block/blk-mq-debugfs.c

   1 /*
   2  * Copyright (C) 2017 Facebook
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/debugfs.h>
  20
  21 #include <linux/blk-mq.h>
  22 #include "blk.h"
  23 #include "blk-mq.h"
  24 #include "blk-mq-debugfs.h"
  25 #include "blk-mq-tag.h"
  26
  27 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  28 {
  29         if (stat->nr_samples) {
  30                 seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
  31                            stat->nr_samples, stat->mean, stat->min, stat->max);
  32         } else {
  33                 seq_puts(m, "samples=0");
  34         }
  35 }
  36
  37 static int queue_poll_stat_show(void *data, struct seq_file *m)
  38 {
  39         struct request_queue *q = data;
  40         int bucket;
  41
  42         for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
  43                 seq_printf(m, "read  (%d Bytes): ", 1 << (9+bucket));
  44                 print_stat(m, &q->poll_stat[2*bucket]);
  45                 seq_puts(m, "\n");
  46
  47                 seq_printf(m, "write (%d Bytes): ",  1 << (9+bucket));
  48                 print_stat(m, &q->poll_stat[2*bucket+1]);
  49                 seq_puts(m, "\n");
  50         }
  51         return 0;
  52 }
  53
  54 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  55         __acquires(&q->requeue_lock)
  56 {
  57         struct request_queue *q = m->private;
  58
  59         spin_lock_irq(&q->requeue_lock);
  60         return seq_list_start(&q->requeue_list, *pos);
  61 }
  62
  63 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  64 {
  65         struct request_queue *q = m->private;
  66
  67         return seq_list_next(v, &q->requeue_list, pos);
  68 }
  69
  70 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  71         __releases(&q->requeue_lock)
  72 {
  73         struct request_queue *q = m->private;
  74
  75         spin_unlock_irq(&q->requeue_lock);
  76 }
  77
  78 static const struct seq_operations queue_requeue_list_seq_ops = {
  79         .start  = queue_requeue_list_start,
  80         .next   = queue_requeue_list_next,
  81         .stop   = queue_requeue_list_stop,
  82         .show   = blk_mq_debugfs_rq_show,
  83 };
  84
  85 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  86                           const char *const *flag_name, int flag_name_count)
  87 {
  88         bool sep = false;
  89         int i;
  90
  91         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  92                 if (!(flags & BIT(i)))
  93                         continue;
  94                 if (sep)
  95                         seq_puts(m, "|");
  96                 sep = true;
  97                 if (i < flag_name_count && flag_name[i])
  98                         seq_puts(m, flag_name[i]);
  99                 else
 100                         seq_printf(m, "%d", i);
 101         }
 102         return 0;
 103 }
 104
 105 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 106 static const char *const blk_queue_flag_name[] = {
 107         QUEUE_FLAG_NAME(QUEUED),
 108         QUEUE_FLAG_NAME(STOPPED),
 109         QUEUE_FLAG_NAME(DYING),
 110         QUEUE_FLAG_NAME(BYPASS),
 111         QUEUE_FLAG_NAME(BIDI),
 112         QUEUE_FLAG_NAME(NOMERGES),
 113         QUEUE_FLAG_NAME(SAME_COMP),
 114         QUEUE_FLAG_NAME(FAIL_IO),
 115         QUEUE_FLAG_NAME(NONROT),
 116         QUEUE_FLAG_NAME(IO_STAT),
 117         QUEUE_FLAG_NAME(DISCARD),
 118         QUEUE_FLAG_NAME(NOXMERGES),
 119         QUEUE_FLAG_NAME(ADD_RANDOM),
 120         QUEUE_FLAG_NAME(SECERASE),
 121         QUEUE_FLAG_NAME(SAME_FORCE),
 122         QUEUE_FLAG_NAME(DEAD),
