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         HCTX_STATE_NAME(INACTIVE),
 217 };
 218 #undef HCTX_STATE_NAME
 219
 220 static int hctx_state_show(void *data, struct seq_file *m)
 221 {
 222         struct blk_mq_hw_ctx *hctx = data;
 223
 224         blk_flags_show(m, hctx->state, hctx_state_name,
 225                        ARRAY_SIZE(hctx_state_name));
 226         seq_puts(m, "\n");
 227         return 0;
 228 }
 229
 230 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 231 static const char *const alloc_policy_name[] = {
 232         BLK_TAG_ALLOC_NAME(FIFO),
 233         BLK_TAG_ALLOC_NAME(RR),
 234 };
 235 #undef BLK_TAG_ALLOC_NAME
 236
 237 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 238 static const char *const hctx_flag_name[] = {
 239         HCTX_FLAG_NAME(SHOULD_MERGE),
 240         HCTX_FLAG_NAME(TAG_SHARED),
 241         HCTX_FLAG_NAME(BLOCKING),
 242         HCTX_FLAG_NAME(NO_SCHED),
 243         HCTX_FLAG_NAME(STACKING),
 244 };
 245 #undef HCTX_FLAG_NAME
 246
 247 static int hctx_flags_show(void *data, struct seq_file *m)
 248 {
 249         struct blk_mq_hw_ctx *hctx = data;
 250         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 251
 252         seq_puts(m, "alloc_policy=");
 253         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 254             alloc_policy_name[alloc_policy])
 255                 seq_puts(m, alloc_policy_name[alloc_policy]);
 256         else
 257                 seq_printf(m, "%d", alloc_policy);
 258         seq_puts(m, " ");
 259         blk_flags_show(m,
 260                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 261                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 262         seq_puts(m, "\n");
 263         return 0;
 264 }
 265
 266 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 267 static const char *const cmd_flag_name[] = {
 268         CMD_FLAG_NAME(FAILFAST_DEV),
 269         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 270         CMD_FLAG_NAME(FAILFAST_DRIVER),
 271         CMD_FLAG_NAME(SYNC),
 272         CMD_FLAG_NAME(META),
 273         CMD_FLAG_NAME(PRIO),
 274         CMD_FLAG_NAME(NOMERGE),
 275         CMD_FLAG_NAME(IDLE),
 276         CMD_FLAG_NAME(INTEGRITY),
 277         CMD_FLAG_NAME(FUA),
 278         CMD_FLAG_NAME(PREFLUSH),
 279         CMD_FLAG_NAME(RAHEAD),
 280         CMD_FLAG_NAME(BACKGROUND),
 281         CMD_FLAG_NAME(NOWAIT),
 282         CMD_FLAG_NAME(NOUNMAP),
 283         CMD_FLAG_NAME(HIPRI),
 284 };
 285 #undef CMD_FLAG_NAME
 286
 287 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 288 static const char *const rqf_name[] = {
 289         RQF_NAME(SORTED),
 290         RQF_NAME(STARTED),
 291         RQF_NAME(SOFTBARRIER),
 292         RQF_NAME(FLUSH_SEQ),
 293         RQF_NAME(MIXED_MERGE),
 294         RQF_NAME(MQ_INFLIGHT),
 295         RQF_NAME(DONTPREP),
 296         RQF_NAME(PREEMPT),
 297         RQF_NAME(FAILED),
 298         RQF_NAME(QUIET),
 299         RQF_NAME(ELVPRIV),
 300         RQF_NAME(IO_STAT),
 301         RQF_NAME(ALLOCED),
 302         RQF_NAME(PM),
 303         RQF_NAME(HASHED),
 304         RQF_NAME(STATS),
 305         RQF_NAME(SPECIAL_PAYLOAD),
 306         RQF_NAME(ZONE_WRITE_LOCKED),
 307         RQF_NAME(MQ_POLL_SLEPT),
 308 };
 309 #undef RQF_NAME
 310
 311 static const char *const blk_mq_rq_state_name_array[] = {
 312         [MQ_RQ_IDLE]            = "idle",
 313         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 314         [MQ_RQ_COMPLETE]        = "complete",
 315 };
 316
 317 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 318 {
 319         if (WARN_ON_ONCE((unsigned int)rq_state >=
 320                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 321                 return "(?)";
 322         return blk_mq_rq_state_name_array[rq_state];
 323 }
 324
 325 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 326 {
 327         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 328         const unsigned int op = req_op(rq);
 329         const char *op_str = blk_op_str(op);
 330
 331         seq_printf(m, "%p {.op=", rq);
 332         if (strcmp(op_str, "UNKNOWN") == 0)
 333                 seq_printf(m, "%u", op);
 334         else
 335                 seq_printf(m, "%s", op_str);
 336         seq_puts(m, ", .cmd_flags=");
 337         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 338                        ARRAY_SIZE(cmd_flag_name));
 339         seq_puts(m, ", .rq_flags=");
