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/blk-mq.h> 13 #include <linux/blk-cgroup.h> 14 #include <linux/debugfs.h> 15 16 #include "blk.h" 17 #include "blk-mq.h" 18 #include "blk-mq-debugfs.h" 19 #include "blk-wbt.h" 20 21 struct queue_sysfs_entry { 22 struct attribute attr; 23 ssize_t (*show)(struct request_queue *, char *); 24 ssize_t (*store)(struct request_queue *, const char *, size_t); 25 }; 26 27 static ssize_t 28 queue_var_show(unsigned long var, char *page) 29 { 30 return sprintf(page, "%lu\n", var); 31 } 32 33 static ssize_t 34 queue_var_store(unsigned long *var, const char *page, size_t count) 35 { 36 int err; 37 unsigned long v; 38 39 err = kstrtoul(page, 10, &v); 40 if (err || v > UINT_MAX) 41 return -EINVAL; 42 43 *var = v; 44 45 return count; 46 } 47 48 static ssize_t queue_var_store64(s64 *var, const char *page) 49 { 50 int err; 51 s64 v; 52 53 err = kstrtos64(page, 10, &v); 54 if (err < 0) 55 return err; 56 57 *var = v; 58 return 0; 59 } 60 61 static ssize_t queue_requests_show(struct request_queue *q, char *page) 62 { 63 return queue_var_show(q->nr_requests, page); 64 } 65 66 static ssize_t 67 queue_requests_store(struct request_queue *q, const char *page, size_t count) 68 { 69 unsigned long nr; 70 int ret, err; 71 72 if (!queue_is_mq(q)) 73 return -EINVAL; 74 75 ret = queue_var_store(&nr, page, count); 76 if (ret < 0) 77 return ret; 78 79 if (nr < BLKDEV_MIN_RQ) 80 nr = BLKDEV_MIN_RQ; 81 82 err = blk_mq_update_nr_requests(q, nr); 83 if (err) 84 return err; 85 86 return ret; 87 } 88 89 static ssize_t queue_ra_show(struct request_queue *q, char *page) 90 { 91 unsigned long ra_kb; 92 93 if (!q->disk) 94 return -EINVAL; 95 ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10); 96 return queue_var_show(ra_kb, page); 97 } 98 99 static ssize_t 100 queue_ra_store(struct request_queue *q, const char *page, size_t count) 101 { 102 unsigned long ra_kb; 103 ssize_t ret; 104 105 if (!q->disk) 106 return -EINVAL; 107 ret = queue_var_store(&ra_kb, page, count); 108 if (ret < 0) 109 return ret; 110 q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10); 111 return ret; 112 } 113 114 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) 115 { 116 int max_sectors_kb = queue_max_sectors(q) >> 1; 117 118 return queue_var_show(max_sectors_kb, page); 119 } 120 121 static ssize_t queue_max_segments_show(struct request_queue *q, char *page) 122 { 123 return queue_var_show(queue_max_segments(q), page); 124 } 125 126 static ssize_t queue_max_discard_segments_show(struct request_queue *q, 127 char *page) 128 { 129 return queue_var_show(queue_max_discard_segments(q), page); 130 } 131 132 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) 133 { 134 return queue_var_show(q->limits.max_integrity_segments, page); 135 } 136 137 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) 138 { 139 return queue_var_show(queue_max_segment_size(q), page); 140 } 141 142 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) 143 { 144 return queue_var_show(queue_logical_block_size(q), page); 145 } 146 147 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) 148 { 149 return queue_var_show(queue_physical_block_size(q), page); 150 } 151 152 static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page) 153 { 154 return queue_var_show(q->limits.chunk_sectors, page); 155 } 156 157 static ssize_t queue_io_min_show(struct request_queue *q, char *page) 158 { 159 return queue_var_show(queue_io_min(q), page); 160 } 161 162 static ssize_t queue_io_opt_show(struct request_queue *q, char *page) 163 { 164 return queue_var_show(queue_io_opt(q), page); 165 } 166 167 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) 168 { 169 return queue_var_show(q->limits.discard_granularity, page); 170 } 171 172 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page) 173 { 174 175 return sprintf(page, "%llu\n", 