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-tag.h"
  25
  26 struct blk_mq_debugfs_attr {
  27         const char *name;
  28         umode_t mode;
  29         const struct file_operations *fops;
  30 };
  31
  32 static int blk_mq_debugfs_seq_open(struct inode *inode, struct file *file,
  33                                    const struct seq_operations *ops)
  34 {
  35         struct seq_file *m;
  36         int ret;
  37
  38         ret = seq_open(file, ops);
  39         if (!ret) {
  40                 m = file->private_data;
  41                 m->private = inode->i_private;
  42         }
  43         return ret;
  44 }
  45
  46 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  47                           const char *const *flag_name, int flag_name_count)
  48 {
  49         bool sep = false;
  50         int i;
  51
  52         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  53                 if (!(flags & BIT(i)))
  54                         continue;
  55                 if (sep)
  56                         seq_puts(m, "|");
  57                 sep = true;
  58                 if (i < flag_name_count && flag_name[i])
  59                         seq_puts(m, flag_name[i]);
  60                 else
  61                         seq_printf(m, "%d", i);
  62         }
  63         return 0;
  64 }
  65
  66 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
  67 static const char *const blk_queue_flag_name[] = {
  68         QUEUE_FLAG_NAME(QUEUED),
  69         QUEUE_FLAG_NAME(STOPPED),
  70         QUEUE_FLAG_NAME(SYNCFULL),
  71         QUEUE_FLAG_NAME(ASYNCFULL),
  72         QUEUE_FLAG_NAME(DYING),
  73         QUEUE_FLAG_NAME(BYPASS),
  74         QUEUE_FLAG_NAME(BIDI),
  75         QUEUE_FLAG_NAME(NOMERGES),
  76         QUEUE_FLAG_NAME(SAME_COMP),
  77         QUEUE_FLAG_NAME(FAIL_IO),
  78         QUEUE_FLAG_NAME(STACKABLE),
  79         QUEUE_FLAG_NAME(NONROT),
  80         QUEUE_FLAG_NAME(IO_STAT),
  81         QUEUE_FLAG_NAME(DISCARD),
  82         QUEUE_FLAG_NAME(NOXMERGES),
  83         QUEUE_FLAG_NAME(ADD_RANDOM),
  84         QUEUE_FLAG_NAME(SECERASE),
  85         QUEUE_FLAG_NAME(SAME_FORCE),
  86         QUEUE_FLAG_NAME(DEAD),
  87         QUEUE_FLAG_NAME(INIT_DONE),
  88         QUEUE_FLAG_NAME(NO_SG_MERGE),
  89         QUEUE_FLAG_NAME(POLL),
  90         QUEUE_FLAG_NAME(WC),
  91         QUEUE_FLAG_NAME(FUA),
  92         QUEUE_FLAG_NAME(FLUSH_NQ),
  93         QUEUE_FLAG_NAME(DAX),
  94         QUEUE_FLAG_NAME(STATS),
  95         QUEUE_FLAG_NAME(POLL_STATS),
  96         QUEUE_FLAG_NAME(REGISTERED),
  97 };
  98 #undef QUEUE_FLAG_NAME
  99
 100 static int blk_queue_flags_show(struct seq_file *m, void *v)
 101 {
 102         struct request_queue *q = m->private;
 103
 104         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 105                        ARRAY_SIZE(blk_queue_flag_name));
 106         seq_puts(m, "\n");
 107         return 0;
 108 }
 109
 110 static ssize_t blk_queue_flags_store(struct file *file, const char __user *buf,
 111                                      size_t count, loff_t *ppos)
 112 {
 113         struct request_queue *q = file_inode(file)->i_private;
 114         char opbuf[16] = { }, *op;
 115
 116         if (count >= sizeof(opbuf)) {
 117                 pr_err("%s: operation too long\n", __func__);
 118                 goto inval;
 119         }
 120
 121         if (copy_from_user(opbuf, buf, count))
 122                 return -EFAULT;
 123         op = strstrip(opbuf);
 124         if (strcmp(op, "run") == 0) {
 125                 blk_mq_run_hw_queues(q, true);
 126         } else if (strcmp(op, "start") == 0) {
 127                 blk_mq_start_stopped_hw_queues(q, true);
 128         } else {
 129                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 130 inval:
 131                 pr_err("%s: use either 'run' or 'start'\n", __func__);
 132                 return -EINVAL;
 133         }
 134         return count;
 135 }
 136
 137 static int blk_queue_flags_open(struct inode *inode, struct file *file)
