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/blk-mq.h>
  13 #include <linux/debugfs.h>
  14
  15 #include "blk.h"
  16 #include "blk-mq.h"
  17 #include "blk-mq-debugfs.h"
  18 #include "blk-mq-sched.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_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 queue_var_show(0, page);
 218 }
 219
 220 static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
 221 {
 222         return sprintf(page, "%llu\n",
 223                 (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
 224 }
 225
 226 static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
 227                                                  char *page)
 228 {
 229         return queue_var_show(queue_zone_write_granularity(q), page);
 230 }
 231
 232 static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
 233 {
 234         unsigned long long max_sectors = q->limits.max_zone_append_sectors;
 235
 236         return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
 237 }
 238
 239 static ssize_t
 240 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 241 {
 242         unsigned long max_sectors_kb,
 243                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
 244                         page_kb = 1 << (PAGE_SHIFT - 10);
 245         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
 246
 247         if (ret < 0)
 248                 return ret;
 249
 250         max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
 251                                          q->limits.max_dev_sectors >> 1);
 252
 253         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
 254                 return -EINVAL;
 255
 256         spin_lock_irq(&q->queue_lock);
 257         q->limits.max_sectors = max_sectors_kb << 1;
 258         if (q->disk)
 259                 q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
 260         spin_unlock_irq(&q->queue_lock);
 261
 262         return ret;
 263 }
 264
 265 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 266 {
 267         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 268
 269         return queue_var_show(max_hw_sectors_kb, page);
 270 }
 271
 272 static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
 273 {
 274         return queue_var_show(q->limits.virt_boundary_mask, page);
 275 }
 276
 277 static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
 278 {
 279         return queue_var_show(queue_dma_alignment(q), page);
 280 }
 281
 282 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
 283 static ssize_t                                                          \
 284 queue_##name##_show(struct request_queue *q, char *page)                \
 285 {                                                                       \
 286         int bit;                                                        \
 287         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
 288         return queue_var_show(neg ? !bit : bit, page);                  \
 289 }                                                                       \
 290 static ssize_t                                                          \
 291 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
 292 {                                                                       \
 293         unsigned long val;                                              \
 294         ssize_t ret;                                                    \
 295         ret = queue_var_store(&val, page, count);                       \
 296         if (ret < 0)                                                    \
 297                  return ret;                                            \
 298         if (neg)                                                        \
 299                 val = !val;                                             \
 300                                                                         \
 301         if (val)                                                        \
 302                 blk_queue_flag_set(QUEUE_FLAG_##flag, q);               \
 303         else                                                            \
 304                 blk_queue_flag_clear(QUEUE_FLAG_##flag, q);             \
 305         return ret;                                                     \
 306 }
 307
 308 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
 309 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
 310 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 311 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
 312 #undef QUEUE_SYSFS_BIT_FNS
 313
 314 static ssize_t queue_zoned_show(struct request_queue *q, char *page)
 315 {
 316         switch (blk_queue_zoned_model(q)) {
 317         case BLK_ZONED_HA:
 318                 return sprintf(page, "host-aware\n");
 319         case BLK_ZONED_HM:
 320                 return sprintf(page, "host-managed\n");
 321         default:
 322                 return sprintf(page, "none\n");
 323         }
 324 }
 325
 326 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
 327 {
 328         return queue_var_show(disk_nr_zones(q->disk), page);
 329 }
 330
 331 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
 332 {
 333         return queue_var_show(bdev_max_open_zones(q->disk->part0), page);
 334 }
 335
 336 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
 337 {
