net: restore gnet_stats_basic to previous definition
[linux-2.6.git] / net / sched / sch_drr.c
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_packed          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 *opt = tca[TCA_OPTIONS];
70         struct nlattr *tb[TCA_DRR_MAX + 1];
71         u32 quantum;
72         int err;
73
74         if (!opt)
75                 return -EINVAL;
76
77         err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
78         if (err < 0)
79                 return err;
80
81         if (tb[TCA_DRR_QUANTUM]) {
82                 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
83                 if (quantum == 0)
84                         return -EINVAL;
85         } else
86                 quantum = psched_mtu(qdisc_dev(sch));
87
88         if (cl != NULL) {
89                 if (tca[TCA_RATE]) {
90                         err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
91                                                     qdisc_root_sleeping_lock(sch),
92                                                     tca[TCA_RATE]);
93                         if (err)
94                                 return err;
95                 }
96
97                 sch_tree_lock(sch);
98                 if (tb[TCA_DRR_QUANTUM])
99                         cl->quantum = quantum;
100                 sch_tree_unlock(sch);
101
102                 return 0;
103         }
104
105         cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
106         if (cl == NULL)
107                 return -ENOBUFS;
108
109         cl->refcnt         = 1;
110         cl->common.classid = classid;
111         cl->quantum        = quantum;
112         cl->qdisc          = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
113                                                &pfifo_qdisc_ops, classid);
114         if (cl->qdisc == NULL)
115                 cl->qdisc = &noop_qdisc;
116
117         if (tca[TCA_RATE]) {
118                 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
119                                             qdisc_root_sleeping_lock(sch),
120                                             tca[TCA_RATE]);
121                 if (err) {
122                         qdisc_destroy(cl->qdisc);
123                         kfree(cl);
124                         return err;
125                 }
126         }
127
128         sch_tree_lock(sch);
129         qdisc_class_hash_insert(&q->clhash, &cl->common);
130         sch_tree_unlock(sch);
131
132         qdisc_class_hash_grow(sch, &q->clhash);
133
134         *arg = (unsigned long)cl;
135         return 0;
136 }
137
138 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
139 {
140         gen_kill_estimator(&cl->bstats, &cl->rate_est);
141         qdisc_destroy(cl->qdisc);
142         kfree(cl);
143 }
144
145 static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
146 {
147         struct drr_sched *q = qdisc_priv(sch);
148         struct drr_class *cl = (struct drr_class *)arg;
149
150         if (cl->filter_cnt > 0)
151                 return -EBUSY;
152
153         sch_tree_lock(sch);
154
155         drr_purge_queue(cl);
156         qdisc_class_hash_remove(&q->clhash, &cl->common);
157
158         BUG_ON(--cl->refcnt == 0);
159         /*
160          * This shouldn't happen: we "hold" one cops->get() when called
161          * from tc_ctl_tclass; the destroy method is done from cops->put().
162          */
163
164         sch_tree_unlock(sch);
165         return 0;
166 }
167
168 static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
169 {
170         struct drr_class *cl = drr_find_class(sch, classid);
171
172         if (cl != NULL)
173                 cl->refcnt++;
174
175         return (unsigned long)cl;
176 }
177
178 static void drr_put_class(struct Qdisc *sch, unsigned long arg)
179 {
180         struct drr_class *cl = (struct drr_class *)arg;
181
182         if (--cl->refcnt == 0)
183                 drr_destroy_class(sch, cl);
184 }
185
186 static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
187 {
188         struct drr_sched *q = qdisc_priv(sch);
189
190         if (cl)
191                 return NULL;
192
193         return &q->filter_list;
194 }
195
196 static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
197                                   u32 classid)
198 {
199         struct drr_class *cl = drr_find_class(sch, classid);
200
201         if (cl != NULL)
202                 cl->filter_cnt++;
203
204         return (unsigned long)cl;
205 }
206
207 static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
208 {
209         struct drr_class *cl = (struct drr_class *)arg;
210
211         cl->filter_cnt--;
212 }
213
214 static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
215                            struct Qdisc *new, struct Qdisc **old)
216 {
217         struct drr_class *cl = (struct drr_class *)arg;
218
219         if (new == NULL) {
220                 new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
221                                         &pfifo_qdisc_ops, cl->common.classid);