 138 {
 139         return single_open(file, blk_queue_flags_show, inode->i_private);
 140 }
 141
 142 static const struct file_operations blk_queue_flags_fops = {
 143         .open           = blk_queue_flags_open,
 144         .read           = seq_read,
 145         .llseek         = seq_lseek,
 146         .release        = single_release,
 147         .write          = blk_queue_flags_store,
 148 };
 149
 150 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
 151 {
 152         if (stat->nr_samples) {
 153                 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
 154                            stat->nr_samples, stat->mean, stat->min, stat->max);
 155         } else {
 156                 seq_puts(m, "samples=0");
 157         }
 158 }
 159
 160 static int queue_poll_stat_show(struct seq_file *m, void *v)
 161 {
 162         struct request_queue *q = m->private;
 163         int bucket;
 164
 165         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
 166                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
 167                 print_stat(m, &q->poll_stat[2*bucket]);
 168                 seq_puts(m, "\n");
 169
 170                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
 171                 print_stat(m, &q->poll_stat[2*bucket+1]);
 172                 seq_puts(m, "\n");
 173         }
 174         return 0;
 175 }
 176
 177 static int queue_poll_stat_open(struct inode *inode, struct file *file)
 178 {
 179         return single_open(file, queue_poll_stat_show, inode->i_private);
 180 }
 181
 182 static const struct file_operations queue_poll_stat_fops = {
 183         .open           = queue_poll_stat_open,
 184         .read           = seq_read,
 185         .llseek         = seq_lseek,
 186         .release        = single_release,
 187 };
 188
 189 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 190 static const char *const hctx_state_name[] = {
 191         HCTX_STATE_NAME(STOPPED),
 192         HCTX_STATE_NAME(TAG_ACTIVE),
 193         HCTX_STATE_NAME(SCHED_RESTART),
 194         HCTX_STATE_NAME(TAG_WAITING),
 195         HCTX_STATE_NAME(START_ON_RUN),
 196 };
 197 #undef HCTX_STATE_NAME
 198
 199 static int hctx_state_show(struct seq_file *m, void *v)
 200 {
 201         struct blk_mq_hw_ctx *hctx = m->private;
 202
 203         blk_flags_show(m, hctx->state, hctx_state_name,
 204                        ARRAY_SIZE(hctx_state_name));
 205         seq_puts(m, "\n");
 206         return 0;
 207 }
 208
 209 static int hctx_state_open(struct inode *inode, struct file *file)
 210 {
 211         return single_open(file, hctx_state_show, inode->i_private);
 212 }
 213
 214 static const struct file_operations hctx_state_fops = {
 215         .open           = hctx_state_open,
 216         .read           = seq_read,
 217         .llseek         = seq_lseek,
 218         .release        = single_release,
 219 };
 220
 221 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 222 static const char *const alloc_policy_name[] = {
 223         BLK_TAG_ALLOC_NAME(FIFO),
 224         BLK_TAG_ALLOC_NAME(RR),
 225 };
 226 #undef BLK_TAG_ALLOC_NAME
 227
 228 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 229 static const char *const hctx_flag_name[] = {
 230         HCTX_FLAG_NAME(SHOULD_MERGE),
 231         HCTX_FLAG_NAME(TAG_SHARED),
 232         HCTX_FLAG_NAME(SG_MERGE),
 233         HCTX_FLAG_NAME(BLOCKING),
 234         HCTX_FLAG_NAME(NO_SCHED),
 235 };
 236 #undef HCTX_FLAG_NAME
 237
 238 static int hctx_flags_show(struct seq_file *m, void *v)
 239 {
 240         struct blk_mq_hw_ctx *hctx = m->private;
 241         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 242
 243         seq_puts(m, "alloc_policy=");
 244         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 245             alloc_policy_name[alloc_policy])
 246                 seq_puts(m, alloc_policy_name[alloc_policy]);
 247         else
 248                 seq_printf(m, "%d", alloc_policy);
 249         seq_puts(m, " ");
 250         blk_flags_show(m,
