block/blk-sysfs.c

   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/debugfs.h>
  13
  14 #include "blk.h"
  15 #include "blk-mq.h"
  16 #include "blk-mq-debugfs.h"
  17 #include "blk-mq-sched.h"
  18 #include "blk-rq-qos.h"
  19 #include "blk-wbt.h"
  20 #include "blk-cgroup.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_requests_show(struct request_queue *q, char *page)
  51 {
  52         return queue_var_show(q->nr_requests, page);
  53 }
  54
  55 static ssize_t
  56 queue_requests_store(struct request_queue *q, const char *page, size_t count)
  57 {
  58         unsigned long nr;
  59         int ret, err;
  60
  61         if (!queue_is_mq(q))
  62                 return -EINVAL;
  63
  64         ret = queue_var_store(&nr, page, count);
  65         if (ret < 0)
  66                 return ret;
  67
  68         if (nr < BLKDEV_MIN_RQ)
  69                 nr = BLKDEV_MIN_RQ;
  70
  71         err = blk_mq_update_nr_requests(q, nr);
  72         if (err)
  73                 return err;
  74
  75         return ret;
  76 }
  77
  78 static ssize_t queue_ra_show(struct request_queue *q, char *page)
  79 {
  80         unsigned long ra_kb;
  81
  82         if (!q->disk)
  83                 return -EINVAL;
  84         ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
  85         return queue_var_show(ra_kb, page);
  86 }
  87
  88 static ssize_t
  89 queue_ra_store(struct request_queue *q, const char *page, size_t count)
  90 {
  91         unsigned long ra_kb;
  92         ssize_t ret;
  93
  94         if (!q->disk)
  95                 return -EINVAL;
  96         ret = queue_var_store(&ra_kb, page, count);
  97         if (ret < 0)
  98                 return ret;
  99         q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
 100         return ret;
 101 }
 102
 103 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
 104 {
 105         int max_sectors_kb = queue_max_sectors(q) >> 1;
 106
 107         return queue_var_show(max_sectors_kb, page);
 108 }
 109
 110 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
 111 {
 112         return queue_var_show(queue_max_segments(q), page);
 113 }
 114
 115 static ssize_t queue_max_discard_segments_show(struct request_queue *q,
 116                 char *page)
 117 {
 118         return queue_var_show(queue_max_discard_segments(q), page);
 119 }
 120
 121 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
 122 {
 123         return queue_var_show(q->limits.max_integrity_segments, page);
 124 }
 125
 126 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
 127 {
 128         return queue_var_show(queue_max_segment_size(q), page);
 129 }
 130
 131 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
 132 {
 133         return queue_var_show(queue_logical_block_size(q), page);
 134 }
 135
 136 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
 137 {
 138         return queue_var_show(queue_physical_block_size(q), page);
 139 }
 140
 141 static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
 142 {
 143         return queue_var_show(q->limits.chunk_sectors, page);
 144 }
 145
 146 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
 147 {
 148         return queue_var_show(queue_io_min(q), page);
 149 }
 150
 151 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
 152 {
 153         return queue_var_show(queue_io_opt(q), page);
 154 }
 155
 156 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
 157 {
 158         return queue_var_show(q->limits.discard_granularity, page);
 159 }
 160
 161 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
 162 {
 163
 164         return sprintf(page, "%llu\n",
 165                 (unsigned long long)q->limits.max_hw_discard_sectors << 9);
 166 }
 167
 168 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
 169 {
 170         return sprintf(page, "%llu\n",
 171                        (unsigned long long)q->limits.max_discard_sectors << 9);
 172 }
 173
 174 static ssize_t queue_discard_max_store(struct request_queue *q,
 175                                        const char *page, size_t count)
 176 {
 177         unsigned long max_discard_bytes;
 178         struct queue_limits lim;
 179         ssize_t ret;
 180         int err;
 181
 182         ret = queue_var_store(&max_discard_bytes, page, count);
 183         if (ret < 0)
 184                 return ret;
 185
 186         if (max_discard_bytes & (q->limits.discard_granularity - 1))
 187                 return -EINVAL;
 188
 189         if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
 190                 return -EINVAL;
 191
 192         blk_mq_freeze_queue(q);
 193         lim = queue_limits_start_update(q);
 194         lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
 195         err = queue_limits_commit_update(q, &lim);
 196         blk_mq_unfreeze_queue(q);
 197
 198         if (err)
 199                 return err;
 200         return ret;
 201 }
 202
 203 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
 204 {
 205         return queue_var_show(0, page);
 206 }
 207
 208 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
 209 {
