blk-mq: no need to check return value of debugfs_create functions
[muen/linux.git] / block / 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/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
17 static 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=%lld, 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
27 static 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
44 static 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
53 static 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
60 static 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
68 static 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
75 static 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
95 static 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
104 static 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
131 static 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
141 static 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);
171 inval:
172                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
173                 return -EINVAL;
174         }
175         return count;
176 }
177
178 static 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
189 static 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
201 static 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
212 static 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
219 static 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
230 static 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
237 static 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
245 static 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 REQ_OP_NAME(name) [REQ_OP_##name] = #name
265 static const char *const op_name[] = {
266         REQ_OP_NAME(READ),
267         REQ_OP_NAME(WRITE),
268         REQ_OP_NAME(FLUSH),
269         REQ_OP_NAME(DISCARD),
270         REQ_OP_NAME(SECURE_ERASE),
271         REQ_OP_NAME(ZONE_RESET),
272         REQ_OP_NAME(WRITE_SAME),
273         REQ_OP_NAME(WRITE_ZEROES),
274         REQ_OP_NAME(SCSI_IN),
275         REQ_OP_NAME(SCSI_OUT),
276         REQ_OP_NAME(DRV_IN),
277         REQ_OP_NAME(DRV_OUT),
278 };
279 #undef REQ_OP_NAME
280
281 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
282 static const char *const cmd_flag_name[] = {
283         CMD_FLAG_NAME(FAILFAST_DEV),
284         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
285         CMD_FLAG_NAME(FAILFAST_DRIVER),
286         CMD_FLAG_NAME(SYNC),
287         CMD_FLAG_NAME(META),
288         CMD_FLAG_NAME(PRIO),
289         CMD_FLAG_NAME(NOMERGE),
290         CMD_FLAG_NAME(IDLE),
291         CMD_FLAG_NAME(INTEGRITY),
292         CMD_FLAG_NAME(FUA),
293         CMD_FLAG_NAME(PREFLUSH),
294         CMD_FLAG_NAME(RAHEAD),
295         CMD_FLAG_NAME(BACKGROUND),
296         CMD_FLAG_NAME(NOWAIT),
297         CMD_FLAG_NAME(NOUNMAP),
298         CMD_FLAG_NAME(HIPRI),
299 };
300 #undef CMD_FLAG_NAME
301
302 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
303 static const char *const rqf_name[] = {
304         RQF_NAME(SORTED),
305         RQF_NAME(STARTED),
306         RQF_NAME(SOFTBARRIER),
307         RQF_NAME(FLUSH_SEQ),
308         RQF_NAME(MIXED_MERGE),
309         RQF_NAME(MQ_INFLIGHT),
310         RQF_NAME(DONTPREP),
311         RQF_NAME(PREEMPT),
312         RQF_NAME(COPY_USER),
313         RQF_NAME(FAILED),
314         RQF_NAME(QUIET),
315         RQF_NAME(ELVPRIV),
316         RQF_NAME(IO_STAT),
317         RQF_NAME(ALLOCED),
318         RQF_NAME(PM),
319         RQF_NAME(HASHED),
320         RQF_NAME(STATS),
321         RQF_NAME(SPECIAL_PAYLOAD),
322         RQF_NAME(ZONE_WRITE_LOCKED),
323         RQF_NAME(MQ_POLL_SLEPT),
324 };
325 #undef RQF_NAME
326
327 static const char *const blk_mq_rq_state_name_array[] = {
328         [MQ_RQ_IDLE]            = "idle",
329         [MQ_RQ_IN_FLIGHT]       = "in_flight",
330         [MQ_RQ_COMPLETE]        = "complete",
331 };
332
333 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
334 {
335         if (WARN_ON_ONCE((unsigned int)rq_state >=
336                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
337                 return "(?)";
338         return blk_mq_rq_state_name_array[rq_state];
339 }
340
341 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
342 {
343         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
344         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
345
346         seq_printf(m, "%p {.op=", rq);
347         if (op < ARRAY_SIZE(op_name) && op_name[op])
348                 seq_printf(m, "%s", op_name[op]);
349         else
350                 seq_printf(m, "%d", op);
351         seq_puts(m, ", .cmd_flags=");
352         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
353                        ARRAY_SIZE(cmd_flag_name));
354         seq_puts(m, ", .rq_flags=");
355         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
356                        ARRAY_SIZE(rqf_name));
357         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
358         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
359                    rq->internal_tag);
360         if (mq_ops->show_rq)
361                 mq_ops->show_rq(m, rq);
362         seq_puts(m, "}\n");
363         return 0;
364 }
365 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
366
367 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
368 {
369         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
370 }
371 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
372
