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 <linux/blk-mq.h>
  11 #include "blk.h"
  12 #include "blk-mq.h"
  13 #include "blk-mq-debugfs.h"
  14 #include "blk-mq-sched.h"
  15 #include "blk-mq-tag.h"
  16 #include "blk-rq-qos.h"
  17
  18 static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
  19 {
  20         if (stat->nr_samples) {
  21                 seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
  22                            stat->nr_samples, stat->mean, stat->min, stat->max);
  23         } else {
  24                 seq_puts(m, "samples=0");
  25         }
  26 }
  27
  28 static int queue_poll_stat_show(void *data, struct seq_file *m)
  29 {
  30         struct request_queue *q = data;
  31         int bucket;
  32
  33         if (!q->poll_stat)
  34                 return 0;
  35
  36         for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
  37                 seq_printf(m, "read  (%d Bytes): ", 1 << (9 + bucket));
  38                 print_stat(m, &q->poll_stat[2 * bucket]);
  39                 seq_puts(m, "\n");
  40
  41                 seq_printf(m, "write (%d Bytes): ",  1 << (9 + bucket));
  42                 print_stat(m, &q->poll_stat[2 * bucket + 1]);
  43                 seq_puts(m, "\n");
  44         }
  45         return 0;
  46 }
  47
  48 static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
  49         __acquires(&q->requeue_lock)
  50 {
  51         struct request_queue *q = m->private;
  52
  53         spin_lock_irq(&q->requeue_lock);
  54         return seq_list_start(&q->requeue_list, *pos);
  55 }
  56
  57 static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
  58 {
  59         struct request_queue *q = m->private;
  60
  61         return seq_list_next(v, &q->requeue_list, pos);
  62 }
  63
  64 static void queue_requeue_list_stop(struct seq_file *m, void *v)
  65         __releases(&q->requeue_lock)
  66 {
  67         struct request_queue *q = m->private;
  68
  69         spin_unlock_irq(&q->requeue_lock);
  70 }
  71
  72 static const struct seq_operations queue_requeue_list_seq_ops = {
  73         .start  = queue_requeue_list_start,
  74         .next   = queue_requeue_list_next,
  75         .stop   = queue_requeue_list_stop,
  76         .show   = blk_mq_debugfs_rq_show,
  77 };
  78
  79 static int blk_flags_show(struct seq_file *m, const unsigned long flags,
  80                           const char *const *flag_name, int flag_name_count)
  81 {
  82         bool sep = false;
  83         int i;
  84
  85         for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
  86                 if (!(flags & BIT(i)))
  87                         continue;
  88                 if (sep)
  89                         seq_puts(m, "|");
  90                 sep = true;
  91                 if (i < flag_name_count && flag_name[i])
  92                         seq_puts(m, flag_name[i]);
  93                 else
  94                         seq_printf(m, "%d", i);
  95         }
  96         return 0;
  97 }
  98
  99 static int queue_pm_only_show(void *data, struct seq_file *m)
 100 {
 101         struct request_queue *q = data;
 102
 103         seq_printf(m, "%d\n", atomic_read(&q->pm_only));
 104         return 0;
 105 }
 106
 107 #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
 108 static const char *const blk_queue_flag_name[] = {
 109         QUEUE_FLAG_NAME(STOPPED),
 110         QUEUE_FLAG_NAME(DYING),
 111         QUEUE_FLAG_NAME(NOMERGES),
 112         QUEUE_FLAG_NAME(SAME_COMP),
 113         QUEUE_FLAG_NAME(FAIL_IO),
 114         QUEUE_FLAG_NAME(NONROT),
 115         QUEUE_FLAG_NAME(IO_STAT),
 116         QUEUE_FLAG_NAME(NOXMERGES),
 117         QUEUE_FLAG_NAME(ADD_RANDOM),
 118         QUEUE_FLAG_NAME(SAME_FORCE),
 119         QUEUE_FLAG_NAME(INIT_DONE),
 120         QUEUE_FLAG_NAME(STABLE_WRITES),
 121         QUEUE_FLAG_NAME(POLL),
 122         QUEUE_FLAG_NAME(WC),
 123         QUEUE_FLAG_NAME(FUA),
 124         QUEUE_FLAG_NAME(DAX),
 125         QUEUE_FLAG_NAME(STATS),
 126         QUEUE_FLAG_NAME(REGISTERED),
 127         QUEUE_FLAG_NAME(QUIESCED),
 128         QUEUE_FLAG_NAME(PCI_P2PDMA),
 129         QUEUE_FLAG_NAME(ZONE_RESETALL),
 130         QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 131         QUEUE_FLAG_NAME(HCTX_ACTIVE),
 132         QUEUE_FLAG_NAME(NOWAIT),
 133 };
 134 #undef QUEUE_FLAG_NAME
 135
 136 static int queue_state_show(void *data, struct seq_file *m)
 137 {
 138         struct request_queue *q = data;
 139
 140         blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
 141                        ARRAY_SIZE(blk_queue_flag_name));
 142         seq_puts(m, "\n");
 143         return 0;
 144 }
 145
 146 static ssize_t queue_state_write(void *data, const char __user *buf,
 147                                  size_t count, loff_t *ppos)
 148 {
 149         struct request_queue *q = data;
 150         char opbuf[16] = { }, *op;
 151
 152         /*
 153          * The "state" attribute is removed when the queue is removed.  Don't
 154          * allow setting the state on a dying queue to avoid a use-after-free.