176 (unsigned long long)q->limits.max_hw_discard_sectors << 9); 177 } 178 179 static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 180 { 181 return sprintf(page, "%llu\n", 182 (unsigned long long)q->limits.max_discard_sectors << 9); 183 } 184 185 static ssize_t queue_discard_max_store(struct request_queue *q, 186 const char *page, size_t count) 187 { 188 unsigned long max_discard; 189 ssize_t ret = queue_var_store(&max_discard, page, count); 190 191 if (ret < 0) 192 return ret; 193 194 if (max_discard & (q->limits.discard_granularity - 1)) 195 return -EINVAL; 196 197 max_discard >>= 9; 198 if (max_discard > UINT_MAX) 199 return -EINVAL; 200 201 if (max_discard > q->limits.max_hw_discard_sectors) 202 max_discard = q->limits.max_hw_discard_sectors; 203 204 q->limits.max_discard_sectors = max_discard; 205 return ret; 206 } 207 208 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 209 { 210 return queue_var_show(0, page); 211 } 212 213 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) 214 { 215 return sprintf(page, "%llu\n", 216 (unsigned long long)q->limits.max_write_same_sectors << 9); 217 } 218 219 static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page) 220 { 221 return sprintf(page, "%llu\n", 222 (unsigned long long)q->limits.max_write_zeroes_sectors << 9); 223 } 224 225 static ssize_t queue_zone_write_granularity_show(struct request_queue *q, 226 char *page) 227 { 228 return queue_var_show(queue_zone_write_granularity(q), page); 229 } 230 231 static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page) 232 { 233 unsigned long long max_sectors = q->limits.max_zone_append_sectors; 234 235 return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT); 236 } 237 238 static ssize_t 239 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 240 { 241 unsigned long max_sectors_kb, 242 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, 243 page_kb = 1 << (PAGE_SHIFT - 10); 244 ssize_t ret = queue_var_store(&max_sectors_kb, page, count); 245 246 if (ret < 0) 247 return ret; 248 249 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) 250 q->limits.max_dev_sectors >> 1); 251 252 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) 253 return -EINVAL; 254 255 spin_lock_irq(&q->queue_lock); 256 q->limits.max_sectors = max_sectors_kb << 1; 257 if (q->disk) 258 q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10); 259 spin_unlock_irq(&q->queue_lock); 260 261 return ret; 262 } 263 264 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 265 { 266 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 267 268 return queue_var_show(max_hw_sectors_kb, page); 269 } 270 271 static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page) 272 { 273 return queue_var_show(q->limits.virt_boundary_mask, page); 274 } 275 276 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 277 static ssize_t \ 278 queue_##name##_show(struct request_queue *q, char *page) \ 279 { \ 280 int bit; \ 281 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 282 return queue_var_show(neg ? !bit : bit, page); \ 283 } \ 284 static ssize_t \ 285 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ 286 { \ 287 unsigned long val; \ 288 ssize_t ret; \ 289 ret = queue_var_store(&val, page, count); \ 290 if (ret < 0) \ 291 return ret; \ 292 if (neg) \ 293 val = !val; \ 294 \ 295 if (val) \ 296 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \ 297 else \ 298 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \ 299 return ret; \ 300 } 301 302 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 303 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 304 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 305 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0); 306 #undef QUEUE_SYSFS_BIT_FNS 307 308 static ssize_t queue_zoned_show(struct request_queue *q, char *page) 309 { 310 switch (blk_queue_zoned_model(q)) { 311 case BLK_ZONED_HA: 312 return sprintf(page, "host-aware\n"); 313 case BLK_ZONED_HM: 314 return sprintf(page, "host-managed\n"); 315 default: 316 return sprintf(page, "none\n"); 317 } 318 } 319 320 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page) 321 { 322 return queue_var_show(blk_queue_nr_zones(q), page); 323 } 324 325 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page) 326 { 327 return queue_var_show(queue_max_open_zones(q), page); 328 } 329 330 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page) 331 { 332 return queue_var_show(queue_max_active_zones(q), page); 333 } 334 335 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 336 { 337 return queue_var_show((blk_queue_nomerges(q) << 1) | 338 blk_queue_noxmerges(q), page); 339 } 340 341 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 342 size_t count) 343 { 344 unsigned long nm; 345 ssize_t ret = queue_var_store(&nm, page, count); 346 347 if (ret < 0) 348 return ret; 349 350 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 351 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 352 if (nm == 2) 353 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); 354 else if (nm) 355 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 356 357 return ret; 358 } 359 360 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 361 { 362 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 363 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 364 365 return queue_var_show(set << force, page); 366 } 367 368 static ssize_t 369 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 370 { 371 ssize_t ret = -EINVAL; 372 #ifdef CONFIG_SMP 373 unsigned long val; 374 375 ret = queue_var_store(&val, page, count); 376 if (ret < 0) 377 return ret; 378 379 if (val == 2) { 380 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 381 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 382 } else if (val == 1) { 383 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 384 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 385 } else if (val == 0) { 386 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 387 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 388 } 389 #endif 390 return ret; 391 } 392 393 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page) 394 { 395 int val; 396 397 if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) 398 val = BLK_MQ_POLL_CLASSIC; 399 else 400 val = q->poll_nsec / 1000; 401 402 return sprintf(page, "%d\n", val); 403 } 404 405 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, 406 size_t count) 407 { 408 int err, val; 409 410 if (!q->mq_ops || !q->mq_ops->poll) 411 return -EINVAL; 412 413 err = kstrtoint(page, 10, &val); 414 if (err < 0) 415 return err; 416 417 if (val == BLK_MQ_POLL_CLASSIC) 418 q->poll_nsec = BLK_MQ_POLL_CLASSIC; 419 else if (val >= 0) 420 q->poll_nsec = val * 1000; 421 else 422 return -EINVAL; 423 424 return count; 425 } 426 427 static ssize_t queue_poll_show(struct request_queue *q, char *page) 428 { 429 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); 430 } 431 432 static ssize_t queue_poll_store(struct request_queue *q, const char *page, 433 size_t count) 434 { 435 unsigned long poll_on; 436 ssize_t ret; 437 438 if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL || 439 !q->tag_set->map[HCTX_TYPE_POLL].nr_queues) 440 return -EINVAL; 441 442 ret = queue_var_store(&poll_on, page, count); 443 if (ret < 0) 444 return ret; 445 446 if (poll_on) { 447 blk_queue_flag_set(QUEUE_FLAG_POLL, q); 448 } else { 449 blk_mq_freeze_queue(q); 450 blk_queue_flag_clear(QUEUE_FLAG_POLL, q); 451 blk_mq_unfreeze_queue(q); 452 } 453 454 return ret; 455 } 456 457 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page) 458 { 459 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout)); 460 } 461 462 