 251                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 252                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 253         seq_puts(m, "\n");
 254         return 0;
 255 }
 256
 257 static int hctx_flags_open(struct inode *inode, struct file *file)
 258 {
 259         return single_open(file, hctx_flags_show, inode->i_private);
 260 }
 261
 262 static const struct file_operations hctx_flags_fops = {
 263         .open           = hctx_flags_open,
 264         .read           = seq_read,
 265         .llseek         = seq_lseek,
 266         .release        = single_release,
 267 };
 268
 269 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 270 static const char *const op_name[] = {
 271         REQ_OP_NAME(READ),
 272         REQ_OP_NAME(WRITE),
 273         REQ_OP_NAME(FLUSH),
 274         REQ_OP_NAME(DISCARD),
 275         REQ_OP_NAME(ZONE_REPORT),
 276         REQ_OP_NAME(SECURE_ERASE),
 277         REQ_OP_NAME(ZONE_RESET),
 278         REQ_OP_NAME(WRITE_SAME),
 279         REQ_OP_NAME(WRITE_ZEROES),
 280         REQ_OP_NAME(SCSI_IN),
 281         REQ_OP_NAME(SCSI_OUT),
 282         REQ_OP_NAME(DRV_IN),
 283         REQ_OP_NAME(DRV_OUT),
 284 };
 285 #undef REQ_OP_NAME
 286
 287 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 288 static const char *const cmd_flag_name[] = {
 289         CMD_FLAG_NAME(FAILFAST_DEV),
 290         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 291         CMD_FLAG_NAME(FAILFAST_DRIVER),
 292         CMD_FLAG_NAME(SYNC),
 293         CMD_FLAG_NAME(META),
 294         CMD_FLAG_NAME(PRIO),
 295         CMD_FLAG_NAME(NOMERGE),
 296         CMD_FLAG_NAME(IDLE),
 297         CMD_FLAG_NAME(INTEGRITY),
 298         CMD_FLAG_NAME(FUA),
 299         CMD_FLAG_NAME(PREFLUSH),
 300         CMD_FLAG_NAME(RAHEAD),
 301         CMD_FLAG_NAME(BACKGROUND),
 302         CMD_FLAG_NAME(NOUNMAP),
 303 };
 304 #undef CMD_FLAG_NAME
 305
 306 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 307 static const char *const rqf_name[] = {
 308         RQF_NAME(SORTED),
 309         RQF_NAME(STARTED),
 310         RQF_NAME(QUEUED),
 311         RQF_NAME(SOFTBARRIER),
 312         RQF_NAME(FLUSH_SEQ),
 313         RQF_NAME(MIXED_MERGE),
 314         RQF_NAME(MQ_INFLIGHT),
 315         RQF_NAME(DONTPREP),
 316         RQF_NAME(PREEMPT),
 317         RQF_NAME(COPY_USER),
 318         RQF_NAME(FAILED),
 319         RQF_NAME(QUIET),
 320         RQF_NAME(ELVPRIV),
 321         RQF_NAME(IO_STAT),
 322         RQF_NAME(ALLOCED),
 323         RQF_NAME(PM),
 324         RQF_NAME(HASHED),
 325         RQF_NAME(STATS),
 326         RQF_NAME(SPECIAL_PAYLOAD),
 327 };
 328 #undef RQF_NAME
 329
 330 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 331 {
 332         struct request *rq = list_entry_rq(v);
 333         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 334         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 335
 336         seq_printf(m, "%p {.op=", rq);
 337         if (op < ARRAY_SIZE(op_name) && op_name[op])
 338                 seq_printf(m, "%s", op_name[op]);
 339         else
 340                 seq_printf(m, "%d", op);
 341         seq_puts(m, ", .cmd_flags=");
 342         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 343                        ARRAY_SIZE(cmd_flag_name));
 344         seq_puts(m, ", .rq_flags=");
 345         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 346                        ARRAY_SIZE(rqf_name));
 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
 355 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 356         __acquires(&hctx->lock)
 357 {
 358         struct blk_mq_hw_ctx *hctx = m->private;
 359
 360         spin_lock(&hctx->lock);
 361         return seq_list_start(&hctx->dispatch, *pos);
 362 }
 363
 364 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 365 {
 366         struct blk_mq_hw_ctx *hctx = m->private;
 367
 368         return seq_list_next(v, &hctx->dispatch, pos);
 369 }
 370
 371 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 372         __releases(&hctx->lock)
