[mirror_ubuntu-jammy-kernel.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);

	if (hctx->flags & BLK_MQ_F_BLOCKING)
		cleanup_srcu_struct(hctx->srcu);
	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;
	int 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;
	int ret, i;

	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:
	while (--i >= 0)
		blk_mq_unregister_hctx(q->queue_hw_ctx[i]);

	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;
	int 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;
	int i, 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 ML	38
	39	if (hctx->flags & BLK_MQ_F_BLOCKING)
	40	cleanup_srcu_struct(hctx->srcu);
	41	blk_free_flush_queue(hctx->fq);
	42	sbitmap_free(&hctx->ctx_map);
01388df3	43	free_cpumask_var(hctx->cpumask);
6c8b232e ML	44	kfree(hctx->ctxs);
	45	kfree(hctx);
	46	}
	47
320ae51f JA	48	struct blk_mq_hw_ctx_sysfs_entry {
	49	struct attribute attr;
	50	ssize_t (show)(struct blk_mq_hw_ctx , char *);
	51	ssize_t (store)(struct blk_mq_hw_ctx , const char *, size_t);
	52	};
	53
320ae51f JA	54	static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
	55	struct attribute attr, char page)
	56	{
	57	struct blk_mq_hw_ctx_sysfs_entry *entry;
	58	struct blk_mq_hw_ctx *hctx;
	59	struct request_queue *q;
	60	ssize_t res;
	61
	62	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	63	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	64	q = hctx->queue;
	65
	66	if (!entry->show)
	67	return -EIO;
	68
320ae51f	69	mutex_lock(&q->sysfs_lock);
bae85c15	70	res = entry->show(hctx, page);
320ae51f JA	71	mutex_unlock(&q->sysfs_lock);
	72	return res;
	73	}
	74
	75	static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
	76	struct attribute attr, const char page,
	77	size_t length)
	78	{
	79	struct blk_mq_hw_ctx_sysfs_entry *entry;
	80	struct blk_mq_hw_ctx *hctx;
	81	struct request_queue *q;
	82	ssize_t res;
	83
	84	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	85	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	86	q = hctx->queue;
	87
	88	if (!entry->store)
	89	return -EIO;
	90
320ae51f	91	mutex_lock(&q->sysfs_lock);
bae85c15	92	res = entry->store(hctx, page, length);
320ae51f JA	93	mutex_unlock(&q->sysfs_lock);
	94	return res;
	95	}
	96
d96b37c0 OS	97	static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
d96b37c0 OS	98	char *page)
bd166ef1	99	{
d96b37c0	100	return sprintf(page, "%u\n", hctx->tags->nr_tags);
bd166ef1 JA	101	}
bd166ef1 JA	102
d96b37c0 OS	103	static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
d96b37c0 OS	104	char *page)
320ae51f	105	{
d96b37c0	106	return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
320ae51f JA	107	}
320ae51f JA	108
676141e4 JA	109	static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx hctx, char page)
676141e4 JA	110	{
8962842c	111	const size_t size = PAGE_SIZE - 1;
cb2da43e	112	unsigned int i, first = 1;
8962842c	113	int ret = 0, pos = 0;
676141e4	114
cb2da43e	115	for_each_cpu(i, hctx->cpumask) {
676141e4	116	if (first)
8962842c	117	ret = snprintf(pos + page, size - pos, "%u", i);
676141e4	118	else
8962842c ML	119	ret = snprintf(pos + page, size - pos, ", %u", i);
