[linux-2.6-block.git] / net / core / gen_stats.c

/*
 * net/core/gen_stats.c
 *
 *             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:  Thomas Graf <tgraf@suug.ch>
 *           Jamal Hadi Salim
 *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * See Documentation/networking/gen_stats.txt
 */

#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)
{
	if (nla_put(d->skb, type, size, buf))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	kfree(d->xstats);
	d->xstats = NULL;
	d->xstats_len = 0;
	spin_unlock_bh(d->lock);
	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
 *
 * 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)
	__acquires(lock)
{
	memset(d, 0, sizeof(*d));

	spin_lock_bh(lock);
	d->lock = lock;
	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;

	if (d->tail)
		return gnet_stats_copy(d, type, NULL, 0);

	return 0;
}
EXPORT_SYMBOL(gnet_stats_start_copy_compat);

/**
 * 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
 * @lock: statistics lock
 * @d: dumping handle
 *
 * 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)
{
	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
}
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;
		u32 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(struct gnet_stats_basic_packed *bstats,
			struct gnet_stats_basic_cpu __percpu *cpu,
			struct gnet_stats_basic_packed *b)
{
	if (cpu) {
		__gnet_stats_copy_basic_cpu(bstats, cpu);
	} else {
		bstats->bytes = b->bytes;
		bstats->packets = b->packets;
	}
}
EXPORT_SYMBOL(__gnet_stats_copy_basic);

/**
 * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 * @d: dumping handle
 * @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(struct gnet_dump *d,
		      struct gnet_stats_basic_cpu __percpu *cpu,
		      struct gnet_stats_basic_packed *b)
{
	struct gnet_stats_basic_packed bstats = {0};

	__gnet_stats_copy_basic(&bstats, cpu, b);

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

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

		memset(&sb, 0, sizeof(sb));
		sb.bytes = bstats.bytes;
		sb.packets = bstats.packets;
		return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
	}
	return 0;
}
EXPORT_SYMBOL(gnet_stats_copy_basic);

/**
 * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 * @d: dumping handle
 * @b: basic statistics
 * @r: rate estimator statistics
 *
 * 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,
			 const struct gnet_stats_basic_packed *b,
			 struct gnet_stats_rate_est64 *r)
{
	struct gnet_stats_rate_est est;
	int res;

	if (b && !gen_estimator_active(b, r))
		return 0;

	est.bps = min_t(u64, UINT_MAX, r->bps);
	/* we have some time before reaching 2^32 packets per second */
	est.pps = r->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));
		if (res < 0 || est.bps == r->bps)
			return res;
		/* emit 64bit stats only if needed */
		return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
	}

	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;
	}
}

static 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;
}

/**
 * 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));

	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);

	return 0;

err_out:
	d->xstats_len = 0;
	spin_unlock_bh(d->lock);
	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)) < 0)
			return -1;