 155          */
 156         if (blk_queue_dying(q))
 157                 return -ENOENT;
 158
 159         if (count >= sizeof(opbuf)) {
 160                 pr_err("%s: operation too long\n", __func__);
 161                 goto inval;
 162         }
 163
 164         if (copy_from_user(opbuf, buf, count))
 165                 return -EFAULT;
 166         op = strstrip(opbuf);
 167         if (strcmp(op, "run") == 0) {
 168                 blk_mq_run_hw_queues(q, true);
 169         } else if (strcmp(op, "start") == 0) {
 170                 blk_mq_start_stopped_hw_queues(q, true);
 171         } else if (strcmp(op, "kick") == 0) {
 172                 blk_mq_kick_requeue_list(q);
 173         } else {
 174                 pr_err("%s: unsupported operation '%s'\n", __func__, op);
 175 inval:
 176                 pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
 177                 return -EINVAL;
 178         }
 179         return count;
 180 }
 181
 182 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 183         { "poll_stat", 0400, queue_poll_stat_show },
 184         { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
 185         { "pm_only", 0600, queue_pm_only_show, NULL },
 186         { "state", 0600, queue_state_show, queue_state_write },
 187         { "zone_wlock", 0400, queue_zone_wlock_show, NULL },
 188         { },
 189 };
 190
 191 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 192 static const char *const hctx_state_name[] = {
 193         HCTX_STATE_NAME(STOPPED),
 194         HCTX_STATE_NAME(TAG_ACTIVE),
 195         HCTX_STATE_NAME(SCHED_RESTART),
 196         HCTX_STATE_NAME(INACTIVE),
 197 };
 198 #undef HCTX_STATE_NAME
 199
 200 static int hctx_state_show(void *data, struct seq_file *m)
 201 {
 202         struct blk_mq_hw_ctx *hctx = data;
 203
 204         blk_flags_show(m, hctx->state, hctx_state_name,
 205                        ARRAY_SIZE(hctx_state_name));
 206         seq_puts(m, "\n");
 207         return 0;
 208 }
 209
 210 #define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
 211 static const char *const alloc_policy_name[] = {
 212         BLK_TAG_ALLOC_NAME(FIFO),
 213         BLK_TAG_ALLOC_NAME(RR),
 214 };
 215 #undef BLK_TAG_ALLOC_NAME
 216
 217 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 218 static const char *const hctx_flag_name[] = {
 219         HCTX_FLAG_NAME(SHOULD_MERGE),
 220         HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 221         HCTX_FLAG_NAME(BLOCKING),
 222         HCTX_FLAG_NAME(NO_SCHED),
 223         HCTX_FLAG_NAME(STACKING),
 224         HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 225 };
 226 #undef HCTX_FLAG_NAME
 227
 228 static int hctx_flags_show(void *data, struct seq_file *m)
 229 {
 230         struct blk_mq_hw_ctx *hctx = data;
 231         const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 232
 233         seq_puts(m, "alloc_policy=");
 234         if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
 235             alloc_policy_name[alloc_policy])
 236                 seq_puts(m, alloc_policy_name[alloc_policy]);
 237         else
 238                 seq_printf(m, "%d", alloc_policy);
 239         seq_puts(m, " ");
 240         blk_flags_show(m,
 241                        hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
 242                        hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
 243         seq_puts(m, "\n");
 244         return 0;
 245 }
 246
 247 #define CMD_FLAG_NAME(name) [__REQ_##name] = #name
 248 static const char *const cmd_flag_name[] = {
 249         CMD_FLAG_NAME(FAILFAST_DEV),
 250         CMD_FLAG_NAME(FAILFAST_TRANSPORT),
 251         CMD_FLAG_NAME(FAILFAST_DRIVER),
 252         CMD_FLAG_NAME(SYNC),
 253         CMD_FLAG_NAME(META),
 254         CMD_FLAG_NAME(PRIO),
 255         CMD_FLAG_NAME(NOMERGE),
 256         CMD_FLAG_NAME(IDLE),
 257         CMD_FLAG_NAME(INTEGRITY),
 258         CMD_FLAG_NAME(FUA),
 259         CMD_FLAG_NAME(PREFLUSH),
 260         CMD_FLAG_NAME(RAHEAD),
 261         CMD_FLAG_NAME(BACKGROUND),
