2 * net/sched/sch_htb.c Hierarchical token bucket, feed tree version
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.
9 * Authors: Martin Devera, <devik@cdi.cz>
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
23 * spotted bug in dequeue code and helped with fix
25 * fixed requeue routine
26 * and many others. thanks.
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 <net/netlink.h>
39 #include <net/pkt_sched.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 /* used internaly to keep status of single class */
67 HTB_CANT_SEND
, /* class can't send and can't borrow */
68 HTB_MAY_BORROW
, /* class can't send but may borrow */
69 HTB_CAN_SEND
/* class can send */
72 /* interior & leaf nodes; props specific to leaves are marked L: */
74 struct Qdisc_class_common common
;
75 /* general class parameters */
76 struct gnet_stats_basic bstats
;
77 struct gnet_stats_queue qstats
;
78 struct gnet_stats_rate_est rate_est
;
79 struct tc_htb_xstats xstats
; /* our special stats */
80 int refcnt
; /* usage count of this class */
83 int level
; /* our level (see above) */
84 unsigned int children
;
85 struct htb_class
*parent
; /* parent class */
87 int prio
; /* these two are used only by leaves... */
88 int quantum
; /* but stored for parent-to-leaf return */
91 struct htb_class_leaf
{
93 int deficit
[TC_HTB_MAXDEPTH
];
94 struct list_head drop_list
;
96 struct htb_class_inner
{
97 struct rb_root feed
[TC_HTB_NUMPRIO
]; /* feed trees */
98 struct rb_node
*ptr
[TC_HTB_NUMPRIO
]; /* current class ptr */
99 /* When class changes from state 1->2 and disconnects from
100 parent's feed then we lost ptr value and start from the
101 first child again. Here we store classid of the
102 last valid ptr (used when ptr is NULL). */
103 u32 last_ptr_id
[TC_HTB_NUMPRIO
];
106 struct rb_node node
[TC_HTB_NUMPRIO
]; /* node for self or feed tree */
107 struct rb_node pq_node
; /* node for event queue */
108 psched_time_t pq_key
;
110 int prio_activity
; /* for which prios are we active */
111 enum htb_cmode cmode
; /* current mode of the class */
113 /* class attached filters */
114 struct tcf_proto
*filter_list
;
117 /* token bucket parameters */
118 struct qdisc_rate_table
*rate
; /* rate table of the class itself */
119 struct qdisc_rate_table
*ceil
; /* ceiling rate (limits borrows too) */
120 long buffer
, cbuffer
; /* token bucket depth/rate */
121 psched_tdiff_t mbuffer
; /* max wait time */
122 long tokens
, ctokens
; /* current number of tokens */
123 psched_time_t t_c
; /* checkpoint time */
127 struct Qdisc_class_hash clhash
;
128 struct list_head drops
[TC_HTB_NUMPRIO
];/* active leaves (for drops) */
130 /* self list - roots of self generating tree */
131 struct rb_root row
[TC_HTB_MAXDEPTH
][TC_HTB_NUMPRIO
];
132 int row_mask
[TC_HTB_MAXDEPTH
];
133 struct rb_node
*ptr
[TC_HTB_MAXDEPTH
][TC_HTB_NUMPRIO
];
134 u32 last_ptr_id
[TC_HTB_MAXDEPTH
][TC_HTB_NUMPRIO
];
136 /* self wait list - roots of wait PQs per row */
137 struct rb_root wait_pq
[TC_HTB_MAXDEPTH
];
139 /* time of nearest event per level (row) */
140 psched_time_t near_ev_cache
[TC_HTB_MAXDEPTH
];
142 int defcls
; /* class where unclassified flows go to */
144 /* filters for qdisc itself */
145 struct tcf_proto
*filter_list
;
147 int rate2quantum
; /* quant = rate / rate2quantum */
148 psched_time_t now
; /* cached dequeue time */
149 struct qdisc_watchdog watchdog
;
151 /* non shaped skbs; let them go directly thru */
152 struct sk_buff_head direct_queue
;
153 int direct_qlen
; /* max qlen of above */
158 /* find class in global hash table using given handle */
159 static inline struct htb_class
*htb_find(u32 handle
, struct Qdisc
*sch
)
161 struct htb_sched
*q
= qdisc_priv(sch
);
162 struct Qdisc_class_common
*clc
;
164 clc
= qdisc_class_find(&q
->clhash
, handle
);
167 return container_of(clc
, struct htb_class
, common
);
171 * htb_classify - classify a packet into class
173 * It returns NULL if the packet should be dropped or -1 if the packet
174 * should be passed directly thru. In all other cases leaf class is returned.
175 * We allow direct class selection by classid in priority. The we examine
176 * filters in qdisc and in inner nodes (if higher filter points to the inner
177 * node). If we end up with classid MAJOR:0 we enqueue the skb into special
178 * internal fifo (direct). These packets then go directly thru. If we still
179 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessfull
180 * then finish and return direct queue.
182 #define HTB_DIRECT (struct htb_class*)-1
184 static struct htb_class
*htb_classify(struct sk_buff
*skb
, struct Qdisc
*sch
,
187 struct htb_sched
*q
= qdisc_priv(sch
);
188 struct htb_class
*cl
;
189 struct tcf_result res
;
190 struct tcf_proto
*tcf
;
193 /* allow to select class by setting skb->priority to valid classid;
194 note that nfmark can be used too by attaching filter fw with no
196 if (skb
->priority
== sch
->handle
)
197 return HTB_DIRECT
; /* X:0 (direct flow) selected */
198 if ((cl
= htb_find(skb
->priority
, sch
)) != NULL
&& cl
->level
== 0)
201 *qerr
= NET_XMIT_SUCCESS
| __NET_XMIT_BYPASS
;
202 tcf
= q
->filter_list
;
203 while (tcf
&& (result
= tc_classify(skb
, tcf
, &res
)) >= 0) {
204 #ifdef CONFIG_NET_CLS_ACT
208 *qerr
= NET_XMIT_SUCCESS
| __NET_XMIT_STOLEN
;
213 if ((cl
= (void *)res
.class) == NULL
) {
214 if (res
.classid
== sch
->handle
)
215 return HTB_DIRECT
; /* X:0 (direct flow) */
216 if ((cl
= htb_find(res
.classid
, sch
)) == NULL
)
217 break; /* filter selected invalid classid */
220 return cl
; /* we hit leaf; return it */
222 /* we have got inner class; apply inner filter chain */
223 tcf
= cl
->filter_list
;
225 /* classification failed; try to use default class */
226 cl
= htb_find(TC_H_MAKE(TC_H_MAJ(sch
->handle
), q
->defcls
), sch
);
227 if (!cl
|| cl
->level
)
228 return HTB_DIRECT
; /* bad default .. this is safe bet */
233 * htb_add_to_id_tree - adds class to the round robin list
235 * Routine adds class to the list (actually tree) sorted by classid.
