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-tag.h"
 15#include "blk-rq-qos.h"
 16
 17static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
 18{
 19	if (stat->nr_samples) {
 20		seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
 21			   stat->nr_samples, stat->mean, stat->min, stat->max);
 22	} else {
 23		seq_puts(m, "samples=0");
 24	}
 25}
 26
 27static int queue_poll_stat_show(void *data, struct seq_file *m)
 28{
 29	struct request_queue *q = data;
 30	int bucket;
 31
 32	for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
 33		seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
 34		print_stat(m, &q->poll_stat[2 * bucket]);
 35		seq_puts(m, "\n");
 36
 37		seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
 38		print_stat(m, &q->poll_stat[2 * bucket + 1]);
 39		seq_puts(m, "\n");
 40	}
 41	return 0;
 42}
 43
 44static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
 45	__acquires(&q->requeue_lock)
 46{
 47	struct request_queue *q = m->private;
 48
 49	spin_lock_irq(&q->requeue_lock);
 50	return seq_list_start(&q->requeue_list, *pos);
 51}
 52
 53static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
 54{
 55	struct request_queue *q = m->private;
 56
 57	return seq_list_next(v, &q->requeue_list, pos);
 58}
 59
 60static void queue_requeue_list_stop(struct seq_file *m, void *v)
 61	__releases(&q->requeue_lock)
 62{
 63	struct request_queue *q = m->private;
 64
 65	spin_unlock_irq(&q->requeue_lock);
 66}
 67
 68static const struct seq_operations queue_requeue_list_seq_ops = {
 69	.start	= queue_requeue_list_start,
 70	.next	= queue_requeue_list_next,
 71	.stop	= queue_requeue_list_stop,
 72	.show	= blk_mq_debugfs_rq_show,
 73};
 74
 75static int blk_flags_show(struct seq_file *m, const unsigned long flags,
 76			  const char *const *flag_name, int flag_name_count)
 77{
 78	bool sep = false;
 79	int i;
 80
 81	for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
 82		if (!(flags & BIT(i)))
 83			continue;
 84		if (sep)
 85			seq_puts(m, "|");
 86		sep = true;
 87		if (i < flag_name_count && flag_name[i])
 88			seq_puts(m, flag_name[i]);
 89		else
 90			seq_printf(m, "%d", i);
 91	}
 92	return 0;
 93}
 94
 95static int queue_pm_only_show(void *data, struct seq_file *m)
 96{
 97	struct request_queue *q = data;
 98
 99	seq_printf(m, "%d\n", atomic_read(&q->pm_only));
100	return 0;
101}
102
103#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
104static const char *const blk_queue_flag_name[] = {
105	QUEUE_FLAG_NAME(STOPPED),
106	QUEUE_FLAG_NAME(DYING),
107	QUEUE_FLAG_NAME(NOMERGES),
108	QUEUE_FLAG_NAME(SAME_COMP),
109	QUEUE_FLAG_NAME(FAIL_IO),
110	QUEUE_FLAG_NAME(NONROT),
111	QUEUE_FLAG_NAME(IO_STAT),
112	QUEUE_FLAG_NAME(DISCARD),
113	QUEUE_FLAG_NAME(NOXMERGES),
114	QUEUE_FLAG_NAME(ADD_RANDOM),
115	QUEUE_FLAG_NAME(SECERASE),
116	QUEUE_FLAG_NAME(SAME_FORCE),
117	QUEUE_FLAG_NAME(DEAD),
118	QUEUE_FLAG_NAME(INIT_DONE),
119	QUEUE_FLAG_NAME(POLL),
120	QUEUE_FLAG_NAME(WC),
121	QUEUE_FLAG_NAME(FUA),
122	QUEUE_FLAG_NAME(DAX),
123	QUEUE_FLAG_NAME(STATS),
124	QUEUE_FLAG_NAME(POLL_STATS),
125	QUEUE_FLAG_NAME(REGISTERED),
126	QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
127	QUEUE_FLAG_NAME(QUIESCED),
128};
129#undef QUEUE_FLAG_NAME
130
131static int queue_state_show(void *data, struct seq_file *m)
132{
133	struct request_queue *q = data;
134
135	blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
136		       ARRAY_SIZE(blk_queue_flag_name));
137	seq_puts(m, "\n");
138	return 0;
139}
140
141static ssize_t queue_state_write(void *data, const char __user *buf,
142				 size_t count, loff_t *ppos)
143{
144	struct request_queue *q = data;
145	char opbuf[16] = { }, *op;
146
147	/*
148	 * The "state" attribute is removed after blk_cleanup_queue() has called
149	 * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
150	 * triggering a use-after-free.