 123         QUEUE_FLAG_NAME(INIT_DONE),
 124         QUEUE_FLAG_NAME(NO_SG_MERGE),
 125         QUEUE_FLAG_NAME(POLL),
 126         QUEUE_FLAG_NAME(WC),
 127         QUEUE_FLAG_NAME(FUA),
 128         QUEUE_FLAG_NAME(FLUSH_NQ),
 129         QUEUE_FLAG_NAME(DAX),
 130         QUEUE_FLAG_NAME(STATS),
 131         QUEUE_FLAG_NAME(POLL_STATS),
 132         QUEUE_FLAG_NAME(REGISTERED),
 133         QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
 134         QUEUE_FLAG_NAME(QUIESCED),
 135         QUEUE_FLAG_NAME(PREEMPT_ONLY),
 136 };
 137 #undef QUEUE_FLAG_NAME
 138
 139 static int queue_state_show(void *data, struct seq_file *m)
 140 {
 141         struct request_queue *q = data;
 142
 143         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 144                        ARRAY_SIZE(blk_queue_flag_name));
 145         seq_puts(m, "\n");
 146         return 0;
 147 }
 148
 149 static ssize_t queue_state_write(void *data, const char __user *buf,
 150                                  size_t count, loff_t *ppos)
 151 {
 152         struct request_queue *q = data;
 153         char opbuf[16] = { }, *op;
 154
 155         /*
 156          * The "state" attribute is removed after blk_cleanup_queue() has called
 157          * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
 158          * triggering a use-after-free.
 159          */
 160         if (blk_queue_dead(q))
 161                 return -ENOENT;
 162
 163         if (count >= sizeof(opbuf)) {
 164                 pr_err("%s: operation too long\n", __func__);
 165                 goto inval;
 166         }
 167
 168         if (copy_from_user(opbuf, buf, count))
 169                 return -EFAULT;
 170         op = strstrip(opbuf);
 171         if (strcmp(op, "run") == 0) {
 172                 blk_mq_run_hw_queues(q, true);
 173         } else if (strcmp(op, "start") == 0) {
 174                 blk_mq_start_stopped_hw_queues(q, true);
 175         } else if (strcmp(op, "kick") == 0) {
 176                 blk_mq_kick_requeue_list(q);
 177         } else {
 178                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 179 inval:
 180                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 181                 return -EINVAL;
 182         }
 183         return count;
 184 }
 185
 186 static int queue_write_hint_show(void *data, struct seq_file *m)
 187 {
 188         struct request_queue *q = data;
 189         int i;
 190
 191         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 192                 seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
 193
 194         return 0;
 195 }
 196
 197 static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 198                                       size_t count, loff_t *ppos)
 199 {
 200         struct request_queue *q = data;
 201         int i;
 202
 203         for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
 204                 q->write_hints[i] = 0;
 205
 206         return count;
 207 }
 208
 209 static int queue_zone_wlock_show(void *data, struct seq_file *m)
 210 {
 211         struct request_queue *q = data;
 212         unsigned int i;
 213
 214         if (!q->seq_zones_wlock)
 215                 return 0;
 216
 217         for (i = 0; i < blk_queue_nr_zones(q); i++)
 218                 if (test_bit(i, q->seq_zones_wlock))
 219                         seq_printf(m, "%u\n", i);
 220
 221         return 0;
 222 }
 223
 224 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 225         { "poll_stat", 0400, queue_poll_stat_show },
 226         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 227         { "state", 0600, queue_state_show, queue_state_write },
