net/core/gen_stats.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/core/gen_stats.c
  *
  * Authors:  Thomas Graf <tgraf@suug.ch>
  *           Jamal Hadi Salim
  *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  *
  * See Documentation/networking/gen_stats.rst
  */

 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/socket.h>
 #include <linux/rtnetlink.h>
 #include <linux/gen_stats.h>
 #include <net/netlink.h>
 #include <net/gen_stats.h>


 static inline int
 gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
 {
 	if (nla_put_64bit(d->skb, type, size, buf, padattr))
 		goto nla_put_failure;
 	return 0;

 nla_put_failure:
 	if (d->lock)
 		spin_unlock_bh(d->lock);
 	kfree(d->xstats);
 	d->xstats = NULL;
 	d->xstats_len = 0;
 	return -1;
 }

 /**
  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
  * @skb: socket buffer to put statistics TLVs into
  * @type: TLV type for top level statistic TLV
  * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
  * @xstats_type: TLV type for backward compatibility xstats TLV
  * @lock: statistics lock
  * @d: dumping handle
  * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all
  * other statistic TLVS.
  *
  * The dumping handle is marked to be in backward compatibility mode telling
  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
  *
  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
 			     int xstats_type, spinlock_t *lock,
 			     struct gnet_dump *d, int padattr)
 	__acquires(lock)
 {
 	memset(d, 0, sizeof(*d));

 	if (type)
 		d->tail = (struct nlattr *)skb_tail_pointer(skb);
 	d->skb = skb;
 	d->compat_tc_stats = tc_stats_type;
 	d->compat_xstats = xstats_type;
 	d->padattr = padattr;
 	if (lock) {
 		d->lock = lock;
 		spin_lock_bh(lock);
 	}
 	if (d->tail) {
 		int ret = gnet_stats_copy(d, type, NULL, 0, padattr);

 		/* The initial attribute added in gnet_stats_copy() may be
 		 * preceded by a padding attribute, in which case d->tail will
 		 * end up pointing at the padding instead of the real attribute.
 		 * Fix this so gnet_stats_finish_copy() adjusts the length of
 		 * the right attribute.
 		 */
 		if (ret == 0 && d->tail->nla_type == padattr)
 			d->tail = (struct nlattr *)((char *)d->tail +
 						    NLA_ALIGN(d->tail->nla_len));
 		return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_start_copy_compat);

 /**
  * gnet_stats_start_copy - start dumping procedure in compatibility mode
  * @skb: socket buffer to put statistics TLVs into
  * @type: TLV type for top level statistic TLV
  * @lock: statistics lock
  * @d: dumping handle
  * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all
  * other statistic TLVS.
  *
  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 		      struct gnet_dump *d, int padattr)
 {
 	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 }
 EXPORT_SYMBOL(gnet_stats_start_copy);

 static void
 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
 			    struct gnet_stats_basic_cpu __percpu *cpu)
 {
 	int i;

 	for_each_possible_cpu(i) {
 		struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
 		unsigned int start;
 		u64 bytes, packets;

 		do {
 			start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 			bytes = bcpu->bstats.bytes;
 			packets = bcpu->bstats.packets;
 		} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));

 		bstats->bytes += bytes;
 		bstats->packets += packets;
 	}
 }

 void
 __gnet_stats_copy_basic(const seqcount_t *running,
 			struct gnet_stats_basic_packed *bstats,
 			struct gnet_stats_basic_cpu __percpu *cpu,
 			struct gnet_stats_basic_packed *b)
 {
 	unsigned int seq;

 	if (cpu) {
 		__gnet_stats_copy_basic_cpu(bstats, cpu);
 		return;
 	}
 	do {
 		if (running)
 			seq = read_seqcount_begin(running);
 		bstats->bytes = b->bytes;
 		bstats->packets = b->packets;
 	} while (running && read_seqcount_retry(running, seq));
 }
 EXPORT_SYMBOL(__gnet_stats_copy_basic);

 static int
 ___gnet_stats_copy_basic(const seqcount_t *running,
 			 struct gnet_dump *d,
 			 struct gnet_stats_basic_cpu __percpu *cpu,
 			 struct gnet_stats_basic_packed *b,
 			 int type)
 {
 	struct gnet_stats_basic_packed bstats = {0};