151	 */
152	if (blk_queue_dead(q))
153		return -ENOENT;
154
155	if (count >= sizeof(opbuf)) {
156		pr_err("%s: operation too long\n", __func__);
157		goto inval;
158	}
159
160	if (copy_from_user(opbuf, buf, count))
161		return -EFAULT;
162	op = strstrip(opbuf);
163	if (strcmp(op, "run") == 0) {
164		blk_mq_run_hw_queues(q, true);
165	} else if (strcmp(op, "start") == 0) {
166		blk_mq_start_stopped_hw_queues(q, true);
167	} else if (strcmp(op, "kick") == 0) {
168		blk_mq_kick_requeue_list(q);
169	} else {
170		pr_err("%s: unsupported operation '%s'\n", __func__, op);
171inval:
172		pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
173		return -EINVAL;
174	}
175	return count;
176}
177
178static int queue_write_hint_show(void *data, struct seq_file *m)
179{
180	struct request_queue *q = data;
181	int i;
182
183	for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
184		seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
185
186	return 0;
187}
188
189static ssize_t queue_write_hint_store(void *data, const char __user *buf,
190				      size_t count, loff_t *ppos)
191{
192	struct request_queue *q = data;
193	int i;
194
195	for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
196		q->write_hints[i] = 0;
197
198	return count;
199}
200
201static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
202	{ "poll_stat", 0400, queue_poll_stat_show },
203	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
204	{ "pm_only", 0600, queue_pm_only_show, NULL },
205	{ "state", 0600, queue_state_show, queue_state_write },
206	{ "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
207	{ "zone_wlock", 0400, queue_zone_wlock_show, NULL },
208	{ },
209};
210
211#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
212static const char *const hctx_state_name[] = {
213	HCTX_STATE_NAME(STOPPED),
214	HCTX_STATE_NAME(TAG_ACTIVE),
215	HCTX_STATE_NAME(SCHED_RESTART),
216};
217#undef HCTX_STATE_NAME
218
219static int hctx_state_show(void *data, struct seq_file *m)
220{
221	struct blk_mq_hw_ctx *hctx = data;
222
223	blk_flags_show(m, hctx->state, hctx_state_name,
224		       ARRAY_SIZE(hctx_state_name));
225	seq_puts(m, "\n");
226	return 0;
227}
228
229#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
230static const char *const alloc_policy_name[] = {
231	BLK_TAG_ALLOC_NAME(FIFO),
232	BLK_TAG_ALLOC_NAME(RR),
233};
234#undef BLK_TAG_ALLOC_NAME
235
236#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
237static const char *const hctx_flag_name[] = {
238	HCTX_FLAG_NAME(SHOULD_MERGE),
239	HCTX_FLAG_NAME(TAG_SHARED),
240	HCTX_FLAG_NAME(BLOCKING),
241	HCTX_FLAG_NAME(NO_SCHED),
242};
243#undef HCTX_FLAG_NAME
244
245static int hctx_flags_show(void *data, struct seq_file *m)
246{
247	struct blk_mq_hw_ctx *hctx = data;
248	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
249
250	seq_puts(m, "alloc_policy=");
251	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
252	    alloc_policy_name[alloc_policy])
253		seq_puts(m, alloc_policy_name[alloc_policy]);
254	else
255		seq_printf(m, "%d", alloc_policy);
256	seq_puts(m, " ");
257	blk_flags_show(m,
258		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
259		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
260	seq_puts(m, "\n");
261	return 0;
262}
263
264#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
265static const char *const cmd_flag_name[] = {
266	CMD_FLAG_NAME(FAILFAST_DEV),
267	CMD_FLAG_NAME(FAILFAST_TRANSPORT),
268	CMD_FLAG_NAME(FAILFAST_DRIVER),
269	CMD_FLAG_NAME(SYNC),
270	CMD_FLAG_NAME(META),
271	CMD_FLAG_NAME(PRIO),
