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; 179 180 if (j < 0 || j >= mddev->raid_disks) { 181 printk(KERN_ERR "md/raid0:%s: bad disk number %d - " 182 "aborting!\n", mdname(mddev), j); 183 goto abort; 184 } 185 if (dev[j]) { 186 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " 187 "aborting!\n", mdname(mddev), j); 188 goto abort; 189 } 190 dev[j] = rdev1; 191 192 disk_stack_limits(mddev->gendisk, rdev1->bdev, 193 rdev1->data_offset << 9); 194 /* as we don't honour merge_bvec_fn, we must never risk 195 * violating it, so limit ->max_segments to 1, lying within 196 * a single page. 197 */ 198 199 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) { 200 blk_queue_max_segments(mddev->queue, 1); 201 blk_queue_segment_boundary(mddev->queue, 202 PAGE_CACHE_SIZE - 1); 203 } 204 if (!smallest || (rdev1->sectors < smallest->sectors)) 205 smallest = rdev1; 206 cnt++; 207 } 208 if (cnt != mddev->raid_disks) { 209 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " 210 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); 211 goto abort; 212 } 213 zone->nb_dev = cnt; 214 zone->zone_end = smallest->sectors * cnt; 215 216 curr_zone_end = zone->zone_end; 217 218 /* now do the other zones */ 219 for (i = 1; i < conf->nr_strip_zones; i++) 220 { 221 int j; 222 223 zone = conf->strip_zone + i; 224 dev = conf->devlist + i * mddev->raid_disks; 225 226 printk(KERN_INFO "md/raid0:%s: zone %d\n", 227 mdname(mddev), i); 228 zone->dev_start = smallest->sectors; 229 smallest = NULL; 230 c = 0; 231 232 for (j=0; j<cnt; j++) { 233 rdev = conf->devlist[j]; 234 printk(KERN_INFO "md/raid0:%s: checking %s ...", 235 mdname(mddev), 236 bdevname(rdev->bdev, b)); 237 if (rdev->sectors <= zone->dev_start) { 238 printk(KERN_CONT " nope.\n"); 239 continue; 240 } 241 printk(KERN_CONT " contained as device %d\n", c); 242 dev[c] = rdev; 243 c++; 244 if (!smallest || rdev->sectors < smallest->sectors) { 245 smallest = rdev; 246 printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n", 247 mdname(mddev), 248 (unsigned long long)rdev->sectors); 249 } 250 } 251 252 zone->nb_dev = c; 253 sectors = (smallest->sectors - zone->dev_start) * c; 254 printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 255 mdname(mddev), 256 zone->nb_dev, (unsigned long long)sectors); 257 258 curr_zone_end += sectors; 259 zone->zone_end = curr_zone_end; 260 261 printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n", 262 mdname(mddev), 263 (unsigned long long)smallest->sectors); 264 } 265 mddev->queue->unplug_fn = raid0_unplug; 266 mddev->queue->backing_dev_info.congested_fn = raid0_congested; 267 mddev->queue->backing_dev_info.congested_data = mddev; 268 269 /* 270 * now since we have the hard sector sizes, we can make sure 271 * chunk size is a multiple of that sector size 272 */ 273 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { 274 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", 275 mdname(mddev), 276 mddev->chunk_sectors << 9); 277 goto abort; 278 } 279 280 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 281 blk_queue_io_opt(mddev->queue, 282 (mddev->chunk_sectors << 9) * mddev->raid_disks); 283 284 printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev)); 285 *private_conf = conf; 286 287 return 0; 288 abort: 289 kfree(conf->strip_zone); 290 kfree(conf->devlist); 291 kfree(conf); 292 *private_conf = NULL; 293 return err; 294 } 295 296 /** 297 * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged 298 * @q: request queue 299 * @bvm: properties of new bio 300 * @biovec: the request that could be merged to it. 301 * 302 * Return amount of bytes we can accept at this offset 303 */ 304 static int raid0_mergeable_bvec(struct request_queue *q, 305 struct bvec_merge_data *bvm, 306 struct bio_vec *biovec) 307 { 308 mddev_t *mddev = q->queuedata; 309 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 