1 /* 2 raid0.c : Multiple Devices driver for Linux 3 Copyright (C) 1994-96 Marc ZYNGIER 4 <zyngier@ufr-info-p7.ibp.fr> or 5 <maz@gloups.fdn.fr> 6 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat 7 8 9 RAID-0 management functions. 10 11 This program is free software; you can redistribute it and/or modify 12 it under the terms of the GNU General Public License as published by 13 the Free Software Foundation; either version 2, or (at your option) 14 any later version. 15 16 You should have received a copy of the GNU General Public License 17 (for example /usr/src/linux/COPYING); if not, write to the Free 18 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 #include <linux/blkdev.h> 22 #include <linux/seq_file.h> 23 #include <linux/slab.h> 24 #include "md.h" 25 #include "raid0.h" 26 #include "raid5.h" 27 28 static void raid0_unplug(struct request_queue *q) 29 { 30 mddev_t *mddev = q->queuedata; 31 raid0_conf_t *conf = mddev->private; 32 mdk_rdev_t **devlist = conf->devlist; 33 int raid_disks = conf->strip_zone[0].nb_dev; 34 int i; 35 36 for (i=0; i < raid_disks; i++) { 37 struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev); 38 39 blk_unplug(r_queue); 40 } 41 } 42 43 static int raid0_congested(void *data, int bits) 44 { 45 mddev_t *mddev = data; 46 raid0_conf_t *conf = mddev->private; 47 mdk_rdev_t **devlist = conf->devlist; 48 int raid_disks = conf->strip_zone[0].nb_dev; 49 int i, ret = 0; 50 51 if (mddev_congested(mddev, bits)) 52 return 1; 53 54 for (i = 0; i < raid_disks && !ret ; i++) { 55 struct request_queue *q = bdev_get_queue(devlist[i]->bdev); 56 57 ret |= bdi_congested(&q->backing_dev_info, bits); 58 } 59 return ret; 60 } 61 62 /* 63 * inform the user of the raid configuration 64 */ 65 static void dump_zones(mddev_t *mddev) 66 { 67 int j, k, h; 68 sector_t zone_size = 0; 69 sector_t zone_start = 0; 70 char b[BDEVNAME_SIZE]; 71 raid0_conf_t *conf = mddev->private; 72 int raid_disks = conf->strip_zone[0].nb_dev; 73 printk(KERN_INFO "******* %s configuration *********\n", 74 mdname(mddev)); 75 h = 0; 76 for (j = 0; j < conf->nr_strip_zones; j++) { 77 printk(KERN_INFO "zone%d=[", j); 78 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 79 printk(KERN_CONT "%s/", 80 bdevname(conf->devlist[j*raid_disks 81 + k]->bdev, b)); 82 printk(KERN_CONT "]\n"); 83 84 zone_size = conf->strip_zone[j].zone_end - zone_start; 85 printk(KERN_INFO " zone offset=%llukb " 86 "device offset=%llukb size=%llukb\n", 87 (unsigned long long)zone_start>>1, 88 (unsigned long long)conf->strip_zone[j].dev_start>>1, 89 (unsigned long long)zone_size>>1); 90 zone_start = conf->strip_zone[j].zone_end; 91 } 92 printk(KERN_INFO "**********************************\n\n"); 93 } 94 95 static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf) 96 { 97 int i, c, err; 98 sector_t curr_zone_end, sectors; 99 mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev; 100 struct strip_zone *zone; 101 int cnt; 102 char b[BDEVNAME_SIZE]; 103 raid0_conf_t *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 104 105 if (!conf) 106 return -ENOMEM; 107 list_for_each_entry(rdev1, &mddev->disks, same_set) { 108 printk(KERN_INFO "md/raid0:%s: looking at %s\n", 109 mdname(mddev), 110 bdevname(rdev1->bdev, b)); 111 c = 0; 112 113 /* round size to chunk_size */ 114 sectors = rdev1->sectors; 115 sector_div(sectors, mddev->chunk_sectors); 116 rdev1->sectors = sectors * mddev->chunk_sectors; 117 118 list_for_each_entry(rdev2, &mddev->disks, same_set) { 119 printk(KERN_INFO "md/raid0:%s: comparing %s(%llu)", 120 mdname(mddev), 121 bdevname(rdev1->bdev,b), 122 (unsigned