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-sched.h"
  15 #include "blk-mq-tag.h"
  16 #include "blk-rq-qos.h"
  17
  18 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  19 {
  20         if (stat->nr_samples) {
  21                 seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
  22                            stat->nr_samples, stat->mean, stat->min, stat->max);
  23         } else {
  24                 seq_puts(m, "samples=0");
  25         }
  26 }
  27
  28 static int queue_poll_stat_show(void *data, struct seq_file *m)
  29 {
  30         struct request_queue *q = data;
  31         int bucket;
  32
  33         if (!q->poll_stat)
  34                 return 0;
  35
  36         for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
  37                 seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
  38                 print_stat(m, &q->poll_stat[2 * bucket]);
  39                 seq_puts(m, "\n");
  40
  41                 seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
  42                 print_stat(m, &q->poll_stat[2 * bucket + 1]);
  43                 seq_puts(m, "\n");
  44         }
  45         return 0;
  46 }
  47
  48 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  49         __acquires(&q->requeue_lock)
  50 {
  51         struct request_queue *q = m->private;
  52
  53         spin_lock_irq(&q->requeue_lock);
  54         return seq_list_start(&q->requeue_list, *pos);
  55 }
  56
  57 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  58 {
  59         struct request_queue *q = m->private;
  60
  61         return seq_list_next(v, &q->requeue_list, pos);
  62 }
  63
  64 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  65         __releases(&q->requeue_lock)
  66 {
  67         struct request_queue *q = m->private;
  68
  69         spin_unlock_irq(&q->requeue_lock);
  70 }
  71
  72 static const struct seq_operations queue_requeue_list_seq_ops = {
  73         .start  = queue_requeue_list_start,
  74         .next   = queue_requeue_list_next,
  75         .stop   = queue_requeue_list_stop,
  76         .show   = blk_mq_debugfs_rq_show,
  77 };
  78
  79 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  80                           const char *const *flag_name, int flag_name_count)
  81 {
  82         bool sep = false;
  83         int i;
  84
  85         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  86                 if (!(flags & BIT(i)))
  87                         continue;
  88                 if (sep)
  89                         seq_puts(m, "|");
  90                 sep = true;
  91                 if (i < flag_name_count && flag_name[i])
  92                         seq_puts(m, flag_name[i]);
  93                 else
  94                         seq_printf(m, "%d", i);
  95         }
  96         return 0;
  97 }
  98
  99 static int queue_pm_only_show(void *data, struct seq_file *m)
 100 {
 101         struct request_queue *q = data;
 102
 103         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 104         return 0;
 105 }
 106
 107 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 108 static const char *const blk_queue_flag_name[] = {
 109         QUEUE_FLAG_NAME(STOPPED),
 110         QUEUE_FLAG_NAME(DYING),
 111         QUEUE_FLAG_NAME(NOMERGES),
 112         QUEUE_FLAG_NAME(SAME_COMP),
 113         QUEUE_FLAG_NAME(FAIL_IO),
 114         QUEUE_FLAG_NAME(NONROT),
 115         QUEUE_FLAG_NAME(IO_STAT),
 116         QUEUE_FLAG_NAME(DISCARD),
 117         QUEUE_FLAG_NAME(NOXMERGES),
 118         QUEUE_FLAG_NAME(ADD_RANDOM),
 119         QUEUE_FLAG_NAME(SECERASE),
 120         QUEUE_FLAG_NAME(SAME_FORCE),
 121         QUEUE_FLAG_NAME(DEAD),
 122         QUEUE_FLAG_NAME(INIT_DONE),
 123         QUEUE_FLAG_NAME(STABLE_WRITES),
 124         QUEUE_FLAG_NAME(POLL),
 125         QUEUE_FLAG_NAME(WC),
 126         QUEUE_FLAG_NAME(FUA),
 127         QUEUE_FLAG_NAME(DAX),
 128         QUEUE_FLAG_NAME(STATS),
 129         QUEUE_FLAG_NAME(REGISTERED),
 130         QUEUE_FLAG_NAME(QUIESCED),
 131         QUEUE_FLAG_NAME(PCI_P2PDMA),
 132         QUEUE_FLAG_NAME(ZONE_RESETALL),
 133         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 134         QUEUE_FLAG_NAME(HCTX_ACTIVE),
 135         QUEUE_FLAG_NAME(NOWAIT),
 136 };
 137 #undef QUEUE_FLAG_NAME
 138
 139 static int queue_state_show(void *data, struct seq_file *m)
