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 char b[BDEVNAME_SIZE]; 41 struct r0conf *conf = mddev->private; 42 int raid_disks = conf->strip_zone[0].nb_dev; 43 pr_debug("md: RAID0 configuration for %s - %d zone%s\n", 44 mdname(mddev), 45 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); 46 for (j = 0; j < conf->nr_strip_zones; j++) { 47 char line[200]; 48 int len = 0; 49 50 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 51 len += snprintf(line+len, 200-len, "%s%s", k?"/":"", 52 bdevname(conf->devlist[j*raid_disks 53 + k]->bdev, b)); 54 pr_debug("md: zone%d=[%s]\n", j, line); 55 56 zone_size = conf->strip_zone[j].zone_end - zone_start; 57 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", 58 (unsigned long long)zone_start>>1, 59 (unsigned long long)conf->strip_zone[j].dev_start>>1, 60 (unsigned long long)zone_size>>1); 61 zone_start = conf->strip_zone[j].zone_end; 62 } 63 } 64 65 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 66 { 67 int i, c, err; 68 sector_t curr_zone_end, sectors; 69 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 70 struct strip_zone *zone; 71 int cnt; 72 char b[BDEVNAME_SIZE]; 73 char b2[BDEVNAME_SIZE]; 74 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 75 unsigned blksize = 512; 76 77 *private_conf = ERR_PTR(-ENOMEM); 78 if (!conf) 79 return -ENOMEM; 80 rdev_for_each(rdev1, mddev) { 81 pr_debug("md/raid0:%s: looking at %s\n", 82 mdname(mddev), 83 bdevname(rdev1->bdev, b)); 84 c = 0; 85 86 /* round size to chunk_size */ 87 sectors = rdev1->sectors; 88 sector_div(sectors, mddev->chunk_sectors); 89 rdev1->sectors = sectors * mddev->chunk_sectors; 90 91 blksize = max(blksize, queue_logical_block_size( 92 rdev1->bdev->bd_disk->queue)); 93 94 rdev_for_each(rdev2, mddev) { 95 pr_debug("md/raid0:%s: comparing %s(%llu)" 96 " with %s(%llu)\n", 97 mdname(mddev), 98 bdevname(rdev1->bdev,b), 99 (unsigned long long)rdev1->sectors, 100 bdevname(rdev2->bdev,b2), 101 (unsigned long long)rdev2->sectors); 102 if (rdev2 == rdev1) { 103 pr_debug("md/raid0:%s: END\n", 104 mdname(mddev)); 105 break; 106 } 107 if (rdev2->sectors == rdev1->sectors) { 108 /* 109 * Not unique, don't count it as a new 110 * group 111 */ 112 pr_debug("md/raid0:%s: EQUAL\n", 113 mdname(mddev)); 114 c = 1; 115 break; 116 } 117 pr_debug("md/raid0:%s: NOT EQUAL\n", 118 mdname(mddev)); 119 } 120 if (!c) { 121 pr_debug("md/raid0:%s: ==> UNIQUE\n", 122 mdname(mddev)); 123 conf->nr_strip_zones++; 124 pr_debug("md/raid0:%s: %d zones\n", 125 mdname(mddev), conf->nr_strip_zones); 126 } 127 } 128 pr_debug("md/raid0:%s: FINAL %d zones\n", 129 mdname(mddev), conf->nr_strip_zones); 130 131 if (conf->nr_strip_zones == 1) { 132 conf->layout = RAID0_ORIG_LAYOUT; 133 } else if (mddev->layout == RAID0_ORIG_LAYOUT || 134 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) { 135 conf->layout = mddev->layout; 136 } else if (default_layout == RAID0_ORIG_LAYOUT || 137 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) { 138 conf->layout = default_layout; 139 } else { 140 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", 141 mdname(mddev)); 142 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n"); 143 err = -ENOTSUPP; 144 goto abort; 145 } 146 /* 147 * now since we have the hard sector sizes, we can make sure 148 * chunk size is a multiple of that sector size 149 */ 150 if ((mddev->chunk_sectors << 9) % blksize) { 151 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", 152 mdname(mddev), 153 mddev->chunk_sectors << 9, blksize); 154 err = -EINVAL; 155 goto