block/blk-mq-debugfs.c

   1 /*
   2  * Copyright (C) 2017 Facebook
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/debugfs.h>
  20
  21 #include <linux/blk-mq.h>
  22 #include "blk.h"
  23 #include "blk-mq.h"
  24 #include "blk-mq-debugfs.h"
  25 #include "blk-mq-tag.h"
  26
  27 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  28 {
  29         if (stat->nr_samples) {
  30                 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
  31                            stat->nr_samples, stat->mean, stat->min, stat->max);
  32         } else {
  33                 seq_puts(m, "samples=0");
  34         }
  35 }
  36
  37 static int queue_poll_stat_show(void *data, struct seq_file *m)
  38 {
  39         struct request_queue *q = data;
  40         int bucket;
  41
  42         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
  43                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
  44                 print_stat(m, &q->poll_stat[2*bucket]);
  45                 seq_puts(m, "\n");
  46
  47                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
  48                 print_stat(m, &q->poll_stat[2*bucket+1]);
  49                 seq_puts(m, "\n");
  50         }
  51         return 0;
  52 }
  53
  54 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  55         __acquires(&q->requeue_lock)
  56 {
  57         struct request_queue *q = m->private;
  58
  59         spin_lock_irq(&q->requeue_lock);
  60         return seq_list_start(&q->requeue_list, *pos);
  61 }
  62
  63 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  64 {
  65         struct request_queue *q = m->private;
  66
  67         return seq_list_next(v, &q->requeue_list, pos);
  68 }
  69
  70 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  71         __releases(&q->requeue_lock)
  72 {
  73         struct request_queue *q = m->private;
  74
  75         spin_unlock_irq(&q->requeue_lock);
  76 }
  77
  78 static const struct seq_operations queue_requeue_list_seq_ops = {
  79         .start  = queue_requeue_list_start,
  80         .next   = queue_requeue_list_next,
  81         .stop   = queue_requeue_list_stop,
  82         .show   = blk_mq_debugfs_rq_show,
  83 };
  84
  85 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  86                           const char *const *flag_name, int flag_name_count)
  87 {
  88         bool sep = false;
  89         int i;
  90
  91         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  92                 if (!(flags & BIT(i)))
  93                         continue;
  94                 if (sep)
  95                         seq_puts(m, "|");
  96                 sep = true;
  97                 if (i < flag_name_count && flag_name[i])
  98                         seq_puts(m, flag_name[i]);
  99                 else
 100                         seq_printf(m, "%d", i);
 101         }
 102         return 0;
 103 }
 104
 105 static int queue_pm_only_show(void *data, struct seq_file *m)
 106 {
 107         struct request_queue *q = data;
 108
 109         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 110         return 0;
 111 }
 112
 113 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 114 static const char *const blk_queue_flag_name[] = {
 115         QUEUE_FLAG_NAME(QUEUED),
 116         QUEUE_FLAG_NAME(STOPPED),
 117         QUEUE_FLAG_NAME(DYING),
 118         QUEUE_FLAG_NAME(BYPASS),
 119         QUEUE_FLAG_NAME(BIDI),
 120         QUEUE_FLAG_NAME(NOMERGES),
 121         QUEUE_FLAG_NAME(SAME_COMP),
 122         QUEUE_FLAG_NAME(FAIL_IO),
 123         QUEUE_FLAG_NAME(NONROT),
 124         QUEUE_FLAG_NAME(IO_STAT),
 125         QUEUE_FLAG_NAME(DISCARD),
 126         QUEUE_FLAG_NAME(NOXMERGES),
 127         QUEUE_FLAG_NAME(ADD_RANDOM),
 128         QUEUE_FLAG_NAME(SECERASE),
 129         QUEUE_FLAG_NAME(SAME_FORCE),
 130         QUEUE_FLAG_NAME(DEAD),
 131         QUEUE_FLAG_NAME(INIT_DONE),
 132         QUEUE_FLAG_NAME(NO_SG_MERGE),
 133         QUEUE_FLAG_NAME(POLL),
 134         QUEUE_FLAG_NAME(WC),
 135         QUEUE_FLAG_NAME(FUA),
 136         QUEUE_FLAG_NAME(FLUSH_NQ),
 137         QUEUE_FLAG_NAME(DAX),
 138         QUEUE_FLAG_NAME(STATS),
 139         QUEUE_FLAG_NAME(POLL_STATS),
 140         QUEUE_FLAG_NAME(REGISTERED),
 141         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 142         QUEUE_FLAG_NAME(QUIESCED),
 143 };
 144 #undef QUEUE_FLAG_NAME
 145
 146 static int queue_state_show(void *data, struct seq_file *m)
 147 {
 148         struct request_queue *q = data;
 149
 150         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 151                        ARRAY_SIZE(blk_queue_flag_name));
 152         seq_puts(m, "\n");
 153         return 0;
 154 }
 155
 156 static ssize_t queue_state_write(void *data, const char __user *buf,
 157                                  size_t count, loff_t *ppos)
 158 {
 159         struct request_queue *q = data;
 160         char opbuf[16] = { }, *op;
 161
 162         /*
 163          * The "state" attribute is removed after blk_cleanup_queue() has called
 164          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 165          * triggering a use-after-free.
