1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Functions related to setting various queue properties from drivers 4 */ 5 #include <linux/kernel.h> 6 #include <linux/module.h> 7 #include <linux/init.h> 8 #include <linux/bio.h> 9 #include <linux/blk-integrity.h> 10 #include <linux/pagemap.h> 11 #include <linux/backing-dev-defs.h> 12 #include <linux/gcd.h> 13 #include <linux/lcm.h> 14 #include <linux/jiffies.h> 15 #include <linux/gfp.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/t10-pi.h> 18 #include <linux/crc64.h> 19 20 #include "blk.h" 21 #include "blk-rq-qos.h" 22 #include "blk-wbt.h" 23 24 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) 25 { 26 WRITE_ONCE(q->rq_timeout, timeout); 27 } 28 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); 29 30 /** 31 * blk_set_stacking_limits - set default limits for stacking devices 32 * @lim: the queue_limits structure to reset 33 * 34 * Prepare queue limits for applying limits from underlying devices using 35 * blk_stack_limits(). 36 */ 37 void blk_set_stacking_limits(struct queue_limits *lim) 38 { 39 memset(lim, 0, sizeof(*lim)); 40 lim->logical_block_size = SECTOR_SIZE; 41 lim->physical_block_size = SECTOR_SIZE; 42 lim->io_min = SECTOR_SIZE; 43 lim->discard_granularity = SECTOR_SIZE; 44 lim->dma_alignment = SECTOR_SIZE - 1; 45 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 46 47 /* Inherit limits from component devices */ 48 lim->max_segments = USHRT_MAX; 49 lim->max_discard_segments = USHRT_MAX; 50 lim->max_hw_sectors = UINT_MAX; 51 lim->max_segment_size = UINT_MAX; 52 lim->max_sectors = UINT_MAX; 53 lim->max_dev_sectors = UINT_MAX; 54 lim->max_write_zeroes_sectors = UINT_MAX; 55 lim->max_hw_wzeroes_unmap_sectors = UINT_MAX; 56 lim->max_user_wzeroes_unmap_sectors = UINT_MAX; 57 lim->max_hw_zone_append_sectors = UINT_MAX; 58 lim->max_user_discard_sectors = UINT_MAX; 59 lim->atomic_write_hw_max = UINT_MAX; 60 } 61 EXPORT_SYMBOL(blk_set_stacking_limits); 62 63 void blk_apply_bdi_limits(struct backing_dev_info *bdi, 64 struct queue_limits *lim) 65 { 66 u64 io_opt = lim->io_opt; 67 68 /* 69 * For read-ahead of large files to be effective, we need to read ahead 70 * at least twice the optimal I/O size. For rotational devices that do 71 * not report an optimal I/O size (e.g. ATA HDDs), use the maximum I/O 72 * size to avoid falling back to the (rather inefficient) small default 73 * read-ahead size. 74 * 75 * There is no hardware limitation for the read-ahead size and the user 76 * might have increased the read-ahead size through sysfs, so don't ever 77 * decrease it. 78 */ 79 if (!io_opt && (lim->features & BLK_FEAT_ROTATIONAL)) 80 io_opt = (u64)lim->max_sectors << SECTOR_SHIFT; 81 82 bdi->ra_pages = max3(bdi->ra_pages, 83 io_opt * 2 >> PAGE_SHIFT, 84 VM_READAHEAD_PAGES); 85 bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT; 86 } 87 88 static int blk_validate_zoned_limits(struct queue_limits *lim) 89 { 90 if (!(lim->features & BLK_FEAT_ZONED)) { 91 if (WARN_ON_ONCE(lim->max_open_zones) || 92 WARN_ON_ONCE(lim->max_active_zones) || 93 WARN_ON_ONCE(lim->zone_write_granularity) || 94 WARN_ON_ONCE(lim->max_zone_append_sectors)) 95 return -EINVAL; 96 return 0; 97 } 98 99 if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED))) 100 return -EINVAL; 101 102 /* 103 * Given that active zones include open zones, the maximum number of 104 * open zones cannot be larger than the maximum number of active zones. 105 */ 106 if (lim->max_active_zones && 107 lim->max_open_zones > lim->max_active_zones) 108 return -EINVAL; 109 110 if (lim->zone_write_granularity < lim->logical_block_size) 111 lim->zone_write_granularity = lim->logical_block_size; 112 113 /* 114 * The Zone Append size is limited by the maximum I/O size and the zone 115 * size given that it can't span zones. 116 * 117 * If no max_hw_zone_append_sectors limit is provided, the block layer 118 * will emulated it, else we're also bound by the hardware limit. 119 */ 120 lim->max_zone_append_sectors = 121 min_not_zero(lim->max_hw_zone_append_sectors, 122 min(lim->chunk_sectors, lim->max_hw_sectors)); 123 return 0; 124 } 125 126 static int blk_validate_integrity_limits(struct queue_limits *lim) 127 { 128 struct blk_integrity *bi = &lim->integrity; 129 130 if (!bi->metadata_size) { 131 if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE || 132 bi->tag_size || ((bi->flags & BLK_INTEGRITY_REF_TAG))) { 133 pr_warn("invalid PI settings.