block/blk-sysfs.c

   1 /*
   2  * Functions related to sysfs handling
   3  */
   4 #include <linux/kernel.h>
   5 #include <linux/slab.h>
   6 #include <linux/module.h>
   7 #include <linux/bio.h>
   8 #include <linux/blkdev.h>
   9 #include <linux/backing-dev.h>
  10 #include <linux/blktrace_api.h>
  11 #include <linux/blk-mq.h>
  12 #include <linux/blk-cgroup.h>
  13
  14 #include "blk.h"
  15 #include "blk-mq.h"
  16
  17 struct queue_sysfs_entry {
  18         struct attribute attr;
  19         ssize_t (*show)(struct request_queue *, char *);
  20         ssize_t (*store)(struct request_queue *, const char *, size_t);
  21 };
  22
  23 static ssize_t
  24 queue_var_show(unsigned long var, char *page)
  25 {
  26         return sprintf(page, "%lu\n", var);
  27 }
  28
  29 static ssize_t
  30 queue_var_store(unsigned long *var, const char *page, size_t count)
  31 {
  32         int err;
  33         unsigned long v;
  34
  35         err = kstrtoul(page, 10, &v);
  36         if (err || v > UINT_MAX)
  37                 return -EINVAL;
  38
  39         *var = v;
  40
  41         return count;
  42 }
  43
  44 static ssize_t queue_requests_show(struct request_queue *q, char *page)
  45 {
  46         return queue_var_show(q->nr_requests, (page));
  47 }
  48
  49 static ssize_t
  50 queue_requests_store(struct request_queue *q, const char *page, size_t count)
  51 {
  52         unsigned long nr;
  53         int ret, err;
  54
  55         if (!q->request_fn && !q->mq_ops)
  56                 return -EINVAL;
  57
  58         ret = queue_var_store(&nr, page, count);
  59         if (ret < 0)
  60                 return ret;
  61
  62         if (nr < BLKDEV_MIN_RQ)
  63                 nr = BLKDEV_MIN_RQ;
  64
  65         if (q->request_fn)
  66                 err = blk_update_nr_requests(q, nr);
  67         else
  68                 err = blk_mq_update_nr_requests(q, nr);
  69
  70         if (err)
  71                 return err;
  72
  73         return ret;
  74 }
  75
  76 static ssize_t queue_ra_show(struct request_queue *q, char *page)
  77 {
  78         unsigned long ra_kb = q->backing_dev_info.ra_pages <<
  79                                         (PAGE_CACHE_SHIFT - 10);
  80
  81         return queue_var_show(ra_kb, (page));
  82 }
  83
  84 static ssize_t
  85 queue_ra_store(struct request_queue *q, const char *page, size_t count)
  86 {
  87         unsigned long ra_kb;
  88         ssize_t ret = queue_var_store(&ra_kb, page, count);
  89
  90         if (ret < 0)
  91                 return ret;
  92
  93         q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
  94
  95         return ret;
  96 }
  97
  98 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
  99 {
 100         int max_sectors_kb = queue_max_sectors(q) >> 1;
 101
 102         return queue_var_show(max_sectors_kb, (page));
 103 }
 104
 105 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
 106 {
 107         return queue_var_show(queue_max_segments(q), (page));
 108 }
 109
 110 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
 111 {
 112         return queue_var_show(q->limits.max_integrity_segments, (page));
 113 }
 114
 115 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
 116 {
 117         if (blk_queue_cluster(q))
 118                 return queue_var_show(queue_max_segment_size(q), (page));
 119
 120         return queue_var_show(PAGE_CACHE_SIZE, (page));
 121 }
 122
 123 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
 124 {
 125         return queue_var_show(queue_logical_block_size(q), page);
 126 }
 127
 128 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
 129 {
 130         return queue_var_show(queue_physical_block_size(q), page);
 131 }
 132
 133 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
 134 {
 135         return queue_var_show(queue_io_min(q), page);
 136 }
 137
 138 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
 139 {
 140         return queue_var_show(queue_io_opt(q), page);
 141 }
 142
 143 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
 144 {
 145         return queue_var_show(q->limits.discard_granularity, page);
 146 }
 147
 148 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
 149 {
 150         unsigned long long val;
 151
 152         val = q->limits.max_hw_discard_sectors << 9;
 153         return sprintf(page, "%llu\n", val);
 154 }
 155
 156 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
 157 {
 158         return sprintf(page, "%llu\n",
 159                        (unsigned long long)q->limits.max_discard_sectors << 9);
 160 }
 161
 162 static ssize_t queue_discard_max_store(struct request_queue *q,
 163                                        const char *page, size_t count)
 164 {
 165         unsigned long max_discard;
 166         ssize_t ret = queue_var_store(&max_discard, page, count);
 167
 168         if (ret < 0)
 169                 return ret;
 170
 171         if (max_discard & (q->limits.discard_granularity - 1))
 172                 return -EINVAL;
 173
 174         max_discard >>= 9;
