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raid0.c
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linux-6.19.14/drivers/md/raid0.c
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 22static int default_layout = 0; 23module_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*/ 35static 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 63static 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 int blksize = 512; 72 73 if (!mddev_is_dm(mddev)) 74 blksize = queue_logical_block_size(mddev->gendisk->queue); 75 76 *private_conf = ERR_PTR(-ENOMEM); 77 if (!conf) 78 return -ENOMEM; 79 rdev_for_each(rdev1, mddev) { 80 pr_debug("md/raid0:%s: looking at %pg\n", 81 mdname(mddev), 82 rdev1->bdev); 83 c = 0; 84 85 /* round size to chunk_size */ 86 sectors = rdev1->sectors; 87 sector_div(sectors, mddev->chunk_sectors); 88 rdev1->sectors = sectors * mddev->chunk_sectors; 89 90 if (mddev_is_dm(mddev)) 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 %pg(%llu)" 96 " with %pg(%llu)\n", 97 mdname(mddev), 98 rdev1->bdev, 99 (unsigned long long)rdev1->sectors, 100 rdev2->bdev, 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 /* 132 * now since we have the hard sector sizes, we can make sure 133 * chunk size is a multiple of that sector size 134 */ 135 if ((mddev->chunk_sectors << 9) % blksize) { 136 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", 137 mdname(mddev), 138 mddev->chunk_sectors << 9, blksize); 139 err = -EINVAL; 140 goto abort; 141 } 142 143 err = -ENOMEM; 144 conf->strip_zone = kcalloc(conf->nr_strip_zones, 145 sizeof(struct strip_zone), 146 GFP_KERNEL); 147 if (!conf->strip_zone) 148 goto abort; 149 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *), 150 conf->nr_strip_zones, 151 mddev->raid_disks), 152 GFP_KERNEL); 153 if (!conf->devlist) 154 goto abort; 155 156 /* The first zone must contain all devices, so here we check that 157 * there is a proper alignment of slots to devices and find them all 158 */ 159 zone = &conf->strip_zone[0]; 160 cnt = 0; 161 smallest = NULL; 162 dev = conf->devlist; 163 err = -EINVAL; 164 rdev_for_each(rdev1, mddev) { 165 int j = rdev1->raid_disk; 166 167 if (mddev->level == 10) { 168 /* taking over a raid10-n2 array */ 169 j /= 2; 170 rdev1->new_raid_disk = j; 171 } 172 173 if (mddev->level == 1) { 174 /* taiking over a raid1 array- 175 * we have only one active disk 176 */ 177 j = 0; 178 rdev1->new_raid_disk = j; 179 } 180 181 if (j < 0) { 182 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", 183 mdname(mddev)); 184 goto abort; 185 } 186 if (j >= mddev->raid_disks) { 187 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", 188 mdname(mddev), j); 189 goto abort; 190 } 191 if (dev[j]) { 192 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", 193 mdname(mddev), j); 194 goto abort; 195 } 196 dev[j] = rdev1; 197 198 if (!smallest || (rdev1->sectors < smallest->sectors)) 199 smallest = rdev1; 200 cnt++; 201 } 202 if (cnt != mddev->raid_disks) { 203 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", 204 mdname(mddev), cnt, mddev->raid_disks); 205 goto abort; 206 } 207 zone->nb_dev = cnt; 208 zone->zone_end = smallest->sectors * cnt; 209 210 curr_zone_end = zone->zone_end; 211 212 /* now do the other zones */ 213 for (i = 1; i < conf->nr_strip_zones; i++) 214 { 215 int j; 216 217 zone = conf->strip_zone + i; 218 dev = conf->devlist + i * mddev->raid_disks; 219 220 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 221 zone->dev_start = smallest->sectors; 222 smallest = NULL; 223 c = 0; 224 225 for (j=0; j<cnt; j++) { 226 rdev = conf->devlist[j]; 227 if (rdev->sectors <= zone->dev_start) { 228 pr_debug("md/raid0:%s: checking %pg ... nope\n", 229 mdname(mddev), 230 rdev->bdev); 231 continue; 232 } 233 pr_debug("md/raid0:%s: checking %pg ..." 