[linux-2.6-block.git] / block / blk-mq-sysfs.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/smp.h>

#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"

static void blk_mq_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);

	free_percpu(ctxs->queue_ctx);
	kfree(ctxs);
}

static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);

	/* ctx->ctxs won't be released until all ctx are freed */
	kobject_put(&ctx->ctxs->kobj);
}

static void blk_mq_hw_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
						  kobj);

	blk_free_flush_queue(hctx->fq);
	sbitmap_free(&hctx->ctx_map);
	free_cpumask_var(hctx->cpumask);
	kfree(hctx->ctxs);
	kfree(hctx);
}

struct blk_mq_hw_ctx_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
	ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
};

static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
				    struct attribute *attr, char *page)
{
	struct blk_mq_hw_ctx_sysfs_entry *entry;
	struct blk_mq_hw_ctx *hctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	q = hctx->queue;

	if (!entry->show)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->show(hctx, page);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
				     struct attribute *attr, const char *page,
				     size_t length)
{
	struct blk_mq_hw_ctx_sysfs_entry *entry;
	struct blk_mq_hw_ctx *hctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	q = hctx->queue;

	if (!entry->store)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->store(hctx, page, length);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
					    char *page)
{
	return sprintf(page, "%u\n", hctx->tags->nr_tags);
}

static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
						     char *page)
{
	return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
}

static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
{
	const size_t size = PAGE_SIZE - 1;
	unsigned int i, first = 1;
	int ret = 0, pos = 0;

	for_each_cpu(i, hctx->cpumask) {
		if (first)
			ret = snprintf(pos + page, size - pos, "%u", i);
		else
			ret = snprintf(pos + page, size - pos, ", %u", i);

		if (ret >= size - pos)
			break;

		first = 0;
		pos += ret;
	}

	ret = snprintf(pos + page, size + 1 - pos, "\n");
	return pos + ret;
}

static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
	.attr = {.name = "nr_tags", .mode = 0444 },
	.show = blk_mq_hw_sysfs_nr_tags_show,
};
static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
	.attr = {.name = "nr_reserved_tags", .mode = 0444 },
	.show = blk_mq_hw_sysfs_nr_reserved_tags_show,
};
static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
	.attr = {.name = "cpu_list", .mode = 0444 },
	.show = blk_mq_hw_sysfs_cpus_show,
};

static struct attribute *default_hw_ctx_attrs[] = {
	&blk_mq_hw_sysfs_nr_tags.attr,
	&blk_mq_hw_sysfs_nr_reserved_tags.attr,
	&blk_mq_hw_sysfs_cpus.attr,
	NULL,
};
ATTRIBUTE_GROUPS(default_hw_ctx);

static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
	.show	= blk_mq_hw_sysfs_show,
	.store	= blk_mq_hw_sysfs_store,
};

static struct kobj_type blk_mq_ktype = {
	.release	= blk_mq_sysfs_release,
};

static struct kobj_type blk_mq_ctx_ktype = {
	.release	= blk_mq_ctx_sysfs_release,
};

static struct kobj_type blk_mq_hw_ktype = {
	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
	.default_groups = default_hw_ctx_groups,
	.release	= blk_mq_hw_sysfs_release,
};

static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
	struct blk_mq_ctx *ctx;
	int i;

	if (!hctx->nr_ctx)
		return;

	hctx_for_each_ctx(hctx, ctx, i)
		kobject_del(&ctx->kobj);

	kobject_del(&hctx->kobj);
}

static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
{
	struct request_queue *q = hctx->queue;
	struct blk_mq_ctx *ctx;
	int i, ret;

	if (!hctx->nr_ctx)
		return 0;

	ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
	if (ret)
		return ret;

	hctx_for_each_ctx(hctx, ctx, i) {
		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
		if (ret)
			break;
	}

	return ret;
}

void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned long i;

	lockdep_assert_held(&q->sysfs_dir_lock);

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_unregister_hctx(hctx);

