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=%lld, min=%llu, max=%llu",
  21                            stat->nr_samples, stat->mean, stat->min, stat->max);
  22         } else {
  23                 seq_puts(m, "samples=0");
  24         }
  25 }
  26
  27 static int queue_poll_stat_show(void *data, struct seq_file *m)
  28 {
  29         struct request_queue *q = data;
  30         int bucket;
  31
  32         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
  33                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
  34                 print_stat(m, &q->poll_stat[2*bucket]);
  35                 seq_puts(m, "\n");
  36
  37                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
  38                 print_stat(m, &q->poll_stat[2*bucket+1]);
  39                 seq_puts(m, "\n");
  40         }
  41         return 0;
  42 }
  43
  44 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  45         __acquires(&q->requeue_lock)
  46 {
  47         struct request_queue *q = m->private;
  48
  49         spin_lock_irq(&q->requeue_lock);
  50         return seq_list_start(&q->requeue_list, *pos);
  51 }
  52
  53 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  54 {
  55         struct request_queue *q = m->private;
  56
  57         return seq_list_next(v, &q->requeue_list, pos);
  58 }
  59
  60 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  61         __releases(&q->requeue_lock)
  62 {
  63         struct request_queue *q = m->private;
  64
  65         spin_unlock_irq(&q->requeue_lock);
  66 }
  67
  68 static const struct seq_operations queue_requeue_list_seq_ops = {
  69         .start  = queue_requeue_list_start,
  70         .next   = queue_requeue_list_next,
  71         .stop   = queue_requeue_list_stop,
  72         .show   = blk_mq_debugfs_rq_show,
  73 };
  74
  75 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  76                           const char *const *flag_name, int flag_name_count)
  77 {
  78         bool sep = false;
  79         int i;
  80
  81         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  82                 if (!(flags & BIT(i)))
  83                         continue;
  84                 if (sep)
  85                         seq_puts(m, "|");
  86                 sep = true;
  87                 if (i < flag_name_count && flag_name[i])
  88                         seq_puts(m, flag_name[i]);
  89                 else
  90                         seq_printf(m, "%d", i);
  91         }
  92         return 0;
  93 }
  94
  95 static int queue_pm_only_show(void *data, struct seq_file *m)
  96 {
  97         struct request_queue *q = data;
  98
  99         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 100         return 0;
 101 }
 102
 103 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 104 static const char *const blk_queue_flag_name[] = {
 105         QUEUE_FLAG_NAME(STOPPED),
 106         QUEUE_FLAG_NAME(DYING),
 107         QUEUE_FLAG_NAME(NOMERGES),
 108         QUEUE_FLAG_NAME(SAME_COMP),
 109         QUEUE_FLAG_NAME(FAIL_IO),
 110         QUEUE_FLAG_NAME(NONROT),
 111         QUEUE_FLAG_NAME(IO_STAT),
 112         QUEUE_FLAG_NAME(DISCARD),
 113         QUEUE_FLAG_NAME(NOXMERGES),
 114         QUEUE_FLAG_NAME(ADD_RANDOM),
 115         QUEUE_FLAG_NAME(SECERASE),
 116         QUEUE_FLAG_NAME(SAME_FORCE),
 117         QUEUE_FLAG_NAME(DEAD),
 118         QUEUE_FLAG_NAME(INIT_DONE),
 119         QUEUE_FLAG_NAME(POLL),
 120         QUEUE_FLAG_NAME(WC),
 121         QUEUE_FLAG_NAME(FUA),
 122         QUEUE_FLAG_NAME(DAX),
 123         QUEUE_FLAG_NAME(STATS),
 124         QUEUE_FLAG_NAME(POLL_STATS),
 125         QUEUE_FLAG_NAME(REGISTERED),
 126         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 127         QUEUE_FLAG_NAME(QUIESCED),
 128 };
 129 #undef QUEUE_FLAG_NAME
 130
 131 static int queue_state_show(void *data, struct seq_file *m)
 132 {
 133         struct request_queue *q = data;
 134
 135         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 136                        ARRAY_SIZE(blk_queue_flag_name));
 137         seq_puts(m, "\n");
 138         return 0;
 139 }
 140
 141 static ssize_t queue_state_write(void *data, const char __user *buf,
 142                                  size_t count, loff_t *ppos)
 143 {
 144         struct request_queue *q = data;
 145         char opbuf[16] = { }, *op;
 146
 147         /*
 148          * The "state" attribute is removed after blk_cleanup_queue() has called
 149          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 150          * triggering a use-after-free.