 373 {
 374         struct blk_mq_hw_ctx *hctx = m->private;
 375
 376         spin_unlock(&hctx->lock);
 377 }
 378
 379 static const struct seq_operations hctx_dispatch_seq_ops = {
 380         .start  = hctx_dispatch_start,
 381         .next   = hctx_dispatch_next,
 382         .stop   = hctx_dispatch_stop,
 383         .show   = blk_mq_debugfs_rq_show,
 384 };
 385
 386 static int hctx_dispatch_open(struct inode *inode, struct file *file)
 387 {
 388         return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops);
 389 }
 390
 391 static const struct file_operations hctx_dispatch_fops = {
 392         .open           = hctx_dispatch_open,
 393         .read           = seq_read,
 394         .llseek         = seq_lseek,
 395         .release        = seq_release,
 396 };
 397
 398 static int hctx_ctx_map_show(struct seq_file *m, void *v)
 399 {
 400         struct blk_mq_hw_ctx *hctx = m->private;
 401
 402         sbitmap_bitmap_show(&hctx->ctx_map, m);
 403         return 0;
 404 }
 405
 406 static int hctx_ctx_map_open(struct inode *inode, struct file *file)
 407 {
 408         return single_open(file, hctx_ctx_map_show, inode->i_private);
 409 }
 410
 411 static const struct file_operations hctx_ctx_map_fops = {
 412         .open           = hctx_ctx_map_open,
 413         .read           = seq_read,
 414         .llseek         = seq_lseek,
 415         .release        = single_release,
 416 };
 417
 418 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 419                                      struct blk_mq_tags *tags)
 420 {
 421         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 422         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 423         seq_printf(m, "active_queues=%d\n",
 424                    atomic_read(&tags->active_queues));
 425
 426         seq_puts(m, "\nbitmap_tags:\n");
 427         sbitmap_queue_show(&tags->bitmap_tags, m);
 428
 429         if (tags->nr_reserved_tags) {
 430                 seq_puts(m, "\nbreserved_tags:\n");
 431                 sbitmap_queue_show(&tags->breserved_tags, m);
 432         }
 433 }
 434
 435 static int hctx_tags_show(struct seq_file *m, void *v)
 436 {
 437         struct blk_mq_hw_ctx *hctx = m->private;
 438         struct request_queue *q = hctx->queue;
 439         int res;
 440
 441         res = mutex_lock_interruptible(&q->sysfs_lock);
 442         if (res)
 443                 goto out;
 444         if (hctx->tags)
 445                 blk_mq_debugfs_tags_show(m, hctx->tags);
 446         mutex_unlock(&q->sysfs_lock);
 447
 448 out:
 449         return res;
 450 }
 451
 452 static int hctx_tags_open(struct inode *inode, struct file *file)
 453 {
 454         return single_open(file, hctx_tags_show, inode->i_private);
 455 }
 456
 457 static const struct file_operations hctx_tags_fops = {
 458         .open           = hctx_tags_open,
 459         .read           = seq_read,
 460         .llseek         = seq_lseek,
 461         .release        = single_release,
 462 };
 463
 464 static int hctx_tags_bitmap_show(struct seq_file *m, void *v)
 465 {
 466         struct blk_mq_hw_ctx *hctx = m->private;
 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                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 475         mutex_unlock(&q->sysfs_lock);
 476
 477 out:
 478         return res;
 479 }
 480
 481 static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)
 482 {
 483         return single_open(file, hctx_tags_bitmap_show, inode->i_private);
 484 }
 485
 486 static const struct file_operations hctx_tags_bitmap_fops = {
 487         .open           = hctx_tags_bitmap_open,
 488         .read           = seq_read,
 489         .llseek         = seq_lseek,
 490         .release        = single_release,
 491 };
 492
 493 static int hctx_sched_tags_show(struct seq_file *m, void *v)
 494 {
 495         struct blk_mq_hw_ctx *hctx = m->private;
 496         struct request_queue *q = hctx->queue;
 497         int res;
 498
 499         res = mutex_lock_interruptible(&q->sysfs_lock);
 500         if (res)