236 * Make sure that class is not already on such list for given prio.
238 static void htb_add_to_id_tree(struct rb_root
*root
,
239 struct htb_class
*cl
, int prio
)
241 struct rb_node
**p
= &root
->rb_node
, *parent
= NULL
;
246 c
= rb_entry(parent
, struct htb_class
, node
[prio
]);
248 if (cl
->common
.classid
> c
->common
.classid
)
249 p
= &parent
->rb_right
;
251 p
= &parent
->rb_left
;
253 rb_link_node(&cl
->node
[prio
], parent
, p
);
254 rb_insert_color(&cl
->node
[prio
], root
);
258 * htb_add_to_wait_tree - adds class to the event queue with delay
260 * The class is added to priority event queue to indicate that class will
261 * change its mode in cl->pq_key microseconds. Make sure that class is not
262 * already in the queue.
264 static void htb_add_to_wait_tree(struct htb_sched
*q
,
265 struct htb_class
*cl
, long delay
)
267 struct rb_node
**p
= &q
->wait_pq
[cl
->level
].rb_node
, *parent
= NULL
;
269 cl
->pq_key
= q
->now
+ delay
;
270 if (cl
->pq_key
== q
->now
)
273 /* update the nearest event cache */
274 if (q
->near_ev_cache
[cl
->level
] > cl
->pq_key
)
275 q
->near_ev_cache
[cl
->level
] = cl
->pq_key
;
280 c
= rb_entry(parent
, struct htb_class
, pq_node
);
281 if (cl
->pq_key
>= c
->pq_key
)
282 p
= &parent
->rb_right
;
284 p
= &parent
->rb_left
;
286 rb_link_node(&cl
->pq_node
, parent
, p
);
287 rb_insert_color(&cl
->pq_node
, &q
->wait_pq
[cl
->level
]);
291 * htb_next_rb_node - finds next node in binary tree
293 * When we are past last key we return NULL.
294 * Average complexity is 2 steps per call.
296 static inline void htb_next_rb_node(struct rb_node
**n
)
302 * htb_add_class_to_row - add class to its row
304 * The class is added to row at priorities marked in mask.
305 * It does nothing if mask == 0.
307 static inline void htb_add_class_to_row(struct htb_sched
*q
,
308 struct htb_class
*cl
, int mask
)
310 q
->row_mask
[cl
->level
] |= mask
;
312 int prio
= ffz(~mask
);
313 mask
&= ~(1 << prio
);
314 htb_add_to_id_tree(q
->row
[cl
->level
] + prio
, cl
, prio
);
318 /* If this triggers, it is a bug in this code, but it need not be fatal */
319 static void htb_safe_rb_erase(struct rb_node
*rb
, struct rb_root
*root
)
321 if (RB_EMPTY_NODE(rb
)) {
331 * htb_remove_class_from_row - removes class from its row
333 * The class is removed from row at priorities marked in mask.
334 * It does nothing if mask == 0.
336 static inline void htb_remove_class_from_row(struct htb_sched
*q
,
337 struct htb_class
*cl
, int mask
)
342 int prio
= ffz(~mask
);
344 mask
&= ~(1 << prio
);
345 if (q
->ptr
[cl
->level
][prio
] == cl
->node
+ prio
)
346 htb_next_rb_node(q
->ptr
[cl
->level
] + prio
);
348 htb_safe_rb_erase(cl
->node
+ prio
, q
->row
[cl
->level
] + prio
);
349 if (!q
->row
[cl
->level
][prio
].rb_node
)
352 q
->row_mask
[cl
->level
] &= ~m
;
356 * htb_activate_prios - creates active classe's feed chain
358 * The class is connected to ancestors and/or appropriate rows
359 * for priorities it is participating on. cl->cmode must be new
360 * (activated) mode. It does nothing if cl->prio_activity == 0.
362 static void htb_activate_prios(struct htb_sched
*q
, struct htb_class
*cl
)
364 struct htb_class
*p
= cl
->parent
;
365 long m
, mask
= cl
->prio_activity
;
367 while (cl
->cmode
== HTB_MAY_BORROW
&& p
&& mask
) {
373 if (p
->un
.inner
.feed
[prio
].rb_node
)
374 /* parent already has its feed in use so that
375 reset bit in mask as parent is already ok */
376 mask
&= ~(1 << prio
);
378 htb_add_to_id_tree(p
->un
.inner
.feed
+ prio
, cl
, prio
);
380 p
->prio_activity
|= mask
;
385 if (cl
->cmode
== HTB_CAN_SEND
&& mask
)
386 htb_add_class_to_row(q
, cl
, mask
);
390 * htb_deactivate_prios - remove class from feed chain
392 * cl->cmode must represent old mode (before deactivation). It does
393 * nothing if cl->prio_activity == 0. Class is removed from all feed
396 static void htb_deactivate_prios(struct htb_sched
*q
, struct htb_class
*cl
)
398 struct htb_class
*p
= cl
->parent
;
399 long m
, mask
= cl
->prio_activity
;
401 while (cl
->cmode
== HTB_MAY_BORROW
&& p
&& mask
) {
408 if (p
->un
.inner
.ptr
[prio
] == cl
->node
+ prio
) {
409 /* we are removing child which is pointed to from
410 parent feed - forget the pointer but remember
412 p
->un
.inner
.last_ptr_id
[prio
] = cl
->common
.classid
;
413 p
->un
.inner
.ptr
[prio
] = NULL
;
416 htb_safe_rb_erase(cl
->node
+ prio
, p
->un
.inner
.feed
+ prio
);
418 if (!p
->un
.inner
.feed
[prio
].rb_node
)
422 p
->prio_activity
&= ~mask
;
427 if (cl
->cmode
== HTB_CAN_SEND
&& mask
)
428 htb_remove_class_from_row(q
, cl
, mask
);
431 static inline long htb_lowater(const struct htb_class
*cl
)
434 return cl
->cmode
!= HTB_CANT_SEND
? -cl
->cbuffer
: 0;
438 static inline long htb_hiwater(const struct htb_class
*cl
)
441 return cl
->cmode
== HTB_CAN_SEND
? -cl
->buffer
: 0;
448 * htb_class_mode - computes and returns current class mode
450 * It computes cl's mode at time cl->t_c+diff and returns it. If mode
451 * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
452 * from now to time when cl will change its state.
