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1 | /* | |
2 | * net/sched/sch_htb.c Hierarchical token bucket, feed tree version | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: Martin Devera, <devik@cdi.cz> | |
10 | * | |
11 | * Credits (in time order) for older HTB versions: | |
12 | * Stef Coene <stef.coene@docum.org> | |
13 | * HTB support at LARTC mailing list | |
14 | * Ondrej Kraus, <krauso@barr.cz> | |
15 | * found missing INIT_QDISC(htb) | |
16 | * Vladimir Smelhaus, Aamer Akhter, Bert Hubert | |
17 | * helped a lot to locate nasty class stall bug | |
18 | * Andi Kleen, Jamal Hadi, Bert Hubert | |
19 | * code review and helpful comments on shaping | |
20 | * Tomasz Wrona, <tw@eter.tym.pl> | |
21 | * created test case so that I was able to fix nasty bug | |
22 | * Wilfried Weissmann | |
23 | * spotted bug in dequeue code and helped with fix | |
24 | * Jiri Fojtasek | |
25 | * fixed requeue routine | |
26 | * and many others. thanks. | |
27 | */ | |
28 | #include <linux/module.h> | |
29 | #include <linux/moduleparam.h> | |
30 | #include <linux/types.h> | |
31 | #include <linux/kernel.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/errno.h> | |
34 | #include <linux/skbuff.h> | |
35 | #include <linux/list.h> | |
36 | #include <linux/compiler.h> | |
37 | #include <linux/rbtree.h> | |
38 | #include <linux/workqueue.h> | |
39 | #include <linux/slab.h> | |
40 | #include <net/netlink.h> | |
41 | #include <net/sch_generic.h> | |
42 | #include <net/pkt_sched.h> | |
43 | ||
44 | /* HTB algorithm. | |
45 | Author: devik@cdi.cz | |
46 | ======================================================================== | |
47 | HTB is like TBF with multiple classes. It is also similar to CBQ because | |
48 | it allows to assign priority to each class in hierarchy. | |
49 | In fact it is another implementation of Floyd's formal sharing. | |
50 | ||
51 | Levels: | |
52 | Each class is assigned level. Leaf has ALWAYS level 0 and root | |
53 | classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level | |
54 | one less than their parent. | |
55 | */ | |
56 | ||
57 | static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */ | |
58 | #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */ | |
59 | ||
60 | #if HTB_VER >> 16 != TC_HTB_PROTOVER | |
61 | #error "Mismatched sch_htb.c and pkt_sch.h" | |
62 | #endif | |
63 | ||
64 | /* Module parameter and sysfs export */ | |
65 | module_param (htb_hysteresis, int, 0640); | |
66 | MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate"); | |
67 | ||
68 | static int htb_rate_est = 0; /* htb classes have a default rate estimator */ | |
69 | module_param(htb_rate_est, int, 0640); | |
70 | MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes"); | |
71 | ||
72 | /* used internaly to keep status of single class */ | |
73 | enum htb_cmode { | |
74 | HTB_CANT_SEND, /* class can't send and can't borrow */ | |
75 | HTB_MAY_BORROW, /* class can't send but may borrow */ | |
76 | HTB_CAN_SEND /* class can send */ | |
77 | }; | |
78 | ||
79 | struct htb_prio { | |
80 | union { | |
81 | struct rb_root row; | |
82 | struct rb_root feed; | |
83 | }; | |
84 | struct rb_node *ptr; | |
85 | /* When class changes from state 1->2 and disconnects from | |
86 | * parent's feed then we lost ptr value and start from the | |
87 | * first child again. Here we store classid of the | |
88 | * last valid ptr (used when ptr is NULL). | |
89 | */ | |
90 | u32 last_ptr_id; | |
91 | }; | |
92 | ||
93 | /* interior & leaf nodes; props specific to leaves are marked L: | |
94 | * To reduce false sharing, place mostly read fields at beginning, | |
95 | * and mostly written ones at the end. | |
96 | */ | |
97 | struct htb_class { | |
98 | struct Qdisc_class_common common; | |
99 | struct psched_ratecfg rate; | |
100 | struct psched_ratecfg ceil; | |
101 | s64 buffer, cbuffer;/* token bucket depth/rate */ | |
102 | s64 mbuffer; /* max wait time */ | |
103 | u32 prio; /* these two are used only by leaves... */ | |
104 | int quantum; /* but stored for parent-to-leaf return */ | |
105 | ||
106 | struct tcf_proto __rcu *filter_list; /* class attached filters */ | |
107 | int filter_cnt; | |
108 | int refcnt; /* usage count of this class */ | |
109 | ||
110 | int level; /* our level (see above) */ | |
111 | unsigned int children; | |
112 | struct htb_class *parent; /* parent class */ | |
113 | ||
114 | struct gnet_stats_rate_est64 rate_est; | |
115 | ||
116 | /* | |
117 | * Written often fields | |
118 | */ | |
119 | struct gnet_stats_basic_packed bstats; | |
120 | struct gnet_stats_queue qstats; | |
121 | struct tc_htb_xstats xstats; /* our special stats */ | |
122 | ||
123 | /* token bucket parameters */ | |
124 | s64 tokens, ctokens;/* current number of tokens */ | |
125 | s64 t_c; /* checkpoint time */ | |
126 | ||
127 | union { | |
128 | struct htb_class_leaf { | |
129 | struct list_head drop_list; | |
130 | int deficit[TC_HTB_MAXDEPTH]; | |
131 | struct Qdisc *q; | |
132 | } leaf; | |
133 | struct htb_class_inner { | |
134 | struct htb_prio clprio[TC_HTB_NUMPRIO]; | |
135 | } inner; | |
136 | } un; | |
137 | s64 pq_key; | |
138 | ||
139 | int prio_activity; /* for which prios are we active */ | |
140 | enum htb_cmode cmode; /* current mode of the class */ | |
141 | struct rb_node pq_node; /* node for event queue */ | |
142 | struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */ | |
143 | }; | |
144 | ||
145 | struct htb_level { | |
146 | struct rb_root wait_pq; | |
147 | struct htb_prio hprio[TC_HTB_NUMPRIO]; | |
148 | }; | |
149 | ||
150 | struct htb_sched { | |
151 | struct Qdisc_class_hash clhash; | |
152 | int defcls; /* class where unclassified flows go to */ | |
153 | int rate2quantum; /* quant = rate / rate2quantum */ | |
154 | ||
155 | /* filters for qdisc itself */ | |
156 | struct tcf_proto __rcu *filter_list; | |
157 | ||
158 | #define HTB_WARN_TOOMANYEVENTS 0x1 | |
159 | unsigned int warned; /* only one warning */ | |
160 | int direct_qlen; | |
161 | struct work_struct work; | |
162 | ||
163 | /* non shaped skbs; let them go directly thru */ | |
164 | struct sk_buff_head direct_queue; | |
165 | long direct_pkts; | |
166 | ||
167 | struct qdisc_watchdog watchdog; | |
168 | ||
169 | s64 now; /* cached dequeue time */ | |
170 | struct list_head drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */ | |
171 | ||
172 | /* time of nearest event per level (row) */ | |
173 | s64 near_ev_cache[TC_HTB_MAXDEPTH]; | |
174 | ||
175 | int row_mask[TC_HTB_MAXDEPTH]; | |
176 | ||
177 | struct htb_level hlevel[TC_HTB_MAXDEPTH]; | |
178 | }; | |
179 | ||
180 | /* find class in global hash table using given handle */ | |
181 | static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch) | |
182 | { | |
183 | struct htb_sched *q = qdisc_priv(sch); | |
184 | struct Qdisc_class_common *clc; | |
185 | ||
186 | clc = qdisc_class_find(&q->clhash, handle); | |
187 | if (clc == NULL) | |
188 | return NULL; | |
189 | return container_of(clc, struct htb_class, common); | |
