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 RAID-0 management functions. 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2, or (at your option) 13 any later version. 14 15 You should have received a copy of the GNU General Public License 16 (for example /usr/src/linux/COPYING); if not, write to the Free 17 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 */ 19 20 #include <linux/blkdev.h> 21 #include <linux/seq_file.h> 22 #include <linux/module.h> 23 #include <linux/slab.h> 24 #include "md.h" 25 #include "raid0.h" 26 #include "raid5.h" 27 28 static int raid0_congested(struct mddev *mddev, int bits) 29 { 30 struct r0conf *conf = mddev->private; 31 struct md_rdev **devlist = conf->devlist; 32 int raid_disks = conf->strip_zone[0].nb_dev; 33 int i, ret = 0; 34 35 for (i = 0; i < raid_disks && !ret ; i++) { 36 struct request_queue *q = bdev_get_queue(devlist[i]->bdev); 37 38 ret |= bdi_congested(&q->backing_dev_info, bits); 39 } 40 return ret; 41 } 42 43 /* 44 * inform the user of the raid configuration 45 */ 46 static void dump_zones(struct mddev *mddev) 47 { 48 int j, k; 49 sector_t zone_size = 0; 50 sector_t zone_start = 0; 51 char b[BDEVNAME_SIZE]; 52 struct r0conf *conf = mddev->private; 53 int raid_disks = conf->strip_zone[0].nb_dev; 54 printk(KERN_INFO "md: RAID0 configuration for %s - %d zone%s\n", 55 mdname(mddev), 56 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); 57 for (j = 0; j < conf->nr_strip_zones; j++) { 58 printk(KERN_INFO "md: zone%d=[", j); 59 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 60 printk(KERN_CONT "%s%s", k?"/":"", 61 bdevname(conf->devlist[j*raid_disks 62 + k]->bdev, b)); 63 printk(KERN_CONT "]\n"); 64 65 zone_size = conf->strip_zone[j].zone_end - zone_start; 66 printk(KERN_INFO " zone-offset=%10lluKB, " 67 "device-offset=%10lluKB, size=%10lluKB\n", 68 (unsigned long long)zone_start>>1, 69 (unsigned long long)conf->strip_zone[j].dev_start>>1, 70 (unsigned long long)zone_size>>1); 71 zone_start = conf->strip_zone[j].zone_end; 72 } 73 printk(KERN_INFO "\n"); 74 } 75 76 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 77 { 78 int i, c, err; 79 sector_t curr_zone_end, sectors; 80 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 81 struct strip_zone *zone; 82 int cnt; 83 char b[BDEVNAME_SIZE]; 84 char b2[BDEVNAME_SIZE]; 85 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 86 bool discard_supported = false; 87 88 if (!conf) 89 return -ENOMEM; 90 rdev_for_each(rdev1, mddev) { 91 pr_debug("md/raid0:%s: looking at %s\n", 92 mdname(mddev), 93 bdevname(rdev1->bdev, b)); 94 c = 0; 95 96 /* round size to chunk_size */ 97 sectors = rdev1->sectors; 98 sector_div(sectors, mddev->chunk_sectors); 99 rdev1->sectors = sectors * mddev->chunk_sectors; 100 101 rdev_for_each(rdev2, mddev) { 102 pr_debug("md/raid0:%s: comparing %s(%llu)" 103 " with %s(%llu)\n", 104 mdname(mddev), 105 bdevname(rdev1->bdev,b), 106 (unsigned long long)rdev1->sectors, 107 bdevname(rdev2->bdev,b2), 108 (unsigned long long)rdev2->sectors); 109 if (rdev2 == rdev1) { 110 pr_debug("md/raid0:%s: END\n", 111 mdname(mddev)); 112 break; 113 } 114 if (rdev2->sectors == rdev1->sectors) { 115 /* 116 * Not unique, don't count it as a new 117 * group 118 */ 119 pr_debug("md/raid0:%s: EQUAL\n", 120 mdname(mddev)); 121 c = 1; 122 break; 123 } 124 pr_debug("md/raid0:%s: NOT EQUAL\n", 125 mdname(mddev)); 126 } 127 if (!c) { 128 pr_debug("md/raid0:%s: ==> UNIQUE\n", 129 mdname(mddev)); 130 conf->nr_strip_zones++; 