1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * net/sched/sch_htb.c Hierarchical token bucket, feed tree version
5 * Authors: Martin Devera, <devik@cdi.cz>
7 * Credits (in time order) for older HTB versions:
8 * Stef Coene <stef.coene@docum.org>
9 * HTB support at LARTC mailing list
10 * Ondrej Kraus, <krauso@barr.cz>
11 * found missing INIT_QDISC(htb)
12 * Vladimir Smelhaus, Aamer Akhter, Bert Hubert
13 * helped a lot to locate nasty class stall bug
14 * Andi Kleen, Jamal Hadi, Bert Hubert
15 * code review and helpful comments on shaping
16 * Tomasz Wrona, <tw@eter.tym.pl>
17 * created test case so that I was able to fix nasty bug
19 * spotted bug in dequeue code and helped with fix
21 * fixed requeue routine
22 * and many others. thanks.
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/errno.h>
30 #include <linux/skbuff.h>
31 #include <linux/list.h>
32 #include <linux/compiler.h>
33 #include <linux/rbtree.h>
34 #include <linux/workqueue.h>
35 #include <linux/slab.h>
36 #include <net/netlink.h>
37 #include <net/sch_generic.h>
38 #include <net/pkt_sched.h>
39 #include <net/pkt_cls.h>
43 ========================================================================
44 HTB is like TBF with multiple classes. It is also similar to CBQ because
45 it allows to assign priority to each class in hierarchy.
46 In fact it is another implementation of Floyd's formal sharing.
49 Each class is assigned level. Leaf has ALWAYS level 0 and root
50 classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
51 one less than their parent.
54 static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */
55 #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */
57 #if HTB_VER >> 16 != TC_HTB_PROTOVER
58 #error "Mismatched sch_htb.c and pkt_sch.h"
61 /* Module parameter and sysfs export */
62 module_param (htb_hysteresis, int, 0640);
63 MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate");
65 static int htb_rate_est = 0; /* htb classes have a default rate estimator */
66 module_param(htb_rate_est, int, 0640);
67 MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes");
69 /* used internaly to keep status of single class */
71 HTB_CANT_SEND, /* class can't send and can't borrow */
72 HTB_MAY_BORROW, /* class can't send but may borrow */
73 HTB_CAN_SEND /* class can send */
82 /* When class changes from state 1->2 and disconnects from
83 * parent's feed then we lost ptr value and start from the
84 * first child again. Here we store classid of the
85 * last valid ptr (used when ptr is NULL).
90 /* interior & leaf nodes; props specific to leaves are marked L:
91 * To reduce false sharing, place mostly read fields at beginning,
92 * and mostly written ones at the end.
95 struct Qdisc_class_common common;
96 struct psched_ratecfg rate;
97 struct psched_ratecfg ceil;
98 s64 buffer, cbuffer;/* token bucket depth/rate */
99 s64 mbuffer; /* max wait time */
100 u32 prio; /* these two are used only by leaves... */
101 int quantum; /* but stored for parent-to-leaf return */
103 struct tcf_proto __rcu *filter_list; /* class attached filters */
104 struct tcf_block *block;
107 int level; /* our level (see above) */
108 unsigned int children;
109 struct htb_class *parent; /* parent class */
111 struct net_rate_estimator __rcu *rate_est;
114 * Written often fields
116 struct gnet_stats_basic_packed bstats;
117 struct gnet_stats_basic_packed bstats_bias;
118 struct tc_htb_xstats xstats; /* our special stats */
120 /* token bucket parameters */
121 s64 tokens, ctokens;/* current number of tokens */
122 s64 t_c; /* checkpoint time */
125 struct htb_class_leaf {
126 int deficit[TC_HTB_MAXDEPTH];
129 struct htb_class_inner {
130 struct htb_prio clprio[TC_HTB_NUMPRIO];
135 int prio_activity; /* for which prios are we active */
136 enum htb_cmode cmode; /* current mode of the class */
137 struct rb_node pq_node; /* node for event queue */
138 struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */
140 unsigned int drops ____cacheline_aligned_in_smp;
141 unsigned int overlimits;
145 struct rb_root wait_pq;
146 struct htb_prio hprio[TC_HTB_NUMPRIO];
150 struct Qdisc_class_hash clhash;
151 int defcls; /* class where unclassified flows go to */
152 int rate2quantum; /* quant = rate / rate2quantum */
154 /* filters for qdisc itself */
155 struct tcf_proto __rcu *filter_list;
156 struct tcf_block *block;
158 #define HTB_WARN_TOOMANYEVENTS 0x1
159 unsigned int warned; /* only one warning */
161 struct work_struct work;
163 /* non shaped skbs; let them go directly thru */
164 struct qdisc_skb_head direct_queue;
168 struct qdisc_watchdog watchdog;
170 s64 now; /* cached dequeue time */
172 /* time of nearest event per level (row) */
173 s64 near_ev_cache[TC_HTB_MAXDEPTH];
175 int row_mask[TC_HTB_MAXDEPTH];
177 struct htb_level hlevel[TC_HTB_MAXDEPTH];
179 struct Qdisc **direct_qdiscs;
180 unsigned int num_direct_qdiscs;
185 /* find class in global hash table using given handle */
186 static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
188 struct htb_sched *q = qdisc_priv(sch);
189 struct Qdisc_class_common *clc;
191 clc = qdisc_class_find(&q->clhash, handle);
194 return container_of(clc, struct htb_class, common);
197 static unsigned long htb_search(struct Qdisc *sch, u32 handle)
199 return (unsigned long)htb_find(handle, sch);
202 * htb_classify - classify a packet into class
204 * It returns NULL if the packet should be dropped or -1 if the packet
205 * should be passed directly thru. In all other cases leaf class is returned.
206 * We allow direct class selection by classid in priority. The we examine
207 * filters in qdisc and in inner nodes (if higher filter points to the inner
208 * node). If we end up with classid MAJOR:0 we enqueue the skb into special
209 * internal fifo (direct). These packets then go directly thru. If we still
210 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful
211 * then finish and return direct queue.
