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_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_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_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 { 150 151 return sprintf(page, "%llu\n", 152 (unsigned long long)q->limits.max_hw_discard_sectors << 9); 153 } 154 155 static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 156 { 157 return sprintf(page, "%llu\n", 158 (unsigned long long)q->limits.max_discard_sectors << 9); 159 } 160 161 static ssize_t queue_discard_max_store(struct request_queue *q, 162 const char *page, size_t count) 163 { 164 unsigned long max_discard; 165 ssize_t ret = queue_var_store(&max_discard, page, count); 166 167 if (ret < 0) 168 return ret; 169 170 if (max_discard & (q->limits.discard_granularity - 1)) 171 return -EINVAL; 172 173 max_discard >>= 9; 174 if (max_discard > UINT_MAX) 175 return -EINVAL; 176 177 if (max_discard > q->limits.max_hw_discard_sectors) 178 max_discard = q->limits.max_hw_discard_sectors; 179 180 q->limits.max_discard_sectors = max_discard; 181 return ret; 182 } 183 184 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 185 { 186 return queue_var_show(queue_discard_zeroes_data(q), page); 187 } 188 189 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) 190 { 191 return sprintf(page, "%llu\n", 192 (unsigned long long)q->limits.max_write_same_sectors << 9); 193 } 194 195 196 static ssize_t 197 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 198 { 199 unsigned long max_sectors_kb, 200 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, 201 page_kb = 1 << (PAGE_SHIFT - 10); 202 ssize_t ret = queue_var_store(&max_sectors_kb, page, count); 203 204 if (ret < 0) 205 return ret; 206 207 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) 208 q->limits.max_dev_sectors >> 1); 209 210 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) 211 return -EINVAL; 212 213 spin_lock_irq(q->queue_lock); 214 q->limits.max_sectors = max_sectors_kb << 1; 215 spin_unlock_irq(q->queue_lock); 216 217 return ret; 218 } 219 220 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 221 { 222 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 223 224 return queue_var_show(max_hw_sectors_kb, (page)); 225 } 226 227 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 228 static ssize_t \ 229 queue_show_##name(struct request_queue *q, char *page) \ 230 { \ 231 int bit; \ 232 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 233 return queue_var_show(neg ? !bit : bit, page); \ 234 } \ 235 static ssize_t \ 236 queue_store_##name(struct request_queue *q, const char *page, size_t count) \ 237 { \ 238 unsigned long val; \ 239 ssize_t ret; \ 240 ret = queue_var_store(&val, page, count); \ 241 if (ret < 0) \ 242 return ret; \ 243 if (neg) \ 244 val = !val; \ 245 \ 246 spin_lock_irq(q->queue_lock); \ 247 if (val) \ 248 queue_flag_set(QUEUE_FLAG_##flag, q); \ 249 else \ 250 queue_flag_clear(QUEUE_FLAG_##flag, q); \ 251 spin_unlock_irq(q->queue_lock); \ 252 return ret; \ 253 } 254 255 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 256 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 257 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 258 #undef QUEUE_SYSFS_BIT_FNS 259 260 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 261 { 262 return queue_var_show((blk_queue_nomerges(q) << 1) | 263 blk_queue_noxmerges(q), page); 264 } 265 266 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 267 size_t count) 268 { 269 unsigned long nm; 270 ssize_t ret = queue_var_store(&nm, page, count); 271 272 if (ret < 0) 273 return ret; 274 275 spin_lock_irq(q->queue_lock); 276 queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 277 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 278 if (nm == 2) 279 queue_flag_set(QUEUE_FLAG_NOMERGES, q); 280 else if (nm) 281 queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 282 spin_unlock_irq(q->queue_lock); 283 284 return ret; 285 } 286 287 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 288 { 289 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 290 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 291 292 return queue_var_show(set << force, page); 293 } 294 295 static ssize_t 296 