 140 {
 141         struct request_queue *q = data;
 142
 143         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 144                        ARRAY_SIZE(blk_queue_flag_name));
 145         seq_puts(m, "\n");
 146         return 0;
 147 }
 148
 149 static ssize_t queue_state_write(void *data, const char __user *buf,
 150                                  size_t count, loff_t *ppos)
 151 {
 152         struct request_queue *q = data;
 153         char opbuf[16] = { }, *op;
 154
 155         /*
 156          * The "state" attribute is removed after blk_cleanup_queue() has called
 157          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 158          * triggering a use-after-free.
 159          */
 160         if (blk_queue_dead(q))
 161                 return -ENOENT;
 162
 163         if (count >= sizeof(opbuf)) {
 164                 pr_err("%s: operation too long\n", __func__);
 165                 goto inval;
 166         }
 167
 168         if (copy_from_user(opbuf, buf, count))
 169                 return -EFAULT;
 170         op = strstrip(opbuf);
 171         if (strcmp(op, "run") == 0) {
 172                 blk_mq_run_hw_queues(q, true);
 173         } else if (strcmp(op, "start") == 0) {
 174                 blk_mq_start_stopped_hw_queues(q, true);
 175         } else if (strcmp(op, "kick") == 0) {
 176                 blk_mq_kick_requeue_list(q);
 177         } else {
 178                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 179 inval:
 180                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 181                 return -EINVAL;
 182         }
 183         return count;
 184 }
 185
 186 static int queue_write_hint_show(void *data, struct seq_file *m)
 187 {
 188         struct request_queue *q = data;
 189         int i;
 190
 191         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 192                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 193
 194         return 0;
 195 }
 196
 197 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 198                                       size_t count, loff_t *ppos)
 199 {
 200         struct request_queue *q = data;
 201         int i;
 202
 203         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 204                 q->write_hints[i] = 0;
 205
 206         return count;
 207 }
 208
 209 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 210         { "poll_stat", 0400, queue_poll_stat_show },
 211         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 212         { "pm_only", 0600, queue_pm_only_show, NULL },
 213         { "state", 0600, queue_state_show, queue_state_write },
 214         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 215         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 216         { },
 217 };
 218
 219 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 220 static const char *const hctx_state_name[] = {
 221         HCTX_STATE_NAME(STOPPED),
 222         HCTX_STATE_NAME(TAG_ACTIVE),
 223         HCTX_STATE_NAME(SCHED_RESTART),
 224         HCTX_STATE_NAME(INACTIVE),
 225 };
 226 #undef HCTX_STATE_NAME
 227
 228 static int hctx_state_show(void *data, struct seq_file *m)
 229 {
 230         struct blk_mq_hw_ctx *hctx = data;
 231
 232         blk_flags_show(m, hctx->state, hctx_state_name,
 233                        ARRAY_SIZE(hctx_state_name));
 234         seq_puts(m, "\n");
 235         return 0;
 236 }
 237
 238 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 239 static const char *const alloc_policy_name[] = {
 240         BLK_TAG_ALLOC_NAME(FIFO),
 241         BLK_TAG_ALLOC_NAME(RR),
 242 };
 243 #undef BLK_TAG_ALLOC_NAME
 244
 245 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 246 static const char *const hctx_flag_name[] = {
 247         HCTX_FLAG_NAME(SHOULD_MERGE),
 248         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 249         HCTX_FLAG_NAME(BLOCKING),
 250         HCTX_FLAG_NAME(NO_SCHED),
 251         HCTX_FLAG_NAME(STACKING),
 252         HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 253 };
 254 #undef HCTX_FLAG_NAME
 255
 256 static int hctx_flags_show(void *data, struct seq_file *m)
 257 {
 258         struct blk_mq_hw_ctx *hctx = data;
 259         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 260
 261         seq_puts(m, "alloc_policy=");
