block/blk-mq-debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2017 Facebook
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/blkdev.h>
   8 #include <linux/debugfs.h>
   9
  10 #include <linux/blk-mq.h>
  11 #include "blk.h"
  12 #include "blk-mq.h"
  13 #include "blk-mq-debugfs.h"
  14 #include "blk-mq-tag.h"
  15 #include "blk-rq-qos.h"
  16
  17 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  18 {
  19         if (stat->nr_samples) {
  20                 seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
  21                            stat->nr_samples, stat->mean, stat->min, stat->max);
  22         } else {
  23                 seq_puts(m, "samples=0");
  24         }
  25 }
  26
  27 static int queue_poll_stat_show(void *data, struct seq_file *m)
  28 {
  29         struct request_queue *q = data;
  30         int bucket;
  31
  32         for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
  33                 seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
  34                 print_stat(m, &q->poll_stat[2 * bucket]);
  35                 seq_puts(m, "\n");
  36
  37                 seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
  38                 print_stat(m, &q->poll_stat[2 * bucket + 1]);
  39                 seq_puts(m, "\n");
  40         }
  41         return 0;
  42 }
  43
  44 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  45         __acquires(&q->requeue_lock)
  46 {
  47         struct request_queue *q = m->private;
  48
  49         spin_lock_irq(&q->requeue_lock);
  50         return seq_list_start(&q->requeue_list, *pos);
  51 }
  52
  53 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  54 {
  55         struct request_queue *q = m->private;
  56
  57         return seq_list_next(v, &q->requeue_list, pos);
  58 }
  59
  60 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  61         __releases(&q->requeue_lock)
  62 {
  63         struct request_queue *q = m->private;
  64
  65         spin_unlock_irq(&q->requeue_lock);
  66 }
  67
  68 static const struct seq_operations queue_requeue_list_seq_ops = {
  69         .start  = queue_requeue_list_start,
  70         .next   = queue_requeue_list_next,
  71         .stop   = queue_requeue_list_stop,
  72         .show   = blk_mq_debugfs_rq_show,
  73 };
  74
  75 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  76                           const char *const *flag_name, int flag_name_count)
  77 {
  78         bool sep = false;
  79         int i;
  80
  81         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  82                 if (!(flags & BIT(i)))
  83                         continue;
  84                 if (sep)
  85                         seq_puts(m, "|");
  86                 sep = true;
  87                 if (i < flag_name_count && flag_name[i])
  88                         seq_puts(m, flag_name[i]);
  89                 else
  90                         seq_printf(m, "%d", i);
  91         }
  92         return 0;
  93 }
  94
  95 static int queue_pm_only_show(void *data, struct seq_file *m)
  96 {
  97         struct request_queue *q = data;
  98
  99         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 100         return 0;
 101 }
 102
 103 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 104 static const char *const blk_queue_flag_name[] = {
 105         QUEUE_FLAG_NAME(STOPPED),
 106         QUEUE_FLAG_NAME(DYING),
 107         QUEUE_FLAG_NAME(NOMERGES),
 108         QUEUE_FLAG_NAME(SAME_COMP),
 109         QUEUE_FLAG_NAME(FAIL_IO),
 110         QUEUE_FLAG_NAME(NONROT),
 111         QUEUE_FLAG_NAME(IO_STAT),
 112         QUEUE_FLAG_NAME(DISCARD),
 113         QUEUE_FLAG_NAME(NOXMERGES),
 114         QUEUE_FLAG_NAME(ADD_RANDOM),
 115         QUEUE_FLAG_NAME(SECERASE),
 116         QUEUE_FLAG_NAME(SAME_FORCE),
 117         QUEUE_FLAG_NAME(DEAD),
 118         QUEUE_FLAG_NAME(INIT_DONE),
 119         QUEUE_FLAG_NAME(STABLE_WRITES),
 120         QUEUE_FLAG_NAME(POLL),
 121         QUEUE_FLAG_NAME(WC),
 122         QUEUE_FLAG_NAME(FUA),
 123         QUEUE_FLAG_NAME(DAX),
 124         QUEUE_FLAG_NAME(STATS),
 125         QUEUE_FLAG_NAME(POLL_STATS),
 126         QUEUE_FLAG_NAME(REGISTERED),
 127         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 128         QUEUE_FLAG_NAME(QUIESCED),
 129         QUEUE_FLAG_NAME(PCI_P2PDMA),
 130         QUEUE_FLAG_NAME(ZONE_RESETALL),
 131         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 132         QUEUE_FLAG_NAME(NOWAIT),
 133 };
 134 #undef QUEUE_FLAG_NAME
 135
 136 static int queue_state_show(void *data, struct seq_file *m)
 137 {
 138         struct request_queue *q = data;
 139
 140         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 141                        ARRAY_SIZE(blk_queue_flag_name));
 142         seq_puts(m, "\n");
 143         return 0;
 144 }
 145
 146 static ssize_t queue_state_write(void *data, const char __user *buf,
 147                                  size_t count, loff_t *ppos)
 148 {
 149         struct request_queue *q = data;
 150         char opbuf[16] = { }, *op;
 151
 152         /*
 153          * The "state" attribute is removed after blk_cleanup_queue() has called
 154          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 155          * triggering a use-after-free.