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 297 { 298 ssize_t ret = -EINVAL; 299 #ifdef CONFIG_SMP 300 unsigned long val; 301 302 ret = queue_var_store(&val, page, count); 303 if (ret < 0) 304 return ret; 305 306 spin_lock_irq(q->queue_lock); 307 if (val == 2) { 308 queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 309 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 310 } else if (val == 1) { 311 queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 312 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 313 } else if (val == 0) { 314 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 315 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 316 } 317 spin_unlock_irq(q->queue_lock); 318 #endif 319 return ret; 320 } 321 322 static ssize_t queue_poll_show(struct request_queue *q, char *page) 323 { 324 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); 325 } 326 327 static ssize_t queue_poll_store(struct request_queue *q, const char *page, 328 size_t count) 329 { 330 unsigned long poll_on; 331 ssize_t ret; 332 333 if (!q->mq_ops || !q->mq_ops->poll) 334 return -EINVAL; 335 336 ret = queue_var_store(&poll_on, page, count); 337 if (ret < 0) 338 return ret; 339 340 spin_lock_irq(q->queue_lock); 341 if (poll_on) 342 queue_flag_set(QUEUE_FLAG_POLL, q); 343 else 344 queue_flag_clear(QUEUE_FLAG_POLL, q); 345 spin_unlock_irq(q->queue_lock); 346 347 return ret; 348 } 349 350 static ssize_t queue_wc_show(struct request_queue *q, char *page) 351 { 352 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 353 return sprintf(page, "write back\n"); 354 355 return sprintf(page, "write through\n"); 356 } 357 358 static ssize_t queue_wc_store(struct request_queue *q, const char *page, 359 size_t count) 360 { 361 int set = -1; 362 363 if (!strncmp(page, "write back", 10)) 364 set = 1; 365 else if (!strncmp(page, "write through", 13) || 366 !strncmp(page, "none", 4)) 367 set = 0; 368 369 if (set == -1) 370 return -EINVAL; 371 372 spin_lock_irq(q->queue_lock); 373 if (set) 374 queue_flag_set(QUEUE_FLAG_WC, q); 375 else 376 queue_flag_clear(QUEUE_FLAG_WC, q); 377 spin_unlock_irq(q->queue_lock); 378 379 return count; 380 } 381 382 static struct queue_sysfs_entry queue_requests_entry = { 383 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, 384 .show = queue_requests_show, 385 .store = queue_requests_store, 386 }; 387 388 static struct queue_sysfs_entry queue_ra_entry = { 389 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR }, 390 .show = queue_ra_show, 391 .store = queue_ra_store, 392 }; 393 394 static struct queue_sysfs_entry queue_max_sectors_entry = { 395 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR }, 396 .show = queue_max_sectors_show, 397 .store = queue_max_sectors_store, 398 }; 399 400 static struct queue_sysfs_entry queue_max_hw_sectors_entry = { 401 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO }, 402 .show = queue_max_hw_sectors_show, 403 }; 404 405 static struct queue_sysfs_entry queue_max_segments_entry = { 406 .attr = {.name = "max_segments", .mode = S_IRUGO }, 407 .show = queue_max_segments_show, 408 }; 409 410 static struct queue_sysfs_entry queue_max_integrity_segments_entry = { 411 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, 412 .show = queue_max_integrity_segments_show, 413 }; 414 415 static struct queue_sysfs_entry queue_max_segment_size_entry = { 416 .attr = {.name = "max_segment_size", .mode = S_IRUGO }, 417 .show = queue_max_segment_size_show, 418 }; 419 420 static struct queue_sysfs_entry queue_iosched_entry = { 421 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, 422 .show = elv_iosched_show, 423 .store = elv_iosched_store, 424 }; 425 426 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 427 .attr = {.name = "hw_sector_size", .mode = S_IRUGO }, 428 .show = queue_logical_block_size_show, 429 }; 430 431 static struct queue_sysfs_entry queue_logical_block_size_entry = { 432 .attr = {.name = "logical_block_size", .mode = S_IRUGO }, 433 .show = queue_logical_block_size_show, 434 }; 435 436 static struct queue_sysfs_entry queue_physical_block_size_entry = { 437 .attr = {.name = "physical_block_size", .mode = S_IRUGO }, 438 .show = queue_physical_block_size_show, 439 }; 440 441 static struct queue_sysfs_entry queue_io_min_entry = { 442 .attr = {.name = "minimum_io_size", .mode = S_IRUGO }, 443 .show = queue_io_min_show, 444 }; 445 446 static struct queue_sysfs_entry queue_io_opt_entry = { 447 .attr = {.name = "optimal_io_size", .mode = S_IRUGO }, 448 .show = queue_io_opt_show, 449 }; 450 451 static struct queue_sysfs_entry queue_discard_granularity_entry = { 452 .attr = {.name = "discard_granularity", .mode = S_IRUGO }, 453 .show = queue_discard_granularity_show, 454 }; 455 456 static struct queue_sysfs_entry queue_discard_max_hw_entry = { 457 .