abort; 156 } 157 158 err = -ENOMEM; 159 conf->strip_zone = kcalloc(conf->nr_strip_zones, 160 sizeof(struct strip_zone), 161 GFP_KERNEL); 162 if (!conf->strip_zone) 163 goto abort; 164 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *), 165 conf->nr_strip_zones, 166 mddev->raid_disks), 167 GFP_KERNEL); 168 if (!conf->devlist) 169 goto abort; 170 171 /* The first zone must contain all devices, so here we check that 172 * there is a proper alignment of slots to devices and find them all 173 */ 174 zone = &conf->strip_zone[0]; 175 cnt = 0; 176 smallest = NULL; 177 dev = conf->devlist; 178 err = -EINVAL; 179 rdev_for_each(rdev1, mddev) { 180 int j = rdev1->raid_disk; 181 182 if (mddev->level == 10) { 183 /* taking over a raid10-n2 array */ 184 j /= 2; 185 rdev1->new_raid_disk = j; 186 } 187 188 if (mddev->level == 1) { 189 /* taiking over a raid1 array- 190 * we have only one active disk 191 */ 192 j = 0; 193 rdev1->new_raid_disk = j; 194 } 195 196 if (j < 0) { 197 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", 198 mdname(mddev)); 199 goto abort; 200 } 201 if (j >= mddev->raid_disks) { 202 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", 203 mdname(mddev), j); 204 goto abort; 205 } 206 if (dev[j]) { 207 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", 208 mdname(mddev), j); 209 goto abort; 210 } 211 dev[j] = rdev1; 212 213 if (!smallest || (rdev1->sectors < smallest->sectors)) 214 smallest = rdev1; 215 cnt++; 216 } 217 if (cnt != mddev->raid_disks) { 218 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", 219 mdname(mddev), cnt, mddev->raid_disks); 220 goto abort; 221 } 222 zone->nb_dev = cnt; 223 zone->zone_end = smallest->sectors * cnt; 224 225 curr_zone_end = zone->zone_end; 226 227 /* now do the other zones */ 228 for (i = 1; i < conf->nr_strip_zones; i++) 229 { 230 int j; 231 232 zone = conf->strip_zone + i; 233 dev = conf->devlist + i * mddev->raid_disks; 234 235 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 236 zone->dev_start = smallest->sectors; 237 smallest = NULL; 238 c = 0; 239 240 for (j=0; j<cnt; j++) { 241 rdev = conf->devlist[j]; 242 if (rdev->sectors <= zone->dev_start) { 243 pr_debug("md/raid0:%s: checking %s ... nope\n", 244 mdname(mddev), 245 bdevname(rdev->bdev, b)); 246 continue; 247 } 248 pr_debug("md/raid0:%s: checking %s ..." 249 " contained as device %d\n", 250 mdname(mddev), 251 bdevname(rdev->bdev, b), c); 252 dev[c] = rdev; 253 c++; 254 if (!smallest || rdev->sectors < smallest->sectors) { 255 smallest = rdev; 256 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 257 mdname(mddev), 258 (unsigned long long)rdev->sectors); 259 } 260 } 261 262 zone->nb_dev = c; 263 sectors = (smallest->sectors - zone->dev_start) * c; 264 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 265 mdname(mddev), 266 zone->nb_dev, (unsigned long long)sectors); 267 268 curr_zone_end += sectors; 269 zone->zone_end = curr_zone_end; 270 271 pr_debug("md/raid0:%s: current zone start: %llu\n", 272 mdname(mddev), 273 (unsigned long long)smallest->sectors); 274 } 275 276 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 277 *private_conf = conf; 278 279 return 0; 280 abort: 281 kfree(conf->strip_zone); 282 kfree(conf->devlist); 283 kfree(conf); 284 *private_conf = ERR_PTR(err); 285 return err; 286 } 287 288 /* Find the zone which holds a particular offset 289 * Update *sectorp to be an offset in that zone 290 */ 291 static struct strip_zone *find_zone(struct r0conf *conf, 292 sector_t *sectorp) 293 { 294 int i; 295 struct strip_zone *z = conf->strip_zone; 296 sector_t sector = *sectorp; 297 298 for (i = 0; i < conf->nr_strip_zones; i++) 299 if (sector < z[i].zone_end) { 300 if (i) 301 *sectorp = sector - z[i-1].zone_end; 302 return z + i; 303 } 304 BUG(); 305 } 306 307 /* 308 * remaps the bio to the target device. we separate two flows. 