 338         return queue_var_show(bdev_max_active_zones(q->disk->part0), page);
 339 }
 340
 341 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 342 {
 343         return queue_var_show((blk_queue_nomerges(q) << 1) |
 344                                blk_queue_noxmerges(q), page);
 345 }
 346
 347 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 348                                     size_t count)
 349 {
 350         unsigned long nm;
 351         ssize_t ret = queue_var_store(&nm, page, count);
 352
 353         if (ret < 0)
 354                 return ret;
 355
 356         blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 357         blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 358         if (nm == 2)
 359                 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 360         else if (nm)
 361                 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 362
 363         return ret;
 364 }
 365
 366 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
 367 {
 368         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
 369         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
 370
 371         return queue_var_show(set << force, page);
 372 }
 373
 374 static ssize_t
 375 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 376 {
 377         ssize_t ret = -EINVAL;
 378 #ifdef CONFIG_SMP
 379         unsigned long val;
 380
 381         ret = queue_var_store(&val, page, count);
 382         if (ret < 0)
 383                 return ret;
 384
 385         if (val == 2) {
 386                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 387                 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
 388         } else if (val == 1) {
 389                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 390                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 391         } else if (val == 0) {
 392                 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 393                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 394         }
 395 #endif
 396         return ret;
 397 }
 398
 399 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
 400 {
 401         int val;
 402
 403         if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
 404                 val = BLK_MQ_POLL_CLASSIC;
 405         else
 406                 val = q->poll_nsec / 1000;
 407
 408         return sprintf(page, "%d\n", val);
 409 }
 410
 411 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
 412                                 size_t count)
 413 {
 414         int err, val;
 415
 416         if (!q->mq_ops || !q->mq_ops->poll)
 417                 return -EINVAL;
 418
 419         err = kstrtoint(page, 10, &val);
 420         if (err < 0)
 421                 return err;
 422
 423         if (val == BLK_MQ_POLL_CLASSIC)
 424                 q->poll_nsec = BLK_MQ_POLL_CLASSIC;
 425         else if (val >= 0)
 426                 q->poll_nsec = val * 1000;
 427         else
 428                 return -EINVAL;
 429
 430         return count;
 431 }
 432
 433 static ssize_t queue_poll_show(struct request_queue *q, char *page)
 434 {
 435         return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
 436 }
 437
 438 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
 439                                 size_t count)
 440 {
 441         if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
 442                 return -EINVAL;
 443         pr_info_ratelimited("writes to the poll attribute are ignored.\n");
 444         pr_info_ratelimited("please use driver specific parameters instead.\n");
 445         return count;
 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 QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
 614 QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
 615
 616 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 617 QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time");
 618 #endif
 619
 620 /* legacy alias for logical_block_size: */
 621 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 622         .attr = {.name = "hw_sector_size", .mode = 0444 },
 623         .show = queue_logical_block_size_show,
 624 };
 625
 626 QUEUE_RW_ENTRY(queue_nonrot, "rotational");
 627 QUEUE_RW_ENTRY(queue_iostats, "iostats");
 628 QUEUE_RW_ENTRY(queue_random, "add_random");
 629 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
 630
 631 static struct attribute *queue_attrs[] = {
 632         &queue_requests_entry.attr,
 633         &queue_ra_entry.attr,
 634         &queue_max_hw_sectors_entry.attr,
 635         &queue_max_sectors_entry.attr,
 636         &queue_max_segments_entry.attr,
 637         &queue_max_discard_segments_entry.attr,
 638         &queue_max_integrity_segments_entry.attr,
 639         &queue_max_segment_size_entry.attr,
 640         &elv_iosched_entry.attr,
 641         &queue_hw_sector_size_entry.attr,
 642         &queue_logical_block_size_entry.attr,
 643         &queue_physical_block_size_entry.attr,
 644         &queue_chunk_sectors_entry.attr,
 645         &queue_io_min_entry.attr,
 646         &queue_io_opt_entry.attr,
 647         &queue_discard_granularity_entry.attr,
 648         &queue_discard_max_entry.attr,
 649         &queue_discard_max_hw_entry.attr,
 650         &queue_discard_zeroes_data_entry.attr,
 651         &queue_write_same_max_entry.attr,