 156          */
 157         if (blk_queue_dead(q))
 158                 return -ENOENT;
 159
 160         if (count >= sizeof(opbuf)) {
 161                 pr_err("%s: operation too long\n", __func__);
 162                 goto inval;
 163         }
 164
 165         if (copy_from_user(opbuf, buf, count))
 166                 return -EFAULT;
 167         op = strstrip(opbuf);
 168         if (strcmp(op, "run") == 0) {
 169                 blk_mq_run_hw_queues(q, true);
 170         } else if (strcmp(op, "start") == 0) {
 171                 blk_mq_start_stopped_hw_queues(q, true);
 172         } else if (strcmp(op, "kick") == 0) {
 173                 blk_mq_kick_requeue_list(q);
 174         } else {
 175                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 176 inval:
 177                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 178                 return -EINVAL;
 179         }
 180         return count;
 181 }
 182
 183 static int queue_write_hint_show(void *data, struct seq_file *m)
 184 {
 185         struct request_queue *q = data;
 186         int i;
 187
 188         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 189                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 190
 191         return 0;
 192 }
 193
 194 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 195                                       size_t count, loff_t *ppos)
 196 {
 197         struct request_queue *q = data;
 198         int i;
 199
 200         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 201                 q->write_hints[i] = 0;
 202
 203         return count;
 204 }
 205
 206 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 207         { "poll_stat", 0400, queue_poll_stat_show },
 208         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 209         { "pm_only", 0600, queue_pm_only_show, NULL },
 210         { "state", 0600, queue_state_show, queue_state_write },
 211         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 212         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 213         { },
 214 };
 215
 216 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 217 static const char *const hctx_state_name[] = {
 218         HCTX_STATE_NAME(STOPPED),
 219         HCTX_STATE_NAME(TAG_ACTIVE),
 220         HCTX_STATE_NAME(SCHED_RESTART),
 221         HCTX_STATE_NAME(INACTIVE),
 222 };
 223 #undef HCTX_STATE_NAME
 224
 225 static int hctx_state_show(void *data, struct seq_file *m)
 226 {
 227         struct blk_mq_hw_ctx *hctx = data;
 228
 229         blk_flags_show(m, hctx->state, hctx_state_name,
 230                        ARRAY_SIZE(hctx_state_name));
 231         seq_puts(m, "\n");
 232         return 0;
 233 }
 234
 235 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 236 static const char *const alloc_policy_name[] = {
 237         BLK_TAG_ALLOC_NAME(FIFO),
 238         BLK_TAG_ALLOC_NAME(RR),
 239 };
 240 #undef BLK_TAG_ALLOC_NAME
 241
 242 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 243 static const char *const hctx_flag_name[] = {
 244         HCTX_FLAG_NAME(SHOULD_MERGE),
 245         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 246         HCTX_FLAG_NAME(BLOCKING),
 247         HCTX_FLAG_NAME(NO_SCHED),
 248         HCTX_FLAG_NAME(STACKING),
 249         HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 250 };
 251 #undef HCTX_FLAG_NAME
 252
 253 static int hctx_flags_show(void *data, struct seq_file *m)
 254 {
 255         struct blk_mq_hw_ctx *hctx = data;
 256         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 257
 258         seq_puts(m, "alloc_policy=");
 259         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 260             alloc_policy_name[alloc_policy])
 261                 seq_puts(m, alloc_policy_name[alloc_policy]);
 262         else
 263                 seq_printf(m, "%d", alloc_policy);
 264         seq_puts(m, " ");
 265         blk_flags_show(m,
 266                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 267                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 268         seq_puts(m, "\n");
 269         return 0;
 270 }
 271
 272 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 273 static const char *const cmd_flag_name[] = {
 274         CMD_FLAG_NAME(FAILFAST_DEV),
 275         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 276         CMD_FLAG_NAME(FAILFAST_DRIVER),