\n"); 134 return -EINVAL; 135 } 136 bi->flags |= BLK_INTEGRITY_NOGENERATE | BLK_INTEGRITY_NOVERIFY; 137 return 0; 138 } 139 140 if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) { 141 pr_warn("integrity support disabled.\n"); 142 return -EINVAL; 143 } 144 145 if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE && 146 (bi->flags & BLK_INTEGRITY_REF_TAG)) { 147 pr_warn("ref tag not support without checksum.\n"); 148 return -EINVAL; 149 } 150 151 if (bi->pi_tuple_size > bi->metadata_size) { 152 pr_warn("pi_tuple_size (%u) exceeds metadata_size (%u)\n", 153 bi->pi_tuple_size, 154 bi->metadata_size); 155 return -EINVAL; 156 } 157 158 switch (bi->csum_type) { 159 case BLK_INTEGRITY_CSUM_NONE: 160 if (bi->pi_tuple_size) { 161 pr_warn("pi_tuple_size must be 0 when checksum type is none\n"); 162 return -EINVAL; 163 } 164 break; 165 case BLK_INTEGRITY_CSUM_CRC: 166 case BLK_INTEGRITY_CSUM_IP: 167 if (bi->pi_tuple_size != sizeof(struct t10_pi_tuple)) { 168 pr_warn("pi_tuple_size mismatch for T10 PI: expected %zu, got %u\n", 169 sizeof(struct t10_pi_tuple), 170 bi->pi_tuple_size); 171 return -EINVAL; 172 } 173 break; 174 case BLK_INTEGRITY_CSUM_CRC64: 175 if (bi->pi_tuple_size != sizeof(struct crc64_pi_tuple)) { 176 pr_warn("pi_tuple_size mismatch for CRC64 PI: expected %zu, got %u\n", 177 sizeof(struct crc64_pi_tuple), 178 bi->pi_tuple_size); 179 return -EINVAL; 180 } 181 break; 182 } 183 184 if (!bi->interval_exp) 185 bi->interval_exp = ilog2(lim->logical_block_size); 186 187 /* 188 * The PI generation / validation helpers do not expect intervals to 189 * straddle multiple bio_vecs. Enforce alignment so that those are 190 * never generated, and that each buffer is aligned as expected. 191 */ 192 if (bi->csum_type) { 193 lim->dma_alignment = max(lim->dma_alignment, 194 (1U << bi->interval_exp) - 1); 195 } 196 197 return 0; 198 } 199 200 /* 201 * Returns max guaranteed bytes which we can fit in a bio. 202 * 203 * We request that an atomic_write is ITER_UBUF iov_iter (so a single vector), 204 * so we assume that we can fit in at least PAGE_SIZE in a segment, apart from 205 * the first and last segments. 206 */ 207 static unsigned int blk_queue_max_guaranteed_bio(struct queue_limits *lim) 208 { 209 unsigned int max_segments = min(BIO_MAX_VECS, lim->max_segments); 210 unsigned int length; 211 212 length = min(max_segments, 2) * lim->logical_block_size; 213 if (max_segments > 2) 214 length += (max_segments - 2) * PAGE_SIZE; 215 216 return length; 217 } 218 219 static void blk_atomic_writes_update_limits(struct queue_limits *lim) 220 { 221 unsigned int unit_limit = min(lim->max_hw_sectors << SECTOR_SHIFT, 222 blk_queue_max_guaranteed_bio(lim)); 223 224 unit_limit = rounddown_pow_of_two(unit_limit); 225 226 lim->atomic_write_max_sectors = 227 min(lim->atomic_write_hw_max >> SECTOR_SHIFT, 228 lim->max_hw_sectors); 229 lim->atomic_write_unit_min = 230 min(lim->atomic_write_hw_unit_min, unit_limit); 231 lim->atomic_write_unit_max = 232 min(lim->atomic_write_hw_unit_max, unit_limit); 233 lim->atomic_write_boundary_sectors = 234 lim->atomic_write_hw_boundary >> SECTOR_SHIFT; 235 } 236 237 /* 238 * Test whether any boundary is aligned with any chunk size. Stacked 239 * devices store any stripe size in t->chunk_sectors. 240 */ 241 static bool blk_valid_atomic_writes_boundary(unsigned int chunk_sectors, 242 unsigned int boundary_sectors) 243 { 244 if (!chunk_sectors || !boundary_sectors) 245 return true; 246 247 if (boundary_sectors > chunk_sectors && 248 boundary_sectors % chunk_sectors) 249 return false; 250 251 if (chunk_sectors > boundary_sectors && 252 chunk_sectors % boundary_sectors) 253 return false; 254 255 return true; 256 } 257 258 static void blk_validate_atomic_write_limits(struct queue_limits *lim) 259 { 260 unsigned int boundary_sectors; 261 unsigned int atomic_write_hw_max_sectors = 262 lim->atomic_write_hw_max >> SECTOR_SHIFT; 263 264 if (!