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_mq_freeze_queue(q); 441 blk_queue_flag_clear(QUEUE_FLAG_POLL, q); 442 blk_mq_unfreeze_queue(q); 443 } 444 445 return ret; 446 } 447 448 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page) 449 { 450 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout)); 451 } 452 453 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, 454 size_t count) 455 { 456 unsigned int val; 457 int err; 458 459 err = kstrtou32(page, 10, &val); 460 if (err || val == 0) 461 return -EINVAL; 462 463 blk_queue_rq_timeout(q, msecs_to_jiffies(val)); 464 465 return count; 466 } 467 468 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page) 469 { 470 if (!wbt_rq_qos(q)) 471 return -EINVAL; 472 473 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000)); 474 } 475 476 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page, 477 size_t count) 478 { 479 struct rq_qos *rqos; 480 ssize_t ret; 481 s64 val; 482 483 ret = queue_var_store64(&val, page); 484 if (ret < 0) 485 return ret; 486 if (val < -1) 487 return -EINVAL; 488 489 rqos = wbt_rq_qos(q); 490 if (!rqos) { 491 ret = wbt_init(q); 492 if (ret) 493 return ret; 494 } 495 496 if (val == -1) 497 val = wbt_default_latency_nsec(q); 498 else if (val >= 0) 499 val *= 1000ULL; 500 501 if (wbt_get_min_lat(q) == val) 502 return count; 503 504 /* 505 * Ensure that the queue is idled, in case the latency update 506 * ends up either enabling or disabling wbt completely. We can't 507 * have IO inflight if that happens. 508 */ 509 blk_mq_freeze_queue(q); 510 blk_mq_quiesce_queue(q); 511 512 wbt_set_min_lat(q, val); 513 514 blk_mq_unquiesce_queue(q); 515 blk_mq_unfreeze_queue(q); 516 517 return count; 518 } 519 520 static ssize_t queue_wc_show(struct request_queue *q, char *page) 521 { 522 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 523 return sprintf(page, "write back\n"); 524 525 return sprintf(page, "write through\n"); 526 } 527 528 static ssize_t queue_wc_store(struct request_queue *q, const char *page, 529 size_t count) 530 { 531 int set = -1; 532 533 if (!strncmp(page, "write back", 10)) 534 set = 1; 535 else if (!strncmp(page, "write through", 13) || 536 !strncmp(page, "none", 4)) 537 set = 0; 538 539 if (set == -1) 540 return -EINVAL; 541 542 if (set) 543 blk_queue_flag_set(QUEUE_FLAG_WC, q); 544 else 545 blk_queue_flag_clear(QUEUE_FLAG_WC, q); 546 547 return count; 548 } 549 550 static ssize_t queue_fua_show(struct request_queue *q, char *page) 551 { 552 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); 553 } 554 555 static ssize_t queue_dax_show(struct request_queue *q, char *page) 556 { 557 return queue_var_show(blk_queue_dax(q), page); 558 } 559 560 #define QUEUE_RO_ENTRY(_prefix, _name) \ 561 static struct queue_sysfs_entry _prefix##_entry = { \ 562 .attr = { .name = _name, .mode = 0444 }, \ 563 .show = _prefix##_show, \ 564 }; 565 566 #define QUEUE_RW_ENTRY(_prefix, _name) \ 567 static struct queue_sysfs_entry _prefix##_entry = { \ 568 .attr = { .name = _name, .mode = 0644 }, \ 569 .show = _prefix##_show, \ 570 .store = _prefix##_store, \ 571 }; 572 573 QUEUE_RW_ENTRY(queue_requests, "nr_requests"); 574 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); 575 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); 576 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); 577 QUEUE_RO_ENTRY(queue_max_segments, "max_segments"); 578 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); 579 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size"); 580 QUEUE_RW_ENTRY(elv_iosched, "scheduler"); 581 582 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size"); 583 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size"); 584 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors"); 585 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size"); 586 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size"); 587 588 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments"); 589 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity"); 