453 * Also it is worth to note that class mode doesn't change simply
454 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
455 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
456 * mode transitions per time unit. The speed gain is about 1/6.
458 static inline enum htb_cmode
459 htb_class_mode(struct htb_class
*cl
, long *diff
)
463 if ((toks
= (cl
->ctokens
+ *diff
)) < htb_lowater(cl
)) {
465 return HTB_CANT_SEND
;
468 if ((toks
= (cl
->tokens
+ *diff
)) >= htb_hiwater(cl
))
472 return HTB_MAY_BORROW
;
476 * htb_change_class_mode - changes classe's mode
478 * This should be the only way how to change classe's mode under normal
479 * cirsumstances. Routine will update feed lists linkage, change mode
480 * and add class to the wait event queue if appropriate. New mode should
481 * be different from old one and cl->pq_key has to be valid if changing
482 * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
485 htb_change_class_mode(struct htb_sched
*q
, struct htb_class
*cl
, long *diff
)
487 enum htb_cmode new_mode
= htb_class_mode(cl
, diff
);
489 if (new_mode
== cl
->cmode
)
492 if (cl
->prio_activity
) { /* not necessary: speed optimization */
493 if (cl
->cmode
!= HTB_CANT_SEND
)
494 htb_deactivate_prios(q
, cl
);
495 cl
->cmode
= new_mode
;
496 if (new_mode
!= HTB_CANT_SEND
)
497 htb_activate_prios(q
, cl
);
499 cl
->cmode
= new_mode
;
503 * htb_activate - inserts leaf cl into appropriate active feeds
505 * Routine learns (new) priority of leaf and activates feed chain
506 * for the prio. It can be called on already active leaf safely.
507 * It also adds leaf into droplist.
509 static inline void htb_activate(struct htb_sched
*q
, struct htb_class
*cl
)
511 WARN_ON(cl
->level
|| !cl
->un
.leaf
.q
|| !cl
->un
.leaf
.q
->q
.qlen
);
513 if (!cl
->prio_activity
) {
514 cl
->prio_activity
= 1 << cl
->prio
;
515 htb_activate_prios(q
, cl
);
516 list_add_tail(&cl
->un
.leaf
.drop_list
,
517 q
->drops
+ cl
->prio
);
522 * htb_deactivate - remove leaf cl from active feeds
524 * Make sure that leaf is active. In the other words it can't be called
525 * with non-active leaf. It also removes class from the drop list.
527 static inline void htb_deactivate(struct htb_sched
*q
, struct htb_class
*cl
)
529 WARN_ON(!cl
->prio_activity
);
531 htb_deactivate_prios(q
, cl
);
532 cl
->prio_activity
= 0;
533 list_del_init(&cl
->un
.leaf
.drop_list
);
536 static int htb_enqueue(struct sk_buff
*skb
, struct Qdisc
*sch
)
538 int uninitialized_var(ret
);
539 struct htb_sched
*q
= qdisc_priv(sch
);
540 struct htb_class
*cl
= htb_classify(skb
, sch
, &ret
);
542 if (cl
== HTB_DIRECT
) {
543 /* enqueue to helper queue */
544 if (q
->direct_queue
.qlen
< q
->direct_qlen
) {
545 __skb_queue_tail(&q
->direct_queue
, skb
);
550 return NET_XMIT_DROP
;
552 #ifdef CONFIG_NET_CLS_ACT
554 if (ret
& __NET_XMIT_BYPASS
)
559 } else if ((ret
= qdisc_enqueue(skb
, cl
->un
.leaf
.q
)) != NET_XMIT_SUCCESS
) {
560 if (net_xmit_drop_count(ret
)) {
566 cl
->bstats
.packets
+=
567 skb_is_gso(skb
)?skb_shinfo(skb
)->gso_segs
:1;
568 cl
->bstats
.bytes
+= qdisc_pkt_len(skb
);
573 sch
->bstats
.packets
+= skb_is_gso(skb
)?skb_shinfo(skb
)->gso_segs
:1;
574 sch
->bstats
.bytes
+= qdisc_pkt_len(skb
);
575 return NET_XMIT_SUCCESS
;
578 static inline void htb_accnt_tokens(struct htb_class
*cl
, int bytes
, long diff
)
580 long toks
= diff
+ cl
->tokens
;
582 if (toks
> cl
->buffer
)
584 toks
-= (long) qdisc_l2t(cl
->rate
, bytes
);
585 if (toks
<= -cl
->mbuffer
)
586 toks
= 1 - cl
->mbuffer
;
591 static inline void htb_accnt_ctokens(struct htb_class
*cl
, int bytes
, long diff
)
593 long toks
= diff
+ cl
->ctokens
;
595 if (toks
> cl
->cbuffer
)
597 toks
-= (long) qdisc_l2t(cl
->ceil
, bytes
);
598 if (toks
<= -cl
->mbuffer
)
599 toks
= 1 - cl
->mbuffer
;
605 * htb_charge_class - charges amount "bytes" to leaf and ancestors
607 * Routine assumes that packet "bytes" long was dequeued from leaf cl
608 * borrowing from "level". It accounts bytes to ceil leaky bucket for
609 * leaf and all ancestors and to rate bucket for ancestors at levels
610 * "level" and higher. It also handles possible change of mode resulting
611 * from the update. Note that mode can also increase here (MAY_BORROW to
612 * CAN_SEND) because we can use more precise clock that event queue here.
613 * In such case we remove class from event queue first.