(lim->features & BLK_FEAT_ATOMIC_WRITES)) 265 goto unsupported; 266 267 /* UINT_MAX indicates stacked limits in initial state */ 268 if (lim->atomic_write_hw_max == UINT_MAX) 269 goto unsupported; 270 271 if (!lim->atomic_write_hw_max) 272 goto unsupported; 273 274 if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_min))) 275 goto unsupported; 276 277 if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_max))) 278 goto unsupported; 279 280 if (WARN_ON_ONCE(lim->atomic_write_hw_unit_min > 281 lim->atomic_write_hw_unit_max)) 282 goto unsupported; 283 284 if (WARN_ON_ONCE(lim->atomic_write_hw_unit_max > 285 lim->atomic_write_hw_max)) 286 goto unsupported; 287 288 if (WARN_ON_ONCE(lim->chunk_sectors && 289 atomic_write_hw_max_sectors > lim->chunk_sectors)) 290 goto unsupported; 291 292 boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT; 293 294 if (boundary_sectors) { 295 if (WARN_ON_ONCE(lim->atomic_write_hw_max > 296 lim->atomic_write_hw_boundary)) 297 goto unsupported; 298 299 if (WARN_ON_ONCE(!blk_valid_atomic_writes_boundary( 300 lim->chunk_sectors, boundary_sectors))) 301 goto unsupported; 302 303 /* 304 * The boundary size just needs to be a multiple of unit_max 305 * (and not necessarily a power-of-2), so this following check 306 * could be relaxed in future. 307 * Furthermore, if needed, unit_max could even be reduced so 308 * that it is compliant with a !power-of-2 boundary. 309 */ 310 if (!is_power_of_2(boundary_sectors)) 311 goto unsupported; 312 } 313 314 blk_atomic_writes_update_limits(lim); 315 return; 316 317 unsupported: 318 lim->atomic_write_max_sectors = 0; 319 lim->atomic_write_boundary_sectors = 0; 320 lim->atomic_write_unit_min = 0; 321 lim->atomic_write_unit_max = 0; 322 } 323 324 /* 325 * Check that the limits in lim are valid, initialize defaults for unset 326 * values, and cap values based on others where needed. 327 */ 328 int blk_validate_limits(struct queue_limits *lim) 329 { 330 unsigned int max_hw_sectors; 331 unsigned int logical_block_sectors; 332 unsigned long seg_size; 333 int err; 334 335 /* 336 * Unless otherwise specified, default to 512 byte logical blocks and a 337 * physical block size equal to the logical block size. 338 */ 339 if (!lim->logical_block_size) 340 lim->logical_block_size = SECTOR_SIZE; 341 else if (blk_validate_block_size(lim->logical_block_size)) { 342 pr_warn("Invalid logical block size (%d)\n", lim->logical_block_size); 343 return -EINVAL; 344 } 345 if (lim->physical_block_size < lim->logical_block_size) { 346 lim->physical_block_size = lim->logical_block_size; 347 } else if (!is_power_of_2(lim->physical_block_size)) { 348 pr_warn("Invalid physical block size (%d)\n", lim->physical_block_size); 349 return -EINVAL; 350 } 351 352 /* 353 * The minimum I/O size defaults to the physical block size unless 354 * explicitly overridden. 355 */ 356 if (lim->io_min < lim->physical_block_size) 357 lim->io_min = lim->physical_block_size; 358 359 /* 360 * The optimal I/O size may not be aligned to physical block size 361 * (because it may be limited by dma engines which have no clue about 362 * block size of the disks attached to them), so we round it down here. 363 */ 364 lim->io_opt = round_down(lim->io_opt, lim->physical_block_size); 365 366 /* 367 * max_hw_sectors has a somewhat weird default for historical reason, 368 * but driver really should set their own instead of relying on this 369 * value. 370 * 371 * The block layer relies on the fact that every driver can 372 * handle at lest a page worth of data per I/O, and needs the value 373 * aligned to the logical block size. 374 */ 375 if (!lim->max_hw_sectors) 376 lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; 377 if (WARN_ON_ONCE(lim->max_hw_sectors < PAGE_SECTORS)) 378 return -EINVAL; 379 logical_block_sectors = lim->logical_block_size >> SECTOR_SHIFT; 380 if (WARN_ON_ONCE(logical_block_sectors > lim->max_hw_sectors)) 381 return -EINVAL; 382 lim->max_hw_sectors = round_down(lim->max_hw_sectors, 383 logical_block_sectors); 384 385 /* 386 * The actual max_sectors value is a complex beast and also takes the 387 * max_dev_sectors value (set by SCSI ULPs) and a user configurable 388 * value into account. The ->max_sectors value is always calculated 389 * from these, so directly setting it won't have any effect. 