 151          */
 152         if (blk_queue_dead(q))
 153                 return -ENOENT;
 154
 155         if (count >= sizeof(opbuf)) {
 156                 pr_err("%s: operation too long\n", __func__);
 157                 goto inval;
 158         }
 159
 160         if (copy_from_user(opbuf, buf, count))
 161                 return -EFAULT;
 162         op = strstrip(opbuf);
 163         if (strcmp(op, "run") == 0) {
 164                 blk_mq_run_hw_queues(q, true);
 165         } else if (strcmp(op, "start") == 0) {
 166                 blk_mq_start_stopped_hw_queues(q, true);
 167         } else if (strcmp(op, "kick") == 0) {
 168                 blk_mq_kick_requeue_list(q);
 169         } else {
 170                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 171 inval:
 172                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 173                 return -EINVAL;
 174         }
 175         return count;
 176 }
 177
 178 static int queue_write_hint_show(void *data, struct seq_file *m)
 179 {
 180         struct request_queue *q = data;
 181         int i;
 182
 183         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 184                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 185
 186         return 0;
 187 }
 188
 189 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 190                                       size_t count, loff_t *ppos)
 191 {
 192         struct request_queue *q = data;
 193         int i;
 194
 195         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 196                 q->write_hints[i] = 0;
 197
 198         return count;
 199 }
 200
 201 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 202         { "poll_stat", 0400, queue_poll_stat_show },
 203         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 204         { "pm_only", 0600, queue_pm_only_show, NULL },
 205         { "state", 0600, queue_state_show, queue_state_write },
 206         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 207         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 208         { },
 209 };
 210
 211 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 212 static const char *const hctx_state_name[] = {
 213         HCTX_STATE_NAME(STOPPED),
 214         HCTX_STATE_NAME(TAG_ACTIVE),
 215         HCTX_STATE_NAME(SCHED_RESTART),
 216 };
 217 #undef HCTX_STATE_NAME
 218
 219 static int hctx_state_show(void *data, struct seq_file *m)
 220 {
 221         struct blk_mq_hw_ctx *hctx = data;
 222
 223         blk_flags_show(m, hctx->state, hctx_state_name,
 224                        ARRAY_SIZE(hctx_state_name));
 225         seq_puts(m, "\n");
 226         return 0;
 227 }
 228
 229 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 230 static const char *const alloc_policy_name[] = {
 231         BLK_TAG_ALLOC_NAME(FIFO),
 232         BLK_TAG_ALLOC_NAME(RR),
 233 };
 234 #undef BLK_TAG_ALLOC_NAME
 235
 236 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 237 static const char *const hctx_flag_name[] = {
 238         HCTX_FLAG_NAME(SHOULD_MERGE),
 239         HCTX_FLAG_NAME(TAG_SHARED),
 240         HCTX_FLAG_NAME(BLOCKING),
 241         HCTX_FLAG_NAME(NO_SCHED),
 242 };
 243 #undef HCTX_FLAG_NAME
 244
 245 static int hctx_flags_show(void *data, struct seq_file *m)
 246 {
 247         struct blk_mq_hw_ctx *hctx = data;
 248         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 249
 250         seq_puts(m, "alloc_policy=");
 251         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 252             alloc_policy_name[alloc_policy])
 253                 seq_puts(m, alloc_policy_name[alloc_policy]);
 254         else
 255                 seq_printf(m, "%d", alloc_policy);
 256         seq_puts(m, " ");
 257         blk_flags_show(m,
 258                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 259                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 260         seq_puts(m, "\n");
 261         return 0;
 262 }
 263
 264 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 265 static const char *const op_name[] = {
 266         REQ_OP_NAME(READ),
 267         REQ_OP_NAME(WRITE),
 268         REQ_OP_NAME(FLUSH),
 269         REQ_OP_NAME(DISCARD),
 270         REQ_OP_NAME(SECURE_ERASE),
 271         REQ_OP_NAME(ZONE_RESET),
 272         REQ_OP_NAME(WRITE_SAME),
 273         REQ_OP_NAME(WRITE_ZEROES),
 274         REQ_OP_NAME(SCSI_IN),
 275         REQ_OP_NAME(SCSI_OUT),
 276         REQ_OP_NAME(DRV_IN),
 277         REQ_OP_NAME(DRV_OUT),
 278 };
 279 #undef REQ_OP_NAME
 280