373 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
374         __acquires(&hctx->lock)
375 {
376         struct blk_mq_hw_ctx *hctx = m->private;
377
378         spin_lock(&hctx->lock);
379         return seq_list_start(&hctx->dispatch, *pos);
380 }
381
382 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
383 {
384         struct blk_mq_hw_ctx *hctx = m->private;
385
386         return seq_list_next(v, &hctx->dispatch, pos);
387 }
388
389 static void hctx_dispatch_stop(struct seq_file *m, void *v)
390         __releases(&hctx->lock)
391 {
392         struct blk_mq_hw_ctx *hctx = m->private;
393
394         spin_unlock(&hctx->lock);
395 }
396
397 static const struct seq_operations hctx_dispatch_seq_ops = {
398         .start  = hctx_dispatch_start,
399         .next   = hctx_dispatch_next,
400         .stop   = hctx_dispatch_stop,
401         .show   = blk_mq_debugfs_rq_show,
402 };
403
404 struct show_busy_params {
405         struct seq_file         *m;
406         struct blk_mq_hw_ctx    *hctx;
407 };
408
409 /*
410  * Note: the state of a request may change while this function is in progress,
411  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
412  * keep iterating requests.
413  */
414 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
415 {
416         const struct show_busy_params *params = data;
417
418         if (rq->mq_hctx == params->hctx)
419                 __blk_mq_debugfs_rq_show(params->m,
420                                          list_entry_rq(&rq->queuelist));
421
422         return true;
423 }
424
425 static int hctx_busy_show(void *data, struct seq_file *m)
426 {
427         struct blk_mq_hw_ctx *hctx = data;
428         struct show_busy_params params = { .m = m, .hctx = hctx };
429
430         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
431                                 &params);
432
433         return 0;
434 }
435
436 static const char *const hctx_types[] = {
437         [HCTX_TYPE_DEFAULT]     = "default",
438         [HCTX_TYPE_READ]        = "read",
439         [HCTX_TYPE_POLL]        = "poll",
440 };
441
442 static int hctx_type_show(void *data, struct seq_file *m)
443 {
444         struct blk_mq_hw_ctx *hctx = data;
445
446         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
447         seq_printf(m, "%s\n", hctx_types[hctx->type]);
448         return 0;
449 }
450
451 static int hctx_ctx_map_show(void *data, struct seq_file *m)
452 {
453         struct blk_mq_hw_ctx *hctx = data;
454
455         sbitmap_bitmap_show(&hctx->ctx_map, m);
456         return 0;
457 }
458
459 static void blk_mq_debugfs_tags_show(struct seq_file *m,
460                                      struct blk_mq_tags *tags)
461 {
462         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
463         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
464         seq_printf(m, "active_queues=%d\n",
465                    atomic_read(&tags->active_queues));
466
467         seq_puts(m, "\nbitmap_tags:\n");
468         sbitmap_queue_show(&tags->bitmap_tags, m);
469
470         if (tags->nr_reserved_tags) {
471                 seq_puts(m, "\nbreserved_tags:\n");
472                 sbitmap_queue_show(&tags->breserved_tags, m);
473         }
474 }
475
476 static int hctx_tags_show(void *data, struct seq_file *m)
477 {
478         struct blk_mq_hw_ctx *hctx = data;
479         struct request_queue *q = hctx->queue;
480         int res;
481
482         res = mutex_lock_interruptible(&q->sysfs_lock);
483         if (res)
484                 goto out;
485         if (hctx->tags)
486                 blk_mq_debugfs_tags_show(m, hctx->tags);
487         mutex_unlock(&q->sysfs_lock);
488
489 out:
490         return res;
491 }
492
493 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
494 {
495         struct blk_mq_hw_ctx *hctx = data;
496         struct request_queue *q = hctx->queue;
497         int res;
498
499         res = mutex_lock_interruptible(&q->sysfs_lock);
500         if (res)
501                 goto out;
502         if (hctx->tags)
503                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
504         mutex_unlock(&q->sysfs_lock);
505
506 out:
507         return res;
508 }
509
510 static int hctx_sched_tags_show(void *data, struct seq_file *m)
511 {
512         struct blk_mq_hw_ctx *hctx = data;
513         struct request_queue *q = hctx->queue;
514         int res;
515
516         res = mutex_lock_interruptible(&q->sysfs_lock);
517         if (res)
518                 goto out;
519         if (hctx->sched_tags)
520                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
521         mutex_unlock(&q->sysfs_lock);
522
523 out:
524         return res;
525 }
526
527 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
528 {
529         struct blk_mq_hw_ctx *hctx = data;
530         struct request_queue *q = hctx->queue;
531         int res;
532
533         res = mutex_lock_interruptible(&q->sysfs_lock);
534         if (res)
535                 goto out;
536         if (hctx->sched_tags)
537                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
538         mutex_unlock(&q->sysfs_lock);
539
540 out:
541         return res;
542 }
543
544 static int hctx_io_poll_show(void *data, struct seq_file *m)
545 {
546         struct blk_mq_hw_ctx *hctx = data;
547
548         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
549         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
550         seq_printf(m, "success=%lu\n", hctx->poll_success);
551         return 0;
552 }
553
554 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