309 * power 2 flow and a general flow for the sake of performance 310 */ 311 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 312 sector_t sector, sector_t *sector_offset) 313 { 314 unsigned int sect_in_chunk; 315 sector_t chunk; 316 struct r0conf *conf = mddev->private; 317 int raid_disks = conf->strip_zone[0].nb_dev; 318 unsigned int chunk_sects = mddev->chunk_sectors; 319 320 if (is_power_of_2(chunk_sects)) { 321 int chunksect_bits = ffz(~chunk_sects); 322 /* find the sector offset inside the chunk */ 323 sect_in_chunk = sector & (chunk_sects - 1); 324 sector >>= chunksect_bits; 325 /* chunk in zone */ 326 chunk = *sector_offset; 327 /* quotient is the chunk in real device*/ 328 sector_div(chunk, zone->nb_dev << chunksect_bits); 329 } else{ 330 sect_in_chunk = sector_div(sector, chunk_sects); 331 chunk = *sector_offset; 332 sector_div(chunk, chunk_sects * zone->nb_dev); 333 } 334 /* 335 * position the bio over the real device 336 * real sector = chunk in device + starting of zone 337 * + the position in the chunk 338 */ 339 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 340 return conf->devlist[(zone - conf->strip_zone)*raid_disks 341 + sector_div(sector, zone->nb_dev)]; 342 } 343 344 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 345 { 346 sector_t array_sectors = 0; 347 struct md_rdev *rdev; 348 349 WARN_ONCE(sectors || raid_disks, 350 "%s does not support generic reshape\n", __func__); 351 352 rdev_for_each(rdev, mddev) 353 array_sectors += (rdev->sectors & 354 ~(sector_t)(mddev->chunk_sectors-1)); 355 356 return array_sectors; 357 } 358 359 static void raid0_free(struct mddev *mddev, void *priv); 360 361 static int raid0_run(struct mddev *mddev) 362 { 363 struct r0conf *conf; 364 int ret; 365 366 if (mddev->chunk_sectors == 0) { 367 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 368 return -EINVAL; 369 } 370 if (md_check_no_bitmap(mddev)) 371 return -EINVAL; 372 373 /* if private is not null, we are here after takeover */ 374 if (mddev->private == NULL) { 375 ret = create_strip_zones(mddev, &conf); 376 if (ret < 0) 377 return ret; 378 mddev->private = conf; 379 } 380 conf = mddev->private; 381 if (mddev->queue) { 382 struct md_rdev *rdev; 383 bool discard_supported = false; 384 385 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 386 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); 387 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors); 388 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX); 389 390 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 391 blk_queue_io_opt(mddev->queue, 392 (mddev->chunk_sectors << 9) * mddev->raid_disks); 393 394 rdev_for_each(rdev, mddev) { 395 disk_stack_limits(mddev->gendisk, rdev->bdev, 396 rdev->data_offset << 9); 397 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 398 discard_supported = true; 399 } 400 if (!discard_supported) 401 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue); 402 else 403 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue); 404 } 405 406 /* calculate array device size */ 407 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 408 409 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 410 mdname(mddev), 411 (unsigned long