272	CMD_FLAG_NAME(NOMERGE),
273	CMD_FLAG_NAME(IDLE),
274	CMD_FLAG_NAME(INTEGRITY),
275	CMD_FLAG_NAME(FUA),
276	CMD_FLAG_NAME(PREFLUSH),
277	CMD_FLAG_NAME(RAHEAD),
278	CMD_FLAG_NAME(BACKGROUND),
279	CMD_FLAG_NAME(NOWAIT),
280	CMD_FLAG_NAME(NOUNMAP),
281	CMD_FLAG_NAME(HIPRI),
282};
283#undef CMD_FLAG_NAME
284
285#define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
286static const char *const rqf_name[] = {
287	RQF_NAME(SORTED),
288	RQF_NAME(STARTED),
289	RQF_NAME(SOFTBARRIER),
290	RQF_NAME(FLUSH_SEQ),
291	RQF_NAME(MIXED_MERGE),
292	RQF_NAME(MQ_INFLIGHT),
293	RQF_NAME(DONTPREP),
294	RQF_NAME(PREEMPT),
295	RQF_NAME(COPY_USER),
296	RQF_NAME(FAILED),
297	RQF_NAME(QUIET),
298	RQF_NAME(ELVPRIV),
299	RQF_NAME(IO_STAT),
300	RQF_NAME(ALLOCED),
301	RQF_NAME(PM),
302	RQF_NAME(HASHED),
303	RQF_NAME(STATS),
304	RQF_NAME(SPECIAL_PAYLOAD),
305	RQF_NAME(ZONE_WRITE_LOCKED),
306	RQF_NAME(MQ_POLL_SLEPT),
307};
308#undef RQF_NAME
309
310static const char *const blk_mq_rq_state_name_array[] = {
311	[MQ_RQ_IDLE]		= "idle",
312	[MQ_RQ_IN_FLIGHT]	= "in_flight",
313	[MQ_RQ_COMPLETE]	= "complete",
314};
315
316static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
317{
318	if (WARN_ON_ONCE((unsigned int)rq_state >=
319			 ARRAY_SIZE(blk_mq_rq_state_name_array)))
320		return "(?)";
321	return blk_mq_rq_state_name_array[rq_state];
322}
323
324int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
325{
326	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
327	const unsigned int op = req_op(rq);
328	const char *op_str = blk_op_str(op);
329
330	seq_printf(m, "%p {.op=", rq);
331	if (strcmp(op_str, "UNKNOWN") == 0)
332		seq_printf(m, "%u", op);
333	else
334		seq_printf(m, "%s", op_str);
335	seq_puts(m, ", .cmd_flags=");
336	blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
337		       ARRAY_SIZE(cmd_flag_name));
338	seq_puts(m, ", .rq_flags=");
339	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
340		       ARRAY_SIZE(rqf_name));
341	seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
342	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
343		   rq->internal_tag);
344	if (mq_ops->show_rq)
345		mq_ops->show_rq(m, rq);
346	seq_puts(m, "}\n");
347	return 0;
348}
349EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
350
351int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
352{
353	return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
354}
355EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
356
357static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
358	__acquires(&hctx->lock)
359{
360	struct blk_mq_hw_ctx *hctx = m->private;
361
362	spin_lock(&hctx->lock);
363	return seq_list_start(&hctx->dispatch, *pos);
364}
365
366static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
367{
368	struct blk_mq_hw_ctx *hctx = m->private;
369
370	return seq_list_next(v, &hctx->dispatch, pos);
371}
372
373static void hctx_dispatch_stop(struct seq_file *m, void *v)
374	__releases(&hctx->lock)
375{
376	struct blk_mq_hw_ctx *hctx = m->private;
377
378	spin_unlock(&hctx->lock);
379}
380
381static const struct seq_operations hctx_dispatch_seq_ops = {
382	.start	= hctx_dispatch_start,
383	.next	= hctx_dispatch_next,
384	.stop	= hctx_dispatch_stop,
385	.show	= blk_mq_debugfs_rq_show,
386};
387
388struct show_busy_params {
389	struct seq_file		*m;
390	struct blk_mq_hw_ctx	*hctx;
391};
392
393/*
394 * Note: the state of a request may change while this function is in progress,
395 * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
396 * keep iterating requests.
