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         max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
 209                                          q->limits.max_dev_sectors >> 1);
 210
 211         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
 212                 return -EINVAL;
 213
 214         spin_lock_irq(q->queue_lock);
 215         q->limits.max_sectors = max_sectors_kb << 1;
 216         spin_unlock_irq(q->queue_lock);
 217
 218         return ret;
 219 }
 220
 221 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 222 {
 223         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 224
 225         return queue_var_show(max_hw_sectors_kb, (page));
 226 }
 227
 228 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
 229 static ssize_t                                                          \
 230 queue_show_##name(struct request_queue *q, char *page)                  \
 231 {                                                                       \
 232         int bit;                                                        \
 233         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
 234         return queue_var_show(neg ? !bit : bit, page);                  \
 235 }                                                                       \
 236 static ssize_t                                                          \
 237 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
 238 {                                                                       \
 239         unsigned long val;                                              \
 240         ssize_t ret;                                                    \
 241         ret = queue_var_store(&val, page, count);                       \
 242         if (ret < 0)                                                    \
 243                  return ret;                                            \
 244         if (neg)                                                        \
 245                 val = !val;                                             \
 246                                                                         \
 247         spin_lock_irq(q->queue_lock);                                   \
 248         if (val)                                                        \
 249                 queue_flag_set(QUEUE_FLAG_##flag, q);                   \
 250         else                                                            \
 251                 queue_flag_clear(QUEUE_FLAG_##flag, q);                 \
 252         spin_unlock_irq(q->queue_lock);                                 \
 253         return ret;                                                     \
 254 }
 255
 256 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
 257 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
 258 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 259 #undef QUEUE_SYSFS_BIT_FNS
 260
 261 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 262 {
 263         return queue_var_show((blk_queue_nomerges(q) << 1) |
 264                                blk_queue_noxmerges(q), page);
 265 }
 266
 267 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 268                                     size_t count)
 269 {
 270         unsigned long nm;
 271         ssize_t ret = queue_var_store(&nm, page, count);
 272
 273         if (ret < 0)
 274                 return ret;
 275
 276         spin_lock_irq(q->queue_lock);
 277         queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 278         queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 279         if (nm == 2)
 280                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 281         else if (nm)
 282                 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 283         spin_unlock_irq(q->queue_lock);
 284
 285         return ret;
 286 }
 287
 288 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
 289 {
 290         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
 291         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
 292
 293         return queue_var_show(set << force, page);
 294 }
 295
 296 static ssize_t
 297 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 298 {
 299         ssize_t ret = -EINVAL;
 300 #ifdef CONFIG_SMP
 301         unsigned long val;
 302
 303         ret = queue_var_store(&val, page, count);
 304         if (ret < 0)
 305                 return ret;
 306
 307         spin_lock_irq(q->queue_lock);
 308         if (val == 2) {
 309                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 310                 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
 311         } else if (val == 1) {
 312                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 313                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 314         } else if (val == 0) {
 315                 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 316                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 317         }
 318         spin_unlock_irq(q->queue_lock);
 319 #endif
 320         return ret;
 321 }
 322
 323 static struct queue_sysfs_entry queue_requests_entry = {
 324         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
 325         .show = queue_requests_show,
 326         .store = queue_requests_store,
 327 };
 328
 329 static struct queue_sysfs_entry queue_ra_entry = {
 330         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
 331         .show = queue_ra_show,
 332         .store = queue_ra_store,
 333 };
 334
 335 static struct queue_sysfs_entry queue_max_sectors_entry = {
 336         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
 337         .show = queue_max_sectors_show,
 338         .store = queue_max_sectors_store,
 339 };
 340
 341 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
 342         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
 343         .show = queue_max_hw_sectors_show,
 344 };
 345
 346 static struct queue_sysfs_entry queue_max_segments_entry = {
 347         .attr = {.name = "max_segments", .mode = S_IRUGO },
 348         .show = queue_max_segments_show,
 349 };
 350
 351 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
 352         .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
 353         .show = queue_max_integrity_segments_show,
 354 };
 355
 356 static struct queue_sysfs_entry queue_max_segment_size_entry = {
 357         .attr = {.name = "max_segment_size", .mode = S_IRUGO },
 358         .show = queue_max_segment_size_show,
 359 };
 360
