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=%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
  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(STABLE_WRITES),
 120         QUEUE_FLAG_NAME(POLL),
 121         QUEUE_FLAG_NAME(WC),
 122         QUEUE_FLAG_NAME(FUA),
 123         QUEUE_FLAG_NAME(DAX),
 124         QUEUE_FLAG_NAME(STATS),
 125         QUEUE_FLAG_NAME(POLL_STATS),
 126         QUEUE_FLAG_NAME(REGISTERED),
 127         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 128         QUEUE_FLAG_NAME(QUIESCED),
 129         QUEUE_FLAG_NAME(PCI_P2PDMA),
 130         QUEUE_FLAG_NAME(ZONE_RESETALL),
 131         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 132         QUEUE_FLAG_NAME(HCTX_ACTIVE),
 133         QUEUE_FLAG_NAME(NOWAIT),
 134 };
 135 #undef QUEUE_FLAG_NAME
 136
 137 static int queue_state_show(void *data, struct seq_file *m)
 138 {
 139         struct request_queue *q = data;
 140
 141         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 142                        ARRAY_SIZE(blk_queue_flag_name));
 143         seq_puts(m, "\n");
 144         return 0;
 145 }
 146
 147 static ssize_t queue_state_write(void *data, const char __user *buf,
 148                                  size_t count, loff_t *ppos)
 149 {
 150         struct request_queue *q = data;
 151         char opbuf[16] = { }, *op;
 152
 153         /*
 154          * The "state" attribute is removed after blk_cleanup_queue() has called
 155          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 156          * triggering a use-after-free.
 157          */
 158         if (blk_queue_dead(q))
 159                 return -ENOENT;
 160
 161         if (count >= sizeof(opbuf)) {
 162                 pr_err("%s: operation too long\n", __func__);
 163                 goto inval;
 164         }
 165
 166         if (copy_from_user(opbuf, buf, count))
 167                 return -EFAULT;
 168         op = strstrip(opbuf);
 169         if (strcmp(op, "run") == 0) {
 170                 blk_mq_run_hw_queues(q, true);
 171         } else if (strcmp(op, "start") == 0) {
 172                 blk_mq_start_stopped_hw_queues(q, true);
 173         } else if (strcmp(op, "kick") == 0) {
 174                 blk_mq_kick_requeue_list(q);
 175         } else {
 176                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 177 inval:
 178                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 179                 return -EINVAL;
 180         }
 181         return count;
 182 }
 183
 184 static int queue_write_hint_show(void *data, struct seq_file *m)
 185 {
 186         struct request_queue *q = data;
 187         int i;
 188
 189         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 190                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 191
 192         return 0;
 193 }
 194
 195 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 196                                       size_t count, loff_t *ppos)
 197 {
 198         struct request_queue *q = data;
 199         int i;
 200
 201         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 202                 q->write_hints[i] = 0;
 203
 204         return count;
 205 }
 206
 207 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 208         { "poll_stat", 0400, queue_poll_stat_show },
 209         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 210         { "pm_only", 0600, queue_pm_only_show, NULL },
 211         { "state", 0600, queue_state_show, queue_state_write },
 212         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 213         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 214         { },
 215 };
 216
 217 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 218 static const char *const hctx_state_name[] = {
 219         HCTX_STATE_NAME(STOPPED),
 220         HCTX_STATE_NAME(TAG_ACTIVE),
 221         HCTX_STATE_NAME(SCHED_RESTART),
 222         HCTX_STATE_NAME(INACTIVE),
 223 };
 224 #undef HCTX_STATE_NAME
 225
 226 static int hctx_state_show(void *data, struct seq_file *m)
 227 {
 228         struct blk_mq_hw_ctx *hctx = data;
 229
 230         blk_flags_show(m, hctx->state, hctx_state_name,
 231                        ARRAY_SIZE(hctx_state_name));
 232         seq_puts(m, "\n");
 233         return 0;
 234 }
 235
 236 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 237 static const char *const alloc_policy_name[] = {
 238         BLK_TAG_ALLOC_NAME(FIFO),
 239         BLK_TAG_ALLOC_NAME(RR),
 240 };
 241 #undef BLK_TAG_ALLOC_NAME
 242
 243 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 244 static const char *const hctx_flag_name[] = {
 245         HCTX_FLAG_NAME(SHOULD_MERGE),
 246         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 247         HCTX_FLAG_NAME(BLOCKING),
 248         HCTX_FLAG_NAME(NO_SCHED),
 249         HCTX_FLAG_NAME(STACKING),
 250         HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 251 };
 252 #undef HCTX_FLAG_NAME
 253
 254 static int hctx_flags_show(void *data, struct seq_file *m)
 255 {
 256         struct blk_mq_hw_ctx *hctx = data;
 257         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 258