	120
	121	if (ret >= size - pos)
	122	break;
676141e4 JA	123
676141e4 JA	124	first = 0;
8962842c	125	pos += ret;
676141e4 JA	126	}
676141e4 JA	127
d2c9be89	128	ret = snprintf(pos + page, size + 1 - pos, "\n");
8962842c	129	return pos + ret;
676141e4 JA	130	}
676141e4 JA	131
d96b37c0	132	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
5657a819	133	.attr = {.name = "nr_tags", .mode = 0444 },
d96b37c0 OS	134	.show = blk_mq_hw_sysfs_nr_tags_show,
	135	};
	136	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
5657a819	137	.attr = {.name = "nr_reserved_tags", .mode = 0444 },
d96b37c0 OS	138	.show = blk_mq_hw_sysfs_nr_reserved_tags_show,
d96b37c0 OS	139	};
676141e4	140	static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
5657a819	141	.attr = {.name = "cpu_list", .mode = 0444 },
676141e4 JA	142	.show = blk_mq_hw_sysfs_cpus_show,
676141e4 JA	143	};
320ae51f JA	144
320ae51f JA	145	static struct attribute *default_hw_ctx_attrs[] = {
d96b37c0 OS	146	&blk_mq_hw_sysfs_nr_tags.attr,
d96b37c0 OS	147	&blk_mq_hw_sysfs_nr_reserved_tags.attr,
676141e4	148	&blk_mq_hw_sysfs_cpus.attr,
320ae51f JA	149	NULL,
320ae51f JA	150	};
800f5aa1	151	ATTRIBUTE_GROUPS(default_hw_ctx);
320ae51f	152
320ae51f JA	153	static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
	154	.show = blk_mq_hw_sysfs_show,
	155	.store = blk_mq_hw_sysfs_store,
	156	};
	157
	158	static struct kobj_type blk_mq_ktype = {
320ae51f JA	159	.release = blk_mq_sysfs_release,
	160	};
	161
	162	static struct kobj_type blk_mq_ctx_ktype = {
1db4909e	163	.release = blk_mq_ctx_sysfs_release,
320ae51f JA	164	};
	165
	166	static struct kobj_type blk_mq_hw_ktype = {
	167	.sysfs_ops = &blk_mq_hw_sysfs_ops,
800f5aa1	168	.default_groups = default_hw_ctx_groups,
6c8b232e	169	.release = blk_mq_hw_sysfs_release,
320ae51f JA	170	};
320ae51f JA	171
ee3c5db0	172	static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
67aec14c JA	173	{
	174	struct blk_mq_ctx *ctx;
	175	int i;
	176
4593fdbe	177	if (!hctx->nr_ctx)
67aec14c JA	178	return;
	179
	180	hctx_for_each_ctx(hctx, ctx, i)
	181	kobject_del(&ctx->kobj);
	182
	183	kobject_del(&hctx->kobj);
	184	}
	185
ee3c5db0	186	static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
67aec14c JA	187	{
	188	struct request_queue *q = hctx->queue;
	189	struct blk_mq_ctx *ctx;
	190	int i, ret;
	191
4593fdbe	192	if (!hctx->nr_ctx)
67aec14c JA	193	return 0;
67aec14c JA	194
1db4909e	195	ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
67aec14c JA	196	if (ret)
	197	return ret;
	198
	199	hctx_for_each_ctx(hctx, ctx, i) {
	200	ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
	201	if (ret)
	202	break;
	203	}
	204
	205	return ret;
	206	}
	207
667257e8	208	void blk_mq_unregister_dev(struct device dev, struct request_queue q)
320ae51f	209	{
85157366	210	struct blk_mq_hw_ctx *hctx;
7ea5fe31	211	int i;
85157366	212
cecf5d87	213	lockdep_assert_held(&q->sysfs_dir_lock);
2d0364c8	214
6c8b232e	215	queue_for_each_hw_ctx(q, hctx, i)
67aec14c JA	216	blk_mq_unregister_hctx(hctx);
67aec14c JA	217
1db4909e ML	218	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
1db4909e ML	219	kobject_del(q->mq_kobj);