190 | } | |
191 | ||
192 | /** | |
193 | * htb_classify - classify a packet into class | |
194 | * | |
195 | * It returns NULL if the packet should be dropped or -1 if the packet | |
196 | * should be passed directly thru. In all other cases leaf class is returned. | |
197 | * We allow direct class selection by classid in priority. The we examine | |
198 | * filters in qdisc and in inner nodes (if higher filter points to the inner | |
199 | * node). If we end up with classid MAJOR:0 we enqueue the skb into special | |
200 | * internal fifo (direct). These packets then go directly thru. If we still | |
201 | * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful | |
202 | * then finish and return direct queue. | |
203 | */ | |
204 | #define HTB_DIRECT ((struct htb_class *)-1L) | |
205 | ||
206 | static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, | |
207 | int *qerr) | |
208 | { | |
209 | struct htb_sched *q = qdisc_priv(sch); | |
210 | struct htb_class *cl; | |
211 | struct tcf_result res; | |
212 | struct tcf_proto *tcf; | |
213 | int result; | |
214 | ||
215 | /* allow to select class by setting skb->priority to valid classid; | |
216 | * note that nfmark can be used too by attaching filter fw with no | |
217 | * rules in it | |
218 | */ | |
219 | if (skb->priority == sch->handle) | |
220 | return HTB_DIRECT; /* X:0 (direct flow) selected */ | |
221 | cl = htb_find(skb->priority, sch); | |
222 | if (cl) { | |
223 | if (cl->level == 0) | |
224 | return cl; | |
225 | /* Start with inner filter chain if a non-leaf class is selected */ | |
226 | tcf = rcu_dereference_bh(cl->filter_list); | |
227 | } else { | |
228 | tcf = rcu_dereference_bh(q->filter_list); | |
229 | } | |
230 | ||
231 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; | |
232 | while (tcf && (result = tc_classify(skb, tcf, &res, false)) >= 0) { | |
233 | #ifdef CONFIG_NET_CLS_ACT | |
234 | switch (result) { | |
235 | case TC_ACT_QUEUED: | |
236 | case TC_ACT_STOLEN: | |
237 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; | |
238 | case TC_ACT_SHOT: | |
239 | return NULL; | |
240 | } | |
241 | #endif | |
242 | cl = (void *)res.class; | |
243 | if (!cl) { | |
244 | if (res.classid == sch->handle) | |
245 | return HTB_DIRECT; /* X:0 (direct flow) */ | |
246 | cl = htb_find(res.classid, sch); | |
247 | if (!cl) | |
248 | break; /* filter selected invalid classid */ | |
249 | } | |
250 | if (!cl->level) | |
251 | return cl; /* we hit leaf; return it */ | |
252 | ||
253 | /* we have got inner class; apply inner filter chain */ | |
254 | tcf = rcu_dereference_bh(cl->filter_list); | |
255 | } | |
256 | /* classification failed; try to use default class */ | |
257 | cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); | |
258 | if (!cl || cl->level) | |
259 | return HTB_DIRECT; /* bad default .. this is safe bet */ | |
260 | return cl; | |
261 | } | |
262 | ||
263 | /** | |
264 | * htb_add_to_id_tree - adds class to the round robin list | |
265 | * | |
266 | * Routine adds class to the list (actually tree) sorted by classid. | |
267 | * Make sure that class is not already on such list for given prio. | |
268 | */ | |
269 | static void htb_add_to_id_tree(struct rb_root *root, | |
270 | struct htb_class *cl, int prio) | |
271 | { | |
272 | struct rb_node **p = &root->rb_node, *parent = NULL; | |
273 | ||
274 | while (*p) { | |
275 | struct htb_class *c; | |
276 | parent = *p; | |
277 | c = rb_entry(parent, struct htb_class, node[prio]); | |
278 | ||
279 | if (cl->common.classid > c->common.classid) | |
280 | p = &parent->rb_right; | |
281 | else | |
282 | p = &parent->rb_left; | |
283 | } | |
284 | rb_link_node(&cl->node[prio], parent, p); | |
285 | rb_insert_color(&cl->node[prio], root); | |
286 | } | |
287 | ||
288 | /** | |
289 | * htb_add_to_wait_tree - adds class to the event queue with delay | |
290 | * | |
291 | * The class is added to priority event queue to indicate that class will | |
292 | * change its mode in cl->pq_key microseconds. Make sure that class is not | |
293 | * already in the queue. | |
294 | */ | |
295 | static void htb_add_to_wait_tree(struct htb_sched *q, | |
296 | struct htb_class *cl, s64 delay) | |
297 | { | |
298 | struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL; | |
299 | ||
300 | cl->pq_key = q->now + delay; | |
301 | if (cl->pq_key == q->now) | |
302 | cl->pq_key++; | |
303 | ||
304 | /* update the nearest event cache */ | |
305 | if (q->near_ev_cache[cl->level] > cl->pq_key) | |
306 | q->near_ev_cache[cl->level] = cl->pq_key; | |
307 | ||
308 | while (*p) { | |
309 | struct htb_class *c; | |
310 | parent = *p; | |
311 | c = rb_entry(parent, struct htb_class, pq_node); | |
312 | if (cl->pq_key >= c->pq_key) | |
313 | p = &parent->rb_right; | |
314 | else | |
315 | p = &parent->rb_left; | |
316 | } | |
317 | rb_link_node(&cl->pq_node, parent, p); | |
318 | rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq); | |
319 | } | |
320 | ||
321 | /** | |
322 | * htb_next_rb_node - finds next node in binary tree | |
323 | * | |
324 | * When we are past last key we return NULL. | |
325 | * Average complexity is 2 steps per call. | |
326 | */ | |
327 | static inline void htb_next_rb_node(struct rb_node **n) | |
328 | { | |
329 | *n = rb_next(*n); | |
330 | } | |
331 | ||
332 | /** | |
333 | * htb_add_class_to_row - add class to its row | |
334 | * | |
335 | * The class is added to row at priorities marked in mask. | |
336 | * It does nothing if mask == 0. | |
337 | */ | |
338 | static inline void htb_add_class_to_row(struct htb_sched *q, | |
339 | struct htb_class *cl, int mask) | |
340 | { | |
341 | q->row_mask[cl->level] |= mask; | |
342 | while (mask) { | |
343 | int prio = ffz(~mask); | |
344 | mask &= ~(1 << prio); | |
345 | htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio); | |
346 | } | |
347 | } | |
348 | ||
349 | /* If this triggers, it is a bug in this code, but it need not be fatal */ | |
350 | static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root) | |
351 | { | |
352 | if (RB_EMPTY_NODE(rb)) { | |
353 | WARN_ON(1); | |
354 | } else { | |
355 | rb_erase(rb, root); | |
356 | RB_CLEAR_NODE(rb); | |
357 | } | |
358 | } | |
359 | ||
360 | ||
361 | /** | |
362 | * htb_remove_class_from_row - removes class from its row | |
363 | * | |
364 | * The class is removed from row at priorities marked in mask. | |
365 | * It does nothing if mask == 0. | |
366 | */ | |
367 | static inline void htb_remove_class_from_row(struct htb_sched *q, | |
368 | struct htb_class *cl, int mask) | |
369 | { | |
370 | int m = 0; | |
371 | struct htb_level *hlevel = &q->hlevel[cl->level]; | |
372 | ||
373 | while (mask) { | |
374 | int prio = ffz(~mask); | |
375 | struct htb_prio *hprio = &hlevel->hprio[prio]; | |
376 | ||
377 | mask &= ~(1 << prio); | |
378 | if (hprio->ptr == cl->node + prio) | |
379 | htb_next_rb_node(&hprio->ptr); | |
380 | ||
381 | htb_safe_rb_erase(cl->node + prio, &hprio->row); | |
382 | if (!hprio->row.rb_node) | |
383 | m |= 1 << prio; | |
