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 28static 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 43static 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*/ 65static 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 95static 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 (j < 0 || j >= mddev->raid_disks) { 183 printk(KERN_ERR "md/raid0:%s: bad disk number %d - " 184 "aborting!\n", mdname(mddev), j); 185 goto abort; 186 } 187 if (dev[j]) { 188 printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " 189 "aborting!\n", mdname(mddev), j); 190 goto abort; 191 } 192 dev[j] = rdev1; 193 194 disk_stack_limits(mddev->gendisk, rdev1->bdev, 195 rdev1->data_offset << 9); 196 /* as we don't honour merge_bvec_fn, we must never risk 197 * violating it, so limit ->max_segments to 1, lying within 198 * a single page. 199 */ 200 201 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) { 202 blk_queue_max_segments(mddev->queue, 1); 203 blk_queue_segment_boundary(mddev->queue, 204 PAGE_CACHE_SIZE - 1); 205 } 206 if (!smallest || (rdev1->sectors < smallest->sectors)) 207 smallest = rdev1; 208 cnt++; 209 } 210 if (cnt != mddev->raid_disks) { 211 printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " 212 "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); 213 goto abort; 214 } 215 zone->nb_dev = cnt; 216 zone->zone_end = smallest->sectors * cnt; 217 218 curr_zone_end = zone->zone_end; 219 220 /* now do the other zones */ 221 for (i = 1; i < conf->nr_strip_zones; i++) 222 { 223 int j; 224 225 zone = conf->strip_zone + i; 226 dev = conf->devlist + i * mddev->raid_disks; 227 228 printk(KERN_INFO "md/raid0:%s: zone %d\n", 229 mdname(mddev), i); 230 zone->dev_start = smallest->sectors; 231 smallest = NULL; 232 c = 0; 233 234 for (j=0; j<cnt; j++) { 235 rdev = conf->devlist[j]; 236 printk(KERN_INFO "md/raid0:%s: checking %s ...", 237 mdname(mddev), 238 bdevname(rdev->bdev, b)); 239 if (rdev->sectors <= zone->dev_start) { 240 printk(KERN_CONT " nope.\n"); 241 continue; 242 } 243 printk(KERN_CONT " contained as device %d\n", c); 244 dev[c] = rdev; 245 c++; 246 if (!smallest || rdev->sectors < smallest->sectors) { 247 smallest = rdev; 248 printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n", 249 mdname(mddev), 250 (unsigned long long)rdev->sectors); 251 } 252 } 253 254 zone->nb_dev = c; 255 sectors = (smallest->sectors - zone->dev_start) * c; 256 printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", 257 mdname(mddev), 258 zone->nb_dev, (unsigned long long)sectors); 259 260 curr_zone_end += sectors; 261 zone->zone_end = curr_zone_end; 262 263 printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n", 264 mdname(mddev), 265 (unsigned long long)smallest->sectors); 266 } 267 mddev->queue->unplug_fn = raid0_unplug; 268 mddev->queue->backing_dev_info.congested_fn = raid0_congested; 269 mddev->queue->backing_dev_info.congested_data = mddev; 270 271 /* 272 * now since we have the hard sector sizes, we can make sure 273 * chunk size is a multiple of that sector size 274 */ 275 if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { 276 printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", 277 mdname(mddev), 278 mddev->chunk_sectors << 9); 279 goto abort; 280 } 281 282 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); 283 blk_queue_io_opt(mddev->queue, 284 (mddev->chunk_sectors << 9) * mddev->raid_disks); 285 286 printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev)); 287 *private_conf = conf; 288 289 return 0; 290abort: 291 kfree(conf->strip_zone); 292 kfree(conf->devlist); 293 kfree(conf); 294 *private_conf = NULL; 295 return err; 296} 297 298/** 299 * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged 300 * @q: request queue 301 * @bvm: properties of new bio 302 * @biovec: the request that could be merged to it. 303 * 304 * Return amount of bytes we can accept at this offset 305 */ 306static