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

	kfree(d->xstats);
	d->xstats = NULL;
	d->xstats_len = 0;
	spin_unlock_bh(d->lock);
	return 0;
}
EXPORT_SYMBOL(gnet_stats_finish_copy);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/core/gen_stats.c
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Thomas Graf <tgraf@suug.ch>
	10	* Jamal Hadi Salim
	11	* Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	12	*
	13	* See Documentation/networking/gen_stats.txt
	14	*/
	15
	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/socket.h>
	21	#include <linux/rtnetlink.h>
	22	#include <linux/gen_stats.h>
1e90474c	23	#include <net/netlink.h>
1da177e4 LT	24	#include <net/gen_stats.h>
	25
	26
	27	static inline int
	28	gnet_stats_copy(struct gnet_dump d, int type, void buf, int size)
	29	{
14ad6647 DM	30	if (nla_put(d->skb, type, size, buf))
14ad6647 DM	31	goto nla_put_failure;
1da177e4 LT	32	return 0;
1da177e4 LT	33
1e90474c	34	nla_put_failure:
1c4cff0c IG	35	kfree(d->xstats);
	36	d->xstats = NULL;
	37	d->xstats_len = 0;
1da177e4 LT	38	spin_unlock_bh(d->lock);
	39	return -1;
	40	}
	41
	42	/**
	43	* gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
	44	* @skb: socket buffer to put statistics TLVs into
	45	* @type: TLV type for top level statistic TLV
	46	* @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
	47	* @xstats_type: TLV type for backward compatibility xstats TLV
	48	* @lock: statistics lock
	49	* @d: dumping handle
	50	*
	51	* Initializes the dumping handle, grabs the statistic lock and appends
	52	* an empty TLV header to the socket buffer for use a container for all
	53	* other statistic TLVS.
	54	*
	55	* The dumping handle is marked to be in backward compatibility mode telling
	56	* all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
	57	*
	58	* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
	59	*/
	60	int
	61	gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
	62	int xstats_type, spinlock_t lock, struct gnet_dump d)
9a429c49	63	__acquires(lock)
1da177e4 LT	64	{
1da177e4 LT	65	memset(d, 0, sizeof(*d));
4ec93edb	66
1da177e4 LT	67	spin_lock_bh(lock);
	68	d->lock = lock;
	69	if (type)
1e90474c	70	d->tail = (struct nlattr *)skb_tail_pointer(skb);
1da177e4 LT	71	d->skb = skb;
	72	d->compat_tc_stats = tc_stats_type;
	73	d->compat_xstats = xstats_type;
	74
	75	if (d->tail)
	76	return gnet_stats_copy(d, type, NULL, 0);
	77
	78	return 0;
	79	}
9e34a5b5	80	EXPORT_SYMBOL(gnet_stats_start_copy_compat);
1da177e4 LT	81
	82	/**
	83	* gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
	84	* @skb: socket buffer to put statistics TLVs into
	85	* @type: TLV type for top level statistic TLV
	86	* @lock: statistics lock
	87	* @d: dumping handle
	88	*
	89	* Initializes the dumping handle, grabs the statistic lock and appends
	90	* an empty TLV header to the socket buffer for use a container for all
	91	* other statistic TLVS.
	92	*
	93	* Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
	94	*/
	95	int
	96	gnet_stats_start_copy(struct sk_buff skb, int type, spinlock_t lock,
	97	struct gnet_dump *d)
	98	{
	99	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
	100	}
9e34a5b5	101	EXPORT_SYMBOL(gnet_stats_start_copy);
1da177e4	102
22e0f8b9 JF	103	static void
	104	__gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
	105	struct gnet_stats_basic_cpu __percpu *cpu)
	106	{
	107	int i;
	108
	109	for_each_possible_cpu(i) {
	110	struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
	111	unsigned int start;
02c0fc1b WC	112	u64 bytes;
02c0fc1b WC	113	u32 packets;
22e0f8b9 JF	114
	115	do {
	116	start = u64_stats_fetch_begin_irq(&bcpu->syncp);
	117	bytes = bcpu->bstats.bytes;
	118	packets = bcpu->bstats.packets;
	119	} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
	120
02c0fc1b WC	121	bstats->bytes += bytes;
02c0fc1b WC	122	bstats->packets += packets;
