1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Functions related to sysfs handling 4 */ 5#include <linux/kernel.h> 6#include <linux/slab.h> 7#include <linux/module.h> 8#include <linux/bio.h> 9#include <linux/blkdev.h> 10#include <linux/backing-dev.h> 11#include <linux/blktrace_api.h> 12#include <linux/debugfs.h> 13 14#include "blk.h" 15#include "blk-mq.h" 16#include "blk-mq-debugfs.h" 17#include "blk-mq-sched.h" 18#include "blk-rq-qos.h" 19#include "blk-wbt.h" 20#include "blk-cgroup.h" 21#include "blk-throttle.h" 22 23struct queue_sysfs_entry { 24 struct attribute attr; 25 ssize_t (*show)(struct request_queue *, char *); 26 ssize_t (*store)(struct request_queue *, const char *, size_t); 27}; 28 29static ssize_t 30queue_var_show(unsigned long var, char *page) 31{ 32 return sprintf(page, "%lu\n", var); 33} 34 35static ssize_t 36queue_var_store(unsigned long *var, const char *page, size_t count) 37{ 38 int err; 39 unsigned long v; 40 41 err = kstrtoul(page, 10, &v); 42 if (err || v > UINT_MAX) 43 return -EINVAL; 44 45 *var = v; 46 47 return count; 48} 49 50static ssize_t queue_requests_show(struct request_queue *q, char *page) 51{ 52 return queue_var_show(q->nr_requests, page); 53} 54 55static ssize_t 56queue_requests_store(struct request_queue *q, const char *page, size_t count) 57{ 58 unsigned long nr; 59 int ret, err; 60 61 if (!queue_is_mq(q)) 62 return -EINVAL; 63 64 ret = queue_var_store(&nr, page, count); 65 if (ret < 0) 66 return ret; 67 68 if (nr < BLKDEV_MIN_RQ) 69 nr = BLKDEV_MIN_RQ; 70 71 err = blk_mq_update_nr_requests(q, nr); 72 if (err) 73 return err; 74 75 return ret; 76} 77 78static ssize_t queue_ra_show(struct request_queue *q, char *page) 79{ 80 unsigned long ra_kb; 81 82 if (!q->disk) 83 return -EINVAL; 84 ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10); 85 return queue_var_show(ra_kb, page); 86} 87 88static ssize_t 89queue_ra_store(struct request_queue *q, const char *page, size_t count) 90{ 91 unsigned long ra_kb; 92 ssize_t ret; 93 94 if (!q->disk) 95 return -EINVAL; 96 ret = queue_var_store(&ra_kb, page, count); 97 if (ret < 0) 98 return ret; 99 q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10); 100 return ret; 101} 102 103static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) 104{ 105 int max_sectors_kb = queue_max_sectors(q) >> 1; 106 107 return queue_var_show(max_sectors_kb, page); 108} 109 110static ssize_t queue_max_segments_show(struct request_queue *q, char *page) 111{ 112 return queue_var_show(queue_max_segments(q), page); 113} 114 115static ssize_t queue_max_discard_segments_show(struct request_queue *q, 116 char *page) 117{ 118 return queue_var_show(queue_max_discard_segments(q), page); 119} 120 121static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) 122{ 123 return queue_var_show(q->limits.max_integrity_segments, page); 124} 125 126static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) 127{ 128 return queue_var_show(queue_max_segment_size(q), page); 129} 130 131static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) 132{ 133 return queue_var_show(queue_logical_block_size(q), page); 134} 135 136static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) 137{ 138 return queue_var_show(queue_physical_block_size(q), page); 139} 140 141static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page) 142{ 143 return queue_var_show(q->limits.chunk_sectors, page); 144} 145 146static ssize_t queue_io_min_show(struct request_queue *q, char *page) 147{ 148 return queue_var_show(queue_io_min(q), page); 149} 150 151static ssize_t queue_io_opt_show(struct request_queue *q, char *page) 152{ 153 return queue_var_show(queue_io_opt(q), page); 154} 155 156static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) 157{ 158 return queue_var_show(q->limits.discard_granularity, page); 159} 160 161static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page) 162{ 163 164 return sprintf(page, "%llu\n", 165 (unsigned long long)q->limits.max_hw_discard_sectors << 9); 166} 167 168static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 169{ 170 return sprintf(page, "%llu\n", 171 (unsigned long long)q->limits.max_discard_sectors << 9); 172} 173 174static ssize_t