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 static int raid0_congested(struct mddev *mddev, int bits) 33 { 34 struct r0conf *conf = mddev->private; 35 struct md_rdev **devlist = conf->devlist; 36 int raid_disks = conf->strip_zone[0].nb_dev; 37 int i, ret = 0; 38 39 for (i = 0; i < raid_disks && !ret ; i++) { 40 struct request_queue *q = bdev_get_queue(devlist[i]->bdev); 41 42 ret |= bdi_congested(q->backing_dev_info, bits); 43 } 44 return ret; 45 } 46 47 /* 48 * inform the user of the raid configuration 49 */ 50 static void dump_zones(struct mddev *mddev) 51 { 52 int j, k; 53 sector_t zone_size = 0; 54 sector_t zone_start = 0; 55 char b[BDEVNAME_SIZE]; 56 struct r0conf *conf = mddev->private; 57 int raid_disks = conf->strip_zone[0].nb_dev; 58 pr_debug("md: RAID0 configuration for %s - %d zone%s\n", 59 mdname(mddev), 60 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); 61 for (j = 0; j < conf->nr_strip_zones; j++) { 62 char line[200]; 63 int len = 0; 64 65 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 66 len += snprintf(line+len, 200-len, "%s%s", k?"/":"", 67 bdevname(conf->devlist[j*raid_disks 68 + k]->bdev, b)); 69 pr_debug("md: zone%d=[%s]\n", j, line); 70 71 zone_size = conf->strip_zone[j].zone_end - zone_start; 72 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", 73 (unsigned long long)zone_start>>1, 74 (unsigned long long)conf->strip_zone[j].dev_start>>1, 75 (unsigned long long)zone_size>>1); 76 zone_start = conf->strip_zone[j].zone_end; 77 } 78 } 79 80 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 81 { 82 int i, c, err; 83 sector_t curr_zone_end, sectors; 84 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 85 struct strip_zone *zone; 86 int cnt; 87 char b[BDEVNAME_SIZE]; 88 char b2[BDEVNAME_SIZE]; 89 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 90 unsigned short blksize = 512; 91 92 *private_conf = ERR_PTR(-ENOMEM); 93 if (!conf) 94 return -ENOMEM; 95 rdev_for_each(rdev1, mddev) { 96 pr_debug("md/raid0:%s: looking at %s\n", 97 mdname(mddev), 98 bdevname(rdev1->bdev, b)); 99 c = 0; 100 101 /* round size to chunk_size */ 102 sectors = rdev1->sectors; 103 sector_div(sectors, mddev->chunk_sectors); 104 rdev1->sectors = sectors * mddev->chunk_sectors; 105 106 blksize = max(blksize, queue_logical_block_size( 107 rdev1->bdev->bd_disk->queue)); 108 109 rdev_for_each(rdev2, mddev) { 110 pr_debug("md/raid0:%s: comparing %s(%llu)" 111 " with %s(%llu)\n", 112 mdname(mddev), 113 bdevname(rdev1->bdev,b), 114 (unsigned long long)rdev1->sectors, 115 bdevname(rdev2->bdev,b2), 116 (unsigned long long)rdev2->sectors); 117 if (rdev2 == rdev1) { 118 pr_debug("md/raid0:%s: END\n", 119 mdname(mddev)); 120 break; 121 } 122 if (rdev2->sectors == rdev1->sectors) { 123 /* 124 * Not unique, don't count it as a new 125 * group 126 */ 127 pr_debug("md/raid0:%s: EQUAL\n", 128 mdname(mddev)); 129 c = 1; 130 break; 131 } 132 pr_debug("md/raid0:%s: NOT EQUAL\n", 133 mdname(mddev)); 134 } 135 if (!c) { 136 pr_debug("md/raid0:%s: ==> UNIQUE\n", 137 mdname(mddev)); 138 conf->nr_strip_zones++; 139 pr_debug("md/raid0:%s: %d zones\n", 140 mdname(mddev), conf->nr_strip_zones); 141 } 142 } 143 pr_debug("md/raid0:%s: FINAL %d zones\n", 144 mdname(mddev), conf->nr_strip_zones); 145 146 if (conf->nr_strip_zones == 1) { 147 conf->layout = RAID0_ORIG_LAYOUT; 148 } else if (mddev->layout == RAID0_ORIG_LAYOUT || 149 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) { 150 conf->layout = mddev->layout; 151 } else if (default_layout == RAID0_ORIG_LAYOUT || 152 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) { 153 conf->layout = default_layout; 154 } else { 155 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n", 156 mdname(mddev)); 157 pr_err("md/raid0: please set raid.default_layout to 1 or 2\n"); 158 err = -ENOTSUPP; 159 goto abort; 160 } 161 /* 162 * now since we have the hard sector sizes, we can make sure 163 * chunk size is a multiple of that sector size 164 */ 165 if ((mddev->chunk_sectors << 9) % blksize) { 166 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", 167 mdname(mddev), 168 mddev->chunk_sectors << 9, blksize); 169 err = -EINVAL; 170 goto abort; 171 } 172 173 err = -ENOMEM; 174 conf->strip_zone = kcalloc(conf->nr_strip_zones, 175 sizeof(struct strip_zone), 176 GFP_KERNEL); 177 if (!conf->strip_zone) 178 goto abort; 179 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *), 180 conf->nr_strip_zones, 181 mddev->raid_disks), 182 GFP_KERNEL); 183 if (!conf->devlist) 184 goto abort; 185 186 /* The first zone must contain all devices, so here we check that 187 * there is a proper alignment of slots to devices and find them all 188 */ 189 zone = &conf->strip_zone[0]; 190 cnt = 0; 191 smallest = NULL; 192 dev = conf->devlist; 193 err = -EINVAL; 194 rdev_for_each(rdev1, mddev) { 195 int j = rdev1->raid_disk; 196 197 if (mddev->level == 10) { 198 /* taking over a raid10-n2 array */ 199 j /= 2; 200 rdev1->new_raid_disk = j; 201 } 202 203 if (mddev->level == 1) { 204 /* taiking over a raid1 array- 205 * we have only one active disk 206 */ 207 j = 0; 208 rdev1->new_raid_disk = j; 209 } 210 211 if (j < 0) { 212 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", 213 mdname(mddev)); 214 goto abort; 215 } 216 if (j >= mddev->raid_disks) { 217 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", 218 mdname(mddev), j); 219 goto abort; 220 } 221 if (dev[j]) { 222 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", 223 mdname(mddev), j); 224 goto abort; 225 } 226 dev[j] = rdev1; 227 228 if (!smallest || (rdev1->sectors < smallest->sectors)) 229 smallest = rdev1; 230 cnt++; 231 } 232 if (cnt != mddev->raid_disks) { 233 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", 234 mdname(mddev), cnt, mddev->raid_disks); 235 goto abort; 236 } 237 zone->nb_dev = cnt; 238 zone->zone_end = smallest->sectors * cnt; 239 240 curr_zone_end = zone->zone_end; 241 242 /* now do the other zones */ 243 for (i = 1; i < conf->nr_strip_zones; i++) 244 { 245 int j; 246 247 zone = conf->strip_zone + i; 248 dev = conf->devlist + i * mddev->raid_disks; 249 250 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 251 zone->dev_start = smallest->sectors; 252 smallest = NULL; 253 c = 0; 254 255 for (j=0; j<cnt; j++) { 256 rdev = conf->devlist[j]; 257 if (rdev->sectors <= zone->dev_start) { 258 pr_debug("md/raid0:%s: checking %s ... nope\n", 259 mdname(mddev), 260 bdevname(rdev->bdev, b)); 261 continue; 262 } 263 pr_debug("md/raid0:%s: checking %s ..." 264 " contained as device %d\n", 265 mdname(mddev), 266 bdevname(rdev->bdev, b), c); 267 dev[c] = rdev; 268 c++; 269 if (!smallest || rdev->sectors < smallest->sectors) { 270 smallest = rdev; 271 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 272 mdname(mddev), 273 (unsigned long long)rdev->sectors); 274 } 275 } 276 277 zone->nb_dev = c; 278 sectors = (smallest->sectors - zone->dev_start) * c; 279 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 280 mdname(mddev), 281 zone->nb_dev, (unsigned long long)sectors); 282 283 curr_zone_end += sectors; 284 zone->zone_end = curr_zone_end; 285 286 pr_debug("md/raid0:%s: current zone start: %llu\n", 287 mdname(mddev), 288 (unsigned long long)smallest->sectors); 289 } 290 291 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 292 *private_conf = conf; 293 294 return 0; 295 abort: 296 kfree(conf->strip_zone); 297 kfree(conf->devlist); 298 kfree(conf); 299 *private_conf = ERR_PTR(err); 300 return err; 301 } 302 303 /* Find the zone which holds a particular offset 304 * Update *sectorp to be an offset in that zone 305 */ 306 static struct strip_zone *find_zone(struct r0conf *conf, 307 sector_t *sectorp) 308 { 309 int i; 310 struct strip_zone *z = conf->strip_zone; 311 sector_t sector = *sectorp; 312 313 for (i = 0; i < conf->nr_strip_zones; i++) 314 if (sector < z[i].zone_end) { 315 if (i) 316 *sectorp = sector - z[i-1].zone_end; 317 return z + i; 318 } 319 BUG(); 320 } 321 322 /* 323 * remaps the bio to the target device. we separate two flows. 