 281 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 282 static const char *const cmd_flag_name[] = {
 283         CMD_FLAG_NAME(FAILFAST_DEV),
 284         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 285         CMD_FLAG_NAME(FAILFAST_DRIVER),
 286         CMD_FLAG_NAME(SYNC),
 287         CMD_FLAG_NAME(META),
 288         CMD_FLAG_NAME(PRIO),
 289         CMD_FLAG_NAME(NOMERGE),
 290         CMD_FLAG_NAME(IDLE),
 291         CMD_FLAG_NAME(INTEGRITY),
 292         CMD_FLAG_NAME(FUA),
 293         CMD_FLAG_NAME(PREFLUSH),
 294         CMD_FLAG_NAME(RAHEAD),
 295         CMD_FLAG_NAME(BACKGROUND),
 296         CMD_FLAG_NAME(NOWAIT),
 297         CMD_FLAG_NAME(NOUNMAP),
 298         CMD_FLAG_NAME(HIPRI),
 299 };
 300 #undef CMD_FLAG_NAME
 301
 302 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 303 static const char *const rqf_name[] = {
 304         RQF_NAME(SORTED),
 305         RQF_NAME(STARTED),
 306         RQF_NAME(SOFTBARRIER),
 307         RQF_NAME(FLUSH_SEQ),
 308         RQF_NAME(MIXED_MERGE),
 309         RQF_NAME(MQ_INFLIGHT),
 310         RQF_NAME(DONTPREP),
 311         RQF_NAME(PREEMPT),
 312         RQF_NAME(COPY_USER),
 313         RQF_NAME(FAILED),
 314         RQF_NAME(QUIET),
 315         RQF_NAME(ELVPRIV),
 316         RQF_NAME(IO_STAT),
 317         RQF_NAME(ALLOCED),
 318         RQF_NAME(PM),
 319         RQF_NAME(HASHED),
 320         RQF_NAME(STATS),
 321         RQF_NAME(SPECIAL_PAYLOAD),
 322         RQF_NAME(ZONE_WRITE_LOCKED),
 323         RQF_NAME(MQ_POLL_SLEPT),
 324 };
 325 #undef RQF_NAME
 326
 327 static const char *const blk_mq_rq_state_name_array[] = {
 328         [MQ_RQ_IDLE]            = "idle",
 329         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 330         [MQ_RQ_COMPLETE]        = "complete",
 331 };
 332
 333 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 334 {
 335         if (WARN_ON_ONCE((unsigned int)rq_state >=
 336                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 337                 return "(?)";
 338         return blk_mq_rq_state_name_array[rq_state];
 339 }
 340
 341 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 342 {
 343         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 344         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 345
 346         seq_printf(m, "%p {.op=", rq);
 347         if (op < ARRAY_SIZE(op_name) && op_name[op])
 348                 seq_printf(m, "%s", op_name[op]);
 349         else
 350                 seq_printf(m, "%d", op);
 351         seq_puts(m, ", .cmd_flags=");
 352         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 353                        ARRAY_SIZE(cmd_flag_name));
 354         seq_puts(m, ", .rq_flags=");
 355         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 356                        ARRAY_SIZE(rqf_name));
 357         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 358         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 359                    rq->internal_tag);
 360         if (mq_ops->show_rq)
 361                 mq_ops->show_rq(m, rq);
 362         seq_puts(m, "}\n");
 363         return 0;
 364 }
 365 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 366
 367 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 368 {
 369         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 370 }
 371 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 372
 373 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 374         __acquires(&hctx->lock)
 375 {
 376         struct blk_mq_hw_ctx *hctx = m->private;
 377
 378         spin_lock(&hctx->lock);
 379         return seq_list_start(&hctx->dispatch, *pos);
 380 }
 381
 382 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 383 {
 384         struct blk_mq_hw_ctx *hctx = m->private;
 385
 386         return seq_list_next(v, &hctx->dispatch, pos);
 387 }
 388
 389 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 390         __releases(&hctx->lock)
 391 {
 392         struct blk_mq_hw_ctx *hctx = m->private;
 393
 394         spin_unlock(&hctx->lock);
 395 }
 396
 397 static const struct seq_operations hctx_dispatch_seq_ops = {
 398         .start  = hctx_dispatch_start,
 399         .next   = hctx_dispatch_next,
 400         .stop   = hctx_dispatch_stop,
 401         .show   = blk_mq_debugfs_rq_show,
 402 };
 403
 404 struct show_busy_params {
 405         struct seq_file         *m;
 406         struct blk_mq_hw_ctx    *hctx;
 407 };
 408
 409 /*
 410  * Note: the state of a request may change while this function is in progress,
 411  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 412  * keep iterating requests.
