1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 raid0.c : Multiple Devices driver for Linux 4 Copyright (C) 1994-96 Marc ZYNGIER 5 <zyngier@ufr-info-p7.ibp.fr> or 6 <maz@gloups.fdn.fr> 7 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat 8 9 RAID-0 management functions. 10 11 */ 12 13 #include <linux/blkdev.h> 14 #include <linux/seq_file.h> 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <trace/events/block.h> 18 #include "md.h" 19 #include "raid0.h" 20 #include "raid5.h" 21 22 static int default_layout = 0; 23 module_param(default_layout, int, 0644); 24 25 #define UNSUPPORTED_MDDEV_FLAGS \ 26 ((1L << MD_HAS_JOURNAL) | \ 27 (1L << MD_JOURNAL_CLEAN) | \ 28 (1L << MD_FAILFAST_SUPPORTED) |\ 29 (1L << MD_HAS_PPL) | \ 30 (1L << MD_HAS_MULTIPLE_PPLS)) 31 32 /* 33 * inform the user of the raid configuration 34 */ 35 static void dump_zones(struct mddev *mddev) 36 { 37 int j, k; 38 sector_t zone_size = 0; 39 sector_t zone_start = 0; 40 struct r0conf *conf = mddev->private; 41 int raid_disks = conf->strip_zone[0].nb_dev; 42 pr_debug("md: RAID0 configuration for %s - %d zone%s\n", 43 mdname(mddev), 44 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); 45 for (j = 0; j < conf->nr_strip_zones; j++) { 46 char line[200]; 47 int len = 0; 48 49 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 50 len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"", 51 conf->devlist[j * raid_disks + k]->bdev); 52 pr_debug("md: zone%d=[%s]\n", j, line); 53 54 zone_size = conf->strip_zone[j].zone_end - zone_start; 55 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", 56 (unsigned long long)zone_start>>1, 57 (unsigned long long)conf->strip_zone[j].dev_start>>1, 58 (unsigned long long)zone_size>>1); 59 zone_start = conf->strip_zone[j].zone_end; 60 } 61 } 62 63 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 64 { 65 int i, c, err; 66 sector_t curr_zone_end, sectors; 67 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 68 struct strip_zone *zone; 69 int cnt; 70 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 71 unsigned blksize = 512; 72 73 *private_conf = ERR_PTR(-ENOMEM); 74 if (!conf) 75 return -ENOMEM; 76 rdev_for_each(rdev1, mddev) { 77 pr_debug("md/raid0:%s: looking at %pg\n", 78 mdname(mddev), 79 rdev1->bdev); 80 c = 0; 81 82 /* round size to chunk_size */ 83 sectors = rdev1->sectors; 84 sector_div(sectors, mddev->chunk_sectors); 85 rdev1->sectors = sectors * mddev->chunk_sectors; 86 87 blksize = max(blksize, queue_logical_block_size( 88 rdev1->bdev->bd_disk->queue)); 89 90 rdev_for_each(rdev2, mddev) { 91 pr_debug("md/raid0:%s: comparing %pg(%llu)" 92 " with %pg(%llu)\n", 93 mdname(mddev), 94 rdev1->bdev, 95 (unsigned long long)rdev1->sectors, 96 rdev2->bdev, 97 (unsigned long long)rdev2->sectors); 98 if (rdev2 == rdev1) { 99 pr_debug("md/raid0:%s: END\n", 100 mdname(mddev)); 101 break; 102 } 103 if (rdev2->sectors == rdev1->sectors) { 104 /* 105 * Not unique, don't count it as a new 106 * group 107 */ 108 pr_debug("md/raid0:%s: EQUAL\n", 109 mdname(mddev)); 110 c = 1; 111 break; 112 } 113 pr_debug("md/raid0:%s: NOT EQUAL\n", 114 mdname(mddev)); 115 } 116 if (!c) { 117 pr_debug("md/raid0:%s: ==> UNIQUE\n", 118 mdname(mddev)); 119 conf->nr_strip_zones++; 120 pr_debug("md/raid0:%s: %d zones\n", 121 mdname(mddev), conf->nr_strip_zones); 122 } 123 } 124 pr_debug("md/raid0:%s: FINAL %d zones\n", 125 mdname(mddev), conf->nr_strip_zones); 126 127 /* 128 * now since we have the hard sector sizes, we can make sure 129 * chunk size is a multiple of that sector size 130 */ 131 if ((mddev->chunk_sectors << 9) % blksize) { 132 