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 = q->backing_dev_info->ra_pages << 92 (PAGE_SHIFT - 10); 93 94 return queue_var_show(ra_kb, page); 95 } 96 97 static ssize_t 98 queue_ra_store(struct request_queue *q, const char *page, size_t count) 99 { 100 unsigned long ra_kb; 101 ssize_t ret = queue_var_store(&ra_kb, page, count); 102 103 if (ret < 0) 104 return ret; 105 106 q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10); 107 108 return ret; 109 } 110 111 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) 112 { 113 int max_sectors_kb = queue_max_sectors(q) >> 1; 114 115 return queue_var_show(max_sectors_kb, page); 116 } 117 118 static ssize_t queue_max_segments_show(struct request_queue *q, char *page) 119 { 120 return queue_var_show(queue_max_segments(q), page); 121 } 122 123 static ssize_t queue_max_discard_segments_show(struct request_queue *q, 124 char *page) 125 { 126 return queue_var_show(queue_max_discard_segments(q), page); 127 } 128 129 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) 130 { 131 return queue_var_show(q->limits.max_integrity_segments, page); 132 } 133 134 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) 135 { 136 return queue_var_show(queue_max_segment_size(q), page); 137 } 138 139 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) 140 { 141 return queue_var_show(queue_logical_block_size(q), page); 142 } 143 144 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) 145 { 146 return queue_var_show(queue_physical_block_size(q), page); 147 } 148 149 static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page) 150 { 151 return queue_var_show(q->limits.chunk_sectors, page); 152 } 153 154 static ssize_t queue_io_min_show(struct request_queue *q, char *page) 155 { 156 return queue_var_show(queue_io_min(q), page); 157 } 158 159 static ssize_t queue_io_opt_show(struct request_queue *q, char *page) 160 { 161 return queue_var_show(queue_io_opt(q), page); 162 } 163 164 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) 165 { 166 return queue_var_show(q->limits.discard_granularity, page); 167 } 168 169 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page) 170 { 171 172 return sprintf(page, "%llu\n", 173 (unsigned long long)q->limits.max_hw_discard_sectors << 9); 174 } 175 176 static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 177 { 178 return sprintf(page, "%llu\n", 179 (unsigned long long)q->limits.max_discard_sectors << 9); 180 } 181 182 static ssize_t queue_discard_max_store(struct request_queue *q, 183 const char *page, size_t count) 184 { 185 unsigned long max_discard; 186 ssize_t ret = queue_var_store(&max_discard, page, count); 187 188 if (ret < 0) 189 return ret; 190 191 if (max_discard & (q->limits.discard_granularity - 1)) 192 return -EINVAL; 193 194 max_discard >>= 9; 195 if (max_discard > UINT_MAX) 196 return -EINVAL; 197 198 if (max_discard > q->limits.max_hw_discard_sectors) 199 max_discard = q->limits.max_hw_discard_sectors; 200 201 q->limits.max_discard_sectors = max_discard; 202 return ret; 203 } 204 205 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 206 { 207 return queue_var_show(0, page); 208 } 209 210 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) 211 { 212 return sprintf(page, "%llu\n", 213 (unsigned long long)q->limits.max_write_same_sectors << 9); 214 } 215 216 static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page) 217 { 218 return sprintf(page, "%llu\n", 219 (unsigned long long)q->limits.max_write_zeroes_sectors << 9); 220 } 221 222 static ssize_t queue_zone_write_granularity_show(struct request_queue *q, 223 char *page) 224 { 225 return queue_var_show(queue_zone_write_granularity(q), page); 226 } 227 228 static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page) 229 { 230 unsigned long long max_sectors = q->limits.max_zone_append_sectors; 231 232 return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT); 233 } 234 235 static ssize_t 236 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 237 { 238 unsigned long max_sectors_kb, 239 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, 240 page_kb = 1 << (PAGE_SHIFT - 10); 241 ssize_t ret = queue_var_store(&max_sectors_kb, page, count); 242 243 if (ret < 0) 244 return ret; 245 246 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) 247 