 340         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 341                        ARRAY_SIZE(rqf_name));
 342         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 343         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 344                    rq->internal_tag);
 345         if (mq_ops->show_rq)
 346                 mq_ops->show_rq(m, rq);
 347         seq_puts(m, "}\n");
 348         return 0;
 349 }
 350 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 351
 352 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 353 {
 354         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 355 }
 356 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 357
 358 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 359         __acquires(&hctx->lock)
 360 {
 361         struct blk_mq_hw_ctx *hctx = m->private;
 362
 363         spin_lock(&hctx->lock);
 364         return seq_list_start(&hctx->dispatch, *pos);
 365 }
 366
 367 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 368 {
 369         struct blk_mq_hw_ctx *hctx = m->private;
 370
 371         return seq_list_next(v, &hctx->dispatch, pos);
 372 }
 373
 374 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 375         __releases(&hctx->lock)
 376 {
 377         struct blk_mq_hw_ctx *hctx = m->private;
 378
 379         spin_unlock(&hctx->lock);
 380 }
 381
 382 static const struct seq_operations hctx_dispatch_seq_ops = {
 383         .start  = hctx_dispatch_start,
 384         .next   = hctx_dispatch_next,
 385         .stop   = hctx_dispatch_stop,
 386         .show   = blk_mq_debugfs_rq_show,
 387 };
 388
 389 struct show_busy_params {
 390         struct seq_file         *m;
 391         struct blk_mq_hw_ctx    *hctx;
 392 };
 393
 394 /*
 395  * Note: the state of a request may change while this function is in progress,
 396  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 397  * keep iterating requests.
 398  */
 399 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 400 {
 401         const struct show_busy_params *params = data;
 402
 403         if (rq->mq_hctx == params->hctx)
 404                 __blk_mq_debugfs_rq_show(params->m,
 405                                          list_entry_rq(&rq->queuelist));
 406
 407         return true;
 408 }
 409
 410 static int hctx_busy_show(void *data, struct seq_file *m)
 411 {
 412         struct blk_mq_hw_ctx *hctx = data;
 413         struct show_busy_params params = { .m = m, .hctx = hctx };
 414
 415         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 416                                 &params);
 417
 418         return 0;
 419 }
 420
 421 static const char *const hctx_types[] = {
 422         [HCTX_TYPE_DEFAULT]     = "default",
 423         [HCTX_TYPE_READ]        = "read",
 424         [HCTX_TYPE_POLL]        = "poll",
 425 };
 426
 427 static int hctx_type_show(void *data, struct seq_file *m)
 428 {
 429         struct blk_mq_hw_ctx *hctx = data;
 430
 431         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 432         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 433         return 0;
 434 }
 435
 436 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 437 {
 438         struct blk_mq_hw_ctx *hctx = data;
 439
 440         sbitmap_bitmap_show(&hctx->ctx_map, m);
 441         return 0;
 442 }
 443
 444 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 445                                      struct blk_mq_tags *tags)
 446 {
 447         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 448         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 449         seq_printf(m, "active_queues=%d\n",
 450                    atomic_read(&tags->active_queues));
 451
 452         seq_puts(m, "\nbitmap_tags:\n");
 453         sbitmap_queue_show(&tags->bitmap_tags, m);
 454
 455         if (tags->nr_reserved_tags) {
 456                 seq_puts(m, "\nbreserved_tags:\n");
 457                 sbitmap_queue_show(&tags->breserved_tags, m);
 458         }
 459 }
 460
 461 static int hctx_tags_show(void *data, struct seq_file *m)
 462 {
 463         struct blk_mq_hw_ctx *hctx = data;
 464         struct request_queue *q = hctx->queue;
 465         int res;
 466
 467         res = mutex_lock_interruptible(&q->sysfs_lock);
 468         if (res)
 469                 goto out;
 470         if (hctx->tags)
 471                 blk_mq_debugfs_tags_show(m, hctx->tags);
 472         mutex_unlock(&q->sysfs_lock);
 473
 474 out:
 475         return res;
 476 }
 477
 478 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 479 {
