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(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         QUEUE_FLAG_NAME(PCI_P2PDMA),
 129         QUEUE_FLAG_NAME(ZONE_RESETALL),
 130         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 131 };
 132 #undef QUEUE_FLAG_NAME
 133
 134 static int queue_state_show(void *data, struct seq_file *m)
 135 {
 136         struct request_queue *q = data;
 137
 138         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 139                        ARRAY_SIZE(blk_queue_flag_name));
 140         seq_puts(m, "\n");
 141         return 0;
 142 }
 143
 144 static ssize_t queue_state_write(void *data, const char __user *buf,
 145                                  size_t count, loff_t *ppos)
 146 {
 147         struct request_queue *q = data;
 148         char opbuf[16] = { }, *op;
 149
 150         /*
 151          * The "state" attribute is removed after blk_cleanup_queue() has called
 152          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 153          * triggering a use-after-free.
 154          */
 155         if (blk_queue_dead(q))
 156                 return -ENOENT;
 157
 158         if (count >= sizeof(opbuf)) {
 159                 pr_err("%s: operation too long\n", __func__);
 160                 goto inval;
 161         }
 162
 163         if (copy_from_user(opbuf, buf, count))
 164                 return -EFAULT;
 165         op = strstrip(opbuf);
 166         if (strcmp(op, "run") == 0) {
 167                 blk_mq_run_hw_queues(q, true);
 168         } else if (strcmp(op, "start") == 0) {
 169                 blk_mq_start_stopped_hw_queues(q, true);
 170         } else if (strcmp(op, "kick") == 0) {
 171                 blk_mq_kick_requeue_list(q);
 172         } else {
 173                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 174 inval:
 175                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 176                 return -EINVAL;
 177         }
 178         return count;
 179 }
 180
 181 static int queue_write_hint_show(void *data, struct seq_file *m)
 182 {
 183         struct request_queue *q = data;
 184         int i;
 185
 186         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 187                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 188
 189         return 0;
 190 }
 191
 192 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 193                                       size_t count, loff_t *ppos)
 194 {
 195         struct request_queue *q = data;
 196         int i;
 197
 198         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 199                 q->write_hints[i] = 0;
 200
 201         return count;
 202 }
 203
 204 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 205         { "poll_stat", 0400, queue_poll_stat_show },
 206         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 207         { "pm_only", 0600, queue_pm_only_show, NULL },
 208         { "state", 0600, queue_state_show, queue_state_write },
 209         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 210         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 211         { },
 212 };
 213
 214 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 215 static const char *const hctx_state_name[] = {
 216         HCTX_STATE_NAME(STOPPED),
 217         HCTX_STATE_NAME(TAG_ACTIVE),
 218         HCTX_STATE_NAME(SCHED_RESTART),
 219 };
 220 #undef HCTX_STATE_NAME
 221
 222 static int hctx_state_show(void *data, struct seq_file *m)
 223 {
 224         struct blk_mq_hw_ctx *hctx = data;
 225
 226         blk_flags_show(m, hctx->state, hctx_state_name,
 227                        ARRAY_SIZE(hctx_state_name));
 228         seq_puts(m, "\n");
 229         return 0;
 230 }
 231
 232 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 233 static const char *const alloc_policy_name[] = {
 234         BLK_TAG_ALLOC_NAME(FIFO),
 235         BLK_TAG_ALLOC_NAME(RR),
 236 };
 237 #undef BLK_TAG_ALLOC_NAME
 238
 239 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 240 static const char *const hctx_flag_name[] = {
 241         HCTX_FLAG_NAME(SHOULD_MERGE),
 242         HCTX_FLAG_NAME(TAG_SHARED),
 243         HCTX_FLAG_NAME(BLOCKING),
 244         HCTX_FLAG_NAME(NO_SCHED),
 245 };
 246 #undef HCTX_FLAG_NAME
 247
 248 static int hctx_flags_show(void *data, struct seq_file *m)
 249 {
 250         struct blk_mq_hw_ctx *hctx = data;
 251         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 252
 253         seq_puts(m, "alloc_policy=");
 254         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 255             alloc_policy_name[alloc_policy])
 256                 seq_puts(m, alloc_policy_name[alloc_policy]);
 257         else
 258                 seq_printf(m, "%d", alloc_policy);
 259         seq_puts(m, " ");
 260         blk_flags_show(m,