 	__gnet_stats_copy_basic(running, &bstats, cpu, b);

 	if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
 		d->tc_stats.bytes = bstats.bytes;
 		d->tc_stats.packets = bstats.packets;
 	}

 	if (d->tail) {
 		struct gnet_stats_basic sb;
 		int res;

 		memset(&sb, 0, sizeof(sb));
 		sb.bytes = bstats.bytes;
 		sb.packets = bstats.packets;
 		res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
 		if (res < 0 || sb.packets == bstats.packets)
 			return res;
 		/* emit 64bit stats only if needed */
 		return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
 				       sizeof(bstats.packets), TCA_STATS_PAD);
 	}
 	return 0;
 }

 /**
  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
  * @running: seqcount_t pointer
  * @d: dumping handle
  * @cpu: copy statistic per cpu
  * @b: basic statistics
  *
  * Appends the basic statistics to the top level TLV created by
  * gnet_stats_start_copy().
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_copy_basic(const seqcount_t *running,
 		      struct gnet_dump *d,
 		      struct gnet_stats_basic_cpu __percpu *cpu,
 		      struct gnet_stats_basic_packed *b)
 {
 	return ___gnet_stats_copy_basic(running, d, cpu, b,
 					TCA_STATS_BASIC);
 }
 EXPORT_SYMBOL(gnet_stats_copy_basic);

 /**
  * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
  * @running: seqcount_t pointer
  * @d: dumping handle
  * @cpu: copy statistic per cpu
  * @b: basic statistics
  *
  * Appends the basic statistics to the top level TLV created by
  * gnet_stats_start_copy().
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_copy_basic_hw(const seqcount_t *running,
 			 struct gnet_dump *d,
 			 struct gnet_stats_basic_cpu __percpu *cpu,
 			 struct gnet_stats_basic_packed *b)
 {
 	return ___gnet_stats_copy_basic(running, d, cpu, b,
 					TCA_STATS_BASIC_HW);
 }
 EXPORT_SYMBOL(gnet_stats_copy_basic_hw);

 /**
  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
  * @d: dumping handle
  * @rate_est: rate estimator
  *
  * Appends the rate estimator statistics to the top level TLV created by
  * gnet_stats_start_copy().
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_copy_rate_est(struct gnet_dump *d,
 			 struct net_rate_estimator __rcu **rate_est)
 {
 	struct gnet_stats_rate_est64 sample;
 	struct gnet_stats_rate_est est;
 	int res;

 	if (!gen_estimator_read(rate_est, &sample))
 		return 0;
 	est.bps = min_t(u64, UINT_MAX, sample.bps);
 	/* we have some time before reaching 2^32 packets per second */
 	est.pps = sample.pps;

 	if (d->compat_tc_stats) {
 		d->tc_stats.bps = est.bps;
 		d->tc_stats.pps = est.pps;
 	}

 	if (d->tail) {
 		res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 				      TCA_STATS_PAD);
 		if (res < 0 || est.bps == sample.bps)
 			return res;
 		/* emit 64bit stats only if needed */
 		return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
 				       sizeof(sample), TCA_STATS_PAD);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_copy_rate_est);

 static void
 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 			    const struct gnet_stats_queue __percpu *q)
 {
 	int i;

 	for_each_possible_cpu(i) {
 		const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);

 		qstats->qlen = 0;
 		qstats->backlog += qcpu->backlog;
 		qstats->drops += qcpu->drops;
 		qstats->requeues += qcpu->requeues;
 		qstats->overlimits += qcpu->overlimits;
 	}
 }

 void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 			     const struct gnet_stats_queue __percpu *cpu,
 			     const struct gnet_stats_queue *q,
 			     __u32 qlen)
 {
 	if (cpu) {
 		__gnet_stats_copy_queue_cpu(qstats, cpu);
 	} else {
 		qstats->qlen = q->qlen;
 		qstats->backlog = q->backlog;
 		qstats->drops = q->drops;
 		qstats->requeues = q->requeues;
 		qstats->overlimits = q->overlimits;
 	}

 	qstats->qlen = qlen;
 }
 EXPORT_SYMBOL(__gnet_stats_copy_queue);

 /**
  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
  * @d: dumping handle
  * @cpu_q: per cpu queue statistics
  * @q: queue statistics
  * @qlen: queue length statistics
  *
  * Appends the queue statistics to the top level TLV created by
  * gnet_stats_start_copy(). Using per cpu queue statistics if
  * they are available.
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_copy_queue(struct gnet_dump *d,
 		      struct gnet_stats_queue __percpu *cpu_q,
 		      struct gnet_stats_queue *q, __u32 qlen)
 {
 	struct gnet_stats_queue qstats = {0};

 	__gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);

 	if (d->compat_tc_stats) {
 		d->tc_stats.drops = qstats.drops;
 		d->tc_stats.qlen = qstats.qlen;
 		d->tc_stats.backlog = qstats.backlog;
 		d->tc_stats.overlimits = qstats.overlimits;
 	}

 	if (d->tail)
 		return gnet_stats_copy(d, TCA_STATS_QUEUE,
 				       &qstats, sizeof(qstats),
 				       TCA_STATS_PAD);