 652         &queue_write_zeroes_max_entry.attr,
 653         &queue_zone_append_max_entry.attr,
 654         &queue_zone_write_granularity_entry.attr,
 655         &queue_nonrot_entry.attr,
 656         &queue_zoned_entry.attr,
 657         &queue_nr_zones_entry.attr,
 658         &queue_max_open_zones_entry.attr,
 659         &queue_max_active_zones_entry.attr,
 660         &queue_nomerges_entry.attr,
 661         &queue_rq_affinity_entry.attr,
 662         &queue_iostats_entry.attr,
 663         &queue_stable_writes_entry.attr,
 664         &queue_random_entry.attr,
 665         &queue_poll_entry.attr,
 666         &queue_wc_entry.attr,
 667         &queue_fua_entry.attr,
 668         &queue_dax_entry.attr,
 669         &queue_wb_lat_entry.attr,
 670         &queue_poll_delay_entry.attr,
 671         &queue_io_timeout_entry.attr,
 672 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 673         &blk_throtl_sample_time_entry.attr,
 674 #endif
 675         &queue_virt_boundary_mask_entry.attr,
 676         &queue_dma_alignment_entry.attr,
 677         NULL,
 678 };
 679
 680 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
 681                                 int n)
 682 {
 683         struct request_queue *q =
 684                 container_of(kobj, struct request_queue, kobj);
 685
 686         if (attr == &queue_io_timeout_entry.attr &&
 687                 (!q->mq_ops || !q->mq_ops->timeout))
 688                         return 0;
 689
 690         if ((attr == &queue_max_open_zones_entry.attr ||
 691              attr == &queue_max_active_zones_entry.attr) &&
 692             !blk_queue_is_zoned(q))
 693                 return 0;
 694
 695         return attr->mode;
 696 }
 697
 698 static struct attribute_group queue_attr_group = {
 699         .attrs = queue_attrs,
 700         .is_visible = queue_attr_visible,
 701 };
 702
 703
 704 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
 705
 706 static ssize_t
 707 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 708 {
 709         struct queue_sysfs_entry *entry = to_queue(attr);
 710         struct request_queue *q =
 711                 container_of(kobj, struct request_queue, kobj);
 712         ssize_t res;
 713
 714         if (!entry->show)
 715                 return -EIO;
 716         mutex_lock(&q->sysfs_lock);
 717         res = entry->show(q, page);
 718         mutex_unlock(&q->sysfs_lock);
 719         return res;
 720 }
 721
 722 static ssize_t
 723 queue_attr_store(struct kobject *kobj, struct attribute *attr,
 724                     const char *page, size_t length)
 725 {
 726         struct queue_sysfs_entry *entry = to_queue(attr);
 727         struct request_queue *q;
 728         ssize_t res;
 729
 730         if (!entry->store)
 731                 return -EIO;
 732
 733         q = container_of(kobj, struct request_queue, kobj);
 734         mutex_lock(&q->sysfs_lock);
 735         res = entry->store(q, page, length);
 736         mutex_unlock(&q->sysfs_lock);
 737         return res;
 738 }
 739
 740 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 741 {
 742         struct request_queue *q = container_of(rcu_head, struct request_queue,
 743                                                rcu_head);
 744
 745         kmem_cache_free(blk_get_queue_kmem_cache(blk_queue_has_srcu(q)), q);
 746 }
 747
 748 /**
 749  * blk_release_queue - releases all allocated resources of the request_queue
 750  * @kobj: pointer to a kobject, whose container is a request_queue
 751  *
 752  * This function releases all allocated resources of the request queue.
 753  *
 754  * The struct request_queue refcount is incremented with blk_get_queue() and
 755  * decremented with blk_put_queue(). Once the refcount reaches 0 this function
 756  * is called.
 757  *
 758  * Drivers exist which depend on the release of the request_queue to be
 759  * synchronous, it should not be deferred.
 760  *
 761  * Context: can sleep
 762  */
 763 static void blk_release_queue(struct kobject *kobj)
 764 {
 765         struct request_queue *q =
 766                 container_of(kobj, struct request_queue, kobj);
 767
 768         might_sleep();
 769
 770         percpu_ref_exit(&q->q_usage_counter);
 771
 772         if (q->poll_stat)
 773                 blk_stat_remove_callback(q, q->poll_cb);
 774         blk_stat_free_callback(q->poll_cb);
 775
 776         blk_free_queue_stats(q->stats);
 777         kfree(q->poll_stat);
 778
 779         if (queue_is_mq(q))
 780                 blk_mq_release(q);
 781
 782         if (blk_queue_has_srcu(q))
 783                 cleanup_srcu_struct(q->srcu);
 784
 785         ida_free(&blk_queue_ida, q->id);
 786         call_rcu(&q->rcu_head, blk_free_queue_rcu);
 787 }
 788
 789 static const struct sysfs_ops queue_sysfs_ops = {
 790         .show   = queue_attr_show,
 791         .store  = queue_attr_store,
 792 };
 793
 794 static const struct attribute_group *blk_queue_attr_groups[] = {
 795         &queue_attr_group,
 796         NULL
 797 };
 798
 799 struct kobj_type blk_queue_ktype = {
 800         .default_groups = blk_queue_attr_groups,
 801         .sysfs_ops      = &queue_sysfs_ops,
 802         .release        = blk_release_queue,
 803 };
 804
 805 /**
 806  * blk_register_queue - register a block layer queue with sysfs
 807  * @disk: Disk of which the request queue should be registered with sysfs.
