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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 | #include <net/pkt_cls.h> | |
44 | ||
45 | /* HTB algorithm. | |
46 | Author: devik@cdi.cz | |
47 | ======================================================================== | |
48 | HTB is like TBF with multiple classes. It is also similar to CBQ because | |
49 | it allows to assign priority to each class in hierarchy. | |
50 | In fact it is another implementation of Floyd's formal sharing. | |
51 | ||
52 | Levels: | |
53 | Each class is assigned level. Leaf has ALWAYS level 0 and root | |
54 | classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level | |
55 | one less than their parent. | |
56 | */ | |
57 | ||
58 | static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */ | |
59 | #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */ | |
60 | ||
61 | #if HTB_VER >> 16 != TC_HTB_PROTOVER | |
62 | #error "Mismatched sch_htb.c and pkt_sch.h" | |
63 | #endif | |
64 | ||
65 | /* Module parameter and sysfs export */ | |
66 | module_param (htb_hysteresis, int, 0640); | |
67 | MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate"); | |
68 | ||
69 | static int htb_rate_est = 0; /* htb classes have a default rate estimator */ | |
70 | module_param(htb_rate_est, int, 0640); | |
71 | MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes"); | |
72 | ||
73 | /* used internaly to keep status of single class */ | |
74 | enum htb_cmode { | |
75 | HTB_CANT_SEND, /* class can't send and can't borrow */ | |
76 | HTB_MAY_BORROW, /* class can't send but may borrow */ | |
77 | HTB_CAN_SEND /* class can send */ | |
78 | }; | |
79 | ||
80 | struct htb_prio { | |
81 | union { | |
82 | struct rb_root row; | |
83 | struct rb_root feed; | |
84 | }; | |
85 | struct rb_node *ptr; | |
86 | /* When class changes from state 1->2 and disconnects from | |
87 | * parent's feed then we lost ptr value and start from the | |
88 | * first child again. Here we store classid of the | |
89 | * last valid ptr (used when ptr is NULL). | |
90 | */ | |
91 | u32 last_ptr_id; | |
92 | }; | |
93 | ||
94 | /* interior & leaf nodes; props specific to leaves are marked L: | |
95 | * To reduce false sharing, place mostly read fields at beginning, | |
96 | * and mostly written ones at the end. | |
97 | */ | |
98 | struct htb_class { | |
99 | struct Qdisc_class_common common; | |
100 | struct psched_ratecfg rate; | |
101 | struct psched_ratecfg ceil; | |
102 | s64 buffer, cbuffer;/* token bucket depth/rate */ | |
103 | s64 mbuffer; /* max wait time */ | |
104 | u32 prio; /* these two are used only by leaves... */ | |
105 | int quantum; /* but stored for parent-to-leaf return */ | |
106 | ||
107 | struct tcf_proto __rcu *filter_list; /* class attached filters */ | |
108 | struct tcf_block *block; | |
109 | int filter_cnt; | |
110 | int refcnt; /* usage count of this class */ | |
111 | ||
112 | int level; /* our level (see above) */ | |
113 | unsigned int children; | |
114 | struct htb_class *parent; /* parent class */ | |
115 | ||
116 | struct net_rate_estimator __rcu *rate_est; | |
117 | ||
118 | /* | |
119 | * Written often fields | |
120 | */ | |
121 | struct gnet_stats_basic_packed bstats; | |
122 | struct tc_htb_xstats xstats; /* our special stats */ | |
123 | ||
124 | /* token bucket parameters */ | |
125 | s64 tokens, ctokens;/* current number of tokens */ | |
126 | s64 t_c; /* checkpoint time */ | |
127 | ||
128 | union { | |
129 | struct htb_class_leaf { | |
130 | struct list_head drop_list; | |
131 | int deficit[TC_HTB_MAXDEPTH]; | |
132 | struct Qdisc *q; | |
133 | } leaf; | |
134 | struct htb_class_inner { | |
135 | struct htb_prio clprio[TC_HTB_NUMPRIO]; | |
136 | } inner; | |
137 | } un; | |
138 | s64 pq_key; | |
139 | ||
140 | int prio_activity; /* for which prios are we active */ | |
141 | enum htb_cmode cmode; /* current mode of the class */ | |
142 | struct rb_node pq_node; /* node for event queue */ | |
143 | struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */ | |
144 | ||
145 | unsigned int drops ____cacheline_aligned_in_smp; | |
146 | }; | |
147 | ||
148 | struct htb_level { | |
149 | struct rb_root wait_pq; | |
150 | struct htb_prio hprio[TC_HTB_NUMPRIO]; | |
151 | }; | |
152 | ||
153 | struct htb_sched { | |
154 | struct Qdisc_class_hash clhash; | |
155 | int defcls; /* class where unclassified flows go to */ | |
156 | int rate2quantum; /* quant = rate / rate2quantum */ | |
157 | ||
158 | /* filters for qdisc itself */ | |
159 | struct tcf_proto __rcu *filter_list; | |
160 | struct tcf_block *block; | |
161 | ||
162 | #define HTB_WARN_TOOMANYEVENTS 0x1 | |
163 | unsigned int warned; /* only one warning */ | |
164 | int direct_qlen; | |
165 | struct work_struct work; | |
166 | ||
167 | /* non shaped skbs; let them go directly thru */ | |
168 | struct qdisc_skb_head direct_queue; | |
169 | long direct_pkts; | |
170 | ||
171 | struct qdisc_watchdog watchdog; | |
172 | ||
173 | s64 now; /* cached dequeue time */ | |
174 | struct list_head drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */ | |
175 | ||
176 | /* time of nearest event per level (row) */ | |
177 | s64 near_ev_cache[TC_HTB_MAXDEPTH]; | |
178 | ||
179 | int row_mask[TC_HTB_MAXDEPTH]; | |
180 | ||
181 | struct htb_level hlevel[TC_HTB_MAXDEPTH]; | |
182 | }; | |
183 | ||
184 | /* find class in global hash table using given handle */ | |
185 | static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch) | |
186 | { | |
187 | struct htb_sched *q = qdisc_priv(sch); | |
188 | struct Qdisc_class_common *clc; | |
189 | ||
190 | clc = qdisc_class_find(&q->clhash, handle); | |
191 | if (clc == NULL) | |
192 | return NULL; | |
193 | return container_of(clc, struct htb_class, common); | |
194 | } | |
195 | ||
196 | /** | |
197 | * htb_classify - classify a packet into class | |
198 | * | |
199 | * It returns NULL if the packet should be dropped or -1 if the packet | |
200 | * should be passed directly thru. In all other cases leaf class is returned. | |
201 | * We allow direct class selection by classid in priority. The we examine | |
202 | * filters in qdisc and in inner nodes (if higher filter points to the inner | |
203 | * node). If we end up with classid MAJOR:0 we enqueue the skb into special | |
204 | * internal fifo (direct). These packets then go directly thru. If we still | |
205 | * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful | |
206 | * then finish and return direct queue. | |
207 | */ | |
208 | #define HTB_DIRECT ((struct htb_class *)-1L) | |
209 | ||
210 | static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, | |
211 | int *qerr) | |
212 | { | |
213 | struct htb_sched *q = qdisc_priv(sch); | |
214 | struct htb_class *cl; | |
215 | struct tcf_result res; | |
216 | struct tcf_proto *tcf; | |
217 | int result; | |
218 | ||
219 | /* allow to select class by setting skb->priority to valid classid; | |
220 | * note that nfmark can be used too by attaching filter fw with no | |