 262         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 263             alloc_policy_name[alloc_policy])
 264                 seq_puts(m, alloc_policy_name[alloc_policy]);
 265         else
 266                 seq_printf(m, "%d", alloc_policy);
 267         seq_puts(m, " ");
 268         blk_flags_show(m,
 269                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 270                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 271         seq_puts(m, "\n");
 272         return 0;
 273 }
 274
 275 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 276 static const char *const cmd_flag_name[] = {
 277         CMD_FLAG_NAME(FAILFAST_DEV),
 278         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 279         CMD_FLAG_NAME(FAILFAST_DRIVER),
 280         CMD_FLAG_NAME(SYNC),
 281         CMD_FLAG_NAME(META),
 282         CMD_FLAG_NAME(PRIO),
 283         CMD_FLAG_NAME(NOMERGE),
 284         CMD_FLAG_NAME(IDLE),
 285         CMD_FLAG_NAME(INTEGRITY),
 286         CMD_FLAG_NAME(FUA),
 287         CMD_FLAG_NAME(PREFLUSH),
 288         CMD_FLAG_NAME(RAHEAD),
 289         CMD_FLAG_NAME(BACKGROUND),
 290         CMD_FLAG_NAME(NOWAIT),
 291         CMD_FLAG_NAME(NOUNMAP),
 292         CMD_FLAG_NAME(POLLED),
 293 };
 294 #undef CMD_FLAG_NAME
 295
 296 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 297 static const char *const rqf_name[] = {
 298         RQF_NAME(STARTED),
 299         RQF_NAME(SOFTBARRIER),
 300         RQF_NAME(FLUSH_SEQ),
 301         RQF_NAME(MIXED_MERGE),
 302         RQF_NAME(MQ_INFLIGHT),
 303         RQF_NAME(DONTPREP),
 304         RQF_NAME(FAILED),
 305         RQF_NAME(QUIET),
 306         RQF_NAME(ELVPRIV),
 307         RQF_NAME(IO_STAT),
 308         RQF_NAME(PM),
 309         RQF_NAME(HASHED),
 310         RQF_NAME(STATS),
 311         RQF_NAME(SPECIAL_PAYLOAD),
 312         RQF_NAME(ZONE_WRITE_LOCKED),
 313         RQF_NAME(MQ_POLL_SLEPT),
 314         RQF_NAME(ELV),
 315 };
 316 #undef RQF_NAME
 317
 318 static const char *const blk_mq_rq_state_name_array[] = {
 319         [MQ_RQ_IDLE]            = "idle",
 320         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 321         [MQ_RQ_COMPLETE]        = "complete",
 322 };
 323
 324 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 325 {
 326         if (WARN_ON_ONCE((unsigned int)rq_state >=
 327                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 328                 return "(?)";
 329         return blk_mq_rq_state_name_array[rq_state];
 330 }
 331
 332 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 333 {
 334         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 335         const unsigned int op = req_op(rq);
 336         const char *op_str = blk_op_str(op);
 337
 338         seq_printf(m, "%p {.op=", rq);
 339         if (strcmp(op_str, "UNKNOWN") == 0)
 340                 seq_printf(m, "%u", op);
 341         else
 342                 seq_printf(m, "%s", op_str);
 343         seq_puts(m, ", .cmd_flags=");
 344         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 345                        ARRAY_SIZE(cmd_flag_name));
 346         seq_puts(m, ", .rq_flags=");
 347         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 348                        ARRAY_SIZE(rqf_name));
 349         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 350         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 351                    rq->internal_tag);
 352         if (mq_ops->show_rq)
 353                 mq_ops->show_rq(m, rq);
 354         seq_puts(m, "}\n");
 355         return 0;
 356 }
 357 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 358
 359 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 360 {
 361         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 362 }
 363 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 364
 365 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 366         __acquires(&hctx->lock)
 367 {
 368         struct blk_mq_hw_ctx *hctx = m->private;
 369
 370         spin_lock(&hctx->lock);
 371         return seq_list_start(&hctx->dispatch, *pos);
 372 }
 373
 374 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 375 {
 376         struct blk_mq_hw_ctx *hctx = m->private;
 377
 378         return seq_list_next(v, &hctx->dispatch, pos);
 379 }
 380
 381 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 382         __releases(&hctx->lock)
 383 {