 166          */
 167         if (blk_queue_dead(q))
 168                 return -ENOENT;
 169
 170         if (count >= sizeof(opbuf)) {
 171                 pr_err("%s: operation too long\n", __func__);
 172                 goto inval;
 173         }
 174
 175         if (copy_from_user(opbuf, buf, count))
 176                 return -EFAULT;
 177         op = strstrip(opbuf);
 178         if (strcmp(op, "run") == 0) {
 179                 blk_mq_run_hw_queues(q, true);
 180         } else if (strcmp(op, "start") == 0) {
 181                 blk_mq_start_stopped_hw_queues(q, true);
 182         } else if (strcmp(op, "kick") == 0) {
 183                 blk_mq_kick_requeue_list(q);
 184         } else {
 185                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 186 inval:
 187                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 188                 return -EINVAL;
 189         }
 190         return count;
 191 }
 192
 193 static int queue_write_hint_show(void *data, struct seq_file *m)
 194 {
 195         struct request_queue *q = data;
 196         int i;
 197
 198         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 199                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 200
 201         return 0;
 202 }
 203
 204 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 205                                       size_t count, loff_t *ppos)
 206 {
 207         struct request_queue *q = data;
 208         int i;
 209
 210         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 211                 q->write_hints[i] = 0;
 212
 213         return count;
 214 }
 215
 216 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 217         { "poll_stat", 0400, queue_poll_stat_show },
 218         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 219         { "pm_only", 0600, queue_pm_only_show, NULL },
 220         { "state", 0600, queue_state_show, queue_state_write },
 221         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 222         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 223         { },
 224 };
 225
 226 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 227 static const char *const hctx_state_name[] = {
 228         HCTX_STATE_NAME(STOPPED),
 229         HCTX_STATE_NAME(TAG_ACTIVE),
 230         HCTX_STATE_NAME(SCHED_RESTART),
 231 };
 232 #undef HCTX_STATE_NAME
 233
 234 static int hctx_state_show(void *data, struct seq_file *m)
 235 {
 236         struct blk_mq_hw_ctx *hctx = data;
 237
 238         blk_flags_show(m, hctx->state, hctx_state_name,
 239                        ARRAY_SIZE(hctx_state_name));
 240         seq_puts(m, "\n");
 241         return 0;
 242 }
 243
 244 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 245 static const char *const alloc_policy_name[] = {
 246         BLK_TAG_ALLOC_NAME(FIFO),
 247         BLK_TAG_ALLOC_NAME(RR),
 248 };
 249 #undef BLK_TAG_ALLOC_NAME
 250
 251 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 252 static const char *const hctx_flag_name[] = {
 253         HCTX_FLAG_NAME(SHOULD_MERGE),
 254         HCTX_FLAG_NAME(TAG_SHARED),
 255         HCTX_FLAG_NAME(SG_MERGE),
 256         HCTX_FLAG_NAME(BLOCKING),
 257         HCTX_FLAG_NAME(NO_SCHED),
 258 };
 259 #undef HCTX_FLAG_NAME
 260
 261 static int hctx_flags_show(void *data, struct seq_file *m)
 262 {
 263         struct blk_mq_hw_ctx *hctx = data;
 264         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 265
 266         seq_puts(m, "alloc_policy=");
 267         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 268             alloc_policy_name[alloc_policy])
 269                 seq_puts(m, alloc_policy_name[alloc_policy]);
 270         else
 271                 seq_printf(m, "%d", alloc_policy);
 272         seq_puts(m, " ");
 273         blk_flags_show(m,
 274                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 275                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 276         seq_puts(m, "\n");
 277         return 0;
 278 }
 279
 280 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 281 static const char *const op_name[] = {
 282         REQ_OP_NAME(READ),
 283         REQ_OP_NAME(WRITE),
 284         REQ_OP_NAME(FLUSH),
 285         REQ_OP_NAME(DISCARD),
 286         REQ_OP_NAME(SECURE_ERASE),
 287         REQ_OP_NAME(ZONE_RESET),
 288         REQ_OP_NAME(WRITE_SAME),
 289         REQ_OP_NAME(WRITE_ZEROES),
 290         REQ_OP_NAME(SCSI_IN),
 291         REQ_OP_NAME(SCSI_OUT),
 292         REQ_OP_NAME(DRV_IN),
 293         REQ_OP_NAME(DRV_OUT),
 294 };
 295 #undef REQ_OP_NAME
 296
 297 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 298 static const char *const cmd_flag_name[] = {
