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