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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/pkt_sched.h> |
42 | |
43 | /* HTB algorithm. |
44 | Author: devik@cdi.cz |
45 | ======================================================================== |
46 | HTB is like TBF with multiple classes. It is also similar to CBQ because |
47 | it allows to assign priority to each class in hierarchy. |
48 | In fact it is another implementation of Floyd's formal sharing. |
49 | |
50 | Levels: |
51 | Each class is assigned level. Leaf has ALWAYS level 0 and root |
52 | classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level |
53 | one less than their parent. |
54 | */ |
55 | |
56 | static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */ |
57 | #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */ |
58 | |
59 | #if HTB_VER >> 16 != TC_HTB_PROTOVER |
60 | #error "Mismatched sch_htb.c and pkt_sch.h" |
61 | #endif |
62 | |
63 | /* Module parameter and sysfs export */ |
64 | module_param (htb_hysteresis, int, 0640); |
65 | MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate"); |
66 | |
67 | /* used internaly to keep status of single class */ |
68 | enum htb_cmode { |
69 | HTB_CANT_SEND, /* class can't send and can't borrow */ |
70 | HTB_MAY_BORROW, /* class can't send but may borrow */ |
71 | HTB_CAN_SEND /* class can send */ |
72 | }; |
73 | |
74 | /* interior & leaf nodes; props specific to leaves are marked L: */ |
75 | struct htb_class { |
76 | struct Qdisc_class_common common; |
77 | /* general class parameters */ |
78 | struct gnet_stats_basic_packed bstats; |
79 | struct gnet_stats_queue qstats; |
80 | struct gnet_stats_rate_est rate_est; |
81 | struct tc_htb_xstats xstats; /* our special stats */ |
82 | int refcnt; /* usage count of this class */ |
83 | |
84 | /* topology */ |
85 | int level; /* our level (see above) */ |
86 | unsigned int children; |
87 | struct htb_class *parent; /* parent class */ |
88 | |
89 | int prio; /* these two are used only by leaves... */ |
90 | int quantum; /* but stored for parent-to-leaf return */ |
91 | |
92 | union { |
93 | struct htb_class_leaf { |
94 | struct Qdisc *q; |
95 | int deficit[TC_HTB_MAXDEPTH]; |
96 | struct list_head drop_list; |
97 | } leaf; |
98 | struct htb_class_inner { |
99 | struct rb_root feed[TC_HTB_NUMPRIO]; /* feed trees */ |
100 | struct rb_node *ptr[TC_HTB_NUMPRIO]; /* current class ptr */ |
101 | /* When class changes from state 1->2 and disconnects from |
102 | parent's feed then we lost ptr value and start from the |
103 | first child again. Here we store classid of the |
104 | last valid ptr (used when ptr is NULL). */ |
105 | u32 last_ptr_id[TC_HTB_NUMPRIO]; |
106 | } inner; |
107 | } un; |
108 | struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */ |
109 | struct rb_node pq_node; /* node for event queue */ |
110 | psched_time_t pq_key; |
111 | |
112 | int prio_activity; /* for which prios are we active */ |
113 | enum htb_cmode cmode; /* current mode of the class */ |
114 | |
115 | /* class attached filters */ |
116 | struct tcf_proto *filter_list; |
117 | int filter_cnt; |
118 | |
119 | /* token bucket parameters */ |
120 | struct qdisc_rate_table *rate; /* rate table of the class itself */ |
121 | struct qdisc_rate_table *ceil; /* ceiling rate (limits borrows too) */ |
122 | long buffer, cbuffer; /* token bucket depth/rate */ |
123 | psched_tdiff_t mbuffer; /* max wait time */ |
124 | long tokens, ctokens; /* current number of tokens */ |
125 | psched_time_t t_c; /* checkpoint time */ |
126 | }; |
127 | |
128 | struct htb_sched { |
129 | struct Qdisc_class_hash clhash; |
130 | struct list_head drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */ |
131 | |
132 | /* self list - roots of self generating tree */ |
133 | struct rb_root row[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; |
134 | int row_mask[TC_HTB_MAXDEPTH]; |
135 | struct rb_node *ptr[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; |
136 | u32 last_ptr_id[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; |
137 | |
138 | /* self wait list - roots of wait PQs per row */ |
139 | struct rb_root wait_pq[TC_HTB_MAXDEPTH]; |
140 | |
141 | /* time of nearest event per level (row) */ |
142 | psched_time_t near_ev_cache[TC_HTB_MAXDEPTH]; |
143 | |
144 | int defcls; /* class where unclassified flows go to */ |
145 | |
146 | /* filters for qdisc itself */ |
147 | struct tcf_proto *filter_list; |
148 | |
149 | int rate2quantum; /* quant = rate / rate2quantum */ |
150 | psched_time_t now; /* cached dequeue time */ |
151 | struct qdisc_watchdog watchdog; |
152 | |
153 | /* non shaped skbs; let them go directly thru */ |
154 | struct sk_buff_head direct_queue; |
155 | int direct_qlen; /* max qlen of above */ |
156 | |
157 | long direct_pkts; |
158 | |
159 | #define HTB_WARN_TOOMANYEVENTS 0x1 |
160 | unsigned int warned; /* only one warning */ |
161 | struct work_struct work; |
162 | }; |
163 | |
164 | /* find class in global hash table using given handle */ |
165 | static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch) |
166 | { |
167 | struct htb_sched *q = qdisc_priv(sch); |
168 | struct Qdisc_class_common *clc; |
169 | |
170 | clc = qdisc_class_find(&q->clhash, handle); |
171 | if (clc == NULL) |
172 | return NULL; |
173 | return container_of(clc, struct htb_class, common); |
174 | } |
175 | |
176 | /** |
177 | * htb_classify - classify a packet into class |
178 | * |
179 | * It returns NULL if the packet should be dropped or -1 if the packet |
180 | * should be passed directly thru. In all other cases leaf class is returned. |
181 | * We allow direct class selection by classid in priority. The we examine |
182 | * filters in qdisc and in inner nodes (if higher filter points to the inner |
183 | * node). If we end up with classid MAJOR:0 we enqueue the skb into special |
184 | * internal fifo (direct). These packets then go directly thru. If we still |
185 | * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessfull |
186 | * then finish and return direct queue. |
187 | */ |
188 | #define HTB_DIRECT (struct htb_class*)-1 |
189 | |
190 | static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, |
191 | int *qerr) |
192 | { |
193 | struct htb_sched *q = qdisc_priv(sch); |
194 | struct htb_class *cl; |
195 | struct tcf_result res; |
196 | struct tcf_proto *tcf; |
197 | int result; |
198 | |
199 | /* allow to select class by setting skb->priority to valid classid; |