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, 463 size_t count) 464 { 465 unsigned int val; 466 int err; 467 468 err = kstrtou32(page, 10, &val); 469 if (err || val == 0) 470 return -EINVAL; 471 472 blk_queue_rq_timeout(q, msecs_to_jiffies(val)); 473 474 return count; 475 } 476 477 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) 478 { 479 if (!wbt_rq_qos(q)) 480 return -EINVAL; 481 482 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); 483 } 484 485 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, 486 size_t count) 487 { 488 struct rq_qos *rqos; 489 ssize_t ret; 490 s64 val; 491 492 ret = queue_var_store64(&val, page); 493 if (ret < 0) 494 return ret; 495 if (val < -1) 496 return -EINVAL; 497 498 rqos = wbt_rq_qos(q); 499 if (!rqos) { 500 ret = wbt_init(q); 501 if (ret) 502 return ret; 503 } 504 505 if (val == -1) 506 val = wbt_default_latency_nsec(q); 507 else if (val >= 0) 508 val *= 1000ULL; 509 510 if (wbt_get_min_lat(q) == val) 511 return count; 512 513 /* 514 * Ensure that the queue is idled, in case the latency update 515 * ends up either enabling or disabling wbt completely. We can't 516 * have IO inflight if that happens. 517 */ 518 blk_mq_freeze_queue(q); 519 blk_mq_quiesce_queue(q); 520 521 wbt_set_min_lat(q, val); 522 523 blk_mq_unquiesce_queue(q); 524 blk_mq_unfreeze_queue(q); 525 526 return count; 527 } 528 529 static ssize_t queue_wc_show(struct request_queue *q, char *page) 530 { 531 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 532 return sprintf(page, "write back\n"); 533 534 return sprintf(page, "write through\n"); 535 } 536 537 static ssize_t queue_wc_store(struct request_queue *q, const char *page, 538 size_t count) 539 { 540 int set = -1; 541 542 if (!strncmp(page, "write back", 10)) 543 set = 1; 544 else if (!strncmp(page, "write through", 13) || 545 !strncmp(page, "none", 4)) 546 set = 0; 547 548 if (set == -1) 549 return -EINVAL; 550 551 if (set) 552 blk_queue_flag_set(QUEUE_FLAG_WC, q); 553 else 554 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 555 556 return count; 557 } 558 559 static ssize_t queue_fua_show(struct request_queue *q, char *page) 560 { 561 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); 562 } 563 564 static ssize_t queue_dax_show(struct request_queue *q, char *page) 565 { 566 return queue_var_show(blk_queue_dax(q), page); 567 } 568 569 #define QUEUE_RO_ENTRY(_prefix, _name) \ 570 static struct queue_sysfs_entry _prefix##_entry = { \ 571 .attr = { .name = _name, .mode = 0444 }, \ 572 .show = _prefix##_show, \ 573 }; 574 575 #define QUEUE_RW_ENTRY(_prefix, _name) \ 576 static struct queue_sysfs_entry _prefix##_entry = { \ 577 .attr = { .name = _name, .mode = 0644 }, \ 578 .show = _prefix##_show, \ 579 .store = _prefix##_store, \ 580 }; 581 582 QUEUE_RW_ENTRY(queue_requests, "nr_requests"); 583 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); 584 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); 585 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 586 QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); 587 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); 588 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); 589 QUEUE_RW_ENTRY(elv_iosched, "scheduler"); 590 591 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); 592 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); 593 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); 594 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); 595 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); 596 597 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); 598 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); 599 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); 600 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); 601 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); 602 603 