234 " contained as device %d\n", 235 mdname(mddev), 236 rdev->bdev, c); 237 dev[c] = rdev; 238 c++; 239 if (!smallest || rdev->sectors < smallest->sectors) { 240 smallest = rdev; 241 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 242 mdname(mddev), 243 (unsigned long long)rdev->sectors); 244 } 245 } 246 247 zone->nb_dev = c; 248 sectors = (smallest->sectors - zone->dev_start) * c; 249 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 250 mdname(mddev), 251 zone->nb_dev, (unsigned long long)sectors); 252 253 curr_zone_end += sectors; 254 zone->zone_end = curr_zone_end; 255 256 pr_debug("md/raid0:%s: current zone start: %llu\n", 257 mdname(mddev), 258 (unsigned long long)smallest->sectors); 259 } 260 261 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) { 262 conf->layout = RAID0_ORIG_LAYOUT; 263 } else if (mddev->layout == RAID0_ORIG_LAYOUT || 264 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) { 265 conf->layout = mddev->layout; 266 } else if (default_layout == RAID0_ORIG_LAYOUT || 267 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) { 268 conf->layout = default_layout; 269 } else { 270 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", 271 mdname(mddev)); 272 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n"); 273 err = -EOPNOTSUPP; 274 goto abort; 275 } 276 277 if (conf->layout == RAID0_ORIG_LAYOUT) { 278 for (i = 1; i < conf->nr_strip_zones; i++) { 279 sector_t first_sector = conf->strip_zone[i-1].zone_end; 280 281 sector_div(first_sector, mddev->chunk_sectors); 282 zone = conf->strip_zone + i; 283 /* disk_shift is first disk index used in the zone */ 284 zone->disk_shift = sector_div(first_sector, 285 zone->nb_dev); 286 } 287 } 288 289 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 290 *private_conf = conf; 291 292 return 0; 293abort: 294 kfree(conf->strip_zone); 295 kfree(conf->devlist); 296 kfree(conf); 297 *private_conf = ERR_PTR(err); 298 return err; 299} 300 301/* Find the zone which holds a particular offset 302 * Update *sectorp to be an offset in that zone 303 */ 304static struct strip_zone *find_zone(struct r0conf *conf, 305 sector_t *sectorp) 306{ 307 int i; 308 struct strip_zone *z = conf->strip_zone; 309 sector_t sector = *sectorp; 310 311 for (i = 0; i < conf->nr_strip_zones; i++) 312 if (sector < z[i].zone_end) { 313 if (i) 314 *sectorp = sector - z[i-1].zone_end; 315 return z + i; 316 } 317 BUG(); 318} 319 320/* 321 * remaps the bio to the target device. we separate two flows. 322 * power 2 flow and a general flow for the sake of performance 323*/ 324static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 325 sector_t sector, sector_t *sector_offset) 326{ 327 unsigned int sect_in_chunk; 328 sector_t chunk; 329 struct r0conf *conf = mddev->private; 330 int raid_disks = conf->strip_zone[0].nb_dev; 331 unsigned int chunk_sects = mddev->chunk_sectors; 332 333 if (is_power_of_2(chunk_sects)) { 334 int chunksect_bits = ffz(~chunk_sects); 335 /* find the sector offset inside the chunk */ 336 sect_in_chunk = sector & (chunk_sects - 1); 337 sector >>= chunksect_bits; 338 /* chunk in zone */ 339 chunk = *sector_offset; 340 /* quotient is the chunk in real device*/ 341 sector_div(chunk, zone->nb_dev << chunksect_bits); 342 } else{ 343 sect_in_chunk = sector_div(sector, chunk_sects); 344 chunk = *sector_offset; 345 