cl->refcnt == 0)
		drr_destroy_class(sch, cl);

	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;
}

static void drr_put_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (--cl->refcnt == 0)
		drr_destroy_class(sch, cl);
}

static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
{
	struct drr_sched *q = qdisc_priv(sch);

	if (cl)
		return NULL;

	return &q->filter_list;
}

static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
				  u32 classid)
{
	struct drr_class *cl = drr_find_class(sch, classid);

	if (cl != NULL)
		cl->filter_cnt++;

	return (unsigned long)cl;
}

static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	cl->filter_cnt--;
}

static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
			   struct Qdisc *new, struct Qdisc **old)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (new == NULL) {
		new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
					&pfifo_qdisc_ops, cl->common.classid);
		if (new == NULL)
			new = &noop_qdisc;
	}

	sch_tree_lock(sch);
	drr_purge_queue(cl);
	*old = cl->qdisc;
	cl->qdisc = new;
	sch_tree_unlock(sch);
	return 0;
}

static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	return cl->qdisc;
}

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);
}

static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct nlattr *nest;

	tcm->tcm_parent	= TC_H_ROOT;
	tcm->tcm_handle	= cl->common.classid;
	tcm->tcm_info	= cl->qdisc->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -EMSGSIZE;
}

static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
				struct gnet_dump *d)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct tc_drr_stats xstats;

	memset(&xstats, 0, sizeof(xstats));
	if (cl->qdisc->q.qlen)
		xstats.deficit = cl->deficit;

	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
		return -1;

	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
}

static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &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;
				return;
			}
			arg->count++;
		}
	}
}

static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
				      int *qerr)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct tcf_result res;
	int result;

	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
		cl = drr_find_class(sch, skb->priority);
		if (cl != NULL)
			return cl;
	}

	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	result = tc_classify(skb, q->filter_list, &res);
	if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
		case TC_ACT_SHOT:
			return NULL;
		}
#endif
		cl = (struct drr_class *)res.class;
		if (cl == NULL)
			cl = drr_find_class(sch, res.classid);
		return cl;
	}
	return NULL;
}

static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	unsigned int len;
	int err;

	cl = drr_classify(skb, sch, &err);
	if (cl == NULL) {
		if (err & __NET_XMIT_BYPASS)
			sch->qstats.drops++;
		kfree_skb(skb);
		return err;
	}

	len = qdisc_pkt_len(skb);
	err = qdisc_enqueue(skb, cl->qdisc);
	if (unlikely(err != NET_XMIT_SUCCESS)) {
		if (net_xmit_drop_count(err)) {
			cl->qstats.drops++;
			sch->qstats.drops++;
		}
		return err;
	}

	if (cl->qdisc->q.qlen == 1) {
		list_add_tail(&cl->alist, &q->active);
		cl->deficit = cl->quantum;
	}

	cl->bstats.packets++;
	cl->bstats.bytes += len;
	sch->bstats.packets++;
	sch->bstats.bytes += len;

	sch->q.qlen++;
	return err;
}

static struct sk_buff *drr_dequeue(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct sk_buff *skb;
	unsigned int len;

	if (list_empty(&q->active))
		goto out;
	while (1) {
		cl = list_first_entry(&q->active, struct drr_class, alist);
		skb = cl->qdisc->ops->peek(cl->qdisc);
		if (skb == NULL)
			goto out;

		len = qdisc_pkt_len(skb);
		if (len <= cl->deficit) {
			cl->deficit -= len;
			skb = qdisc_dequeue_peeked(cl->qdisc);
			if (cl->qdisc->q.qlen == 0)
				list_del(&cl->alist);
			sch->q.qlen--;
			return skb;
		}

		cl->deficit += cl->quantum;
		list_move_tail(&cl->alist, &q->active);
	}
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)
{
	struct drr_sched *q = qdisc_priv(sch);
	int err;