 808  */
 809 int blk_register_queue(struct gendisk *disk)
 810 {
 811         struct request_queue *q = disk->queue;
 812         int ret;
 813
 814         mutex_lock(&q->sysfs_dir_lock);
 815
 816         ret = kobject_add(&q->kobj, &disk_to_dev(disk)->kobj, "queue");
 817         if (ret < 0)
 818                 goto unlock;
 819
 820         if (queue_is_mq(q))
 821                 blk_mq_sysfs_register(disk);
 822         mutex_lock(&q->sysfs_lock);
 823
 824         mutex_lock(&q->debugfs_mutex);
 825         q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
 826                                             blk_debugfs_root);
 827         if (queue_is_mq(q))
 828                 blk_mq_debugfs_register(q);
 829         mutex_unlock(&q->debugfs_mutex);
 830
 831         ret = disk_register_independent_access_ranges(disk);
 832         if (ret)
 833                 goto put_dev;
 834
 835         if (q->elevator) {
 836                 ret = elv_register_queue(q, false);
 837                 if (ret)
 838                         goto put_dev;
 839         }
 840
 841         ret = blk_crypto_sysfs_register(q);
 842         if (ret)
 843                 goto put_dev;
 844
 845         blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
 846         wbt_enable_default(q);
 847         blk_throtl_register_queue(q);
 848
 849         /* Now everything is ready and send out KOBJ_ADD uevent */
 850         kobject_uevent(&q->kobj, KOBJ_ADD);
 851         if (q->elevator)
 852                 kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 853         mutex_unlock(&q->sysfs_lock);
 854
 855 unlock:
 856         mutex_unlock(&q->sysfs_dir_lock);
 857
 858         /*
 859          * SCSI probing may synchronously create and destroy a lot of
 860          * request_queues for non-existent devices.  Shutting down a fully
 861          * functional queue takes measureable wallclock time as RCU grace
 862          * periods are involved.  To avoid excessive latency in these
 863          * cases, a request_queue starts out in a degraded mode which is
 864          * faster to shut down and is made fully functional here as
 865          * request_queues for non-existent devices never get registered.
 866          */
 867         if (!blk_queue_init_done(q)) {
 868                 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
 869                 percpu_ref_switch_to_percpu(&q->q_usage_counter);
 870         }
 871
 872         return ret;
 873
 874 put_dev:
 875         elv_unregister_queue(q);
 876         disk_unregister_independent_access_ranges(disk);
 877         mutex_unlock(&q->sysfs_lock);
 878         mutex_unlock(&q->sysfs_dir_lock);
 879         kobject_del(&q->kobj);
 880
 881         return ret;
 882 }
 883
 884 /**
 885  * blk_unregister_queue - counterpart of blk_register_queue()
 886  * @disk: Disk of which the request queue should be unregistered from sysfs.
 887  *
 888  * Note: the caller is responsible for guaranteeing that this function is called
 889  * after blk_register_queue() has finished.
 890  */
 891 void blk_unregister_queue(struct gendisk *disk)
 892 {
 893         struct request_queue *q = disk->queue;
 894
 895         if (WARN_ON(!q))
 896                 return;
 897
 898         /* Return early if disk->queue was never registered. */
 899         if (!blk_queue_registered(q))
 900                 return;
 901
 902         /*
 903          * Since sysfs_remove_dir() prevents adding new directory entries
 904          * before removal of existing entries starts, protect against
 905          * concurrent elv_iosched_store() calls.
 906          */
 907         mutex_lock(&q->sysfs_lock);
 908         blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
 909         mutex_unlock(&q->sysfs_lock);
 910
 911         mutex_lock(&q->sysfs_dir_lock);
 912         /*
 913          * Remove the sysfs attributes before unregistering the queue data
 914          * structures that can be modified through sysfs.
 915          */
 916         if (queue_is_mq(q))
 917                 blk_mq_sysfs_unregister(disk);
 918         blk_crypto_sysfs_unregister(q);
 919
 920         mutex_lock(&q->sysfs_lock);
 921         elv_unregister_queue(q);
 922         disk_unregister_independent_access_ranges(disk);
 923         mutex_unlock(&q->sysfs_lock);
 924
 925         /* Now that we've deleted all child objects, we can delete the queue. */
 926         kobject_uevent(&q->kobj, KOBJ_REMOVE);
 927         kobject_del(&q->kobj);
 928         mutex_unlock(&q->sysfs_dir_lock);
 929
 930         mutex_lock(&q->debugfs_mutex);
 931         blk_trace_shutdown(q);
 932         debugfs_remove_recursive(q->debugfs_dir);
 933         q->debugfs_dir = NULL;
 934         q->sched_debugfs_dir = NULL;
 935         q->rqos_debugfs_dir = NULL;
 936         mutex_unlock(&q->debugfs_mutex);
 937 }