 480         struct blk_mq_hw_ctx *hctx = data;
 481         struct request_queue *q = hctx->queue;
 482         int res;
 483
 484         res = mutex_lock_interruptible(&q->sysfs_lock);
 485         if (res)
 486                 goto out;
 487         if (hctx->tags)
 488                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 489         mutex_unlock(&q->sysfs_lock);
 490
 491 out:
 492         return res;
 493 }
 494
 495 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 496 {
 497         struct blk_mq_hw_ctx *hctx = data;
 498         struct request_queue *q = hctx->queue;
 499         int res;
 500
 501         res = mutex_lock_interruptible(&q->sysfs_lock);
 502         if (res)
 503                 goto out;
 504         if (hctx->sched_tags)
 505                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 506         mutex_unlock(&q->sysfs_lock);
 507
 508 out:
 509         return res;
 510 }
 511
 512 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 513 {
 514         struct blk_mq_hw_ctx *hctx = data;
 515         struct request_queue *q = hctx->queue;
 516         int res;
 517
 518         res = mutex_lock_interruptible(&q->sysfs_lock);
 519         if (res)
 520                 goto out;
 521         if (hctx->sched_tags)
 522                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 523         mutex_unlock(&q->sysfs_lock);
 524
 525 out:
 526         return res;
 527 }
 528
 529 static int hctx_io_poll_show(void *data, struct seq_file *m)
 530 {
 531         struct blk_mq_hw_ctx *hctx = data;
 532
 533         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 534         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 535         seq_printf(m, "success=%lu\n", hctx->poll_success);
 536         return 0;
 537 }
 538
 539 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 540                                   size_t count, loff_t *ppos)
 541 {
 542         struct blk_mq_hw_ctx *hctx = data;
 543
 544         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 545         return count;
 546 }
 547
 548 static int hctx_dispatched_show(void *data, struct seq_file *m)
 549 {
 550         struct blk_mq_hw_ctx *hctx = data;
 551         int i;
 552
 553         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 554
 555         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 556                 unsigned int d = 1U << (i - 1);
 557
 558                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 559         }
 560
 561         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 562         return 0;
 563 }
 564
 565 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 566                                      size_t count, loff_t *ppos)
 567 {
 568         struct blk_mq_hw_ctx *hctx = data;
 569         int i;
 570
 571         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 572                 hctx->dispatched[i] = 0;
 573         return count;
 574 }
 575
 576 static int hctx_queued_show(void *data, struct seq_file *m)
 577 {
 578         struct blk_mq_hw_ctx *hctx = data;
 579
 580         seq_printf(m, "%lu\n", hctx->queued);
 581         return 0;
 582 }
 583
 584 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 585                                  size_t count, loff_t *ppos)
 586 {
 587         struct blk_mq_hw_ctx *hctx = data;
 588
 589         hctx->queued = 0;
 590         return count;
 591 }
 592
 593 static int hctx_run_show(void *data, struct seq_file *m)
 594 {
 595         struct blk_mq_hw_ctx *hctx = data;
 596
 597         seq_printf(m, "%lu\n", hctx->run);
 598         return 0;
 599 }
 600
 601 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 602                               loff_t *ppos)
 603 {
 604         struct blk_mq_hw_ctx *hctx = data;
 605
 606         hctx->run = 0;
 607         return count;
 608 }
 609
 610 static int hctx_active_show(void *data, struct seq_file *m)
 611 {
 612         struct blk_mq_hw_ctx *hctx = data;
 613
 614         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 615         return 0;
 616 }
 617
 618 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 619 {
 620         struct blk_mq_hw_ctx *hctx = data;
 621
 622         seq_printf(m, "%u\n", hctx->dispatch_busy);
 623         return 0;
 624 }
 625
 626 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 627 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 628         __acquires(&ctx->lock)                                          \
