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/module.h> 24 #include <linux/slab.h> 25 #include "md.h" 26 #include "raid0.h" 27 #include "raid5.h" 28 29 static int raid0_congested(void *data, int bits) 30 { 31 struct mddev *mddev = data; 32 struct r0conf *conf = mddev->private; 33 struct md_rdev **devlist = conf->devlist; 34 int raid_disks = conf->strip_zone[0].nb_dev; 35 int i, ret = 0; 36 37 if (mddev_congested(mddev, bits)) 38 return 1; 39 40 for (i = 0; i < raid_disks && !ret ; i++) { 41 struct request_queue *q = bdev_get_queue(devlist[i]->bdev); 42 43 ret |= bdi_congested(&q->backing_dev_info, bits); 44 } 45 return ret; 46 } 47 48 /* 49 * inform the user of the raid configuration 50 */ 51 static void dump_zones(struct mddev *mddev) 52 { 53 int j, k; 54 sector_t zone_size = 0; 55 sector_t zone_start = 0; 56 char b[BDEVNAME_SIZE]; 57 struct r0conf *conf = mddev->private; 58 int raid_disks = conf->strip_zone[0].nb_dev; 59 printk(KERN_INFO "md: RAID0 configuration for %s - %d zone%s\n", 60 mdname(mddev), 61 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); 62 for (j = 0; j < conf->nr_strip_zones; j++) { 63 printk(KERN_INFO "md: zone%d=[", j); 64 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 65 printk(KERN_CONT "%s%s", k?"/":"", 66 bdevname(conf->devlist[j*raid_disks 67 + k]->bdev, b)); 68 printk(KERN_CONT "]\n"); 69 70 zone_size = conf->strip_zone[j].zone_end - zone_start; 71 printk(KERN_INFO " zone-offset=%10lluKB, " 72 "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 printk(KERN_INFO "\n"); 79 } 80 81 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) 82 { 83 int i, c, err; 84 sector_t curr_zone_end, sectors; 85 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; 86 struct strip_zone *zone; 87 int cnt; 88 char b[BDEVNAME_SIZE]; 89 char b2[BDEVNAME_SIZE]; 90 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); 91 92 if (!conf) 93 return -ENOMEM; 94 rdev_for_each(rdev1, mddev) { 95 pr_debug("md/raid0:%s: looking at %s\n", 96 mdname(mddev), 97 bdevname(rdev1->bdev, b)); 98 c = 0; 99 100 /* round size to chunk_size */ 101 sectors = rdev1->sectors; 102 sector_div(sectors, mddev->chunk_sectors); 103 rdev1->sectors = sectors * mddev->chunk_sectors; 104 105 rdev_for_each(rdev2, mddev) { 106 pr_debug("md/raid0:%s: comparing %s(%llu)" 107 " with %s(%llu)\n", 108 mdname(mddev), 109 bdevname(rdev1->bdev,b), 110 (unsigned long long)rdev1->sectors, 111 bdevname(rdev2->bdev,b2), 112 (unsigned long long)rdev2->sectors); 113 if (rdev2 == rdev1) { 114 pr_debug("md/raid0:%s: END\n", 115 mdname(mddev)); 116 break; 117 } 118 if (rdev2->sectors == rdev1->sectors) { 119 /* 120 * Not unique, don't count it as a new 121 * group 122 */ 123 pr_debug("md/raid0:%s: EQUAL\n", 124 mdname(mddev)); 125 c = 1; 126 break; 127 } 128 pr_debug("md/raid0:%s: NOT EQUAL\n", 129 mdname(mddev)); 130 } 131 if (!c) { 132 pr_debug("md/raid0:%s: ==> UNIQUE\n", 133 mdname(mddev)); 134 conf->nr_strip_zones++; 135 pr_debug("md/raid0:%s: %d zones\n", 136 mdname(mddev), conf->nr_strip_zones); 137 } 138 } 139 pr_debug("md/raid0:%s: FINAL %d zones\n", 140 mdname(mddev), conf->nr_strip_zones); 141 err = -ENOMEM; 142 conf->strip_zone = kzalloc(sizeof(struct strip_zone)* 143 conf->nr_strip_zones, GFP_KERNEL); 144 if (!conf->strip_zone) 145 goto abort; 146 conf->devlist = kzalloc(sizeof(struct md_rdev*)* 147 conf->nr_strip_zones*mddev->raid_disks, 148 GFP_KERNEL); 149 if (!conf->devlist) 150 goto abort; 151 152 /* The first zone must contain all devices, so here we check that 153 * there is a proper alignment of slots to devices and find them all 154 */ 155 zone = &conf->strip_zone[0]; 156 cnt = 0; 157 smallest = NULL; 158 dev = conf->devlist; 159 err = -EINVAL; 160 rdev_for_each(rdev1, mddev) { 161 int j = rdev1->raid_disk; 162 163 if (mddev->level == 10) { 164 /* taking over a raid10-n2 array */ 165 j /= 2; 166 rdev1->new_raid_disk = j; 167 } 168 169 if (mddev->level == 1) { 170 /* taiking over a raid1 array- 171 * we have only one active disk 172 */ 173 j = 0; 174 rdev1->new_raid_disk = j; 175 } 176 177 if (j < 0 || j >= mddev->raid_disks) { 178 printk(KERN_ERR "md/raid0:%s: bad disk number %d - " 179 "aborting!