 259         seq_puts(m, "alloc_policy=");
 260         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 261             alloc_policy_name[alloc_policy])
 262                 seq_puts(m, alloc_policy_name[alloc_policy]);
 263         else
 264                 seq_printf(m, "%d", alloc_policy);
 265         seq_puts(m, " ");
 266         blk_flags_show(m,
 267                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 268                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 269         seq_puts(m, "\n");
 270         return 0;
 271 }
 272
 273 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 274 static const char *const cmd_flag_name[] = {
 275         CMD_FLAG_NAME(FAILFAST_DEV),
 276         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 277         CMD_FLAG_NAME(FAILFAST_DRIVER),
 278         CMD_FLAG_NAME(SYNC),
 279         CMD_FLAG_NAME(META),
 280         CMD_FLAG_NAME(PRIO),
 281         CMD_FLAG_NAME(NOMERGE),
 282         CMD_FLAG_NAME(IDLE),
 283         CMD_FLAG_NAME(INTEGRITY),
 284         CMD_FLAG_NAME(FUA),
 285         CMD_FLAG_NAME(PREFLUSH),
 286         CMD_FLAG_NAME(RAHEAD),
 287         CMD_FLAG_NAME(BACKGROUND),
 288         CMD_FLAG_NAME(NOWAIT),
 289         CMD_FLAG_NAME(NOUNMAP),
 290         CMD_FLAG_NAME(HIPRI),
 291 };
 292 #undef CMD_FLAG_NAME
 293
 294 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 295 static const char *const rqf_name[] = {
 296         RQF_NAME(SORTED),
 297         RQF_NAME(STARTED),
 298         RQF_NAME(SOFTBARRIER),
 299         RQF_NAME(FLUSH_SEQ),
 300         RQF_NAME(MIXED_MERGE),
 301         RQF_NAME(MQ_INFLIGHT),
 302         RQF_NAME(DONTPREP),
 303         RQF_NAME(FAILED),
 304         RQF_NAME(QUIET),
 305         RQF_NAME(ELVPRIV),
 306         RQF_NAME(IO_STAT),
 307         RQF_NAME(ALLOCED),
 308         RQF_NAME(PM),
 309         RQF_NAME(HASHED),
 310         RQF_NAME(STATS),
 311         RQF_NAME(SPECIAL_PAYLOAD),
 312         RQF_NAME(ZONE_WRITE_LOCKED),
 313         RQF_NAME(MQ_POLL_SLEPT),
 314 };
 315 #undef RQF_NAME
 316
 317 static const char *const blk_mq_rq_state_name_array[] = {
 318         [MQ_RQ_IDLE]            = "idle",
 319         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 320         [MQ_RQ_COMPLETE]        = "complete",
 321 };
 322
 323 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 324 {
 325         if (WARN_ON_ONCE((unsigned int)rq_state >=
 326                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 327                 return "(?)";
 328         return blk_mq_rq_state_name_array[rq_state];
 329 }
 330
 331 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 332 {
 333         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 334         const unsigned int op = req_op(rq);
 335         const char *op_str = blk_op_str(op);
 336
 337         seq_printf(m, "%p {.op=", rq);
 338         if (strcmp(op_str, "UNKNOWN") == 0)
 339                 seq_printf(m, "%u", op);
 340         else
 341                 seq_printf(m, "%s", op_str);
 342         seq_puts(m, ", .cmd_flags=");
 343         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 344                        ARRAY_SIZE(cmd_flag_name));
 345         seq_puts(m, ", .rq_flags=");
 346         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 347                        ARRAY_SIZE(rqf_name));
 348         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 349         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 350                    rq->internal_tag);
 351         if (mq_ops->show_rq)
 352                 mq_ops->show_rq(m, rq);
 353         seq_puts(m, "}\n");
 354         return 0;
 355 }
 356 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 357
 358 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 359 {
 360         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 361 }
 362 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 363
 364 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 365         __acquires(&hctx->lock)
 366 {
 367         struct blk_mq_hw_ctx *hctx = m->private;
 368
 369         spin_lock(&hctx->lock);
 370         return seq_list_start(&hctx->dispatch, *pos);
 371 }
 372
 373 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 374 {
 375         struct blk_mq_hw_ctx *hctx = m->private;
 376
 377         return seq_list_next(v, &hctx->dispatch, pos);
 378 }
 379
 380 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 381         __releases(&hctx->lock)
 382 {
 383         struct blk_mq_hw_ctx *hctx = m->private;
 384
 385         spin_unlock(&hctx->lock);
 386 }
 387
 388 static const struct seq_operations hctx_dispatch_seq_ops = {
 389         .start  = hctx_dispatch_start,
 390         .next   = hctx_dispatch_next,
 391         .stop   = hctx_dispatch_stop,
 392         .show   = blk_mq_debugfs_rq_show,
 393 };
 394
 395 struct show_busy_params {
 396         struct seq_file         *m;
 397         struct blk_mq_hw_ctx    *hctx;
 398 };
 399
 400 /*
 401  * Note: the state of a request may change while this function is in progress,
 402  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 403  * keep iterating requests.