	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		return err;
	INIT_LIST_HEAD(&q->active);
	return 0;
}

static void drr_reset_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n;
	unsigned int i;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
			if (cl->qdisc->q.qlen)
				list_del(&cl->alist);
			qdisc_reset(cl->qdisc);
		}
	}
	sch->q.qlen = 0;
}

static void drr_destroy_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n, *next;
	unsigned int i;

	tcf_destroy_chain(&q->filter_list);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
					  common.hnode)
			drr_destroy_class(sch, cl);
	}
	qdisc_class_hash_destroy(&q->clhash);
}

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,
	.bind_tcf	= drr_bind_tcf,
	.unbind_tcf	= drr_unbind_tcf,
	.graft		= drr_graft_class,
	.leaf		= drr_class_leaf,
	.qlen_notify	= drr_qlen_notify,
	.dump		= drr_dump_class,
	.dump_stats	= drr_dump_class_stats,
	.walk		= drr_walk,
};

static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	.cl_ops		= &drr_class_ops,
	.id		= "drr",
	.priv_size	= sizeof(struct drr_sched),
	.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,
};

static int __init drr_init(void)
{
	return register_qdisc(&drr_qdisc_ops);
}

static void __exit drr_exit(void)
{
	unregister_qdisc(&drr_qdisc_ops);
}

module_init(drr_init);
module_exit(drr_exit);
MODULE_LICENSE("GPL");
Commit	Line	Data
13d2a1d2 PM	1	/*
	2	* net/sched/sch_drr.c Deficit Round Robin scheduler
	3	*
	4	* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* version 2 as published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/errno.h>
	14	#include <linux/netdevice.h>
	15	#include <linux/pkt_sched.h>
	16	#include <net/sch_generic.h>
	17	#include <net/pkt_sched.h>
	18	#include <net/pkt_cls.h>
	19
	20	struct drr_class {
	21	struct Qdisc_class_common common;
	22	unsigned int refcnt;
	23	unsigned int filter_cnt;
	24
	25	struct gnet_stats_basic bstats;
	26	struct gnet_stats_queue qstats;
	27	struct gnet_stats_rate_est rate_est;
	28	struct list_head alist;
	29	struct Qdisc *qdisc;
	30
	31	u32 quantum;
	32	u32 deficit;
	33	};
	34
	35	struct drr_sched {
	36	struct list_head active;
	37	struct tcf_proto *filter_list;
	38	struct Qdisc_class_hash clhash;
	39	};
	40
	41	static struct drr_class drr_find_class(struct Qdisc sch, u32 classid)
	42	{
	43	struct drr_sched *q = qdisc_priv(sch);
	44	struct Qdisc_class_common *clc;
	45
	46	clc = qdisc_class_find(&q->clhash, classid);
	47	if (clc == NULL)
	48	return NULL;
	49	return container_of(clc, struct drr_class, common);
	50	}
	51
	52	static void drr_purge_queue(struct drr_class *cl)
	53	{
	54	unsigned int len = cl->qdisc->q.qlen;
	55
	56	qdisc_reset(cl->qdisc);
	57	qdisc_tree_decrease_qlen(cl->qdisc, len);
	58	}
	59
	60	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	61	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	62	};
	63
	64	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
65	struct nlattr *tca, unsigned long arg)
66	{
67	struct drr_sched *q = qdisc_priv(sch);
68	struct drr_class cl = (struct drr_class )*arg;
69	struct nlattr *tb[TCA_DRR_MAX + 1];
70	u32 quantum;
71	int err;
72
73	err = nla_parse_nested(tb, TCA_DRR_MAX, tca[TCA_OPTIONS], drr_policy);
74	if (err < 0)
75	return err;
76
77	if (tb[TCA_DRR_QUANTUM]) {
78	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
79	if (quantum == 0)
80	return -EINVAL;
81	} else
82	quantum = psched_mtu(qdisc_dev(sch));
83
84	if (cl != NULL) {
71bcb09a SH	85	if (tca[TCA_RATE]) {
	86	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	87	qdisc_root_sleeping_lock(sch),