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", 133 mdname(mddev), 134 mddev->chunk_sectors << 9, blksize); 135 err = -EINVAL; 136 goto abort; 137 } 138 139 err = -ENOMEM; 140 conf->strip_zone = kcalloc(conf->nr_strip_zones, 141 sizeof(struct strip_zone), 142 GFP_KERNEL); 143 if (!conf->strip_zone) 144 goto abort; 145 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *), 146 conf->nr_strip_zones, 147 mddev->raid_disks), 148 GFP_KERNEL); 149 if (!conf->devlist) 150 goto abort; 151 152 /* The first zone must contain all devices, so here we check that 153 * there is a proper alignment of slots to devices and find them all 154 */ 155 zone = &conf->strip_zone[0]; 156 cnt = 0; 157 smallest = NULL; 158 dev = conf->devlist; 159 err = -EINVAL; 160 rdev_for_each(rdev1, mddev) { 161 int j = rdev1->raid_disk; 162 163 if (mddev->level == 10) { 164 /* taking over a raid10-n2 array */ 165 j /= 2; 166 rdev1->new_raid_disk = j; 167 } 168 169 if (mddev->level == 1) { 170 /* taiking over a raid1 array- 171 * we have only one active disk 172 */ 173 j = 0; 174 rdev1->new_raid_disk = j; 175 } 176 177 if (j < 0) { 178 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", 179 mdname(mddev)); 180 goto abort; 181 } 182 if (j >= mddev->raid_disks) { 183 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", 184 mdname(mddev), j); 185 goto abort; 186 } 187 if (dev[j]) { 188 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", 189 mdname(mddev), j); 190 goto abort; 191 } 192 dev[j] = rdev1; 193 194 if (!smallest || (rdev1->sectors < smallest->sectors)) 195 smallest = rdev1; 196 cnt++; 197 } 198 if (cnt != mddev->raid_disks) { 199 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", 200 mdname(mddev), cnt, mddev->raid_disks); 201 goto abort; 202 } 203 zone->nb_dev = cnt; 204 zone->zone_end = smallest->sectors * cnt; 205 206 curr_zone_end = zone->zone_end; 207 208 /* now do the other zones */ 209 for (i = 1; i < conf->nr_strip_zones; i++) 210 { 211 int j; 212 213 zone = conf->strip_zone + i; 214 dev = conf->devlist + i * mddev->raid_disks; 215 216 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 217 zone->dev_start = smallest->sectors; 218 smallest = NULL; 219 c = 0; 220 221 for (j=0; j<cnt; j++) { 222 rdev = conf->devlist[j]; 223 if (rdev->sectors <= zone->dev_start) { 224 pr_debug("md/raid0:%s: checking %pg ... nope\n", 225 mdname(mddev), 226 rdev->bdev); 227 continue; 228 } 229 pr_debug("md/raid0:%s: checking %pg ..." 230 " contained as device %d\n", 231 mdname(mddev), 232 rdev->bdev, c); 233 dev[c] = rdev; 234 c++; 235 if (!smallest || rdev->sectors < smallest->sectors) { 236 smallest = rdev; 237 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 238 mdname(mddev), 239 (unsigned long long)rdev->sectors); 240 } 241 } 242 243 zone->nb_dev = c; 244 sectors = (smallest->sectors - zone->dev_start) * c; 245 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 246 mdname(mddev), 247 zone->nb_dev, (unsigned long long)sectors); 248 249 curr_zone_end += sectors; 250 zone->zone_end = curr_zone_end; 251 252 pr_debug("md/raid0:%s: current zone start: %llu\n", 253 mdname(mddev), 254 (unsigned long long)smallest->sectors); 255 } 256 257 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) { 258 conf->layout = RAID0_ORIG_LAYOUT; 259 } else if (mddev->layout == RAID0_ORIG_LAYOUT || 260 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) { 261 conf->layout = mddev->layout; 262 } else if (default_layout == RAID0_ORIG_LAYOUT || 263 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) { 264 conf->layout = default_layout; 265 } else { 266 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", 