221 | * rules in it | |
222 | */ | |
223 | if (skb->priority == sch->handle) | |
224 | return HTB_DIRECT; /* X:0 (direct flow) selected */ | |
225 | cl = htb_find(skb->priority, sch); | |
226 | if (cl) { | |
227 | if (cl->level == 0) | |
228 | return cl; | |
229 | /* Start with inner filter chain if a non-leaf class is selected */ | |
230 | tcf = rcu_dereference_bh(cl->filter_list); | |
231 | } else { | |
232 | tcf = rcu_dereference_bh(q->filter_list); | |
233 | } | |
234 | ||
235 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; | |
236 | while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) { | |
237 | #ifdef CONFIG_NET_CLS_ACT | |
238 | switch (result) { | |
239 | case TC_ACT_QUEUED: | |
240 | case TC_ACT_STOLEN: | |
241 | case TC_ACT_TRAP: | |
242 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; | |
243 | case TC_ACT_SHOT: | |
244 | return NULL; | |
245 | } | |
246 | #endif | |
247 | cl = (void *)res.class; | |
248 | if (!cl) { | |
249 | if (res.classid == sch->handle) | |
250 | return HTB_DIRECT; /* X:0 (direct flow) */ | |
251 | cl = htb_find(res.classid, sch); | |
252 | if (!cl) | |
253 | break; /* filter selected invalid classid */ | |
254 | } | |
255 | if (!cl->level) | |
256 | return cl; /* we hit leaf; return it */ | |
257 | ||
258 | /* we have got inner class; apply inner filter chain */ | |
259 | tcf = rcu_dereference_bh(cl->filter_list); | |
260 | } | |
261 | /* classification failed; try to use default class */ | |
262 | cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); | |
263 | if (!cl || cl->level) | |
264 | return HTB_DIRECT; /* bad default .. this is safe bet */ | |
265 | return cl; | |
266 | } | |
267 | ||
268 | /** | |
269 | * htb_add_to_id_tree - adds class to the round robin list | |
270 | * | |
271 | * Routine adds class to the list (actually tree) sorted by classid. | |
272 | * Make sure that class is not already on such list for given prio. | |
273 | */ | |
274 | static void htb_add_to_id_tree(struct rb_root *root, | |
275 | struct htb_class *cl, int prio) | |
276 | { | |
277 | struct rb_node **p = &root->rb_node, *parent = NULL; | |
278 | ||
279 | while (*p) { | |
280 | struct htb_class *c; | |
281 | parent = *p; | |
282 | c = rb_entry(parent, struct htb_class, node[prio]); | |
283 | ||
284 | if (cl->common.classid > c->common.classid) | |
285 | p = &parent->rb_right; | |
286 | else | |
287 | p = &parent->rb_left; | |
288 | } | |
289 | rb_link_node(&cl->node[prio], parent, p); | |
290 | rb_insert_color(&cl->node[prio], root); | |
291 | } | |
292 | ||
293 | /** | |
294 | * htb_add_to_wait_tree - adds class to the event queue with delay | |
295 | * | |
296 | * The class is added to priority event queue to indicate that class will | |
297 | * change its mode in cl->pq_key microseconds. Make sure that class is not | |
298 | * already in the queue. | |
299 | */ | |
300 | static void htb_add_to_wait_tree(struct htb_sched *q, | |
301 | struct htb_class *cl, s64 delay) | |
302 | { | |
303 | struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL; | |
304 | ||
305 | cl->pq_key = q->now + delay; | |
306 | if (cl->pq_key == q->now) | |
307 | cl->pq_key++; | |
308 | ||
309 | /* update the nearest event cache */ | |
310 | if (q->near_ev_cache[cl->level] > cl->pq_key) | |
311 | q->near_ev_cache[cl->level] = cl->pq_key; | |
312 | ||
313 | while (*p) { | |
314 | struct htb_class *c; | |
315 | parent = *p; | |
316 | c = rb_entry(parent, struct htb_class, pq_node); | |
317 | if (cl->pq_key >= c->pq_key) | |
318 | p = &parent->rb_right; | |
319 | else | |
320 | p = &parent->rb_left; | |
321 | } | |
322 | rb_link_node(&cl->pq_node, parent, p); | |
323 | rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq); | |
324 | } | |
325 | ||
326 | /** | |
327 | * htb_next_rb_node - finds next node in binary tree | |
328 | * | |
329 | * When we are past last key we return NULL. | |
330 | * Average complexity is 2 steps per call. | |
331 | */ | |
332 | static inline void htb_next_rb_node(struct rb_node **n) | |
333 | { | |
334 | *n = rb_next(*n); | |
335 | } | |
336 | ||
337 | /** | |
338 | * htb_add_class_to_row - add class to its row | |
339 | * | |
340 | * The class is added to row at priorities marked in mask. | |
341 | * It does nothing if mask == 0. | |
342 | */ | |
343 | static inline void htb_add_class_to_row(struct htb_sched *q, | |
344 | struct htb_class *cl, int mask) | |
345 | { | |
346 | q->row_mask[cl->level] |= mask; | |
347 | while (mask) { | |
348 | int prio = ffz(~mask); | |
349 | mask &= ~(1 << prio); | |
350 | htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio); | |
351 | } | |
352 | } | |
353 | ||
354 | /* If this triggers, it is a bug in this code, but it need not be fatal */ | |
355 | static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root) | |
356 | { | |
357 | if (RB_EMPTY_NODE(rb)) { | |
358 | WARN_ON(1); | |
359 | } else { | |
360 | rb_erase(rb, root); | |
361 | RB_CLEAR_NODE(rb); | |
362 | } | |
363 | } | |
364 | ||
365 | ||
366 | /** | |
367 | * htb_remove_class_from_row - removes class from its row | |
368 | * | |
369 | * The class is removed from row at priorities marked in mask. | |
370 | * It does nothing if mask == 0. | |
371 | */ | |
372 | static inline void htb_remove_class_from_row(struct htb_sched *q, | |
373 | struct htb_class *cl, int mask) | |
374 | { | |
375 | int m = 0; | |
376 | struct htb_level *hlevel = &q->hlevel[cl->level]; | |
377 | ||
378 | while (mask) { | |
379 | int prio = ffz(~mask); | |
380 | struct htb_prio *hprio = &hlevel->hprio[prio]; | |
381 | ||
382 | mask &= ~(1 << prio); | |
383 | if (hprio->ptr == cl->node + prio) | |
384 | htb_next_rb_node(&hprio->ptr); | |
385 | ||
386 | htb_safe_rb_erase(cl->node + prio, &hprio->row); | |
387 | if (!hprio->row.rb_node) | |
388 | m |= 1 << prio; | |
389 | } | |
390 | q->row_mask[cl->level] &= ~m; | |
391 | } | |
392 | ||
393 | /** | |
394 | * htb_activate_prios - creates active classe's feed chain | |
395 | * | |
396 | * The class is connected to ancestors and/or appropriate rows | |
397 | * for priorities it is participating on. cl->cmode must be new | |
398 | * (activated) mode. It does nothing if cl->prio_activity == 0. | |
399 | */ | |
400 | static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl) | |
401 | { | |
402 | struct htb_class *p = cl->parent; | |
403 | long m, mask = cl->prio_activity; | |
404 | ||
405 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { | |
406 | m = mask; | |
407 | while (m) { | |
408 | int prio = ffz(~m); | |
409 | m &= ~(1 << prio); | |
410 | ||
411 | if (p->un.inner.clprio[prio].feed.rb_node) | |
412 | /* parent already has its feed in use so that | |
413 | * reset bit in mask as parent is already ok | |
414 | */ | |
415 | mask &= ~(1 << prio); | |
416 | ||
417 | htb_add_to_id_tree(&p->un.inner.clprio[prio].feed, cl, prio); | |
418 | } | |
419 | p->prio_activity |= mask; | |
420 | cl = p; | |
421 | p = cl->parent; | |
422 | ||
423 | } | |
424 | if (cl->cmode == HTB_CAN_SEND && mask) | |
