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 #include "blk-rq-qos.h"
  27
  28 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  29 {
  30         if (stat->nr_samples) {
  31                 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
  32                            stat->nr_samples, stat->mean, stat->min, stat->max);
  33         } else {
  34                 seq_puts(m, "samples=0");
  35         }
  36 }
  37
  38 static int queue_poll_stat_show(void *data, struct seq_file *m)
  39 {
  40         struct request_queue *q = data;
  41         int bucket;
  42
  43         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
  44                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
  45                 print_stat(m, &q->poll_stat[2*bucket]);
  46                 seq_puts(m, "\n");
  47
  48                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
  49                 print_stat(m, &q->poll_stat[2*bucket+1]);
  50                 seq_puts(m, "\n");
  51         }
  52         return 0;
  53 }
  54
  55 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  56         __acquires(&q->requeue_lock)
  57 {
  58         struct request_queue *q = m->private;
  59
  60         spin_lock_irq(&q->requeue_lock);
  61         return seq_list_start(&q->requeue_list, *pos);
  62 }
  63
  64 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  65 {
  66         struct request_queue *q = m->private;
  67
  68         return seq_list_next(v, &q->requeue_list, pos);
  69 }
  70
  71 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  72         __releases(&q->requeue_lock)
  73 {
  74         struct request_queue *q = m->private;
  75
  76         spin_unlock_irq(&q->requeue_lock);
  77 }
  78
  79 static const struct seq_operations queue_requeue_list_seq_ops = {
  80         .start  = queue_requeue_list_start,
  81         .next   = queue_requeue_list_next,
  82         .stop   = queue_requeue_list_stop,
  83         .show   = blk_mq_debugfs_rq_show,
  84 };
  85
  86 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  87                           const char *const *flag_name, int flag_name_count)
  88 {
  89         bool sep = false;
  90         int i;
  91
  92         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  93                 if (!(flags & BIT(i)))
  94                         continue;
  95                 if (sep)
  96                         seq_puts(m, "|");
  97                 sep = true;
  98                 if (i < flag_name_count && flag_name[i])
  99                         seq_puts(m, flag_name[i]);
 100                 else
 101                         seq_printf(m, "%d", i);
 102         }
 103         return 0;
 104 }
 105
 106 static int queue_pm_only_show(void *data, struct seq_file *m)
 107 {
 108         struct request_queue *q = data;
 109
 110         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 111         return 0;
 112 }
 113
 114 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 115 static const char *const blk_queue_flag_name[] = {
 116         QUEUE_FLAG_NAME(STOPPED),
 117         QUEUE_FLAG_NAME(DYING),
 118         QUEUE_FLAG_NAME(BIDI),
 119         QUEUE_FLAG_NAME(NOMERGES),
 120         QUEUE_FLAG_NAME(SAME_COMP),
 121         QUEUE_FLAG_NAME(FAIL_IO),
 122         QUEUE_FLAG_NAME(NONROT),
 123         QUEUE_FLAG_NAME(IO_STAT),
 124         QUEUE_FLAG_NAME(DISCARD),
 125         QUEUE_FLAG_NAME(NOXMERGES),
 126         QUEUE_FLAG_NAME(ADD_RANDOM),
 127         QUEUE_FLAG_NAME(SECERASE),
 128         QUEUE_FLAG_NAME(SAME_FORCE),
 129         QUEUE_FLAG_NAME(DEAD),
 130         QUEUE_FLAG_NAME(INIT_DONE),
 131         QUEUE_FLAG_NAME(NO_SG_MERGE),
 132         QUEUE_FLAG_NAME(POLL),
 133         QUEUE_FLAG_NAME(WC),
 134         QUEUE_FLAG_NAME(FUA),
 135         QUEUE_FLAG_NAME(FLUSH_NQ),
 136         QUEUE_FLAG_NAME(DAX),
 137         QUEUE_FLAG_NAME(STATS),
 138         QUEUE_FLAG_NAME(POLL_STATS),
 139         QUEUE_FLAG_NAME(REGISTERED),
 140         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 141         QUEUE_FLAG_NAME(QUIESCED),
 142 };
 143 #undef QUEUE_FLAG_NAME
 144
 145 static int queue_state_show(void *data, struct seq_file *m)
 146 {
 147         struct request_queue *q = data;
 148
 149         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 150                        ARRAY_SIZE(blk_queue_flag_name));
 151         seq_puts(m, "\n");
 152         return 0;
 153 }
 154
 155 static ssize_t queue_state_write(void *data, const char __user *buf,
 156                                  size_t count, loff_t *ppos)
 157 {
 158         struct request_queue *q = data;
 159         char opbuf[16] = { }, *op;
 160
 161         /*
 162          * The "state" attribute is removed after blk_cleanup_queue() has called
 163          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 164          * triggering a use-after-free.
