sch_htb.c 42.7 KB
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/*
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 * 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
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 *		Ondrej Kraus, <krauso@barr.cz>
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 *			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>
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#include <linux/moduleparam.h>
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#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>
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#include <linux/rbtree.h>
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#include <linux/workqueue.h>
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#include <linux/slab.h>
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#include <net/netlink.h>
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#include <net/sch_generic.h>
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#include <net/pkt_sched.h>

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

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

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static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */
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#define HTB_VER 0x30011		/* major must be matched with number suplied by TC as version */
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#if HTB_VER >> 16 != TC_HTB_PROTOVER
#error "Mismatched sch_htb.c and pkt_sch.h"
#endif

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

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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");

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/* used internaly to keep status of single class */
enum htb_cmode {
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	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 */
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};

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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;
};

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

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	struct tcf_proto __rcu	*filter_list;	/* class attached filters */
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	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 */

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	struct gnet_stats_rate_est64 rate_est;
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	/*
	 * Written often fields
	 */
	struct gnet_stats_basic_packed bstats;
	struct gnet_stats_queue	qstats;
	struct tc_htb_xstats	xstats;	/* our special stats */
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	/* token bucket parameters */
	s64			tokens, ctokens;/* current number of tokens */
	s64			t_c;		/* checkpoint time */
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	union {
		struct htb_class_leaf {
			struct list_head drop_list;
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			int		deficit[TC_HTB_MAXDEPTH];
			struct Qdisc	*q;
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		} leaf;
		struct htb_class_inner {
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			struct htb_prio clprio[TC_HTB_NUMPRIO];
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		} inner;
	} un;
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	s64			pq_key;
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	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 */
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};

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

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struct htb_sched {
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	struct Qdisc_class_hash clhash;
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	int			defcls;		/* class where unclassified flows go to */
	int			rate2quantum;	/* quant = rate / rate2quantum */
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	/* filters for qdisc itself */
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	struct tcf_proto __rcu	*filter_list;
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#define HTB_WARN_TOOMANYEVENTS	0x1
	unsigned int		warned;	/* only one warning */
	int			direct_qlen;
	struct work_struct	work;
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	/* non shaped skbs; let them go directly thru */
	struct sk_buff_head	direct_queue;
	long			direct_pkts;
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	struct qdisc_watchdog	watchdog;
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	s64			now;	/* cached dequeue time */
	struct list_head	drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */
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	/* time of nearest event per level (row) */
	s64			near_ev_cache[TC_HTB_MAXDEPTH];
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	int			row_mask[TC_HTB_MAXDEPTH];
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	struct htb_level	hlevel[TC_HTB_MAXDEPTH];
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};

/* find class in global hash table using given handle */
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static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
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{
	struct htb_sched *q = qdisc_priv(sch);
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	struct Qdisc_class_common *clc;
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	clc = qdisc_class_find(&q->clhash, handle);
	if (clc == NULL)
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		return NULL;
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	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
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 * internal fifo (direct). These packets then go directly thru. If we still
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 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful
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 * then finish and return direct queue.
 */
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#define HTB_DIRECT ((struct htb_class *)-1L)
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static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
				      int *qerr)
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{
	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;
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	 * note that nfmark can be used too by attaching filter fw with no
	 * rules in it
	 */
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	if (skb->priority == sch->handle)
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		return HTB_DIRECT;	/* X:0 (direct flow) selected */
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	cl = htb_find(skb->priority, sch);
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	if (cl) {
		if (cl->level == 0)
			return cl;
		/* Start with inner filter chain if a non-leaf class is selected */
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		tcf = rcu_dereference_bh(cl->filter_list);
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	} else {
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		tcf = rcu_dereference_bh(q->filter_list);
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	}
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	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
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	while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
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		case TC_ACT_STOLEN:
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			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
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		case TC_ACT_SHOT:
			return NULL;
		}
#endif
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		cl = (void *)res.class;
		if (!cl) {
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			if (res.classid == sch->handle)
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				return HTB_DIRECT;	/* X:0 (direct flow) */
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			cl = htb_find(res.classid, sch);
			if (!cl)
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				break;	/* filter selected invalid classid */
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		}
		if (!cl->level)
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			return cl;	/* we hit leaf; return it */
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		/* we have got inner class; apply inner filter chain */
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		tcf = rcu_dereference_bh(cl->filter_list);
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	}
	/* classification failed; try to use default class */
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	cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
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	if (!cl || cl->level)
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		return HTB_DIRECT;	/* bad default .. this is safe bet */
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	return cl;
}

/**
 * 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.
 */
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static void htb_add_to_id_tree(struct rb_root *root,
			       struct htb_class *cl, int prio)
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{
	struct rb_node **p = &root->rb_node, *parent = NULL;
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	while (*p) {
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		struct htb_class *c;
		parent = *p;
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		c = rb_entry(parent, struct htb_class, node[prio]);
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		if (cl->common.classid > c->common.classid)
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			p = &parent->rb_right;
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		else
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			p = &parent->rb_left;
	}
	rb_link_node(&cl->node[prio], parent, p);
	rb_insert_color(&cl->node[prio], root);
}

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

	/* update the nearest event cache */
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	if (q->near_ev_cache[cl->level] > cl->pq_key)
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		q->near_ev_cache[cl->level] = cl->pq_key;
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	while (*p) {
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		struct htb_class *c;
		parent = *p;
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		c = rb_entry(parent, struct htb_class, pq_node);
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		if (cl->pq_key >= c->pq_key)
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			p = &parent->rb_right;
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		else
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			p = &parent->rb_left;
	}
	rb_link_node(&cl->pq_node, parent, p);
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	rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
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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.
 */
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static inline void htb_next_rb_node(struct rb_node **n)
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{
	*n = rb_next(*n);
}

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

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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)
{
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	if (RB_EMPTY_NODE(rb)) {
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		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.
 */
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static inline void htb_remove_class_from_row(struct htb_sched *q,
						 struct htb_class *cl, int mask)
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{
	int m = 0;
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	struct htb_level *hlevel = &q->hlevel[cl->level];
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	while (mask) {
		int prio = ffz(~mask);
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		struct htb_prio *hprio = &hlevel->hprio[prio];
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		mask &= ~(1 << prio);
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		if (hprio->ptr == cl->node + prio)
			htb_next_rb_node(&hprio->ptr);
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		htb_safe_rb_erase(cl->node + prio, &hprio->row);
		if (!hprio->row.rb_node)
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			m |= 1 << prio;
	}
	q->row_mask[cl->level] &= ~m;
}

/**
 * htb_activate_prios - creates active classe's feed chain
 *
 * The class is connected to ancestors and/or appropriate rows
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 * for priorities it is participating on. cl->cmode must be new
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 * (activated) mode. It does nothing if cl->prio_activity == 0.
 */
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static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl)
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{
	struct htb_class *p = cl->parent;
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	long m, mask = cl->prio_activity;
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	while (cl->cmode == HTB_MAY_BORROW && p && mask) {
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		m = mask;
		while (m) {
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			int prio = ffz(~m);
			m &= ~(1 << prio);
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			if (p->un.inner.clprio[prio].feed.rb_node)
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				/* parent already has its feed in use so that
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				 * reset bit in mask as parent is already ok
				 */
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				mask &= ~(1 << prio);
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			htb_add_to_id_tree(&p->un.inner.clprio[prio].feed, cl, prio);
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		}
		p->prio_activity |= mask;
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		cl = p;
		p = cl->parent;
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	}
	if (cl->cmode == HTB_CAN_SEND && mask)
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		htb_add_class_to_row(q, cl, mask);
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}