324 * power 2 flow and a general flow for the sake of performance 325 */ 326 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 327 sector_t sector, sector_t *sector_offset) 328 { 329 unsigned int sect_in_chunk; 330 sector_t chunk; 331 struct r0conf *conf = mddev->private; 332 int raid_disks = conf->strip_zone[0].nb_dev; 333 unsigned int chunk_sects = mddev->chunk_sectors; 334 335 if (is_power_of_2(chunk_sects)) { 336 int chunksect_bits = ffz(~chunk_sects); 337 /* find the sector offset inside the chunk */ 338 sect_in_chunk = sector & (chunk_sects - 1); 339 sector >>= chunksect_bits; 340 /* chunk in zone */ 341 chunk = *sector_offset; 342 /* quotient is the chunk in real device*/ 343 sector_div(chunk, zone->nb_dev << chunksect_bits); 344 } else{ 345 sect_in_chunk = sector_div(sector, chunk_sects); 346 chunk = *sector_offset; 347 sector_div(chunk, chunk_sects * zone->nb_dev); 348 } 349 /* 350 * position the bio over the real device 351 * real sector = chunk in device + starting of zone 352 * + the position in the chunk 353 */ 354 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 355 return conf->devlist[(zone - conf->strip_zone)*raid_disks 356 + sector_div(sector, zone->nb_dev)]; 357 } 358 359 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 360 { 361 sector_t array_sectors = 0; 362 struct md_rdev *rdev; 363 364 WARN_ONCE(sectors || raid_disks, 365 "%s does not support generic reshape\n", __func__); 366 367 rdev_for_each(rdev, mddev) 368 array_sectors += (rdev->sectors & 369 ~(sector_t)(mddev->chunk_sectors-1)); 370 371 return array_sectors; 372 } 373 374 static void raid0_free(struct mddev *mddev, void *priv); 375 376 static int raid0_run(struct mddev *mddev) 377 { 378 struct r0conf *conf; 379 int ret; 380 381 if (mddev->chunk_sectors == 0) { 382 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); 383 return -EINVAL; 384 } 385 if (md_check_no_bitmap(mddev)) 386 return -EINVAL; 387 388 /* if private is not null, we are here after takeover */ 389 if (mddev->private == NULL) { 390 ret = create_strip_zones(mddev, &conf); 391 if (ret < 0) 392 return ret; 393 mddev->private = conf; 394 } 395 conf = mddev->private; 396 if (mddev->queue) { 397 struct md_rdev *rdev; 398 bool discard_supported = false; 399 400 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 401 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); 402 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors); 403 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX); 404 405 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 406 blk_queue_io_opt(mddev->queue, 407 (mddev->chunk_sectors << 9) * mddev->raid_disks); 408 409 rdev_for_each(rdev, mddev) { 410 disk_stack_limits(mddev->gendisk, rdev->bdev, 411 rdev->data_offset << 9); 412 if (blk_queue_discard(bdev_get_queue(rdev->bdev))) 413 discard_supported = true; 414 } 415 if (!discard_supported) 416 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue); 417 else 418 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue); 419 } 420 421 /* calculate array device size */ 422 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 423 424 pr_debug("md/raid0:%s: md_size is %llu sectors.\n", 425 mdname(mddev), 426 (unsigned long long)mddev->array_sectors); 427 428 if (mddev->queue) { 429 /* calculate the max read-ahead size. 430 * For read-ahead of large files to be effective, we need to 431 * readahead at least twice a whole stripe. i.e. number of devices 432 * multiplied by chunk size times 2. 