 501                 goto out;
 502         if (hctx->sched_tags)
 503                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 504         mutex_unlock(&q->sysfs_lock);
 505
 506 out:
 507         return res;
 508 }
 509
 510 static int hctx_sched_tags_open(struct inode *inode, struct file *file)
 511 {
 512         return single_open(file, hctx_sched_tags_show, inode->i_private);
 513 }
 514
 515 static const struct file_operations hctx_sched_tags_fops = {
 516         .open           = hctx_sched_tags_open,
 517         .read           = seq_read,
 518         .llseek         = seq_lseek,
 519         .release        = single_release,
 520 };
 521
 522 static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v)
 523 {
 524         struct blk_mq_hw_ctx *hctx = m->private;
 525         struct request_queue *q = hctx->queue;
 526         int res;
 527
 528         res = mutex_lock_interruptible(&q->sysfs_lock);
 529         if (res)
 530                 goto out;
 531         if (hctx->sched_tags)
 532                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 533         mutex_unlock(&q->sysfs_lock);
 534
 535 out:
 536         return res;
 537 }
 538
 539 static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)
 540 {
 541         return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private);
 542 }
 543
 544 static const struct file_operations hctx_sched_tags_bitmap_fops = {
 545         .open           = hctx_sched_tags_bitmap_open,
 546         .read           = seq_read,
 547         .llseek         = seq_lseek,
 548         .release        = single_release,
 549 };
 550
 551 static int hctx_io_poll_show(struct seq_file *m, void *v)
 552 {
 553         struct blk_mq_hw_ctx *hctx = m->private;
 554
 555         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 556         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 557         seq_printf(m, "success=%lu\n", hctx->poll_success);
 558         return 0;
 559 }
 560
 561 static int hctx_io_poll_open(struct inode *inode, struct file *file)
 562 {
 563         return single_open(file, hctx_io_poll_show, inode->i_private);
 564 }
 565
 566 static ssize_t hctx_io_poll_write(struct file *file, const char __user *buf,
 567                                   size_t count, loff_t *ppos)
 568 {
 569         struct seq_file *m = file->private_data;
 570         struct blk_mq_hw_ctx *hctx = m->private;
 571
 572         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 573         return count;
 574 }
 575
 576 static const struct file_operations hctx_io_poll_fops = {
 577         .open           = hctx_io_poll_open,
 578         .read           = seq_read,
 579         .write          = hctx_io_poll_write,
 580         .llseek         = seq_lseek,
 581         .release        = single_release,
 582 };
 583
 584 static int hctx_dispatched_show(struct seq_file *m, void *v)
 585 {
 586         struct blk_mq_hw_ctx *hctx = m->private;
 587         int i;
 588
 589         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 590
 591         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 592                 unsigned int d = 1U << (i - 1);
 593
 594                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 595         }
 596
 597         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 598         return 0;
 599 }
 600
 601 static int hctx_dispatched_open(struct inode *inode, struct file *file)
 602 {
 603         return single_open(file, hctx_dispatched_show, inode->i_private);
 604 }
 605
 606 static ssize_t hctx_dispatched_write(struct file *file, const char __user *buf,
 607                                      size_t count, loff_t *ppos)
 608 {
 609         struct seq_file *m = file->private_data;
 610         struct blk_mq_hw_ctx *hctx = m->private;
 611         int i;
 612
 613         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 614                 hctx->dispatched[i] = 0;
 615         return count;
 616 }
 617
 618 static const struct file_operations hctx_dispatched_fops = {