267 mdname(mddev)); 268 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n"); 269 err = -EOPNOTSUPP; 270 goto abort; 271 } 272 273 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 274 *private_conf = conf; 275 276 return 0; 277 abort: 278 kfree(conf->strip_zone); 279 kfree(conf->devlist); 280 kfree(conf); 281 *private_conf = ERR_PTR(err); 282 return err; 283 } 284 285 /* Find the zone which holds a particular offset 286 * Update *sectorp to be an offset in that zone 287 */ 288 static struct strip_zone *find_zone(struct r0conf *conf, 289 sector_t *sectorp) 290 { 291 int i; 292 struct strip_zone *z = conf->strip_zone; 293 sector_t sector = *sectorp; 294 295 for (i = 0; i < conf->nr_strip_zones; i++) 296 if (sector < z[i].zone_end) { 297 if (i) 298 *sectorp = sector - z[i-1].zone_end; 299 return z + i; 300 } 301 BUG(); 302 } 303 304 /* 305 * remaps the bio to the target device. we separate two flows. 306 * power 2 flow and a general flow for the sake of performance 307 */ 308 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 309 sector_t sector, sector_t *sector_offset) 310 { 311 unsigned int sect_in_chunk; 312 sector_t chunk; 313 struct r0conf *conf = mddev->private; 314 int raid_disks = conf->strip_zone[0].nb_dev; 315 unsigned int chunk_sects = mddev->chunk_sectors; 316 317 if (is_power_of_2(chunk_sects)) { 318 int chunksect_bits = ffz(~chunk_sects); 319 /* find the sector offset inside the chunk */ 320 sect_in_chunk = sector & (chunk_sects - 1); 321 sector >>= chunksect_bits; 322 /* chunk in zone */ 323 chunk = *sector_offset; 324 /* quotient is the chunk in real device*/ 325 sector_div(chunk, zone->nb_dev << chunksect_bits); 326 } else{ 327 sect_in_chunk = sector_div(sector, chunk_sects); 328 chunk = *sector_offset; 329 sector_div(chunk, chunk_sects * zone->nb_dev); 330 } 331 /* 332 * position the bio over the real device 333 * real sector = chunk in device + starting of zone 334 * + the position in the chunk 335 */ 336 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 337 return conf->devlist[(zone - conf->strip_zone)*raid_disks 338 + sector_div(sector, zone->nb_dev)]; 339 } 340 341 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 342 { 343 sector_t array_sectors = 0; 344 struct md_rdev *rdev; 345 346 WARN_ONCE(sectors || raid_disks, 347 "%s does not support generic reshape\n", __func__); 348 349 rdev_for_each(rdev, mddev) 350 array_sectors += (rdev->sectors & 351 ~(sector_t)(mddev->chunk_sectors-1)); 352 353 return array_sectors; 354 } 355 356 static void free_conf(struct mddev *mddev, struct r0conf *conf) 357 { 358 kfree(conf->strip_zone); 359 kfree(conf->devlist); 360 kfree(conf); 361 } 362 363 static void raid0_free(struct mddev *mddev, void *priv) 364 { 365 struct r0conf *conf = priv; 366 367 free_conf(mddev, conf); 368 acct_bioset_exit(mddev); 369 } 370 371 static int raid0_run(struct mddev *mddev) 372 { 373 struct r0conf *conf; 374 int ret; 375 376 if (mddev->chunk_sectors == 0) { 377 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 378 return -EINVAL; 379 } 380 if (md_check_no_bitmap(mddev)) 381 return -EINVAL; 382 383 if (acct_bioset_init(mddev)) { 384 pr_err("md/raid0:%s: alloc acct bioset failed.