 404  */
 405 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 406 {
 407         const struct show_busy_params *params = data;
 408
 409         if (rq->mq_hctx == params->hctx)
 410                 __blk_mq_debugfs_rq_show(params->m, rq);
 411
 412         return true;
 413 }
 414
 415 static int hctx_busy_show(void *data, struct seq_file *m)
 416 {
 417         struct blk_mq_hw_ctx *hctx = data;
 418         struct show_busy_params params = { .m = m, .hctx = hctx };
 419
 420         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 421                                 &params);
 422
 423         return 0;
 424 }
 425
 426 static const char *const hctx_types[] = {
 427         [HCTX_TYPE_DEFAULT]     = "default",
 428         [HCTX_TYPE_READ]        = "read",
 429         [HCTX_TYPE_POLL]        = "poll",
 430 };
 431
 432 static int hctx_type_show(void *data, struct seq_file *m)
 433 {
 434         struct blk_mq_hw_ctx *hctx = data;
 435
 436         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 437         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 438         return 0;
 439 }
 440
 441 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 442 {
 443         struct blk_mq_hw_ctx *hctx = data;
 444
 445         sbitmap_bitmap_show(&hctx->ctx_map, m);
 446         return 0;
 447 }
 448
 449 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 450                                      struct blk_mq_tags *tags)
 451 {
 452         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 453         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 454         seq_printf(m, "active_queues=%d\n",
 455                    atomic_read(&tags->active_queues));
 456
 457         seq_puts(m, "\nbitmap_tags:\n");
 458         sbitmap_queue_show(tags->bitmap_tags, m);
 459
 460         if (tags->nr_reserved_tags) {
 461                 seq_puts(m, "\nbreserved_tags:\n");
 462                 sbitmap_queue_show(tags->breserved_tags, m);
 463         }
 464 }
 465
 466 static int hctx_tags_show(void *data, struct seq_file *m)
 467 {
 468         struct blk_mq_hw_ctx *hctx = data;
 469         struct request_queue *q = hctx->queue;
 470         int res;
 471
 472         res = mutex_lock_interruptible(&q->sysfs_lock);
 473         if (res)
 474                 goto out;
 475         if (hctx->tags)
 476                 blk_mq_debugfs_tags_show(m, hctx->tags);
 477         mutex_unlock(&q->sysfs_lock);
 478
 479 out:
 480         return res;
 481 }
 482
 483 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 484 {
 485         struct blk_mq_hw_ctx *hctx = data;
 486         struct request_queue *q = hctx->queue;
 487         int res;
 488
 489         res = mutex_lock_interruptible(&q->sysfs_lock);
 490         if (res)
 491                 goto out;
 492         if (hctx->tags)
 493                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m);
 494         mutex_unlock(&q->sysfs_lock);
 495
 496 out:
 497         return res;
 498 }
 499
 500 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 501 {
 502         struct blk_mq_hw_ctx *hctx = data;
 503         struct request_queue *q = hctx->queue;
 504         int res;
 505
 506         res = mutex_lock_interruptible(&q->sysfs_lock);
 507         if (res)
 508                 goto out;
 509         if (hctx->sched_tags)
 510                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 511         mutex_unlock(&q->sysfs_lock);
 512
 513 out:
 514         return res;
 515 }
 516
 517 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 518 {
 519         struct blk_mq_hw_ctx *hctx = data;
 520         struct request_queue *q = hctx->queue;
 521         int res;
 522
 523         res = mutex_lock_interruptible(&q->sysfs_lock);
 524         if (res)
 525                 goto out;
 526         if (hctx->sched_tags)
 527                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m);
 528         mutex_unlock(&q->sysfs_lock);
 529
 530 out:
 531         return res;
 532 }
 533
 534 static int hctx_io_poll_show(void *data, struct seq_file *m)
 535 {
 536         struct blk_mq_hw_ctx *hctx = data;
 537
 538         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 539         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 540         seq_printf(m, "success=%lu\n", hctx->poll_success);
 541         return 0;
 542 }
 543
 544 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 545                                   size_t count, loff_t *ppos)
 546 {
 547         struct blk_mq_hw_ctx *hctx = data;
 548
 549         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 550         return count;
 551 }
 552
 553 static int hctx_dispatched_show(void *data, struct seq_file *m)
 554 {
 555         struct blk_mq_hw_ctx *hctx = data;
 556         int i;
 557
 558         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 559
 560         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 561                 unsigned int d = 1U << (i - 1);
 562
 563                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 564         }
 565