 619         .open           = hctx_dispatched_open,
 620         .read           = seq_read,
 621         .write          = hctx_dispatched_write,
 622         .llseek         = seq_lseek,
 623         .release        = single_release,
 624 };
 625
 626 static int hctx_queued_show(struct seq_file *m, void *v)
 627 {
 628         struct blk_mq_hw_ctx *hctx = m->private;
 629
 630         seq_printf(m, "%lu\n", hctx->queued);
 631         return 0;
 632 }
 633
 634 static int hctx_queued_open(struct inode *inode, struct file *file)
 635 {
 636         return single_open(file, hctx_queued_show, inode->i_private);
 637 }
 638
 639 static ssize_t hctx_queued_write(struct file *file, const char __user *buf,
 640                                  size_t count, loff_t *ppos)
 641 {
 642         struct seq_file *m = file->private_data;
 643         struct blk_mq_hw_ctx *hctx = m->private;
 644
 645         hctx->queued = 0;
 646         return count;
 647 }
 648
 649 static const struct file_operations hctx_queued_fops = {
 650         .open           = hctx_queued_open,
 651         .read           = seq_read,
 652         .write          = hctx_queued_write,
 653         .llseek         = seq_lseek,
 654         .release        = single_release,
 655 };
 656
 657 static int hctx_run_show(struct seq_file *m, void *v)
 658 {
 659         struct blk_mq_hw_ctx *hctx = m->private;
 660
 661         seq_printf(m, "%lu\n", hctx->run);
 662         return 0;
 663 }
 664
 665 static int hctx_run_open(struct inode *inode, struct file *file)
 666 {
 667         return single_open(file, hctx_run_show, inode->i_private);
 668 }
 669
 670 static ssize_t hctx_run_write(struct file *file, const char __user *buf,
 671                                  size_t count, loff_t *ppos)
 672 {
 673         struct seq_file *m = file->private_data;
 674         struct blk_mq_hw_ctx *hctx = m->private;
 675
 676         hctx->run = 0;
 677         return count;
 678 }
 679
 680 static const struct file_operations hctx_run_fops = {
 681         .open           = hctx_run_open,
 682         .read           = seq_read,
 683         .write          = hctx_run_write,
 684         .llseek         = seq_lseek,
 685         .release        = single_release,
 686 };
 687
 688 static int hctx_active_show(struct seq_file *m, void *v)
 689 {
 690         struct blk_mq_hw_ctx *hctx = m->private;
 691
 692         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 693         return 0;
 694 }
 695
 696 static int hctx_active_open(struct inode *inode, struct file *file)
 697 {
 698         return single_open(file, hctx_active_show, inode->i_private);
 699 }
 700
 701 static const struct file_operations hctx_active_fops = {
 702         .open           = hctx_active_open,
 703         .read           = seq_read,
 704         .llseek         = seq_lseek,
 705         .release        = single_release,
 706 };
 707
 708 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 709         __acquires(&ctx->lock)
 710 {
 711         struct blk_mq_ctx *ctx = m->private;
 712
 713         spin_lock(&ctx->lock);
 714         return seq_list_start(&ctx->rq_list, *pos);
 715 }
 716
 717 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 718 {
 719         struct blk_mq_ctx *ctx = m->private;
 720
 721         return seq_list_next(v, &ctx->rq_list, pos);
 722 }
 723
 724 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 725         __releases(&ctx->lock)
 726 {
 727         struct blk_mq_ctx *ctx = m->private;
 728
 729         spin_unlock(&ctx->lock);
 730 }
 731
 732 static const struct seq_operations ctx_rq_list_seq_ops = {
 733         .start  = ctx_rq_list_start,
 734         .next   = ctx_rq_list_next,
 735         .stop   = ctx_rq_list_stop,
 736         .show   = blk_mq_debugfs_rq_show,
 737 };
 738
 739 static int ctx_rq_list_open(struct inode *inode, struct file *file)
 740 {
 741         return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops);
 742 }
 743
 744 static const struct file_operations ctx_rq_list_fops = {
 745         .open           = ctx_rq_list_open,