425 | htb_add_class_to_row(q, cl, mask); | |
426 | } | |
427 | ||
428 | /** | |
429 | * htb_deactivate_prios - remove class from feed chain | |
430 | * | |
431 | * cl->cmode must represent old mode (before deactivation). It does | |
432 | * nothing if cl->prio_activity == 0. Class is removed from all feed | |
433 | * chains and rows. | |
434 | */ | |
435 | static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl) | |
436 | { | |
437 | struct htb_class *p = cl->parent; | |
438 | long m, mask = cl->prio_activity; | |
439 | ||
440 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { | |
441 | m = mask; | |
442 | mask = 0; | |
443 | while (m) { | |
444 | int prio = ffz(~m); | |
445 | m &= ~(1 << prio); | |
446 | ||
447 | if (p->un.inner.clprio[prio].ptr == cl->node + prio) { | |
448 | /* we are removing child which is pointed to from | |
449 | * parent feed - forget the pointer but remember | |
450 | * classid | |
451 | */ | |
452 | p->un.inner.clprio[prio].last_ptr_id = cl->common.classid; | |
453 | p->un.inner.clprio[prio].ptr = NULL; | |
454 | } | |
455 | ||
456 | htb_safe_rb_erase(cl->node + prio, | |
457 | &p->un.inner.clprio[prio].feed); | |
458 | ||
459 | if (!p->un.inner.clprio[prio].feed.rb_node) | |
460 | mask |= 1 << prio; | |
461 | } | |
462 | ||
463 | p->prio_activity &= ~mask; | |
464 | cl = p; | |
465 | p = cl->parent; | |
466 | ||
467 | } | |
468 | if (cl->cmode == HTB_CAN_SEND && mask) | |
469 | htb_remove_class_from_row(q, cl, mask); | |
470 | } | |
471 | ||
472 | static inline s64 htb_lowater(const struct htb_class *cl) | |
473 | { | |
474 | if (htb_hysteresis) | |
475 | return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0; | |
476 | else | |
477 | return 0; | |
478 | } | |
479 | static inline s64 htb_hiwater(const struct htb_class *cl) | |
480 | { | |
481 | if (htb_hysteresis) | |
482 | return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0; | |
483 | else | |
484 | return 0; | |
485 | } | |
486 | ||
487 | ||
488 | /** | |
489 | * htb_class_mode - computes and returns current class mode | |
490 | * | |
491 | * It computes cl's mode at time cl->t_c+diff and returns it. If mode | |
492 | * is not HTB_CAN_SEND then cl->pq_key is updated to time difference | |
493 | * from now to time when cl will change its state. | |
494 | * Also it is worth to note that class mode doesn't change simply | |
495 | * at cl->{c,}tokens == 0 but there can rather be hysteresis of | |
496 | * 0 .. -cl->{c,}buffer range. It is meant to limit number of | |
497 | * mode transitions per time unit. The speed gain is about 1/6. | |
498 | */ | |
499 | static inline enum htb_cmode | |
500 | htb_class_mode(struct htb_class *cl, s64 *diff) | |
501 | { | |
502 | s64 toks; | |
503 | ||
504 | if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) { | |
505 | *diff = -toks; | |
506 | return HTB_CANT_SEND; | |
507 | } | |
508 | ||
509 | if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl)) | |
510 | return HTB_CAN_SEND; | |
511 | ||
512 | *diff = -toks; | |
513 | return HTB_MAY_BORROW; | |
514 | } | |
515 | ||
516 | /** | |
517 | * htb_change_class_mode - changes classe's mode | |
518 | * | |
519 | * This should be the only way how to change classe's mode under normal | |
520 | * cirsumstances. Routine will update feed lists linkage, change mode | |
521 | * and add class to the wait event queue if appropriate. New mode should | |
522 | * be different from old one and cl->pq_key has to be valid if changing | |
523 | * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree). | |
524 | */ | |
525 | static void | |
526 | htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff) | |
527 | { | |
528 | enum htb_cmode new_mode = htb_class_mode(cl, diff); | |
529 | ||
530 | if (new_mode == cl->cmode) | |
531 | return; | |
532 | ||
533 | if (cl->prio_activity) { /* not necessary: speed optimization */ | |
534 | if (cl->cmode != HTB_CANT_SEND) | |
535 | htb_deactivate_prios(q, cl); | |
536 | cl->cmode = new_mode; | |
537 | if (new_mode != HTB_CANT_SEND) | |
538 | htb_activate_prios(q, cl); | |
539 | } else | |
540 | cl->cmode = new_mode; | |
541 | } | |
542 | ||
543 | /** | |
544 | * htb_activate - inserts leaf cl into appropriate active feeds | |
545 | * | |
546 | * Routine learns (new) priority of leaf and activates feed chain | |
547 | * for the prio. It can be called on already active leaf safely. | |
548 | * It also adds leaf into droplist. | |
549 | */ | |
550 | static inline void htb_activate(struct htb_sched *q, struct htb_class *cl) | |
551 | { | |
552 | WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen); | |
553 | ||
554 | if (!cl->prio_activity) { | |
555 | cl->prio_activity = 1 << cl->prio; | |
556 | htb_activate_prios(q, cl); | |
557 | list_add_tail(&cl->un.leaf.drop_list, | |
558 | q->drops + cl->prio); | |
559 | } | |
560 | } | |
561 | ||
562 | /** | |
563 | * htb_deactivate - remove leaf cl from active feeds | |
564 | * | |
565 | * Make sure that leaf is active. In the other words it can't be called | |
566 | * with non-active leaf. It also removes class from the drop list. | |
567 | */ | |
568 | static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl) | |
569 | { | |
570 | WARN_ON(!cl->prio_activity); | |
571 | ||
572 | htb_deactivate_prios(q, cl); | |
573 | cl->prio_activity = 0; | |
574 | list_del_init(&cl->un.leaf.drop_list); | |
575 | } | |
576 | ||
577 | static void htb_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, | |
578 | struct qdisc_skb_head *qh) | |
579 | { | |
580 | struct sk_buff *last = qh->tail; | |
581 | ||
582 | if (last) { | |
583 | skb->next = NULL; | |
584 | last->next = skb; | |
585 | qh->tail = skb; | |
586 | } else { | |
587 | qh->tail = skb; | |
588 | qh->head = skb; | |
589 | } | |
590 | qh->qlen++; | |
591 | } | |
592 | ||
593 | static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, | |
594 | struct sk_buff **to_free) | |
595 | { | |
596 | int uninitialized_var(ret); | |
597 | struct htb_sched *q = qdisc_priv(sch); | |
598 | struct htb_class *cl = htb_classify(skb, sch, &ret); | |
599 | ||
600 | if (cl == HTB_DIRECT) { | |
601 | /* enqueue to helper queue */ | |
602 | if (q->direct_queue.qlen < q->direct_qlen) { | |
603 | htb_enqueue_tail(skb, sch, &q->direct_queue); | |
604 | q->direct_pkts++; | |
605 | } else { | |
606 | return qdisc_drop(skb, sch, to_free); | |
607 | } | |
608 | #ifdef CONFIG_NET_CLS_ACT | |
609 | } else if (!cl) { | |
610 | if (ret & __NET_XMIT_BYPASS) | |
611 | qdisc_qstats_drop(sch); | |
612 | __qdisc_drop(skb, to_free); | |
613 | return ret; | |
614 | #endif | |
615 | } else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q, | |
616 | to_free)) != NET_XMIT_SUCCESS) { | |
617 | if (net_xmit_drop_count(ret)) { | |
618 | qdisc_qstats_drop(sch); | |
619 | cl->drops++; | |
620 | } | |
621 | return ret; | |
622 | } else { | |
623 | htb_activate(q, cl); | |
624 | } | |
625 | ||
626 | qdisc_qstats_backlog_inc(sch, skb); | |
627 | sch->q.qlen++; | |
628 | return NET_XMIT_SUCCESS; | |