/**
 * htb_deactivate_prios - remove class from feed chain
 *
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 * cl->cmode must represent old mode (before deactivation). It does
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 * 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;
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	long m, mask = cl->prio_activity;
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	while (cl->cmode == HTB_MAY_BORROW && p && mask) {
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		m = mask;
		mask = 0;
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		while (m) {
			int prio = ffz(~m);
			m &= ~(1 << prio);
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			if (p->un.inner.clprio[prio].ptr == cl->node + prio) {
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				/* we are removing child which is pointed to from
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				 * parent feed - forget the pointer but remember
				 * classid
				 */
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				p->un.inner.clprio[prio].last_ptr_id = cl->common.classid;
				p->un.inner.clprio[prio].ptr = NULL;
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			}
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			htb_safe_rb_erase(cl->node + prio,
					  &p->un.inner.clprio[prio].feed);
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			if (!p->un.inner.clprio[prio].feed.rb_node)
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				mask |= 1 << prio;
		}
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		p->prio_activity &= ~mask;
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		cl = p;
		p = cl->parent;
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	}
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	if (cl->cmode == HTB_CAN_SEND && mask)
		htb_remove_class_from_row(q, cl, mask);
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}

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static inline s64 htb_lowater(const struct htb_class *cl)
468
{
469 470 471 472
	if (htb_hysteresis)
		return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
	else
		return 0;
473
}
V
Vimalkumar 已提交
474
static inline s64 htb_hiwater(const struct htb_class *cl)
475
{
476 477 478 479
	if (htb_hysteresis)
		return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
	else
		return 0;
480
}
481

482

L
Linus Torvalds 已提交
483 484 485 486 487
/**
 * 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
488
 * from now to time when cl will change its state.
L
Linus Torvalds 已提交
489
 * Also it is worth to note that class mode doesn't change simply
490
 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
L
Linus Torvalds 已提交
491 492 493
 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
 * mode transitions per time unit. The speed gain is about 1/6.
 */
S
Stephen Hemminger 已提交
494
static inline enum htb_cmode
V
Vimalkumar 已提交
495
htb_class_mode(struct htb_class *cl, s64 *diff)
L
Linus Torvalds 已提交
496
{
V
Vimalkumar 已提交
497
	s64 toks;
L
Linus Torvalds 已提交
498

S
Stephen Hemminger 已提交
499 500 501 502
	if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
		*diff = -toks;
		return HTB_CANT_SEND;
	}
503

S
Stephen Hemminger 已提交
504 505
	if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl))
		return HTB_CAN_SEND;
L
Linus Torvalds 已提交
506

S
Stephen Hemminger 已提交
507 508
	*diff = -toks;
	return HTB_MAY_BORROW;
L
Linus Torvalds 已提交
509 510 511 512 513 514 515 516 517 518 519
}

/**
 * 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).
 */
S
Stephen Hemminger 已提交
520
static void
V
Vimalkumar 已提交
521
htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
S
Stephen Hemminger 已提交
522 523
{
	enum htb_cmode new_mode = htb_class_mode(cl, diff);
L
Linus Torvalds 已提交
524 525

	if (new_mode == cl->cmode)
S
Stephen Hemminger 已提交
526 527 528 529 530
		return;

	if (cl->prio_activity) {	/* not necessary: speed optimization */
		if (cl->cmode != HTB_CANT_SEND)
			htb_deactivate_prios(q, cl);
L
Linus Torvalds 已提交
531
		cl->cmode = new_mode;
S
Stephen Hemminger 已提交
532 533 534
		if (new_mode != HTB_CANT_SEND)
			htb_activate_prios(q, cl);
	} else
L
Linus Torvalds 已提交
535 536 537 538
		cl->cmode = new_mode;
}

/**
539
 * htb_activate - inserts leaf cl into appropriate active feeds
L
Linus Torvalds 已提交
540 541 542 543 544
 *
 * 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.
 */
S
Stephen Hemminger 已提交
545
static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
L
Linus Torvalds 已提交
546
{
547
	WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen);
548

L
Linus Torvalds 已提交
549
	if (!cl->prio_activity) {
550
		cl->prio_activity = 1 << cl->prio;
S
Stephen Hemminger 已提交
551 552
		htb_activate_prios(q, cl);
		list_add_tail(&cl->un.leaf.drop_list,
553
			      q->drops + cl->prio);
L
Linus Torvalds 已提交
554 555 556 557
	}
}

/**
558
 * htb_deactivate - remove leaf cl from active feeds
L
Linus Torvalds 已提交
559 560 561 562
 *
 * 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.
 */
S
Stephen Hemminger 已提交
563
static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
L
Linus Torvalds 已提交
564
{
565
	WARN_ON(!cl->prio_activity);
566

S
Stephen Hemminger 已提交
567
	htb_deactivate_prios(q, cl);
L
Linus Torvalds 已提交
568 569 570 571 572 573
	cl->prio_activity = 0;
	list_del_init(&cl->un.leaf.drop_list);
}

static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
574
	int uninitialized_var(ret);
S
Stephen Hemminger 已提交
575 576 577 578 579 580 581 582 583
	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) {
			__skb_queue_tail(&q->direct_queue, skb);
			q->direct_pkts++;
		} else {
584
			return qdisc_drop(skb, sch);
S
Stephen Hemminger 已提交
585
		}
L
Linus Torvalds 已提交
586
#ifdef CONFIG_NET_CLS_ACT
S
Stephen Hemminger 已提交
587
	} else if (!cl) {
588
		if (ret & __NET_XMIT_BYPASS)
589
			qdisc_qstats_drop(sch);
S
Stephen Hemminger 已提交
590 591
		kfree_skb(skb);
		return ret;
L
Linus Torvalds 已提交
592
#endif
593 594
	} else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q)) != NET_XMIT_SUCCESS) {
		if (net_xmit_drop_count(ret)) {
595
			qdisc_qstats_drop(sch);
596 597
			cl->qstats.drops++;
		}
598
		return ret;
S
Stephen Hemminger 已提交
599 600 601 602 603 604
	} else {
		htb_activate(q, cl);
	}

	sch->q.qlen++;
	return NET_XMIT_SUCCESS;
L
Linus Torvalds 已提交
605 606
}

V
Vimalkumar 已提交
607
static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
608
{
V
Vimalkumar 已提交
609
	s64 toks = diff + cl->tokens;
610 611 612

	if (toks > cl->buffer)
		toks = cl->buffer;
613
	toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
614 615 616 617 618 619
	if (toks <= -cl->mbuffer)
		toks = 1 - cl->mbuffer;

	cl->tokens = toks;
}

V
Vimalkumar 已提交
620
static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
621
{
V
Vimalkumar 已提交
622
	s64 toks = diff + cl->ctokens;
623 624 625

