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 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 += scnprintf(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 65static 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 /* 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 %s ... nope\n", 229 mdname(mddev), 230 bdevname(rdev->bdev, b)); 231 continue; 232 } 233 pr_debug("md/raid0:%s: checking %s ..." 234 " contained as device %d\n", 235 mdname(mddev), 236 bdevname(rdev->bdev, b), 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 374static int raid0_run(struct mddev *mddev) 375{ 376 struct r0conf *conf; 377 int ret; 378 379 if (mddev->chunk_sectors == 0) { 380 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 381 return -EINVAL; 382 } 383 if (md_check_no_bitmap(mddev)) 384 return -EINVAL; 385 386 /* if private is not null, we are here after takeover */ 387 if (mddev->private == NULL) { 388 ret = create_strip_zones(mddev, &conf); 389 if (ret < 0) 390 return ret; 391 mddev->private = conf; 392 } 393 conf = mddev->private; 394 if (mddev->queue) { 395 struct md_rdev *rdev; 396 bool discard_supported = false; 397 398 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 399 blk_queue_max_write_same_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 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 411 discard_supported = true; 412 } 413 if (!discard_supported) 414 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue); 415 else 416 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue); 417 } 418 419 /* calculate array device size */ 420 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 421 422 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 423 mdname(mddev), 424 (unsigned long long)mddev->array_sectors); 425 426 dump_zones(mddev); 427 428 ret = md_integrity_register(mddev); 429 430 return ret; 431} 432 433static void raid0_free(struct mddev *mddev, void *priv) 434{ 435 struct r0conf *conf = priv; 436 437 kfree(conf->strip_zone); 438 kfree(conf->devlist); 439 kfree(conf); 440} 441 442/* 443 * Convert disk_index to the disk order in which it is read/written. 444 * For example, if we have 4 disks, they are numbered 0,1,2,3. If we 445 * write the disks starting at disk 3, then the read/write order would 446 * be disk 3, then 0, then 1, and then disk 2 and we want map_disk_shift() 447 * to map the disks as follows 0,1,2,3 => 1,2,3,0. So disk 0 would map 448 * to 1, 1 to 2, 2 to 3, and 3 to 0. That way we can compare disks in 449 * that 'output' space to understand the read/write disk ordering. 450 */ 451static int map_disk_shift(int disk_index, int num_disks, int disk_shift) 452{ 453 return ((disk_index + num_disks - disk_shift) % num_disks); 454} 455 456static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) 457{ 458 struct r0conf *conf = mddev->private; 459 struct strip_zone *zone; 460 sector_t start = bio->bi_iter.bi_sector; 461 sector_t end; 462 unsigned int stripe_size; 463 sector_t first_stripe_index, last_stripe_index; 464 sector_t start_disk_offset; 465 unsigned int start_disk_index; 466 sector_t end_disk_offset; 467 unsigned int end_disk_index; 468 unsigned int disk; 469 sector_t orig_start, orig_end; 470 471 orig_start = start; 472 zone = find_zone(conf, &start); 473 474 if (bio_end_sector(bio) > zone->zone_end) { 475 struct bio *split = bio_split(bio, 476 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, 477 &mddev->bio_set); 478 bio_chain(split, bio); 479 submit_bio_noacct(bio); 480 bio = split; 481 end = zone->zone_end; 482 } else 483 end = bio_end_sector(bio); 484 485 orig_end = end; 486 if (zone != conf->strip_zone) 487 end = end - zone[-1].zone_end; 488 489 /* Now start and end is the offset in zone */ 490 stripe_size = zone->nb_dev * mddev->chunk_sectors; 491 492 first_stripe_index = start; 493 sector_div(first_stripe_index, stripe_size); 494 last_stripe_index = end; 495 sector_div(last_stripe_index, stripe_size); 496 497 /* In the first zone the original and alternate layouts are the same */ 498 if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) { 499 sector_div(orig_start, mddev->chunk_sectors); 500 start_disk_index = sector_div(orig_start, zone->nb_dev); 501 start_disk_index = map_disk_shift(start_disk_index, 502 zone->nb_dev, 503 zone->disk_shift); 504 sector_div(orig_end, mddev->chunk_sectors); 505 end_disk_index = sector_div(orig_end, zone->nb_dev); 506 end_disk_index = map_disk_shift(end_disk_index, 507 zone->nb_dev, zone->disk_shift); 508 } else { 509 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 510 mddev->chunk_sectors; 511 