long long)rdev1->sectors); 123 printk(KERN_CONT " with %s(%llu)\n", 124 bdevname(rdev2->bdev,b), 125 (unsigned long long)rdev2->sectors); 126 if (rdev2 == rdev1) { 127 printk(KERN_INFO "md/raid0:%s: END\n", 128 mdname(mddev)); 129 break; 130 } 131 if (rdev2->sectors == rdev1->sectors) { 132 /* 133 * Not unique, don't count it as a new 134 * group 135 */ 136 printk(KERN_INFO "md/raid0:%s: EQUAL\n", 137 mdname(mddev)); 138 c = 1; 139 break; 140 } 141 printk(KERN_INFO "md/raid0:%s: NOT EQUAL\n", 142 mdname(mddev)); 143 } 144 if (!c) { 145 printk(KERN_INFO "md/raid0:%s: ==> UNIQUE\n", 146 mdname(mddev)); 147 conf->nr_strip_zones++; 148 printk(KERN_INFO "md/raid0:%s: %d zones\n", 149 mdname(mddev), conf->nr_strip_zones); 150 } 151 } 152 printk(KERN_INFO "md/raid0:%s: FINAL %d zones\n", 153 mdname(mddev), conf->nr_strip_zones); 154 err = -ENOMEM; 155 conf->strip_zone = kzalloc(sizeof(struct strip_zone)* 156 conf->nr_strip_zones, GFP_KERNEL); 157 if (!conf->strip_zone) 158 goto abort; 159 conf->devlist = kzalloc(sizeof(mdk_rdev_t*)* 160 conf->nr_strip_zones*mddev->raid_disks, 161 GFP_KERNEL); 162 if (!conf->devlist) 163 goto abort; 164 165 /* The first zone must contain all devices, so here we check that 166 * there is a proper alignment of slots to devices and find them all 167 */ 168 zone = &conf->strip_zone[0]; 169 cnt = 0; 170 smallest = NULL; 171 dev = conf->devlist; 172 err = -EINVAL; 173 list_for_each_entry(rdev1, &mddev->disks, same_set) { 174 int j = rdev1->raid_disk; 175 176 if (mddev->level == 10) { 177 /* taking over a raid10-n2 array */ 178 j /= 2; 179 rdev1->new_raid_disk = j; 180 } 181 182 if (mddev->level == 1) { 183 /* taiking over a raid1 array- 184 * we have only one active disk 185 */ 186 j = 0; 187 rdev1->new_raid_disk = j; 188 } 189 190 if (j < 0 || j >= mddev->raid_disks) { 191 printk(KERN_ERR "md/raid0:%s: bad disk number %d - " 192 "aborting!\n", mdname(mddev), j); 193 goto abort; 194 } 195 if (dev[j]) { 196 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " 197 "aborting!\n", mdname(mddev), j); 198 goto abort; 199 } 200 dev[j] = rdev1; 201 202 disk_stack_limits(mddev->gendisk, rdev1->bdev, 203 rdev1->data_offset << 9); 204 /* as we don't honour merge_bvec_fn, we must never risk 205 * violating it, so limit ->max_segments to 1, lying within 206 * a single page. 207 */ 208 209 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) { 210 blk_queue_max_segments(mddev->queue, 1); 211 blk_queue_segment_boundary(mddev->queue, 212 PAGE_CACHE_SIZE - 1); 213 } 214 if (!smallest || (rdev1->sectors < smallest->sectors)) 215 smallest = rdev1; 216 cnt++; 217 } 218 if (cnt != mddev->raid_disks) { 219 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " 220 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); 221 goto abort; 222 } 223 zone->nb_dev = cnt; 224 zone->zone_end = smallest->sectors * cnt; 225 226 curr_zone_end = zone->zone_end; 227 228 /* now do the other zones */ 229 for (i = 1; i < conf->nr_strip_zones; i++) 230 { 231 int j; 232 233 zone = conf->strip_zone + i; 234 dev = conf->devlist + i * mddev->raid_disks; 235 236 printk(KERN_INFO "md/raid0:%s: zone %d\n", 237 mdname(mddev), i); 238 zone->dev_start = smallest->sectors; 239 smallest = NULL; 240 c = 0; 241 242 for (j=0; j<cnt; j++) { 243 rdev = conf->devlist[j]; 244 printk(KERN_INFO "md/raid0:%s: checking %s ...", 245 mdname(mddev), 246 bdevname(rdev->bdev, b)); 247 if (rdev->sectors <= zone->dev_start) { 248 printk(KERN_CONT " nope.