200 | note that nfmark can be used too by attaching filter fw with no |
201 | rules in it */ |
202 | if (skb->priority == sch->handle) |
203 | return HTB_DIRECT; /* X:0 (direct flow) selected */ |
204 | if ((cl = htb_find(skb->priority, sch)) != NULL && cl->level == 0) |
205 | return cl; |
206 | |
207 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
208 | tcf = q->filter_list; |
209 | while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) { |
210 | #ifdef CONFIG_NET_CLS_ACT |
211 | switch (result) { |
212 | case TC_ACT_QUEUED: |
213 | case TC_ACT_STOLEN: |
214 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
215 | case TC_ACT_SHOT: |
216 | return NULL; |
217 | } |
218 | #endif |
219 | if ((cl = (void *)res.class) == NULL) { |
220 | if (res.classid == sch->handle) |
221 | return HTB_DIRECT; /* X:0 (direct flow) */ |
222 | if ((cl = htb_find(res.classid, sch)) == NULL) |
223 | break; /* filter selected invalid classid */ |
224 | } |
225 | if (!cl->level) |
226 | return cl; /* we hit leaf; return it */ |
227 | |
228 | /* we have got inner class; apply inner filter chain */ |
229 | tcf = cl->filter_list; |
230 | } |
231 | /* classification failed; try to use default class */ |
232 | cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); |
233 | if (!cl || cl->level) |
234 | return HTB_DIRECT; /* bad default .. this is safe bet */ |
235 | return cl; |
236 | } |
237 | |
238 | /** |
239 | * htb_add_to_id_tree - adds class to the round robin list |
240 | * |
241 | * Routine adds class to the list (actually tree) sorted by classid. |
242 | * Make sure that class is not already on such list for given prio. |
243 | */ |
244 | static void htb_add_to_id_tree(struct rb_root *root, |
245 | struct htb_class *cl, int prio) |
246 | { |
247 | struct rb_node **p = &root->rb_node, *parent = NULL; |
248 | |
249 | while (*p) { |
250 | struct htb_class *c; |
251 | parent = *p; |
252 | c = rb_entry(parent, struct htb_class, node[prio]); |
253 | |
254 | if (cl->common.classid > c->common.classid) |
255 | p = &parent->rb_right; |
256 | else |
257 | p = &parent->rb_left; |
258 | } |
259 | rb_link_node(&cl->node[prio], parent, p); |
260 | rb_insert_color(&cl->node[prio], root); |
261 | } |
262 | |
263 | /** |
264 | * htb_add_to_wait_tree - adds class to the event queue with delay |
265 | * |
266 | * The class is added to priority event queue to indicate that class will |
267 | * change its mode in cl->pq_key microseconds. Make sure that class is not |
268 | * already in the queue. |
269 | */ |
270 | static void htb_add_to_wait_tree(struct htb_sched *q, |
271 | struct htb_class *cl, long delay) |
272 | { |
273 | struct rb_node **p = &q->wait_pq[cl->level].rb_node, *parent = NULL; |
274 | |
275 | cl->pq_key = q->now + delay; |
276 | if (cl->pq_key == q->now) |
277 | cl->pq_key++; |
278 | |
279 | /* update the nearest event cache */ |
280 | if (q->near_ev_cache[cl->level] > cl->pq_key) |
281 | q->near_ev_cache[cl->level] = cl->pq_key; |
282 | |
283 | while (*p) { |
284 | struct htb_class *c; |
285 | parent = *p; |
286 | c = rb_entry(parent, struct htb_class, pq_node); |
287 | if (cl->pq_key >= c->pq_key) |
288 | p = &parent->rb_right; |
289 | else |
290 | p = &parent->rb_left; |
291 | } |
292 | rb_link_node(&cl->pq_node, parent, p); |
293 | rb_insert_color(&cl->pq_node, &q->wait_pq[cl->level]); |
294 | } |
295 | |
296 | /** |
297 | * htb_next_rb_node - finds next node in binary tree |
298 | * |
299 | * When we are past last key we return NULL. |
300 | * Average complexity is 2 steps per call. |
301 | */ |
302 | static inline void htb_next_rb_node(struct rb_node **n) |
303 | { |
304 | *n = rb_next(*n); |
305 | } |
306 | |
307 | /** |
308 | * htb_add_class_to_row - add class to its row |
309 | * |
310 | * The class is added to row at priorities marked in mask. |
311 | * It does nothing if mask == 0. |
312 | */ |
313 | static inline void htb_add_class_to_row(struct htb_sched *q, |
314 | struct htb_class *cl, int mask) |
315 | { |
316 | q->row_mask[cl->level] |= mask; |
317 | while (mask) { |
318 | int prio = ffz(~mask); |
319 | mask &= ~(1 << prio); |
320 | htb_add_to_id_tree(q->row[cl->level] + prio, cl, prio); |
321 | } |
322 | } |
323 | |
324 | /* If this triggers, it is a bug in this code, but it need not be fatal */ |
325 | static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root) |
326 | { |
327 | if (RB_EMPTY_NODE(rb)) { |
328 | WARN_ON(1); |
329 | } else { |
330 | rb_erase(rb, root); |
331 | RB_CLEAR_NODE(rb); |
332 | } |
333 | } |
334 | |
335 | |
336 | /** |
337 | * htb_remove_class_from_row - removes class from its row |
338 | * |
339 | * The class is removed from row at priorities marked in mask. |
340 | * It does nothing if mask == 0. |
341 | */ |
342 | static inline void htb_remove_class_from_row(struct htb_sched *q, |
343 | struct htb_class *cl, int mask) |
344 | { |
345 | int m = 0; |
346 | |
347 | while (mask) { |
348 | int prio = ffz(~mask); |
349 | |
350 | mask &= ~(1 << prio); |
351 | if (q->ptr[cl->level][prio] == cl->node + prio) |
352 | htb_next_rb_node(q->ptr[cl->level] + prio); |
353 | |
354 | htb_safe_rb_erase(cl->node + prio, q->row[cl->level] + prio); |
355 | if (!q->row[cl->level][prio].rb_node) |
356 | m |= 1 << prio; |
357 | } |
358 | q->row_mask[cl->level] &= ~m; |
359 | } |
360 | |
361 | /** |
362 | * htb_activate_prios - creates active classe's feed chain |
363 | * |
364 | * The class is connected to ancestors and/or appropriate rows |
365 | * for priorities it is participating on. cl->cmode must be new |
366 | * (activated) mode. It does nothing if cl->prio_activity == 0. |
367 | */ |
368 | static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl) |
369 | { |
370 | struct htb_class *p = cl->parent; |
371 | long m, mask = cl->prio_activity; |
372 | |
373 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { |
374 | m = mask; |
375 | while (m) { |
376 | int prio = ffz(~m); |
377 | m &= ~(1 << prio); |
378 | |
379 | if (p->un.inner.feed[prio].rb_node) |
380 | /* parent already has its feed in use so that |
381 | reset bit in mask as parent is already ok */ |
382 | mask &= ~(1 << prio); |
383 | |
384 | htb_add_to_id_tree(p->un.inner.feed + prio, cl, prio); |
385 | } |
386 | p->prio_activity |= mask; |
387 | cl = p; |
388 | p = cl->parent; |
389 | |
390 | } |
391 | if (cl->cmode == HTB_CAN_SEND && mask) |
392 | htb_add_class_to_row(q, cl, mask); |
393 | } |
394 | |
395 | /** |
396 | * htb_deactivate_prios - remove class from feed chain |
397 | * |
