block/blk-mq-debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2017 Facebook
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/blkdev.h>
   8 #include <linux/debugfs.h>
   9
  10 #include <linux/blk-mq.h>
  11 #include "blk.h"
  12 #include "blk-mq.h"
  13 #include "blk-mq-debugfs.h"
  14 #include "blk-mq-tag.h"
  15 #include "blk-rq-qos.h"
  16
  17 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  18 {
  19         if (stat->nr_samples) {
  20                 seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
  21                            stat->nr_samples, stat->mean, stat->min, stat->max);
  22         } else {
  23                 seq_puts(m, "samples=0");
  24         }
  25 }
  26
  27 static int queue_poll_stat_show(void *data, struct seq_file *m)
  28 {
  29         struct request_queue *q = data;
  30         int bucket;
  31
  32         for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
  33                 seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
  34                 print_stat(m, &q->poll_stat[2 * bucket]);
  35                 seq_puts(m, "\n");
  36
  37                 seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
  38                 print_stat(m, &q->poll_stat[2 * bucket + 1]);
  39                 seq_puts(m, "\n");
  40         }
  41         return 0;
  42 }
  43
  44 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  45         __acquires(&q->requeue_lock)
  46 {
  47         struct request_queue *q = m->private;
  48
  49         spin_lock_irq(&q->requeue_lock);
  50         return seq_list_start(&q->requeue_list, *pos);
  51 }
  52
  53 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  54 {
  55         struct request_queue *q = m->private;
  56
  57         return seq_list_next(v, &q->requeue_list, pos);
  58 }
  59
  60 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  61         __releases(&q->requeue_lock)
  62 {
  63         struct request_queue *q = m->private;
  64
  65         spin_unlock_irq(&q->requeue_lock);
  66 }
  67
  68 static const struct seq_operations queue_requeue_list_seq_ops = {
  69         .start  = queue_requeue_list_start,
  70         .next   = queue_requeue_list_next,
  71         .stop   = queue_requeue_list_stop,
  72         .show   = blk_mq_debugfs_rq_show,
  73 };
  74
  75 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  76                           const char *const *flag_name, int flag_name_count)
  77 {
  78         bool sep = false;
  79         int i;
  80
  81         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  82                 if (!(flags & BIT(i)))
  83                         continue;
  84                 if (sep)
  85                         seq_puts(m, "|");
  86                 sep = true;
  87                 if (i < flag_name_count && flag_name[i])
  88                         seq_puts(m, flag_name[i]);
  89                 else
  90                         seq_printf(m, "%d", i);
  91         }
  92         return 0;
  93 }
  94
  95 static int queue_pm_only_show(void *data, struct seq_file *m)
  96 {
  97         struct request_queue *q = data;
  98
  99         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 100         return 0;
 101 }
 102
 103 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 104 static const char *const blk_queue_flag_name[] = {
 105         QUEUE_FLAG_NAME(STOPPED),
 106         QUEUE_FLAG_NAME(DYING),
 107         QUEUE_FLAG_NAME(NOMERGES),
 108         QUEUE_FLAG_NAME(SAME_COMP),
 109         QUEUE_FLAG_NAME(FAIL_IO),
 110         QUEUE_FLAG_NAME(NONROT),
 111         QUEUE_FLAG_NAME(IO_STAT),
 112         QUEUE_FLAG_NAME(DISCARD),
 113         QUEUE_FLAG_NAME(NOXMERGES),
 114         QUEUE_FLAG_NAME(ADD_RANDOM),
 115         QUEUE_FLAG_NAME(SECERASE),
 116         QUEUE_FLAG_NAME(SAME_FORCE),
 117         QUEUE_FLAG_NAME(DEAD),
 118         QUEUE_FLAG_NAME(INIT_DONE),
 119         QUEUE_FLAG_NAME(STABLE_WRITES),
 120         QUEUE_FLAG_NAME(POLL),
 121         QUEUE_FLAG_NAME(WC),
 122         QUEUE_FLAG_NAME(FUA),
 123         QUEUE_FLAG_NAME(DAX),
 124         QUEUE_FLAG_NAME(STATS),
 125         QUEUE_FLAG_NAME(POLL_STATS),
 126         QUEUE_FLAG_NAME(REGISTERED),
 127         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 128         QUEUE_FLAG_NAME(QUIESCED),
 129         QUEUE_FLAG_NAME(PCI_P2PDMA),
 130         QUEUE_FLAG_NAME(ZONE_RESETALL),
 131         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 132         QUEUE_FLAG_NAME(NOWAIT),
 133 };
 134 #undef QUEUE_FLAG_NAME
 135
 136 static int queue_state_show(void *data, struct seq_file *m)
 137 {
 138         struct request_queue *q = data;
 139
 140         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 141                        ARRAY_SIZE(blk_queue_flag_name));
 142         seq_puts(m, "\n");
 143         return 0;
 144 }
 145
 146 static ssize_t queue_state_write(void *data, const char __user *buf,
 147                                  size_t count, loff_t *ppos)
 148 {
 149         struct request_queue *q = data;
 150         char opbuf[16] = { }, *op;
 151
 152         /*
 153          * The "state" attribute is removed after blk_cleanup_queue() has called
 154          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 155          * triggering a use-after-free.
