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(QUIESCED),
 128         QUEUE_FLAG_NAME(PCI_P2PDMA),
 129         QUEUE_FLAG_NAME(ZONE_RESETALL),
 130         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 131         QUEUE_FLAG_NAME(HCTX_ACTIVE),
 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(POLLED),
 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(STARTED),
 296         RQF_NAME(SOFTBARRIER),
 297         RQF_NAME(FLUSH_SEQ),
 298         RQF_NAME(MIXED_MERGE),
 299         RQF_NAME(MQ_INFLIGHT),
 300         RQF_NAME(DONTPREP),
 301         RQF_NAME(FAILED),
 302         RQF_NAME(QUIET),
 303         RQF_NAME(ELVPRIV),
 304         RQF_NAME(IO_STAT),
 305         RQF_NAME(PM),
 306         RQF_NAME(HASHED),
 307         RQF_NAME(STATS),
 308         RQF_NAME(SPECIAL_PAYLOAD),
 309         RQF_NAME(ZONE_WRITE_LOCKED),
 310         RQF_NAME(MQ_POLL_SLEPT),
 311 };
 312 #undef RQF_NAME
 313
 314 static const char *const blk_mq_rq_state_name_array[] = {
 315         [MQ_RQ_IDLE]            = "idle",
 316         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 317         [MQ_RQ_COMPLETE]        = "complete",
 318 };
 319
 320 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 321 {
 322         if (WARN_ON_ONCE((unsigned int)rq_state >=
 323                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 324                 return "(?)";
 325         return blk_mq_rq_state_name_array[rq_state];
 326 }
 327
 328 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 329 {
 330         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 331         const unsigned int op = req_op(rq);
 332         const char *op_str = blk_op_str(op);
 333
 334         seq_printf(m, "%p {.op=", rq);
 335         if (strcmp(op_str, "UNKNOWN") == 0)
 336                 seq_printf(m, "%u", op);
 337         else
 338                 seq_printf(m, "%s", op_str);
 339         seq_puts(m, ", .cmd_flags=");
 340         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 341                        ARRAY_SIZE(cmd_flag_name));
 342         seq_puts(m, ", .rq_flags=");
 343         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 344                        ARRAY_SIZE(rqf_name));
 345         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 346         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 347                    rq->internal_tag);
 348         if (mq_ops->show_rq)
 349                 mq_ops->show_rq(m, rq);
 350         seq_puts(m, "}\n");
 351         return 0;
 352 }
 353 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 354
 355 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 356 {
 357         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 358 }
 359 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 360
 361 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 362         __acquires(&hctx->lock)
 363 {
 364         struct blk_mq_hw_ctx *hctx = m->private;
 365
 366         spin_lock(&hctx->lock);
 367         return seq_list_start(&hctx->dispatch, *pos);
 368 }
 369
 370 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 371 {
 372         struct blk_mq_hw_ctx *hctx = m->private;
 373
 374         return seq_list_next(v, &hctx->dispatch, pos);
 375 }
 376
 377 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 378         __releases(&hctx->lock)
 379 {
 380         struct blk_mq_hw_ctx *hctx = m->private;
 381
 382         spin_unlock(&hctx->lock);
 383 }
 384
 385 static const struct seq_operations hctx_dispatch_seq_ops = {
 386         .start  = hctx_dispatch_start,
 387         .next   = hctx_dispatch_next,
 388         .stop   = hctx_dispatch_stop,
 389         .show   = blk_mq_debugfs_rq_show,
 390 };
 391
 392 struct show_busy_params {
 393         struct seq_file         *m;
 394         struct blk_mq_hw_ctx    *hctx;
 395 };
 396
 397 /*
 398  * Note: the state of a request may change while this function is in progress,
 399  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 400  * keep iterating requests.