	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
	kobject_del(q->mq_kobj);
	kobject_put(&dev->kobj);

	q->mq_sysfs_init_done = false;
}

void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
{
	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
}

void blk_mq_sysfs_deinit(struct request_queue *q)
{
	struct blk_mq_ctx *ctx;
	int cpu;

	for_each_possible_cpu(cpu) {
		ctx = per_cpu_ptr(q->queue_ctx, cpu);
		kobject_put(&ctx->kobj);
	}
	kobject_put(q->mq_kobj);
}

void blk_mq_sysfs_init(struct request_queue *q)
{
	struct blk_mq_ctx *ctx;
	int cpu;

	kobject_init(q->mq_kobj, &blk_mq_ktype);

	for_each_possible_cpu(cpu) {
		ctx = per_cpu_ptr(q->queue_ctx, cpu);

		kobject_get(q->mq_kobj);
		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
	}
}

int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned long i, j;
	int ret;

	WARN_ON_ONCE(!q->kobj.parent);
	lockdep_assert_held(&q->sysfs_dir_lock);

	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
	if (ret < 0)
		goto out;

	kobject_uevent(q->mq_kobj, KOBJ_ADD);

	queue_for_each_hw_ctx(q, hctx, i) {
		ret = blk_mq_register_hctx(hctx);
		if (ret)
			goto unreg;
	}

	q->mq_sysfs_init_done = true;

out:
	return ret;

unreg:
	queue_for_each_hw_ctx(q, hctx, j) {
		if (j < i)
			blk_mq_unregister_hctx(hctx);
	}

	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
	kobject_del(q->mq_kobj);
	kobject_put(&dev->kobj);
	return ret;
}

void blk_mq_sysfs_unregister(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned long i;

	mutex_lock(&q->sysfs_dir_lock);
	if (!q->mq_sysfs_init_done)
		goto unlock;

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_unregister_hctx(hctx);

unlock:
	mutex_unlock(&q->sysfs_dir_lock);
}

int blk_mq_sysfs_register(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned long i;
	int ret = 0;

	mutex_lock(&q->sysfs_dir_lock);
	if (!q->mq_sysfs_init_done)
		goto unlock;

	queue_for_each_hw_ctx(q, hctx, i) {
		ret = blk_mq_register_hctx(hctx);
		if (ret)
			break;
	}

unlock:
	mutex_unlock(&q->sysfs_dir_lock);