 261                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 262                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 263         seq_puts(m, "\n");
 264         return 0;
 265 }
 266
 267 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 268 static const char *const cmd_flag_name[] = {
 269         CMD_FLAG_NAME(FAILFAST_DEV),
 270         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 271         CMD_FLAG_NAME(FAILFAST_DRIVER),
 272         CMD_FLAG_NAME(SYNC),
 273         CMD_FLAG_NAME(META),
 274         CMD_FLAG_NAME(PRIO),
 275         CMD_FLAG_NAME(NOMERGE),
 276         CMD_FLAG_NAME(IDLE),
 277         CMD_FLAG_NAME(INTEGRITY),
 278         CMD_FLAG_NAME(FUA),
 279         CMD_FLAG_NAME(PREFLUSH),
 280         CMD_FLAG_NAME(RAHEAD),
 281         CMD_FLAG_NAME(BACKGROUND),
 282         CMD_FLAG_NAME(NOWAIT),
 283         CMD_FLAG_NAME(NOUNMAP),
 284         CMD_FLAG_NAME(HIPRI),
 285 };
 286 #undef CMD_FLAG_NAME
 287
 288 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 289 static const char *const rqf_name[] = {
 290         RQF_NAME(SORTED),
 291         RQF_NAME(STARTED),
 292         RQF_NAME(SOFTBARRIER),
 293         RQF_NAME(FLUSH_SEQ),
 294         RQF_NAME(MIXED_MERGE),
 295         RQF_NAME(MQ_INFLIGHT),
 296         RQF_NAME(DONTPREP),
 297         RQF_NAME(PREEMPT),
 298         RQF_NAME(COPY_USER),
 299         RQF_NAME(FAILED),
 300         RQF_NAME(QUIET),
 301         RQF_NAME(ELVPRIV),
 302         RQF_NAME(IO_STAT),
 303         RQF_NAME(ALLOCED),
 304         RQF_NAME(PM),
 305         RQF_NAME(HASHED),
 306         RQF_NAME(STATS),
 307         RQF_NAME(SPECIAL_PAYLOAD),
 308         RQF_NAME(ZONE_WRITE_LOCKED),
 309         RQF_NAME(MQ_POLL_SLEPT),
 310 };
 311 #undef RQF_NAME
 312
 313 static const char *const blk_mq_rq_state_name_array[] = {
 314         [MQ_RQ_IDLE]            = "idle",
 315         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 316         [MQ_RQ_COMPLETE]        = "complete",
 317 };
 318
 319 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 320 {
 321         if (WARN_ON_ONCE((unsigned int)rq_state >=
 322                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 323                 return "(?)";
 324         return blk_mq_rq_state_name_array[rq_state];
 325 }
 326
 327 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 328 {
 329         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 330         const unsigned int op = req_op(rq);
 331         const char *op_str = blk_op_str(op);
 332
 333         seq_printf(m, "%p {.op=", rq);
 334         if (strcmp(op_str, "UNKNOWN") == 0)
 335                 seq_printf(m, "%u", op);
 336         else
 337                 seq_printf(m, "%s", op_str);
 338         seq_puts(m, ", .cmd_flags=");
 339         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 340                        ARRAY_SIZE(cmd_flag_name));
 341         seq_puts(m, ", .rq_flags=");
 342         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 343                        ARRAY_SIZE(rqf_name));
 344         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 345         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 346                    rq->internal_tag);
 347         if (mq_ops->show_rq)
 348                 mq_ops->show_rq(m, rq);
 349         seq_puts(m, "}\n");
 350         return 0;
 351 }
 352 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 353
 354 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 355 {
 356         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 357 }
 358 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 359
 360 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 361         __acquires(&hctx->lock)
 362 {
 363         struct blk_mq_hw_ctx *hctx = m->private;
 364
 365         spin_lock(&hctx->lock);
 366         return seq_list_start(&hctx->dispatch, *pos);
 367 }
 368
 369 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 370 {
 371         struct blk_mq_hw_ctx *hctx = m->private;
 372
 373         return seq_list_next(v, &hctx->dispatch, pos);
 374 }
 375
 376 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 377         __releases(&hctx->lock)
 378 {
 379         struct blk_mq_hw_ctx *hctx = m->private;
 380
 381         spin_unlock(&hctx->lock);
 382 }
 383
 384 static const struct seq_operations hctx_dispatch_seq_ops = {
 385         .start  = hctx_dispatch_start,
 386         .next   = hctx_dispatch_next,
 387         .stop   = hctx_dispatch_stop,
 388         .show   = blk_mq_debugfs_rq_show,
 389 };
 390
 391 struct show_busy_params {
 392         struct seq_file         *m;
 393         struct blk_mq_hw_ctx    *hctx;
 394 };
 395
 396 /*
 397  * Note: the state of a request may change while this function is in progress,
 398  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 399  * keep iterating requests.