 401  */
 402 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 403 {
 404         const struct show_busy_params *params = data;
 405
 406         if (rq->mq_hctx == params->hctx)
 407                 __blk_mq_debugfs_rq_show(params->m, rq);
 408
 409         return true;
 410 }
 411
 412 static int hctx_busy_show(void *data, struct seq_file *m)
 413 {
 414         struct blk_mq_hw_ctx *hctx = data;
 415         struct show_busy_params params = { .m = m, .hctx = hctx };
 416
 417         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 418                                 &params);
 419
 420         return 0;
 421 }
 422
 423 static const char *const hctx_types[] = {
 424         [HCTX_TYPE_DEFAULT]     = "default",
 425         [HCTX_TYPE_READ]        = "read",
 426         [HCTX_TYPE_POLL]        = "poll",
 427 };
 428
 429 static int hctx_type_show(void *data, struct seq_file *m)
 430 {
 431         struct blk_mq_hw_ctx *hctx = data;
 432
 433         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 434         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 435         return 0;
 436 }
 437
 438 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 439 {
 440         struct blk_mq_hw_ctx *hctx = data;
 441
 442         sbitmap_bitmap_show(&hctx->ctx_map, m);
 443         return 0;
 444 }
 445
 446 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 447                                      struct blk_mq_tags *tags)
 448 {
 449         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 450         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 451         seq_printf(m, "active_queues=%d\n",
 452                    atomic_read(&tags->active_queues));
 453
 454         seq_puts(m, "\nbitmap_tags:\n");
 455         sbitmap_queue_show(&tags->bitmap_tags, m);
 456
 457         if (tags->nr_reserved_tags) {
 458                 seq_puts(m, "\nbreserved_tags:\n");
 459                 sbitmap_queue_show(&tags->breserved_tags, m);
 460         }
 461 }
 462
 463 static int hctx_tags_show(void *data, struct seq_file *m)
 464 {
 465         struct blk_mq_hw_ctx *hctx = data;
 466         struct request_queue *q = hctx->queue;
 467         int res;
 468
 469         res = mutex_lock_interruptible(&q->sysfs_lock);
 470         if (res)
 471                 goto out;
 472         if (hctx->tags)
 473                 blk_mq_debugfs_tags_show(m, hctx->tags);
 474         mutex_unlock(&q->sysfs_lock);
 475
 476 out:
 477         return res;
 478 }
 479
 480 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 481 {
 482         struct blk_mq_hw_ctx *hctx = data;
 483         struct request_queue *q = hctx->queue;
 484         int res;
 485
 486         res = mutex_lock_interruptible(&q->sysfs_lock);
 487         if (res)
 488                 goto out;
 489         if (hctx->tags)
 490                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 491         mutex_unlock(&q->sysfs_lock);
 492
 493 out:
 494         return res;
 495 }
 496
 497 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 498 {
 499         struct blk_mq_hw_ctx *hctx = data;
 500         struct request_queue *q = hctx->queue;
 501         int res;
 502
 503         res = mutex_lock_interruptible(&q->sysfs_lock);
 504         if (res)
 505                 goto out;
 506         if (hctx->sched_tags)
 507                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 508         mutex_unlock(&q->sysfs_lock);
 509
 510 out:
 511         return res;
 512 }
 513
 514 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 515 {
 516         struct blk_mq_hw_ctx *hctx = data;
 517         struct request_queue *q = hctx->queue;
 518         int res;
 519
 520         res = mutex_lock_interruptible(&q->sysfs_lock);
 521         if (res)
 522                 goto out;
 523         if (hctx->sched_tags)
 524                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 525         mutex_unlock(&q->sysfs_lock);
 526
 527 out:
 528         return res;
 529 }
 530
 531 static int hctx_run_show(void *data, struct seq_file *m)
 532 {
 533         struct blk_mq_hw_ctx *hctx = data;
 534
 535         seq_printf(m, "%lu\n", hctx->run);
 536         return 0;
 537 }
 538
 539 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 540                               loff_t *ppos)
 541 {
 542         struct blk_mq_hw_ctx *hctx = data;
 543
 544         hctx->run = 0;
 545         return count;
 546 }
 547
 548 static int hctx_active_show(void *data, struct seq_file *m)
 549 {
 550         struct blk_mq_hw_ctx *hctx = data;
 551
 552         seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
 553         return 0;
 554 }
 555
 556 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 557 {
 558         struct blk_mq_hw_ctx *hctx = data;
 559
 560         seq_printf(m, "%u\n", hctx->dispatch_busy);
 561         return 0;
 562 }
 563
 564 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 565 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 566         __acquires(&ctx->lock)                                          \
 567 {                                                                       \
 568         struct blk_mq_ctx *ctx = m->private;                            \
 569                                                                         \
 570         spin_lock(&ctx->lock);                                          \
 571         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 572 }                                                                       \
 573                                                                         \
 574 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 575                                      loff_t *pos)                       \
 576 {                                                                       \
 577         struct blk_mq_ctx *ctx = m->private;                            \
 578                                                                         \
 579         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 580 }                                                                       \
 581                                                                         \
 582 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 583         __releases(&ctx->lock)                                          \
 584 {                                                                       \
 585         struct blk_mq_ctx *ctx = m->private;                            \
 586                                                                         \
 587         spin_unlock(&ctx->lock);                                        \
 588 }                                                                       \
 589                                                                         \
 590 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 591         .start  = ctx_##name##_rq_list_start,                           \
 592         .next   = ctx_##name##_rq_list_next,                            \
 593         .stop   = ctx_##name##_rq_list_stop,                            \
 594         .show   = blk_mq_debugfs_rq_show,                               \
 595 }
 596
 597 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 598 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 599 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 600
 601 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 602 {
 603         const struct blk_mq_debugfs_attr *attr = m->private;
 604         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 605
 606         return attr->show(data, m);
 607 }
 608
 609 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 610                                     size_t count, loff_t *ppos)
 611 {
 612         struct seq_file *m = file->private_data;
 613         const struct blk_mq_debugfs_attr *attr = m->private;
 614         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 615
 616         /*
 617          * Attributes that only implement .seq_ops are read-only and 'attr' is
 618          * the same with 'data' in this case.