615 static void htb_charge_class(struct htb_sched
*q
, struct htb_class
*cl
,
616 int level
, struct sk_buff
*skb
)
618 int bytes
= qdisc_pkt_len(skb
);
619 enum htb_cmode old_mode
;
623 diff
= psched_tdiff_bounded(q
->now
, cl
->t_c
, cl
->mbuffer
);
624 if (cl
->level
>= level
) {
625 if (cl
->level
== level
)
627 htb_accnt_tokens(cl
, bytes
, diff
);
629 cl
->xstats
.borrows
++;
630 cl
->tokens
+= diff
; /* we moved t_c; update tokens */
632 htb_accnt_ctokens(cl
, bytes
, diff
);
635 old_mode
= cl
->cmode
;
637 htb_change_class_mode(q
, cl
, &diff
);
638 if (old_mode
!= cl
->cmode
) {
639 if (old_mode
!= HTB_CAN_SEND
)
640 htb_safe_rb_erase(&cl
->pq_node
, q
->wait_pq
+ cl
->level
);
641 if (cl
->cmode
!= HTB_CAN_SEND
)
642 htb_add_to_wait_tree(q
, cl
, diff
);
645 /* update byte stats except for leaves which are already updated */
647 cl
->bstats
.bytes
+= bytes
;
648 cl
->bstats
.packets
+= skb_is_gso(skb
)?
649 skb_shinfo(skb
)->gso_segs
:1;
656 * htb_do_events - make mode changes to classes at the level
658 * Scans event queue for pending events and applies them. Returns time of
659 * next pending event (0 for no event in pq).
660 * Note: Applied are events whose have cl->pq_key <= q->now.
662 static psched_time_t
htb_do_events(struct htb_sched
*q
, int level
,
665 /* don't run for longer than 2 jiffies; 2 is used instead of
666 1 to simplify things when jiffy is going to be incremented
668 unsigned long stop_at
= start
+ 2;
669 while (time_before(jiffies
, stop_at
)) {
670 struct htb_class
*cl
;
672 struct rb_node
*p
= rb_first(&q
->wait_pq
[level
]);
677 cl
= rb_entry(p
, struct htb_class
, pq_node
);
678 if (cl
->pq_key
> q
->now
)
681 htb_safe_rb_erase(p
, q
->wait_pq
+ level
);
682 diff
= psched_tdiff_bounded(q
->now
, cl
->t_c
, cl
->mbuffer
);
683 htb_change_class_mode(q
, cl
, &diff
);
684 if (cl
->cmode
!= HTB_CAN_SEND
)
685 htb_add_to_wait_tree(q
, cl
, diff
);
687 /* too much load - let's continue on next jiffie (including above) */
688 return q
->now
+ 2 * PSCHED_TICKS_PER_SEC
/ HZ
;
691 /* Returns class->node+prio from id-tree where classe's id is >= id. NULL
692 is no such one exists. */
693 static struct rb_node
*htb_id_find_next_upper(int prio
, struct rb_node
*n
,
696 struct rb_node
*r
= NULL
;
698 struct htb_class
*cl
=
699 rb_entry(n
, struct htb_class
, node
[prio
]);
701 if (id
> cl
->common
.classid
) {
703 } else if (id
< cl
->common
.classid
) {
714 * htb_lookup_leaf - returns next leaf class in DRR order
716 * Find leaf where current feed pointers points to.
718 static struct htb_class
*htb_lookup_leaf(struct rb_root
*tree
, int prio
,
719 struct rb_node
**pptr
, u32
* pid
)
723 struct rb_node
*root
;
724 struct rb_node
**pptr
;
726 } stk
[TC_HTB_MAXDEPTH
], *sp
= stk
;
728 BUG_ON(!tree
->rb_node
);
729 sp
->root
= tree
->rb_node
;
733 for (i
= 0; i
< 65535; i
++) {
734 if (!*sp
->pptr
&& *sp
->pid
) {
735 /* ptr was invalidated but id is valid - try to recover
736 the original or next ptr */
738 htb_id_find_next_upper(prio
, sp
->root
, *sp
->pid
);
740 *sp
->pid
= 0; /* ptr is valid now so that remove this hint as it
741 can become out of date quickly */
742 if (!*sp
->pptr
) { /* we are at right end; rewind & go up */
743 *sp
->pptr
= sp
->root
;
744 while ((*sp
->pptr
)->rb_left
)
745 *sp
->pptr
= (*sp
->pptr
)->rb_left
;
752 htb_next_rb_node(sp
->pptr
);
755 struct htb_class
*cl
;
756 cl
= rb_entry(*sp
->pptr
, struct htb_class
, node
[prio
]);
759 (++sp
)->root
= cl
->un
.inner
.feed
[prio
].rb_node
;
760 sp
->pptr
= cl
->un
.inner
.ptr
+ prio
;
761 sp
->pid
= cl
->un
.inner
.last_ptr_id
+ prio
;
768 /* dequeues packet at given priority and level; call only if
769 you are sure that there is active class at prio/level */
770 static struct sk_buff
*htb_dequeue_tree(struct htb_sched
*q
, int prio
,
773 struct sk_buff
*skb
= NULL
;
774 struct htb_class
*cl
, *start
;
775 /* look initial class up in the row */
776 start
= cl
= htb_lookup_leaf(q
->row
[level
] + prio
, prio
,
777 q
->ptr
[level
] + prio
,
778 q
->last_ptr_id
[level
] + prio
);
785 /* class can be empty - it is unlikely but can be true if leaf
786 qdisc drops packets in enqueue routine or if someone used
787 graft operation on the leaf since last dequeue;
788 simply deactivate and skip such class */
789 if (unlikely(cl
->un
.leaf
.q
->q
.qlen
== 0)) {
790 struct htb_class
*next
;
791 htb_deactivate(q
, cl
);
793 /* row/level might become empty */
794 if ((q
->row_mask
[level
] & (1 << prio
)) == 0)
797 next
= htb_lookup_leaf(q
->row
[level