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); 604 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); 605 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); 606 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); 607 608 QUEUE_RO_ENTRY(queue_zoned, "zoned"); 609 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); 610 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); 611 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); 612 613 QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); 614 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); 615 QUEUE_RW_ENTRY(queue_poll, "io_poll"); 616 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); 617 QUEUE_RW_ENTRY(queue_wc, "write_cache"); 618 QUEUE_RO_ENTRY(queue_fua, "fua"); 619 QUEUE_RO_ENTRY(queue_dax, "dax"); 620 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); 621 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); 622 QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); 623 624 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 625 QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); 626 #endif 627 628 /* legacy alias for logical_block_size: */ 629 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 630 .attr = {.name = "hw_sector_size", .mode = 0444 }, 631 .show = queue_logical_block_size_show, 632 }; 633 634 QUEUE_RW_ENTRY(queue_nonrot, "rotational"); 635 QUEUE_RW_ENTRY(queue_iostats, "iostats"); 636 QUEUE_RW_ENTRY(queue_random, "add_random"); 637 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); 638 639 static struct attribute *queue_attrs[] = { 640 &queue_requests_entry.attr, 641 &queue_ra_entry.attr, 642 &queue_max_hw_sectors_entry.attr, 643 &queue_max_sectors_entry.attr, 644 &queue_max_segments_entry.attr, 645 &queue_max_discard_segments_entry.attr, 646 &queue_max_integrity_segments_entry.attr, 647 &queue_max_segment_size_entry.attr, 648 &elv_iosched_entry.attr, 649 &queue_hw_sector_size_entry.attr, 650 &queue_logical_block_size_entry.attr, 651 &queue_physical_block_size_entry.attr, 652 &queue_chunk_sectors_entry.attr, 653 &queue_io_min_entry.attr, 654 &queue_io_opt_entry.attr, 655 &queue_discard_granularity_entry.attr, 656 &queue_discard_max_entry.attr, 657 &queue_discard_max_hw_entry.attr, 658 &queue_discard_zeroes_data_entry.attr, 659 &queue_write_same_max_entry.attr, 660 &queue_write_zeroes_max_entry.attr, 661 &queue_zone_append_max_entry.attr, 662 &queue_zone_write_granularity_entry.attr, 663 &queue_nonrot_entry.attr, 664 &queue_zoned_entry.attr, 665 &queue_nr_zones_entry.attr, 666 &queue_max_open_zones_entry.attr, 667 &queue_max_active_zones_entry.attr, 668 &queue_nomerges_entry.attr, 669 &queue_rq_affinity_entry.attr, 670 &queue_iostats_entry.attr, 671 &queue_stable_writes_entry.attr, 672 &queue_random_entry.attr, 673 &queue_poll_entry.attr, 674 &queue_wc_entry.attr, 675 &queue_fua_entry.attr, 676 &queue_dax_entry.attr, 677 &queue_wb_lat_entry.attr, 678 &queue_poll_delay_entry.attr, 679 &queue_io_timeout_entry.attr, 680 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 681 &blk_throtl_sample_time_entry.attr, 682 #endif 683 &queue_virt_boundary_mask_entry.attr, 684 NULL, 685 }; 686 687 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr, 688 int n) 689 { 690 struct request_queue *q = 691 container_of(kobj, struct request_queue, kobj); 692 693 if (attr == &queue_io_timeout_entry.attr && 694 (!q->mq_ops || !q->mq_ops->timeout)) 695 return 0; 696 697 if ((attr == &queue_max_open_zones_entry.attr || 698 attr == &queue_max_active_zones_entry.attr) && 699 !blk_queue_is_zoned(q)) 700 return 0; 701 702 return attr->mode; 703 } 704 705 static struct attribute_group queue_attr_group = { 706 .attrs = queue_attrs, 707 .is_visible = queue_attr_visible, 708 }; 709 710 711 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 712 713 static ssize_t 714 