397 */
398static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
399{
400	const struct show_busy_params *params = data;
401
402	if (rq->mq_hctx == params->hctx)
403		__blk_mq_debugfs_rq_show(params->m,
404					 list_entry_rq(&rq->queuelist));
405
406	return true;
407}
408
409static int hctx_busy_show(void *data, struct seq_file *m)
410{
411	struct blk_mq_hw_ctx *hctx = data;
412	struct show_busy_params params = { .m = m, .hctx = hctx };
413
414	blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
415				&params);
416
417	return 0;
418}
419
420static const char *const hctx_types[] = {
421	[HCTX_TYPE_DEFAULT]	= "default",
422	[HCTX_TYPE_READ]	= "read",
423	[HCTX_TYPE_POLL]	= "poll",
424};
425
426static int hctx_type_show(void *data, struct seq_file *m)
427{
428	struct blk_mq_hw_ctx *hctx = data;
429
430	BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
431	seq_printf(m, "%s\n", hctx_types[hctx->type]);
432	return 0;
433}
434
435static int hctx_ctx_map_show(void *data, struct seq_file *m)
436{
437	struct blk_mq_hw_ctx *hctx = data;
438
439	sbitmap_bitmap_show(&hctx->ctx_map, m);
440	return 0;
441}
442
443static void blk_mq_debugfs_tags_show(struct seq_file *m,
444				     struct blk_mq_tags *tags)
445{
446	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
447	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
448	seq_printf(m, "active_queues=%d\n",
449		   atomic_read(&tags->active_queues));
450
451	seq_puts(m, "\nbitmap_tags:\n");
452	sbitmap_queue_show(&tags->bitmap_tags, m);
453
454	if (tags->nr_reserved_tags) {
455		seq_puts(m, "\nbreserved_tags:\n");
456		sbitmap_queue_show(&tags->breserved_tags, m);
457	}
458}
459
460static int hctx_tags_show(void *data, struct seq_file *m)
461{
462	struct blk_mq_hw_ctx *hctx = data;
463	struct request_queue *q = hctx->queue;
464	int res;
465
466	res = mutex_lock_interruptible(&q->sysfs_lock);
467	if (res)
468		goto out;
469	if (hctx->tags)
470		blk_mq_debugfs_tags_show(m, hctx->tags);
471	mutex_unlock(&q->sysfs_lock);
472
473out:
474	return res;
475}
476
477static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
478{
479	struct blk_mq_hw_ctx *hctx = data;
480	struct request_queue *q = hctx->queue;
481	int res;
482
483	res = mutex_lock_interruptible(&q->sysfs_lock);
484	if (res)
485		goto out;
486	if (hctx->tags)
487		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
488	mutex_unlock(&q->sysfs_lock);
489
490out:
491	return res;
492}
493
494static int hctx_sched_tags_show(void *data, struct seq_file *m)
495{
496	struct blk_mq_hw_ctx *hctx = data;
497	struct request_queue *q = hctx->queue;
498	int res;
499
500	res = mutex_lock_interruptible(&q->sysfs_lock);
501	if (res)
502		goto out;
503	if (hctx->sched_tags)
504		blk_mq_debugfs_tags_show(m, hctx->sched_tags);
505	mutex_unlock(&q->sysfs_lock);
506
507out:
508	return res;
509}
510
511static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
512{
513	struct blk_mq_hw_ctx *hctx = data;
514	struct request_queue *q = hctx->queue;
515	int res;
516
517	res = mutex_lock_interruptible(&q->sysfs_lock);
518	if (res)
519		goto out;
520	if (hctx->sched_tags)
521		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
522	mutex_unlock(&q->sysfs_lock);
523
524out:
525	return res;
526}
527
528static int hctx_io_poll_show(void *data, struct seq_file *m)
529{
530	struct blk_mq_hw_ctx *hctx = data;
531
532	seq_printf(m, "considered=%lu\n", hctx->poll_considered);
533	seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
534	seq_printf(m, "success=%lu\n", hctx->poll_success);
535	return 0;
536}
537
538static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
539				  size_t count, loff_t *ppos)
540{
541	struct blk_mq_hw_ctx *hctx = data;
542
543	hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
544	return count;
545}
546
547static int hctx_dispatched_show(void *data, struct seq_file *m)
548{
549	struct blk_mq_hw_ctx *hctx = data;
550	int i;
551
552	seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
553
554	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
555		unsigned int d = 1U << (i - 1);
556
557		seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
558	}
559
560	seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
561	return 0;
562}
563
564static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
565				     size_t count, loff_t *ppos)
566{
567	struct blk_mq_hw_ctx *hctx = data;