 746         .read           = seq_read,
 747         .llseek         = seq_lseek,
 748         .release        = seq_release,
 749 };
 750
 751 static int ctx_dispatched_show(struct seq_file *m, void *v)
 752 {
 753         struct blk_mq_ctx *ctx = m->private;
 754
 755         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 756         return 0;
 757 }
 758
 759 static int ctx_dispatched_open(struct inode *inode, struct file *file)
 760 {
 761         return single_open(file, ctx_dispatched_show, inode->i_private);
 762 }
 763
 764 static ssize_t ctx_dispatched_write(struct file *file, const char __user *buf,
 765                                     size_t count, loff_t *ppos)
 766 {
 767         struct seq_file *m = file->private_data;
 768         struct blk_mq_ctx *ctx = m->private;
 769
 770         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 771         return count;
 772 }
 773
 774 static const struct file_operations ctx_dispatched_fops = {
 775         .open           = ctx_dispatched_open,
 776         .read           = seq_read,
 777         .write          = ctx_dispatched_write,
 778         .llseek         = seq_lseek,
 779         .release        = single_release,
 780 };
 781
 782 static int ctx_merged_show(struct seq_file *m, void *v)
 783 {
 784         struct blk_mq_ctx *ctx = m->private;
 785
 786         seq_printf(m, "%lu\n", ctx->rq_merged);
 787         return 0;
 788 }
 789
 790 static int ctx_merged_open(struct inode *inode, struct file *file)
 791 {
 792         return single_open(file, ctx_merged_show, inode->i_private);
 793 }
 794
 795 static ssize_t ctx_merged_write(struct file *file, const char __user *buf,
 796                                     size_t count, loff_t *ppos)
 797 {
 798         struct seq_file *m = file->private_data;
 799         struct blk_mq_ctx *ctx = m->private;
 800
 801         ctx->rq_merged = 0;
 802         return count;
 803 }
 804
 805 static const struct file_operations ctx_merged_fops = {
 806         .open           = ctx_merged_open,
 807         .read           = seq_read,
 808         .write          = ctx_merged_write,
 809         .llseek         = seq_lseek,
 810         .release        = single_release,
 811 };
 812
 813 static int ctx_completed_show(struct seq_file *m, void *v)
 814 {
 815         struct blk_mq_ctx *ctx = m->private;
 816
 817         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 818         return 0;
 819 }
 820
 821 static int ctx_completed_open(struct inode *inode, struct file *file)
 822 {
 823         return single_open(file, ctx_completed_show, inode->i_private);
 824 }
 825
 826 static ssize_t ctx_completed_write(struct file *file, const char __user *buf,
 827                                    size_t count, loff_t *ppos)
 828 {
 829         struct seq_file *m = file->private_data;
 830         struct blk_mq_ctx *ctx = m->private;
 831
 832         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 833         return count;
 834 }
 835
 836 static const struct file_operations ctx_completed_fops = {
 837         .open           = ctx_completed_open,
 838         .read           = seq_read,
 839         .write          = ctx_completed_write,
 840         .llseek         = seq_lseek,
 841         .release        = single_release,
 842 };
 843
 844 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 845         {"poll_stat", 0400, &queue_poll_stat_fops},
 846         {"state", 0600, &blk_queue_flags_fops},
 847         {},
 848 };
 849
 850 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 851         {"state", 0400, &hctx_state_fops},
 852         {"flags", 0400, &hctx_flags_fops},
 853         {"dispatch", 0400, &hctx_dispatch_fops},
 854         {"ctx_map", 0400, &hctx_ctx_map_fops},
 855         {"tags", 0400, &hctx_tags_fops},
 856         {"tags_bitmap", 0400, &hctx_tags_bitmap_fops},
 857         {"sched_tags", 0400, &hctx_sched_tags_fops},
 858         {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops},
 859         {"io_poll", 0600, &hctx_io_poll_fops},