433 * If an individual device has an ra_pages greater than the 434 * chunk size, then we will not drive that device as hard as it 435 * wants. We consider this a configuration error: a larger 436 * chunksize should be used in that case. 437 */ 438 int stripe = mddev->raid_disks * 439 (mddev->chunk_sectors << 9) / PAGE_SIZE; 440 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe) 441 mddev->queue->backing_dev_info->ra_pages = 2* stripe; 442 } 443 444 dump_zones(mddev); 445 446 ret = md_integrity_register(mddev); 447 448 return ret; 449 } 450 451 static void raid0_free(struct mddev *mddev, void *priv) 452 { 453 struct r0conf *conf = priv; 454 455 kfree(conf->strip_zone); 456 kfree(conf->devlist); 457 kfree(conf); 458 } 459 460 /* 461 * Is io distribute over 1 or more chunks ? 462 */ 463 static inline int is_io_in_chunk_boundary(struct mddev *mddev, 464 unsigned int chunk_sects, struct bio *bio) 465 { 466 if (likely(is_power_of_2(chunk_sects))) { 467 return chunk_sects >= 468 ((bio->bi_iter.bi_sector & (chunk_sects-1)) 469 + bio_sectors(bio)); 470 } else{ 471 sector_t sector = bio->bi_iter.bi_sector; 472 return chunk_sects >= (sector_div(sector, chunk_sects) 473 + bio_sectors(bio)); 474 } 475 } 476 477 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) 478 { 479 struct r0conf *conf = mddev->private; 480 struct strip_zone *zone; 481 sector_t start = bio->bi_iter.bi_sector; 482 sector_t end; 483 unsigned int stripe_size; 484 sector_t first_stripe_index, last_stripe_index; 485 sector_t start_disk_offset; 486 unsigned int start_disk_index; 487 sector_t end_disk_offset; 488 unsigned int end_disk_index; 489 unsigned int disk; 490 491 zone = find_zone(conf, &start); 492 493 if (bio_end_sector(bio) > zone->zone_end) { 494 struct bio *split = bio_split(bio, 495 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, 496 &mddev->bio_set); 497 bio_chain(split, bio); 498 generic_make_request(bio); 499 bio = split; 500 end = zone->zone_end; 501 } else 502 end = bio_end_sector(bio); 503 504 if (zone != conf->strip_zone) 505 end = end - zone[-1].zone_end; 506 507 /* Now start and end is the offset in zone */ 508 stripe_size = zone->nb_dev * mddev->chunk_sectors; 509 510 first_stripe_index = start; 511 sector_div(first_stripe_index, stripe_size); 512 last_stripe_index = end; 513 sector_div(last_stripe_index, stripe_size); 514 515 start_disk_index = (int)(start - first_stripe_index * stripe_size) / 516 mddev->chunk_sectors; 517 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) % 518 mddev->chunk_sectors) + 519 first_stripe_index * mddev->chunk_sectors; 520 end_disk_index = (int)(end - last_stripe_index * stripe_size) / 521 mddev->chunk_sectors; 522 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) % 523 mddev->chunk_sectors) + 524 last_stripe_index * mddev->chunk_sectors; 525 526 for (disk = 0; disk < zone->nb_dev; disk++) { 527 sector_t dev_start, dev_end; 528 struct bio *discard_bio = NULL; 529 struct md_rdev *rdev; 530 531 if (disk < start_disk_index) 532 dev_start = (first_stripe_index + 1) * 533 mddev->chunk_sectors; 534 else if (disk > start_disk_index) 535 dev_start = first_stripe_index * mddev->chunk_sectors; 536 else 537 dev_start = start_disk_offset; 538 539 if (disk < end_disk_index) 540 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; 541 else if (disk > end_disk_index) 542 dev_end = last_stripe_index * mddev->chunk_sectors; 543 else 544 dev_end = end_disk_offset; 545 546 if (dev_end <= dev_start) 547 continue; 548 549 rdev = conf->devlist[(zone - conf->strip_zone) * 550 conf->strip_zone[0].nb_dev + disk]; 551 if (__blkdev_issue_discard(rdev->bdev, 552 dev_start + zone->dev_start + rdev->data_offset, 553 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) || 554 !discard_bio) 555 continue; 556 bio_chain(discard_bio, bio); 557 bio_clone_blkg_association(discard_bio, bio); 