block/blk-mq-debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2017 Facebook
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/blkdev.h>
   8 #include <linux/debugfs.h>
   9
  10 #include "blk.h"
  11 #include "blk-mq.h"
  12 #include "blk-mq-debugfs.h"
  13 #include "blk-mq-sched.h"
  14 #include "blk-rq-qos.h"
  15
  16 static int queue_poll_stat_show(void *data, struct seq_file *m)
  17 {
  18         return 0;
  19 }
  20
  21 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  22         __acquires(&q->requeue_lock)
  23 {
  24         struct request_queue *q = m->private;
  25
  26         spin_lock_irq(&q->requeue_lock);
  27         return seq_list_start(&q->requeue_list, *pos);
  28 }
  29
  30 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  31 {
  32         struct request_queue *q = m->private;
  33
  34         return seq_list_next(v, &q->requeue_list, pos);
  35 }
  36
  37 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  38         __releases(&q->requeue_lock)
  39 {
  40         struct request_queue *q = m->private;
  41
  42         spin_unlock_irq(&q->requeue_lock);
  43 }
  44
  45 static const struct seq_operations queue_requeue_list_seq_ops = {
  46         .start  = queue_requeue_list_start,
  47         .next   = queue_requeue_list_next,
  48         .stop   = queue_requeue_list_stop,
  49         .show   = blk_mq_debugfs_rq_show,
  50 };
  51
  52 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  53                           const char *const *flag_name, int flag_name_count)
  54 {
  55         bool sep = false;
  56         int i;
  57
  58         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  59                 if (!(flags & BIT(i)))
  60                         continue;
  61                 if (sep)
  62                         seq_puts(m, "|");
  63                 sep = true;
  64                 if (i < flag_name_count && flag_name[i])
  65                         seq_puts(m, flag_name[i]);
  66                 else
  67                         seq_printf(m, "%d", i);
  68         }
  69         return 0;
  70 }
  71
  72 static int queue_pm_only_show(void *data, struct seq_file *m)
  73 {
  74         struct request_queue *q = data;
  75
  76         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
  77         return 0;
  78 }
  79
  80 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
  81 static const char *const blk_queue_flag_name[] = {
  82         QUEUE_FLAG_NAME(STOPPED),
  83         QUEUE_FLAG_NAME(DYING),
  84         QUEUE_FLAG_NAME(NOMERGES),
  85         QUEUE_FLAG_NAME(SAME_COMP),
  86         QUEUE_FLAG_NAME(FAIL_IO),
  87         QUEUE_FLAG_NAME(NONROT),
  88         QUEUE_FLAG_NAME(IO_STAT),
  89         QUEUE_FLAG_NAME(NOXMERGES),
  90         QUEUE_FLAG_NAME(ADD_RANDOM),
  91         QUEUE_FLAG_NAME(SYNCHRONOUS),
  92         QUEUE_FLAG_NAME(SAME_FORCE),
  93         QUEUE_FLAG_NAME(INIT_DONE),
  94         QUEUE_FLAG_NAME(STABLE_WRITES),
  95         QUEUE_FLAG_NAME(POLL),
  96         QUEUE_FLAG_NAME(WC),
  97         QUEUE_FLAG_NAME(FUA),
  98         QUEUE_FLAG_NAME(DAX),
  99         QUEUE_FLAG_NAME(STATS),
 100         QUEUE_FLAG_NAME(REGISTERED),
 101         QUEUE_FLAG_NAME(QUIESCED),
 102         QUEUE_FLAG_NAME(PCI_P2PDMA),
 103         QUEUE_FLAG_NAME(ZONE_RESETALL),
 104         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 105         QUEUE_FLAG_NAME(HCTX_ACTIVE),
 106         QUEUE_FLAG_NAME(NOWAIT),
 107         QUEUE_FLAG_NAME(SQ_SCHED),
 108         QUEUE_FLAG_NAME(SKIP_TAGSET_QUIESCE),
 109 };
 110 #undef QUEUE_FLAG_NAME
 111
 112 static int queue_state_show(void *data, struct seq_file *m)
 113 {
 114         struct request_queue *q = data;
 115
 116         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 117                        ARRAY_SIZE(blk_queue_flag_name));
 118         seq_puts(m, "\n");
 119         return 0;
 120 }
 121
 122 static ssize_t queue_state_write(void *data, const char __user *buf,
 123                                  size_t count, loff_t *ppos)
 124 {
 125         struct request_queue *q = data;
 126         char opbuf[16] = { }, *op;
 127
 128         /*
 129          * The "state" attribute is removed when the queue is removed.  Don't
 130          * allow setting the state on a dying queue to avoid a use-after-free.