390 */ 391 max_hw_sectors = min_not_zero(lim->max_hw_sectors, 392 lim->max_dev_sectors); 393 if (lim->max_user_sectors) { 394 if (lim->max_user_sectors < BLK_MIN_SEGMENT_SIZE / SECTOR_SIZE) 395 return -EINVAL; 396 lim->max_sectors = min(max_hw_sectors, lim->max_user_sectors); 397 } else if (lim->io_opt > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { 398 lim->max_sectors = 399 min(max_hw_sectors, lim->io_opt >> SECTOR_SHIFT); 400 } else if (lim->io_min > (BLK_DEF_MAX_SECTORS_CAP << SECTOR_SHIFT)) { 401 lim->max_sectors = 402 min(max_hw_sectors, lim->io_min >> SECTOR_SHIFT); 403 } else { 404 lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP); 405 } 406 lim->max_sectors = round_down(lim->max_sectors, 407 logical_block_sectors); 408 409 /* 410 * Random default for the maximum number of segments. Driver should not 411 * rely on this and set their own. 412 */ 413 if (!lim->max_segments) 414 lim->max_segments = BLK_MAX_SEGMENTS; 415 416 if (lim->max_hw_wzeroes_unmap_sectors && 417 lim->max_hw_wzeroes_unmap_sectors != lim->max_write_zeroes_sectors) 418 return -EINVAL; 419 lim->max_wzeroes_unmap_sectors = min(lim->max_hw_wzeroes_unmap_sectors, 420 lim->max_user_wzeroes_unmap_sectors); 421 422 lim->max_discard_sectors = 423 min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors); 424 425 /* 426 * When discard is not supported, discard_granularity should be reported 427 * as 0 to userspace. 428 */ 429 if (lim->max_discard_sectors) 430 lim->discard_granularity = 431 max(lim->discard_granularity, lim->physical_block_size); 432 else 433 lim->discard_granularity = 0; 434 435 if (!lim->max_discard_segments) 436 lim->max_discard_segments = 1; 437 438 /* 439 * By default there is no limit on the segment boundary alignment, 440 * but if there is one it can't be smaller than the page size as 441 * that would break all the normal I/O patterns. 442 */ 443 if (!lim->seg_boundary_mask) 444 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 445 if (WARN_ON_ONCE(lim->seg_boundary_mask < BLK_MIN_SEGMENT_SIZE - 1)) 446 return -EINVAL; 447 448 /* 449 * Stacking device may have both virtual boundary and max segment 450 * size limit, so allow this setting now, and long-term the two 451 * might need to move out of stacking limits since we have immutable 452 * bvec and lower layer bio splitting is supposed to handle the two 453 * correctly. 454 */ 455 if (lim->virt_boundary_mask) { 456 if (!lim->max_segment_size) 457 lim->max_segment_size = UINT_MAX; 458 } else { 459 /* 460 * The maximum segment size has an odd historic 64k default that 461 * drivers probably should override. Just like the I/O size we 462 * require drivers to at least handle a full page per segment. 463 */ 464 if (!lim->max_segment_size) 465 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; 466 if (WARN_ON_ONCE(lim->max_segment_size < BLK_MIN_SEGMENT_SIZE)) 467 return -EINVAL; 468 } 469 470 /* setup min segment size for building new segment in fast path */ 471 if (lim->seg_boundary_mask > lim->max_segment_size - 1) 472 seg_size = lim->max_segment_size; 473 else 474 seg_size = lim->seg_boundary_mask + 1; 475 lim->min_segment_size = min_t(unsigned int, seg_size, PAGE_SIZE); 476 477 /* 478 * We require drivers to at least do logical block aligned I/O, but 479 * historically could not check for that due to the separate calls 480 * to set the limits. Once the transition is finished the check 481 * below should be narrowed down to check the logical block size. 482 */ 483 if (!lim->dma_alignment) 484 lim->dma_alignment = SECTOR_SIZE - 1; 485 if (WARN_ON_ONCE(lim->dma_alignment > PAGE_SIZE)) 486 return -EINVAL; 487 488 if (lim->alignment_offset) { 489 lim->alignment_offset &= (lim->physical_block_size - 1); 490 lim->flags &= ~BLK_FLAG_MISALIGNED; 491 } 492 493 if (!(lim->features & BLK_FEAT_WRITE_CACHE)) 494 lim->features &= ~BLK_FEAT_FUA; 495 496 blk_validate_atomic_write_limits(lim); 497 498 err = blk_validate_integrity_limits(lim); 499 if (err) 500 return err; 501 return blk_validate_zoned_limits(lim); 502 } 503 EXPORT_SYMBOL_GPL(blk_validate_limits); 504 505 /* 506 * Set the default limits for a newly allocated queue. @lim contains the 507 * initial limits set by the driver, which could be no limit in which case 508 * all fields are cleared to zero. 509 */ 510 int blk_set_default_limits(struct queue_limits *lim) 511 { 512 /* 513 * Most defaults are set by capping the bounds in blk_validate_limits, 514 * but these limits are special and need an explicit initialization to 515 * the max value here. 516 */ 517 lim->max_user_discard_sectors = UINT_MAX; 518 lim->max_user_wzeroes_unmap_sectors = UINT_MAX; 519 return blk_validate_limits(lim); 520 } 521 522 /** 523 * queue_limits_commit_update - commit an atomic update of queue limits 524 * @q: queue to update 525 * @lim: limits to apply 526 * 527 * Apply the limits in @lim that were obtained from queue_limits_start_update() 528 * and updated by the caller to @q. The caller must have frozen the queue or 529 * ensure that there are no outstanding I/Os by other means. 