22e0f8b9 JF	123	}
	124	}
	125
	126	void
	127	__gnet_stats_copy_basic(struct gnet_stats_basic_packed *bstats,
	128	struct gnet_stats_basic_cpu __percpu *cpu,
	129	struct gnet_stats_basic_packed *b)
	130	{
	131	if (cpu) {
	132	__gnet_stats_copy_basic_cpu(bstats, cpu);
	133	} else {
	134	bstats->bytes = b->bytes;
	135	bstats->packets = b->packets;
	136	}
	137	}
	138	EXPORT_SYMBOL(__gnet_stats_copy_basic);
	139
1da177e4 LT	140	/**
	141	* gnet_stats_copy_basic - copy basic statistics into statistic TLV
	142	* @d: dumping handle
	143	* @b: basic statistics
	144	*
	145	* Appends the basic statistics to the top level TLV created by
	146	* gnet_stats_start_copy().
	147	*
	148	* Returns 0 on success or -1 with the statistic lock released
	149	* if the room in the socket buffer was not sufficient.
	150	*/
	151	int
22e0f8b9 JF	152	gnet_stats_copy_basic(struct gnet_dump *d,
	153	struct gnet_stats_basic_cpu __percpu *cpu,
	154	struct gnet_stats_basic_packed *b)
1da177e4	155	{
22e0f8b9 JF	156	struct gnet_stats_basic_packed bstats = {0};
	157
	158	__gnet_stats_copy_basic(&bstats, cpu, b);
	159
1da177e4	160	if (d->compat_tc_stats) {
22e0f8b9 JF	161	d->tc_stats.bytes = bstats.bytes;
22e0f8b9 JF	162	d->tc_stats.packets = bstats.packets;
1da177e4 LT	163	}
1da177e4 LT	164
c1a8f1f1 ED	165	if (d->tail) {
c1a8f1f1 ED	166	struct gnet_stats_basic sb;
1da177e4	167
c1a8f1f1	168	memset(&sb, 0, sizeof(sb));
22e0f8b9 JF	169	sb.bytes = bstats.bytes;
22e0f8b9 JF	170	sb.packets = bstats.packets;
c1a8f1f1 ED	171	return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
c1a8f1f1 ED	172	}
1da177e4 LT	173	return 0;
1da177e4 LT	174	}
9e34a5b5	175	EXPORT_SYMBOL(gnet_stats_copy_basic);
1da177e4 LT	176
	177	/**
	178	* gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
	179	* @d: dumping handle
d250a5f9	180	* @b: basic statistics
1da177e4 LT	181	* @r: rate estimator statistics
	182	*
	183	* Appends the rate estimator statistics to the top level TLV created by
	184	* gnet_stats_start_copy().
	185	*
	186	* Returns 0 on success or -1 with the statistic lock released
	187	* if the room in the socket buffer was not sufficient.
	188	*/
	189	int
d250a5f9 ED	190	gnet_stats_copy_rate_est(struct gnet_dump *d,
d250a5f9 ED	191	const struct gnet_stats_basic_packed *b,
45203a3b	192	struct gnet_stats_rate_est64 *r)
1da177e4	193	{
45203a3b ED	194	struct gnet_stats_rate_est est;
	195	int res;
	196
d250a5f9 ED	197	if (b && !gen_estimator_active(b, r))
	198	return 0;
	199
45203a3b ED	200	est.bps = min_t(u64, UINT_MAX, r->bps);
	201	/* we have some time before reaching 2^32 packets per second */
	202	est.pps = r->pps;
	203
1da177e4	204	if (d->compat_tc_stats) {
45203a3b ED	205	d->tc_stats.bps = est.bps;
45203a3b ED	206	d->tc_stats.pps = est.pps;
1da177e4 LT	207	}
1da177e4 LT	208
45203a3b ED	209	if (d->tail) {
	210	res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
	211	if (res < 0 \|\| est.bps == r->bps)
	212	return res;
	213	/* emit 64bit stats only if needed */
	214	return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
	215	}
1da177e4 LT	216
	217	return 0;
	218	}
9e34a5b5	219	EXPORT_SYMBOL(gnet_stats_copy_rate_est);
1da177e4	220
b0ab6f92 JF	221	static void
	222	__gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
	223	const struct gnet_stats_queue __percpu *q)
	224	{
	225	int i;
	226
	227	for_each_possible_cpu(i) {
	228	const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
	229
	230	qstats->qlen = 0;
	231	qstats->backlog += qcpu->backlog;
	232	qstats->drops += qcpu->drops;
	233	qstats->requeues += qcpu->requeues;
	234	qstats->overlimits += qcpu->overlimits;
	235	}
	236	}
	237
	238	static void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
	239	const struct gnet_stats_queue __percpu *cpu,
	240	const struct gnet_stats_queue *q,
	241	__u32 qlen)
	242	{
	243	if (cpu) {
	244	__gnet_stats_copy_queue_cpu(qstats, cpu);