 277         CMD_FLAG_NAME(SYNC),
 278         CMD_FLAG_NAME(META),
 279         CMD_FLAG_NAME(PRIO),
 280         CMD_FLAG_NAME(NOMERGE),
 281         CMD_FLAG_NAME(IDLE),
 282         CMD_FLAG_NAME(INTEGRITY),
 283         CMD_FLAG_NAME(FUA),
 284         CMD_FLAG_NAME(PREFLUSH),
 285         CMD_FLAG_NAME(RAHEAD),
 286         CMD_FLAG_NAME(BACKGROUND),
 287         CMD_FLAG_NAME(NOWAIT),
 288         CMD_FLAG_NAME(NOUNMAP),
 289         CMD_FLAG_NAME(HIPRI),
 290 };
 291 #undef CMD_FLAG_NAME
 292
 293 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 294 static const char *const rqf_name[] = {
 295         RQF_NAME(SORTED),
 296         RQF_NAME(STARTED),
 297         RQF_NAME(SOFTBARRIER),
 298         RQF_NAME(FLUSH_SEQ),
 299         RQF_NAME(MIXED_MERGE),
 300         RQF_NAME(MQ_INFLIGHT),
 301         RQF_NAME(DONTPREP),
 302         RQF_NAME(FAILED),
 303         RQF_NAME(QUIET),
 304         RQF_NAME(ELVPRIV),
 305         RQF_NAME(IO_STAT),
 306         RQF_NAME(ALLOCED),
 307         RQF_NAME(PM),
 308         RQF_NAME(HASHED),
 309         RQF_NAME(STATS),
 310         RQF_NAME(SPECIAL_PAYLOAD),
 311         RQF_NAME(ZONE_WRITE_LOCKED),
 312         RQF_NAME(MQ_POLL_SLEPT),
 313 };
 314 #undef RQF_NAME
 315
 316 static const char *const blk_mq_rq_state_name_array[] = {
 317         [MQ_RQ_IDLE]            = "idle",
 318         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 319         [MQ_RQ_COMPLETE]        = "complete",
 320 };
 321
 322 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 323 {
 324         if (WARN_ON_ONCE((unsigned int)rq_state >=
 325                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 326                 return "(?)";
 327         return blk_mq_rq_state_name_array[rq_state];
 328 }
 329
 330 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 331 {
 332         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 333         const unsigned int op = req_op(rq);
 334         const char *op_str = blk_op_str(op);
 335
 336         seq_printf(m, "%p {.op=", rq);
 337         if (strcmp(op_str, "UNKNOWN") == 0)
 338                 seq_printf(m, "%u", op);
 339         else
 340                 seq_printf(m, "%s", op_str);
 341         seq_puts(m, ", .cmd_flags=");
 342         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 343                        ARRAY_SIZE(cmd_flag_name));
 344         seq_puts(m, ", .rq_flags=");
 345         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 346                        ARRAY_SIZE(rqf_name));
 347         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 348         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 349                    rq->internal_tag);
 350         if (mq_ops->show_rq)
 351                 mq_ops->show_rq(m, rq);
 352         seq_puts(m, "}\n");
 353         return 0;
 354 }
 355 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 356
 357 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 358 {
 359         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 360 }
 361 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 362
 363 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 364         __acquires(&hctx->lock)
 365 {
 366         struct blk_mq_hw_ctx *hctx = m->private;
 367
 368         spin_lock(&hctx->lock);
 369         return seq_list_start(&hctx->dispatch, *pos);
 370 }
 371
 372 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 373 {
 374         struct blk_mq_hw_ctx *hctx = m->private;
 375
 376         return seq_list_next(v, &hctx->dispatch, pos);
 377 }
 378
 379 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 380         __releases(&hctx->lock)
 381 {
 382         struct blk_mq_hw_ctx *hctx = m->private;
 383
 384         spin_unlock(&hctx->lock);
 385 }
 386
 387 static const struct seq_operations hctx_dispatch_seq_ops = {
 388         .start  = hctx_dispatch_start,
 389         .next   = hctx_dispatch_next,
 390         .stop   = hctx_dispatch_stop,
 391         .show   = blk_mq_debugfs_rq_show,
 392 };
 393
 394 struct show_busy_params {
 395         struct seq_file         *m;
 396         struct blk_mq_hw_ctx    *hctx;
 397 };
 398
 399 /*
 400  * Note: the state of a request may change while this function is in progress,
 401  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 402  * keep iterating requests.
