sch_fq.c 20.7 KB
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/*
 * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing)
 *
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 *  Copyright (C) 2013-2015 Eric Dumazet <edumazet@google.com>
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 *
 *	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.
 *
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 *  Meant to be mostly used for locally generated traffic :
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 *  Fast classification depends on skb->sk being set before reaching us.
 *  If not, (router workload), we use rxhash as fallback, with 32 bits wide hash.
 *  All packets belonging to a socket are considered as a 'flow'.
 *
 *  Flows are dynamically allocated and stored in a hash table of RB trees
 *  They are also part of one Round Robin 'queues' (new or old flows)
 *
 *  Burst avoidance (aka pacing) capability :
 *
 *  Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a
 *  bunch of packets, and this packet scheduler adds delay between
 *  packets to respect rate limitation.
 *
 *  enqueue() :
 *   - lookup one RB tree (out of 1024 or more) to find the flow.
 *     If non existent flow, create it, add it to the tree.
 *     Add skb to the per flow list of skb (fifo).
 *   - Use a special fifo for high prio packets
 *
 *  dequeue() : serves flows in Round Robin
 *  Note : When a flow becomes empty, we do not immediately remove it from
 *  rb trees, for performance reasons (its expected to send additional packets,
 *  or SLAB cache will reuse socket for another flow)
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/rbtree.h>
#include <linux/hash.h>
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#include <linux/prefetch.h>
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#include <linux/vmalloc.h>
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#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/sock.h>
#include <net/tcp_states.h>
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#include <net/tcp.h>
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/*
 * Per flow structure, dynamically allocated
 */
struct fq_flow {
	struct sk_buff	*head;		/* list of skbs for this flow : first skb */
	union {
		struct sk_buff *tail;	/* last skb in the list */
		unsigned long  age;	/* jiffies when flow was emptied, for gc */
	};
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	struct rb_node	fq_node;	/* anchor in fq_root[] trees */
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	struct sock	*sk;
	int		qlen;		/* number of packets in flow queue */
	int		credit;
	u32		socket_hash;	/* sk_hash */
	struct fq_flow *next;		/* next pointer in RR lists, or &detached */

	struct rb_node  rate_node;	/* anchor in q->delayed tree */
	u64		time_next_packet;
};

struct fq_flow_head {
	struct fq_flow *first;
	struct fq_flow *last;
};

struct fq_sched_data {
	struct fq_flow_head new_flows;

	struct fq_flow_head old_flows;

	struct rb_root	delayed;	/* for rate limited flows */
	u64		time_next_delayed_flow;

	struct fq_flow	internal;	/* for non classified or high prio packets */
	u32		quantum;
	u32		initial_quantum;
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	u32		flow_refill_delay;
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	u32		flow_max_rate;	/* optional max rate per flow */
	u32		flow_plimit;	/* max packets per flow */
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	u32		orphan_mask;	/* mask for orphaned skb */
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	struct rb_root	*fq_root;
	u8		rate_enable;
	u8		fq_trees_log;

	u32		flows;
	u32		inactive_flows;
	u32		throttled_flows;

	u64		stat_gc_flows;
	u64		stat_internal_packets;
	u64		stat_tcp_retrans;
	u64		stat_throttled;
	u64		stat_flows_plimit;
	u64		stat_pkts_too_long;
	u64		stat_allocation_errors;
	struct qdisc_watchdog watchdog;
};

/* special value to mark a detached flow (not on old/new list) */
static struct fq_flow detached, throttled;

static void fq_flow_set_detached(struct fq_flow *f)
{
	f->next = &detached;
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	f->age = jiffies;
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}

static bool fq_flow_is_detached(const struct fq_flow *f)
{
	return f->next == &detached;
}

static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
{
	struct rb_node **p = &q->delayed.rb_node, *parent = NULL;

	while (*p) {
		struct fq_flow *aux;

		parent = *p;
		aux = container_of(parent, struct fq_flow, rate_node);
		if (f->time_next_packet >= aux->time_next_packet)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}
	rb_link_node(&f->rate_node, parent, p);
	rb_insert_color(&f->rate_node, &q->delayed);
	q->throttled_flows++;
	q->stat_throttled++;

	f->next = &throttled;
	if (q->time_next_delayed_flow > f->time_next_packet)
		q->time_next_delayed_flow = f->time_next_packet;
}


static struct kmem_cache *fq_flow_cachep __read_mostly;

static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
{
	if (head->first)
		head->last->next = flow;
	else
		head->first = flow;
	head->last = flow;
	flow->next = NULL;
}