	if (toks > cl->cbuffer)
		toks = cl->cbuffer;
626
	toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
627 628 629 630 631 632
	if (toks <= -cl->mbuffer)
		toks = 1 - cl->mbuffer;

	cl->ctokens = toks;
}

L
Linus Torvalds 已提交
633 634 635 636 637 638 639 640 641 642 643
/**
 * 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.
 */
S
Stephen Hemminger 已提交
644
static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
645
			     int level, struct sk_buff *skb)
S
Stephen Hemminger 已提交
646
{
647
	int bytes = qdisc_pkt_len(skb);
L
Linus Torvalds 已提交
648
	enum htb_cmode old_mode;
V
Vimalkumar 已提交
649
	s64 diff;
L
Linus Torvalds 已提交
650 651

	while (cl) {
V
Vimalkumar 已提交
652
		diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
L
Linus Torvalds 已提交
653
		if (cl->level >= level) {
S
Stephen Hemminger 已提交
654 655
			if (cl->level == level)
				cl->xstats.lends++;
656
			htb_accnt_tokens(cl, bytes, diff);
L
Linus Torvalds 已提交
657 658
		} else {
			cl->xstats.borrows++;
S
Stephen Hemminger 已提交
659
			cl->tokens += diff;	/* we moved t_c; update tokens */
L
Linus Torvalds 已提交
660
		}
661
		htb_accnt_ctokens(cl, bytes, diff);
L
Linus Torvalds 已提交
662 663
		cl->t_c = q->now;

S
Stephen Hemminger 已提交
664 665 666
		old_mode = cl->cmode;
		diff = 0;
		htb_change_class_mode(q, cl, &diff);
L
Linus Torvalds 已提交
667 668
		if (old_mode != cl->cmode) {
			if (old_mode != HTB_CAN_SEND)
669
				htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
L
Linus Torvalds 已提交
670
			if (cl->cmode != HTB_CAN_SEND)
S
Stephen Hemminger 已提交
671
				htb_add_to_wait_tree(q, cl, diff);
L
Linus Torvalds 已提交
672 673
		}

674 675 676 677
		/* update basic stats except for leaves which are already updated */
		if (cl->level)
			bstats_update(&cl->bstats, skb);

L
Linus Torvalds 已提交
678 679 680 681 682 683 684
		cl = cl->parent;
	}
}

/**
 * htb_do_events - make mode changes to classes at the level
 *
685
 * Scans event queue for pending events and applies them. Returns time of
686
 * next pending event (0 for no event in pq, q->now for too many events).
687
 * Note: Applied are events whose have cl->pq_key <= q->now.
L
Linus Torvalds 已提交
688
 */
689
static s64 htb_do_events(struct htb_sched *q, const int level,
690
			 unsigned long start)
L
Linus Torvalds 已提交
691
{
692
	/* don't run for longer than 2 jiffies; 2 is used instead of
E
Eric Dumazet 已提交
693 694 695
	 * 1 to simplify things when jiffy is going to be incremented
	 * too soon
	 */
696
	unsigned long stop_at = start + 2;
697 698
	struct rb_root *wait_pq = &q->hlevel[level].wait_pq;

699
	while (time_before(jiffies, stop_at)) {
L
Linus Torvalds 已提交
700
		struct htb_class *cl;
V
Vimalkumar 已提交
701
		s64 diff;
702
		struct rb_node *p = rb_first(wait_pq);
703

S
Stephen Hemminger 已提交
704 705
		if (!p)
			return 0;
L
Linus Torvalds 已提交
706 707

		cl = rb_entry(p, struct htb_class, pq_node);
708 709 710
		if (cl->pq_key > q->now)
			return cl->pq_key;

711
		htb_safe_rb_erase(p, wait_pq);
V
Vimalkumar 已提交
712
		diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
S
Stephen Hemminger 已提交
713
		htb_change_class_mode(q, cl, &diff);
L
Linus Torvalds 已提交
714
		if (cl->cmode != HTB_CAN_SEND)
S
Stephen Hemminger 已提交
715
			htb_add_to_wait_tree(q, cl, diff);
L
Linus Torvalds 已提交
716
	}
717 718

	/* too much load - let's continue after a break for scheduling */
719
	if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
720
		pr_warn("htb: too many events!\n");
721 722
		q->warned |= HTB_WARN_TOOMANYEVENTS;
	}
723 724

	return q->now;
L
Linus Torvalds 已提交
725 726 727
}

/* Returns class->node+prio from id-tree where classe's id is >= id. NULL
E
Eric Dumazet 已提交
728 729
 * is no such one exists.
 */
S
Stephen Hemminger 已提交
730 731
static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
					      u32 id)
L
Linus Torvalds 已提交
732 733 734
{
	struct rb_node *r = NULL;
	while (n) {
S
Stephen Hemminger 已提交
735 736 737
		struct htb_class *cl =
		    rb_entry(n, struct htb_class, node[prio]);

738
		if (id > cl->common.classid) {
L
Linus Torvalds 已提交
739
			n = n->rb_right;
740
		} else if (id < cl->common.classid) {
L
Linus Torvalds 已提交
741 742
			r = n;
			n = n->rb_left;
743 744
		} else {
			return n;
L
Linus Torvalds 已提交
745 746 747 748 749 750 751 752 753 754
		}
	}
	return r;
}

/**
 * htb_lookup_leaf - returns next leaf class in DRR order
 *
 * Find leaf where current feed pointers points to.
 */
755
static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio)
L
Linus Torvalds 已提交
756 757 758 759 760 761
{
	int i;
	struct {
		struct rb_node *root;
		struct rb_node **pptr;
		u32 *pid;
S
Stephen Hemminger 已提交
762 763
	} stk[TC_HTB_MAXDEPTH], *sp = stk;

764 765 766 767
	BUG_ON(!hprio->row.rb_node);
	sp->root = hprio->row.rb_node;
	sp->pptr = &hprio->ptr;
	sp->pid = &hprio->last_ptr_id;
L
Linus Torvalds 已提交
768 769

	for (i = 0; i < 65535; i++) {
S
Stephen Hemminger 已提交
770
		if (!*sp->pptr && *sp->pid) {
771
			/* ptr was invalidated but id is valid - try to recover
E
Eric Dumazet 已提交
772 773
			 * the original or next ptr
			 */
S
Stephen Hemminger 已提交
774 775
			*sp->pptr =
			    htb_id_find_next_upper(prio, sp->root, *sp->pid);
L
Linus Torvalds 已提交
776
		}
S
Stephen Hemminger 已提交
777
		*sp->pid = 0;	/* ptr is valid now so that remove this hint as it
E
Eric Dumazet 已提交
778 779
				 * can become out of date quickly
				 */
S
Stephen Hemminger 已提交
780
		if (!*sp->pptr) {	/* we are at right end; rewind & go up */
L
Linus Torvalds 已提交
781
			*sp->pptr = sp->root;
S
Stephen Hemminger 已提交
782
			while ((*sp->pptr)->rb_left)
L
Linus Torvalds 已提交
783 784 785
				*sp->pptr = (*sp->pptr)->rb_left;
			if (sp > stk) {
				sp--;
786 787
				if (!*sp->pptr) {
					WARN_ON(1);
S
Stephen Hemminger 已提交
788
					return NULL;
789
				}
S
Stephen Hemminger 已提交
790
				htb_next_rb_node(sp->pptr);
L
Linus Torvalds 已提交
791 792 793
			}
		} else {
			struct htb_class *cl;
794 795
			struct htb_prio *clp;