queue_discard_max_store(struct request_queue *q, 175 const char *page, size_t count) 176{ 177 unsigned long max_discard_bytes; 178 struct queue_limits lim; 179 ssize_t ret; 180 int err; 181 182 ret = queue_var_store(&max_discard_bytes, page, count); 183 if (ret < 0) 184 return ret; 185 186 if (max_discard_bytes & (q->limits.discard_granularity - 1)) 187 return -EINVAL; 188 189 if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX) 190 return -EINVAL; 191 192 blk_mq_freeze_queue(q); 193 lim = queue_limits_start_update(q); 194 lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT; 195 err = queue_limits_commit_update(q, &lim); 196 blk_mq_unfreeze_queue(q); 197 198 if (err) 199 return err; 200 return ret; 201} 202 203static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 204{ 205 return queue_var_show(0, page); 206} 207 208static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) 209{ 210 return queue_var_show(0, page); 211} 212 213static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page) 214{ 215 return sprintf(page, "%llu\n", 216 (unsigned long long)q->limits.max_write_zeroes_sectors << 9); 217} 218 219static ssize_t queue_zone_write_granularity_show(struct request_queue *q, 220 char *page) 221{ 222 return queue_var_show(queue_zone_write_granularity(q), page); 223} 224 225static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page) 226{ 227 unsigned long long max_sectors = queue_max_zone_append_sectors(q); 228 229 return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT); 230} 231 232static ssize_t 233queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 234{ 235 unsigned long max_sectors_kb; 236 struct queue_limits lim; 237 ssize_t ret; 238 int err; 239 240 ret = queue_var_store(&max_sectors_kb, page, count); 241 if (ret < 0) 242 return ret; 243 244 blk_mq_freeze_queue(q); 245 lim = queue_limits_start_update(q); 246 lim.max_user_sectors = max_sectors_kb << 1; 247 err = queue_limits_commit_update(q, &lim); 248 blk_mq_unfreeze_queue(q); 249 if (err) 250 return err; 251 return ret; 252} 253 254static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 255{ 256 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 257 258 return queue_var_show(max_hw_sectors_kb, page); 259} 260 261static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page) 262{ 263 return queue_var_show(q->limits.virt_boundary_mask, page); 264} 265 266static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page) 267{ 268 return queue_var_show(queue_dma_alignment(q), page); 269} 270 271#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 272static ssize_t \ 273queue_##name##_show(struct request_queue *q, char *page) \ 274{ \ 275 int bit; \ 276 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 277 return queue_var_show(neg ? !bit : bit, page); \ 278} \ 279static ssize_t \ 280queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ 281{ \ 282 unsigned long val; \ 283 ssize_t ret; \ 284 ret = queue_var_store(&val, page, count); \ 285 if (ret < 0) \ 286 return ret; \ 287 if (neg) \ 288 val = !val; \ 289 \ 290 if (val) \ 291 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \ 292 else \ 293 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \ 294 return ret; \ 295} 296 297QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 298QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 299QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 300QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0); 301#undef QUEUE_SYSFS_BIT_FNS 302 303static ssize_t queue_zoned_show(struct request_queue *q, char *page) 304{ 305 if (blk_queue_is_zoned(q)) 306 return sprintf(page, "host-managed\n"); 307 return sprintf(page, "none\n"); 308} 309 310static ssize_t queue_nr_zones_show(struct request_queue *q, char *page) 311{ 312 return queue_var_show(disk_nr_zones(q->disk), page); 313} 314 315static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page) 316{ 317 return queue_var_show(bdev_max_open_zones(q->disk->part0), page); 318} 319 320static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page) 321{ 322 return queue_var_show(bdev_max_active_zones(q->disk->part0), page); 323} 324 325static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 326{ 327 return