 131          */
 132         if (blk_queue_dying(q))
 133                 return -ENOENT;
 134
 135         if (count >= sizeof(opbuf)) {
 136                 pr_err("%s: operation too long\n", __func__);
 137                 goto inval;
 138         }
 139
 140         if (copy_from_user(opbuf, buf, count))
 141                 return -EFAULT;
 142         op = strstrip(opbuf);
 143         if (strcmp(op, "run") == 0) {
 144                 blk_mq_run_hw_queues(q, true);
 145         } else if (strcmp(op, "start") == 0) {
 146                 blk_mq_start_stopped_hw_queues(q, true);
 147         } else if (strcmp(op, "kick") == 0) {
 148                 blk_mq_kick_requeue_list(q);
 149         } else {
 150                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 151 inval:
 152                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 153                 return -EINVAL;
 154         }
 155         return count;
 156 }
 157
 158 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 159         { "poll_stat", 0400, queue_poll_stat_show },
 160         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 161         { "pm_only", 0600, queue_pm_only_show, NULL },
 162         { "state", 0600, queue_state_show, queue_state_write },
 163         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 164         { },
 165 };
 166
 167 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 168 static const char *const hctx_state_name[] = {
 169         HCTX_STATE_NAME(STOPPED),
 170         HCTX_STATE_NAME(TAG_ACTIVE),
 171         HCTX_STATE_NAME(SCHED_RESTART),
 172         HCTX_STATE_NAME(INACTIVE),
 173 };
 174 #undef HCTX_STATE_NAME
 175
 176 static int hctx_state_show(void *data, struct seq_file *m)
 177 {
 178         struct blk_mq_hw_ctx *hctx = data;
 179
 180         blk_flags_show(m, hctx->state, hctx_state_name,
 181                        ARRAY_SIZE(hctx_state_name));
 182         seq_puts(m, "\n");
 183         return 0;
 184 }
 185
 186 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 187 static const char *const alloc_policy_name[] = {
 188         BLK_TAG_ALLOC_NAME(FIFO),
 189         BLK_TAG_ALLOC_NAME(RR),
 190 };
 191 #undef BLK_TAG_ALLOC_NAME
 192
 193 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 194 static const char *const hctx_flag_name[] = {
 195         HCTX_FLAG_NAME(SHOULD_MERGE),
 196         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 197         HCTX_FLAG_NAME(BLOCKING),
 198         HCTX_FLAG_NAME(NO_SCHED),
 199         HCTX_FLAG_NAME(STACKING),
 200         HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 201 };
 202 #undef HCTX_FLAG_NAME
 203
 204 static int hctx_flags_show(void *data, struct seq_file *m)
 205 {
 206         struct blk_mq_hw_ctx *hctx = data;
 207         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 208
 209         seq_puts(m, "alloc_policy=");
 210         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 211             alloc_policy_name[alloc_policy])
 212                 seq_puts(m, alloc_policy_name[alloc_policy]);
 213         else
 214                 seq_printf(m, "%d", alloc_policy);
 215         seq_puts(m, " ");
 216         blk_flags_show(m,
 217                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 218                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 219         seq_puts(m, "\n");
 220         return 0;
 221 }
 222
 223 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 224 static const char *const cmd_flag_name[] = {
 225         CMD_FLAG_NAME(FAILFAST_DEV),
 226         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 227         CMD_FLAG_NAME(FAILFAST_DRIVER),
 228         CMD_FLAG_NAME(SYNC),
 229         CMD_FLAG_NAME(META),
 230         CMD_FLAG_NAME(PRIO),
 231         CMD_FLAG_NAME(NOMERGE),
 232         CMD_FLAG_NAME(IDLE),
 233         CMD_FLAG_NAME(INTEGRITY),
 234         CMD_FLAG_NAME(FUA),
 235         CMD_FLAG_NAME(PREFLUSH),
 236         CMD_FLAG_NAME(RAHEAD),