\n"); 249 continue; 250 } 251 printk(KERN_CONT " contained as device %d\n", c); 252 dev[c] = rdev; 253 c++; 254 if (!smallest || rdev->sectors < smallest->sectors) { 255 smallest = rdev; 256 printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n", 257 mdname(mddev), 258 (unsigned long long)rdev->sectors); 259 } 260 } 261 262 zone->nb_dev = c; 263 sectors = (smallest->sectors - zone->dev_start) * c; 264 printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 265 mdname(mddev), 266 zone->nb_dev, (unsigned long long)sectors); 267 268 curr_zone_end += sectors; 269 zone->zone_end = curr_zone_end; 270 271 printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n", 272 mdname(mddev), 273 (unsigned long long)smallest->sectors); 274 } 275 mddev->queue->unplug_fn = raid0_unplug; 276 mddev->queue->backing_dev_info.congested_fn = raid0_congested; 277 mddev->queue->backing_dev_info.congested_data = mddev; 278 279 /* 280 * now since we have the hard sector sizes, we can make sure 281 * chunk size is a multiple of that sector size 282 */ 283 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { 284 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", 285 mdname(mddev), 286 mddev->chunk_sectors << 9); 287 goto abort; 288 } 289 290 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 291 blk_queue_io_opt(mddev->queue, 292 (mddev->chunk_sectors << 9) * mddev->raid_disks); 293 294 printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev)); 295 *private_conf = conf; 296 297 return 0; 298 abort: 299 kfree(conf->strip_zone); 300 kfree(conf->devlist); 301 kfree(conf); 302 *private_conf = NULL; 303 return err; 304 } 305 306 /** 307 * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged 308 * @q: request queue 309 * @bvm: properties of new bio 310 * @biovec: the request that could be merged to it. 311 * 312 * Return amount of bytes we can accept at this offset 313 */ 314 static int raid0_mergeable_bvec(struct request_queue *q, 315 struct bvec_merge_data *bvm, 316 struct bio_vec *biovec) 317 { 318 mddev_t *mddev = q->queuedata; 319 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 320 int max; 321 unsigned int chunk_sectors = mddev->chunk_sectors; 322 unsigned int bio_sectors = bvm->bi_size >> 9; 323 324 if (is_power_of_2(chunk_sectors)) 325 max = (chunk_sectors - ((sector & (chunk_sectors-1)) 326 + bio_sectors)) << 9; 327 else 328 max = (chunk_sectors - (sector_div(sector, chunk_sectors) 329 + bio_sectors)) << 9; 330 if (max < 0) max = 0; /* bio_add cannot handle a negative return */ 331 if (max <= biovec->bv_len && bio_sectors == 0) 332 return biovec->bv_len; 333 else 334 return max; 335 } 336 337 static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) 338 { 339 sector_t array_sectors = 0; 340 mdk_rdev_t *rdev; 341 342 WARN_ONCE(sectors || raid_disks, 343 "%s does not support generic reshape\n", __func__); 344 345 list_for_each_entry(rdev, &mddev->disks, same_set) 346 array_sectors += rdev->sectors; 347 348 return array_sectors; 349 } 350 351 static int raid0_run(mddev_t *mddev) 352 { 353 raid0_conf_t *conf; 354 int ret; 355 356 if (mddev->chunk_sectors == 0) { 357 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", 358 mdname(mddev)); 359 return -EINVAL; 360 } 361 if (md_check_no_bitmap(mddev)) 362 return -EINVAL; 363 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 364 365 /* if private is not null, we are here after takeover */ 366 if (mddev->private == NULL) { 367 ret = create_strip_zones(mddev, &conf); 368 if (ret < 0) 369 return ret; 370 mddev->private = conf; 371 } 372 conf = mddev->private; 373 374 /* calculate array device size */ 375 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 376 377 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", 378 mdname(mddev), 379 (unsigned long long)mddev->array_sectors); 380 /* calculate the max read-ahead size. 381 * For read-ahead of large files to be effective, we need to 382 * readahead at least twice a whole stripe. i.e. number of devices 383 * multiplied by chunk size times 2. 