629 | } | |
630 | ||
631 | static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff) | |
632 | { | |
633 | s64 toks = diff + cl->tokens; | |
634 | ||
635 | if (toks > cl->buffer) | |
636 | toks = cl->buffer; | |
637 | toks -= (s64) psched_l2t_ns(&cl->rate, bytes); | |
638 | if (toks <= -cl->mbuffer) | |
639 | toks = 1 - cl->mbuffer; | |
640 | ||
641 | cl->tokens = toks; | |
642 | } | |
643 | ||
644 | static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff) | |
645 | { | |
646 | s64 toks = diff + cl->ctokens; | |
647 | ||
648 | if (toks > cl->cbuffer) | |
649 | toks = cl->cbuffer; | |
650 | toks -= (s64) psched_l2t_ns(&cl->ceil, bytes); | |
651 | if (toks <= -cl->mbuffer) | |
652 | toks = 1 - cl->mbuffer; | |
653 | ||
654 | cl->ctokens = toks; | |
655 | } | |
656 | ||
657 | /** | |
658 | * htb_charge_class - charges amount "bytes" to leaf and ancestors | |
659 | * | |
660 | * Routine assumes that packet "bytes" long was dequeued from leaf cl | |
661 | * borrowing from "level". It accounts bytes to ceil leaky bucket for | |
662 | * leaf and all ancestors and to rate bucket for ancestors at levels | |
663 | * "level" and higher. It also handles possible change of mode resulting | |
664 | * from the update. Note that mode can also increase here (MAY_BORROW to | |
665 | * CAN_SEND) because we can use more precise clock that event queue here. | |
666 | * In such case we remove class from event queue first. | |
667 | */ | |
668 | static void htb_charge_class(struct htb_sched *q, struct htb_class *cl, | |
669 | int level, struct sk_buff *skb) | |
670 | { | |
671 | int bytes = qdisc_pkt_len(skb); | |
672 | enum htb_cmode old_mode; | |
673 | s64 diff; | |
674 | ||
675 | while (cl) { | |
676 | diff = min_t(s64, q->now - cl->t_c, cl->mbuffer); | |
677 | if (cl->level >= level) { | |
678 | if (cl->level == level) | |
679 | cl->xstats.lends++; | |
680 | htb_accnt_tokens(cl, bytes, diff); | |
681 | } else { | |
682 | cl->xstats.borrows++; | |
683 | cl->tokens += diff; /* we moved t_c; update tokens */ | |
684 | } | |
685 | htb_accnt_ctokens(cl, bytes, diff); | |
686 | cl->t_c = q->now; | |
687 | ||
688 | old_mode = cl->cmode; | |
689 | diff = 0; | |
690 | htb_change_class_mode(q, cl, &diff); | |
691 | if (old_mode != cl->cmode) { | |
692 | if (old_mode != HTB_CAN_SEND) | |
693 | htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq); | |
694 | if (cl->cmode != HTB_CAN_SEND) | |
695 | htb_add_to_wait_tree(q, cl, diff); | |
696 | } | |
697 | ||
698 | /* update basic stats except for leaves which are already updated */ | |
699 | if (cl->level) | |
700 | bstats_update(&cl->bstats, skb); | |
701 | ||
702 | cl = cl->parent; | |
703 | } | |
704 | } | |
705 | ||
706 | /** | |
707 | * htb_do_events - make mode changes to classes at the level | |
708 | * | |
709 | * Scans event queue for pending events and applies them. Returns time of | |
710 | * next pending event (0 for no event in pq, q->now for too many events). | |
711 | * Note: Applied are events whose have cl->pq_key <= q->now. | |
712 | */ | |
713 | static s64 htb_do_events(struct htb_sched *q, const int level, | |
714 | unsigned long start) | |
715 | { | |
716 | /* don't run for longer than 2 jiffies; 2 is used instead of | |
717 | * 1 to simplify things when jiffy is going to be incremented | |
718 | * too soon | |
719 | */ | |
720 | unsigned long stop_at = start + 2; | |
721 | struct rb_root *wait_pq = &q->hlevel[level].wait_pq; | |
722 | ||
723 | while (time_before(jiffies, stop_at)) { | |
724 | struct htb_class *cl; | |
725 | s64 diff; | |
726 | struct rb_node *p = rb_first(wait_pq); | |
727 | ||
728 | if (!p) | |
729 | return 0; | |
730 | ||
731 | cl = rb_entry(p, struct htb_class, pq_node); | |
732 | if (cl->pq_key > q->now) | |
733 | return cl->pq_key; | |
734 | ||
735 | htb_safe_rb_erase(p, wait_pq); | |
736 | diff = min_t(s64, q->now - cl->t_c, cl->mbuffer); | |
737 | htb_change_class_mode(q, cl, &diff); | |
738 | if (cl->cmode != HTB_CAN_SEND) | |
739 | htb_add_to_wait_tree(q, cl, diff); | |
740 | } | |
741 | ||
742 | /* too much load - let's continue after a break for scheduling */ | |
743 | if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) { | |
744 | pr_warn("htb: too many events!\n"); | |
745 | q->warned |= HTB_WARN_TOOMANYEVENTS; | |
746 | } | |
747 | ||
748 | return q->now; | |
749 | } | |
750 | ||
751 | /* Returns class->node+prio from id-tree where classe's id is >= id. NULL | |
752 | * is no such one exists. | |
753 | */ | |
754 | static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n, | |
755 | u32 id) | |
756 | { | |
757 | struct rb_node *r = NULL; | |
758 | while (n) { | |
759 | struct htb_class *cl = | |
760 | rb_entry(n, struct htb_class, node[prio]); | |
761 | ||
762 | if (id > cl->common.classid) { | |
763 | n = n->rb_right; | |
764 | } else if (id < cl->common.classid) { | |
765 | r = n; | |
766 | n = n->rb_left; | |
767 | } else { | |
768 | return n; | |
769 | } | |
770 | } | |
771 | return r; | |
772 | } | |
773 | ||
774 | /** | |
775 | * htb_lookup_leaf - returns next leaf class in DRR order | |
776 | * | |
777 | * Find leaf where current feed pointers points to. | |
778 | */ | |
779 | static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio) | |
780 | { | |
781 | int i; | |
782 | struct { | |
783 | struct rb_node *root; | |
784 | struct rb_node **pptr; | |
785 | u32 *pid; | |
786 | } stk[TC_HTB_MAXDEPTH], *sp = stk; | |
787 | ||
788 | BUG_ON(!hprio->row.rb_node); | |
789 | sp->root = hprio->row.rb_node; | |
790 | sp->pptr = &hprio->ptr; | |
791 | sp->pid = &hprio->last_ptr_id; | |
792 | ||
793 | for (i = 0; i < 65535; i++) { | |
794 | if (!*sp->pptr && *sp->pid) { | |
795 | /* ptr was invalidated but id is valid - try to recover | |
796 | * the original or next ptr | |
797 | */ | |
798 | *sp->pptr = | |
799 | htb_id_find_next_upper(prio, sp->root, *sp->pid); | |
800 | } | |
801 | *sp->pid = 0; /* ptr is valid now so that remove this hint as it | |
802 | * can become out of date quickly | |
803 | */ | |
804 | if (!*sp->pptr) { /* we are at right end; rewind & go up */ | |
805 | *sp->pptr = sp->root; | |
806 | while ((*sp->pptr)->rb_left) | |
807 | *sp->pptr = (*sp->pptr)->rb_left; | |
808 | if (sp > stk) { | |
809 | sp--; | |
810 | if (!*sp->pptr) { | |
811 | WARN_ON(1); | |
812 | return NULL; | |
813 | } | |
814 | htb_next_rb_node(sp->pptr); | |
815 | } | |
816 | } else { | |
817 | struct htb_class *cl; | |
818 | struct htb_prio *clp; | |
819 | ||
820 | cl = rb_entry(*sp->pptr, struct htb_class, node[prio]); | |
821 | if (!cl->level) | |
822 | return cl; | |
823 | clp = &cl->un.inner.clprio[prio]; | |
824 | (++sp)->root = clp->feed.rb_node; | |
825 | sp->pptr = &clp->ptr; | |
826 | sp->pid = &clp->last_ptr_id; | |
827 | } | |
828 | } | |
829 | WARN_ON(1); | |
830 | return NULL; | |
831 | } | |
832 | ||
833 | /* dequeues packet at given priority and level; call only if | |
834 | * you are sure that there is active class at prio/level | |
835 | */ | |