 413  */
 414 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 415 {
 416         const struct show_busy_params *params = data;
 417
 418         if (rq->mq_hctx == params->hctx)
 419                 __blk_mq_debugfs_rq_show(params->m,
 420                                          list_entry_rq(&rq->queuelist));
 421
 422         return true;
 423 }
 424
 425 static int hctx_busy_show(void *data, struct seq_file *m)
 426 {
 427         struct blk_mq_hw_ctx *hctx = data;
 428         struct show_busy_params params = { .m = m, .hctx = hctx };
 429
 430         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 431                                 &params);
 432
 433         return 0;
 434 }
 435
 436 static const char *const hctx_types[] = {
 437         [HCTX_TYPE_DEFAULT]     = "default",
 438         [HCTX_TYPE_READ]        = "read",
 439         [HCTX_TYPE_POLL]        = "poll",
 440 };
 441
 442 static int hctx_type_show(void *data, struct seq_file *m)
 443 {
 444         struct blk_mq_hw_ctx *hctx = data;
 445
 446         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 447         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 448         return 0;
 449 }
 450
 451 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 452 {
 453         struct blk_mq_hw_ctx *hctx = data;
 454
 455         sbitmap_bitmap_show(&hctx->ctx_map, m);
 456         return 0;
 457 }
 458
 459 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 460                                      struct blk_mq_tags *tags)
 461 {
 462         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 463         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 464         seq_printf(m, "active_queues=%d\n",
 465                    atomic_read(&tags->active_queues));
 466
 467         seq_puts(m, "\nbitmap_tags:\n");
 468         sbitmap_queue_show(&tags->bitmap_tags, m);
 469
 470         if (tags->nr_reserved_tags) {
 471                 seq_puts(m, "\nbreserved_tags:\n");
 472                 sbitmap_queue_show(&tags->breserved_tags, m);
 473         }
 474 }
 475
 476 static int hctx_tags_show(void *data, struct seq_file *m)
 477 {
 478         struct blk_mq_hw_ctx *hctx = data;
 479         struct request_queue *q = hctx->queue;
 480         int res;
 481
 482         res = mutex_lock_interruptible(&q->sysfs_lock);
 483         if (res)
 484                 goto out;
 485         if (hctx->tags)
 486                 blk_mq_debugfs_tags_show(m, hctx->tags);
 487         mutex_unlock(&q->sysfs_lock);
 488
 489 out:
 490         return res;
 491 }
 492
 493 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 494 {
 495         struct blk_mq_hw_ctx *hctx = data;
 496         struct request_queue *q = hctx->queue;
 497         int res;
 498
 499         res = mutex_lock_interruptible(&q->sysfs_lock);
 500         if (res)
 501                 goto out;
 502         if (hctx->tags)
 503                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 504         mutex_unlock(&q->sysfs_lock);
 505
 506 out:
 507         return res;
 508 }
 509
 510 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 511 {
 512         struct blk_mq_hw_ctx *hctx = data;
 513         struct request_queue *q = hctx->queue;
 514         int res;
 515
 516         res = mutex_lock_interruptible(&q->sysfs_lock);
 517         if (res)
 518                 goto out;
 519         if (hctx->sched_tags)
 520                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 521         mutex_unlock(&q->sysfs_lock);
 522
 523 out:
 524         return res;
 525 }
 526
 527 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 528 {
 529         struct blk_mq_hw_ctx *hctx = data;
 530         struct request_queue *q = hctx->queue;
 531         int res;
 532
 533         res = mutex_lock_interruptible(&q->sysfs_lock);
 534         if (res)
 535                 goto out;
 536         if (hctx->sched_tags)
 537                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 538         mutex_unlock(&q->sysfs_lock);
 539
 540 out:
 541         return res;
 542 }
 543
 544 static int hctx_io_poll_show(void *data, struct seq_file *m)
 545 {
 546         struct blk_mq_hw_ctx *hctx = data;
 547
 548         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 549         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 550         seq_printf(m, "success=%lu\n", hctx->poll_success);
 551         return 0;
 552 }
 553
 554 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 555                                   size_t count, loff_t *ppos)