 384         struct blk_mq_hw_ctx *hctx = m->private;
 385
 386         spin_unlock(&hctx->lock);
 387 }
 388
 389 static const struct seq_operations hctx_dispatch_seq_ops = {
 390         .start  = hctx_dispatch_start,
 391         .next   = hctx_dispatch_next,
 392         .stop   = hctx_dispatch_stop,
 393         .show   = blk_mq_debugfs_rq_show,
 394 };
 395
 396 struct show_busy_params {
 397         struct seq_file         *m;
 398         struct blk_mq_hw_ctx    *hctx;
 399 };
 400
 401 /*
 402  * Note: the state of a request may change while this function is in progress,
 403  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 404  * keep iterating requests.
 405  */
 406 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 407 {
 408         const struct show_busy_params *params = data;
 409
 410         if (rq->mq_hctx == params->hctx)
 411                 __blk_mq_debugfs_rq_show(params->m, rq);
 412
 413         return true;
 414 }
 415
 416 static int hctx_busy_show(void *data, struct seq_file *m)
 417 {
 418         struct blk_mq_hw_ctx *hctx = data;
 419         struct show_busy_params params = { .m = m, .hctx = hctx };
 420
 421         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 422                                 &params);
 423
 424         return 0;
 425 }
 426
 427 static const char *const hctx_types[] = {
 428         [HCTX_TYPE_DEFAULT]     = "default",
 429         [HCTX_TYPE_READ]        = "read",
 430         [HCTX_TYPE_POLL]        = "poll",
 431 };
 432
 433 static int hctx_type_show(void *data, struct seq_file *m)
 434 {
 435         struct blk_mq_hw_ctx *hctx = data;
 436
 437         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 438         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 439         return 0;
 440 }
 441
 442 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 443 {
 444         struct blk_mq_hw_ctx *hctx = data;
 445
 446         sbitmap_bitmap_show(&hctx->ctx_map, m);
 447         return 0;
 448 }
 449
 450 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 451                                      struct blk_mq_tags *tags)
 452 {
 453         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 454         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 455         seq_printf(m, "active_queues=%d\n",
 456                    atomic_read(&tags->active_queues));
 457
 458         seq_puts(m, "\nbitmap_tags:\n");
 459         sbitmap_queue_show(&tags->bitmap_tags, m);
 460
 461         if (tags->nr_reserved_tags) {
 462                 seq_puts(m, "\nbreserved_tags:\n");
 463                 sbitmap_queue_show(&tags->breserved_tags, m);
 464         }
 465 }
 466
 467 static int hctx_tags_show(void *data, struct seq_file *m)
 468 {
 469         struct blk_mq_hw_ctx *hctx = data;
 470         struct request_queue *q = hctx->queue;
 471         int res;
 472
 473         res = mutex_lock_interruptible(&q->sysfs_lock);
 474         if (res)
 475                 goto out;
 476         if (hctx->tags)
 477                 blk_mq_debugfs_tags_show(m, hctx->tags);
 478         mutex_unlock(&q->sysfs_lock);
 479
 480 out:
 481         return res;
 482 }
 483
 484 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 485 {
 486         struct blk_mq_hw_ctx *hctx = data;
 487         struct request_queue *q = hctx->queue;
 488         int res;
 489
 490         res = mutex_lock_interruptible(&q->sysfs_lock);
 491         if (res)
 492                 goto out;
 493         if (hctx->tags)
 494                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 495         mutex_unlock(&q->sysfs_lock);
 496
 497 out:
 498         return res;
 499 }
 500
 501 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 502 {
 503         struct blk_mq_hw_ctx *hctx = data;
 504         struct request_queue *q = hctx->queue;
 505         int res;
 506
 507         res = mutex_lock_interruptible(&q->sysfs_lock);
 508         if (res)
 509                 goto out;
 510         if (hctx->sched_tags)
 511                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 512         mutex_unlock(&q->sysfs_lock);
 513
 514 out:
 515         return res;
 516 }
 517
 518 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 519 {
 520         struct blk_mq_hw_ctx *hctx = data;
 521         struct request_queue *q = hctx->queue;
 522         int res;
 523