 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_copy_queue);

 /**
  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
  * @d: dumping handle
  * @st: application specific statistics data
  * @len: length of data
  *
  * Appends the application specific statistics to the top level TLV created by
  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
  * handle is in backward compatibility mode.
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 {
 	if (d->compat_xstats) {
 		d->xstats = kmemdup(st, len, GFP_ATOMIC);
 		if (!d->xstats)
 			goto err_out;
 		d->xstats_len = len;
 	}

 	if (d->tail)
 		return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 				       TCA_STATS_PAD);

 	return 0;

 err_out:
 	if (d->lock)
 		spin_unlock_bh(d->lock);
 	d->xstats_len = 0;
 	return -1;
 }
 EXPORT_SYMBOL(gnet_stats_copy_app);

 /**
  * gnet_stats_finish_copy - finish dumping procedure
  * @d: dumping handle
  *
  * Corrects the length of the top level TLV to include all TLVs added
  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
  * if gnet_stats_start_copy_compat() was used and releases the statistics
  * lock.
  *
  * Returns 0 on success or -1 with the statistic lock released
  * if the room in the socket buffer was not sufficient.
  */
 int
 gnet_stats_finish_copy(struct gnet_dump *d)
 {
 	if (d->tail)
 		d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;

 	if (d->compat_tc_stats)
 		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 				    sizeof(d->tc_stats), d->padattr) < 0)
 			return -1;

 	if (d->compat_xstats && d->xstats) {
 		if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 				    d->xstats_len, d->padattr) < 0)
 			return -1;
 	}

 	if (d->lock)
 		spin_unlock_bh(d->lock);
 	kfree(d->xstats);
 	d->xstats = NULL;
 	d->xstats_len = 0;
 	return 0;
 }
 EXPORT_SYMBOL(gnet_stats_finish_copy);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* net/core/gen_stats.c
	*
	* Authors: Thomas Graf <tgraf@suug.ch>
	* Jamal Hadi Salim
	* Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	*
	* See Documentation/networking/gen_stats.rst
	*/

	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/socket.h>
	#include <linux/rtnetlink.h>
	#include <linux/gen_stats.h>
	#include <net/netlink.h>
	#include <net/gen_stats.h>


	static inline int
	gnet_stats_copy(struct gnet_dump d, int type, void buf, int size, int padattr)
	{
	if (nla_put_64bit(d->skb, type, size, buf, padattr))
	goto nla_put_failure;
	return 0;

	nla_put_failure:
	if (d->lock)
	spin_unlock_bh(d->lock);
	kfree(d->xstats);
	d->xstats = NULL;
	d->xstats_len = 0;
	return -1;
	}

	/**
	* gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
	* @skb: socket buffer to put statistics TLVs into
	* @type: TLV type for top level statistic TLV
	* @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
	* @xstats_type: TLV type for backward compatibility xstats TLV
	* @lock: statistics lock
	* @d: dumping handle
	* @padattr: padding attribute
	*
	* Initializes the dumping handle, grabs the statistic lock and appends
	* an empty TLV header to the socket buffer for use a container for all
	* other statistic TLVS.
	*
	* The dumping handle is marked to be in backward compatibility mode telling
	* all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
	*
	* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
	int xstats_type, spinlock_t *lock,
	struct gnet_dump *d, int padattr)
	__acquires(lock)
	{
	memset(d, 0, sizeof(*d));

	if (type)
	d->tail = (struct nlattr *)skb_tail_pointer(skb);
	d->skb = skb;
	d->compat_tc_stats = tc_stats_type;
	d->compat_xstats = xstats_type;
	d->padattr = padattr;
	if (lock) {
	d->lock = lock;
	spin_lock_bh(lock);
	}
	if (d->tail) {
	int ret = gnet_stats_copy(d, type, NULL, 0, padattr);

	/* The initial attribute added in gnet_stats_copy() may be
	* preceded by a padding attribute, in which case d->tail will
	* end up pointing at the padding instead of the real attribute.
	* Fix this so gnet_stats_finish_copy() adjusts the length of
	* the right attribute.
	*/
	if (ret == 0 && d->tail->nla_type == padattr)
	d->tail = (struct nlattr )((char )d->tail +
	NLA_ALIGN(d->tail->nla_len));
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL(gnet_stats_start_copy_compat);