131 pr_debug("md/raid0:%s: %d zones\n", 132 mdname(mddev), conf->nr_strip_zones); 133 } 134 } 135 pr_debug("md/raid0:%s: FINAL %d zones\n", 136 mdname(mddev), conf->nr_strip_zones); 137 err = -ENOMEM; 138 conf->strip_zone = kzalloc(sizeof(struct strip_zone)* 139 conf->nr_strip_zones, GFP_KERNEL); 140 if (!conf->strip_zone) 141 goto abort; 142 conf->devlist = kzalloc(sizeof(struct md_rdev*)* 143 conf->nr_strip_zones*mddev->raid_disks, 144 GFP_KERNEL); 145 if (!conf->devlist) 146 goto abort; 147 148 /* The first zone must contain all devices, so here we check that 149 * there is a proper alignment of slots to devices and find them all 150 */ 151 zone = &conf->strip_zone[0]; 152 cnt = 0; 153 smallest = NULL; 154 dev = conf->devlist; 155 err = -EINVAL; 156 rdev_for_each(rdev1, mddev) { 157 int j = rdev1->raid_disk; 158 159 if (mddev->level == 10) { 160 /* taking over a raid10-n2 array */ 161 j /= 2; 162 rdev1->new_raid_disk = j; 163 } 164 165 if (mddev->level == 1) { 166 /* taiking over a raid1 array- 167 * we have only one active disk 168 */ 169 j = 0; 170 rdev1->new_raid_disk = j; 171 } 172 173 if (j < 0) { 174 printk(KERN_ERR 175 "md/raid0:%s: remove inactive devices before converting to RAID0\n", 176 mdname(mddev)); 177 goto abort; 178 } 179 if (j >= mddev->raid_disks) { 180 printk(KERN_ERR "md/raid0:%s: bad disk number %d - " 181 "aborting!\n", mdname(mddev), j); 182 goto abort; 183 } 184 if (dev[j]) { 185 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " 186 "aborting!\n", mdname(mddev), j); 187 goto abort; 188 } 189 dev[j] = rdev1; 190 191 disk_stack_limits(mddev->gendisk, rdev1->bdev, 192 rdev1->data_offset << 9); 193 194 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) 195 conf->has_merge_bvec = 1; 196 197 if (!smallest || (rdev1->sectors < smallest->sectors)) 198 smallest = rdev1; 199 cnt++; 200 201 if (blk_queue_discard(bdev_get_queue(rdev1->bdev))) 202 discard_supported = true; 203 } 204 if (cnt != mddev->raid_disks) { 205 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " 206 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); 207 goto abort; 208 } 209 zone->nb_dev = cnt; 210 zone->zone_end = smallest->sectors * cnt; 211 212 curr_zone_end = zone->zone_end; 213 214 /* now do the other zones */ 215 for (i = 1; i < conf->nr_strip_zones; i++) 216 { 217 int j; 218 219 zone = conf->strip_zone + i; 220 dev = conf->devlist + i * mddev->raid_disks; 221 222 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 223 zone->dev_start = smallest->sectors; 224 smallest = NULL; 225 c = 0; 226 227 for (j=0; j<cnt; j++) { 228 rdev = conf->devlist[j]; 229 if (rdev->sectors <= zone->dev_start) { 230 pr_debug("md/raid0:%s: checking %s ... nope\n", 231 mdname(mddev), 232 bdevname(rdev->bdev, b)); 233 continue; 234 } 235 pr_debug("md/raid0:%s: checking %s ..." 236 " contained as device %d\n", 237 mdname(mddev), 238 bdevname(rdev->bdev, b), c); 239 dev[c] = rdev; 240 c++; 241 if (!smallest || rdev->sectors < smallest->sectors) { 242 smallest = rdev; 243 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 244 mdname(mddev), 245 (unsigned long long)rdev->sectors); 246 } 247 } 248 249 zone->nb_dev = c; 250 sectors = (smallest->sectors - zone->dev_start) * c; 251 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 252 mdname(mddev), 253 zone->nb_dev, (unsigned long long)sectors); 254 255 curr_zone_end += sectors; 256 zone->zone_end = curr_zone_end; 257 258 pr_debug("md/raid0:%s: current zone start: %llu\n", 