 299         CMD_FLAG_NAME(FAILFAST_DEV),
 300         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 301         CMD_FLAG_NAME(FAILFAST_DRIVER),
 302         CMD_FLAG_NAME(SYNC),
 303         CMD_FLAG_NAME(META),
 304         CMD_FLAG_NAME(PRIO),
 305         CMD_FLAG_NAME(NOMERGE),
 306         CMD_FLAG_NAME(IDLE),
 307         CMD_FLAG_NAME(INTEGRITY),
 308         CMD_FLAG_NAME(FUA),
 309         CMD_FLAG_NAME(PREFLUSH),
 310         CMD_FLAG_NAME(RAHEAD),
 311         CMD_FLAG_NAME(BACKGROUND),
 312         CMD_FLAG_NAME(NOUNMAP),
 313         CMD_FLAG_NAME(NOWAIT),
 314 };
 315 #undef CMD_FLAG_NAME
 316
 317 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 318 static const char *const rqf_name[] = {
 319         RQF_NAME(SORTED),
 320         RQF_NAME(STARTED),
 321         RQF_NAME(QUEUED),
 322         RQF_NAME(SOFTBARRIER),
 323         RQF_NAME(FLUSH_SEQ),
 324         RQF_NAME(MIXED_MERGE),
 325         RQF_NAME(MQ_INFLIGHT),
 326         RQF_NAME(DONTPREP),
 327         RQF_NAME(PREEMPT),
 328         RQF_NAME(COPY_USER),
 329         RQF_NAME(FAILED),
 330         RQF_NAME(QUIET),
 331         RQF_NAME(ELVPRIV),
 332         RQF_NAME(IO_STAT),
 333         RQF_NAME(ALLOCED),
 334         RQF_NAME(PM),
 335         RQF_NAME(HASHED),
 336         RQF_NAME(STATS),
 337         RQF_NAME(SPECIAL_PAYLOAD),
 338         RQF_NAME(ZONE_WRITE_LOCKED),
 339         RQF_NAME(MQ_POLL_SLEPT),
 340 };
 341 #undef RQF_NAME
 342
 343 static const char *const blk_mq_rq_state_name_array[] = {
 344         [MQ_RQ_IDLE]            = "idle",
 345         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 346         [MQ_RQ_COMPLETE]        = "complete",
 347 };
 348
 349 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 350 {
 351         if (WARN_ON_ONCE((unsigned int)rq_state >=
 352                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 353                 return "(?)";
 354         return blk_mq_rq_state_name_array[rq_state];
 355 }
 356
 357 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 358 {
 359         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 360         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 361
 362         seq_printf(m, "%p {.op=", rq);
 363         if (op < ARRAY_SIZE(op_name) && op_name[op])
 364                 seq_printf(m, "%s", op_name[op]);
 365         else
 366                 seq_printf(m, "%d", op);
 367         seq_puts(m, ", .cmd_flags=");
 368         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 369                        ARRAY_SIZE(cmd_flag_name));
 370         seq_puts(m, ", .rq_flags=");
 371         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 372                        ARRAY_SIZE(rqf_name));
 373         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 374         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 375                    rq->internal_tag);
 376         if (mq_ops->show_rq)
 377                 mq_ops->show_rq(m, rq);
 378         seq_puts(m, "}\n");
 379         return 0;
 380 }
 381 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 382
 383 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 384 {
 385         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 386 }
 387 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 388
 389 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 390         __acquires(&hctx->lock)
 391 {
 392         struct blk_mq_hw_ctx *hctx = m->private;
 393
 394         spin_lock(&hctx->lock);
 395         return seq_list_start(&hctx->dispatch, *pos);
 396 }
 397
 398 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 399 {
 400         struct blk_mq_hw_ctx *hctx = m->private;
 401
 402         return seq_list_next(v, &hctx->dispatch, pos);
 403 }
 404
 405 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 406         __releases(&hctx->lock)
 407 {
 408         struct blk_mq_hw_ctx *hctx = m->private;
 409
 410         spin_unlock(&hctx->lock);
 411 }
 412
 413 static const struct seq_operations hctx_dispatch_seq_ops = {
 414         .start  = hctx_dispatch_start,
 415         .next   = hctx_dispatch_next,
 416         .stop   = hctx_dispatch_stop,
 417         .show   = blk_mq_debugfs_rq_show,
 418 };
 419
 420 struct show_busy_params {
 421         struct seq_file         *m;
 422         struct blk_mq_hw_ctx    *hctx;
 423 };
 424
 425 /*
 426  * Note: the state of a request may change while this function is in progress,
 427  * e.g. due to a concurrent blk_mq_finish_request() call.
 428  */
 429 static void hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 430 {
 431         const struct show_busy_params *params = data;
 432