384 * If an individual device has an ra_pages greater than the 385 * chunk size, then we will not drive that device as hard as it 386 * wants. We consider this a configuration error: a larger 387 * chunksize should be used in that case. 388 */ 389 { 390 int stripe = mddev->raid_disks * 391 (mddev->chunk_sectors << 9) / PAGE_SIZE; 392 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) 393 mddev->queue->backing_dev_info.ra_pages = 2* stripe; 394 } 395 396 blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); 397 dump_zones(mddev); 398 md_integrity_register(mddev); 399 return 0; 400 } 401 402 static int raid0_stop(mddev_t *mddev) 403 { 404 raid0_conf_t *conf = mddev->private; 405 406 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 407 kfree(conf->strip_zone); 408 kfree(conf->devlist); 409 kfree(conf); 410 mddev->private = NULL; 411 return 0; 412 } 413 414 /* Find the zone which holds a particular offset 415 * Update *sectorp to be an offset in that zone 416 */ 417 static struct strip_zone *find_zone(struct raid0_private_data *conf, 418 sector_t *sectorp) 419 { 420 int i; 421 struct strip_zone *z = conf->strip_zone; 422 sector_t sector = *sectorp; 423 424 for (i = 0; i < conf->nr_strip_zones; i++) 425 if (sector < z[i].zone_end) { 426 if (i) 427 *sectorp = sector - z[i-1].zone_end; 428 return z + i; 429 } 430 BUG(); 431 } 432 433 /* 434 * remaps the bio to the target device. we separate two flows. 435 * power 2 flow and a general flow for the sake of perfromance 436 */ 437 static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, 438 sector_t sector, sector_t *sector_offset) 439 { 440 unsigned int sect_in_chunk; 441 sector_t chunk; 442 raid0_conf_t *conf = mddev->private; 443 int raid_disks = conf->strip_zone[0].nb_dev; 444 unsigned int chunk_sects = mddev->chunk_sectors; 445 446 if (is_power_of_2(chunk_sects)) { 447 int chunksect_bits = ffz(~chunk_sects); 448 /* find the sector offset inside the chunk */ 449 sect_in_chunk = sector & (chunk_sects - 1); 450 sector >>= chunksect_bits; 451 /* chunk in zone */ 452 chunk = *sector_offset; 453 /* quotient is the chunk in real device*/ 454 sector_div(chunk, zone->nb_dev << chunksect_bits); 455 } else{ 456 sect_in_chunk = sector_div(sector, chunk_sects); 457 chunk = *sector_offset; 458 sector_div(chunk, chunk_sects * zone->nb_dev); 459 } 460 /* 461 * position the bio over the real device 462 * real sector = chunk in device + starting of zone 463 * + the position in the chunk 464 */ 465 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 466 return conf->devlist[(zone - conf->strip_zone)*raid_disks 467 + sector_div(sector, zone->nb_dev)]; 468 } 469 470 /* 471 * Is io distribute over 1 or more chunks ? 472 */ 473 static inline int is_io_in_chunk_boundary(mddev_t *mddev, 474 unsigned int chunk_sects, struct bio *bio) 475 { 476 if (likely(is_power_of_2(chunk_sects))) { 477 return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) 478 + (bio->bi_size >> 9)); 479 } else{ 480 sector_t sector = bio->bi_sector; 481 return chunk_sects >= (sector_div(sector, chunk_sects) 482 + (bio->bi_size >> 9)); 483 } 484 } 485 486 static int raid0_make_request(mddev_t *mddev, struct bio *bio) 487 { 488 unsigned int chunk_sects; 489 sector_t sector_offset; 490 struct strip_zone *zone; 491 mdk_rdev_t *tmp_dev; 492 493 if (unlikely(bio->bi_rw & REQ_FLUSH)) { 494 md_flush_request(mddev, bio); 495 return 0; 496 } 497 498 chunk_sects = mddev->chunk_sectors; 499 if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { 500 sector_t sector = bio->bi_sector; 501 struct bio_pair *bp; 502 /* Sanity check -- queue functions should prevent this happening */ 503 if (bio->bi_vcnt != 1 || 504 bio->bi_idx != 0) 505 goto bad_map; 506 /* This is a one page bio that upper layers 507 * refuse to split for us, so we need to split it. 508 */ 509 if (likely(is_power_of_2(chunk_sects))) 510 bp = bio_split(bio, chunk_sects - (sector & 511 (chunk_sects-1))); 512 else 513 bp = bio_split(bio, chunk_sects - 514 sector_div(sector, chunk_sects)); 515 if (raid0_make_request(mddev, &bp->bio1)) 516 generic_make_request(&bp->bio1); 517 if (raid0_make_request(mddev, &bp->bio2)) 518 generic_make_request(&bp->bio2); 519 520 bio_pair_release(bp); 521 return 0; 522 } 523 524 sector_offset = bio->bi_sector; 525 zone = find_zone(mddev->private, §or_offset); 526 tmp_dev = map_sector(mddev, zone, bio->bi_sector, 527 §or_offset); 528 bio->bi_bdev = tmp_dev->bdev; 529 bio->bi_sector = sector_offset + zone->dev_start + 530 tmp_dev->data_offset; 531 /* 532 * Let the main block layer submit the IO and resolve recursion: 533 */ 534 return 1; 535 536 bad_map: 537 printk("md/raid0:%s: make_request bug: can't convert block across chunks" 538 " or bigger than %dk %llu %d\n", 539 mdname(mddev), chunk_sects / 2, 540 (unsigned long long)bio->bi_sector, bio->bi_size >> 10); 541 542 bio_io_error(bio); 543 return 0; 544 } 545 546 static void raid0_status(struct seq_file *seq, mddev_t *mddev) 547 { 548 #undef MD_DEBUG 549 #ifdef MD_DEBUG 550 int j, k, h; 551 char b[BDEVNAME_SIZE]; 552 raid0_conf_t *conf = mddev->private; 553 int raid_disks = conf->strip_zone[0].nb_dev; 554 555 sector_t zone_size; 556 sector_t zone_start = 0; 557 h = 0; 558 559 for (j = 0; j < conf->nr_strip_zones; j++) { 560 seq_printf(seq, " z%d", j); 561 seq_printf(seq, "=["); 562 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 563 seq_printf(seq, "%s/", bdevname( 564 conf->devlist[j*raid_disks + k] 565 ->bdev, b)); 566 567 zone_size = conf->strip_zone[j].zone_end - zone_start; 568 seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n", 569 (unsigned long long)zone_start>>1, 570 (unsigned long long)conf->strip_zone[j].dev_start>>1, 571 (unsigned long long)zone_size>>1); 572 zone_start = conf->strip_zone[j].zone_end; 573 } 574 #endif 575 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 576 return; 577 } 578 579 static void *raid0_takeover_raid45(mddev_t *mddev) 580 { 581 mdk_rdev_t *rdev; 582 raid0_conf_t *priv_conf; 583 584 if (mddev->degraded != 1) { 585 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 586 mdname(mddev), 587 mddev->degraded); 588 return ERR_PTR(-EINVAL); 589 } 590 591 list_for_each_entry(rdev, &mddev->disks, same_set) { 592 /* check slot number for a disk */ 593 if (rdev->raid_disk == mddev->raid_disks-1) { 594 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", 595 mdname(mddev)); 596 return ERR_PTR(-EINVAL); 597 } 598 } 599 600 /* Set new parameters */ 601 mddev->new_level = 0; 602 mddev->new_layout = 0; 603 mddev->new_chunk_sectors = mddev->chunk_sectors; 604 mddev->raid_disks--; 605 mddev->delta_disks = -1; 606 /* make sure it will be not marked as dirty */ 607 mddev->recovery_cp = MaxSector; 608 609 create_strip_zones(mddev, &priv_conf); 610 return priv_conf; 611 } 612 613 static void *raid0_takeover_raid10(mddev_t *mddev) 614 { 615 raid0_conf_t *priv_conf; 616 617 /* Check