590 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes"); 591 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes"); 592 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data"); 593 594 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes"); 595 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes"); 596 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes"); 597 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity"); 598 599 QUEUE_RO_ENTRY(queue_zoned, "zoned"); 600 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones"); 601 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones"); 602 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones"); 603 604 QUEUE_RW_ENTRY(queue_nomerges, "nomerges"); 605 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity"); 606 QUEUE_RW_ENTRY(queue_poll, "io_poll"); 607 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay"); 608 QUEUE_RW_ENTRY(queue_wc, "write_cache"); 609 QUEUE_RO_ENTRY(queue_fua, "fua"); 610 QUEUE_RO_ENTRY(queue_dax, "dax"); 611 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); 612 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); 613 614 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 615 QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); 616 #endif 617 618 /* legacy alias for logical_block_size: */ 619 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 620 .attr = {.name = "hw_sector_size", .mode = 0444 }, 621 .show = queue_logical_block_size_show, 622 }; 623 624 QUEUE_RW_ENTRY(queue_nonrot, "rotational"); 625 QUEUE_RW_ENTRY(queue_iostats, "iostats"); 626 QUEUE_RW_ENTRY(queue_random, "add_random"); 627 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes"); 628 629 static struct attribute *queue_attrs[] = { 630 &queue_requests_entry.attr, 631 &queue_ra_entry.attr, 632 &queue_max_hw_sectors_entry.attr, 633 &queue_max_sectors_entry.attr, 634 &queue_max_segments_entry.attr, 635 &queue_max_discard_segments_entry.attr, 636 &queue_max_integrity_segments_entry.attr, 637 &queue_max_segment_size_entry.attr, 638 &elv_iosched_entry.attr, 639 &queue_hw_sector_size_entry.attr, 640 &queue_logical_block_size_entry.attr, 641 &queue_physical_block_size_entry.attr, 642 &queue_chunk_sectors_entry.attr, 643 &queue_io_min_entry.attr, 644 &queue_io_opt_entry.attr, 645 &queue_discard_granularity_entry.attr, 646 &queue_discard_max_entry.attr, 647 &queue_discard_max_hw_entry.attr, 648 &queue_discard_zeroes_data_entry.attr, 649 &queue_write_same_max_entry.attr, 650 &queue_write_zeroes_max_entry.attr, 651 &queue_zone_append_max_entry.attr, 652 &queue_zone_write_granularity_entry.attr, 653 &queue_nonrot_entry.attr, 654 &queue_zoned_entry.attr, 655 &queue_nr_zones_entry.attr, 656 &queue_max_open_zones_entry.attr, 657 &queue_max_active_zones_entry.attr, 658 &queue_nomerges_entry.attr, 659 &queue_rq_affinity_entry.attr, 660 &queue_iostats_entry.attr, 661 &queue_stable_writes_entry.attr, 662 &queue_random_entry.attr, 663 &queue_poll_entry.attr, 664 &queue_wc_entry.attr, 665 &queue_fua_entry.attr, 666 &queue_dax_entry.attr, 667 &queue_wb_lat_entry.attr, 668 &queue_poll_delay_entry.attr, 669 &queue_io_timeout_entry.attr, 670 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 671 &blk_throtl_sample_time_entry.attr, 672 #endif 673 NULL, 674 }; 675 676 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr, 677 int n) 678 { 679 struct request_queue *q = 680 container_of(kobj, struct request_queue, kobj); 681 682 if (attr == &queue_io_timeout_entry.attr && 683 (!q->mq_ops || !q->mq_ops->timeout)) 684 return 0; 685 686 if ((attr == &queue_max_open_zones_entry.attr || 687 attr == &queue_max_active_zones_entry.attr) && 688 !blk_queue_is_zoned(q)) 689 return 0; 690 691 return attr->mode; 692 } 693 694 static struct attribute_group queue_attr_group = { 695 .attrs = queue_attrs, 696 .is_visible = queue_attr_visible, 697 }; 698 699 700 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 701 702 static ssize_t 703 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 