 228         { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
 229         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 230         { },
 231 };
 232
 233 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 234 static const char *const hctx_state_name[] = {
 235         HCTX_STATE_NAME(STOPPED),
 236         HCTX_STATE_NAME(TAG_ACTIVE),
 237         HCTX_STATE_NAME(SCHED_RESTART),
 238 };
 239 #undef HCTX_STATE_NAME
 240
 241 static int hctx_state_show(void *data, struct seq_file *m)
 242 {
 243         struct blk_mq_hw_ctx *hctx = data;
 244
 245         blk_flags_show(m, hctx->state, hctx_state_name,
 246                        ARRAY_SIZE(hctx_state_name));
 247         seq_puts(m, "\n");
 248         return 0;
 249 }
 250
 251 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 252 static const char *const alloc_policy_name[] = {
 253         BLK_TAG_ALLOC_NAME(FIFO),
 254         BLK_TAG_ALLOC_NAME(RR),
 255 };
 256 #undef BLK_TAG_ALLOC_NAME
 257
 258 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 259 static const char *const hctx_flag_name[] = {
 260         HCTX_FLAG_NAME(SHOULD_MERGE),
 261         HCTX_FLAG_NAME(TAG_SHARED),
 262         HCTX_FLAG_NAME(SG_MERGE),
 263         HCTX_FLAG_NAME(BLOCKING),
 264         HCTX_FLAG_NAME(NO_SCHED),
 265 };
 266 #undef HCTX_FLAG_NAME
 267
 268 static int hctx_flags_show(void *data, struct seq_file *m)
 269 {
 270         struct blk_mq_hw_ctx *hctx = data;
 271         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 272
 273         seq_puts(m, "alloc_policy=");
 274         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 275             alloc_policy_name[alloc_policy])
 276                 seq_puts(m, alloc_policy_name[alloc_policy]);
 277         else
 278                 seq_printf(m, "%d", alloc_policy);
 279         seq_puts(m, " ");
 280         blk_flags_show(m,
 281                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 282                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 283         seq_puts(m, "\n");
 284         return 0;
 285 }
 286
 287 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 288 static const char *const op_name[] = {
 289         REQ_OP_NAME(READ),
 290         REQ_OP_NAME(WRITE),
 291         REQ_OP_NAME(FLUSH),
 292         REQ_OP_NAME(DISCARD),
 293         REQ_OP_NAME(ZONE_REPORT),
 294         REQ_OP_NAME(SECURE_ERASE),
 295         REQ_OP_NAME(ZONE_RESET),
 296         REQ_OP_NAME(WRITE_SAME),
 297         REQ_OP_NAME(WRITE_ZEROES),
 298         REQ_OP_NAME(SCSI_IN),
 299         REQ_OP_NAME(SCSI_OUT),
 300         REQ_OP_NAME(DRV_IN),
 301         REQ_OP_NAME(DRV_OUT),
 302 };
 303 #undef REQ_OP_NAME
 304
 305 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 306 static const char *const cmd_flag_name[] = {
 307         CMD_FLAG_NAME(FAILFAST_DEV),
 308         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 309         CMD_FLAG_NAME(FAILFAST_DRIVER),
 310         CMD_FLAG_NAME(SYNC),
 311         CMD_FLAG_NAME(META),
 312         CMD_FLAG_NAME(PRIO),
 313         CMD_FLAG_NAME(NOMERGE),
 314         CMD_FLAG_NAME(IDLE),
 315         CMD_FLAG_NAME(INTEGRITY),
 316         CMD_FLAG_NAME(FUA),
 317         CMD_FLAG_NAME(PREFLUSH),
 318         CMD_FLAG_NAME(RAHEAD),
 319         CMD_FLAG_NAME(BACKGROUND),
 320         CMD_FLAG_NAME(NOUNMAP),
 321         CMD_FLAG_NAME(NOWAIT),
 322 };
 323 #undef CMD_FLAG_NAME
 324
 325 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 326 static const char *const rqf_name[] = {
 327         RQF_NAME(SORTED),
 328         RQF_NAME(STARTED),
 329         RQF_NAME(QUEUED),
 330         RQF_NAME(SOFTBARRIER),
 331         RQF_NAME(FLUSH_SEQ),
