Release 4.11 net/sched/sch_htb.c

/*
 * net/sched/sch_htb.c  Hierarchical token bucket, feed tree version
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Authors:     Martin Devera, <devik@cdi.cz>
 *
 * Credits (in time order) for older HTB versions:
 *              Stef Coene <stef.coene@docum.org>
 *                      HTB support at LARTC mailing list
 *              Ondrej Kraus, <krauso@barr.cz>
 *                      found missing INIT_QDISC(htb)
 *              Vladimir Smelhaus, Aamer Akhter, Bert Hubert
 *                      helped a lot to locate nasty class stall bug
 *              Andi Kleen, Jamal Hadi, Bert Hubert
 *                      code review and helpful comments on shaping
 *              Tomasz Wrona, <tw@eter.tym.pl>
 *                      created test case so that I was able to fix nasty bug
 *              Wilfried Weissmann
 *                      spotted bug in dequeue code and helped with fix
 *              Jiri Fojtasek
 *                      fixed requeue routine
 *              and many others. thanks.
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/list.h>
#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <net/netlink.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

/* HTB algorithm.
    Author: devik@cdi.cz
    ========================================================================
    HTB is like TBF with multiple classes. It is also similar to CBQ because
    it allows to assign priority to each class in hierarchy.
    In fact it is another implementation of Floyd's formal sharing.

    Levels:
    Each class is assigned level. Leaf has ALWAYS level 0 and root
    classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
    one less than their parent.
*/


static int htb_hysteresis __read_mostly = 0; 
/* whether to use mode hysteresis for speedup */

#define HTB_VER 0x30011		
/* major must be matched with number suplied by TC as version */

#if HTB_VER >> 16 != TC_HTB_PROTOVER
#error "Mismatched sch_htb.c and pkt_sch.h"
#endif

/* Module parameter and sysfs export */
module_param    (htb_hysteresis, int, 0640);
MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate");


static int htb_rate_est = 0; 
/* htb classes have a default rate estimator */
module_param(htb_rate_est, int, 0640);
MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes");

/* used internaly to keep status of single class */

enum htb_cmode {
	
HTB_CANT_SEND,		/* class can't send and can't borrow */
	
HTB_MAY_BORROW,		/* class can't send but may borrow */
	
HTB_CAN_SEND		/* class can send */
};


struct htb_prio {
	union {
		
struct rb_root	row;
		
struct rb_root	feed;
	};
	
struct rb_node	*ptr;
	/* When class changes from state 1->2 and disconnects from
         * parent's feed then we lost ptr value and start from the
         * first child again. Here we store classid of the
         * last valid ptr (used when ptr is NULL).
         */
	
u32		last_ptr_id;
};

/* interior & leaf nodes; props specific to leaves are marked L:
 * To reduce false sharing, place mostly read fields at beginning,
 * and mostly written ones at the end.
 */

struct htb_class {
	
struct Qdisc_class_common common;
	
struct psched_ratecfg	rate;
	
struct psched_ratecfg	ceil;
	

s64			buffer, cbuffer;/* token bucket depth/rate */
	
s64			mbuffer;	/* max wait time */
	
u32			prio;		/* these two are used only by leaves... */
	
int			quantum;	/* but stored for parent-to-leaf return */

	
struct tcf_proto __rcu	*filter_list;	/* class attached filters */
	
int			filter_cnt;
	
int			refcnt;		/* usage count of this class */

	
int			level;		/* our level (see above) */
	
unsigned int		children;
	
struct htb_class	*parent;	/* parent class */

	
struct net_rate_estimator __rcu *rate_est;

	/*
         * Written often fields
         */
	
struct gnet_stats_basic_packed bstats;
	
struct tc_htb_xstats	xstats;	/* our special stats */

	/* token bucket parameters */
	

s64			tokens, ctokens;/* current number of tokens */
	
s64			t_c;		/* checkpoint time */

	union {
		
struct htb_class_leaf {
			
struct list_head drop_list;
			
int		deficit[TC_HTB_MAXDEPTH];
			
struct Qdisc	*q;
		} 
leaf;
		
struct htb_class_inner {
			
struct htb_prio clprio[TC_HTB_NUMPRIO];
		} 
inner;
	} 
un;
	
s64			pq_key;

	
int			prio_activity;	/* for which prios are we active */
	
enum htb_cmode		cmode;		/* current mode of the class */
	
struct rb_node		pq_node;	/* node for event queue */
	
struct rb_node		node[TC_HTB_NUMPRIO];	/* node for self or feed tree */

	
unsigned int drops ____cacheline_aligned_in_smp;
};


struct htb_level {
	
struct rb_root	wait_pq;
	
struct htb_prio hprio[TC_HTB_NUMPRIO];
};


struct htb_sched {
	
struct Qdisc_class_hash clhash;
	
int			defcls;		/* class where unclassified flows go to */
	
int			rate2quantum;	/* quant = rate / rate2quantum */

	/* filters for qdisc itself */
	
struct tcf_proto __rcu	*filter_list;


#define HTB_WARN_TOOMANYEVENTS	0x1
	
unsigned int		warned;	/* only one warning */
	
int			direct_qlen;
	
struct work_struct	work;

	/* non shaped skbs; let them go directly thru */
	
struct qdisc_skb_head	direct_queue;
	
long			direct_pkts;

	
struct qdisc_watchdog	watchdog;

	
s64			now;	/* cached dequeue time */
	
struct list_head	drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */

	/* time of nearest event per level (row) */
	
s64			near_ev_cache[TC_HTB_MAXDEPTH];

	
int			row_mask[TC_HTB_MAXDEPTH];

	
struct htb_level	hlevel[TC_HTB_MAXDEPTH];
};

/* find class in global hash table using given handle */


static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct Qdisc_class_common *clc;

	clc = qdisc_class_find(&q->clhash, handle);
	if (clc == NULL)
		return NULL;
	return container_of(clc, struct htb_class, common);
}

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/**
 * htb_classify - classify a packet into class
 *
 * It returns NULL if the packet should be dropped or -1 if the packet
 * should be passed directly thru. In all other cases leaf class is returned.
 * We allow direct class selection by classid in priority. The we examine
 * filters in qdisc and in inner nodes (if higher filter points to the inner
 * node). If we end up with classid MAJOR:0 we enqueue the skb into special
 * internal fifo (direct). These packets then go directly thru. If we still
 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful
 * then finish and return direct queue.
 */

#define HTB_DIRECT ((struct htb_class *)-1L)



static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
				      int *qerr)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl;
	struct tcf_result res;
	struct tcf_proto *tcf;
	int result;

	/* allow to select class by setting skb->priority to valid classid;
         * note that nfmark can be used too by attaching filter fw with no
         * rules in it
         */
	if (skb->priority == sch->handle)
		return HTB_DIRECT;	/* X:0 (direct flow) selected */
	cl = htb_find(skb->priority, sch);
	if (cl) {
		if (cl->level == 0)
			return cl;
		/* Start with inner filter chain if a non-leaf class is selected */
		tcf = rcu_dereference_bh(cl->filter_list);
	} else {
		tcf = rcu_dereference_bh(q->filter_list);
	}

