blk-mq-debugfs.c

  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	QUEUE_FLAG_NAME(DISABLE_WBT_DEF),
 97	QUEUE_FLAG_NAME(NO_ELV_SWITCH),
 98	QUEUE_FLAG_NAME(QOS_ENABLED),
 99	QUEUE_FLAG_NAME(BIO_ISSUE_TIME),
100};
101#undef QUEUE_FLAG_NAME
102
103static int queue_state_show(void *data, struct seq_file *m)
104{
105	struct request_queue *q = data;
106
107	BUILD_BUG_ON(ARRAY_SIZE(blk_queue_flag_name) != QUEUE_FLAG_MAX);
108	blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
109		       ARRAY_SIZE(blk_queue_flag_name));
110	seq_puts(m, "\n");
111	return 0;
112}
113
114static ssize_t queue_state_write(void *data, const char __user *buf,
115				 size_t count, loff_t *ppos)
116{
117	struct request_queue *q = data;
118	char opbuf[16] = { }, *op;
119
120	/*
121	 * The "state" attribute is removed when the queue is removed.  Don't
122	 * allow setting the state on a dying queue to avoid a use-after-free.
123	 */
124	if (blk_queue_dying(q))
125		return -ENOENT;
126
127	if (count >= sizeof(opbuf)) {
128		pr_err("%s: operation too long\n", __func__);
129		goto inval;
130	}
131
132	if (copy_from_user(opbuf, buf, count))
133		return -EFAULT;
134	op = strstrip(opbuf);
135	if (strcmp(op, "run") == 0) {
136		blk_mq_run_hw_queues(q, true);
137	} else if (strcmp(op, "start") == 0) {
138		blk_mq_start_stopped_hw_queues(q, true);
139	} else if (strcmp(op, "kick") == 0) {
140		blk_mq_kick_requeue_list(q);
141	} else {
142		pr_err("%s: unsupported operation '%s'\n", __func__, op);
143inval:
144		pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
145		return -EINVAL;
146	}
147	return count;
148}
149
150static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
151	{ "poll_stat", 0400, queue_poll_stat_show },
152	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
153	{ "pm_only", 0600, queue_pm_only_show, NULL },
154	{ "state", 0600, queue_state_show, queue_state_write },
155	{ "zone_wplugs", 0400, queue_zone_wplugs_show, NULL },
156	{ },
157};
158
159#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
160static const char *const hctx_state_name[] = {
161	HCTX_STATE_NAME(STOPPED),
162	HCTX_STATE_NAME(TAG_ACTIVE),
163	HCTX_STATE_NAME(SCHED_RESTART),
164	HCTX_STATE_NAME(INACTIVE),
165};
166#undef HCTX_STATE_NAME
167
168static int hctx_state_show(void *data, struct seq_file *m)
169{
170	struct blk_mq_hw_ctx *hctx = data;
171
172	BUILD_BUG_ON(ARRAY_SIZE(hctx_state_name) != BLK_MQ_S_MAX);
173	blk_flags_show(m, hctx->state, hctx_state_name,
174		       ARRAY_SIZE(hctx_state_name));
175	seq_puts(m, "\n");
176	return 0;
177}
178
179#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
180static const char *const hctx_flag_name[] = {
181	HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
182	HCTX_FLAG_NAME(STACKING),
183	HCTX_FLAG_NAME(TAG_HCTX_SHARED),
184	HCTX_FLAG_NAME(BLOCKING),
185	HCTX_FLAG_NAME(TAG_RR),
186	HCTX_FLAG_NAME(NO_SCHED_BY_DEFAULT),
187};
188#undef HCTX_FLAG_NAME
189
190static int hctx_flags_show(void *data, struct seq_file *m)
191{
192	struct blk_mq_hw_ctx *hctx = data;
193
194	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) != ilog2(BLK_MQ_F_MAX));
195
196	blk_flags_show(m, hctx->flags, hctx_flag_name,
197			ARRAY_SIZE(hctx_flag_name));
198	seq_puts(m, "\n");
199	return 0;
200}
201
202#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
203static const char *const cmd_flag_name[] = {
204	CMD_FLAG_NAME(FAILFAST_DEV),
205	CMD_FLAG_NAME(FAILFAST_TRANSPORT),
206	CMD_FLAG_NAME(FAILFAST_DRIVER),
207	CMD_FLAG_NAME(SYNC),
208	CMD_FLAG_NAME(META),
209	CMD_FLAG_NAME(PRIO),
210	CMD_FLAG_NAME(NOMERGE),
211	CMD_FLAG_NAME(IDLE),
212	CMD_FLAG_NAME(INTEGRITY),
