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 <linux/string_choices.h> 18 #include <trace/events/block.h> 19 #include "md.h" 20 #include "raid0.h" 21 #include "raid5.h" 22 23 static int default_layout = 0; 24 module_param(default_layout, int, 0644); 25 26 #define UNSUPPORTED_MDDEV_FLAGS \ 27 ((1L << MD_HAS_JOURNAL) | \ 28 (1L << MD_JOURNAL_CLEAN) | \ 29 (1L << MD_FAILFAST_SUPPORTED) |\ 30 (1L << MD_HAS_PPL) | \ 31 (1L << MD_HAS_MULTIPLE_PPLS) | \ 32 (1L << MD_FAILLAST_DEV) | \ 33 (1L << MD_SERIALIZE_POLICY)) 34 35 /* 36 * inform the user of the raid configuration 37 */ 38 static void dump_zones(struct mddev *mddev) 39 { 40 int j, k; 41 sector_t zone_size = 0; 42 sector_t zone_start = 0; 43 struct r0conf *conf = mddev->private; 44 int raid_disks = conf->strip_zone[0].nb_dev; 45 pr_debug("md: RAID0 configuration for %s - %d zone%s\n", 46 mdname(mddev), 47 conf->nr_strip_zones, str_plural(conf->nr_strip_zones)); 48 for (j = 0; j < conf->nr_strip_zones; j++) { 49 char line[200]; 50 int len = 0; 51 52 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 53 len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"", 54 conf->devlist[j * raid_disks + k]->bdev); 55 pr_debug("md: zone%d=[%s]\n", j, line); 56 57 zone_size = conf->strip_zone[j].zone_end - zone_start; 58 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", 59 (unsigned long long)zone_start>>1, 60 (unsigned long long)conf->strip_zone[j].dev_start>>1, 61 (unsigned long long)zone_size>>1); 62 zone_start = conf->strip_zone[j].zone_end; 63 } 64 } 65 66 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 67 { 68 int i, c, err; 69 sector_t curr_zone_end, sectors; 70 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 71 struct strip_zone *zone; 72 int cnt; 73 struct r0conf *conf = kzalloc_obj(*conf); 74 unsigned int blksize = 512; 75 76 if (!mddev_is_dm(mddev)) 77 blksize = queue_logical_block_size(mddev->gendisk->queue); 78 79 *private_conf = ERR_PTR(-ENOMEM); 80 if (!conf) 81 return -ENOMEM; 82 rdev_for_each(rdev1, mddev) { 83 pr_debug("md/raid0:%s: looking at %pg\n", 84 mdname(mddev), 85 rdev1->bdev); 86 c = 0; 87 88 /* round size to chunk_size */ 89 sectors = rdev1->sectors; 90 sector_div(sectors, mddev->chunk_sectors); 91 rdev1->sectors = sectors * mddev->chunk_sectors; 92 93 if (mddev_is_dm(mddev)) 94 blksize = max(blksize, queue_logical_block_size( 95 rdev1->bdev->bd_disk->queue)); 96 97 rdev_for_each(rdev2, mddev) { 98 pr_debug("md/raid0:%s: comparing %pg(%llu)" 99 " with %pg(%llu)\n", 100 mdname(mddev), 101 rdev1->bdev, 102 (unsigned long long)rdev1->sectors, 103 rdev2->bdev, 104 (unsigned long long)rdev2->sectors); 105 if (rdev2 == rdev1) { 106 pr_debug("md/raid0:%s: END\n", 107 mdname(mddev)); 108 break; 109 } 110 if (rdev2->sectors == rdev1->sectors) { 111 /* 112 * Not unique, don't count it as a new 113 * group 114 */ 115 pr_debug("md/raid0:%s: EQUAL\n", 116 mdname(mddev)); 117 c = 1; 118 break; 119 } 120 pr_debug("md/raid0:%s: NOT EQUAL\n", 121 mdname(mddev)); 122 } 123 if (!c) { 124 pr_debug("md/raid0:%s: ==> UNIQUE\n", 125 mdname(mddev)); 126 conf->nr_strip_zones++; 127 pr_debug("md/raid0:%s: %d zones\n", 128 mdname(mddev), conf->nr_strip_zones); 129 } 130 } 131 pr_debug("md/raid0:%s: FINAL %d zones\n", 132 mdname(mddev), conf->nr_strip_zones); 133 134 /* 135 * now since we have the hard sector sizes, we can make sure 136 * chunk size is a multiple of that sector size 137 */ 138 if ((mddev->chunk_sectors << 9) % blksize) { 139 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", 140 mdname(mddev), 141 mddev->chunk_sectors << 9, blksize); 142 err = -EINVAL; 143 goto abort; 144 } 145 146 err = -ENOMEM; 147 conf->strip_zone = kvzalloc_objs(struct strip_zone, conf->nr_strip_zones); 148 if (!conf->strip_zone) 149 goto abort; 150 conf->devlist = kvzalloc(array3_size(sizeof(struct md_rdev *), 151 conf->nr_strip_zones, 152 mddev->raid_disks), 153 GFP_KERNEL); 154 if (!conf->devlist) 155 goto abort; 156 157 /* The first zone must contain all devices, so here we check that 158 * there is a proper alignment of slots to devices and find them all 159 */ 160 zone = &conf->strip_zone[0]; 161 cnt = 0; 162 smallest = NULL; 163 dev = conf->devlist; 164 err = -EINVAL; 165 rdev_for_each(rdev1, mddev) { 166 int j = rdev1->raid_disk; 167 168 if (mddev->level == 10) { 169 /* taking over a raid10-n2 array */ 170 j /= 2; 171 rdev1->new_raid_disk = j; 172 } 173 174 if (mddev->level == 1) { 175 /* taiking over a raid1 array- 176 * we have only one active disk 177 */ 178 j = 0; 179 rdev1->new_raid_disk = j; 180 } 181 182 if (j < 0) { 183 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", 184 mdname(mddev)); 185 goto abort; 186 } 187 if (j >= mddev->raid_disks) { 188 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", 189 mdname(mddev), j); 190 goto abort; 191 } 192 if (dev[j]) { 193 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", 194 mdname(mddev), j); 195 goto abort; 196 } 197 dev[j] = rdev1; 198 199 if (!smallest || (rdev1->sectors < smallest->sectors)) 200 smallest = rdev1; 201 cnt++; 202 } 203 if (cnt != mddev->raid_disks) { 204 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", 205 mdname(mddev), cnt, mddev->raid_disks); 206 goto abort; 207 } 208 zone->nb_dev = cnt; 209 zone->zone_end = smallest->sectors * cnt; 210 211 curr_zone_end = zone->zone_end; 212 213 /* now do the other zones */ 214 for (i = 1; i < conf->nr_strip_zones; i++) 215 { 216 int j; 217 218 zone = conf->strip_zone + i; 219 dev = conf->devlist + i * mddev->raid_disks; 220 221 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 222 zone->dev_start = smallest->sectors; 223 smallest = NULL; 224 c = 0; 225 226 for (j=0; j<cnt; j++) { 227 rdev = conf->devlist[j]; 228 if (rdev->sectors <= zone->dev_start) { 229 pr_debug("md/raid0:%s: checking %pg ... nope\n", 230 mdname(mddev), 231 rdev->bdev); 232 continue; 233 } 234 pr_debug("md/raid0:%s: checking %pg ..." 235 " contained as device %d\n", 236 mdname(mddev), 237 rdev->bdev, c); 238 dev[c] = rdev; 239 c++; 240 if (!smallest || rdev->sectors < smallest->sectors) { 241 smallest = rdev; 242 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 243 mdname(mddev), 244 (unsigned long long)rdev->sectors); 245 } 246 } 247 248 zone->nb_dev = c; 249 sectors = (smallest->sectors - zone->dev_start) * c; 250 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 251 mdname(mddev), 252 zone->nb_dev, (unsigned long long)sectors); 253 254 curr_zone_end += sectors; 255 zone->zone_end = curr_zone_end; 256 257 pr_debug("md/raid0:%s: current zone start: %llu\n", 258 mdname(mddev), 259 (unsigned long long)smallest->sectors); 260 } 261 262 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) { 263 conf->layout = RAID0_ORIG_LAYOUT; 264 } else if (mddev->layout == RAID0_ORIG_LAYOUT || 265 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) { 266 conf->layout = mddev->layout; 267 } else if (default_layout == RAID0_ORIG_LAYOUT || 268 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) { 269 conf->layout = default_layout; 270 } else { 271 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", 272 mdname(mddev)); 273 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n"); 