long)mddev->array_sectors); 412 413 dump_zones(mddev); 414 415 ret = md_integrity_register(mddev); 416 417 return ret; 418 } 419 420 static void raid0_free(struct mddev *mddev, void *priv) 421 { 422 struct r0conf *conf = priv; 423 424 kfree(conf->strip_zone); 425 kfree(conf->devlist); 426 kfree(conf); 427 } 428 429 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) 430 { 431 struct r0conf *conf = mddev->private; 432 struct strip_zone *zone; 433 sector_t start = bio->bi_iter.bi_sector; 434 sector_t end; 435 unsigned int stripe_size; 436 sector_t first_stripe_index, last_stripe_index; 437 sector_t start_disk_offset; 438 unsigned int start_disk_index; 439 sector_t end_disk_offset; 440 unsigned int end_disk_index; 441 unsigned int disk; 442 443 zone = find_zone(conf, &start); 444 445 if (bio_end_sector(bio) > zone->zone_end) { 446 struct bio *split = bio_split(bio, 447 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, 448 &mddev->bio_set); 449 bio_chain(split, bio); 450 submit_bio_noacct(bio); 451 bio = split; 452 end = zone->zone_end; 453 } else 454 end = bio_end_sector(bio); 455 456 if (zone != conf->strip_zone) 457 end = end - zone[-1].zone_end; 458 459 /* Now start and end is the offset in zone */ 460 stripe_size = zone->nb_dev * mddev->chunk_sectors; 461 462 first_stripe_index = start; 463 sector_div(first_stripe_index, stripe_size); 464 last_stripe_index = end; 465 sector_div(last_stripe_index, stripe_size); 466 467 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 468 mddev->chunk_sectors; 469 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 470 mddev->chunk_sectors) + 471 first_stripe_index * mddev->chunk_sectors; 472 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 473 mddev->chunk_sectors; 474 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 475 mddev->chunk_sectors) + 476 last_stripe_index * mddev->chunk_sectors; 477 478 for (disk = 0; disk < zone->nb_dev; disk++) { 479 sector_t dev_start, dev_end; 480 struct bio *discard_bio = NULL; 481 struct md_rdev *rdev; 482 483 if (disk < start_disk_index) 484 dev_start = (first_stripe_index + 1) * 485 mddev->chunk_sectors; 486 else if (disk > start_disk_index) 487 dev_start = first_stripe_index * mddev->chunk_sectors; 488 else 489 dev_start = start_disk_offset; 490 491 if (disk < end_disk_index) 492 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; 493 else if (disk > end_disk_index) 494 dev_end = last_stripe_index * mddev->chunk_sectors; 495 else 496 dev_end = end_disk_offset; 497 498 if (dev_end <= dev_start) 499 continue; 500 501 rdev = conf->devlist[(zone - conf->strip_zone) * 502 conf->strip_zone[0].nb_dev + disk]; 503 if (__blkdev_issue_discard(rdev->bdev, 504 dev_start + zone->dev_start + rdev->data_offset, 505 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) || 506 !discard_bio) 507 continue; 508 bio_chain(discard_bio, bio); 509 bio_clone_blkg_association(discard_bio, bio); 510 if (mddev->gendisk) 511 trace_block_bio_remap(discard_bio, 512 disk_devt(mddev->gendisk), 513 bio->bi_iter.bi_sector); 514 submit_bio_noacct(discard_bio); 515 } 516 bio_endio(bio); 517 } 518 519 static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 520 { 521 struct r0conf *conf = mddev->private; 522 struct strip_zone *zone; 523 struct md_rdev *tmp_dev; 524 sector_t bio_sector; 525 sector_t sector; 526 sector_t orig_sector; 527 unsigned chunk_sects; 528 unsigned sectors; 529 530 if (unlikely(bio->bi_opf & REQ_PREFLUSH) 531 && md_flush_request(mddev, bio)) 532 return true; 533 534 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 