558 if (mddev->gendisk) 559 trace_block_bio_remap(bdev_get_queue(rdev->bdev), 560 discard_bio, disk_devt(mddev->gendisk), 561 bio->bi_iter.bi_sector); 562 generic_make_request(discard_bio); 563 } 564 bio_endio(bio); 565 } 566 567 static bool raid0_make_request(struct mddev *mddev, struct bio *bio) 568 { 569 struct r0conf *conf = mddev->private; 570 struct strip_zone *zone; 571 struct md_rdev *tmp_dev; 572 sector_t bio_sector; 573 sector_t sector; 574 sector_t orig_sector; 575 unsigned chunk_sects; 576 unsigned sectors; 577 578 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) { 579 md_flush_request(mddev, bio); 580 return true; 581 } 582 583 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) { 584 raid0_handle_discard(mddev, bio); 585 return true; 586 } 587 588 bio_sector = bio->bi_iter.bi_sector; 589 sector = bio_sector; 590 chunk_sects = mddev->chunk_sectors; 591 592 sectors = chunk_sects - 593 (likely(is_power_of_2(chunk_sects)) 594 ? (sector & (chunk_sects-1)) 595 : sector_div(sector, chunk_sects)); 596 597 /* Restore due to sector_div */ 598 sector = bio_sector; 599 600 if (sectors < bio_sectors(bio)) { 601 struct bio *split = bio_split(bio, sectors, GFP_NOIO, 602 &mddev->bio_set); 603 bio_chain(split, bio); 604 generic_make_request(bio); 605 bio = split; 606 } 607 608 orig_sector = sector; 609 zone = find_zone(mddev->private, §or); 610 switch (conf->layout) { 611 case RAID0_ORIG_LAYOUT: 612 tmp_dev = map_sector(mddev, zone, orig_sector, §or); 613 break; 614 case RAID0_ALT_MULTIZONE_LAYOUT: 615 tmp_dev = map_sector(mddev, zone, sector, §or); 616 break; 617 default: 618 WARN("md/raid0:%s: Invalid layout\n", mdname(mddev)); 619 bio_io_error(bio); 620 return true; 621 } 622 623 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) { 624 bio_io_error(bio); 625 return true; 626 } 627 628 bio_set_dev(bio, tmp_dev->bdev); 629 bio->bi_iter.bi_sector = sector + zone->dev_start + 630 tmp_dev->data_offset; 631 632 if (mddev->gendisk) 633 trace_block_bio_remap(bio->bi_disk->queue, bio, 634 disk_devt(mddev->gendisk), bio_sector); 635 mddev_check_writesame(mddev, bio); 636 mddev_check_write_zeroes(mddev, bio); 637 generic_make_request(bio); 638 return true; 639 } 640 641 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 642 { 643 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 644 return; 645 } 646 647 static void *raid0_takeover_raid45(struct mddev *mddev) 648 { 649 struct md_rdev *rdev; 650 struct r0conf *priv_conf; 651 652 if (mddev->degraded != 1) { 653 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 654 mdname(mddev), 655 mddev->degraded); 656 return ERR_PTR(-EINVAL); 657 } 658 659 rdev_for_each(rdev, mddev) { 660 /* check slot number for a disk */ 661 if (rdev->raid_disk == mddev->raid_disks-1) { 662 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n", 663 mdname(mddev)); 664 return ERR_PTR(-EINVAL); 665 } 666 rdev->sectors = mddev->dev_sectors; 667 } 668 669 /* Set new parameters */ 670 mddev->new_level = 0; 671 mddev->new_layout = 0; 672 mddev->new_chunk_sectors = mddev->chunk_sectors; 673 mddev->raid_disks--; 674 mddev->delta_disks = -1; 675 /* make sure it will be not marked as dirty */ 676 mddev->recovery_cp = MaxSector; 677 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 678 679 create_strip_zones(mddev, &priv_conf); 680 681 return priv_conf; 682 } 683 684 static void *raid0_takeover_raid10(struct mddev *mddev) 685 { 686 struct r0conf *priv_conf; 687 688 /* Check layout: 689 * - far_copies must be 1 690 * - near_copies must be 2 691 * - disks number must be even 692 * - all mirrors must be already degraded 693 */ 694 if (mddev->layout != ((1 << 8) + 2)) { 695 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", 696 mdname(mddev), 697 mddev->layout); 698 return ERR_PTR(-EINVAL); 699 } 700 if (mddev->raid_disks & 1) { 701 