	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	while (tcf && (result = tc_classify(skb, tcf, &res, false)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
		case TC_ACT_SHOT:
			return NULL;
		}
#endif
		cl = (void *)res.class;
		if (!cl) {
			if (res.classid == sch->handle)
				return HTB_DIRECT;	/* X:0 (direct flow) */
			cl = htb_find(res.classid, sch);
			if (!cl)
				break;	/* filter selected invalid classid */
		}
		if (!cl->level)
			return cl;	/* we hit leaf; return it */

		/* we have got inner class; apply inner filter chain */
		tcf = rcu_dereference_bh(cl->filter_list);
	}
	/* classification failed; try to use default class */
	cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
	if (!cl || cl->level)
		return HTB_DIRECT;	/* bad default .. this is safe bet */
	return cl;
}

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Eric Dumazet
15
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1
9.09%
John Fastabend
9
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Patrick McHardy
7
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1
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Martin Devera
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Stephen Hemminger
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Jarek Poplawski
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1
9.09%
Daniel Borkmann
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/**
 * htb_add_to_id_tree - adds class to the round robin list
 *
 * Routine adds class to the list (actually tree) sorted by classid.
 * Make sure that class is not already on such list for given prio.
 */


static void htb_add_to_id_tree(struct rb_root *root,
			       struct htb_class *cl, int prio)
{
	struct rb_node **p = &root->rb_node, *parent = NULL;

	while (*p) {
		struct htb_class *c;
		parent = *p;
		c = rb_entry(parent, struct htb_class, node[prio]);

		if (cl->common.classid > c->common.classid)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}
	rb_link_node(&cl->node[prio], parent, p);
	rb_insert_color(&cl->node[prio], root);
}

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48
38.71%
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4
3.23%
1
25.00%
David Woodhouse
1
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/**
 * htb_add_to_wait_tree - adds class to the event queue with delay
 *
 * The class is added to priority event queue to indicate that class will
 * change its mode in cl->pq_key microseconds. Make sure that class is not
 * already in the queue.
 */


static void htb_add_to_wait_tree(struct htb_sched *q,
				 struct htb_class *cl, s64 delay)
{
	struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL;

	cl->pq_key = q->now + delay;
	if (cl->pq_key == q->now)
		cl->pq_key++;

	/* update the nearest event cache */
	if (q->near_ev_cache[cl->level] > cl->pq_key)
		q->near_ev_cache[cl->level] = cl->pq_key;

	while (*p) {
		struct htb_class *c;
		parent = *p;
		c = rb_entry(parent, struct htb_class, pq_node);
		if (cl->pq_key >= c->pq_key)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}
	rb_link_node(&cl->pq_node, parent, p);
	rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
}

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3.26%
1
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Patrick McHardy
4
2.17%
1
16.67%
Martin Devera
4
2.17%
1
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David Woodhouse
2
1.09%
1
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Vimalkumar
1
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/**
 * htb_next_rb_node - finds next node in binary tree
 *
 * When we are past last key we return NULL.
 * Average complexity is 2 steps per call.
 */


static inline void htb_next_rb_node(struct rb_node **n)
{
	*n = rb_next(*n);
}

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1
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/**
 * htb_add_class_to_row - add class to its row
 *
 * The class is added to row at priorities marked in mask.
 * It does nothing if mask == 0.
 */


static inline void htb_add_class_to_row(struct htb_sched *q,
					struct htb_class *cl, int mask)
{
	q->row_mask[cl->level] |= mask;
	while (mask) {
		int prio = ffz(~mask);
		mask &= ~(1 << prio);
		htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio);
	}
}

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/* If this triggers, it is a bug in this code, but it need not be fatal */


static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root)
{
	if (RB_EMPTY_NODE(rb)) {
		WARN_ON(1);
	} else {
		rb_erase(rb, root);
		RB_CLEAR_NODE(rb);
	}
}


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/**
 * htb_remove_class_from_row - removes class from its row
 *
 * The class is removed from row at priorities marked in mask.
 * It does nothing if mask == 0.
 */


static inline void htb_remove_class_from_row(struct htb_sched *q,
						 struct htb_class *cl, int mask)
{
	int m = 0;
	struct htb_level *hlevel = &q->hlevel[cl->level];

	while (mask) {
		int prio = ffz(~mask);
		struct htb_prio *hprio = &hlevel->hprio[prio];

		mask &= ~(1 << prio);
		if (hprio->ptr == cl->node + prio)
			htb_next_rb_node(&hprio->ptr);

		htb_safe_rb_erase(cl->node + prio, &hprio->row);
		if (!hprio->row.rb_node)
			m |= 1 << prio;
	}
	q->row_mask[cl->level] &= ~m;
}

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1.45%
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/**
 * htb_activate_prios - creates active classe's feed chain
 *
 * The class is connected to ancestors and/or appropriate rows
 * for priorities it is participating on. cl->cmode must be new
 * (activated) mode. It does nothing if cl->prio_activity == 0.
 */


static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl)
{
	struct htb_class *p = cl->parent;
	long m, mask = cl->prio_activity;

	while (cl->cmode == HTB_MAY_BORROW && p && mask) {
		m = mask;
		while (m) {
			int prio = ffz(~m);
			m &= ~(1 << prio);

			if (p->un.inner.clprio[prio].feed.rb_node)
				/* parent already has its feed in use so that
                                 * reset bit in mask as parent is already ok
                                 */
				mask &= ~(1 << prio);

			htb_add_to_id_tree(&p->un.inner.clprio[prio].feed, cl, prio);
		}
		p->prio_activity |= mask;
		cl = p;
		p = cl->parent;

	}
	if (cl->cmode == HTB_CAN_SEND && mask)
		htb_add_class_to_row(q, cl, mask);
}

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/**
 * htb_deactivate_prios - remove class from feed chain
 *
 * cl->cmode must represent old mode (before deactivation). It does
 * nothing if cl->prio_activity == 0. Class is removed from all feed
 * chains and rows.
 */


static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
{
	struct htb_class *p = cl->parent;
	long m, mask = cl->prio_activity;

	while (cl->cmode == HTB_MAY_BORROW && p && mask) {
		m = mask;
		mask = 0;
		while (m) {
			int prio = ffz(~m);
			m &= ~(1 << prio);

			if (p->un.inner.clprio[prio].ptr == cl->node + prio) {
				/* we are removing child which is pointed to from
                                 * parent feed - forget the pointer but remember
                                 * classid
                                 */
				p->un.inner.clprio[prio].last_ptr_id = cl->common.classid;
				p->un.inner.clprio[prio].ptr = NULL;
			}

			htb_safe_rb_erase(cl->node + prio,
					  &p->un.inner.clprio[prio].feed);

			if (!p->un.inner.clprio[prio].feed.rb_node)
				mask |= 1 << prio;
		}

		p->prio_activity &= ~mask;
		cl = p;
		p = cl->parent;

	}
	if (cl->cmode == HTB_CAN_SEND && mask)
		htb_remove_class_from_row(q, cl, mask);
}