555                                   size_t count, loff_t *ppos)
556 {
557         struct blk_mq_hw_ctx *hctx = data;
558
559         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
560         return count;
561 }
562
563 static int hctx_dispatched_show(void *data, struct seq_file *m)
564 {
565         struct blk_mq_hw_ctx *hctx = data;
566         int i;
567
568         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
569
570         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
571                 unsigned int d = 1U << (i - 1);
572
573                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
574         }
575
576         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
577         return 0;
578 }
579
580 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
581                                      size_t count, loff_t *ppos)
582 {
583         struct blk_mq_hw_ctx *hctx = data;
584         int i;
585
586         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
587                 hctx->dispatched[i] = 0;
588         return count;
589 }
590
591 static int hctx_queued_show(void *data, struct seq_file *m)
592 {
593         struct blk_mq_hw_ctx *hctx = data;
594
595         seq_printf(m, "%lu\n", hctx->queued);
596         return 0;
597 }
598
599 static ssize_t hctx_queued_write(void *data, const char __user *buf,
600                                  size_t count, loff_t *ppos)
601 {
602         struct blk_mq_hw_ctx *hctx = data;
603
604         hctx->queued = 0;
605         return count;
606 }
607
608 static int hctx_run_show(void *data, struct seq_file *m)
609 {
610         struct blk_mq_hw_ctx *hctx = data;
611
612         seq_printf(m, "%lu\n", hctx->run);
613         return 0;
614 }
615
616 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
617                               loff_t *ppos)
618 {
619         struct blk_mq_hw_ctx *hctx = data;
620
621         hctx->run = 0;
622         return count;
623 }
624
625 static int hctx_active_show(void *data, struct seq_file *m)
626 {
627         struct blk_mq_hw_ctx *hctx = data;
628
629         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
630         return 0;
631 }
632
633 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
634 {
635         struct blk_mq_hw_ctx *hctx = data;
636
637         seq_printf(m, "%u\n", hctx->dispatch_busy);
638         return 0;
639 }
640
641 #define CTX_RQ_SEQ_OPS(name, type)                                      \
642 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
643         __acquires(&ctx->lock)                                          \
644 {                                                                       \
645         struct blk_mq_ctx *ctx = m->private;                            \
646                                                                         \
647         spin_lock(&ctx->lock);                                          \
648         return seq_list_start(&ctx->rq_lists[type], *pos);              \
649 }                                                                       \
650                                                                         \
651 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
652                                      loff_t *pos)                       \
653 {                                                                       \
654         struct blk_mq_ctx *ctx = m->private;                            \
655                                                                         \
656         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
657 }                                                                       \
658                                                                         \
659 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
660         __releases(&ctx->lock)                                          \
661 {                                                                       \
662         struct blk_mq_ctx *ctx = m->private;                            \
663                                                                         \
664         spin_unlock(&ctx->lock);                                        \
665 }                                                                       \
666                                                                         \
667 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
668         .start  = ctx_##name##_rq_list_start,                           \
669         .next   = ctx_##name##_rq_list_next,                            \
670         .stop   = ctx_##name##_rq_list_stop,                            \
671         .show   = blk_mq_debugfs_rq_show,                               \
672 }
673
674 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
675 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
676 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
677
678 static int ctx_dispatched_show(void *data, struct seq_file *m)
679 {
680         struct blk_mq_ctx *ctx = data;
681
682         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
683         return 0;
684 }
685
686 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
687                                     size_t count, loff_t *ppos)
688 {
689         struct blk_mq_ctx *ctx = data;
690
691         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
692         return count;
693 }
694
695 static int ctx_merged_show(void *data, struct seq_file *m)
696 {
697         struct blk_mq_ctx *ctx = data;
698