 524         res = mutex_lock_interruptible(&q->sysfs_lock);
 525         if (res)
 526                 goto out;
 527         if (hctx->sched_tags)
 528                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 529         mutex_unlock(&q->sysfs_lock);
 530
 531 out:
 532         return res;
 533 }
 534
 535 static int hctx_run_show(void *data, struct seq_file *m)
 536 {
 537         struct blk_mq_hw_ctx *hctx = data;
 538
 539         seq_printf(m, "%lu\n", hctx->run);
 540         return 0;
 541 }
 542
 543 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 544                               loff_t *ppos)
 545 {
 546         struct blk_mq_hw_ctx *hctx = data;
 547
 548         hctx->run = 0;
 549         return count;
 550 }
 551
 552 static int hctx_active_show(void *data, struct seq_file *m)
 553 {
 554         struct blk_mq_hw_ctx *hctx = data;
 555
 556         seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
 557         return 0;
 558 }
 559
 560 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 561 {
 562         struct blk_mq_hw_ctx *hctx = data;
 563
 564         seq_printf(m, "%u\n", hctx->dispatch_busy);
 565         return 0;
 566 }
 567
 568 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 569 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 570         __acquires(&ctx->lock)                                          \
 571 {                                                                       \
 572         struct blk_mq_ctx *ctx = m->private;                            \
 573                                                                         \
 574         spin_lock(&ctx->lock);                                          \
 575         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 576 }                                                                       \
 577                                                                         \
 578 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 579                                      loff_t *pos)                       \
 580 {                                                                       \
 581         struct blk_mq_ctx *ctx = m->private;                            \
 582                                                                         \
 583         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 584 }                                                                       \
 585                                                                         \
 586 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 587         __releases(&ctx->lock)                                          \
 588 {                                                                       \
 589         struct blk_mq_ctx *ctx = m->private;                            \
 590                                                                         \
 591         spin_unlock(&ctx->lock);                                        \
 592 }                                                                       \
 593                                                                         \
 594 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 595         .start  = ctx_##name##_rq_list_start,                           \
 596         .next   = ctx_##name##_rq_list_next,                            \
 597         .stop   = ctx_##name##_rq_list_stop,                            \
 598         .show   = blk_mq_debugfs_rq_show,                               \
 599 }
 600
 601 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 602 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 603 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 604
 605 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 606 {
 607         const struct blk_mq_debugfs_attr *attr = m->private;
 608         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 609
 610         return attr->show(data, m);
 611 }
 612
 613 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 614                                     size_t count, loff_t *ppos)
 615 {
 616         struct seq_file *m = file->private_data;
 617         const struct blk_mq_debugfs_attr *attr = m->private;
 618         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 619
 620         /*
 621          * Attributes that only implement .seq_ops are read-only and 'attr' is
 622          * the same with 'data' in this case.