 619          */
 620         if (attr == data || !attr->write)
 621                 return -EPERM;
 622
 623         return attr->write(data, buf, count, ppos);
 624 }
 625
 626 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 627 {
 628         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 629         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 630         struct seq_file *m;
 631         int ret;
 632
 633         if (attr->seq_ops) {
 634                 ret = seq_open(file, attr->seq_ops);
 635                 if (!ret) {
 636                         m = file->private_data;
 637                         m->private = data;
 638                 }
 639                 return ret;
 640         }
 641
 642         if (WARN_ON_ONCE(!attr->show))
 643                 return -EPERM;
 644
 645         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 646 }
 647
 648 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 649 {
 650         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 651
 652         if (attr->show)
 653                 return single_release(inode, file);
 654
 655         return seq_release(inode, file);
 656 }
 657
 658 static const struct file_operations blk_mq_debugfs_fops = {
 659         .open           = blk_mq_debugfs_open,
 660         .read           = seq_read,
 661         .write          = blk_mq_debugfs_write,
 662         .llseek         = seq_lseek,
 663         .release        = blk_mq_debugfs_release,
 664 };
 665
 666 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 667         {"state", 0400, hctx_state_show},
 668         {"flags", 0400, hctx_flags_show},
 669         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 670         {"busy", 0400, hctx_busy_show},
 671         {"ctx_map", 0400, hctx_ctx_map_show},
 672         {"tags", 0400, hctx_tags_show},
 673         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 674         {"sched_tags", 0400, hctx_sched_tags_show},
 675         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 676         {"run", 0600, hctx_run_show, hctx_run_write},
 677         {"active", 0400, hctx_active_show},
 678         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 679         {"type", 0400, hctx_type_show},
 680         {},
 681 };
 682
 683 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 684         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 685         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 686         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 687         {},
 688 };
 689
 690 static void debugfs_create_files(struct dentry *parent, void *data,
 691                                  const struct blk_mq_debugfs_attr *attr)
 692 {
 693         if (IS_ERR_OR_NULL(parent))
 694                 return;
 695
 696         d_inode(parent)->i_private = data;
 697
 698         for (; attr->name; attr++)
 699                 debugfs_create_file(attr->name, attr->mode, parent,
 700                                     (void *)attr, &blk_mq_debugfs_fops);
 701 }
 702
 703 void blk_mq_debugfs_register(struct request_queue *q)
 704 {
 705         struct blk_mq_hw_ctx *hctx;
 706         int i;
 707
 708         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 709
 710         /*
 711          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 712          * didn't exist yet (because we don't know what to name the directory
 713          * until the queue is registered to a gendisk).