	/**
	* gnet_stats_start_copy - start dumping procedure in compatibility mode
	* @skb: socket buffer to put statistics TLVs into
	* @type: TLV type for top level statistic TLV
	* @lock: statistics lock
	* @d: dumping handle
	* @padattr: padding attribute
	*
	* Initializes the dumping handle, grabs the statistic lock and appends
	* an empty TLV header to the socket buffer for use a container for all
	* other statistic TLVS.
	*
	* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_start_copy(struct sk_buff skb, int type, spinlock_t lock,
	struct gnet_dump *d, int padattr)
	{
	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
	}
	EXPORT_SYMBOL(gnet_stats_start_copy);

	static void
	__gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
	struct gnet_stats_basic_cpu __percpu *cpu)
	{
	int i;

	for_each_possible_cpu(i) {
	struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
	unsigned int start;
	u64 bytes, packets;

	do {
	start = u64_stats_fetch_begin_irq(&bcpu->syncp);
	bytes = bcpu->bstats.bytes;
	packets = bcpu->bstats.packets;
	} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));

	bstats->bytes += bytes;
	bstats->packets += packets;
	}
	}

	void
	__gnet_stats_copy_basic(const seqcount_t *running,
	struct gnet_stats_basic_packed *bstats,
	struct gnet_stats_basic_cpu __percpu *cpu,
	struct gnet_stats_basic_packed *b)
	{
	unsigned int seq;

	if (cpu) {
	__gnet_stats_copy_basic_cpu(bstats, cpu);
	return;
	}
	do {
	if (running)
	seq = read_seqcount_begin(running);
	bstats->bytes = b->bytes;
	bstats->packets = b->packets;
	} while (running && read_seqcount_retry(running, seq));
	}
	EXPORT_SYMBOL(__gnet_stats_copy_basic);

	static int
	___gnet_stats_copy_basic(const seqcount_t *running,
	struct gnet_dump *d,
	struct gnet_stats_basic_cpu __percpu *cpu,
	struct gnet_stats_basic_packed *b,
	int type)
	{
	struct gnet_stats_basic_packed bstats = {0};

	__gnet_stats_copy_basic(running, &bstats, cpu, b);

	if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
	d->tc_stats.bytes = bstats.bytes;
	d->tc_stats.packets = bstats.packets;
	}

	if (d->tail) {
	struct gnet_stats_basic sb;
	int res;

	memset(&sb, 0, sizeof(sb));
	sb.bytes = bstats.bytes;
	sb.packets = bstats.packets;
	res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
	if (res < 0 \|\| sb.packets == bstats.packets)
	return res;
	/* emit 64bit stats only if needed */
	return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
	sizeof(bstats.packets), TCA_STATS_PAD);
	}
	return 0;
	}

	/**
	* gnet_stats_copy_basic - copy basic statistics into statistic TLV
	* @running: seqcount_t pointer
	* @d: dumping handle
	* @cpu: copy statistic per cpu
	* @b: basic statistics
	*
	* Appends the basic statistics to the top level TLV created by
	* gnet_stats_start_copy().
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_copy_basic(const seqcount_t *running,
	struct gnet_dump *d,
	struct gnet_stats_basic_cpu __percpu *cpu,
	struct gnet_stats_basic_packed *b)
	{
	return ___gnet_stats_copy_basic(running, d, cpu, b,
	TCA_STATS_BASIC);
	}
	EXPORT_SYMBOL(gnet_stats_copy_basic);

	/**
	* gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
	* @running: seqcount_t pointer
	* @d: dumping handle
	* @cpu: copy statistic per cpu
	* @b: basic statistics
	*
	* Appends the basic statistics to the top level TLV created by
	* gnet_stats_start_copy().
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_copy_basic_hw(const seqcount_t *running,
	struct gnet_dump *d,
	struct gnet_stats_basic_cpu __percpu *cpu,
	struct gnet_stats_basic_packed *b)
	{
	return ___gnet_stats_copy_basic(running, d, cpu, b,
	TCA_STATS_BASIC_HW);
	}
	EXPORT_SYMBOL(gnet_stats_copy_basic_hw);