 623          */
 624         if (attr == data || !attr->write)
 625                 return -EPERM;
 626
 627         return attr->write(data, buf, count, ppos);
 628 }
 629
 630 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 631 {
 632         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 633         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 634         struct seq_file *m;
 635         int ret;
 636
 637         if (attr->seq_ops) {
 638                 ret = seq_open(file, attr->seq_ops);
 639                 if (!ret) {
 640                         m = file->private_data;
 641                         m->private = data;
 642                 }
 643                 return ret;
 644         }
 645
 646         if (WARN_ON_ONCE(!attr->show))
 647                 return -EPERM;
 648
 649         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 650 }
 651
 652 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 653 {
 654         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 655
 656         if (attr->show)
 657                 return single_release(inode, file);
 658
 659         return seq_release(inode, file);
 660 }
 661
 662 static const struct file_operations blk_mq_debugfs_fops = {
 663         .open           = blk_mq_debugfs_open,
 664         .read           = seq_read,
 665         .write          = blk_mq_debugfs_write,
 666         .llseek         = seq_lseek,
 667         .release        = blk_mq_debugfs_release,
 668 };
 669
 670 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 671         {"state", 0400, hctx_state_show},
 672         {"flags", 0400, hctx_flags_show},
 673         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 674         {"busy", 0400, hctx_busy_show},
 675         {"ctx_map", 0400, hctx_ctx_map_show},
 676         {"tags", 0400, hctx_tags_show},
 677         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 678         {"sched_tags", 0400, hctx_sched_tags_show},
 679         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 680         {"run", 0600, hctx_run_show, hctx_run_write},
 681         {"active", 0400, hctx_active_show},
 682         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 683         {"type", 0400, hctx_type_show},
 684         {},
 685 };
 686
 687 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 688         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 689         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 690         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 691         {},
 692 };
 693
 694 static void debugfs_create_files(struct dentry *parent, void *data,
 695                                  const struct blk_mq_debugfs_attr *attr)
 696 {
 697         if (IS_ERR_OR_NULL(parent))
 698                 return;
 699
 700         d_inode(parent)->i_private = data;
 701
 702         for (; attr->name; attr++)
 703                 debugfs_create_file(attr->name, attr->mode, parent,
 704                                     (void *)attr, &blk_mq_debugfs_fops);
 705 }
 706
 707 void blk_mq_debugfs_register(struct request_queue *q)
 708 {
 709         struct blk_mq_hw_ctx *hctx;
 710         int i;
 711
 712         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 713
 714         /*
 715          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 716          * didn't exist yet (because we don't know what to name the directory
 717          * until the queue is registered to a gendisk).