213 #define HTB_DIRECT ((struct htb_class *)-1L)
215 static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
218 struct htb_sched *q = qdisc_priv(sch);
219 struct htb_class *cl;
220 struct tcf_result res;
221 struct tcf_proto *tcf;
224 /* allow to select class by setting skb->priority to valid classid;
225 * note that nfmark can be used too by attaching filter fw with no
228 if (skb->priority == sch->handle)
229 return HTB_DIRECT; /* X:0 (direct flow) selected */
230 cl = htb_find(skb->priority, sch);
234 /* Start with inner filter chain if a non-leaf class is selected */
235 tcf = rcu_dereference_bh(cl->filter_list);
237 tcf = rcu_dereference_bh(q->filter_list);
240 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
241 while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
242 #ifdef CONFIG_NET_CLS_ACT
247 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
253 cl = (void *)res.class;
255 if (res.classid == sch->handle)
256 return HTB_DIRECT; /* X:0 (direct flow) */
257 cl = htb_find(res.classid, sch);
259 break; /* filter selected invalid classid */
262 return cl; /* we hit leaf; return it */
264 /* we have got inner class; apply inner filter chain */
265 tcf = rcu_dereference_bh(cl->filter_list);
267 /* classification failed; try to use default class */
268 cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
269 if (!cl || cl->level)
270 return HTB_DIRECT; /* bad default .. this is safe bet */
275 * htb_add_to_id_tree - adds class to the round robin list
277 * Routine adds class to the list (actually tree) sorted by classid.
278 * Make sure that class is not already on such list for given prio.
280 static void htb_add_to_id_tree(struct rb_root *root,
281 struct htb_class *cl, int prio)
283 struct rb_node **p = &root->rb_node, *parent = NULL;
288 c = rb_entry(parent, struct htb_class, node[prio]);
290 if (cl->common.classid > c->common.classid)
291 p = &parent->rb_right;
293 p = &parent->rb_left;
295 rb_link_node(&cl->node[prio], parent, p);
296 rb_insert_color(&cl->node[prio], root);
300 * htb_add_to_wait_tree - adds class to the event queue with delay
302 * The class is added to priority event queue to indicate that class will
303 * change its mode in cl->pq_key microseconds. Make sure that class is not
304 * already in the queue.
306 static void htb_add_to_wait_tree(struct htb_sched *q,
307 struct htb_class *cl, s64 delay)
309 struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL;
311 cl->pq_key = q->now + delay;
312 if (cl->pq_key == q->now)
315 /* update the nearest event cache */
316 if (q->near_ev_cache[cl->level] > cl->pq_key)
317 q->near_ev_cache[cl->level] = cl->pq_key;
322 c = rb_entry(parent, struct htb_class, pq_node);
323 if (cl->pq_key >= c->pq_key)
324 p = &parent->rb_right;
326 p = &parent->rb_left;
328 rb_link_node(&cl->pq_node, parent, p);
329 rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
333 * htb_next_rb_node - finds next node in binary tree
335 * When we are past last key we return NULL.
336 * Average complexity is 2 steps per call.
338 static inline void htb_next_rb_node(struct rb_node **n)
344 * htb_add_class_to_row - add class to its row
346 * The class is added to row at priorities marked in mask.
347 * It does nothing if mask == 0.
349 static inline void htb_add_class_to_row(struct htb_sched *q,
350 struct htb_class *cl, int mask)
352 q->row_mask[cl->level] |= mask;
354 int prio = ffz(~mask);
355 mask &= ~(1 << prio);
356 htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio);
360 /* If this triggers, it is a bug in this code, but it need not be fatal */
361 static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root)
363 if (RB_EMPTY_NODE(rb)) {
373 * htb_remove_class_from_row - removes class from its row
375 * The class is removed from row at priorities marked in mask.
376 * It does nothing if mask == 0.
378 static inline void htb_remove_class_from_row(struct htb_sched *q,
379 struct htb_class *cl, int mask)
382 struct htb_level *hlevel = &q->hlevel[cl->level];
385 int prio = ffz(~mask);
386 struct htb_prio *hprio = &hlevel->hprio[prio];
388 mask &= ~(1 << prio);
389 if (hprio->ptr == cl->node + prio)
390 htb_next_rb_node(&hprio->ptr);
392 htb_safe_rb_erase(cl->node + prio, &hprio->row);
393 if (!hprio->row.rb_node)
396 q->row_mask[cl->level] &= ~m;
400 * htb_activate_prios - creates active classe's feed chain
402 * The class is connected to ancestors and/or appropriate rows
403 * for priorities it is participating on. cl->cmode must be new
404 * (activated) mode. It does nothing if cl->prio_activity == 0.
406 static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl)
408 struct htb_class *p = cl->parent;
409 long m, mask = cl->prio_activity;
411 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
417 if (p->inner.clprio[prio].feed.rb_node)
418 /* parent already has its feed in use so that
419 * reset bit in mask as parent is already ok
421 mask &= ~(1 << prio);
423 htb_add_to_id_tree(&p->inner.clprio[prio].feed, cl, prio);
425 p->prio_activity |= mask;
430 if (cl->cmode == HTB_CAN_SEND && mask)
431 htb_add_class_to_row(q, cl, mask);
435 * htb_deactivate_prios - remove class from feed chain
437 * cl->cmode must represent old mode (before deactivation). It does
438 * nothing if cl->prio_activity == 0. Class is removed from all feed
441 static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
443 struct htb_class *p = cl->parent;
444 long m, mask = cl->prio_activity;
446 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
453 if (p->inner.clprio[prio].ptr == cl->node + prio) {
454 /* we are removing child which is pointed to from
455 * parent feed - forget the pointer but remember
458 p->inner.clprio[prio].last_ptr_id = cl->common.classid;
459 p->inner.clprio[prio].ptr = NULL;
462 htb_safe_rb_erase(cl->node + prio,
463 &p->inner.clprio[prio].feed);
465 if (!p->inner.clprio[prio].feed.rb_node)
469 p->prio_activity &= ~mask;
474 if (cl->cmode == HTB_CAN_SEND && mask)
475 htb_remove_class_from_row(q, cl, mask);
478 static inline s64 htb_lowater(const struct htb_class *cl)
481 return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
485 static inline s64 htb_hiwater(const struct htb_class *cl)
488 return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
495 * htb_class_mode - computes and returns current class mode
497 * It computes cl's mode at time cl->t_c+diff and returns it. If mode
498 * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
499 * from now to time when cl will change its state.
500 * Also it is worth to note that class mode doesn't change simply
501 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
502 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
503 * mode transitions per time unit. The speed gain is about 1/6.
505 static inline enum htb_cmode
506 htb_class_mode(struct htb_class *cl, s64 *diff)
510 if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
512 return HTB_CANT_SEND;
515 if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl))
519 return HTB_MAY_BORROW;
523 * htb_change_class_mode - changes classe's mode
525 * This should be the only way how to change classe's mode under normal
526 * cirsumstances. Routine will update feed lists linkage, change mode
527 * and add class to the wait event queue if appropriate. New mode should
528 * be different from old one and cl->pq_key has to be valid if changing
529 * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
532 htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
534 enum htb_cmode new_mode = htb_class_mode(cl, diff);
536 if (new_mode == cl->cmode)
539 if (new_mode == HTB_CANT_SEND) {
544 if (cl->prio_activity) { /* not necessary: speed optimization */
545 if (cl->cmode != HTB_CANT_SEND)
546 htb_deactivate_prios(q, cl);
547 cl->cmode = new_mode;
548 if (new_mode != HTB_CANT_SEND)
549 htb_activate_prios(q, cl);
551 cl->cmode = new_mode;
555 * htb_activate - inserts leaf cl into appropriate active feeds
557 * Routine learns (new) priority of leaf and activates feed chain
558 * for the prio. It can be called on already active leaf safely.