699         seq_printf(m, "%lu\n", ctx->rq_merged);
700         return 0;
701 }
702
703 static ssize_t ctx_merged_write(void *data, const char __user *buf,
704                                 size_t count, loff_t *ppos)
705 {
706         struct blk_mq_ctx *ctx = data;
707
708         ctx->rq_merged = 0;
709         return count;
710 }
711
712 static int ctx_completed_show(void *data, struct seq_file *m)
713 {
714         struct blk_mq_ctx *ctx = data;
715
716         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
717         return 0;
718 }
719
720 static ssize_t ctx_completed_write(void *data, const char __user *buf,
721                                    size_t count, loff_t *ppos)
722 {
723         struct blk_mq_ctx *ctx = data;
724
725         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
726         return count;
727 }
728
729 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
730 {
731         const struct blk_mq_debugfs_attr *attr = m->private;
732         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
733
734         return attr->show(data, m);
735 }
736
737 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
738                                     size_t count, loff_t *ppos)
739 {
740         struct seq_file *m = file->private_data;
741         const struct blk_mq_debugfs_attr *attr = m->private;
742         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
743
744         /*
745          * Attributes that only implement .seq_ops are read-only and 'attr' is
746          * the same with 'data' in this case.
747          */
748         if (attr == data || !attr->write)
749                 return -EPERM;
750
751         return attr->write(data, buf, count, ppos);
752 }
753
754 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
755 {
756         const struct blk_mq_debugfs_attr *attr = inode->i_private;
757         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
758         struct seq_file *m;
759         int ret;
760
761         if (attr->seq_ops) {
762                 ret = seq_open(file, attr->seq_ops);
763                 if (!ret) {
764                         m = file->private_data;
765                         m->private = data;
766                 }
767                 return ret;
768         }
769
770         if (WARN_ON_ONCE(!attr->show))
771                 return -EPERM;
772
773         return single_open(file, blk_mq_debugfs_show, inode->i_private);
774 }
775
776 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
777 {
778         const struct blk_mq_debugfs_attr *attr = inode->i_private;
779
780         if (attr->show)
781                 return single_release(inode, file);
782         else
783                 return seq_release(inode, file);
784 }
785
786 static const struct file_operations blk_mq_debugfs_fops = {
787         .open           = blk_mq_debugfs_open,
788         .read           = seq_read,
789         .write          = blk_mq_debugfs_write,
790         .llseek         = seq_lseek,
791         .release        = blk_mq_debugfs_release,
792 };
793
794 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
795         {"state", 0400, hctx_state_show},
796         {"flags", 0400, hctx_flags_show},
797         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
798         {"busy", 0400, hctx_busy_show},
799         {"ctx_map", 0400, hctx_ctx_map_show},
800         {"tags", 0400, hctx_tags_show},
801         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
802         {"sched_tags", 0400, hctx_sched_tags_show},
803         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
804         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
805         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
806         {"queued", 0600, hctx_queued_show, hctx_queued_write},
807         {"run", 0600, hctx_run_show, hctx_run_write},
808         {"active", 0400, hctx_active_show},
809         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
810         {"type", 0400, hctx_type_show},
811         {},
812 };
813
814 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
815         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
816         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
817         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
818         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
819         {"merged", 0600, ctx_merged_show, ctx_merged_write},
820         {"completed", 0600, ctx_completed_show, ctx_completed_write},
821         {},
822 };
823
824 static void debugfs_create_files(struct dentry *parent, void *data,
825                                  const struct blk_mq_debugfs_attr *attr)
826 {
827         if (IS_ERR_OR_NULL(parent))
828                 return;
829
830         d_inode(parent)->i_private = data;
831
832         for (; attr->name; attr++)
833                 debugfs_create_file(attr->name, attr->mode, parent,
834                                     (void *)attr, &blk_mq_debugfs_fops);
835 }
836
837 void blk_mq_debugfs_register(struct request_queue *q)
838 {
839         struct blk_mq_hw_ctx *hctx;
840         int i;
841
842         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
843                                             blk_debugfs_root);
844
845         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
846
847         /*
848          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
849          * didn't exist yet (because we don't know what to name the directory
850          * until the queue is registered to a gendisk).