 860         {"dispatched", 0600, &hctx_dispatched_fops},
 861         {"queued", 0600, &hctx_queued_fops},
 862         {"run", 0600, &hctx_run_fops},
 863         {"active", 0400, &hctx_active_fops},
 864         {},
 865 };
 866
 867 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 868         {"rq_list", 0400, &ctx_rq_list_fops},
 869         {"dispatched", 0600, &ctx_dispatched_fops},
 870         {"merged", 0600, &ctx_merged_fops},
 871         {"completed", 0600, &ctx_completed_fops},
 872         {},
 873 };
 874
 875 int blk_mq_debugfs_register(struct request_queue *q)
 876 {
 877         if (!blk_debugfs_root)
 878                 return -ENOENT;
 879
 880         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 881                                             blk_debugfs_root);
 882         if (!q->debugfs_dir)
 883                 goto err;
 884
 885         if (blk_mq_debugfs_register_mq(q))
 886                 goto err;
 887
 888         return 0;
 889
 890 err:
 891         blk_mq_debugfs_unregister(q);
 892         return -ENOMEM;
 893 }
 894
 895 void blk_mq_debugfs_unregister(struct request_queue *q)
 896 {
 897         debugfs_remove_recursive(q->debugfs_dir);
 898         q->mq_debugfs_dir = NULL;
 899         q->debugfs_dir = NULL;
 900 }
 901
 902 static bool debugfs_create_files(struct dentry *parent, void *data,
 903                                 const struct blk_mq_debugfs_attr *attr)
 904 {
 905         for (; attr->name; attr++) {
 906                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 907                                          data, attr->fops))
 908                         return false;
 909         }
 910         return true;
 911 }
 912
 913 static int blk_mq_debugfs_register_ctx(struct request_queue *q,
 914                                        struct blk_mq_ctx *ctx,
 915                                        struct dentry *hctx_dir)
 916 {
 917         struct dentry *ctx_dir;
 918         char name[20];
 919
 920         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 921         ctx_dir = debugfs_create_dir(name, hctx_dir);
 922         if (!ctx_dir)
 923                 return -ENOMEM;
 924
 925         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 926                 return -ENOMEM;
 927
 928         return 0;
 929 }
 930
 931 static int blk_mq_debugfs_register_hctx(struct request_queue *q,
 932                                         struct blk_mq_hw_ctx *hctx)
 933 {
 934         struct blk_mq_ctx *ctx;
 935         struct dentry *hctx_dir;
 936         char name[20];
 937         int i;
 938
 939         snprintf(name, sizeof(name), "%u", hctx->queue_num);
 940         hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
 941         if (!hctx_dir)
 942                 return -ENOMEM;
 943
 944         if (!debugfs_create_files(hctx_dir, hctx, blk_mq_debugfs_hctx_attrs))
 945                 return -ENOMEM;
 946
 947         hctx_for_each_ctx(hctx, ctx, i) {
 948                 if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
 949                         return -ENOMEM;
 950         }
 951
 952         return 0;
 953 }
 954
 955 int blk_mq_debugfs_register_mq(struct request_queue *q)
 956 {
 957         struct blk_mq_hw_ctx *hctx;
 958         int i;
 959
 960         if (!q->debugfs_dir)
 961                 return -ENOENT;
 962
 963         q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
 964         if (!q->mq_debugfs_dir)
 965                 goto err;
 966
 967         if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs))
 968                 goto err;
 969
 970         queue_for_each_hw_ctx(q, hctx, i) {
 971                 if (blk_mq_debugfs_register_hctx(q, hctx))
 972                         goto err;
 973         }
 974
 975         return 0;
 976
 977 err:
 978         blk_mq_debugfs_unregister_mq(q);
 979         return -ENOMEM;
 980 }
 981
 982 void blk_mq_debugfs_unregister_mq(struct request_queue *q)
 983 {
 984         debugfs_remove_recursive(q->mq_debugfs_dir);
 985         q->mq_debugfs_dir = NULL;
 986 }