 361 static struct queue_sysfs_entry queue_iosched_entry = {
 362         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
 363         .show = elv_iosched_show,
 364         .store = elv_iosched_store,
 365 };
 366
 367 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 368         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
 369         .show = queue_logical_block_size_show,
 370 };
 371
 372 static struct queue_sysfs_entry queue_logical_block_size_entry = {
 373         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
 374         .show = queue_logical_block_size_show,
 375 };
 376
 377 static struct queue_sysfs_entry queue_physical_block_size_entry = {
 378         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
 379         .show = queue_physical_block_size_show,
 380 };
 381
 382 static struct queue_sysfs_entry queue_io_min_entry = {
 383         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
 384         .show = queue_io_min_show,
 385 };
 386
 387 static struct queue_sysfs_entry queue_io_opt_entry = {
 388         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
 389         .show = queue_io_opt_show,
 390 };
 391
 392 static struct queue_sysfs_entry queue_discard_granularity_entry = {
 393         .attr = {.name = "discard_granularity", .mode = S_IRUGO },
 394         .show = queue_discard_granularity_show,
 395 };
 396
 397 static struct queue_sysfs_entry queue_discard_max_hw_entry = {
 398         .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
 399         .show = queue_discard_max_hw_show,
 400 };
 401
 402 static struct queue_sysfs_entry queue_discard_max_entry = {
 403         .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
 404         .show = queue_discard_max_show,
 405         .store = queue_discard_max_store,
 406 };
 407
 408 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
 409         .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
 410         .show = queue_discard_zeroes_data_show,
 411 };
 412
 413 static struct queue_sysfs_entry queue_write_same_max_entry = {
 414         .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
 415         .show = queue_write_same_max_show,
 416 };
 417
 418 static struct queue_sysfs_entry queue_nonrot_entry = {
 419         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
 420         .show = queue_show_nonrot,
 421         .store = queue_store_nonrot,
 422 };
 423
 424 static struct queue_sysfs_entry queue_nomerges_entry = {
 425         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
 426         .show = queue_nomerges_show,
 427         .store = queue_nomerges_store,
 428 };
 429
 430 static struct queue_sysfs_entry queue_rq_affinity_entry = {
 431         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
 432         .show = queue_rq_affinity_show,
 433         .store = queue_rq_affinity_store,
 434 };
 435
 436 static struct queue_sysfs_entry queue_iostats_entry = {
 437         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
 438         .show = queue_show_iostats,
 439         .store = queue_store_iostats,
 440 };
 441
 442 static struct queue_sysfs_entry queue_random_entry = {
 443         .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
 444         .show = queue_show_random,
 445         .store = queue_store_random,
 446 };
 447
 448 static struct attribute *default_attrs[] = {
 449         &queue_requests_entry.attr,
 450         &queue_ra_entry.attr,
 451         &queue_max_hw_sectors_entry.attr,
 452         &queue_max_sectors_entry.attr,
 453         &queue_max_segments_entry.attr,
 454         &queue_max_integrity_segments_entry.attr,
 455         &queue_max_segment_size_entry.attr,
 456         &queue_iosched_entry.attr,
 457         &queue_hw_sector_size_entry.attr,
 458         &queue_logical_block_size_entry.attr,
 459         &queue_physical_block_size_entry.attr,
 460         &queue_io_min_entry.attr,
 461         &queue_io_opt_entry.attr,
 462         &queue_discard_granularity_entry.attr,
 463         &queue_discard_max_entry.attr,
 464         &queue_discard_max_hw_entry.attr,
 465         &queue_discard_zeroes_data_entry.attr,
 466         &queue_write_same_max_entry.attr,
 467         &queue_nonrot_entry.attr,
 468         &queue_nomerges_entry.attr,
 469         &queue_rq_affinity_entry.attr,
 470         &queue_iostats_entry.attr,
 471         &queue_random_entry.attr,
 472         NULL,
 473 };
 474
 475 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
 476
 477 static ssize_t
 478 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 479 {
 480         struct queue_sysfs_entry *entry = to_queue(attr);
 481         struct request_queue *q =
 482                 container_of(kobj, struct request_queue, kobj);
 483         ssize_t res;
 484
 485         if (!entry->show)
 486                 return -EIO;
 487         mutex_lock(&q->sysfs_lock);
 488         if (blk_queue_dying(q)) {
 489                 mutex_unlock(&q->sysfs_lock);
 490                 return -ENOENT;
 491         }
 492         res = entry->show(q, page);
 493         mutex_unlock(&q->sysfs_lock);
 494         return res;
 495 }
 496
 497 static ssize_t
 498 queue_attr_store(struct kobject *kobj, struct attribute *attr,
 499                     const char *page, size_t length)
 500 {
 501         struct queue_sysfs_entry *entry = to_queue(attr);
 502         struct request_queue *q;
 503         ssize_t res;
 504
 505         if (!entry->store)
 506                 return -EIO;
 507
 508         q = container_of(kobj, struct request_queue, kobj);
 509         mutex_lock(&q->sysfs_lock);
 510         if (blk_queue_dying(q)) {
 511                 mutex_unlock(&q->sysfs_lock);
 512                 return -ENOENT;
 513         }
 514         res = entry->store(q, page, length);
 515         mutex_unlock(&q->sysfs_lock);
 516         return res;
 517 }
 518
 519 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 520 {
 521         struct request_queue *q = container_of(rcu_head, struct request_queue,
 522                                                rcu_head);
 523         kmem_cache_free(blk_requestq_cachep, q);
 524 }
 525
 526 /**
 527  * blk_release_queue: - release a &struct request_queue when it is no longer needed
 528  * @kobj:    the kobj belonging to the request queue to be released
 529  *
 530  * Description:
 531  *     blk_release_queue is the pair to blk_init_queue() or
 532  *     blk_queue_make_request().  It should be called when a request queue is
 533  *     being released; typically when a block device is being de-registered.