/* limit number of collected flows per round */
#define FQ_GC_MAX 8
#define FQ_GC_AGE (3*HZ)

static bool fq_gc_candidate(const struct fq_flow *f)
{
	return fq_flow_is_detached(f) &&
	       time_after(jiffies, f->age + FQ_GC_AGE);
}

static void fq_gc(struct fq_sched_data *q,
		  struct rb_root *root,
		  struct sock *sk)
{
	struct fq_flow *f, *tofree[FQ_GC_MAX];
	struct rb_node **p, *parent;
	int fcnt = 0;

	p = &root->rb_node;
	parent = NULL;
	while (*p) {
		parent = *p;

		f = container_of(parent, struct fq_flow, fq_node);
		if (f->sk == sk)
			break;

		if (fq_gc_candidate(f)) {
			tofree[fcnt++] = f;
			if (fcnt == FQ_GC_MAX)
				break;
		}

		if (f->sk > sk)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}

	q->flows -= fcnt;
	q->inactive_flows -= fcnt;
	q->stat_gc_flows += fcnt;
	while (fcnt) {
		struct fq_flow *f = tofree[--fcnt];

		rb_erase(&f->fq_node, root);
		kmem_cache_free(fq_flow_cachep, f);
	}
}

static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
{
	struct rb_node **p, *parent;
	struct sock *sk = skb->sk;
	struct rb_root *root;
	struct fq_flow *f;

	/* warning: no starvation prevention... */
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	if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
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		return &q->internal;

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	/* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
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	 * or a listener (SYNCOOKIE mode)
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	 * 1) request sockets are not full blown,
	 *    they do not contain sk_pacing_rate
	 * 2) They are not part of a 'flow' yet
	 * 3) We do not want to rate limit them (eg SYNFLOOD attack),
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	 *    especially if the listener set SO_MAX_PACING_RATE
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	 * 4) We pretend they are orphaned
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	 */
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	if (!sk || sk_listener(sk)) {
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		unsigned long hash = skb_get_hash(skb) & q->orphan_mask;

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		/* By forcing low order bit to 1, we make sure to not
		 * collide with a local flow (socket pointers are word aligned)
		 */
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		sk = (struct sock *)((hash << 1) | 1UL);
		skb_orphan(skb);
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	}

	root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];

	if (q->flows >= (2U << q->fq_trees_log) &&
	    q->inactive_flows > q->flows/2)
		fq_gc(q, root, sk);

	p = &root->rb_node;
	parent = NULL;
	while (*p) {
		parent = *p;

		f = container_of(parent, struct fq_flow, fq_node);
		if (f->sk == sk) {
			/* socket might have been reallocated, so check
			 * if its sk_hash is the same.
			 * It not, we need to refill credit with
			 * initial quantum
			 */
			if (unlikely(skb->sk &&
				     f->socket_hash != sk->sk_hash)) {
				f->credit = q->initial_quantum;
				f->socket_hash = sk->sk_hash;
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				f->time_next_packet = 0ULL;
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			}
			return f;
		}
		if (f->sk > sk)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}

	f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
	if (unlikely(!f)) {
		q->stat_allocation_errors++;
		return &q->internal;
	}
	fq_flow_set_detached(f);
	f->sk = sk;
	if (skb->sk)
		f->socket_hash = sk->sk_hash;
	f->credit = q->initial_quantum;

	rb_link_node(&f->fq_node, parent, p);
	rb_insert_color(&f->fq_node, root);

	q->flows++;
	q->inactive_flows++;
	return f;
}


/* remove one skb from head of flow queue */
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static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
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{
	struct sk_buff *skb = flow->head;

	if (skb) {
		flow->head = skb->next;
		skb->next = NULL;
		flow->qlen--;
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		qdisc_qstats_backlog_dec(sch, skb);
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		sch->q.qlen--;
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	}
	return skb;
}