 262         CMD_FLAG_NAME(NOWAIT),
 263         CMD_FLAG_NAME(NOUNMAP),
 264         CMD_FLAG_NAME(POLLED),
 265 };
 266 #undef CMD_FLAG_NAME
 267
 268 #define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
 269 static const char *const rqf_name[] = {
 270         RQF_NAME(STARTED),
 271         RQF_NAME(SOFTBARRIER),
 272         RQF_NAME(FLUSH_SEQ),
 273         RQF_NAME(MIXED_MERGE),
 274         RQF_NAME(MQ_INFLIGHT),
 275         RQF_NAME(DONTPREP),
 276         RQF_NAME(FAILED),
 277         RQF_NAME(QUIET),
 278         RQF_NAME(ELVPRIV),
 279         RQF_NAME(IO_STAT),
 280         RQF_NAME(PM),
 281         RQF_NAME(HASHED),
 282         RQF_NAME(STATS),
 283         RQF_NAME(SPECIAL_PAYLOAD),
 284         RQF_NAME(ZONE_WRITE_LOCKED),
 285         RQF_NAME(MQ_POLL_SLEPT),
 286         RQF_NAME(ELV),
 287 };
 288 #undef RQF_NAME
 289
 290 static const char *const blk_mq_rq_state_name_array[] = {
 291         [MQ_RQ_IDLE]            = "idle",
 292         [MQ_RQ_IN_FLIGHT]       = "in_flight",
 293         [MQ_RQ_COMPLETE]        = "complete",
 294 };
 295
 296 static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
 297 {
 298         if (WARN_ON_ONCE((unsigned int)rq_state >=
 299                          ARRAY_SIZE(blk_mq_rq_state_name_array)))
 300                 return "(?)";
 301         return blk_mq_rq_state_name_array[rq_state];
 302 }
 303
 304 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 305 {
 306         const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
 307         const enum req_op op = req_op(rq);
 308         const char *op_str = blk_op_str(op);
 309
 310         seq_printf(m, "%p {.op=", rq);
 311         if (strcmp(op_str, "UNKNOWN") == 0)
 312                 seq_printf(m, "%u", op);
 313         else
 314                 seq_printf(m, "%s", op_str);
 315         seq_puts(m, ", .cmd_flags=");
 316         blk_flags_show(m, (__force unsigned int)(rq->cmd_flags & ~REQ_OP_MASK),
 317                        cmd_flag_name, ARRAY_SIZE(cmd_flag_name));
 318         seq_puts(m, ", .rq_flags=");
 319         blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 320                        ARRAY_SIZE(rqf_name));
 321         seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 322         seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 323                    rq->internal_tag);
 324         if (mq_ops->show_rq)
 325                 mq_ops->show_rq(m, rq);
 326         seq_puts(m, "}\n");
 327         return 0;
 328 }
 329 EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
 330
 331 int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 332 {
 333         return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
 334 }
 335 EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
 336
 337 static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
 338         __acquires(&hctx->lock)
 339 {
 340         struct blk_mq_hw_ctx *hctx = m->private;
 341
 342         spin_lock(&hctx->lock);
 343         return seq_list_start(&hctx->dispatch, *pos);
 344 }
 345
 346 static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
 347 {
 348         struct blk_mq_hw_ctx *hctx = m->private;
 349
 350         return seq_list_next(v, &hctx->dispatch, pos);
 351 }
 352
 353 static void hctx_dispatch_stop(struct seq_file *m, void *v)
 354         __releases(&hctx->lock)
 355 {
 356         struct blk_mq_hw_ctx *hctx = m->private;
 357
 358         spin_unlock(&hctx->lock);
 359 }
 360
 361 static const struct seq_operations hctx_dispatch_seq_ops = {
 362         .start  = hctx_dispatch_start,
 363         .next   = hctx_dispatch_next,
 364         .stop   = hctx_dispatch_stop,
 365         .show   = blk_mq_debugfs_rq_show,
 366 };
 367
 368 struct show_busy_params {
 369         struct seq_file         *m;
 370         struct blk_mq_hw_ctx    *hctx;
 371 };
 372
 373 /*
 374  * Note: the state of a request may change while this function is in progress,
 375  * e.g. due to a concurrent blk_mq_finish_request() call. Returns true to
 376  * keep iterating requests.
