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 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 268 static ssize_t \ 269 queue_##name##_show(struct request_queue *q, char *page) \ 270 { \ 271 int bit; \ 272 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 273 return queue_var_show(neg ? !bit : bit, page); \ 274 } \ 275 static ssize_t \ 276 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \ 277 { \ 278 unsigned long val; \ 279 ssize_t ret; \ 280 ret = queue_var_store(&val, page, count); \ 281 if (ret < 0) \ 282 return ret; \ 283 if (neg) \ 284 val = !val; \ 285 \ 286 if (val) \ 287 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \ 288 else \ 289 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \ 290 return ret; \ 291 } 292 293 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 294 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 295 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 296 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0); 297 #undef QUEUE_SYSFS_BIT_FNS 298 299 static ssize_t queue_zoned_show(struct request_queue *q, char *page) 300 { 301 switch (blk_queue_zoned_model(q)) { 302 case BLK_ZONED_HA: 303 return sprintf(page, "host-aware\n"); 304 case BLK_ZONED_HM: 305 return sprintf(page, "host-managed\n"); 306 default: 307 return sprintf(page, "none\n"); 308 } 309 } 310 311 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page) 312 { 313 return queue_var_show(blk_queue_nr_zones(q), page); 314 } 315 316 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page) 317 { 318 return queue_var_show(queue_max_open_zones(q), page); 319 } 320 321 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page) 322 { 323 return queue_var_show(queue_max_active_zones(q), page); 324 } 325 326 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 327 { 328 return queue_var_show((blk_queue_nomerges(q) << 1) | 329 blk_queue_noxmerges(q), page); 330 } 331 332 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 333 size_t count) 334 { 335 unsigned long nm; 336 ssize_t ret = queue_var_store(&nm, page, count); 337 338 if (ret < 0) 339 return ret; 340 341 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 342 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 343 if (nm == 2) 344 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); 345 else if (nm) 346 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 347 348 return ret; 349 } 350 351 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 352 { 353 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 354 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 355 356 return queue_var_show(set << force, page); 357 } 358 359 static ssize_t 360 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 361 { 362 ssize_t ret = -EINVAL; 363 #ifdef CONFIG_SMP 364 unsigned long val; 365 366 ret = queue_var_store(&val, page, count); 367 if (ret < 0) 368 return ret; 369 370 if (val == 2) { 371 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 372 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 373 } else if (val == 1) { 374 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 375 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 376 } else if (val == 0) { 377 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 378 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 379 } 380 #endif 381 return ret; 382 } 383 384 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page) 385 { 386 int val; 387 388 if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) 389 val = BLK_MQ_POLL_CLASSIC; 390 else 391 val = q->poll_nsec / 1000; 392 393 return sprintf(page, "%d\n", val); 394 } 395 396 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, 397 size_t count) 398 { 399 int err, val; 400 401 if (!q->mq_ops || !q->mq_ops->poll) 402 return -EINVAL; 403 404 err = kstrtoint(page, 10, &val); 405 if (err < 0) 406 return err; 407 408 if (val == BLK_MQ_POLL_CLASSIC) 409 q->poll_nsec = BLK_MQ_POLL_CLASSIC; 410 else if (val >= 0) 411 q->poll_nsec = val * 1000; 412 else 413 return -EINVAL; 414 415 return count; 416 } 417 