384 | } | |
385 | q->row_mask[cl->level] &= ~m; | |
386 | } | |
387 | ||
388 | /** | |
389 | * htb_activate_prios - creates active classe's feed chain | |
390 | * | |
391 | * The class is connected to ancestors and/or appropriate rows | |
392 | * for priorities it is participating on. cl->cmode must be new | |
393 | * (activated) mode. It does nothing if cl->prio_activity == 0. | |
394 | */ | |
395 | static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl) | |
396 | { | |
397 | struct htb_class *p = cl->parent; | |
398 | long m, mask = cl->prio_activity; | |
399 | ||
400 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { | |
401 | m = mask; | |
402 | while (m) { | |
403 | int prio = ffz(~m); | |
404 | m &= ~(1 << prio); | |
405 | ||
406 | if (p->un.inner.clprio[prio].feed.rb_node) | |
407 | /* parent already has its feed in use so that | |
408 | * reset bit in mask as parent is already ok | |
409 | */ | |
410 | mask &= ~(1 << prio); | |
411 | ||
412 | htb_add_to_id_tree(&p->un.inner.clprio[prio].feed, cl, prio); | |
413 | } | |
414 | p->prio_activity |= mask; | |
415 | cl = p; | |
416 | p = cl->parent; | |
417 | ||
418 | } | |
419 | if (cl->cmode == HTB_CAN_SEND && mask) | |
420 | htb_add_class_to_row(q, cl, mask); | |
421 | } | |
422 | ||
423 | /** | |
424 | * htb_deactivate_prios - remove class from feed chain | |
425 | * | |
426 | * cl->cmode must represent old mode (before deactivation). It does | |
427 | * nothing if cl->prio_activity == 0. Class is removed from all feed | |
428 | * chains and rows. | |
429 | */ | |
430 | static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl) | |
431 | { | |
432 | struct htb_class *p = cl->parent; | |
433 | long m, mask = cl->prio_activity; | |
434 | ||
435 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { | |
436 | m = mask; | |
437 | mask = 0; | |
438 | while (m) { | |
439 | int prio = ffz(~m); | |
440 | m &= ~(1 << prio); | |
441 | ||
442 | if (p->un.inner.clprio[prio].ptr == cl->node + prio) { | |
443 | /* we are removing child which is pointed to from | |
444 | * parent feed - forget the pointer but remember | |
445 | * classid | |
446 | */ | |
447 | p->un.inner.clprio[prio].last_ptr_id = cl->common.classid; | |
448 | p->un.inner.clprio[prio].ptr = NULL; | |
449 | } | |
450 | ||
451 | htb_safe_rb_erase(cl->node + prio, | |
452 | &p->un.inner.clprio[prio].feed); | |
453 | ||
454 | if (!p->un.inner.clprio[prio].feed.rb_node) | |
455 | mask |= 1 << prio; | |
456 | } | |
457 | ||
458 | p->prio_activity &= ~mask; | |
459 | cl = p; | |
460 | p = cl->parent; | |
461 | ||
462 | } | |
463 | if (cl->cmode == HTB_CAN_SEND && mask) | |
464 | htb_remove_class_from_row(q, cl, mask); | |
465 | } | |
466 | ||
467 | static inline s64 htb_lowater(const struct htb_class *cl) | |
468 | { | |
469 | if (htb_hysteresis) | |
470 | return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0; | |
471 | else | |
472 | return 0; | |
473 | } | |
474 | static inline s64 htb_hiwater(const struct htb_class *cl) | |
475 | { | |
476 | if (htb_hysteresis) | |
477 | return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0; | |
478 | else | |
479 | return 0; | |
480 | } | |
481 | ||
482 | ||
483 | /** | |
484 | * htb_class_mode - computes and returns current class mode | |
485 | * | |
486 | * It computes cl's mode at time cl->t_c+diff and returns it. If mode | |
487 | * is not HTB_CAN_SEND then cl->pq_key is updated to time difference | |
488 | * from now to time when cl will change its state. | |
489 | * Also it is worth to note that class mode doesn't change simply | |
490 | * at cl->{c,}tokens == 0 but there can rather be hysteresis of | |
491 | * 0 .. -cl->{c,}buffer range. It is meant to limit number of | |
492 | * mode transitions per time unit. The speed gain is about 1/6. | |
493 | */ | |
494 | static inline enum htb_cmode | |
495 | htb_class_mode(struct htb_class *cl, s64 *diff) | |
496 | { | |
497 | s64 toks; | |
498 | ||
499 | if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) { | |
500 | *diff = -toks; | |
501 | return HTB_CANT_SEND; | |
502 | } | |
503 | ||
504 | if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl)) | |
505 | return HTB_CAN_SEND; | |
506 | ||
507 | *diff = -toks; | |
508 | return HTB_MAY_BORROW; | |
509 | } | |
510 | ||
511 | /** | |
512 | * htb_change_class_mode - changes classe's mode | |
513 | * | |
514 | * This should be the only way how to change classe's mode under normal | |
515 | * cirsumstances. Routine will update feed lists linkage, change mode | |
516 | * and add class to the wait event queue if appropriate. New mode should | |
517 | * be different from old one and cl->pq_key has to be valid if changing | |
518 | * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree). | |
519 | */ | |
520 | static void | |
521 | htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff) | |
522 | { | |
523 | enum htb_cmode new_mode = htb_class_mode(cl, diff); | |
524 | ||
525 | if (new_mode == cl->cmode) | |
526 | return; | |
527 | ||
528 | if (cl->prio_activity) { /* not necessary: speed optimization */ | |
529 | if (cl->cmode != HTB_CANT_SEND) | |
530 | htb_deactivate_prios(q, cl); | |
531 | cl->cmode = new_mode; | |
532 | if (new_mode != HTB_CANT_SEND) | |
533 | htb_activate_prios(q, cl); | |
534 | } else | |
535 | cl->cmode = new_mode; | |
536 | } | |
537 | ||
538 | /** | |
539 | * htb_activate - inserts leaf cl into appropriate active feeds | |
540 | * | |
541 | * Routine learns (new) priority of leaf and activates feed chain | |
542 | * for the prio. It can be called on already active leaf safely. | |
543 | * It also adds leaf into droplist. | |
544 | */ | |
545 | static inline void htb_activate(struct htb_sched *q, struct htb_class *cl) | |
546 | { | |
547 | WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen); | |
548 | ||
549 | if (!cl->prio_activity) { | |
550 | cl->prio_activity = 1 << cl->prio; | |
551 | htb_activate_prios(q, cl); | |
552 | list_add_tail(&cl->un.leaf.drop_list, | |
553 | q->drops + cl->prio); | |
554 | } | |
555 | } | |
556 | ||
557 | /** | |
558 | * htb_deactivate - remove leaf cl from active feeds | |
559 | * | |
560 | * Make sure that leaf is active. In the other words it can't be called | |
561 | * with non-active leaf. It also removes class from the drop list. | |
562 | */ | |
563 | static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl) | |
564 | { | |
565 | WARN_ON(!cl->prio_activity); | |
566 | ||
567 | htb_deactivate_prios(q, cl); | |
568 | cl->prio_activity = 0; | |
569 | list_del_init(&cl->un.leaf.drop_list); | |
570 | } | |
571 | ||
572 | static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch) | |
573 | { | |
574 | int uninitialized_var(ret); | |
575 | struct htb_sched *q = qdisc_priv(sch); | |
576 | struct htb_class *cl = htb_classify(skb, sch, &ret); | |
577 | ||
578 | if (cl == HTB_DIRECT) { | |
579 | /* enqueue to helper queue */ | |
580 | if (q->direct_queue.qlen < q->direct_qlen) { | |
581 | __skb_queue_tail(&q->direct_queue, skb); | |