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Eric Dumazet
19
8.60%
2
33.33%
Patrick McHardy
2
0.90%
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16.67%
Stephen Hemminger
1
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static inline s64 htb_lowater(const struct htb_class *cl)
{
	if (htb_hysteresis)
		return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
	else
		return 0;
}
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static inline s64 htb_hiwater(const struct htb_class *cl)
{
	if (htb_hysteresis)
		return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
	else
		return 0;
}


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/**
 * htb_class_mode - computes and returns current class mode
 *
 * It computes cl's mode at time cl->t_c+diff and returns it. If mode
 * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
 * from now to time when cl will change its state.
 * Also it is worth to note that class mode doesn't change simply
 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
 * mode transitions per time unit. The speed gain is about 1/6.
 */

static inline enum htb_cmode

htb_class_mode(struct htb_class *cl, s64 *diff)
{
	s64 toks;

	if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
		*diff = -toks;
		return HTB_CANT_SEND;
	}

	if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl))
		return HTB_CAN_SEND;

	*diff = -toks;
	return HTB_MAY_BORROW;
}

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/**
 * htb_change_class_mode - changes classe's mode
 *
 * This should be the only way how to change classe's mode under normal
 * cirsumstances. Routine will update feed lists linkage, change mode
 * and add class to the wait event queue if appropriate. New mode should
 * be different from old one and cl->pq_key has to be valid if changing
 * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
 */

static void

htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
{
	enum htb_cmode new_mode = htb_class_mode(cl, diff);

	if (new_mode == cl->cmode)
		return;

	if (cl->prio_activity) {	/* not necessary: speed optimization */
		if (cl->cmode != HTB_CANT_SEND)
			htb_deactivate_prios(q, cl);
		cl->cmode = new_mode;
		if (new_mode != HTB_CANT_SEND)
			htb_activate_prios(q, cl);
	} else
		cl->cmode = new_mode;
}

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/**
 * htb_activate - inserts leaf cl into appropriate active feeds
 *
 * Routine learns (new) priority of leaf and activates feed chain
 * for the prio. It can be called on already active leaf safely.
 * It also adds leaf into droplist.
 */


static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
{
	WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen);

	if (!cl->prio_activity) {
		cl->prio_activity = 1 << cl->prio;
		htb_activate_prios(q, cl);
		list_add_tail(&cl->un.leaf.drop_list,
			      q->drops + cl->prio);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
85
92.39%
1
25.00%
Ilpo Järvinen
5
5.43%
1
25.00%
Stephen Hemminger
1
1.09%
1
25.00%
Jarek Poplawski
1
1.09%
1
25.00%
Total
92
100.00%
4
100.00%

/**
 * htb_deactivate - remove leaf cl from active feeds
 *
 * Make sure that leaf is active. In the other words it can't be called
 * with non-active leaf. It also removes class from the drop list.
 */


static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
{
	WARN_ON(!cl->prio_activity);

	htb_deactivate_prios(q, cl);
	cl->prio_activity = 0;
	list_del_init(&cl->un.leaf.drop_list);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
47
94.00%
1
33.33%
Ilpo Järvinen
2
4.00%
1
33.33%
Stephen Hemminger
1
2.00%
1
33.33%
Total
50
100.00%
3
100.00%



static void htb_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
			     struct qdisc_skb_head *qh)
{
	struct sk_buff *last = qh->tail;

	if (last) {
		skb->next = NULL;
		last->next = skb;
		qh->tail = skb;
	} else {
		qh->tail = skb;
		qh->head = skb;
	}
	qh->qlen++;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Florian Westphal
74
100.00%
1
100.00%
Total
74
100.00%
1
100.00%



static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
		       struct sk_buff **to_free)
{
	int uninitialized_var(ret);
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl = htb_classify(skb, sch, &ret);

	if (cl == HTB_DIRECT) {
		/* enqueue to helper queue */
		if (q->direct_queue.qlen < q->direct_qlen) {
			htb_enqueue_tail(skb, sch, &q->direct_queue);
			q->direct_pkts++;
		} else {
			return qdisc_drop(skb, sch, to_free);
		}
#ifdef CONFIG_NET_CLS_ACT
	} else if (!cl) {
		if (ret & __NET_XMIT_BYPASS)
			qdisc_qstats_drop(sch);
		__qdisc_drop(skb, to_free);
		return ret;
#endif
	} else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q,
					to_free)) != NET_XMIT_SUCCESS) {
		if (net_xmit_drop_count(ret)) {
			qdisc_qstats_drop(sch);
			cl->drops++;
		}
		return ret;
	} else {
		htb_activate(q, cl);
	}

	qdisc_qstats_backlog_inc(sch, skb);
	sch->q.qlen++;
	return NET_XMIT_SUCCESS;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
90
41.86%
2
13.33%
Jamal Hadi Salim
55
25.58%
1
6.67%
Jarek Poplawski
18
8.37%
3
20.00%
Eric Dumazet
17
7.91%
2
13.33%
Asim Shankar
7
3.26%
1
6.67%
Américo Wang
7
3.26%
1
6.67%
John Fastabend
6
2.79%
1
6.67%
Patrick McHardy
6
2.79%
1
6.67%
Florian Westphal
5
2.33%
1
6.67%
Stephen Hemminger
3
1.40%
1
6.67%
Jussi Kivilinna
1
0.47%
1
6.67%
Total
215
100.00%
15
100.00%



static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
{
	s64 toks = diff + cl->tokens;

	if (toks > cl->buffer)
		toks = cl->buffer;
	toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
	if (toks <= -cl->mbuffer)
		toks = 1 - cl->mbuffer;

	cl->tokens = toks;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarek Poplawski
74
93.67%
1
33.33%
Vimalkumar
4
5.06%
1
33.33%
Jiri Pirko
1
1.27%
1
33.33%
Total
79
100.00%
3
100.00%



static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
{
	s64 toks = diff + cl->ctokens;

	if (toks > cl->cbuffer)
		toks = cl->cbuffer;
	toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
	if (toks <= -cl->mbuffer)
		toks = 1 - cl->mbuffer;

	cl->ctokens = toks;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarek Poplawski
74
93.67%
1
33.33%
Vimalkumar
4
5.06%
1
33.33%
Jiri Pirko
1
1.27%
1
33.33%
Total
79
100.00%
3
100.00%

/**
 * htb_charge_class - charges amount "bytes" to leaf and ancestors
 *
 * Routine assumes that packet "bytes" long was dequeued from leaf cl
 * borrowing from "level". It accounts bytes to ceil leaky bucket for
 * leaf and all ancestors and to rate bucket for ancestors at levels
 * "level" and higher. It also handles possible change of mode resulting
 * from the update. Note that mode can also increase here (MAY_BORROW to
 * CAN_SEND) because we can use more precise clock that event queue here.
 * In such case we remove class from event queue first.
 */


static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
			     int level, struct sk_buff *skb)
{
	int bytes = qdisc_pkt_len(skb);
	enum htb_cmode old_mode;
	s64 diff;

	while (cl) {
		diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
		if (cl->level >= level) {
			if (cl->level == level)
				cl->xstats.lends++;
			htb_accnt_tokens(cl, bytes, diff);
		} else {
			cl->xstats.borrows++;
			cl->tokens += diff;	/* we moved t_c; update tokens */
		}
		htb_accnt_ctokens(cl, bytes, diff);
		cl->t_c = q->now;

		old_mode = cl->cmode;
		diff = 0;
		htb_change_class_mode(q, cl, &diff);
		if (old_mode != cl->cmode) {
			if (old_mode != HTB_CAN_SEND)
				htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
			if (cl->cmode != HTB_CAN_SEND)
				htb_add_to_wait_tree(q, cl, diff);
		}

