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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2017 Facebook4 */5 6#include <linux/kernel.h>7#include <linux/blkdev.h>8#include <linux/build_bug.h>9#include <linux/debugfs.h>10 11#include "blk.h"12#include "blk-mq.h"13#include "blk-mq-debugfs.h"14#include "blk-mq-sched.h"15#include "blk-rq-qos.h"16 17static int queue_poll_stat_show(void *data, struct seq_file *m)18{19	return 0;20}21 22static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)23	__acquires(&q->requeue_lock)24{25	struct request_queue *q = m->private;26 27	spin_lock_irq(&q->requeue_lock);28	return seq_list_start(&q->requeue_list, *pos);29}30 31static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)32{33	struct request_queue *q = m->private;34 35	return seq_list_next(v, &q->requeue_list, pos);36}37 38static void queue_requeue_list_stop(struct seq_file *m, void *v)39	__releases(&q->requeue_lock)40{41	struct request_queue *q = m->private;42 43	spin_unlock_irq(&q->requeue_lock);44}45 46static const struct seq_operations queue_requeue_list_seq_ops = {47	.start	= queue_requeue_list_start,48	.next	= queue_requeue_list_next,49	.stop	= queue_requeue_list_stop,50	.show	= blk_mq_debugfs_rq_show,51};52 53static int blk_flags_show(struct seq_file *m, const unsigned long flags,54			  const char *const *flag_name, int flag_name_count)55{56	bool sep = false;57	int i;58 59	for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {60		if (!(flags & BIT(i)))61			continue;62		if (sep)63			seq_puts(m, "|");64		sep = true;65		if (i < flag_name_count && flag_name[i])66			seq_puts(m, flag_name[i]);67		else68			seq_printf(m, "%d", i);69	}70	return 0;71}72 73static int queue_pm_only_show(void *data, struct seq_file *m)74{75	struct request_queue *q = data;76 77	seq_printf(m, "%d\n", atomic_read(&q->pm_only));78	return 0;79}80 81#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name82static const char *const blk_queue_flag_name[] = {83	QUEUE_FLAG_NAME(DYING),84	QUEUE_FLAG_NAME(NOMERGES),85	QUEUE_FLAG_NAME(SAME_COMP),86	QUEUE_FLAG_NAME(FAIL_IO),87	QUEUE_FLAG_NAME(NOXMERGES),88	QUEUE_FLAG_NAME(SAME_FORCE),89	QUEUE_FLAG_NAME(INIT_DONE),90	QUEUE_FLAG_NAME(STATS),91	QUEUE_FLAG_NAME(REGISTERED),92	QUEUE_FLAG_NAME(QUIESCED),93	QUEUE_FLAG_NAME(RQ_ALLOC_TIME),94	QUEUE_FLAG_NAME(HCTX_ACTIVE),95	QUEUE_FLAG_NAME(SQ_SCHED),96};97#undef QUEUE_FLAG_NAME98 99static int queue_state_show(void *data, struct seq_file *m)100{101	struct request_queue *q = data;102 103	BUILD_BUG_ON(ARRAY_SIZE(blk_queue_flag_name) != QUEUE_FLAG_MAX);104	blk_flags_show(m, q->queue_flags, blk_queue_flag_name,105		       ARRAY_SIZE(blk_queue_flag_name));106	seq_puts(m, "\n");107	return 0;108}109 110static ssize_t queue_state_write(void *data, const char __user *buf,111				 size_t count, loff_t *ppos)112{113	struct request_queue *q = data;114	char opbuf[16] = { }, *op;115 116	/*117	 * The "state" attribute is removed when the queue is removed.  Don't118	 * allow setting the state on a dying queue to avoid a use-after-free.119	 */120	if (blk_queue_dying(q))121		return -ENOENT;122 123	if (count >= sizeof(opbuf)) {124		pr_err("%s: operation too long\n", __func__);125		goto inval;126	}127 128	if (copy_from_user(opbuf, buf, count))129		return -EFAULT;130	op = strstrip(opbuf);131	if (strcmp(op, "run") == 0) {132		blk_mq_run_hw_queues(q, true);133	} else if (strcmp(op, "start") == 0) {134		blk_mq_start_stopped_hw_queues(q, true);135	} else if (strcmp(op, "kick") == 0) {136		blk_mq_kick_requeue_list(q);137	} else {138		pr_err("%s: unsupported operation '%s'\n", __func__, op);139inval:140		pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);141		return -EINVAL;142	}143	return count;144}145 146static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {147	{ "poll_stat", 0400, queue_poll_stat_show },148	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },149	{ "pm_only", 0600, queue_pm_only_show, NULL },150	{ "state", 0600, queue_state_show, queue_state_write },151	{ "zone_wplugs", 0400, queue_zone_wplugs_show, NULL },152	{ },153};154 155#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name156static const char *const hctx_state_name[] = {157	HCTX_STATE_NAME(STOPPED),158	HCTX_STATE_NAME(TAG_ACTIVE),159	HCTX_STATE_NAME(SCHED_RESTART),160	HCTX_STATE_NAME(INACTIVE),161};162#undef HCTX_STATE_NAME163 164static int hctx_state_show(void *data, struct seq_file *m)165{166	struct blk_mq_hw_ctx *hctx = data;167 168	BUILD_BUG_ON(ARRAY_SIZE(hctx_state_name) != BLK_MQ_S_MAX);169	blk_flags_show(m, hctx->state, hctx_state_name,170		       ARRAY_SIZE(hctx_state_name));171	seq_puts(m, "\n");172	return 0;173}174 175#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name176static const char *const alloc_policy_name[] = {177	BLK_TAG_ALLOC_NAME(FIFO),178	BLK_TAG_ALLOC_NAME(RR),179};180#undef BLK_TAG_ALLOC_NAME181 182#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name183static const char *const hctx_flag_name[] = {184	HCTX_FLAG_NAME(SHOULD_MERGE),185	HCTX_FLAG_NAME(TAG_QUEUE_SHARED),186	HCTX_FLAG_NAME(STACKING),187	HCTX_FLAG_NAME(TAG_HCTX_SHARED),188	HCTX_FLAG_NAME(BLOCKING),189	HCTX_FLAG_NAME(NO_SCHED),190	HCTX_FLAG_NAME(NO_SCHED_BY_DEFAULT),191};192#undef HCTX_FLAG_NAME193 194static int hctx_flags_show(void *data, struct seq_file *m)195{196	struct blk_mq_hw_ctx *hctx = data;197	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);198 199	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) !=200			BLK_MQ_F_ALLOC_POLICY_START_BIT);201	BUILD_BUG_ON(ARRAY_SIZE(alloc_policy_name) != BLK_TAG_ALLOC_MAX);202 203	seq_puts(m, "alloc_policy=");204	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&205	    alloc_policy_name[alloc_policy])206		seq_puts(m, alloc_policy_name[alloc_policy]);207	else208		seq_printf(m, "%d", alloc_policy);209	seq_puts(m, " ");210	blk_flags_show(m,211		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),212		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));213	seq_puts(m, "\n");214	return 0;215}216 217#define CMD_FLAG_NAME(name) [__REQ_##name] = #name218static const char *const cmd_flag_name[] = {219	CMD_FLAG_NAME(FAILFAST_DEV),220	CMD_FLAG_NAME(FAILFAST_TRANSPORT),221	CMD_FLAG_NAME(FAILFAST_DRIVER),222	CMD_FLAG_NAME(SYNC),223	CMD_FLAG_NAME(META),224	CMD_FLAG_NAME(PRIO),225	CMD_FLAG_NAME(NOMERGE),226	CMD_FLAG_NAME(IDLE),227	CMD_FLAG_NAME(INTEGRITY),228	CMD_FLAG_NAME(FUA),229	CMD_FLAG_NAME(PREFLUSH),230	CMD_FLAG_NAME(RAHEAD),231	CMD_FLAG_NAME(BACKGROUND),232	CMD_FLAG_NAME(NOWAIT),233	CMD_FLAG_NAME(POLLED),234	CMD_FLAG_NAME(ALLOC_CACHE),235	CMD_FLAG_NAME(SWAP),236	CMD_FLAG_NAME(DRV),237	CMD_FLAG_NAME(FS_PRIVATE),238	CMD_FLAG_NAME(ATOMIC),239	CMD_FLAG_NAME(NOUNMAP),240};241#undef CMD_FLAG_NAME242 243#define RQF_NAME(name) [__RQF_##name] = #name244static const char *const rqf_name[] = {245	RQF_NAME(STARTED),246	RQF_NAME(FLUSH_SEQ),247	RQF_NAME(MIXED_MERGE),248	RQF_NAME(DONTPREP),249	RQF_NAME(SCHED_TAGS),250	RQF_NAME(USE_SCHED),251	RQF_NAME(FAILED),252	RQF_NAME(QUIET),253	RQF_NAME(IO_STAT),254	RQF_NAME(PM),255	RQF_NAME(HASHED),256	RQF_NAME(STATS),257	RQF_NAME(SPECIAL_PAYLOAD),258	RQF_NAME(ZONE_WRITE_PLUGGING),259	RQF_NAME(TIMED_OUT),260	RQF_NAME(RESV),261};262#undef RQF_NAME263 264static const char *const blk_mq_rq_state_name_array[] = {265	[MQ_RQ_IDLE]		= "idle",266	[MQ_RQ_IN_FLIGHT]	= "in_flight",267	[MQ_RQ_COMPLETE]	= "complete",268};269 270static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)271{272	if (WARN_ON_ONCE((unsigned int)rq_state >=273			 ARRAY_SIZE(blk_mq_rq_state_name_array)))274		return "(?)";275	return