	/**
	* gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
	* @d: dumping handle
	* @rate_est: rate estimator
	*
	* Appends the rate estimator statistics to the top level TLV created by
	* gnet_stats_start_copy().
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_copy_rate_est(struct gnet_dump *d,
	struct net_rate_estimator __rcu **rate_est)
	{
	struct gnet_stats_rate_est64 sample;
	struct gnet_stats_rate_est est;
	int res;

	if (!gen_estimator_read(rate_est, &sample))
	return 0;
	est.bps = min_t(u64, UINT_MAX, sample.bps);
	/* we have some time before reaching 2^32 packets per second */
	est.pps = sample.pps;

	if (d->compat_tc_stats) {
	d->tc_stats.bps = est.bps;
	d->tc_stats.pps = est.pps;
	}

	if (d->tail) {
	res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
	TCA_STATS_PAD);
	if (res < 0 \|\| est.bps == sample.bps)
	return res;
	/* emit 64bit stats only if needed */
	return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
	sizeof(sample), TCA_STATS_PAD);
	}

	return 0;
	}
	EXPORT_SYMBOL(gnet_stats_copy_rate_est);

	static void
	__gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
	const struct gnet_stats_queue __percpu *q)
	{
	int i;

	for_each_possible_cpu(i) {
	const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);

	qstats->qlen = 0;
	qstats->backlog += qcpu->backlog;
	qstats->drops += qcpu->drops;
	qstats->requeues += qcpu->requeues;
	qstats->overlimits += qcpu->overlimits;
	}
	}

	void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
	const struct gnet_stats_queue __percpu *cpu,
	const struct gnet_stats_queue *q,
	__u32 qlen)
	{
	if (cpu) {
	__gnet_stats_copy_queue_cpu(qstats, cpu);
	} else {
	qstats->qlen = q->qlen;
	qstats->backlog = q->backlog;
	qstats->drops = q->drops;
	qstats->requeues = q->requeues;
	qstats->overlimits = q->overlimits;
	}

	qstats->qlen = qlen;
	}
	EXPORT_SYMBOL(__gnet_stats_copy_queue);

	/**
	* gnet_stats_copy_queue - copy queue statistics into statistics TLV
	* @d: dumping handle
	* @cpu_q: per cpu queue statistics
	* @q: queue statistics
	* @qlen: queue length statistics
	*
	* Appends the queue statistics to the top level TLV created by
	* gnet_stats_start_copy(). Using per cpu queue statistics if
	* they are available.
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_copy_queue(struct gnet_dump *d,
	struct gnet_stats_queue __percpu *cpu_q,
	struct gnet_stats_queue *q, __u32 qlen)
	{
	struct gnet_stats_queue qstats = {0};

	__gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);

	if (d->compat_tc_stats) {
	d->tc_stats.drops = qstats.drops;
	d->tc_stats.qlen = qstats.qlen;
	d->tc_stats.backlog = qstats.backlog;
	d->tc_stats.overlimits = qstats.overlimits;
	}

	if (d->tail)
	return gnet_stats_copy(d, TCA_STATS_QUEUE,
	&qstats, sizeof(qstats),
	TCA_STATS_PAD);

	return 0;
	}
	EXPORT_SYMBOL(gnet_stats_copy_queue);

	/**
	* gnet_stats_copy_app - copy application specific statistics into statistics TLV
	* @d: dumping handle
	* @st: application specific statistics data
	* @len: length of data
	*
	* Appends the application specific statistics to the top level TLV created by
	* gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
	* handle is in backward compatibility mode.
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_copy_app(struct gnet_dump d, void st, int len)
	{
	if (d->compat_xstats) {
	d->xstats = kmemdup(st, len, GFP_ATOMIC);
	if (!d->xstats)
	goto err_out;
	d->xstats_len = len;
	}

	if (d->tail)
	return gnet_stats_copy(d, TCA_STATS_APP, st, len,
	TCA_STATS_PAD);

	return 0;

	err_out:
	if (d->lock)
	spin_unlock_bh(d->lock);
	d->xstats_len = 0;
	return -1;
	}
	EXPORT_SYMBOL(gnet_stats_copy_app);

	/**
	* gnet_stats_finish_copy - finish dumping procedure
	* @d: dumping handle
	*
	* Corrects the length of the top level TLV to include all TLVs added
	* by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
	* if gnet_stats_start_copy_compat() was used and releases the statistics
	* lock.
	*
	* Returns 0 on success or -1 with the statistic lock released
	* if the room in the socket buffer was not sufficient.
	*/
	int
	gnet_stats_finish_copy(struct gnet_dump *d)
	{
	if (d->tail)
	d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;

	if (d->compat_tc_stats)
	if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
	sizeof(d->tc_stats), d->padattr) < 0)
	return -1;

	if (d->compat_xstats && d->xstats) {
	if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
	d->xstats_len, d->padattr) < 0)
	return -1;
	}

	if (d->lock)
	spin_unlock_bh(d->lock);
	kfree(d->xstats);
	d->xstats = NULL;
	d->xstats_len = 0;
	return 0;
	}
	EXPORT_SYMBOL(gnet_stats_finish_copy);