274 err = -EOPNOTSUPP; 275 goto abort; 276 } 277 278 if (conf->layout == RAID0_ORIG_LAYOUT) { 279 for (i = 1; i < conf->nr_strip_zones; i++) { 280 sector_t first_sector = conf->strip_zone[i-1].zone_end; 281 282 sector_div(first_sector, mddev->chunk_sectors); 283 zone = conf->strip_zone + i; 284 /* disk_shift is first disk index used in the zone */ 285 zone->disk_shift = sector_div(first_sector, 286 zone->nb_dev); 287 } 288 } 289 290 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 291 *private_conf = conf; 292 293 return 0; 294 abort: 295 kvfree(conf->strip_zone); 296 kvfree(conf->devlist); 297 kfree(conf); 298 *private_conf = ERR_PTR(err); 299 return err; 300 } 301 302 /* Find the zone which holds a particular offset 303 * Update *sectorp to be an offset in that zone 304 */ 305 static struct strip_zone *find_zone(struct r0conf *conf, 306 sector_t *sectorp) 307 { 308 int i; 309 struct strip_zone *z = conf->strip_zone; 310 sector_t sector = *sectorp; 311 312 for (i = 0; i < conf->nr_strip_zones; i++) 313 if (sector < z[i].zone_end) { 314 if (i) 315 *sectorp = sector - z[i-1].zone_end; 316 return z + i; 317 } 318 BUG(); 319 } 320 321 /* 322 * remaps the bio to the target device. we separate two flows. 323 * power 2 flow and a general flow for the sake of performance 324 */ 325 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 326 sector_t sector, sector_t *sector_offset) 327 { 328 unsigned int sect_in_chunk; 329 sector_t chunk; 330 struct r0conf *conf = mddev->private; 331 int raid_disks = conf->strip_zone[0].nb_dev; 332 unsigned int chunk_sects = mddev->chunk_sectors; 333 334 if (is_power_of_2(chunk_sects)) { 335 int chunksect_bits = ffz(~chunk_sects); 336 /* find the sector offset inside the chunk */ 337 sect_in_chunk = sector & (chunk_sects - 1); 338 sector >>= chunksect_bits; 339 /* chunk in zone */ 340 chunk = *sector_offset; 341 /* quotient is the chunk in real device*/ 342 sector_div(chunk, zone->nb_dev << chunksect_bits); 343 } else{ 344 sect_in_chunk = sector_div(sector, chunk_sects); 345 chunk = *sector_offset; 346 sector_div(chunk, chunk_sects * zone->nb_dev); 347 } 348 /* 349 * position the bio over the real device 350 * real sector = chunk in device + starting of zone 351 * + the position in the chunk 352 */ 353 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 354 return conf->devlist[(zone - conf->strip_zone)*raid_disks 355 + sector_div(sector, zone->nb_dev)]; 356 } 357 358 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 359 { 360 sector_t array_sectors = 0; 361 struct md_rdev *rdev; 362 363 WARN_ONCE(sectors || raid_disks, 364 "%s does not support generic reshape\n", __func__); 365 366 rdev_for_each(rdev, mddev) 367 array_sectors += (rdev->sectors & 368 ~(sector_t)(mddev->chunk_sectors-1)); 369 370 return array_sectors; 371 } 372 373 static void raid0_free(struct mddev *mddev, void *priv) 374 { 375 struct r0conf *conf = priv; 376 377 kvfree(conf->strip_zone); 378 kvfree(conf->devlist); 379 kfree(conf); 380 } 381 382 static int raid0_set_limits(struct mddev *mddev) 383 { 384 struct queue_limits lim; 385 int err; 386 387 md_init_stacking_limits(&lim); 388 lim.max_hw_sectors = mddev->chunk_sectors; 389 lim.max_write_zeroes_sectors = mddev->chunk_sectors; 390 lim.max_hw_wzeroes_unmap_sectors = mddev->chunk_sectors; 391 lim.logical_block_size = mddev->logical_block_size; 392 lim.io_min = mddev->chunk_sectors << 9; 393 lim.io_opt = lim.io_min * mddev->raid_disks; 394 lim.chunk_sectors = mddev->chunk_sectors; 395 lim.features |= BLK_FEAT_ATOMIC_WRITES; 396 lim.features |= BLK_FEAT_PCI_P2PDMA; 397 