	88	tca[TCA_RATE]);
	89	if (err)
	90	return err;
	91	}
	92
13d2a1d2 PM	93	sch_tree_lock(sch);
	94	if (tb[TCA_DRR_QUANTUM])
	95	cl->quantum = quantum;
	96	sch_tree_unlock(sch);
	97
13d2a1d2 PM	98	return 0;
	99	}
	100
	101	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	102	if (cl == NULL)
	103	return -ENOBUFS;
	104
	105	cl->refcnt = 1;
	106	cl->common.classid = classid;
	107	cl->quantum = quantum;
	108	cl->qdisc = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
	109	&pfifo_qdisc_ops, classid);
	110	if (cl->qdisc == NULL)
	111	cl->qdisc = &noop_qdisc;
	112
71bcb09a SH	113	if (tca[TCA_RATE]) {
	114	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	115	qdisc_root_sleeping_lock(sch),
	116	tca[TCA_RATE]);
	117	if (err) {
	118	qdisc_destroy(cl->qdisc);
	119	kfree(cl);
	120	return err;
	121	}
	122	}
13d2a1d2 PM	123
	124	sch_tree_lock(sch);
	125	qdisc_class_hash_insert(&q->clhash, &cl->common);
	126	sch_tree_unlock(sch);
	127
	128	qdisc_class_hash_grow(sch, &q->clhash);
	129
	130	*arg = (unsigned long)cl;
	131	return 0;
	132	}
	133
	134	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	135	{
	136	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	137	qdisc_destroy(cl->qdisc);
	138	kfree(cl);
	139	}
	140
	141	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	142	{
	143	struct drr_sched *q = qdisc_priv(sch);
	144	struct drr_class cl = (struct drr_class )arg;
	145
	146	if (cl->filter_cnt > 0)
	147	return -EBUSY;
	148
	149	sch_tree_lock(sch);
	150
	151	drr_purge_queue(cl);
	152	qdisc_class_hash_remove(&q->clhash, &cl->common);
	153
	154	if (--cl->refcnt == 0)
	155	drr_destroy_class(sch, cl);
	156
	157	sch_tree_unlock(sch);
	158	return 0;
	159	}
	160
	161	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	162	{
	163	struct drr_class *cl = drr_find_class(sch, classid);
	164
	165	if (cl != NULL)
	166	cl->refcnt++;
	167
	168	return (unsigned long)cl;
	169	}
	170
	171	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	172	{
	173	struct drr_class cl = (struct drr_class )arg;
	174
	175	if (--cl->refcnt == 0)
	176	drr_destroy_class(sch, cl);
	177	}
	178
	179	static struct tcf_proto *drr_tcf_chain(struct Qdisc sch, unsigned long cl)
	180	{
	181	struct drr_sched *q = qdisc_priv(sch);
	182
	183	if (cl)
	184	return NULL;
	185
	186	return &q->filter_list;
187	}
188
189	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
190	u32 classid)
191	{
192	struct drr_class *cl = drr_find_class(sch, classid);
193
194	if (cl != NULL)
195	cl->filter_cnt++;
196
197	return (unsigned long)cl;
198	}
199
200	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
201	{
202	struct drr_class cl = (struct drr_class )arg;
203
204	cl->filter_cnt--;
205	}
206
207	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
208	struct Qdisc new, struct Qdisc *old)
209	{
210	struct drr_class cl = (struct drr_class )arg;
211
212	if (new == NULL) {
213	new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
214	&pfifo_qdisc_ops, cl->common.classid);
215	if (new == NULL)
216	new = &noop_qdisc;
217	}
218
219	sch_tree_lock(sch);
220	drr_purge_queue(cl);
b94c8afc PM	221	*old = cl->qdisc;
b94c8afc PM	222	cl->qdisc = new;
13d2a1d2 PM	223	sch_tree_unlock(sch);
	224	return 0;
	225	}
	226
	227	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	228	{
	229	struct drr_class cl = (struct drr_class )arg;
	230
	231	return cl->qdisc;
	232	}
	233
	234	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	235	{
	236	struct drr_class cl = (struct drr_class )arg;
	237