 210         return queue_var_show(0, page);
 211 }
 212
 213 static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
 214 {
 215         return sprintf(page, "%llu\n",
 216                 (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
 217 }
 218
 219 static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
 220                                                  char *page)
 221 {
 222         return queue_var_show(queue_zone_write_granularity(q), page);
 223 }
 224
 225 static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
 226 {
 227         unsigned long long max_sectors = queue_max_zone_append_sectors(q);
 228
 229         return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
 230 }
 231
 232 static ssize_t
 233 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 234 {
 235         unsigned long max_sectors_kb;
 236         struct queue_limits lim;
 237         ssize_t ret;
 238         int err;
 239
 240         ret = queue_var_store(&max_sectors_kb, page, count);
 241         if (ret < 0)
 242                 return ret;
 243
 244         blk_mq_freeze_queue(q);
 245         lim = queue_limits_start_update(q);
 246         lim.max_user_sectors = max_sectors_kb << 1;
 247         err = queue_limits_commit_update(q, &lim);
 248         blk_mq_unfreeze_queue(q);
 249         if (err)
 250                 return err;
 251         return ret;
 252 }
 253
 254 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 255 {
 256         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 257
 258         return queue_var_show(max_hw_sectors_kb, page);
 259 }
 260
 261 static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
 262 {
 263         return queue_var_show(q->limits.virt_boundary_mask, page);
 264 }
 265
 266 static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
 267 {
 268         return queue_var_show(queue_dma_alignment(q), page);
 269 }
 270
 271 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
 272 static ssize_t                                                          \
 273 queue_##name##_show(struct request_queue *q, char *page)                \
 274 {                                                                       \
 275         int bit;                                                        \
 276         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
 277         return queue_var_show(neg ? !bit : bit, page);                  \
 278 }                                                                       \
 279 static ssize_t                                                          \
 280 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
 281 {                                                                       \
 282         unsigned long val;                                              \
 283         ssize_t ret;                                                    \
 284         ret = queue_var_store(&val, page, count);                       \
 285         if (ret < 0)                                                    \
 286                  return ret;                                            \
 287         if (neg)                                                        \
 288                 val = !val;                                             \
 289                                                                         \
 290         if (val)                                                        \
 291                 blk_queue_flag_set(QUEUE_FLAG_##flag, q);               \
 292         else                                                            \
 293                 blk_queue_flag_clear(QUEUE_FLAG_##flag, q);             \
 294         return ret;                                                     \
 295 }
 296
 297 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
 298 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
 299 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 300 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
 301 #undef QUEUE_SYSFS_BIT_FNS
 302
 303 static ssize_t queue_zoned_show(struct request_queue *q, char *page)
 304 {
 305         if (blk_queue_is_zoned(q))
 306                 return sprintf(page, "host-managed\n");
 307         return sprintf(page, "none\n");
 308 }
 309
 310 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
 311 {
 312         return queue_var_show(disk_nr_zones(q->disk), page);
 313 }
 314
 315 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
 316 {
 317         return queue_var_show(bdev_max_open_zones(q->disk->part0), page);
 318 }
 319
 320 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
 321 {
 322         return queue_var_show(bdev_max_active_zones(q->disk->part0), page);
 323 }
 324
 325 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 326 {
 327         return queue_var_show((blk_queue_nomerges(q) << 1) |
 328                                blk_queue_noxmerges(q), page);
 329 }
 330
 331 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 332                                     size_t count)
 333 {
 334         unsigned long nm;
 335         ssize_t ret = queue_var_store(&nm, page, count);
 336
 337         if (ret < 0)
