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/debugfs.h>
  9
 10#include <linux/blk-mq.h>
 11#include "blk.h"
 12#include "blk-mq.h"
 13#include "blk-mq-debugfs.h"
 14#include "blk-mq-sched.h"
 15#include "blk-mq-tag.h"
 16#include "blk-rq-qos.h"
 17
 18static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
 19{
 20	if (stat->nr_samples) {
 21		seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
 22			   stat->nr_samples, stat->mean, stat->min, stat->max);
 23	} else {
 24		seq_puts(m, "samples=0");
 25	}
 26}
 27
 28static int queue_poll_stat_show(void *data, struct seq_file *m)
 29{
 30	struct request_queue *q = data;
 31	int bucket;
 32
 33	if (!q->poll_stat)
 34		return 0;
 35
 36	for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
 37		seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
 38		print_stat(m, &q->poll_stat[2 * bucket]);
 39		seq_puts(m, "\n");
 40
 41		seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
 42		print_stat(m, &q->poll_stat[2 * bucket + 1]);
 43		seq_puts(m, "\n");
 44	}
 45	return 0;
 46}
 47
 48static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
 49	__acquires(&q->requeue_lock)
 50{
 51	struct request_queue *q = m->private;
 52
 53	spin_lock_irq(&q->requeue_lock);
 54	return seq_list_start(&q->requeue_list, *pos);
 55}
 56
 57static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
 58{
 59	struct request_queue *q = m->private;
 60
 61	return seq_list_next(v, &q->requeue_list, pos);
 62}
 63
 64static void queue_requeue_list_stop(struct seq_file *m, void *v)
 65	__releases(&q->requeue_lock)
 66{
 67	struct request_queue *q = m->private;
 68
 69	spin_unlock_irq(&q->requeue_lock);
 70}
 71
 72static const struct seq_operations queue_requeue_list_seq_ops = {
 73	.start	= queue_requeue_list_start,
 74	.next	= queue_requeue_list_next,
 75	.stop	= queue_requeue_list_stop,
 76	.show	= blk_mq_debugfs_rq_show,
 77};
 78
 79static int blk_flags_show(struct seq_file *m, const unsigned long flags,
 80			  const char *const *flag_name, int flag_name_count)
 81{
 82	bool sep = false;
 83	int i;
 84
 85	for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
 86		if (!(flags & BIT(i)))
 87			continue;
 88		if (sep)
 89			seq_puts(m, "|");
 90		sep = true;
 91		if (i < flag_name_count && flag_name[i])
 92			seq_puts(m, flag_name[i]);
 93		else
 94			seq_printf(m, "%d", i);
 95	}
 96	return 0;
 97}
 98
 99static int queue_pm_only_show(void *data, struct seq_file *m)
100{
101	struct request_queue *q = data;
102
103	seq_printf(m, "%d\n", atomic_read(&q->pm_only));
104	return 0;
105}
106
107#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
108static const char *const blk_queue_flag_name[] = {
109	QUEUE_FLAG_NAME(STOPPED),
110	QUEUE_FLAG_NAME(DYING),
111	QUEUE_FLAG_NAME(NOMERGES),
112	QUEUE_FLAG_NAME(SAME_COMP),
113	QUEUE_FLAG_NAME(FAIL_IO),
114	QUEUE_FLAG_NAME(NONROT),
115	QUEUE_FLAG_NAME(IO_STAT),
116	QUEUE_FLAG_NAME(NOXMERGES),
117	QUEUE_FLAG_NAME(ADD_RANDOM),
118	QUEUE_FLAG_NAME(SAME_FORCE),
119	QUEUE_FLAG_NAME(INIT_DONE),
120	QUEUE_FLAG_NAME(STABLE_WRITES),
121	QUEUE_FLAG_NAME(POLL),
122	QUEUE_FLAG_NAME(WC),
123	QUEUE_FLAG_NAME(FUA),
124	QUEUE_FLAG_NAME(DAX),
125	QUEUE_FLAG_NAME(STATS),
126	QUEUE_FLAG_NAME(REGISTERED),
127	QUEUE_FLAG_NAME(QUIESCED),
128	QUEUE_FLAG_NAME(PCI_P2PDMA),