 556 {
 557         struct blk_mq_hw_ctx *hctx = data;
 558
 559         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 560         return count;
 561 }
 562
 563 static int hctx_dispatched_show(void *data, struct seq_file *m)
 564 {
 565         struct blk_mq_hw_ctx *hctx = data;
 566         int i;
 567
 568         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 569
 570         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 571                 unsigned int d = 1U << (i - 1);
 572
 573                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 574         }
 575
 576         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 577         return 0;
 578 }
 579
 580 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 581                                      size_t count, loff_t *ppos)
 582 {
 583         struct blk_mq_hw_ctx *hctx = data;
 584         int i;
 585
 586         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 587                 hctx->dispatched[i] = 0;
 588         return count;
 589 }
 590
 591 static int hctx_queued_show(void *data, struct seq_file *m)
 592 {
 593         struct blk_mq_hw_ctx *hctx = data;
 594
 595         seq_printf(m, "%lu\n", hctx->queued);
 596         return 0;
 597 }
 598
 599 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 600                                  size_t count, loff_t *ppos)
 601 {
 602         struct blk_mq_hw_ctx *hctx = data;
 603
 604         hctx->queued = 0;
 605         return count;
 606 }
 607
 608 static int hctx_run_show(void *data, struct seq_file *m)
 609 {
 610         struct blk_mq_hw_ctx *hctx = data;
 611
 612         seq_printf(m, "%lu\n", hctx->run);
 613         return 0;
 614 }
 615
 616 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 617                               loff_t *ppos)
 618 {
 619         struct blk_mq_hw_ctx *hctx = data;
 620
 621         hctx->run = 0;
 622         return count;
 623 }
 624
 625 static int hctx_active_show(void *data, struct seq_file *m)
 626 {
 627         struct blk_mq_hw_ctx *hctx = data;
 628
 629         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 630         return 0;
 631 }
 632
 633 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 634 {
 635         struct blk_mq_hw_ctx *hctx = data;
 636
 637         seq_printf(m, "%u\n", hctx->dispatch_busy);
 638         return 0;
 639 }
 640
 641 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 642 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 643         __acquires(&ctx->lock)                                          \
 644 {                                                                       \
 645         struct blk_mq_ctx *ctx = m->private;                            \
 646                                                                         \
 647         spin_lock(&ctx->lock);                                          \
 648         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 649 }                                                                       \
 650                                                                         \
 651 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 652                                      loff_t *pos)                       \
 653 {                                                                       \
 654         struct blk_mq_ctx *ctx = m->private;                            \
 655                                                                         \
 656         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 657 }                                                                       \
 658                                                                         \
 659 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 660         __releases(&ctx->lock)                                          \
 661 {                                                                       \
 662         struct blk_mq_ctx *ctx = m->private;                            \
 663                                                                         \
 664         spin_unlock(&ctx->lock);                                        \
 665 }                                                                       \
 666                                                                         \
 667 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 668         .start  = ctx_##name##_rq_list_start,                           \
 669         .next   = ctx_##name##_rq_list_next,                            \
 670         .stop   = ctx_##name##_rq_list_stop,                            \