 433         if (blk_mq_map_queue(rq->q, rq->mq_ctx->cpu) == params->hctx)
 434                 __blk_mq_debugfs_rq_show(params->m,
 435                                          list_entry_rq(&rq->queuelist));
 436 }
 437
 438 static int hctx_busy_show(void *data, struct seq_file *m)
 439 {
 440         struct blk_mq_hw_ctx *hctx = data;
 441         struct show_busy_params params = { .m = m, .hctx = hctx };
 442
 443         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 444                                 &params);
 445
 446         return 0;
 447 }
 448
 449 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 450 {
 451         struct blk_mq_hw_ctx *hctx = data;
 452
 453         sbitmap_bitmap_show(&hctx->ctx_map, m);
 454         return 0;
 455 }
 456
 457 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 458                                      struct blk_mq_tags *tags)
 459 {
 460         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 461         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 462         seq_printf(m, "active_queues=%d\n",
 463                    atomic_read(&tags->active_queues));
 464
 465         seq_puts(m, "\nbitmap_tags:\n");
 466         sbitmap_queue_show(&tags->bitmap_tags, m);
 467
 468         if (tags->nr_reserved_tags) {
 469                 seq_puts(m, "\nbreserved_tags:\n");
 470                 sbitmap_queue_show(&tags->breserved_tags, m);
 471         }
 472 }
 473
 474 static int hctx_tags_show(void *data, struct seq_file *m)
 475 {
 476         struct blk_mq_hw_ctx *hctx = data;
 477         struct request_queue *q = hctx->queue;
 478         int res;
 479
 480         res = mutex_lock_interruptible(&q->sysfs_lock);
 481         if (res)
 482                 goto out;
 483         if (hctx->tags)
 484                 blk_mq_debugfs_tags_show(m, hctx->tags);
 485         mutex_unlock(&q->sysfs_lock);
 486
 487 out:
 488         return res;
 489 }
 490
 491 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 492 {
 493         struct blk_mq_hw_ctx *hctx = data;
 494         struct request_queue *q = hctx->queue;
 495         int res;
 496
 497         res = mutex_lock_interruptible(&q->sysfs_lock);
 498         if (res)
 499                 goto out;
 500         if (hctx->tags)
 501                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 502         mutex_unlock(&q->sysfs_lock);
 503
 504 out:
 505         return res;
 506 }
 507
 508 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 509 {
 510         struct blk_mq_hw_ctx *hctx = data;
 511         struct request_queue *q = hctx->queue;
 512         int res;
 513
 514         res = mutex_lock_interruptible(&q->sysfs_lock);
 515         if (res)
 516                 goto out;
 517         if (hctx->sched_tags)
 518                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 519         mutex_unlock(&q->sysfs_lock);
 520
 521 out:
 522         return res;
 523 }
 524
 525 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 526 {
 527         struct blk_mq_hw_ctx *hctx = data;
 528         struct request_queue *q = hctx->queue;
 529         int res;
 530
 531         res = mutex_lock_interruptible(&q->sysfs_lock);
 532         if (res)
 533                 goto out;
 534         if (hctx->sched_tags)
 535                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 536         mutex_unlock(&q->sysfs_lock);
 537
 538 out:
 539         return res;
 540 }
 541
 542 static int hctx_io_poll_show(void *data, struct seq_file *m)
 543 {
 544         struct blk_mq_hw_ctx *hctx = data;
 545
 546         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 547         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 548         seq_printf(m, "success=%lu\n", hctx->poll_success);
 549         return 0;
 550 }
 551
 552 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 553                                   size_t count, loff_t *ppos)
 554 {
 555         struct blk_mq_hw_ctx *hctx = data;
 556
 557         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 558         return count;
 559 }
 560
 561 static int hctx_dispatched_show(void *data, struct seq_file *m)
 562 {
 563         struct blk_mq_hw_ctx *hctx = data;
 564         int i;
 565
 566         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 567
 568         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 569                 unsigned int d = 1U << (i - 1);
 570
 571                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 572         }
 573
 574         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 575         return 0;
 576 }
 577
 578 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 579                                      size_t count, loff_t *ppos)