568	int i;
569
570	for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
571		hctx->dispatched[i] = 0;
572	return count;
573}
574
575static int hctx_queued_show(void *data, struct seq_file *m)
576{
577	struct blk_mq_hw_ctx *hctx = data;
578
579	seq_printf(m, "%lu\n", hctx->queued);
580	return 0;
581}
582
583static ssize_t hctx_queued_write(void *data, const char __user *buf,
584				 size_t count, loff_t *ppos)
585{
586	struct blk_mq_hw_ctx *hctx = data;
587
588	hctx->queued = 0;
589	return count;
590}
591
592static int hctx_run_show(void *data, struct seq_file *m)
593{
594	struct blk_mq_hw_ctx *hctx = data;
595
596	seq_printf(m, "%lu\n", hctx->run);
597	return 0;
598}
599
600static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
601			      loff_t *ppos)
602{
603	struct blk_mq_hw_ctx *hctx = data;
604
605	hctx->run = 0;
606	return count;
607}
608
609static int hctx_active_show(void *data, struct seq_file *m)
610{
611	struct blk_mq_hw_ctx *hctx = data;
612
613	seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
614	return 0;
615}
616
617static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
618{
619	struct blk_mq_hw_ctx *hctx = data;
620
621	seq_printf(m, "%u\n", hctx->dispatch_busy);
622	return 0;
623}
624
625#define CTX_RQ_SEQ_OPS(name, type)					\
626static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
627	__acquires(&ctx->lock)						\
628{									\
629	struct blk_mq_ctx *ctx = m->private;				\
630									\
631	spin_lock(&ctx->lock);						\
632	return seq_list_start(&ctx->rq_lists[type], *pos);		\
633}									\
634									\
635static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,	\
636				     loff_t *pos)			\
637{									\
638	struct blk_mq_ctx *ctx = m->private;				\
639									\
640	return seq_list_next(v, &ctx->rq_lists[type], pos);		\
641}									\
642									\
643static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)	\
644	__releases(&ctx->lock)						\
645{									\
646	struct blk_mq_ctx *ctx = m->private;				\
647									\
648	spin_unlock(&ctx->lock);					\
649}									\
650									\
651static const struct seq_operations ctx_##name##_rq_list_seq_ops = {	\
652	.start	= ctx_##name##_rq_list_start,				\
653	.next	= ctx_##name##_rq_list_next,				\
654	.stop	= ctx_##name##_rq_list_stop,				\
655	.show	= blk_mq_debugfs_rq_show,				\
656}
657
658CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
659CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
660CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
661
662static int ctx_dispatched_show(void *data, struct seq_file *m)
663{
664	struct blk_mq_ctx *ctx = data;
665
666	seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
667	return 0;
668}
669
670static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
671				    size_t count, loff_t *ppos)
672{
673	struct blk_mq_ctx *ctx = data;
674
675	ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
676	return count;
677}
678
679static int ctx_merged_show(void *data, struct seq_file *m)
680{
681	struct blk_mq_ctx *ctx = data;
682
683	seq_printf(m, "%lu\n", ctx->rq_merged);
684	return 0;
685}
686
687static ssize_t ctx_merged_write(void *data, const char __user *buf,
688				size_t count, loff_t *ppos)
689{
690	struct blk_mq_ctx *ctx = data;
691
692	ctx->rq_merged = 0;
693	return count;
694}
695
696static int ctx_completed_show(void *data, struct seq_file *m)
697{
698	struct blk_mq_ctx *ctx = data;
699
700	seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
701	return 0;
702}
703
704static ssize_t ctx_completed_write(void *data, const char __user *buf,
705				   size_t count, loff_t *ppos)
706{
707	struct blk_mq_ctx *ctx = data;
708
709	ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
710	return count;
711}
712
713static int blk_mq_debugfs_show(struct seq_file *m, void *v)
714{
715	const struct blk_mq_debugfs_attr *attr = m->private;
716	void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
717
718	return attr->show(data, m);
719}
720
721static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
722				    size_t count, loff_t *ppos)
723{
724	struct seq_file *m = file->private_data;
725	const struct blk_mq_debugfs_attr *attr = m->private;
726	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
727
728	/*
729	 * Attributes that only implement .seq_ops are read-only and 'attr' is
730	 * the same with 'data' in this case.