418 static ssize_t queue_poll_show(struct request_queue *q, char *page) 419 { 420 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); 421 } 422 423 static ssize_t queue_poll_store(struct request_queue *q, const char *page, 424 size_t count) 425 { 426 unsigned long poll_on; 427 ssize_t ret; 428 429 if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL || 430 !q->tag_set->map[HCTX_TYPE_POLL].nr_queues) 431 return -EINVAL; 432 433 ret = queue_var_store(&poll_on, page, count); 434 if (ret < 0) 435 return ret; 436 437 if (poll_on) 438 blk_queue_flag_set(QUEUE_FLAG_POLL, q); 439 else 440 blk_queue_flag_clear(QUEUE_FLAG_POLL, q); 441 442 return ret; 443 } 444 445 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page) 446 { 447 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout)); 448 } 449 450 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, 451 size_t count) 452 { 453 unsigned int val; 454 int err; 455 456 err = kstrtou32(page, 10, &val); 457 if (err || val == 0) 458 return -EINVAL; 459 460 blk_queue_rq_timeout(q, msecs_to_jiffies(val)); 461 462 return count; 463 } 464 465 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) 466 { 467 if (!wbt_rq_qos(q)) 468 return -EINVAL; 469 470 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); 471 } 472 473 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, 474 size_t count) 475 { 476 struct rq_qos *rqos; 477 ssize_t ret; 478 s64 val; 479 480 ret = queue_var_store64(&val, page); 481 if (ret < 0) 482 return ret; 483 if (val < -1) 484 return -EINVAL; 485 486 rqos = wbt_rq_qos(q); 487 if (!rqos) { 488 ret = wbt_init(q); 489 if (ret) 490 return ret; 491 } 492 493 if (val == -1) 494 val = wbt_default_latency_nsec(q); 495 else if (val >= 0) 496 val *= 1000ULL; 497 498 if (wbt_get_min_lat(q) == val) 499 return count; 500 501 /* 502 * Ensure that the queue is idled, in case the latency update 503 * ends up either enabling or disabling wbt completely. We can't 504 * have IO inflight if that happens. 505 */ 506 blk_mq_freeze_queue(q); 507 blk_mq_quiesce_queue(q); 508 509 wbt_set_min_lat(q, val); 510 511 blk_mq_unquiesce_queue(q); 512 blk_mq_unfreeze_queue(q); 513 514 return count; 515 } 516 517 static ssize_t queue_wc_show(struct request_queue *q, char *page) 518 { 519 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 520 return sprintf(page, "write back\n"); 521 522 return sprintf(page, "write through\n"); 523 } 524 525 static ssize_t queue_wc_store(struct request_queue *q, const char *page, 526 size_t count) 527 { 528 int set = -1; 529 530 if (!strncmp(page, "write back", 10)) 531 set = 1; 532 else if (!strncmp(page, "write through", 13) || 533 !strncmp(page, "none", 4)) 534 set = 0; 535 536 if (set == -1) 537 return -EINVAL; 538 539 if (set) 540 blk_queue_flag_set(QUEUE_FLAG_WC, q); 541 else 542 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 543 544 return count; 545 } 546 547 static ssize_t queue_fua_show(struct request_queue *q, char *page) 548 { 549 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); 550 } 551 552 static ssize_t queue_dax_show(struct request_queue *q, char *page) 553 { 554 return queue_var_show(blk_queue_dax(q), page); 555 } 556 557 #define QUEUE_RO_ENTRY(_prefix, _name) \ 558 static struct queue_sysfs_entry _prefix##_entry = { \ 559 .attr = { .name = _name, .mode = 0444 }, \ 560 .show = _prefix##_show, \ 561 }; 562 563 #define QUEUE_RW_ENTRY(_prefix, _name) \ 564 static struct queue_sysfs_entry _prefix##_entry = { \ 565 .attr = { .name = _name, .mode = 0644 }, \ 566 .show = _prefix##_show, \ 567 .store = _prefix##_store, \ 568 }; 569 570 QUEUE_RW_ENTRY(queue_requests, "nr_requests"); 571 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); 572 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); 573 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 574 QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); 575 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); 576 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); 577 QUEUE_RW_ENTRY(elv_iosched, "scheduler"); 578 579 