 165          */
 166         if (blk_queue_dead(q))
 167                 return -ENOENT;
 168
 169         if (count >= sizeof(opbuf)) {
 170                 pr_err("%s: operation too long\n", __func__);
 171                 goto inval;
 172         }
 173
 174         if (copy_from_user(opbuf, buf, count))
 175                 return -EFAULT;
 176         op = strstrip(opbuf);
 177         if (strcmp(op, "run") == 0) {
 178                 blk_mq_run_hw_queues(q, true);
 179         } else if (strcmp(op, "start") == 0) {
 180                 blk_mq_start_stopped_hw_queues(q, true);
 181         } else if (strcmp(op, "kick") == 0) {
 182                 blk_mq_kick_requeue_list(q);
 183         } else {
 184                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 185 inval:
 186                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 187                 return -EINVAL;
 188         }
 189         return count;
 190 }
 191
 192 static int queue_write_hint_show(void *data, struct seq_file *m)
 193 {
 194         struct request_queue *q = data;
 195         int i;
 196
 197         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 198                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 199
 200         return 0;
 201 }
 202
 203 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 204                                       size_t count, loff_t *ppos)
 205 {
 206         struct request_queue *q = data;
 207         int i;
 208
 209         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 210                 q->write_hints[i] = 0;
 211
 212         return count;
 213 }
 214
 215 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 216         { "poll_stat", 0400, queue_poll_stat_show },
 217         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 218         { "pm_only", 0600, queue_pm_only_show, NULL },
 219         { "state", 0600, queue_state_show, queue_state_write },
 220         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 221         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 222         { },
 223 };
 224
 225 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 226 static const char *const hctx_state_name[] = {
 227         HCTX_STATE_NAME(STOPPED),
 228         HCTX_STATE_NAME(TAG_ACTIVE),
 229         HCTX_STATE_NAME(SCHED_RESTART),
 230 };
 231 #undef HCTX_STATE_NAME
 232
 233 static int hctx_state_show(void *data, struct seq_file *m)
 234 {
 235         struct blk_mq_hw_ctx *hctx = data;
 236
 237         blk_flags_show(m, hctx->state, hctx_state_name,
 238                        ARRAY_SIZE(hctx_state_name));
 239         seq_puts(m, "\n");
 240         return 0;
 241 }
 242
 243 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 244 static const char *const alloc_policy_name[] = {
 245         BLK_TAG_ALLOC_NAME(FIFO),
 246         BLK_TAG_ALLOC_NAME(RR),
 247 };
 248 #undef BLK_TAG_ALLOC_NAME
 249
 250 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 251 static const char *const hctx_flag_name[] = {
 252         HCTX_FLAG_NAME(SHOULD_MERGE),
 253         HCTX_FLAG_NAME(TAG_SHARED),
 254         HCTX_FLAG_NAME(SG_MERGE),
 255         HCTX_FLAG_NAME(BLOCKING),
 256         HCTX_FLAG_NAME(NO_SCHED),
 257 };
 258 #undef HCTX_FLAG_NAME
 259
 260 static int hctx_flags_show(void *data, struct seq_file *m)
 261 {
 262         struct blk_mq_hw_ctx *hctx = data;
 263         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 264
 265         seq_puts(m, "alloc_policy=");
 266         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 267             alloc_policy_name[alloc_policy])
 268                 seq_puts(m, alloc_policy_name[alloc_policy]);
 269         else
 270                 seq_printf(m, "%d", alloc_policy);
 271         seq_puts(m, " ");
 272         blk_flags_show(m,
 273                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 274                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 275         seq_puts(m, "\n");
 276         return 0;
 277 }
 278
 279 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 280 static const char *const op_name[] = {
 281         REQ_OP_NAME(READ),
 282         REQ_OP_NAME(WRITE),
 283         REQ_OP_NAME(FLUSH),
 284         REQ_OP_NAME(DISCARD),
 285         REQ_OP_NAME(SECURE_ERASE),
 286         REQ_OP_NAME(ZONE_RESET),
 287         REQ_OP_NAME(WRITE_SAME),
 288         REQ_OP_NAME(WRITE_ZEROES),
 289         REQ_OP_NAME(SCSI_IN),
 290         REQ_OP_NAME(SCSI_OUT),
 291         REQ_OP_NAME(DRV_IN),
