1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2017 Facebook
  4 */
  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		else
 68			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] = #name
 82static 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_NAME
 98
 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't
118	 * 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] = #name
156static 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_NAME
163
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] = #name
176static const char *const alloc_policy_name[] = {
177	BLK_TAG_ALLOC_NAME(FIFO),
178	BLK_TAG_ALLOC_NAME(RR),
179};
180#undef BLK_TAG_ALLOC_NAME
181
182#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
183static 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_NAME
193
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	else
208		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] = #name
218static 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_NAME
242
243#define RQF_NAME(name) [__RQF_##name] = #name
244static 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_NAME
263
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	else
291		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 to
353 * 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' is
554	 * 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_dir
647	 * didn't exist yet (because we don't know what to name the directory
648	 * 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 be
737	 * 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 debugfs
809	 * 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}