559 * It also adds leaf into droplist.
561 static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
563 WARN_ON(cl->level || !cl->leaf.q || !cl->leaf.q->q.qlen);
565 if (!cl->prio_activity) {
566 cl->prio_activity = 1 << cl->prio;
567 htb_activate_prios(q, cl);
572 * htb_deactivate - remove leaf cl from active feeds
574 * Make sure that leaf is active. In the other words it can't be called
575 * with non-active leaf. It also removes class from the drop list.
577 static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
579 WARN_ON(!cl->prio_activity);
581 htb_deactivate_prios(q, cl);
582 cl->prio_activity = 0;
585 static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
586 struct sk_buff **to_free)
589 unsigned int len = qdisc_pkt_len(skb);
590 struct htb_sched *q = qdisc_priv(sch);
591 struct htb_class *cl = htb_classify(skb, sch, &ret);
593 if (cl == HTB_DIRECT) {
594 /* enqueue to helper queue */
595 if (q->direct_queue.qlen < q->direct_qlen) {
596 __qdisc_enqueue_tail(skb, &q->direct_queue);
599 return qdisc_drop(skb, sch, to_free);
601 #ifdef CONFIG_NET_CLS_ACT
603 if (ret & __NET_XMIT_BYPASS)
604 qdisc_qstats_drop(sch);
605 __qdisc_drop(skb, to_free);
608 } else if ((ret = qdisc_enqueue(skb, cl->leaf.q,
609 to_free)) != NET_XMIT_SUCCESS) {
610 if (net_xmit_drop_count(ret)) {
611 qdisc_qstats_drop(sch);
619 sch->qstats.backlog += len;
621 return NET_XMIT_SUCCESS;
624 static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
626 s64 toks = diff + cl->tokens;
628 if (toks > cl->buffer)
630 toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
631 if (toks <= -cl->mbuffer)
632 toks = 1 - cl->mbuffer;
637 static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
639 s64 toks = diff + cl->ctokens;
641 if (toks > cl->cbuffer)
643 toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
644 if (toks <= -cl->mbuffer)
645 toks = 1 - cl->mbuffer;
651 * htb_charge_class - charges amount "bytes" to leaf and ancestors
653 * Routine assumes that packet "bytes" long was dequeued from leaf cl
654 * borrowing from "level". It accounts bytes to ceil leaky bucket for
655 * leaf and all ancestors and to rate bucket for ancestors at levels
656 * "level" and higher. It also handles possible change of mode resulting
657 * from the update. Note that mode can also increase here (MAY_BORROW to
658 * CAN_SEND) because we can use more precise clock that event queue here.
659 * In such case we remove class from event queue first.
661 static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
662 int level, struct sk_buff *skb)
664 int bytes = qdisc_pkt_len(skb);
665 enum htb_cmode old_mode;
669 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
670 if (cl->level >= level) {
671 if (cl->level == level)
673 htb_accnt_tokens(cl, bytes, diff);
675 cl->xstats.borrows++;
676 cl->tokens += diff; /* we moved t_c; update tokens */
678 htb_accnt_ctokens(cl, bytes, diff);
681 old_mode = cl->cmode;
683 htb_change_class_mode(q, cl, &diff);
684 if (old_mode != cl->cmode) {
685 if (old_mode != HTB_CAN_SEND)
686 htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
687 if (cl->cmode != HTB_CAN_SEND)
688 htb_add_to_wait_tree(q, cl, diff);
691 /* update basic stats except for leaves which are already updated */
693 bstats_update(&cl->bstats, skb);
700 * htb_do_events - make mode changes to classes at the level
702 * Scans event queue for pending events and applies them. Returns time of
703 * next pending event (0 for no event in pq, q->now for too many events).
704 * Note: Applied are events whose have cl->pq_key <= q->now.
706 static s64 htb_do_events(struct htb_sched *q, const int level,
709 /* don't run for longer than 2 jiffies; 2 is used instead of
710 * 1 to simplify things when jiffy is going to be incremented
713 unsigned long stop_at = start + 2;
714 struct rb_root *wait_pq = &q->hlevel[level].wait_pq;
716 while (time_before(jiffies, stop_at)) {
717 struct htb_class *cl;
719 struct rb_node *p = rb_first(wait_pq);
724 cl = rb_entry(p, struct htb_class, pq_node);
725 if (cl->pq_key > q->now)
728 htb_safe_rb_erase(p, wait_pq);
729 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
730 htb_change_class_mode(q, cl, &diff);
731 if (cl->cmode != HTB_CAN_SEND)
732 htb_add_to_wait_tree(q, cl, diff);
735 /* too much load - let's continue after a break for scheduling */
736 if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
737 pr_warn("htb: too many events!\n");
738 q->warned |= HTB_WARN_TOOMANYEVENTS;
744 /* Returns class->node+prio from id-tree where classe's id is >= id. NULL
745 * is no such one exists.
747 static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
750 struct rb_node *r = NULL;
752 struct htb_class *cl =
753 rb_entry(n, struct htb_class, node[prio]);
755 if (id > cl->common.classid) {
757 } else if (id < cl->common.classid) {
768 * htb_lookup_leaf - returns next leaf class in DRR order
770 * Find leaf where current feed pointers points to.