 377  */
 378 static bool hctx_show_busy_rq(struct request *rq, void *data)
 379 {
 380         const struct show_busy_params *params = data;
 381
 382         if (rq->mq_hctx == params->hctx)
 383                 __blk_mq_debugfs_rq_show(params->m, rq);
 384
 385         return true;
 386 }
 387
 388 static int hctx_busy_show(void *data, struct seq_file *m)
 389 {
 390         struct blk_mq_hw_ctx *hctx = data;
 391         struct show_busy_params params = { .m = m, .hctx = hctx };
 392
 393         blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
 394                                 &params);
 395
 396         return 0;
 397 }
 398
 399 static const char *const hctx_types[] = {
 400         [HCTX_TYPE_DEFAULT]     = "default",
 401         [HCTX_TYPE_READ]        = "read",
 402         [HCTX_TYPE_POLL]        = "poll",
 403 };
 404
 405 static int hctx_type_show(void *data, struct seq_file *m)
 406 {
 407         struct blk_mq_hw_ctx *hctx = data;
 408
 409         BUILD_BUG_ON(ARRAY_SIZE(hctx_types) != HCTX_MAX_TYPES);
 410         seq_printf(m, "%s\n", hctx_types[hctx->type]);
 411         return 0;
 412 }
 413
 414 static int hctx_ctx_map_show(void *data, struct seq_file *m)
 415 {
 416         struct blk_mq_hw_ctx *hctx = data;
 417
 418         sbitmap_bitmap_show(&hctx->ctx_map, m);
 419         return 0;
 420 }
 421
 422 static void blk_mq_debugfs_tags_show(struct seq_file *m,
 423                                      struct blk_mq_tags *tags)
 424 {
 425         seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 426         seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 427         seq_printf(m, "active_queues=%d\n",
 428                    atomic_read(&tags->active_queues));
 429
 430         seq_puts(m, "\nbitmap_tags:\n");
 431         sbitmap_queue_show(&tags->bitmap_tags, m);
 432
 433         if (tags->nr_reserved_tags) {
 434                 seq_puts(m, "\nbreserved_tags:\n");
 435                 sbitmap_queue_show(&tags->breserved_tags, m);
 436         }
 437 }
 438
 439 static int hctx_tags_show(void *data, struct seq_file *m)
 440 {
 441         struct blk_mq_hw_ctx *hctx = data;
 442         struct request_queue *q = hctx->queue;
 443         int res;
 444
 445         res = mutex_lock_interruptible(&q->sysfs_lock);
 446         if (res)
 447                 goto out;
 448         if (hctx->tags)
 449                 blk_mq_debugfs_tags_show(m, hctx->tags);
 450         mutex_unlock(&q->sysfs_lock);
 451
 452 out:
 453         return res;
 454 }
 455
 456 static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 457 {
 458         struct blk_mq_hw_ctx *hctx = data;
 459         struct request_queue *q = hctx->queue;
 460         int res;
 461
 462         res = mutex_lock_interruptible(&q->sysfs_lock);
 463         if (res)
 464                 goto out;
 465         if (hctx->tags)
 466                 sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
 467         mutex_unlock(&q->sysfs_lock);
 468
 469 out:
 470         return res;
 471 }
 472
 473 static int hctx_sched_tags_show(void *data, struct seq_file *m)
 474 {
 475         struct blk_mq_hw_ctx *hctx = data;
 476         struct request_queue *q = hctx->queue;
 477         int res;
 478
 479         res = mutex_lock_interruptible(&q->sysfs_lock);
 480         if (res)
 481                 goto out;
 482         if (hctx->sched_tags)
 483                 blk_mq_debugfs_tags_show(m, hctx->sched_tags);
 484         mutex_unlock(&q->sysfs_lock);
 485
 486 out:
 487         return res;
 488 }
 489
 490 static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 491 {
 492         struct blk_mq_hw_ctx *hctx = data;
 493         struct request_queue *q = hctx->queue;
 494         int res;
 495
 496         res = mutex_lock_interruptible(&q->sysfs_lock);
 497         if (res)
 498                 goto out;
 499         if (hctx->sched_tags)
 500                 sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
 501         mutex_unlock(&q->sysfs_lock);
 502
 503 out:
 504         return res;
 505 }
 506
 507 static int hctx_run_show(void *data, struct seq_file *m)
 508 {
 509         struct blk_mq_hw_ctx *hctx = data;