\n", mdname(mddev)); 385 return -ENOMEM; 386 } 387 388 /* if private is not null, we are here after takeover */ 389 if (mddev->private == NULL) { 390 ret = create_strip_zones(mddev, &conf); 391 if (ret < 0) 392 goto exit_acct_set; 393 mddev->private = conf; 394 } 395 conf = mddev->private; 396 if (mddev->queue) { 397 struct md_rdev *rdev; 398 399 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 400 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors); 401 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX); 402 403 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 404 blk_queue_io_opt(mddev->queue, 405 (mddev->chunk_sectors << 9) * mddev->raid_disks); 406 407 rdev_for_each(rdev, mddev) { 408 disk_stack_limits(mddev->gendisk, rdev->bdev, 409 rdev->data_offset << 9); 410 } 411 } 412 413 /* calculate array device size */ 414 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 415 416 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 417 mdname(mddev), 418 (unsigned long long)mddev->array_sectors); 419 420 dump_zones(mddev); 421 422 ret = md_integrity_register(mddev); 423 if (ret) 424 goto free; 425 426 return ret; 427 428 free: 429 free_conf(mddev, conf); 430 exit_acct_set: 431 acct_bioset_exit(mddev); 432 return ret; 433 } 434 435 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) 436 { 437 struct r0conf *conf = mddev->private; 438 struct strip_zone *zone; 439 sector_t start = bio->bi_iter.bi_sector; 440 sector_t end; 441 unsigned int stripe_size; 442 sector_t first_stripe_index, last_stripe_index; 443 sector_t start_disk_offset; 444 unsigned int start_disk_index; 445 sector_t end_disk_offset; 446 unsigned int end_disk_index; 447 unsigned int disk; 448 449 zone = find_zone(conf, &start); 450 451 if (bio_end_sector(bio) > zone->zone_end) { 452 struct bio *split = bio_split(bio, 453 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, 454 &mddev->bio_set); 455 bio_chain(split, bio); 456 submit_bio_noacct(bio); 457 bio = split; 458 end = zone->zone_end; 459 } else 460 end = bio_end_sector(bio); 461 462 if (zone != conf->strip_zone) 463 end = end - zone[-1].zone_end; 464 465 /* Now start and end is the offset in zone */ 466 stripe_size = zone->nb_dev * mddev->chunk_sectors; 467 468 first_stripe_index = start; 469 sector_div(first_stripe_index, stripe_size); 470 last_stripe_index = end; 471 sector_div(last_stripe_index, stripe_size); 472 473 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 474 mddev->chunk_sectors; 475 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 476 mddev->chunk_sectors) + 477 first_stripe_index * mddev->chunk_sectors; 478 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 479 mddev->chunk_sectors; 480 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 481 mddev->chunk_sectors) + 482 last_stripe_index * mddev->chunk_sectors; 483 484 for (disk = 0; disk < zone->nb_dev; disk++) { 485 sector_t dev_start, dev_end; 486 struct md_rdev *rdev; 487 488 if (disk < start_disk_index) 489 dev_start = (first_stripe_index + 1) * 490 mddev->chunk_sectors; 491 else if (disk > start_disk_index) 492 dev_start = first_stripe_index * mddev->chunk_sectors; 493 else 494 dev_start = start_disk_offset; 495 496 if (disk < end_disk_index) 497 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; 498 else if (disk > end_disk_index) 499 dev_end = last_stripe_index * mddev->chunk_sectors; 500 else 501 dev_end = end_disk_offset; 502 503 if (dev_end <= dev_start) 504 continue; 505 506 rdev = conf->devlist[(zone - conf->strip_zone) * 507 conf->strip_zone[0].nb_dev + disk]; 508 md_submit_discard_bio(mddev, rdev, bio, 509 dev_start + zone->dev_start + rdev->data_offset, 510 dev_end - dev_start); 511 } 512 bio_endio(bio); 513 } 514 515 static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 516 { 517 struct r0conf *conf = mddev->private; 518 struct strip_zone *zone; 519 struct md_rdev *tmp_dev; 520 sector_t bio_sector; 521 sector_t sector; 522 sector_t orig_sector; 523 unsigned chunk_sects; 524 unsigned sectors; 525 526 if (unlikely(bio->bi_opf & REQ_PREFLUSH) 527 && md_flush_request(mddev, bio)) 528 return true; 529 530 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 531 raid0_handle_discard(mddev, bio); 532 return true; 533 } 534 535 bio_sector = bio->bi_iter.bi_sector; 536 sector = bio_sector; 537 chunk_sects = mddev->chunk_sectors; 538 539 sectors = chunk_sects - 540 (likely(is_power_of_2(chunk_sects)) 541 ? (sector & (chunk_sects-1)) 542 : sector_div(sector, chunk_sects)); 543 544 /* Restore due to sector_div */ 545 sector = bio_sector; 546 547 if (sectors < bio_sectors(bio)) { 548 struct bio *split = bio_split(bio, sectors, GFP_NOIO, 549 &mddev->bio_set); 550 bio_chain(split, bio); 551 submit_bio_noacct(bio); 552 bio = split; 553 } 554 555 if (bio->bi_pool != &mddev->bio_set) 556 md_account_bio(mddev, &bio); 557 558 orig_sector = sector; 559 zone = find_zone(mddev->private, §or); 560 switch (conf->layout) { 561 case RAID0_ORIG_LAYOUT: 562 tmp_dev = map_sector(mddev, zone, orig_sector, §or); 563 break; 564 case RAID0_ALT_MULTIZONE_LAYOUT: 565 tmp_dev = map_sector(mddev, zone, sector, §or); 566 break; 567 default: 568 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev)); 569 bio_io_error(bio); 570 return true; 571 } 572 573 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) { 574 bio_io_error(bio); 575 return true; 576 } 577 578 bio_set_dev(bio, tmp_dev->bdev); 579 bio->bi_iter.bi_sector = sector + zone->dev_start + 580 tmp_dev->data_offset; 581 582 if (mddev->gendisk) 583 trace_block_bio_remap(bio, disk_devt(mddev->gendisk), 584 bio_sector); 585 mddev_check_write_zeroes(mddev, bio); 586 submit_bio_noacct(bio); 587 return true; 588 } 589 590 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 591 { 592 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 593 return; 594 } 595 596 static void *raid0_takeover_raid45(struct mddev *mddev) 597 { 598 struct md_rdev *rdev; 599 struct r0conf *priv_conf; 600 601 if (mddev->degraded != 1) { 602 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 603 mdname(mddev), 604 mddev->degraded); 605 return ERR_PTR(-EINVAL); 606 } 607 608 rdev_for_each(rdev, mddev) { 609 /* check slot number for a disk */ 610 if (rdev->raid_disk == mddev->raid_disks-1) { 611 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n", 612 mdname(mddev)); 613 return ERR_PTR(-EINVAL); 614 } 615 rdev->sectors = mddev->dev_sectors; 616 } 617 618 /* Set new parameters */ 619 mddev->new_level = 0; 620 mddev->new_layout = 0; 621 mddev->new_chunk_sectors = mddev->chunk_sectors; 622 mddev->raid_disks--; 623 mddev->delta_disks = -1; 624 /* make sure it will be not marked as dirty */ 625 mddev->recovery_cp = MaxSector; 626 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 627 628 create_strip_zones(mddev, &priv_conf); 629 630 return priv_conf; 631 } 632 633 static void *raid0_takeover_raid10(struct mddev *mddev) 634 { 635 struct r0conf *priv_conf; 636 637 /* Check layout: 638 * - far_copies must be 1 639 * - near_copies must be 2 640 * - disks number must be even 641 * - all mirrors must be already degraded 642 */ 643 if (mddev->layout != ((1 << 8) + 2)) { 644 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", 645 mdname(mddev), 646 mddev->layout); 647 return ERR_PTR(-EINVAL); 648 } 649 if (mddev->raid_disks & 1) { 650 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", 651 mdname(mddev)); 652 return ERR_PTR(-EINVAL); 653 } 654 if (mddev->degraded != (mddev->raid_disks>>1)) { 655 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n", 656 mdname(mddev)); 657 return ERR_PTR(-EINVAL); 658 } 659 660 /* Set new parameters */ 661 mddev->new_level = 0; 662 mddev->new_layout = 0; 663 mddev->new_chunk_sectors = mddev->chunk_sectors; 664 mddev->delta_disks = - mddev->raid_disks / 2; 665 mddev->raid_disks += mddev->delta_disks; 666 mddev->degraded = 0; 667 /* make sure it will be not marked as dirty */ 668 mddev->recovery_cp = MaxSector; 669 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 670 671 create_strip_zones(mddev, &priv_conf); 672 return priv_conf; 673 } 674 675 static void *raid0_takeover_raid1(struct mddev *mddev) 676 { 677 struct r0conf *priv_conf; 678 int chunksect; 679 680 /* Check layout: 681 * - (N - 1) mirror drives must be already faulty 682 */ 683 if ((mddev->raid_disks - 1) != mddev->degraded) { 684 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 685 mdname(mddev)); 686 return ERR_PTR(-EINVAL); 687 } 688 689 /* 690 * a raid1 doesn't have the notion of chunk size, so 691 * figure out the largest suitable size we can use. 692 */ 693 chunksect = 64 * 2; /* 64K by default */ 694 695 /* The array must be an exact multiple of chunksize */ 696 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 697 chunksect >>= 1; 698 699 if ((chunksect << 9) < PAGE_SIZE) 700 /* array size does not allow a suitable chunk size */ 701 return ERR_PTR(-EINVAL); 702 703 /* Set new parameters */ 704 mddev->new_level = 0; 705 mddev->new_layout = 0; 706 mddev->new_chunk_sectors = chunksect; 707 mddev->chunk_sectors = chunksect; 708 mddev->delta_disks = 1 - mddev->raid_disks; 709 mddev->raid_disks = 1; 710 /* make sure it will be not marked as dirty */ 711 mddev->recovery_cp = MaxSector; 712 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 713 714 create_strip_zones(mddev, &priv_conf); 715 return priv_conf; 716 } 717 718 static void *raid0_takeover(struct mddev *mddev) 719 { 720 /* raid0 can take over: 721 * raid4 - if all data disks are active. 722 * raid5 - providing it is Raid4 layout and one disk is faulty 723 * raid10 - assuming we have all necessary active disks 724 * raid1 - with (N -1) mirror drives faulty 725 */ 726 727 if (mddev->bitmap) { 728 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n", 729 mdname(mddev)); 730 return ERR_PTR(-EBUSY); 731 } 732 if (mddev->level == 4) 733 return raid0_takeover_raid45(mddev); 734 735 if (mddev->level == 5) { 736 if (mddev->layout == ALGORITHM_PARITY_N) 737 return raid0_takeover_raid45(mddev); 738 739 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 740 mdname(mddev), ALGORITHM_PARITY_N); 741 } 742 743 if (mddev->level == 10) 744 return raid0_takeover_raid10(mddev); 745 746 if (mddev->level == 1) 747 return raid0_takeover_raid1(mddev); 748 749 pr_warn("Takeover from raid%i to raid0 not supported\n", 750 mddev->level); 751 752 return ERR_PTR(-EINVAL); 753 } 754 755 static void raid0_quiesce(struct mddev *mddev, int quiesce) 756 { 757 } 758 759 static struct md_personality raid0_personality= 760 { 761 .name = "raid0", 762 .level = 0, 763 .owner = THIS_MODULE, 764 .make_request = raid0_make_request, 765 .run = raid0_run, 766 .free = raid0_free, 767 .status = raid0_status, 768 .size = raid0_size, 769 .takeover = raid0_takeover, 770 .quiesce = raid0_quiesce, 771 }; 772 773 static int __init raid0_init (void) 774 { 775 return register_md_personality (&raid0_personality); 776 } 777 778 static void raid0_exit (void) 779 { 780 unregister_md_personality (&raid0_personality); 781 } 782 783 module_init(raid0_init); 784 module_exit(raid0_exit); 785 MODULE_LICENSE("GPL"); 786 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 787 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 788 MODULE_ALIAS("md-raid0"); 789 MODULE_ALIAS("md-level-0"); 790