 175         if (max_discard > UINT_MAX)
 176                 return -EINVAL;
 177
 178         if (max_discard > q->limits.max_hw_discard_sectors)
 179                 max_discard = q->limits.max_hw_discard_sectors;
 180
 181         q->limits.max_discard_sectors = max_discard;
 182         return ret;
 183 }
 184
 185 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
 186 {
 187         return queue_var_show(queue_discard_zeroes_data(q), page);
 188 }
 189
 190 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
 191 {
 192         return sprintf(page, "%llu\n",
 193                 (unsigned long long)q->limits.max_write_same_sectors << 9);
 194 }
 195
 196
 197 static ssize_t
 198 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 199 {
 200         unsigned long max_sectors_kb,
 201                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
 202                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
 203         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
 204
 205         if (ret < 0)
 206                 return ret;
 207
 208         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
 209                 return -EINVAL;
 210
 211         spin_lock_irq(q->queue_lock);
 212         q->limits.max_sectors = max_sectors_kb << 1;
 213         spin_unlock_irq(q->queue_lock);
 214
 215         return ret;
 216 }
 217
 218 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 219 {
 220         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 221
 222         return queue_var_show(max_hw_sectors_kb, (page));
 223 }
 224
 225 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
 226 static ssize_t                                                          \
 227 queue_show_##name(struct request_queue *q, char *page)                  \
 228 {                                                                       \
 229         int bit;                                                        \
 230         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
 231         return queue_var_show(neg ? !bit : bit, page);                  \
 232 }                                                                       \
 233 static ssize_t                                                          \
 234 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
 235 {                                                                       \
 236         unsigned long val;                                              \
 237         ssize_t ret;                                                    \
 238         ret = queue_var_store(&val, page, count);                       \
 239         if (ret < 0)                                                    \
 240                  return ret;                                            \
 241         if (neg)                                                        \
 242                 val = !val;                                             \
 243                                                                         \
 244         spin_lock_irq(q->queue_lock);                                   \
 245         if (val)                                                        \
 246                 queue_flag_set(QUEUE_FLAG_##flag, q);                   \
 247         else                                                            \
 248                 queue_flag_clear(QUEUE_FLAG_##flag, q);                 \
 249         spin_unlock_irq(q->queue_lock);                                 \
 250         return ret;                                                     \
 251 }
 252
 253 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
 254 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
 255 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 256 #undef QUEUE_SYSFS_BIT_FNS
 257
 258 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 259 {
 260         return queue_var_show((blk_queue_nomerges(q) << 1) |
 261                                blk_queue_noxmerges(q), page);
 262 }
 263
 264 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 265                                     size_t count)
 266 {
 267         unsigned long nm;
 268         ssize_t ret = queue_var_store(&nm, page, count);
 269
 270         if (ret < 0)
 271                 return ret;
 272
 273         spin_lock_irq(q->queue_lock);
 274         queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 275         queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 276         if (nm == 2)
 277                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 278         else if (nm)
 279                 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 280         spin_unlock_irq(q->queue_lock);
 281
 282         return ret;
 283 }
 284
 285 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
 286 {
 287         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
 288         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
 289
 290         return queue_var_show(set << force, page);
 291 }
 292
 293 static ssize_t