	return ret;
}
Commit	Line	Data
3dcf60bc	1	// SPDX-License-Identifier: GPL-2.0
320ae51f JA	2	#include <linux/kernel.h>
	3	#include <linux/module.h>
	4	#include <linux/backing-dev.h>
	5	#include <linux/bio.h>
	6	#include <linux/blkdev.h>
	7	#include <linux/mm.h>
	8	#include <linux/init.h>
	9	#include <linux/slab.h>
	10	#include <linux/workqueue.h>
	11	#include <linux/smp.h>
	12
	13	#include <linux/blk-mq.h>
c7e2d94b	14	#include "blk.h"
320ae51f JA	15	#include "blk-mq.h"
	16	#include "blk-mq-tag.h"
	17
	18	static void blk_mq_sysfs_release(struct kobject *kobj)
	19	{
1db4909e ML	20	struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
	21
	22	free_percpu(ctxs->queue_ctx);
	23	kfree(ctxs);
	24	}
	25
	26	static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
	27	{
	28	struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
	29
	30	/* ctx->ctxs won't be released until all ctx are freed */
	31	kobject_put(&ctx->ctxs->kobj);
320ae51f JA	32	}
320ae51f JA	33
6c8b232e ML	34	static void blk_mq_hw_sysfs_release(struct kobject *kobj)
	35	{
	36	struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
	37	kobj);
c7e2d94b	38
c7e2d94b ML	39	blk_free_flush_queue(hctx->fq);
c7e2d94b ML	40	sbitmap_free(&hctx->ctx_map);
01388df3	41	free_cpumask_var(hctx->cpumask);
6c8b232e ML	42	kfree(hctx->ctxs);
	43	kfree(hctx);
	44	}
	45
320ae51f JA	46	struct blk_mq_hw_ctx_sysfs_entry {
	47	struct attribute attr;
	48	ssize_t (show)(struct blk_mq_hw_ctx , char *);
	49	ssize_t (store)(struct blk_mq_hw_ctx , const char *, size_t);
	50	};
	51
320ae51f JA	52	static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
	53	struct attribute attr, char page)
	54	{
	55	struct blk_mq_hw_ctx_sysfs_entry *entry;
	56	struct blk_mq_hw_ctx *hctx;
	57	struct request_queue *q;
	58	ssize_t res;
	59
	60	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	61	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	62	q = hctx->queue;
	63
	64	if (!entry->show)
	65	return -EIO;
	66
320ae51f	67	mutex_lock(&q->sysfs_lock);
bae85c15	68	res = entry->show(hctx, page);
320ae51f JA	69	mutex_unlock(&q->sysfs_lock);
	70	return res;
	71	}
	72
	73	static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
	74	struct attribute attr, const char page,
	75	size_t length)
	76	{
	77	struct blk_mq_hw_ctx_sysfs_entry *entry;
	78	struct blk_mq_hw_ctx *hctx;
	79	struct request_queue *q;
	80	ssize_t res;
	81
	82	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	83	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	84	q = hctx->queue;
	85
	86	if (!entry->store)
	87	return -EIO;
	88
320ae51f	89	mutex_lock(&q->sysfs_lock);
bae85c15	90	res = entry->store(hctx, page, length);
320ae51f JA	91	mutex_unlock(&q->sysfs_lock);
	92	return res;
	93	}
	94
d96b37c0 OS	95	static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
d96b37c0 OS	96	char *page)
bd166ef1	97	{
d96b37c0	98	return sprintf(page, "%u\n", hctx->tags->nr_tags);
bd166ef1 JA	99	}
bd166ef1 JA	100
d96b37c0 OS	101	static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
d96b37c0 OS	102	char *page)
320ae51f	103	{
d96b37c0	104	return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
320ae51f JA	105	}
320ae51f JA	106
676141e4 JA	107	static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx hctx, char page)
676141e4 JA	108	{
8962842c	109	const size_t size = PAGE_SIZE - 1;
cb2da43e	110	unsigned int i, first = 1;