213	CMD_FLAG_NAME(FUA),
214	CMD_FLAG_NAME(PREFLUSH),
215	CMD_FLAG_NAME(RAHEAD),
216	CMD_FLAG_NAME(BACKGROUND),
217	CMD_FLAG_NAME(NOWAIT),
218	CMD_FLAG_NAME(POLLED),
219	CMD_FLAG_NAME(ALLOC_CACHE),
220	CMD_FLAG_NAME(SWAP),
221	CMD_FLAG_NAME(DRV),
222	CMD_FLAG_NAME(FS_PRIVATE),
223	CMD_FLAG_NAME(ATOMIC),
224	CMD_FLAG_NAME(NOUNMAP),
225};
226#undef CMD_FLAG_NAME
227
228#define RQF_NAME(name) [__RQF_##name] = #name
229static const char *const rqf_name[] = {
230	RQF_NAME(STARTED),
231	RQF_NAME(FLUSH_SEQ),
232	RQF_NAME(MIXED_MERGE),
233	RQF_NAME(DONTPREP),
234	RQF_NAME(SCHED_TAGS),
235	RQF_NAME(USE_SCHED),
236	RQF_NAME(FAILED),
237	RQF_NAME(QUIET),
238	RQF_NAME(IO_STAT),
239	RQF_NAME(PM),
240	RQF_NAME(HASHED),
241	RQF_NAME(STATS),
242	RQF_NAME(SPECIAL_PAYLOAD),
243	RQF_NAME(ZONE_WRITE_PLUGGING),
244	RQF_NAME(TIMED_OUT),
245	RQF_NAME(RESV),
246};
247#undef RQF_NAME
248
249static const char *const blk_mq_rq_state_name_array[] = {
250	[MQ_RQ_IDLE]		= "idle",
251	[MQ_RQ_IN_FLIGHT]	= "in_flight",
252	[MQ_RQ_COMPLETE]	= "complete",
253};
254
255static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
256{
257	if (WARN_ON_ONCE((unsigned int)rq_state >=
258			 ARRAY_SIZE(blk_mq_rq_state_name_array)))
259		return "(?)";
260	return blk_mq_rq_state_name_array[rq_state];
261}
262
263int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
264{
265	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
266	const enum req_op op = req_op(rq);
267	const char *op_str = blk_op_str(op);
268
269	BUILD_BUG_ON(ARRAY_SIZE(cmd_flag_name) != __REQ_NR_BITS);
270	BUILD_BUG_ON(ARRAY_SIZE(rqf_name) != __RQF_BITS);
271
272	seq_printf(m, "%p {.op=", rq);
273	if (strcmp(op_str, "UNKNOWN") == 0)
274		seq_printf(m, "%u", op);
275	else
276		seq_printf(m, "%s", op_str);
277	seq_puts(m, ", .cmd_flags=");
278	blk_flags_show(m, (__force unsigned int)(rq->cmd_flags & ~REQ_OP_MASK),
279		       cmd_flag_name, ARRAY_SIZE(cmd_flag_name));
280	seq_puts(m, ", .rq_flags=");
281	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
282		       ARRAY_SIZE(rqf_name));
283	seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
284	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
285		   rq->internal_tag);
286	if (mq_ops->show_rq)
287		mq_ops->show_rq(m, rq);
288	seq_puts(m, "}\n");
289	return 0;
290}
291EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
292
293int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
294{
295	return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
296}
297EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
298
299static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
300	__acquires(&hctx->lock)
301{
302	struct blk_mq_hw_ctx *hctx = m->private;
303
304	spin_lock(&hctx->lock);
305	return seq_list_start(&hctx->dispatch, *pos);
306}
307
308static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
309{
310	struct blk_mq_hw_ctx *hctx = m->private;
311
312	return seq_list_next(v, &hctx->dispatch, pos);
313}
314
315static void hctx_dispatch_stop(struct seq_file *m, void *v)
316	__releases(&hctx->lock)
317{
318	struct blk_mq_hw_ctx *hctx = m->private;
319
320	spin_unlock(&hctx->lock);
321}
322
323static const struct seq_operations hctx_dispatch_seq_ops = {
324	.start	= hctx_dispatch_start,
325	.next	= hctx_dispatch_next,
326	.stop	= hctx_dispatch_stop,
327	.show	= blk_mq_debugfs_rq_show,
328};
329
330struct show_busy_params {
331	struct seq_file		*m;
332	struct blk_mq_hw_ctx	*hctx;
333};
334
335/*
336 * Note: the state of a request may change while this function is in progress,
337 * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
338 * keep iterating requests.
