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