 403  */
 404 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 405 {
 406         const struct show_busy_params *params = data;
 407
 408         if (rq->mq_hctx == params->hctx)
 409                 __blk_mq_debugfs_rq_show(params->m, rq);
 410
 411         return true;
 412 }
 413
 414 static int hctx_busy_show(void *data, struct seq_file *m)
 415 {
 416         struct blk_mq_hw_ctx *hctx = data;
 417         struct show_busy_params params = { .m = m, .hctx = hctx };
 418
 419         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 420                                 &params);
 421
 422         return 0;
 423 }
 424
 425 static const char *const hctx_types[] = {
 426         [HCTX_TYPE_DEFAULT]     = "default",
 427         [HCTX_TYPE_READ]        = "read",
 428         [HCTX_TYPE_POLL]        = "poll",
 429 };
 430
 431 static int hctx_type_show(void *data, struct seq_file *m)
 432 {
 433         struct blk_mq_hw_ctx *hctx = data;
 434
 435         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 436         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 437         return 0;
 438 }
 439
 440 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 441 {
 442         struct blk_mq_hw_ctx *hctx = data;
 443
 444         sbitmap_bitmap_show(&hctx->ctx_map, m);
 445         return 0;
 446 }
 447
 448 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 449                                      struct blk_mq_tags *tags)
 450 {
 451         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 452         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 453         seq_printf(m, "active_queues=%d\n",
 454                    atomic_read(&tags->active_queues));
 455
 456         seq_puts(m, "\nbitmap_tags:\n");
 457         sbitmap_queue_show(tags->bitmap_tags, m);
 458
 459         if (tags->nr_reserved_tags) {
 460                 seq_puts(m, "\nbreserved_tags:\n");
 461                 sbitmap_queue_show(tags->breserved_tags, m);
 462         }
 463 }
 464
 465 static int hctx_tags_show(void *data, struct seq_file *m)
 466 {
 467         struct blk_mq_hw_ctx *hctx = data;
 468         struct request_queue *q = hctx->queue;
 469         int res;
 470
 471         res = mutex_lock_interruptible(&q->sysfs_lock);
 472         if (res)
 473                 goto out;
 474         if (hctx->tags)
 475                 blk_mq_debugfs_tags_show(m, hctx->tags);
 476         mutex_unlock(&q->sysfs_lock);
 477
 478 out:
 479         return res;
 480 }
 481
 482 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 483 {
 484         struct blk_mq_hw_ctx *hctx = data;
 485         struct request_queue *q = hctx->queue;
 486         int res;
 487
 488         res = mutex_lock_interruptible(&q->sysfs_lock);
 489         if (res)
 490                 goto out;
 491         if (hctx->tags)
 492                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m);
 493         mutex_unlock(&q->sysfs_lock);
 494
 495 out:
 496         return res;
 497 }
 498
 499 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 500 {
 501         struct blk_mq_hw_ctx *hctx = data;
 502         struct request_queue *q = hctx->queue;
 503         int res;
 504
 505         res = mutex_lock_interruptible(&q->sysfs_lock);
 506         if (res)
 507                 goto out;
 508         if (hctx->sched_tags)
 509                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 510         mutex_unlock(&q->sysfs_lock);
 511
 512 out:
 513         return res;
 514 }
 515
 516 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 517 {
 518         struct blk_mq_hw_ctx *hctx = data;
 519         struct request_queue *q = hctx->queue;
 520         int res;
 521
 522         res = mutex_lock_interruptible(&q->sysfs_lock);
 523         if (res)
 524                 goto out;
 525         if (hctx->sched_tags)
 526                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m);
 527         mutex_unlock(&q->sysfs_lock);
 528
 529 out:
 530         return res;
 531 }
 532
 533 static int hctx_io_poll_show(void *data, struct seq_file *m)
 534 {
 535         struct blk_mq_hw_ctx *hctx = data;
 536
 537         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 538         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 539         seq_printf(m, "success=%lu\n", hctx->poll_success);
 540         return 0;
 541 }
 542
 543 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 544                                   size_t count, loff_t *ppos)
 545 {
 546         struct blk_mq_hw_ctx *hctx = data;
 547
 548         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 549         return count;
 550 }
 551
 552 static int hctx_dispatched_show(void *data, struct seq_file *m)
 553 {
 554         struct blk_mq_hw_ctx *hctx = data;
 555         int i;
 556
 557         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 558
 559         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 560                 unsigned int d = 1U << (i - 1);
 561
 562                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 563         }
 564
 565         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 566         return 0;
 567 }
 568
 569 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 570                                      size_t count, loff_t *ppos)
 571 {
 572         struct blk_mq_hw_ctx *hctx = data;
 573         int i;
 574
 575         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 576                 hctx->dispatched[i] = 0;
 577         return count;
 578 }
 579
 580 static int hctx_queued_show(void *data, struct seq_file *m)
 581 {
 582         struct blk_mq_hw_ctx *hctx = data;
 583
 584         seq_printf(m, "%lu\n", hctx->queued);
 585         return 0;
 586 }
 587