310 int max; 311 unsigned int chunk_sectors = mddev->chunk_sectors; 312 unsigned int bio_sectors = bvm->bi_size >> 9; 313 314 if (is_power_of_2(chunk_sectors)) 315 max = (chunk_sectors - ((sector & (chunk_sectors-1)) 316 + bio_sectors)) << 9; 317 else 318 max = (chunk_sectors - (sector_div(sector, chunk_sectors) 319 + bio_sectors)) << 9; 320 if (max < 0) max = 0; /* bio_add cannot handle a negative return */ 321 if (max <= biovec->bv_len && bio_sectors == 0) 322 return biovec->bv_len; 323 else 324 return max; 325 } 326 327 static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) 328 { 329 sector_t array_sectors = 0; 330 mdk_rdev_t *rdev; 331 332 WARN_ONCE(sectors || raid_disks, 333 "%s does not support generic reshape\n", __func__); 334 335 list_for_each_entry(rdev, &mddev->disks, same_set) 336 array_sectors += rdev->sectors; 337 338 return array_sectors; 339 } 340 341 static int raid0_run(mddev_t *mddev) 342 { 343 raid0_conf_t *conf; 344 int ret; 345 346 if (mddev->chunk_sectors == 0) { 347 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", 348 mdname(mddev)); 349 return -EINVAL; 350 } 351 if (md_check_no_bitmap(mddev)) 352 return -EINVAL; 353 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 354 mddev->queue->queue_lock = &mddev->queue->__queue_lock; 355 356 /* if private is not null, we are here after takeover */ 357 if (mddev->private == NULL) { 358 ret = create_strip_zones(mddev, &conf); 359 if (ret < 0) 360 return ret; 361 mddev->private = conf; 362 } 363 conf = mddev->private; 364 if (conf->scale_raid_disks) { 365 int i; 366 for (i=0; i < conf->strip_zone[0].nb_dev; i++) 367 conf->devlist[i]->raid_disk /= conf->scale_raid_disks; 368 /* FIXME update sysfs rd links */ 369 } 370 371 /* calculate array device size */ 372 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 373 374 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", 375 mdname(mddev), 376 (unsigned long long)mddev->array_sectors); 377 /* calculate the max read-ahead size. 378 * For read-ahead of large files to be effective, we need to 379 * readahead at least twice a whole stripe. i.e. number of devices 380 * multiplied by chunk size times 2. 381 * If an individual device has an ra_pages greater than the 382 * chunk size, then we will not drive that device as hard as it 383 * wants. We consider this a configuration error: a larger 384 * chunksize should be used in that case. 385 */ 386 { 387 int stripe = mddev->raid_disks * 388 (mddev->chunk_sectors << 9) / PAGE_SIZE; 389 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) 390 mddev->queue->backing_dev_info.ra_pages = 2* stripe; 391 } 392 393 blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); 394 dump_zones(mddev); 395 md_integrity_register(mddev); 396 return 0; 397 } 398 399 static int raid0_stop(mddev_t *mddev) 400 { 401 raid0_conf_t *conf = mddev->private; 402 403 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 404 kfree(conf->strip_zone); 405 kfree(conf->devlist); 406 kfree(conf); 407 mddev->private = NULL; 408 return 0; 409 } 410 411 /* Find the zone which holds a particular offset 412 * Update *sectorp to be an offset in that zone 413 */ 414 static struct strip_zone *find_zone(struct raid0_private_data *conf, 415 sector_t *sectorp) 416 { 417 int i; 418 struct strip_zone *z = conf->strip_zone; 419 sector_t sector = *sectorp; 420 421 for (i = 0; i < conf->nr_strip_zones; i++) 422 if (sector < z[i].zone_end) { 423 if (i) 424 *sectorp = sector - z[i-1].zone_end; 425 return z + i; 426 } 427 BUG(); 428 } 429 430 /* 431 * remaps the bio to the target device. we separate two flows. 