 580 {
 581         struct blk_mq_hw_ctx *hctx = data;
 582         int i;
 583
 584         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 585                 hctx->dispatched[i] = 0;
 586         return count;
 587 }
 588
 589 static int hctx_queued_show(void *data, struct seq_file *m)
 590 {
 591         struct blk_mq_hw_ctx *hctx = data;
 592
 593         seq_printf(m, "%lu\n", hctx->queued);
 594         return 0;
 595 }
 596
 597 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 598                                  size_t count, loff_t *ppos)
 599 {
 600         struct blk_mq_hw_ctx *hctx = data;
 601
 602         hctx->queued = 0;
 603         return count;
 604 }
 605
 606 static int hctx_run_show(void *data, struct seq_file *m)
 607 {
 608         struct blk_mq_hw_ctx *hctx = data;
 609
 610         seq_printf(m, "%lu\n", hctx->run);
 611         return 0;
 612 }
 613
 614 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 615                               loff_t *ppos)
 616 {
 617         struct blk_mq_hw_ctx *hctx = data;
 618
 619         hctx->run = 0;
 620         return count;
 621 }
 622
 623 static int hctx_active_show(void *data, struct seq_file *m)
 624 {
 625         struct blk_mq_hw_ctx *hctx = data;
 626
 627         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 628         return 0;
 629 }
 630
 631 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 632 {
 633         struct blk_mq_hw_ctx *hctx = data;
 634
 635         seq_printf(m, "%u\n", hctx->dispatch_busy);
 636         return 0;
 637 }
 638
 639 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 640         __acquires(&ctx->lock)
 641 {
 642         struct blk_mq_ctx *ctx = m->private;
 643
 644         spin_lock(&ctx->lock);
 645         return seq_list_start(&ctx->rq_list, *pos);
 646 }
 647
 648 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 649 {
 650         struct blk_mq_ctx *ctx = m->private;
 651
 652         return seq_list_next(v, &ctx->rq_list, pos);
 653 }
 654
 655 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 656         __releases(&ctx->lock)
 657 {
 658         struct blk_mq_ctx *ctx = m->private;
 659
 660         spin_unlock(&ctx->lock);
 661 }
 662
 663 static const struct seq_operations ctx_rq_list_seq_ops = {
 664         .start  = ctx_rq_list_start,
 665         .next   = ctx_rq_list_next,
 666         .stop   = ctx_rq_list_stop,
 667         .show   = blk_mq_debugfs_rq_show,
 668 };
 669 static int ctx_dispatched_show(void *data, struct seq_file *m)
 670 {
 671         struct blk_mq_ctx *ctx = data;
 672
 673         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 674         return 0;
 675 }
 676
 677 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 678                                     size_t count, loff_t *ppos)
 679 {
 680         struct blk_mq_ctx *ctx = data;
 681
 682         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 683         return count;
 684 }
 685
 686 static int ctx_merged_show(void *data, struct seq_file *m)
 687 {
 688         struct blk_mq_ctx *ctx = data;
 689
 690         seq_printf(m, "%lu\n", ctx->rq_merged);
 691         return 0;
 692 }
 693
 694 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 695                                 size_t count, loff_t *ppos)
 696 {
 697         struct blk_mq_ctx *ctx = data;
 698
 699         ctx->rq_merged = 0;
 700         return count;
 701 }
 702
 703 static int ctx_completed_show(void *data, struct seq_file *m)
 704 {
 705         struct blk_mq_ctx *ctx = data;
 706
 707         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 708         return 0;
 709 }
 710
 711 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 712                                    size_t count, loff_t *ppos)
 713 {
 714         struct blk_mq_ctx *ctx = data;
 715
 716         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 717         return count;
 718 }
 719
 720 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 721 {
 722         const struct blk_mq_debugfs_attr *attr = m->private;
 723         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 724
 725         return attr->show(data, m);
 726 }
 727
 728 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 729                                     size_t count, loff_t *ppos)
 730 {
 731         struct seq_file *m = file->private_data;
 732         const struct blk_mq_debugfs_attr *attr = m->private;
 733         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 734
 735         /*
 736          * Attributes that only implement .seq_ops are read-only and 'attr' is
 737          * the same with 'data' in this case.