 332         RQF_NAME(MIXED_MERGE),
 333         RQF_NAME(MQ_INFLIGHT),
 334         RQF_NAME(DONTPREP),
 335         RQF_NAME(PREEMPT),
 336         RQF_NAME(COPY_USER),
 337         RQF_NAME(FAILED),
 338         RQF_NAME(QUIET),
 339         RQF_NAME(ELVPRIV),
 340         RQF_NAME(IO_STAT),
 341         RQF_NAME(ALLOCED),
 342         RQF_NAME(PM),
 343         RQF_NAME(HASHED),
 344         RQF_NAME(STATS),
 345         RQF_NAME(SPECIAL_PAYLOAD),
 346         RQF_NAME(ZONE_WRITE_LOCKED),
 347         RQF_NAME(MQ_TIMEOUT_EXPIRED),
 348         RQF_NAME(MQ_POLL_SLEPT),
 349 };
 350 #undef RQF_NAME
 351
 352 static const char *const blk_mq_rq_state_name_array[] = {
 353         [MQ_RQ_IDLE]            = "idle",
 354         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 355         [MQ_RQ_COMPLETE]        = "complete",
 356 };
 357
 358 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 359 {
 360         if (WARN_ON_ONCE((unsigned int)rq_state >
 361                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 362                 return "(?)";
 363         return blk_mq_rq_state_name_array[rq_state];
 364 }
 365
 366 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 367 {
 368         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 369         const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 370
 371         seq_printf(m, "%p {.op=", rq);
 372         if (op < ARRAY_SIZE(op_name) && op_name[op])
 373                 seq_printf(m, "%s", op_name[op]);
 374         else
 375                 seq_printf(m, "%d", op);
 376         seq_puts(m, ", .cmd_flags=");
 377         blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
 378                        ARRAY_SIZE(cmd_flag_name));
 379         seq_puts(m, ", .rq_flags=");
 380         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 381                        ARRAY_SIZE(rqf_name));
 382         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 383         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 384                    rq->internal_tag);
 385         if (mq_ops->show_rq)
 386                 mq_ops->show_rq(m, rq);
 387         seq_puts(m, "}\n");
 388         return 0;
 389 }
 390 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 391
 392 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 393 {
 394         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 395 }
 396 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 397
 398 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 399         __acquires(&hctx->lock)
 400 {
 401         struct blk_mq_hw_ctx *hctx = m->private;
 402
 403         spin_lock(&hctx->lock);
 404         return seq_list_start(&hctx->dispatch, *pos);
 405 }
 406
 407 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 408 {
 409         struct blk_mq_hw_ctx *hctx = m->private;
 410
 411         return seq_list_next(v, &hctx->dispatch, pos);
 412 }
 413
 414 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 415         __releases(&hctx->lock)
 416 {
 417         struct blk_mq_hw_ctx *hctx = m->private;
 418
 419         spin_unlock(&hctx->lock);
 420 }
 421
 422 static const struct seq_operations hctx_dispatch_seq_ops = {
 423         .start  = hctx_dispatch_start,
 424         .next   = hctx_dispatch_next,
 425         .stop   = hctx_dispatch_stop,
 426         .show   = blk_mq_debugfs_rq_show,
 427 };
 428
 429 struct show_busy_params {
 430         struct seq_file         *m;
 431         struct blk_mq_hw_ctx    *hctx;
 432 };
 433
 434 /*
 435  * Note: the state of a request may change while this function is in progress,
 436  * e.g. due to a concurrent blk_mq_finish_request() call.