731	 */
732	if (attr == data || !attr->write)
733		return -EPERM;
734
735	return attr->write(data, buf, count, ppos);
736}
737
738static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
739{
740	const struct blk_mq_debugfs_attr *attr = inode->i_private;
741	void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
742	struct seq_file *m;
743	int ret;
744
745	if (attr->seq_ops) {
746		ret = seq_open(file, attr->seq_ops);
747		if (!ret) {
748			m = file->private_data;
749			m->private = data;
750		}
751		return ret;
752	}
753
754	if (WARN_ON_ONCE(!attr->show))
755		return -EPERM;
756
757	return single_open(file, blk_mq_debugfs_show, inode->i_private);
758}
759
760static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
761{
762	const struct blk_mq_debugfs_attr *attr = inode->i_private;
763
764	if (attr->show)
765		return single_release(inode, file);
766
767	return seq_release(inode, file);
768}
769
770static const struct file_operations blk_mq_debugfs_fops = {
771	.open		= blk_mq_debugfs_open,
772	.read		= seq_read,
773	.write		= blk_mq_debugfs_write,
774	.llseek		= seq_lseek,
775	.release	= blk_mq_debugfs_release,
776};
777
778static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
779	{"state", 0400, hctx_state_show},
780	{"flags", 0400, hctx_flags_show},
781	{"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
782	{"busy", 0400, hctx_busy_show},
783	{"ctx_map", 0400, hctx_ctx_map_show},
784	{"tags", 0400, hctx_tags_show},
785	{"tags_bitmap", 0400, hctx_tags_bitmap_show},
786	{"sched_tags", 0400, hctx_sched_tags_show},
787	{"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
788	{"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
789	{"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
790	{"queued", 0600, hctx_queued_show, hctx_queued_write},
791	{"run", 0600, hctx_run_show, hctx_run_write},
792	{"active", 0400, hctx_active_show},
793	{"dispatch_busy", 0400, hctx_dispatch_busy_show},
794	{"type", 0400, hctx_type_show},
795	{},
796};
797
798static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
799	{"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
800	{"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
801	{"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
802	{"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
803	{"merged", 0600, ctx_merged_show, ctx_merged_write},
804	{"completed", 0600, ctx_completed_show, ctx_completed_write},
805	{},
806};
807
808static void debugfs_create_files(struct dentry *parent, void *data,
809				 const struct blk_mq_debugfs_attr *attr)
810{
811	if (IS_ERR_OR_NULL(parent))
812		return;
813
814	d_inode(parent)->i_private = data;
815
816	for (; attr->name; attr++)
817		debugfs_create_file(attr->name, attr->mode, parent,
818				    (void *)attr, &blk_mq_debugfs_fops);
819}
820
821void blk_mq_debugfs_register(struct request_queue *q)
822{
823	struct blk_mq_hw_ctx *hctx;
824	int i;
825
826	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
827					    blk_debugfs_root);
828
829	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
830
831	/*
832	 * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
833	 * didn't exist yet (because we don't know what to name the directory
834	 * until the queue is registered to a gendisk).