\n", mdname(mddev), j); 180 goto abort; 181 } 182 if (dev[j]) { 183 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " 184 "aborting!\n", mdname(mddev), j); 185 goto abort; 186 } 187 dev[j] = rdev1; 188 189 disk_stack_limits(mddev->gendisk, rdev1->bdev, 190 rdev1->data_offset << 9); 191 192 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) 193 conf->has_merge_bvec = 1; 194 195 if (!smallest || (rdev1->sectors < smallest->sectors)) 196 smallest = rdev1; 197 cnt++; 198 } 199 if (cnt != mddev->raid_disks) { 200 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " 201 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); 202 goto abort; 203 } 204 zone->nb_dev = cnt; 205 zone->zone_end = smallest->sectors * cnt; 206 207 curr_zone_end = zone->zone_end; 208 209 /* now do the other zones */ 210 for (i = 1; i < conf->nr_strip_zones; i++) 211 { 212 int j; 213 214 zone = conf->strip_zone + i; 215 dev = conf->devlist + i * mddev->raid_disks; 216 217 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); 218 zone->dev_start = smallest->sectors; 219 smallest = NULL; 220 c = 0; 221 222 for (j=0; j<cnt; j++) { 223 rdev = conf->devlist[j]; 224 if (rdev->sectors <= zone->dev_start) { 225 pr_debug("md/raid0:%s: checking %s ... nope\n", 226 mdname(mddev), 227 bdevname(rdev->bdev, b)); 228 continue; 229 } 230 pr_debug("md/raid0:%s: checking %s ..." 231 " contained as device %d\n", 232 mdname(mddev), 233 bdevname(rdev->bdev, b), c); 234 dev[c] = rdev; 235 c++; 236 if (!smallest || rdev->sectors < smallest->sectors) { 237 smallest = rdev; 238 pr_debug("md/raid0:%s: (%llu) is smallest!.\n", 239 mdname(mddev), 240 (unsigned long long)rdev->sectors); 241 } 242 } 243 244 zone->nb_dev = c; 245 sectors = (smallest->sectors - zone->dev_start) * c; 246 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 247 mdname(mddev), 248 zone->nb_dev, (unsigned long long)sectors); 249 250 curr_zone_end += sectors; 251 zone->zone_end = curr_zone_end; 252 253 pr_debug("md/raid0:%s: current zone start: %llu\n", 254 mdname(mddev), 255 (unsigned long long)smallest->sectors); 256 } 257 mddev->queue->backing_dev_info.congested_fn = raid0_congested; 258 mddev->queue->backing_dev_info.congested_data = mddev; 259 260 /* 261 * now since we have the hard sector sizes, we can make sure 262 * chunk size is a multiple of that sector size 263 */ 264 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { 265 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", 266 mdname(mddev), 267 mddev->chunk_sectors << 9); 268 goto abort; 269 } 270 271 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 272 blk_queue_io_opt(mddev->queue, 273 (mddev->chunk_sectors << 9) * mddev->raid_disks); 274 275 pr_debug("md/raid0:%s: done.\n", mdname(mddev)); 276 *private_conf = conf; 277 278 return 0; 279 abort: 280 kfree(conf->strip_zone); 281 kfree(conf->devlist); 282 kfree(conf); 283 *private_conf = NULL; 284 return err; 285 } 286 287 /* Find the zone which holds a particular offset 288 * Update *sectorp to be an offset in that zone 289 */ 290 static struct strip_zone *find_zone(struct r0conf *conf, 291 sector_t *sectorp) 292 { 293 int i; 294 struct strip_zone *z = conf->strip_zone; 295 sector_t sector = *sectorp; 296 297 for (i = 0; i < conf->nr_strip_zones; i++) 298 if (sector < z[i].zone_end) { 299 if (i) 300 *sectorp = sector - z[i-1].zone_end; 301 return z + i; 302 } 303 BUG(); 304 } 305 306 /* 307 * remaps the bio to the target device. we separate two flows. 