/* We might add in the future detection of retransmits
 * For the time being, just return false
 */
static bool skb_is_retransmit(struct sk_buff *skb)
{
	return false;
}

/* add skb to flow queue
 * flow queue is a linked list, kind of FIFO, except for TCP retransmits
 * We special case tcp retransmits to be transmitted before other packets.
 * We rely on fact that TCP retransmits are unlikely, so we do not waste
 * a separate queue or a pointer.
 * head->  [retrans pkt 1]
 *         [retrans pkt 2]
 *         [ normal pkt 1]
 *         [ normal pkt 2]
 *         [ normal pkt 3]
 * tail->  [ normal pkt 4]
 */
static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
{
	struct sk_buff *prev, *head = flow->head;

	skb->next = NULL;
	if (!head) {
		flow->head = skb;
		flow->tail = skb;
		return;
	}
	if (likely(!skb_is_retransmit(skb))) {
		flow->tail->next = skb;
		flow->tail = skb;
		return;
	}

	/* This skb is a tcp retransmit,
	 * find the last retrans packet in the queue
	 */
	prev = NULL;
	while (skb_is_retransmit(head)) {
		prev = head;
		head = head->next;
		if (!head)
			break;
	}
	if (!prev) { /* no rtx packet in queue, become the new head */
		skb->next = flow->head;
		flow->head = skb;
	} else {
		if (prev == flow->tail)
			flow->tail = skb;
		else
			skb->next = prev->next;
		prev->next = skb;
	}
}

static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	struct fq_flow *f;

	if (unlikely(sch->q.qlen >= sch->limit))
		return qdisc_drop(skb, sch);

	f = fq_classify(skb, q);
	if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
		q->stat_flows_plimit++;
		return qdisc_drop(skb, sch);
	}

	f->qlen++;
	if (skb_is_retransmit(skb))
		q->stat_tcp_retrans++;
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	qdisc_qstats_backlog_inc(sch, skb);
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	if (fq_flow_is_detached(f)) {
		fq_flow_add_tail(&q->new_flows, f);
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		if (time_after(jiffies, f->age + q->flow_refill_delay))
			f->credit = max_t(u32, f->credit, q->quantum);
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		q->inactive_flows--;
	}
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	/* Note: this overwrites f->age */
	flow_queue_add(f, skb);

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	if (unlikely(f == &q->internal)) {
		q->stat_internal_packets++;
	}
	sch->q.qlen++;

	return NET_XMIT_SUCCESS;
}

static void fq_check_throttled(struct fq_sched_data *q, u64 now)
{
	struct rb_node *p;

	if (q->time_next_delayed_flow > now)
		return;

	q->time_next_delayed_flow = ~0ULL;
	while ((p = rb_first(&q->delayed)) != NULL) {
		struct fq_flow *f = container_of(p, struct fq_flow, rate_node);

		if (f->time_next_packet > now) {
			q->time_next_delayed_flow = f->time_next_packet;
			break;
		}
		rb_erase(p, &q->delayed);
		q->throttled_flows--;
		fq_flow_add_tail(&q->old_flows, f);
	}
}

static struct sk_buff *fq_dequeue(struct Qdisc *sch)
{
	struct fq_sched_data *q = qdisc_priv(sch);
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	u64 now = ktime_get_ns();
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	struct fq_flow_head *head;
	struct sk_buff *skb;
	struct fq_flow *f;
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	u32 rate;
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	skb = fq_dequeue_head(sch, &q->internal);
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	if (skb)
		goto out;
	fq_check_throttled(q, now);
begin:
	head = &q->new_flows;
	if (!head->first) {
		head = &q->old_flows;
		if (!head->first) {
			if (q->time_next_delayed_flow != ~0ULL)
				qdisc_watchdog_schedule_ns(&q->watchdog,
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							   q->time_next_delayed_flow,
							   false);
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			return NULL;
		}
	}
	f = head->first;

	if (f->credit <= 0) {
		f->credit += q->quantum;
		head->first = f->next;
		fq_flow_add_tail(&q->old_flows, f);
		goto begin;
	}