 718          */
 719         if (q->elevator && !q->sched_debugfs_dir)
 720                 blk_mq_debugfs_register_sched(q);
 721
 722         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 723         queue_for_each_hw_ctx(q, hctx, i) {
 724                 if (!hctx->debugfs_dir)
 725                         blk_mq_debugfs_register_hctx(q, hctx);
 726                 if (q->elevator && !hctx->sched_debugfs_dir)
 727                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 728         }
 729
 730         if (q->rq_qos) {
 731                 struct rq_qos *rqos = q->rq_qos;
 732
 733                 while (rqos) {
 734                         blk_mq_debugfs_register_rqos(rqos);
 735                         rqos = rqos->next;
 736                 }
 737         }
 738 }
 739
 740 void blk_mq_debugfs_unregister(struct request_queue *q)
 741 {
 742         q->sched_debugfs_dir = NULL;
 743 }
 744
 745 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 746                                         struct blk_mq_ctx *ctx)
 747 {
 748         struct dentry *ctx_dir;
 749         char name[20];
 750
 751         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 752         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 753
 754         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 755 }
 756
 757 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 758                                   struct blk_mq_hw_ctx *hctx)
 759 {
 760         struct blk_mq_ctx *ctx;
 761         char name[20];
 762         int i;
 763
 764         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 765         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 766
 767         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 768
 769         hctx_for_each_ctx(hctx, ctx, i)
 770                 blk_mq_debugfs_register_ctx(hctx, ctx);
 771 }
 772
 773 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 774 {
 775         debugfs_remove_recursive(hctx->debugfs_dir);
 776         hctx->sched_debugfs_dir = NULL;
 777         hctx->debugfs_dir = NULL;
 778 }
 779
 780 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 781 {
 782         struct blk_mq_hw_ctx *hctx;
 783         int i;
 784
 785         queue_for_each_hw_ctx(q, hctx, i)
 786                 blk_mq_debugfs_register_hctx(q, hctx);
 787 }
 788
 789 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 790 {
 791         struct blk_mq_hw_ctx *hctx;
 792         int i;
 793
 794         queue_for_each_hw_ctx(q, hctx, i)
 795                 blk_mq_debugfs_unregister_hctx(hctx);
 796 }
 797
 798 void blk_mq_debugfs_register_sched(struct request_queue *q)
 799 {
 800         struct elevator_type *e = q->elevator->type;
 801
 802         /*
 803          * If the parent directory has not been created yet, return, we will be
 804          * called again later on and the directory/files will be created then.
 805          */
 806         if (!q->debugfs_dir)
 807                 return;
 808
 809         if (!e->queue_debugfs_attrs)
 810                 return;
 811
 812         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 813
 814         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 815 }
 816
 817 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 818 {
 819         debugfs_remove_recursive(q->sched_debugfs_dir);
 820         q->sched_debugfs_dir = NULL;
 821 }
 822
 823 static const char *rq_qos_id_to_name(enum rq_qos_id id)
 824 {
 825         switch (id) {
 826         case RQ_QOS_WBT:
 827                 return "wbt";
 828         case RQ_QOS_LATENCY:
 829                 return "latency";
 830         case RQ_QOS_COST:
 831                 return "cost";
 832         case RQ_QOS_IOPRIO:
 833                 return "ioprio";
 834         }
 835         return "unknown";
 836 }
 837
 838 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 839 {
 840         debugfs_remove_recursive(rqos->debugfs_dir);
 841         rqos->debugfs_dir = NULL;
 842 }
 843
 844 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 845 {
 846         struct request_queue *q = rqos->q;
 847         const char *dir_name = rq_qos_id_to_name(rqos->id);
 848
 849         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 850                 return;
 851
 852         if (!q->rqos_debugfs_dir)
 853                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 854                                                          q->debugfs_dir);
 855
 856         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 857                                                rqos->q->rqos_debugfs_dir);
 858
 859         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 860 }
 861
 862 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 863 {
 864         debugfs_remove_recursive(q->rqos_debugfs_dir);
 865         q->rqos_debugfs_dir = NULL;
 866 }
 867
 868 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 869                                         struct blk_mq_hw_ctx *hctx)
 870 {
 871         struct elevator_type *e = q->elevator->type;
 872
 873         /*
 874          * If the parent debugfs directory has not been created yet, return;
 875          * We will be called again later on with appropriate parent debugfs
 876          * directory from blk_register_queue()
 877          */
 878         if (!hctx->debugfs_dir)
 879                 return;
 880
 881         if (!e->hctx_debugfs_attrs)
 882                 return;
 883
 884         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 885                                                      hctx->debugfs_dir);
 886         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 887                              e->hctx_debugfs_attrs);
 888 }
 889
 890 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 891 {
 892         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 893         hctx->sched_debugfs_dir = NULL;
 894 }