 294 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 295 {
 296         ssize_t ret = -EINVAL;
 297 #ifdef CONFIG_SMP
 298         unsigned long val;
 299
 300         ret = queue_var_store(&val, page, count);
 301         if (ret < 0)
 302                 return ret;
 303
 304         spin_lock_irq(q->queue_lock);
 305         if (val == 2) {
 306                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 307                 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
 308         } else if (val == 1) {
 309                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 310                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 311         } else if (val == 0) {
 312                 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 313                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 314         }
 315         spin_unlock_irq(q->queue_lock);
 316 #endif
 317         return ret;
 318 }
 319
 320 static ssize_t queue_poll_show(struct request_queue *q, char *page)
 321 {
 322         return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
 323 }
 324
 325 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
 326                                 size_t count)
 327 {
 328         unsigned long poll_on;
 329         ssize_t ret;
 330
 331         if (!q->mq_ops || !q->mq_ops->poll)
 332                 return -EINVAL;
 333
 334         ret = queue_var_store(&poll_on, page, count);
 335         if (ret < 0)
 336                 return ret;
 337
 338         spin_lock_irq(q->queue_lock);
 339         if (poll_on)
 340                 queue_flag_set(QUEUE_FLAG_POLL, q);
 341         else
 342                 queue_flag_clear(QUEUE_FLAG_POLL, q);
 343         spin_unlock_irq(q->queue_lock);
 344
 345         return ret;
 346 }
 347
 348 static struct queue_sysfs_entry queue_requests_entry = {
 349         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
 350         .show = queue_requests_show,
 351         .store = queue_requests_store,
 352 };
 353
 354 static struct queue_sysfs_entry queue_ra_entry = {
 355         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
 356         .show = queue_ra_show,
 357         .store = queue_ra_store,
 358 };
 359
 360 static struct queue_sysfs_entry queue_max_sectors_entry = {
 361         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
 362         .show = queue_max_sectors_show,
 363         .store = queue_max_sectors_store,
 364 };
 365
 366 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
 367         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
 368         .show = queue_max_hw_sectors_show,
 369 };
 370
 371 static struct queue_sysfs_entry queue_max_segments_entry = {
 372         .attr = {.name = "max_segments", .mode = S_IRUGO },
 373         .show = queue_max_segments_show,
 374 };
 375
 376 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
 377         .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
 378         .show = queue_max_integrity_segments_show,
 379 };
 380
 381 static struct queue_sysfs_entry queue_max_segment_size_entry = {
 382         .attr = {.name = "max_segment_size", .mode = S_IRUGO },
 383         .show = queue_max_segment_size_show,
 384 };
 385
 386 static struct queue_sysfs_entry queue_iosched_entry = {
 387         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
 388         .show = elv_iosched_show,
 389         .store = elv_iosched_store,
 390 };
 391
 392 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 393         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
 394         .show = queue_logical_block_size_show,
 395 };
 396
 397 static struct queue_sysfs_entry queue_logical_block_size_entry = {
 398         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
 399         .show = queue_logical_block_size_show,
 400 };
 401
 402 static struct queue_sysfs_entry queue_physical_block_size_entry = {
 403         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
 404         .show = queue_physical_block_size_show,
 405 };
 406
 407 static struct queue_sysfs_entry queue_io_min_entry = {
 408         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
 409         .show = queue_io_min_show,
 410 };
 411
 412 static struct queue_sysfs_entry queue_io_opt_entry = {
 413         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
 414         .show = queue_io_opt_show,
 415 };
 416
 417 static struct queue_sysfs_entry queue_discard_granularity_entry = {
 418         .attr = {.name = "discard_granularity", .mode = S_IRUGO },
 419         .show = queue_discard_granularity_show,
 420 };
 421
 422 static struct queue_sysfs_entry queue_discard_max_hw_entry = {
 423         .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
 424         .show = queue_discard_max_hw_show,
 425 };
 426
 427 static struct queue_sysfs_entry queue_discard_max_entry = {
 428         .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
 429         .show = queue_discard_max_show,
 430         .store = queue_discard_max_store,