836 | static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio, | |
837 | const int level) | |
838 | { | |
839 | struct sk_buff *skb = NULL; | |
840 | struct htb_class *cl, *start; | |
841 | struct htb_level *hlevel = &q->hlevel[level]; | |
842 | struct htb_prio *hprio = &hlevel->hprio[prio]; | |
843 | ||
844 | /* look initial class up in the row */ | |
845 | start = cl = htb_lookup_leaf(hprio, prio); | |
846 | ||
847 | do { | |
848 | next: | |
849 | if (unlikely(!cl)) | |
850 | return NULL; | |
851 | ||
852 | /* class can be empty - it is unlikely but can be true if leaf | |
853 | * qdisc drops packets in enqueue routine or if someone used | |
854 | * graft operation on the leaf since last dequeue; | |
855 | * simply deactivate and skip such class | |
856 | */ | |
857 | if (unlikely(cl->un.leaf.q->q.qlen == 0)) { | |
858 | struct htb_class *next; | |
859 | htb_deactivate(q, cl); | |
860 | ||
861 | /* row/level might become empty */ | |
862 | if ((q->row_mask[level] & (1 << prio)) == 0) | |
863 | return NULL; | |
864 | ||
865 | next = htb_lookup_leaf(hprio, prio); | |
866 | ||
867 | if (cl == start) /* fix start if we just deleted it */ | |
868 | start = next; | |
869 | cl = next; | |
870 | goto next; | |
871 | } | |
872 | ||
873 | skb = cl->un.leaf.q->dequeue(cl->un.leaf.q); | |
874 | if (likely(skb != NULL)) | |
875 | break; | |
876 | ||
877 | qdisc_warn_nonwc("htb", cl->un.leaf.q); | |
878 | htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr: | |
879 | &q->hlevel[0].hprio[prio].ptr); | |
880 | cl = htb_lookup_leaf(hprio, prio); | |
881 | ||
882 | } while (cl != start); | |
883 | ||
884 | if (likely(skb != NULL)) { | |
885 | bstats_update(&cl->bstats, skb); | |
886 | cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb); | |
887 | if (cl->un.leaf.deficit[level] < 0) { | |
888 | cl->un.leaf.deficit[level] += cl->quantum; | |
889 | htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr : | |
890 | &q->hlevel[0].hprio[prio].ptr); | |
891 | } | |
892 | /* this used to be after charge_class but this constelation | |
893 | * gives us slightly better performance | |
894 | */ | |
895 | if (!cl->un.leaf.q->q.qlen) | |
896 | htb_deactivate(q, cl); | |
897 | htb_charge_class(q, cl, level, skb); | |
898 | } | |
899 | return skb; | |
900 | } | |
901 | ||
902 | static struct sk_buff *htb_dequeue(struct Qdisc *sch) | |
903 | { | |
904 | struct sk_buff *skb; | |
905 | struct htb_sched *q = qdisc_priv(sch); | |
906 | int level; | |
907 | s64 next_event; | |
908 | unsigned long start_at; | |
909 | ||
910 | /* try to dequeue direct packets as high prio (!) to minimize cpu work */ | |
911 | skb = __qdisc_dequeue_head(&q->direct_queue); | |
912 | if (skb != NULL) { | |
913 | ok: | |
914 | qdisc_bstats_update(sch, skb); | |
915 | qdisc_qstats_backlog_dec(sch, skb); | |
916 | sch->q.qlen--; | |
917 | return skb; | |
918 | } | |
919 | ||
920 | if (!sch->q.qlen) | |
921 | goto fin; | |
922 | q->now = ktime_get_ns(); | |
923 | start_at = jiffies; | |
924 | ||
925 | next_event = q->now + 5LLU * NSEC_PER_SEC; | |
926 | ||
927 | for (level = 0; level < TC_HTB_MAXDEPTH; level++) { | |
928 | /* common case optimization - skip event handler quickly */ | |
929 | int m; | |
930 | s64 event = q->near_ev_cache[level]; | |
931 | ||
932 | if (q->now >= event) { | |
933 | event = htb_do_events(q, level, start_at); | |
934 | if (!event) | |
935 | event = q->now + NSEC_PER_SEC; | |
936 | q->near_ev_cache[level] = event; | |
937 | } | |
938 | ||
939 | if (next_event > event) | |
940 | next_event = event; | |
941 | ||
942 | m = ~q->row_mask[level]; | |
943 | while (m != (int)(-1)) { | |
944 | int prio = ffz(m); | |
945 | ||
946 | m |= 1 << prio; | |
947 | skb = htb_dequeue_tree(q, prio, level); | |
948 | if (likely(skb != NULL)) | |
949 | goto ok; | |
950 | } | |
951 | } | |
952 | qdisc_qstats_overlimit(sch); | |
953 | if (likely(next_event > q->now)) | |
954 | qdisc_watchdog_schedule_ns(&q->watchdog, next_event); | |
955 | else | |
956 | schedule_work(&q->work); | |
957 | fin: | |
958 | return skb; | |
959 | } | |
960 | ||
961 | /* reset all classes */ | |
962 | /* always caled under BH & queue lock */ | |
963 | static void htb_reset(struct Qdisc *sch) | |
964 | { | |
965 | struct htb_sched *q = qdisc_priv(sch); | |
966 | struct htb_class *cl; | |
967 | unsigned int i; | |
968 | ||
969 | for (i = 0; i < q->clhash.hashsize; i++) { | |
970 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { | |
971 | if (cl->level) | |
972 | memset(&cl->un.inner, 0, sizeof(cl->un.inner)); | |
973 | else { | |
974 | if (cl->un.leaf.q) | |
975 | qdisc_reset(cl->un.leaf.q); | |
976 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); | |
977 | } | |
978 | cl->prio_activity = 0; | |
979 | cl->cmode = HTB_CAN_SEND; | |
980 | } | |
981 | } | |
982 | qdisc_watchdog_cancel(&q->watchdog); | |
983 | __qdisc_reset_queue(&q->direct_queue); | |
984 | sch->q.qlen = 0; | |
985 | sch->qstats.backlog = 0; | |
986 | memset(q->hlevel, 0, sizeof(q->hlevel)); | |
987 | memset(q->row_mask, 0, sizeof(q->row_mask)); | |
988 | for (i = 0; i < TC_HTB_NUMPRIO; i++) | |
989 | INIT_LIST_HEAD(q->drops + i); | |
990 | } | |
991 | ||
992 | static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = { | |
993 | [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) }, | |
994 | [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) }, | |
995 | [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, | |
996 | [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, | |
997 | [TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 }, | |
998 | [TCA_HTB_RATE64] = { .type = NLA_U64 }, | |
999 | [TCA_HTB_CEIL64] = { .type = NLA_U64 }, | |
1000 | }; | |
1001 | ||
1002 | static void htb_work_func(struct work_struct *work) | |
1003 | { | |
1004 | struct htb_sched *q = container_of(work, struct htb_sched, work); | |
1005 | struct Qdisc *sch = q->watchdog.qdisc; | |
1006 | ||
1007 | rcu_read_lock(); | |
1008 | __netif_schedule(qdisc_root(sch)); | |
1009 | rcu_read_unlock(); | |
1010 | } | |
1011 | ||
1012 | static int htb_init(struct Qdisc *sch, struct nlattr *opt) | |
1013 | { | |
1014 | struct htb_sched *q = qdisc_priv(sch); | |
1015 | struct nlattr *tb[TCA_HTB_MAX + 1]; | |
1016 | struct tc_htb_glob *gopt; | |
1017 | int err; | |
1018 | int i; | |
1019 | ||
1020 | if (!opt) | |
1021 | return -EINVAL; | |
1022 | ||
1023 | err = tcf_block_get(&q->block, &q->filter_list); | |
1024 | if (err) | |
1025 | return err; | |
1026 | ||
1027 | err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy, NULL); | |
1028 | if (err < 0) | |
1029 | return err; | |
1030 | ||
1031 | if (!tb[TCA_HTB_INIT]) | |
1032 | return -EINVAL; | |
1033 | ||
1034 | gopt = nla_data(tb[TCA_HTB_INIT]); | |
1035 | if (gopt->version != HTB_VER >> 16) | |
1036 | return -EINVAL; | |
1037 | ||
1038 | err = qdisc_class_hash_init(&q->clhash); | |
1039 | if (err < 0) | |
1040 | return err; | |
1041 | for (i = 0; i < TC_HTB_NUMPRIO; i++) | |
1042 | INIT_LIST_HEAD(q->drops + i); | |
1043 | ||