535 raid0_handle_discard(mddev, bio); 536 return true; 537 } 538 539 bio_sector = bio->bi_iter.bi_sector; 540 sector = bio_sector; 541 chunk_sects = mddev->chunk_sectors; 542 543 sectors = chunk_sects - 544 (likely(is_power_of_2(chunk_sects)) 545 ? (sector & (chunk_sects-1)) 546 : sector_div(sector, chunk_sects)); 547 548 /* Restore due to sector_div */ 549 sector = bio_sector; 550 551 if (sectors < bio_sectors(bio)) { 552 struct bio *split = bio_split(bio, sectors, GFP_NOIO, 553 &mddev->bio_set); 554 bio_chain(split, bio); 555 submit_bio_noacct(bio); 556 bio = split; 557 } 558 559 orig_sector = sector; 560 zone = find_zone(mddev->private, §or); 561 switch (conf->layout) { 562 case RAID0_ORIG_LAYOUT: 563 tmp_dev = map_sector(mddev, zone, orig_sector, §or); 564 break; 565 case RAID0_ALT_MULTIZONE_LAYOUT: 566 tmp_dev = map_sector(mddev, zone, sector, §or); 567 break; 568 default: 569 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev)); 570 bio_io_error(bio); 571 return true; 572 } 573 574 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) { 575 bio_io_error(bio); 576 return true; 577 } 578 579 bio_set_dev(bio, tmp_dev->bdev); 580 bio->bi_iter.bi_sector = sector + zone->dev_start + 581 tmp_dev->data_offset; 582 583 if (mddev->gendisk) 584 trace_block_bio_remap(bio, disk_devt(mddev->gendisk), 585 bio_sector); 586 mddev_check_writesame(mddev, bio); 587 mddev_check_write_zeroes(mddev, bio); 588 submit_bio_noacct(bio); 589 return true; 590 } 591 592 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 593 { 594 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 595 return; 596 } 597 598 static void *raid0_takeover_raid45(struct mddev *mddev) 599 { 600 struct md_rdev *rdev; 601 struct r0conf *priv_conf; 602 603 if (mddev->degraded != 1) { 604 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 605 mdname(mddev), 606 mddev->degraded); 607 return ERR_PTR(-EINVAL); 608 } 609 610 rdev_for_each(rdev, mddev) { 611 /* check slot number for a disk */ 612 if (rdev->raid_disk == mddev->raid_disks-1) { 613 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n", 614 mdname(mddev)); 615 return ERR_PTR(-EINVAL); 616 } 617 rdev->sectors = mddev->dev_sectors; 618 } 619 620 /* Set new parameters */ 621 mddev->new_level = 0; 622 mddev->new_layout = 0; 623 mddev->new_chunk_sectors = mddev->chunk_sectors; 624 mddev->raid_disks--; 625 mddev->delta_disks = -1; 626 /* make sure it will be not marked as dirty */ 627 mddev->recovery_cp = MaxSector; 628 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 629 630 create_strip_zones(mddev, &priv_conf); 631 632 return priv_conf; 633 } 634 635 static void *raid0_takeover_raid10(struct mddev *mddev) 636 { 637 struct r0conf *priv_conf; 638 639 /* Check layout: 640 * - far_copies must be 1 641 * - near_copies must be 2 642 * - disks number must be even 643 * - all mirrors must be already degraded 644 */ 645 if (mddev->layout != ((1 << 8) + 2)) { 646 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", 647 mdname(mddev), 648 mddev->layout); 649 return ERR_PTR(-EINVAL); 650 } 651 if (mddev->raid_disks & 1) { 652 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", 653 mdname(mddev)); 654 return ERR_PTR(-EINVAL); 655 } 656 if (mddev->degraded != (mddev->raid_disks>>1)) { 657 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n", 658 mdname(mddev)); 659 return ERR_PTR(-EINVAL); 660 } 661 662 /* Set new parameters */ 663 mddev->new_level = 0; 664 mddev->new_layout = 0; 665 mddev->new_chunk_sectors = mddev->chunk_sectors; 