398 | * cl->cmode must represent old mode (before deactivation). It does |
399 | * nothing if cl->prio_activity == 0. Class is removed from all feed |
400 | * chains and rows. |
401 | */ |
402 | static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl) |
403 | { |
404 | struct htb_class *p = cl->parent; |
405 | long m, mask = cl->prio_activity; |
406 | |
407 | while (cl->cmode == HTB_MAY_BORROW && p && mask) { |
408 | m = mask; |
409 | mask = 0; |
410 | while (m) { |
411 | int prio = ffz(~m); |
412 | m &= ~(1 << prio); |
413 | |
414 | if (p->un.inner.ptr[prio] == cl->node + prio) { |
415 | /* we are removing child which is pointed to from |
416 | parent feed - forget the pointer but remember |
417 | classid */ |
418 | p->un.inner.last_ptr_id[prio] = cl->common.classid; |
419 | p->un.inner.ptr[prio] = NULL; |
420 | } |
421 | |
422 | htb_safe_rb_erase(cl->node + prio, p->un.inner.feed + prio); |
423 | |
424 | if (!p->un.inner.feed[prio].rb_node) |
425 | mask |= 1 << prio; |
426 | } |
427 | |
428 | p->prio_activity &= ~mask; |
429 | cl = p; |
430 | p = cl->parent; |
431 | |
432 | } |
433 | if (cl->cmode == HTB_CAN_SEND && mask) |
434 | htb_remove_class_from_row(q, cl, mask); |
435 | } |
436 | |
437 | static inline long htb_lowater(const struct htb_class *cl) |
438 | { |
439 | if (htb_hysteresis) |
440 | return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0; |
441 | else |
442 | return 0; |
443 | } |
444 | static inline long htb_hiwater(const struct htb_class *cl) |
445 | { |
446 | if (htb_hysteresis) |
447 | return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0; |
448 | else |
449 | return 0; |
450 | } |
451 | |
452 | |
453 | /** |
454 | * htb_class_mode - computes and returns current class mode |
455 | * |
456 | * It computes cl's mode at time cl->t_c+diff and returns it. If mode |
457 | * is not HTB_CAN_SEND then cl->pq_key is updated to time difference |
458 | * from now to time when cl will change its state. |
459 | * Also it is worth to note that class mode doesn't change simply |
460 | * at cl->{c,}tokens == 0 but there can rather be hysteresis of |
461 | * 0 .. -cl->{c,}buffer range. It is meant to limit number of |
462 | * mode transitions per time unit. The speed gain is about 1/6. |
463 | */ |
464 | static inline enum htb_cmode |
465 | htb_class_mode(struct htb_class *cl, long *diff) |
466 | { |
467 | long toks; |
468 | |
469 | if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) { |
470 | *diff = -toks; |
471 | return HTB_CANT_SEND; |
472 | } |
473 | |
474 | if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl)) |
475 | return HTB_CAN_SEND; |
476 | |
477 | *diff = -toks; |
478 | return HTB_MAY_BORROW; |
479 | } |
480 | |
481 | /** |
482 | * htb_change_class_mode - changes classe's mode |
483 | * |
484 | * This should be the only way how to change classe's mode under normal |
485 | * cirsumstances. Routine will update feed lists linkage, change mode |
486 | * and add class to the wait event queue if appropriate. New mode should |
487 | * be different from old one and cl->pq_key has to be valid if changing |
488 | * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree). |
489 | */ |
490 | static void |
491 | htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, long *diff) |
492 | { |
493 | enum htb_cmode new_mode = htb_class_mode(cl, diff); |
494 | |
495 | if (new_mode == cl->cmode) |
496 | return; |
497 | |
498 | if (cl->prio_activity) { /* not necessary: speed optimization */ |
499 | if (cl->cmode != HTB_CANT_SEND) |
500 | htb_deactivate_prios(q, cl); |
501 | cl->cmode = new_mode; |
502 | if (new_mode != HTB_CANT_SEND) |
503 | htb_activate_prios(q, cl); |
504 | } else |
505 | cl->cmode = new_mode; |
506 | } |
507 | |
508 | /** |
509 | * htb_activate - inserts leaf cl into appropriate active feeds |
510 | * |
511 | * Routine learns (new) priority of leaf and activates feed chain |
512 | * for the prio. It can be called on already active leaf safely. |
513 | * It also adds leaf into droplist. |
514 | */ |
515 | static inline void htb_activate(struct htb_sched *q, struct htb_class *cl) |
516 | { |
517 | WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen); |
518 | |
519 | if (!cl->prio_activity) { |
520 | cl->prio_activity = 1 << cl->prio; |
521 | htb_activate_prios(q, cl); |
522 | list_add_tail(&cl->un.leaf.drop_list, |
523 | q->drops + cl->prio); |
524 | } |
525 | } |
526 | |
527 | /** |
528 | * htb_deactivate - remove leaf cl from active feeds |
529 | * |
530 | * Make sure that leaf is active. In the other words it can't be called |
531 | * with non-active leaf. It also removes class from the drop list. |
532 | */ |
533 | static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl) |
534 | { |
535 | WARN_ON(!cl->prio_activity); |
536 | |
537 | htb_deactivate_prios(q, cl); |
538 | cl->prio_activity = 0; |
539 | list_del_init(&cl->un.leaf.drop_list); |
540 | } |
541 | |
542 | static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
543 | { |
544 | int uninitialized_var(ret); |
545 | struct htb_sched *q = qdisc_priv(sch); |
546 | struct htb_class *cl = htb_classify(skb, sch, &ret); |
547 | |
548 | if (cl == HTB_DIRECT) { |
549 | /* enqueue to helper queue */ |
550 | if (q->direct_queue.qlen < q->direct_qlen) { |
551 | __skb_queue_tail(&q->direct_queue, skb); |
552 | q->direct_pkts++; |
553 | } else { |
554 | kfree_skb(skb); |
555 | sch->qstats.drops++; |
556 | return NET_XMIT_DROP; |
557 | } |
558 | #ifdef CONFIG_NET_CLS_ACT |
559 | } else if (!cl) { |
560 | if (ret & __NET_XMIT_BYPASS) |
561 | sch->qstats.drops++; |
562 | kfree_skb(skb); |
563 | return ret; |
564 | #endif |
565 | } else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q)) != NET_XMIT_SUCCESS) { |
566 | if (net_xmit_drop_count(ret)) { |
567 | sch->qstats.drops++; |
568 | cl->qstats.drops++; |
569 | } |
570 | return ret; |
571 | } else { |
572 | cl->bstats.packets += |
573 | skb_is_gso(skb)?skb_shinfo(skb)->gso_segs:1; |
574 | cl->bstats.bytes += qdisc_pkt_len(skb); |
575 | htb_activate(q, cl); |
576 | } |
577 | |
578 | sch->q.qlen++; |
579 | sch->bstats.packets += skb_is_gso(skb)?skb_shinfo(skb)->gso_segs:1; |
580 | sch->bstats.bytes += qdisc_pkt_len(skb); |
581 | return NET_XMIT_SUCCESS; |
582 | } |
583 | |
584 | static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, long diff) |
585 | { |
586 | long toks = diff + cl->tokens; |
587 | |
588 | if (toks > cl->buffer) |
589 | toks = cl->buffer; |
590 | toks -= (long) qdisc_l2t(cl->rate, bytes); |