 510
 511         seq_printf(m, "%lu\n", hctx->run);
 512         return 0;
 513 }
 514
 515 static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
 516                               loff_t *ppos)
 517 {
 518         struct blk_mq_hw_ctx *hctx = data;
 519
 520         hctx->run = 0;
 521         return count;
 522 }
 523
 524 static int hctx_active_show(void *data, struct seq_file *m)
 525 {
 526         struct blk_mq_hw_ctx *hctx = data;
 527
 528         seq_printf(m, "%d\n", __blk_mq_active_requests(hctx));
 529         return 0;
 530 }
 531
 532 static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
 533 {
 534         struct blk_mq_hw_ctx *hctx = data;
 535
 536         seq_printf(m, "%u\n", hctx->dispatch_busy);
 537         return 0;
 538 }
 539
 540 #define CTX_RQ_SEQ_OPS(name, type)                                      \
 541 static void *ctx_##name##_rq_list_start(struct seq_file *m, loff_t *pos) \
 542         __acquires(&ctx->lock)                                          \
 543 {                                                                       \
 544         struct blk_mq_ctx *ctx = m->private;                            \
 545                                                                         \
 546         spin_lock(&ctx->lock);                                          \
 547         return seq_list_start(&ctx->rq_lists[type], *pos);              \
 548 }                                                                       \
 549                                                                         \
 550 static void *ctx_##name##_rq_list_next(struct seq_file *m, void *v,     \
 551                                      loff_t *pos)                       \
 552 {                                                                       \
 553         struct blk_mq_ctx *ctx = m->private;                            \
 554                                                                         \
 555         return seq_list_next(v, &ctx->rq_lists[type], pos);             \
 556 }                                                                       \
 557                                                                         \
 558 static void ctx_##name##_rq_list_stop(struct seq_file *m, void *v)      \
 559         __releases(&ctx->lock)                                          \
 560 {                                                                       \
 561         struct blk_mq_ctx *ctx = m->private;                            \
 562                                                                         \
 563         spin_unlock(&ctx->lock);                                        \
 564 }                                                                       \
 565                                                                         \
 566 static const struct seq_operations ctx_##name##_rq_list_seq_ops = {     \
 567         .start  = ctx_##name##_rq_list_start,                           \
 568         .next   = ctx_##name##_rq_list_next,                            \
 569         .stop   = ctx_##name##_rq_list_stop,                            \
 570         .show   = blk_mq_debugfs_rq_show,                               \
 571 }
 572
 573 CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT);
 574 CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);
 575 CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);
 576
 577 static int blk_mq_debugfs_show(struct seq_file *m, void *v)
 578 {
 579         const struct blk_mq_debugfs_attr *attr = m->private;
 580         void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
 581
 582         return attr->show(data, m);
 583 }
 584
 585 static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
 586                                     size_t count, loff_t *ppos)
 587 {
 588         struct seq_file *m = file->private_data;
 589         const struct blk_mq_debugfs_attr *attr = m->private;
 590         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 591
 592         /*
 593          * Attributes that only implement .seq_ops are read-only and 'attr' is
 594          * the same with 'data' in this case.
