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