err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY); 398 if (err) 399 return err; 400 return queue_limits_set(mddev->gendisk->queue, &lim); 401 } 402 403 static int raid0_run(struct mddev *mddev) 404 { 405 struct r0conf *conf; 406 int ret; 407 408 if (mddev->chunk_sectors == 0) { 409 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 410 return -EINVAL; 411 } 412 if (md_check_no_bitmap(mddev)) 413 return -EINVAL; 414 415 if (!mddev_is_dm(mddev)) { 416 ret = raid0_set_limits(mddev); 417 if (ret) 418 return ret; 419 } 420 421 /* if private is not null, we are here after takeover */ 422 if (mddev->private == NULL) { 423 ret = create_strip_zones(mddev, &conf); 424 if (ret < 0) 425 return ret; 426 mddev->private = conf; 427 } 428 conf = mddev->private; 429 430 /* calculate array device size */ 431 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 432 433 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 434 mdname(mddev), 435 (unsigned long long)mddev->array_sectors); 436 437 dump_zones(mddev); 438 439 return md_integrity_register(mddev); 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 */ 451 static 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 } 455 456 static 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 bio = bio_submit_split_bioset(bio, 476 zone->zone_end - bio->bi_iter.bi_sector, 477 &mddev->bio_set); 478 if (!bio) 479 return; 480 481 end = zone->zone_end; 482 } else { 483 end = bio_end_sector(bio); 484 } 485 486 orig_end = end; 487 if (zone != conf->strip_zone) 488 end = end - zone[-1].zone_end; 489 490 /* Now start and end is the offset in zone */ 491 stripe_size = zone->nb_dev * mddev->chunk_sectors; 492 493 first_stripe_index = start; 494 sector_div(first_stripe_index, stripe_size); 495 last_stripe_index = end; 496 sector_div(last_stripe_index, stripe_size); 497 498 /* In the first zone the original and alternate layouts are the same */ 499 if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) { 500 sector_div(orig_start, mddev->chunk_sectors); 501 start_disk_index = sector_div(orig_start, zone->nb_dev); 502 start_disk_index = map_disk_shift(start_disk_index, 503 zone->nb_dev, 504 zone->disk_shift); 505 sector_div(orig_end, mddev->chunk_sectors); 506 end_disk_index = sector_div(orig_end, zone->nb_dev); 507 end_disk_index = map_disk_shift(end_disk_index, 508 zone->nb_dev, zone->disk_shift); 509 } else { 510 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 511 mddev->chunk_sectors; 512 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 513 mddev->chunk_sectors; 514 } 515 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 516 mddev->chunk_sectors) + 517 first_stripe_index * mddev->chunk_sectors; 518 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 519 mddev->chunk_sectors) + 520 last_stripe_index * mddev->chunk_sectors; 521 522 for (disk = 0; disk < zone->nb_dev; disk++) { 523 sector_t dev_start, dev_end; 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 md_submit_discard_bio(mddev, rdev, bio, 551 dev_start + zone->dev_start + rdev->data_offset, 552 dev_end - dev_start); 553 } 554 bio_endio(bio); 555 } 556 557 static void raid0_map_submit_bio(struct mddev *mddev, struct bio *bio) 558 { 559 struct r0conf *conf = mddev->private; 560 struct strip_zone *zone; 561 struct md_rdev *tmp_dev; 562 sector_t bio_sector = bio->bi_iter.bi_sector; 563 sector_t sector = bio_sector; 564 565 md_account_bio(mddev, &bio); 566 567 zone = find_zone(mddev->private, §or); 568 switch (conf->layout) { 569 case RAID0_ORIG_LAYOUT: 570 tmp_dev = map_sector(mddev, zone, bio_sector, §or); 571 break; 