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); 580 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); 581 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); 582 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); 583 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); 584 585 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); 586 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); 587 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); 588 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); 589 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); 590 591 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); 592 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); 593 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); 594 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); 595 596 QUEUE_RO_ENTRY(queue_zoned, "zoned"); 597 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); 598 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); 599 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); 600 601 QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); 602 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); 603 QUEUE_RW_ENTRY(queue_poll, "io_poll"); 604 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); 605 QUEUE_RW_ENTRY(queue_wc, "write_cache"); 606 QUEUE_RO_ENTRY(queue_fua, "fua"); 607 QUEUE_RO_ENTRY(queue_dax, "dax"); 608 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); 609 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); 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 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 * Since the cgroup code may dereference the @q->backing_dev_info 762 * pointer, only decrease its reference count after having removed the 763 * association with the block cgroup controller. 764 */ 765 bdi_put(q->backing_dev_info); 766 } 767 768 /** 769 * blk_release_queue - releases all allocated resources of the request_queue 770 * @kobj: pointer to a kobject, whose container is a request_queue 771 * 772 * This function releases all allocated resources of the request queue. 773 * 774 * The struct request_queue refcount is incremented with blk_get_queue() and 775 * decremented with blk_put_queue(). Once the refcount reaches 0 this function 776 * is called. 777 * 778 * For drivers that have a request_queue on a gendisk and added with 779 * __device_add_disk() the refcount to request_queue will reach 0 with 780 * the last put_disk() called by the driver. For drivers which don't use 781 * __device_add_disk() this happens with blk_cleanup_queue(). 782 * 783 * Drivers exist which depend on the release of the request_queue to be 784 * synchronous, it should not be deferred. 785 * 786 * Context: can sleep 787 */ 788 static void blk_release_queue(struct kobject *kobj) 789 { 790 struct request_queue *q = 791 container_of(kobj, struct request_queue, kobj); 792 793 might_sleep(); 794 795 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) 796 blk_stat_remove_callback(q, q->poll_cb); 797 blk_stat_free_callback(q->poll_cb); 798 799 blk_free_queue_stats(q->stats); 800 801 if (queue_is_mq(q)) { 802 struct blk_mq_hw_ctx *hctx; 803 int i; 804 805 cancel_delayed_work_sync(&q->requeue_work); 806 807 queue_for_each_hw_ctx(q, hctx, i) 808 cancel_delayed_work_sync(&hctx->run_work); 809 } 810 811 blk_exit_queue(q); 812 813 blk_queue_free_zone_bitmaps(q); 814 815 if (queue_is_mq(q)) 816 blk_mq_release(q); 817 818 blk_trace_shutdown(q); 819 mutex_lock(&q->debugfs_mutex); 820 debugfs_remove_recursive(q->debugfs_dir); 821 mutex_unlock(&q->debugfs_mutex); 822 823 if (queue_is_mq(q)) 824 blk_mq_debugfs_unregister(q); 825 826 bioset_exit(&q->bio_split); 827 828 ida_simple_remove(&blk_queue_ida, q->id); 829 call_rcu(&q->rcu_head, blk_free_queue_rcu); 830 } 831 832 static const struct sysfs_ops queue_sysfs_ops = { 833 .show = queue_attr_show, 834 .store = queue_attr_store, 835 }; 836 837 struct kobj_type blk_queue_ktype = { 838 .sysfs_ops = &queue_sysfs_ops, 839 .release = blk_release_queue, 840 }; 841 842 /** 843 * blk_register_queue - register a block layer queue with sysfs 844 * @disk: Disk of which the request queue should be registered with sysfs. 