 292         REQ_OP_NAME(DRV_OUT),
 293 };
 294 #undef REQ_OP_NAME
 295
 296 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 297 static const char *const cmd_flag_name[] = {
 298         CMD_FLAG_NAME(FAILFAST_DEV),
 299         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 300         CMD_FLAG_NAME(FAILFAST_DRIVER),
 301         CMD_FLAG_NAME(SYNC),
 302         CMD_FLAG_NAME(META),
 303         CMD_FLAG_NAME(PRIO),
 304         CMD_FLAG_NAME(NOMERGE),
 305         CMD_FLAG_NAME(IDLE),
 306         CMD_FLAG_NAME(INTEGRITY),
 307         CMD_FLAG_NAME(FUA),
 308         CMD_FLAG_NAME(PREFLUSH),
 309         CMD_FLAG_NAME(RAHEAD),
 310         CMD_FLAG_NAME(BACKGROUND),
 311         CMD_FLAG_NAME(NOUNMAP),
 312         CMD_FLAG_NAME(NOWAIT),
 313 };
 314 #undef CMD_FLAG_NAME
 315
 316 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 317 static const char *const rqf_name[] = {
 318         RQF_NAME(SORTED),
 319         RQF_NAME(STARTED),
 320         RQF_NAME(SOFTBARRIER),
 321         RQF_NAME(FLUSH_SEQ),
 322         RQF_NAME(MIXED_MERGE),
 323         RQF_NAME(MQ_INFLIGHT),
 324         RQF_NAME(DONTPREP),
 325         RQF_NAME(PREEMPT),
 326         RQF_NAME(COPY_USER),
 327         RQF_NAME(FAILED),
 328         RQF_NAME(QUIET),
 329         RQF_NAME(ELVPRIV),
 330         RQF_NAME(IO_STAT),
 331         RQF_NAME(ALLOCED),
 332         RQF_NAME(PM),
 333         RQF_NAME(HASHED),
 334         RQF_NAME(STATS),
 335         RQF_NAME(SPECIAL_PAYLOAD),
 336         RQF_NAME(ZONE_WRITE_LOCKED),
 337         RQF_NAME(MQ_POLL_SLEPT),
 338 };
 339 #undef RQF_NAME
 340
 341 static const char *const blk_mq_rq_state_name_array[] = {
 342         [MQ_RQ_IDLE]            = "idle",
 343         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 344         [MQ_RQ_COMPLETE]        = "complete",
 345 };
 346
 347 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 348 {
 349         if (WARN_ON_ONCE((unsigned int)rq_state >=
 350                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 351                 return "(?)";
 352         return blk_mq_rq_state_name_array[rq_state];
 353 }
 354
 355 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 356 {
 357         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 358         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 359
 360         seq_printf(m, "%p {.op=", rq);
 361         if (op < ARRAY_SIZE(op_name) && op_name[op])
 362                 seq_printf(m, "%s", op_name[op]);
 363         else
 364                 seq_printf(m, "%d", op);
 365         seq_puts(m, ", .cmd_flags=");
 366         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 367                        ARRAY_SIZE(cmd_flag_name));
 368         seq_puts(m, ", .rq_flags=");
 369         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 370                        ARRAY_SIZE(rqf_name));
 371         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 372         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 373                    rq->internal_tag);
 374         if (mq_ops->show_rq)
 375                 mq_ops->show_rq(m, rq);
 376         seq_puts(m, "}\n");
 377         return 0;
 378 }
 379 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 380
 381 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 382 {
 383         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 384 }
 385 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 386
 387 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 388         __acquires(&hctx->lock)
 389 {
 390         struct blk_mq_hw_ctx *hctx = m->private;
 391
 392         spin_lock(&hctx->lock);
 393         return seq_list_start(&hctx->dispatch, *pos);
 394 }
 395
 396 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 397 {
 398         struct blk_mq_hw_ctx *hctx = m->private;
 399
 400         return seq_list_next(v, &hctx->dispatch, pos);
 401 }
 402
 403 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 404         __releases(&hctx->lock)
 405 {
 406         struct blk_mq_hw_ctx *hctx = m->private;
 407
 408         spin_unlock(&hctx->lock);
 409 }
 410
 411 static const struct seq_operations hctx_dispatch_seq_ops = {
 412         .start  = hctx_dispatch_start,
 413         .next   = hctx_dispatch_next,
 414         .stop   = hctx_dispatch_stop,
 415         .show   = blk_mq_debugfs_rq_show,
 416 };
 417
 418 struct show_busy_params {
 419         struct seq_file         *m;
 420         struct blk_mq_hw_ctx    *hctx;