b21d5b30	220	kobject_put(&dev->kobj);
4593fdbe AM	221
4593fdbe AM	222	q->mq_sysfs_init_done = false;
c0f3fd2b JA	223	}
c0f3fd2b JA	224
868f2f0b KB	225	void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
	226	{
	227	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
	228	}
	229
7ea5fe31 ML	230	void blk_mq_sysfs_deinit(struct request_queue *q)
	231	{
	232	struct blk_mq_ctx *ctx;
	233	int cpu;
	234
	235	for_each_possible_cpu(cpu) {
	236	ctx = per_cpu_ptr(q->queue_ctx, cpu);
	237	kobject_put(&ctx->kobj);
	238	}
1db4909e	239	kobject_put(q->mq_kobj);
7ea5fe31 ML	240	}
7ea5fe31 ML	241
737f98cf	242	void blk_mq_sysfs_init(struct request_queue *q)
67aec14c	243	{
67aec14c	244	struct blk_mq_ctx *ctx;
897bb0c7	245	int cpu;
67aec14c	246
1db4909e	247	kobject_init(q->mq_kobj, &blk_mq_ktype);
67aec14c	248
897bb0c7 TG	249	for_each_possible_cpu(cpu) {
897bb0c7 TG	250	ctx = per_cpu_ptr(q->queue_ctx, cpu);
1db4909e ML	251
1db4909e ML	252	kobject_get(q->mq_kobj);
06a41a99	253	kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
897bb0c7	254	}
67aec14c JA	255	}
67aec14c JA	256
2d0364c8	257	int __blk_mq_register_dev(struct device dev, struct request_queue q)
320ae51f	258	{
320ae51f	259	struct blk_mq_hw_ctx *hctx;
67aec14c	260	int ret, i;
320ae51f	261
2d0364c8	262	WARN_ON_ONCE(!q->kobj.parent);
cecf5d87	263	lockdep_assert_held(&q->sysfs_dir_lock);
4593fdbe	264
1db4909e	265	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
320ae51f	266	if (ret < 0)
4593fdbe	267	goto out;
320ae51f	268
1db4909e	269	kobject_uevent(q->mq_kobj, KOBJ_ADD);
320ae51f JA	270
320ae51f JA	271	queue_for_each_hw_ctx(q, hctx, i) {
67aec14c	272	ret = blk_mq_register_hctx(hctx);
320ae51f	273	if (ret)
f05d1ba7	274	goto unreg;
320ae51f JA	275	}
320ae51f JA	276
f05d1ba7	277	q->mq_sysfs_init_done = true;
2d0364c8	278
4593fdbe	279	out:
2d0364c8	280	return ret;
f05d1ba7 BVA	281
	282	unreg:
	283	while (--i >= 0)
	284	blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
	285
1db4909e ML	286	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
1db4909e ML	287	kobject_del(q->mq_kobj);
f05d1ba7 BVA	288	kobject_put(&dev->kobj);
f05d1ba7 BVA	289	return ret;
2d0364c8 BVA	290	}
2d0364c8 BVA	291
67aec14c JA	292	void blk_mq_sysfs_unregister(struct request_queue *q)
	293	{
	294	struct blk_mq_hw_ctx *hctx;
	295	int i;
	296
cecf5d87	297	mutex_lock(&q->sysfs_dir_lock);
4593fdbe	298	if (!q->mq_sysfs_init_done)
2d0364c8	299	goto unlock;
4593fdbe	300
67aec14c JA	301	queue_for_each_hw_ctx(q, hctx, i)
67aec14c JA	302	blk_mq_unregister_hctx(hctx);
2d0364c8 BVA	303
2d0364c8 BVA	304	unlock:
cecf5d87	305	mutex_unlock(&q->sysfs_dir_lock);
67aec14c JA	306	}
	307
	308	int blk_mq_sysfs_register(struct request_queue *q)
	309	{
	310	struct blk_mq_hw_ctx *hctx;
	311	int i, ret = 0;
	312
cecf5d87	313	mutex_lock(&q->sysfs_dir_lock);
4593fdbe	314	if (!q->mq_sysfs_init_done)
2d0364c8	315	goto unlock;
4593fdbe	316
67aec14c JA	317	queue_for_each_hw_ctx(q, hctx, i) {
	318	ret = blk_mq_register_hctx(hctx);
	319	if (ret)
	320	break;
	321	}
	322
2d0364c8	323	unlock:
cecf5d87	324	mutex_unlock(&q->sysfs_dir_lock);
2d0364c8	325
67aec14c JA	326	return ret;
67aec14c JA	327	}