		/* update basic stats except for leaves which are already updated */
		if (cl->level)
			bstats_update(&cl->bstats, skb);

		cl = cl->parent;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
175
76.75%
1
9.09%
Ranjit Manomohan
11
4.82%
1
9.09%
Eric Dumazet
11
4.82%
2
18.18%
Jarek Poplawski
10
4.39%
1
9.09%
Patrick McHardy
6
2.63%
1
9.09%
Stephen Hemminger
6
2.63%
2
18.18%
Vimalkumar
5
2.19%
1
9.09%
Jussi Kivilinna
3
1.32%
1
9.09%
Thomas Graf
1
0.44%
1
9.09%
Total
228
100.00%
11
100.00%

/**
 * htb_do_events - make mode changes to classes at the level
 *
 * Scans event queue for pending events and applies them. Returns time of
 * next pending event (0 for no event in pq, q->now for too many events).
 * Note: Applied are events whose have cl->pq_key <= q->now.
 */


static s64 htb_do_events(struct htb_sched *q, const int level,
			 unsigned long start)
{
	/* don't run for longer than 2 jiffies; 2 is used instead of
         * 1 to simplify things when jiffy is going to be incremented
         * too soon
         */
	unsigned long stop_at = start + 2;
	struct rb_root *wait_pq = &q->hlevel[level].wait_pq;

	while (time_before(jiffies, stop_at)) {
		struct htb_class *cl;
		s64 diff;
		struct rb_node *p = rb_first(wait_pq);

		if (!p)
			return 0;

		cl = rb_entry(p, struct htb_class, pq_node);
		if (cl->pq_key > q->now)
			return cl->pq_key;

		htb_safe_rb_erase(p, wait_pq);
		diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
		htb_change_class_mode(q, cl, &diff);
		if (cl->cmode != HTB_CAN_SEND)
			htb_add_to_wait_tree(q, cl, diff);
	}

	/* too much load - let's continue after a break for scheduling */
	if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
		pr_warn("htb: too many events!\n");
		q->warned |= HTB_WARN_TOOMANYEVENTS;
	}

	return q->now;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
109
57.37%
1
6.67%
Jarek Poplawski
29
15.26%
3
20.00%
Eric Dumazet
18
9.47%
3
20.00%
Martin Devera
17
8.95%
2
13.33%
Patrick McHardy
5
2.63%
1
6.67%
Vimalkumar
5
2.63%
1
6.67%
Akinobu Mita
3
1.58%
1
6.67%
David Woodhouse
2
1.05%
1
6.67%
Yang Yingliang
1
0.53%
1
6.67%
Stephen Hemminger
1
0.53%
1
6.67%
Total
190
100.00%
15
100.00%

/* Returns class->node+prio from id-tree where classe's id is >= id. NULL
 * is no such one exists.
 */


static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
					      u32 id)
{
	struct rb_node *r = NULL;
	while (n) {
		struct htb_class *cl =
		    rb_entry(n, struct htb_class, node[prio]);

		if (id > cl->common.classid) {
			n = n->rb_right;
		} else if (id < cl->common.classid) {
			r = n;
			n = n->rb_left;
		} else {
			return n;
		}
	}
	return r;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Martin Devera
80
80.00%
1
33.33%
Jarek Poplawski
16
16.00%
1
33.33%
Patrick McHardy
4
4.00%
1
33.33%
Total
100
100.00%
3
100.00%

/**
 * htb_lookup_leaf - returns next leaf class in DRR order
 *
 * Find leaf where current feed pointers points to.
 */


static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio)
{
	int i;
	struct {
		struct rb_node *root;
		struct rb_node **pptr;
		u32 *pid;
	} stk[TC_HTB_MAXDEPTH], *sp = stk;

	BUG_ON(!hprio->row.rb_node);
	sp->root = hprio->row.rb_node;
	sp->pptr = &hprio->ptr;
	sp->pid = &hprio->last_ptr_id;

	for (i = 0; i < 65535; i++) {
		if (!*sp->pptr && *sp->pid) {
			/* ptr was invalidated but id is valid - try to recover
                         * the original or next ptr
                         */
			*sp->pptr =
			    htb_id_find_next_upper(prio, sp->root, *sp->pid);
		}
		*sp->pid = 0;	/* ptr is valid now so that remove this hint as it
                                 * can become out of date quickly
                                 */
		if (!*sp->pptr) {	/* we are at right end; rewind & go up */
			*sp->pptr = sp->root;
			while ((*sp->pptr)->rb_left)
				*sp->pptr = (*sp->pptr)->rb_left;
			if (sp > stk) {
				sp--;
				if (!*sp->pptr) {
					WARN_ON(1);
					return NULL;
				}
				htb_next_rb_node(sp->pptr);
			}
		} else {
			struct htb_class *cl;
			struct htb_prio *clp;

			cl = rb_entry(*sp->pptr, struct htb_class, node[prio]);
			if (!cl->level)
				return cl;
			clp = &cl->un.inner.clprio[prio];
			(++sp)->root = clp->feed.rb_node;
			sp->pptr = &clp->ptr;
			sp->pid = &clp->last_ptr_id;
		}
	}
	WARN_ON(1);
	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
194
60.82%
1
11.11%
Martin Devera
63
19.75%
2
22.22%
Eric Dumazet
44
13.79%
2
22.22%
Jarek Poplawski
8
2.51%
1
11.11%
David Woodhouse
5
1.57%
1
11.11%
Ilpo Järvinen
3
0.94%
1
11.11%
Stephen Hemminger
2
0.63%
1
11.11%
Total
319
100.00%
9
100.00%

/* dequeues packet at given priority and level; call only if
 * you are sure that there is active class at prio/level
 */


static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio,
					const int level)
{
	struct sk_buff *skb = NULL;
	struct htb_class *cl, *start;
	struct htb_level *hlevel = &q->hlevel[level];
	struct htb_prio *hprio = &hlevel->hprio[prio];

	/* look initial class up in the row */
	start = cl = htb_lookup_leaf(hprio, prio);

	do {
next:
		if (unlikely(!cl))
			return NULL;

		/* class can be empty - it is unlikely but can be true if leaf
                 * qdisc drops packets in enqueue routine or if someone used
                 * graft operation on the leaf since last dequeue;
                 * simply deactivate and skip such class
                 */
		if (unlikely(cl->un.leaf.q->q.qlen == 0)) {
			struct htb_class *next;
			htb_deactivate(q, cl);

			/* row/level might become empty */
			if ((q->row_mask[level] & (1 << prio)) == 0)
				return NULL;

			next = htb_lookup_leaf(hprio, prio);

			if (cl == start)	/* fix start if we just deleted it */
				start = next;
			cl = next;
			goto next;
		}

		skb = cl->un.leaf.q->dequeue(cl->un.leaf.q);
		if (likely(skb != NULL))
			break;

		qdisc_warn_nonwc("htb", cl->un.leaf.q);
		htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr:
					 &q->hlevel[0].hprio[prio].ptr);
		cl = htb_lookup_leaf(hprio, prio);