	245	} else {
	246	qstats->qlen = q->qlen;
	247	qstats->backlog = q->backlog;
	248	qstats->drops = q->drops;
	249	qstats->requeues = q->requeues;
	250	qstats->overlimits = q->overlimits;
	251	}
	252
	253	qstats->qlen = qlen;
	254	}
	255
1da177e4 LT	256	/**
	257	* gnet_stats_copy_queue - copy queue statistics into statistics TLV
	258	* @d: dumping handle
b0ab6f92	259	* @cpu_q: per cpu queue statistics
1da177e4	260	* @q: queue statistics
64015853	261	* @qlen: queue length statistics
1da177e4 LT	262	*
1da177e4 LT	263	* Appends the queue statistics to the top level TLV created by
b0ab6f92 JF	264	* gnet_stats_start_copy(). Using per cpu queue statistics if
b0ab6f92 JF	265	* they are available.
1da177e4 LT	266	*
	267	* Returns 0 on success or -1 with the statistic lock released
	268	* if the room in the socket buffer was not sufficient.
	269	*/
	270	int
64015853	271	gnet_stats_copy_queue(struct gnet_dump *d,
b0ab6f92	272	struct gnet_stats_queue __percpu *cpu_q,
64015853	273	struct gnet_stats_queue *q, __u32 qlen)
1da177e4	274	{
b0ab6f92 JF	275	struct gnet_stats_queue qstats = {0};
	276
	277	__gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
64015853	278
1da177e4	279	if (d->compat_tc_stats) {
b0ab6f92 JF	280	d->tc_stats.drops = qstats.drops;
	281	d->tc_stats.qlen = qstats.qlen;
	282	d->tc_stats.backlog = qstats.backlog;
	283	d->tc_stats.overlimits = qstats.overlimits;
1da177e4 LT	284	}
	285
	286	if (d->tail)
b0ab6f92 JF	287	return gnet_stats_copy(d, TCA_STATS_QUEUE,
b0ab6f92 JF	288	&qstats, sizeof(qstats));
1da177e4 LT	289
	290	return 0;
	291	}
9e34a5b5	292	EXPORT_SYMBOL(gnet_stats_copy_queue);
1da177e4 LT	293
	294	/**
	295	* gnet_stats_copy_app - copy application specific statistics into statistics TLV
	296	* @d: dumping handle
	297	* @st: application specific statistics data
	298	* @len: length of data
	299	*
e793c0f7	300	* Appends the application specific statistics to the top level TLV created by
1da177e4 LT	301	* gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
	302	* handle is in backward compatibility mode.
	303	*
	304	* Returns 0 on success or -1 with the statistic lock released
	305	* if the room in the socket buffer was not sufficient.
	306	*/
	307	int
	308	gnet_stats_copy_app(struct gnet_dump d, void st, int len)
	309	{
	310	if (d->compat_xstats) {
1c4cff0c IG	311	d->xstats = kmemdup(st, len, GFP_ATOMIC);
	312	if (!d->xstats)
	313	goto err_out;
1da177e4 LT	314	d->xstats_len = len;
	315	}
	316
	317	if (d->tail)
	318	return gnet_stats_copy(d, TCA_STATS_APP, st, len);
	319
	320	return 0;
1c4cff0c IG	321
	322	err_out:
	323	d->xstats_len = 0;
	324	spin_unlock_bh(d->lock);
	325	return -1;
1da177e4	326	}
9e34a5b5	327	EXPORT_SYMBOL(gnet_stats_copy_app);
1da177e4 LT	328
	329	/**
	330	* gnet_stats_finish_copy - finish dumping procedure
	331	* @d: dumping handle
	332	*
	333	* Corrects the length of the top level TLV to include all TLVs added
	334	* by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
	335	* if gnet_stats_start_copy_compat() was used and releases the statistics
	336	* lock.
	337	*
	338	* Returns 0 on success or -1 with the statistic lock released
	339	* if the room in the socket buffer was not sufficient.
	340	*/
	341	int
	342	gnet_stats_finish_copy(struct gnet_dump *d)
	343	{
	344	if (d->tail)
1e90474c	345	d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
1da177e4 LT	346
	347	if (d->compat_tc_stats)
	348	if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
	349	sizeof(d->tc_stats)) < 0)
	350	return -1;
	351
	352	if (d->compat_xstats && d->xstats) {
	353	if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
	354	d->xstats_len) < 0)
	355	return -1;
	356	}
	357
1c4cff0c IG	358	kfree(d->xstats);
	359	d->xstats = NULL;
	360	d->xstats_len = 0;
1da177e4 LT	361	spin_unlock_bh(d->lock);
	362	return 0;
	363	}
1da177e4	364	EXPORT_SYMBOL(gnet_stats_finish_copy);