530 * 531 * Returns 0 if successful, else a negative error code. 532 */ 533 int queue_limits_commit_update(struct request_queue *q, 534 struct queue_limits *lim) 535 { 536 int error; 537 538 error = blk_validate_limits(lim); 539 if (error) 540 goto out_unlock; 541 542 #ifdef CONFIG_BLK_INLINE_ENCRYPTION 543 if (q->crypto_profile && lim->integrity.tag_size) { 544 pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together.\n"); 545 error = -EINVAL; 546 goto out_unlock; 547 } 548 #endif 549 550 q->limits = *lim; 551 if (q->disk) 552 blk_apply_bdi_limits(q->disk->bdi, lim); 553 out_unlock: 554 mutex_unlock(&q->limits_lock); 555 return error; 556 } 557 EXPORT_SYMBOL_GPL(queue_limits_commit_update); 558 559 /** 560 * queue_limits_commit_update_frozen - commit an atomic update of queue limits 561 * @q: queue to update 562 * @lim: limits to apply 563 * 564 * Apply the limits in @lim that were obtained from queue_limits_start_update() 565 * and updated with the new values by the caller to @q. Freezes the queue 566 * before the update and unfreezes it after. 567 * 568 * Returns 0 if successful, else a negative error code. 569 */ 570 int queue_limits_commit_update_frozen(struct request_queue *q, 571 struct queue_limits *lim) 572 { 573 unsigned int memflags; 574 int ret; 575 576 memflags = blk_mq_freeze_queue(q); 577 ret = queue_limits_commit_update(q, lim); 578 blk_mq_unfreeze_queue(q, memflags); 579 580 return ret; 581 } 582 EXPORT_SYMBOL_GPL(queue_limits_commit_update_frozen); 583 584 /** 585 * queue_limits_set - apply queue limits to queue 586 * @q: queue to update 587 * @lim: limits to apply 588 * 589 * Apply the limits in @lim that were freshly initialized to @q. 590 * To update existing limits use queue_limits_start_update() and 591 * queue_limits_commit_update() instead. 592 * 593 * Returns 0 if successful, else a negative error code. 594 */ 595 int queue_limits_set(struct request_queue *q, struct queue_limits *lim) 596 { 597 mutex_lock(&q->limits_lock); 598 return queue_limits_commit_update(q, lim); 599 } 600 EXPORT_SYMBOL_GPL(queue_limits_set); 601 602 static int queue_limit_alignment_offset(const struct queue_limits *lim, 603 sector_t sector) 604 { 605 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 606 unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) 607 << SECTOR_SHIFT; 608 609 return (granularity + lim->alignment_offset - alignment) % granularity; 610 } 611 612 static unsigned int queue_limit_discard_alignment( 613 const struct queue_limits *lim, sector_t sector) 614 { 615 unsigned int alignment, granularity, offset; 616 617 if (!lim->max_discard_sectors) 618 return 0; 619 620 /* Why are these in bytes, not sectors? */ 621 alignment = lim->discard_alignment >> SECTOR_SHIFT; 622 granularity = lim->discard_granularity >> SECTOR_SHIFT; 623 624 /* Offset of the partition start in 'granularity' sectors */ 625 offset = sector_div(sector, granularity); 626 627 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 628 offset = (granularity + alignment - offset) % granularity; 629 630 /* Turn it back into bytes, gaah */ 631 return offset << SECTOR_SHIFT; 632 } 633 634 static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int lbs) 635 { 636 sectors = round_down(sectors, lbs >> SECTOR_SHIFT); 637 if (sectors < PAGE_SIZE >> SECTOR_SHIFT) 638 sectors = PAGE_SIZE >> SECTOR_SHIFT; 639 return sectors; 640 } 641 642 /* Check if second and later bottom devices are compliant */ 643 static bool blk_stack_atomic_writes_tail(struct queue_limits *t, 644 struct queue_limits *b) 645 { 646 /* We're not going to support different boundary sizes.. yet */ 647 if (t->atomic_write_hw_boundary != b->atomic_write_hw_boundary) 648 return false; 649 650 /* Can't support this */ 651 if (t->atomic_write_hw_unit_min > b->atomic_write_hw_unit_max) 652 return false; 653 654 /* Or this */ 655 if (t->atomic_write_hw_unit_max < b->atomic_write_hw_unit_min) 656 return false; 657 658 t->atomic_write_hw_max = min(t->atomic_write_hw_max, 659 b->atomic_write_hw_max); 660 t->atomic_write_hw_unit_min = max(t->atomic_write_hw_unit_min, 661 b->atomic_write_hw_unit_min); 662 t->atomic_write_hw_unit_max = min(t->atomic_write_hw_unit_max, 663 b->atomic_write_hw_unit_max); 664 return true; 665 } 666 667 static void blk_stack_atomic_writes_chunk_sectors(struct queue_limits *t) 668 { 669 unsigned int chunk_bytes; 670 671 if (!t->chunk_sectors) 672 return; 673 674 /* 675 * If chunk sectors is so large that its value in bytes overflows 676 * UINT_MAX, then just shift it down so it definitely will fit. 677 * We don't support atomic writes of such a large size anyway. 