 237         CMD_FLAG_NAME(BACKGROUND),
 238         CMD_FLAG_NAME(NOWAIT),
 239         CMD_FLAG_NAME(NOUNMAP),
 240         CMD_FLAG_NAME(POLLED),
 241 };
 242 #undef CMD_FLAG_NAME
 243
 244 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 245 static const char *const rqf_name[] = {
 246         RQF_NAME(STARTED),
 247         RQF_NAME(FLUSH_SEQ),
 248         RQF_NAME(MIXED_MERGE),
 249         RQF_NAME(MQ_INFLIGHT),
 250         RQF_NAME(DONTPREP),
 251         RQF_NAME(SCHED_TAGS),
 252         RQF_NAME(USE_SCHED),
 253         RQF_NAME(FAILED),
 254         RQF_NAME(QUIET),
 255         RQF_NAME(IO_STAT),
 256         RQF_NAME(PM),
 257         RQF_NAME(HASHED),
 258         RQF_NAME(STATS),
 259         RQF_NAME(SPECIAL_PAYLOAD),
 260         RQF_NAME(ZONE_WRITE_LOCKED),
 261         RQF_NAME(TIMED_OUT),
 262         RQF_NAME(RESV),
 263 };
 264 #undef RQF_NAME
 265
 266 static const char *const blk_mq_rq_state_name_array[] = {
 267         [MQ_RQ_IDLE]            = "idle",
 268         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 269         [MQ_RQ_COMPLETE]        = "complete",
 270 };
 271
 272 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 273 {
 274         if (WARN_ON_ONCE((unsigned int)rq_state >=
 275                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 276                 return "(?)";
 277         return blk_mq_rq_state_name_array[rq_state];
 278 }
 279
 280 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 281 {
 282         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 283         const enum req_op op = req_op(rq);
 284         const char *op_str = blk_op_str(op);
 285
 286         seq_printf(m, "%p {.op=", rq);
 287         if (strcmp(op_str, "UNKNOWN") == 0)
 288                 seq_printf(m, "%u", op);
 289         else
 290                 seq_printf(m, "%s", op_str);
 291         seq_puts(m, ", .cmd_flags=");
 292         blk_flags_show(m, (__force unsigned int)(rq->cmd_flags & ~REQ_OP_MASK),
 293                        cmd_flag_name, ARRAY_SIZE(cmd_flag_name));
 294         seq_puts(m, ", .rq_flags=");
 295         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 296                        ARRAY_SIZE(rqf_name));
 297         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 298         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 299                    rq->internal_tag);
 300         if (mq_ops->show_rq)
 301                 mq_ops->show_rq(m, rq);
 302         seq_puts(m, "}\n");
 303         return 0;
 304 }
 305 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 306
 307 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 308 {
 309         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 310 }
 311 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 312
 313 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 314         __acquires(&hctx->lock)
 315 {
 316         struct blk_mq_hw_ctx *hctx = m->private;
 317
 318         spin_lock(&hctx->lock);
 319         return seq_list_start(&hctx->dispatch, *pos);
 320 }
 321
 322 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 323 {
 324         struct blk_mq_hw_ctx *hctx = m->private;
 325
 326         return seq_list_next(v, &hctx->dispatch, pos);
 327 }
 328
 329 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 330         __releases(&hctx->lock)
 331 {
 332         struct blk_mq_hw_ctx *hctx = m->private;
 333
 334         spin_unlock(&hctx->lock);
 335 }
 336
 337 static const struct seq_operations hctx_dispatch_seq_ops = {
 338         .start  = hctx_dispatch_start,
 339         .next   = hctx_dispatch_next,
 340         .stop   = hctx_dispatch_stop,
 341         .show   = blk_mq_debugfs_rq_show,
 342 };
 343
 344 struct show_busy_params {
 345         struct seq_file         *m;
 346         struct blk_mq_hw_ctx    *hctx;
 347 };
 348
 349 /*
 350  * Note: the state of a request may change while this function is in progress,
 351  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 352  * keep iterating requests.