772 static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio)
776 struct rb_node *root;
777 struct rb_node **pptr;
779 } stk[TC_HTB_MAXDEPTH], *sp = stk;
781 BUG_ON(!hprio->row.rb_node);
782 sp->root = hprio->row.rb_node;
783 sp->pptr = &hprio->ptr;
784 sp->pid = &hprio->last_ptr_id;
786 for (i = 0; i < 65535; i++) {
787 if (!*sp->pptr && *sp->pid) {
788 /* ptr was invalidated but id is valid - try to recover
789 * the original or next ptr
792 htb_id_find_next_upper(prio, sp->root, *sp->pid);
794 *sp->pid = 0; /* ptr is valid now so that remove this hint as it
795 * can become out of date quickly
797 if (!*sp->pptr) { /* we are at right end; rewind & go up */
798 *sp->pptr = sp->root;
799 while ((*sp->pptr)->rb_left)
800 *sp->pptr = (*sp->pptr)->rb_left;
807 htb_next_rb_node(sp->pptr);
810 struct htb_class *cl;
811 struct htb_prio *clp;
813 cl = rb_entry(*sp->pptr, struct htb_class, node[prio]);
816 clp = &cl->inner.clprio[prio];
817 (++sp)->root = clp->feed.rb_node;
818 sp->pptr = &clp->ptr;
819 sp->pid = &clp->last_ptr_id;
826 /* dequeues packet at given priority and level; call only if
827 * you are sure that there is active class at prio/level
829 static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio,
832 struct sk_buff *skb = NULL;
833 struct htb_class *cl, *start;
834 struct htb_level *hlevel = &q->hlevel[level];
835 struct htb_prio *hprio = &hlevel->hprio[prio];
837 /* look initial class up in the row */
838 start = cl = htb_lookup_leaf(hprio, prio);
845 /* class can be empty - it is unlikely but can be true if leaf
846 * qdisc drops packets in enqueue routine or if someone used
847 * graft operation on the leaf since last dequeue;
848 * simply deactivate and skip such class
850 if (unlikely(cl->leaf.q->q.qlen == 0)) {
851 struct htb_class *next;
852 htb_deactivate(q, cl);
854 /* row/level might become empty */
855 if ((q->row_mask[level] & (1 << prio)) == 0)
858 next = htb_lookup_leaf(hprio, prio);
860 if (cl == start) /* fix start if we just deleted it */
866 skb = cl->leaf.q->dequeue(cl->leaf.q);
867 if (likely(skb != NULL))
870 qdisc_warn_nonwc("htb", cl->leaf.q);
871 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr:
872 &q->hlevel[0].hprio[prio].ptr);
873 cl = htb_lookup_leaf(hprio, prio);
875 } while (cl != start);
877 if (likely(skb != NULL)) {
878 bstats_update(&cl->bstats, skb);
879 cl->leaf.deficit[level] -= qdisc_pkt_len(skb);
880 if (cl->leaf.deficit[level] < 0) {
881 cl->leaf.deficit[level] += cl->quantum;
882 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr :
883 &q->hlevel[0].hprio[prio].ptr);
885 /* this used to be after charge_class but this constelation
886 * gives us slightly better performance
888 if (!cl->leaf.q->q.qlen)
889 htb_deactivate(q, cl);
890 htb_charge_class(q, cl, level, skb);
895 static struct sk_buff *htb_dequeue(struct Qdisc *sch)
898 struct htb_sched *q = qdisc_priv(sch);
901 unsigned long start_at;
903 /* try to dequeue direct packets as high prio (!) to minimize cpu work */
904 skb = __qdisc_dequeue_head(&q->direct_queue);
907 qdisc_bstats_update(sch, skb);
908 qdisc_qstats_backlog_dec(sch, skb);
915 q->now = ktime_get_ns();
918 next_event = q->now + 5LLU * NSEC_PER_SEC;
920 for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
921 /* common case optimization - skip event handler quickly */
923 s64 event = q->near_ev_cache[level];
925 if (q->now >= event) {
926 event = htb_do_events(q, level, start_at);
928 event = q->now + NSEC_PER_SEC;
929 q->near_ev_cache[level] = event;
932 if (next_event > event)
935 m = ~q->row_mask[level];
936 while (m != (int)(-1)) {
940 skb = htb_dequeue_tree(q, prio, level);
941 if (likely(skb != NULL))
945 if (likely(next_event > q->now))
946 qdisc_watchdog_schedule_ns(&q->watchdog, next_event);
948 schedule_work(&q->work);
953 /* reset all classes */
954 /* always caled under BH & queue lock */
955 static void htb_reset(struct Qdisc *sch)
957 struct htb_sched *q = qdisc_priv(sch);
958 struct htb_class *cl;
961 for (i = 0; i < q->clhash.hashsize; i++) {
962 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
964 memset(&cl->inner, 0, sizeof(cl->inner));
966 if (cl->leaf.q && !q->offload)
967 qdisc_reset(cl->leaf.q);
969 cl->prio_activity = 0;
970 cl->cmode = HTB_CAN_SEND;
973 qdisc_watchdog_cancel(&q->watchdog);
974 __qdisc_reset_queue(&q->direct_queue);
976 sch->qstats.backlog = 0;
977 memset(q->hlevel, 0, sizeof(q->hlevel));
978 memset(q->row_mask, 0, sizeof(q->row_mask));
981 static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = {
982 [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) },
983 [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) },
984 [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
985 [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
986 [TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 },
987 [TCA_HTB_RATE64] = { .type = NLA_U64 },
988 [TCA_HTB_CEIL64] = { .type = NLA_U64 },
989 [TCA_HTB_OFFLOAD] = { .type = NLA_FLAG },
992 static void htb_work_func(struct work_struct *work)
994 struct htb_sched *q = container_of(work, struct htb_sched, work);
995 struct Qdisc *sch = q->watchdog.qdisc;
998 __netif_schedule(qdisc_root(sch));
1002 static void htb_set_lockdep_class_child(struct Qdisc *q)
1004 static struct lock_class_key child_key;
1006 lockdep_set_class(qdisc_lock(q), &child_key);
1009 static int htb_offload(struct net_device *dev, struct tc_htb_qopt_offload *opt)
1011 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_HTB, opt);
1014 static int htb_init(struct Qdisc *sch, struct nlattr *opt,
1015 struct netlink_ext_ack *extack)
1017 struct net_device *dev = qdisc_dev(sch);
1018 struct tc_htb_qopt_offload offload_opt;
1019 struct htb_sched *q = qdisc_priv(sch);
1020 struct nlattr *tb[TCA_HTB_MAX + 1];
1021 struct tc_htb_glob *gopt;
1025 qdisc_watchdog_init(&q->watchdog, sch);
1026 INIT_WORK(&q->work, htb_work_func);
1031 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
1035 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1040 if (!tb[TCA_HTB_INIT])
1043 gopt = nla_data(tb[TCA_HTB_INIT]);
1044 if (gopt->version != HTB_VER >> 16)
1047 q->offload = nla_get_flag(tb[TCA_HTB_OFFLOAD]);
1050 if (sch->parent != TC_H_ROOT)
1053 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
1056 q->num_direct_qdiscs = dev->real_num_tx_queues;
1057 q->direct_qdiscs = kcalloc(q->num_direct_qdiscs,
1058 sizeof(*q->direct_qdiscs),
1060 if (!q->direct_qdiscs)
1064 err = qdisc_class_hash_init(&q->clhash);
1066 goto err_free_direct_qdiscs;
1068 qdisc_skb_head_init(&q->direct_queue);
1070 if (tb[TCA_HTB_DIRECT_QLEN])
1071 q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]);
1073 q->direct_qlen = qdisc_dev(sch)->tx_queue_len;
1075 if ((q->rate2quantum = gopt->rate2quantum) < 1)
1076 q->rate2quantum = 1;
1077 q->defcls = gopt->defcls;
1082 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1083 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1084 struct Qdisc *qdisc;
1086 qdisc = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1087 TC_H_MAKE(sch->handle, 0), extack);
1090 goto err_free_qdiscs;
1093 htb_set_lockdep_class_child(qdisc);
1094 q->direct_qdiscs[ntx] = qdisc;
1095 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1098 sch->flags |= TCQ_F_MQROOT;
1100 offload_opt = (struct tc_htb_qopt_offload) {
1101 .command = TC_HTB_CREATE,
1102 .parent_classid = TC_H_MAJ(sch->handle) >> 16,
1103 .classid = TC_H_MIN(q->defcls),
1106 err = htb_offload(dev, &offload_opt);
1108 goto err_free_qdiscs;
1113 /* TC_HTB_CREATE call failed, avoid any further calls to the driver. */
1116 for (ntx = 0; ntx < q->num_direct_qdiscs && q->direct_qdiscs[ntx];
1118 qdisc_put(q->direct_qdiscs[ntx]);
1120 qdisc_class_hash_destroy(&q->clhash);
1121 /* Prevent use-after-free and double-free when htb_destroy gets called.