 738          */
 739         if (attr == data || !attr->write)
 740                 return -EPERM;
 741
 742         return attr->write(data, buf, count, ppos);
 743 }
 744
 745 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 746 {
 747         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 748         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 749         struct seq_file *m;
 750         int ret;
 751
 752         if (attr->seq_ops) {
 753                 ret = seq_open(file, attr->seq_ops);
 754                 if (!ret) {
 755                         m = file->private_data;
 756                         m->private = data;
 757                 }
 758                 return ret;
 759         }
 760
 761         if (WARN_ON_ONCE(!attr->show))
 762                 return -EPERM;
 763
 764         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 765 }
 766
 767 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 768 {
 769         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 770
 771         if (attr->show)
 772                 return single_release(inode, file);
 773         else
 774                 return seq_release(inode, file);
 775 }
 776
 777 static const struct file_operations blk_mq_debugfs_fops = {
 778         .open           = blk_mq_debugfs_open,
 779         .read           = seq_read,
 780         .write          = blk_mq_debugfs_write,
 781         .llseek         = seq_lseek,
 782         .release        = blk_mq_debugfs_release,
 783 };
 784
 785 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 786         {"state", 0400, hctx_state_show},
 787         {"flags", 0400, hctx_flags_show},
 788         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 789         {"busy", 0400, hctx_busy_show},
 790         {"ctx_map", 0400, hctx_ctx_map_show},
 791         {"tags", 0400, hctx_tags_show},
 792         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 793         {"sched_tags", 0400, hctx_sched_tags_show},
 794         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 795         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 796         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 797         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 798         {"run", 0600, hctx_run_show, hctx_run_write},
 799         {"active", 0400, hctx_active_show},
 800         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 801         {},
 802 };
 803
 804 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 805         {"rq_list", 0400, .seq_ops = &ctx_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 bool debugfs_create_files(struct dentry *parent, void *data,
 813                                  const struct blk_mq_debugfs_attr *attr)
 814 {
 815         d_inode(parent)->i_private = data;
 816
 817         for (; attr->name; attr++) {
 818                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 819                                          (void *)attr, &blk_mq_debugfs_fops))
 820                         return false;
 821         }
 822         return true;
 823 }
 824
 825 int blk_mq_debugfs_register(struct request_queue *q)
 826 {
 827         struct blk_mq_hw_ctx *hctx;
 828         int i;
 829
 830         if (!blk_debugfs_root)
 831                 return -ENOENT;
 832
 833         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 834                                             blk_debugfs_root);
 835         if (!q->debugfs_dir)
 836                 return -ENOMEM;
 837
 838         if (!debugfs_create_files(q->debugfs_dir, q,
 839                                   blk_mq_debugfs_queue_attrs))
 840                 goto err;
 841
 842         /*
 843          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 844          * didn't exist yet (because we don't know what to name the directory
 845          * until the queue is registered to a gendisk).