8962842c	111	int ret = 0, pos = 0;
676141e4	112
cb2da43e	113	for_each_cpu(i, hctx->cpumask) {
676141e4	114	if (first)
8962842c	115	ret = snprintf(pos + page, size - pos, "%u", i);
676141e4	116	else
8962842c ML	117	ret = snprintf(pos + page, size - pos, ", %u", i);
	118
	119	if (ret >= size - pos)
	120	break;
676141e4 JA	121
676141e4 JA	122	first = 0;
8962842c	123	pos += ret;
676141e4 JA	124	}
676141e4 JA	125
d2c9be89	126	ret = snprintf(pos + page, size + 1 - pos, "\n");
8962842c	127	return pos + ret;
676141e4 JA	128	}
676141e4 JA	129
d96b37c0	130	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
5657a819	131	.attr = {.name = "nr_tags", .mode = 0444 },
d96b37c0 OS	132	.show = blk_mq_hw_sysfs_nr_tags_show,
	133	};
	134	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
5657a819	135	.attr = {.name = "nr_reserved_tags", .mode = 0444 },
d96b37c0 OS	136	.show = blk_mq_hw_sysfs_nr_reserved_tags_show,
d96b37c0 OS	137	};
676141e4	138	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
5657a819	139	.attr = {.name = "cpu_list", .mode = 0444 },
676141e4 JA	140	.show = blk_mq_hw_sysfs_cpus_show,
676141e4 JA	141	};
320ae51f JA	142
320ae51f JA	143	static struct attribute *default_hw_ctx_attrs[] = {
d96b37c0 OS	144	&blk_mq_hw_sysfs_nr_tags.attr,
d96b37c0 OS	145	&blk_mq_hw_sysfs_nr_reserved_tags.attr,
676141e4	146	&blk_mq_hw_sysfs_cpus.attr,
320ae51f JA	147	NULL,
320ae51f JA	148	};
800f5aa1	149	ATTRIBUTE_GROUPS(default_hw_ctx);
320ae51f	150
320ae51f JA	151	static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
	152	.show = blk_mq_hw_sysfs_show,
	153	.store = blk_mq_hw_sysfs_store,
	154	};
	155
	156	static struct kobj_type blk_mq_ktype = {
320ae51f JA	157	.release = blk_mq_sysfs_release,
	158	};
	159
	160	static struct kobj_type blk_mq_ctx_ktype = {
1db4909e	161	.release = blk_mq_ctx_sysfs_release,
320ae51f JA	162	};
	163
	164	static struct kobj_type blk_mq_hw_ktype = {
	165	.sysfs_ops = &blk_mq_hw_sysfs_ops,
800f5aa1	166	.default_groups = default_hw_ctx_groups,
6c8b232e	167	.release = blk_mq_hw_sysfs_release,
320ae51f JA	168	};
320ae51f JA	169
ee3c5db0	170	static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
67aec14c JA	171	{
	172	struct blk_mq_ctx *ctx;
	173	int i;
	174
4593fdbe	175	if (!hctx->nr_ctx)
67aec14c JA	176	return;
	177
	178	hctx_for_each_ctx(hctx, ctx, i)
	179	kobject_del(&ctx->kobj);
	180
	181	kobject_del(&hctx->kobj);
	182	}
	183
ee3c5db0	184	static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
67aec14c JA	185	{
	186	struct request_queue *q = hctx->queue;
	187	struct blk_mq_ctx *ctx;
	188	int i, ret;
	189
4593fdbe	190	if (!hctx->nr_ctx)
67aec14c JA	191	return 0;
67aec14c JA	192
1db4909e	193	ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
67aec14c JA	194	if (ret)
	195	return ret;
	196
	197	hctx_for_each_ctx(hctx, ctx, i) {
	198	ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
	199	if (ret)
	200	break;
	201	}
	202
	203	return ret;
	204	}
	205
667257e8	206	void blk_mq_unregister_dev(struct device dev, struct request_queue q)
320ae51f	207	{
85157366	208	struct blk_mq_hw_ctx *hctx;
4f481208	209	unsigned long i;
85157366	210
cecf5d87	211	lockdep_assert_held(&q->sysfs_dir_lock);
2d0364c8	212
6c8b232e	213	queue_for_each_hw_ctx(q, hctx, i)
67aec14c JA	214	blk_mq_unregister_hctx(hctx);
67aec14c JA	215
1db4909e ML	216	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