1123 q->clhash.hash = NULL;
1124 q->clhash.hashsize = 0;
1126 err_free_direct_qdiscs:
1127 kfree(q->direct_qdiscs);
1128 q->direct_qdiscs = NULL;
1132 static void htb_attach_offload(struct Qdisc *sch)
1134 struct net_device *dev = qdisc_dev(sch);
1135 struct htb_sched *q = qdisc_priv(sch);
1138 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1139 struct Qdisc *old, *qdisc = q->direct_qdiscs[ntx];
1141 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
1143 qdisc_hash_add(qdisc, false);
1145 for (ntx = q->num_direct_qdiscs; ntx < dev->num_tx_queues; ntx++) {
1146 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1147 struct Qdisc *old = dev_graft_qdisc(dev_queue, NULL);
1152 kfree(q->direct_qdiscs);
1153 q->direct_qdiscs = NULL;
1156 static void htb_attach_software(struct Qdisc *sch)
1158 struct net_device *dev = qdisc_dev(sch);
1161 /* Resemble qdisc_graft behavior. */
1162 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
1163 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1164 struct Qdisc *old = dev_graft_qdisc(dev_queue, sch);
1166 qdisc_refcount_inc(sch);
1172 static void htb_attach(struct Qdisc *sch)
1174 struct htb_sched *q = qdisc_priv(sch);
1177 htb_attach_offload(sch);
1179 htb_attach_software(sch);
1182 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
1184 struct htb_sched *q = qdisc_priv(sch);
1185 struct nlattr *nest;
1186 struct tc_htb_glob gopt;
1189 sch->flags |= TCQ_F_OFFLOADED;
1191 sch->flags &= ~TCQ_F_OFFLOADED;
1193 sch->qstats.overlimits = q->overlimits;
1194 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1195 * no change can happen on the qdisc parameters.
1198 gopt.direct_pkts = q->direct_pkts;
1199 gopt.version = HTB_VER;
1200 gopt.rate2quantum = q->rate2quantum;
1201 gopt.defcls = q->defcls;
1204 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1206 goto nla_put_failure;
1207 if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) ||
1208 nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen))
1209 goto nla_put_failure;
1210 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1211 goto nla_put_failure;
1213 return nla_nest_end(skb, nest);
1216 nla_nest_cancel(skb, nest);
1220 static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
1221 struct sk_buff *skb, struct tcmsg *tcm)
1223 struct htb_class *cl = (struct htb_class *)arg;
1224 struct htb_sched *q = qdisc_priv(sch);
1225 struct nlattr *nest;
1226 struct tc_htb_opt opt;
1228 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1229 * no change can happen on the class parameters.
1231 tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT;
1232 tcm->tcm_handle = cl->common.classid;
1233 if (!cl->level && cl->leaf.q)
1234 tcm->tcm_info = cl->leaf.q->handle;
1236 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1238 goto nla_put_failure;
1240 memset(&opt, 0, sizeof(opt));
1242 psched_ratecfg_getrate(&opt.rate, &cl->rate);
1243 opt.buffer = PSCHED_NS2TICKS(cl->buffer);
1244 psched_ratecfg_getrate(&opt.ceil, &cl->ceil);
1245 opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
1246 opt.quantum = cl->quantum;
1247 opt.prio = cl->prio;
1248 opt.level = cl->level;
1249 if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt))
1250 goto nla_put_failure;
1251 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1252 goto nla_put_failure;
1253 if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) &&
1254 nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps,
1256 goto nla_put_failure;
1257 if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) &&
1258 nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps,
1260 goto nla_put_failure;
1262 return nla_nest_end(skb, nest);
1265 nla_nest_cancel(skb, nest);
1269 static void htb_offload_aggregate_stats(struct htb_sched *q,
1270 struct htb_class *cl)
1272 struct htb_class *c;
1275 memset(&cl->bstats, 0, sizeof(cl->bstats));
1277 for (i = 0; i < q->clhash.hashsize; i++) {
1278 hlist_for_each_entry(c, &q->clhash.hash[i], common.hnode) {
1279 struct htb_class *p = c;
1281 while (p && p->level < cl->level)
1287 cl->bstats.bytes += c->bstats_bias.bytes;
1288 cl->bstats.packets += c->bstats_bias.packets;
1289 if (c->level == 0) {
1290 cl->bstats.bytes += c->leaf.q->bstats.bytes;
1291 cl->bstats.packets += c->leaf.q->bstats.packets;
1298 htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
1300 struct htb_class *cl = (struct htb_class *)arg;
1301 struct htb_sched *q = qdisc_priv(sch);
1302 struct gnet_stats_queue qs = {
1304 .overlimits = cl->overlimits,
1308 if (!cl->level && cl->leaf.q)
1309 qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);
1311 cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),
1313 cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),
1319 cl->bstats = cl->leaf.q->bstats;
1321 memset(&cl->bstats, 0, sizeof(cl->bstats));
1322 cl->bstats.bytes += cl->bstats_bias.bytes;
1323 cl->bstats.packets += cl->bstats_bias.packets;
1325 htb_offload_aggregate_stats(q, cl);
1329 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1330 d, NULL, &cl->bstats) < 0 ||
1331 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1332 gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0)
1335 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1338 static struct netdev_queue *
1339 htb_select_queue(struct Qdisc *sch, struct tcmsg *tcm)
1341 struct net_device *dev = qdisc_dev(sch);