 156          */
 157         if (blk_queue_dead(q))
 158                 return -ENOENT;
 159
 160         if (count >= sizeof(opbuf)) {
 161                 pr_err("%s: operation too long\n", __func__);
 162                 goto inval;
 163         }
 164
 165         if (copy_from_user(opbuf, buf, count))
 166                 return -EFAULT;
 167         op = strstrip(opbuf);
 168         if (strcmp(op, "run") == 0) {
 169                 blk_mq_run_hw_queues(q, true);
 170         } else if (strcmp(op, "start") == 0) {
 171                 blk_mq_start_stopped_hw_queues(q, true);
 172         } else if (strcmp(op, "kick") == 0) {
 173                 blk_mq_kick_requeue_list(q);
 174         } else {
 175                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 176 inval:
 177                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 178                 return -EINVAL;
 179         }
 180         return count;
 181 }
 182
 183 static int queue_write_hint_show(void *data, struct seq_file *m)
 184 {
 185         struct request_queue *q = data;
 186         int i;
 187
 188         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 189                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 190
 191         return 0;
 192 }
 193
 194 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 195                                       size_t count, loff_t *ppos)
 196 {
 197         struct request_queue *q = data;
 198         int i;
 199
 200         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 201                 q->write_hints[i] = 0;
 202
 203         return count;
 204 }
 205
 206 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 207         { "poll_stat", 0400, queue_poll_stat_show },
 208         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 209         { "pm_only", 0600, queue_pm_only_show, NULL },
 210         { "state", 0600, queue_state_show, queue_state_write },
 211         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 212         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 213         { },
 214 };
 215
 216 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 217 static const char *const hctx_state_name[] = {
 218         HCTX_STATE_NAME(STOPPED),
 219         HCTX_STATE_NAME(TAG_ACTIVE),
 220         HCTX_STATE_NAME(SCHED_RESTART),
 221         HCTX_STATE_NAME(INACTIVE),
 222 };
 223 #undef HCTX_STATE_NAME
 224
 225 static int hctx_state_show(void *data, struct seq_file *m)
 226 {
 227         struct blk_mq_hw_ctx *hctx = data;
 228
 229         blk_flags_show(m, hctx->state, hctx_state_name,
 230                        ARRAY_SIZE(hctx_state_name));
 231         seq_puts(m, "\n");
 232         return 0;
 233 }
 234
 235 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 236 static const char *const alloc_policy_name[] = {
 237         BLK_TAG_ALLOC_NAME(FIFO),
 238         BLK_TAG_ALLOC_NAME(RR),
 239 };
 240 #undef BLK_TAG_ALLOC_NAME
 241
 242 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 243 static const char *const hctx_flag_name[] = {
 244         HCTX_FLAG_NAME(SHOULD_MERGE),
 245         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 246         HCTX_FLAG_NAME(BLOCKING),
 247         HCTX_FLAG_NAME(NO_SCHED),
 248         HCTX_FLAG_NAME(STACKING),
 249 };
 250 #undef HCTX_FLAG_NAME
 251
 252 static int hctx_flags_show(void *data, struct seq_file *m)
 253 {
 254         struct blk_mq_hw_ctx *hctx = data;
 255         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 256
 257         seq_puts(m, "alloc_policy=");
 258         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 259             alloc_policy_name[alloc_policy])
 260                 seq_puts(m, alloc_policy_name[alloc_policy]);
 261         else
 262                 seq_printf(m, "%d", alloc_policy);
 263         seq_puts(m, " ");
 264         blk_flags_show(m,
 265                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 266                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 267         seq_puts(m, "\n");
 268         return 0;
 269 }
 270
 271 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 272 static const char *const cmd_flag_name[] = {