259 mdname(mddev), 260 (unsigned long long)smallest->sectors); 261 } 262 263 /* 264 * now since we have the hard sector sizes, we can make sure 265 * chunk size is a multiple of that sector size 266 */ 267 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { 268 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", 269 mdname(mddev), 270 mddev->chunk_sectors << 9); 271 goto abort; 272 } 273 274 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 275 blk_queue_io_opt(mddev->queue, 276 (mddev->chunk_sectors << 9) * mddev->raid_disks); 277 278 if (!discard_supported) 279 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 280 else 281 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 282 283 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 284 *private_conf = conf; 285 286 return 0; 287 abort: 288 kfree(conf->strip_zone); 289 kfree(conf->devlist); 290 kfree(conf); 291 *private_conf = ERR_PTR(err); 292 return err; 293 } 294 295 /* Find the zone which holds a particular offset 296 * Update *sectorp to be an offset in that zone 297 */ 298 static struct strip_zone *find_zone(struct r0conf *conf, 299 sector_t *sectorp) 300 { 301 int i; 302 struct strip_zone *z = conf->strip_zone; 303 sector_t sector = *sectorp; 304 305 for (i = 0; i < conf->nr_strip_zones; i++) 306 if (sector < z[i].zone_end) { 307 if (i) 308 *sectorp = sector - z[i-1].zone_end; 309 return z + i; 310 } 311 BUG(); 312 } 313 314 /* 315 * remaps the bio to the target device. we separate two flows. 316 * power 2 flow and a general flow for the sake of perfromance 317 */ 318 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 319 sector_t sector, sector_t *sector_offset) 320 { 321 unsigned int sect_in_chunk; 322 sector_t chunk; 323 struct r0conf *conf = mddev->private; 324 int raid_disks = conf->strip_zone[0].nb_dev; 325 unsigned int chunk_sects = mddev->chunk_sectors; 326 327 if (is_power_of_2(chunk_sects)) { 328 int chunksect_bits = ffz(~chunk_sects); 329 /* find the sector offset inside the chunk */ 330 sect_in_chunk = sector & (chunk_sects - 1); 331 sector >>= chunksect_bits; 332 /* chunk in zone */ 333 chunk = *sector_offset; 334 /* quotient is the chunk in real device*/ 335 sector_div(chunk, zone->nb_dev << chunksect_bits); 336 } else{ 337 sect_in_chunk = sector_div(sector, chunk_sects); 338 chunk = *sector_offset; 339 sector_div(chunk, chunk_sects * zone->nb_dev); 340 } 341 /* 342 * position the bio over the real device 343 * real sector = chunk in device + starting of zone 344 * + the position in the chunk 345 */ 346 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 347 return conf->devlist[(zone - conf->strip_zone)*raid_disks 348 + sector_div(sector, zone->nb_dev)]; 349 } 350 351 /** 352 * raid0_mergeable_bvec -- tell bio layer if two requests can be merged 353 * @mddev: the md device 354 * @bvm: properties of new bio 355 * @biovec: the request that could be merged to it. 356 * 357 * Return amount of bytes we can accept at this offset 358 */ 359 static int raid0_mergeable_bvec(struct mddev *mddev, 360 struct bvec_merge_data *bvm, 361 struct bio_vec *biovec) 362 { 363 struct r0conf *conf = mddev->private; 364 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 365 sector_t sector_offset = sector; 366 int max; 367 unsigned int chunk_sectors = mddev->chunk_sectors; 368 unsigned int bio_sectors = bvm->bi_size >> 9; 369 struct strip_zone *zone; 370 struct md_rdev *rdev; 371 struct request_queue *subq; 372 373 if (is_power_of_2(chunk_sectors)) 