591 | if (toks <= -cl->mbuffer) |
592 | toks = 1 - cl->mbuffer; |
593 | |
594 | cl->tokens = toks; |
595 | } |
596 | |
597 | static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, long diff) |
598 | { |
599 | long toks = diff + cl->ctokens; |
600 | |
601 | if (toks > cl->cbuffer) |
602 | toks = cl->cbuffer; |
603 | toks -= (long) qdisc_l2t(cl->ceil, bytes); |
604 | if (toks <= -cl->mbuffer) |
605 | toks = 1 - cl->mbuffer; |
606 | |
607 | cl->ctokens = toks; |
608 | } |
609 | |
610 | /** |
611 | * htb_charge_class - charges amount "bytes" to leaf and ancestors |
612 | * |
613 | * Routine assumes that packet "bytes" long was dequeued from leaf cl |
614 | * borrowing from "level". It accounts bytes to ceil leaky bucket for |
615 | * leaf and all ancestors and to rate bucket for ancestors at levels |
616 | * "level" and higher. It also handles possible change of mode resulting |
617 | * from the update. Note that mode can also increase here (MAY_BORROW to |
618 | * CAN_SEND) because we can use more precise clock that event queue here. |
619 | * In such case we remove class from event queue first. |
620 | */ |
621 | static void htb_charge_class(struct htb_sched *q, struct htb_class *cl, |
622 | int level, struct sk_buff *skb) |
623 | { |
624 | int bytes = qdisc_pkt_len(skb); |
625 | enum htb_cmode old_mode; |
626 | long diff; |
627 | |
628 | while (cl) { |
629 | diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer); |
630 | if (cl->level >= level) { |
631 | if (cl->level == level) |
632 | cl->xstats.lends++; |
633 | htb_accnt_tokens(cl, bytes, diff); |
634 | } else { |
635 | cl->xstats.borrows++; |
636 | cl->tokens += diff; /* we moved t_c; update tokens */ |
637 | } |
638 | htb_accnt_ctokens(cl, bytes, diff); |
639 | cl->t_c = q->now; |
640 | |
641 | old_mode = cl->cmode; |
642 | diff = 0; |
643 | htb_change_class_mode(q, cl, &diff); |
644 | if (old_mode != cl->cmode) { |
645 | if (old_mode != HTB_CAN_SEND) |
646 | htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); |
647 | if (cl->cmode != HTB_CAN_SEND) |
648 | htb_add_to_wait_tree(q, cl, diff); |
649 | } |
650 | |
651 | /* update byte stats except for leaves which are already updated */ |
652 | if (cl->level) { |
653 | cl->bstats.bytes += bytes; |
654 | cl->bstats.packets += skb_is_gso(skb)? |
655 | skb_shinfo(skb)->gso_segs:1; |
656 | } |
657 | cl = cl->parent; |
658 | } |
659 | } |
660 | |
661 | /** |
662 | * htb_do_events - make mode changes to classes at the level |
663 | * |
664 | * Scans event queue for pending events and applies them. Returns time of |
665 | * next pending event (0 for no event in pq, q->now for too many events). |
666 | * Note: Applied are events whose have cl->pq_key <= q->now. |
667 | */ |
668 | static psched_time_t htb_do_events(struct htb_sched *q, int level, |
669 | unsigned long start) |
670 | { |
671 | /* don't run for longer than 2 jiffies; 2 is used instead of |
672 | 1 to simplify things when jiffy is going to be incremented |
673 | too soon */ |
674 | unsigned long stop_at = start + 2; |
675 | while (time_before(jiffies, stop_at)) { |
676 | struct htb_class *cl; |
677 | long diff; |
678 | struct rb_node *p = rb_first(&q->wait_pq[level]); |
679 | |
680 | if (!p) |
681 | return 0; |
682 | |
683 | cl = rb_entry(p, struct htb_class, pq_node); |
684 | if (cl->pq_key > q->now) |
685 | return cl->pq_key; |
686 | |
687 | htb_safe_rb_erase(p, q->wait_pq + level); |
688 | diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer); |
689 | htb_change_class_mode(q, cl, &diff); |
690 | if (cl->cmode != HTB_CAN_SEND) |
691 | htb_add_to_wait_tree(q, cl, diff); |
692 | } |
693 | |
694 | /* too much load - let's continue after a break for scheduling */ |
695 | if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) { |
696 | printk(KERN_WARNING "htb: too many events!\n"); |
697 | q->warned |= HTB_WARN_TOOMANYEVENTS; |
698 | } |
699 | |
700 | return q->now; |
701 | } |
702 | |
703 | /* Returns class->node+prio from id-tree where classe's id is >= id. NULL |
704 | is no such one exists. */ |
705 | static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n, |
706 | u32 id) |
707 | { |
708 | struct rb_node *r = NULL; |
709 | while (n) { |
710 | struct htb_class *cl = |
711 | rb_entry(n, struct htb_class, node[prio]); |
712 | |
713 | if (id > cl->common.classid) { |
714 | n = n->rb_right; |
715 | } else if (id < cl->common.classid) { |
716 | r = n; |
717 | n = n->rb_left; |
718 | } else { |
719 | return n; |
720 | } |
721 | } |
722 | return r; |
723 | } |
724 | |
725 | /** |
726 | * htb_lookup_leaf - returns next leaf class in DRR order |
727 | * |
728 | * Find leaf where current feed pointers points to. |
729 | */ |
730 | static struct htb_class *htb_lookup_leaf(struct rb_root *tree, int prio, |
731 | struct rb_node **pptr, u32 * pid) |
732 | { |
733 | int i; |
734 | struct { |
735 | struct rb_node *root; |
736 | struct rb_node **pptr; |
737 | u32 *pid; |
738 | } stk[TC_HTB_MAXDEPTH], *sp = stk; |
739 | |
740 | BUG_ON(!tree->rb_node); |
741 | sp->root = tree->rb_node; |
742 | sp->pptr = pptr; |
743 | sp->pid = pid; |
744 | |
745 | for (i = 0; i < 65535; i++) { |
746 | if (!*sp->pptr && *sp->pid) { |
747 | /* ptr was invalidated but id is valid - try to recover |
748 | the original or next ptr */ |
749 | *sp->pptr = |
750 | htb_id_find_next_upper(prio, sp->root, *sp->pid); |
751 | } |
752 | *sp->pid = 0; /* ptr is valid now so that remove this hint as it |
753 | can become out of date quickly */ |
754 | if (!*sp->pptr) { /* we are at right end; rewind & go up */ |
755 | *sp->pptr = sp->root; |
756 | while ((*sp->pptr)->rb_left) |
757 | *sp->pptr = (*sp->pptr)->rb_left; |
758 | if (sp > stk) { |
759 | sp--; |
760 | if (!*sp->pptr) { |
761 | WARN_ON(1); |
762 | return NULL; |
763 | } |
764 | htb_next_rb_node(sp->pptr); |
765 | } |
766 | } else { |
767 | struct htb_class *cl; |
768 | cl = rb_entry(*sp->pptr, struct htb_class, node[prio]); |
769 | if (!cl->level) |
770 | return cl; |
771 | (++sp)->root = cl->un.inner.feed[prio].rb_node; |
772 | sp->pptr = cl->un.inner.ptr + prio; |
773 | sp->pid = cl->un.inner.last_ptr_id + prio; |
774 | } |
775 | } |
776 | WARN_ON(1); |
777 | return NULL; |
778 | } |
779 | |
780 | /* dequeues packet at given priority and level; call only if |
781 | you are sure that there is active class at prio/level */ |
782 | static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, int prio, |
783 | int level) |
784 | { |
785 | struct sk_buff *skb = NULL; |
786 | struct htb_class *cl, *start; |