 671         .show   = blk_mq_debugfs_rq_show,                               \
 672 }
 673
 674 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 675 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 676 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 677
 678 static int ctx_dispatched_show(void *data, struct seq_file *m)
 679 {
 680         struct blk_mq_ctx *ctx = data;
 681
 682         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 683         return 0;
 684 }
 685
 686 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 687                                     size_t count, loff_t *ppos)
 688 {
 689         struct blk_mq_ctx *ctx = data;
 690
 691         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 692         return count;
 693 }
 694
 695 static int ctx_merged_show(void *data, struct seq_file *m)
 696 {
 697         struct blk_mq_ctx *ctx = data;
 698
 699         seq_printf(m, "%lu\n", ctx->rq_merged);
 700         return 0;
 701 }
 702
 703 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 704                                 size_t count, loff_t *ppos)
 705 {
 706         struct blk_mq_ctx *ctx = data;
 707
 708         ctx->rq_merged = 0;
 709         return count;
 710 }
 711
 712 static int ctx_completed_show(void *data, struct seq_file *m)
 713 {
 714         struct blk_mq_ctx *ctx = data;
 715
 716         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 717         return 0;
 718 }
 719
 720 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 721                                    size_t count, loff_t *ppos)
 722 {
 723         struct blk_mq_ctx *ctx = data;
 724
 725         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 726         return count;
 727 }
 728
 729 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 730 {
 731         const struct blk_mq_debugfs_attr *attr = m->private;
 732         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 733
 734         return attr->show(data, m);
 735 }
 736
 737 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 738                                     size_t count, loff_t *ppos)
 739 {
 740         struct seq_file *m = file->private_data;
 741         const struct blk_mq_debugfs_attr *attr = m->private;
 742         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 743
 744         /*
 745          * Attributes that only implement .seq_ops are read-only and 'attr' is
 746          * the same with 'data' in this case.
 747          */
 748         if (attr == data || !attr->write)
 749                 return -EPERM;
 750
 751         return attr->write(data, buf, count, ppos);
 752 }
 753
 754 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 755 {
 756         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 757         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 758         struct seq_file *m;
 759         int ret;
 760
 761         if (attr->seq_ops) {
 762                 ret = seq_open(file, attr->seq_ops);
 763                 if (!ret) {
 764                         m = file->private_data;
 765                         m->private = data;
 766                 }
 767                 return ret;
 768         }
 769
 770         if (WARN_ON_ONCE(!attr->show))
 771                 return -EPERM;
 772
 773         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 774 }
 775
 776 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 777 {
 778         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 779
 780         if (attr->show)
 781                 return single_release(inode, file);
 782         else
 783                 return seq_release(inode, file);
 784 }
 785
 786 static const struct file_operations blk_mq_debugfs_fops = {
 787         .open           = blk_mq_debugfs_open,
 788         .read           = seq_read,
 789         .write          = blk_mq_debugfs_write,
 790         .llseek         = seq_lseek,
 791         .release        = blk_mq_debugfs_release,
 792 };
 793
 794 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 795         {"state", 0400, hctx_state_show},
 796         {"flags", 0400, hctx_flags_show},
 797         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 798         {"busy", 0400, hctx_busy_show},
 799         {"ctx_map", 0400, hctx_ctx_map_show},
 800         {"tags", 0400, hctx_tags_show},
 801         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 802         {"sched_tags", 0400, hctx_sched_tags_show},