835	 */
836	if (q->elevator && !q->sched_debugfs_dir)
837		blk_mq_debugfs_register_sched(q);
838
839	/* Similarly, blk_mq_init_hctx() couldn't do this previously. */
840	queue_for_each_hw_ctx(q, hctx, i) {
841		if (!hctx->debugfs_dir)
842			blk_mq_debugfs_register_hctx(q, hctx);
843		if (q->elevator && !hctx->sched_debugfs_dir)
844			blk_mq_debugfs_register_sched_hctx(q, hctx);
845	}
846
847	if (q->rq_qos) {
848		struct rq_qos *rqos = q->rq_qos;
849
850		while (rqos) {
851			blk_mq_debugfs_register_rqos(rqos);
852			rqos = rqos->next;
853		}
854	}
855}
856
857void blk_mq_debugfs_unregister(struct request_queue *q)
858{
859	debugfs_remove_recursive(q->debugfs_dir);
860	q->sched_debugfs_dir = NULL;
861	q->debugfs_dir = NULL;
862}
863
864static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
865					struct blk_mq_ctx *ctx)
866{
867	struct dentry *ctx_dir;
868	char name[20];
869
870	snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
871	ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
872
873	debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
874}
875
876void blk_mq_debugfs_register_hctx(struct request_queue *q,
877				  struct blk_mq_hw_ctx *hctx)
878{
879	struct blk_mq_ctx *ctx;
880	char name[20];
881	int i;
882
883	snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
884	hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
885
886	debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
887
888	hctx_for_each_ctx(hctx, ctx, i)
889		blk_mq_debugfs_register_ctx(hctx, ctx);
890}
891
892void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
893{
894	debugfs_remove_recursive(hctx->debugfs_dir);
895	hctx->sched_debugfs_dir = NULL;
896	hctx->debugfs_dir = NULL;
897}
898
899void blk_mq_debugfs_register_hctxs(struct request_queue *q)
900{
901	struct blk_mq_hw_ctx *hctx;
902	int i;
903
904	queue_for_each_hw_ctx(q, hctx, i)
905		blk_mq_debugfs_register_hctx(q, hctx);
906}
907
908void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
909{
910	struct blk_mq_hw_ctx *hctx;
911	int i;
912
913	queue_for_each_hw_ctx(q, hctx, i)
914		blk_mq_debugfs_unregister_hctx(hctx);
915}
916
917void blk_mq_debugfs_register_sched(struct request_queue *q)
918{
919	struct elevator_type *e = q->elevator->type;
920
921	/*
922	 * If the parent directory has not been created yet, return, we will be
923	 * called again later on and the directory/files will be created then.
924	 */
925	if (!q->debugfs_dir)
926		return;
927
928	if (!e->queue_debugfs_attrs)
929		return;
930
931	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
932
933	debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
934}
935
936void blk_mq_debugfs_unregister_sched(struct request_queue *q)
937{
938	debugfs_remove_recursive(q->sched_debugfs_dir);
939	q->sched_debugfs_dir = NULL;
940}
941
942void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
943{
944	debugfs_remove_recursive(rqos->debugfs_dir);
945	rqos->debugfs_dir = NULL;
946}
947
948void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
949{
950	struct request_queue *q = rqos->q;
951	const char *dir_name = rq_qos_id_to_name(rqos->id);
952
953	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
954		return;
955
956	if (!q->rqos_debugfs_dir)
957		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
958							 q->debugfs_dir);
959
960	rqos->debugfs_dir = debugfs_create_dir(dir_name,
961					       rqos->q->rqos_debugfs_dir);
962
963	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
964}
965
966void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
967{
968	debugfs_remove_recursive(q->rqos_debugfs_dir);
969	q->rqos_debugfs_dir = NULL;
970}
971
972void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
973					struct blk_mq_hw_ctx *hctx)
974{
975	struct elevator_type *e = q->elevator->type;
976
977	if (!e->hctx_debugfs_attrs)
978		return;
979
980	hctx->sched_debugfs_dir = debugfs_create_dir("sched",
981						     hctx->debugfs_dir);
982	debugfs_create_files(hctx->sched_debugfs_dir, hctx,
983			     e->hctx_debugfs_attrs);
984}
985
986void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
987{
988	debugfs_remove_recursive(hctx->sched_debugfs_dir);
989	hctx->sched_debugfs_dir = NULL;
990}