int raid0_mergeable_bvec(struct request_queue *q, 307 struct bvec_merge_data *bvm, 308 struct bio_vec *biovec) 309{ 310 mddev_t *mddev = q->queuedata; 311 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); 312 int max; 313 unsigned int chunk_sectors = mddev->chunk_sectors; 314 unsigned int bio_sectors = bvm->bi_size >> 9; 315 316 if (is_power_of_2(chunk_sectors)) 317 max = (chunk_sectors - ((sector & (chunk_sectors-1)) 318 + bio_sectors)) << 9; 319 else 320 max = (chunk_sectors - (sector_div(sector, chunk_sectors) 321 + bio_sectors)) << 9; 322 if (max < 0) max = 0; /* bio_add cannot handle a negative return */ 323 if (max <= biovec->bv_len && bio_sectors == 0) 324 return biovec->bv_len; 325 else 326 return max; 327} 328 329static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) 330{ 331 sector_t array_sectors = 0; 332 mdk_rdev_t *rdev; 333 334 WARN_ONCE(sectors || raid_disks, 335 "%s does not support generic reshape\n", __func__); 336 337 list_for_each_entry(rdev, &mddev->disks, same_set) 338 array_sectors += rdev->sectors; 339 340 return array_sectors; 341} 342 343static int raid0_run(mddev_t *mddev) 344{ 345 raid0_conf_t *conf; 346 int ret; 347 348 if (mddev->chunk_sectors == 0) { 349 printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", 350 mdname(mddev)); 351 return -EINVAL; 352 } 353 if (md_check_no_bitmap(mddev)) 354 return -EINVAL; 355 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); 356 mddev->queue->queue_lock = &mddev->queue->__queue_lock; 357 358 /* if private is not null, we are here after takeover */ 359 if (mddev->private == NULL) { 360 ret = create_strip_zones(mddev, &conf); 361 if (ret < 0) 362 return ret; 363 mddev->private = conf; 364 } 365 conf = mddev->private; 366 367 /* calculate array device size */ 368 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); 369 370 printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", 371 mdname(mddev), 372 (unsigned long long)mddev->array_sectors); 373 /* calculate the max read-ahead size. 374 * For read-ahead of large files to be effective, we need to 375 * readahead at least twice a whole stripe. i.e. number of devices 376 * multiplied by chunk size times 2. 377 * If an individual device has an ra_pages greater than the 378 * chunk size, then we will not drive that device as hard as it 379 * wants. We consider this a configuration error: a larger 380 * chunksize should be used in that case. 381 */ 382 { 383 int stripe = mddev->raid_disks * 384 (mddev->chunk_sectors << 9) / PAGE_SIZE; 385 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) 386 mddev->queue->backing_dev_info.ra_pages = 2* stripe; 387 } 388 389 blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); 390 dump_zones(mddev); 391 md_integrity_register(mddev); 392 return 0; 393} 394 395static int raid0_stop(mddev_t *mddev) 396{ 397 raid0_conf_t *conf = mddev->private; 398 399 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ 400 kfree(conf->strip_zone); 401 kfree(conf->devlist); 402 kfree(conf); 403 mddev->private = NULL; 404 return 0; 405} 406 407/* Find the zone which holds a particular offset 408 * Update *sectorp to be an offset in that zone 409 */ 410static struct strip_zone *find_zone(struct raid0_private_data *conf, 411 sector_t *sectorp) 412{ 413 int i; 414 struct strip_zone *z = conf->strip_zone; 415 sector_t sector = *sectorp; 416 417 for (i = 0; i < conf->nr_strip_zones; i++) 418 if (sector < z[i].zone_end) { 419 if (i) 420 *sectorp = sector - z[i-1].zone_end; 421 return z + i; 422 } 423 BUG(); 424} 425 426/* 427 * remaps the bio to the target device. we separate two flows. 