	} while (cl != start);

	if (likely(skb != NULL)) {
		bstats_update(&cl->bstats, skb);
		cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb);
		if (cl->un.leaf.deficit[level] < 0) {
			cl->un.leaf.deficit[level] += cl->quantum;
			htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr :
						 &q->hlevel[0].hprio[prio].ptr);
		}
		/* this used to be after charge_class but this constelation
                 * gives us slightly better performance
                 */
		if (!cl->un.leaf.q->q.qlen)
			htb_deactivate(q, cl);
		htb_charge_class(q, cl, level, skb);
	}
	return skb;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
215
52.18%
1
8.33%
Martin Devera
84
20.39%
2
16.67%
Eric Dumazet
70
16.99%
3
25.00%
Stephen Hemminger
18
4.37%
2
16.67%
Jussi Kivilinna
15
3.64%
1
8.33%
Jarek Poplawski
9
2.18%
2
16.67%
Patrick McHardy
1
0.24%
1
8.33%
Total
412
100.00%
12
100.00%



static struct sk_buff *htb_dequeue(struct Qdisc *sch)
{
	struct sk_buff *skb;
	struct htb_sched *q = qdisc_priv(sch);
	int level;
	s64 next_event;
	unsigned long start_at;

	/* try to dequeue direct packets as high prio (!) to minimize cpu work */
	skb = __qdisc_dequeue_head(&q->direct_queue);
	if (skb != NULL) {
ok:
		qdisc_bstats_update(sch, skb);
		qdisc_qstats_backlog_dec(sch, skb);
		sch->q.qlen--;
		return skb;
	}

	if (!sch->q.qlen)
		goto fin;
	q->now = ktime_get_ns();
	start_at = jiffies;

	next_event = q->now + 5LLU * NSEC_PER_SEC;

	for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
		/* common case optimization - skip event handler quickly */
		int m;
		s64 event = q->near_ev_cache[level];

		if (q->now >= event) {
			event = htb_do_events(q, level, start_at);
			if (!event)
				event = q->now + NSEC_PER_SEC;
			q->near_ev_cache[level] = event;
		}

		if (next_event > event)
			next_event = event;

		m = ~q->row_mask[level];
		while (m != (int)(-1)) {
			int prio = ffz(m);

			m |= 1 << prio;
			skb = htb_dequeue_tree(q, prio, level);
			if (likely(skb != NULL))
				goto ok;
		}
	}
	qdisc_qstats_overlimit(sch);
	if (likely(next_event > q->now))
		qdisc_watchdog_schedule_ns(&q->watchdog, next_event);
	else
		schedule_work(&q->work);
fin:
	return skb;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
175
58.53%
1
4.76%
Patrick McHardy
36
12.04%
3
14.29%
Jarek Poplawski
30
10.03%
2
9.52%
Eric Dumazet
23
7.69%
5
23.81%
Stephen Hemminger
15
5.02%
3
14.29%
Américo Wang
7
2.34%
1
4.76%
Vimalkumar
4
1.34%
1
4.76%
Martin Devera
4
1.34%
2
9.52%
John Fastabend
3
1.00%
1
4.76%
Florian Westphal
1
0.33%
1
4.76%
Stefan Hasko
1
0.33%
1
4.76%
Total
299
100.00%
21
100.00%

/* reset all classes */
/* always caled under BH & queue lock */


static void htb_reset(struct Qdisc *sch)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl;
	unsigned int i;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
			if (cl->level)
				memset(&cl->un.inner, 0, sizeof(cl->un.inner));
			else {
				if (cl->un.leaf.q)
					qdisc_reset(cl->un.leaf.q);
				INIT_LIST_HEAD(&cl->un.leaf.drop_list);
			}
			cl->prio_activity = 0;
			cl->cmode = HTB_CAN_SEND;
		}
	}
	qdisc_watchdog_cancel(&q->watchdog);
	__qdisc_reset_queue(&q->direct_queue);
	sch->q.qlen = 0;
	sch->qstats.backlog = 0;
	memset(q->hlevel, 0, sizeof(q->hlevel));
	memset(q->row_mask, 0, sizeof(q->row_mask));
	for (i = 0; i < TC_HTB_NUMPRIO; i++)
		INIT_LIST_HEAD(q->drops + i);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
187
85.00%
1
12.50%
Patrick McHardy
15
6.82%
2
25.00%
Américo Wang
8
3.64%
1
12.50%
Stephen Hemminger
7
3.18%
2
25.00%
Eric Dumazet
3
1.36%
2
25.00%
Total
220
100.00%
8
100.00%


static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = {
	[TCA_HTB_PARMS]	= { .len = sizeof(struct tc_htb_opt) },
	[TCA_HTB_INIT]	= { .len = sizeof(struct tc_htb_glob) },
	[TCA_HTB_CTAB]	= { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	[TCA_HTB_RTAB]	= { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	[TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 },
	[TCA_HTB_RATE64] = { .type = NLA_U64 },
	[TCA_HTB_CEIL64] = { .type = NLA_U64 },
};



static void htb_work_func(struct work_struct *work)
{
	struct htb_sched *q = container_of(work, struct htb_sched, work);
	struct Qdisc *sch = q->watchdog.qdisc;

	rcu_read_lock();
	__netif_schedule(qdisc_root(sch));
	rcu_read_unlock();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarek Poplawski
45
88.24%
1
50.00%
Florian Westphal
6
11.76%
1
50.00%
Total
51
100.00%
2
100.00%



static int htb_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_HTB_MAX + 1];
	struct tc_htb_glob *gopt;
	int err;
	int i;

	if (!opt)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy);
	if (err < 0)
		return err;

	if (!tb[TCA_HTB_INIT])
		return -EINVAL;

	gopt = nla_data(tb[TCA_HTB_INIT]);
	if (gopt->version != HTB_VER >> 16)
		return -EINVAL;

	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		return err;
	for (i = 0; i < TC_HTB_NUMPRIO; i++)
		INIT_LIST_HEAD(q->drops + i);

	qdisc_watchdog_init(&q->watchdog, sch);
	INIT_WORK(&q->work, htb_work_func);
	qdisc_skb_head_init(&q->direct_queue);

	if (tb[TCA_HTB_DIRECT_QLEN])
		q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]);
	else
		q->direct_qlen = qdisc_dev(sch)->tx_queue_len;

	if ((q->rate2quantum = gopt->rate2quantum) < 1)
		q->rate2quantum = 1;
	q->defcls = gopt->defcls;

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
159
64.90%
2
16.67%
Patrick McHardy
47
19.18%
5
41.67%
Eric Dumazet
23
9.39%
1
8.33%
Jarek Poplawski
10
4.08%
1
8.33%
Stephen Hemminger
3
1.22%
1
8.33%
Martin Devera
2
0.82%
1
8.33%
Florian Westphal
1
0.41%
1
8.33%
Total
245
100.00%
12
100.00%



static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct nlattr *nest;
	struct tc_htb_glob gopt;