 595          */
 596         if (attr == data || !attr->write)
 597                 return -EPERM;
 598
 599         return attr->write(data, buf, count, ppos);
 600 }
 601
 602 static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
 603 {
 604         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 605         void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
 606         struct seq_file *m;
 607         int ret;
 608
 609         if (attr->seq_ops) {
 610                 ret = seq_open(file, attr->seq_ops);
 611                 if (!ret) {
 612                         m = file->private_data;
 613                         m->private = data;
 614                 }
 615                 return ret;
 616         }
 617
 618         if (WARN_ON_ONCE(!attr->show))
 619                 return -EPERM;
 620
 621         return single_open(file, blk_mq_debugfs_show, inode->i_private);
 622 }
 623
 624 static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 625 {
 626         const struct blk_mq_debugfs_attr *attr = inode->i_private;
 627
 628         if (attr->show)
 629                 return single_release(inode, file);
 630
 631         return seq_release(inode, file);
 632 }
 633
 634 static const struct file_operations blk_mq_debugfs_fops = {
 635         .open           = blk_mq_debugfs_open,
 636         .read           = seq_read,
 637         .write          = blk_mq_debugfs_write,
 638         .llseek         = seq_lseek,
 639         .release        = blk_mq_debugfs_release,
 640 };
 641
 642 static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 643         {"state", 0400, hctx_state_show},
 644         {"flags", 0400, hctx_flags_show},
 645         {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
 646         {"busy", 0400, hctx_busy_show},
 647         {"ctx_map", 0400, hctx_ctx_map_show},
 648         {"tags", 0400, hctx_tags_show},
 649         {"tags_bitmap", 0400, hctx_tags_bitmap_show},
 650         {"sched_tags", 0400, hctx_sched_tags_show},
 651         {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
 652         {"run", 0600, hctx_run_show, hctx_run_write},
 653         {"active", 0400, hctx_active_show},
 654         {"dispatch_busy", 0400, hctx_dispatch_busy_show},
 655         {"type", 0400, hctx_type_show},
 656         {},
 657 };
 658
 659 static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 660         {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},
 661         {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},
 662         {"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},
 663         {},
 664 };
 665
 666 static void debugfs_create_files(struct dentry *parent, void *data,
 667                                  const struct blk_mq_debugfs_attr *attr)
 668 {
 669         if (IS_ERR_OR_NULL(parent))
 670                 return;
 671
 672         d_inode(parent)->i_private = data;
 673
 674         for (; attr->name; attr++)
 675                 debugfs_create_file(attr->name, attr->mode, parent,
 676                                     (void *)attr, &blk_mq_debugfs_fops);
 677 }
 678
 679 void blk_mq_debugfs_register(struct request_queue *q)
 680 {
 681         struct blk_mq_hw_ctx *hctx;
 682         unsigned long i;
 683
 684         debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
 685
 686         /*
 687          * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
 688          * didn't exist yet (because we don't know what to name the directory
 689          * until the queue is registered to a gendisk).
 690          */
 691         if (q->elevator && !q->sched_debugfs_dir)
 692                 blk_mq_debugfs_register_sched(q);
 693
 694         /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
 695         queue_for_each_hw_ctx(q, hctx, i) {
 696                 if (!hctx->debugfs_dir)
 697                         blk_mq_debugfs_register_hctx(q, hctx);
 698                 if (q->elevator && !hctx->sched_debugfs_dir)
 699                         blk_mq_debugfs_register_sched_hctx(q, hctx);
 700         }
 701
 702         if (q->rq_qos) {
 703                 struct rq_qos *rqos = q->rq_qos;
 704
 705                 while (rqos) {
 706                         blk_mq_debugfs_register_rqos(rqos);
 707                         rqos = rqos->next;
 708                 }
 709         }
 710 }
 711
 712 static void blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
 713                                         struct blk_mq_ctx *ctx)
 714 {
 715         struct dentry *ctx_dir;
 716         char name[20];
 717
 718         snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
 719         ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
 720
 721         debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs);
 722 }
 723
 724 void blk_mq_debugfs_register_hctx(struct request_queue *q,
 725                                   struct blk_mq_hw_ctx *hctx)
 726 {
 727         struct blk_mq_ctx *ctx;
 728         char name[20];
 729         int i;
 730
 731         if (!q->debugfs_dir)
 732                 return;
 733
 734         snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
 735         hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
 736
 737         debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs);
 738
 739         hctx_for_each_ctx(hctx, ctx, i)
 740                 blk_mq_debugfs_register_ctx(hctx, ctx);
 741 }
 742
 743 void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
 744 {
 745         if (!hctx->queue->debugfs_dir)
 746                 return;
 747         debugfs_remove_recursive(hctx->debugfs_dir);
 748         hctx->sched_debugfs_dir = NULL;
 749         hctx->debugfs_dir = NULL;
 750 }
 751
 752 void blk_mq_debugfs_register_hctxs(struct request_queue *q)
 753 {
 754         struct blk_mq_hw_ctx *hctx;
 755         unsigned long i;
 756
 757         queue_for_each_hw_ctx(q, hctx, i)
 758                 blk_mq_debugfs_register_hctx(q, hctx);
 759 }
 760
 761 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 762 {
 763         struct blk_mq_hw_ctx *hctx;
 764         unsigned long i;
 765
 766         queue_for_each_hw_ctx(q, hctx, i)
 767                 blk_mq_debugfs_unregister_hctx(hctx);
 768 }
 769
 770 void blk_mq_debugfs_register_sched(struct request_queue *q)
 771 {
 772         struct elevator_type *e = q->elevator->type;
 773
 774         lockdep_assert_held(&q->debugfs_mutex);
 775
 776         /*
 777          * If the parent directory has not been created yet, return, we will be
 778          * called again later on and the directory/files will be created then.