 846          */
 847         if (q->elevator && !q->sched_debugfs_dir)
 848                 blk_mq_debugfs_register_sched(q);
 849
 850         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 851         queue_for_each_hw_ctx(q, hctx, i) {
 852                 if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
 853                         goto err;
 854                 if (q->elevator && !hctx->sched_debugfs_dir &&
 855                     blk_mq_debugfs_register_sched_hctx(q, hctx))
 856                         goto err;
 857         }
 858
 859         return 0;
 860
 861 err:
 862         blk_mq_debugfs_unregister(q);
 863         return -ENOMEM;
 864 }
 865
 866 void blk_mq_debugfs_unregister(struct request_queue *q)
 867 {
 868         debugfs_remove_recursive(q->debugfs_dir);
 869         q->sched_debugfs_dir = NULL;
 870         q->debugfs_dir = NULL;
 871 }
 872
 873 static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 874                                        struct blk_mq_ctx *ctx)
 875 {
 876         struct dentry *ctx_dir;
 877         char name[20];
 878
 879         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 880         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 881         if (!ctx_dir)
 882                 return -ENOMEM;
 883
 884         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 885                 return -ENOMEM;
 886
 887         return 0;
 888 }
 889
 890 int blk_mq_debugfs_register_hctx(struct request_queue *q,
 891                                  struct blk_mq_hw_ctx *hctx)
 892 {
 893         struct blk_mq_ctx *ctx;
 894         char name[20];
 895         int i;
 896
 897         if (!q->debugfs_dir)
 898                 return -ENOENT;
 899
 900         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 901         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 902         if (!hctx->debugfs_dir)
 903                 return -ENOMEM;
 904
 905         if (!debugfs_create_files(hctx->debugfs_dir, hctx,
 906                                   blk_mq_debugfs_hctx_attrs))
 907                 goto err;
 908
 909         hctx_for_each_ctx(hctx, ctx, i) {
 910                 if (blk_mq_debugfs_register_ctx(hctx, ctx))
 911                         goto err;
 912         }
 913
 914         return 0;
 915
 916 err:
 917         blk_mq_debugfs_unregister_hctx(hctx);
 918         return -ENOMEM;
 919 }
 920
 921 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 922 {
 923         debugfs_remove_recursive(hctx->debugfs_dir);
 924         hctx->sched_debugfs_dir = NULL;
 925         hctx->debugfs_dir = NULL;
 926 }
 927
 928 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 929 {
 930         struct blk_mq_hw_ctx *hctx;
 931         int i;
 932
 933         queue_for_each_hw_ctx(q, hctx, i) {
 934                 if (blk_mq_debugfs_register_hctx(q, hctx))
 935                         return -ENOMEM;
 936         }
 937
 938         return 0;
 939 }
 940
 941 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 942 {
 943         struct blk_mq_hw_ctx *hctx;
 944         int i;
 945
 946         queue_for_each_hw_ctx(q, hctx, i)
 947                 blk_mq_debugfs_unregister_hctx(hctx);
 948 }
 949
 950 int blk_mq_debugfs_register_sched(struct request_queue *q)
 951 {
 952         struct elevator_type *e = q->elevator->type;
 953
 954         if (!q->debugfs_dir)
 955                 return -ENOENT;
 956
 957         if (!e->queue_debugfs_attrs)
 958                 return 0;
 959
 960         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 961         if (!q->sched_debugfs_dir)
 962                 return -ENOMEM;
 963
 964         if (!debugfs_create_files(q->sched_debugfs_dir, q,
 965                                   e->queue_debugfs_attrs))
 966                 goto err;
 967
 968         return 0;
 969
 970 err:
 971         blk_mq_debugfs_unregister_sched(q);
 972         return -ENOMEM;
 973 }
 974
 975 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 976 {
 977         debugfs_remove_recursive(q->sched_debugfs_dir);
 978         q->sched_debugfs_dir = NULL;
 979 }
 980
 981 int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 982                                        struct blk_mq_hw_ctx *hctx)
 983 {
 984         struct elevator_type *e = q->elevator->type;
 985
 986         if (!hctx->debugfs_dir)
 987                 return -ENOENT;
 988
 989         if (!e->hctx_debugfs_attrs)
 990                 return 0;
 991
 992         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 993                                                      hctx->debugfs_dir);
 994         if (!hctx->sched_debugfs_dir)
 995                 return -ENOMEM;
 996
 997         if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 998                                   e->hctx_debugfs_attrs))
 999                 return -ENOMEM;
1000
1001         return 0;
1002 }
1003
1004 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
1005 {
1006         debugfs_remove_recursive(hctx->sched_debugfs_dir);
1007         hctx->sched_debugfs_dir = NULL;
1008 }