 714          */
 715         if (q->elevator && !q->sched_debugfs_dir)
 716                 blk_mq_debugfs_register_sched(q);
 717
 718         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 719         queue_for_each_hw_ctx(q, hctx, i) {
 720                 if (!hctx->debugfs_dir)
 721                         blk_mq_debugfs_register_hctx(q, hctx);
 722                 if (q->elevator && !hctx->sched_debugfs_dir)
 723                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 724         }
 725
 726         if (q->rq_qos) {
 727                 struct rq_qos *rqos = q->rq_qos;
 728
 729                 while (rqos) {
 730                         blk_mq_debugfs_register_rqos(rqos);
 731                         rqos = rqos->next;
 732                 }
 733         }
 734 }
 735
 736 void blk_mq_debugfs_unregister(struct request_queue *q)
 737 {
 738         q->sched_debugfs_dir = NULL;
 739 }
 740
 741 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 742                                         struct blk_mq_ctx *ctx)
 743 {
 744         struct dentry *ctx_dir;
 745         char name[20];
 746
 747         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 748         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 749
 750         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 751 }
 752
 753 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 754                                   struct blk_mq_hw_ctx *hctx)
 755 {
 756         struct blk_mq_ctx *ctx;
 757         char name[20];
 758         int i;
 759
 760         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 761         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 762
 763         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 764
 765         hctx_for_each_ctx(hctx, ctx, i)
 766                 blk_mq_debugfs_register_ctx(hctx, ctx);
 767 }
 768
 769 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 770 {
 771         debugfs_remove_recursive(hctx->debugfs_dir);
 772         hctx->sched_debugfs_dir = NULL;
 773         hctx->debugfs_dir = NULL;
 774 }
 775
 776 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 777 {
 778         struct blk_mq_hw_ctx *hctx;
 779         int i;
 780
 781         queue_for_each_hw_ctx(q, hctx, i)
 782                 blk_mq_debugfs_register_hctx(q, hctx);
 783 }
 784
 785 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 786 {
 787         struct blk_mq_hw_ctx *hctx;
 788         int i;
 789
 790         queue_for_each_hw_ctx(q, hctx, i)
 791                 blk_mq_debugfs_unregister_hctx(hctx);
 792 }
 793
 794 void blk_mq_debugfs_register_sched(struct request_queue *q)
 795 {
 796         struct elevator_type *e = q->elevator->type;
 797
 798         /*
 799          * If the parent directory has not been created yet, return, we will be
 800          * called again later on and the directory/files will be created then.
 801          */
 802         if (!q->debugfs_dir)
 803                 return;
 804
 805         if (!e->queue_debugfs_attrs)
 806                 return;
 807
 808         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 809
 810         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 811 }
 812
 813 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 814 {
 815         debugfs_remove_recursive(q->sched_debugfs_dir);
 816         q->sched_debugfs_dir = NULL;
 817 }
 818
 819 static const char *rq_qos_id_to_name(enum rq_qos_id id)
 820 {
 821         switch (id) {
 822         case RQ_QOS_WBT:
 823                 return "wbt";
 824         case RQ_QOS_LATENCY:
 825                 return "latency";
 826         case RQ_QOS_COST:
 827                 return "cost";
 828         case RQ_QOS_IOPRIO:
 829                 return "ioprio";
 830         }
 831         return "unknown";
 832 }
 833
 834 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 835 {
 836         debugfs_remove_recursive(rqos->debugfs_dir);
 837         rqos->debugfs_dir = NULL;
 838 }
 839
 840 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 841 {
 842         struct request_queue *q = rqos->q;
 843         const char *dir_name = rq_qos_id_to_name(rqos->id);
 844
 845         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 846                 return;
 847
 848         if (!q->rqos_debugfs_dir)
 849                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 850                                                          q->debugfs_dir);
 851
 852         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 853                                                rqos->q->rqos_debugfs_dir);
 854
 855         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 856 }
 857
 858 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 859 {
 860         debugfs_remove_recursive(q->rqos_debugfs_dir);
 861         q->rqos_debugfs_dir = NULL;
 862 }
 863
 864 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 865                                         struct blk_mq_hw_ctx *hctx)
 866 {
 867         struct elevator_type *e = q->elevator->type;
 868
 869         /*
 870          * If the parent debugfs directory has not been created yet, return;
 871          * We will be called again later on with appropriate parent debugfs
 872          * directory from blk_register_queue()
 873          */
 874         if (!hctx->debugfs_dir)
 875                 return;
 876
 877         if (!e->hctx_debugfs_attrs)
 878                 return;
 879
 880         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 881                                                      hctx->debugfs_dir);
 882         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 883                              e->hctx_debugfs_attrs);
 884 }
 885
 886 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 887 {
 888         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 889         hctx->sched_debugfs_dir = NULL;
 890 }