blk_mq_rq_state_name_array[rq_state];276}277 278int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)279{280	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;281	const enum req_op op = req_op(rq);282	const char *op_str = blk_op_str(op);283 284	BUILD_BUG_ON(ARRAY_SIZE(cmd_flag_name) != __REQ_NR_BITS);285	BUILD_BUG_ON(ARRAY_SIZE(rqf_name) != __RQF_BITS);286 287	seq_printf(m, "%p {.op=", rq);288	if (strcmp(op_str, "UNKNOWN") == 0)289		seq_printf(m, "%u", op);290	else291		seq_printf(m, "%s", op_str);292	seq_puts(m, ", .cmd_flags=");293	blk_flags_show(m, (__force unsigned int)(rq->cmd_flags & ~REQ_OP_MASK),294		       cmd_flag_name, ARRAY_SIZE(cmd_flag_name));295	seq_puts(m, ", .rq_flags=");296	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,297		       ARRAY_SIZE(rqf_name));298	seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));299	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,300		   rq->internal_tag);301	if (mq_ops->show_rq)302		mq_ops->show_rq(m, rq);303	seq_puts(m, "}\n");304	return 0;305}306EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);307 308int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)309{310	return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));311}312EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);313 314static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)315	__acquires(&hctx->lock)316{317	struct blk_mq_hw_ctx *hctx = m->private;318 319	spin_lock(&hctx->lock);320	return seq_list_start(&hctx->dispatch, *pos);321}322 323static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)324{325	struct blk_mq_hw_ctx *hctx = m->private;326 327	return seq_list_next(v, &hctx->dispatch, pos);328}329 330static void hctx_dispatch_stop(struct seq_file *m, void *v)331	__releases(&hctx->lock)332{333	struct blk_mq_hw_ctx *hctx = m->private;334 335	spin_unlock(&hctx->lock);336}337 338static const struct seq_operations hctx_dispatch_seq_ops = {339	.start	= hctx_dispatch_start,340	.next	= hctx_dispatch_next,341	.stop	= hctx_dispatch_stop,342	.show	= blk_mq_debugfs_rq_show,343};344 345struct show_busy_params {346	struct seq_file		*m;347	struct blk_mq_hw_ctx	*hctx;348};349 350/*351 * Note: the state of a request may change while this function is in progress,352 * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to353 * keep iterating requests.354 */355static bool hctx_show_busy_rq(struct request *rq, void *data)356{357	const struct show_busy_params *params = data;358 359	if (rq->mq_hctx == params->hctx)360		__blk_mq_debugfs_rq_show(params->m, rq);361 362	return true;363}364 365static int hctx_busy_show(void *data, struct seq_file *m)366{367	struct blk_mq_hw_ctx *hctx = data;368	struct show_busy_params params = { .m = m, .hctx = hctx };369 370	blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,371				&params);372 373	return 0;374}375 376static const char *const hctx_types[] = {377	[HCTX_TYPE_DEFAULT]	= "default",378	[HCTX_TYPE_READ]	= "read",379	[HCTX_TYPE_POLL]	= "poll",380};381 382static int hctx_type_show(void *data, struct seq_file *m)383{384	struct blk_mq_hw_ctx *hctx = data;385 386	BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);387	seq_printf(m, "%s\n", hctx_types[hctx->type]);388	return 0;389}390 391static int hctx_ctx_map_show(void *data, struct seq_file *m)392{393	struct blk_mq_hw_ctx *hctx = data;394 395	sbitmap_bitmap_show(&hctx->ctx_map, m);396	return 0;397}398 399static void blk_mq_debugfs_tags_show(struct seq_file *m,400				     struct blk_mq_tags *tags)401{402	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);403	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);404	seq_printf(m, "active_queues=%d\n",405		   READ_ONCE(tags->active_queues));406 407	seq_puts(m, "\nbitmap_tags:\n");408	sbitmap_queue_show(&tags->bitmap_tags, m);409 410	if (tags->nr_reserved_tags) {411		seq_puts(m, "\nbreserved_tags:\n");412		sbitmap_queue_show(&tags->breserved_tags, m);413	}414}415 416static int hctx_tags_show(void *data, struct seq_file *m)417{418	struct blk_mq_hw_ctx *hctx = data;419	struct request_queue *q = hctx->queue;420	int res;421 422	res = mutex_lock_interruptible(&q->sysfs_lock);423	if (res)424		goto out;425	if (hctx->tags)426		blk_mq_debugfs_tags_show(m, hctx->tags);427	mutex_unlock(&q->sysfs_lock);428 429out:430	return res;431}432 433static int hctx_tags_bitmap_show(void *data, struct seq_file *m)434{435	struct blk_mq_hw_ctx *hctx = data;436	struct request_queue *q = hctx->queue;437	int res;438 439	res = mutex_lock_interruptible(&q->sysfs_lock);440	if (res)441		goto out;442	if (hctx->tags)443		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);444	mutex_unlock(&q->sysfs_lock);445 446out:447	return res;448}449 450static int hctx_sched_tags_show(void *data, struct seq_file *m)451{452	struct blk_mq_hw_ctx *hctx = data;453	struct request_queue *q = hctx->queue;454	int res;455 456	res = mutex_lock_interruptible(&q->sysfs_lock);457	if (res)458		goto out;459	if (hctx->sched_tags)460		blk_mq_debugfs_tags_show(m, hctx->sched_tags);461	mutex_unlock(&q->sysfs_lock);462 463out:464	return res;465}466 467static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)468{469	struct blk_mq_hw_ctx *hctx = data;470	struct request_queue *q = hctx->queue;471	int res;472 473	res = mutex_lock_interruptible(&q->sysfs_lock);474	if (res)475		goto out;476	if (hctx->sched_tags)477		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);478	mutex_unlock(&q->sysfs_lock);479 480out:481	return res;482}483 484static int hctx_active_show(void *data, struct seq_file *m)485{486	struct blk_mq_hw_ctx *hctx = data;487 488	seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));489	return 0;490}491 492static int hctx_dispatch_busy_show(void *data, struct seq_file *m)493{494	struct blk_mq_hw_ctx *hctx = data;495 496	seq_printf(m, "%u\n", hctx->dispatch_busy);497	return 0;498}499 500#define CTX_RQ_SEQ_OPS(name, type)					\501static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \502	__acquires(&ctx->lock)						\503{									\504	struct blk_mq_ctx *ctx = m->private;				\505									\506	spin_lock(&ctx->lock);						\507	return seq_list_start(&ctx->rq_lists[type], *pos);		\508}									\509									\510static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,	\511				     loff_t *pos)			\512{									\513	struct blk_mq_ctx *ctx = m->private;				\514									\515	return seq_list_next(v, &ctx->rq_lists[type], pos);		\516}									\517									\518static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)	\519	__releases(&ctx->lock)						\520{									\521	struct blk_mq_ctx *ctx = m->private;				\522									\523	spin_unlock(&ctx->lock);					\524}									\525									\526static const struct seq_operations ctx_##name##_rq_list_seq_ops = {	\527	.start	= ctx_##name##_rq_list_start,				\528	.next	= ctx_##name##_rq_list_next,				\529	.stop	= ctx_##name##_rq_list_stop,				\530	.show	= blk_mq_debugfs_rq_show,				\531}532 533CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);534CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);535CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);536 537static int blk_mq_debugfs_show(struct seq_file *m, void *v)538{539	const struct blk_mq_debugfs_attr *attr = m->private;540	void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;541 542	return attr->show(data, m);543}544 545static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,546				    size_t count, loff_t *ppos)547{548	struct seq_file *m = file->private_data;549	const struct blk_mq_debugfs_attr *attr = m->private;550	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;551 552	/*553	 * Attributes that only implement .seq_ops are read-only and 'attr' is554	 * the same with 'data' in this case.555	 */556	if (attr == data || !attr->write)557		return -EPERM;558 559	return attr->write(data, buf, count, ppos);560}561 562static int blk_mq_debugfs_open(struct inode *inode, struct file *file)563{564	const struct blk_mq_debugfs_attr *attr = inode->i_private;565	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;566	struct seq_file *m;567	int ret;568 569	if (attr->seq_ops) {570		ret = seq_open(file, attr->seq_ops);571		if (!ret) {572			m = file->private_data;573			m->private = data;574		}575		return ret;576	}577 578	if (WARN_ON_ONCE(!attr->show))579		return -EPERM;580 581	return single_open(file, blk_mq_debugfs_show, inode->i_private);582}583 584static int blk_mq_debugfs_release(struct inode *inode, struct file *file)585{586	const struct blk_mq_debugfs_attr *attr = inode->i_private;587 588	if (attr->show)589		return single_release(inode, file);590 591	return seq_release(inode, file);592}593 594static const struct file_operations blk_mq_debugfs_fops = {595	.open		= blk_mq_debugfs_open,596	.read		= seq_read,597	.write		= blk_mq_debugfs_write,598	.llseek		= seq_lseek,599	.release	= blk_mq_debugfs_release,600};601 602static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {603	{"state", 0400, hctx_state_show},604	{"flags", 0400, hctx_flags_show},605	{"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},606	{"busy", 0400, hctx_busy_show},607	{"ctx_map", 0400, hctx_ctx_map_show},608	{"tags", 0400, hctx_tags_show},609	{"tags_bitmap", 0400, hctx_tags_bitmap_show},610	{"sched_tags", 0400, hctx_sched_tags_show},611	{"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},612	{"active", 0400, hctx_active_show},613	{"dispatch_busy", 0400, hctx_dispatch_busy_show},614	{"type", 0400, hctx_type_show},615	{},616};617 618static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {619	{"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},620	{"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},621	{"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},622	{},623};624 625static void debugfs_create_files(struct dentry *parent, void *data,626				 const struct blk_mq_debugfs_attr *attr)627{628	if (IS_ERR_OR_NULL(parent))629		return;630 631	d_inode(parent)->i_private = data;632 633	for (; attr->name; attr++)634		debugfs_create_file(attr->name, attr->mode, parent,635				    (void *)attr, &blk_mq_debugfs_fops);636}637 638void blk_mq_debugfs_register(struct request_queue *q)639{640	struct blk_mq_hw_ctx *hctx;641	unsigned long i;642 643	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);644 645	/*646	 * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir647	 * didn't exist yet (because we don't know what to name the directory648	 * until the queue is registered to a gendisk).649	 */650	if (q->elevator && !q->sched_debugfs_dir)651		blk_mq_debugfs_register_sched(q);652 653	/* Similarly, blk_mq_init_hctx() couldn't do this previously. */654	queue_for_each_hw_ctx(q, hctx, i) {655		if (!hctx->debugfs_dir)656			blk_mq_debugfs_register_hctx(q, hctx);657		if (q->elevator && !hctx->sched_debugfs_dir)658			blk_mq_debugfs_register_sched_hctx(q, hctx);659	}660 661	if (q->rq_qos) {662		struct rq_qos *rqos = q->rq_qos;663 664		while (rqos) {665			blk_mq_debugfs_register_rqos(rqos);666			rqos = rqos->next;667		}668	}669}670 671static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,672					struct blk_mq_ctx *ctx)673{674	struct dentry *ctx_dir;675	char name[20];676 677	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);678	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);679 680	debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);681}682 683void blk_mq_debugfs_register_hctx(struct request_queue *q,684				  