 273         CMD_FLAG_NAME(FAILFAST_DEV),
 274         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 275         CMD_FLAG_NAME(FAILFAST_DRIVER),
 276         CMD_FLAG_NAME(SYNC),
 277         CMD_FLAG_NAME(META),
 278         CMD_FLAG_NAME(PRIO),
 279         CMD_FLAG_NAME(NOMERGE),
 280         CMD_FLAG_NAME(IDLE),
 281         CMD_FLAG_NAME(INTEGRITY),
 282         CMD_FLAG_NAME(FUA),
 283         CMD_FLAG_NAME(PREFLUSH),
 284         CMD_FLAG_NAME(RAHEAD),
 285         CMD_FLAG_NAME(BACKGROUND),
 286         CMD_FLAG_NAME(NOWAIT),
 287         CMD_FLAG_NAME(NOUNMAP),
 288         CMD_FLAG_NAME(HIPRI),
 289 };
 290 #undef CMD_FLAG_NAME
 291
 292 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 293 static const char *const rqf_name[] = {
 294         RQF_NAME(SORTED),
 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(ALLOCED),
 306         RQF_NAME(PM),
 307         RQF_NAME(HASHED),
 308         RQF_NAME(STATS),
 309         RQF_NAME(SPECIAL_PAYLOAD),
 310         RQF_NAME(ZONE_WRITE_LOCKED),
 311         RQF_NAME(MQ_POLL_SLEPT),
 312 };
 313 #undef RQF_NAME
 314
 315 static const char *const blk_mq_rq_state_name_array[] = {
 316         [MQ_RQ_IDLE]            = "idle",
 317         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 318         [MQ_RQ_COMPLETE]        = "complete",
 319 };
 320
 321 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 322 {
 323         if (WARN_ON_ONCE((unsigned int)rq_state >=
 324                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 325                 return "(?)";
 326         return blk_mq_rq_state_name_array[rq_state];
 327 }
 328
 329 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 330 {
 331         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 332         const unsigned int op = req_op(rq);
 333         const char *op_str = blk_op_str(op);
 334
 335         seq_printf(m, "%p {.op=", rq);
 336         if (strcmp(op_str, "UNKNOWN") == 0)
 337                 seq_printf(m, "%u", op);
 338         else
 339                 seq_printf(m, "%s", op_str);
 340         seq_puts(m, ", .cmd_flags=");
 341         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 342                        ARRAY_SIZE(cmd_flag_name));
 343         seq_puts(m, ", .rq_flags=");
 344         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 345                        ARRAY_SIZE(rqf_name));
 346         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 347         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 348                    rq->internal_tag);
 349         if (mq_ops->show_rq)
 350                 mq_ops->show_rq(m, rq);
 351         seq_puts(m, "}\n");
 352         return 0;
 353 }
 354 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 355
 356 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 357 {
 358         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 359 }
 360 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 361
 362 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 363         __acquires(&hctx->lock)
 364 {
 365         struct blk_mq_hw_ctx *hctx = m->private;
 366
 367         spin_lock(&hctx->lock);
 368         return seq_list_start(&hctx->dispatch, *pos);
 369 }
 370
 371 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 372 {
 373         struct blk_mq_hw_ctx *hctx = m->private;
 374
 375         return seq_list_next(v, &hctx->dispatch, pos);
 376 }
 377
 378 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 379         __releases(&hctx->lock)
 380 {
 381         struct blk_mq_hw_ctx *hctx = m->private;
 382
 383         spin_unlock(&hctx->lock);
 384 }
 385
 386 static const struct seq_operations hctx_dispatch_seq_ops = {
 387         .start  = hctx_dispatch_start,
 388         .next   = hctx_dispatch_next,
 389         .stop   = hctx_dispatch_stop,
 390         .show   = blk_mq_debugfs_rq_show,
 391 };
 392
 393 struct show_busy_params {
 394         struct seq_file         *m;
 395         struct blk_mq_hw_ctx    *hctx;
 396 };
 397
 398 /*
 399  * Note: the state of a request may change while this function is in progress,
 400  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 401  * keep iterating requests.