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	skb = f->head;
	if (unlikely(skb && now < f->time_next_packet &&
		     !skb_is_tcp_pure_ack(skb))) {
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		head->first = f->next;
		fq_flow_set_throttled(q, f);
		goto begin;
	}

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	skb = fq_dequeue_head(sch, f);
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	if (!skb) {
		head->first = f->next;
		/* force a pass through old_flows to prevent starvation */
		if ((head == &q->new_flows) && q->old_flows.first) {
			fq_flow_add_tail(&q->old_flows, f);
		} else {
			fq_flow_set_detached(f);
			q->inactive_flows++;
		}
		goto begin;
	}
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	prefetch(&skb->end);
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	f->credit -= qdisc_pkt_len(skb);

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	if (f->credit > 0 || !q->rate_enable)
		goto out;
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	/* Do not pace locally generated ack packets */
	if (skb_is_tcp_pure_ack(skb))
		goto out;

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	rate = q->flow_max_rate;
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	if (skb->sk)
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		rate = min(skb->sk->sk_pacing_rate, rate);
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	if (rate != ~0U) {
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		u32 plen = max(qdisc_pkt_len(skb), q->quantum);
		u64 len = (u64)plen * NSEC_PER_SEC;

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		if (likely(rate))
			do_div(len, rate);
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		/* Since socket rate can change later,
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		 * clamp the delay to 1 second.
		 * Really, providers of too big packets should be fixed !
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		 */
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		if (unlikely(len > NSEC_PER_SEC)) {
			len = NSEC_PER_SEC;
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			q->stat_pkts_too_long++;
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		}
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		f->time_next_packet = now + len;
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	}
out:
	qdisc_bstats_update(sch, skb);
	return skb;
}

static void fq_reset(struct Qdisc *sch)
{
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	struct fq_sched_data *q = qdisc_priv(sch);
	struct rb_root *root;
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	struct sk_buff *skb;
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	struct rb_node *p;
	struct fq_flow *f;
	unsigned int idx;
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	while ((skb = fq_dequeue_head(sch, &q->internal)) != NULL)
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		kfree_skb(skb);
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	if (!q->fq_root)
		return;

	for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
		root = &q->fq_root[idx];
		while ((p = rb_first(root)) != NULL) {
			f = container_of(p, struct fq_flow, fq_node);
			rb_erase(p, root);

			while ((skb = fq_dequeue_head(sch, f)) != NULL)
				kfree_skb(skb);

			kmem_cache_free(fq_flow_cachep, f);
		}
	}
	q->new_flows.first	= NULL;
	q->old_flows.first	= NULL;
	q->delayed		= RB_ROOT;
	q->flows		= 0;
	q->inactive_flows	= 0;
	q->throttled_flows	= 0;
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}

static void fq_rehash(struct fq_sched_data *q,
		      struct rb_root *old_array, u32 old_log,
		      struct rb_root *new_array, u32 new_log)
{
	struct rb_node *op, **np, *parent;
	struct rb_root *oroot, *nroot;
	struct fq_flow *of, *nf;
	int fcnt = 0;
	u32 idx;

	for (idx = 0; idx < (1U << old_log); idx++) {
		oroot = &old_array[idx];
		while ((op = rb_first(oroot)) != NULL) {
			rb_erase(op, oroot);
			of = container_of(op, struct fq_flow, fq_node);
			if (fq_gc_candidate(of)) {
				fcnt++;
				kmem_cache_free(fq_flow_cachep, of);
				continue;
			}
			nroot = &new_array[hash_32((u32)(long)of->sk, new_log)];

			np = &nroot->rb_node;
			parent = NULL;
			while (*np) {
				parent = *np;

				nf = container_of(parent, struct fq_flow, fq_node);
				BUG_ON(nf->sk == of->sk);

				if (nf->sk > of->sk)
					np = &parent->rb_right;
				else
					np = &parent->rb_left;
			}

			rb_link_node(&of->fq_node, parent, np);
			rb_insert_color(&of->fq_node, nroot);
		}
	}
	q->flows -= fcnt;
	q->inactive_flows -= fcnt;
	q->stat_gc_flows += fcnt;
}