queue_var_show((blk_queue_nomerges(q) << 1) | 328 blk_queue_noxmerges(q), page); 329} 330 331static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 332 size_t count) 333{ 334 unsigned long nm; 335 ssize_t ret = queue_var_store(&nm, page, count); 336 337 if (ret < 0) 338 return ret; 339 340 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 341 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 342 if (nm == 2) 343 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); 344 else if (nm) 345 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 346 347 return ret; 348} 349 350static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 351{ 352 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 353 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 354 355 return queue_var_show(set << force, page); 356} 357 358static ssize_t 359queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 360{ 361 ssize_t ret = -EINVAL; 362#ifdef CONFIG_SMP 363 unsigned long val; 364 365 ret = queue_var_store(&val, page, count); 366 if (ret < 0) 367 return ret; 368 369 if (val == 2) { 370 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 371 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 372 } else if (val == 1) { 373 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 374 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 375 } else if (val == 0) { 376 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 377 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 378 } 379#endif 380 return ret; 381} 382 383static ssize_t queue_poll_delay_show(struct request_queue *q, char *page) 384{ 385 return sprintf(page, "%d\n", -1); 386} 387 388static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, 389 size_t count) 390{ 391 return count; 392} 393 394static ssize_t queue_poll_show(struct request_queue *q, char *page) 395{ 396 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); 397} 398 399static ssize_t queue_poll_store(struct request_queue *q, const char *page, 400 size_t count) 401{ 402 if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) 403 return -EINVAL; 404 pr_info_ratelimited("writes to the poll attribute are ignored.\n"); 405 pr_info_ratelimited("please use driver specific parameters instead.\n"); 406 return count; 407} 408 409static ssize_t queue_io_timeout_show(struct request_queue *q, char *page) 410{ 411 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout)); 412} 413 414static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, 415 size_t count) 416{ 417 unsigned int val; 418 int err; 419 420 err = kstrtou32(page, 10, &val); 421 if (err || val == 0) 422 return -EINVAL; 423 424 blk_queue_rq_timeout(q, msecs_to_jiffies(val)); 425 426 return count; 427} 428 429static ssize_t queue_wc_show(struct request_queue *q, char *page) 430{ 431 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 432 return sprintf(page, "write back\n"); 433 434 return sprintf(page, "write through\n"); 435} 436 437static ssize_t queue_wc_store(struct request_queue *q, const char *page, 438 size_t count) 439{ 440 if (!strncmp(page, "write back", 10)) { 441 if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags)) 442 return -EINVAL; 443 blk_queue_flag_set(QUEUE_FLAG_WC, q); 444 } else if (!strncmp(page, "write through", 13) || 445 !strncmp(page, "none", 4)) { 446 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 447 } else { 448 return -EINVAL; 449 } 450 451 return count; 452} 453 454static ssize_t queue_fua_show(struct request_queue *q, char *page) 455{ 456 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); 457} 458 459static ssize_t queue_dax_show(struct request_queue *q, char *page) 460{ 461 return queue_var_show(blk_queue_dax(q), page); 462} 463 464#define QUEUE_RO_ENTRY(_prefix, _name) \ 465static struct queue_sysfs_entry _prefix##_entry = { \ 466 .attr = { .name = _name, .mode = 0444 }, \ 467 .show = _prefix##_show, \ 468}; 469 470#define QUEUE_RW_ENTRY(_prefix, _name) \ 471static struct queue_sysfs_entry _prefix##_entry = { \ 472 .attr = { .name = _name, .mode = 0644 }, \ 473 .show = _prefix##_show, \ 474 .store = _prefix##_store, \ 475}; 476 477QUEUE_RW_ENTRY(queue_requests, "nr_requests"); 478QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); 479QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); 480QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 481QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); 482QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); 483QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); 484QUEUE_RW_ENTRY(elv_iosched, "scheduler"); 485 486QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); 487QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); 488QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); 489QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); 490QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); 491 492QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); 493QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); 494QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); 495QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); 496QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); 497 498QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); 499QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); 500QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); 501QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); 502 503QUEUE_RO_ENTRY(queue_zoned, "zoned"); 504QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); 505QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); 506QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); 507 508QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); 509QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); 510QUEUE_RW_ENTRY(queue_poll, "io_poll"); 511QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); 512QUEUE_RW_ENTRY(queue_wc, "write_cache"); 513QUEUE_RO_ENTRY(queue_fua, "fua"); 514QUEUE_RO_ENTRY(queue_dax, "dax"); 515QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); 516QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); 517QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment"); 518 519/* legacy alias for logical_block_size: */ 520static struct queue_sysfs_entry queue_hw_sector_size_entry = { 521 .attr = {.name = "hw_sector_size", .mode = 0444 }, 522 .show = queue_logical_block_size_show, 523}; 524 525QUEUE_RW_ENTRY(queue_nonrot, "rotational"); 526QUEUE_RW_ENTRY(queue_iostats, "iostats"); 527QUEUE_RW_ENTRY(queue_random, "add_random"); 528QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); 529 530#ifdef CONFIG_BLK_WBT 531static ssize_t queue_var_store64(s64 *var, const char *page) 532{ 533 int err; 534 s64 v; 535 536 err = kstrtos64(page, 10, &v); 537 if (err < 0) 538 return err; 539 540 *var = v; 541 return 0; 542} 543 544static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) 545{ 546 if (!wbt_rq_qos(q)) 547 return -EINVAL; 548 549 if (wbt_disabled(q)) 550 return sprintf(page, "0\n"); 551 552 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); 553} 554 555static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, 556 size_t count) 557{ 558 struct rq_qos *rqos; 559 ssize_t ret; 560 s64 val; 561 562 ret = queue_var_store64(&val, page); 563 if (ret < 0) 564 return ret; 565 if (val < -1) 566 return -EINVAL; 567 568 rqos = wbt_rq_qos(q); 569 if (!rqos) { 570 ret = wbt_init(q->disk); 571 if (ret) 572 return ret; 573 } 574 575 if (val == -1) 576 val = wbt_default_latency_nsec(q); 577 else if (val >= 0) 578 val *= 1000ULL; 579 580 if (wbt_get_min_lat(q) == val) 581 return count; 582 583 /* 584 * Ensure that the queue is idled, in case the latency update 585 * ends up either enabling or disabling wbt completely. We can't 586 * have IO inflight if that happens. 