1342 struct tc_htb_qopt_offload offload_opt;
1345 offload_opt = (struct tc_htb_qopt_offload) {
1346 .command = TC_HTB_LEAF_QUERY_QUEUE,
1347 .classid = TC_H_MIN(tcm->tcm_parent),
1349 err = htb_offload(dev, &offload_opt);
1350 if (err || offload_opt.qid >= dev->num_tx_queues)
1352 return netdev_get_tx_queue(dev, offload_opt.qid);
1355 static struct Qdisc *
1356 htb_graft_helper(struct netdev_queue *dev_queue, struct Qdisc *new_q)
1358 struct net_device *dev = dev_queue->dev;
1359 struct Qdisc *old_q;
1361 if (dev->flags & IFF_UP)
1362 dev_deactivate(dev);
1363 old_q = dev_graft_qdisc(dev_queue, new_q);
1365 new_q->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1366 if (dev->flags & IFF_UP)
1372 static void htb_offload_move_qdisc(struct Qdisc *sch, u16 qid_old, u16 qid_new)
1374 struct netdev_queue *queue_old, *queue_new;
1375 struct net_device *dev = qdisc_dev(sch);
1376 struct Qdisc *qdisc;
1378 queue_old = netdev_get_tx_queue(dev, qid_old);
1379 queue_new = netdev_get_tx_queue(dev, qid_new);
1381 if (dev->flags & IFF_UP)
1382 dev_deactivate(dev);
1383 qdisc = dev_graft_qdisc(queue_old, NULL);
1384 qdisc->dev_queue = queue_new;
1385 qdisc = dev_graft_qdisc(queue_new, qdisc);
1386 if (dev->flags & IFF_UP)
1389 WARN_ON(!(qdisc->flags & TCQ_F_BUILTIN));
1392 static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1393 struct Qdisc **old, struct netlink_ext_ack *extack)
1395 struct netdev_queue *dev_queue = sch->dev_queue;
1396 struct htb_class *cl = (struct htb_class *)arg;
1397 struct htb_sched *q = qdisc_priv(sch);
1398 struct Qdisc *old_q;
1404 dev_queue = new->dev_queue;
1405 WARN_ON(dev_queue != cl->leaf.q->dev_queue);
1409 new = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1410 cl->common.classid, extack);
1416 htb_set_lockdep_class_child(new);
1417 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1418 qdisc_refcount_inc(new);
1419 old_q = htb_graft_helper(dev_queue, new);
1422 *old = qdisc_replace(sch, new, &cl->leaf.q);
1425 WARN_ON(old_q != *old);
1432 static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
1434 struct htb_class *cl = (struct htb_class *)arg;
1435 return !cl->level ? cl->leaf.q : NULL;
1438 static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
1440 struct htb_class *cl = (struct htb_class *)arg;
1442 htb_deactivate(qdisc_priv(sch), cl);
1445 static inline int htb_parent_last_child(struct htb_class *cl)
1448 /* the root class */
1450 if (cl->parent->children > 1)
1451 /* not the last child */
1456 static void htb_parent_to_leaf(struct Qdisc *sch, struct htb_class *cl,
1457 struct Qdisc *new_q)
1459 struct htb_sched *q = qdisc_priv(sch);
1460 struct htb_class *parent = cl->parent;
1462 WARN_ON(cl->level || !cl->leaf.q || cl->prio_activity);
1464 if (parent->cmode != HTB_CAN_SEND)
1465 htb_safe_rb_erase(&parent->pq_node,
1466 &q->hlevel[parent->level].wait_pq);
1469 memset(&parent->inner, 0, sizeof(parent->inner));
1470 parent->leaf.q = new_q ? new_q : &noop_qdisc;
1471 parent->tokens = parent->buffer;
1472 parent->ctokens = parent->cbuffer;
1473 parent->t_c = ktime_get_ns();
1474 parent->cmode = HTB_CAN_SEND;
1477 static void htb_parent_to_leaf_offload(struct Qdisc *sch,
1478 struct netdev_queue *dev_queue,
1479 struct Qdisc *new_q)
1481 struct Qdisc *old_q;
1483 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1484 qdisc_refcount_inc(new_q);
1485 old_q = htb_graft_helper(dev_queue, new_q);
1486 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1489 static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl,
1490 bool last_child, bool destroying,
1491 struct netlink_ext_ack *extack)
1493 struct tc_htb_qopt_offload offload_opt;
1494 struct Qdisc *q = cl->leaf.q;
1495 struct Qdisc *old = NULL;
1503 /* On destroy of HTB, two cases are possible:
1504 * 1. q is a normal qdisc, but q->dev_queue has noop qdisc.
1505 * 2. q is a noop qdisc (for nodes that were inner),
1506 * q->dev_queue is noop_netdev_queue.
1508 old = htb_graft_helper(q->dev_queue, NULL);
1514 cl->parent->bstats_bias.bytes += q->bstats.bytes;
1515 cl->parent->bstats_bias.packets += q->bstats.packets;
1518 offload_opt = (struct tc_htb_qopt_offload) {
1519 .command = !last_child ? TC_HTB_LEAF_DEL :
1520 destroying ? TC_HTB_LEAF_DEL_LAST_FORCE :
1521 TC_HTB_LEAF_DEL_LAST,
1522 .classid = cl->common.classid,
1525 err = htb_offload(qdisc_dev(sch), &offload_opt);
1527 if (!err || destroying)
1530 htb_graft_helper(q->dev_queue, old);
1535 if (!err && offload_opt.moved_qid != 0) {
1537 q->dev_queue = netdev_get_tx_queue(qdisc_dev(sch),
1540 htb_offload_move_qdisc(sch, offload_opt.moved_qid,
1547 static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
1550 WARN_ON(!cl->leaf.q);
1551 qdisc_put(cl->leaf.q);
1553 gen_kill_estimator(&cl->rate_est);
1554 tcf_block_put(cl->block);
1558 static void htb_destroy(struct Qdisc *sch)
1560 struct net_device *dev = qdisc_dev(sch);
1561 struct tc_htb_qopt_offload offload_opt;
1562 struct htb_sched *q = qdisc_priv(sch);
1563 struct hlist_node *next;
1564 bool nonempty, changed;
1565 struct htb_class *cl;
1568 cancel_work_sync(&q->work);
1569 qdisc_watchdog_cancel(&q->watchdog);
1570 /* This line used to be after htb_destroy_class call below
1571 * and surprisingly it worked in 2.4. But it must precede it
1572 * because filter need its target class alive to be able to call
1573 * unbind_filter on it (without Oops).