 437  */
 438 static void hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
 439 {
 440         const struct show_busy_params *params = data;
 441
 442         if (blk_mq_map_queue(rq->q, rq->mq_ctx->cpu) == params->hctx &&
 443             blk_mq_rq_state(rq) != MQ_RQ_IDLE)
 444                 __blk_mq_debugfs_rq_show(params->m,
 445                                          list_entry_rq(&rq->queuelist));
 446 }
 447
 448 static int hctx_busy_show(void *data, struct seq_file *m)
 449 {
 450         struct blk_mq_hw_ctx *hctx = data;
 451         struct show_busy_params params = { .m = m, .hctx = hctx };
 452
 453         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 454                                 &params);
 455
 456         return 0;
 457 }
 458
 459 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 460 {
 461         struct blk_mq_hw_ctx *hctx = data;
 462
 463         sbitmap_bitmap_show(&hctx->ctx_map, m);
 464         return 0;
 465 }
 466
 467 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 468                                      struct blk_mq_tags *tags)
 469 {
 470         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 471         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 472         seq_printf(m, "active_queues=%d\n",
 473                    atomic_read(&tags->active_queues));
 474
 475         seq_puts(m, "\nbitmap_tags:\n");
 476         sbitmap_queue_show(&tags->bitmap_tags, m);
 477
 478         if (tags->nr_reserved_tags) {
 479                 seq_puts(m, "\nbreserved_tags:\n");
 480                 sbitmap_queue_show(&tags->breserved_tags, m);
 481         }
 482 }
 483
 484 static int hctx_tags_show(void *data, struct seq_file *m)
 485 {
 486         struct blk_mq_hw_ctx *hctx = data;
 487         struct request_queue *q = hctx->queue;
 488         int res;
 489
 490         res = mutex_lock_interruptible(&q->sysfs_lock);
 491         if (res)
 492                 goto out;
 493         if (hctx->tags)
 494                 blk_mq_debugfs_tags_show(m, hctx->tags);
 495         mutex_unlock(&q->sysfs_lock);
 496
 497 out:
 498         return res;
 499 }
 500
 501 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 502 {
 503         struct blk_mq_hw_ctx *hctx = data;
 504         struct request_queue *q = hctx->queue;
 505         int res;
 506
 507         res = mutex_lock_interruptible(&q->sysfs_lock);
 508         if (res)
 509                 goto out;
 510         if (hctx->tags)
 511                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 512         mutex_unlock(&q->sysfs_lock);
 513
 514 out:
 515         return res;
 516 }
 517
 518 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 519 {
 520         struct blk_mq_hw_ctx *hctx = data;
 521         struct request_queue *q = hctx->queue;
 522         int res;
 523
 524         res = mutex_lock_interruptible(&q->sysfs_lock);
 525         if (res)
 526                 goto out;
 527         if (hctx->sched_tags)
 528                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 529         mutex_unlock(&q->sysfs_lock);
 530
 531 out:
 532         return res;
 533 }
 534
 535 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 536 {
 537         struct blk_mq_hw_ctx *hctx = data;
 538         struct request_queue *q = hctx->queue;
 539         int res;
 540
 541         res = mutex_lock_interruptible(&q->sysfs_lock);
 542         if (res)
 543                 goto out;
 544         if (hctx->sched_tags)
 545                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 546         mutex_unlock(&q->sysfs_lock);
 547
 548 out:
 549         return res;
 550 }
 551
 552 static int hctx_io_poll_show(void *data, struct seq_file *m)
 553 {
 554         struct blk_mq_hw_ctx *hctx = data;
 555
 556         seq_printf(m, "considered=%lu\n", hctx->poll_considered);
 557         seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
 558         seq_printf(m, "success=%lu\n", hctx->poll_success);
 559         return 0;
 560 }
 561
 562 static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
 563                                   size_t count, loff_t *ppos)
 564 {
 565         struct blk_mq_hw_ctx *hctx = data;
 566
 567         hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
 568         return count;
 569 }
 570
 571 static int hctx_dispatched_show(void *data, struct seq_file *m)
 572 {
 573         struct blk_mq_hw_ctx *hctx = data;
 574         int i;
 575
 576         seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
 577
 578         for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
 579                 unsigned int d = 1U << (i - 1);
 580
 581                 seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
 582         }
 583