 629 {                                                                       \
 630         struct blk_mq_ctx *ctx = m->private;                            \
 631                                                                         \
 632         spin_lock(&ctx->lock);                                          \
 633         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 634 }                                                                       \
 635                                                                         \
 636 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 637                                      loff_t *pos)                       \
 638 {                                                                       \
 639         struct blk_mq_ctx *ctx = m->private;                            \
 640                                                                         \
 641         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 642 }                                                                       \
 643                                                                         \
 644 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 645         __releases(&ctx->lock)                                          \
 646 {                                                                       \
 647         struct blk_mq_ctx *ctx = m->private;                            \
 648                                                                         \
 649         spin_unlock(&ctx->lock);                                        \
 650 }                                                                       \
 651                                                                         \
 652 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 653         .start  = ctx_##name##_rq_list_start,                           \
 654         .next   = ctx_##name##_rq_list_next,                            \
 655         .stop   = ctx_##name##_rq_list_stop,                            \
 656         .show   = blk_mq_debugfs_rq_show,                               \
 657 }
 658
 659 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 660 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 661 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 662
 663 static int ctx_dispatched_show(void *data, struct seq_file *m)
 664 {
 665         struct blk_mq_ctx *ctx = data;
 666
 667         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 668         return 0;
 669 }
 670
 671 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 672                                     size_t count, loff_t *ppos)
 673 {
 674         struct blk_mq_ctx *ctx = data;
 675
 676         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 677         return count;
 678 }
 679
 680 static int ctx_merged_show(void *data, struct seq_file *m)
 681 {
 682         struct blk_mq_ctx *ctx = data;
 683
 684         seq_printf(m, "%lu\n", ctx->rq_merged);
 685         return 0;
 686 }
 687
 688 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 689                                 size_t count, loff_t *ppos)
 690 {
 691         struct blk_mq_ctx *ctx = data;
 692
 693         ctx->rq_merged = 0;
 694         return count;
 695 }
 696
 697 static int ctx_completed_show(void *data, struct seq_file *m)
 698 {
 699         struct blk_mq_ctx *ctx = data;
 700
 701         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 702         return 0;
 703 }
 704
 705 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 706                                    size_t count, loff_t *ppos)
 707 {
 708         struct blk_mq_ctx *ctx = data;
 709
 710         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 711         return count;
 712 }
 713
 714 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 715 {
 716         const struct blk_mq_debugfs_attr *attr = m->private;
 717         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 718
 719         return attr->show(data, m);
 720 }
 721
 722 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 723                                     size_t count, loff_t *ppos)
 724 {
 725         struct seq_file *m = file->private_data;
 726         const struct blk_mq_debugfs_attr *attr = m->private;
 727         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 728
 729         /*
 730          * Attributes that only implement .seq_ops are read-only and 'attr' is
 731          * the same with 'data' in this case.