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 512 mddev->chunk_sectors; 513 } 514 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 515 mddev->chunk_sectors) + 516 first_stripe_index * mddev->chunk_sectors; 517 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 518 mddev->chunk_sectors) + 519 last_stripe_index * mddev->chunk_sectors; 520 521 for (disk = 0; disk < zone->nb_dev; disk++) { 522 sector_t dev_start, dev_end; 523 struct bio *discard_bio = NULL; 524 struct md_rdev *rdev; 525 int compare_disk; 526 527 compare_disk = map_disk_shift(disk, zone->nb_dev, 528 zone->disk_shift); 529 530 if (compare_disk < start_disk_index) 531 dev_start = (first_stripe_index + 1) * 532 mddev->chunk_sectors; 533 else if (compare_disk > start_disk_index) 534 dev_start = first_stripe_index * mddev->chunk_sectors; 535 else 536 dev_start = start_disk_offset; 537 538 if (compare_disk < end_disk_index) 539 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; 540 else if (compare_disk > end_disk_index) 541 dev_end = last_stripe_index * mddev->chunk_sectors; 542 else 543 dev_end = end_disk_offset; 544 545 if (dev_end <= dev_start) 546 continue; 547 548 rdev = conf->devlist[(zone - conf->strip_zone) * 549 conf->strip_zone[0].nb_dev + disk]; 550 if (__blkdev_issue_discard(rdev->bdev, 551 dev_start + zone->dev_start + rdev->data_offset, 552 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) || 553 !discard_bio) 554 continue; 555 bio_chain(discard_bio, bio); 556 bio_clone_blkg_association(discard_bio, bio); 557 if (mddev->gendisk) 558 trace_block_bio_remap(bdev_get_queue(rdev->bdev), 559 discard_bio, disk_devt(mddev->gendisk), 560 bio->bi_iter.bi_sector); 561 submit_bio_noacct(discard_bio); 562 } 563 bio_endio(bio); 564} 565 566static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 567{ 568 struct r0conf *conf = mddev->private; 569 struct strip_zone *zone; 570 struct md_rdev *tmp_dev; 571 sector_t bio_sector; 572 sector_t sector; 573 sector_t orig_sector; 574 unsigned chunk_sects; 575 unsigned sectors; 576 577 if (unlikely(bio->bi_opf & REQ_PREFLUSH) 578 && md_flush_request(mddev, bio)) 579 return true; 580 581 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 582 raid0_handle_discard(mddev, bio); 583 return true; 584 } 585 586 bio_sector = bio->bi_iter.bi_sector; 587 sector = bio_sector; 588 chunk_sects = mddev->chunk_sectors; 589 590 sectors = chunk_sects - 591 (likely(is_power_of_2(chunk_sects)) 592 ? (sector & (chunk_sects-1)) 593 : sector_div(sector, chunk_sects)); 594 595 /* Restore due to sector_div */ 596 sector = bio_sector; 597 598 if (sectors < bio_sectors(bio)) { 599 struct bio *split = bio_split(bio, sectors, GFP_NOIO, 600 &mddev->bio_set); 601 bio_chain(split, bio); 602 submit_bio_noacct(bio); 603 bio = split; 604 } 605 606 orig_sector = sector; 607 zone = find_zone(mddev->private, §or); 608 switch (conf->layout) { 609 case RAID0_ORIG_LAYOUT: 610 tmp_dev = map_sector(mddev, zone, orig_sector, §or); 611 break; 612 case RAID0_ALT_MULTIZONE_LAYOUT: 613 tmp_dev = map_sector(mddev, zone, sector, §or); 614 break; 615 default: 616 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev)); 617 bio_io_error(bio); 618 return true; 619 } 620 621 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) { 622 bio_io_error(bio); 623 return true; 624 } 625 626 bio_set_dev(bio, tmp_dev->bdev); 627 bio->bi_iter.bi_sector = sector + zone->dev_start + 628 tmp_dev->data_offset; 629 630 if (mddev->gendisk) 631 trace_block_bio_remap(bio->bi_disk->queue, bio, 632 disk_devt(mddev->gendisk), bio_sector); 633 mddev_check_writesame(mddev, bio); 634 mddev_check_write_zeroes(mddev, bio); 635 submit_bio_noacct(bio); 636 return true; 637} 638 639static void raid0_status(struct seq_file *seq, struct mddev *mddev) 640{ 641 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 642 return; 643} 644 645static void *raid0_takeover_raid45(struct mddev *mddev) 646{ 647 struct md_rdev *rdev; 648 struct r0conf *priv_conf; 649 650 if (mddev->degraded != 1) { 651 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 652 mdname(mddev), 653 mddev->degraded); 654 return ERR_PTR(-EINVAL); 655 } 656 657 rdev_for_each(rdev, mddev) { 658 /* check slot number for a disk */ 659 if (rdev->raid_disk == mddev->raid_disks-1) { 660 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n", 661 mdname(mddev)); 662 return ERR_PTR(-EINVAL); 663 } 664 rdev->sectors = mddev->dev_sectors; 665 } 666 667 /* Set new parameters */ 668 mddev->new_level = 0; 669 mddev->new_layout = 0; 670 mddev->new_chunk_sectors = mddev->chunk_sectors; 671 mddev->raid_disks--; 672 mddev->delta_disks = -1; 673 /* make