sector_div(chunk, chunk_sects * zone->nb_dev); 346 } 347 /* 348 * position the bio over the real device 349 * real sector = chunk in device + starting of zone 350 * + the position in the chunk 351 */ 352 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 353 return conf->devlist[(zone - conf->strip_zone)*raid_disks 354 + sector_div(sector, zone->nb_dev)]; 355} 356 357static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 358{ 359 sector_t array_sectors = 0; 360 struct md_rdev *rdev; 361 362 WARN_ONCE(sectors || raid_disks, 363 "%s does not support generic reshape\n", __func__); 364 365 rdev_for_each(rdev, mddev) 366 array_sectors += (rdev->sectors & 367 ~(sector_t)(mddev->chunk_sectors-1)); 368 369 return array_sectors; 370} 371 372static void raid0_free(struct mddev *mddev, void *priv) 373{ 374 struct r0conf *conf = priv; 375 376 kfree(conf->strip_zone); 377 kfree(conf->devlist); 378 kfree(conf); 379} 380 381static int raid0_set_limits(struct mddev *mddev) 382{ 383 struct queue_limits lim; 384 int err; 385 386 md_init_stacking_limits(&lim); 387 lim.max_hw_sectors = mddev->chunk_sectors; 388 lim.max_write_zeroes_sectors = mddev->chunk_sectors; 389 lim.max_hw_wzeroes_unmap_sectors = mddev->chunk_sectors; 390 lim.logical_block_size = mddev->logical_block_size; 391 lim.io_min = mddev->chunk_sectors << 9; 392 lim.io_opt = lim.io_min * mddev->raid_disks; 393 lim.chunk_sectors = mddev->chunk_sectors; 394 lim.features |= BLK_FEAT_ATOMIC_WRITES; 395 err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY); 396 if (err) 397 return err; 398 return queue_limits_set(mddev->gendisk->queue, &lim); 399} 400 401static int raid0_run(struct mddev *mddev) 402{ 403 struct r0conf *conf; 404 int ret; 405 406 if (mddev->chunk_sectors == 0) { 407 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 408 return -EINVAL; 409 } 410 if (md_check_no_bitmap(mddev)) 411 return -EINVAL; 412 413 if (!mddev_is_dm(mddev)) { 414 ret = raid0_set_limits(mddev); 415 if (ret) 416 return ret; 417 } 418 419 /* if private is not null, we are here after takeover */ 420 if (mddev->private == NULL) { 421 ret = create_strip_zones(mddev, &conf); 422 if (ret < 0) 423 return ret; 424 mddev->private = conf; 425 } 426 conf = mddev->private; 427 428 /* calculate array device size */ 429 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 430 431 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 432 mdname(mddev), 433 (unsigned long long)mddev->array_sectors); 434 435 dump_zones(mddev); 436 437 return md_integrity_register(mddev); 438} 439 440/* 441 * Convert disk_index to the disk order in which it is read/written. 442 * For example, if we have 4 disks, they are numbered 0,1,2,3. If we 443 * write the disks starting at disk 3, then the read/write order would 444 * be disk 3, then 0, then 1, and then disk 2 and we want map_disk_shift() 445 * to map the disks as follows 0,1,2,3 => 1,2,3,0. So disk 0 would map 446 * to 1, 1 to 2, 2 to 3, and 3 to 0. That way we can compare disks in 447 * that 'output' space to understand the read/write disk ordering. 