] + prio
,
798 prio
, q
->ptr
[level
] + prio
,
799 q
->last_ptr_id
[level
] + prio
);
801 if (cl
== start
) /* fix start if we just deleted it */
807 skb
= cl
->un
.leaf
.q
->dequeue(cl
->un
.leaf
.q
);
808 if (likely(skb
!= NULL
))
811 qdisc_warn_nonwc("htb", cl
->un
.leaf
.q
);
812 htb_next_rb_node((level
? cl
->parent
->un
.inner
.ptr
: q
->
814 cl
= htb_lookup_leaf(q
->row
[level
] + prio
, prio
,
815 q
->ptr
[level
] + prio
,
816 q
->last_ptr_id
[level
] + prio
);
818 } while (cl
!= start
);
820 if (likely(skb
!= NULL
)) {
821 cl
->un
.leaf
.deficit
[level
] -= qdisc_pkt_len(skb
);
822 if (cl
->un
.leaf
.deficit
[level
] < 0) {
823 cl
->un
.leaf
.deficit
[level
] += cl
->quantum
;
824 htb_next_rb_node((level
? cl
->parent
->un
.inner
.ptr
: q
->
827 /* this used to be after charge_class but this constelation
828 gives us slightly better performance */
829 if (!cl
->un
.leaf
.q
->q
.qlen
)
830 htb_deactivate(q
, cl
);
831 htb_charge_class(q
, cl
, level
, skb
);
836 static struct sk_buff
*htb_dequeue(struct Qdisc
*sch
)
838 struct sk_buff
*skb
= NULL
;
839 struct htb_sched
*q
= qdisc_priv(sch
);
841 psched_time_t next_event
;
842 unsigned long start_at
;
844 /* try to dequeue direct packets as high prio (!) to minimize cpu work */
845 skb
= __skb_dequeue(&q
->direct_queue
);
847 sch
->flags
&= ~TCQ_F_THROTTLED
;
854 q
->now
= psched_get_time();
857 next_event
= q
->now
+ 5 * PSCHED_TICKS_PER_SEC
;
859 for (level
= 0; level
< TC_HTB_MAXDEPTH
; level
++) {
860 /* common case optimization - skip event handler quickly */
864 if (q
->now
>= q
->near_ev_cache
[level
]) {
865 event
= htb_do_events(q
, level
, start_at
);
867 event
= q
->now
+ PSCHED_TICKS_PER_SEC
;
868 q
->near_ev_cache
[level
] = event
;
870 event
= q
->near_ev_cache
[level
];
872 if (next_event
> event
)
875 m
= ~q
->row_mask
[level
];
876 while (m
!= (int)(-1)) {
879 skb
= htb_dequeue_tree(q
, prio
, level
);
880 if (likely(skb
!= NULL
)) {
882 sch
->flags
&= ~TCQ_F_THROTTLED
;
887 sch
->qstats
.overlimits
++;
888 qdisc_watchdog_schedule(&q
->watchdog
, next_event
);
893 /* try to drop from each class (by prio) until one succeed */
894 static unsigned int htb_drop(struct Qdisc
*sch
)
896 struct htb_sched
*q
= qdisc_priv(sch
);
899 for (prio
= TC_HTB_NUMPRIO
- 1; prio
>= 0; prio
--) {
901 list_for_each(p
, q
->drops
+ prio
) {
902 struct htb_class
*cl
= list_entry(p
, struct htb_class
,
905 if (cl
->un
.leaf
.q
->ops
->drop
&&
906 (len
= cl
->un
.leaf
.q
->ops
->drop(cl
->un
.leaf
.q
))) {
908 if (!cl
->un
.leaf
.q
->q
.qlen
)
909 htb_deactivate(q
, cl
);
917 /* reset all classes */
918 /* always caled under BH & queue lock */
919 static void htb_reset(struct Qdisc
*sch
)
921 struct htb_sched
*q
= qdisc_priv(sch
);
922 struct htb_class
*cl
;
923 struct hlist_node
*n
;
926 for (i
= 0; i
< q
->clhash
.hashsize
; i
++) {
927 hlist_for_each_entry(cl
, n
, &q
->clhash
.hash
[i
], common
.hnode
) {
929 memset(&cl
->un
.inner
, 0, sizeof(cl
->un
.inner
));
932 qdisc_reset(cl
->un
.leaf
.q
);
933 INIT_LIST_HEAD(&cl
->un
.leaf
.drop_list
);
935 cl
->prio_activity
= 0;
936 cl
->cmode
= HTB_CAN_SEND
;
940 qdisc_watchdog_cancel(&q
->watchdog
);
941 __skb_queue_purge(&q
->direct_queue
);
943 memset(q
->row
, 0, sizeof(q
->row
));
944 memset(q
->row_mask
, 0, sizeof(q
->row_mask
));
945 memset(q
->wait_pq
, 0, sizeof(q
->wait_pq
));
946 memset(q
->ptr
, 0, sizeof(q
->ptr
));
947 for (i
= 0; i
< TC_HTB_NUMPRIO
; i
++)
948 INIT_LIST_HEAD(q
->drops
+ i
);
951 static const struct nla_policy htb_policy
[TCA_HTB_MAX
+ 1] = {
952 [TCA_HTB_PARMS
] = { .len
= sizeof(struct tc_htb_opt
) },
953 [TCA_HTB_INIT
] = { .len
= sizeof(struct tc_htb_glob
) },
954 [TCA_HTB_CTAB
] = { .type
= NLA_BINARY
, .len
= TC_RTAB_SIZE
},
955 [TCA_HTB_RTAB
] = { .type
= NLA_BINARY
, .len
= TC_RTAB_SIZE
},
958 static int htb_init(struct Qdisc
*sch
, struct nlattr
*opt
)
960 struct htb_sched
*q
= qdisc_priv(sch
);
961 struct nlattr
*tb
[TCA_HTB_INIT
+ 1];
962 struct tc_htb_glob
*gopt
;
969 err
= nla_parse_nested(tb
, TCA_HTB_INIT
, opt
, htb_policy
);
973 if (tb
[TCA_HTB_INIT
] == NULL
) {
974 printk(KERN_ERR
"HTB: hey probably you have bad tc tool ?\n");
977 gopt
= nla_data(tb
[TCA_HTB_INIT
]);
978 if (gopt
->version
!= HTB_VER
>> 16) {
980 "HTB: need tc/htb version %d (minor is %d), you have %d\n",
981 HTB_VER
>> 16, HTB_VER
& 0xffff, gopt
->version
);
985 err
= qdisc_class_hash_init(&q
->clhash
);
988 for (i
= 0; i
< TC_HTB_NUMPRIO
; i
++)
989 INIT_LIST_HEAD(q
->drops
+ i
);
991 qdisc_watchdog_init(&q
->watchdog