339 */
340static bool hctx_show_busy_rq(struct request *rq, void *data)
341{
342	const struct show_busy_params *params = data;
343
344	if (rq->mq_hctx == params->hctx)
345		__blk_mq_debugfs_rq_show(params->m, rq);
346
347	return true;
348}
349
350static int hctx_busy_show(void *data, struct seq_file *m)
351{
352	struct blk_mq_hw_ctx *hctx = data;
353	struct show_busy_params params = { .m = m, .hctx = hctx };
354	int res;
355
356	res = mutex_lock_interruptible(&hctx->queue->elevator_lock);
357	if (res)
358		return res;
359	blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
360				&params);
361	mutex_unlock(&hctx->queue->elevator_lock);
362
363	return 0;
364}
365
366static const char *const hctx_types[] = {
367	[HCTX_TYPE_DEFAULT]	= "default",
368	[HCTX_TYPE_READ]	= "read",
369	[HCTX_TYPE_POLL]	= "poll",
370};
371
372static int hctx_type_show(void *data, struct seq_file *m)
373{
374	struct blk_mq_hw_ctx *hctx = data;
375
376	BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
377	seq_printf(m, "%s\n", hctx_types[hctx->type]);
378	return 0;
379}
380
381static int hctx_ctx_map_show(void *data, struct seq_file *m)
382{
383	struct blk_mq_hw_ctx *hctx = data;
384
385	sbitmap_bitmap_show(&hctx->ctx_map, m);
386	return 0;
387}
388
389static void blk_mq_debugfs_tags_show(struct seq_file *m,
390				     struct blk_mq_tags *tags)
391{
392	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
393	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
394	seq_printf(m, "active_queues=%d\n",
395		   READ_ONCE(tags->active_queues));
396
397	seq_puts(m, "\nbitmap_tags:\n");
398	sbitmap_queue_show(&tags->bitmap_tags, m);
399
400	if (tags->nr_reserved_tags) {
401		seq_puts(m, "\nbreserved_tags:\n");
402		sbitmap_queue_show(&tags->breserved_tags, m);
403	}
404}
405
406static int hctx_tags_show(void *data, struct seq_file *m)
407{
408	struct blk_mq_hw_ctx *hctx = data;
409	struct request_queue *q = hctx->queue;
410	int res;
411
412	res = mutex_lock_interruptible(&q->elevator_lock);
413	if (res)
414		return res;
415	if (hctx->tags)
416		blk_mq_debugfs_tags_show(m, hctx->tags);
417	mutex_unlock(&q->elevator_lock);
418
419	return 0;
420}
421
422static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
423{
424	struct blk_mq_hw_ctx *hctx = data;
425	struct request_queue *q = hctx->queue;
426	int res;
427
428	res = mutex_lock_interruptible(&q->elevator_lock);
429	if (res)
430		return res;
431	if (hctx->tags)
432		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
433	mutex_unlock(&q->elevator_lock);
434
435	return 0;
436}
437
438static int hctx_sched_tags_show(void *data, struct seq_file *m)
439{
440	struct blk_mq_hw_ctx *hctx = data;
441	struct request_queue *q = hctx->queue;
442	int res;
443
444	res = mutex_lock_interruptible(&q->elevator_lock);
445	if (res)
446		return res;
447	if (hctx->sched_tags)
448		blk_mq_debugfs_tags_show(m, hctx->sched_tags);
449	mutex_unlock(&q->elevator_lock);
450
451	return 0;
452}
453
454static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
455{
456	struct blk_mq_hw_ctx *hctx = data;
457	struct request_queue *q = hctx->queue;
458	int res;
459
460	res = mutex_lock_interruptible(&q->elevator_lock);
461	if (res)
462		return res;
463	if (hctx->sched_tags)
464		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
465	mutex_unlock(&q->elevator_lock);
466
467	return 0;
468}
469
470static int hctx_active_show(void *data, struct seq_file *m)
471{
472	struct blk_mq_hw_ctx *hctx = data;
473
474	seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
475	return 0;
476}
477
478static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
479{
480	struct blk_mq_hw_ctx *hctx = data;
481
482	seq_printf(m, "%u\n", hctx->dispatch_busy);
483	return 0;
484}
485
486#define CTX_RQ_SEQ_OPS(name, type)					\
487static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
488	__acquires(&ctx->lock)						\
489{									\
490	struct blk_mq_ctx *ctx = m->private;				\
491									\
492	spin_lock(&ctx->lock);						\
493	return seq_list_start(&ctx->rq_lists[type], *pos);		\
494}									\
495									\
496static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,	\
497				     loff_t *pos)			\
498{									\
499	struct blk_mq_ctx *ctx = m->private;				\
500									\