 566         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 567         return 0;
 568 }
 569
 570 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 571                                      size_t count, loff_t *ppos)
 572 {
 573         struct blk_mq_hw_ctx *hctx = data;
 574         int i;
 575
 576         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 577                 hctx->dispatched[i] = 0;
 578         return count;
 579 }
 580
 581 static int hctx_queued_show(void *data, struct seq_file *m)
 582 {
 583         struct blk_mq_hw_ctx *hctx = data;
 584
 585         seq_printf(m, "%lu\n", hctx->queued);
 586         return 0;
 587 }
 588
 589 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 590                                  size_t count, loff_t *ppos)
 591 {
 592         struct blk_mq_hw_ctx *hctx = data;
 593
 594         hctx->queued = 0;
 595         return count;
 596 }
 597
 598 static int hctx_run_show(void *data, struct seq_file *m)
 599 {
 600         struct blk_mq_hw_ctx *hctx = data;
 601
 602         seq_printf(m, "%lu\n", hctx->run);
 603         return 0;
 604 }
 605
 606 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 607                               loff_t *ppos)
 608 {
 609         struct blk_mq_hw_ctx *hctx = data;
 610
 611         hctx->run = 0;
 612         return count;
 613 }
 614
 615 static int hctx_active_show(void *data, struct seq_file *m)
 616 {
 617         struct blk_mq_hw_ctx *hctx = data;
 618
 619         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 620         return 0;
 621 }
 622
 623 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 624 {
 625         struct blk_mq_hw_ctx *hctx = data;
 626
 627         seq_printf(m, "%u\n", hctx->dispatch_busy);
 628         return 0;
 629 }
 630
 631 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 632 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 633         __acquires(&ctx->lock)                                          \
 634 {                                                                       \
 635         struct blk_mq_ctx *ctx = m->private;                            \
 636                                                                         \
 637         spin_lock(&ctx->lock);                                          \
 638         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 639 }                                                                       \
 640                                                                         \
 641 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 642                                      loff_t *pos)                       \
 643 {                                                                       \
 644         struct blk_mq_ctx *ctx = m->private;                            \
 645                                                                         \
 646         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 647 }                                                                       \
 648                                                                         \
 649 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 650         __releases(&ctx->lock)                                          \
 651 {                                                                       \
 652         struct blk_mq_ctx *ctx = m->private;                            \
 653                                                                         \
 654         spin_unlock(&ctx->lock);                                        \
 655 }                                                                       \
 656                                                                         \
 657 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 658         .start  = ctx_##name##_rq_list_start,                           \
 659         .next   = ctx_##name##_rq_list_next,                            \
 660         .stop   = ctx_##name##_rq_list_stop,                            \
 661         .show   = blk_mq_debugfs_rq_show,                               \
 662 }
 663
 664 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 665 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 666 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 667
 668 static int ctx_dispatched_show(void *data, struct seq_file *m)
 669 {
 670         struct blk_mq_ctx *ctx = data;
 671
 672         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 673         return 0;
 674 }
 675
 676 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 677                                     size_t count, loff_t *ppos)
 678 {
 679         struct blk_mq_ctx *ctx = data;
 680
 681         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 682         return count;
 683 }
 684
 685 static int ctx_merged_show(void *data, struct seq_file *m)
 686 {
 687         struct blk_mq_ctx *ctx = data;
 688
 689         seq_printf(m, "%lu\n", ctx->rq_merged);
 690         return 0;
 691 }
 692
 693 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 694                                 size_t count, loff_t *ppos)
 695 {
 696         struct blk_mq_ctx *ctx = data;
 697
 698         ctx->rq_merged = 0;