222                 if (new == NULL)
223                         new = &noop_qdisc;
224         }
225
226         sch_tree_lock(sch);
227         drr_purge_queue(cl);
228         *old = cl->qdisc;
229         cl->qdisc = new;
230         sch_tree_unlock(sch);
231         return 0;
232 }
233
234 static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
235 {
236         struct drr_class *cl = (struct drr_class *)arg;
237
238         return cl->qdisc;
239 }
240
241 static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
242 {
243         struct drr_class *cl = (struct drr_class *)arg;
244
245         if (cl->qdisc->q.qlen == 0)
246                 list_del(&cl->alist);
247 }
248
249 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
250                           struct sk_buff *skb, struct tcmsg *tcm)
251 {
252         struct drr_class *cl = (struct drr_class *)arg;
253         struct nlattr *nest;
254
255         tcm->tcm_parent = TC_H_ROOT;
256         tcm->tcm_handle = cl->common.classid;
257         tcm->tcm_info   = cl->qdisc->handle;
258
259         nest = nla_nest_start(skb, TCA_OPTIONS);
260         if (nest == NULL)
261                 goto nla_put_failure;
262         NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
263         return nla_nest_end(skb, nest);
264
265 nla_put_failure:
266         nla_nest_cancel(skb, nest);
267         return -EMSGSIZE;
268 }
269
270 static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
271                                 struct gnet_dump *d)
272 {
273         struct drr_class *cl = (struct drr_class *)arg;
274         struct tc_drr_stats xstats;
275
276         memset(&xstats, 0, sizeof(xstats));
277         if (cl->qdisc->q.qlen)
278                 xstats.deficit = cl->deficit;
279
280         if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
281             gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
282             gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
283                 return -1;
284
285         return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
286 }
287
288 static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
289 {
290         struct drr_sched *q = qdisc_priv(sch);
291         struct drr_class *cl;
292         struct hlist_node *n;
293         unsigned int i;
294
295         if (arg->stop)
296                 return;
297
298         for (i = 0; i < q->clhash.hashsize; i++) {
299                 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
300                         if (arg->count < arg->skip) {
301                                 arg->count++;
302                                 continue;
303                         }
304                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
305                                 arg->stop = 1;
306                                 return;
307                         }
308                         arg->count++;
309                 }
310         }
311 }
312
313 static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
314                                       int *qerr)
315 {
316         struct drr_sched *q = qdisc_priv(sch);
317         struct drr_class *cl;
318         struct tcf_result res;
319         int result;
320
321         if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
322                 cl = drr_find_class(sch, skb->priority);
323                 if (cl != NULL)
324                         return cl;
325         }
326
327         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
328         result = tc_classify(skb, q->filter_list, &res);
329         if (result >= 0) {
330 #ifdef CONFIG_NET_CLS_ACT
331                 switch (result) {
332                 case TC_ACT_QUEUED:
333                 case TC_ACT_STOLEN:
334                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
335                 case TC_ACT_SHOT:
336                         return NULL;
337                 }
338 #endif
339                 cl = (struct drr_class *)res.class;
340                 if (cl == NULL)
341                         cl = drr_find_class(sch, res.classid);
342                 return cl;
343         }
344         return NULL;
345 }
346
347 static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
348 {
349         struct drr_sched *q = qdisc_priv(sch);
350         struct drr_class *cl;
351         unsigned int len;
352         int err;
353
354         cl = drr_classify(skb, sch, &err);
355         if (cl == NULL) {
356                 if (err & __NET_XMIT_BYPASS)
357                         sch->qstats.drops++;
358                 kfree_skb(skb);
359                 return err;
360         }
361
362         len = qdisc_pkt_len(skb);
363         err = qdisc_enqueue(skb, cl->qdisc);
364         if (unlikely(err != NET_XMIT_SUCCESS)) {
365                 if (net_xmit_drop_count(err)) {
366                         cl->qstats.drops++;
367                         sch->qstats.drops++;
368                 }
369                 return err;
370         }
371
372         if (cl->qdisc->q.qlen == 1) {
373                 list_add_tail(&cl->alist, &q->active);