 402  */
 403 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 404 {
 405         const struct show_busy_params *params = data;
 406
 407         if (rq->mq_hctx == params->hctx)
 408                 __blk_mq_debugfs_rq_show(params->m, rq);
 409
 410         return true;
 411 }
 412
 413 static int hctx_busy_show(void *data, struct seq_file *m)
 414 {
 415         struct blk_mq_hw_ctx *hctx = data;
 416         struct show_busy_params params = { .m = m, .hctx = hctx };
 417
 418         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 419                                 &params);
 420
 421         return 0;
 422 }
 423
 424 static const char *const hctx_types[] = {
 425         [HCTX_TYPE_DEFAULT]     = "default",
 426         [HCTX_TYPE_READ]        = "read",
 427         [HCTX_TYPE_POLL]        = "poll",
 428 };
 429
 430 static int hctx_type_show(void *data, struct seq_file *m)
 431 {
 432         struct blk_mq_hw_ctx *hctx = data;
 433
 434         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 435         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 436         return 0;
 437 }
 438
 439 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 440 {
 441         struct blk_mq_hw_ctx *hctx = data;
 442
 443         sbitmap_bitmap_show(&hctx->ctx_map, m);
 444         return 0;
 445 }
 446
 447 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 448                                      struct blk_mq_tags *tags)
 449 {
 450         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 451         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 452         seq_printf(m, "active_queues=%d\n",
 453                    atomic_read(&tags->active_queues));
 454
 455         seq_puts(m, "\nbitmap_tags:\n");
 456         sbitmap_queue_show(tags->bitmap_tags, m);
 457
 458         if (tags->nr_reserved_tags) {
 459                 seq_puts(m, "\nbreserved_tags:\n");
 460                 sbitmap_queue_show(tags->breserved_tags, m);
 461         }
 462 }
 463
 464 static int hctx_tags_show(void *data, struct seq_file *m)
 465 {
 466         struct blk_mq_hw_ctx *hctx = data;
 467         struct request_queue *q = hctx->queue;
 468         int res;
 469
 470         res = mutex_lock_interruptible(&q->sysfs_lock);
 471         if (res)
 472                 goto out;
 473         if (hctx->tags)
 474                 blk_mq_debugfs_tags_show(m, hctx->tags);
 475         mutex_unlock(&q->sysfs_lock);
 476
 477 out:
 478         return res;
 479 }
 480
 481 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 482 {
 483         struct blk_mq_hw_ctx *hctx = data;
 484         struct request_queue *q = hctx->queue;
 485         int res;
 486
 487         res = mutex_lock_interruptible(&q->sysfs_lock);
 488         if (res)
 489                 goto out;
 490         if (hctx->tags)
 491                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m);
 492         mutex_unlock(&q->sysfs_lock);
 493
 494 out:
 495         return res;
 496 }
 497
 498 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 499 {
 500         struct blk_mq_hw_ctx *hctx = data;
 501         struct request_queue *q = hctx->queue;
 502         int res;
 503
 504         res = mutex_lock_interruptible(&q->sysfs_lock);
 505         if (res)
 506                 goto out;
 507         if (hctx->sched_tags)
 508                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 509         mutex_unlock(&q->sysfs_lock);
 510
 511 out:
 512         return res;
 513 }
 514
 515 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 516 {
 517         struct blk_mq_hw_ctx *hctx = data;
 518         struct request_queue *q = hctx->queue;
 519         int res;
 520
 521         res = mutex_lock_interruptible(&q->sysfs_lock);
 522         if (res)
 523                 goto out;
 524         if (hctx->sched_tags)
 525                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m);
 526         mutex_unlock(&q->sysfs_lock);
 527
 528 out:
 529         return res;
 530 }
 531
 532 static int hctx_io_poll_show(void *data, struct seq_file *m)
 533 {
 534         struct blk_mq_hw_ctx *hctx = data;
 535
 536         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 537         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 538         seq_printf(m, "success=%lu\n", hctx->poll_success);
 539         return 0;
 540 }
 541
 542 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 543                                   size_t count, loff_t *ppos)
 544 {
 545         struct blk_mq_hw_ctx *hctx = data;
 546
 547         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 548         return count;
 549 }
 550
 551 static int hctx_dispatched_show(void *data, struct seq_file *m)
 552 {
 553         struct blk_mq_hw_ctx *hctx = data;
 554         int i;
 555
 556         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 557
 558         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 559                 unsigned int d = 1U << (i - 1);
 560
 561                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 562         }
 563
 564         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 565         return 0;