, sch
);
992 skb_queue_head_init(&q
->direct_queue
);
994 q
->direct_qlen
= qdisc_dev(sch
)->tx_queue_len
;
995 if (q
->direct_qlen
< 2) /* some devices have zero tx_queue_len */
998 if ((q
->rate2quantum
= gopt
->rate2quantum
) < 1)
1000 q
->defcls
= gopt
->defcls
;
1005 static int htb_dump(struct Qdisc
*sch
, struct sk_buff
*skb
)
1007 spinlock_t
*root_lock
= qdisc_root_sleeping_lock(sch
);
1008 struct htb_sched
*q
= qdisc_priv(sch
);
1009 struct nlattr
*nest
;
1010 struct tc_htb_glob gopt
;
1012 spin_lock_bh(root_lock
);
1014 gopt
.direct_pkts
= q
->direct_pkts
;
1015 gopt
.version
= HTB_VER
;
1016 gopt
.rate2quantum
= q
->rate2quantum
;
1017 gopt
.defcls
= q
->defcls
;
1020 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
1022 goto nla_put_failure
;
1023 NLA_PUT(skb
, TCA_HTB_INIT
, sizeof(gopt
), &gopt
);
1024 nla_nest_end(skb
, nest
);
1026 spin_unlock_bh(root_lock
);
1030 spin_unlock_bh(root_lock
);
1031 nla_nest_cancel(skb
, nest
);
1035 static int htb_dump_class(struct Qdisc
*sch
, unsigned long arg
,
1036 struct sk_buff
*skb
, struct tcmsg
*tcm
)
1038 struct htb_class
*cl
= (struct htb_class
*)arg
;
1039 spinlock_t
*root_lock
= qdisc_root_sleeping_lock(sch
);
1040 struct nlattr
*nest
;
1041 struct tc_htb_opt opt
;
1043 spin_lock_bh(root_lock
);
1044 tcm
->tcm_parent
= cl
->parent
? cl
->parent
->common
.classid
: TC_H_ROOT
;
1045 tcm
->tcm_handle
= cl
->common
.classid
;
1046 if (!cl
->level
&& cl
->un
.leaf
.q
)
1047 tcm
->tcm_info
= cl
->un
.leaf
.q
->handle
;
1049 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
1051 goto nla_put_failure
;
1053 memset(&opt
, 0, sizeof(opt
));
1055 opt
.rate
= cl
->rate
->rate
;
1056 opt
.buffer
= cl
->buffer
;
1057 opt
.ceil
= cl
->ceil
->rate
;
1058 opt
.cbuffer
= cl
->cbuffer
;
1059 opt
.quantum
= cl
->quantum
;
1060 opt
.prio
= cl
->prio
;
1061 opt
.level
= cl
->level
;
1062 NLA_PUT(skb
, TCA_HTB_PARMS
, sizeof(opt
), &opt
);
1064 nla_nest_end(skb
, nest
);
1065 spin_unlock_bh(root_lock
);
1069 spin_unlock_bh(root_lock
);
1070 nla_nest_cancel(skb
, nest
);
1075 htb_dump_class_stats(struct Qdisc
*sch
, unsigned long arg
, struct gnet_dump
*d
)
1077 struct htb_class
*cl
= (struct htb_class
*)arg
;
1079 if (!cl
->level
&& cl
->un
.leaf
.q
)
1080 cl
->qstats
.qlen
= cl
->un
.leaf
.q
->q
.qlen
;
1081 cl
->xstats
.tokens
= cl
->tokens
;
1082 cl
->xstats
.ctokens
= cl
->ctokens
;
1084 if (gnet_stats_copy_basic(d
, &cl
->bstats
) < 0 ||
1085 gnet_stats_copy_rate_est(d
, &cl
->rate_est
) < 0 ||
1086 gnet_stats_copy_queue(d
, &cl
->qstats
) < 0)
1089 return gnet_stats_copy_app(d
, &cl
->xstats
, sizeof(cl
->xstats
));
1092 static int htb_graft(struct Qdisc
*sch
, unsigned long arg
, struct Qdisc
*new,
1095 struct htb_class
*cl
= (struct htb_class
*)arg
;
1097 if (cl
&& !cl
->level
) {
1099 (new = qdisc_create_dflt(qdisc_dev(sch
), sch
->dev_queue
,
1101 cl
->common
.classid
))
1105 *old
= cl
->un
.leaf
.q
;
1106 cl
->un
.leaf
.q
= new;
1108 qdisc_tree_decrease_qlen(*old
, (*old
)->q
.qlen
);
1111 sch_tree_unlock(sch
);
1117 static struct Qdisc
*htb_leaf(struct Qdisc
*sch
, unsigned long arg
)
1119 struct htb_class
*cl
= (struct htb_class
*)arg
;
1120 return (cl
&& !cl
->level
) ? cl
->un
.leaf
.q
: NULL
;
1123 static void htb_qlen_notify(struct Qdisc
*sch
, unsigned long arg
)
1125 struct htb_class
*cl
= (struct htb_class
*)arg
;
1127 if (cl
->un
.leaf
.q
->q
.qlen
== 0)
1128 htb_deactivate(qdisc_priv(sch
), cl
);
1131 static unsigned long htb_get(struct Qdisc
*sch
, u32 classid
)
1133 struct htb_class
*cl
= htb_find(classid
, sch
);
1136 return (unsigned long)cl
;
1139 static inline int htb_parent_last_child(struct htb_class
*cl
)
1142 /* the root class */
1144 if (cl
->parent
->children
> 1)
1145 /* not the last child */
1150 static void htb_parent_to_leaf(struct htb_sched
*q
, struct htb_class
*cl
,
1151 struct Qdisc
*new_q
)
1153 struct htb_class
*parent
= cl
->parent
;
1155 WARN_ON(cl
->level
|| !cl
->un
.leaf
.q
|| cl
->prio_activity
);
1157 if (parent
->cmode
!= HTB_CAN_SEND
)
1158 htb_safe_rb_erase(&parent
->pq_node
, q
->wait_pq
+ parent
->level
);
1161 memset(&parent
->un
.inner
, 0, sizeof(parent
->un
.inner
));
1162 INIT_LIST_HEAD(&parent
->un
.leaf
.drop_list
);
1163 parent
->un
.leaf
.q
= new_q
? new_q
: &noop_qdisc
;
1164 parent
->tokens
= parent
->buffer
;
1165 parent
->ctokens
= parent
->cbuffer
;
1166 parent
->t_c
= psched_get_time();
1167 parent
->cmode
= HTB_CAN_SEND
;
1170 static void htb_destroy_class(struct Qdisc
*sch
, struct htb_class
*cl
)
1173 WARN_ON(!cl
->un