 338                 return ret;
 339
 340         blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 341         blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 342         if (nm == 2)
 343                 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 344         else if (nm)
 345                 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 346
 347         return ret;
 348 }
 349
 350 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
 351 {
 352         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
 353         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
 354
 355         return queue_var_show(set << force, page);
 356 }
 357
 358 static ssize_t
 359 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 360 {
 361         ssize_t ret = -EINVAL;
 362 #ifdef CONFIG_SMP
 363         unsigned long val;
 364
 365         ret = queue_var_store(&val, page, count);
 366         if (ret < 0)
 367                 return ret;
 368
 369         if (val == 2) {
 370                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 371                 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
 372         } else if (val == 1) {
 373                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 374                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 375         } else if (val == 0) {
 376                 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 377                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 378         }
 379 #endif
 380         return ret;
 381 }
 382
 383 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
 384 {
 385         return sprintf(page, "%d\n", -1);
 386 }
 387
 388 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
 389                                 size_t count)
 390 {
 391         return count;
 392 }
 393
 394 static ssize_t queue_poll_show(struct request_queue *q, char *page)
 395 {
 396         return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
 397 }
 398
 399 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
 400                                 size_t count)
 401 {
 402         if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
 403                 return -EINVAL;
 404         pr_info_ratelimited("writes to the poll attribute are ignored.\n");
 405         pr_info_ratelimited("please use driver specific parameters instead.\n");
 406         return count;
 407 }
 408
 409 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
 410 {
 411         return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
 412 }
 413
 414 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
 415                                   size_t count)
 416 {
 417         unsigned int val;
 418         int err;
 419
 420         err = kstrtou32(page, 10, &val);
 421         if (err || val == 0)
 422                 return -EINVAL;
 423
 424         blk_queue_rq_timeout(q, msecs_to_jiffies(val));
 425
 426         return count;
 427 }
 428
 429 static ssize_t queue_wc_show(struct request_queue *q, char *page)
 430 {
 431         if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 432                 return sprintf(page, "write back\n");
 433
 434         return sprintf(page, "write through\n");
 435 }
 436
 437 static ssize_t queue_wc_store(struct request_queue *q, const char *page,
 438                               size_t count)
 439 {
 440         if (!strncmp(page, "write back", 10)) {
 441                 if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags))
 442                         return -EINVAL;
 443                 blk_queue_flag_set(QUEUE_FLAG_WC, q);
 444         } else if (!strncmp(page, "write through", 13) ||
 445                  !strncmp(page, "none", 4)) {
 446                 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
 447         } else {
 448                 return -EINVAL;
 449         }
 450
 451         return count;
 452 }
 453
 454 static ssize_t queue_fua_show(struct request_queue *q, char *page)
 455 {
 456         return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
 457 }
 458
 459 static ssize_t queue_dax_show(struct request_queue *q, char *page)
 460 {
 461         return queue_var_show(blk_queue_dax(q), page);
 462 }
 463
 464 #define QUEUE_RO_ENTRY(_prefix, _name)                  \
 465 static struct queue_sysfs_entry _prefix##_entry = {     \
 466         .attr   = { .name = _name, .mode = 0444 },      \
 467         .show   = _prefix##_show,                       \
 468 };
 469
 470 #define QUEUE_RW_ENTRY(_prefix, _name)                  \
 471 static struct queue_sysfs_entry _prefix##_entry = {     \
 472         .attr   = { .name = _name, .mode = 0644 },      \
 473         .show   = _prefix##_show,                       \
 474         .store  = _prefix##_store,                      \
 475 };
 476
 477 QUEUE_RW_ENTRY(queue_requests, "nr_requests");
 478 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
 479 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
 480 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
 481 QUEUE_RO_ENTRY(queue_max_segments, "max_segments");
