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