 421 };
 422
 423 /*
 424  * Note: the state of a request may change while this function is in progress,
 425  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 426  * keep iterating requests.
 427  */
 428 static bool hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 429 {
 430         const struct show_busy_params *params = data;
 431
 432         if (rq->mq_hctx == params->hctx)
 433                 __blk_mq_debugfs_rq_show(params->m,
 434                                          list_entry_rq(&rq->queuelist));
 435
 436         return true;
 437 }
 438
 439 static int hctx_busy_show(void *data, struct seq_file *m)
 440 {
 441         struct blk_mq_hw_ctx *hctx = data;
 442         struct show_busy_params params = { .m = m, .hctx = hctx };
 443
 444         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 445                                 &params);
 446
 447         return 0;
 448 }
 449
 450 static const char *const hctx_types[] = {
 451         [HCTX_TYPE_DEFAULT]     = "default",
 452         [HCTX_TYPE_READ]        = "read",
 453         [HCTX_TYPE_POLL]        = "poll",
 454 };
 455
 456 static int hctx_type_show(void *data, struct seq_file *m)
 457 {
 458         struct blk_mq_hw_ctx *hctx = data;
 459
 460         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 461         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 462         return 0;
 463 }
 464
 465 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 466 {
 467         struct blk_mq_hw_ctx *hctx = data;
 468
 469         sbitmap_bitmap_show(&hctx->ctx_map, m);
 470         return 0;
 471 }
 472
 473 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 474                                      struct blk_mq_tags *tags)
 475 {
 476         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 477         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 478         seq_printf(m, "active_queues=%d\n",
 479                    atomic_read(&tags->active_queues));
 480
 481         seq_puts(m, "\nbitmap_tags:\n");
 482         sbitmap_queue_show(&tags->bitmap_tags, m);
 483
 484         if (tags->nr_reserved_tags) {
 485                 seq_puts(m, "\nbreserved_tags:\n");
 486                 sbitmap_queue_show(&tags->breserved_tags, m);
 487         }
 488 }
 489
 490 static int hctx_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->tags)
 500                 blk_mq_debugfs_tags_show(m, hctx->tags);
 501         mutex_unlock(&q->sysfs_lock);
 502
 503 out:
 504         return res;
 505 }
 506
 507 static int hctx_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->tags)
 517                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 518         mutex_unlock(&q->sysfs_lock);
 519
 520 out:
 521         return res;
 522 }
 523
 524 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 525 {
 526         struct blk_mq_hw_ctx *hctx = data;
 527         struct request_queue *q = hctx->queue;
 528         int res;
 529
 530         res = mutex_lock_interruptible(&q->sysfs_lock);
 531         if (res)
 532                 goto out;
 533         if (hctx->sched_tags)
 534                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 535         mutex_unlock(&q->sysfs_lock);
 536
 537 out:
 538         return res;
 539 }
 540
 541 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 542 {
 543         struct blk_mq_hw_ctx *hctx = data;
 544         struct request_queue *q = hctx->queue;
 545         int res;
 546
 547         res = mutex_lock_interruptible(&q->sysfs_lock);
 548         if (res)
 549                 goto out;
 550         if (hctx->sched_tags)
 551                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 552         mutex_unlock(&q->sysfs_lock);
 553
 554 out:
 555         return res;
 556 }
 557
 558 static int hctx_io_poll_show(void *data, struct seq_file *m)
 559 {
 560         struct blk_mq_hw_ctx *hctx = data;
 561
 562         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 563         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 564         seq_printf(m, "success=%lu\n", hctx->poll_success);
 565         return 0;
 566 }
 567
 568 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 569                                   size_t count, loff_t *ppos)
 570 {
 571         struct blk_mq_hw_ctx *hctx = data;
 572
 573         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 574         return count;
 575 }
 576
 577 static int hctx_dispatched_show(void *data, struct seq_file *m)
 578 {