787 | /* look initial class up in the row */ |
788 | start = cl = htb_lookup_leaf(q->row[level] + prio, prio, |
789 | q->ptr[level] + prio, |
790 | q->last_ptr_id[level] + prio); |
791 | |
792 | do { |
793 | next: |
794 | if (unlikely(!cl)) |
795 | return NULL; |
796 | |
797 | /* class can be empty - it is unlikely but can be true if leaf |
798 | qdisc drops packets in enqueue routine or if someone used |
799 | graft operation on the leaf since last dequeue; |
800 | simply deactivate and skip such class */ |
801 | if (unlikely(cl->un.leaf.q->q.qlen == 0)) { |
802 | struct htb_class *next; |
803 | htb_deactivate(q, cl); |
804 | |
805 | /* row/level might become empty */ |
806 | if ((q->row_mask[level] & (1 << prio)) == 0) |
807 | return NULL; |
808 | |
809 | next = htb_lookup_leaf(q->row[level] + prio, |
810 | prio, q->ptr[level] + prio, |
811 | q->last_ptr_id[level] + prio); |
812 | |
813 | if (cl == start) /* fix start if we just deleted it */ |
814 | start = next; |
815 | cl = next; |
816 | goto next; |
817 | } |
818 | |
819 | skb = cl->un.leaf.q->dequeue(cl->un.leaf.q); |
820 | if (likely(skb != NULL)) |
821 | break; |
822 | |
823 | qdisc_warn_nonwc("htb", cl->un.leaf.q); |
824 | htb_next_rb_node((level ? cl->parent->un.inner.ptr : q-> |
825 | ptr[0]) + prio); |
826 | cl = htb_lookup_leaf(q->row[level] + prio, prio, |
827 | q->ptr[level] + prio, |
828 | q->last_ptr_id[level] + prio); |
829 | |
830 | } while (cl != start); |
831 | |
832 | if (likely(skb != NULL)) { |
833 | cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb); |
834 | if (cl->un.leaf.deficit[level] < 0) { |
835 | cl->un.leaf.deficit[level] += cl->quantum; |
836 | htb_next_rb_node((level ? cl->parent->un.inner.ptr : q-> |
837 | ptr[0]) + prio); |
838 | } |
839 | /* this used to be after charge_class but this constelation |
840 | gives us slightly better performance */ |
841 | if (!cl->un.leaf.q->q.qlen) |
842 | htb_deactivate(q, cl); |
843 | htb_charge_class(q, cl, level, skb); |
844 | } |
845 | return skb; |
846 | } |
847 | |
848 | static struct sk_buff *htb_dequeue(struct Qdisc *sch) |
849 | { |
850 | struct sk_buff *skb = NULL; |
851 | struct htb_sched *q = qdisc_priv(sch); |
852 | int level; |
853 | psched_time_t next_event; |
854 | unsigned long start_at; |
855 | |
856 | /* try to dequeue direct packets as high prio (!) to minimize cpu work */ |
857 | skb = __skb_dequeue(&q->direct_queue); |
858 | if (skb != NULL) { |
859 | sch->flags &= ~TCQ_F_THROTTLED; |
860 | sch->q.qlen--; |
861 | return skb; |
862 | } |
863 | |
864 | if (!sch->q.qlen) |
865 | goto fin; |
866 | q->now = psched_get_time(); |
867 | start_at = jiffies; |
868 | |
869 | next_event = q->now + 5 * PSCHED_TICKS_PER_SEC; |
870 | |
871 | for (level = 0; level < TC_HTB_MAXDEPTH; level++) { |
872 | /* common case optimization - skip event handler quickly */ |
873 | int m; |
874 | psched_time_t event; |
875 | |
876 | if (q->now >= q->near_ev_cache[level]) { |
877 | event = htb_do_events(q, level, start_at); |
878 | if (!event) |
879 | event = q->now + PSCHED_TICKS_PER_SEC; |
880 | q->near_ev_cache[level] = event; |
881 | } else |
882 | event = q->near_ev_cache[level]; |
883 | |
884 | if (next_event > event) |
885 | next_event = event; |
886 | |
887 | m = ~q->row_mask[level]; |
888 | while (m != (int)(-1)) { |
889 | int prio = ffz(m); |
890 | m |= 1 << prio; |
891 | skb = htb_dequeue_tree(q, prio, level); |
892 | if (likely(skb != NULL)) { |
893 | sch->q.qlen--; |
894 | sch->flags &= ~TCQ_F_THROTTLED; |
895 | goto fin; |
896 | } |
897 | } |
898 | } |
899 | sch->qstats.overlimits++; |
900 | if (likely(next_event > q->now)) |
901 | qdisc_watchdog_schedule(&q->watchdog, next_event); |
902 | else |
903 | schedule_work(&q->work); |
904 | fin: |
905 | return skb; |
906 | } |
907 | |
908 | /* try to drop from each class (by prio) until one succeed */ |
909 | static unsigned int htb_drop(struct Qdisc *sch) |
910 | { |
911 | struct htb_sched *q = qdisc_priv(sch); |
912 | int prio; |
913 | |
914 | for (prio = TC_HTB_NUMPRIO - 1; prio >= 0; prio--) { |
915 | struct list_head *p; |
916 | list_for_each(p, q->drops + prio) { |
917 | struct htb_class *cl = list_entry(p, struct htb_class, |
918 | un.leaf.drop_list); |
919 | unsigned int len; |
920 | if (cl->un.leaf.q->ops->drop && |
921 | (len = cl->un.leaf.q->ops->drop(cl->un.leaf.q))) { |
922 | sch->q.qlen--; |
923 | if (!cl->un.leaf.q->q.qlen) |
924 | htb_deactivate(q, cl); |
925 | return len; |
926 | } |
927 | } |
928 | } |
929 | return 0; |
930 | } |
931 | |
932 | /* reset all classes */ |
933 | /* always caled under BH & queue lock */ |
934 | static void htb_reset(struct Qdisc *sch) |
935 | { |
936 | struct htb_sched *q = qdisc_priv(sch); |
937 | struct htb_class *cl; |
938 | struct hlist_node *n; |
939 | unsigned int i; |
940 | |
941 | for (i = 0; i < q->clhash.hashsize; i++) { |
942 | hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { |
943 | if (cl->level) |
944 | memset(&cl->un.inner, 0, sizeof(cl->un.inner)); |
945 | else { |
946 | if (cl->un.leaf.q) |
947 | qdisc_reset(cl->un.leaf.q); |
948 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); |
949 | } |
950 | cl->prio_activity = 0; |
951 | cl->cmode = HTB_CAN_SEND; |
952 | |
953 | } |
954 | } |
955 | qdisc_watchdog_cancel(&q->watchdog); |
956 | __skb_queue_purge(&q->direct_queue); |
957 | sch->q.qlen = 0; |
958 | memset(q->row, 0, sizeof(q->row)); |
959 | memset(q->row_mask, 0, sizeof(q->row_mask)); |
960 | memset(q->wait_pq, 0, sizeof(q->wait_pq)); |
961 | memset(q->ptr, 0, sizeof(q->ptr)); |
962 | for (i = 0; i < TC_HTB_NUMPRIO; i++) |
963 | INIT_LIST_HEAD(q->drops + i); |
964 | } |
965 | |
966 | static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = { |
967 | [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) }, |
968 | [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) }, |
969 | [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, |
970 | [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, |
971 | }; |
972 | |
973 | static void htb_work_func(struct work_struct *work) |
974 | { |
975 | struct htb_sched *q = container_of(work, struct htb_sched, work); |
976 | struct Qdisc *sch = q->watchdog.qdisc; |
977 | |
978 | __netif_schedule(qdisc_root(sch)); |
979 | } |
980 | |
981 | static int htb_init(struct Qdisc *sch, struct nlattr *opt) |
982 | { |
983 | struct htb_sched *q = qdisc_priv(sch); |
984 | struct nlattr *tb[TCA_HTB_INIT + 1]; |
985 | struct tc_htb_glob *gopt; |
986 | int err; |