 584         seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
 585         return 0;
 586 }
 587
 588 static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
 589                                      size_t count, loff_t *ppos)
 590 {
 591         struct blk_mq_hw_ctx *hctx = data;
 592         int i;
 593
 594         for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
 595                 hctx->dispatched[i] = 0;
 596         return count;
 597 }
 598
 599 static int hctx_queued_show(void *data, struct seq_file *m)
 600 {
 601         struct blk_mq_hw_ctx *hctx = data;
 602
 603         seq_printf(m, "%lu\n", hctx->queued);
 604         return 0;
 605 }
 606
 607 static ssize_t hctx_queued_write(void *data, const char __user *buf,
 608                                  size_t count, loff_t *ppos)
 609 {
 610         struct blk_mq_hw_ctx *hctx = data;
 611
 612         hctx->queued = 0;
 613         return count;
 614 }
 615
 616 static int hctx_run_show(void *data, struct seq_file *m)
 617 {
 618         struct blk_mq_hw_ctx *hctx = data;
 619
 620         seq_printf(m, "%lu\n", hctx->run);
 621         return 0;
 622 }
 623
 624 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 625                               loff_t *ppos)
 626 {
 627         struct blk_mq_hw_ctx *hctx = data;
 628
 629         hctx->run = 0;
 630         return count;
 631 }
 632
 633 static int hctx_active_show(void *data, struct seq_file *m)
 634 {
 635         struct blk_mq_hw_ctx *hctx = data;
 636
 637         seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
 638         return 0;
 639 }
 640
 641 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 642         __acquires(&ctx->lock)
 643 {
 644         struct blk_mq_ctx *ctx = m->private;
 645
 646         spin_lock(&ctx->lock);
 647         return seq_list_start(&ctx->rq_list, *pos);
 648 }
 649
 650 static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
 651 {
 652         struct blk_mq_ctx *ctx = m->private;
 653
 654         return seq_list_next(v, &ctx->rq_list, pos);
 655 }
 656
 657 static void ctx_rq_list_stop(struct seq_file *m, void *v)
 658         __releases(&ctx->lock)
 659 {
 660         struct blk_mq_ctx *ctx = m->private;
 661
 662         spin_unlock(&ctx->lock);
 663 }
 664
 665 static const struct seq_operations ctx_rq_list_seq_ops = {
 666         .start  = ctx_rq_list_start,
 667         .next   = ctx_rq_list_next,
 668         .stop   = ctx_rq_list_stop,
 669         .show   = blk_mq_debugfs_rq_show,
 670 };
 671 static int ctx_dispatched_show(void *data, struct seq_file *m)
 672 {
 673         struct blk_mq_ctx *ctx = data;
 674
 675         seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
 676         return 0;
 677 }
 678
 679 static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
 680                                     size_t count, loff_t *ppos)
 681 {
 682         struct blk_mq_ctx *ctx = data;
 683
 684         ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
 685         return count;
 686 }
 687
 688 static int ctx_merged_show(void *data, struct seq_file *m)
 689 {
 690         struct blk_mq_ctx *ctx = data;
 691
 692         seq_printf(m, "%lu\n", ctx->rq_merged);
 693         return 0;
 694 }
 695
 696 static ssize_t ctx_merged_write(void *data, const char __user *buf,
 697                                 size_t count, loff_t *ppos)
 698 {
 699         struct blk_mq_ctx *ctx = data;
 700
 701         ctx->rq_merged = 0;
 702         return count;
 703 }
 704
 705 static int ctx_completed_show(void *data, struct seq_file *m)
 706 {
 707         struct blk_mq_ctx *ctx = data;
 708
 709         seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
 710         return 0;
 711 }
 712
 713 static ssize_t ctx_completed_write(void *data, const char __user *buf,
 714                                    size_t count, loff_t *ppos)
 715 {
 716         struct blk_mq_ctx *ctx = data;
 717
 718         ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
 719         return count;
 720 }
 721
 722 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 723 {
 724         const struct blk_mq_debugfs_attr *attr = m->private;
 725         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 726
 727         return attr->show(data, m);
 728 }
 729
 730 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 731                                     size_t count, loff_t *ppos)
 732 {
 733         struct seq_file *m = file->private_data;
 734         const struct blk_mq_debugfs_attr *attr = m->private;
 735         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 736
 737         /*
 738          * Attributes that only implement .seq_ops are read-only and 'attr' is
 739          * the same with 'data' in this case.