 353  */
 354 static bool hctx_show_busy_rq(struct request *rq, void *data)
 355 {
 356         const struct show_busy_params *params = data;
 357
 358         if (rq->mq_hctx == params->hctx)
 359                 __blk_mq_debugfs_rq_show(params->m, rq);
 360
 361         return true;
 362 }
 363
 364 static int hctx_busy_show(void *data, struct seq_file *m)
 365 {
 366         struct blk_mq_hw_ctx *hctx = data;
 367         struct show_busy_params params = { .m = m, .hctx = hctx };
 368
 369         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 370                                 &params);
 371
 372         return 0;
 373 }
 374
 375 static const char *const hctx_types[] = {
 376         [HCTX_TYPE_DEFAULT]     = "default",
 377         [HCTX_TYPE_READ]        = "read",
 378         [HCTX_TYPE_POLL]        = "poll",
 379 };
 380
 381 static int hctx_type_show(void *data, struct seq_file *m)
 382 {
 383         struct blk_mq_hw_ctx *hctx = data;
 384
 385         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 386         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 387         return 0;
 388 }
 389
 390 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 391 {
 392         struct blk_mq_hw_ctx *hctx = data;
 393
 394         sbitmap_bitmap_show(&hctx->ctx_map, m);
 395         return 0;
 396 }
 397
 398 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 399                                      struct blk_mq_tags *tags)
 400 {
 401         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 402         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 403         seq_printf(m, "active_queues=%d\n",
 404                    READ_ONCE(tags->active_queues));
 405
 406         seq_puts(m, "\nbitmap_tags:\n");
 407         sbitmap_queue_show(&tags->bitmap_tags, m);
 408
 409         if (tags->nr_reserved_tags) {
 410                 seq_puts(m, "\nbreserved_tags:\n");
 411                 sbitmap_queue_show(&tags->breserved_tags, m);
 412         }
 413 }
 414
 415 static int hctx_tags_show(void *data, struct seq_file *m)
 416 {
 417         struct blk_mq_hw_ctx *hctx = data;
 418         struct request_queue *q = hctx->queue;
 419         int res;
 420
 421         res = mutex_lock_interruptible(&q->sysfs_lock);
 422         if (res)
 423                 goto out;
 424         if (hctx->tags)
 425                 blk_mq_debugfs_tags_show(m, hctx->tags);
 426         mutex_unlock(&q->sysfs_lock);
 427
 428 out:
 429         return res;
 430 }
 431
 432 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 433 {
 434         struct blk_mq_hw_ctx *hctx = data;
 435         struct request_queue *q = hctx->queue;
 436         int res;
 437
 438         res = mutex_lock_interruptible(&q->sysfs_lock);
 439         if (res)
 440                 goto out;
 441         if (hctx->tags)
 442                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 443         mutex_unlock(&q->sysfs_lock);
 444
 445 out:
 446         return res;
 447 }
 448
 449 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 450 {
 451         struct blk_mq_hw_ctx *hctx = data;
 452         struct request_queue *q = hctx->queue;
 453         int res;
 454
 455         res = mutex_lock_interruptible(&q->sysfs_lock);
 456         if (res)
 457                 goto out;
 458         if (hctx->sched_tags)
 459                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 460         mutex_unlock(&q->sysfs_lock);
 461
 462 out:
 463         return res;
 464 }
 465
 466 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 467 {
 468         struct blk_mq_hw_ctx *hctx = data;
 469         struct request_queue *q = hctx->queue;
 470         int res;
 471
 472         res = mutex_lock_interruptible(&q->sysfs_lock);
 473         if (res)
 474                 goto out;
 475         if (hctx->sched_tags)
 476                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 477         mutex_unlock(&q->sysfs_lock);
 478
 479 out:
 480         return res;
 481 }
 482
 483 static int hctx_run_show(void *data, struct seq_file *m)
 484 {
 485         struct blk_mq_hw_ctx *hctx = data;
 486
 487         seq_printf(m, "%lu\n", hctx->run);
 488         return 0;
 489 }
 490
 491 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 492                               loff_t *ppos)
 493 {
 494         struct blk_mq_hw_ctx *hctx = data;
 495
 496         hctx->run = 0;
 497         return count;
 498 }
 499
 500 static int hctx_active_show(void *data, struct seq_file *m)
 501 {
 502         struct blk_mq_hw_ctx *hctx = data;
 503
 504         seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
 505         return 0;
 506 }
 507
 508 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 509 {
 510         struct blk_mq_hw_ctx *hctx = data;
 511
 512         seq_printf(m, "%u\n", hctx->dispatch_busy);
 513         return 0;
 514 }
 515
 516 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 517 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 518         __acquires(&ctx->lock)                                          \
 519 {                                                                       \
 520         struct blk_mq_ctx *ctx = m->private;                            \
 521                                                                         \
 522         spin_lock(&ctx->lock);                                          \
 523         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 524 }                                                                       \
 525                                                                         \
 526 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 527                                      loff_t *pos)                       \
 528 {                                                                       \
 529         struct blk_mq_ctx *ctx = m->private;                            \
 530                                                                         \
 531         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 532 }                                                                       \
 533                                                                         \
 534 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 535         __releases(&ctx->lock)                                          \
 536 {                                                                       \
 537         struct blk_mq_ctx *ctx = m->private;                            \
 538                                                                         \
 539         spin_unlock(&ctx->lock);                                        \
 540 }                                                                       \
 541                                                                         \
 542 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 543         .start  = ctx_##name##_rq_list_start,                           \
 544         .next   = ctx_##name##_rq_list_next,                            \
 545         .stop   = ctx_##name##_rq_list_stop,                            \
 546         .show   = blk_mq_debugfs_rq_show,                               \
 547 }
 548
 549 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 550 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 551 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 552
 553 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 554 {
 555         const struct blk_mq_debugfs_attr *attr = m->private;
 556         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 557
 558         return attr->show(data, m);
 559 }
 560
 561 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 562                                     size_t count, loff_t *ppos)
 563 {
 564         struct seq_file *m = file->private_data;
 565         const struct blk_mq_debugfs_attr *attr = m->private;
 566         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 567
 568         /*
 569          * Attributes that only implement .seq_ops are read-only and 'attr' is
 570          * the same with 'data' in this case.