987 | int i; |
988 | |
989 | if (!opt) |
990 | return -EINVAL; |
991 | |
992 | err = nla_parse_nested(tb, TCA_HTB_INIT, opt, htb_policy); |
993 | if (err < 0) |
994 | return err; |
995 | |
996 | if (tb[TCA_HTB_INIT] == NULL) { |
997 | printk(KERN_ERR "HTB: hey probably you have bad tc tool ?\n"); |
998 | return -EINVAL; |
999 | } |
1000 | gopt = nla_data(tb[TCA_HTB_INIT]); |
1001 | if (gopt->version != HTB_VER >> 16) { |
1002 | printk(KERN_ERR |
1003 | "HTB: need tc/htb version %d (minor is %d), you have %d\n", |
1004 | HTB_VER >> 16, HTB_VER & 0xffff, gopt->version); |
1005 | return -EINVAL; |
1006 | } |
1007 | |
1008 | err = qdisc_class_hash_init(&q->clhash); |
1009 | if (err < 0) |
1010 | return err; |
1011 | for (i = 0; i < TC_HTB_NUMPRIO; i++) |
1012 | INIT_LIST_HEAD(q->drops + i); |
1013 | |
1014 | qdisc_watchdog_init(&q->watchdog, sch); |
1015 | INIT_WORK(&q->work, htb_work_func); |
1016 | skb_queue_head_init(&q->direct_queue); |
1017 | |
1018 | q->direct_qlen = qdisc_dev(sch)->tx_queue_len; |
1019 | if (q->direct_qlen < 2) /* some devices have zero tx_queue_len */ |
1020 | q->direct_qlen = 2; |
1021 | |
1022 | if ((q->rate2quantum = gopt->rate2quantum) < 1) |
1023 | q->rate2quantum = 1; |
1024 | q->defcls = gopt->defcls; |
1025 | |
1026 | return 0; |
1027 | } |
1028 | |
1029 | static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) |
1030 | { |
1031 | spinlock_t *root_lock = qdisc_root_sleeping_lock(sch); |
1032 | struct htb_sched *q = qdisc_priv(sch); |
1033 | struct nlattr *nest; |
1034 | struct tc_htb_glob gopt; |
1035 | |
1036 | spin_lock_bh(root_lock); |
1037 | |
1038 | gopt.direct_pkts = q->direct_pkts; |
1039 | gopt.version = HTB_VER; |
1040 | gopt.rate2quantum = q->rate2quantum; |
1041 | gopt.defcls = q->defcls; |
1042 | gopt.debug = 0; |
1043 | |
1044 | nest = nla_nest_start(skb, TCA_OPTIONS); |
1045 | if (nest == NULL) |
1046 | goto nla_put_failure; |
1047 | NLA_PUT(skb, TCA_HTB_INIT, sizeof(gopt), &gopt); |
1048 | nla_nest_end(skb, nest); |
1049 | |
1050 | spin_unlock_bh(root_lock); |
1051 | return skb->len; |
1052 | |
1053 | nla_put_failure: |
1054 | spin_unlock_bh(root_lock); |
1055 | nla_nest_cancel(skb, nest); |
1056 | return -1; |
1057 | } |
1058 | |
1059 | static int htb_dump_class(struct Qdisc *sch, unsigned long arg, |
1060 | struct sk_buff *skb, struct tcmsg *tcm) |
1061 | { |
1062 | struct htb_class *cl = (struct htb_class *)arg; |
1063 | spinlock_t *root_lock = qdisc_root_sleeping_lock(sch); |
1064 | struct nlattr *nest; |
1065 | struct tc_htb_opt opt; |
1066 | |
1067 | spin_lock_bh(root_lock); |
1068 | tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT; |
1069 | tcm->tcm_handle = cl->common.classid; |
1070 | if (!cl->level && cl->un.leaf.q) |
1071 | tcm->tcm_info = cl->un.leaf.q->handle; |
1072 | |
1073 | nest = nla_nest_start(skb, TCA_OPTIONS); |
1074 | if (nest == NULL) |
1075 | goto nla_put_failure; |
1076 | |
1077 | memset(&opt, 0, sizeof(opt)); |
1078 | |
1079 | opt.rate = cl->rate->rate; |
1080 | opt.buffer = cl->buffer; |
1081 | opt.ceil = cl->ceil->rate; |
1082 | opt.cbuffer = cl->cbuffer; |
1083 | opt.quantum = cl->quantum; |
1084 | opt.prio = cl->prio; |
1085 | opt.level = cl->level; |
1086 | NLA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt); |
1087 | |
1088 | nla_nest_end(skb, nest); |
1089 | spin_unlock_bh(root_lock); |
1090 | return skb->len; |
1091 | |
1092 | nla_put_failure: |
1093 | spin_unlock_bh(root_lock); |
1094 | nla_nest_cancel(skb, nest); |
1095 | return -1; |
1096 | } |
1097 | |
1098 | static int |
1099 | htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) |
1100 | { |
1101 | struct htb_class *cl = (struct htb_class *)arg; |
1102 | |
1103 | if (!cl->level && cl->un.leaf.q) |
1104 | cl->qstats.qlen = cl->un.leaf.q->q.qlen; |
1105 | cl->xstats.tokens = cl->tokens; |
1106 | cl->xstats.ctokens = cl->ctokens; |
1107 | |
1108 | if (gnet_stats_copy_basic(d, &cl->bstats) < 0 || |
1109 | gnet_stats_copy_rate_est(d, NULL, &cl->rate_est) < 0 || |
1110 | gnet_stats_copy_queue(d, &cl->qstats) < 0) |
1111 | return -1; |
1112 | |
1113 | return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats)); |
1114 | } |
1115 | |
1116 | static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, |
1117 | struct Qdisc **old) |
1118 | { |
1119 | struct htb_class *cl = (struct htb_class *)arg; |
1120 | |
1121 | if (cl->level) |
1122 | return -EINVAL; |
1123 | if (new == NULL && |
1124 | (new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, |
1125 | &pfifo_qdisc_ops, |
1126 | cl->common.classid)) == NULL) |
1127 | return -ENOBUFS; |
1128 | |
1129 | sch_tree_lock(sch); |
1130 | *old = cl->un.leaf.q; |
1131 | cl->un.leaf.q = new; |
1132 | if (*old != NULL) { |
1133 | qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); |
1134 | qdisc_reset(*old); |
1135 | } |
1136 | sch_tree_unlock(sch); |
1137 | return 0; |
1138 | } |
1139 | |
1140 | static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg) |
1141 | { |
1142 | struct htb_class *cl = (struct htb_class *)arg; |
1143 | return !cl->level ? cl->un.leaf.q : NULL; |
1144 | } |
1145 | |
1146 | static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg) |
1147 | { |
1148 | struct htb_class *cl = (struct htb_class *)arg; |
1149 | |
1150 | if (cl->un.leaf.q->q.qlen == 0) |
1151 | htb_deactivate(qdisc_priv(sch), cl); |
1152 | } |
1153 | |
1154 | static unsigned long htb_get(struct Qdisc *sch, u32 classid) |
1155 | { |
1156 | struct htb_class *cl = htb_find(classid, sch); |
1157 | if (cl) |
1158 | cl->refcnt++; |
1159 | return (unsigned long)cl; |
1160 | } |
1161 | |
1162 | static inline int htb_parent_last_child(struct htb_class *cl) |
1163 | { |
1164 | if (!cl->parent) |
1165 | /* the root class */ |
1166 | return 0; |
1167 | if (cl->parent->children > 1) |
1168 | /* not the last child */ |
1169 | return 0; |
1170 | return 1; |
1171 | } |
1172 | |
1173 | static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, |
1174 | struct Qdisc *new_q) |
1175 | { |
1176 | struct htb_class *parent = cl->parent; |
1177 | |
1178 | WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity); |
1179 | |
1180 | if (parent->cmode != HTB_CAN_SEND) |
1181 | htb_safe_rb_erase(&parent->pq_node, q->wait_pq + parent->level); |
1182 | |
1183 | parent->level = 0; |
1184 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); |
1185 | INIT_LIST_HEAD(&parent->un.leaf.drop_list); |
1186 | parent->un.leaf.q = new_q ? new_q : &noop_qdisc; |
1187 | parent->tokens = parent->buffer; |