678 */ 679 if (check_shl_overflow(t->chunk_sectors, SECTOR_SHIFT, &chunk_bytes)) 680 chunk_bytes = t->chunk_sectors; 681 682 /* 683 * Find values for limits which work for chunk size. 684 * b->atomic_write_hw_unit_{min, max} may not be aligned with chunk 685 * size, as the chunk size is not restricted to a power-of-2. 686 * So we need to find highest power-of-2 which works for the chunk 687 * size. 688 * As an example scenario, we could have t->unit_max = 16K and 689 * t->chunk_sectors = 24KB. For this case, reduce t->unit_max to a 690 * value aligned with both limits, i.e. 8K in this example. 691 */ 692 t->atomic_write_hw_unit_max = min(t->atomic_write_hw_unit_max, 693 max_pow_of_two_factor(chunk_bytes)); 694 695 t->atomic_write_hw_unit_min = min(t->atomic_write_hw_unit_min, 696 t->atomic_write_hw_unit_max); 697 t->atomic_write_hw_max = min(t->atomic_write_hw_max, chunk_bytes); 698 } 699 700 /* Check stacking of first bottom device */ 701 static bool blk_stack_atomic_writes_head(struct queue_limits *t, 702 struct queue_limits *b) 703 { 704 if (!blk_valid_atomic_writes_boundary(t->chunk_sectors, 705 b->atomic_write_hw_boundary >> SECTOR_SHIFT)) 706 return false; 707 708 t->atomic_write_hw_unit_max = b->atomic_write_hw_unit_max; 709 t->atomic_write_hw_unit_min = b->atomic_write_hw_unit_min; 710 t->atomic_write_hw_max = b->atomic_write_hw_max; 711 t->atomic_write_hw_boundary = b->atomic_write_hw_boundary; 712 return true; 713 } 714 715 static void blk_stack_atomic_writes_limits(struct queue_limits *t, 716 struct queue_limits *b, sector_t start) 717 { 718 if (!(b->features & BLK_FEAT_ATOMIC_WRITES)) 719 goto unsupported; 720 721 if (!b->atomic_write_hw_unit_min) 722 goto unsupported; 723 724 if (!blk_atomic_write_start_sect_aligned(start, b)) 725 goto unsupported; 726 727 /* UINT_MAX indicates no stacking of bottom devices yet */ 728 if (t->atomic_write_hw_max == UINT_MAX) { 729 if (!blk_stack_atomic_writes_head(t, b)) 730 goto unsupported; 731 } else { 732 if (!blk_stack_atomic_writes_tail(t, b)) 733 goto unsupported; 734 } 735 blk_stack_atomic_writes_chunk_sectors(t); 736 return; 737 738 unsupported: 739 t->atomic_write_hw_max = 0; 740 t->atomic_write_hw_unit_max = 0; 741 t->atomic_write_hw_unit_min = 0; 742 t->atomic_write_hw_boundary = 0; 743 } 744 745 /** 746 * blk_stack_limits - adjust queue_limits for stacked devices 747 * @t: the stacking driver limits (top device) 748 * @b: the underlying queue limits (bottom, component device) 749 * @start: first data sector within component device 750 * 751 * Description: 752 * This function is used by stacking drivers like MD and DM to ensure 753 * that all component devices have compatible block sizes and 754 * alignments. The stacking driver must provide a queue_limits 755 * struct (top) and then iteratively call the stacking function for 756 * all component (bottom) devices. The stacking function will 757 * attempt to combine the values and ensure proper alignment. 758 * 759 * Returns 0 if the top and bottom queue_limits are compatible. The 760 * top device's block sizes and alignment offsets may be adjusted to 761 * ensure alignment with the bottom device. If no compatible sizes 762 * and alignments exist, -1 is returned and the resulting top 763 * queue_limits will have the misaligned flag set to indicate that 764 * the alignment_offset is undefined. 765 */ 766 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 767 sector_t start) 768 { 769 unsigned int top, bottom, alignment; 770 int ret = 0; 771 772 t->features |= (b->features & BLK_FEAT_INHERIT_MASK); 773 774 /* 775 * Some feaures need to be supported both by the stacking driver and all 776 * underlying devices. The stacking driver sets these flags before 777 * stacking the limits, and this will clear the flags if any of the 778 * underlying devices does not support it. 779 */ 780 if (!(b->features & BLK_FEAT_NOWAIT)) 781 t->features &= ~BLK_FEAT_NOWAIT; 782 if (!