 803         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 804         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 805         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 806         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 807         {"run", 0600, hctx_run_show, hctx_run_write},
 808         {"active", 0400, hctx_active_show},
 809         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 810         {"type", 0400, hctx_type_show},
 811         {},
 812 };
 813
 814 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 815         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 816         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 817         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 818         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 819         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 820         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 821         {},
 822 };
 823
 824 static bool debugfs_create_files(struct dentry *parent, void *data,
 825                                  const struct blk_mq_debugfs_attr *attr)
 826 {
 827         if (IS_ERR_OR_NULL(parent))
 828                 return false;
 829
 830         d_inode(parent)->i_private = data;
 831
 832         for (; attr->name; attr++) {
 833                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 834                                          (void *)attr, &blk_mq_debugfs_fops))
 835                         return false;
 836         }
 837         return true;
 838 }
 839
 840 int blk_mq_debugfs_register(struct request_queue *q)
 841 {
 842         struct blk_mq_hw_ctx *hctx;
 843         int i;
 844
 845         if (!blk_debugfs_root)
 846                 return -ENOENT;
 847
 848         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 849                                             blk_debugfs_root);
 850         if (!q->debugfs_dir)
 851                 return -ENOMEM;
 852
 853         if (!debugfs_create_files(q->debugfs_dir, q,
 854                                   blk_mq_debugfs_queue_attrs))
 855                 goto err;
 856
 857         /*
 858          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 859          * didn't exist yet (because we don't know what to name the directory
 860          * until the queue is registered to a gendisk).
 861          */
 862         if (q->elevator && !q->sched_debugfs_dir)
 863                 blk_mq_debugfs_register_sched(q);
 864
 865         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 866         queue_for_each_hw_ctx(q, hctx, i) {
 867                 if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
 868                         goto err;
 869                 if (q->elevator && !hctx->sched_debugfs_dir &&
 870                     blk_mq_debugfs_register_sched_hctx(q, hctx))
 871                         goto err;
 872         }
 873
 874         if (q->rq_qos) {
 875                 struct rq_qos *rqos = q->rq_qos;
 876
 877                 while (rqos) {
 878                         blk_mq_debugfs_register_rqos(rqos);
 879                         rqos = rqos->next;
 880                 }
 881         }
 882
 883         return 0;
 884
 885 err:
 886         blk_mq_debugfs_unregister(q);
 887         return -ENOMEM;
 888 }
 889
 890 void blk_mq_debugfs_unregister(struct request_queue *q)
 891 {
 892         debugfs_remove_recursive(q->debugfs_dir);
 893         q->sched_debugfs_dir = NULL;
 894         q->debugfs_dir = NULL;
 895 }
 896
 897 static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 898                                        struct blk_mq_ctx *ctx)
 899 {
 900         struct dentry *ctx_dir;
 901         char name[20];
 902
 903         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 904         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 905         if (!ctx_dir)
 906                 return -ENOMEM;
 907
 908         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 909                 return -ENOMEM;
 910
 911         return 0;
 912 }
 913
 914 int blk_mq_debugfs_register_hctx(struct request_queue *q,
 915                                  struct blk_mq_hw_ctx *hctx)
 916 {
 917         struct blk_mq_ctx *ctx;
 918         char name[20];
 919         int i;
 920
 921         if (!q->debugfs_dir)
 922                 return -ENOENT;
 923
 924         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 925         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 926         if (!hctx->debugfs_dir)
 927                 return -ENOMEM;
 928
 929         if (!debugfs_create_files(hctx->debugfs_dir, hctx,