S
Stephen Hemminger 已提交
796 797
			cl = rb_entry(*sp->pptr, struct htb_class, node[prio]);
			if (!cl->level)
L
Linus Torvalds 已提交
798
				return cl;
799 800 801 802
			clp = &cl->un.inner.clprio[prio];
			(++sp)->root = clp->feed.rb_node;
			sp->pptr = &clp->ptr;
			sp->pid = &clp->last_ptr_id;
L
Linus Torvalds 已提交
803 804
		}
	}
805
	WARN_ON(1);
L
Linus Torvalds 已提交
806 807 808 809
	return NULL;
}

/* dequeues packet at given priority and level; call only if
E
Eric Dumazet 已提交
810 811
 * you are sure that there is active class at prio/level
 */
812 813
static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio,
					const int level)
L
Linus Torvalds 已提交
814 815
{
	struct sk_buff *skb = NULL;
S
Stephen Hemminger 已提交
816
	struct htb_class *cl, *start;
817 818 819
	struct htb_level *hlevel = &q->hlevel[level];
	struct htb_prio *hprio = &hlevel->hprio[prio];

L
Linus Torvalds 已提交
820
	/* look initial class up in the row */
821
	start = cl = htb_lookup_leaf(hprio, prio);
S
Stephen Hemminger 已提交
822

L
Linus Torvalds 已提交
823 824
	do {
next:
825
		if (unlikely(!cl))
S
Stephen Hemminger 已提交
826
			return NULL;
L
Linus Torvalds 已提交
827 828

		/* class can be empty - it is unlikely but can be true if leaf
E
Eric Dumazet 已提交
829 830 831 832
		 * qdisc drops packets in enqueue routine or if someone used
		 * graft operation on the leaf since last dequeue;
		 * simply deactivate and skip such class
		 */
L
Linus Torvalds 已提交
833 834
		if (unlikely(cl->un.leaf.q->q.qlen == 0)) {
			struct htb_class *next;
S
Stephen Hemminger 已提交
835
			htb_deactivate(q, cl);
L
Linus Torvalds 已提交
836 837 838

			/* row/level might become empty */
			if ((q->row_mask[level] & (1 << prio)) == 0)
S
Stephen Hemminger 已提交
839
				return NULL;
L
Linus Torvalds 已提交
840

841
			next = htb_lookup_leaf(hprio, prio);
S
Stephen Hemminger 已提交
842 843

			if (cl == start)	/* fix start if we just deleted it */
L
Linus Torvalds 已提交
844 845 846 847
				start = next;
			cl = next;
			goto next;
		}
S
Stephen Hemminger 已提交
848 849 850

		skb = cl->un.leaf.q->dequeue(cl->un.leaf.q);
		if (likely(skb != NULL))
L
Linus Torvalds 已提交
851
			break;
852

853
		qdisc_warn_nonwc("htb", cl->un.leaf.q);
854 855 856
		htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr:
					 &q->hlevel[0].hprio[prio].ptr);
		cl = htb_lookup_leaf(hprio, prio);
L
Linus Torvalds 已提交
857 858 859 860

	} while (cl != start);

	if (likely(skb != NULL)) {
E
Eric Dumazet 已提交
861
		bstats_update(&cl->bstats, skb);
862 863
		cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb);
		if (cl->un.leaf.deficit[level] < 0) {
864
			cl->un.leaf.deficit[level] += cl->quantum;
865 866
			htb_next_rb_node(level ? &cl->parent->un.inner.clprio[prio].ptr :
						 &q->hlevel[0].hprio[prio].ptr);
L
Linus Torvalds 已提交
867 868
		}
		/* this used to be after charge_class but this constelation
E
Eric Dumazet 已提交
869 870
		 * gives us slightly better performance
		 */
L
Linus Torvalds 已提交
871
		if (!cl->un.leaf.q->q.qlen)
S
Stephen Hemminger 已提交
872
			htb_deactivate(q, cl);
873
		htb_charge_class(q, cl, level, skb);
L
Linus Torvalds 已提交
874 875 876 877 878 879
	}
	return skb;
}

static struct sk_buff *htb_dequeue(struct Qdisc *sch)
{
880
	struct sk_buff *skb;
L
Linus Torvalds 已提交
881 882
	struct htb_sched *q = qdisc_priv(sch);
	int level;
883
	s64 next_event;
884
	unsigned long start_at;
L
Linus Torvalds 已提交
885 886

	/* try to dequeue direct packets as high prio (!) to minimize cpu work */
S
Stephen Hemminger 已提交
887 888
	skb = __skb_dequeue(&q->direct_queue);
	if (skb != NULL) {
889 890
ok:
		qdisc_bstats_update(sch, skb);
891
		qdisc_unthrottled(sch);
L
Linus Torvalds 已提交
892 893 894 895
		sch->q.qlen--;
		return skb;
	}

S
Stephen Hemminger 已提交
896 897
	if (!sch->q.qlen)
		goto fin;
898
	q->now = ktime_get_ns();
899
	start_at = jiffies;
L
Linus Torvalds 已提交
900

S
Stefan Hasko 已提交
901
	next_event = q->now + 5LLU * NSEC_PER_SEC;
902

L
Linus Torvalds 已提交
903 904 905
	for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
		/* common case optimization - skip event handler quickly */
		int m;
906
		s64 event = q->near_ev_cache[level];
907

908
		if (q->now >= event) {
909
			event = htb_do_events(q, level, start_at);
910
			if (!event)
V
Vimalkumar 已提交
911
				event = q->now + NSEC_PER_SEC;
912
			q->near_ev_cache[level] = event;
913
		}
914

915
		if (next_event > event)
916
			next_event = event;
S
Stephen Hemminger 已提交
917

L
Linus Torvalds 已提交
918 919
		m = ~q->row_mask[level];
		while (m != (int)(-1)) {
S
Stephen Hemminger 已提交
920
			int prio = ffz(m);
E
Eric Dumazet 已提交
921

L
Linus Torvalds 已提交
922
			m |= 1 << prio;
S
Stephen Hemminger 已提交
923
			skb = htb_dequeue_tree(q, prio, level);
924 925
			if (likely(skb != NULL))
				goto ok;
L
Linus Torvalds 已提交
926 927
		}
	}
928
	qdisc_qstats_overlimit(sch);
V
Vimalkumar 已提交
929 930 931 932 933 934
	if (likely(next_event > q->now)) {
		if (!test_bit(__QDISC_STATE_DEACTIVATED,
			      &qdisc_root_sleeping(q->watchdog.qdisc)->state)) {
			ktime_t time = ns_to_ktime(next_event);
			qdisc_throttled(q->watchdog.qdisc);
			hrtimer_start(&q->watchdog.timer, time,
E
Eric Dumazet 已提交
935
				      HRTIMER_MODE_ABS_PINNED);
V
Vimalkumar 已提交
936 937
		}
	} else {
938
		schedule_work(&q->work);
V
Vimalkumar 已提交
939
	}
L
Linus Torvalds 已提交
940 941 942 943 944
fin:
	return skb;
}