	238	if (cl->qdisc->q.qlen == 0)
	239	list_del(&cl->alist);
	240	}
	241
	242	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	243	struct sk_buff skb, struct tcmsg tcm)
	244	{
	245	struct drr_class cl = (struct drr_class )arg;
	246	struct nlattr *nest;
	247
	248	tcm->tcm_parent = TC_H_ROOT;
	249	tcm->tcm_handle = cl->common.classid;
	250	tcm->tcm_info = cl->qdisc->handle;
	251
	252	nest = nla_nest_start(skb, TCA_OPTIONS);
	253	if (nest == NULL)
	254	goto nla_put_failure;
	255	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	256	return nla_nest_end(skb, nest);
	257
	258	nla_put_failure:
	259	nla_nest_cancel(skb, nest);
	260	return -EMSGSIZE;
	261	}
	262
	263	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	264	struct gnet_dump *d)
	265	{
	266	struct drr_class cl = (struct drr_class )arg;
	267	struct tc_drr_stats xstats;
	268
	269	memset(&xstats, 0, sizeof(xstats));
	270	if (cl->qdisc->q.qlen)
	271	xstats.deficit = cl->deficit;
	272
	273	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 \|\|
	274	gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 \|\|
	275	gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
	276	return -1;
	277
	278	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	279	}
	280
	281	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	282	{
	283	struct drr_sched *q = qdisc_priv(sch);
	284	struct drr_class *cl;
	285	struct hlist_node *n;
	286	unsigned int i;
287
288	if (arg->stop)
289	return;
290
291	for (i = 0; i < q->clhash.hashsize; i++) {
292	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
293	if (arg->count < arg->skip) {
294	arg->count++;
295	continue;
296	}
297	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
298	arg->stop = 1;
299	return;
300	}
301	arg->count++;
302	}
303	}
304	}
305
306	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
307	int *qerr)
308	{
309	struct drr_sched *q = qdisc_priv(sch);
310	struct drr_class *cl;
311	struct tcf_result res;
312	int result;
313
314	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
315	cl = drr_find_class(sch, skb->priority);
316	if (cl != NULL)
317	return cl;
318	}
319
320	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
321	result = tc_classify(skb, q->filter_list, &res);
322	if (result >= 0) {
323	#ifdef CONFIG_NET_CLS_ACT
324	switch (result) {
325	case TC_ACT_QUEUED:
326	case TC_ACT_STOLEN:
327	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
328	case TC_ACT_SHOT:
329	return NULL;
330	}
331	#endif
332	cl = (struct drr_class *)res.class;
333	if (cl == NULL)
334	cl = drr_find_class(sch, res.classid);
335	return cl;
336	}
337	return NULL;
338	}
339
340	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
341	{
342	struct drr_sched *q = qdisc_priv(sch);
343	struct drr_class *cl;
344	unsigned int len;
345	int err;
346
347	cl = drr_classify(skb, sch, &err);
348	if (cl == NULL) {
349	if (err & __NET_XMIT_BYPASS)
350	sch->qstats.drops++;
351	kfree_skb(skb);
352	return err;
353	}
354
355	len = qdisc_pkt_len(skb);
356	err = qdisc_enqueue(skb, cl->qdisc);
357	if (unlikely(err != NET_XMIT_SUCCESS)) {
358	if (net_xmit_drop_count(err)) {
359	cl->qstats.drops++;
360	sch->qstats.drops++;
361	}
362	return err;
363	}
364
365	if (cl->qdisc->q.qlen == 1) {
366	list_add_tail(&cl->alist, &q->active);
367	cl->deficit = cl->quantum;
368	}
369
370	cl->bstats.packets++;
371	cl->bstats.bytes += len;
372	sch->bstats.packets++;
373	sch->bstats.bytes += len;
374
375	sch->q.qlen++;
376	return err;
377	}
378
379	static struct sk_buff drr_dequeue(struct Qdisc sch)
380	{