 732          */
 733         if (attr == data || !attr->write)
 734                 return -EPERM;
 735
 736         return attr->write(data, buf, count, ppos);
 737 }
 738
 739 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 740 {
 741         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 742         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 743         struct seq_file *m;
 744         int ret;
 745
 746         if (attr->seq_ops) {
 747                 ret = seq_open(file, attr->seq_ops);
 748                 if (!ret) {
 749                         m = file->private_data;
 750                         m->private = data;
 751                 }
 752                 return ret;
 753         }
 754
 755         if (WARN_ON_ONCE(!attr->show))
 756                 return -EPERM;
 757
 758         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 759 }
 760
 761 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 762 {
 763         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 764
 765         if (attr->show)
 766                 return single_release(inode, file);
 767
 768         return seq_release(inode, file);
 769 }
 770
 771 static const struct file_operations blk_mq_debugfs_fops = {
 772         .open           = blk_mq_debugfs_open,
 773         .read           = seq_read,
 774         .write          = blk_mq_debugfs_write,
 775         .llseek         = seq_lseek,
 776         .release        = blk_mq_debugfs_release,
 777 };
 778
 779 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 780         {"state", 0400, hctx_state_show},
 781         {"flags", 0400, hctx_flags_show},
 782         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 783         {"busy", 0400, hctx_busy_show},
 784         {"ctx_map", 0400, hctx_ctx_map_show},
 785         {"tags", 0400, hctx_tags_show},
 786         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 787         {"sched_tags", 0400, hctx_sched_tags_show},
 788         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 789         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 790         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 791         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 792         {"run", 0600, hctx_run_show, hctx_run_write},
 793         {"active", 0400, hctx_active_show},
 794         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 795         {"type", 0400, hctx_type_show},
 796         {},
 797 };
 798
 799 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 800         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 801         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 802         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 803         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 804         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 805         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 806         {},
 807 };
 808
 809 static void debugfs_create_files(struct dentry *parent, void *data,
 810                                  const struct blk_mq_debugfs_attr *attr)
 811 {
 812         if (IS_ERR_OR_NULL(parent))
 813                 return;
 814
 815         d_inode(parent)->i_private = data;
 816
 817         for (; attr->name; attr++)
 818                 debugfs_create_file(attr->name, attr->mode, parent,
 819                                     (void *)attr, &blk_mq_debugfs_fops);
 820 }
 821
 822 void blk_mq_debugfs_register(struct request_queue *q)
 823 {
 824         struct blk_mq_hw_ctx *hctx;
 825         int i;
 826
 827         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 828                                             blk_debugfs_root);
 829
 830         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 831
 832         /*
 833          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 834          * didn't exist yet (because we don't know what to name the directory
 835          * until the queue is registered to a gendisk).
 836          */
 837         if (q->elevator && !q->sched_debugfs_dir)
 838                 blk_mq_debugfs_register_sched(q);
 839
 840         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 841         queue_for_each_hw_ctx(q, hctx, i) {
 842                 if (!hctx->debugfs_dir)
 843                         blk_mq_debugfs_register_hctx(q, hctx);
 844                 if (q->elevator && !hctx->sched_debugfs_dir)
 845                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 846         }
 847
 848         if (q->rq_qos) {
 849                 struct rq_qos *rqos = q->rq_qos;
 850
 851                 while (rqos) {
 852                         blk_mq_debugfs_register_rqos(rqos);
 853                         rqos = rqos->next;
 854                 }
 855         }
 856 }
 857
 858 void blk_mq_debugfs_unregister(struct request_queue *q)
 859 {
 860         debugfs_remove_recursive(q->debugfs_dir);
 861         q->sched_debugfs_dir = NULL;
 862         q->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 }