 400  */
 401 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 402 {
 403         const struct show_busy_params *params = data;
 404
 405         if (rq->mq_hctx == params->hctx)
 406                 __blk_mq_debugfs_rq_show(params->m,
 407                                          list_entry_rq(&rq->queuelist));
 408
 409         return true;
 410 }
 411
 412 static int hctx_busy_show(void *data, struct seq_file *m)
 413 {
 414         struct blk_mq_hw_ctx *hctx = data;
 415         struct show_busy_params params = { .m = m, .hctx = hctx };
 416
 417         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 418                                 &params);
 419
 420         return 0;
 421 }
 422
 423 static const char *const hctx_types[] = {
 424         [HCTX_TYPE_DEFAULT]     = "default",
 425         [HCTX_TYPE_READ]        = "read",
 426         [HCTX_TYPE_POLL]        = "poll",
 427 };
 428
 429 static int hctx_type_show(void *data, struct seq_file *m)
 430 {
 431         struct blk_mq_hw_ctx *hctx = data;
 432
 433         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 434         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 435         return 0;
 436 }
 437
 438 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 439 {
 440         struct blk_mq_hw_ctx *hctx = data;
 441
 442         sbitmap_bitmap_show(&hctx->ctx_map, m);
 443         return 0;
 444 }
 445
 446 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 447                                      struct blk_mq_tags *tags)
 448 {
 449         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 450         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 451         seq_printf(m, "active_queues=%d\n",
 452                    atomic_read(&tags->active_queues));
 453
 454         seq_puts(m, "\nbitmap_tags:\n");
 455         sbitmap_queue_show(&tags->bitmap_tags, m);
 456
 457         if (tags->nr_reserved_tags) {
 458                 seq_puts(m, "\nbreserved_tags:\n");
 459                 sbitmap_queue_show(&tags->breserved_tags, m);
 460         }
 461 }
 462
 463 static int hctx_tags_show(void *data, struct seq_file *m)
 464 {
 465         struct blk_mq_hw_ctx *hctx = data;
 466         struct request_queue *q = hctx->queue;
 467         int res;
 468
 469         res = mutex_lock_interruptible(&q->sysfs_lock);
 470         if (res)
 471                 goto out;
 472         if (hctx->tags)
 473                 blk_mq_debugfs_tags_show(m, hctx->tags);
 474         mutex_unlock(&q->sysfs_lock);
 475
 476 out:
 477         return res;
 478 }
 479
 480 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 481 {
 482         struct blk_mq_hw_ctx *hctx = data;
 483         struct request_queue *q = hctx->queue;
 484         int res;
 485
 486         res = mutex_lock_interruptible(&q->sysfs_lock);
 487         if (res)
 488                 goto out;
 489         if (hctx->tags)
 490                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 491         mutex_unlock(&q->sysfs_lock);
 492
 493 out:
 494         return res;
 495 }
 496
 497 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 498 {
 499         struct blk_mq_hw_ctx *hctx = data;
 500         struct request_queue *q = hctx->queue;
 501         int res;
 502
 503         res = mutex_lock_interruptible(&q->sysfs_lock);
 504         if (res)
 505                 goto out;
 506         if (hctx->sched_tags)
 507                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 508         mutex_unlock(&q->sysfs_lock);
 509
 510 out:
 511         return res;
 512 }
 513
 514 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 515 {
 516         struct blk_mq_hw_ctx *hctx = data;
 517         struct request_queue *q = hctx->queue;
 518         int res;
 519
 520         res = mutex_lock_interruptible(&q->sysfs_lock);
 521         if (res)
 522                 goto out;
 523         if (hctx->sched_tags)
 524                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 525         mutex_unlock(&q->sysfs_lock);
 526
 527 out:
 528         return res;
 529 }
 530
 531 static int hctx_io_poll_show(void *data, struct seq_file *m)
 532 {
 533         struct blk_mq_hw_ctx *hctx = data;
 534
 535         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 536         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 537         seq_printf(m, "success=%lu\n", hctx->poll_success);
 538         return 0;
 539 }
 540
 541 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 542                                   size_t count, loff_t *ppos)
 543 {
 544         struct blk_mq_hw_ctx *hctx = data;
 545
 546         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 547         return count;
 548 }
 549
 550 static int hctx_dispatched_show(void *data, struct seq_file *m)
 551 {
 552         struct blk_mq_hw_ctx *hctx = data;
 553         int i;
 554
 555         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 556