582 | q->direct_pkts++; | |
583 | } else { | |
584 | return qdisc_drop(skb, sch); | |
585 | } | |
586 | #ifdef CONFIG_NET_CLS_ACT | |
587 | } else if (!cl) { | |
588 | if (ret & __NET_XMIT_BYPASS) | |
589 | qdisc_qstats_drop(sch); | |
590 | kfree_skb(skb); | |
591 | return ret; | |
592 | #endif | |
593 | } else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q)) != NET_XMIT_SUCCESS) { | |
594 | if (net_xmit_drop_count(ret)) { | |
595 | qdisc_qstats_drop(sch); | |
596 | cl->qstats.drops++; | |
597 | } | |
598 | return ret; | |
599 | } else { | |
600 | htb_activate(q, cl); | |
601 | } | |
602 | ||
603 | qdisc_qstats_backlog_inc(sch, skb); | |
604 | sch->q.qlen++; | |
605 | return NET_XMIT_SUCCESS; | |
606 | } | |
607 | ||
608 | static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff) | |
609 | { | |
610 | s64 toks = diff + cl->tokens; | |
611 | ||
612 | if (toks > cl->buffer) | |
613 | toks = cl->buffer; | |
614 | toks -= (s64) psched_l2t_ns(&cl->rate, bytes); | |
615 | if (toks <= -cl->mbuffer) | |
616 | toks = 1 - cl->mbuffer; | |
617 | ||
618 | cl->tokens = toks; | |
619 | } | |
620 | ||
621 | static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff) | |
622 | { | |
623 | s64 toks = diff + cl->ctokens; | |
624 | ||
625 | if (toks > cl->cbuffer) | |
626 | toks = cl->cbuffer; | |
627 | toks -= (s64) psched_l2t_ns(&cl->ceil, bytes); | |
628 | if (toks <= -cl->mbuffer) | |
629 | toks = 1 - cl->mbuffer; | |
630 | ||
631 | cl->ctokens = toks; | |
632 | } | |
633 | ||
634 | /** | |
635 | * htb_charge_class - charges amount "bytes" to leaf and ancestors | |
636 | * | |
637 | * Routine assumes that packet "bytes" long was dequeued from leaf cl | |
638 | * borrowing from "level". It accounts bytes to ceil leaky bucket for | |
639 | * leaf and all ancestors and to rate bucket for ancestors at levels | |
640 | * "level" and higher. It also handles possible change of mode resulting | |
641 | * from the update. Note that mode can also increase here (MAY_BORROW to | |
642 | * CAN_SEND) because we can use more precise clock that event queue here. | |
643 | * In such case we remove class from event queue first. | |
644 | */ | |
645 | static void htb_charge_class(struct htb_sched *q, struct htb_class *cl, | |
646 | int level, struct sk_buff *skb) | |
647 | { | |
648 | int bytes = qdisc_pkt_len(skb); | |
649 | enum htb_cmode old_mode; | |
650 | s64 diff; | |
651 | ||
652 | while (cl) { | |
653 | diff = min_t(s64, q->now - cl->t_c, cl->mbuffer); | |
654 | if (cl->level >= level) { | |
655 | if (cl->level == level) | |
656 | cl->xstats.lends++; | |
657 | htb_accnt_tokens(cl, bytes, diff); | |
658 | } else { | |
659 | cl->xstats.borrows++; | |
660 | cl->tokens += diff; /* we moved t_c; update tokens */ | |
661 | } | |
662 | htb_accnt_ctokens(cl, bytes, diff); | |
663 | cl->t_c = q->now; | |
664 | ||
665 | old_mode = cl->cmode; | |
666 | diff = 0; | |
667 | htb_change_class_mode(q, cl, &diff); | |
668 | if (old_mode != cl->cmode) { | |
669 | if (old_mode != HTB_CAN_SEND) | |
670 | htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq); | |
671 | if (cl->cmode != HTB_CAN_SEND) | |
672 | htb_add_to_wait_tree(q, cl, diff); | |
673 | } | |
674 | ||
675 | /* update basic stats except for leaves which are already updated */ | |
676 | if (cl->level) | |
677 | bstats_update(&cl->bstats, skb); | |
678 | ||
679 | cl = cl->parent; | |
680 | } | |
681 | } | |
682 | ||
683 | /** | |
684 | * htb_do_events - make mode changes to classes at the level | |
685 | * | |
686 | * Scans event queue for pending events and applies them. Returns time of | |
687 | * next pending event (0 for no event in pq, q->now for too many events). | |
688 | * Note: Applied are events whose have cl->pq_key <= q->now. | |
689 | */ | |
690 | static s64 htb_do_events(struct htb_sched *q, const int level, | |
691 | unsigned long start) | |
692 | { | |
693 | /* don't run for longer than 2 jiffies; 2 is used instead of | |
694 | * 1 to simplify things when jiffy is going to be incremented | |
695 | * too soon | |
696 | */ | |
697 | unsigned long stop_at = start + 2; | |
698 | struct rb_root *wait_pq = &q->hlevel[level].wait_pq; | |
699 | ||
700 | while (time_before(jiffies, stop_at)) { | |
701 | struct htb_class *cl; | |
702 | s64 diff; | |
703 | struct rb_node *p = rb_first(wait_pq); | |
704 | ||
705 | if (!p) | |
706 | return 0; | |
707 | ||
708 | cl = rb_entry(p, struct htb_class, pq_node); | |
709 | if (cl->pq_key > q->now) | |
710 | return cl->pq_key; | |
711 | ||
712 | htb_safe_rb_erase(p, wait_pq); | |
713 | diff = min_t(s64, q->now - cl->t_c, cl->mbuffer); | |
714 | htb_change_class_mode(q, cl, &diff); | |
715 | if (cl->cmode != HTB_CAN_SEND) | |
716 | htb_add_to_wait_tree(q, cl, diff); | |
717 | } | |
718 | ||
719 | /* too much load - let's continue after a break for scheduling */ | |
720 | if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) { | |
721 | pr_warn("htb: too many events!\n"); | |
722 | q->warned |= HTB_WARN_TOOMANYEVENTS; | |
723 | } | |
724 | ||
725 | return q->now; | |
726 | } | |
727 | ||
728 | /* Returns class->node+prio from id-tree where classe's id is >= id. NULL | |
729 | * is no such one exists. | |
730 | */ | |
731 | static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n, | |
732 | u32 id) | |
733 | { | |
734 | struct rb_node *r = NULL; | |
735 | while (n) { | |
736 | struct htb_class *cl = | |
737 | rb_entry(n, struct htb_class, node[prio]); | |
738 | ||
739 | if (id > cl->common.classid) { | |
740 | n = n->rb_right; | |
741 | } else if (id < cl->common.classid) { | |
742 | r = n; | |
743 | n = n->rb_left; | |
744 | } else { | |
745 | return n; | |
746 | } | |
747 | } | |
748 | return r; | |
749 | } | |
750 | ||
751 | /** | |
752 | * htb_lookup_leaf - returns next leaf class in DRR order | |
753 | * | |
754 | * Find leaf where current feed pointers points to. | |
755 | */ | |
756 | static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio) | |
757 | { | |
758 | int i; | |
759 | struct { | |
760 | struct rb_node *root; | |
761 | struct rb_node **pptr; | |
762 | u32 *pid; | |
763 | } stk[TC_HTB_MAXDEPTH], *sp = stk; | |
764 | ||
765 | BUG_ON(!hprio->row.rb_node); | |
766 | sp->root = hprio->row.rb_node; | |
767 | sp->pptr = &hprio->ptr; | |
768 | sp->pid = &hprio->last_ptr_id; | |
769 | ||
770 | for (i = 0; i < 65535; i++) { | |
771 | if (!*sp->pptr && *sp->pid) { | |
772 | /* ptr was invalidated but id is valid - try to recover | |
773 | * the original or next ptr | |
774 | */ | |
775 | *sp->pptr = | |
776 | htb_id_find_next_upper(prio, sp->root, *sp->pid); | |
777 | } | |
778 | *sp->pid = 0; /* ptr is valid now so that remove this hint as it | |
779 | * can become out of date quickly | |
780 | */ | |
781 | if (!*sp->pptr) { /* we are at right end; rewind & go up */ | |
782 | *sp->pptr = sp->root; | |
783 | while ((*sp->pptr)->rb_left) | |
784 | *sp->pptr = (*sp->pptr)->rb_left; | |
785 | if (sp > stk) { | |
786 | sp--; | |
787 | if (!*sp->pptr) { | |
788 | WARN_ON(1); | |
789 | return NULL; | |