572 case RAID0_ALT_MULTIZONE_LAYOUT: 573 tmp_dev = map_sector(mddev, zone, sector, §or); 574 break; 575 default: 576 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev)); 577 bio_io_error(bio); 578 return; 579 } 580 581 if (unlikely(is_rdev_broken(tmp_dev))) { 582 bio_io_error(bio); 583 md_error(mddev, tmp_dev); 584 return; 585 } 586 587 bio_set_dev(bio, tmp_dev->bdev); 588 bio->bi_iter.bi_sector = sector + zone->dev_start + 589 tmp_dev->data_offset; 590 mddev_trace_remap(mddev, bio, bio_sector); 591 mddev_check_write_zeroes(mddev, bio); 592 submit_bio_noacct(bio); 593 } 594 595 static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 596 { 597 sector_t sector; 598 unsigned chunk_sects; 599 unsigned sectors; 600 601 if (unlikely(bio->bi_opf & REQ_PREFLUSH) 602 && md_flush_request(mddev, bio)) 603 return true; 604 605 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 606 raid0_handle_discard(mddev, bio); 607 return true; 608 } 609 610 sector = bio->bi_iter.bi_sector; 611 chunk_sects = mddev->chunk_sectors; 612 613 sectors = chunk_sects - 614 (likely(is_power_of_2(chunk_sects)) 615 ? (sector & (chunk_sects-1)) 616 : sector_div(sector, chunk_sects)); 617 618 if (sectors < bio_sectors(bio)) { 619 bio = bio_submit_split_bioset(bio, sectors, 620 &mddev->bio_set); 621 if (!bio) 622 return true; 623 } 624 625 raid0_map_submit_bio(mddev, bio); 626 return true; 627 } 628 629 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 630 { 631 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 632 return; 633 } 634 635 static void raid0_error(struct mddev *mddev, struct md_rdev *rdev) 636 { 637 if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) { 638 char *md_name = mdname(mddev); 639 640 pr_crit("md/raid0%s: Disk failure on %pg detected, failing array.\n", 641 md_name, rdev->bdev); 642 } 643 } 644 645 static 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->resync_offset = MaxSector; 675 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 676 677 create_strip_zones(mddev, &priv_conf); 678 679 return priv_conf; 680 } 681 682 static 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->resync_offset = MaxSector; 718 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 719 720 create_strip_zones(mddev, &priv_conf); 721 return priv_conf; 722 } 723 724 static 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->resync_offset = MaxSector; 761 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 762 763 create_strip_zones(mddev, &priv_conf); 764 return priv_conf; 765 } 766 767 static 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 } 803 804 static void raid0_quiesce(struct mddev *mddev, int quiesce) 805 { 806 } 807 808 static struct md_personality raid0_personality= 809 { 810 .head = { 811 .type = MD_PERSONALITY, 812 .id = ID_RAID0, 813 .name = "raid0", 814 .owner = THIS_MODULE, 815 }, 816 817 .make_request = raid0_make_request, 818 .run = raid0_run, 819 .free = raid0_free, 820 .status = raid0_status, 821 .size = raid0_size, 822 .takeover = raid0_takeover, 823 .quiesce = raid0_quiesce, 824 .error_handler = raid0_error, 825 }; 826 827 static int __init raid0_init(void) 828 { 829 return register_md_submodule(&raid0_personality.head); 830 } 831 832 static void __exit raid0_exit(void) 833 { 834 unregister_md_submodule(&raid0_personality.head); 835 } 836 837 module_init(raid0_init); 838 module_exit(raid0_exit); 839 MODULE_LICENSE("GPL"); 840 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 841 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 842 MODULE_ALIAS("md-raid0"); 843 MODULE_ALIAS("md-level-0"); 844