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 715 { 716 struct queue_sysfs_entry *entry = to_queue(attr); 717 struct request_queue *q = 718 container_of(kobj, struct request_queue, kobj); 719 ssize_t res; 720 721 if (!entry->show) 722 return -EIO; 723 mutex_lock(&q->sysfs_lock); 724 res = entry->show(q, page); 725 mutex_unlock(&q->sysfs_lock); 726 return res; 727 } 728 729 static ssize_t 730 queue_attr_store(struct kobject *kobj, struct attribute *attr, 731 const char *page, size_t length) 732 { 733 struct queue_sysfs_entry *entry = to_queue(attr); 734 struct request_queue *q; 735 ssize_t res; 736 737 if (!entry->store) 738 return -EIO; 739 740 q = container_of(kobj, struct request_queue, kobj); 741 mutex_lock(&q->sysfs_lock); 742 res = entry->store(q, page, length); 743 mutex_unlock(&q->sysfs_lock); 744 return res; 745 } 746 747 static void blk_free_queue_rcu(struct rcu_head *rcu_head) 748 { 749 struct request_queue *q = container_of(rcu_head, struct request_queue, 750 rcu_head); 751 kmem_cache_free(blk_requestq_cachep, q); 752 } 753 754 /* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */ 755 static void blk_exit_queue(struct request_queue *q) 756 { 757 /* 758 * Since the I/O scheduler exit code may access cgroup information, 759 * perform I/O scheduler exit before disassociating from the block 760 * cgroup controller. 761 */ 762 if (q->elevator) { 763 ioc_clear_queue(q); 764 __elevator_exit(q, q->elevator); 765 } 766 767 /* 768 * Remove all references to @q from the block cgroup controller before 769 * restoring @q->queue_lock to avoid that restoring this pointer causes 770 * e.g. blkcg_print_blkgs() to crash. 771 */ 772 blkcg_exit_queue(q); 773 } 774 775 /** 776 * blk_release_queue - releases all allocated resources of the request_queue 777 * @kobj: pointer to a kobject, whose container is a request_queue 778 * 779 * This function releases all allocated resources of the request queue. 780 * 781 * The struct request_queue refcount is incremented with blk_get_queue() and 782 * decremented with blk_put_queue(). Once the refcount reaches 0 this function 783 * is called. 784 * 785 * For drivers that have a request_queue on a gendisk and added with 786 * __device_add_disk() the refcount to request_queue will reach 0 with 787 * the last put_disk() called by the driver. For drivers which don't use 788 * __device_add_disk() this happens with blk_cleanup_queue(). 789 * 790 * Drivers exist which depend on the release of the request_queue to be 791 * synchronous, it should not be deferred. 792 * 793 * Context: can sleep 794 */ 795 static void blk_release_queue(struct kobject *kobj) 796 { 797 struct request_queue *q = 798 container_of(kobj, struct request_queue, kobj); 799 800 might_sleep(); 801 802 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) 803 blk_stat_remove_callback(q, q->poll_cb); 804 blk_stat_free_callback(q->poll_cb); 805 806 blk_free_queue_stats(q->stats); 807 808 if (queue_is_mq(q)) { 809 struct blk_mq_hw_ctx *hctx; 810 int i; 811 812 cancel_delayed_work_sync(&q->requeue_work); 813 814 queue_for_each_hw_ctx(q, hctx, i) 815 cancel_delayed_work_sync(&hctx->run_work); 816 } 817 818 blk_exit_queue(q); 819 820 blk_queue_free_zone_bitmaps(q); 821 822 if (queue_is_mq(q)) 823 blk_mq_release(q); 824 825 blk_trace_shutdown(q); 826 mutex_lock(&q->debugfs_mutex); 827 debugfs_remove_recursive(q->debugfs_dir); 828 mutex_unlock(&q->debugfs_mutex); 829 830 if (queue_is_mq(q)) 831 blk_mq_debugfs_unregister(q); 832 833 bioset_exit(&q->bio_split); 834 835 ida_simple_remove(&blk_queue_ida, q->id); 836 call_rcu(&q->rcu_head, blk_free_queue_rcu); 837 } 838 839 static const struct sysfs_ops queue_sysfs_ops = { 840 .show = queue_attr_show, 841 .store = queue_attr_store, 842 }; 843 844 struct kobj_type blk_queue_ktype = { 845 .sysfs_ops = &queue_sysfs_ops, 846 .release = blk_release_queue, 847 }; 848 849 /** 850 * blk_register_queue - register a block layer queue with sysfs 851 * @disk: Disk of which the request queue should be registered with sysfs. 