 588 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 589                                  size_t count, loff_t *ppos)
 590 {
 591         struct blk_mq_hw_ctx *hctx = data;
 592
 593         hctx->queued = 0;
 594         return count;
 595 }
 596
 597 static int hctx_run_show(void *data, struct seq_file *m)
 598 {
 599         struct blk_mq_hw_ctx *hctx = data;
 600
 601         seq_printf(m, "%lu\n", hctx->run);
 602         return 0;
 603 }
 604
 605 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 606                               loff_t *ppos)
 607 {
 608         struct blk_mq_hw_ctx *hctx = data;
 609
 610         hctx->run = 0;
 611         return count;
 612 }
 613
 614 static int hctx_active_show(void *data, struct seq_file *m)
 615 {
 616         struct blk_mq_hw_ctx *hctx = data;
 617
 618         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 619         return 0;
 620 }
 621
 622 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 623 {
 624         struct blk_mq_hw_ctx *hctx = data;
 625
 626         seq_printf(m, "%u\n", hctx->dispatch_busy);
 627         return 0;
 628 }
 629
 630 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 631 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 632         __acquires(&ctx->lock)                                          \
 633 {                                                                       \
 634         struct blk_mq_ctx *ctx = m->private;                            \
 635                                                                         \
 636         spin_lock(&ctx->lock);                                          \
 637         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 638 }                                                                       \
 639                                                                         \
 640 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 641                                      loff_t *pos)                       \
 642 {                                                                       \
 643         struct blk_mq_ctx *ctx = m->private;                            \
 644                                                                         \
 645         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 646 }                                                                       \
 647                                                                         \
 648 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 649         __releases(&ctx->lock)                                          \
 650 {                                                                       \
 651         struct blk_mq_ctx *ctx = m->private;                            \
 652                                                                         \
 653         spin_unlock(&ctx->lock);                                        \
 654 }                                                                       \
 655                                                                         \
 656 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 657         .start  = ctx_##name##_rq_list_start,                           \
 658         .next   = ctx_##name##_rq_list_next,                            \
 659         .stop   = ctx_##name##_rq_list_stop,                            \
 660         .show   = blk_mq_debugfs_rq_show,                               \
 661 }
 662
 663 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 664 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 665 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 666
 667 static int ctx_dispatched_show(void *data, struct seq_file *m)
 668 {
 669         struct blk_mq_ctx *ctx = data;
 670
 671         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 672         return 0;
 673 }
 674
 675 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 676                                     size_t count, loff_t *ppos)
 677 {
 678         struct blk_mq_ctx *ctx = data;
 679
 680         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 681         return count;
 682 }
 683
 684 static int ctx_merged_show(void *data, struct seq_file *m)
 685 {
 686         struct blk_mq_ctx *ctx = data;
 687
 688         seq_printf(m, "%lu\n", ctx->rq_merged);
 689         return 0;
 690 }
 691
 692 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 693                                 size_t count, loff_t *ppos)
 694 {
 695         struct blk_mq_ctx *ctx = data;
 696
 697         ctx->rq_merged = 0;
 698         return count;
 699 }
 700
 701 static int ctx_completed_show(void *data, struct seq_file *m)
 702 {
 703         struct blk_mq_ctx *ctx = data;
 704
 705         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 706         return 0;
 707 }
 708
 709 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 710                                    size_t count, loff_t *ppos)
 711 {
 712         struct blk_mq_ctx *ctx = data;
 713
 714         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 715         return count;
 716 }
 717
 718 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 719 {
 720         const struct blk_mq_debugfs_attr *attr = m->private;
 721         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 722
 723         return attr->show(data, m);
 724 }
 725
 726 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 727                                     size_t count, loff_t *ppos)
 728 {
 729         struct seq_file *m = file->private_data;
 730         const struct blk_mq_debugfs_attr *attr = m->private;
 731         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 732
 733         /*
 734          * Attributes that only implement .seq_ops are read-only and 'attr' is
 735          * the same with 'data' in this case.