845 */ 846 int blk_register_queue(struct gendisk *disk) 847 { 848 int ret; 849 struct device *dev = disk_to_dev(disk); 850 struct request_queue *q = disk->queue; 851 852 if (WARN_ON(!q)) 853 return -ENXIO; 854 855 WARN_ONCE(blk_queue_registered(q), 856 "%s is registering an already registered queue\n", 857 kobject_name(&dev->kobj)); 858 859 /* 860 * SCSI probing may synchronously create and destroy a lot of 861 * request_queues for non-existent devices. Shutting down a fully 862 * functional queue takes measureable wallclock time as RCU grace 863 * periods are involved. To avoid excessive latency in these 864 * cases, a request_queue starts out in a degraded mode which is 865 * faster to shut down and is made fully functional here as 866 * request_queues for non-existent devices never get registered. 867 */ 868 if (!blk_queue_init_done(q)) { 869 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); 870 percpu_ref_switch_to_percpu(&q->q_usage_counter); 871 } 872 873 blk_queue_update_readahead(q); 874 875 ret = blk_trace_init_sysfs(dev); 876 if (ret) 877 return ret; 878 879 mutex_lock(&q->sysfs_dir_lock); 880 881 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 882 if (ret < 0) { 883 blk_trace_remove_sysfs(dev); 884 goto unlock; 885 } 886 887 ret = sysfs_create_group(&q->kobj, &queue_attr_group); 888 if (ret) { 889 blk_trace_remove_sysfs(dev); 890 kobject_del(&q->kobj); 891 kobject_put(&dev->kobj); 892 goto unlock; 893 } 894 895 mutex_lock(&q->debugfs_mutex); 896 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), 897 blk_debugfs_root); 898 mutex_unlock(&q->debugfs_mutex); 899 900 if (queue_is_mq(q)) { 901 __blk_mq_register_dev(dev, q); 902 blk_mq_debugfs_register(q); 903 } 904 905 mutex_lock(&q->sysfs_lock); 906 if (q->elevator) { 907 ret = elv_register_queue(q, false); 908 if (ret) { 909 mutex_unlock(&q->sysfs_lock); 910 mutex_unlock(&q->sysfs_dir_lock); 911 kobject_del(&q->kobj); 912 blk_trace_remove_sysfs(dev); 913 kobject_put(&dev->kobj); 914 return ret; 915 } 916 } 917 918 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); 919 wbt_enable_default(q); 920 blk_throtl_register_queue(q); 921 922 /* Now everything is ready and send out KOBJ_ADD uevent */ 923 kobject_uevent(&q->kobj, KOBJ_ADD); 924 if (q->elevator) 925 kobject_uevent(&q->elevator->kobj, KOBJ_ADD); 926 mutex_unlock(&q->sysfs_lock); 927 928 ret = 0; 929 unlock: 930 mutex_unlock(&q->sysfs_dir_lock); 931 return ret; 932 } 933 EXPORT_SYMBOL_GPL(blk_register_queue); 934 935 /** 936 * blk_unregister_queue - counterpart of blk_register_queue() 937 * @disk: Disk of which the request queue should be unregistered from sysfs. 938 * 939 * Note: the caller is responsible for guaranteeing that this function is called 940 * after blk_register_queue() has finished. 941 */ 942 void blk_unregister_queue(struct gendisk *disk) 943 { 944 struct request_queue *q = disk->queue; 945 946 if (WARN_ON(!q)) 947 return; 948 949 /* Return early if disk->queue was never registered. */ 950 if (!blk_queue_registered(q)) 951 return; 952 953 /* 954 * Since sysfs_remove_dir() prevents adding new directory entries 955 * before removal of existing entries starts, protect against 956 * concurrent elv_iosched_store() calls. 957 */ 958 mutex_lock(&q->sysfs_lock); 959 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); 960 mutex_unlock(&q->sysfs_lock); 961 962 mutex_lock(&q->sysfs_dir_lock); 963 /* 964 * Remove the sysfs attributes before unregistering the queue data 965 * structures that can be modified through sysfs. 966 */ 967 if (queue_is_mq(q)) 968 blk_mq_unregister_dev(disk_to_dev(disk), q); 969 970 kobject_uevent(&q->kobj, KOBJ_REMOVE); 971 kobject_del(&q->kobj); 972 blk_trace_remove_sysfs(disk_to_dev(disk)); 973 974 mutex_lock(&q->sysfs_lock); 975 if (q->elevator) 976 elv_unregister_queue(q); 977 mutex_unlock(&q->sysfs_lock); 978 mutex_unlock(&q->sysfs_dir_lock); 979 980 kobject_put(&disk_to_dev(disk)->kobj); 981 } 982