852 */ 853 int blk_register_queue(struct gendisk *disk) 854 { 855 int ret; 856 struct device *dev = disk_to_dev(disk); 857 struct request_queue *q = disk->queue; 858 859 ret = blk_trace_init_sysfs(dev); 860 if (ret) 861 return ret; 862 863 mutex_lock(&q->sysfs_dir_lock); 864 865 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 866 if (ret < 0) { 867 blk_trace_remove_sysfs(dev); 868 goto unlock; 869 } 870 871 ret = sysfs_create_group(&q->kobj, &queue_attr_group); 872 if (ret) { 873 blk_trace_remove_sysfs(dev); 874 kobject_del(&q->kobj); 875 kobject_put(&dev->kobj); 876 goto unlock; 877 } 878 879 mutex_lock(&q->debugfs_mutex); 880 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), 881 blk_debugfs_root); 882 mutex_unlock(&q->debugfs_mutex); 883 884 if (queue_is_mq(q)) { 885 __blk_mq_register_dev(dev, q); 886 blk_mq_debugfs_register(q); 887 } 888 889 mutex_lock(&q->sysfs_lock); 890 if (q->elevator) { 891 ret = elv_register_queue(q, false); 892 if (ret) { 893 mutex_unlock(&q->sysfs_lock); 894 mutex_unlock(&q->sysfs_dir_lock); 895 kobject_del(&q->kobj); 896 blk_trace_remove_sysfs(dev); 897 kobject_put(&dev->kobj); 898 return ret; 899 } 900 } 901 902 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); 903 wbt_enable_default(q); 904 blk_throtl_register_queue(q); 905 906 /* Now everything is ready and send out KOBJ_ADD uevent */ 907 kobject_uevent(&q->kobj, KOBJ_ADD); 908 if (q->elevator) 909 kobject_uevent(&q->elevator->kobj, KOBJ_ADD); 910 mutex_unlock(&q->sysfs_lock); 911 912 ret = 0; 913 unlock: 914 mutex_unlock(&q->sysfs_dir_lock); 915 916 /* 917 * SCSI probing may synchronously create and destroy a lot of 918 * request_queues for non-existent devices. Shutting down a fully 919 * functional queue takes measureable wallclock time as RCU grace 920 * periods are involved. To avoid excessive latency in these 921 * cases, a request_queue starts out in a degraded mode which is 922 * faster to shut down and is made fully functional here as 923 * request_queues for non-existent devices never get registered. 924 */ 925 if (!blk_queue_init_done(q)) { 926 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); 927 percpu_ref_switch_to_percpu(&q->q_usage_counter); 928 } 929 930 return ret; 931 } 932 933 /** 934 * blk_unregister_queue - counterpart of blk_register_queue() 935 * @disk: Disk of which the request queue should be unregistered from sysfs. 936 * 937 * Note: the caller is responsible for guaranteeing that this function is called 938 * after blk_register_queue() has finished. 939 */ 940 void blk_unregister_queue(struct gendisk *disk) 941 { 942 struct request_queue *q = disk->queue; 943 944 if (WARN_ON(!q)) 945 return; 946 947 /* Return early if disk->queue was never registered. */ 948 if (!blk_queue_registered(q)) 949 return; 950 951 /* 952 * Since sysfs_remove_dir() prevents adding new directory entries 953 * before removal of existing entries starts, protect against 954 * concurrent elv_iosched_store() calls. 955 */ 956 mutex_lock(&q->sysfs_lock); 957 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); 958 mutex_unlock(&q->sysfs_lock); 959 960 mutex_lock(&q->sysfs_dir_lock); 961 /* 962 * Remove the sysfs attributes before unregistering the queue data 963 * structures that can be modified through sysfs. 964 */ 965 if (queue_is_mq(q)) 966 blk_mq_unregister_dev(disk_to_dev(disk), q); 967 968 kobject_uevent(&q->kobj, KOBJ_REMOVE); 969 kobject_del(&q->kobj); 970 blk_trace_remove_sysfs(disk_to_dev(disk)); 971 972 mutex_lock(&q->sysfs_lock); 973 if (q->elevator) 974 elv_unregister_queue(q); 975 mutex_unlock(&q->sysfs_lock); 976 mutex_unlock(&q->sysfs_dir_lock); 977 978 kobject_put(&disk_to_dev(disk)->kobj); 979 } 980