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