 930                                   blk_mq_debugfs_hctx_attrs))
 931                 goto err;
 932
 933         hctx_for_each_ctx(hctx, ctx, i) {
 934                 if (blk_mq_debugfs_register_ctx(hctx, ctx))
 935                         goto err;
 936         }
 937
 938         return 0;
 939
 940 err:
 941         blk_mq_debugfs_unregister_hctx(hctx);
 942         return -ENOMEM;
 943 }
 944
 945 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 946 {
 947         debugfs_remove_recursive(hctx->debugfs_dir);
 948         hctx->sched_debugfs_dir = NULL;
 949         hctx->debugfs_dir = NULL;
 950 }
 951
 952 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 953 {
 954         struct blk_mq_hw_ctx *hctx;
 955         int i;
 956
 957         queue_for_each_hw_ctx(q, hctx, i) {
 958                 if (blk_mq_debugfs_register_hctx(q, hctx))
 959                         return -ENOMEM;
 960         }
 961
 962         return 0;
 963 }
 964
 965 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 966 {
 967         struct blk_mq_hw_ctx *hctx;
 968         int i;
 969
 970         queue_for_each_hw_ctx(q, hctx, i)
 971                 blk_mq_debugfs_unregister_hctx(hctx);
 972 }
 973
 974 int blk_mq_debugfs_register_sched(struct request_queue *q)
 975 {
 976         struct elevator_type *e = q->elevator->type;
 977
 978         if (!q->debugfs_dir)
 979                 return -ENOENT;
 980
 981         if (!e->queue_debugfs_attrs)
 982                 return 0;
 983
 984         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 985         if (!q->sched_debugfs_dir)
 986                 return -ENOMEM;
 987
 988         if (!debugfs_create_files(q->sched_debugfs_dir, q,
 989                                   e->queue_debugfs_attrs))
 990                 goto err;
 991
 992         return 0;
 993
 994 err:
 995         blk_mq_debugfs_unregister_sched(q);
 996         return -ENOMEM;
 997 }
 998
 999 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
1000 {
1001         debugfs_remove_recursive(q->sched_debugfs_dir);
1002         q->sched_debugfs_dir = NULL;
1003 }
1004
1005 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
1006 {
1007         debugfs_remove_recursive(rqos->debugfs_dir);
1008         rqos->debugfs_dir = NULL;
1009 }
1010
1011 int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
1012 {
1013         struct request_queue *q = rqos->q;
1014         const char *dir_name = rq_qos_id_to_name(rqos->id);
1015
1016         if (!q->debugfs_dir)
1017                 return -ENOENT;
1018
1019         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
1020                 return 0;
1021
1022         if (!q->rqos_debugfs_dir) {
1023                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
1024                                                          q->debugfs_dir);
1025                 if (!q->rqos_debugfs_dir)
1026                         return -ENOMEM;
1027         }
1028
1029         rqos->debugfs_dir = debugfs_create_dir(dir_name,
1030                                                rqos->q->rqos_debugfs_dir);
1031         if (!rqos->debugfs_dir)
1032                 return -ENOMEM;
1033
1034         if (!debugfs_create_files(rqos->debugfs_dir, rqos,
1035                                   rqos->ops->debugfs_attrs))
1036                 goto err;
1037         return 0;
1038  err:
1039         blk_mq_debugfs_unregister_rqos(rqos);
1040         return -ENOMEM;
1041 }
1042
1043 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
1044 {
1045         debugfs_remove_recursive(q->rqos_debugfs_dir);
1046         q->rqos_debugfs_dir = NULL;
1047 }
1048
1049 int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
1050                                        struct blk_mq_hw_ctx *hctx)
1051 {
1052         struct elevator_type *e = q->elevator->type;
1053
1054         if (!hctx->debugfs_dir)
1055                 return -ENOENT;
1056
1057         if (!e->hctx_debugfs_attrs)
1058                 return 0;
1059
1060         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
1061                                                      hctx->debugfs_dir);
1062         if (!hctx->sched_debugfs_dir)
1063                 return -ENOMEM;
1064
1065         if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
1066                                   e->hctx_debugfs_attrs))
1067                 return -ENOMEM;
1068
1069         return 0;
1070 }
1071
1072 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
1073 {
1074         debugfs_remove_recursive(hctx->sched_debugfs_dir);
1075         hctx->sched_debugfs_dir = NULL;
1076 }