1575 tcf_block_put(q->block);
1577 for (i = 0; i < q->clhash.hashsize; i++) {
1578 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
1579 tcf_block_put(cl->block);
1587 for (i = 0; i < q->clhash.hashsize; i++) {
1588 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1593 htb_destroy_class(sch, cl);
1604 last_child = htb_parent_last_child(cl);
1605 htb_destroy_class_offload(sch, cl, last_child,
1607 qdisc_class_hash_remove(&q->clhash,
1610 cl->parent->children--;
1612 htb_parent_to_leaf(sch, cl, NULL);
1613 htb_destroy_class(sch, cl);
1619 qdisc_class_hash_destroy(&q->clhash);
1620 __qdisc_reset_queue(&q->direct_queue);
1625 offload_opt = (struct tc_htb_qopt_offload) {
1626 .command = TC_HTB_DESTROY,
1628 htb_offload(dev, &offload_opt);
1630 if (!q->direct_qdiscs)
1632 for (i = 0; i < q->num_direct_qdiscs && q->direct_qdiscs[i]; i++)
1633 qdisc_put(q->direct_qdiscs[i]);
1634 kfree(q->direct_qdiscs);
1637 static int htb_delete(struct Qdisc *sch, unsigned long arg,
1638 struct netlink_ext_ack *extack)
1640 struct htb_sched *q = qdisc_priv(sch);
1641 struct htb_class *cl = (struct htb_class *)arg;
1642 struct Qdisc *new_q = NULL;
1646 /* TODO: why don't allow to delete subtree ? references ? does
1647 * tc subsys guarantee us that in htb_destroy it holds no class
1648 * refs so that we can remove children safely there ?
1650 if (cl->children || cl->filter_cnt)
1653 if (!cl->level && htb_parent_last_child(cl))
1657 err = htb_destroy_class_offload(sch, cl, last_child, false,
1664 struct netdev_queue *dev_queue;
1666 dev_queue = q->offload ? cl->leaf.q->dev_queue : sch->dev_queue;
1667 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1668 cl->parent->common.classid,
1672 htb_set_lockdep_class_child(new_q);
1673 htb_parent_to_leaf_offload(sch, dev_queue, new_q);
1680 qdisc_purge_queue(cl->leaf.q);
1682 /* delete from hash and active; remainder in destroy_class */
1683 qdisc_class_hash_remove(&q->clhash, &cl->common);
1685 cl->parent->children--;
1687 if (cl->prio_activity)
1688 htb_deactivate(q, cl);
1690 if (cl->cmode != HTB_CAN_SEND)
1691 htb_safe_rb_erase(&cl->pq_node,
1692 &q->hlevel[cl->level].wait_pq);
1695 htb_parent_to_leaf(sch, cl, new_q);
1697 sch_tree_unlock(sch);
1699 htb_destroy_class(sch, cl);
1703 static int htb_change_class(struct Qdisc *sch, u32 classid,
1704 u32 parentid, struct nlattr **tca,
1705 unsigned long *arg, struct netlink_ext_ack *extack)
1708 struct htb_sched *q = qdisc_priv(sch);
1709 struct htb_class *cl = (struct htb_class *)*arg, *parent;
1710 struct tc_htb_qopt_offload offload_opt;
1711 struct nlattr *opt = tca[TCA_OPTIONS];
1712 struct nlattr *tb[TCA_HTB_MAX + 1];
1713 struct Qdisc *parent_qdisc = NULL;
1714 struct netdev_queue *dev_queue;
1715 struct tc_htb_opt *hopt;
1719 /* extract all subattrs from opt attr */
1723 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1729 if (tb[TCA_HTB_PARMS] == NULL)
1732 parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch);
1734 hopt = nla_data(tb[TCA_HTB_PARMS]);
1735 if (!hopt->rate.rate || !hopt->ceil.rate)
1738 /* Keeping backward compatible with rate_table based iproute2 tc */
1739 if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
1740 qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB],
1743 if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE)
1744 qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB],
1747 rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0;
1748 ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0;
1750 if (!cl) { /* new class */
1751 struct net_device *dev = qdisc_dev(sch);
1752 struct Qdisc *new_q, *old_q;
1756 struct gnet_estimator opt;
1759 .nla_len = nla_attr_size(sizeof(est.opt)),
1760 .nla_type = TCA_RATE,
1763 /* 4s interval, 16s averaging constant */
1769 /* check for valid classid */
1770 if (!classid || TC_H_MAJ(classid ^ sch->handle) ||
1771 htb_find(classid, sch))
1774 /* check maximal depth */
1775 if (parent && parent->parent && parent->parent->level < 2) {
1776 pr_err("htb: tree is too deep\n");
1780 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1784 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1789 if (htb_rate_est || tca[TCA_RATE]) {
1790 err = gen_new_estimator(&cl->bstats, NULL,
1793 qdisc_root_sleeping_running(sch),
1794 tca[TCA_RATE] ? : &est.nla);
1800 RB_CLEAR_NODE(&cl->pq_node);
1802 for (prio = 0; prio < TC_HTB_NUMPRIO; prio++)
1803 RB_CLEAR_NODE(&cl->node[prio]);
1805 cl->common.classid = classid;
1807 /* Make sure nothing interrupts us in between of two
1808 * ndo_setup_tc calls.
1812 /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
1813 * so that can't be used inside of sch_tree_lock
1814 * -- thanks to Karlis Peisenieks
1817 dev_queue = sch->dev_queue;
1818 } else if (!(parent && !parent->level)) {
1819 /* Assign a dev_queue to this classid. */
1820 offload_opt = (struct tc_htb_qopt_offload) {
1821 .command = TC_HTB_LEAF_ALLOC_QUEUE,
1822 .classid = cl->common.classid,
1823 .parent_classid = parent ?