129	QUEUE_FLAG_NAME(ZONE_RESETALL),
130	QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
131	QUEUE_FLAG_NAME(HCTX_ACTIVE),
132	QUEUE_FLAG_NAME(NOWAIT),
133};
134#undef QUEUE_FLAG_NAME
135
136static int queue_state_show(void *data, struct seq_file *m)
137{
138	struct request_queue *q = data;
139
140	blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
141		       ARRAY_SIZE(blk_queue_flag_name));
142	seq_puts(m, "\n");
143	return 0;
144}
145
146static ssize_t queue_state_write(void *data, const char __user *buf,
147				 size_t count, loff_t *ppos)
148{
149	struct request_queue *q = data;
150	char opbuf[16] = { }, *op;
151
152	/*
153	 * The "state" attribute is removed when the queue is removed.  Don't
154	 * allow setting the state on a dying queue to avoid a use-after-free.
155	 */
156	if (blk_queue_dying(q))
157		return -ENOENT;
158
159	if (count >= sizeof(opbuf)) {
160		pr_err("%s: operation too long\n", __func__);
161		goto inval;
162	}
163
164	if (copy_from_user(opbuf, buf, count))
165		return -EFAULT;
166	op = strstrip(opbuf);
167	if (strcmp(op, "run") == 0) {
168		blk_mq_run_hw_queues(q, true);
169	} else if (strcmp(op, "start") == 0) {
170		blk_mq_start_stopped_hw_queues(q, true);
171	} else if (strcmp(op, "kick") == 0) {
172		blk_mq_kick_requeue_list(q);
173	} else {
174		pr_err("%s: unsupported operation '%s'\n", __func__, op);
175inval:
176		pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
177		return -EINVAL;
178	}
179	return count;
180}
181
182static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
183	{ "poll_stat", 0400, queue_poll_stat_show },
184	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
185	{ "pm_only", 0600, queue_pm_only_show, NULL },
186	{ "state", 0600, queue_state_show, queue_state_write },
187	{ "zone_wlock", 0400, queue_zone_wlock_show, NULL },
188	{ },
189};
190
191#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
192static const char *const hctx_state_name[] = {
193	HCTX_STATE_NAME(STOPPED),
194	HCTX_STATE_NAME(TAG_ACTIVE),
195	HCTX_STATE_NAME(SCHED_RESTART),
196	HCTX_STATE_NAME(INACTIVE),
197};
198#undef HCTX_STATE_NAME
199
200static int hctx_state_show(void *data, struct seq_file *m)
201{
202	struct blk_mq_hw_ctx *hctx = data;
203
204	blk_flags_show(m, hctx->state, hctx_state_name,
205		       ARRAY_SIZE(hctx_state_name));
206	seq_puts(m, "\n");
207	return 0;
208}
209
210#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
211static const char *const alloc_policy_name[] = {
212	BLK_TAG_ALLOC_NAME(FIFO),
213	BLK_TAG_ALLOC_NAME(RR),
214};
215#undef BLK_TAG_ALLOC_NAME
216
217#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
218static const char *const hctx_flag_name[] = {
219	HCTX_FLAG_NAME(SHOULD_MERGE),
220	HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
221	HCTX_FLAG_NAME(BLOCKING),
222	HCTX_FLAG_NAME(NO_SCHED),
223	HCTX_FLAG_NAME(STACKING),
224	HCTX_FLAG_NAME(TAG_HCTX_SHARED),
225};
226#undef HCTX_FLAG_NAME
227
228static int hctx_flags_show(void *data, struct seq_file *m)
229{
230	struct blk_mq_hw_ctx *hctx = data;
231	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
232
233	seq_puts(m, "alloc_policy=");
234	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
235	    alloc_policy_name[alloc_policy])
236		seq_puts(m, alloc_policy_name[alloc_policy]);
237	else