1044 | qdisc_watchdog_init(&q->watchdog, sch); | |
1045 | INIT_WORK(&q->work, htb_work_func); | |
1046 | qdisc_skb_head_init(&q->direct_queue); | |
1047 | ||
1048 | if (tb[TCA_HTB_DIRECT_QLEN]) | |
1049 | q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]); | |
1050 | else | |
1051 | q->direct_qlen = qdisc_dev(sch)->tx_queue_len; | |
1052 | ||
1053 | if ((q->rate2quantum = gopt->rate2quantum) < 1) | |
1054 | q->rate2quantum = 1; | |
1055 | q->defcls = gopt->defcls; | |
1056 | ||
1057 | return 0; | |
1058 | } | |
1059 | ||
1060 | static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) | |
1061 | { | |
1062 | struct htb_sched *q = qdisc_priv(sch); | |
1063 | struct nlattr *nest; | |
1064 | struct tc_htb_glob gopt; | |
1065 | ||
1066 | /* Its safe to not acquire qdisc lock. As we hold RTNL, | |
1067 | * no change can happen on the qdisc parameters. | |
1068 | */ | |
1069 | ||
1070 | gopt.direct_pkts = q->direct_pkts; | |
1071 | gopt.version = HTB_VER; | |
1072 | gopt.rate2quantum = q->rate2quantum; | |
1073 | gopt.defcls = q->defcls; | |
1074 | gopt.debug = 0; | |
1075 | ||
1076 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
1077 | if (nest == NULL) | |
1078 | goto nla_put_failure; | |
1079 | if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) || | |
1080 | nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen)) | |
1081 | goto nla_put_failure; | |
1082 | ||
1083 | return nla_nest_end(skb, nest); | |
1084 | ||
1085 | nla_put_failure: | |
1086 | nla_nest_cancel(skb, nest); | |
1087 | return -1; | |
1088 | } | |
1089 | ||
1090 | static int htb_dump_class(struct Qdisc *sch, unsigned long arg, | |
1091 | struct sk_buff *skb, struct tcmsg *tcm) | |
1092 | { | |
1093 | struct htb_class *cl = (struct htb_class *)arg; | |
1094 | struct nlattr *nest; | |
1095 | struct tc_htb_opt opt; | |
1096 | ||
1097 | /* Its safe to not acquire qdisc lock. As we hold RTNL, | |
1098 | * no change can happen on the class parameters. | |
1099 | */ | |
1100 | tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT; | |
1101 | tcm->tcm_handle = cl->common.classid; | |
1102 | if (!cl->level && cl->un.leaf.q) | |
1103 | tcm->tcm_info = cl->un.leaf.q->handle; | |
1104 | ||
1105 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
1106 | if (nest == NULL) | |
1107 | goto nla_put_failure; | |
1108 | ||
1109 | memset(&opt, 0, sizeof(opt)); | |
1110 | ||
1111 | psched_ratecfg_getrate(&opt.rate, &cl->rate); | |
1112 | opt.buffer = PSCHED_NS2TICKS(cl->buffer); | |
1113 | psched_ratecfg_getrate(&opt.ceil, &cl->ceil); | |
1114 | opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer); | |
1115 | opt.quantum = cl->quantum; | |
1116 | opt.prio = cl->prio; | |
1117 | opt.level = cl->level; | |
1118 | if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt)) | |
1119 | goto nla_put_failure; | |
1120 | if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) && | |
1121 | nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps, | |
1122 | TCA_HTB_PAD)) | |
1123 | goto nla_put_failure; | |
1124 | if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) && | |
1125 | nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps, | |
1126 | TCA_HTB_PAD)) | |
1127 | goto nla_put_failure; | |
1128 | ||
1129 | return nla_nest_end(skb, nest); | |
1130 | ||
1131 | nla_put_failure: | |
1132 | nla_nest_cancel(skb, nest); | |
1133 | return -1; | |
1134 | } | |
1135 | ||
1136 | static int | |
1137 | htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) | |
1138 | { | |
1139 | struct htb_class *cl = (struct htb_class *)arg; | |
1140 | struct gnet_stats_queue qs = { | |
1141 | .drops = cl->drops, | |
1142 | }; | |
1143 | __u32 qlen = 0; | |
1144 | ||
1145 | if (!cl->level && cl->un.leaf.q) { | |
1146 | qlen = cl->un.leaf.q->q.qlen; | |
1147 | qs.backlog = cl->un.leaf.q->qstats.backlog; | |
1148 | } | |
1149 | cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens), | |
1150 | INT_MIN, INT_MAX); | |
1151 | cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens), | |
1152 | INT_MIN, INT_MAX); | |
1153 | ||
1154 | if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), | |
1155 | d, NULL, &cl->bstats) < 0 || | |
1156 | gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 || | |
1157 | gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0) | |
1158 | return -1; | |
1159 | ||
1160 | return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats)); | |
1161 | } | |
1162 | ||
1163 | static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
1164 | struct Qdisc **old) | |
1165 | { | |
1166 | struct htb_class *cl = (struct htb_class *)arg; | |
1167 | ||
1168 | if (cl->level) | |
1169 | return -EINVAL; | |
1170 | if (new == NULL && | |
1171 | (new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, | |
1172 | cl->common.classid)) == NULL) | |
1173 | return -ENOBUFS; | |
1174 | ||
1175 | *old = qdisc_replace(sch, new, &cl->un.leaf.q); | |
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg) | |
1180 | { | |
1181 | struct htb_class *cl = (struct htb_class *)arg; | |
1182 | return !cl->level ? cl->un.leaf.q : NULL; | |
1183 | } | |
1184 | ||
1185 | static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg) | |
1186 | { | |
1187 | struct htb_class *cl = (struct htb_class *)arg; | |
1188 | ||
1189 | if (cl->un.leaf.q->q.qlen == 0) | |
1190 | htb_deactivate(qdisc_priv(sch), cl); | |
1191 | } | |
1192 | ||
1193 | static unsigned long htb_get(struct Qdisc *sch, u32 classid) | |
1194 | { | |
1195 | struct htb_class *cl = htb_find(classid, sch); | |
1196 | if (cl) | |
1197 | cl->refcnt++; | |
1198 | return (unsigned long)cl; | |
1199 | } | |
1200 | ||
1201 | static inline int htb_parent_last_child(struct htb_class *cl) | |
1202 | { | |
1203 | if (!cl->parent) | |
1204 | /* the root class */ | |
1205 | return 0; | |
1206 | if (cl->parent->children > 1) | |
1207 | /* not the last child */ | |
1208 | return 0; | |
1209 | return 1; | |
1210 | } | |
1211 | ||
1212 | static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, | |
1213 | struct Qdisc *new_q) | |
1214 | { | |
1215 | struct htb_class *parent = cl->parent; | |
1216 | ||
1217 | WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity); | |
1218 | ||
1219 | if (parent->cmode != HTB_CAN_SEND) | |
1220 | htb_safe_rb_erase(&parent->pq_node, | |
1221 | &q->hlevel[parent->level].wait_pq); | |
1222 | ||
1223 | parent->level = 0; | |
1224 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); | |
1225 | INIT_LIST_HEAD(&parent->un.leaf.drop_list); | |
1226 | parent->un.leaf.q = new_q ? new_q : &noop_qdisc; | |
1227 | parent->tokens = parent->buffer; | |
1228 | parent->ctokens = parent->cbuffer; | |
1229 | parent->t_c = ktime_get_ns(); | |
1230 | parent->cmode = HTB_CAN_SEND; | |
1231 | } | |
1232 | ||
1233 | static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl) | |
1234 | { | |
1235 | if (!cl->level) { | |
1236 | WARN_ON(!cl->un.leaf.q); | |
1237 | qdisc_destroy(cl->un.leaf.q); | |
1238 | } | |
1239 | gen_kill_estimator(&cl->rate_est); | |