q->limits.max_dev_sectors >> 1); 248 249 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) 250 return -EINVAL; 251 252 spin_lock_irq(&q->queue_lock); 253 q->limits.max_sectors = max_sectors_kb << 1; 254 q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10); 255 spin_unlock_irq(&q->queue_lock); 256 257 return ret; 258 } 259 260 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 261 { 262 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 263 264 return queue_var_show(max_hw_sectors_kb, page); 265 } 266 267 static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page) 268 { 269 return queue_var_show(q->limits.virt_boundary_mask, page); 270 } 271 272 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 273 static ssize_t \ 274 queue_##name##_show(struct request_queue *q, char *page) \ 275 { \ 276 int bit; \ 277 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 278 return queue_var_show(neg ? !bit : bit, page); \ 279 } \ 280 static ssize_t \ 281 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ 282 { \ 283 unsigned long val; \ 284 ssize_t ret; \ 285 ret = queue_var_store(&val, page, count); \ 286 if (ret < 0) \ 287 return ret; \ 288 if (neg) \ 289 val = !val; \ 290 \ 291 if (val) \ 292 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \ 293 else \ 294 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \ 295 return ret; \ 296 } 297 298 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 299 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 300 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 301 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0); 302 #undef QUEUE_SYSFS_BIT_FNS 303 304 static ssize_t queue_zoned_show(struct request_queue *q, char *page) 305 { 306 switch (blk_queue_zoned_model(q)) { 307 case BLK_ZONED_HA: 308 return sprintf(page, "host-aware\n"); 309 case BLK_ZONED_HM: 310 return sprintf(page, "host-managed\n"); 311 default: 312 return sprintf(page, "none\n"); 313 } 314 } 315 316 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page) 317 { 318 return queue_var_show(blk_queue_nr_zones(q), page); 319 } 320 321 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page) 322 { 323 return queue_var_show(queue_max_open_zones(q), page); 324 } 325 326 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page) 327 { 328 return queue_var_show(queue_max_active_zones(q), page); 329 } 330 331 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 332 { 333 return queue_var_show((blk_queue_nomerges(q) << 1) | 334 blk_queue_noxmerges(q), page); 335 } 336 337 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 338 size_t count) 339 { 340 unsigned long nm; 341 ssize_t ret = queue_var_store(&nm, page, count); 342 343 if (ret < 0) 344 return ret; 345 346 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 347 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 348 if (nm == 2) 349 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); 350 else if (nm) 351 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 352 353 return ret; 354 } 355 356 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 357 { 358 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 359 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 360 361 return queue_var_show(set << force, page); 362 } 363 364 static ssize_t 365 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 366 { 367 ssize_t ret = -EINVAL; 368 #ifdef CONFIG_SMP 369 unsigned long val; 370 371 ret = queue_var_store(&val, page, count); 372 if (ret < 0) 373 return ret; 374 375 if (val == 2) { 376 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 377 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 378 } else if (val == 1) { 379 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 380 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 381 } else if (val == 0) { 382 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 383 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 384 } 385 #endif 386 return ret; 387 } 388 389 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page) 390 { 391 int val; 392 393 if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) 394 val = BLK_MQ_POLL_CLASSIC; 395 else 396 val = q->poll_nsec / 1000; 397 398 return sprintf(page, "%d\n", val); 399 } 400 401 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, 