 579         struct blk_mq_hw_ctx *hctx = data;
 580         int i;
 581
 582         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 583
 584         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 585                 unsigned int d = 1U << (i - 1);
 586
 587                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 588         }
 589
 590         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 591         return 0;
 592 }
 593
 594 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 595                                      size_t count, loff_t *ppos)
 596 {
 597         struct blk_mq_hw_ctx *hctx = data;
 598         int i;
 599
 600         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 601                 hctx->dispatched[i] = 0;
 602         return count;
 603 }
 604
 605 static int hctx_queued_show(void *data, struct seq_file *m)
 606 {
 607         struct blk_mq_hw_ctx *hctx = data;
 608
 609         seq_printf(m, "%lu\n", hctx->queued);
 610         return 0;
 611 }
 612
 613 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 614                                  size_t count, loff_t *ppos)
 615 {
 616         struct blk_mq_hw_ctx *hctx = data;
 617
 618         hctx->queued = 0;
 619         return count;
 620 }
 621
 622 static int hctx_run_show(void *data, struct seq_file *m)
 623 {
 624         struct blk_mq_hw_ctx *hctx = data;
 625
 626         seq_printf(m, "%lu\n", hctx->run);
 627         return 0;
 628 }
 629
 630 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 631                               loff_t *ppos)
 632 {
 633         struct blk_mq_hw_ctx *hctx = data;
 634
 635         hctx->run = 0;
 636         return count;
 637 }
 638
 639 static int hctx_active_show(void *data, struct seq_file *m)
 640 {
 641         struct blk_mq_hw_ctx *hctx = data;
 642
 643         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 644         return 0;
 645 }
 646
 647 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 648 {
 649         struct blk_mq_hw_ctx *hctx = data;
 650
 651         seq_printf(m, "%u\n", hctx->dispatch_busy);
 652         return 0;
 653 }
 654
 655 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 656 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 657         __acquires(&ctx->lock)                                          \
 658 {                                                                       \
 659         struct blk_mq_ctx *ctx = m->private;                            \
 660                                                                         \
 661         spin_lock(&ctx->lock);                                          \
 662         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 663 }                                                                       \
 664                                                                         \
 665 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 666                                      loff_t *pos)                       \
 667 {                                                                       \
 668         struct blk_mq_ctx *ctx = m->private;                            \
 669                                                                         \
 670         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 671 }                                                                       \
 672                                                                         \
 673 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 674         __releases(&ctx->lock)                                          \
 675 {                                                                       \
 676         struct blk_mq_ctx *ctx = m->private;                            \
 677                                                                         \
 678         spin_unlock(&ctx->lock);                                        \
 679 }                                                                       \
 680                                                                         \
 681 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 682         .start  = ctx_##name##_rq_list_start,                           \
 683         .next   = ctx_##name##_rq_list_next,                            \
 684         .stop   = ctx_##name##_rq_list_stop,                            \
 685         .show   = blk_mq_debugfs_rq_show,                               \
 686 }
 687