 736          */
 737         if (attr == data || !attr->write)
 738                 return -EPERM;
 739
 740         return attr->write(data, buf, count, ppos);
 741 }
 742
 743 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 744 {
 745         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 746         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 747         struct seq_file *m;
 748         int ret;
 749
 750         if (attr->seq_ops) {
 751                 ret = seq_open(file, attr->seq_ops);
 752                 if (!ret) {
 753                         m = file->private_data;
 754                         m->private = data;
 755                 }
 756                 return ret;
 757         }
 758
 759         if (WARN_ON_ONCE(!attr->show))
 760                 return -EPERM;
 761
 762         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 763 }
 764
 765 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 766 {
 767         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 768
 769         if (attr->show)
 770                 return single_release(inode, file);
 771
 772         return seq_release(inode, file);
 773 }
 774
 775 static const struct file_operations blk_mq_debugfs_fops = {
 776         .open           = blk_mq_debugfs_open,
 777         .read           = seq_read,
 778         .write          = blk_mq_debugfs_write,
 779         .llseek         = seq_lseek,
 780         .release        = blk_mq_debugfs_release,
 781 };
 782
 783 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 784         {"state", 0400, hctx_state_show},
 785         {"flags", 0400, hctx_flags_show},
 786         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 787         {"busy", 0400, hctx_busy_show},
 788         {"ctx_map", 0400, hctx_ctx_map_show},
 789         {"tags", 0400, hctx_tags_show},
 790         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 791         {"sched_tags", 0400, hctx_sched_tags_show},
 792         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 793         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 794         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 795         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 796         {"run", 0600, hctx_run_show, hctx_run_write},
 797         {"active", 0400, hctx_active_show},
 798         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 799         {"type", 0400, hctx_type_show},
 800         {},
 801 };
 802
 803 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 804         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 805         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 806         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 807         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 808         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 809         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 810         {},
 811 };
 812
 813 static void debugfs_create_files(struct dentry *parent, void *data,
 814                                  const struct blk_mq_debugfs_attr *attr)
 815 {
 816         if (IS_ERR_OR_NULL(parent))
 817                 return;
 818
 819         d_inode(parent)->i_private = data;
 820
 821         for (; attr->name; attr++)
 822                 debugfs_create_file(attr->name, attr->mode, parent,
 823                                     (void *)attr, &blk_mq_debugfs_fops);
 824 }
 825
 826 void blk_mq_debugfs_register(struct request_queue *q)
 827 {
 828         struct blk_mq_hw_ctx *hctx;
 829         int i;
 830
 831         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 832
 833         /*
 834          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 835          * didn't exist yet (because we don't know what to name the directory
 836          * until the queue is registered to a gendisk).
 837          */
 838         if (q->elevator && !q->sched_debugfs_dir)
 839                 blk_mq_debugfs_register_sched(q);
 840
 841         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 842         queue_for_each_hw_ctx(q, hctx, i) {
 843                 if (!hctx->debugfs_dir)
 844                         blk_mq_debugfs_register_hctx(q, hctx);
 845                 if (q->elevator && !hctx->sched_debugfs_dir)
 846                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 847         }
 848
 849         if (q->rq_qos) {
 850                 struct rq_qos *rqos = q->rq_qos;
 851
 852                 while (rqos) {
 853                         blk_mq_debugfs_register_rqos(rqos);
 854                         rqos = rqos->next;
 855                 }
 856         }
 857 }
 858
 859 void blk_mq_debugfs_unregister(struct request_queue *q)
 860 {
 861         q->sched_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 }