 557         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 558                 unsigned int d = 1U << (i - 1);
 559
 560                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 561         }
 562
 563         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 564         return 0;
 565 }
 566
 567 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 568                                      size_t count, loff_t *ppos)
 569 {
 570         struct blk_mq_hw_ctx *hctx = data;
 571         int i;
 572
 573         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 574                 hctx->dispatched[i] = 0;
 575         return count;
 576 }
 577
 578 static int hctx_queued_show(void *data, struct seq_file *m)
 579 {
 580         struct blk_mq_hw_ctx *hctx = data;
 581
 582         seq_printf(m, "%lu\n", hctx->queued);
 583         return 0;
 584 }
 585
 586 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 587                                  size_t count, loff_t *ppos)
 588 {
 589         struct blk_mq_hw_ctx *hctx = data;
 590
 591         hctx->queued = 0;
 592         return count;
 593 }
 594
 595 static int hctx_run_show(void *data, struct seq_file *m)
 596 {
 597         struct blk_mq_hw_ctx *hctx = data;
 598
 599         seq_printf(m, "%lu\n", hctx->run);
 600         return 0;
 601 }
 602
 603 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 604                               loff_t *ppos)
 605 {
 606         struct blk_mq_hw_ctx *hctx = data;
 607
 608         hctx->run = 0;
 609         return count;
 610 }
 611
 612 static int hctx_active_show(void *data, struct seq_file *m)
 613 {
 614         struct blk_mq_hw_ctx *hctx = data;
 615
 616         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 617         return 0;
 618 }
 619
 620 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 621 {
 622         struct blk_mq_hw_ctx *hctx = data;
 623
 624         seq_printf(m, "%u\n", hctx->dispatch_busy);
 625         return 0;
 626 }
 627
 628 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 629 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 630         __acquires(&ctx->lock)                                          \
 631 {                                                                       \
 632         struct blk_mq_ctx *ctx = m->private;                            \
 633                                                                         \
 634         spin_lock(&ctx->lock);                                          \
 635         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 636 }                                                                       \
 637                                                                         \
 638 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 639                                      loff_t *pos)                       \
 640 {                                                                       \
 641         struct blk_mq_ctx *ctx = m->private;                            \
 642                                                                         \
 643         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 644 }                                                                       \
 645                                                                         \
 646 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 647         __releases(&ctx->lock)                                          \
 648 {                                                                       \
 649         struct blk_mq_ctx *ctx = m->private;                            \
 650                                                                         \
 651         spin_unlock(&ctx->lock);                                        \
 652 }                                                                       \
 653                                                                         \
 654 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 655         .start  = ctx_##name##_rq_list_start,                           \
 656         .next   = ctx_##name##_rq_list_next,                            \
 657         .stop   = ctx_##name##_rq_list_stop,                            \
 658         .show   = blk_mq_debugfs_rq_show,                               \
 659 }
 660
 661 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 662 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 663 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 664
 665 static int ctx_dispatched_show(void *data, struct seq_file *m)
 666 {
 667         struct blk_mq_ctx *ctx = data;
 668
 669         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 670         return 0;
 671 }
 672
 673 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 674                                     size_t count, loff_t *ppos)
 675 {
 676         struct blk_mq_ctx *ctx = data;
 677
 678         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 679         return count;