layout: 618 * - far_copies must be 1 619 * - near_copies must be 2 620 * - disks number must be even 621 * - all mirrors must be already degraded 622 */ 623 if (mddev->layout != ((1 << 8) + 2)) { 624 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", 625 mdname(mddev), 626 mddev->layout); 627 return ERR_PTR(-EINVAL); 628 } 629 if (mddev->raid_disks & 1) { 630 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", 631 mdname(mddev)); 632 return ERR_PTR(-EINVAL); 633 } 634 if (mddev->degraded != (mddev->raid_disks>>1)) { 635 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", 636 mdname(mddev)); 637 return ERR_PTR(-EINVAL); 638 } 639 640 /* Set new parameters */ 641 mddev->new_level = 0; 642 mddev->new_layout = 0; 643 mddev->new_chunk_sectors = mddev->chunk_sectors; 644 mddev->delta_disks = - mddev->raid_disks / 2; 645 mddev->raid_disks += mddev->delta_disks; 646 mddev->degraded = 0; 647 /* make sure it will be not marked as dirty */ 648 mddev->recovery_cp = MaxSector; 649 650 create_strip_zones(mddev, &priv_conf); 651 return priv_conf; 652 } 653 654 static void *raid0_takeover_raid1(mddev_t *mddev) 655 { 656 raid0_conf_t *priv_conf; 657 658 /* Check layout: 659 * - (N - 1) mirror drives must be already faulty 660 */ 661 if ((mddev->raid_disks - 1) != mddev->degraded) { 662 printk(KERN_ERR "md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 663 mdname(mddev)); 664 return ERR_PTR(-EINVAL); 665 } 666 667 /* Set new parameters */ 668 mddev->new_level = 0; 669 mddev->new_layout = 0; 670 mddev->new_chunk_sectors = 128; /* by default set chunk size to 64k */ 671 mddev->delta_disks = 1 - mddev->raid_disks; 672 mddev->raid_disks = 1; 673 /* make sure it will be not marked as dirty */ 674 mddev->recovery_cp = MaxSector; 675 676 create_strip_zones(mddev, &priv_conf); 677 return priv_conf; 678 } 679 680 static void *raid0_takeover(mddev_t *mddev) 681 { 682 /* raid0 can take over: 683 * raid4 - if all data disks are active. 684 * raid5 - providing it is Raid4 layout and one disk is faulty 685 * raid10 - assuming we have all necessary active disks 686 * raid1 - with (N -1) mirror drives faulty 687 */ 688 if (mddev->level == 4) 689 return raid0_takeover_raid45(mddev); 690 691 if (mddev->level == 5) { 692 if (mddev->layout == ALGORITHM_PARITY_N) 693 return raid0_takeover_raid45(mddev); 694 695 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 696 mdname(mddev), ALGORITHM_PARITY_N); 697 } 698 699 if (mddev->level == 10) 700 return raid0_takeover_raid10(mddev); 701 702 if (mddev->level == 1) 703 return raid0_takeover_raid1(mddev); 704 705 printk(KERN_ERR "Takeover from raid%i to raid0 not supported\n", 706 mddev->level); 707 708 return ERR_PTR(-EINVAL); 709 } 710 711 static void raid0_quiesce(mddev_t *mddev, int state) 712 { 713 } 714 715 static struct mdk_personality raid0_personality= 716 { 717 .name = "raid0", 718 .level = 0, 719 .owner = THIS_MODULE, 720 .make_request = raid0_make_request, 721 .run = raid0_run, 722 .stop = raid0_stop, 723 .status = raid0_status, 724 .size = raid0_size, 725 .takeover = raid0_takeover, 726 .quiesce = raid0_quiesce, 727 }; 728 729 static int __init raid0_init (void) 730 { 731 return register_md_personality (&raid0_personality); 732 } 733 734 static void raid0_exit (void) 735 { 736 unregister_md_personality (&raid0_personality); 737 } 738 739 module_init(raid0_init); 740 module_exit(raid0_exit); 741 MODULE_LICENSE("GPL"); 742 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 743 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 744 MODULE_ALIAS("md-raid0"); 745 MODULE_ALIAS("md-level-0"); 746