 740          */
 741         if (attr == data || !attr->write)
 742                 return -EPERM;
 743
 744         return attr->write(data, buf, count, ppos);
 745 }
 746
 747 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 748 {
 749         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 750         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 751         struct seq_file *m;
 752         int ret;
 753
 754         if (attr->seq_ops) {
 755                 ret = seq_open(file, attr->seq_ops);
 756                 if (!ret) {
 757                         m = file->private_data;
 758                         m->private = data;
 759                 }
 760                 return ret;
 761         }
 762
 763         if (WARN_ON_ONCE(!attr->show))
 764                 return -EPERM;
 765
 766         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 767 }
 768
 769 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 770 {
 771         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 772
 773         if (attr->show)
 774                 return single_release(inode, file);
 775         else
 776                 return seq_release(inode, file);
 777 }
 778
 779 static const struct file_operations blk_mq_debugfs_fops = {
 780         .open           = blk_mq_debugfs_open,
 781         .read           = seq_read,
 782         .write          = blk_mq_debugfs_write,
 783         .llseek         = seq_lseek,
 784         .release        = blk_mq_debugfs_release,
 785 };
 786
 787 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 788         {"state", 0400, hctx_state_show},
 789         {"flags", 0400, hctx_flags_show},
 790         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 791         {"busy", 0400, hctx_busy_show},
 792         {"ctx_map", 0400, hctx_ctx_map_show},
 793         {"tags", 0400, hctx_tags_show},
 794         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 795         {"sched_tags", 0400, hctx_sched_tags_show},
 796         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 797         {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
 798         {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
 799         {"queued", 0600, hctx_queued_show, hctx_queued_write},
 800         {"run", 0600, hctx_run_show, hctx_run_write},
 801         {"active", 0400, hctx_active_show},
 802         {},
 803 };
 804
 805 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 806         {"rq_list", 0400, .seq_ops = &ctx_rq_list_seq_ops},
 807         {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
 808         {"merged", 0600, ctx_merged_show, ctx_merged_write},
 809         {"completed", 0600, ctx_completed_show, ctx_completed_write},
 810         {},
 811 };
 812
 813 static bool debugfs_create_files(struct dentry *parent, void *data,
 814                                  const struct blk_mq_debugfs_attr *attr)
 815 {
 816         d_inode(parent)->i_private = data;
 817
 818         for (; attr->name; attr++) {
 819                 if (!debugfs_create_file(attr->name, attr->mode, parent,
 820                                          (void *)attr, &blk_mq_debugfs_fops))
 821                         return false;
 822         }
 823         return true;
 824 }
 825
 826 int blk_mq_debugfs_register(struct request_queue *q)
 827 {
 828         struct blk_mq_hw_ctx *hctx;
 829         int i;
 830
 831         if (!blk_debugfs_root)
 832                 return -ENOENT;
 833
 834         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 835                                             blk_debugfs_root);
 836         if (!q->debugfs_dir)
 837                 return -ENOMEM;
 838
 839         if (!debugfs_create_files(q->debugfs_dir, q,
 840                                   blk_mq_debugfs_queue_attrs))
 841                 goto err;
 842
 843         /*
 844          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 845          * didn't exist yet (because we don't know what to name the directory
 846          * until the queue is registered to a gendisk).