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static void *fq_alloc_node(size_t sz, int node)
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{
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	void *ptr;

	ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node);
	if (!ptr)
		ptr = vmalloc_node(sz, node);
	return ptr;
}

static void fq_free(void *addr)
{
W
WANG Cong 已提交
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	kvfree(addr);
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}

static int fq_resize(struct Qdisc *sch, u32 log)
{
	struct fq_sched_data *q = qdisc_priv(sch);
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	struct rb_root *array;
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	void *old_fq_root;
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	u32 idx;

	if (q->fq_root && log == q->fq_trees_log)
		return 0;

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	/* If XPS was setup, we can allocate memory on right NUMA node */
	array = fq_alloc_node(sizeof(struct rb_root) << log,
			      netdev_queue_numa_node_read(sch->dev_queue));
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	if (!array)
		return -ENOMEM;

	for (idx = 0; idx < (1U << log); idx++)
		array[idx] = RB_ROOT;

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	sch_tree_lock(sch);

	old_fq_root = q->fq_root;
	if (old_fq_root)
		fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);

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	q->fq_root = array;
	q->fq_trees_log = log;

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	sch_tree_unlock(sch);

	fq_free(old_fq_root);

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	return 0;
}

static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
	[TCA_FQ_PLIMIT]			= { .type = NLA_U32 },
	[TCA_FQ_FLOW_PLIMIT]		= { .type = NLA_U32 },
	[TCA_FQ_QUANTUM]		= { .type = NLA_U32 },
	[TCA_FQ_INITIAL_QUANTUM]	= { .type = NLA_U32 },
	[TCA_FQ_RATE_ENABLE]		= { .type = NLA_U32 },
	[TCA_FQ_FLOW_DEFAULT_RATE]	= { .type = NLA_U32 },
	[TCA_FQ_FLOW_MAX_RATE]		= { .type = NLA_U32 },
	[TCA_FQ_BUCKETS_LOG]		= { .type = NLA_U32 },
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	[TCA_FQ_FLOW_REFILL_DELAY]	= { .type = NLA_U32 },
658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691
};

static int fq_change(struct Qdisc *sch, struct nlattr *opt)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_FQ_MAX + 1];
	int err, drop_count = 0;
	u32 fq_log;

	if (!opt)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy);
	if (err < 0)
		return err;

	sch_tree_lock(sch);

	fq_log = q->fq_trees_log;

	if (tb[TCA_FQ_BUCKETS_LOG]) {
		u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);

		if (nval >= 1 && nval <= ilog2(256*1024))
			fq_log = nval;
		else
			err = -EINVAL;
	}
	if (tb[TCA_FQ_PLIMIT])
		sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);

	if (tb[TCA_FQ_FLOW_PLIMIT])
		q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);

692 693 694 695 696 697 698 699
	if (tb[TCA_FQ_QUANTUM]) {
		u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);

		if (quantum > 0)
			q->quantum = quantum;
		else
			err = -EINVAL;
	}
700 701

	if (tb[TCA_FQ_INITIAL_QUANTUM])
702
		q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
703 704

	if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
705 706
		pr_warn_ratelimited("sch_fq: defrate %u ignored.\n",
				    nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]));
707 708 709 710 711 712 713 714 715 716 717 718 719

	if (tb[TCA_FQ_FLOW_MAX_RATE])
		q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);

	if (tb[TCA_FQ_RATE_ENABLE]) {
		u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);

		if (enable <= 1)
			q->rate_enable = enable;
		else
			err = -EINVAL;
	}

720 721 722 723 724 725
	if (tb[TCA_FQ_FLOW_REFILL_DELAY]) {
		u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ;

		q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
	}

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	if (tb[TCA_FQ_ORPHAN_MASK])
		q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]);

729 730
	if (!err) {
		sch_tree_unlock(sch);
731
		err = fq_resize(sch, fq_log);
732 733
		sch_tree_lock(sch);
	}
734 735 736
	while (sch->q.qlen > sch->limit) {
		struct sk_buff *skb = fq_dequeue(sch);