 688 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 689 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 690 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 691
 692 static int ctx_dispatched_show(void *data, struct seq_file *m)
 693 {
 694         struct blk_mq_ctx *ctx = data;
 695
 696         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 697         return 0;
 698 }
 699
 700 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 701                                     size_t count, loff_t *ppos)
 702 {
 703         struct blk_mq_ctx *ctx = data;
 704
 705         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 706         return count;
 707 }
 708
 709 static int ctx_merged_show(void *data, struct seq_file *m)
 710 {
 711         struct blk_mq_ctx *ctx = data;
 712
 713         seq_printf(m, "%lu\n", ctx->rq_merged);
 714         return 0;
 715 }
 716
 717 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 718                                 size_t count, loff_t *ppos)
 719 {
 720         struct blk_mq_ctx *ctx = data;
 721
 722         ctx->rq_merged = 0;
 723         return count;
 724 }
 725
 726 static int ctx_completed_show(void *data, struct seq_file *m)
 727 {
 728         struct blk_mq_ctx *ctx = data;
 729
 730         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 731         return 0;
 732 }
 733
 734 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 735                                    size_t count, loff_t *ppos)
 736 {
 737         struct blk_mq_ctx *ctx = data;
 738
 739         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 740         return count;
 741 }
 742
 743 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 744 {
 745         const struct blk_mq_debugfs_attr *attr = m->private;
 746         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 747
 748         return attr->show(data, m);
 749 }
 750
 751 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 752                                     size_t count, loff_t *ppos)
 753 {
 754         struct seq_file *m = file->private_data;
 755         const struct blk_mq_debugfs_attr *attr = m->private;
 756         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 757
 758         /*
 759          * Attributes that only implement .seq_ops are read-only and 'attr' is
 760          * the same with 'data' in this case.
 761          */
 762         if (attr == data || !attr->write)
 763                 return -EPERM;
 764
 765         return attr->write(data, buf, count, ppos);
 766 }
 767
 768 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 769 {
 770         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 771         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 772         struct seq_file *m;
 773         int ret;
 774
 775         if (attr->seq_ops) {
 776                 ret = seq_open(file, attr->seq_ops);
 777                 if (!ret) {
 778                         m = file->private_data;
 779                         m->private = data;
 780                 }
 781                 return ret;
 782         }
 783
 784         if (WARN_ON_ONCE(!attr->show))
 785                 return -EPERM;
 786
 787         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 788 }
 789
 790 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 791 {
 792         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 793
 794         if (attr->show)
 795                 return single_release(inode, file);
 796         else
 797                 return seq_release(inode, file);
 798 }
 799
 800 static const struct file_operations blk_mq_debugfs_fops = {
 801         .open           = blk_mq_debugfs_open,
 802         .read           = seq_read,
 803         .write          = blk_mq_debugfs_write,
 804         .llseek         = seq_lseek,
 805         .release        = blk_mq_debugfs_release,
 806 };
 807
 808 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 809         {"state", 0400, hctx_state_show},
 810         {"flags", 0400, hctx_flags_show},
 811         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 812         {"busy", 0400, hctx_busy_show},
 813         {"ctx_map", 0400, hctx_ctx_map_show},
 814         {"tags", 0400, hctx_tags_show},
 815         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 816         {"sched_tags", 0400, hctx_sched_tags_show},
 817         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 818         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 819         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 820         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 821         {"run", 0600, hctx_run_show, hctx_run_write},