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO }, 458 .show = queue_discard_max_hw_show, 459 }; 460 461 static struct queue_sysfs_entry queue_discard_max_entry = { 462 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR }, 463 .show = queue_discard_max_show, 464 .store = queue_discard_max_store, 465 }; 466 467 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { 468 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO }, 469 .show = queue_discard_zeroes_data_show, 470 }; 471 472 static struct queue_sysfs_entry queue_write_same_max_entry = { 473 .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO }, 474 .show = queue_write_same_max_show, 475 }; 476 477 static struct queue_sysfs_entry queue_nonrot_entry = { 478 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, 479 .show = queue_show_nonrot, 480 .store = queue_store_nonrot, 481 }; 482 483 static struct queue_sysfs_entry queue_nomerges_entry = { 484 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, 485 .show = queue_nomerges_show, 486 .store = queue_nomerges_store, 487 }; 488 489 static struct queue_sysfs_entry queue_rq_affinity_entry = { 490 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR }, 491 .show = queue_rq_affinity_show, 492 .store = queue_rq_affinity_store, 493 }; 494 495 static struct queue_sysfs_entry queue_iostats_entry = { 496 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, 497 .show = queue_show_iostats, 498 .store = queue_store_iostats, 499 }; 500 501 static struct queue_sysfs_entry queue_random_entry = { 502 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR }, 503 .show = queue_show_random, 504 .store = queue_store_random, 505 }; 506 507 static struct queue_sysfs_entry queue_poll_entry = { 508 .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR }, 509 .show = queue_poll_show, 510 .store = queue_poll_store, 511 }; 512 513 static struct queue_sysfs_entry queue_wc_entry = { 514 .attr = {.name = "write_cache", .mode = S_IRUGO | S_IWUSR }, 515 .show = queue_wc_show, 516 .store = queue_wc_store, 517 }; 518 519 static struct attribute *default_attrs[] = { 520 &queue_requests_entry.attr, 521 &queue_ra_entry.attr, 522 &queue_max_hw_sectors_entry.attr, 523 &queue_max_sectors_entry.attr, 524 &queue_max_segments_entry.attr, 525 &queue_max_integrity_segments_entry.attr, 526 &queue_max_segment_size_entry.attr, 527 &queue_iosched_entry.attr, 528 &queue_hw_sector_size_entry.attr, 529 &queue_logical_block_size_entry.attr, 530 &queue_physical_block_size_entry.attr, 531 &queue_io_min_entry.attr, 532 &queue_io_opt_entry.attr, 533 &queue_discard_granularity_entry.attr, 534 &queue_discard_max_entry.attr, 535 &queue_discard_max_hw_entry.attr, 536 &queue_discard_zeroes_data_entry.attr, 537 &queue_write_same_max_entry.attr, 538 &queue_nonrot_entry.attr, 539 &queue_nomerges_entry.attr, 540 &queue_rq_affinity_entry.attr, 541 &queue_iostats_entry.attr, 542 &queue_random_entry.attr, 543 &queue_poll_entry.attr, 544 &queue_wc_entry.attr, 545 NULL, 546 }; 547 548 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 549 550 static ssize_t 551 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 552 { 553 struct queue_sysfs_entry *entry = to_queue(attr); 554 struct request_queue *q = 555 container_of(kobj, struct request_queue, kobj); 556 ssize_t res; 557 558 if (!entry->show) 559 return -EIO; 560 mutex_lock(&q->sysfs_lock); 561 if (blk_queue_dying(q)) { 562 mutex_unlock(&q->sysfs_lock); 563 return -ENOENT; 564 } 565 res = entry->show(q, page); 566 mutex_unlock(&q->sysfs_lock); 567 return res; 568 } 569 570 static ssize_t 571 queue_attr_store(struct kobject *kobj, struct attribute *attr, 572 const char *page, size_t