	/* Its safe to not acquire qdisc lock. As we hold RTNL,
         * no change can happen on the qdisc parameters.
         */

	gopt.direct_pkts = q->direct_pkts;
	gopt.version = HTB_VER;
	gopt.rate2quantum = q->rate2quantum;
	gopt.defcls = q->defcls;
	gopt.debug = 0;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) ||
	    nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen))
		goto nla_put_failure;

	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
104
73.24%
2
22.22%
Patrick McHardy
19
13.38%
2
22.22%
Eric Dumazet
13
9.15%
2
22.22%
Stephen Hemminger
4
2.82%
2
22.22%
Arnaldo Carvalho de Melo
2
1.41%
1
11.11%
Total
142
100.00%
9
100.00%



static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct htb_class *cl = (struct htb_class *)arg;
	struct nlattr *nest;
	struct tc_htb_opt opt;

	/* Its safe to not acquire qdisc lock. As we hold RTNL,
         * no change can happen on the class parameters.
         */
	tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT;
	tcm->tcm_handle = cl->common.classid;
	if (!cl->level && cl->un.leaf.q)
		tcm->tcm_info = cl->un.leaf.q->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	memset(&opt, 0, sizeof(opt));

	psched_ratecfg_getrate(&opt.rate, &cl->rate);
	opt.buffer = PSCHED_NS2TICKS(cl->buffer);
	psched_ratecfg_getrate(&opt.ceil, &cl->ceil);
	opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
	opt.quantum = cl->quantum;
	opt.prio = cl->prio;
	opt.level = cl->level;
	if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;
	if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) &&
	    nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps,
			      TCA_HTB_PAD))
		goto nla_put_failure;
	if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) &&
	    nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps,
			      TCA_HTB_PAD))
		goto nla_put_failure;

	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
191
60.44%
2
15.38%
Eric Dumazet
72
22.78%
3
23.08%
Patrick McHardy
23
7.28%
3
23.08%
Thomas Graf
12
3.80%
1
7.69%
Jiri Pirko
10
3.16%
2
15.38%
Nicolas Dichtel
6
1.90%
1
7.69%
Arnaldo Carvalho de Melo
2
0.63%
1
7.69%
Total
316
100.00%
13
100.00%


static int

htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
{
	struct htb_class *cl = (struct htb_class *)arg;
	struct gnet_stats_queue qs = {
		.drops = cl->drops,
        };
	__u32 qlen = 0;

	if (!cl->level && cl->un.leaf.q) {
		qlen = cl->un.leaf.q->q.qlen;
		qs.backlog = cl->un.leaf.q->qstats.backlog;
	}
	cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),
				    INT_MIN, INT_MAX);
	cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),
				     INT_MIN, INT_MAX);

	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
				  d, NULL, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0)
		return -1;

	return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Thomas Graf
94
44.76%
1
10.00%
Eric Dumazet
46
21.90%
4
40.00%
David S. Miller
41
19.52%
1
10.00%
Konstantin Khlebnikov
18
8.57%
1
10.00%
John Fastabend
11
5.24%
3
30.00%
Total
210
100.00%
10
100.00%



static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct htb_class *cl = (struct htb_class *)arg;

	if (cl->level)
		return -EINVAL;
	if (new == NULL &&
	    (new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
				     cl->common.classid)) == NULL)
		return -ENOBUFS;

	*old = qdisc_replace(sch, new, &cl->un.leaf.q);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
85
83.33%
2
33.33%
Patrick McHardy
10
9.80%
3
50.00%
Américo Wang
7
6.86%
1
16.67%
Total
102
100.00%
6
100.00%



static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct htb_class *cl = (struct htb_class *)arg;
	return !cl->level ? cl->un.leaf.q : NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
45
100.00%
1
100.00%
Total
45
100.00%
1
100.00%



static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
{
	struct htb_class *cl = (struct htb_class *)arg;

	if (cl->un.leaf.q->q.qlen == 0)
		htb_deactivate(qdisc_priv(sch), cl);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick McHardy
53
100.00%
1
100.00%
Total
53
100.00%
1
100.00%



static unsigned long htb_get(struct Qdisc *sch, u32 classid)
{
	struct htb_class *cl = htb_find(classid, sch);
	if (cl)
		cl->refcnt++;
	return (unsigned long)cl;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%



static inline int htb_parent_last_child(struct htb_class *cl)
{
	if (!cl->parent)
		/* the root class */
		return 0;
	if (cl->parent->children > 1)
		/* not the last child */
		return 0;
	return 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarek Poplawski
38
95.00%
1
50.00%
Patrick McHardy
2
5.00%
1
50.00%
Total
40
100.00%
2
100.00%



static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl,
			       struct Qdisc *new_q)
{
	struct htb_class *parent = cl->parent;

	WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity);

	if (parent->cmode != HTB_CAN_SEND)
		htb_safe_rb_erase(&parent->pq_node,
				  &q->hlevel[parent->level].wait_pq);

	parent->level = 0;
	memset(&parent->un.inner, 0, sizeof(parent->un.inner));
	INIT_LIST_HEAD(&parent->un.leaf.drop_list);
	parent->un.leaf.q = new_q ? new_q : &noop_qdisc;
	parent->tokens = parent->buffer;
	parent->ctokens = parent->cbuffer;
	parent->t_c = ktime_get_ns();
	parent->cmode = HTB_CAN_SEND;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarek Poplawski
148
91.93%
2
33.33%
Eric Dumazet
7
4.35%
2
33.33%
Ilpo Järvinen
4
2.48%
1
16.67%
Patrick McHardy
2
1.24%
1
16.67%
Total
161
100.00%
6
100.00%



static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
{
	if (!cl->level) {
		WARN_ON(!cl->un.leaf.q);
		qdisc_destroy(cl->un.leaf.q);
	}
	gen_kill_estimator(&cl->rate_est);
	tcf_destroy_chain(&cl->filter_list);
	kfree(cl);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
53
76.81%
1
16.67%
Patrick McHardy
10
14.49%
3
50.00%
Stephen Hemminger
4
5.80%
1
16.67%
Ilpo Järvinen
2
2.90%
1
16.67%
Total
69
100.00%
6
100.00%



static void htb_destroy(struct Qdisc *sch)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct hlist_node *next;
	struct htb_class *cl;
	unsigned int i;

	cancel_work_sync(&q->work);
	qdisc_watchdog_cancel(&q->watchdog);
	/* This line used to be after htb_destroy_class call below
         * and surprisingly it worked in 2.4. But it must precede it
         * because filter need its target class alive to be able to call
         * unbind_filter on it (without Oops).
         */
	tcf_destroy_chain(&q->filter_list);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode)
			tcf_destroy_chain(&cl->filter_list);
	}
	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
					  common.hnode)
			htb_destroy_class(sch, cl);
	}
	qdisc_class_hash_destroy(&q->clhash);
	__qdisc_reset_queue(&q->direct_queue);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick McHardy
87
59.18%
5
45.45%
David S. Miller
41
27.89%
1
9.09%
Jarek Poplawski
8
5.44%
1
9.09%
Martin Devera
6
4.08%
1
9.09%
Stephen Hemminger
3
2.04%
1
9.09%
Eric Dumazet
2
1.36%
2
18.18%
Total
147
100.00%
11
100.00%



static int htb_delete(struct Qdisc *sch, unsigned long arg)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl = (struct htb_class *)arg;
	struct Qdisc *new_q = NULL;
	int last_child = 0;