374 max = (chunk_sectors - ((sector & (chunk_sectors-1)) 375 + bio_sectors)) << 9; 376 else 377 max = (chunk_sectors - (sector_div(sector, chunk_sectors) 378 + bio_sectors)) << 9; 379 if (max < 0) 380 max = 0; /* bio_add cannot handle a negative return */ 381 if (max <= biovec->bv_len && bio_sectors == 0) 382 return biovec->bv_len; 383 if (max < biovec->bv_len) 384 /* too small already, no need to check further */ 385 return max; 386 if (!conf->has_merge_bvec) 387 return max; 388 389 /* May need to check subordinate device */ 390 sector = sector_offset; 391 zone = find_zone(mddev->private, §or_offset); 392 rdev = map_sector(mddev, zone, sector, §or_offset); 393 subq = bdev_get_queue(rdev->bdev); 394 if (subq->merge_bvec_fn) { 395 bvm->bi_bdev = rdev->bdev; 396 bvm->bi_sector = sector_offset + zone->dev_start + 397 rdev->data_offset; 398 return min(max, subq->merge_bvec_fn(subq, bvm, biovec)); 399 } else 400 return max; 401 } 402 403 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 404 { 405 sector_t array_sectors = 0; 406 struct md_rdev *rdev; 407 408 WARN_ONCE(sectors || raid_disks, 409 "%s does not support generic reshape\n", __func__); 410 411 rdev_for_each(rdev, mddev) 412 array_sectors += (rdev->sectors & 413 ~(sector_t)(mddev->chunk_sectors-1)); 414 415 return array_sectors; 416 } 417 418 static void raid0_free(struct mddev *mddev, void *priv); 419 420 static int raid0_run(struct mddev *mddev) 421 { 422 struct r0conf *conf; 423 int ret; 424 425 if (mddev->chunk_sectors == 0) { 426 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", 427 mdname(mddev)); 428 return -EINVAL; 429 } 430 if (md_check_no_bitmap(mddev)) 431 return -EINVAL; 432 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 433 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); 434 blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); 435 436 /* if private is not null, we are here after takeover */ 437 if (mddev->private == NULL) { 438 ret = create_strip_zones(mddev, &conf); 439 if (ret < 0) 440 return ret; 441 mddev->private = conf; 442 } 443 conf = mddev->private; 444 445 /* calculate array device size */ 446 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 447 448 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", 449 mdname(mddev), 450 (unsigned long long)mddev->array_sectors); 451 /* calculate the max read-ahead size. 452 * For read-ahead of large files to be effective, we need to 453 * readahead at least twice a whole stripe. i.e. number of devices 454 * multiplied by chunk size times 2. 455 * If an individual device has an ra_pages greater than the 456 * chunk size, then we will not drive that device as hard as it 457 * wants. We consider this a configuration error: a larger 458 * chunksize should be used in that case. 459 */ 460 { 461 int stripe = mddev->raid_disks * 462 (mddev->chunk_sectors << 9) / PAGE_SIZE; 463 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) 464 mddev->queue->backing_dev_info.ra_pages = 2* stripe; 465 } 466 467 dump_zones(mddev); 468 469 ret = md_integrity_register(mddev); 470 471 return ret; 472 } 473 474 static void raid0_free(struct mddev *mddev, void *priv) 475 { 476 struct r0conf *conf = priv; 477 478 kfree(conf->strip_zone); 479 kfree(conf->devlist); 480 kfree(conf); 481 } 482 483 /* 484 * Is io distribute over 1 or more chunks ? 