 482 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
 483 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size");
 484 QUEUE_RW_ENTRY(elv_iosched, "scheduler");
 485
 486 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size");
 487 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size");
 488 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors");
 489 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size");
 490 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size");
 491
 492 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
 493 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity");
 494 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes");
 495 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes");
 496 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
 497
 498 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");
 499 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes");
 500 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes");
 501 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");
 502
 503 QUEUE_RO_ENTRY(queue_zoned, "zoned");
 504 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones");
 505 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones");
 506 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones");
 507
 508 QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
 509 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
 510 QUEUE_RW_ENTRY(queue_poll, "io_poll");
 511 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
 512 QUEUE_RW_ENTRY(queue_wc, "write_cache");
 513 QUEUE_RO_ENTRY(queue_fua, "fua");
 514 QUEUE_RO_ENTRY(queue_dax, "dax");
 515 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
 516 QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
 517 QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
 518
 519 /* legacy alias for logical_block_size: */
 520 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 521         .attr = {.name = "hw_sector_size", .mode = 0444 },
 522         .show = queue_logical_block_size_show,
 523 };
 524
 525 QUEUE_RW_ENTRY(queue_nonrot, "rotational");
 526 QUEUE_RW_ENTRY(queue_iostats, "iostats");
 527 QUEUE_RW_ENTRY(queue_random, "add_random");
 528 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
 529
 530 #ifdef CONFIG_BLK_WBT
 531 static ssize_t queue_var_store64(s64 *var, const char *page)
 532 {
 533         int err;
 534         s64 v;
 535
 536         err = kstrtos64(page, 10, &v);
 537         if (err < 0)
 538                 return err;
 539
 540         *var = v;
 541         return 0;
 542 }
 543
 544 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
 545 {
 546         if (!wbt_rq_qos(q))
 547                 return -EINVAL;
 548
 549         if (wbt_disabled(q))
 550                 return sprintf(page, "0\n");
 551
 552         return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
 553 }
 554
 555 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 556                                   size_t count)
 557 {
 558         struct rq_qos *rqos;
 559         ssize_t ret;
 560         s64 val;
 561
 562         ret = queue_var_store64(&val, page);
 563         if (ret < 0)
 564                 return ret;
 565         if (val < -1)
 566                 return -EINVAL;
 567
 568         rqos = wbt_rq_qos(q);
 569         if (!rqos) {
 570                 ret = wbt_init(q->disk);
 571                 if (ret)
 572                         return ret;
 573         }
 574
 575         if (val == -1)
 576                 val = wbt_default_latency_nsec(q);
 577         else if (val >= 0)
 578                 val *= 1000ULL;
 579
 580         if (wbt_get_min_lat(q) == val)
 581                 return count;
 582
 583         /*
 584          * Ensure that the queue is idled, in case the latency update
 585          * ends up either enabling or disabling wbt completely. We can't
 586          * have IO inflight if that happens.
 587          */
 588         blk_mq_freeze_queue(q);
 589         blk_mq_quiesce_queue(q);
 590
 591         wbt_set_min_lat(q, val);
 592
 593         blk_mq_unquiesce_queue(q);
 594         blk_mq_unfreeze_queue(q);
 595
 596         return count;
 597 }
 598
 599 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
 600 #endif
 601
 602 /* Common attributes for bio-based and request-based queues. */
 603 static struct attribute *queue_attrs[] = {
 604         &queue_ra_entry.attr,
 605         &queue_max_hw_sectors_entry.attr,
 606         &queue_max_sectors_entry.attr,
 607         &queue_max_segments_entry.attr,
 608         &queue_max_discard_segments_entry.attr,
 609         &queue_max_integrity_segments_entry.attr,
 610         &queue_max_segment_size_entry.attr,
 611         &queue_hw_sector_size_entry.attr,
 612         &queue_logical_block_size_entry.attr,
 613         &queue_physical_block_size_entry.attr,
 614         &queue_chunk_sectors_entry.attr,
 615         &queue_io_min_entry.attr,
 616         &queue_io_opt_entry.attr,
 617         &queue_discard_granularity_entry.attr,
 618         &queue_discard_max_entry.attr,
 619         &queue_discard_max_hw_entry.attr,