308 * power 2 flow and a general flow for the sake of perfromance 309 */ 310 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, 311 sector_t sector, sector_t *sector_offset) 312 { 313 unsigned int sect_in_chunk; 314 sector_t chunk; 315 struct r0conf *conf = mddev->private; 316 int raid_disks = conf->strip_zone[0].nb_dev; 317 unsigned int chunk_sects = mddev->chunk_sectors; 318 319 if (is_power_of_2(chunk_sects)) { 320 int chunksect_bits = ffz(~chunk_sects); 321 /* find the sector offset inside the chunk */ 322 sect_in_chunk = sector & (chunk_sects - 1); 323 sector >>= chunksect_bits; 324 /* chunk in zone */ 325 chunk = *sector_offset; 326 /* quotient is the chunk in real device*/ 327 sector_div(chunk, zone->nb_dev << chunksect_bits); 328 } else{ 329 sect_in_chunk = sector_div(sector, chunk_sects); 330 chunk = *sector_offset; 331 sector_div(chunk, chunk_sects * zone->nb_dev); 332 } 333 /* 334 * position the bio over the real device 335 * real sector = chunk in device + starting of zone 336 * + the position in the chunk 337 */ 338 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 339 return conf->devlist[(zone - conf->strip_zone)*raid_disks 340 + sector_div(sector, zone->nb_dev)]; 341 } 342 343 /** 344 * raid0_mergeable_bvec -- tell bio layer if two requests can be merged 345 * @q: request queue 346 * @bvm: properties of new bio 347 * @biovec: the request that could be merged to it. 348 * 349 * Return amount of bytes we can accept at this offset 350 */ 351 static int raid0_mergeable_bvec(struct request_queue *q, 352 struct bvec_merge_data *bvm, 353 struct bio_vec *biovec) 354 { 355 struct mddev *mddev = q->queuedata; 356 struct r0conf *conf = mddev->private; 357 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 358 sector_t sector_offset = sector; 359 int max; 360 unsigned int chunk_sectors = mddev->chunk_sectors; 361 unsigned int bio_sectors = bvm->bi_size >> 9; 362 struct strip_zone *zone; 363 struct md_rdev *rdev; 364 struct request_queue *subq; 365 366 if (is_power_of_2(chunk_sectors)) 367 max = (chunk_sectors - ((sector & (chunk_sectors-1)) 368 + bio_sectors)) << 9; 369 else 370 max = (chunk_sectors - (sector_div(sector, chunk_sectors) 371 + bio_sectors)) << 9; 372 if (max < 0) 373 max = 0; /* bio_add cannot handle a negative return */ 374 if (max <= biovec->bv_len && bio_sectors == 0) 375 return biovec->bv_len; 376 if (max < biovec->bv_len) 377 /* too small already, no need to check further */ 378 return max; 379 if (!conf->has_merge_bvec) 380 return max; 381 382 /* May need to check subordinate device */ 383 sector = sector_offset; 384 zone = find_zone(mddev->private, §or_offset); 385 rdev = map_sector(mddev, zone, sector, §or_offset); 386 subq = bdev_get_queue(rdev->bdev); 387 if (subq->merge_bvec_fn) { 388 bvm->bi_bdev = rdev->bdev; 389 bvm->bi_sector = sector_offset + zone->dev_start + 390 rdev->data_offset; 391 return min(max, subq->merge_bvec_fn(subq, bvm, biovec)); 392 } else 393 return max; 394 } 395 396 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) 397 { 398 sector_t array_sectors = 0; 399 struct md_rdev *rdev; 400 401 WARN_ONCE(sectors || raid_disks, 402 "%s does not support generic reshape\n", __func__); 403 404 rdev_for_each(rdev, mddev) 405 array_sectors += rdev->sectors; 406 407 return array_sectors; 408 } 409 410 static int raid0_run(struct mddev *mddev) 411 { 412 struct r0conf *conf; 413 int ret; 414 415 if (mddev->chunk_sectors == 0) { 416 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", 417 mdname(mddev)); 418 return -EINVAL; 419 } 420 if (md_check_no_bitmap(mddev)) 421 return -EINVAL; 422 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 423 424 /* if private is not null, we are here after takeover */ 425 if (mddev->private == NULL) { 426 ret = create_strip_zones(mddev, &conf); 427 if (ret < 0) 428 return ret; 429 mddev->private = conf; 430 } 431 conf = mddev->private; 432 433 /* calculate array device size */ 434 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 435 436 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", 437 mdname(mddev), 438 (unsigned long long)mddev->array_sectors); 439 /* calculate the max read-ahead size. 440 * For read-ahead of large files to be effective, we need to 441 * readahead at least twice a whole stripe. i.e. number of devices 442 * multiplied by chunk size times 2. 