 571          */
 572         if (attr == data || !attr->write)
 573                 return -EPERM;
 574
 575         return attr->write(data, buf, count, ppos);
 576 }
 577
 578 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 579 {
 580         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 581         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 582         struct seq_file *m;
 583         int ret;
 584
 585         if (attr->seq_ops) {
 586                 ret = seq_open(file, attr->seq_ops);
 587                 if (!ret) {
 588                         m = file->private_data;
 589                         m->private = data;
 590                 }
 591                 return ret;
 592         }
 593
 594         if (WARN_ON_ONCE(!attr->show))
 595                 return -EPERM;
 596
 597         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 598 }
 599
 600 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 601 {
 602         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 603
 604         if (attr->show)
 605                 return single_release(inode, file);
 606
 607         return seq_release(inode, file);
 608 }
 609
 610 static const struct file_operations blk_mq_debugfs_fops = {
 611         .open           = blk_mq_debugfs_open,
 612         .read           = seq_read,
 613         .write          = blk_mq_debugfs_write,
 614         .llseek         = seq_lseek,
 615         .release        = blk_mq_debugfs_release,
 616 };
 617
 618 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 619         {"state", 0400, hctx_state_show},
 620         {"flags", 0400, hctx_flags_show},
 621         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 622         {"busy", 0400, hctx_busy_show},
 623         {"ctx_map", 0400, hctx_ctx_map_show},
 624         {"tags", 0400, hctx_tags_show},
 625         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 626         {"sched_tags", 0400, hctx_sched_tags_show},
 627         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 628         {"run", 0600, hctx_run_show, hctx_run_write},
 629         {"active", 0400, hctx_active_show},
 630         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 631         {"type", 0400, hctx_type_show},
 632         {},
 633 };
 634
 635 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 636         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 637         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 638         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 639         {},
 640 };
 641
 642 static void debugfs_create_files(struct dentry *parent, void *data,
 643                                  const struct blk_mq_debugfs_attr *attr)
 644 {
 645         if (IS_ERR_OR_NULL(parent))
 646                 return;
 647
 648         d_inode(parent)->i_private = data;
 649
 650         for (; attr->name; attr++)
 651                 debugfs_create_file(attr->name, attr->mode, parent,
 652                                     (void *)attr, &blk_mq_debugfs_fops);
 653 }
 654
 655 void blk_mq_debugfs_register(struct request_queue *q)
 656 {
 657         struct blk_mq_hw_ctx *hctx;
 658         unsigned long i;
 659
 660         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 661
 662         /*
 663          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 664          * didn't exist yet (because we don't know what to name the directory
 665          * until the queue is registered to a gendisk).