	/* TODO: why don't allow to delete subtree ? references ? does
         * tc subsys guarantee us that in htb_destroy it holds no class
         * refs so that we can remove children safely there ?
         */
	if (cl->children || cl->filter_cnt)
		return -EBUSY;

	if (!cl->level && htb_parent_last_child(cl)) {
		new_q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
					  cl->parent->common.classid);
		last_child = 1;
	}

	sch_tree_lock(sch);

	if (!cl->level) {
		unsigned int qlen = cl->un.leaf.q->q.qlen;
		unsigned int backlog = cl->un.leaf.q->qstats.backlog;

		qdisc_reset(cl->un.leaf.q);
		qdisc_tree_reduce_backlog(cl->un.leaf.q, qlen, backlog);
	}

	/* delete from hash and active; remainder in destroy_class */
	qdisc_class_hash_remove(&q->clhash, &cl->common);
	if (cl->parent)
		cl->parent->children--;

	if (cl->prio_activity)
		htb_deactivate(q, cl);

	if (cl->cmode != HTB_CAN_SEND)
		htb_safe_rb_erase(&cl->pq_node,
				  &q->hlevel[cl->level].wait_pq);

	if (last_child)
		htb_parent_to_leaf(q, cl, new_q);

	BUG_ON(--cl->refcnt == 0);
	/*
         * This shouldn't happen: we "hold" one cops->get() when called
         * from tc_ctl_tclass; the destroy method is done from cops->put().
         */

	sch_tree_unlock(sch);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick McHardy
89
32.48%
6
37.50%
David S. Miller
88
32.12%
2
12.50%
Jarek Poplawski
64
23.36%
4
25.00%
Américo Wang
23
8.39%
1
6.25%
Eric Dumazet
6
2.19%
1
6.25%
Stephen Hemminger
3
1.09%
1
6.25%
Yang Yingliang
1
0.36%
1
6.25%
Total
274
100.00%
16
100.00%



static void htb_put(struct Qdisc *sch, unsigned long arg)
{
	struct htb_class *cl = (struct htb_class *)arg;

	if (--cl->refcnt == 0)
		htb_destroy_class(sch, cl);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%



static int htb_change_class(struct Qdisc *sch, u32 classid,
			    u32 parentid, struct nlattr **tca,
			    unsigned long *arg)
{
	int err = -EINVAL;
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl = (struct htb_class *)*arg, *parent;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_HTB_MAX + 1];
	struct tc_htb_opt *hopt;
	u64 rate64, ceil64;

	/* extract all subattrs from opt attr */
	if (!opt)
		goto failure;

	err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy);
	if (err < 0)
		goto failure;

	err = -EINVAL;
	if (tb[TCA_HTB_PARMS] == NULL)
		goto failure;

	parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch);

	hopt = nla_data(tb[TCA_HTB_PARMS]);
	if (!hopt->rate.rate || !hopt->ceil.rate)
		goto failure;

	/* Keeping backward compatible with rate_table based iproute2 tc */
	if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
		qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB]));

	if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE)
		qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB]));

	if (!cl) {		/* new class */
		struct Qdisc *new_q;
		int prio;
		struct {
			struct nlattr		nla;
			struct gnet_estimator	opt;
		} est = {
			.nla = {
				.nla_len	= nla_attr_size(sizeof(est.opt)),
				.nla_type	= TCA_RATE,
                        },
			.opt = {
				/* 4s interval, 16s averaging constant */
				.interval	= 2,
				.ewma_log	= 2,
                        },
                };

		/* check for valid classid */
		if (!classid || TC_H_MAJ(classid ^ sch->handle) ||
		    htb_find(classid, sch))
			goto failure;

		/* check maximal depth */
		if (parent && parent->parent && parent->parent->level < 2) {
			pr_err("htb: tree is too deep\n");
			goto failure;
		}
		err = -ENOBUFS;
		cl = kzalloc(sizeof(*cl), GFP_KERNEL);
		if (!cl)
			goto failure;

		if (htb_rate_est || tca[TCA_RATE]) {
			err = gen_new_estimator(&cl->bstats, NULL,
						&cl->rate_est,
						NULL,
						qdisc_root_sleeping_running(sch),
						tca[TCA_RATE] ? : &est.nla);
			if (err) {
				kfree(cl);
				goto failure;
			}
		}

		cl->refcnt = 1;
		cl->children = 0;
		INIT_LIST_HEAD(&cl->un.leaf.drop_list);
		RB_CLEAR_NODE(&cl->pq_node);

		for (prio = 0; prio < TC_HTB_NUMPRIO; prio++)
			RB_CLEAR_NODE(&cl->node[prio]);

		/* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
                 * so that can't be used inside of sch_tree_lock
                 * -- thanks to Karlis Peisenieks
                 */
		new_q = qdisc_create_dflt(sch->dev_queue,
					  &pfifo_qdisc_ops, classid);
		sch_tree_lock(sch);
		if (parent && !parent->level) {
			unsigned int qlen = parent->un.leaf.q->q.qlen;
			unsigned int backlog = parent->un.leaf.q->qstats.backlog;

			/* turn parent into inner node */
			qdisc_reset(parent->un.leaf.q);
			qdisc_tree_reduce_backlog(parent->un.leaf.q, qlen, backlog);
			qdisc_destroy(parent->un.leaf.q);
			if (parent->prio_activity)
				htb_deactivate(q, parent);

			/* remove from evt list because of level change */
			if (parent->cmode != HTB_CAN_SEND) {
				htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq);
				parent->cmode = HTB_CAN_SEND;
			}
			parent->level = (parent->parent ? parent->parent->level
					 : TC_HTB_MAXDEPTH) - 1;
			memset(&parent->un.inner, 0, sizeof(parent->un.inner));
		}
		/* leaf (we) needs elementary qdisc */
		cl->un.leaf.q = new_q ? new_q : &noop_qdisc;

		cl->common.classid = classid;
		cl->parent = parent;

		/* set class to be in HTB_CAN_SEND state */
		cl->tokens = PSCHED_TICKS2NS(hopt->buffer);
		cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer);
		cl->mbuffer = 60ULL * NSEC_PER_SEC;	/* 1min */
		cl->t_c = ktime_get_ns();
		cl->cmode = HTB_CAN_SEND;

		/* attach to the hash list and parent's family */
		qdisc_class_hash_insert(&q->clhash, &cl->common);
		if (parent)
			parent->children++;
	} else {
		if (tca[TCA_RATE]) {
			err = gen_replace_estimator(&cl->bstats, NULL,
						    &cl->rate_est,
						    NULL,
						    qdisc_root_sleeping_running(sch),
						    tca[TCA_RATE]);
			if (err)
				return err;
		}
		sch_tree_lock(sch);
	}

	rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0;

	ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0;

	psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64);
	psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64);