587 */ 588 blk_mq_freeze_queue(q); 589 blk_mq_quiesce_queue(q); 590 591 wbt_set_min_lat(q, val); 592 593 blk_mq_unquiesce_queue(q); 594 blk_mq_unfreeze_queue(q); 595 596 return count; 597} 598 599QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); 600#endif 601 602/* Common attributes for bio-based and request-based queues. */ 603static struct attribute *queue_attrs[] = { 604 &queue_ra_entry.attr, 605 &queue_max_hw_sectors_entry.attr, 606 &queue_max_sectors_entry.attr, 607 &queue_max_segments_entry.attr, 608 &queue_max_discard_segments_entry.attr, 609 &queue_max_integrity_segments_entry.attr, 610 &queue_max_segment_size_entry.attr, 611 &queue_hw_sector_size_entry.attr, 612 &queue_logical_block_size_entry.attr, 613 &queue_physical_block_size_entry.attr, 614 &queue_chunk_sectors_entry.attr, 615 &queue_io_min_entry.attr, 616 &queue_io_opt_entry.attr, 617 &queue_discard_granularity_entry.attr, 618 &queue_discard_max_entry.attr, 619 &queue_discard_max_hw_entry.attr, 620 &queue_discard_zeroes_data_entry.attr, 621 &queue_write_same_max_entry.attr, 622 &queue_write_zeroes_max_entry.attr, 623 &queue_zone_append_max_entry.attr, 624 &queue_zone_write_granularity_entry.attr, 625 &queue_nonrot_entry.attr, 626 &queue_zoned_entry.attr, 627 &queue_nr_zones_entry.attr, 628 &queue_max_open_zones_entry.attr, 629 &queue_max_active_zones_entry.attr, 630 &queue_nomerges_entry.attr, 631 &queue_iostats_entry.attr, 632 &queue_stable_writes_entry.attr, 633 &queue_random_entry.attr, 634 &queue_poll_entry.attr, 635 &queue_wc_entry.attr, 636 &queue_fua_entry.attr, 637 &queue_dax_entry.attr, 638 &queue_poll_delay_entry.attr, 639 &queue_virt_boundary_mask_entry.attr, 640 &queue_dma_alignment_entry.attr, 641 NULL, 642}; 643 644/* Request-based queue attributes that are not relevant for bio-based queues. */ 645static struct attribute *blk_mq_queue_attrs[] = { 646 &queue_requests_entry.attr, 647 &elv_iosched_entry.attr, 648 &queue_rq_affinity_entry.attr, 649 &queue_io_timeout_entry.attr, 650#ifdef CONFIG_BLK_WBT 651 &queue_wb_lat_entry.attr, 652#endif 653 NULL, 654}; 655 656static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr, 657 int n) 658{ 659 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); 660 struct request_queue *q = disk->queue; 661 662 if ((attr == &queue_max_open_zones_entry.attr || 663 attr == &queue_max_active_zones_entry.attr) && 664 !blk_queue_is_zoned(q)) 665 return 0; 666 667 return attr->mode; 668} 669 670static umode_t blk_mq_queue_attr_visible(struct kobject *kobj, 671 struct attribute *attr, int n) 672{ 673 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); 674 struct request_queue *q = disk->queue; 675 676 if (!queue_is_mq(q)) 677 return 0; 678 679 if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout) 680 return 0; 681 682 return attr->mode; 683} 684 685static struct attribute_group queue_attr_group = { 686 .attrs = queue_attrs, 687 .is_visible = queue_attr_visible, 688}; 689 690static struct attribute_group blk_mq_queue_attr_group = { 691 .attrs = blk_mq_queue_attrs, 692 .is_visible = blk_mq_queue_attr_visible, 693}; 694 695#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 696 697static ssize_t 698queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 699{ 700 struct queue_sysfs_entry *entry = to_queue(attr); 701 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); 702 struct request_queue *q = disk->queue; 703 ssize_t res; 704 705 if (!entry->show) 706 return -EIO; 707 mutex_lock(&q->sysfs_lock); 708 res = entry->show(q, page); 709 mutex_unlock(&q->sysfs_lock); 710 return res; 711} 712 713static ssize_t 714queue_attr_store(struct kobject *kobj, struct attribute *attr, 715 const char *page, size_t length) 716{ 717 struct queue_sysfs_entry *entry = to_queue(attr); 718 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); 719 struct request_queue *q = disk->queue; 720 ssize_t res; 721 722 if (!entry->store) 723 return -EIO; 724 725 mutex_lock(&q->sysfs_lock); 726 res = entry->store(q, page, length); 727 mutex_unlock(&q->sysfs_lock); 728 return res; 729} 730 731static const struct sysfs_ops queue_sysfs_ops = { 732 .show = queue_attr_show, 733 .store = queue_attr_store, 734}; 735 736static const struct attribute_group *blk_queue_attr_groups[] = { 737 &queue_attr_group, 738 &blk_mq_queue_attr_group, 739 NULL 740}; 741 742static void blk_queue_release(struct kobject *kobj) 743{ 744 /* nothing to do here, all data is associated with the parent gendisk */ 745} 746 747static const struct kobj_type blk_queue_ktype = { 748 .default_groups = blk_queue_attr_groups, 749 .sysfs_ops = &queue_sysfs_ops, 750 .release = blk_queue_release, 751}; 752 753static void blk_debugfs_remove(struct gendisk *disk) 754{ 755 struct request_queue *q = disk->queue; 756 757 mutex_lock(&q->debugfs_mutex); 758 blk_trace_shutdown(q); 759 debugfs_remove_recursive(q->debugfs_dir); 760 q->debugfs_dir = NULL; 761 q->sched_debugfs_dir = NULL; 762 q->rqos_debugfs_dir = NULL; 763 mutex_unlock(&q->debugfs_mutex); 764} 765 766/** 767 * blk_register_queue - register a block layer queue with sysfs 768 * @disk: Disk of which the request queue should be registered with sysfs. 