238		seq_printf(m, "%d", alloc_policy);
239	seq_puts(m, " ");
240	blk_flags_show(m,
241		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
242		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
243	seq_puts(m, "\n");
244	return 0;
245}
246
247#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
248static const char *const cmd_flag_name[] = {
249	CMD_FLAG_NAME(FAILFAST_DEV),
250	CMD_FLAG_NAME(FAILFAST_TRANSPORT),
251	CMD_FLAG_NAME(FAILFAST_DRIVER),
252	CMD_FLAG_NAME(SYNC),
253	CMD_FLAG_NAME(META),
254	CMD_FLAG_NAME(PRIO),
255	CMD_FLAG_NAME(NOMERGE),
256	CMD_FLAG_NAME(IDLE),
257	CMD_FLAG_NAME(INTEGRITY),
258	CMD_FLAG_NAME(FUA),
259	CMD_FLAG_NAME(PREFLUSH),
260	CMD_FLAG_NAME(RAHEAD),
261	CMD_FLAG_NAME(BACKGROUND),
262	CMD_FLAG_NAME(NOWAIT),
263	CMD_FLAG_NAME(NOUNMAP),
264	CMD_FLAG_NAME(POLLED),
265};
266#undef CMD_FLAG_NAME
267
268#define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
269static const char *const rqf_name[] = {
270	RQF_NAME(STARTED),
271	RQF_NAME(SOFTBARRIER),
272	RQF_NAME(FLUSH_SEQ),
273	RQF_NAME(MIXED_MERGE),
274	RQF_NAME(MQ_INFLIGHT),
275	RQF_NAME(DONTPREP),
276	RQF_NAME(FAILED),
277	RQF_NAME(QUIET),
278	RQF_NAME(ELVPRIV),
279	RQF_NAME(IO_STAT),
280	RQF_NAME(PM),
281	RQF_NAME(HASHED),
282	RQF_NAME(STATS),
283	RQF_NAME(SPECIAL_PAYLOAD),
284	RQF_NAME(ZONE_WRITE_LOCKED),
285	RQF_NAME(MQ_POLL_SLEPT),
286	RQF_NAME(TIMED_OUT),
287	RQF_NAME(ELV),
288	RQF_NAME(RESV),
289};
290#undef RQF_NAME
291
292static const char *const blk_mq_rq_state_name_array[] = {
293	[MQ_RQ_IDLE]		= "idle",
294	[MQ_RQ_IN_FLIGHT]	= "in_flight",
295	[MQ_RQ_COMPLETE]	= "complete",
296};
297
298static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
299{
300	if (WARN_ON_ONCE((unsigned int)rq_state >=
301			 ARRAY_SIZE(blk_mq_rq_state_name_array)))
302		return "(?)";
303	return blk_mq_rq_state_name_array[rq_state];
304}
305
306int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
307{
308	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
309	const enum req_op op = req_op(rq);
310	const char *op_str = blk_op_str(op);
311
312	seq_printf(m, "%p {.op=", rq);
313	if (strcmp(op_str, "UNKNOWN") == 0)
314		seq_printf(m, "%u", op);
315	else
316		seq_printf(m, "%s", op_str);
317	seq_puts(m, ", .cmd_flags=");
318	blk_flags_show(m, (__force unsigned int)(rq->cmd_flags & ~REQ_OP_MASK),
319		       cmd_flag_name, ARRAY_SIZE(cmd_flag_name));
320	seq_puts(m, ", .rq_flags=");
321	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
322		       ARRAY_SIZE(rqf_name));
323	seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
324	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
325		   rq->internal_tag);
326	if (mq_ops->show_rq)
327		mq_ops->show_rq(m, rq);
328	seq_puts(m, "}\n");
329	return 0;
330}
331EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
332
333int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
334{
335	return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
336}
337EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
338
339static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
340	__acquires(&hctx->lock)
341{
342	struct blk_mq_hw_ctx *hctx = m->private;
343
344	spin_lock(&hctx->lock);
345	return seq_list_start(&hctx->dispatch, *pos);
346}
347
348static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
349{