 699         return count;
 700 }
 701
 702 static int ctx_completed_show(void *data, struct seq_file *m)
 703 {
 704         struct blk_mq_ctx *ctx = data;
 705
 706         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 707         return 0;
 708 }
 709
 710 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 711                                    size_t count, loff_t *ppos)
 712 {
 713         struct blk_mq_ctx *ctx = data;
 714
 715         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 716         return count;
 717 }
 718
 719 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 720 {
 721         const struct blk_mq_debugfs_attr *attr = m->private;
 722         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 723
 724         return attr->show(data, m);
 725 }
 726
 727 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 728                                     size_t count, loff_t *ppos)
 729 {
 730         struct seq_file *m = file->private_data;
 731         const struct blk_mq_debugfs_attr *attr = m->private;
 732         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 733
 734         /*
 735          * Attributes that only implement .seq_ops are read-only and 'attr' is
 736          * the same with 'data' in this case.
 737          */
 738         if (attr == data || !attr->write)
 739                 return -EPERM;
 740
 741         return attr->write(data, buf, count, ppos);
 742 }
 743
 744 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 745 {
 746         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 747         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 748         struct seq_file *m;
 749         int ret;
 750
 751         if (attr->seq_ops) {
 752                 ret = seq_open(file, attr->seq_ops);
 753                 if (!ret) {
 754                         m = file->private_data;
 755                         m->private = data;
 756                 }
 757                 return ret;
 758         }
 759
 760         if (WARN_ON_ONCE(!attr->show))
 761                 return -EPERM;
 762
 763         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 764 }
 765
 766 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 767 {
 768         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 769
 770         if (attr->show)
 771                 return single_release(inode, file);
 772
 773         return seq_release(inode, file);
 774 }
 775
 776 static const struct file_operations blk_mq_debugfs_fops = {
 777         .open           = blk_mq_debugfs_open,
 778         .read           = seq_read,
 779         .write          = blk_mq_debugfs_write,
 780         .llseek         = seq_lseek,
 781         .release        = blk_mq_debugfs_release,
 782 };
 783
 784 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 785         {"state", 0400, hctx_state_show},
 786         {"flags", 0400, hctx_flags_show},
 787         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 788         {"busy", 0400, hctx_busy_show},
 789         {"ctx_map", 0400, hctx_ctx_map_show},
 790         {"tags", 0400, hctx_tags_show},
 791         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 792         {"sched_tags", 0400, hctx_sched_tags_show},
 793         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 794         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 795         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 796         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 797         {"run", 0600, hctx_run_show, hctx_run_write},
 798         {"active", 0400, hctx_active_show},
 799         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 800         {"type", 0400, hctx_type_show},
 801         {},
 802 };
 803
 804 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 805         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 806         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 807         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 808         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 809         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 810         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 811         {},
 812 };
 813
 814 static void debugfs_create_files(struct dentry *parent, void *data,
 815                                  const struct blk_mq_debugfs_attr *attr)
 816 {
 817         if (IS_ERR_OR_NULL(parent))
 818                 return;
 819
 820         d_inode(parent)->i_private = data;
 821
 822         for (; attr->name; attr++)
 823                 debugfs_create_file(attr->name, attr->mode, parent,
 824                                     (void *)attr, &blk_mq_debugfs_fops);
 825 }
 826
 827 void blk_mq_debugfs_register(struct request_queue *q)
 828 {
 829         struct blk_mq_hw_ctx *hctx;
 830         int i;
 831
 832         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 833
 834         /*
 835          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 836          * didn't exist yet (because we don't know what to name the directory
 837          * until the queue is registered to a gendisk).