704 { 705 struct queue_sysfs_entry *entry = to_queue(attr); 706 struct request_queue *q = 707 container_of(kobj, struct request_queue, kobj); 708 ssize_t res; 709 710 if (!entry->show) 711 return -EIO; 712 mutex_lock(&q->sysfs_lock); 713 res = entry->show(q, page); 714 mutex_unlock(&q->sysfs_lock); 715 return res; 716 } 717 718 static ssize_t 719 queue_attr_store(struct kobject *kobj, struct attribute *attr, 720 const char *page, size_t length) 721 { 722 struct queue_sysfs_entry *entry = to_queue(attr); 723 struct request_queue *q; 724 ssize_t res; 725 726 if (!entry->store) 727 return -EIO; 728 729 q = container_of(kobj, struct request_queue, kobj); 730 mutex_lock(&q->sysfs_lock); 731 res = entry->store(q, page, length); 732 mutex_unlock(&q->sysfs_lock); 733 return res; 734 } 735 736 static void blk_free_queue_rcu(struct rcu_head *rcu_head) 737 { 738 struct request_queue *q = container_of(rcu_head, struct request_queue, 739 rcu_head); 740 kmem_cache_free(blk_requestq_cachep, q); 741 } 742 743 /* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */ 744 static void blk_exit_queue(struct request_queue *q) 745 { 746 /* 747 * Since the I/O scheduler exit code may access cgroup information, 748 * perform I/O scheduler exit before disassociating from the block 749 * cgroup controller. 750 */ 751 if (q->elevator) { 752 ioc_clear_queue(q); 753 __elevator_exit(q, q->elevator); 754 } 755 756 /* 757 * Remove all references to @q from the block cgroup controller before 758 * restoring @q->queue_lock to avoid that restoring this pointer causes 759 * e.g. blkcg_print_blkgs() to crash. 760 */ 761 blkcg_exit_queue(q); 762 763 /* 764 * Since the cgroup code may dereference the @q->backing_dev_info 765 * pointer, only decrease its reference count after having removed the 766 * association with the block cgroup controller. 767 */ 768 bdi_put(q->backing_dev_info); 769 } 770 771 /** 772 * blk_release_queue - releases all allocated resources of the request_queue 773 * @kobj: pointer to a kobject, whose container is a request_queue 774 * 775 * This function releases all allocated resources of the request queue. 776 * 777 * The struct request_queue refcount is incremented with blk_get_queue() and 778 * decremented with blk_put_queue(). Once the refcount reaches 0 this function 779 * is called. 780 * 781 * For drivers that have a request_queue on a gendisk and added with 782 * __device_add_disk() the refcount to request_queue will reach 0 with 783 * the last put_disk() called by the driver. For drivers which don't use 784 * __device_add_disk() this happens with blk_cleanup_queue(). 785 * 786 * Drivers exist which depend on the release of the request_queue to be 787 * synchronous, it should not be deferred. 788 * 789 * Context: can sleep 790 */ 791 static void blk_release_queue(struct kobject *kobj) 792 { 793 struct request_queue *q = 794 container_of(kobj, struct request_queue, kobj); 795 796 might_sleep(); 797 798 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) 799 blk_stat_remove_callback(q, q->poll_cb); 800 blk_stat_free_callback(q->poll_cb); 801 802 blk_free_queue_stats(q->stats); 803 804 if (queue_is_mq(q)) { 805 struct blk_mq_hw_ctx *hctx; 806 int i; 807 808 cancel_delayed_work_sync(&q->requeue_work); 809 810 queue_for_each_hw_ctx(q, hctx, i) 811 cancel_delayed_work_sync(&hctx->run_work); 812 } 813 814 blk_exit_queue(q); 815 816 blk_queue_free_zone_bitmaps(q); 817 818 if (queue_is_mq(q)) 819 blk_mq_release(q); 820 821 blk_trace_shutdown(q); 822 mutex_lock(&q->debugfs_mutex); 823 debugfs_remove_recursive(q->debugfs_dir); 824 mutex_unlock(&q->debugfs_mutex); 825 826 if (queue_is_mq(q)) 827 blk_mq_debugfs_unregister(q); 828 829 bioset_exit(&q->bio_split); 830 831 ida_simple_remove(&blk_queue_ida, q->id); 832 call_rcu(&q->rcu_head, blk_free_queue_rcu); 833 } 834 835 static const struct sysfs_ops queue_sysfs_ops = { 836 .show = queue_attr_show, 837 .store = queue_attr_store, 838 }; 839 840 struct kobj_type blk_queue_ktype = { 841 .sysfs_ops = &queue_sysfs_ops, 842 .release = blk_release_queue, 843 }; 844 845 /** 846 * blk_register_queue - register a block layer queue with sysfs 847 * @disk: Disk of which the request queue should be registered with sysfs. 