 822         {"active", 0400, hctx_active_show},
 823         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 824         {"type", 0400, hctx_type_show},
 825         {},
 826 };
 827
 828 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 829         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 830         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 831         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 832         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 833         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 834         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 835         {},
 836 };
 837
 838 static bool debugfs_create_files(struct dentry *parent, void *data,
 839                                  const struct blk_mq_debugfs_attr *attr)
 840 {
 841         d_inode(parent)->i_private = data;
 842
 843         for (; attr->name; attr++) {
 844                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 845                                          (void *)attr, &blk_mq_debugfs_fops))
 846                         return false;
 847         }
 848         return true;
 849 }
 850
 851 int blk_mq_debugfs_register(struct request_queue *q)
 852 {
 853         struct blk_mq_hw_ctx *hctx;
 854         int i;
 855
 856         if (!blk_debugfs_root)
 857                 return -ENOENT;
 858
 859         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 860                                             blk_debugfs_root);
 861         if (!q->debugfs_dir)
 862                 return -ENOMEM;
 863
 864         if (!debugfs_create_files(q->debugfs_dir, q,
 865                                   blk_mq_debugfs_queue_attrs))
 866                 goto err;
 867
 868         /*
 869          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 870          * didn't exist yet (because we don't know what to name the directory
 871          * until the queue is registered to a gendisk).
 872          */
 873         if (q->elevator && !q->sched_debugfs_dir)
 874                 blk_mq_debugfs_register_sched(q);
 875
 876         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 877         queue_for_each_hw_ctx(q, hctx, i) {
 878                 if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
 879                         goto err;
 880                 if (q->elevator && !hctx->sched_debugfs_dir &&
 881                     blk_mq_debugfs_register_sched_hctx(q, hctx))
 882                         goto err;
 883         }
 884
 885         if (q->rq_qos) {
 886                 struct rq_qos *rqos = q->rq_qos;
 887
 888                 while (rqos) {
 889                         blk_mq_debugfs_register_rqos(rqos);
 890                         rqos = rqos->next;
 891                 }
 892         }
 893
 894         return 0;
 895
 896 err:
 897         blk_mq_debugfs_unregister(q);
 898         return -ENOMEM;
 899 }
 900
 901 void blk_mq_debugfs_unregister(struct request_queue *q)
 902 {
 903         debugfs_remove_recursive(q->debugfs_dir);
 904         q->sched_debugfs_dir = NULL;
 905         q->debugfs_dir = NULL;
 906 }
 907
 908 static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 909                                        struct blk_mq_ctx *ctx)
 910 {
 911         struct dentry *ctx_dir;
 912         char name[20];
 913
 914         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 915         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 916         if (!ctx_dir)
 917                 return -ENOMEM;
 918
 919         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 920                 return -ENOMEM;
 921
 922         return 0;
 923 }
 924
 925 int blk_mq_debugfs_register_hctx(struct request_queue *q,
 926                                  struct blk_mq_hw_ctx *hctx)
 927 {
 928         struct blk_mq_ctx *ctx;
 929         char name[20];
 930         int i;
 931
 932         if (!q->debugfs_dir)
 933                 return -ENOENT;
 934
 935         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 936         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 937         if (!hctx->debugfs_dir)
 938                 return -ENOMEM;
 939
 940         if (!debugfs_create_files(hctx->debugfs_dir, hctx,
 941                                   blk_mq_debugfs_hctx_attrs))
 942                 goto err;
 943