.leaf
.q
);
1174 qdisc_destroy(cl
->un
.leaf
.q
);
1176 gen_kill_estimator(&cl
->bstats
, &cl
->rate_est
);
1177 qdisc_put_rtab(cl
->rate
);
1178 qdisc_put_rtab(cl
->ceil
);
1180 tcf_destroy_chain(&cl
->filter_list
);
1184 /* always caled under BH & queue lock */
1185 static void htb_destroy(struct Qdisc
*sch
)
1187 struct htb_sched
*q
= qdisc_priv(sch
);
1188 struct hlist_node
*n
, *next
;
1189 struct htb_class
*cl
;
1192 qdisc_watchdog_cancel(&q
->watchdog
);
1193 /* This line used to be after htb_destroy_class call below
1194 and surprisingly it worked in 2.4. But it must precede it
1195 because filter need its target class alive to be able to call
1196 unbind_filter on it (without Oops). */
1197 tcf_destroy_chain(&q
->filter_list
);
1199 for (i
= 0; i
< q
->clhash
.hashsize
; i
++) {
1200 hlist_for_each_entry(cl
, n
, &q
->clhash
.hash
[i
], common
.hnode
)
1201 tcf_destroy_chain(&cl
->filter_list
);
1203 for (i
= 0; i
< q
->clhash
.hashsize
; i
++) {
1204 hlist_for_each_entry_safe(cl
, n
, next
, &q
->clhash
.hash
[i
],
1206 htb_destroy_class(sch
, cl
);
1208 qdisc_class_hash_destroy(&q
->clhash
);
1209 __skb_queue_purge(&q
->direct_queue
);
1212 static int htb_delete(struct Qdisc
*sch
, unsigned long arg
)
1214 struct htb_sched
*q
= qdisc_priv(sch
);
1215 struct htb_class
*cl
= (struct htb_class
*)arg
;
1217 struct Qdisc
*new_q
= NULL
;
1220 // TODO: why don't allow to delete subtree ? references ? does
1221 // tc subsys quarantee us that in htb_destroy it holds no class
1222 // refs so that we can remove children safely there ?
1223 if (cl
->children
|| cl
->filter_cnt
)
1226 if (!cl
->level
&& htb_parent_last_child(cl
)) {
1227 new_q
= qdisc_create_dflt(qdisc_dev(sch
), sch
->dev_queue
,
1229 cl
->parent
->common
.classid
);
1236 qlen
= cl
->un
.leaf
.q
->q
.qlen
;
1237 qdisc_reset(cl
->un
.leaf
.q
);
1238 qdisc_tree_decrease_qlen(cl
->un
.leaf
.q
, qlen
);
1241 /* delete from hash and active; remainder in destroy_class */
1242 qdisc_class_hash_remove(&q
->clhash
, &cl
->common
);
1244 cl
->parent
->children
--;
1246 if (cl
->prio_activity
)
1247 htb_deactivate(q
, cl
);
1249 if (cl
->cmode
!= HTB_CAN_SEND
)
1250 htb_safe_rb_erase(&cl
->pq_node
, q
->wait_pq
+ cl
->level
);
1253 htb_parent_to_leaf(q
, cl
, new_q
);
1255 if (--cl
->refcnt
== 0)
1256 htb_destroy_class(sch
, cl
);
1258 sch_tree_unlock(sch
);
1262 static void htb_put(struct Qdisc
*sch
, unsigned long arg
)
1264 struct htb_class
*cl
= (struct htb_class
*)arg
;
1266 if (--cl
->refcnt
== 0)
1267 htb_destroy_class(sch
, cl
);
1270 static int htb_change_class(struct Qdisc
*sch
, u32 classid
,
1271 u32 parentid
, struct nlattr
**tca
,
1275 struct htb_sched
*q
= qdisc_priv(sch
);
1276 struct htb_class
*cl
= (struct htb_class
*)*arg
, *parent
;
1277 struct nlattr
*opt
= tca
[TCA_OPTIONS
];
1278 struct qdisc_rate_table
*rtab
= NULL
, *ctab
= NULL
;
1279 struct nlattr
*tb
[TCA_HTB_RTAB
+ 1];
1280 struct tc_htb_opt
*hopt
;
1282 /* extract all subattrs from opt attr */
1286 err
= nla_parse_nested(tb
, TCA_HTB_RTAB
, opt
, htb_policy
);
1291 if (tb
[TCA_HTB_PARMS
] == NULL
)
1294 parent
= parentid
== TC_H_ROOT
? NULL
: htb_find(parentid
, sch
);
1296 hopt
= nla_data(tb
[TCA_HTB_PARMS
]);
1298 rtab
= qdisc_get_rtab(&hopt
->rate
, tb
[TCA_HTB_RTAB
]);
1299 ctab
= qdisc_get_rtab(&hopt
->ceil
, tb
[TCA_HTB_CTAB
]);
1303 if (!cl
) { /* new class */
1304 struct Qdisc
*new_q
;
1308 struct gnet_estimator opt
;
1311 .nla_len
= nla_attr_size(sizeof(est
.opt
)),
1312 .nla_type
= TCA_RATE
,
1315 /* 4s interval, 16s averaging constant */
1321 /* check for valid classid */
1322 if (!classid
|| TC_H_MAJ(classid
^ sch
->handle
)
1323 || htb_find(classid
, sch
))
1326 /* check maximal depth */
1327 if (parent
&& parent
->parent
&& parent
->parent
->level
< 2) {
1328 printk(KERN_ERR
"htb: tree is too deep\n");
1332 if ((cl
= kzalloc(sizeof(*cl
), GFP_KERNEL
)) == NULL
)
1335 err
= gen_new_estimator(&cl
->bstats
, &cl
->rate_est
,
1336 qdisc_root_sleeping_lock(sch
),
1337 tca
[TCA_RATE
] ? : &est
.nla
);
1345 INIT_LIST_HEAD(&cl
->un
.leaf
.drop_list
);
1346 RB_CLEAR_NODE(&cl
->pq_node
);
1348 for (prio
= 0; prio
< TC_HTB_NUMPRIO
; prio
++)
1349 RB_CLEAR_NODE(&cl
->node
[prio
]);
1351 /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
1352 so that can't be used inside of sch_tree_lock
1353 -- thanks to Karlis Peisenieks */
1354 new_q
= qdisc_create_dflt(qdisc_dev(sch
), sch
->dev_queue
,
1355 &pfifo_qdisc_ops
, classid
);
1357 if (parent
&& !parent
->level
) {
1358 unsigned int qlen
= parent
->un