 431 };
 432
 433 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
 434         .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
 435         .show = queue_discard_zeroes_data_show,
 436 };
 437
 438 static struct queue_sysfs_entry queue_write_same_max_entry = {
 439         .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
 440         .show = queue_write_same_max_show,
 441 };
 442
 443 static struct queue_sysfs_entry queue_nonrot_entry = {
 444         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
 445         .show = queue_show_nonrot,
 446         .store = queue_store_nonrot,
 447 };
 448
 449 static struct queue_sysfs_entry queue_nomerges_entry = {
 450         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
 451         .show = queue_nomerges_show,
 452         .store = queue_nomerges_store,
 453 };
 454
 455 static struct queue_sysfs_entry queue_rq_affinity_entry = {
 456         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
 457         .show = queue_rq_affinity_show,
 458         .store = queue_rq_affinity_store,
 459 };
 460
 461 static struct queue_sysfs_entry queue_iostats_entry = {
 462         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
 463         .show = queue_show_iostats,
 464         .store = queue_store_iostats,
 465 };
 466
 467 static struct queue_sysfs_entry queue_random_entry = {
 468         .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
 469         .show = queue_show_random,
 470         .store = queue_store_random,
 471 };
 472
 473 static struct queue_sysfs_entry queue_poll_entry = {
 474         .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR },
 475         .show = queue_poll_show,
 476         .store = queue_poll_store,
 477 };
 478
 479 static struct attribute *default_attrs[] = {
 480         &queue_requests_entry.attr,
 481         &queue_ra_entry.attr,
 482         &queue_max_hw_sectors_entry.attr,
 483         &queue_max_sectors_entry.attr,
 484         &queue_max_segments_entry.attr,
 485         &queue_max_integrity_segments_entry.attr,
 486         &queue_max_segment_size_entry.attr,
 487         &queue_iosched_entry.attr,
 488         &queue_hw_sector_size_entry.attr,
 489         &queue_logical_block_size_entry.attr,
 490         &queue_physical_block_size_entry.attr,
 491         &queue_io_min_entry.attr,
 492         &queue_io_opt_entry.attr,
 493         &queue_discard_granularity_entry.attr,
 494         &queue_discard_max_entry.attr,
 495         &queue_discard_max_hw_entry.attr,
 496         &queue_discard_zeroes_data_entry.attr,
 497         &queue_write_same_max_entry.attr,
 498         &queue_nonrot_entry.attr,
 499         &queue_nomerges_entry.attr,
 500         &queue_rq_affinity_entry.attr,
 501         &queue_iostats_entry.attr,
 502         &queue_random_entry.attr,
 503         &queue_poll_entry.attr,
 504         NULL,
 505 };
 506
 507 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
 508
 509 static ssize_t
 510 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 511 {
 512         struct queue_sysfs_entry *entry = to_queue(attr);
 513         struct request_queue *q =
 514                 container_of(kobj, struct request_queue, kobj);
 515         ssize_t res;
 516
 517         if (!entry->show)
 518                 return -EIO;
 519         mutex_lock(&q->sysfs_lock);
 520         if (blk_queue_dying(q)) {
 521                 mutex_unlock(&q->sysfs_lock);
 522                 return -ENOENT;
 523         }
 524         res = entry->show(q, page);
 525         mutex_unlock(&q->sysfs_lock);
 526         return res;
 527 }
 528
 529 static ssize_t
 530 queue_attr_store(struct kobject *kobj, struct attribute *attr,
 531                     const char *page, size_t length)
 532 {
 533         struct queue_sysfs_entry *entry = to_queue(attr);
 534         struct request_queue *q;
 535         ssize_t res;
 536
 537         if (!entry->store)
 538                 return -EIO;
 539
 540         q = container_of(kobj, struct request_queue, kobj);
 541         mutex_lock(&q->sysfs_lock);
 542         if (blk_queue_dying(q)) {
 543                 mutex_unlock(&q->sysfs_lock);
 544                 return -ENOENT;
 545         }
 546         res = entry->store(q, page, length);
 547         mutex_unlock(&q->sysfs_lock);
 548         return res;
 549 }
 550
 551 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 552 {
 553         struct request_queue *q = container_of(rcu_head, struct request_queue,
 554                                                rcu_head);
 555         kmem_cache_free(blk_requestq_cachep, q);
 556 }
 557
 558 /**
 559  * blk_release_queue: - release a &struct request_queue when it is no longer needed
 560  * @kobj:    the kobj belonging to the request queue to be released
 561  *
 562  * Description:
 563  *     blk_release_queue is the pair to blk_init_queue() or
 564  *     blk_queue_make_request().  It should be called when a request queue is
 565  *     being released; typically when a block device is being de-registered.