struct blk_mq_hw_ctx *hctx)685{686	struct blk_mq_ctx *ctx;687	char name[20];688	int i;689 690	if (!q->debugfs_dir)691		return;692 693	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);694	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);695 696	debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);697 698	hctx_for_each_ctx(hctx, ctx, i)699		blk_mq_debugfs_register_ctx(hctx, ctx);700}701 702void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)703{704	if (!hctx->queue->debugfs_dir)705		return;706	debugfs_remove_recursive(hctx->debugfs_dir);707	hctx->sched_debugfs_dir = NULL;708	hctx->debugfs_dir = NULL;709}710 711void blk_mq_debugfs_register_hctxs(struct request_queue *q)712{713	struct blk_mq_hw_ctx *hctx;714	unsigned long i;715 716	queue_for_each_hw_ctx(q, hctx, i)717		blk_mq_debugfs_register_hctx(q, hctx);718}719 720void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)721{722	struct blk_mq_hw_ctx *hctx;723	unsigned long i;724 725	queue_for_each_hw_ctx(q, hctx, i)726		blk_mq_debugfs_unregister_hctx(hctx);727}728 729void blk_mq_debugfs_register_sched(struct request_queue *q)730{731	struct elevator_type *e = q->elevator->type;732 733	lockdep_assert_held(&q->debugfs_mutex);734 735	/*736	 * If the parent directory has not been created yet, return, we will be737	 * called again later on and the directory/files will be created then.738	 */739	if (!q->debugfs_dir)740		return;741 742	if (!e->queue_debugfs_attrs)743		return;744 745	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);746 747	debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);748}749 750void blk_mq_debugfs_unregister_sched(struct request_queue *q)751{752	lockdep_assert_held(&q->debugfs_mutex);753 754	debugfs_remove_recursive(q->sched_debugfs_dir);755	q->sched_debugfs_dir = NULL;756}757 758static const char *rq_qos_id_to_name(enum rq_qos_id id)759{760	switch (id) {761	case RQ_QOS_WBT:762		return "wbt";763	case RQ_QOS_LATENCY:764		return "latency";765	case RQ_QOS_COST:766		return "cost";767	}768	return "unknown";769}770 771void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)772{773	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);774 775	if (!rqos->disk->queue->debugfs_dir)776		return;777	debugfs_remove_recursive(rqos->debugfs_dir);778	rqos->debugfs_dir = NULL;779}780 781void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)782{783	struct request_queue *q = rqos->disk->queue;784	const char *dir_name = rq_qos_id_to_name(rqos->id);785 786	lockdep_assert_held(&q->debugfs_mutex);787 788	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)789		return;790 791	if (!q->rqos_debugfs_dir)792		q->rqos_debugfs_dir = debugfs_create_dir("rqos",793							 q->debugfs_dir);794 795	rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);796	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);797}798 799void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,800					struct blk_mq_hw_ctx *hctx)801{802	struct elevator_type *e = q->elevator->type;803 804	lockdep_assert_held(&q->debugfs_mutex);805 806	/*807	 * If the parent debugfs directory has not been created yet, return;808	 * We will be called again later on with appropriate parent debugfs809	 * directory from blk_register_queue()810	 */811	if (!hctx->debugfs_dir)812		return;813 814	if (!e->hctx_debugfs_attrs)815		return;816 817	hctx->sched_debugfs_dir = debugfs_create_dir("sched",818						     hctx->debugfs_dir);819	debugfs_create_files(hctx->sched_debugfs_dir, hctx,820			     e->hctx_debugfs_attrs);821}822 823void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)824{825	lockdep_assert_held(&hctx->queue->debugfs_mutex);826 827	if (!hctx->queue->debugfs_dir)828		return;829	debugfs_remove_recursive(hctx->sched_debugfs_dir);830	hctx->sched_debugfs_dir = NULL;831}832