/* try to drop from each class (by prio) until one succeed */
S
Stephen Hemminger 已提交
945
static unsigned int htb_drop(struct Qdisc *sch)
L
Linus Torvalds 已提交
946 947 948 949 950 951
{
	struct htb_sched *q = qdisc_priv(sch);
	int prio;

	for (prio = TC_HTB_NUMPRIO - 1; prio >= 0; prio--) {
		struct list_head *p;
S
Stephen Hemminger 已提交
952
		list_for_each(p, q->drops + prio) {
L
Linus Torvalds 已提交
953 954 955
			struct htb_class *cl = list_entry(p, struct htb_class,
							  un.leaf.drop_list);
			unsigned int len;
S
Stephen Hemminger 已提交
956 957
			if (cl->un.leaf.q->ops->drop &&
			    (len = cl->un.leaf.q->ops->drop(cl->un.leaf.q))) {
L
Linus Torvalds 已提交
958 959
				sch->q.qlen--;
				if (!cl->un.leaf.q->q.qlen)
S
Stephen Hemminger 已提交
960
					htb_deactivate(q, cl);
L
Linus Torvalds 已提交
961 962 963 964 965 966 967 968 969
				return len;
			}
		}
	}
	return 0;
}

/* reset all classes */
/* always caled under BH & queue lock */
S
Stephen Hemminger 已提交
970
static void htb_reset(struct Qdisc *sch)
L
Linus Torvalds 已提交
971 972
{
	struct htb_sched *q = qdisc_priv(sch);
973 974
	struct htb_class *cl;
	unsigned int i;
975

976
	for (i = 0; i < q->clhash.hashsize; i++) {
977
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
L
Linus Torvalds 已提交
978
			if (cl->level)
S
Stephen Hemminger 已提交
979
				memset(&cl->un.inner, 0, sizeof(cl->un.inner));
L
Linus Torvalds 已提交
980
			else {
S
Stephen Hemminger 已提交
981
				if (cl->un.leaf.q)
L
Linus Torvalds 已提交
982 983 984 985 986 987 988 989
					qdisc_reset(cl->un.leaf.q);
				INIT_LIST_HEAD(&cl->un.leaf.drop_list);
			}
			cl->prio_activity = 0;
			cl->cmode = HTB_CAN_SEND;

		}
	}
990
	qdisc_watchdog_cancel(&q->watchdog);
L
Linus Torvalds 已提交
991 992
	__skb_queue_purge(&q->direct_queue);
	sch->q.qlen = 0;
993
	memset(q->hlevel, 0, sizeof(q->hlevel));
S
Stephen Hemminger 已提交
994
	memset(q->row_mask, 0, sizeof(q->row_mask));
L
Linus Torvalds 已提交
995
	for (i = 0; i < TC_HTB_NUMPRIO; i++)
S
Stephen Hemminger 已提交
996
		INIT_LIST_HEAD(q->drops + i);
L
Linus Torvalds 已提交
997 998
}

999 1000 1001 1002 1003
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 },
1004
	[TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 },
1005 1006
	[TCA_HTB_RATE64] = { .type = NLA_U64 },
	[TCA_HTB_CEIL64] = { .type = NLA_U64 },
1007 1008
};

1009 1010 1011 1012 1013 1014 1015 1016
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;

	__netif_schedule(qdisc_root(sch));
}

1017
static int htb_init(struct Qdisc *sch, struct nlattr *opt)
L
Linus Torvalds 已提交
1018 1019
{
	struct htb_sched *q = qdisc_priv(sch);
1020
	struct nlattr *tb[TCA_HTB_MAX + 1];
L
Linus Torvalds 已提交
1021
	struct tc_htb_glob *gopt;
1022
	int err;
L
Linus Torvalds 已提交
1023
	int i;
1024 1025 1026 1027

	if (!opt)
		return -EINVAL;

1028
	err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy);
1029 1030 1031
	if (err < 0)
		return err;

1032
	if (!tb[TCA_HTB_INIT])
L
Linus Torvalds 已提交
1033
		return -EINVAL;
1034

1035
	gopt = nla_data(tb[TCA_HTB_INIT]);
1036
	if (gopt->version != HTB_VER >> 16)
L
Linus Torvalds 已提交
1037 1038
		return -EINVAL;

1039 1040 1041
	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		return err;
L
Linus Torvalds 已提交
1042
	for (i = 0; i < TC_HTB_NUMPRIO; i++)
S
Stephen Hemminger 已提交
1043
		INIT_LIST_HEAD(q->drops + i);
L
Linus Torvalds 已提交
1044

1045
	qdisc_watchdog_init(&q->watchdog, sch);
1046
	INIT_WORK(&q->work, htb_work_func);
1047
	__skb_queue_head_init(&q->direct_queue);
L
Linus Torvalds 已提交
1048

1049 1050 1051 1052 1053 1054 1055
	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->direct_qlen < 2)	/* some devices have zero tx_queue_len */
			q->direct_qlen = 2;
	}
L
Linus Torvalds 已提交
1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	if ((q->rate2quantum = gopt->rate2quantum) < 1)
		q->rate2quantum = 1;
	q->defcls = gopt->defcls;

	return 0;
}

static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct htb_sched *q = qdisc_priv(sch);
1066
	struct nlattr *nest;
L
Linus Torvalds 已提交
1067
	struct tc_htb_glob gopt;
1068

1069 1070 1071
	/* Its safe to not acquire qdisc lock. As we hold RTNL,
	 * no change can happen on the qdisc parameters.
	 */
L
Linus Torvalds 已提交
1072

1073
	gopt.direct_pkts = q->direct_pkts;
L
Linus Torvalds 已提交
1074 1075 1076
	gopt.version = HTB_VER;
	gopt.rate2quantum = q->rate2quantum;
	gopt.defcls = q->defcls;
1077
	gopt.debug = 0;
1078 1079 1080 1081

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
1082 1083
	if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) ||
	    nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen))
1084
		goto nla_put_failure;
1085

1086
	return nla_nest_end(skb, nest);
1087

1088
nla_put_failure:
1089
	nla_nest_cancel(skb, nest);
L
Linus Torvalds 已提交
1090 1091 1092 1093
	return -1;
}

static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
S
Stephen Hemminger 已提交
1094
			  struct sk_buff *skb, struct tcmsg *tcm)
L
Linus Torvalds 已提交
1095
{
S
Stephen Hemminger 已提交
1096
	struct htb_class *cl = (struct htb_class *)arg;
1097
	struct nlattr *nest;
L
Linus Torvalds 已提交
1098 1099
	struct tc_htb_opt opt;

1100 1101 1102
	/* Its safe to not acquire qdisc lock. As we hold RTNL,
	 * no change can happen on the class parameters.
	 */
1103 1104
	tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT;
	tcm->tcm_handle = cl->common.classid;
L
Linus Torvalds 已提交
1105 1106 1107
	if (!cl->level && cl->un.leaf.q)
		tcm->tcm_info = cl->un.leaf.q->handle;

1108 1109 1110
	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
L
Linus Torvalds 已提交
1111

S
Stephen Hemminger 已提交
1112
	memset(&opt, 0, sizeof(opt));
L
Linus Torvalds 已提交
1113