374                 cl->deficit = cl->quantum;
375         }
376
377         cl->bstats.packets++;
378         cl->bstats.bytes += len;
379         sch->bstats.packets++;
380         sch->bstats.bytes += len;
381
382         sch->q.qlen++;
383         return err;
384 }
385
386 static struct sk_buff *drr_dequeue(struct Qdisc *sch)
387 {
388         struct drr_sched *q = qdisc_priv(sch);
389         struct drr_class *cl;
390         struct sk_buff *skb;
391         unsigned int len;
392
393         if (list_empty(&q->active))
394                 goto out;
395         while (1) {
396                 cl = list_first_entry(&q->active, struct drr_class, alist);
397                 skb = cl->qdisc->ops->peek(cl->qdisc);
398                 if (skb == NULL)
399                         goto out;
400
401                 len = qdisc_pkt_len(skb);
402                 if (len <= cl->deficit) {
403                         cl->deficit -= len;
404                         skb = qdisc_dequeue_peeked(cl->qdisc);
405                         if (cl->qdisc->q.qlen == 0)
406                                 list_del(&cl->alist);
407                         sch->q.qlen--;
408                         return skb;
409                 }
410
411                 cl->deficit += cl->quantum;
412                 list_move_tail(&cl->alist, &q->active);
413         }
414 out:
415         return NULL;
416 }
417
418 static unsigned int drr_drop(struct Qdisc *sch)
419 {
420         struct drr_sched *q = qdisc_priv(sch);
421         struct drr_class *cl;
422         unsigned int len;
423
424         list_for_each_entry(cl, &q->active, alist) {
425                 if (cl->qdisc->ops->drop) {
426                         len = cl->qdisc->ops->drop(cl->qdisc);
427                         if (len > 0) {
428                                 sch->q.qlen--;
429                                 if (cl->qdisc->q.qlen == 0)
430                                         list_del(&cl->alist);
431                                 return len;
432                         }
433                 }
434         }
435         return 0;
436 }
437
438 static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
439 {
440         struct drr_sched *q = qdisc_priv(sch);
441         int err;
442
443         err = qdisc_class_hash_init(&q->clhash);
444         if (err < 0)
445                 return err;
446         INIT_LIST_HEAD(&q->active);
447         return 0;
448 }
449
450 static void drr_reset_qdisc(struct Qdisc *sch)
451 {
452         struct drr_sched *q = qdisc_priv(sch);
453         struct drr_class *cl;
454         struct hlist_node *n;
455         unsigned int i;
456
457         for (i = 0; i < q->clhash.hashsize; i++) {
458                 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
459                         if (cl->qdisc->q.qlen)
460                                 list_del(&cl->alist);
461                         qdisc_reset(cl->qdisc);
462                 }
463         }
464         sch->q.qlen = 0;
465 }
466
467 static void drr_destroy_qdisc(struct Qdisc *sch)
468 {
469         struct drr_sched *q = qdisc_priv(sch);
470         struct drr_class *cl;
471         struct hlist_node *n, *next;
472         unsigned int i;
473
474         tcf_destroy_chain(&q->filter_list);
475
476         for (i = 0; i < q->clhash.hashsize; i++) {
477                 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
478                                           common.hnode)
479                         drr_destroy_class(sch, cl);
480         }
481         qdisc_class_hash_destroy(&q->clhash);
482 }
483
484 static const struct Qdisc_class_ops drr_class_ops = {
485         .change         = drr_change_class,
486         .delete         = drr_delete_class,
487         .get            = drr_get_class,
488         .put            = drr_put_class,
489         .tcf_chain      = drr_tcf_chain,
490         .bind_tcf       = drr_bind_tcf,
491         .unbind_tcf     = drr_unbind_tcf,
492         .graft          = drr_graft_class,
493         .leaf           = drr_class_leaf,
494         .qlen_notify    = drr_qlen_notify,
495         .dump           = drr_dump_class,
496         .dump_stats     = drr_dump_class_stats,
497         .walk           = drr_walk,
498 };
499
500 static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
501         .cl_ops         = &drr_class_ops,
502         .id             = "drr",
503         .priv_size      = sizeof(struct drr_sched),
504         .enqueue        = drr_enqueue,
505         .dequeue        = drr_dequeue,
506         .peek           = qdisc_peek_dequeued,
507         .drop           = drr_drop,
508         .init           = drr_init_qdisc,
509         .reset          = drr_reset_qdisc,
510         .destroy        = drr_destroy_qdisc,
511         .owner          = THIS_MODULE,
512 };
513
514 static int __init drr_init(void)
515 {
516         return register_qdisc(&drr_qdisc_ops);
517 }
518
519 static void __exit drr_exit(void)
520 {
521         unregister_qdisc(&drr_qdisc_ops);
522 }
523
524 module_init(drr_init);
525 module_exit(drr_exit);
526 MODULE_LICENSE("GPL");