350	struct blk_mq_hw_ctx *hctx = m->private;
351
352	return seq_list_next(v, &hctx->dispatch, pos);
353}
354
355static void hctx_dispatch_stop(struct seq_file *m, void *v)
356	__releases(&hctx->lock)
357{
358	struct blk_mq_hw_ctx *hctx = m->private;
359
360	spin_unlock(&hctx->lock);
361}
362
363static const struct seq_operations hctx_dispatch_seq_ops = {
364	.start	= hctx_dispatch_start,
365	.next	= hctx_dispatch_next,
366	.stop	= hctx_dispatch_stop,
367	.show	= blk_mq_debugfs_rq_show,
368};
369
370struct show_busy_params {
371	struct seq_file		*m;
372	struct blk_mq_hw_ctx	*hctx;
373};
374
375/*
376 * Note: the state of a request may change while this function is in progress,
377 * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
378 * keep iterating requests.
379 */
380static bool hctx_show_busy_rq(struct request *rq, void *data)
381{
382	const struct show_busy_params *params = data;
383
384	if (rq->mq_hctx == params->hctx)
385		__blk_mq_debugfs_rq_show(params->m, rq);
386
387	return true;
388}
389
390static int hctx_busy_show(void *data, struct seq_file *m)
391{
392	struct blk_mq_hw_ctx *hctx = data;
393	struct show_busy_params params = { .m = m, .hctx = hctx };
394
395	blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
396				&params);
397
398	return 0;
399}
400
401static const char *const hctx_types[] = {
402	[HCTX_TYPE_DEFAULT]	= "default",
403	[HCTX_TYPE_READ]	= "read",
404	[HCTX_TYPE_POLL]	= "poll",
405};
406
407static int hctx_type_show(void *data, struct seq_file *m)
408{
409	struct blk_mq_hw_ctx *hctx = data;
410
411	BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
412	seq_printf(m, "%s\n", hctx_types[hctx->type]);
413	return 0;
414}
415
416static int hctx_ctx_map_show(void *data, struct seq_file *m)
417{
418	struct blk_mq_hw_ctx *hctx = data;
419
420	sbitmap_bitmap_show(&hctx->ctx_map, m);
421	return 0;
422}
423
424static void blk_mq_debugfs_tags_show(struct seq_file *m,
425				     struct blk_mq_tags *tags)
426{
427	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
428	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
429	seq_printf(m, "active_queues=%d\n",
430		   atomic_read(&tags->active_queues));
431
432	seq_puts(m, "\nbitmap_tags:\n");
433	sbitmap_queue_show(&tags->bitmap_tags, m);
434
435	if (tags->nr_reserved_tags) {
436		seq_puts(m, "\nbreserved_tags:\n");
437		sbitmap_queue_show(&tags->breserved_tags, m);
438	}
439}
440
441static int hctx_tags_show(void *data, struct seq_file *m)
442{
443	struct blk_mq_hw_ctx *hctx = data;
444	struct request_queue *q = hctx->queue;
445	int res;
446
447	res = mutex_lock_interruptible(&q->sysfs_lock);
448	if (res)
449		goto out;
450	if (hctx->tags)
451		blk_mq_debugfs_tags_show(m, hctx->tags);
452	mutex_unlock(&q->sysfs_lock);
453
454out:
455	return res;
456}
457
458static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
459{
460	struct blk_mq_hw_ctx *hctx = data;
461	struct request_queue *q = hctx->queue;
462	int res;
463
464	res = mutex_lock_interruptible(&q->sysfs_lock);
465	if (res)
466		goto out;
467	if (hctx->tags)
468		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
469	mutex_unlock(&q->sysfs_lock);
470
471out:
472	return res;
473}
474
475static int hctx_sched_tags_show(void *data, struct seq_file *m)
476{
477	struct blk_mq_hw_ctx *hctx = data;