485 */ 486 static inline int is_io_in_chunk_boundary(struct mddev *mddev, 487 unsigned int chunk_sects, struct bio *bio) 488 { 489 if (likely(is_power_of_2(chunk_sects))) { 490 return chunk_sects >= 491 ((bio->bi_iter.bi_sector & (chunk_sects-1)) 492 + bio_sectors(bio)); 493 } else{ 494 sector_t sector = bio->bi_iter.bi_sector; 495 return chunk_sects >= (sector_div(sector, chunk_sects) 496 + bio_sectors(bio)); 497 } 498 } 499 500 static void raid0_make_request(struct mddev *mddev, struct bio *bio) 501 { 502 struct strip_zone *zone; 503 struct md_rdev *tmp_dev; 504 struct bio *split; 505 506 if (unlikely(bio->bi_rw & REQ_FLUSH)) { 507 md_flush_request(mddev, bio); 508 return; 509 } 510 511 do { 512 sector_t sector = bio->bi_iter.bi_sector; 513 unsigned chunk_sects = mddev->chunk_sectors; 514 515 unsigned sectors = chunk_sects - 516 (likely(is_power_of_2(chunk_sects)) 517 ? (sector & (chunk_sects-1)) 518 : sector_div(sector, chunk_sects)); 519 520 if (sectors < bio_sectors(bio)) { 521 split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set); 522 bio_chain(split, bio); 523 } else { 524 split = bio; 525 } 526 527 zone = find_zone(mddev->private, §or); 528 tmp_dev = map_sector(mddev, zone, sector, §or); 529 split->bi_bdev = tmp_dev->bdev; 530 split->bi_iter.bi_sector = sector + zone->dev_start + 531 tmp_dev->data_offset; 532 533 if (unlikely((split->bi_rw & REQ_DISCARD) && 534 !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { 535 /* Just ignore it */ 536 bio_endio(split, 0); 537 } else 538 generic_make_request(split); 539 } while (split != bio); 540 } 541 542 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 543 { 544 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 545 return; 546 } 547 548 static void *raid0_takeover_raid45(struct mddev *mddev) 549 { 550 struct md_rdev *rdev; 551 struct r0conf *priv_conf; 552 553 if (mddev->degraded != 1) { 554 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 555 mdname(mddev), 556 mddev->degraded); 557 return ERR_PTR(-EINVAL); 558 } 559 560 rdev_for_each(rdev, mddev) { 561 /* check slot number for a disk */ 562 if (rdev->raid_disk == mddev->raid_disks-1) { 563 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", 564 mdname(mddev)); 565 return ERR_PTR(-EINVAL); 566 } 567 rdev->sectors = mddev->dev_sectors; 568 } 569 570 /* Set new parameters */ 571 mddev->new_level = 0; 572 mddev->new_layout = 0; 573 mddev->new_chunk_sectors = mddev->chunk_sectors; 574 mddev->raid_disks--; 575 mddev->delta_disks = -1; 576 /* make sure it will be not marked as dirty */ 577 mddev->recovery_cp = MaxSector; 578 579 create_strip_zones(mddev, &priv_conf); 580 return priv_conf; 581 } 582 583 static void *raid0_takeover_raid10(struct mddev *mddev) 584 { 585 struct r0conf *priv_conf; 586 587 /* Check layout: 588 * - far_copies must be 1 589 * - near_copies must be 2 590 * - disks number must be even 591 * - all mirrors must be already degraded 592 */ 593 if (mddev->layout != ((1 << 8) + 2)) { 594 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", 595 mdname(mddev), 596 mddev->layout); 597 return ERR_PTR(-EINVAL); 598 } 599 if (mddev->raid_disks & 1) { 600 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", 601 mdname(mddev)); 602 return ERR_PTR(-EINVAL); 603 } 604 if (mddev->degraded != (mddev->raid_disks>>1)) { 605 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", 606 mdname(mddev)); 607 return ERR_PTR(-EINVAL); 608 } 609 610 /* Set new parameters */ 611 mddev->new_level = 0; 612 mddev->new_layout = 0; 613 mddev->new_chunk_sectors = mddev->chunk_sectors; 614 mddev->delta_disks = - mddev->raid_disks / 2; 615 