1db4909e ML	217	kobject_del(q->mq_kobj);
b21d5b30	218	kobject_put(&dev->kobj);
4593fdbe AM	219
4593fdbe AM	220	q->mq_sysfs_init_done = false;
c0f3fd2b JA	221	}
c0f3fd2b JA	222
868f2f0b KB	223	void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
	224	{
	225	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
	226	}
	227
7ea5fe31 ML	228	void blk_mq_sysfs_deinit(struct request_queue *q)
	229	{
	230	struct blk_mq_ctx *ctx;
	231	int cpu;
	232
	233	for_each_possible_cpu(cpu) {
	234	ctx = per_cpu_ptr(q->queue_ctx, cpu);
	235	kobject_put(&ctx->kobj);
	236	}
1db4909e	237	kobject_put(q->mq_kobj);
7ea5fe31 ML	238	}
7ea5fe31 ML	239
737f98cf	240	void blk_mq_sysfs_init(struct request_queue *q)
67aec14c	241	{
67aec14c	242	struct blk_mq_ctx *ctx;
897bb0c7	243	int cpu;
67aec14c	244
1db4909e	245	kobject_init(q->mq_kobj, &blk_mq_ktype);
67aec14c	246
897bb0c7 TG	247	for_each_possible_cpu(cpu) {
897bb0c7 TG	248	ctx = per_cpu_ptr(q->queue_ctx, cpu);
1db4909e ML	249
1db4909e ML	250	kobject_get(q->mq_kobj);
06a41a99	251	kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
897bb0c7	252	}
67aec14c JA	253	}
67aec14c JA	254
2d0364c8	255	int __blk_mq_register_dev(struct device dev, struct request_queue q)
320ae51f	256	{
320ae51f	257	struct blk_mq_hw_ctx *hctx;
4f481208 ML	258	unsigned long i, j;
4f481208 ML	259	int ret;
320ae51f	260
2d0364c8	261	WARN_ON_ONCE(!q->kobj.parent);
cecf5d87	262	lockdep_assert_held(&q->sysfs_dir_lock);
4593fdbe	263
1db4909e	264	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
320ae51f	265	if (ret < 0)
4593fdbe	266	goto out;
320ae51f	267
1db4909e	268	kobject_uevent(q->mq_kobj, KOBJ_ADD);
320ae51f JA	269
320ae51f JA	270	queue_for_each_hw_ctx(q, hctx, i) {
67aec14c	271	ret = blk_mq_register_hctx(hctx);
320ae51f	272	if (ret)
f05d1ba7	273	goto unreg;
320ae51f JA	274	}
320ae51f JA	275
f05d1ba7	276	q->mq_sysfs_init_done = true;
2d0364c8	277
4593fdbe	278	out:
2d0364c8	279	return ret;
f05d1ba7 BVA	280
f05d1ba7 BVA	281	unreg:
4f481208 ML	282	queue_for_each_hw_ctx(q, hctx, j) {
	283	if (j < i)
	284	blk_mq_unregister_hctx(hctx);
	285	}
f05d1ba7	286
1db4909e ML	287	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
1db4909e ML	288	kobject_del(q->mq_kobj);
f05d1ba7 BVA	289	kobject_put(&dev->kobj);
f05d1ba7 BVA	290	return ret;
2d0364c8 BVA	291	}
2d0364c8 BVA	292
67aec14c JA	293	void blk_mq_sysfs_unregister(struct request_queue *q)
	294	{
	295	struct blk_mq_hw_ctx *hctx;
4f481208	296	unsigned long i;
67aec14c	297
cecf5d87	298	mutex_lock(&q->sysfs_dir_lock);
4593fdbe	299	if (!q->mq_sysfs_init_done)
2d0364c8	300	goto unlock;
4593fdbe	301
67aec14c JA	302	queue_for_each_hw_ctx(q, hctx, i)
67aec14c JA	303	blk_mq_unregister_hctx(hctx);
2d0364c8 BVA	304
2d0364c8 BVA	305	unlock:
cecf5d87	306	mutex_unlock(&q->sysfs_dir_lock);
67aec14c JA	307	}
	308
	309	int blk_mq_sysfs_register(struct request_queue *q)
	310	{
	311	struct blk_mq_hw_ctx *hctx;
4f481208 ML	312	unsigned long i;
4f481208 ML	313	int ret = 0;
67aec14c	314
cecf5d87	315	mutex_lock(&q->sysfs_dir_lock);
4593fdbe	316	if (!q->mq_sysfs_init_done)
2d0364c8	317	goto unlock;
4593fdbe	318
67aec14c JA	319	queue_for_each_hw_ctx(q, hctx, i) {
	320	ret = blk_mq_register_hctx(hctx);
	321	if (ret)
	322	break;
	323	}
	324
2d0364c8	325	unlock:
cecf5d87	326	mutex_unlock(&q->sysfs_dir_lock);
2d0364c8	327
67aec14c JA	328	return ret;
67aec14c JA	329	}