478	struct request_queue *q = hctx->queue;
479	int res;
480
481	res = mutex_lock_interruptible(&q->sysfs_lock);
482	if (res)
483		goto out;
484	if (hctx->sched_tags)
485		blk_mq_debugfs_tags_show(m, hctx->sched_tags);
486	mutex_unlock(&q->sysfs_lock);
487
488out:
489	return res;
490}
491
492static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
493{
494	struct blk_mq_hw_ctx *hctx = data;
495	struct request_queue *q = hctx->queue;
496	int res;
497
498	res = mutex_lock_interruptible(&q->sysfs_lock);
499	if (res)
500		goto out;
501	if (hctx->sched_tags)
502		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
503	mutex_unlock(&q->sysfs_lock);
504
505out:
506	return res;
507}
508
509static int hctx_run_show(void *data, struct seq_file *m)
510{
511	struct blk_mq_hw_ctx *hctx = data;
512
513	seq_printf(m, "%lu\n", hctx->run);
514	return 0;
515}
516
517static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
518			      loff_t *ppos)
519{
520	struct blk_mq_hw_ctx *hctx = data;
521
522	hctx->run = 0;
523	return count;
524}
525
526static int hctx_active_show(void *data, struct seq_file *m)
527{
528	struct blk_mq_hw_ctx *hctx = data;
529
530	seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
531	return 0;
532}
533
534static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
535{
536	struct blk_mq_hw_ctx *hctx = data;
537
538	seq_printf(m, "%u\n", hctx->dispatch_busy);
539	return 0;
540}
541
542#define CTX_RQ_SEQ_OPS(name, type)					\
543static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
544	__acquires(&ctx->lock)						\
545{									\
546	struct blk_mq_ctx *ctx = m->private;				\
547									\
548	spin_lock(&ctx->lock);						\
549	return seq_list_start(&ctx->rq_lists[type], *pos);		\
550}									\
551									\
552static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,	\
553				     loff_t *pos)			\
554{									\
555	struct blk_mq_ctx *ctx = m->private;				\
556									\
557	return seq_list_next(v, &ctx->rq_lists[type], pos);		\
558}									\
559									\
560static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)	\
561	__releases(&ctx->lock)						\
562{									\
563	struct blk_mq_ctx *ctx = m->private;				\
564									\
565	spin_unlock(&ctx->lock);					\
566}									\
567									\
568static const struct seq_operations ctx_##name##_rq_list_seq_ops = {	\
569	.start	= ctx_##name##_rq_list_start,				\
570	.next	= ctx_##name##_rq_list_next,				\
571	.stop	= ctx_##name##_rq_list_stop,				\
572	.show	= blk_mq_debugfs_rq_show,				\
573}
574
575CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
576CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
577CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
578
579static int blk_mq_debugfs_show(struct seq_file *m, void *v)
580{
581	const struct blk_mq_debugfs_attr *attr = m->private;
582	void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
583
584	return attr->show(data, m);
585}
586
587static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
588				    size_t count, loff_t *ppos)
589{
590	struct seq_file *m = file->private_data;
591	const struct blk_mq_debugfs_attr *attr = m->private;
592	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
593
594	/*
595	 * Attributes that only implement .seq_ops are read-only and 'attr' is
596	 * the same with 'data' in this case.