790 | } | |
791 | htb_next_rb_node(sp->pptr); | |
792 | } | |
793 | } else { | |
794 | struct htb_class *cl; | |
795 | struct htb_prio *clp; | |
796 | ||
797 | cl = rb_entry(*sp->pptr, struct htb_class, node[prio]); | |
798 | if (!cl->level) | |
799 | return cl; | |
800 | clp = &cl->un.inner.clprio[prio]; | |
801 | (++sp)->root = clp->feed.rb_node; | |
802 | sp->pptr = &clp->ptr; | |
803 | sp->pid = &clp->last_ptr_id; | |
804 | } | |
805 | } | |
806 | WARN_ON(1); | |
807 | return NULL; | |
808 | } | |
809 | ||
810 | /* dequeues packet at given priority and level; call only if | |
811 | * you are sure that there is active class at prio/level | |
812 | */ | |
813 | static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio, | |
814 | const int level) | |
815 | { | |
816 | struct sk_buff *skb = NULL; | |
817 | struct htb_class *cl, *start; | |
818 | struct htb_level *hlevel = &q->hlevel[level]; | |
819 | struct htb_prio *hprio = &hlevel->hprio[prio]; | |
820 | ||
821 | /* look initial class up in the row */ | |
822 | start = cl = htb_lookup_leaf(hprio, prio); | |
823 | ||
824 | do { | |
825 | next: | |
826 | if (unlikely(!cl)) | |
827 | return NULL; | |
828 | ||
829 | /* class can be empty - it is unlikely but can be true if leaf | |
830 | * qdisc drops packets in enqueue routine or if someone used | |
831 | * graft operation on the leaf since last dequeue; | |
832 | * simply deactivate and skip such class | |
833 | */ | |
834 | if (unlikely(cl->un.leaf.q->q.qlen == 0)) { | |
835 | struct htb_class *next; | |
836 | htb_deactivate(q, cl); | |
837 | ||
838 | /* row/level might become empty */ | |
839 | if ((q->row_mask[level] & (1 << prio)) == 0) | |
840 | return NULL; | |
841 | ||
842 | next = htb_lookup_leaf(hprio, prio); | |
843 | ||
844 | if (cl == start) /* fix start if we just deleted it */ | |
845 | start = next; | |
846 | cl = next; | |
847 | goto next; | |
848 | } | |
849 | ||
850 | skb = cl->un.leaf.q->dequeue(cl->un.leaf.q); | |
851 | if (likely(skb != NULL)) | |
852 | break; | |
853 | ||
854 | qdisc_warn_nonwc("htb", cl->un.leaf.q); | |
855 | htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr: | |
856 | &q->hlevel[0].hprio[prio].ptr); | |
857 | cl = htb_lookup_leaf(hprio, prio); | |
858 | ||
859 | } while (cl != start); | |
860 | ||
861 | if (likely(skb != NULL)) { | |
862 | bstats_update(&cl->bstats, skb); | |
863 | cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb); | |
864 | if (cl->un.leaf.deficit[level] < 0) { | |
865 | cl->un.leaf.deficit[level] += cl->quantum; | |
866 | htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr : | |
867 | &q->hlevel[0].hprio[prio].ptr); | |
868 | } | |
869 | /* this used to be after charge_class but this constelation | |
870 | * gives us slightly better performance | |
871 | */ | |
872 | if (!cl->un.leaf.q->q.qlen) | |
873 | htb_deactivate(q, cl); | |
874 | htb_charge_class(q, cl, level, skb); | |
875 | } | |
876 | return skb; | |
877 | } | |
878 | ||
879 | static struct sk_buff *htb_dequeue(struct Qdisc *sch) | |
880 | { | |
881 | struct sk_buff *skb; | |
882 | struct htb_sched *q = qdisc_priv(sch); | |
883 | int level; | |
884 | s64 next_event; | |
885 | unsigned long start_at; | |
886 | ||
887 | /* try to dequeue direct packets as high prio (!) to minimize cpu work */ | |
888 | skb = __skb_dequeue(&q->direct_queue); | |
889 | if (skb != NULL) { | |
890 | ok: | |
891 | qdisc_bstats_update(sch, skb); | |
892 | qdisc_unthrottled(sch); | |
893 | qdisc_qstats_backlog_dec(sch, skb); | |
894 | sch->q.qlen--; | |
895 | return skb; | |
896 | } | |
897 | ||
898 | if (!sch->q.qlen) | |
899 | goto fin; | |
900 | q->now = ktime_get_ns(); | |
901 | start_at = jiffies; | |
902 | ||
903 | next_event = q->now + 5LLU * NSEC_PER_SEC; | |
904 | ||
905 | for (level = 0; level < TC_HTB_MAXDEPTH; level++) { | |
906 | /* common case optimization - skip event handler quickly */ | |
907 | int m; | |
908 | s64 event = q->near_ev_cache[level]; | |
909 | ||
910 | if (q->now >= event) { | |
911 | event = htb_do_events(q, level, start_at); | |
912 | if (!event) | |
913 | event = q->now + NSEC_PER_SEC; | |
914 | q->near_ev_cache[level] = event; | |
915 | } | |
916 | ||
917 | if (next_event > event) | |
918 | next_event = event; | |
919 | ||
920 | m = ~q->row_mask[level]; | |
921 | while (m != (int)(-1)) { | |
922 | int prio = ffz(m); | |
923 | ||
924 | m |= 1 << prio; | |
925 | skb = htb_dequeue_tree(q, prio, level); | |
926 | if (likely(skb != NULL)) | |
927 | goto ok; | |
928 | } | |
929 | } | |
930 | qdisc_qstats_overlimit(sch); | |
931 | if (likely(next_event > q->now)) | |
932 | qdisc_watchdog_schedule_ns(&q->watchdog, next_event, true); | |
933 | else | |
934 | schedule_work(&q->work); | |
935 | fin: | |
936 | return skb; | |
937 | } | |
938 | ||
939 | /* reset all classes */ | |
940 | /* always caled under BH & queue lock */ | |
941 | static void htb_reset(struct Qdisc *sch) | |
942 | { | |
943 | struct htb_sched *q = qdisc_priv(sch); | |
944 | struct htb_class *cl; | |
945 | unsigned int i; | |
946 | ||
947 | for (i = 0; i < q->clhash.hashsize; i++) { | |
948 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { | |
949 | if (cl->level) | |
950 | memset(&cl->un.inner, 0, sizeof(cl->un.inner)); | |
951 | else { | |
952 | if (cl->un.leaf.q) | |
953 | qdisc_reset(cl->un.leaf.q); | |
954 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); | |
955 | } | |
956 | cl->prio_activity = 0; | |
957 | cl->cmode = HTB_CAN_SEND; | |
958 | } | |
959 | } | |
960 | qdisc_watchdog_cancel(&q->watchdog); | |
961 | __skb_queue_purge(&q->direct_queue); | |
962 | sch->q.qlen = 0; | |
963 | sch->qstats.backlog = 0; | |
964 | memset(q->hlevel, 0, sizeof(q->hlevel)); | |
965 | memset(q->row_mask, 0, sizeof(q->row_mask)); | |
966 | for (i = 0; i < TC_HTB_NUMPRIO; i++) | |
967 | INIT_LIST_HEAD(q->drops + i); | |
968 | } | |
969 | ||
970 | static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = { | |
971 | [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) }, | |
972 | [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) }, | |
973 | [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, | |
974 | [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, | |
975 | [TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 }, | |
976 | [TCA_HTB_RATE64] = { .type = NLA_U64 }, | |
977 | [TCA_HTB_CEIL64] = { .type = NLA_U64 }, | |
978 | }; | |
979 | ||
980 | static void htb_work_func(struct work_struct *work) | |
981 | { | |
982 | struct htb_sched *q = container_of(work, struct htb_sched, work); | |
983 | struct Qdisc *sch = q->watchdog.qdisc; | |
984 | ||
985 | __netif_schedule(qdisc_root(sch)); | |
986 | } | |
987 | ||
988 | static int htb_init(struct Qdisc *sch, struct nlattr *opt) | |
989 | { | |
990 | struct htb_sched *q = qdisc_priv(sch); | |
991 | struct nlattr *tb[TCA_HTB_MAX + 1]; | |
992 | struct tc_htb_glob *gopt; | |
993 | int err; | |
994 | int i; | |
995 | ||
996 | if (!opt) | |
997 | return -EINVAL; | |
998 | ||