 944         hctx_for_each_ctx(hctx, ctx, i) {
 945                 if (blk_mq_debugfs_register_ctx(hctx, ctx))
 946                         goto err;
 947         }
 948
 949         return 0;
 950
 951 err:
 952         blk_mq_debugfs_unregister_hctx(hctx);
 953         return -ENOMEM;
 954 }
 955
 956 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 957 {
 958         debugfs_remove_recursive(hctx->debugfs_dir);
 959         hctx->sched_debugfs_dir = NULL;
 960         hctx->debugfs_dir = NULL;
 961 }
 962
 963 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 964 {
 965         struct blk_mq_hw_ctx *hctx;
 966         int i;
 967
 968         queue_for_each_hw_ctx(q, hctx, i) {
 969                 if (blk_mq_debugfs_register_hctx(q, hctx))
 970                         return -ENOMEM;
 971         }
 972
 973         return 0;
 974 }
 975
 976 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 977 {
 978         struct blk_mq_hw_ctx *hctx;
 979         int i;
 980
 981         queue_for_each_hw_ctx(q, hctx, i)
 982                 blk_mq_debugfs_unregister_hctx(hctx);
 983 }
 984
 985 int blk_mq_debugfs_register_sched(struct request_queue *q)
 986 {
 987         struct elevator_type *e = q->elevator->type;
 988
 989         if (!q->debugfs_dir)
 990                 return -ENOENT;
 991
 992         if (!e->queue_debugfs_attrs)
 993                 return 0;
 994
 995         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 996         if (!q->sched_debugfs_dir)
 997                 return -ENOMEM;
 998
 999         if (!debugfs_create_files(q->sched_debugfs_dir, q,
1000                                   e->queue_debugfs_attrs))
1001                 goto err;
1002
1003         return 0;
1004
1005 err:
1006         blk_mq_debugfs_unregister_sched(q);
1007         return -ENOMEM;
1008 }
1009
1010 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
1011 {
1012         debugfs_remove_recursive(q->sched_debugfs_dir);
1013         q->sched_debugfs_dir = NULL;
1014 }
1015
1016 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
1017 {
1018         debugfs_remove_recursive(rqos->debugfs_dir);
1019         rqos->debugfs_dir = NULL;
1020 }
1021
1022 int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
1023 {
1024         struct request_queue *q = rqos->q;
1025         const char *dir_name = rq_qos_id_to_name(rqos->id);
1026
1027         if (!q->debugfs_dir)
1028                 return -ENOENT;
1029
1030         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
1031                 return 0;
1032
1033         if (!q->rqos_debugfs_dir) {
1034                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
1035                                                          q->debugfs_dir);
1036                 if (!q->rqos_debugfs_dir)
1037                         return -ENOMEM;
1038         }
1039
1040         rqos->debugfs_dir = debugfs_create_dir(dir_name,
1041                                                rqos->q->rqos_debugfs_dir);
1042         if (!rqos->debugfs_dir)
1043                 return -ENOMEM;
1044
1045         if (!debugfs_create_files(rqos->debugfs_dir, rqos,
1046                                   rqos->ops->debugfs_attrs))
1047                 goto err;
1048         return 0;
1049  err:
1050         blk_mq_debugfs_unregister_rqos(rqos);
1051         return -ENOMEM;
1052 }
1053
1054 void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
1055 {
1056         debugfs_remove_recursive(q->rqos_debugfs_dir);
1057         q->rqos_debugfs_dir = NULL;
1058 }
1059
1060 int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
1061                                        struct blk_mq_hw_ctx *hctx)
1062 {
1063         struct elevator_type *e = q->elevator->type;
1064
1065         if (!hctx->debugfs_dir)
1066                 return -ENOENT;
1067
1068         if (!e->hctx_debugfs_attrs)
1069                 return 0;
1070
1071         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
1072                                                      hctx->debugfs_dir);
1073         if (!hctx->sched_debugfs_dir)
1074                 return -ENOMEM;
1075
1076         if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
1077                                   e->hctx_debugfs_attrs))
1078                 return -ENOMEM;
1079
1080         return 0;
1081 }
1082
1083 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
1084 {
1085         debugfs_remove_recursive(hctx->sched_debugfs_dir);
1086         hctx->sched_debugfs_dir = NULL;
1087 }