381	struct drr_sched *q = qdisc_priv(sch);
382	struct drr_class *cl;
383	struct sk_buff *skb;
384	unsigned int len;
385
3f0947c3 PM	386	if (list_empty(&q->active))
	387	goto out;
	388	while (1) {
13d2a1d2 PM	389	cl = list_first_entry(&q->active, struct drr_class, alist);
	390	skb = cl->qdisc->ops->peek(cl->qdisc);
	391	if (skb == NULL)
3f0947c3	392	goto out;
13d2a1d2 PM	393
	394	len = qdisc_pkt_len(skb);
	395	if (len <= cl->deficit) {
	396	cl->deficit -= len;
	397	skb = qdisc_dequeue_peeked(cl->qdisc);
	398	if (cl->qdisc->q.qlen == 0)
	399	list_del(&cl->alist);
	400	sch->q.qlen--;
	401	return skb;
	402	}
	403
	404	cl->deficit += cl->quantum;
13d2a1d2 PM	405	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	406	}
3f0947c3	407	out:
13d2a1d2 PM	408	return NULL;
	409	}
	410
	411	static unsigned int drr_drop(struct Qdisc *sch)
	412	{
	413	struct drr_sched *q = qdisc_priv(sch);
	414	struct drr_class *cl;
	415	unsigned int len;
	416
	417	list_for_each_entry(cl, &q->active, alist) {
	418	if (cl->qdisc->ops->drop) {
	419	len = cl->qdisc->ops->drop(cl->qdisc);
	420	if (len > 0) {
98aa9c80	421	sch->q.qlen--;
13d2a1d2 PM	422	if (cl->qdisc->q.qlen == 0)
	423	list_del(&cl->alist);
	424	return len;
	425	}
	426	}
	427	}
	428	return 0;
	429	}
	430
	431	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	432	{
	433	struct drr_sched *q = qdisc_priv(sch);
	434	int err;
	435
	436	err = qdisc_class_hash_init(&q->clhash);
	437	if (err < 0)
	438	return err;
	439	INIT_LIST_HEAD(&q->active);
	440	return 0;
	441	}
	442
	443	static void drr_reset_qdisc(struct Qdisc *sch)
	444	{
	445	struct drr_sched *q = qdisc_priv(sch);
	446	struct drr_class *cl;
	447	struct hlist_node *n;
	448	unsigned int i;
	449
	450	for (i = 0; i < q->clhash.hashsize; i++) {
	451	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
	452	if (cl->qdisc->q.qlen)
	453	list_del(&cl->alist);
	454	qdisc_reset(cl->qdisc);
	455	}
	456	}
	457	sch->q.qlen = 0;
	458	}
	459
	460	static void drr_destroy_qdisc(struct Qdisc *sch)
	461	{
	462	struct drr_sched *q = qdisc_priv(sch);
	463	struct drr_class *cl;
	464	struct hlist_node n, next;
	465	unsigned int i;
	466
	467	tcf_destroy_chain(&q->filter_list);
	468
	469	for (i = 0; i < q->clhash.hashsize; i++) {
	470	hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
	471	common.hnode)
	472	drr_destroy_class(sch, cl);
	473	}
	474	qdisc_class_hash_destroy(&q->clhash);
	475	}
	476
	477	static const struct Qdisc_class_ops drr_class_ops = {
	478	.change = drr_change_class,
	479	.delete = drr_delete_class,
	480	.get = drr_get_class,
	481	.put = drr_put_class,
	482	.tcf_chain = drr_tcf_chain,
	483	.bind_tcf = drr_bind_tcf,
	484	.unbind_tcf = drr_unbind_tcf,
	485	.graft = drr_graft_class,
486	.leaf = drr_class_leaf,
487	.qlen_notify = drr_qlen_notify,
488	.dump = drr_dump_class,
489	.dump_stats = drr_dump_class_stats,
490	.walk = drr_walk,
491	};
492
493	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
494	.cl_ops = &drr_class_ops,
495	.id = "drr",
496	.priv_size = sizeof(struct drr_sched),
497	.enqueue = drr_enqueue,
498	.dequeue = drr_dequeue,
499	.peek = qdisc_peek_dequeued,
500	.drop = drr_drop,
501	.init = drr_init_qdisc,
502	.reset = drr_reset_qdisc,
503	.destroy = drr_destroy_qdisc,
504	.owner = THIS_MODULE,
505	};
506
507	static int __init drr_init(void)
508	{
509	return register_qdisc(&drr_qdisc_ops);
510	}
511
512	static void __exit drr_exit(void)
513	{
514	unregister_qdisc(&drr_qdisc_ops);
515	}
516
517	module_init(drr_init);
518	module_exit(drr_exit);
519	MODULE_LICENSE("GPL");