999 | err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy); | |
1000 | if (err < 0) | |
1001 | return err; | |
1002 | ||
1003 | if (!tb[TCA_HTB_INIT]) | |
1004 | return -EINVAL; | |
1005 | ||
1006 | gopt = nla_data(tb[TCA_HTB_INIT]); | |
1007 | if (gopt->version != HTB_VER >> 16) | |
1008 | return -EINVAL; | |
1009 | ||
1010 | err = qdisc_class_hash_init(&q->clhash); | |
1011 | if (err < 0) | |
1012 | return err; | |
1013 | for (i = 0; i < TC_HTB_NUMPRIO; i++) | |
1014 | INIT_LIST_HEAD(q->drops + i); | |
1015 | ||
1016 | qdisc_watchdog_init(&q->watchdog, sch); | |
1017 | INIT_WORK(&q->work, htb_work_func); | |
1018 | __skb_queue_head_init(&q->direct_queue); | |
1019 | ||
1020 | if (tb[TCA_HTB_DIRECT_QLEN]) | |
1021 | q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]); | |
1022 | else | |
1023 | q->direct_qlen = qdisc_dev(sch)->tx_queue_len; | |
1024 | ||
1025 | if ((q->rate2quantum = gopt->rate2quantum) < 1) | |
1026 | q->rate2quantum = 1; | |
1027 | q->defcls = gopt->defcls; | |
1028 | ||
1029 | return 0; | |
1030 | } | |
1031 | ||
1032 | static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) | |
1033 | { | |
1034 | struct htb_sched *q = qdisc_priv(sch); | |
1035 | struct nlattr *nest; | |
1036 | struct tc_htb_glob gopt; | |
1037 | ||
1038 | /* Its safe to not acquire qdisc lock. As we hold RTNL, | |
1039 | * no change can happen on the qdisc parameters. | |
1040 | */ | |
1041 | ||
1042 | gopt.direct_pkts = q->direct_pkts; | |
1043 | gopt.version = HTB_VER; | |
1044 | gopt.rate2quantum = q->rate2quantum; | |
1045 | gopt.defcls = q->defcls; | |
1046 | gopt.debug = 0; | |
1047 | ||
1048 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
1049 | if (nest == NULL) | |
1050 | goto nla_put_failure; | |
1051 | if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) || | |
1052 | nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen)) | |
1053 | goto nla_put_failure; | |
1054 | ||
1055 | return nla_nest_end(skb, nest); | |
1056 | ||
1057 | nla_put_failure: | |
1058 | nla_nest_cancel(skb, nest); | |
1059 | return -1; | |
1060 | } | |
1061 | ||
1062 | static int htb_dump_class(struct Qdisc *sch, unsigned long arg, | |
1063 | struct sk_buff *skb, struct tcmsg *tcm) | |
1064 | { | |
1065 | struct htb_class *cl = (struct htb_class *)arg; | |
1066 | struct nlattr *nest; | |
1067 | struct tc_htb_opt opt; | |
1068 | ||
1069 | /* Its safe to not acquire qdisc lock. As we hold RTNL, | |
1070 | * no change can happen on the class parameters. | |
1071 | */ | |
1072 | tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT; | |
1073 | tcm->tcm_handle = cl->common.classid; | |
1074 | if (!cl->level && cl->un.leaf.q) | |
1075 | tcm->tcm_info = cl->un.leaf.q->handle; | |
1076 | ||
1077 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
1078 | if (nest == NULL) | |
1079 | goto nla_put_failure; | |
1080 | ||
1081 | memset(&opt, 0, sizeof(opt)); | |
1082 | ||
1083 | psched_ratecfg_getrate(&opt.rate, &cl->rate); | |
1084 | opt.buffer = PSCHED_NS2TICKS(cl->buffer); | |
1085 | psched_ratecfg_getrate(&opt.ceil, &cl->ceil); | |
1086 | opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer); | |
1087 | opt.quantum = cl->quantum; | |
1088 | opt.prio = cl->prio; | |
1089 | opt.level = cl->level; | |
1090 | if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt)) | |
1091 | goto nla_put_failure; | |
1092 | if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) && | |
1093 | nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps, | |
1094 | TCA_HTB_PAD)) | |
1095 | goto nla_put_failure; | |
1096 | if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) && | |
1097 | nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps, | |
1098 | TCA_HTB_PAD)) | |
1099 | goto nla_put_failure; | |
1100 | ||
1101 | return nla_nest_end(skb, nest); | |
1102 | ||
1103 | nla_put_failure: | |
1104 | nla_nest_cancel(skb, nest); | |
1105 | return -1; | |
1106 | } | |
1107 | ||
1108 | static int | |
1109 | htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) | |
1110 | { | |
1111 | struct htb_class *cl = (struct htb_class *)arg; | |
1112 | __u32 qlen = 0; | |
1113 | ||
1114 | if (!cl->level && cl->un.leaf.q) | |
1115 | qlen = cl->un.leaf.q->q.qlen; | |
1116 | cl->xstats.tokens = PSCHED_NS2TICKS(cl->tokens); | |
1117 | cl->xstats.ctokens = PSCHED_NS2TICKS(cl->ctokens); | |
1118 | ||
1119 | if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), | |
1120 | d, NULL, &cl->bstats) < 0 || | |
1121 | gnet_stats_copy_rate_est(d, NULL, &cl->rate_est) < 0 || | |
1122 | gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0) | |
1123 | return -1; | |
1124 | ||
1125 | return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats)); | |
1126 | } | |
1127 | ||
1128 | static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
1129 | struct Qdisc **old) | |
1130 | { | |
1131 | struct htb_class *cl = (struct htb_class *)arg; | |
1132 | ||
1133 | if (cl->level) | |
1134 | return -EINVAL; | |
1135 | if (new == NULL && | |
1136 | (new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, | |
1137 | cl->common.classid)) == NULL) | |
1138 | return -ENOBUFS; | |
1139 | ||
1140 | *old = qdisc_replace(sch, new, &cl->un.leaf.q); | |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg) | |
1145 | { | |
1146 | struct htb_class *cl = (struct htb_class *)arg; | |
1147 | return !cl->level ? cl->un.leaf.q : NULL; | |
1148 | } | |
1149 | ||
1150 | static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg) | |
1151 | { | |
1152 | struct htb_class *cl = (struct htb_class *)arg; | |
1153 | ||
1154 | if (cl->un.leaf.q->q.qlen == 0) | |
1155 | htb_deactivate(qdisc_priv(sch), cl); | |
1156 | } | |
1157 | ||
1158 | static unsigned long htb_get(struct Qdisc *sch, u32 classid) | |
1159 | { | |
1160 | struct htb_class *cl = htb_find(classid, sch); | |
1161 | if (cl) | |
1162 | cl->refcnt++; | |
1163 | return (unsigned long)cl; | |
1164 | } | |
1165 | ||
1166 | static inline int htb_parent_last_child(struct htb_class *cl) | |
1167 | { | |
1168 | if (!cl->parent) | |
1169 | /* the root class */ | |
1170 | return 0; | |
1171 | if (cl->parent->children > 1) | |
1172 | /* not the last child */ | |
1173 | return 0; | |
1174 | return 1; | |
1175 | } | |
1176 | ||
1177 | static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, | |
1178 | struct Qdisc *new_q) | |
1179 | { | |
1180 | struct htb_class *parent = cl->parent; | |
1181 | ||
1182 | WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity); | |
1183 | ||
1184 | if (parent->cmode != HTB_CAN_SEND) | |
1185 | htb_safe_rb_erase(&parent->pq_node, | |
1186 | &q->hlevel[parent->level].wait_pq); | |
1187 | ||
1188 | parent->level = 0; | |
1189 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); | |
1190 | INIT_LIST_HEAD(&parent->un.leaf.drop_list); | |
1191 | parent->un.leaf.q = new_q ? new_q : &noop_qdisc; | |
1192 | parent->tokens = parent->buffer; | |
1193 | parent->ctokens = parent->cbuffer; | |
1194 | parent->t_c = ktime_get_ns(); | |
1195 | parent->cmode = HTB_CAN_SEND; | |
1196 | } | |
1197 | ||