666 mddev->delta_disks = - mddev->raid_disks / 2; 667 mddev->raid_disks += mddev->delta_disks; 668 mddev->degraded = 0; 669 /* make sure it will be not marked as dirty */ 670 mddev->recovery_cp = MaxSector; 671 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 672 673 create_strip_zones(mddev, &priv_conf); 674 return priv_conf; 675 } 676 677 static void *raid0_takeover_raid1(struct mddev *mddev) 678 { 679 struct r0conf *priv_conf; 680 int chunksect; 681 682 /* Check layout: 683 * - (N - 1) mirror drives must be already faulty 684 */ 685 if ((mddev->raid_disks - 1) != mddev->degraded) { 686 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 687 mdname(mddev)); 688 return ERR_PTR(-EINVAL); 689 } 690 691 /* 692 * a raid1 doesn't have the notion of chunk size, so 693 * figure out the largest suitable size we can use. 694 */ 695 chunksect = 64 * 2; /* 64K by default */ 696 697 /* The array must be an exact multiple of chunksize */ 698 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 699 chunksect >>= 1; 700 701 if ((chunksect << 9) < PAGE_SIZE) 702 /* array size does not allow a suitable chunk size */ 703 return ERR_PTR(-EINVAL); 704 705 /* Set new parameters */ 706 mddev->new_level = 0; 707 mddev->new_layout = 0; 708 mddev->new_chunk_sectors = chunksect; 709 mddev->chunk_sectors = chunksect; 710 mddev->delta_disks = 1 - mddev->raid_disks; 711 mddev->raid_disks = 1; 712 /* make sure it will be not marked as dirty */ 713 mddev->recovery_cp = MaxSector; 714 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 715 716 create_strip_zones(mddev, &priv_conf); 717 return priv_conf; 718 } 719 720 static void *raid0_takeover(struct mddev *mddev) 721 { 722 /* raid0 can take over: 723 * raid4 - if all data disks are active. 724 * raid5 - providing it is Raid4 layout and one disk is faulty 725 * raid10 - assuming we have all necessary active disks 726 * raid1 - with (N -1) mirror drives faulty 727 */ 728 729 if (mddev->bitmap) { 730 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n", 731 mdname(mddev)); 732 return ERR_PTR(-EBUSY); 733 } 734 if (mddev->level == 4) 735 return raid0_takeover_raid45(mddev); 736 737 if (mddev->level == 5) { 738 if (mddev->layout == ALGORITHM_PARITY_N) 739 return raid0_takeover_raid45(mddev); 740 741 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 742 mdname(mddev), ALGORITHM_PARITY_N); 743 } 744 745 if (mddev->level == 10) 746 return raid0_takeover_raid10(mddev); 747 748 if (mddev->level == 1) 749 return raid0_takeover_raid1(mddev); 750 751 pr_warn("Takeover from raid%i to raid0 not supported\n", 752 mddev->level); 753 754 return ERR_PTR(-EINVAL); 755 } 756 757 static void raid0_quiesce(struct mddev *mddev, int quiesce) 758 { 759 } 760 761 static struct md_personality raid0_personality= 762 { 763 .name = "raid0", 764 .level = 0, 765 .owner = THIS_MODULE, 766 .make_request = raid0_make_request, 767 .run = raid0_run, 768 .free = raid0_free, 769 .status = raid0_status, 770 .size = raid0_size, 771 .takeover = raid0_takeover, 772 .quiesce = raid0_quiesce, 773 }; 774 775 static int __init raid0_init (void) 776 { 777 return register_md_personality (&raid0_personality); 778 } 779 780 static void raid0_exit (void) 781 { 782 unregister_md_personality (&raid0_personality); 783 } 784 785 module_init(raid0_init); 786 module_exit(raid0_exit); 787 MODULE_LICENSE("GPL"); 788 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 789 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 790 MODULE_ALIAS("md-raid0"); 791 MODULE_ALIAS("md-level-0"); 792