 620         &queue_discard_zeroes_data_entry.attr,
 621         &queue_write_same_max_entry.attr,
 622         &queue_write_zeroes_max_entry.attr,
 623         &queue_zone_append_max_entry.attr,
 624         &queue_zone_write_granularity_entry.attr,
 625         &queue_nonrot_entry.attr,
 626         &queue_zoned_entry.attr,
 627         &queue_nr_zones_entry.attr,
 628         &queue_max_open_zones_entry.attr,
 629         &queue_max_active_zones_entry.attr,
 630         &queue_nomerges_entry.attr,
 631         &queue_iostats_entry.attr,
 632         &queue_stable_writes_entry.attr,
 633         &queue_random_entry.attr,
 634         &queue_poll_entry.attr,
 635         &queue_wc_entry.attr,
 636         &queue_fua_entry.attr,
 637         &queue_dax_entry.attr,
 638         &queue_poll_delay_entry.attr,
 639         &queue_virt_boundary_mask_entry.attr,
 640         &queue_dma_alignment_entry.attr,
 641         NULL,
 642 };
 643
 644 /* Request-based queue attributes that are not relevant for bio-based queues. */
 645 static struct attribute *blk_mq_queue_attrs[] = {
 646         &queue_requests_entry.attr,
 647         &elv_iosched_entry.attr,
 648         &queue_rq_affinity_entry.attr,
 649         &queue_io_timeout_entry.attr,
 650 #ifdef CONFIG_BLK_WBT
 651         &queue_wb_lat_entry.attr,
 652 #endif
 653         NULL,
 654 };
 655
 656 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
 657                                 int n)
 658 {
 659         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
 660         struct request_queue *q = disk->queue;
 661
 662         if ((attr == &queue_max_open_zones_entry.attr ||
 663              attr == &queue_max_active_zones_entry.attr) &&
 664             !blk_queue_is_zoned(q))
 665                 return 0;
 666
 667         return attr->mode;
 668 }
 669
 670 static umode_t blk_mq_queue_attr_visible(struct kobject *kobj,
 671                                          struct attribute *attr, int n)
 672 {
 673         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
 674         struct request_queue *q = disk->queue;
 675
 676         if (!queue_is_mq(q))
 677                 return 0;
 678
 679         if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout)
 680                 return 0;
 681
 682         return attr->mode;
 683 }
 684
 685 static struct attribute_group queue_attr_group = {
 686         .attrs = queue_attrs,
 687         .is_visible = queue_attr_visible,
 688 };
 689
 690 static struct attribute_group blk_mq_queue_attr_group = {
 691         .attrs = blk_mq_queue_attrs,
 692         .is_visible = blk_mq_queue_attr_visible,
 693 };
 694
 695 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
 696
 697 static ssize_t
 698 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 699 {
 700         struct queue_sysfs_entry *entry = to_queue(attr);
 701         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
 702         struct request_queue *q = disk->queue;
 703         ssize_t res;
 704
 705         if (!entry->show)
 706                 return -EIO;
 707         mutex_lock(&q->sysfs_lock);
 708         res = entry->show(q, page);
 709         mutex_unlock(&q->sysfs_lock);
 710         return res;
 711 }
 712
 713 static ssize_t
 714 queue_attr_store(struct kobject *kobj, struct attribute *attr,
 715                     const char *page, size_t length)
 716 {
 717         struct queue_sysfs_entry *entry = to_queue(attr);
 718         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
 719         struct request_queue *q = disk->queue;
 720         ssize_t res;
 721
 722         if (!entry->store)
 723                 return -EIO;
 724
 725         mutex_lock(&q->sysfs_lock);
 726         res = entry->store(q, page, length);
 727         mutex_unlock(&q->sysfs_lock);
 728         return res;
 729 }
 730
 731 static const struct sysfs_ops queue_sysfs_ops = {
 732         .show   = queue_attr_show,
 733         .store  = queue_attr_store,
 734 };
 735
 736 static const struct attribute_group *blk_queue_attr_groups[] = {
 737         &queue_attr_group,
 738         &blk_mq_queue_attr_group,
 739         NULL
 740 };
 741
 742 static void blk_queue_release(struct kobject *kobj)
 743 {
 744         /* nothing to do here, all data is associated with the parent gendisk */
 745 }
 746
 747 static const struct kobj_type blk_queue_ktype = {
 748         .default_groups = blk_queue_attr_groups,
 749         .sysfs_ops      = &queue_sysfs_ops,
 750         .release        = blk_queue_release,
 751 };
 752
 753 static void blk_debugfs_remove(struct gendisk *disk)
 754 {
 755         struct request_queue *q = disk->queue;
 756
 757         mutex_lock(&q->debugfs_mutex);
 758         blk_trace_shutdown(q);
 759         debugfs_remove_recursive(q->debugfs_dir);
 760         q->debugfs_dir = NULL;
 761         q->sched_debugfs_dir = NULL;
 762         q->rqos_debugfs_dir = NULL;
 763         mutex_unlock(&q->debugfs_mutex);
 764 }
 765
 766 /**
 767  * blk_register_queue - register a block layer queue with sysfs
 768  * @disk: Disk of which the request queue should be registered with sysfs.