1198 | static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl) | |
1199 | { | |
1200 | if (!cl->level) { | |
1201 | WARN_ON(!cl->un.leaf.q); | |
1202 | qdisc_destroy(cl->un.leaf.q); | |
1203 | } | |
1204 | gen_kill_estimator(&cl->bstats, &cl->rate_est); | |
1205 | tcf_destroy_chain(&cl->filter_list); | |
1206 | kfree(cl); | |
1207 | } | |
1208 | ||
1209 | static void htb_destroy(struct Qdisc *sch) | |
1210 | { | |
1211 | struct htb_sched *q = qdisc_priv(sch); | |
1212 | struct hlist_node *next; | |
1213 | struct htb_class *cl; | |
1214 | unsigned int i; | |
1215 | ||
1216 | cancel_work_sync(&q->work); | |
1217 | qdisc_watchdog_cancel(&q->watchdog); | |
1218 | /* This line used to be after htb_destroy_class call below | |
1219 | * and surprisingly it worked in 2.4. But it must precede it | |
1220 | * because filter need its target class alive to be able to call | |
1221 | * unbind_filter on it (without Oops). | |
1222 | */ | |
1223 | tcf_destroy_chain(&q->filter_list); | |
1224 | ||
1225 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1226 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) | |
1227 | tcf_destroy_chain(&cl->filter_list); | |
1228 | } | |
1229 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1230 | hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i], | |
1231 | common.hnode) | |
1232 | htb_destroy_class(sch, cl); | |
1233 | } | |
1234 | qdisc_class_hash_destroy(&q->clhash); | |
1235 | __skb_queue_purge(&q->direct_queue); | |
1236 | } | |
1237 | ||
1238 | static int htb_delete(struct Qdisc *sch, unsigned long arg) | |
1239 | { | |
1240 | struct htb_sched *q = qdisc_priv(sch); | |
1241 | struct htb_class *cl = (struct htb_class *)arg; | |
1242 | struct Qdisc *new_q = NULL; | |
1243 | int last_child = 0; | |
1244 | ||
1245 | /* TODO: why don't allow to delete subtree ? references ? does | |
1246 | * tc subsys guarantee us that in htb_destroy it holds no class | |
1247 | * refs so that we can remove children safely there ? | |
1248 | */ | |
1249 | if (cl->children || cl->filter_cnt) | |
1250 | return -EBUSY; | |
1251 | ||
1252 | if (!cl->level && htb_parent_last_child(cl)) { | |
1253 | new_q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, | |
1254 | cl->parent->common.classid); | |
1255 | last_child = 1; | |
1256 | } | |
1257 | ||
1258 | sch_tree_lock(sch); | |
1259 | ||
1260 | if (!cl->level) { | |
1261 | unsigned int qlen = cl->un.leaf.q->q.qlen; | |
1262 | unsigned int backlog = cl->un.leaf.q->qstats.backlog; | |
1263 | ||
1264 | qdisc_reset(cl->un.leaf.q); | |
1265 | qdisc_tree_reduce_backlog(cl->un.leaf.q, qlen, backlog); | |
1266 | } | |
1267 | ||
1268 | /* delete from hash and active; remainder in destroy_class */ | |
1269 | qdisc_class_hash_remove(&q->clhash, &cl->common); | |
1270 | if (cl->parent) | |
1271 | cl->parent->children--; | |
1272 | ||
1273 | if (cl->prio_activity) | |
1274 | htb_deactivate(q, cl); | |
1275 | ||
1276 | if (cl->cmode != HTB_CAN_SEND) | |
1277 | htb_safe_rb_erase(&cl->pq_node, | |
1278 | &q->hlevel[cl->level].wait_pq); | |
1279 | ||
1280 | if (last_child) | |
1281 | htb_parent_to_leaf(q, cl, new_q); | |
1282 | ||
1283 | BUG_ON(--cl->refcnt == 0); | |
1284 | /* | |
1285 | * This shouldn't happen: we "hold" one cops->get() when called | |
1286 | * from tc_ctl_tclass; the destroy method is done from cops->put(). | |
1287 | */ | |
1288 | ||
1289 | sch_tree_unlock(sch); | |
1290 | return 0; | |
1291 | } | |
1292 | ||
1293 | static void htb_put(struct Qdisc *sch, unsigned long arg) | |
1294 | { | |
1295 | struct htb_class *cl = (struct htb_class *)arg; | |
1296 | ||
1297 | if (--cl->refcnt == 0) | |
1298 | htb_destroy_class(sch, cl); | |
1299 | } | |
1300 | ||
1301 | static int htb_change_class(struct Qdisc *sch, u32 classid, | |
1302 | u32 parentid, struct nlattr **tca, | |
1303 | unsigned long *arg) | |
1304 | { | |
1305 | int err = -EINVAL; | |
1306 | struct htb_sched *q = qdisc_priv(sch); | |
1307 | struct htb_class *cl = (struct htb_class *)*arg, *parent; | |
1308 | struct nlattr *opt = tca[TCA_OPTIONS]; | |
1309 | struct nlattr *tb[TCA_HTB_MAX + 1]; | |
1310 | struct tc_htb_opt *hopt; | |
1311 | u64 rate64, ceil64; | |
1312 | ||
1313 | /* extract all subattrs from opt attr */ | |
1314 | if (!opt) | |
1315 | goto failure; | |
1316 | ||
1317 | err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy); | |
1318 | if (err < 0) | |
1319 | goto failure; | |
1320 | ||
1321 | err = -EINVAL; | |
1322 | if (tb[TCA_HTB_PARMS] == NULL) | |
1323 | goto failure; | |
1324 | ||
1325 | parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch); | |
1326 | ||
1327 | hopt = nla_data(tb[TCA_HTB_PARMS]); | |
1328 | if (!hopt->rate.rate || !hopt->ceil.rate) | |
1329 | goto failure; | |
1330 | ||
1331 | /* Keeping backward compatible with rate_table based iproute2 tc */ | |
1332 | if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE) | |
1333 | qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB])); | |
1334 | ||
1335 | if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE) | |
1336 | qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB])); | |
1337 | ||
1338 | if (!cl) { /* new class */ | |
1339 | struct Qdisc *new_q; | |
1340 | int prio; | |
1341 | struct { | |
1342 | struct nlattr nla; | |
1343 | struct gnet_estimator opt; | |
1344 | } est = { | |
1345 | .nla = { | |
1346 | .nla_len = nla_attr_size(sizeof(est.opt)), | |
1347 | .nla_type = TCA_RATE, | |
1348 | }, | |
1349 | .opt = { | |
1350 | /* 4s interval, 16s averaging constant */ | |
1351 | .interval = 2, | |
1352 | .ewma_log = 2, | |
1353 | }, | |
1354 | }; | |
1355 | ||
1356 | /* check for valid classid */ | |
1357 | if (!classid || TC_H_MAJ(classid ^ sch->handle) || | |
1358 | htb_find(classid, sch)) | |
1359 | goto failure; | |
1360 | ||
1361 | /* check maximal depth */ | |
1362 | if (parent && parent->parent && parent->parent->level < 2) { | |
1363 | pr_err("htb: tree is too deep\n"); | |
1364 | goto failure; | |
1365 | } | |
1366 | err = -ENOBUFS; | |
1367 | cl = kzalloc(sizeof(*cl), GFP_KERNEL); | |
1368 | if (!cl) | |
1369 | goto failure; | |
1370 | ||
1371 | if (htb_rate_est || tca[TCA_RATE]) { | |
1372 | err = gen_new_estimator(&cl->bstats, NULL, | |
1373 | &cl->rate_est, | |
1374 | NULL, | |
1375 | qdisc_root_sleeping_running(sch), | |
1376 | tca[TCA_RATE] ? : &est.nla); | |
1377 | if (err) { | |
1378 | kfree(cl); | |
1379 | goto failure; | |
1380 | } | |
1381 | } | |
1382 | ||
1383 | cl->refcnt = 1; | |
1384 | cl->children = 0; | |
1385 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); | |
1386 | RB_CLEAR_NODE(&cl->pq_node); | |
1387 | ||
1388 | for (prio = 0; prio < TC_HTB_NUMPRIO; prio++) | |
1389 | RB_CLEAR_NODE(&cl->node[prio]); | |
1390 | ||
1391 | /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL) | |
1392 | * so that can't be used inside of sch_tree_lock | |
1393 | * -- thanks to Karlis Peisenieks | |
1394 | */ | |
1395 | new_q = qdisc_create_dflt(sch->dev_queue, | |
1396 | &pfifo_qdisc_ops, classid); | |
1397 | sch_tree_lock(sch); | |