.leaf
.q
->q
.qlen
;
1360 /* turn parent into inner node */
1361 qdisc_reset(parent
->un
.leaf
.q
);
1362 qdisc_tree_decrease_qlen(parent
->un
.leaf
.q
, qlen
);
1363 qdisc_destroy(parent
->un
.leaf
.q
);
1364 if (parent
->prio_activity
)
1365 htb_deactivate(q
, parent
);
1367 /* remove from evt list because of level change */
1368 if (parent
->cmode
!= HTB_CAN_SEND
) {
1369 htb_safe_rb_erase(&parent
->pq_node
, q
->wait_pq
);
1370 parent
->cmode
= HTB_CAN_SEND
;
1372 parent
->level
= (parent
->parent
? parent
->parent
->level
1373 : TC_HTB_MAXDEPTH
) - 1;
1374 memset(&parent
->un
.inner
, 0, sizeof(parent
->un
.inner
));
1376 /* leaf (we) needs elementary qdisc */
1377 cl
->un
.leaf
.q
= new_q
? new_q
: &noop_qdisc
;
1379 cl
->common
.classid
= classid
;
1380 cl
->parent
= parent
;
1382 /* set class to be in HTB_CAN_SEND state */
1383 cl
->tokens
= hopt
->buffer
;
1384 cl
->ctokens
= hopt
->cbuffer
;
1385 cl
->mbuffer
= 60 * PSCHED_TICKS_PER_SEC
; /* 1min */
1386 cl
->t_c
= psched_get_time();
1387 cl
->cmode
= HTB_CAN_SEND
;
1389 /* attach to the hash list and parent's family */
1390 qdisc_class_hash_insert(&q
->clhash
, &cl
->common
);
1394 if (tca
[TCA_RATE
]) {
1395 err
= gen_replace_estimator(&cl
->bstats
, &cl
->rate_est
,
1396 qdisc_root_sleeping_lock(sch
),
1404 /* it used to be a nasty bug here, we have to check that node
1405 is really leaf before changing cl->un.leaf ! */
1407 cl
->quantum
= rtab
->rate
.rate
/ q
->rate2quantum
;
1408 if (!hopt
->quantum
&& cl
->quantum
< 1000) {
1410 "HTB: quantum of class %X is small. Consider r2q change.\n",
1411 cl
->common
.classid
);
1414 if (!hopt
->quantum
&& cl
->quantum
> 200000) {
1416 "HTB: quantum of class %X is big. Consider r2q change.\n",
1417 cl
->common
.classid
);
1418 cl
->quantum
= 200000;
1421 cl
->quantum
= hopt
->quantum
;
1422 if ((cl
->prio
= hopt
->prio
) >= TC_HTB_NUMPRIO
)
1423 cl
->prio
= TC_HTB_NUMPRIO
- 1;
1426 cl
->buffer
= hopt
->buffer
;
1427 cl
->cbuffer
= hopt
->cbuffer
;
1429 qdisc_put_rtab(cl
->rate
);
1432 qdisc_put_rtab(cl
->ceil
);
1434 sch_tree_unlock(sch
);
1436 qdisc_class_hash_grow(sch
, &q
->clhash
);
1438 *arg
= (unsigned long)cl
;
1443 qdisc_put_rtab(rtab
);
1445 qdisc_put_rtab(ctab
);
1449 static struct tcf_proto
**htb_find_tcf(struct Qdisc
*sch
, unsigned long arg
)
1451 struct htb_sched
*q
= qdisc_priv(sch
);
1452 struct htb_class
*cl
= (struct htb_class
*)arg
;
1453 struct tcf_proto
**fl
= cl
? &cl
->filter_list
: &q
->filter_list
;
1458 static unsigned long htb_bind_filter(struct Qdisc
*sch
, unsigned long parent
,
1461 struct htb_class
*cl
= htb_find(classid
, sch
);
1463 /*if (cl && !cl->level) return 0;
1464 The line above used to be there to prevent attaching filters to
1465 leaves. But at least tc_index filter uses this just to get class
1466 for other reasons so that we have to allow for it.
1468 19.6.2002 As Werner explained it is ok - bind filter is just
1469 another way to "lock" the class - unlike "get" this lock can
1470 be broken by class during destroy IIUC.
1474 return (unsigned long)cl
;
1477 static void htb_unbind_filter(struct Qdisc
*sch
, unsigned long arg
)
1479 struct htb_class
*cl
= (struct htb_class
*)arg
;
1485 static void htb_walk(struct Qdisc
*sch
, struct qdisc_walker
*arg
)
1487 struct htb_sched
*q
= qdisc_priv(sch
);
1488 struct htb_class
*cl
;
1489 struct hlist_node
*n
;
1495 for (i
= 0; i
< q
->clhash
.hashsize
; i
++) {
1496 hlist_for_each_entry(cl
, n
, &q
->clhash
.hash
[i
], common
.hnode
) {
1497 if (arg
->count
< arg
->skip
) {
1501 if (arg
->fn(sch
, (unsigned long)cl
, arg
) < 0) {
1510 static const struct Qdisc_class_ops htb_class_ops
= {
1513 .qlen_notify
= htb_qlen_notify
,
1516 .change
= htb_change_class
,
1517 .delete = htb_delete
,
1519 .tcf_chain
= htb_find_tcf
,
1520 .bind_tcf
= htb_bind_filter
,
1521 .unbind_tcf
= htb_unbind_filter
,
1522 .dump
= htb_dump_class
,
1523 .dump_stats
= htb_dump_class_stats
,
1526 static struct Qdisc_ops htb_qdisc_ops __read_mostly
= {
1528 .cl_ops
= &htb_class_ops
,
1530 .priv_size
= sizeof(struct htb_sched
),
1531 .enqueue
= htb_enqueue
,
1532 .dequeue
= htb_dequeue
,
1533 .peek
= qdisc_peek_dequeued
,
1537 .destroy
= htb_destroy
,
1538 .change
= NULL
/* htb_change */,
1540 .owner
= THIS_MODULE
,
1543 static int __init
htb_module_init(void)
1545 return register_qdisc(&htb_qdisc_ops
);
1547 static void __exit
htb_module_exit(void)
1549 unregister_qdisc(&htb_qdisc_ops
);
1552 module_init(htb_module_init
)
1553 module_exit(htb_module_exit
)
1554 MODULE_LICENSE("GPL");