 680 }
 681
 682 static int ctx_merged_show(void *data, struct seq_file *m)
 683 {
 684         struct blk_mq_ctx *ctx = data;
 685
 686         seq_printf(m, "%lu\n", ctx->rq_merged);
 687         return 0;
 688 }
 689
 690 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 691                                 size_t count, loff_t *ppos)
 692 {
 693         struct blk_mq_ctx *ctx = data;
 694
 695         ctx->rq_merged = 0;
 696         return count;
 697 }
 698
 699 static int ctx_completed_show(void *data, struct seq_file *m)
 700 {
 701         struct blk_mq_ctx *ctx = data;
 702
 703         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 704         return 0;
 705 }
 706
 707 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 708                                    size_t count, loff_t *ppos)
 709 {
 710         struct blk_mq_ctx *ctx = data;
 711
 712         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 713         return count;
 714 }
 715
 716 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 717 {
 718         const struct blk_mq_debugfs_attr *attr = m->private;
 719         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 720
 721         return attr->show(data, m);
 722 }
 723
 724 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 725                                     size_t count, loff_t *ppos)
 726 {
 727         struct seq_file *m = file->private_data;
 728         const struct blk_mq_debugfs_attr *attr = m->private;
 729         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 730
 731         /*
 732          * Attributes that only implement .seq_ops are read-only and 'attr' is
 733          * the same with 'data' in this case.
 734          */
 735         if (attr == data || !attr->write)
 736                 return -EPERM;
 737
 738         return attr->write(data, buf, count, ppos);
 739 }
 740
 741 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 742 {
 743         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 744         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 745         struct seq_file *m;
 746         int ret;
 747
 748         if (attr->seq_ops) {
 749                 ret = seq_open(file, attr->seq_ops);
 750                 if (!ret) {
 751                         m = file->private_data;
 752                         m->private = data;
 753                 }
 754                 return ret;
 755         }
 756
 757         if (WARN_ON_ONCE(!attr->show))
 758                 return -EPERM;
 759
 760         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 761 }
 762
 763 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 764 {
 765         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 766
 767         if (attr->show)
 768                 return single_release(inode, file);
 769
 770         return seq_release(inode, file);
 771 }
 772
 773 static const struct file_operations blk_mq_debugfs_fops = {
 774         .open           = blk_mq_debugfs_open,
 775         .read           = seq_read,
 776         .write          = blk_mq_debugfs_write,
 777         .llseek         = seq_lseek,
 778         .release        = blk_mq_debugfs_release,
 779 };
 780
 781 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 782         {"state", 0400, hctx_state_show},
 783         {"flags", 0400, hctx_flags_show},
 784         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 785         {"busy", 0400, hctx_busy_show},
 786         {"ctx_map", 0400, hctx_ctx_map_show},
 787         {"tags", 0400, hctx_tags_show},
 788         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 789         {"sched_tags", 0400, hctx_sched_tags_show},
 790         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 791         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 792         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 793         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 794         {"run", 0600, hctx_run_show, hctx_run_write},
 795         {"active", 0400, hctx_active_show},
 796         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 797         {"type", 0400, hctx_type_show},
 798         {},
 799 };
 800
 801 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 802         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 803         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 804         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 805         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 806         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 807         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 808         {},
 809 };
 810
 811 static void debugfs_create_files(struct dentry *parent, void *data,
 812                                  const struct blk_mq_debugfs_attr *attr)
 813 {
 814         if (IS_ERR_OR_NULL(parent))
 815                 return;
 816
 817         d_inode(parent)->i_private = data;