 566  *     Currently, its primary task it to free all the &struct request
 567  *     structures that were allocated to the queue and the queue itself.
 568  *
 569  * Note:
 570  *     The low level driver must have finished any outstanding requests first
 571  *     via blk_cleanup_queue().
 572  **/
 573 static void blk_release_queue(struct kobject *kobj)
 574 {
 575         struct request_queue *q =
 576                 container_of(kobj, struct request_queue, kobj);
 577
 578         bdi_exit(&q->backing_dev_info);
 579         blkcg_exit_queue(q);
 580
 581         if (q->elevator) {
 582                 spin_lock_irq(q->queue_lock);
 583                 ioc_clear_queue(q);
 584                 spin_unlock_irq(q->queue_lock);
 585                 elevator_exit(q->elevator);
 586         }
 587
 588         blk_exit_rl(&q->root_rl);
 589
 590         if (q->queue_tags)
 591                 __blk_queue_free_tags(q);
 592
 593         if (!q->mq_ops)
 594                 blk_free_flush_queue(q->fq);
 595         else
 596                 blk_mq_release(q);
 597
 598         blk_trace_shutdown(q);
 599
 600         if (q->bio_split)
 601                 bioset_free(q->bio_split);
 602
 603         ida_simple_remove(&blk_queue_ida, q->id);
 604         call_rcu(&q->rcu_head, blk_free_queue_rcu);
 605 }
 606
 607 static const struct sysfs_ops queue_sysfs_ops = {
 608         .show   = queue_attr_show,
 609         .store  = queue_attr_store,
 610 };
 611
 612 struct kobj_type blk_queue_ktype = {
 613         .sysfs_ops      = &queue_sysfs_ops,
 614         .default_attrs  = default_attrs,
 615         .release        = blk_release_queue,
 616 };
 617
 618 int blk_register_queue(struct gendisk *disk)
 619 {
 620         int ret;
 621         struct device *dev = disk_to_dev(disk);
 622         struct request_queue *q = disk->queue;
 623
 624         if (WARN_ON(!q))
 625                 return -ENXIO;
 626
 627         /*
 628          * SCSI probing may synchronously create and destroy a lot of
 629          * request_queues for non-existent devices.  Shutting down a fully
 630          * functional queue takes measureable wallclock time as RCU grace
 631          * periods are involved.  To avoid excessive latency in these
 632          * cases, a request_queue starts out in a degraded mode which is
 633          * faster to shut down and is made fully functional here as
 634          * request_queues for non-existent devices never get registered.
 635          */
 636         if (!blk_queue_init_done(q)) {
 637                 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
 638                 percpu_ref_switch_to_percpu(&q->q_usage_counter);
 639                 blk_queue_bypass_end(q);
 640         }
 641
 642         ret = blk_trace_init_sysfs(dev);
 643         if (ret)
 644                 return ret;
 645
 646         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
 647         if (ret < 0) {
 648                 blk_trace_remove_sysfs(dev);
 649                 return ret;
 650         }
 651
 652         kobject_uevent(&q->kobj, KOBJ_ADD);
 653
 654         if (q->mq_ops)
 655                 blk_mq_register_disk(disk);
 656
 657         if (!q->request_fn)
 658                 return 0;
 659
 660         ret = elv_register_queue(q);
 661         if (ret) {
 662                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
 663                 kobject_del(&q->kobj);
 664                 blk_trace_remove_sysfs(dev);
 665                 kobject_put(&dev->kobj);
 666                 return ret;
 667         }
 668
 669         return 0;
 670 }
 671
 672 void blk_unregister_queue(struct gendisk *disk)
 673 {
 674         struct request_queue *q = disk->queue;
 675
 676         if (WARN_ON(!q))
 677                 return;
 678
 679         if (q->mq_ops)
 680                 blk_mq_unregister_disk(disk);
 681
 682         if (q->request_fn)
 683                 elv_unregister_queue(q);
 684
 685         kobject_uevent(&q->kobj, KOBJ_REMOVE);
 686         kobject_del(&q->kobj);
 687         blk_trace_remove_sysfs(disk_to_dev(disk));
 688         kobject_put(&disk_to_dev(disk)->kobj);
 689 }