597	 */
598	if (attr == data || !attr->write)
599		return -EPERM;
600
601	return attr->write(data, buf, count, ppos);
602}
603
604static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
605{
606	const struct blk_mq_debugfs_attr *attr = inode->i_private;
607	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
608	struct seq_file *m;
609	int ret;
610
611	if (attr->seq_ops) {
612		ret = seq_open(file, attr->seq_ops);
613		if (!ret) {
614			m = file->private_data;
615			m->private = data;
616		}
617		return ret;
618	}
619
620	if (WARN_ON_ONCE(!attr->show))
621		return -EPERM;
622
623	return single_open(file, blk_mq_debugfs_show, inode->i_private);
624}
625
626static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
627{
628	const struct blk_mq_debugfs_attr *attr = inode->i_private;
629
630	if (attr->show)
631		return single_release(inode, file);
632
633	return seq_release(inode, file);
634}
635
636static const struct file_operations blk_mq_debugfs_fops = {
637	.open		= blk_mq_debugfs_open,
638	.read		= seq_read,
639	.write		= blk_mq_debugfs_write,
640	.llseek		= seq_lseek,
641	.release	= blk_mq_debugfs_release,
642};
643
644static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
645	{"state", 0400, hctx_state_show},
646	{"flags", 0400, hctx_flags_show},
647	{"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
648	{"busy", 0400, hctx_busy_show},
649	{"ctx_map", 0400, hctx_ctx_map_show},
650	{"tags", 0400, hctx_tags_show},
651	{"tags_bitmap", 0400, hctx_tags_bitmap_show},
652	{"sched_tags", 0400, hctx_sched_tags_show},
653	{"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
654	{"run", 0600, hctx_run_show, hctx_run_write},
655	{"active", 0400, hctx_active_show},
656	{"dispatch_busy", 0400, hctx_dispatch_busy_show},
657	{"type", 0400, hctx_type_show},
658	{},
659};
660
661static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
662	{"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
663	{"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
664	{"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
665	{},
666};
667
668static void debugfs_create_files(struct dentry *parent, void *data,
669				 const struct blk_mq_debugfs_attr *attr)
670{
671	if (IS_ERR_OR_NULL(parent))
672		return;
673
674	d_inode(parent)->i_private = data;
675
676	for (; attr->name; attr++)
677		debugfs_create_file(attr->name, attr->mode, parent,
678				    (void *)attr, &blk_mq_debugfs_fops);
679}
680
681void blk_mq_debugfs_register(struct request_queue *q)
682{
683	struct blk_mq_hw_ctx *hctx;
684	unsigned long i;
685
686	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
687
688	/*
689	 * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
690	 * didn't exist yet (because we don't know what to name the directory
691	 * until the queue is registered to a gendisk).
692	 */
693	if (q->elevator && !q->sched_debugfs_dir)
694		blk_mq_debugfs_register_sched(q);
695
696	/* Similarly, blk_mq_init_hctx() couldn't do this previously. */
697	queue_for_each_hw_ctx(q, hctx, i) {
698		if (!hctx->debugfs_dir)
699			blk_mq_debugfs_register_hctx(q, hctx);
700		if (q->elevator && !hctx->sched_debugfs_dir)
701			blk_mq_debugfs_register_sched_hctx(q, hctx);
702	}
703
704	if (q->rq_qos) {
705		struct rq_qos *rqos = q->rq_qos;
706
707		while (rqos) {
708			blk_mq_debugfs_register_rqos(rqos);
709			rqos = rqos->next;
710		}
711	}
712}
713
714static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
715					struct blk_mq_ctx *ctx)
716{
717	struct dentry *ctx_dir;
718	char name[20];
719
720	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
721	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
722
723	debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
724}
725
726void blk_mq_debugfs_register_hctx(struct request_queue *q,
727				  struct blk_mq_hw_ctx *hctx)
728{
729	struct blk_mq_ctx *ctx;