 818
 819         for (; attr->name; attr++)
 820                 debugfs_create_file(attr->name, attr->mode, parent,
 821                                     (void *)attr, &blk_mq_debugfs_fops);
 822 }
 823
 824 void blk_mq_debugfs_register(struct request_queue *q)
 825 {
 826         struct blk_mq_hw_ctx *hctx;
 827         int i;
 828
 829         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 830                                             blk_debugfs_root);
 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         debugfs_remove_recursive(q->debugfs_dir);
 863         q->sched_debugfs_dir = NULL;
 864         q->debugfs_dir = NULL;
 865 }
 866
 867 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 868                                         struct blk_mq_ctx *ctx)
 869 {
 870         struct dentry *ctx_dir;
 871         char name[20];
 872
 873         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 874         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 875
 876         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 877 }
 878
 879 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 880                                   struct blk_mq_hw_ctx *hctx)
 881 {
 882         struct blk_mq_ctx *ctx;
 883         char name[20];
 884         int i;
 885
 886         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 887         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 888
 889         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 890
 891         hctx_for_each_ctx(hctx, ctx, i)
 892                 blk_mq_debugfs_register_ctx(hctx, ctx);
 893 }
 894
 895 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 896 {
 897         debugfs_remove_recursive(hctx->debugfs_dir);
 898         hctx->sched_debugfs_dir = NULL;
 899         hctx->debugfs_dir = NULL;
 900 }
 901
 902 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 903 {
 904         struct blk_mq_hw_ctx *hctx;
 905         int i;
 906
 907         queue_for_each_hw_ctx(q, hctx, i)
 908                 blk_mq_debugfs_register_hctx(q, hctx);
 909 }
 910
 911 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 912 {
 913         struct blk_mq_hw_ctx *hctx;
 914         int i;
 915
 916         queue_for_each_hw_ctx(q, hctx, i)
 917                 blk_mq_debugfs_unregister_hctx(hctx);
 918 }
 919
 920 void blk_mq_debugfs_register_sched(struct request_queue *q)
 921 {
 922         struct elevator_type *e = q->elevator->type;
 923
 924         /*
 925          * If the parent directory has not been created yet, return, we will be
 926          * called again later on and the directory/files will be created then.
 927          */
 928         if (!q->debugfs_dir)
 929                 return;
 930
 931         if (!e->queue_debugfs_attrs)
 932                 return;
 933
 934         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 935
 936         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 937 }
 938
 939 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 940 {
 941         debugfs_remove_recursive(q->sched_debugfs_dir);
 942         q->sched_debugfs_dir = NULL;
 943 }
 944
 945 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 946 {
 947         debugfs_remove_recursive(rqos->debugfs_dir);
 948         rqos->debugfs_dir = NULL;
 949 }
 950
 951 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 952 {
 953         struct request_queue *q = rqos->q;
 954         const char *dir_name = rq_qos_id_to_name(rqos->id);
 955
 956         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 957                 return;
 958
 959         if (!q->rqos_debugfs_dir)
 960                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 961                                                          q->debugfs_dir);
 962
 963         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 964                                                rqos->q->rqos_debugfs_dir);
 965
 966         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 967 }
 968
 969 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 970 {
 971         debugfs_remove_recursive(q->rqos_debugfs_dir);
 972         q->rqos_debugfs_dir = NULL;
 973 }
 974
 975 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 976                                         struct blk_mq_hw_ctx *hctx)
 977 {
 978         struct elevator_type *e = q->elevator->type;
 979
 980         if (!e->hctx_debugfs_attrs)
 981                 return;
 982
 983         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 984                                                      hctx->debugfs_dir);
 985         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 986                              e->hctx_debugfs_attrs);
 987 }
 988
 989 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 990 {
 991         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 992         hctx->sched_debugfs_dir = NULL;
 993 }