sure it will be not marked as dirty */ 674 mddev->recovery_cp = MaxSector; 675 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 676 677 create_strip_zones(mddev, &priv_conf); 678 679 return priv_conf; 680} 681 682static void *raid0_takeover_raid10(struct mddev *mddev) 683{ 684 struct r0conf *priv_conf; 685 686 /* Check layout: 687 * - far_copies must be 1 688 * - near_copies must be 2 689 * - disks number must be even 690 * - all mirrors must be already degraded 691 */ 692 if (mddev->layout != ((1 << 8) + 2)) { 693 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", 694 mdname(mddev), 695 mddev->layout); 696 return ERR_PTR(-EINVAL); 697 } 698 if (mddev->raid_disks & 1) { 699 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", 700 mdname(mddev)); 701 return ERR_PTR(-EINVAL); 702 } 703 if (mddev->degraded != (mddev->raid_disks>>1)) { 704 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n", 705 mdname(mddev)); 706 return ERR_PTR(-EINVAL); 707 } 708 709 /* Set new parameters */ 710 mddev->new_level = 0; 711 mddev->new_layout = 0; 712 mddev->new_chunk_sectors = mddev->chunk_sectors; 713 mddev->delta_disks = - mddev->raid_disks / 2; 714 mddev->raid_disks += mddev->delta_disks; 715 mddev->degraded = 0; 716 /* make sure it will be not marked as dirty */ 717 mddev->recovery_cp = MaxSector; 718 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 719 720 create_strip_zones(mddev, &priv_conf); 721 return priv_conf; 722} 723 724static void *raid0_takeover_raid1(struct mddev *mddev) 725{ 726 struct r0conf *priv_conf; 727 int chunksect; 728 729 /* Check layout: 730 * - (N - 1) mirror drives must be already faulty 731 */ 732 if ((mddev->raid_disks - 1) != mddev->degraded) { 733 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 734 mdname(mddev)); 735 return ERR_PTR(-EINVAL); 736 } 737 738 /* 739 * a raid1 doesn't have the notion of chunk size, so 740 * figure out the largest suitable size we can use. 741 */ 742 chunksect = 64 * 2; /* 64K by default */ 743 744 /* The array must be an exact multiple of chunksize */ 745 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 746 chunksect >>= 1; 747 748 if ((chunksect << 9) < PAGE_SIZE) 749 /* array size does not allow a suitable chunk size */ 750 return ERR_PTR(-EINVAL); 751 752 /* Set new parameters */ 753 mddev->new_level = 0; 754 mddev->new_layout = 0; 755 mddev->new_chunk_sectors = chunksect; 756 mddev->chunk_sectors = chunksect; 757 mddev->delta_disks = 1 - mddev->raid_disks; 758 mddev->raid_disks = 1; 759 /* make sure it will be not marked as dirty */ 760 mddev->recovery_cp = MaxSector; 761 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 762 763 create_strip_zones(mddev, &priv_conf); 764 return priv_conf; 765} 766 767static void *raid0_takeover(struct mddev *mddev) 768{ 769 /* raid0 can take over: 770 * raid4 - if all data disks are active. 771 * raid5 - providing it is Raid4 layout and one disk is faulty 772 * raid10 - assuming we have all necessary active disks 773 * raid1 - with (N -1) mirror drives faulty 774 */ 775 776 if (mddev->bitmap) { 777 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n", 778 mdname(mddev)); 779 return ERR_PTR(-EBUSY); 780 } 781 if (mddev->level == 4) 782 return raid0_takeover_raid45(mddev); 783 784 if (mddev->level == 5) { 785 if (mddev->layout == ALGORITHM_PARITY_N) 786 return raid0_takeover_raid45(mddev); 787 788 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 789 mdname(mddev), ALGORITHM_PARITY_N); 790 } 791 792 if (mddev->level == 10) 793 return raid0_takeover_raid10(mddev); 794 795 if (mddev->level == 1) 796 return raid0_takeover_raid1(mddev); 797 798 pr_warn("Takeover from raid%i to raid0 not supported\n", 799 mddev->level); 800 801 return ERR_PTR(-EINVAL); 802} 803 804static void raid0_quiesce(struct mddev *mddev, int quiesce) 805{ 806} 807 808static struct md_personality raid0_personality= 809{ 810 .name = "raid0", 811 .level = 0, 812 .owner = THIS_MODULE, 813 .make_request = raid0_make_request, 814 .run = raid0_run, 815 .free = raid0_free, 816 .status = raid0_status, 817 .size = raid0_size, 818 .takeover = raid0_takeover, 819 .quiesce = raid0_quiesce, 820}; 821 822static int __init raid0_init (void) 823{ 824 return register_md_personality (&raid0_personality); 825} 826 827static void raid0_exit (void) 828{ 829 unregister_md_personality (&raid0_personality); 830} 831 832module_init(raid0_init); 833module_exit(raid0_exit); 834MODULE_LICENSE("GPL"); 835MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 836MODULE_ALIAS("md-personality-2"); /* RAID0 */ 837MODULE_ALIAS("md-raid0"); 838MODULE_ALIAS("md-level-0"); 839