 666          */
 667         if (q->elevator && !q->sched_debugfs_dir)
 668                 blk_mq_debugfs_register_sched(q);
 669
 670         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 671         queue_for_each_hw_ctx(q, hctx, i) {
 672                 if (!hctx->debugfs_dir)
 673                         blk_mq_debugfs_register_hctx(q, hctx);
 674                 if (q->elevator && !hctx->sched_debugfs_dir)
 675                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 676         }
 677
 678         if (q->rq_qos) {
 679                 struct rq_qos *rqos = q->rq_qos;
 680
 681                 while (rqos) {
 682                         blk_mq_debugfs_register_rqos(rqos);
 683                         rqos = rqos->next;
 684                 }
 685         }
 686 }
 687
 688 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 689                                         struct blk_mq_ctx *ctx)
 690 {
 691         struct dentry *ctx_dir;
 692         char name[20];
 693
 694         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 695         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 696
 697         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 698 }
 699
 700 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 701                                   struct blk_mq_hw_ctx *hctx)
 702 {
 703         struct blk_mq_ctx *ctx;
 704         char name[20];
 705         int i;
 706
 707         if (!q->debugfs_dir)
 708                 return;
 709
 710         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 711         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 712
 713         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 714
 715         hctx_for_each_ctx(hctx, ctx, i)
 716                 blk_mq_debugfs_register_ctx(hctx, ctx);
 717 }
 718
 719 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 720 {
 721         if (!hctx->queue->debugfs_dir)
 722                 return;
 723         debugfs_remove_recursive(hctx->debugfs_dir);
 724         hctx->sched_debugfs_dir = NULL;
 725         hctx->debugfs_dir = NULL;
 726 }
 727
 728 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 729 {
 730         struct blk_mq_hw_ctx *hctx;
 731         unsigned long i;
 732
 733         queue_for_each_hw_ctx(q, hctx, i)
 734                 blk_mq_debugfs_register_hctx(q, hctx);
 735 }
 736
 737 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 738 {
 739         struct blk_mq_hw_ctx *hctx;
 740         unsigned long i;
 741
 742         queue_for_each_hw_ctx(q, hctx, i)
 743                 blk_mq_debugfs_unregister_hctx(hctx);
 744 }
 745
 746 void blk_mq_debugfs_register_sched(struct request_queue *q)
 747 {
 748         struct elevator_type *e = q->elevator->type;
 749
 750         lockdep_assert_held(&q->debugfs_mutex);
 751
 752         /*
 753          * If the parent directory has not been created yet, return, we will be
 754          * called again later on and the directory/files will be created then.
 755          */
 756         if (!q->debugfs_dir)
 757                 return;
 758
 759         if (!e->queue_debugfs_attrs)
 760                 return;
 761
 762         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 763
 764         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 765 }
 766
 767 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 768 {
 769         lockdep_assert_held(&q->debugfs_mutex);
 770
 771         debugfs_remove_recursive(q->sched_debugfs_dir);
 772         q->sched_debugfs_dir = NULL;
 773 }
 774
 775 static const char *rq_qos_id_to_name(enum rq_qos_id id)
 776 {
 777         switch (id) {
 778         case RQ_QOS_WBT:
 779                 return "wbt";
 780         case RQ_QOS_LATENCY:
 781                 return "latency";
 782         case RQ_QOS_COST:
 783                 return "cost";
 784         }
 785         return "unknown";
 786 }
 787
 788 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 789 {
 790         lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
 791
 792         if (!rqos->disk->queue->debugfs_dir)
 793                 return;
 794         debugfs_remove_recursive(rqos->debugfs_dir);
 795         rqos->debugfs_dir = NULL;
 796 }
 797
 798 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 799 {
 800         struct request_queue *q = rqos->disk->queue;
 801         const char *dir_name = rq_qos_id_to_name(rqos->id);
 802
 803         lockdep_assert_held(&q->debugfs_mutex);
 804
 805         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 806                 return;
 807
 808         if (!q->rqos_debugfs_dir)
 809                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 810                                                          q->debugfs_dir);
 811
 812         rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);
 813         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 814 }
 815
 816 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 817                                         struct blk_mq_hw_ctx *hctx)
 818 {
 819         struct elevator_type *e = q->elevator->type;
 820
 821         lockdep_assert_held(&q->debugfs_mutex);
 822
 823         /*
 824          * If the parent debugfs directory has not been created yet, return;
 825          * We will be called again later on with appropriate parent debugfs
 826          * directory from blk_register_queue()
 827          */
 828         if (!hctx->debugfs_dir)
 829                 return;
 830
 831         if (!e->hctx_debugfs_attrs)
 832                 return;
 833
 834         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 835                                                      hctx->debugfs_dir);
 836         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 837                              e->hctx_debugfs_attrs);
 838 }
 839
 840 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 841 {
 842         lockdep_assert_held(&hctx->queue->debugfs_mutex);
 843
 844         if (!hctx->queue->debugfs_dir)
 845                 return;
 846         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 847         hctx->sched_debugfs_dir = NULL;
 848 }