448 */ 449static int map_disk_shift(int disk_index, int num_disks, int disk_shift) 450{ 451 return ((disk_index + num_disks - disk_shift) % num_disks); 452} 453 454static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) 455{ 456 struct r0conf *conf = mddev->private; 457 struct strip_zone *zone; 458 sector_t start = bio->bi_iter.bi_sector; 459 sector_t end; 460 unsigned int stripe_size; 461 sector_t first_stripe_index, last_stripe_index; 462 sector_t start_disk_offset; 463 unsigned int start_disk_index; 464 sector_t end_disk_offset; 465 unsigned int end_disk_index; 466 unsigned int disk; 467 sector_t orig_start, orig_end; 468 469 orig_start = start; 470 zone = find_zone(conf, &start); 471 472 if (bio_end_sector(bio) > zone->zone_end) { 473 bio = bio_submit_split_bioset(bio, 474 zone->zone_end - bio->bi_iter.bi_sector, 475 &mddev->bio_set); 476 if (!bio) 477 return; 478 479 end = zone->zone_end; 480 } else { 481 end = bio_end_sector(bio); 482 } 483 484 orig_end = end; 485 if (zone != conf->strip_zone) 486 end = end - zone[-1].zone_end; 487 488 /* Now start and end is the offset in zone */ 489 stripe_size = zone->nb_dev * mddev->chunk_sectors; 490 491 first_stripe_index = start; 492 sector_div(first_stripe_index, stripe_size); 493 last_stripe_index = end; 494 sector_div(last_stripe_index, stripe_size); 495 496 /* In the first zone the original and alternate layouts are the same */ 497 if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) { 498 sector_div(orig_start, mddev->chunk_sectors); 499 start_disk_index = sector_div(orig_start, zone->nb_dev); 500 start_disk_index = map_disk_shift(start_disk_index, 501 zone->nb_dev, 502 zone->disk_shift); 503 sector_div(orig_end, mddev->chunk_sectors); 504 end_disk_index = sector_div(orig_end, zone->nb_dev); 505 end_disk_index = map_disk_shift(end_disk_index, 506 zone->nb_dev, zone->disk_shift); 507 } else { 508 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 509 mddev->chunk_sectors; 510 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 511 mddev->chunk_sectors; 512 } 513 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 514 mddev->chunk_sectors) + 515 first_stripe_index * mddev->chunk_sectors; 516 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 517 mddev->chunk_sectors) + 518 last_stripe_index * mddev->chunk_sectors; 519 520 for (disk = 0; disk < zone->nb_dev; disk++) { 521 sector_t dev_start, dev_end; 522 struct md_rdev *rdev; 523 int compare_disk; 524 525 compare_disk = map_disk_shift(disk, zone->nb_dev, 526 zone->disk_shift); 527 528 if (compare_disk < start_disk_index) 529 dev_start = (first_stripe_index + 1) * 530 mddev->chunk_sectors; 531 else if (compare_disk > start_disk_index) 532 dev_start = first_stripe_index * mddev->chunk_sectors; 533 else 534 dev_start = start_disk_offset; 535 536 if (compare_disk < end_disk_index) 537 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; 538 else if (compare_disk > end_disk_index) 539 dev_end = last_stripe_index * mddev->chunk_sectors; 540 else 541 dev_end = end_disk_offset; 542 543 if (dev_end <= dev_start) 544 continue; 545 546 rdev = conf->devlist[(zone - conf->strip_zone) * 547 conf->strip_zone[0].nb_dev + disk]; 548 md_submit_discard_bio(mddev, rdev, bio, 549 dev_start + zone->dev_start + rdev->data_offset, 550 dev_end - dev_start); 551 } 552 bio_endio(bio); 553} 554 555static void raid0_map_submit_bio(struct mddev *mddev, struct bio *bio) 556{ 557 struct r0conf *conf = mddev->private; 558 struct strip_zone *zone; 559 struct md_rdev *tmp_dev; 560 sector_t bio_sector = bio->bi_iter.bi_sector; 561 sector_t sector = bio_sector; 562 563 md_account_bio(mddev, &bio); 564 565 zone = find_zone(mddev->private, §or); 566 switch (conf->layout) { 567 case RAID0_ORIG_LAYOUT: 568 tmp_dev = map_sector(mddev, zone, bio_sector, §or); 569 break; 570 case RAID0_ALT_MULTIZONE_LAYOUT: 571 tmp_dev = map_sector(mddev, zone, sector, §or); 572 break; 573 default: 574 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev)); 575 bio_io_error(bio); 576 return; 577 } 578 579 if (unlikely(is_rdev_broken(tmp_dev))) { 