 534  *     Currently, its primary task it to free all the &struct request
 535  *     structures that were allocated to the queue and the queue itself.
 536  *
 537  * Note:
 538  *     The low level driver must have finished any outstanding requests first
 539  *     via blk_cleanup_queue().
 540  **/
 541 static void blk_release_queue(struct kobject *kobj)
 542 {
 543         struct request_queue *q =
 544                 container_of(kobj, struct request_queue, kobj);
 545
 546         blkcg_exit_queue(q);
 547
 548         if (q->elevator) {
 549                 spin_lock_irq(q->queue_lock);
 550                 ioc_clear_queue(q);
 551                 spin_unlock_irq(q->queue_lock);
 552                 elevator_exit(q->elevator);
 553         }
 554
 555         blk_exit_rl(&q->root_rl);
 556
 557         if (q->queue_tags)
 558                 __blk_queue_free_tags(q);
 559
 560         if (!q->mq_ops)
 561                 blk_free_flush_queue(q->fq);
 562         else
 563                 blk_mq_release(q);
 564
 565         blk_trace_shutdown(q);
 566
 567         if (q->bio_split)
 568                 bioset_free(q->bio_split);
 569
 570         ida_simple_remove(&blk_queue_ida, q->id);
 571         call_rcu(&q->rcu_head, blk_free_queue_rcu);
 572 }
 573
 574 static const struct sysfs_ops queue_sysfs_ops = {
 575         .show   = queue_attr_show,
 576         .store  = queue_attr_store,
 577 };
 578
 579 struct kobj_type blk_queue_ktype = {
 580         .sysfs_ops      = &queue_sysfs_ops,
 581         .default_attrs  = default_attrs,
 582         .release        = blk_release_queue,
 583 };
 584
 585 int blk_register_queue(struct gendisk *disk)
 586 {
 587         int ret;
 588         struct device *dev = disk_to_dev(disk);
 589         struct request_queue *q = disk->queue;
 590
 591         if (WARN_ON(!q))
 592                 return -ENXIO;
 593
 594         /*
 595          * SCSI probing may synchronously create and destroy a lot of
 596          * request_queues for non-existent devices.  Shutting down a fully
 597          * functional queue takes measureable wallclock time as RCU grace
 598          * periods are involved.  To avoid excessive latency in these
 599          * cases, a request_queue starts out in a degraded mode which is
 600          * faster to shut down and is made fully functional here as
 601          * request_queues for non-existent devices never get registered.
 602          */
 603         if (!blk_queue_init_done(q)) {
 604                 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
 605                 blk_queue_bypass_end(q);
 606                 if (q->mq_ops)
 607                         blk_mq_finish_init(q);
 608         }
 609
 610         ret = blk_trace_init_sysfs(dev);
 611         if (ret)
 612                 return ret;
 613
 614         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
 615         if (ret < 0) {
 616                 blk_trace_remove_sysfs(dev);
 617                 return ret;
 618         }
 619
 620         kobject_uevent(&q->kobj, KOBJ_ADD);
 621
 622         if (q->mq_ops)
 623                 blk_mq_register_disk(disk);
 624
 625         if (!q->request_fn)
 626                 return 0;
 627
 628         ret = elv_register_queue(q);
 629         if (ret) {
 630                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
 631                 kobject_del(&q->kobj);
 632                 blk_trace_remove_sysfs(dev);
 633                 kobject_put(&dev->kobj);
 634                 return ret;
 635         }
 636
 637         return 0;
 638 }
 639
 640 void blk_unregister_queue(struct gendisk *disk)
 641 {
 642         struct request_queue *q = disk->queue;
 643
 644         if (WARN_ON(!q))
 645                 return;
 646
 647         if (q->mq_ops)
 648                 blk_mq_unregister_disk(disk);
 649
 650         if (q->request_fn)
 651                 elv_unregister_queue(q);
 652
 653         kobject_uevent(&q->kobj, KOBJ_REMOVE);
 654         kobject_del(&q->kobj);
 655         blk_trace_remove_sysfs(disk_to_dev(disk));
 656         kobject_put(&disk_to_dev(disk)->kobj);
 657 }