1240 | tcf_block_put(cl->block); | |
1241 | kfree(cl); | |
1242 | } | |
1243 | ||
1244 | static void htb_destroy(struct Qdisc *sch) | |
1245 | { | |
1246 | struct htb_sched *q = qdisc_priv(sch); | |
1247 | struct hlist_node *next; | |
1248 | struct htb_class *cl; | |
1249 | unsigned int i; | |
1250 | ||
1251 | cancel_work_sync(&q->work); | |
1252 | qdisc_watchdog_cancel(&q->watchdog); | |
1253 | /* This line used to be after htb_destroy_class call below | |
1254 | * and surprisingly it worked in 2.4. But it must precede it | |
1255 | * because filter need its target class alive to be able to call | |
1256 | * unbind_filter on it (without Oops). | |
1257 | */ | |
1258 | tcf_block_put(q->block); | |
1259 | ||
1260 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1261 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { | |
1262 | tcf_block_put(cl->block); | |
1263 | cl->block = NULL; | |
1264 | } | |
1265 | } | |
1266 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1267 | hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i], | |
1268 | common.hnode) | |
1269 | htb_destroy_class(sch, cl); | |
1270 | } | |
1271 | qdisc_class_hash_destroy(&q->clhash); | |
1272 | __qdisc_reset_queue(&q->direct_queue); | |
1273 | } | |
1274 | ||
1275 | static int htb_delete(struct Qdisc *sch, unsigned long arg) | |
1276 | { | |
1277 | struct htb_sched *q = qdisc_priv(sch); | |
1278 | struct htb_class *cl = (struct htb_class *)arg; | |
1279 | struct Qdisc *new_q = NULL; | |
1280 | int last_child = 0; | |
1281 | ||
1282 | /* TODO: why don't allow to delete subtree ? references ? does | |
1283 | * tc subsys guarantee us that in htb_destroy it holds no class | |
1284 | * refs so that we can remove children safely there ? | |
1285 | */ | |
1286 | if (cl->children || cl->filter_cnt) | |
1287 | return -EBUSY; | |
1288 | ||
1289 | if (!cl->level && htb_parent_last_child(cl)) { | |
1290 | new_q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, | |
1291 | cl->parent->common.classid); | |
1292 | last_child = 1; | |
1293 | } | |
1294 | ||
1295 | sch_tree_lock(sch); | |
1296 | ||
1297 | if (!cl->level) { | |
1298 | unsigned int qlen = cl->un.leaf.q->q.qlen; | |
1299 | unsigned int backlog = cl->un.leaf.q->qstats.backlog; | |
1300 | ||
1301 | qdisc_reset(cl->un.leaf.q); | |
1302 | qdisc_tree_reduce_backlog(cl->un.leaf.q, qlen, backlog); | |
1303 | } | |
1304 | ||
1305 | /* delete from hash and active; remainder in destroy_class */ | |
1306 | qdisc_class_hash_remove(&q->clhash, &cl->common); | |
1307 | if (cl->parent) | |
1308 | cl->parent->children--; | |
1309 | ||
1310 | if (cl->prio_activity) | |
1311 | htb_deactivate(q, cl); | |
1312 | ||
1313 | if (cl->cmode != HTB_CAN_SEND) | |
1314 | htb_safe_rb_erase(&cl->pq_node, | |
1315 | &q->hlevel[cl->level].wait_pq); | |
1316 | ||
1317 | if (last_child) | |
1318 | htb_parent_to_leaf(q, cl, new_q); | |
1319 | ||
1320 | BUG_ON(--cl->refcnt == 0); | |
1321 | /* | |
1322 | * This shouldn't happen: we "hold" one cops->get() when called | |
1323 | * from tc_ctl_tclass; the destroy method is done from cops->put(). | |
1324 | */ | |
1325 | ||
1326 | sch_tree_unlock(sch); | |
1327 | return 0; | |
1328 | } | |
1329 | ||
1330 | static void htb_put(struct Qdisc *sch, unsigned long arg) | |
1331 | { | |
1332 | struct htb_class *cl = (struct htb_class *)arg; | |
1333 | ||
1334 | if (--cl->refcnt == 0) | |
1335 | htb_destroy_class(sch, cl); | |
1336 | } | |
1337 | ||
1338 | static int htb_change_class(struct Qdisc *sch, u32 classid, | |
1339 | u32 parentid, struct nlattr **tca, | |
1340 | unsigned long *arg) | |
1341 | { | |
1342 | int err = -EINVAL; | |
1343 | struct htb_sched *q = qdisc_priv(sch); | |
1344 | struct htb_class *cl = (struct htb_class *)*arg, *parent; | |
1345 | struct nlattr *opt = tca[TCA_OPTIONS]; | |
1346 | struct nlattr *tb[TCA_HTB_MAX + 1]; | |
1347 | struct tc_htb_opt *hopt; | |
1348 | u64 rate64, ceil64; | |
1349 | ||
1350 | /* extract all subattrs from opt attr */ | |
1351 | if (!opt) | |
1352 | goto failure; | |
1353 | ||
1354 | err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy, NULL); | |
1355 | if (err < 0) | |
1356 | goto failure; | |
1357 | ||
1358 | err = -EINVAL; | |
1359 | if (tb[TCA_HTB_PARMS] == NULL) | |
1360 | goto failure; | |
1361 | ||
1362 | parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch); | |
1363 | ||
1364 | hopt = nla_data(tb[TCA_HTB_PARMS]); | |
1365 | if (!hopt->rate.rate || !hopt->ceil.rate) | |
1366 | goto failure; | |
1367 | ||
1368 | /* Keeping backward compatible with rate_table based iproute2 tc */ | |
1369 | if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE) | |
1370 | qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB])); | |
1371 | ||
1372 | if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE) | |
1373 | qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB])); | |
1374 | ||
1375 | if (!cl) { /* new class */ | |
1376 | struct Qdisc *new_q; | |
1377 | int prio; | |
1378 | struct { | |
1379 | struct nlattr nla; | |
1380 | struct gnet_estimator opt; | |
1381 | } est = { | |
1382 | .nla = { | |
1383 | .nla_len = nla_attr_size(sizeof(est.opt)), | |
1384 | .nla_type = TCA_RATE, | |
1385 | }, | |
1386 | .opt = { | |
1387 | /* 4s interval, 16s averaging constant */ | |
1388 | .interval = 2, | |
1389 | .ewma_log = 2, | |
1390 | }, | |
1391 | }; | |
1392 | ||
1393 | /* check for valid classid */ | |
1394 | if (!classid || TC_H_MAJ(classid ^ sch->handle) || | |
1395 | htb_find(classid, sch)) | |
1396 | goto failure; | |
1397 | ||
1398 | /* check maximal depth */ | |
1399 | if (parent && parent->parent && parent->parent->level < 2) { | |
1400 | pr_err("htb: tree is too deep\n"); | |
1401 | goto failure; | |
1402 | } | |
1403 | err = -ENOBUFS; | |
1404 | cl = kzalloc(sizeof(*cl), GFP_KERNEL); | |
1405 | if (!cl) | |
1406 | goto failure; | |
1407 | ||
1408 | err = tcf_block_get(&cl->block, &cl->filter_list); | |
1409 | if (err) { | |
1410 | kfree(cl); | |
1411 | goto failure; | |
1412 | } | |
1413 | if (htb_rate_est || tca[TCA_RATE]) { | |
1414 | err = gen_new_estimator(&cl->bstats, NULL, | |
1415 | &cl->rate_est, | |
1416 | NULL, | |
1417 | qdisc_root_sleeping_running(sch), | |
1418 | tca[TCA_RATE] ? : &est.nla); | |
1419 | if (err) { | |
1420 | tcf_block_put(cl->block); | |
1421 | kfree(cl); | |
1422 | goto failure; | |
1423 | } | |
1424 | } | |
1425 | ||
1426 | cl->refcnt = 1; | |
1427 | cl->children = 0; | |
1428 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); | |
1429 | RB_CLEAR_NODE(&cl->pq_node); | |
1430 | ||
1431 | for (prio = 0; prio < TC_HTB_NUMPRIO; prio++) | |
1432 | RB_CLEAR_NODE(&cl->node[prio]); | |
1433 | ||
1434 | /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL) | |
1435 | * so that can't be used inside of sch_tree_lock | |
1436 | * -- thanks to Karlis Peisenieks | |
1437 | */ | |
1438 | new_q = qdisc_create_dflt(sch->dev_queue, | |
1439 | &pfifo_qdisc_ops, classid); | |
1440 | sch_tree_lock(sch); | |
1441 | if (parent && !parent->level) { | |