501	return seq_list_next(v, &ctx->rq_lists[type], pos);		\
502}									\
503									\
504static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)	\
505	__releases(&ctx->lock)						\
506{									\
507	struct blk_mq_ctx *ctx = m->private;				\
508									\
509	spin_unlock(&ctx->lock);					\
510}									\
511									\
512static const struct seq_operations ctx_##name##_rq_list_seq_ops = {	\
513	.start	= ctx_##name##_rq_list_start,				\
514	.next	= ctx_##name##_rq_list_next,				\
515	.stop	= ctx_##name##_rq_list_stop,				\
516	.show	= blk_mq_debugfs_rq_show,				\
517}
518
519CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
520CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
521CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
522
523static int blk_mq_debugfs_show(struct seq_file *m, void *v)
524{
525	const struct blk_mq_debugfs_attr *attr = m->private;
526	void *data = debugfs_get_aux(m->file);
527
528	return attr->show(data, m);
529}
530
531static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
532				    size_t count, loff_t *ppos)
533{
534	struct seq_file *m = file->private_data;
535	const struct blk_mq_debugfs_attr *attr = m->private;
536	void *data = debugfs_get_aux(file);
537
538	/*
539	 * Attributes that only implement .seq_ops are read-only and 'attr' is
540	 * the same with 'data' in this case.
541	 */
542	if (attr == data || !attr->write)
543		return -EPERM;
544
545	return attr->write(data, buf, count, ppos);
546}
547
548static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
549{
550	const struct blk_mq_debugfs_attr *attr = inode->i_private;
551	void *data = debugfs_get_aux(file);
552	struct seq_file *m;
553	int ret;
554
555	if (attr->seq_ops) {
556		ret = seq_open(file, attr->seq_ops);
557		if (!ret) {
558			m = file->private_data;
559			m->private = data;
560		}
561		return ret;
562	}
563
564	if (WARN_ON_ONCE(!attr->show))
565		return -EPERM;
566
567	return single_open(file, blk_mq_debugfs_show, inode->i_private);
568}
569
570static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
571{
572	const struct blk_mq_debugfs_attr *attr = inode->i_private;
573
574	if (attr->show)
575		return single_release(inode, file);
576
577	return seq_release(inode, file);
578}
579
580static const struct file_operations blk_mq_debugfs_fops = {
581	.open		= blk_mq_debugfs_open,
582	.read		= seq_read,
583	.write		= blk_mq_debugfs_write,
584	.llseek		= seq_lseek,
585	.release	= blk_mq_debugfs_release,
586};
587
588static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
589	{"state", 0400, hctx_state_show},
590	{"flags", 0400, hctx_flags_show},
591	{"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
592	{"busy", 0400, hctx_busy_show},
593	{"ctx_map", 0400, hctx_ctx_map_show},
594	{"tags", 0400, hctx_tags_show},
595	{"tags_bitmap", 0400, hctx_tags_bitmap_show},
596	{"sched_tags", 0400, hctx_sched_tags_show},
597	{"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
598	{"active", 0400, hctx_active_show},
599	{"dispatch_busy", 0400, hctx_dispatch_busy_show},
600	{"type", 0400, hctx_type_show},
601	{},
602};
603
604static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
605	{"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
606	{"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
607	{"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
608	{},
609};
610
611static void debugfs_create_files(struct dentry *parent, void *data,
612				 const struct blk_mq_debugfs_attr *attr)
613{
614	if (IS_ERR_OR_NULL(parent))
615		return;
616
617	for (; attr->name; attr++)
618		debugfs_create_file_aux(attr->name, attr->mode, parent,
619				    (void *)attr, data, &blk_mq_debugfs_fops);
620}
621
622void blk_mq_debugfs_register(struct request_queue *q)
623{
624	struct blk_mq_hw_ctx *hctx;
625	unsigned long i;
626
627	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
628
629	queue_for_each_hw_ctx(q, hctx, i) {
630		if (!hctx->debugfs_dir)
631			blk_mq_debugfs_register_hctx(q, hctx);
632	}
633
634	if (q->rq_qos) {
635		struct rq_qos *rqos = q->rq_qos;
636
637		while (rqos) {
638			blk_mq_debugfs_register_rqos(rqos);
639			rqos = rqos->next;
640		}
641	}
642}
643
644static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
645					struct blk_mq_ctx *ctx)
646{