 779          */
 780         if (!q->debugfs_dir)
 781                 return;
 782
 783         if (!e->queue_debugfs_attrs)
 784                 return;
 785
 786         q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
 787
 788         debugfs_create_files(q->sched_debugfs_dir, q, e->queue_debugfs_attrs);
 789 }
 790
 791 void blk_mq_debugfs_unregister_sched(struct request_queue *q)
 792 {
 793         lockdep_assert_held(&q->debugfs_mutex);
 794
 795         debugfs_remove_recursive(q->sched_debugfs_dir);
 796         q->sched_debugfs_dir = NULL;
 797 }
 798
 799 static const char *rq_qos_id_to_name(enum rq_qos_id id)
 800 {
 801         switch (id) {
 802         case RQ_QOS_WBT:
 803                 return "wbt";
 804         case RQ_QOS_LATENCY:
 805                 return "latency";
 806         case RQ_QOS_COST:
 807                 return "cost";
 808         case RQ_QOS_IOPRIO:
 809                 return "ioprio";
 810         }
 811         return "unknown";
 812 }
 813
 814 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 815 {
 816         lockdep_assert_held(&rqos->q->debugfs_mutex);
 817
 818         if (!rqos->q->debugfs_dir)
 819                 return;
 820         debugfs_remove_recursive(rqos->debugfs_dir);
 821         rqos->debugfs_dir = NULL;
 822 }
 823
 824 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 825 {
 826         struct request_queue *q = rqos->q;
 827         const char *dir_name = rq_qos_id_to_name(rqos->id);
 828
 829         lockdep_assert_held(&q->debugfs_mutex);
 830
 831         if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
 832                 return;
 833
 834         if (!q->rqos_debugfs_dir)
 835                 q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 836                                                          q->debugfs_dir);
 837
 838         rqos->debugfs_dir = debugfs_create_dir(dir_name,
 839                                                rqos->q->rqos_debugfs_dir);
 840
 841         debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 842 }
 843
 844 void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 845                                         struct blk_mq_hw_ctx *hctx)
 846 {
 847         struct elevator_type *e = q->elevator->type;
 848
 849         lockdep_assert_held(&q->debugfs_mutex);
 850
 851         /*
 852          * If the parent debugfs directory has not been created yet, return;
 853          * We will be called again later on with appropriate parent debugfs
 854          * directory from blk_register_queue()
 855          */
 856         if (!hctx->debugfs_dir)
 857                 return;
 858
 859         if (!e->hctx_debugfs_attrs)
 860                 return;
 861
 862         hctx->sched_debugfs_dir = debugfs_create_dir("sched",
 863                                                      hctx->debugfs_dir);
 864         debugfs_create_files(hctx->sched_debugfs_dir, hctx,
 865                              e->hctx_debugfs_attrs);
 866 }
 867
 868 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
 869 {
 870         lockdep_assert_held(&hctx->queue->debugfs_mutex);
 871
 872         if (!hctx->queue->debugfs_dir)
 873                 return;
 874         debugfs_remove_recursive(hctx->sched_debugfs_dir);
 875         hctx->sched_debugfs_dir = NULL;
 876 }