1114
	psched_ratecfg_getrate(&opt.rate, &cl->rate);
J
Jiri Pirko 已提交
1115
	opt.buffer = PSCHED_NS2TICKS(cl->buffer);
1116
	psched_ratecfg_getrate(&opt.ceil, &cl->ceil);
J
Jiri Pirko 已提交
1117
	opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
1118 1119
	opt.quantum = cl->quantum;
	opt.prio = cl->prio;
S
Stephen Hemminger 已提交
1120
	opt.level = cl->level;
1121 1122
	if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;
1123 1124 1125 1126 1127 1128
	if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) &&
	    nla_put_u64(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps))
		goto nla_put_failure;
	if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) &&
	    nla_put_u64(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps))
		goto nla_put_failure;
1129

1130
	return nla_nest_end(skb, nest);
1131

1132
nla_put_failure:
1133
	nla_nest_cancel(skb, nest);
L
Linus Torvalds 已提交
1134 1135 1136 1137
	return -1;
}

static int
S
Stephen Hemminger 已提交
1138
htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
L
Linus Torvalds 已提交
1139
{
S
Stephen Hemminger 已提交
1140
	struct htb_class *cl = (struct htb_class *)arg;
1141
	__u32 qlen = 0;
L
Linus Torvalds 已提交
1142 1143

	if (!cl->level && cl->un.leaf.q)
1144
		qlen = cl->un.leaf.q->q.qlen;
1145 1146
	cl->xstats.tokens = PSCHED_NS2TICKS(cl->tokens);
	cl->xstats.ctokens = PSCHED_NS2TICKS(cl->ctokens);
L
Linus Torvalds 已提交
1147

1148
	if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
1149
	    gnet_stats_copy_rate_est(d, NULL, &cl->rate_est) < 0 ||
1150
	    gnet_stats_copy_queue(d, &cl->qstats, qlen) < 0)
L
Linus Torvalds 已提交
1151 1152 1153 1154 1155 1156
		return -1;

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

static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
S
Stephen Hemminger 已提交
1157
		     struct Qdisc **old)
L
Linus Torvalds 已提交
1158
{
S
Stephen Hemminger 已提交
1159
	struct htb_class *cl = (struct htb_class *)arg;
L
Linus Torvalds 已提交
1160

1161 1162 1163
	if (cl->level)
		return -EINVAL;
	if (new == NULL &&
1164
	    (new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1165 1166 1167 1168 1169 1170 1171 1172 1173
				     cl->common.classid)) == NULL)
		return -ENOBUFS;

	sch_tree_lock(sch);
	*old = cl->un.leaf.q;
	cl->un.leaf.q = new;
	if (*old != NULL) {
		qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
		qdisc_reset(*old);
L
Linus Torvalds 已提交
1174
	}
1175 1176
	sch_tree_unlock(sch);
	return 0;
L
Linus Torvalds 已提交
1177 1178
}

S
Stephen Hemminger 已提交
1179
static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
L
Linus Torvalds 已提交
1180
{
S
Stephen Hemminger 已提交
1181
	struct htb_class *cl = (struct htb_class *)arg;
1182
	return !cl->level ? cl->un.leaf.q : NULL;
L
Linus Torvalds 已提交
1183 1184
}

1185 1186 1187 1188 1189 1190 1191 1192
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);
}

L
Linus Torvalds 已提交
1193 1194
static unsigned long htb_get(struct Qdisc *sch, u32 classid)
{
S
Stephen Hemminger 已提交
1195 1196
	struct htb_class *cl = htb_find(classid, sch);
	if (cl)
L
Linus Torvalds 已提交
1197 1198 1199 1200
		cl->refcnt++;
	return (unsigned long)cl;
}

1201 1202 1203 1204 1205
static inline int htb_parent_last_child(struct htb_class *cl)
{
	if (!cl->parent)
		/* the root class */
		return 0;
1206
	if (cl->parent->children > 1)
1207 1208 1209 1210 1211
		/* not the last child */
		return 0;
	return 1;
}

1212 1213
static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl,
			       struct Qdisc *new_q)
1214 1215 1216
{
	struct htb_class *parent = cl->parent;

1217
	WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity);
1218

1219
	if (parent->cmode != HTB_CAN_SEND)
1220 1221
		htb_safe_rb_erase(&parent->pq_node,
				  &q->hlevel[parent->level].wait_pq);
1222

1223 1224 1225 1226 1227 1228
	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;
1229
	parent->t_c = ktime_get_ns();
1230 1231 1232
	parent->cmode = HTB_CAN_SEND;
}

S
Stephen Hemminger 已提交
1233
static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
L
Linus Torvalds 已提交
1234 1235
{
	if (!cl->level) {
1236
		WARN_ON(!cl->un.leaf.q);
L
Linus Torvalds 已提交
1237 1238
		qdisc_destroy(cl->un.leaf.q);
	}
1239
	gen_kill_estimator(&cl->bstats, &cl->rate_est);
1240
	tcf_destroy_chain(&cl->filter_list);
L
Linus Torvalds 已提交
1241 1242 1243
	kfree(cl);
}

S
Stephen Hemminger 已提交
1244
static void htb_destroy(struct Qdisc *sch)
L
Linus Torvalds 已提交
1245 1246
{
	struct htb_sched *q = qdisc_priv(sch);
1247
	struct hlist_node *next;
1248 1249
	struct htb_class *cl;
	unsigned int i;
L
Linus Torvalds 已提交
1250

1251
	cancel_work_sync(&q->work);
1252
	qdisc_watchdog_cancel(&q->watchdog);
L
Linus Torvalds 已提交
1253
	/* This line used to be after htb_destroy_class call below
E
Eric Dumazet 已提交
1254 1255 1256 1257
	 * 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).
	 */
1258
	tcf_destroy_chain(&q->filter_list);
S
Stephen Hemminger 已提交
1259

1260
	for (i = 0; i < q->clhash.hashsize; i++) {
1261
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode)
1262 1263
			tcf_destroy_chain(&cl->filter_list);
	}
1264
	for (i = 0; i < q->clhash.hashsize; i++) {
1265
		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1266
					  common.hnode)
1267 1268
			htb_destroy_class(sch, cl);
	}
1269
	qdisc_class_hash_destroy(&q->clhash);
L
Linus Torvalds 已提交
1270 1271 1272 1273 1274 1275
	__skb_queue_purge(&q->direct_queue);
}

static int htb_delete(struct Qdisc *sch, unsigned long arg)
{
	struct htb_sched *q = qdisc_priv(sch);
S
Stephen Hemminger 已提交
1276
	struct htb_class *cl = (struct htb_class *)arg;
1277
	unsigned int qlen;
1278 1279
	struct Qdisc *new_q = NULL;
	int last_child = 0;
L
Linus Torvalds 已提交
1280

Y
Yang Yingliang 已提交
1281 1282 1283 1284
	/* 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 ?
	 */
1285
	if (cl->children || cl->filter_cnt)
L
Linus Torvalds 已提交
1286
		return -EBUSY;
S
Stephen Hemminger 已提交
1287

1288
	if (!cl->level && htb_parent_last_child(cl)) {
1289
		new_q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1290
					  cl->parent->common.classid);
1291 1292 1293
		last_child = 1;
	}