647	struct dentry *ctx_dir;
648	char name[20];
649
650	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
651	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
652
653	debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
654}
655
656void blk_mq_debugfs_register_hctx(struct request_queue *q,
657				  struct blk_mq_hw_ctx *hctx)
658{
659	struct blk_mq_ctx *ctx;
660	char name[20];
661	int i;
662
663	if (!q->debugfs_dir)
664		return;
665
666	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
667	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
668
669	debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
670
671	hctx_for_each_ctx(hctx, ctx, i)
672		blk_mq_debugfs_register_ctx(hctx, ctx);
673}
674
675void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
676{
677	if (!hctx->queue->debugfs_dir)
678		return;
679	debugfs_remove_recursive(hctx->debugfs_dir);
680	hctx->sched_debugfs_dir = NULL;
681	hctx->debugfs_dir = NULL;
682}
683
684void blk_mq_debugfs_register_hctxs(struct request_queue *q)
685{
686	struct blk_mq_hw_ctx *hctx;
687	unsigned long i;
688
689	mutex_lock(&q->debugfs_mutex);
690	queue_for_each_hw_ctx(q, hctx, i)
691		blk_mq_debugfs_register_hctx(q, hctx);
692	mutex_unlock(&q->debugfs_mutex);
693}
694
695void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
696{
697	struct blk_mq_hw_ctx *hctx;
698	unsigned long i;
699
700	queue_for_each_hw_ctx(q, hctx, i)
701		blk_mq_debugfs_unregister_hctx(hctx);
702}
703
704void blk_mq_debugfs_register_sched(struct request_queue *q)
705{
706	struct elevator_type *e = q->elevator->type;
707
708	lockdep_assert_held(&q->debugfs_mutex);
709
710	/*
711	 * If the parent directory has not been created yet, return, we will be
712	 * called again later on and the directory/files will be created then.
713	 */
714	if (!q->debugfs_dir)
715		return;
716
717	if (!e->queue_debugfs_attrs)
718		return;
719
720	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
721
722	debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
723}
724
725void blk_mq_debugfs_unregister_sched(struct request_queue *q)
726{
727	lockdep_assert_held(&q->debugfs_mutex);
728
729	debugfs_remove_recursive(q->sched_debugfs_dir);
730	q->sched_debugfs_dir = NULL;
731}
732
733static const char *rq_qos_id_to_name(enum rq_qos_id id)
734{
735	switch (id) {
736	case RQ_QOS_WBT:
737		return "wbt";
738	case RQ_QOS_LATENCY:
739		return "latency";
740	case RQ_QOS_COST:
741		return "cost";
742	}
743	return "unknown";
744}
745
746void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
747{
748	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
749
750	if (!rqos->disk->queue->debugfs_dir)
751		return;
752	debugfs_remove_recursive(rqos->debugfs_dir);
753	rqos->debugfs_dir = NULL;
754}
755
756void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
757{
758	struct request_queue *q = rqos->disk->queue;
759	const char *dir_name = rq_qos_id_to_name(rqos->id);
760
761	lockdep_assert_held(&q->debugfs_mutex);
762
763	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
764		return;
765
766	if (!q->rqos_debugfs_dir)
767		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
768							 q->debugfs_dir);
769
770	rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);
771	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
772}
773
774void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
775					struct blk_mq_hw_ctx *hctx)
776{
777	struct elevator_type *e = q->elevator->type;
778
779	lockdep_assert_held(&q->debugfs_mutex);
780
781	/*
782	 * If the parent debugfs directory has not been created yet, return;
783	 * We will be called again later on with appropriate parent debugfs
784	 * directory from blk_register_queue()
785	 */
786	if (!hctx->debugfs_dir)
787		return;
788
789	if (!e->hctx_debugfs_attrs)
790		return;
791
792	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
793						     hctx->debugfs_dir);
794	debugfs_create_files(hctx->sched_debugfs_dir, hctx,
795			     e->hctx_debugfs_attrs);
796}
797
798void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
799{
800	lockdep_assert_held(&hctx->queue->debugfs_mutex);
801
802	if (!hctx->queue->debugfs_dir)
803		return;
804	debugfs_remove_recursive(hctx->sched_debugfs_dir);
805	hctx->sched_debugfs_dir = NULL;
806}