848 */ 849 int blk_register_queue(struct gendisk *disk) 850 { 851 int ret; 852 struct device *dev = disk_to_dev(disk); 853 struct request_queue *q = disk->queue; 854 855 if (WARN_ON(!q)) 856 return -ENXIO; 857 858 WARN_ONCE(blk_queue_registered(q), 859 "%s is registering an already registered queue\n", 860 kobject_name(&dev->kobj)); 861 862 /* 863 * SCSI probing may synchronously create and destroy a lot of 864 * request_queues for non-existent devices. Shutting down a fully 865 * functional queue takes measureable wallclock time as RCU grace 866 * periods are involved. To avoid excessive latency in these 867 * cases, a request_queue starts out in a degraded mode which is 868 * faster to shut down and is made fully functional here as 869 * request_queues for non-existent devices never get registered. 870 */ 871 if (!blk_queue_init_done(q)) { 872 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q); 873 percpu_ref_switch_to_percpu(&q->q_usage_counter); 874 } 875 876 blk_queue_update_readahead(q); 877 878 ret = blk_trace_init_sysfs(dev); 879 if (ret) 880 return ret; 881 882 mutex_lock(&q->sysfs_dir_lock); 883 884 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 885 if (ret < 0) { 886 blk_trace_remove_sysfs(dev); 887 goto unlock; 888 } 889 890 ret = sysfs_create_group(&q->kobj, &queue_attr_group); 891 if (ret) { 892 blk_trace_remove_sysfs(dev); 893 kobject_del(&q->kobj); 894 kobject_put(&dev->kobj); 895 goto unlock; 896 } 897 898 mutex_lock(&q->debugfs_mutex); 899 q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), 900 blk_debugfs_root); 901 mutex_unlock(&q->debugfs_mutex); 902 903 if (queue_is_mq(q)) { 904 __blk_mq_register_dev(dev, q); 905 blk_mq_debugfs_register(q); 906 } 907 908 mutex_lock(&q->sysfs_lock); 909 if (q->elevator) { 910 ret = elv_register_queue(q, false); 911 if (ret) { 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 return ret; 918 } 919 } 920 921 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); 922 wbt_enable_default(q); 923 blk_throtl_register_queue(q); 924 925 /* Now everything is ready and send out KOBJ_ADD uevent */ 926 kobject_uevent(&q->kobj, KOBJ_ADD); 927 if (q->elevator) 928 kobject_uevent(&q->elevator->kobj, KOBJ_ADD); 929 mutex_unlock(&q->sysfs_lock); 930 931 ret = 0; 932 unlock: 933 mutex_unlock(&q->sysfs_dir_lock); 934 return ret; 935 } 936 EXPORT_SYMBOL_GPL(blk_register_queue); 937 938 /** 939 * blk_unregister_queue - counterpart of blk_register_queue() 940 * @disk: Disk of which the request queue should be unregistered from sysfs. 941 * 942 * Note: the caller is responsible for guaranteeing that this function is called 943 * after blk_register_queue() has finished. 944 */ 945 void blk_unregister_queue(struct gendisk *disk) 946 { 947 struct request_queue *q = disk->queue; 948 949 if (WARN_ON(!q)) 950 return; 951 952 /* Return early if disk->queue was never registered. */ 953 if (!blk_queue_registered(q)) 954 return; 955 956 /* 957 * Since sysfs_remove_dir() prevents adding new directory entries 958 * before removal of existing entries starts, protect against 959 * concurrent elv_iosched_store() calls. 960 */ 961 mutex_lock(&q->sysfs_lock); 962 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q); 963 mutex_unlock(&q->sysfs_lock); 964 965 mutex_lock(&q->sysfs_dir_lock); 966 /* 967 * Remove the sysfs attributes before unregistering the queue data 968 * structures that can be modified through sysfs. 969 */ 970 if (queue_is_mq(q)) 971 blk_mq_unregister_dev(disk_to_dev(disk), q); 972 973 kobject_uevent(&q->kobj, KOBJ_REMOVE); 974 kobject_del(&q->kobj); 975 blk_trace_remove_sysfs(disk_to_dev(disk)); 976 977 mutex_lock(&q->sysfs_lock); 978 if (q->elevator) 979 elv_unregister_queue(q); 980 mutex_unlock(&q->sysfs_lock); 981 mutex_unlock(&q->sysfs_dir_lock); 982 983 kobject_put(&disk_to_dev(disk)->kobj); 984 } 985