432 * power 2 flow and a general flow for the sake of perfromance 433 */ 434 static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, 435 sector_t sector, sector_t *sector_offset) 436 { 437 unsigned int sect_in_chunk; 438 sector_t chunk; 439 raid0_conf_t *conf = mddev->private; 440 int raid_disks = conf->strip_zone[0].nb_dev; 441 unsigned int chunk_sects = mddev->chunk_sectors; 442 443 if (is_power_of_2(chunk_sects)) { 444 int chunksect_bits = ffz(~chunk_sects); 445 /* find the sector offset inside the chunk */ 446 sect_in_chunk = sector & (chunk_sects - 1); 447 sector >>= chunksect_bits; 448 /* chunk in zone */ 449 chunk = *sector_offset; 450 /* quotient is the chunk in real device*/ 451 sector_div(chunk, zone->nb_dev << chunksect_bits); 452 } else{ 453 sect_in_chunk = sector_div(sector, chunk_sects); 454 chunk = *sector_offset; 455 sector_div(chunk, chunk_sects * zone->nb_dev); 456 } 457 /* 458 * position the bio over the real device 459 * real sector = chunk in device + starting of zone 460 * + the position in the chunk 461 */ 462 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 463 return conf->devlist[(zone - conf->strip_zone)*raid_disks 464 + sector_div(sector, zone->nb_dev)]; 465 } 466 467 /* 468 * Is io distribute over 1 or more chunks ? 469 */ 470 static inline int is_io_in_chunk_boundary(mddev_t *mddev, 471 unsigned int chunk_sects, struct bio *bio) 472 { 473 if (likely(is_power_of_2(chunk_sects))) { 474 return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) 475 + (bio->bi_size >> 9)); 476 } else{ 477 sector_t sector = bio->bi_sector; 478 return chunk_sects >= (sector_div(sector, chunk_sects) 479 + (bio->bi_size >> 9)); 480 } 481 } 482 483 static int raid0_make_request(mddev_t *mddev, struct bio *bio) 484 { 485 unsigned int chunk_sects; 486 sector_t sector_offset; 487 struct strip_zone *zone; 488 mdk_rdev_t *tmp_dev; 489 490 if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) { 491 md_barrier_request(mddev, bio); 492 return 0; 493 } 494 495 chunk_sects = mddev->chunk_sectors; 496 if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { 497 sector_t sector = bio->bi_sector; 498 struct bio_pair *bp; 499 /* Sanity check -- queue functions should prevent this happening */ 500 if (bio->bi_vcnt != 1 || 501 bio->bi_idx != 0) 502 goto bad_map; 503 /* This is a one page bio that upper layers 504 * refuse to split for us, so we need to split it. 505 */ 506 if (likely(is_power_of_2(chunk_sects))) 507 bp = bio_split(bio, chunk_sects - (sector & 508 (chunk_sects-1))); 509 else 510 bp = bio_split(bio, chunk_sects - 511 sector_div(sector, chunk_sects)); 512 if (raid0_make_request(mddev, &bp->bio1)) 513 generic_make_request(&bp->bio1); 514 if (raid0_make_request(mddev, &bp->bio2)) 515 generic_make_request(&bp->bio2); 516 517 bio_pair_release(bp); 518 return 0; 519 } 520 521 sector_offset = bio->bi_sector; 522 zone = find_zone(mddev->private, §or_offset); 523 tmp_dev = map_sector(mddev, zone, bio->bi_sector, 524 §or_offset); 525 bio->bi_bdev = tmp_dev->bdev; 526 bio->bi_sector = sector_offset + zone->dev_start + 527 tmp_dev->data_offset; 528 /* 529 * Let the main block layer submit the IO and resolve recursion: 530 */ 531 return 1; 532 533 bad_map: 534 printk("md/raid0:%s: make_request bug: can't convert block across chunks" 535 " or bigger than %dk %llu %d\n", 536 mdname(mddev), chunk_sects / 2, 537 (unsigned long long)bio->bi_sector, bio->bi_size >> 10); 538 539 bio_io_error(bio); 540 return 0; 541 } 542 543 static void raid0_status(struct seq_file *seq, mddev_t *mddev) 544 { 545 #undef MD_DEBUG 546 #ifdef MD_DEBUG 547 int j, k, h; 548 char b[BDEVNAME_SIZE]; 549 raid0_conf_t *conf = mddev->private; 550 int raid_disks = conf->strip_zone[0].nb_dev; 551 552 sector_t zone_size; 553 sector_t zone_start = 0; 554 h = 0; 555 556 for (j = 0; j < conf->nr_strip_zones; j++) { 557 seq_printf(seq, " z%d", j); 558 seq_printf(seq, "=["); 559 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 560 seq_printf(seq, "%s/", bdevname( 561 conf->devlist[j*raid_disks + k] 562 ->bdev, b)); 563 564 zone_size = conf->strip_zone[j].zone_end - zone_start; 565 seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n", 566 (unsigned long long)zone_start>>1, 567 (unsigned long long)conf->strip_zone[j].dev_start>>1, 568 (unsigned long long)zone_size>>1); 569 zone_start = conf->strip_zone[j].zone_end; 570 } 571 #endif 572 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 573 return; 574 } 575 576 static void *raid0_takeover_raid5(mddev_t *mddev) 577 { 578 mdk_rdev_t *rdev; 579 raid0_conf_t *priv_conf; 580 581 if (mddev->degraded != 1) { 582 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 583 mdname(mddev), 584 mddev->degraded); 585 return ERR_PTR(-EINVAL); 586 } 587 588 list_for_each_entry(rdev, &mddev->disks, same_set) { 589 /* check slot number for a disk */ 590 if (rdev->raid_disk == mddev->raid_disks-1) { 591 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", 592 mdname(mddev)); 593 return ERR_PTR(-EINVAL); 594 } 595 } 596 597 /* Set new parameters */ 598 mddev->new_level = 0; 599 mddev->new_chunk_sectors = mddev->chunk_sectors; 600 mddev->raid_disks--; 601 mddev->delta_disks = -1; 602 /* make sure it will be not marked as dirty */ 603 mddev->recovery_cp = MaxSector; 604 605 create_strip_zones(mddev, &priv_conf); 606 return priv_conf; 607 } 608 609 static void *raid0_takeover_raid10(mddev_t *mddev) 610 { 611 raid0_conf_t *priv_conf; 612 613 /* Check layout: 614 * - far_copies must be 1 615 * - near_copies must be 2 616 * - disks number must be even 617 * - all mirrors must be already degraded 618 */ 619 if (mddev->layout != ((1 << 8) + 2)) { 620 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", 621 mdname(mddev), 622 mddev->layout); 623 return ERR_PTR(-EINVAL); 624 } 625 if (mddev->raid_disks & 1) { 626 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", 627 mdname(mddev)); 628 return ERR_PTR(-EINVAL); 629 } 630 if (mddev->degraded != (mddev->raid_disks>>1)) { 631 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", 632 mdname(mddev)); 633 return ERR_PTR(-EINVAL); 634 } 635 636 /* Set new parameters */ 637 mddev->new_level = 0; 638 mddev->new_chunk_sectors = mddev->chunk_sectors; 639 mddev->delta_disks = - mddev->raid_disks / 2; 640 mddev->raid_disks += mddev->delta_disks; 641 mddev->degraded = 0; 642 /* make sure it will be not marked as dirty */ 643 mddev->recovery_cp = MaxSector; 644 645 create_strip_zones(mddev, &priv_conf); 646 priv_conf->scale_raid_disks = 2; 647 return priv_conf; 648 } 649 650 static void *raid0_takeover(mddev_t *mddev) 651 { 652 /* raid0 can take over: 653 * raid5 - providing it is Raid4 layout and one disk is faulty 654 * raid10 - assuming we have all necessary active disks 655 */ 656 if (mddev->level == 5) { 657 if (mddev->layout == ALGORITHM_PARITY_N) 658 return raid0_takeover_raid5(mddev); 659 660 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 661 mdname(mddev), ALGORITHM_PARITY_N); 662 } 663 664 if (mddev->level == 10) 665 return raid0_takeover_raid10(mddev); 666 667 return ERR_PTR(-EINVAL); 668 } 669 670 static void raid0_quiesce(mddev_t *mddev, int state) 671 { 672 } 673 674 static struct mdk_personality raid0_personality= 675 { 676 .name = "raid0", 677 .level = 0, 678 .owner = THIS_MODULE, 679 .make_request = raid0_make_request, 680 .run = raid0_run, 681 .stop = raid0_stop, 682 .status = raid0_status, 683 .size = raid0_size, 684 .takeover = raid0_takeover, 685 .quiesce = raid0_quiesce, 686 }; 687 688 static int __init raid0_init (void) 689 { 690 return register_md_personality (&raid0_personality); 691 } 692 693 static void raid0_exit (void) 694 { 695 unregister_md_personality (&raid0_personality); 696 } 697 698 module_init(raid0_init); 699 module_exit(raid0_exit); 700 MODULE_LICENSE("GPL"); 701 MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 702 MODULE_ALIAS("md-personality-2"); /* RAID0 */ 703 MODULE_ALIAS("md-raid0"); 704 MODULE_ALIAS("md-level-0"); 705