402 size_t count) 403 { 404 int err, val; 405 406 if (!q->mq_ops || !q->mq_ops->poll) 407 return -EINVAL; 408 409 err = kstrtoint(page, 10, &val); 410 if (err < 0) 411 return err; 412 413 if (val == BLK_MQ_POLL_CLASSIC) 414 q->poll_nsec = BLK_MQ_POLL_CLASSIC; 415 else if (val >= 0) 416 q->poll_nsec = val * 1000; 417 else 418 return -EINVAL; 419 420 return count; 421 } 422 423 static ssize_t queue_poll_show(struct request_queue *q, char *page) 424 { 425 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); 426 } 427 428 static ssize_t queue_poll_store(struct request_queue *q, const char *page, 429 size_t count) 430 { 431 unsigned long poll_on; 432 ssize_t ret; 433 434 if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL || 435 !q->tag_set->map[HCTX_TYPE_POLL].nr_queues) 436 return -EINVAL; 437 438 ret = queue_var_store(&poll_on, page, count); 439 if (ret < 0) 440 return ret; 441 442 if (poll_on) { 443 blk_queue_flag_set(QUEUE_FLAG_POLL, q); 444 } else { 445 blk_mq_freeze_queue(q); 446 blk_queue_flag_clear(QUEUE_FLAG_POLL, q); 447 blk_mq_unfreeze_queue(q); 448 } 449 450 return ret; 451 } 452 453 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page) 454 { 455 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout)); 456 } 457 458 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, 459 size_t count) 460 { 461 unsigned int val; 462 int err; 463 464 err = kstrtou32(page, 10, &val); 465 if (err || val == 0) 466 return -EINVAL; 467 468 blk_queue_rq_timeout(q, msecs_to_jiffies(val)); 469 470 return count; 471 } 472 473 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) 474 { 475 if (!wbt_rq_qos(q)) 476 return -EINVAL; 477 478 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); 479 } 480 481 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, 482 size_t count) 483 { 484 struct rq_qos *rqos; 485 ssize_t ret; 486 s64 val; 487 488 ret = queue_var_store64(&val, page); 489 if (ret < 0) 490 return ret; 491 if (val < -1) 492 return -EINVAL; 493 494 rqos = wbt_rq_qos(q); 495 if (!rqos) { 496 ret = wbt_init(q); 497 if (ret) 498 return ret; 499 } 500 501 if (val == -1) 502 val = wbt_default_latency_nsec(q); 503 else if (val >= 0) 504 val *= 1000ULL; 505 506 if (wbt_get_min_lat(q) == val) 507 return count; 508 509 /* 510 * Ensure that the queue is idled, in case the latency update 511 * ends up either enabling or disabling wbt completely. We can't 512 * have IO inflight if that happens. 513 */ 514 blk_mq_freeze_queue(q); 515 blk_mq_quiesce_queue(q); 516 517 wbt_set_min_lat(q, val); 518 519 blk_mq_unquiesce_queue(q); 520 blk_mq_unfreeze_queue(q); 521 522 return count; 523 } 524 525 static ssize_t queue_wc_show(struct request_queue *q, char *page) 526 { 527 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 528 return sprintf(page, "write back\n"); 529 530 return sprintf(page, "write through\n"); 531 } 532 533 static ssize_t queue_wc_store(struct request_queue *q, const char *page, 534 size_t count) 535 { 536 int set = -1; 537 538 if (!strncmp(page, "write back", 10)) 539 set = 1; 540 else if (!strncmp(page, "write through", 13) || 541 !strncmp(page, "none", 4)) 542 set = 0; 543 544 if (set == -1) 545 return -EINVAL; 546 547 if (set) 548 blk_queue_flag_set(QUEUE_FLAG_WC, q); 549 else 550 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 551 552 return count; 553 } 554 555 static ssize_t queue_fua_show(struct request_queue *q, char *page) 556 { 557 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); 558 } 559 560 static ssize_t queue_dax_show(struct request_queue *q, char *page) 561 { 562 return queue_var_show(blk_queue_dax(q), page); 563 } 564 565 #define QUEUE_RO_ENTRY(_prefix, _name) \ 566 static struct queue_sysfs_entry _prefix##_entry = { \ 567 .attr = { .name = _name, .mode = 0444 }, \ 568 .show = _prefix##_show, \ 569 }; 570 571 #define QUEUE_RW_ENTRY(_prefix, _name) \ 572 static struct queue_sysfs_entry _prefix##_entry = { \ 573 .attr = { .name = _name, .mode = 0644 }, \ 574 .show = _prefix##_show, \ 575 .store = _prefix##_store, \ 576 }; 577 578 QUEUE_RW_ENTRY(queue_requests, "nr_requests"); 579 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); 580 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); 581 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 582 QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); 583 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); 584 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); 585 QUEUE_RW_ENTRY(elv_iosched, "scheduler"); 586 587 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); 588 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); 589 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); 590 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); 591 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); 592 593 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); 594 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); 595 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); 596 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); 597 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); 598 599 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); 600 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); 601 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); 602 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); 603 604 QUEUE_RO_ENTRY(queue_zoned, "zoned"); 605 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); 606 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); 607 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); 608 609 QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); 610 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); 611 QUEUE_RW_ENTRY(queue_poll, "io_poll"); 612 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); 613 QUEUE_RW_ENTRY(queue_wc, "write_cache"); 614 QUEUE_RO_ENTRY(queue_fua, "fua"); 615 QUEUE_RO_ENTRY(queue_dax, "dax"); 616 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); 617 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); 618 QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); 619 620 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 621 QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); 622 #endif 623 624 /* legacy alias for logical_block_size: */ 625 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 626 .attr = {.name = "hw_sector_size", .mode = 0444 }, 627 .show = queue_logical_block_size_show, 628 }; 629 630 QUEUE_RW_ENTRY(queue_nonrot, "rotational"); 631 QUEUE_RW_ENTRY(queue_iostats, "iostats"); 632 QUEUE_RW_ENTRY(queue_random, "add_random"); 633 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); 634 635 static struct attribute *queue_attrs[] = { 636 &queue_requests_entry.attr, 637 &queue_ra_entry.attr, 638 &queue_max_hw_sectors_entry.attr, 639 &queue_max_sectors_entry.attr, 640 &queue_max_segments_entry.attr, 641 &queue_max_discard_segments_entry.attr, 642 &queue_max_integrity_segments_entry.attr, 643 &queue_max_segment_size_entry.attr, 644 &elv_iosched_entry.attr, 645 &queue_hw_sector_size_entry.attr, 646 &queue_logical_block_size_entry.attr, 647 &queue_physical_block_size_entry.attr, 648 &queue_chunk_sectors_entry.attr, 649 &queue_io_min_entry.attr, 650 &queue_io_opt_entry.attr, 651 &queue_discard_granularity_entry.attr, 652 &queue_discard_max_entry.attr, 653 &queue_discard_max_hw_entry.attr, 654 &queue_discard_zeroes_data_entry.attr, 655 &queue_write_same_max_entry.attr, 656 &queue_write_zeroes_max_entry.attr, 657 &queue_zone_append_max_entry.attr, 658 &queue_zone_write_granularity_entry.attr, 659 &queue_nonrot_entry.attr, 660 &queue_zoned_entry.attr, 661 &queue_nr_zones_entry.attr, 662 &queue_max_open_zones_entry.attr, 663 &queue_max_active_zones_entry.attr, 664 &queue_nomerges_entry.attr, 665 &queue_rq_affinity_entry.attr, 666 &queue_iostats_entry.attr, 667 &queue_stable_writes_entry.attr, 668 &queue_random_entry.attr, 669 &queue_poll_entry.attr, 670 &queue_wc_entry.attr, 671 &queue_fua_entry.attr, 672 &queue_dax_entry.attr, 673 &queue_wb_lat_entry.attr, 674 &queue_poll_delay_entry.attr, 675 &queue_io_timeout_entry.attr, 676 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 677 &blk_throtl_sample_time_entry.attr, 678 #endif 679 &queue_virt_boundary_mask_entry.attr, 680 NULL, 681 }; 682 683 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr, 684 int n) 685 { 686 struct request_queue *q = 687 container_of(kobj, struct request_queue, kobj); 688 689 if (attr == &queue_io_timeout_entry.attr && 690 (!q->mq_ops || !q->mq_ops->timeout)) 691 return 0; 692 693 if ((attr == &queue_max_open_zones_entry.attr || 694 attr == &queue_max_active_zones_entry.attr) && 695 !blk_queue_is_zoned(q)) 696 return 0; 697 698 return attr->mode; 699 } 700 701 static struct attribute_group queue_attr_group = { 702 .attrs = queue_attrs, 703 .is_visible = queue_attr_visible, 704 }; 705 706 707 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 708 709 static ssize_t 710 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 711 { 712 struct queue_sysfs_entry *entry = to_queue(attr); 713 struct request_queue *q = 714 container_of(kobj, struct request_queue, kobj); 715 ssize_t res; 716 717 if (!entry->show) 718 return -EIO; 719 mutex_lock(&q->sysfs_lock); 720 res = entry->show(q, page); 721 mutex_unlock(&q->sysfs_lock); 722 return res; 723 } 724 725 static ssize_t 726 queue_attr_store(struct kobject *kobj, struct attribute *attr, 727 const char *page, size_t length) 728 { 729 struct queue_sysfs_entry *entry = to_queue(attr); 730 struct request_queue *q; 731 ssize_t res; 732 733 if (!entry->store) 734 return -EIO; 735 736 q = container_of(kobj, struct request_queue, kobj); 737 mutex_lock(&q->sysfs_lock); 738 res = entry->store(q, page, length); 739 mutex_unlock(&q->sysfs_lock); 740 return res; 741 } 742 743 static void blk_free_queue_rcu(struct rcu_head *rcu_head) 744 { 745 struct request_queue *q = container_of(rcu_head, struct request_queue, 746 rcu_head); 747 kmem_cache_free(blk_requestq_cachep, q); 748 } 749 750 /* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */ 751 static void blk_exit_queue(struct request_queue *q) 752 { 753 /* 754 * Since the I/O scheduler exit code may access cgroup information, 755 * perform I/O scheduler exit before disassociating from the block 756 * cgroup controller. 757 */ 758 if (q->elevator) { 759 ioc_clear_queue(q); 760 __elevator_exit(q, q->elevator); 761 } 762 763 /* 764 * Remove all references to @q from the block cgroup controller before 765 * restoring @q->queue_lock to avoid that restoring this pointer causes 766 * e.g. blkcg_print_blkgs() to crash. 767 */ 768 blkcg_exit_queue(q); 769 770 /* 771 * Since the cgroup code may dereference the @q->backing_dev_info 772 * pointer, only decrease its reference count after having removed the 773 * association with the block cgroup controller. 774 */ 775 bdi_put(q->backing_dev_info); 776 } 777 778 /** 779 * blk_release_queue - releases all allocated resources of the request_queue 780 * @kobj: pointer to a kobject, whose container is a request_queue 781 * 782 * This function releases all allocated resources of the request queue. 783 * 784 * The struct request_queue refcount is incremented with blk_get_queue() and 785 * decremented with blk_put_queue(). Once the refcount reaches 0 this function 786 * is called. 787 * 788 * For drivers that have a request_queue on a gendisk and added with 789 * __device_add_disk() the refcount to request_queue will reach 0 with 790 * the last put_disk() called by the driver. For drivers which don't use 791 * __device_add_disk() this happens with blk_cleanup_queue(). 792 * 793 * Drivers exist which depend on the release of the request_queue to be 794 * synchronous, it should not be deferred. 795 * 796 * Context: can sleep 797 */ 798 static void blk_release_queue(struct kobject *kobj) 799 { 800 struct request_queue *q = 801 container_of(kobj, struct request_queue, kobj); 802 803 might_sleep(); 804 805 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) 806 blk_stat_remove_callback(q, q->poll_cb); 807 blk_stat_free_callback(q->poll_cb); 808 809 blk_free_queue_stats(q->stats); 810 811 if (queue_is_mq(q)) { 812 struct blk_mq_hw_ctx *hctx; 813 int i; 814 815 cancel_delayed_work_sync(&q->requeue_work); 816 817 queue_for_each_hw_ctx(q, hctx, i) 818 cancel_delayed_work_sync(&hctx->run_work); 819 } 820 821 blk_exit_queue(q); 822 823 blk_queue_free_zone_bitmaps(q); 824 825 if (queue_is_mq(q)) 826 blk_mq_release(q); 827 828 blk_trace_shutdown(q); 829 mutex_lock(&q->debugfs_mutex); 830 debugfs_remove_recursive(q->debugfs_dir); 831 mutex_unlock(&q->debugfs_mutex); 832 833 if (queue_is_mq(q)) 834 blk_mq_debugfs_unregister(q); 835 836 bioset_exit(&q->bio_split); 837 838 ida_simple_remove(&blk_queue_ida, q->id); 839 call_rcu(&q->rcu_head, blk_free_queue_rcu); 840 } 841 842 static const struct sysfs_ops queue_sysfs_ops = { 843 .show = queue_attr_show, 844 .store = queue_attr_store, 845 }; 846 847 struct kobj_type blk_queue_ktype = { 848 .sysfs_ops = &queue_sysfs_ops, 849 .release = blk_release_queue, 850 }; 851 852 /** 853 * blk_register_queue - register a block layer queue with sysfs 854 * @disk: Disk of which the request queue should be registered with sysfs. 