mddev->raid_disks += mddev->delta_disks; 616 mddev->degraded = 0; 617 /* make sure it will be not marked as dirty */ 618 mddev->recovery_cp = MaxSector; 619 620 create_strip_zones(mddev, &priv_conf); 621 return priv_conf; 622 } 623 624 static void *raid0_takeover_raid1(struct mddev *mddev) 625 { 626 struct r0conf *priv_conf; 627 int chunksect; 628 629 /* Check layout: 630 * - (N - 1) mirror drives must be already faulty 631 */ 632 if ((mddev->raid_disks - 1) != mddev->degraded) { 633 printk(KERN_ERR "md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", 634 mdname(mddev)); 635 return ERR_PTR(-EINVAL); 636 } 637 638 /* 639 * a raid1 doesn't have the notion of chunk size, so 640 * figure out the largest suitable size we can use. 641 */ 642 chunksect = 64 * 2; /* 64K by default */ 643 644 /* The array must be an exact multiple of chunksize */ 645 while (chunksect && (mddev->array_sectors & (chunksect - 1))) 646 chunksect >>= 1; 647 648 if ((chunksect << 9) < PAGE_SIZE) 649 /* array size does not allow a suitable chunk size */ 650 return ERR_PTR(-EINVAL); 651 652 /* Set new parameters */ 653 mddev->new_level = 0; 654 mddev->new_layout = 0; 655 mddev->new_chunk_sectors = chunksect; 656 mddev->chunk_sectors = chunksect; 657 mddev->delta_disks = 1 - mddev->raid_disks; 658 mddev->raid_disks = 1; 659 /* make sure it will be not marked as dirty */ 660 mddev->recovery_cp = MaxSector; 661 662 create_strip_zones(mddev, &priv_conf); 663 return priv_conf; 664 } 665 666 static void *raid0_takeover(struct mddev *mddev) 667 { 668 /* raid0 can take over: 669 * raid4 - if all data disks are active. 670 * raid5 - providing it is Raid4 layout and one disk is faulty 671 * raid10 - assuming we have all necessary active disks 672 * raid1 - with (N -1) mirror drives faulty 673 */ 674 675 if (mddev->bitmap) { 676 printk(KERN_ERR "md/raid0: %s: cannot takeover array with bitmap\n", 677 mdname(mddev)); 678 return ERR_PTR(-EBUSY); 679 } 680 if (mddev->level == 4) 681 return raid0_takeover_raid45(mddev); 682 683 if (mddev->level == 5) { 684 if (mddev->layout == ALGORITHM_PARITY_N) 685 return raid0_takeover_raid45(mddev); 686 687 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 688 mdname(mddev), ALGORITHM_PARITY_N); 689 } 690 691 if (mddev->level == 10) 692 return raid0_takeover_raid10(mddev); 693 694 if (mddev->level == 1) 695 return raid0_takeover_raid1(mddev); 696 697 printk(KERN_ERR "Takeover from raid%i to raid0 not supported\n", 698 mddev->level); 699 700 return ERR_PTR(-EINVAL); 701 } 702 703 static void raid0_quiesce(struct mddev *mddev, int state) 704 { 705 } 706 707 static struct md_personality raid0_personality= 708 { 709 .name = "raid0", 710 .level = 0, 711 .owner = THIS_MODULE, 712 .make_request = raid0_make_request, 713 .run = raid0_run, 714 .free = raid0_free, 715 .status = raid0_status, 716 .size = raid0_size, 717 .takeover = raid0_takeover, 718 .quiesce = raid0_quiesce, 719 .congested = raid0_congested, 720 .mergeable_bvec = raid0_mergeable_bvec, 721 }; 722 723 static int __init raid0_init (void) 724 { 725 return register_md_personality (&raid0_personality); 726 } 727 728 static void raid0_exit (void) 729 { 730 unregister_md_personality (&raid0_personality); 731 } 732 733 module_init(raid0_init); 734 module_exit(raid0_exit); 735 MODULE_LICENSE("GPL"); 736 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 737 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 738 MODULE_ALIAS("md-raid0"); 739 MODULE_ALIAS("md-level-0"); 740