737 738
		if (!skb)
			break;
739 740 741 742 743 744 745 746 747 748 749 750 751
		kfree_skb(skb);
		drop_count++;
	}
	qdisc_tree_decrease_qlen(sch, drop_count);

	sch_tree_unlock(sch);
	return err;
}

static void fq_destroy(struct Qdisc *sch)
{
	struct fq_sched_data *q = qdisc_priv(sch);

752
	fq_reset(sch);
753
	fq_free(q->fq_root);
754 755 756 757 758 759 760 761 762 763 764 765
	qdisc_watchdog_cancel(&q->watchdog);
}

static int fq_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	int err;

	sch->limit		= 10000;
	q->flow_plimit		= 100;
	q->quantum		= 2 * psched_mtu(qdisc_dev(sch));
	q->initial_quantum	= 10 * psched_mtu(qdisc_dev(sch));
766
	q->flow_refill_delay	= msecs_to_jiffies(40);
767 768 769 770 771 772 773
	q->flow_max_rate	= ~0U;
	q->rate_enable		= 1;
	q->new_flows.first	= NULL;
	q->old_flows.first	= NULL;
	q->delayed		= RB_ROOT;
	q->fq_root		= NULL;
	q->fq_trees_log		= ilog2(1024);
774
	q->orphan_mask		= 1024 - 1;
775 776 777 778 779
	qdisc_watchdog_init(&q->watchdog, sch);

	if (opt)
		err = fq_change(sch, opt);
	else
780
		err = fq_resize(sch, q->fq_trees_log);
781 782 783 784 785 786 787 788 789 790 791 792 793

	return err;
}

static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	struct nlattr *opts;

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

794 795
	/* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */

796 797 798 799 800 801
	if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
	    nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
	    nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
	    nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
	    nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
	    nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
802 803
	    nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY,
			jiffies_to_usecs(q->flow_refill_delay)) ||
804
	    nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) ||
805 806 807
	    nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
		goto nla_put_failure;

808
	return nla_nest_end(skb, opts);
809 810 811 812 813 814 815 816

nla_put_failure:
	return -1;
}

static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct fq_sched_data *q = qdisc_priv(sch);
817
	u64 now = ktime_get_ns();
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	struct tc_fq_qd_stats st = {
		.gc_flows		= q->stat_gc_flows,
		.highprio_packets	= q->stat_internal_packets,
		.tcp_retrans		= q->stat_tcp_retrans,
		.throttled		= q->stat_throttled,
		.flows_plimit		= q->stat_flows_plimit,
		.pkts_too_long		= q->stat_pkts_too_long,
		.allocation_errors	= q->stat_allocation_errors,
		.flows			= q->flows,
		.inactive_flows		= q->inactive_flows,
		.throttled_flows	= q->throttled_flows,
		.time_next_delayed_flow	= q->time_next_delayed_flow - now,
	};

	return gnet_stats_copy_app(d, &st, sizeof(st));
}

static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
	.id		=	"fq",
	.priv_size	=	sizeof(struct fq_sched_data),

	.enqueue	=	fq_enqueue,
	.dequeue	=	fq_dequeue,
	.peek		=	qdisc_peek_dequeued,
	.init		=	fq_init,
	.reset		=	fq_reset,
	.destroy	=	fq_destroy,
	.change		=	fq_change,
	.dump		=	fq_dump,
	.dump_stats	=	fq_dump_stats,
	.owner		=	THIS_MODULE,
};

static int __init fq_module_init(void)
{
	int ret;

	fq_flow_cachep = kmem_cache_create("fq_flow_cache",
					   sizeof(struct fq_flow),
					   0, 0, NULL);
	if (!fq_flow_cachep)
		return -ENOMEM;

	ret = register_qdisc(&fq_qdisc_ops);
	if (ret)
		kmem_cache_destroy(fq_flow_cachep);
	return ret;
}

static void __exit fq_module_exit(void)
{
	unregister_qdisc(&fq_qdisc_ops);
	kmem_cache_destroy(fq_flow_cachep);
}

module_init(fq_module_init)
module_exit(fq_module_exit)
MODULE_AUTHOR("Eric Dumazet");
MODULE_LICENSE("GPL");
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