580 bio_io_error(bio); 581 md_error(mddev, tmp_dev); 582 return; 583 } 584 585 bio_set_dev(bio, tmp_dev->bdev); 586 bio->bi_iter.bi_sector = sector + zone->dev_start + 587 tmp_dev->data_offset; 588 mddev_trace_remap(mddev, bio, bio_sector); 589 mddev_check_write_zeroes(mddev, bio); 590 submit_bio_noacct(bio); 591} 592 593static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 594{ 595 sector_t sector; 596 unsigned chunk_sects; 597 unsigned sectors; 598 599 if (unlikely(bio->bi_opf & REQ_PREFLUSH) 600 && md_flush_request(mddev, bio)) 601 return true; 602 603 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 604 raid0_handle_discard(mddev, bio); 605 return true; 606 } 607 608 sector = bio->bi_iter.bi_sector; 609 chunk_sects = mddev->chunk_sectors; 610 611 sectors = chunk_sects - 612 (likely(is_power_of_2(chunk_sects)) 613 ? (sector & (chunk_sects-1)) 614 : sector_div(sector, chunk_sects)); 615 616 if (sectors < bio_sectors(bio)) { 617 bio = bio_submit_split_bioset(bio, sectors, 618 &mddev->bio_set); 619 if (!bio) 620 return true; 621 } 622 623 raid0_map_submit_bio(mddev, bio); 624 return true; 625} 626 627static void raid0_status(struct seq_file *seq, struct mddev *mddev) 628{ 629 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 630 return; 631} 632 633static void raid0_error(struct mddev *mddev, struct md_rdev *rdev) 634{ 635 if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) { 636 char *md_name = mdname(mddev); 637 638 pr_crit("md/raid0%s: Disk failure on %pg detected, failing array.\n", 639 md_name, rdev->bdev); 640 } 641} 642 643static void *raid0_takeover_raid45(struct mddev *mddev) 644{ 645 struct md_rdev *rdev; 646 struct r0conf *priv_conf; 647 648 if (mddev->degraded != 1) { 649 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 650 mdname(mddev), 651 mddev->degraded); 652 return ERR_PTR(-EINVAL); 653 } 654 655 rdev_for_each(rdev, mddev) { 656 /* check slot number for a disk */ 657 if (rdev->raid_disk == mddev->raid_disks-1) { 658 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n", 659 mdname(mddev)); 660 return ERR_PTR(-EINVAL); 661 } 662 rdev->sectors = mddev->dev_sectors; 663 } 664 665 /* Set new parameters */ 666 mddev->new_level = 0; 667 mddev->new_layout = 0; 668 mddev->new_chunk_sectors = mddev->chunk_sectors; 669 mddev->raid_disks--; 670 mddev->delta_disks = -1; 671 /* make sure it will be not marked as dirty */ 672 mddev->resync_offset = MaxSector; 673 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 674 675 create_strip_zones(mddev, &priv_conf); 676 677 return priv_conf; 678} 679 680static void *raid0_takeover_raid10(struct mddev *mddev) 681{ 682 struct r0conf *priv_conf; 683 684 /* Check layout: 685 * - far_copies must be 1 686 * - near_copies must be 2 687 * - disks number must be even 688 * - all mirrors must be already degraded 689 */ 690 if (mddev->layout != ((1 << 8) + 2)) { 691 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", 692 mdname(mddev), 693 mddev->layout); 694 return ERR_PTR(-EINVAL); 695 } 696 if (mddev->raid_disks & 1) { 697 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", 698 mdname(mddev)); 699 return ERR_PTR(-EINVAL); 700 } 701 if (mddev->degraded != (mddev->raid_disks>>1)) { 702 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n", 703 mdname(mddev)); 704 return ERR_PTR(-EINVAL); 705 } 706 707 /* Set new parameters */ 708 mddev->new_level = 0; 709 mddev->new_layout = 0; 710 mddev->new_chunk_sectors = mddev->chunk_sectors; 711 mddev->delta_disks = - mddev->raid_disks / 2; 712 mddev->raid_disks += mddev->delta_disks; 