1188 | parent->ctokens = parent->cbuffer; |
1189 | parent->t_c = psched_get_time(); |
1190 | parent->cmode = HTB_CAN_SEND; |
1191 | } |
1192 | |
1193 | static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl) |
1194 | { |
1195 | if (!cl->level) { |
1196 | WARN_ON(!cl->un.leaf.q); |
1197 | qdisc_destroy(cl->un.leaf.q); |
1198 | } |
1199 | gen_kill_estimator(&cl->bstats, &cl->rate_est); |
1200 | qdisc_put_rtab(cl->rate); |
1201 | qdisc_put_rtab(cl->ceil); |
1202 | |
1203 | tcf_destroy_chain(&cl->filter_list); |
1204 | kfree(cl); |
1205 | } |
1206 | |
1207 | static void htb_destroy(struct Qdisc *sch) |
1208 | { |
1209 | struct htb_sched *q = qdisc_priv(sch); |
1210 | struct hlist_node *n, *next; |
1211 | struct htb_class *cl; |
1212 | unsigned int i; |
1213 | |
1214 | cancel_work_sync(&q->work); |
1215 | qdisc_watchdog_cancel(&q->watchdog); |
1216 | /* This line used to be after htb_destroy_class call below |
1217 | and surprisingly it worked in 2.4. But it must precede it |
1218 | because filter need its target class alive to be able to call |
1219 | unbind_filter on it (without Oops). */ |
1220 | tcf_destroy_chain(&q->filter_list); |
1221 | |
1222 | for (i = 0; i < q->clhash.hashsize; i++) { |
1223 | hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) |
1224 | tcf_destroy_chain(&cl->filter_list); |
1225 | } |
1226 | for (i = 0; i < q->clhash.hashsize; i++) { |
1227 | hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i], |
1228 | common.hnode) |
1229 | htb_destroy_class(sch, cl); |
1230 | } |
1231 | qdisc_class_hash_destroy(&q->clhash); |
1232 | __skb_queue_purge(&q->direct_queue); |
1233 | } |
1234 | |
1235 | static int htb_delete(struct Qdisc *sch, unsigned long arg) |
1236 | { |
1237 | struct htb_sched *q = qdisc_priv(sch); |
1238 | struct htb_class *cl = (struct htb_class *)arg; |
1239 | unsigned int qlen; |
1240 | struct Qdisc *new_q = NULL; |
1241 | int last_child = 0; |
1242 | |
1243 | // TODO: why don't allow to delete subtree ? references ? does |
1244 | // tc subsys quarantee us that in htb_destroy it holds no class |
1245 | // refs so that we can remove children safely there ? |
1246 | if (cl->children || cl->filter_cnt) |
1247 | return -EBUSY; |
1248 | |
1249 | if (!cl->level && htb_parent_last_child(cl)) { |
1250 | new_q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, |
1251 | &pfifo_qdisc_ops, |
1252 | cl->parent->common.classid); |
1253 | last_child = 1; |
1254 | } |
1255 | |
1256 | sch_tree_lock(sch); |
1257 | |
1258 | if (!cl->level) { |
1259 | qlen = cl->un.leaf.q->q.qlen; |
1260 | qdisc_reset(cl->un.leaf.q); |
1261 | qdisc_tree_decrease_qlen(cl->un.leaf.q, qlen); |
1262 | } |
1263 | |
1264 | /* delete from hash and active; remainder in destroy_class */ |
1265 | qdisc_class_hash_remove(&q->clhash, &cl->common); |
1266 | if (cl->parent) |
1267 | cl->parent->children--; |
1268 | |
1269 | if (cl->prio_activity) |
1270 | htb_deactivate(q, cl); |
1271 | |
1272 | if (cl->cmode != HTB_CAN_SEND) |
1273 | htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); |
1274 | |
1275 | if (last_child) |
1276 | htb_parent_to_leaf(q, cl, new_q); |
1277 | |
1278 | BUG_ON(--cl->refcnt == 0); |
1279 | /* |
1280 | * This shouldn't happen: we "hold" one cops->get() when called |
1281 | * from tc_ctl_tclass; the destroy method is done from cops->put(). |
1282 | */ |
1283 | |
1284 | sch_tree_unlock(sch); |
1285 | return 0; |
1286 | } |
1287 | |
1288 | static void htb_put(struct Qdisc *sch, unsigned long arg) |
1289 | { |
1290 | struct htb_class *cl = (struct htb_class *)arg; |
1291 | |
1292 | if (--cl->refcnt == 0) |
1293 | htb_destroy_class(sch, cl); |
1294 | } |
1295 | |
1296 | static int htb_change_class(struct Qdisc *sch, u32 classid, |
1297 | u32 parentid, struct nlattr **tca, |
1298 | unsigned long *arg) |
1299 | { |
1300 | int err = -EINVAL; |
1301 | struct htb_sched *q = qdisc_priv(sch); |
1302 | struct htb_class *cl = (struct htb_class *)*arg, *parent; |
1303 | struct nlattr *opt = tca[TCA_OPTIONS]; |
1304 | struct qdisc_rate_table *rtab = NULL, *ctab = NULL; |
1305 | struct nlattr *tb[TCA_HTB_RTAB + 1]; |
1306 | struct tc_htb_opt *hopt; |
1307 | |
1308 | /* extract all subattrs from opt attr */ |
1309 | if (!opt) |
1310 | goto failure; |
1311 | |
1312 | err = nla_parse_nested(tb, TCA_HTB_RTAB, opt, htb_policy); |
1313 | if (err < 0) |
1314 | goto failure; |
1315 | |
1316 | err = -EINVAL; |
1317 | if (tb[TCA_HTB_PARMS] == NULL) |
1318 | goto failure; |
1319 | |
1320 | parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch); |
1321 | |
1322 | hopt = nla_data(tb[TCA_HTB_PARMS]); |
1323 | |
1324 | rtab = qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB]); |
1325 | ctab = qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB]); |
1326 | if (!rtab || !ctab) |
1327 | goto failure; |
1328 | |
1329 | if (!cl) { /* new class */ |
1330 | struct Qdisc *new_q; |
1331 | int prio; |
1332 | struct { |
1333 | struct nlattr nla; |
1334 | struct gnet_estimator opt; |
1335 | } est = { |
1336 | .nla = { |
1337 | .nla_len = nla_attr_size(sizeof(est.opt)), |
1338 | .nla_type = TCA_RATE, |
1339 | }, |
1340 | .opt = { |
1341 | /* 4s interval, 16s averaging constant */ |
1342 | .interval = 2, |
1343 | .ewma_log = 2, |
1344 | }, |
1345 | }; |
1346 | |
1347 | /* check for valid classid */ |
1348 | if (!classid || TC_H_MAJ(classid ^ sch->handle) || |
1349 | htb_find(classid, sch)) |
1350 | goto failure; |
1351 | |
1352 | /* check maximal depth */ |
1353 | if (parent && parent->parent && parent->parent->level < 2) { |
1354 | printk(KERN_ERR "htb: tree is too deep\n"); |
1355 | goto failure; |
1356 | } |
1357 | err = -ENOBUFS; |
1358 | if ((cl = kzalloc(sizeof(*cl), GFP_KERNEL)) == NULL) |
1359 | goto failure; |
1360 | |
1361 | err = gen_new_estimator(&cl->bstats, &cl->rate_est, |
1362 | qdisc_root_sleeping_lock(sch), |
1363 | tca[TCA_RATE] ? : &est.nla); |
1364 | if (err) { |
1365 | kfree(cl); |
1366 | goto failure; |
1367 | } |
1368 | |
1369 | cl->refcnt = 1; |
1370 | cl->children = 0; |
1371 | INIT_LIST_HEAD(&cl->un.leaf.drop_list); |
1372 | RB_CLEAR_NODE(&cl->pq_node); |
1373 | |
1374 | for (prio = 0; prio < TC_HTB_NUMPRIO; prio++) |
1375 | RB_CLEAR_NODE(&cl->node[prio]); |
1376 | |
1377 | /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL) |
1378 | so that can't be used inside of sch_tree_lock |
1379 | -- thanks to Karlis Peisenieks */ |
1380 | new_q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, |
1381 | &pfifo_qdisc_ops, classid); |
1382 | sch_tree_lock(sch); |