769 */ 770int blk_register_queue(struct gendisk *disk) 771{ 772 struct request_queue *q = disk->queue; 773 int ret; 774 775 mutex_lock(&q->sysfs_dir_lock); 776 kobject_init(&disk->queue_kobj, &blk_queue_ktype); 777 ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue"); 778 if (ret < 0) 779 goto out_put_queue_kobj; 780 781 if (queue_is_mq(q)) { 782 ret = blk_mq_sysfs_register(disk); 783 if (ret) 784 goto out_put_queue_kobj; 785 } 786 mutex_lock(&q->sysfs_lock); 787 788 mutex_lock(&q->debugfs_mutex); 789 q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root); 790 if (queue_is_mq(q)) 791 blk_mq_debugfs_register(q); 792 mutex_unlock(&q->debugfs_mutex); 793 794 ret = disk_register_independent_access_ranges(disk); 795 if (ret) 796 goto out_debugfs_remove; 797 798 if (q->elevator) { 799 ret = elv_register_queue(q, false); 800 if (ret) 801 goto out_unregister_ia_ranges; 802 } 803 804 ret = blk_crypto_sysfs_register(disk); 805 if (ret) 806 goto out_elv_unregister; 807 808 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); 809 wbt_enable_default(disk); 810 811 /* Now everything is ready and send out KOBJ_ADD uevent */ 812 kobject_uevent(&disk->queue_kobj, KOBJ_ADD); 813 if (q->elevator) 814 kobject_uevent(&q->elevator->kobj, KOBJ_ADD); 815 mutex_unlock(&q->sysfs_lock); 816 mutex_unlock(&q->sysfs_dir_lock); 817 818 /* 819 * SCSI probing may synchronously create and destroy a lot of 820 * request_queues for non-existent devices. Shutting down a fully 821 * functional queue takes measureable wallclock time as RCU grace 822 * periods are involved. To avoid excessive latency in these 823 * cases, a request_queue starts out in a degraded mode which is 824 * faster to shut down and is made fully functional here as 825 * request_queues for non-existent devices never get registered. 826 */ 827 if (!blk_queue_init_done(q)) { 828 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); 829 percpu_ref_switch_to_percpu(&q->q_usage_counter); 830 } 831 832 return ret; 833 834out_elv_unregister: 835 elv_unregister_queue(q); 836out_unregister_ia_ranges: 837 disk_unregister_independent_access_ranges(disk); 838out_debugfs_remove: 839 blk_debugfs_remove(disk); 840 mutex_unlock(&q->sysfs_lock); 841out_put_queue_kobj: 842 kobject_put(&disk->queue_kobj); 843 mutex_unlock(&q->sysfs_dir_lock); 844 return ret; 845} 846 847/** 848 * blk_unregister_queue - counterpart of blk_register_queue() 849 * @disk: Disk of which the request queue should be unregistered from sysfs. 850 * 851 * Note: the caller is responsible for guaranteeing that this function is called 852 * after blk_register_queue() has finished. 853 */ 854void blk_unregister_queue(struct gendisk *disk) 855{ 856 struct request_queue *q = disk->queue; 857 858 if (WARN_ON(!q)) 859 return; 860 861 /* Return early if disk->queue was never registered. */ 862 if (!blk_queue_registered(q)) 863 return; 864 865 /* 866 * Since sysfs_remove_dir() prevents adding new directory entries 867 * before removal of existing entries starts, protect against 868 * concurrent elv_iosched_store() calls. 869 */ 870 mutex_lock(&q->sysfs_lock); 871 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); 872 mutex_unlock(&q->sysfs_lock); 873 874 mutex_lock(&q->sysfs_dir_lock); 875 /* 876 * Remove the sysfs attributes before unregistering the queue data 877 * structures that can be modified through sysfs. 878 */ 879 if (queue_is_mq(q)) 880 blk_mq_sysfs_unregister(disk); 881 blk_crypto_sysfs_unregister(disk); 882 883 mutex_lock(&q->sysfs_lock); 884 elv_unregister_queue(q); 885 disk_unregister_independent_access_ranges(disk); 886 mutex_unlock(&q->sysfs_lock); 887 888 /* Now that we've deleted all child objects, we can delete the queue. */ 889 kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE); 890 kobject_del(&disk->queue_kobj); 891 mutex_unlock(&q->sysfs_dir_lock); 892 893 blk_debugfs_remove(disk); 894} 895