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