(b->features & BLK_FEAT_POLL)) 783 t->features &= ~BLK_FEAT_POLL; 784 785 t->flags |= (b->flags & BLK_FLAG_MISALIGNED); 786 787 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); 788 t->max_user_sectors = min_not_zero(t->max_user_sectors, 789 b->max_user_sectors); 790 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); 791 t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); 792 t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, 793 b->max_write_zeroes_sectors); 794 t->max_user_wzeroes_unmap_sectors = 795 min(t->max_user_wzeroes_unmap_sectors, 796 b->max_user_wzeroes_unmap_sectors); 797 t->max_hw_wzeroes_unmap_sectors = 798 min(t->max_hw_wzeroes_unmap_sectors, 799 b->max_hw_wzeroes_unmap_sectors); 800 801 t->max_hw_zone_append_sectors = min(t->max_hw_zone_append_sectors, 802 b->max_hw_zone_append_sectors); 803 804 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, 805 b->seg_boundary_mask); 806 t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, 807 b->virt_boundary_mask); 808 809 t->max_segments = min_not_zero(t->max_segments, b->max_segments); 810 t->max_discard_segments = min_not_zero(t->max_discard_segments, 811 b->max_discard_segments); 812 t->max_integrity_segments = min_not_zero(t->max_integrity_segments, 813 b->max_integrity_segments); 814 815 t->max_segment_size = min_not_zero(t->max_segment_size, 816 b->max_segment_size); 817 818 alignment = queue_limit_alignment_offset(b, start); 819 820 /* Bottom device has different alignment. Check that it is 821 * compatible with the current top alignment. 822 */ 823 if (t->alignment_offset != alignment) { 824 825 top = max(t->physical_block_size, t->io_min) 826 + t->alignment_offset; 827 bottom = max(b->physical_block_size, b->io_min) + alignment; 828 829 /* Verify that top and bottom intervals line up */ 830 if (max(top, bottom) % min(top, bottom)) { 831 t->flags |= BLK_FLAG_MISALIGNED; 832 ret = -1; 833 } 834 } 835 836 t->logical_block_size = max(t->logical_block_size, 837 b->logical_block_size); 838 839 t->physical_block_size = max(t->physical_block_size, 840 b->physical_block_size); 841 842 t->io_min = max(t->io_min, b->io_min); 843 t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); 844 t->dma_alignment = max(t->dma_alignment, b->dma_alignment); 845 846 /* Set non-power-of-2 compatible chunk_sectors boundary */ 847 if (b->chunk_sectors) 848 t->chunk_sectors = gcd(t->chunk_sectors, b->chunk_sectors); 849 850 /* Physical block size a multiple of the logical block size? */ 851 if (t->physical_block_size & (t->logical_block_size - 1)) { 852 t->physical_block_size = t->logical_block_size; 853 t->flags |= BLK_FLAG_MISALIGNED; 854 ret = -1; 855 } 856 857 /* Minimum I/O a multiple of the physical block size? */ 858 if (t->io_min & (t->physical_block_size - 1)) { 859 t->io_min = t->physical_block_size; 860 t->flags |= BLK_FLAG_MISALIGNED; 861 ret = -1; 862 } 863 864 /* Optimal I/O a multiple of the physical block size? */ 865 if (t->io_opt & (t->physical_block_size - 1)) { 866 t->io_opt = 0; 867 t->flags |= BLK_FLAG_MISALIGNED; 868 ret = -1; 869 } 870 871 /* chunk_sectors a multiple of the physical block size? */ 872 if (t->chunk_sectors % (t->physical_block_size >> SECTOR_SHIFT)) { 873 t->chunk_sectors = 0; 874 t->flags |= BLK_FLAG_MISALIGNED; 875 ret = -1; 876 } 877 878 /* Find lowest common alignment_offset */ 879 t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) 880 % max(t->physical_block_size, t->io_min); 881 882 /* Verify that new alignment_offset is on a logical block boundary */ 883 if (t->alignment_offset & (t->logical_block_size - 1)) { 884 t->flags |= BLK_FLAG_MISALIGNED; 885 ret = -1; 886 } 887 888 t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); 889 t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); 890 t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors, t->logical_block_size); 891 892 /* Discard alignment and granularity */ 893 if (b->discard_granularity) { 894 alignment = queue_limit_discard_alignment(b, start); 895 896 t->max_discard_sectors = min_not_zero(t->max_discard_sectors, 897 b->max_discard_sectors); 898 t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, 899 b->max_hw_discard_sectors); 900 t->discard_granularity = max(t->discard_granularity, 901 b->discard_granularity); 902 t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % 903 t->discard_granularity; 904 } 905 t->max_secure_erase_sectors = min_not_zero(t->max_secure_erase_sectors, 906 b->max_secure_erase_sectors); 907 t->zone_write_granularity = max(t->zone_write_granularity, 908 b->zone_write_granularity); 909 if (!