730	char name[20];
731	int i;
732
733	if (!q->debugfs_dir)
734		return;
735
736	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
737	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
738
739	debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
740
741	hctx_for_each_ctx(hctx, ctx, i)
742		blk_mq_debugfs_register_ctx(hctx, ctx);
743}
744
745void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
746{
747	if (!hctx->queue->debugfs_dir)
748		return;
749	debugfs_remove_recursive(hctx->debugfs_dir);
750	hctx->sched_debugfs_dir = NULL;
751	hctx->debugfs_dir = NULL;
752}
753
754void blk_mq_debugfs_register_hctxs(struct request_queue *q)
755{
756	struct blk_mq_hw_ctx *hctx;
757	unsigned long i;
758
759	queue_for_each_hw_ctx(q, hctx, i)
760		blk_mq_debugfs_register_hctx(q, hctx);
761}
762
763void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
764{
765	struct blk_mq_hw_ctx *hctx;
766	unsigned long i;
767
768	queue_for_each_hw_ctx(q, hctx, i)
769		blk_mq_debugfs_unregister_hctx(hctx);
770}
771
772void blk_mq_debugfs_register_sched(struct request_queue *q)
773{
774	struct elevator_type *e = q->elevator->type;
775
776	lockdep_assert_held(&q->debugfs_mutex);
777
778	/*
779	 * If the parent directory has not been created yet, return, we will be
780	 * called again later on and the directory/files will be created then.
781	 */
782	if (!q->debugfs_dir)
783		return;
784
785	if (!e->queue_debugfs_attrs)
786		return;
787
788	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
789
790	debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
791}
792
793void blk_mq_debugfs_unregister_sched(struct request_queue *q)
794{
795	lockdep_assert_held(&q->debugfs_mutex);
796
797	debugfs_remove_recursive(q->sched_debugfs_dir);
798	q->sched_debugfs_dir = NULL;
799}
800
801static const char *rq_qos_id_to_name(enum rq_qos_id id)
802{
803	switch (id) {
804	case RQ_QOS_WBT:
805		return "wbt";
806	case RQ_QOS_LATENCY:
807		return "latency";
808	case RQ_QOS_COST:
809		return "cost";
810	}
811	return "unknown";
812}
813
814void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
815{
816	lockdep_assert_held(&rqos->q->debugfs_mutex);
817
818	if (!rqos->q->debugfs_dir)
819		return;
820	debugfs_remove_recursive(rqos->debugfs_dir);
821	rqos->debugfs_dir = NULL;
822}
823
824void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
825{
826	struct request_queue *q = rqos->q;
827	const char *dir_name = rq_qos_id_to_name(rqos->id);
828
829	lockdep_assert_held(&q->debugfs_mutex);
830
831	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
832		return;
833
834	if (!q->rqos_debugfs_dir)
835		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
836							 q->debugfs_dir);
837
838	rqos->debugfs_dir = debugfs_create_dir(dir_name,
839					       rqos->q->rqos_debugfs_dir);
840
841	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
842}
843
844void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
845					struct blk_mq_hw_ctx *hctx)
846{
847	struct elevator_type *e = q->elevator->type;
848
849	lockdep_assert_held(&q->debugfs_mutex);
850
851	/*
852	 * If the parent debugfs directory has not been created yet, return;
853	 * We will be called again later on with appropriate parent debugfs
854	 * directory from blk_register_queue()
855	 */
856	if (!hctx->debugfs_dir)
857		return;
858
859	if (!e->hctx_debugfs_attrs)
860		return;
861
862	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
863						     hctx->debugfs_dir);
864	debugfs_create_files(hctx->sched_debugfs_dir, hctx,
865			     e->hctx_debugfs_attrs);
866}
867
868void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
869{
870	lockdep_assert_held(&hctx->queue->debugfs_mutex);
871
872	if (!hctx->queue->debugfs_dir)
873		return;
874	debugfs_remove_recursive(hctx->sched_debugfs_dir);
875	hctx->sched_debugfs_dir = NULL;
876}