1824 TC_H_MIN(parent->common.classid) :
1825 TC_HTB_CLASSID_ROOT,
1826 .rate = max_t(u64, hopt->rate.rate, rate64),
1827 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1830 err = htb_offload(dev, &offload_opt);
1832 pr_err("htb: TC_HTB_LEAF_ALLOC_QUEUE failed with err = %d\n",
1834 goto err_kill_estimator;
1836 dev_queue = netdev_get_tx_queue(dev, offload_opt.qid);
1837 } else { /* First child. */
1838 dev_queue = parent->leaf.q->dev_queue;
1839 old_q = htb_graft_helper(dev_queue, NULL);
1840 WARN_ON(old_q != parent->leaf.q);
1841 offload_opt = (struct tc_htb_qopt_offload) {
1842 .command = TC_HTB_LEAF_TO_INNER,
1843 .classid = cl->common.classid,
1845 TC_H_MIN(parent->common.classid),
1846 .rate = max_t(u64, hopt->rate.rate, rate64),
1847 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1850 err = htb_offload(dev, &offload_opt);
1852 pr_err("htb: TC_HTB_LEAF_TO_INNER failed with err = %d\n",
1854 htb_graft_helper(dev_queue, old_q);
1855 goto err_kill_estimator;
1857 parent->bstats_bias.bytes += old_q->bstats.bytes;
1858 parent->bstats_bias.packets += old_q->bstats.packets;
1861 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1865 htb_set_lockdep_class_child(new_q);
1866 /* One ref for cl->leaf.q, the other for
1869 qdisc_refcount_inc(new_q);
1871 old_q = htb_graft_helper(dev_queue, new_q);
1872 /* No qdisc_put needed. */
1873 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1876 if (parent && !parent->level) {
1877 /* turn parent into inner node */
1878 qdisc_purge_queue(parent->leaf.q);
1879 parent_qdisc = parent->leaf.q;
1880 if (parent->prio_activity)
1881 htb_deactivate(q, parent);
1883 /* remove from evt list because of level change */
1884 if (parent->cmode != HTB_CAN_SEND) {
1885 htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq);
1886 parent->cmode = HTB_CAN_SEND;
1888 parent->level = (parent->parent ? parent->parent->level
1889 : TC_HTB_MAXDEPTH) - 1;
1890 memset(&parent->inner, 0, sizeof(parent->inner));
1893 /* leaf (we) needs elementary qdisc */
1894 cl->leaf.q = new_q ? new_q : &noop_qdisc;
1896 cl->parent = parent;
1898 /* set class to be in HTB_CAN_SEND state */
1899 cl->tokens = PSCHED_TICKS2NS(hopt->buffer);
1900 cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer);
1901 cl->mbuffer = 60ULL * NSEC_PER_SEC; /* 1min */
1902 cl->t_c = ktime_get_ns();
1903 cl->cmode = HTB_CAN_SEND;
1905 /* attach to the hash list and parent's family */
1906 qdisc_class_hash_insert(&q->clhash, &cl->common);
1909 if (cl->leaf.q != &noop_qdisc)
1910 qdisc_hash_add(cl->leaf.q, true);
1912 if (tca[TCA_RATE]) {
1913 err = gen_replace_estimator(&cl->bstats, NULL,
1916 qdisc_root_sleeping_running(sch),
1923 struct net_device *dev = qdisc_dev(sch);
1925 offload_opt = (struct tc_htb_qopt_offload) {
1926 .command = TC_HTB_NODE_MODIFY,
1927 .classid = cl->common.classid,
1928 .rate = max_t(u64, hopt->rate.rate, rate64),
1929 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1932 err = htb_offload(dev, &offload_opt);
1934 /* Estimator was replaced, and rollback may fail
1935 * as well, so we don't try to recover it, and
1936 * the estimator won't work property with the
1937 * offload anyway, because bstats are updated
1938 * only when the stats are queried.
1946 psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64);
1947 psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64);
1949 /* it used to be a nasty bug here, we have to check that node
1950 * is really leaf before changing cl->leaf !
1953 u64 quantum = cl->rate.rate_bytes_ps;
1955 do_div(quantum, q->rate2quantum);
1956 cl->quantum = min_t(u64, quantum, INT_MAX);
1958 if (!hopt->quantum && cl->quantum < 1000) {
1962 if (!hopt->quantum && cl->quantum > 200000) {
1964 cl->quantum = 200000;
1967 cl->quantum = hopt->quantum;
1968 if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
1969 cl->prio = TC_HTB_NUMPRIO - 1;
1972 cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
1973 cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);
1975 sch_tree_unlock(sch);
1976 qdisc_put(parent_qdisc);
1979 pr_warn("HTB: quantum of class %X is %s. Consider r2q change.\n",
1980 cl->common.classid, (warn == -1 ? "small" : "big"));
1982 qdisc_class_hash_grow(sch, &q->clhash);
1984 *arg = (unsigned long)cl;
1988 gen_kill_estimator(&cl->rate_est);
1990 tcf_block_put(cl->block);
1996 static struct tcf_block *htb_tcf_block(struct Qdisc *sch, unsigned long arg,
1997 struct netlink_ext_ack *extack)
1999 struct htb_sched *q = qdisc_priv(sch);
2000 struct htb_class *cl = (struct htb_class *)arg;
2002 return cl ? cl->block : q->block;
2005 static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
2008 struct htb_class *cl = htb_find(classid, sch);
2010 /*if (cl && !cl->level) return 0;
2011 * The line above used to be there to prevent attaching filters to
2012 * leaves. But at least tc_index filter uses this just to get class
2013 * for other reasons so that we have to allow for it.
2015 * 19.6.2002 As Werner explained it is ok - bind filter is just
2016 * another way to "lock" the class - unlike "get" this lock can
2017 * be broken by class during destroy IIUC.
2021 return (unsigned long)cl;
2024 static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
2026 struct htb_class *cl = (struct htb_class *)arg;
2032 static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2034 struct htb_sched *q = qdisc_priv(sch);
2035 struct htb_class *cl;
2041 for (i = 0; i < q->clhash.hashsize; i++) {
2042 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
2043 if (arg->count < arg->skip) {
2047 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2056 static const struct Qdisc_class_ops htb_class_ops = {
2057 .select_queue = htb_select_queue,
2060 .qlen_notify = htb_qlen_notify,
2062 .change = htb_change_class,
2063 .delete = htb_delete,
2065 .tcf_block = htb_tcf_block,
2066 .bind_tcf = htb_bind_filter,
2067 .unbind_tcf = htb_unbind_filter,
2068 .dump = htb_dump_class,
2069 .dump_stats = htb_dump_class_stats,
2072 static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
2073 .cl_ops = &htb_class_ops,
2075 .priv_size = sizeof(struct htb_sched),
2076 .enqueue = htb_enqueue,
2077 .dequeue = htb_dequeue,
2078 .peek = qdisc_peek_dequeued,
2080 .attach = htb_attach,
2082 .destroy = htb_destroy,
2084 .owner = THIS_MODULE,
2087 static int __init htb_module_init(void)
2089 return register_qdisc(&htb_qdisc_ops);
2091 static void __exit htb_module_exit(void)
2093 unregister_qdisc(&htb_qdisc_ops);
2096 module_init(htb_module_init)
2097 module_exit(htb_module_exit)
2098 MODULE_LICENSE("GPL");