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", 702 mdname(mddev)); 703 return ERR_PTR(-EINVAL); 704 } 705 if (mddev->degraded != (mddev->raid_disks>>1)) { 706 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n", 707 mdname(mddev)); 708 return ERR_PTR(-EINVAL); 709 } 710 711 /* Set new parameters */ 712 mddev->new_level = 0; 713 mddev->new_layout = 0; 714 mddev->new_chunk_sectors = mddev->chunk_sectors; 715 mddev->delta_disks = - mddev->raid_disks / 2; 716 mddev->raid_disks += mddev->delta_disks; 717 mddev->degraded = 0; 718 /* make sure it will be not marked as dirty */ 719 mddev->recovery_cp = MaxSector; 720 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 721 722 create_strip_zones(mddev, &priv_conf); 723 return priv_conf; 724 } 725 726 static void *raid0_takeover_raid1(struct mddev *mddev) 727 { 728 struct r0conf *priv_conf; 729 int chunksect; 730 731 /* Check layout: 732 * - (N - 1) mirror drives must be already faulty 733 */ 734 if ((mddev->raid_disks - 1) != mddev->degraded) { 735 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 736 mdname(mddev)); 737 return ERR_PTR(-EINVAL); 738 } 739 740 /* 741 * a raid1 doesn't have the notion of chunk size, so 742 * figure out the largest suitable size we can use. 743 */ 744 chunksect = 64 * 2; /* 64K by default */ 745 746 /* The array must be an exact multiple of chunksize */ 747 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 748 chunksect >>= 1; 749 750 if ((chunksect << 9) < PAGE_SIZE) 751 /* array size does not allow a suitable chunk size */ 752 return ERR_PTR(-EINVAL); 753 754 /* Set new parameters */ 755 mddev->new_level = 0; 756 mddev->new_layout = 0; 757 mddev->new_chunk_sectors = chunksect; 758 mddev->chunk_sectors = chunksect; 759 mddev->delta_disks = 1 - mddev->raid_disks; 760 mddev->raid_disks = 1; 761 /* make sure it will be not marked as dirty */ 762 mddev->recovery_cp = MaxSector; 763 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS); 764 765 create_strip_zones(mddev, &priv_conf); 766 return priv_conf; 767 } 768 769 static void *raid0_takeover(struct mddev *mddev) 770 { 771 /* raid0 can take over: 772 * raid4 - if all data disks are active. 773 * raid5 - providing it is Raid4 layout and one disk is faulty 774 * raid10 - assuming we have all necessary active disks 775 * raid1 - with (N -1) mirror drives faulty 776 */ 777 778 if (mddev->bitmap) { 779 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n", 780 mdname(mddev)); 781 return ERR_PTR(-EBUSY); 782 } 783 if (mddev->level == 4) 784 return raid0_takeover_raid45(mddev); 785 786 if (mddev->level == 5) { 787 if (mddev->layout == ALGORITHM_PARITY_N) 788 return raid0_takeover_raid45(mddev); 789 790 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 791 mdname(mddev), ALGORITHM_PARITY_N); 792 } 793 794 if (mddev->level == 10) 795 return raid0_takeover_raid10(mddev); 796 797 if (mddev->level == 1) 798 return raid0_takeover_raid1(mddev); 799 800 pr_warn("Takeover from raid%i to raid0 not supported\n", 801 mddev->level); 802 803 return ERR_PTR(-EINVAL); 804 } 805 806 static void raid0_quiesce(struct mddev *mddev, int quiesce) 807 { 808 } 809 810 static struct md_personality raid0_personality= 811 { 812 .name = "raid0", 813 .level = 0, 814 .owner = THIS_MODULE, 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 .congested = raid0_congested, 823 }; 824 825 static int __init raid0_init (void) 826 { 827 return register_md_personality (&raid0_personality); 828 } 829 830 static void raid0_exit (void) 831 { 832 unregister_md_personality (&raid0_personality); 833 } 834 835 module_init(raid0_init); 836 module_exit(raid0_exit); 837 MODULE_LICENSE("GPL"); 838 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 839 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 840 MODULE_ALIAS("md-raid0"); 841 MODULE_ALIAS("md-level-0"); 842