 566 }
 567
 568 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 569                                      size_t count, loff_t *ppos)
 570 {
 571         struct blk_mq_hw_ctx *hctx = data;
 572         int i;
 573
 574         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 575                 hctx->dispatched[i] = 0;
 576         return count;
 577 }
 578
 579 static int hctx_queued_show(void *data, struct seq_file *m)
 580 {
 581         struct blk_mq_hw_ctx *hctx = data;
 582
 583         seq_printf(m, "%lu\n", hctx->queued);
 584         return 0;
 585 }
 586
 587 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 588                                  size_t count, loff_t *ppos)
 589 {
 590         struct blk_mq_hw_ctx *hctx = data;
 591
 592         hctx->queued = 0;
 593         return count;
 594 }
 595
 596 static int hctx_run_show(void *data, struct seq_file *m)
 597 {
 598         struct blk_mq_hw_ctx *hctx = data;
 599
 600         seq_printf(m, "%lu\n", hctx->run);
 601         return 0;
 602 }
 603
 604 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 605                               loff_t *ppos)
 606 {
 607         struct blk_mq_hw_ctx *hctx = data;
 608
 609         hctx->run = 0;
 610         return count;
 611 }
 612
 613 static int hctx_active_show(void *data, struct seq_file *m)
 614 {
 615         struct blk_mq_hw_ctx *hctx = data;
 616
 617         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 618         return 0;
 619 }
 620
 621 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 622 {
 623         struct blk_mq_hw_ctx *hctx = data;
 624
 625         seq_printf(m, "%u\n", hctx->dispatch_busy);
 626         return 0;
 627 }
 628
 629 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 630 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 631         __acquires(&ctx->lock)                                          \
 632 {                                                                       \
 633         struct blk_mq_ctx *ctx = m->private;                            \
 634                                                                         \
 635         spin_lock(&ctx->lock);                                          \
 636         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 637 }                                                                       \
 638                                                                         \
 639 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 640                                      loff_t *pos)                       \
 641 {                                                                       \
 642         struct blk_mq_ctx *ctx = m->private;                            \
 643                                                                         \
 644         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 645 }                                                                       \
 646                                                                         \
 647 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 648         __releases(&ctx->lock)                                          \
 649 {                                                                       \
 650         struct blk_mq_ctx *ctx = m->private;                            \
 651                                                                         \
 652         spin_unlock(&ctx->lock);                                        \
 653 }                                                                       \
 654                                                                         \
 655 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 656         .start  = ctx_##name##_rq_list_start,                           \
 657         .next   = ctx_##name##_rq_list_next,                            \
 658         .stop   = ctx_##name##_rq_list_stop,                            \
 659         .show   = blk_mq_debugfs_rq_show,                               \
 660 }
 661
 662 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 663 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 664 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 665
 666 static int ctx_dispatched_show(void *data, struct seq_file *m)
 667 {
 668         struct blk_mq_ctx *ctx = data;
 669
 670         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 671         return 0;
 672 }
 673
 674 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 675                                     size_t count, loff_t *ppos)
 676 {
 677         struct blk_mq_ctx *ctx = data;
 678
 679         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 680         return count;
 681 }
 682
 683 static int ctx_merged_show(void *data, struct seq_file *m)
 684 {
 685         struct blk_mq_ctx *ctx = data;
 686
 687         seq_printf(m, "%lu\n", ctx->rq_merged);
 688         return 0;
 689 }
 690
 691 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 692                                 size_t count, loff_t *ppos)
 693 {
 694         struct blk_mq_ctx *ctx = data;
 695
 696         ctx->rq_merged = 0;