 769  */
 770 int blk_register_queue(struct gendisk *disk)
 771 {
 772         struct request_queue *q = disk->queue;
 773         int ret;
 774
 775         mutex_lock(&q->sysfs_dir_lock);
 776         kobject_init(&disk->queue_kobj, &blk_queue_ktype);
 777         ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue");
 778         if (ret < 0)
 779                 goto out_put_queue_kobj;
 780
 781         if (queue_is_mq(q)) {
 782                 ret = blk_mq_sysfs_register(disk);
 783                 if (ret)
 784                         goto out_put_queue_kobj;
 785         }
 786         mutex_lock(&q->sysfs_lock);
 787
 788         mutex_lock(&q->debugfs_mutex);
 789         q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root);
 790         if (queue_is_mq(q))
 791                 blk_mq_debugfs_register(q);
 792         mutex_unlock(&q->debugfs_mutex);
 793
 794         ret = disk_register_independent_access_ranges(disk);
 795         if (ret)
 796                 goto out_debugfs_remove;
 797
 798         if (q->elevator) {
 799                 ret = elv_register_queue(q, false);
 800                 if (ret)
 801                         goto out_unregister_ia_ranges;
 802         }
 803
 804         ret = blk_crypto_sysfs_register(disk);
 805         if (ret)
 806                 goto out_elv_unregister;
 807
 808         blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
 809         wbt_enable_default(disk);
 810
 811         /* Now everything is ready and send out KOBJ_ADD uevent */
 812         kobject_uevent(&disk->queue_kobj, KOBJ_ADD);
 813         if (q->elevator)
 814                 kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 815         mutex_unlock(&q->sysfs_lock);
 816         mutex_unlock(&q->sysfs_dir_lock);
 817
 818         /*
 819          * SCSI probing may synchronously create and destroy a lot of
 820          * request_queues for non-existent devices.  Shutting down a fully
 821          * functional queue takes measureable wallclock time as RCU grace
 822          * periods are involved.  To avoid excessive latency in these
 823          * cases, a request_queue starts out in a degraded mode which is
 824          * faster to shut down and is made fully functional here as
 825          * request_queues for non-existent devices never get registered.
 826          */
 827         if (!blk_queue_init_done(q)) {
 828                 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
 829                 percpu_ref_switch_to_percpu(&q->q_usage_counter);
 830         }
 831
 832         return ret;
 833
 834 out_elv_unregister:
 835         elv_unregister_queue(q);
 836 out_unregister_ia_ranges:
 837         disk_unregister_independent_access_ranges(disk);
 838 out_debugfs_remove:
 839         blk_debugfs_remove(disk);
 840         mutex_unlock(&q->sysfs_lock);
 841 out_put_queue_kobj:
 842         kobject_put(&disk->queue_kobj);
 843         mutex_unlock(&q->sysfs_dir_lock);
 844         return ret;
 845 }
 846
 847 /**
 848  * blk_unregister_queue - counterpart of blk_register_queue()
 849  * @disk: Disk of which the request queue should be unregistered from sysfs.
 850  *
 851  * Note: the caller is responsible for guaranteeing that this function is called
 852  * after blk_register_queue() has finished.
 853  */
 854 void blk_unregister_queue(struct gendisk *disk)
 855 {
 856         struct request_queue *q = disk->queue;
 857
 858         if (WARN_ON(!q))
 859                 return;
 860
 861         /* Return early if disk->queue was never registered. */
 862         if (!blk_queue_registered(q))
 863                 return;
 864
 865         /*
 866          * Since sysfs_remove_dir() prevents adding new directory entries
 867          * before removal of existing entries starts, protect against
 868          * concurrent elv_iosched_store() calls.
 869          */
 870         mutex_lock(&q->sysfs_lock);
 871         blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
 872         mutex_unlock(&q->sysfs_lock);
 873
 874         mutex_lock(&q->sysfs_dir_lock);
 875         /*
 876          * Remove the sysfs attributes before unregistering the queue data
 877          * structures that can be modified through sysfs.
 878          */
 879         if (queue_is_mq(q))
 880                 blk_mq_sysfs_unregister(disk);
 881         blk_crypto_sysfs_unregister(disk);
 882
 883         mutex_lock(&q->sysfs_lock);
 884         elv_unregister_queue(q);
 885         disk_unregister_independent_access_ranges(disk);
 886         mutex_unlock(&q->sysfs_lock);
 887
 888         /* Now that we've deleted all child objects, we can delete the queue. */
 889         kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE);
 890         kobject_del(&disk->queue_kobj);
 891         mutex_unlock(&q->sysfs_dir_lock);
 892
 893         blk_debugfs_remove(disk);
 894 }