1383 | if (parent && !parent->level) { |
1384 | unsigned int qlen = parent->un.leaf.q->q.qlen; |
1385 | |
1386 | /* turn parent into inner node */ |
1387 | qdisc_reset(parent->un.leaf.q); |
1388 | qdisc_tree_decrease_qlen(parent->un.leaf.q, qlen); |
1389 | qdisc_destroy(parent->un.leaf.q); |
1390 | if (parent->prio_activity) |
1391 | htb_deactivate(q, parent); |
1392 | |
1393 | /* remove from evt list because of level change */ |
1394 | if (parent->cmode != HTB_CAN_SEND) { |
1395 | htb_safe_rb_erase(&parent->pq_node, q->wait_pq); |
1396 | parent->cmode = HTB_CAN_SEND; |
1397 | } |
1398 | parent->level = (parent->parent ? parent->parent->level |
1399 | : TC_HTB_MAXDEPTH) - 1; |
1400 | memset(&parent->un.inner, 0, sizeof(parent->un.inner)); |
1401 | } |
1402 | /* leaf (we) needs elementary qdisc */ |
1403 | cl->un.leaf.q = new_q ? new_q : &noop_qdisc; |
1404 | |
1405 | cl->common.classid = classid; |
1406 | cl->parent = parent; |
1407 | |
1408 | /* set class to be in HTB_CAN_SEND state */ |
1409 | cl->tokens = hopt->buffer; |
1410 | cl->ctokens = hopt->cbuffer; |
1411 | cl->mbuffer = 60 * PSCHED_TICKS_PER_SEC; /* 1min */ |
1412 | cl->t_c = psched_get_time(); |
1413 | cl->cmode = HTB_CAN_SEND; |
1414 | |
1415 | /* attach to the hash list and parent's family */ |
1416 | qdisc_class_hash_insert(&q->clhash, &cl->common); |
1417 | if (parent) |
1418 | parent->children++; |
1419 | } else { |
1420 | if (tca[TCA_RATE]) { |
1421 | err = gen_replace_estimator(&cl->bstats, &cl->rate_est, |
1422 | qdisc_root_sleeping_lock(sch), |
1423 | tca[TCA_RATE]); |
1424 | if (err) |
1425 | return err; |
1426 | } |
1427 | sch_tree_lock(sch); |
1428 | } |
1429 | |
1430 | /* it used to be a nasty bug here, we have to check that node |
1431 | is really leaf before changing cl->un.leaf ! */ |
1432 | if (!cl->level) { |
1433 | cl->quantum = rtab->rate.rate / q->rate2quantum; |
1434 | if (!hopt->quantum && cl->quantum < 1000) { |
1435 | printk(KERN_WARNING |
1436 | "HTB: quantum of class %X is small. Consider r2q change.\n", |
1437 | cl->common.classid); |
1438 | cl->quantum = 1000; |
1439 | } |
1440 | if (!hopt->quantum && cl->quantum > 200000) { |
1441 | printk(KERN_WARNING |
1442 | "HTB: quantum of class %X is big. Consider r2q change.\n", |
1443 | cl->common.classid); |
1444 | cl->quantum = 200000; |
1445 | } |
1446 | if (hopt->quantum) |
1447 | cl->quantum = hopt->quantum; |
1448 | if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO) |
1449 | cl->prio = TC_HTB_NUMPRIO - 1; |
1450 | } |
1451 | |
1452 | cl->buffer = hopt->buffer; |
1453 | cl->cbuffer = hopt->cbuffer; |
1454 | if (cl->rate) |
1455 | qdisc_put_rtab(cl->rate); |
1456 | cl->rate = rtab; |
1457 | if (cl->ceil) |
1458 | qdisc_put_rtab(cl->ceil); |
1459 | cl->ceil = ctab; |
1460 | sch_tree_unlock(sch); |
1461 | |
1462 | qdisc_class_hash_grow(sch, &q->clhash); |
1463 | |
1464 | *arg = (unsigned long)cl; |
1465 | return 0; |
1466 | |
1467 | failure: |
1468 | if (rtab) |
1469 | qdisc_put_rtab(rtab); |
1470 | if (ctab) |
1471 | qdisc_put_rtab(ctab); |
1472 | return err; |
1473 | } |
1474 | |
1475 | static struct tcf_proto **htb_find_tcf(struct Qdisc *sch, unsigned long arg) |
1476 | { |
1477 | struct htb_sched *q = qdisc_priv(sch); |
1478 | struct htb_class *cl = (struct htb_class *)arg; |
1479 | struct tcf_proto **fl = cl ? &cl->filter_list : &q->filter_list; |
1480 | |
1481 | return fl; |
1482 | } |
1483 | |
1484 | static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent, |
1485 | u32 classid) |
1486 | { |
1487 | struct htb_class *cl = htb_find(classid, sch); |
1488 | |
1489 | /*if (cl && !cl->level) return 0; |
1490 | The line above used to be there to prevent attaching filters to |
1491 | leaves. But at least tc_index filter uses this just to get class |
1492 | for other reasons so that we have to allow for it. |
1493 | ---- |
1494 | 19.6.2002 As Werner explained it is ok - bind filter is just |
1495 | another way to "lock" the class - unlike "get" this lock can |
1496 | be broken by class during destroy IIUC. |
1497 | */ |
1498 | if (cl) |
1499 | cl->filter_cnt++; |
1500 | return (unsigned long)cl; |
1501 | } |
1502 | |
1503 | static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg) |
1504 | { |
1505 | struct htb_class *cl = (struct htb_class *)arg; |
1506 | |
1507 | if (cl) |
1508 | cl->filter_cnt--; |
1509 | } |
1510 | |
1511 | static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
1512 | { |
1513 | struct htb_sched *q = qdisc_priv(sch); |
1514 | struct htb_class *cl; |
1515 | struct hlist_node *n; |
1516 | unsigned int i; |
1517 | |
1518 | if (arg->stop) |
1519 | return; |
1520 | |
1521 | for (i = 0; i < q->clhash.hashsize; i++) { |
1522 | hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { |
1523 | if (arg->count < arg->skip) { |
1524 | arg->count++; |
1525 | continue; |
1526 | } |
1527 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { |
1528 | arg->stop = 1; |
1529 | return; |
1530 | } |
1531 | arg->count++; |
1532 | } |
1533 | } |
1534 | } |
1535 | |
1536 | static const struct Qdisc_class_ops htb_class_ops = { |
1537 | .graft = htb_graft, |
1538 | .leaf = htb_leaf, |
1539 | .qlen_notify = htb_qlen_notify, |
1540 | .get = htb_get, |
1541 | .put = htb_put, |
1542 | .change = htb_change_class, |
1543 | .delete = htb_delete, |
1544 | .walk = htb_walk, |
1545 | .tcf_chain = htb_find_tcf, |
1546 | .bind_tcf = htb_bind_filter, |
1547 | .unbind_tcf = htb_unbind_filter, |
1548 | .dump = htb_dump_class, |
1549 | .dump_stats = htb_dump_class_stats, |
1550 | }; |
1551 | |
1552 | static struct Qdisc_ops htb_qdisc_ops __read_mostly = { |
1553 | .next = NULL, |
1554 | .cl_ops = &htb_class_ops, |
1555 | .id = "htb", |
1556 | .priv_size = sizeof(struct htb_sched), |
1557 | .enqueue = htb_enqueue, |
1558 | .dequeue = htb_dequeue, |
1559 | .peek = qdisc_peek_dequeued, |
1560 | .drop = htb_drop, |
1561 | .init = htb_init, |
1562 | .reset = htb_reset, |
1563 | .destroy = htb_destroy, |
1564 | .change = NULL /* htb_change */, |
1565 | .dump = htb_dump, |
1566 | .owner = THIS_MODULE, |
1567 | }; |
1568 | |
1569 | static int __init htb_module_init(void) |
1570 | { |
1571 | return register_qdisc(&htb_qdisc_ops); |
1572 | } |
1573 | static void __exit htb_module_exit(void) |
1574 | { |
1575 | unregister_qdisc(&htb_qdisc_ops); |
1576 | } |
1577 | |
1578 | module_init(htb_module_init) |
1579 | module_exit(htb_module_exit) |
1580 | MODULE_LICENSE("GPL"); |
1581 |
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