 697         return count;
 698 }
 699
 700 static int ctx_completed_show(void *data, struct seq_file *m)
 701 {
 702         struct blk_mq_ctx *ctx = data;
 703
 704         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 705         return 0;
 706 }
 707
 708 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 709                                    size_t count, loff_t *ppos)
 710 {
 711         struct blk_mq_ctx *ctx = data;
 712
 713         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 714         return count;
 715 }
 716
 717 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 718 {
 719         const struct blk_mq_debugfs_attr *attr = m->private;
 720         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 721
 722         return attr->show(data, m);
 723 }
 724
 725 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 726                                     size_t count, loff_t *ppos)
 727 {
 728         struct seq_file *m = file->private_data;
 729         const struct blk_mq_debugfs_attr *attr = m->private;
 730         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 731
 732         /*
 733          * Attributes that only implement .seq_ops are read-only and 'attr' is
 734          * the same with 'data' in this case.
 735          */
 736         if (attr == data || !attr->write)
 737                 return -EPERM;
 738
 739         return attr->write(data, buf, count, ppos);
 740 }
 741
 742 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 743 {
 744         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 745         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 746         struct seq_file *m;
 747         int ret;
 748
 749         if (attr->seq_ops) {
 750                 ret = seq_open(file, attr->seq_ops);
 751                 if (!ret) {
 752                         m = file->private_data;
 753                         m->private = data;
 754                 }
 755                 return ret;
 756         }
 757
 758         if (WARN_ON_ONCE(!attr->show))
 759                 return -EPERM;
 760
 761         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 762 }
 763
 764 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 765 {
 766         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 767
 768         if (attr->show)
 769                 return single_release(inode, file);
 770
 771         return seq_release(inode, file);
 772 }
 773
 774 static const struct file_operations blk_mq_debugfs_fops = {
 775         .open           = blk_mq_debugfs_open,
 776         .read           = seq_read,
 777         .write          = blk_mq_debugfs_write,
 778         .llseek         = seq_lseek,
 779         .release        = blk_mq_debugfs_release,
 780 };
 781
 782 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 783         {"state", 0400, hctx_state_show},
 784         {"flags", 0400, hctx_flags_show},
 785         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 786         {"busy", 0400, hctx_busy_show},
 787         {"ctx_map", 0400, hctx_ctx_map_show},
 788         {"tags", 0400, hctx_tags_show},
 789         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 790         {"sched_tags", 0400, hctx_sched_tags_show},
 791         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 792         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 793         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 794         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 795         {"run", 0600, hctx_run_show, hctx_run_write},
 796         {"active", 0400, hctx_active_show},
 797         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 798         {"type", 0400, hctx_type_show},
 799         {},
 800 };
 801
 802 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 803         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 804         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 805         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 806         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 807         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 808         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 809         {},
 810 };
 811
 812 static void debugfs_create_files(struct dentry *parent, void *data,
 813                                  const struct blk_mq_debugfs_attr *attr)
 814 {
 815         if (IS_ERR_OR_NULL(parent))
 816                 return;
 817
 818         d_inode(parent)->i_private = data;
 819
 820         for (; attr->name; attr++)
 821                 debugfs_create_file(attr->name, attr->mode, parent,
 822                                     (void *)attr, &blk_mq_debugfs_fops);
 823 }
 824
 825 void blk_mq_debugfs_register(struct request_queue *q)
 826 {
 827         struct blk_mq_hw_ctx *hctx;
 828         int i;
 829
 830         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 831
 832         /*
 833          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 834          * didn't exist yet (because we don't know what to name the directory
 835          * until the queue is registered to a gendisk).