1398 | if (parent && !parent->level) { | |
1399 | unsigned int qlen = parent->un.leaf.q->q.qlen; | |
1400 | unsigned int backlog = parent->un.leaf.q->qstats.backlog; | |
1401 | ||
1402 | /* turn parent into inner node */ | |
1403 | qdisc_reset(parent->un.leaf.q); | |
1404 | qdisc_tree_reduce_backlog(parent->un.leaf.q, qlen, backlog); | |
1405 | qdisc_destroy(parent->un.leaf.q); | |
1406 | if (parent->prio_activity) | |
1407 | htb_deactivate(q, parent); | |
1408 | ||
1409 | /* remove from evt list because of level change */ | |
1410 | if (parent->cmode != HTB_CAN_SEND) { | |
1411 | htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq); | |
1412 | parent->cmode = HTB_CAN_SEND; | |
1413 | } | |
1414 | parent->level = (parent->parent ? parent->parent->level | |
1415 | : TC_HTB_MAXDEPTH) - 1; | |
1416 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); | |
1417 | } | |
1418 | /* leaf (we) needs elementary qdisc */ | |
1419 | cl->un.leaf.q = new_q ? new_q : &noop_qdisc; | |
1420 | ||
1421 | cl->common.classid = classid; | |
1422 | cl->parent = parent; | |
1423 | ||
1424 | /* set class to be in HTB_CAN_SEND state */ | |
1425 | cl->tokens = PSCHED_TICKS2NS(hopt->buffer); | |
1426 | cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer); | |
1427 | cl->mbuffer = 60ULL * NSEC_PER_SEC; /* 1min */ | |
1428 | cl->t_c = ktime_get_ns(); | |
1429 | cl->cmode = HTB_CAN_SEND; | |
1430 | ||
1431 | /* attach to the hash list and parent's family */ | |
1432 | qdisc_class_hash_insert(&q->clhash, &cl->common); | |
1433 | if (parent) | |
1434 | parent->children++; | |
1435 | } else { | |
1436 | if (tca[TCA_RATE]) { | |
1437 | err = gen_replace_estimator(&cl->bstats, NULL, | |
1438 | &cl->rate_est, | |
1439 | NULL, | |
1440 | qdisc_root_sleeping_running(sch), | |
1441 | tca[TCA_RATE]); | |
1442 | if (err) | |
1443 | return err; | |
1444 | } | |
1445 | sch_tree_lock(sch); | |
1446 | } | |
1447 | ||
1448 | rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0; | |
1449 | ||
1450 | ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0; | |
1451 | ||
1452 | psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64); | |
1453 | psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64); | |
1454 | ||
1455 | /* it used to be a nasty bug here, we have to check that node | |
1456 | * is really leaf before changing cl->un.leaf ! | |
1457 | */ | |
1458 | if (!cl->level) { | |
1459 | u64 quantum = cl->rate.rate_bytes_ps; | |
1460 | ||
1461 | do_div(quantum, q->rate2quantum); | |
1462 | cl->quantum = min_t(u64, quantum, INT_MAX); | |
1463 | ||
1464 | if (!hopt->quantum && cl->quantum < 1000) { | |
1465 | pr_warn("HTB: quantum of class %X is small. Consider r2q change.\n", | |
1466 | cl->common.classid); | |
1467 | cl->quantum = 1000; | |
1468 | } | |
1469 | if (!hopt->quantum && cl->quantum > 200000) { | |
1470 | pr_warn("HTB: quantum of class %X is big. Consider r2q change.\n", | |
1471 | cl->common.classid); | |
1472 | cl->quantum = 200000; | |
1473 | } | |
1474 | if (hopt->quantum) | |
1475 | cl->quantum = hopt->quantum; | |
1476 | if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO) | |
1477 | cl->prio = TC_HTB_NUMPRIO - 1; | |
1478 | } | |
1479 | ||
1480 | cl->buffer = PSCHED_TICKS2NS(hopt->buffer); | |
1481 | cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer); | |
1482 | ||
1483 | sch_tree_unlock(sch); | |
1484 | ||
1485 | qdisc_class_hash_grow(sch, &q->clhash); | |
1486 | ||
1487 | *arg = (unsigned long)cl; | |
1488 | return 0; | |
1489 | ||
1490 | failure: | |
1491 | return err; | |
1492 | } | |
1493 | ||
1494 | static struct tcf_proto __rcu **htb_find_tcf(struct Qdisc *sch, | |
1495 | unsigned long arg) | |
1496 | { | |
1497 | struct htb_sched *q = qdisc_priv(sch); | |
1498 | struct htb_class *cl = (struct htb_class *)arg; | |
1499 | struct tcf_proto __rcu **fl = cl ? &cl->filter_list : &q->filter_list; | |
1500 | ||
1501 | return fl; | |
1502 | } | |
1503 | ||
1504 | static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent, | |
1505 | u32 classid) | |
1506 | { | |
1507 | struct htb_class *cl = htb_find(classid, sch); | |
1508 | ||
1509 | /*if (cl && !cl->level) return 0; | |
1510 | * The line above used to be there to prevent attaching filters to | |
1511 | * leaves. But at least tc_index filter uses this just to get class | |
1512 | * for other reasons so that we have to allow for it. | |
1513 | * ---- | |
1514 | * 19.6.2002 As Werner explained it is ok - bind filter is just | |
1515 | * another way to "lock" the class - unlike "get" this lock can | |
1516 | * be broken by class during destroy IIUC. | |
1517 | */ | |
1518 | if (cl) | |
1519 | cl->filter_cnt++; | |
1520 | return (unsigned long)cl; | |
1521 | } | |
1522 | ||
1523 | static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg) | |
1524 | { | |
1525 | struct htb_class *cl = (struct htb_class *)arg; | |
1526 | ||
1527 | if (cl) | |
1528 | cl->filter_cnt--; | |
1529 | } | |
1530 | ||
1531 | static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
1532 | { | |
1533 | struct htb_sched *q = qdisc_priv(sch); | |
1534 | struct htb_class *cl; | |
1535 | unsigned int i; | |
1536 | ||
1537 | if (arg->stop) | |
1538 | return; | |
1539 | ||
1540 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1541 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { | |
1542 | if (arg->count < arg->skip) { | |
1543 | arg->count++; | |
1544 | continue; | |
1545 | } | |
1546 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { | |
1547 | arg->stop = 1; | |
1548 | return; | |
1549 | } | |
1550 | arg->count++; | |
1551 | } | |
1552 | } | |
1553 | } | |
1554 | ||
1555 | static const struct Qdisc_class_ops htb_class_ops = { | |
1556 | .graft = htb_graft, | |
1557 | .leaf = htb_leaf, | |
1558 | .qlen_notify = htb_qlen_notify, | |
1559 | .get = htb_get, | |
1560 | .put = htb_put, | |
1561 | .change = htb_change_class, | |
1562 | .delete = htb_delete, | |
1563 | .walk = htb_walk, | |
1564 | .tcf_chain = htb_find_tcf, | |
1565 | .bind_tcf = htb_bind_filter, | |
1566 | .unbind_tcf = htb_unbind_filter, | |
1567 | .dump = htb_dump_class, | |
1568 | .dump_stats = htb_dump_class_stats, | |
1569 | }; | |
1570 | ||
1571 | static struct Qdisc_ops htb_qdisc_ops __read_mostly = { | |
1572 | .cl_ops = &htb_class_ops, | |
1573 | .id = "htb", | |
1574 | .priv_size = sizeof(struct htb_sched), | |
1575 | .enqueue = htb_enqueue, | |
1576 | .dequeue = htb_dequeue, | |
1577 | .peek = qdisc_peek_dequeued, | |
1578 | .init = htb_init, | |
1579 | .reset = htb_reset, | |
1580 | .destroy = htb_destroy, | |
1581 | .dump = htb_dump, | |
1582 | .owner = THIS_MODULE, | |
1583 | }; | |
1584 | ||
1585 | static int __init htb_module_init(void) | |
1586 | { | |
1587 | return register_qdisc(&htb_qdisc_ops); | |
1588 | } | |
1589 | static void __exit htb_module_exit(void) | |
1590 | { | |
1591 | unregister_qdisc(&htb_qdisc_ops); | |
1592 | } | |
1593 | ||
1594 | module_init(htb_module_init) | |
1595 | module_exit(htb_module_exit) | |
1596 | MODULE_LICENSE("GPL"); |