 847          */
 848         if (q->elevator && !q->sched_debugfs_dir)
 849                 blk_mq_debugfs_register_sched(q);
 850
 851         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 852         queue_for_each_hw_ctx(q, hctx, i) {
 853                 if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
 854                         goto err;
 855                 if (q->elevator && !hctx->sched_debugfs_dir &&
 856                     blk_mq_debugfs_register_sched_hctx(q, hctx))
 857                         goto err;
 858         }
 859
 860         return 0;
 861
 862 err:
 863         blk_mq_debugfs_unregister(q);
 864         return -ENOMEM;
 865 }
 866
 867 void blk_mq_debugfs_unregister(struct request_queue *q)
 868 {
 869         debugfs_remove_recursive(q->debugfs_dir);
 870         q->sched_debugfs_dir = NULL;
 871         q->debugfs_dir = NULL;
 872 }
 873
 874 static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 875                                        struct blk_mq_ctx *ctx)
 876 {
 877         struct dentry *ctx_dir;
 878         char name[20];
 879
 880         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 881         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 882         if (!ctx_dir)
 883                 return -ENOMEM;
 884
 885         if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
 886                 return -ENOMEM;
 887
 888         return 0;
 889 }
 890
 891 int blk_mq_debugfs_register_hctx(struct request_queue *q,
 892                                  struct blk_mq_hw_ctx *hctx)
 893 {
 894         struct blk_mq_ctx *ctx;
 895         char name[20];
 896         int i;
 897
 898         if (!q->debugfs_dir)
 899                 return -ENOENT;
 900
 901         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 902         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 903         if (!hctx->debugfs_dir)
 904                 return -ENOMEM;
 905
 906         if (!debugfs_create_files(hctx->debugfs_dir, hctx,
 907                                   blk_mq_debugfs_hctx_attrs))
 908                 goto err;
 909
 910         hctx_for_each_ctx(hctx, ctx, i) {
 911                 if (blk_mq_debugfs_register_ctx(hctx, ctx))
 912                         goto err;
 913         }
 914
 915         return 0;
 916
 917 err:
 918         blk_mq_debugfs_unregister_hctx(hctx);
 919         return -ENOMEM;
 920 }
 921
 922 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 923 {
 924         debugfs_remove_recursive(hctx->debugfs_dir);
 925         hctx->sched_debugfs_dir = NULL;
 926         hctx->debugfs_dir = NULL;
 927 }
 928
 929 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 930 {
 931         struct blk_mq_hw_ctx *hctx;
 932         int i;
 933
 934         queue_for_each_hw_ctx(q, hctx, i) {
 935                 if (blk_mq_debugfs_register_hctx(q, hctx))
 936                         return -ENOMEM;
 937         }
 938
 939         return 0;
 940 }
 941
 942 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 943 {
 944         struct blk_mq_hw_ctx *hctx;
 945         int i;
 946
 947         queue_for_each_hw_ctx(q, hctx, i)
 948                 blk_mq_debugfs_unregister_hctx(hctx);
 949 }
 950
 951 int blk_mq_debugfs_register_sched(struct request_queue *q)
 952 {
 953         struct elevator_type *e = q->elevator->type;
 954
 955         if (!q->debugfs_dir)
 956                 return -ENOENT;
 957
 958         if (!e->queue_debugfs_attrs)
 959                 return 0;
 960
 961         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 962         if (!q->sched_debugfs_dir)
 963                 return -ENOMEM;
 964
 965         if (!debugfs_create_files(q->sched_debugfs_dir, q,
 966                                   e->queue_debugfs_attrs))
 967                 goto err;
 968
 969         return 0;
 970
 971 err:
 972         blk_mq_debugfs_unregister_sched(q);
 973         return -ENOMEM;
 974 }
 975
 976 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 977 {
 978         debugfs_remove_recursive(q->sched_debugfs_dir);
 979         q->sched_debugfs_dir = NULL;
 980 }
 981
 982 int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 983                                        struct blk_mq_hw_ctx *hctx)
 984 {
 985         struct elevator_type *e = q->elevator->type;
 986
 987         if (!hctx->debugfs_dir)
 988                 return -ENOENT;
 989
 990         if (!e->hctx_debugfs_attrs)
 991                 return 0;
 992
 993         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 994                                                      hctx->debugfs_dir);
 995         if (!hctx->sched_debugfs_dir)
 996                 return -ENOMEM;
 997
 998         if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 999                                   e->hctx_debugfs_attrs))
1000                 return -ENOMEM;
1001
1002         return 0;
1003 }
1004
1005 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
1006 {
1007         debugfs_remove_recursive(hctx->sched_debugfs_dir);
1008         hctx->sched_debugfs_dir = NULL;
1009 }