(t->features & BLK_FEAT_ZONED)) { 910 t->zone_write_granularity = 0; 911 t->max_zone_append_sectors = 0; 912 } 913 blk_stack_atomic_writes_limits(t, b, start); 914 915 return ret; 916 } 917 EXPORT_SYMBOL(blk_stack_limits); 918 919 /** 920 * queue_limits_stack_bdev - adjust queue_limits for stacked devices 921 * @t: the stacking driver limits (top device) 922 * @bdev: the underlying block device (bottom) 923 * @offset: offset to beginning of data within component device 924 * @pfx: prefix to use for warnings logged 925 * 926 * Description: 927 * This function is used by stacking drivers like MD and DM to ensure 928 * that all component devices have compatible block sizes and 929 * alignments. The stacking driver must provide a queue_limits 930 * struct (top) and then iteratively call the stacking function for 931 * all component (bottom) devices. The stacking function will 932 * attempt to combine the values and ensure proper alignment. 933 */ 934 void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev, 935 sector_t offset, const char *pfx) 936 { 937 if (blk_stack_limits(t, bdev_limits(bdev), 938 get_start_sect(bdev) + offset)) 939 pr_notice("%s: Warning: Device %pg is misaligned\n", 940 pfx, bdev); 941 } 942 EXPORT_SYMBOL_GPL(queue_limits_stack_bdev); 943 944 /** 945 * queue_limits_stack_integrity - stack integrity profile 946 * @t: target queue limits 947 * @b: base queue limits 948 * 949 * Check if the integrity profile in the @b can be stacked into the 950 * target @t. Stacking is possible if either: 951 * 952 * a) does not have any integrity information stacked into it yet 953 * b) the integrity profile in @b is identical to the one in @t 954 * 955 * If @b can be stacked into @t, return %true. Else return %false and clear the 956 * integrity information in @t. 957 */ 958 bool queue_limits_stack_integrity(struct queue_limits *t, 959 struct queue_limits *b) 960 { 961 struct blk_integrity *ti = &t->integrity; 962 struct blk_integrity *bi = &b->integrity; 963 964 if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) 965 return true; 966 967 if (ti->flags & BLK_INTEGRITY_STACKED) { 968 if (ti->metadata_size != bi->metadata_size) 969 goto incompatible; 970 if (ti->interval_exp != bi->interval_exp) 971 goto incompatible; 972 if (ti->tag_size != bi->tag_size) 973 goto incompatible; 974 if (ti->csum_type != bi->csum_type) 975 goto incompatible; 976 if (ti->pi_tuple_size != bi->pi_tuple_size) 977 goto incompatible; 978 if ((ti->flags & BLK_INTEGRITY_REF_TAG) != 979 (bi->flags & BLK_INTEGRITY_REF_TAG)) 980 goto incompatible; 981 } else { 982 ti->flags = BLK_INTEGRITY_STACKED; 983 ti->flags |= (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) | 984 (bi->flags & BLK_INTEGRITY_REF_TAG); 985 ti->csum_type = bi->csum_type; 986 ti->pi_tuple_size = bi->pi_tuple_size; 987 ti->metadata_size = bi->metadata_size; 988 ti->pi_offset = bi->pi_offset; 989 ti->interval_exp = bi->interval_exp; 990 ti->tag_size = bi->tag_size; 991 } 992 return true; 993 994 incompatible: 995 memset(ti, 0, sizeof(*ti)); 996 return false; 997 } 998 EXPORT_SYMBOL_GPL(queue_limits_stack_integrity); 999 1000 /** 1001 * blk_set_queue_depth - tell the block layer about the device queue depth 1002 * @q: the request queue for the device 1003 * @depth: queue depth 1004 * 1005 */ 1006 void blk_set_queue_depth(struct request_queue *q, unsigned int depth) 1007 { 1008 q->queue_depth = depth; 1009 rq_qos_queue_depth_changed(q); 1010 } 1011 EXPORT_SYMBOL(blk_set_queue_depth); 1012 1013 int bdev_alignment_offset(struct block_device *bdev) 1014 { 1015 struct request_queue *q = bdev_get_queue(bdev); 1016 1017 if (q->limits.flags & BLK_FLAG_MISALIGNED) 1018 return -1; 1019 if (bdev_is_partition(bdev)) 1020 return queue_limit_alignment_offset(&q->limits, 1021 bdev->bd_start_sect); 1022 return q->limits.alignment_offset; 1023 } 1024 EXPORT_SYMBOL_GPL(bdev_alignment_offset); 1025 1026 unsigned int bdev_discard_alignment(struct block_device *bdev) 1027 { 1028 struct request_queue *q = bdev_get_queue(bdev); 1029 1030 if (bdev_is_partition(bdev)) 1031 return queue_limit_discard_alignment(&q->limits, 1032 bdev->bd_start_sect); 1033 return q->limits.discard_alignment; 1034 } 1035 EXPORT_SYMBOL_GPL(bdev_discard_alignment); 1036