713 mddev->degraded = 0; 714 /* make sure it will be not marked as dirty */ 715 mddev->resync_offset = MaxSector; 716 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 717 718 create_strip_zones(mddev, &priv_conf); 719 return priv_conf; 720} 721 722static void *raid0_takeover_raid1(struct mddev *mddev) 723{ 724 struct r0conf *priv_conf; 725 int chunksect; 726 727 /* Check layout: 728 * - (N - 1) mirror drives must be already faulty 729 */ 730 if ((mddev->raid_disks - 1) != mddev->degraded) { 731 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 732 mdname(mddev)); 733 return ERR_PTR(-EINVAL); 734 } 735 736 /* 737 * a raid1 doesn't have the notion of chunk size, so 738 * figure out the largest suitable size we can use. 739 */ 740 chunksect = 64 * 2; /* 64K by default */ 741 742 /* The array must be an exact multiple of chunksize */ 743 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 744 chunksect >>= 1; 745 746 if ((chunksect << 9) < PAGE_SIZE) 747 /* array size does not allow a suitable chunk size */ 748 return ERR_PTR(-EINVAL); 749 750 /* Set new parameters */ 751 mddev->new_level = 0; 752 mddev->new_layout = 0; 753 mddev->new_chunk_sectors = chunksect; 754 mddev->chunk_sectors = chunksect; 755 mddev->delta_disks = 1 - mddev->raid_disks; 756 mddev->raid_disks = 1; 757 /* make sure it will be not marked as dirty */ 758 mddev->resync_offset = MaxSector; 759 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 760 761 create_strip_zones(mddev, &priv_conf); 762 return priv_conf; 763} 764 765static void *raid0_takeover(struct mddev *mddev) 766{ 767 /* raid0 can take over: 768 * raid4 - if all data disks are active. 769 * raid5 - providing it is Raid4 layout and one disk is faulty 770 * raid10 - assuming we have all necessary active disks 771 * raid1 - with (N -1) mirror drives faulty 772 */ 773 774 if (mddev->bitmap) { 775 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n", 776 mdname(mddev)); 777 return ERR_PTR(-EBUSY); 778 } 779 if (mddev->level == 4) 780 return raid0_takeover_raid45(mddev); 781 782 if (mddev->level == 5) { 783 if (mddev->layout == ALGORITHM_PARITY_N) 784 return raid0_takeover_raid45(mddev); 785 786 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 787 mdname(mddev), ALGORITHM_PARITY_N); 788 } 789 790 if (mddev->level == 10) 791 return raid0_takeover_raid10(mddev); 792 793 if (mddev->level == 1) 794 return raid0_takeover_raid1(mddev); 795 796 pr_warn("Takeover from raid%i to raid0 not supported\n", 797 mddev->level); 798 799 return ERR_PTR(-EINVAL); 800} 801 802static void raid0_quiesce(struct mddev *mddev, int quiesce) 803{ 804} 805 806static struct md_personality raid0_personality= 807{ 808 .head = { 809 .type = MD_PERSONALITY, 810 .id = ID_RAID0, 811 .name = "raid0", 812 .owner = THIS_MODULE, 813 }, 814 815 .make_request = raid0_make_request, 816 .run = raid0_run, 817 .free = raid0_free, 818 .status = raid0_status, 819 .size = raid0_size, 820 .takeover = raid0_takeover, 821 .quiesce = raid0_quiesce, 822 .error_handler = raid0_error, 823}; 824 825static int __init raid0_init(void) 826{ 827 return register_md_submodule(&raid0_personality.head); 828} 829 830static void __exit raid0_exit(void) 831{ 832 unregister_md_submodule(&raid0_personality.head); 833} 834 835module_init(raid0_init); 836module_exit(raid0_exit); 837MODULE_LICENSE("GPL"); 838MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 839MODULE_ALIAS("md-personality-2"); /* RAID0 */ 840MODULE_ALIAS("md-raid0"); 841MODULE_ALIAS("md-level-0");
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