443 * If an individual device has an ra_pages greater than the 444 * chunk size, then we will not drive that device as hard as it 445 * wants. We consider this a configuration error: a larger 446 * chunksize should be used in that case. 447 */ 448 { 449 int stripe = mddev->raid_disks * 450 (mddev->chunk_sectors << 9) / PAGE_SIZE; 451 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) 452 mddev->queue->backing_dev_info.ra_pages = 2* stripe; 453 } 454 455 blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); 456 dump_zones(mddev); 457 return md_integrity_register(mddev); 458 } 459 460 static int raid0_stop(struct mddev *mddev) 461 { 462 struct r0conf *conf = mddev->private; 463 464 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 465 kfree(conf->strip_zone); 466 kfree(conf->devlist); 467 kfree(conf); 468 mddev->private = NULL; 469 return 0; 470 } 471 472 /* 473 * Is io distribute over 1 or more chunks ? 474 */ 475 static inline int is_io_in_chunk_boundary(struct mddev *mddev, 476 unsigned int chunk_sects, struct bio *bio) 477 { 478 if (likely(is_power_of_2(chunk_sects))) { 479 return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) 480 + (bio->bi_size >> 9)); 481 } else{ 482 sector_t sector = bio->bi_sector; 483 return chunk_sects >= (sector_div(sector, chunk_sects) 484 + (bio->bi_size >> 9)); 485 } 486 } 487 488 static void raid0_make_request(struct mddev *mddev, struct bio *bio) 489 { 490 unsigned int chunk_sects; 491 sector_t sector_offset; 492 struct strip_zone *zone; 493 struct md_rdev *tmp_dev; 494 495 if (unlikely(bio->bi_rw & REQ_FLUSH)) { 496 md_flush_request(mddev, bio); 497 return; 498 } 499 500 chunk_sects = mddev->chunk_sectors; 501 if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { 502 sector_t sector = bio->bi_sector; 503 struct bio_pair *bp; 504 /* Sanity check -- queue functions should prevent this happening */ 505 if (bio->bi_vcnt != 1 || 506 bio->bi_idx != 0) 507 goto bad_map; 508 /* This is a one page bio that upper layers 509 * refuse to split for us, so we need to split it. 510 */ 511 if (likely(is_power_of_2(chunk_sects))) 512 bp = bio_split(bio, chunk_sects - (sector & 513 (chunk_sects-1))); 514 else 515 bp = bio_split(bio, chunk_sects - 516 sector_div(sector, chunk_sects)); 517 raid0_make_request(mddev, &bp->bio1); 518 raid0_make_request(mddev, &bp->bio2); 519 bio_pair_release(bp); 520 return; 521 } 522 523 sector_offset = bio->bi_sector; 524 zone = find_zone(mddev->private, §or_offset); 525 tmp_dev = map_sector(mddev, zone, bio->bi_sector, 526 §or_offset); 527 bio->bi_bdev = tmp_dev->bdev; 528 bio->bi_sector = sector_offset + zone->dev_start + 529 tmp_dev->data_offset; 530 531 generic_make_request(bio); 532 return; 533 534 bad_map: 535 printk("md/raid0:%s: make_request bug: can't convert block across chunks" 536 " or bigger than %dk %llu %d\n", 537 mdname(mddev), chunk_sects / 2, 538 (unsigned long long)bio->bi_sector, bio->bi_size >> 10); 539 540 bio_io_error(bio); 541 return; 542 } 543 544 static void raid0_status(struct seq_file *seq, struct mddev *mddev) 545 { 546 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 547 return; 548 } 549 550 static void *raid0_takeover_raid45(struct mddev *mddev) 551 { 552 struct md_rdev *rdev; 553 struct r0conf *priv_conf; 554 555 if (mddev->degraded != 1) { 556 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 557 mdname(mddev), 558 mddev->degraded); 559 return ERR_PTR(-EINVAL); 560 } 561 562 rdev_for_each(rdev, mddev) { 563 /* check slot number for a disk */ 564 if (rdev->raid_disk == mddev->raid_disks-1) { 565 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", 566 mdname(mddev)); 