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