	/* it used to be a nasty bug here, we have to check that node
         * is really leaf before changing cl->un.leaf !
         */
	if (!cl->level) {
		u64 quantum = cl->rate.rate_bytes_ps;

		do_div(quantum, q->rate2quantum);
		cl->quantum = min_t(u64, quantum, INT_MAX);

		if (!hopt->quantum && cl->quantum < 1000) {
			pr_warn("HTB: quantum of class %X is small. Consider r2q change.\n",
				cl->common.classid);
			cl->quantum = 1000;
		}
		if (!hopt->quantum && cl->quantum > 200000) {
			pr_warn("HTB: quantum of class %X is big. Consider r2q change.\n",
				cl->common.classid);
			cl->quantum = 200000;
		}
		if (hopt->quantum)
			cl->quantum = hopt->quantum;
		if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
			cl->prio = TC_HTB_NUMPRIO - 1;
	}

	cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
	cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);

	sch_tree_unlock(sch);

	qdisc_class_hash_grow(sch, &q->clhash);

	*arg = (unsigned long)cl;
	return 0;

failure:
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
538
48.95%
3
7.32%
Patrick McHardy
196
17.83%
10
24.39%
Yang Yingliang
93
8.46%
3
7.32%
Stephen Hemminger
66
6.01%
3
7.32%
Eric Dumazet
54
4.91%
9
21.95%
Martin Devera
53
4.82%
3
7.32%
Jesper Dangaard Brouer
49
4.46%
1
2.44%
Américo Wang
19
1.73%
1
2.44%
Vimalkumar
12
1.09%
2
4.88%
Jiri Pirko
12
1.09%
2
4.88%
John Fastabend
4
0.36%
1
2.44%
Panagiotis Issaris
1
0.09%
1
2.44%
Changli Gao
1
0.09%
1
2.44%
Dave Jones
1
0.09%
1
2.44%
Total
1099
100.00%
41
100.00%



static struct tcf_proto __rcu **htb_find_tcf(struct Qdisc *sch,
					     unsigned long arg)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl = (struct htb_class *)arg;
	struct tcf_proto __rcu **fl = cl ? &cl->filter_list : &q->filter_list;

	return fl;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
58
92.06%
1
33.33%
Stephen Hemminger
3
4.76%
1
33.33%
John Fastabend
2
3.17%
1
33.33%
Total
63
100.00%
3
100.00%



static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
				     u32 classid)
{
	struct htb_class *cl = htb_find(classid, sch);

	/*if (cl && !cl->level) return 0;
         * The line above used to be there to prevent attaching filters to
         * leaves. But at least tc_index filter uses this just to get class
         * for other reasons so that we have to allow for it.
         * ----
         * 19.6.2002 As Werner explained it is ok - bind filter is just
         * another way to "lock" the class - unlike "get" this lock can
         * be broken by class during destroy IIUC.
         */
	if (cl)
		cl->filter_cnt++;
	return (unsigned long)cl;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
47
97.92%
1
50.00%
Eric Dumazet
1
2.08%
1
50.00%
Total
48
100.00%
2
100.00%



static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
{
	struct htb_class *cl = (struct htb_class *)arg;

	if (cl)
		cl->filter_cnt--;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
36
100.00%
1
100.00%
Total
36
100.00%
1
100.00%



static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
102
83.61%
1
25.00%
Patrick McHardy
13
10.66%
1
25.00%
Stephen Hemminger
7
5.74%
2
50.00%
Total
122
100.00%
4
100.00%


static const struct Qdisc_class_ops htb_class_ops = {
	.graft		=	htb_graft,
	.leaf		=	htb_leaf,
	.qlen_notify	=	htb_qlen_notify,
	.get		=	htb_get,
	.put		=	htb_put,
	.change		=	htb_change_class,
	.delete		=	htb_delete,
	.walk		=	htb_walk,
	.tcf_chain	=	htb_find_tcf,
	.bind_tcf	=	htb_bind_filter,
	.unbind_tcf	=	htb_unbind_filter,
	.dump		=	htb_dump_class,
	.dump_stats	=	htb_dump_class_stats,
};


static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
	.cl_ops		=	&htb_class_ops,
	.id		=	"htb",
	.priv_size	=	sizeof(struct htb_sched),
	.enqueue	=	htb_enqueue,
	.dequeue	=	htb_dequeue,
	.peek		=	qdisc_peek_dequeued,
	.init		=	htb_init,
	.reset		=	htb_reset,
	.destroy	=	htb_destroy,
	.dump		=	htb_dump,
	.owner		=	THIS_MODULE,
};



static int __init htb_module_init(void)
{
	return register_qdisc(&htb_qdisc_ops);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
13
81.25%
1
50.00%
Al Viro
3
18.75%
1
50.00%
Total
16
100.00%
2
100.00%



static void __exit htb_module_exit(void)
{
	unregister_qdisc(&htb_qdisc_ops);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
12
80.00%
1
50.00%
Al Viro
3
20.00%
1
50.00%
Total
15
100.00%
2
100.00%

module_init(htb_module_init)
module_exit(htb_module_exit)
MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
4381
55.02%
8
5.88%
Patrick McHardy
752
9.44%
22
16.18%
Eric Dumazet
722
9.07%
22
16.18%
Jarek Poplawski
599
7.52%
17
12.50%
Stephen Hemminger
357
4.48%
8
5.88%
Martin Devera
343
4.31%
9
6.62%
Thomas Graf
115
1.44%
2
1.47%
Yang Yingliang
95
1.19%
4
2.94%
Jesper Dangaard Brouer
94
1.18%
2
1.47%
Florian Westphal
88
1.11%
2
1.47%
Jamal Hadi Salim
78
0.98%
1
0.74%
Américo Wang
71
0.89%
3
2.21%
Vimalkumar
40
0.50%
2
1.47%
John Fastabend
37
0.46%
5
3.68%
Jiri Pirko
30
0.38%
5
3.68%
Harry Mason
20
0.25%
1
0.74%
David Woodhouse
20
0.25%
1
0.74%
Jussi Kivilinna
19
0.24%
2
1.47%
Konstantin Khlebnikov
18
0.23%
1
0.74%
Ilpo Järvinen
16
0.20%
1
0.74%
Al Viro
15
0.19%
1
0.74%
Ranjit Manomohan
11
0.14%
1
0.74%
Asim Shankar
7
0.09%
1
0.74%
Nicolas Dichtel
6
0.08%
1
0.74%
Hideaki Yoshifuji / 吉藤英明
6
0.08%
1
0.74%
Arnaldo Carvalho de Melo
6
0.08%
2
1.47%
Tejun Heo
3
0.04%
1
0.74%
Akinobu Mita
3
0.04%
1
0.74%
Daniel Borkmann
2
0.03%
1
0.74%
Adrian Bunk
1
0.01%
1
0.74%
Steven Cole
1
0.01%
1
0.74%
Lucas De Marchi
1
0.01%
1
0.74%
Changli Gao
1
0.01%
1
0.74%
Michael Hayes
1
0.01%
1
0.74%
Dave Jones
1
0.01%
1
0.74%
Panagiotis Issaris
1
0.01%
1
0.74%
Stefan Hasko
1
0.01%
1
0.74%
Total
7962
100.00%
136
100.00%
Directory: net/sched

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