855 */ 856 int blk_register_queue(struct gendisk *disk) 857 { 858 int ret; 859 struct device *dev = disk_to_dev(disk); 860 struct request_queue *q = disk->queue; 861 862 if (WARN_ON(!q)) 863 return -ENXIO; 864 865 WARN_ONCE(blk_queue_registered(q), 866 "%s is registering an already registered queue\n", 867 kobject_name(&dev->kobj)); 868 869 blk_queue_update_readahead(q); 870 871 ret = blk_trace_init_sysfs(dev); 872 if (ret) 873 return ret; 874 875 mutex_lock(&q->sysfs_dir_lock); 876 877 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 878 if (ret < 0) { 879 blk_trace_remove_sysfs(dev); 880 goto unlock; 881 } 882 883 ret = sysfs_create_group(&q->kobj, &queue_attr_group); 884 if (ret) { 885 blk_trace_remove_sysfs(dev); 886 kobject_del(&q->kobj); 887 kobject_put(&dev->kobj); 888 goto unlock; 889 } 890 891 mutex_lock(&q->debugfs_mutex); 892 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), 893 blk_debugfs_root); 894 mutex_unlock(&q->debugfs_mutex); 895 896 if (queue_is_mq(q)) { 897 __blk_mq_register_dev(dev, q); 898 blk_mq_debugfs_register(q); 899 } 900 901 mutex_lock(&q->sysfs_lock); 902 if (q->elevator) { 903 ret = elv_register_queue(q, false); 904 if (ret) { 905 mutex_unlock(&q->sysfs_lock); 906 mutex_unlock(&q->sysfs_dir_lock); 907 kobject_del(&q->kobj); 908 blk_trace_remove_sysfs(dev); 909 kobject_put(&dev->kobj); 910 return ret; 911 } 912 } 913 914 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); 915 wbt_enable_default(q); 916 blk_throtl_register_queue(q); 917 918 /* Now everything is ready and send out KOBJ_ADD uevent */ 919 kobject_uevent(&q->kobj, KOBJ_ADD); 920 if (q->elevator) 921 kobject_uevent(&q->elevator->kobj, KOBJ_ADD); 922 mutex_unlock(&q->sysfs_lock); 923 924 ret = 0; 925 unlock: 926 mutex_unlock(&q->sysfs_dir_lock); 927 928 /* 929 * SCSI probing may synchronously create and destroy a lot of 930 * request_queues for non-existent devices. Shutting down a fully 931 * functional queue takes measureable wallclock time as RCU grace 932 * periods are involved. To avoid excessive latency in these 933 * cases, a request_queue starts out in a degraded mode which is 934 * faster to shut down and is made fully functional here as 935 * request_queues for non-existent devices never get registered. 936 */ 937 if (!blk_queue_init_done(q)) { 938 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); 939 percpu_ref_switch_to_percpu(&q->q_usage_counter); 940 } 941 942 return ret; 943 } 944 EXPORT_SYMBOL_GPL(blk_register_queue); 945 946 /** 947 * blk_unregister_queue - counterpart of blk_register_queue() 948 * @disk: Disk of which the request queue should be unregistered from sysfs. 949 * 950 * Note: the caller is responsible for guaranteeing that this function is called 951 * after blk_register_queue() has finished. 952 */ 953 void blk_unregister_queue(struct gendisk *disk) 954 { 955 struct request_queue *q = disk->queue; 956 957 if (WARN_ON(!q)) 958 return; 959 960 /* Return early if disk->queue was never registered. */ 961 if (!blk_queue_registered(q)) 962 return; 963 964 /* 965 * Since sysfs_remove_dir() prevents adding new directory entries 966 * before removal of existing entries starts, protect against 967 * concurrent elv_iosched_store() calls. 968 */ 969 mutex_lock(&q->sysfs_lock); 970 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); 971 mutex_unlock(&q->sysfs_lock); 972 973 mutex_lock(&q->sysfs_dir_lock); 974 /* 975 * Remove the sysfs attributes before unregistering the queue data 976 * structures that can be modified through sysfs. 977 */ 978 if (queue_is_mq(q)) 979 blk_mq_unregister_dev(disk_to_dev(disk), q); 980 981 kobject_uevent(&q->kobj, KOBJ_REMOVE); 982 kobject_del(&q->kobj); 983 blk_trace_remove_sysfs(disk_to_dev(disk)); 984 985 mutex_lock(&q->sysfs_lock); 986 if (q->elevator) 987 elv_unregister_queue(q); 988 mutex_unlock(&q->sysfs_lock); 989 mutex_unlock(&q->sysfs_dir_lock); 990 991 kobject_put(&disk_to_dev(disk)->kobj); 992 } 993