 838          */
 839         if (q->elevator && !q->sched_debugfs_dir)
 840                 blk_mq_debugfs_register_sched(q);
 841
 842         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 843         queue_for_each_hw_ctx(q, hctx, i) {
 844                 if (!hctx->debugfs_dir)
 845                         blk_mq_debugfs_register_hctx(q, hctx);
 846                 if (q->elevator && !hctx->sched_debugfs_dir)
 847                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 848         }
 849
 850         if (q->rq_qos) {
 851                 struct rq_qos *rqos = q->rq_qos;
 852
 853                 while (rqos) {
 854                         blk_mq_debugfs_register_rqos(rqos);
 855                         rqos = rqos->next;
 856                 }
 857         }
 858 }
 859
 860 void blk_mq_debugfs_unregister(struct request_queue *q)
 861 {
 862         q->sched_debugfs_dir = NULL;
 863 }
 864
 865 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 866                                         struct blk_mq_ctx *ctx)
 867 {
 868         struct dentry *ctx_dir;
 869         char name[20];
 870
 871         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 872         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 873
 874         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 875 }
 876
 877 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 878                                   struct blk_mq_hw_ctx *hctx)
 879 {
 880         struct blk_mq_ctx *ctx;
 881         char name[20];
 882         int i;
 883
 884         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 885         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 886
 887         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 888
 889         hctx_for_each_ctx(hctx, ctx, i)
 890                 blk_mq_debugfs_register_ctx(hctx, ctx);
 891 }
 892
 893 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 894 {
 895         debugfs_remove_recursive(hctx->debugfs_dir);
 896         hctx->sched_debugfs_dir = NULL;
 897         hctx->debugfs_dir = NULL;
 898 }
 899
 900 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 901 {
 902         struct blk_mq_hw_ctx *hctx;
 903         int i;
 904
 905         queue_for_each_hw_ctx(q, hctx, i)
 906                 blk_mq_debugfs_register_hctx(q, hctx);
 907 }
 908
 909 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 910 {
 911         struct blk_mq_hw_ctx *hctx;
 912         int i;
 913
 914         queue_for_each_hw_ctx(q, hctx, i)
 915                 blk_mq_debugfs_unregister_hctx(hctx);
 916 }
 917
 918 void blk_mq_debugfs_register_sched(struct request_queue *q)
 919 {
 920         struct elevator_type *e = q->elevator->type;
 921
 922         /*
 923          * If the parent directory has not been created yet, return, we will be
 924          * called again later on and the directory/files will be created then.
 925          */
 926         if (!q->debugfs_dir)
 927                 return;
 928
 929         if (!e->queue_debugfs_attrs)
 930                 return;
 931
 932         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 933
 934         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 935 }
 936
 937 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 938 {
 939         debugfs_remove_recursive(q->sched_debugfs_dir);
 940         q->sched_debugfs_dir = NULL;
 941 }
 942
 943 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 944 {
 945         debugfs_remove_recursive(rqos->debugfs_dir);
 946         rqos->debugfs_dir = NULL;
 947 }
 948
 949 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 950 {
 951         struct request_queue *q = rqos->q;
 952         const char *dir_name = rq_qos_id_to_name(rqos->id);
 953
 954         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 955                 return;
 956
 957         if (!q->rqos_debugfs_dir)
 958                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 959                                                          q->debugfs_dir);
 960
 961         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 962                                                rqos->q->rqos_debugfs_dir);
 963
 964         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 965 }
 966
 967 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 968 {
 969         debugfs_remove_recursive(q->rqos_debugfs_dir);
 970         q->rqos_debugfs_dir = NULL;
 971 }
 972
 973 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 974                                         struct blk_mq_hw_ctx *hctx)
 975 {
 976         struct elevator_type *e = q->elevator->type;
 977
 978         if (!e->hctx_debugfs_attrs)
 979                 return;
 980
 981         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 982                                                      hctx->debugfs_dir);
 983         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 984                              e->hctx_debugfs_attrs);
 985 }
 986
 987 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 988 {
 989         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 990         hctx->sched_debugfs_dir = NULL;
 991 }