length) 573 { 574 struct queue_sysfs_entry *entry = to_queue(attr); 575 struct request_queue *q; 576 ssize_t res; 577 578 if (!entry->store) 579 return -EIO; 580 581 q = container_of(kobj, struct request_queue, kobj); 582 mutex_lock(&q->sysfs_lock); 583 if (blk_queue_dying(q)) { 584 mutex_unlock(&q->sysfs_lock); 585 return -ENOENT; 586 } 587 res = entry->store(q, page, length); 588 mutex_unlock(&q->sysfs_lock); 589 return res; 590 } 591 592 static void blk_free_queue_rcu(struct rcu_head *rcu_head) 593 { 594 struct request_queue *q = container_of(rcu_head, struct request_queue, 595 rcu_head); 596 kmem_cache_free(blk_requestq_cachep, q); 597 } 598 599 /** 600 * blk_release_queue: - release a &struct request_queue when it is no longer needed 601 * @kobj: the kobj belonging to the request queue to be released 602 * 603 * Description: 604 * blk_release_queue is the pair to blk_init_queue() or 605 * blk_queue_make_request(). It should be called when a request queue is 606 * being released; typically when a block device is being de-registered. 607 * Currently, its primary task it to free all the &struct request 608 * structures that were allocated to the queue and the queue itself. 609 * 610 * Note: 611 * The low level driver must have finished any outstanding requests first 612 * via blk_cleanup_queue(). 613 **/ 614 static void blk_release_queue(struct kobject *kobj) 615 { 616 struct request_queue *q = 617 container_of(kobj, struct request_queue, kobj); 618 619 bdi_exit(&q->backing_dev_info); 620 blkcg_exit_queue(q); 621 622 if (q->elevator) { 623 spin_lock_irq(q->queue_lock); 624 ioc_clear_queue(q); 625 spin_unlock_irq(q->queue_lock); 626 elevator_exit(q->elevator); 627 } 628 629 blk_exit_rl(&q->root_rl); 630 631 if (q->queue_tags) 632 __blk_queue_free_tags(q); 633 634 if (!q->mq_ops) 635 blk_free_flush_queue(q->fq); 636 else 637 blk_mq_release(q); 638 639 blk_trace_shutdown(q); 640 641 if (q->bio_split) 642 bioset_free(q->bio_split); 643 644 ida_simple_remove(&blk_queue_ida, q->id); 645 call_rcu(&q->rcu_head, blk_free_queue_rcu); 646 } 647 648 static const struct sysfs_ops queue_sysfs_ops = { 649 .show = queue_attr_show, 650 .store = queue_attr_store, 651 }; 652 653 struct kobj_type blk_queue_ktype = { 654 .sysfs_ops = &queue_sysfs_ops, 655 .default_attrs = default_attrs, 656 .release = blk_release_queue, 657 }; 658 659 int blk_register_queue(struct gendisk *disk) 660 { 661 int ret; 662 struct device *dev = disk_to_dev(disk); 663 struct request_queue *q = disk->queue; 664 665 if (WARN_ON(!q)) 666 return -ENXIO; 667 668 /* 669 * SCSI probing may synchronously create and destroy a lot of 670 * request_queues for non-existent devices. Shutting down a fully 671 * functional queue takes measureable wallclock time as RCU grace 672 * periods are involved. To avoid excessive latency in these 673 * cases, a request_queue starts out in a degraded mode which is 674 * faster to shut down and is made fully functional here as 675 * request_queues for non-existent devices never get registered. 676 */ 677 if (!blk_queue_init_done(q)) { 678 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q); 679 percpu_ref_switch_to_percpu(&q->q_usage_counter); 680 blk_queue_bypass_end(q); 681 } 682 683 ret = blk_trace_init_sysfs(dev); 684 if (ret) 685 return ret; 686 687 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 688 if (ret < 0) { 689 blk_trace_remove_sysfs(dev); 690 return ret; 691 } 692 693 kobject_uevent(&q->kobj, KOBJ_ADD); 694 695 if (q->mq_ops) 696 blk_mq_register_disk(disk); 697 698 if (!q->request_fn) 699 return 0; 700 701 ret = elv_register_queue(q); 702 if (ret) { 703 kobject_uevent(&q->kobj, KOBJ_REMOVE); 704 kobject_del(&q->kobj); 705 blk_trace_remove_sysfs(dev); 706 kobject_put(&dev->kobj); 707 return ret; 708 } 709 710 return 0; 711 } 712 713 void blk_unregister_queue(struct gendisk *disk) 714 { 715 struct request_queue *q = disk->queue; 716 717 if (WARN_ON(!q)) 718 return; 719 720 if (q->mq_ops) 721 blk_mq_unregister_disk(disk); 722 723 if (q->request_fn) 724 elv_unregister_queue(q); 725 726 kobject_uevent(&q->kobj, KOBJ_REMOVE); 727 kobject_del(&q->kobj); 728 blk_trace_remove_sysfs(disk_to_dev(disk)); 729 kobject_put(&disk_to_dev(disk)->kobj); 730 } 731