567 return ERR_PTR(-EINVAL); 568 } 569 } 570 571 /* Set new parameters */ 572 mddev->new_level = 0; 573 mddev->new_layout = 0; 574 mddev->new_chunk_sectors = mddev->chunk_sectors; 575 mddev->raid_disks--; 576 mddev->delta_disks = -1; 577 /* make sure it will be not marked as dirty */ 578 mddev->recovery_cp = MaxSector; 579 580 create_strip_zones(mddev, &priv_conf); 581 return priv_conf; 582 } 583 584 static void *raid0_takeover_raid10(struct mddev *mddev) 585 { 586 struct r0conf *priv_conf; 587 588 /* Check layout: 589 * - far_copies must be 1 590 * - near_copies must be 2 591 * - disks number must be even 592 * - all mirrors must be already degraded 593 */ 594 if (mddev->layout != ((1 << 8) + 2)) { 595 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", 596 mdname(mddev), 597 mddev->layout); 598 return ERR_PTR(-EINVAL); 599 } 600 if (mddev->raid_disks & 1) { 601 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", 602 mdname(mddev)); 603 return ERR_PTR(-EINVAL); 604 } 605 if (mddev->degraded != (mddev->raid_disks>>1)) { 606 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", 607 mdname(mddev)); 608 return ERR_PTR(-EINVAL); 609 } 610 611 /* Set new parameters */ 612 mddev->new_level = 0; 613 mddev->new_layout = 0; 614 mddev->new_chunk_sectors = mddev->chunk_sectors; 615 mddev->delta_disks = - mddev->raid_disks / 2; 616 mddev->raid_disks += mddev->delta_disks; 617 mddev->degraded = 0; 618 /* make sure it will be not marked as dirty */ 619 mddev->recovery_cp = MaxSector; 620 621 create_strip_zones(mddev, &priv_conf); 622 return priv_conf; 623 } 624 625 static void *raid0_takeover_raid1(struct mddev *mddev) 626 { 627 struct r0conf *priv_conf; 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 /* Set new parameters */ 639 mddev->new_level = 0; 640 mddev->new_layout = 0; 641 mddev->new_chunk_sectors = 128; /* by default set chunk size to 64k */ 642 mddev->delta_disks = 1 - mddev->raid_disks; 643 mddev->raid_disks = 1; 644 /* make sure it will be not marked as dirty */ 645 mddev->recovery_cp = MaxSector; 646 647 create_strip_zones(mddev, &priv_conf); 648 return priv_conf; 649 } 650 651 static void *raid0_takeover(struct mddev *mddev) 652 { 653 /* raid0 can take over: 654 * raid4 - if all data disks are active. 655 * raid5 - providing it is Raid4 layout and one disk is faulty 656 * raid10 - assuming we have all necessary active disks 657 * raid1 - with (N -1) mirror drives faulty 658 */ 659 if (mddev->level == 4) 660 return raid0_takeover_raid45(mddev); 661 662 if (mddev->level == 5) { 663 if (mddev->layout == ALGORITHM_PARITY_N) 664 return raid0_takeover_raid45(mddev); 665 666 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 667 mdname(mddev), ALGORITHM_PARITY_N); 668 } 669 670 if (mddev->level == 10) 671 return raid0_takeover_raid10(mddev); 672 673 if (mddev->level == 1) 674 return raid0_takeover_raid1(mddev); 675 676 printk(KERN_ERR "Takeover from raid%i to raid0 not supported\n", 677 mddev->level); 678 679 return ERR_PTR(-EINVAL); 680 } 681 682 static void raid0_quiesce(struct mddev *mddev, int state) 683 { 684 } 685 686 static struct md_personality raid0_personality= 687 { 688 .name = "raid0", 689 .level = 0, 690 .owner = THIS_MODULE, 691 .make_request = raid0_make_request, 692 .run = raid0_run, 693 .stop = raid0_stop, 694 .status = raid0_status, 695 .size = raid0_size, 696 .takeover = raid0_takeover, 697 .quiesce = raid0_quiesce, 698 }; 699 700 static int __init raid0_init (void) 701 { 702 return register_md_personality (&raid0_personality); 703 } 704 705 static void raid0_exit (void) 706 { 707 unregister_md_personality (&raid0_personality); 708 } 709 710 module_init(raid0_init); 711 module_exit(raid0_exit); 712 MODULE_LICENSE("GPL"); 713 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 714 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 715 MODULE_ALIAS("md-raid0"); 716 MODULE_ALIAS("md-level-0"); 717