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TOMOYO Linux Cross Reference
Linux/block/blk-mq-debugfs.c

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

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