 836          */
 837         if (q->elevator && !q->sched_debugfs_dir)
 838                 blk_mq_debugfs_register_sched(q);
 839
 840         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 841         queue_for_each_hw_ctx(q, hctx, i) {
 842                 if (!hctx->debugfs_dir)
 843                         blk_mq_debugfs_register_hctx(q, hctx);
 844                 if (q->elevator && !hctx->sched_debugfs_dir)
 845                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 846         }
 847
 848         if (q->rq_qos) {
 849                 struct rq_qos *rqos = q->rq_qos;
 850
 851                 while (rqos) {
 852                         blk_mq_debugfs_register_rqos(rqos);
 853                         rqos = rqos->next;
 854                 }
 855         }
 856 }
 857
 858 void blk_mq_debugfs_unregister(struct request_queue *q)
 859 {
 860         q->sched_debugfs_dir = NULL;
 861 }
 862
 863 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 864                                         struct blk_mq_ctx *ctx)
 865 {
 866         struct dentry *ctx_dir;
 867         char name[20];
 868
 869         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 870         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 871
 872         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 873 }
 874
 875 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 876                                   struct blk_mq_hw_ctx *hctx)
 877 {
 878         struct blk_mq_ctx *ctx;
 879         char name[20];
 880         int i;
 881
 882         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 883         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 884
 885         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 886
 887         hctx_for_each_ctx(hctx, ctx, i)
 888                 blk_mq_debugfs_register_ctx(hctx, ctx);
 889 }
 890
 891 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 892 {
 893         debugfs_remove_recursive(hctx->debugfs_dir);
 894         hctx->sched_debugfs_dir = NULL;
 895         hctx->debugfs_dir = NULL;
 896 }
 897
 898 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 899 {
 900         struct blk_mq_hw_ctx *hctx;
 901         int i;
 902
 903         queue_for_each_hw_ctx(q, hctx, i)
 904                 blk_mq_debugfs_register_hctx(q, hctx);
 905 }
 906
 907 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 908 {
 909         struct blk_mq_hw_ctx *hctx;
 910         int i;
 911
 912         queue_for_each_hw_ctx(q, hctx, i)
 913                 blk_mq_debugfs_unregister_hctx(hctx);
 914 }
 915
 916 void blk_mq_debugfs_register_sched(struct request_queue *q)
 917 {
 918         struct elevator_type *e = q->elevator->type;
 919
 920         /*
 921          * If the parent directory has not been created yet, return, we will be
 922          * called again later on and the directory/files will be created then.
 923          */
 924         if (!q->debugfs_dir)
 925                 return;
 926
 927         if (!e->queue_debugfs_attrs)
 928                 return;
 929
 930         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 931
 932         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 933 }
 934
 935 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 936 {
 937         debugfs_remove_recursive(q->sched_debugfs_dir);
 938         q->sched_debugfs_dir = NULL;
 939 }
 940
 941 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 942 {
 943         debugfs_remove_recursive(rqos->debugfs_dir);
 944         rqos->debugfs_dir = NULL;
 945 }
 946
 947 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 948 {
 949         struct request_queue *q = rqos->q;
 950         const char *dir_name = rq_qos_id_to_name(rqos->id);
 951
 952         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 953                 return;
 954
 955         if (!q->rqos_debugfs_dir)
 956                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 957                                                          q->debugfs_dir);
 958
 959         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 960                                                rqos->q->rqos_debugfs_dir);
 961
 962         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 963 }
 964
 965 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
 966 {
 967         debugfs_remove_recursive(q->rqos_debugfs_dir);
 968         q->rqos_debugfs_dir = NULL;
 969 }
 970
 971 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 972                                         struct blk_mq_hw_ctx *hctx)
 973 {
 974         struct elevator_type *e = q->elevator->type;
 975
 976         if (!e->hctx_debugfs_attrs)
 977                 return;
 978
 979         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 980                                                      hctx->debugfs_dir);
 981         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 982                              e->hctx_debugfs_attrs);
 983 }
 984
 985 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 986 {
 987         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 988         hctx->sched_debugfs_dir = NULL;
 989 }