L
Linus Torvalds 已提交
1294
	sch_tree_lock(sch);
S
Stephen Hemminger 已提交
1295

1296
	if (!cl->level) {
1297
		qlen = cl->un.leaf.q->q.qlen;
1298
		qdisc_reset(cl->un.leaf.q);
1299
		qdisc_tree_decrease_qlen(cl->un.leaf.q, qlen);
1300 1301
	}

1302 1303
	/* delete from hash and active; remainder in destroy_class */
	qdisc_class_hash_remove(&q->clhash, &cl->common);
1304 1305
	if (cl->parent)
		cl->parent->children--;
1306

L
Linus Torvalds 已提交
1307
	if (cl->prio_activity)
S
Stephen Hemminger 已提交
1308
		htb_deactivate(q, cl);
L
Linus Torvalds 已提交
1309

1310
	if (cl->cmode != HTB_CAN_SEND)
1311 1312
		htb_safe_rb_erase(&cl->pq_node,
				  &q->hlevel[cl->level].wait_pq);
1313

1314
	if (last_child)
1315
		htb_parent_to_leaf(q, cl, new_q);
1316

1317 1318 1319 1320 1321
	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().
	 */
L
Linus Torvalds 已提交
1322 1323 1324 1325 1326 1327 1328

	sch_tree_unlock(sch);
	return 0;
}

static void htb_put(struct Qdisc *sch, unsigned long arg)
{
S
Stephen Hemminger 已提交
1329
	struct htb_class *cl = (struct htb_class *)arg;
L
Linus Torvalds 已提交
1330 1331

	if (--cl->refcnt == 0)
S
Stephen Hemminger 已提交
1332
		htb_destroy_class(sch, cl);
L
Linus Torvalds 已提交
1333 1334
}

S
Stephen Hemminger 已提交
1335
static int htb_change_class(struct Qdisc *sch, u32 classid,
1336
			    u32 parentid, struct nlattr **tca,
S
Stephen Hemminger 已提交
1337
			    unsigned long *arg)
L
Linus Torvalds 已提交
1338 1339 1340
{
	int err = -EINVAL;
	struct htb_sched *q = qdisc_priv(sch);
S
Stephen Hemminger 已提交
1341
	struct htb_class *cl = (struct htb_class *)*arg, *parent;
1342
	struct nlattr *opt = tca[TCA_OPTIONS];
1343
	struct nlattr *tb[TCA_HTB_MAX + 1];
L
Linus Torvalds 已提交
1344
	struct tc_htb_opt *hopt;
1345
	u64 rate64, ceil64;
L
Linus Torvalds 已提交
1346 1347

	/* extract all subattrs from opt attr */
1348 1349 1350
	if (!opt)
		goto failure;

1351
	err = nla_parse_nested(tb, TCA_HTB_MAX, opt, htb_policy);
1352 1353 1354 1355
	if (err < 0)
		goto failure;

	err = -EINVAL;
1356
	if (tb[TCA_HTB_PARMS] == NULL)
L
Linus Torvalds 已提交
1357 1358
		goto failure;

S
Stephen Hemminger 已提交
1359 1360
	parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch);

1361
	hopt = nla_data(tb[TCA_HTB_PARMS]);
E
Eric Dumazet 已提交
1362
	if (!hopt->rate.rate || !hopt->ceil.rate)
S
Stephen Hemminger 已提交
1363
		goto failure;
L
Linus Torvalds 已提交
1364

1365
	/* Keeping backward compatible with rate_table based iproute2 tc */
1366 1367 1368 1369 1370
	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]));
1371

S
Stephen Hemminger 已提交
1372
	if (!cl) {		/* new class */
L
Linus Torvalds 已提交
1373
		struct Qdisc *new_q;
S
Stephen Hemminger 已提交
1374
		int prio;
1375
		struct {
1376
			struct nlattr		nla;
1377 1378
			struct gnet_estimator	opt;
		} est = {
1379 1380 1381
			.nla = {
				.nla_len	= nla_attr_size(sizeof(est.opt)),
				.nla_type	= TCA_RATE,
1382 1383 1384 1385 1386 1387 1388
			},
			.opt = {
				/* 4s interval, 16s averaging constant */
				.interval	= 2,
				.ewma_log	= 2,
			},
		};
S
Stephen Hemminger 已提交
1389

L
Linus Torvalds 已提交
1390
		/* check for valid classid */
1391 1392
		if (!classid || TC_H_MAJ(classid ^ sch->handle) ||
		    htb_find(classid, sch))
L
Linus Torvalds 已提交
1393 1394 1395 1396
			goto failure;

		/* check maximal depth */
		if (parent && parent->parent && parent->parent->level < 2) {
E
Eric Dumazet 已提交
1397
			pr_err("htb: tree is too deep\n");
L
Linus Torvalds 已提交
1398 1399 1400
			goto failure;
		}
		err = -ENOBUFS;
E
Eric Dumazet 已提交
1401 1402
		cl = kzalloc(sizeof(*cl), GFP_KERNEL);
		if (!cl)
L
Linus Torvalds 已提交
1403
			goto failure;
S
Stephen Hemminger 已提交
1404

1405
		if (htb_rate_est || tca[TCA_RATE]) {
1406 1407
			err = gen_new_estimator(&cl->bstats, NULL,
						&cl->rate_est,
1408 1409 1410 1411 1412 1413
						qdisc_root_sleeping_lock(sch),
						tca[TCA_RATE] ? : &est.nla);
			if (err) {
				kfree(cl);
				goto failure;
			}
1414 1415
		}

L
Linus Torvalds 已提交
1416
		cl->refcnt = 1;
1417
		cl->children = 0;
L
Linus Torvalds 已提交
1418
		INIT_LIST_HEAD(&cl->un.leaf.drop_list);
S
Stephen Hemminger 已提交
1419 1420 1421 1422
		RB_CLEAR_NODE(&cl->pq_node);

		for (prio = 0; prio < TC_HTB_NUMPRIO; prio++)
			RB_CLEAR_NODE(&cl->node[prio]);
L
Linus Torvalds 已提交
1423 1424

		/* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
E
Eric Dumazet 已提交
1425 1426 1427
		 * so that can't be used inside of sch_tree_lock
		 * -- thanks to Karlis Peisenieks
		 */
1428
		new_q = qdisc_create_dflt(sch->dev_queue,
1429
					  &pfifo_qdisc_ops, classid);
L
Linus Torvalds 已提交
1430 1431
		sch_tree_lock(sch);
		if (parent && !parent->level) {
1432 1433
			unsigned int qlen = parent->un.leaf.q->q.qlen;

L
Linus Torvalds 已提交
1434
			/* turn parent into inner node */
1435 1436
			qdisc_reset(parent->un.leaf.q);
			qdisc_tree_decrease_qlen(parent->un.leaf.q, qlen);
S
Stephen Hemminger 已提交
1437 1438 1439
			qdisc_destroy(parent->un.leaf.q);
			if (parent->prio_activity)
				htb_deactivate(q, parent);
L
Linus Torvalds 已提交
1440 1441 1442