1442 | unsigned int qlen = parent->un.leaf.q->q.qlen; | |
1443 | unsigned int backlog = parent->un.leaf.q->qstats.backlog; | |
1444 | ||
1445 | /* turn parent into inner node */ | |
1446 | qdisc_reset(parent->un.leaf.q); | |
1447 | qdisc_tree_reduce_backlog(parent->un.leaf.q, qlen, backlog); | |
1448 | qdisc_destroy(parent->un.leaf.q); | |
1449 | if (parent->prio_activity) | |
1450 | htb_deactivate(q, parent); | |
1451 | ||
1452 | /* remove from evt list because of level change */ | |
1453 | if (parent->cmode != HTB_CAN_SEND) { | |
1454 | htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq); | |
1455 | parent->cmode = HTB_CAN_SEND; | |
1456 | } | |
1457 | parent->level = (parent->parent ? parent->parent->level | |
1458 | : TC_HTB_MAXDEPTH) - 1; | |
1459 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); | |
1460 | } | |
1461 | /* leaf (we) needs elementary qdisc */ | |
1462 | cl->un.leaf.q = new_q ? new_q : &noop_qdisc; | |
1463 | ||
1464 | cl->common.classid = classid; | |
1465 | cl->parent = parent; | |
1466 | ||
1467 | /* set class to be in HTB_CAN_SEND state */ | |
1468 | cl->tokens = PSCHED_TICKS2NS(hopt->buffer); | |
1469 | cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer); | |
1470 | cl->mbuffer = 60ULL * NSEC_PER_SEC; /* 1min */ | |
1471 | cl->t_c = ktime_get_ns(); | |
1472 | cl->cmode = HTB_CAN_SEND; | |
1473 | ||
1474 | /* attach to the hash list and parent's family */ | |
1475 | qdisc_class_hash_insert(&q->clhash, &cl->common); | |
1476 | if (parent) | |
1477 | parent->children++; | |
1478 | if (cl->un.leaf.q != &noop_qdisc) | |
1479 | qdisc_hash_add(cl->un.leaf.q, true); | |
1480 | } else { | |
1481 | if (tca[TCA_RATE]) { | |
1482 | err = gen_replace_estimator(&cl->bstats, NULL, | |
1483 | &cl->rate_est, | |
1484 | NULL, | |
1485 | qdisc_root_sleeping_running(sch), | |
1486 | tca[TCA_RATE]); | |
1487 | if (err) | |
1488 | return err; | |
1489 | } | |
1490 | sch_tree_lock(sch); | |
1491 | } | |
1492 | ||
1493 | rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0; | |
1494 | ||
1495 | ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0; | |
1496 | ||
1497 | psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64); | |
1498 | psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64); | |
1499 | ||
1500 | /* it used to be a nasty bug here, we have to check that node | |
1501 | * is really leaf before changing cl->un.leaf ! | |
1502 | */ | |
1503 | if (!cl->level) { | |
1504 | u64 quantum = cl->rate.rate_bytes_ps; | |
1505 | ||
1506 | do_div(quantum, q->rate2quantum); | |
1507 | cl->quantum = min_t(u64, quantum, INT_MAX); | |
1508 | ||
1509 | if (!hopt->quantum && cl->quantum < 1000) { | |
1510 | pr_warn("HTB: quantum of class %X is small. Consider r2q change.\n", | |
1511 | cl->common.classid); | |
1512 | cl->quantum = 1000; | |
1513 | } | |
1514 | if (!hopt->quantum && cl->quantum > 200000) { | |
1515 | pr_warn("HTB: quantum of class %X is big. Consider r2q change.\n", | |
1516 | cl->common.classid); | |
1517 | cl->quantum = 200000; | |
1518 | } | |
1519 | if (hopt->quantum) | |
1520 | cl->quantum = hopt->quantum; | |
1521 | if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO) | |
1522 | cl->prio = TC_HTB_NUMPRIO - 1; | |
1523 | } | |
1524 | ||
1525 | cl->buffer = PSCHED_TICKS2NS(hopt->buffer); | |
1526 | cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer); | |
1527 | ||
1528 | sch_tree_unlock(sch); | |
1529 | ||
1530 | qdisc_class_hash_grow(sch, &q->clhash); | |
1531 | ||
1532 | *arg = (unsigned long)cl; | |
1533 | return 0; | |
1534 | ||
1535 | failure: | |
1536 | return err; | |
1537 | } | |
1538 | ||
1539 | static struct tcf_block *htb_tcf_block(struct Qdisc *sch, unsigned long arg) | |
1540 | { | |
1541 | struct htb_sched *q = qdisc_priv(sch); | |
1542 | struct htb_class *cl = (struct htb_class *)arg; | |
1543 | ||
1544 | return cl ? cl->block : q->block; | |
1545 | } | |
1546 | ||
1547 | static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent, | |
1548 | u32 classid) | |
1549 | { | |
1550 | struct htb_class *cl = htb_find(classid, sch); | |
1551 | ||
1552 | /*if (cl && !cl->level) return 0; | |
1553 | * The line above used to be there to prevent attaching filters to | |
1554 | * leaves. But at least tc_index filter uses this just to get class | |
1555 | * for other reasons so that we have to allow for it. | |
1556 | * ---- | |
1557 | * 19.6.2002 As Werner explained it is ok - bind filter is just | |
1558 | * another way to "lock" the class - unlike "get" this lock can | |
1559 | * be broken by class during destroy IIUC. | |
1560 | */ | |
1561 | if (cl) | |
1562 | cl->filter_cnt++; | |
1563 | return (unsigned long)cl; | |
1564 | } | |
1565 | ||
1566 | static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg) | |
1567 | { | |
1568 | struct htb_class *cl = (struct htb_class *)arg; | |
1569 | ||
1570 | if (cl) | |
1571 | cl->filter_cnt--; | |
1572 | } | |
1573 | ||
1574 | static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
1575 | { | |
1576 | struct htb_sched *q = qdisc_priv(sch); | |
1577 | struct htb_class *cl; | |
1578 | unsigned int i; | |
1579 | ||
1580 | if (arg->stop) | |
1581 | return; | |
1582 | ||
1583 | for (i = 0; i < q->clhash.hashsize; i++) { | |
1584 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { | |
1585 | if (arg->count < arg->skip) { | |
1586 | arg->count++; | |
1587 | continue; | |
1588 | } | |
1589 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { | |
1590 | arg->stop = 1; | |
1591 | return; | |
1592 | } | |
1593 | arg->count++; | |
1594 | } | |
1595 | } | |
1596 | } | |
1597 | ||
1598 | static const struct Qdisc_class_ops htb_class_ops = { | |
1599 | .graft = htb_graft, | |
1600 | .leaf = htb_leaf, | |
1601 | .qlen_notify = htb_qlen_notify, | |
1602 | .get = htb_get, | |
1603 | .put = htb_put, | |
1604 | .change = htb_change_class, | |
1605 | .delete = htb_delete, | |
1606 | .walk = htb_walk, | |
1607 | .tcf_block = htb_tcf_block, | |
1608 | .bind_tcf = htb_bind_filter, | |
1609 | .unbind_tcf = htb_unbind_filter, | |
1610 | .dump = htb_dump_class, | |
1611 | .dump_stats = htb_dump_class_stats, | |
1612 | }; | |
1613 | ||
1614 | static struct Qdisc_ops htb_qdisc_ops __read_mostly = { | |
1615 | .cl_ops = &htb_class_ops, | |
1616 | .id = "htb", | |
1617 | .priv_size = sizeof(struct htb_sched), | |
1618 | .enqueue = htb_enqueue, | |
1619 | .dequeue = htb_dequeue, | |
1620 | .peek = qdisc_peek_dequeued, | |
1621 | .init = htb_init, | |
1622 | .reset = htb_reset, | |
1623 | .destroy = htb_destroy, | |
1624 | .dump = htb_dump, | |
1625 | .owner = THIS_MODULE, | |
1626 | }; | |
1627 | ||
1628 | static int __init htb_module_init(void) | |
1629 | { | |
1630 | return register_qdisc(&htb_qdisc_ops); | |
1631 | } | |
1632 | static void __exit htb_module_exit(void) | |
1633 | { | |
1634 | unregister_qdisc(&htb_qdisc_ops); | |
1635 | } | |
1636 | ||
1637 | module_init(htb_module_init) | |
1638 | module_exit(htb_module_exit) | |
1639 | MODULE_LICENSE("GPL"); |