851          */
852         if (q->elevator && !q->sched_debugfs_dir)
853                 blk_mq_debugfs_register_sched(q);
854
855         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
856         queue_for_each_hw_ctx(q, hctx, i) {
857                 if (!hctx->debugfs_dir)
858                         blk_mq_debugfs_register_hctx(q, hctx);
859                 if (q->elevator && !hctx->sched_debugfs_dir)
860                         blk_mq_debugfs_register_sched_hctx(q, hctx);
861         }
862
863         if (q->rq_qos) {
864                 struct rq_qos *rqos = q->rq_qos;
865
866                 while (rqos) {
867                         blk_mq_debugfs_register_rqos(rqos);
868                         rqos = rqos->next;
869                 }
870         }
871 }
872
873 void blk_mq_debugfs_unregister(struct request_queue *q)
874 {
875         debugfs_remove_recursive(q->debugfs_dir);
876         q->sched_debugfs_dir = NULL;
877         q->debugfs_dir = NULL;
878 }
879
880 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
881                                         struct blk_mq_ctx *ctx)
882 {
883         struct dentry *ctx_dir;
884         char name[20];
885
886         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
887         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
888
889         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
890 }
891
892 void blk_mq_debugfs_register_hctx(struct request_queue *q,
893                                   struct blk_mq_hw_ctx *hctx)
894 {
895         struct blk_mq_ctx *ctx;
896         char name[20];
897         int i;
898
899         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
900         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
901
902         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
903
904         hctx_for_each_ctx(hctx, ctx, i)
905                 blk_mq_debugfs_register_ctx(hctx, ctx);
906 }
907
908 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
909 {
910         debugfs_remove_recursive(hctx->debugfs_dir);
911         hctx->sched_debugfs_dir = NULL;
912         hctx->debugfs_dir = NULL;
913 }
914
915 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
916 {
917         struct blk_mq_hw_ctx *hctx;
918         int i;
919
920         queue_for_each_hw_ctx(q, hctx, i)
921                 blk_mq_debugfs_register_hctx(q, hctx);
922 }
923
924 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
925 {
926         struct blk_mq_hw_ctx *hctx;
927         int i;
928
929         queue_for_each_hw_ctx(q, hctx, i)
930                 blk_mq_debugfs_unregister_hctx(hctx);
931 }
932
933 void blk_mq_debugfs_register_sched(struct request_queue *q)
934 {
935         struct elevator_type *e = q->elevator->type;
936
937         if (!e->queue_debugfs_attrs)
938                 return;
939
940         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
941
942         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
943 }
944
945 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
946 {
947         debugfs_remove_recursive(q->sched_debugfs_dir);
948         q->sched_debugfs_dir = NULL;
949 }
950
951 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
952 {
953         debugfs_remove_recursive(rqos->debugfs_dir);
954         rqos->debugfs_dir = NULL;
955 }
956
957 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
958 {
959         struct request_queue *q = rqos->q;
960         const char *dir_name = rq_qos_id_to_name(rqos->id);
961
962         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
963                 return;
964
965         if (!q->rqos_debugfs_dir)
966                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
967                                                          q->debugfs_dir);
968
969         rqos->debugfs_dir = debugfs_create_dir(dir_name,
970                                                rqos->q->rqos_debugfs_dir);
971
972         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
973 }
974
975 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
976 {
977         debugfs_remove_recursive(q->rqos_debugfs_dir);
978         q->rqos_debugfs_dir = NULL;
979 }
980
981 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
982                                         struct blk_mq_hw_ctx *hctx)
983 {
984         struct elevator_type *e = q->elevator->type;
985
986         if (!e->hctx_debugfs_attrs)
987                 return;
988
989         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
990                                                      hctx->debugfs_dir);
991         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
992                              e->hctx_debugfs_attrs);
993 }
994
995 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
996 {
997         debugfs_remove_recursive(hctx->sched_debugfs_dir);
998         hctx->sched_debugfs_dir = NULL;
999 }