			/* remove from evt list because of level change */
			if (parent->cmode != HTB_CAN_SEND) {
1443
				htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq);
L
Linus Torvalds 已提交
1444 1445 1446
				parent->cmode = HTB_CAN_SEND;
			}
			parent->level = (parent->parent ? parent->parent->level
S
Stephen Hemminger 已提交
1447 1448
					 : TC_HTB_MAXDEPTH) - 1;
			memset(&parent->un.inner, 0, sizeof(parent->un.inner));
L
Linus Torvalds 已提交
1449 1450 1451 1452
		}
		/* leaf (we) needs elementary qdisc */
		cl->un.leaf.q = new_q ? new_q : &noop_qdisc;

1453
		cl->common.classid = classid;
S
Stephen Hemminger 已提交
1454
		cl->parent = parent;
L
Linus Torvalds 已提交
1455 1456

		/* set class to be in HTB_CAN_SEND state */
1457 1458
		cl->tokens = PSCHED_TICKS2NS(hopt->buffer);
		cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer);
1459
		cl->mbuffer = 60ULL * NSEC_PER_SEC;	/* 1min */
1460
		cl->t_c = ktime_get_ns();
L
Linus Torvalds 已提交
1461 1462 1463
		cl->cmode = HTB_CAN_SEND;

		/* attach to the hash list and parent's family */
1464
		qdisc_class_hash_insert(&q->clhash, &cl->common);
1465 1466
		if (parent)
			parent->children++;
1467
	} else {
1468
		if (tca[TCA_RATE]) {
1469 1470 1471 1472 1473
			spinlock_t *lock = qdisc_root_sleeping_lock(sch);

			err = gen_replace_estimator(&cl->bstats, NULL,
						    &cl->rate_est,
						    lock,
1474 1475 1476 1477
						    tca[TCA_RATE]);
			if (err)
				return err;
		}
S
Stephen Hemminger 已提交
1478
		sch_tree_lock(sch);
1479
	}
L
Linus Torvalds 已提交
1480

1481 1482 1483 1484 1485 1486 1487
	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);

L
Linus Torvalds 已提交
1488
	/* it used to be a nasty bug here, we have to check that node
E
Eric Dumazet 已提交
1489 1490
	 * is really leaf before changing cl->un.leaf !
	 */
L
Linus Torvalds 已提交
1491
	if (!cl->level) {
1492 1493 1494 1495 1496
		u64 quantum = cl->rate.rate_bytes_ps;

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

1497
		if (!hopt->quantum && cl->quantum < 1000) {
1498 1499
			pr_warn("HTB: quantum of class %X is small. Consider r2q change.\n",
				cl->common.classid);
1500
			cl->quantum = 1000;
L
Linus Torvalds 已提交
1501
		}
1502
		if (!hopt->quantum && cl->quantum > 200000) {
1503 1504
			pr_warn("HTB: quantum of class %X is big. Consider r2q change.\n",
				cl->common.classid);
1505
			cl->quantum = 200000;
L
Linus Torvalds 已提交
1506 1507
		}
		if (hopt->quantum)
1508 1509 1510
			cl->quantum = hopt->quantum;
		if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
			cl->prio = TC_HTB_NUMPRIO - 1;
L
Linus Torvalds 已提交
1511 1512
	}

J
Jiri Pirko 已提交
1513
	cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
1514
	cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);
V
Vimalkumar 已提交
1515

L
Linus Torvalds 已提交
1516 1517
	sch_tree_unlock(sch);

1518 1519
	qdisc_class_hash_grow(sch, &q->clhash);

L
Linus Torvalds 已提交
1520 1521 1522 1523 1524 1525 1526
	*arg = (unsigned long)cl;
	return 0;

failure:
	return err;
}

J
John Fastabend 已提交
1527 1528
static struct tcf_proto __rcu **htb_find_tcf(struct Qdisc *sch,
					     unsigned long arg)
L
Linus Torvalds 已提交
1529 1530 1531
{
	struct htb_sched *q = qdisc_priv(sch);
	struct htb_class *cl = (struct htb_class *)arg;
J
John Fastabend 已提交
1532
	struct tcf_proto __rcu **fl = cl ? &cl->filter_list : &q->filter_list;
1533

L
Linus Torvalds 已提交
1534 1535 1536 1537
	return fl;
}

static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
S
Stephen Hemminger 已提交
1538
				     u32 classid)
L
Linus Torvalds 已提交
1539
{
S
Stephen Hemminger 已提交
1540
	struct htb_class *cl = htb_find(classid, sch);
1541

L
Linus Torvalds 已提交
1542
	/*if (cl && !cl->level) return 0;
E
Eric Dumazet 已提交
1543 1544 1545 1546 1547 1548 1549
	 * 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.
L
Linus Torvalds 已提交
1550
	 */
S
Stephen Hemminger 已提交
1551 1552
	if (cl)
		cl->filter_cnt++;
L
Linus Torvalds 已提交
1553 1554 1555 1556 1557 1558
	return (unsigned long)cl;
}

static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
{
	struct htb_class *cl = (struct htb_class *)arg;
1559

S
Stephen Hemminger 已提交
1560 1561
	if (cl)
		cl->filter_cnt--;
L
Linus Torvalds 已提交
1562 1563 1564 1565 1566
}

static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct htb_sched *q = qdisc_priv(sch);
1567 1568
	struct htb_class *cl;
	unsigned int i;
L
Linus Torvalds 已提交
1569 1570 1571 1572

	if (arg->stop)
		return;

1573
	for (i = 0; i < q->clhash.hashsize; i++) {
1574
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
L
Linus Torvalds 已提交
1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

1588
static const struct Qdisc_class_ops htb_class_ops = {
L
Linus Torvalds 已提交
1589 1590
	.graft		=	htb_graft,
	.leaf		=	htb_leaf,
1591
	.qlen_notify	=	htb_qlen_notify,
L
Linus Torvalds 已提交
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603
	.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,
};

1604
static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
L
Linus Torvalds 已提交
1605 1606 1607 1608 1609
	.cl_ops		=	&htb_class_ops,
	.id		=	"htb",
	.priv_size	=	sizeof(struct htb_sched),
	.enqueue	=	htb_enqueue,
	.dequeue	=	htb_dequeue,
1610
	.peek		=	qdisc_peek_dequeued,
L
Linus Torvalds 已提交
1611 1612 1613 1614 1615 1616 1617 1618 1619 1620
	.drop		=	htb_drop,
	.init		=	htb_init,
	.reset		=	htb_reset,
	.destroy	=	htb_destroy,
	.dump		=	htb_dump,
	.owner		=	THIS_MODULE,
};

static int __init htb_module_init(void)
{
S
Stephen Hemminger 已提交
1621
	return register_qdisc(&htb_qdisc_ops);
L
Linus Torvalds 已提交
1622
}
S
Stephen Hemminger 已提交
1623
static void __exit htb_module_exit(void)
L
Linus Torvalds 已提交
1624
{
S
Stephen Hemminger 已提交
1625
	unregister_qdisc(&htb_qdisc_ops);
L
Linus Torvalds 已提交
1626
}
S
Stephen Hemminger 已提交
1627

L
Linus Torvalds 已提交
1628 1629 1630
module_init(htb_module_init)
module_exit(htb_module_exit)
MODULE_LICENSE("GPL");