428 * power 2 flow and a general flow for the sake of perfromance 429*/ 430static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, 431 sector_t sector, sector_t *sector_offset) 432{ 433 unsigned int sect_in_chunk; 434 sector_t chunk; 435 raid0_conf_t *conf = mddev->private; 436 int raid_disks = conf->strip_zone[0].nb_dev; 437 unsigned int chunk_sects = mddev->chunk_sectors; 438 439 if (is_power_of_2(chunk_sects)) { 440 int chunksect_bits = ffz(~chunk_sects); 441 /* find the sector offset inside the chunk */ 442 sect_in_chunk = sector & (chunk_sects - 1); 443 sector >>= chunksect_bits; 444 /* chunk in zone */ 445 chunk = *sector_offset; 446 /* quotient is the chunk in real device*/ 447 sector_div(chunk, zone->nb_dev << chunksect_bits); 448 } else{ 449 sect_in_chunk = sector_div(sector, chunk_sects); 450 chunk = *sector_offset; 451 sector_div(chunk, chunk_sects * zone->nb_dev); 452 } 453 /* 454 * position the bio over the real device 455 * real sector = chunk in device + starting of zone 456 * + the position in the chunk 457 */ 458 *sector_offset = (chunk * chunk_sects) + sect_in_chunk; 459 return conf->devlist[(zone - conf->strip_zone)*raid_disks 460 + sector_div(sector, zone->nb_dev)]; 461} 462 463/* 464 * Is io distribute over 1 or more chunks ? 465*/ 466static inline int is_io_in_chunk_boundary(mddev_t *mddev, 467 unsigned int chunk_sects, struct bio *bio) 468{ 469 if (likely(is_power_of_2(chunk_sects))) { 470 return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) 471 + (bio->bi_size >> 9)); 472 } else{ 473 sector_t sector = bio->bi_sector; 474 return chunk_sects >= (sector_div(sector, chunk_sects) 475 + (bio->bi_size >> 9)); 476 } 477} 478 479static int raid0_make_request(mddev_t *mddev, struct bio *bio) 480{ 481 unsigned int chunk_sects; 482 sector_t sector_offset; 483 struct strip_zone *zone; 484 mdk_rdev_t *tmp_dev; 485 486 if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { 487 md_barrier_request(mddev, bio); 488 return 0; 489 } 490 491 chunk_sects = mddev->chunk_sectors; 492 if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { 493 sector_t sector = bio->bi_sector; 494 struct bio_pair *bp; 495 /* Sanity check -- queue functions should prevent this happening */ 496 if (bio->bi_vcnt != 1 || 497 bio->bi_idx != 0) 498 goto bad_map; 499 /* This is a one page bio that upper layers 500 * refuse to split for us, so we need to split it. 501 */ 502 if (likely(is_power_of_2(chunk_sects))) 503 bp = bio_split(bio, chunk_sects - (sector & 504 (chunk_sects-1))); 505 else 506 bp = bio_split(bio, chunk_sects - 507 sector_div(sector, chunk_sects)); 508 if (raid0_make_request(mddev, &bp->bio1)) 509 generic_make_request(&bp->bio1); 510 if (raid0_make_request(mddev, &bp->bio2)) 511 generic_make_request(&bp->bio2); 512 513 bio_pair_release(bp); 514 return 0; 515 } 516 517 sector_offset = bio->bi_sector; 518 zone = find_zone(mddev->private, §or_offset); 519 tmp_dev = map_sector(mddev, zone, bio->bi_sector, 520 §or_offset); 521 bio->bi_bdev = tmp_dev->bdev; 522 bio->bi_sector = sector_offset + zone->dev_start + 523 tmp_dev->data_offset; 524 /* 525 * Let the main block layer submit the IO and resolve recursion: 526 */ 527 return 1; 528 529bad_map: 530 printk("md/raid0:%s: make_request bug: can't convert block across chunks" 531 " or bigger than %dk %llu %d\n", 532 mdname(mddev), chunk_sects / 2, 533 (unsigned long long)bio->bi_sector, bio->bi_size >> 10); 534 535 bio_io_error(bio); 536 return 0; 537} 538 539static void raid0_status(struct seq_file *seq, mddev_t *mddev) 540{ 541#undef MD_DEBUG 542#ifdef MD_DEBUG 543 int j, k, h; 544 char b[BDEVNAME_SIZE]; 545 raid0_conf_t *conf = mddev->private; 546 int raid_disks = conf->strip_zone[0].nb_dev; 547 548 sector_t zone_size; 549 sector_t zone_start = 0; 550 h = 0; 551 552 for (j = 0; j < conf->nr_strip_zones; j++) { 553 seq_printf(seq, " z%d", j); 554 seq_printf(seq, "=["); 555 for (k = 0; k < conf->strip_zone[j].nb_dev; k++) 556 seq_printf(seq, "%s/", bdevname( 557 conf->devlist[j*raid_disks + k] 558 ->bdev, b)); 559 560 zone_size = conf->strip_zone[j].zone_end - zone_start; 561 seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n", 562 (unsigned long long)zone_start>>1, 563 (unsigned long long)conf->strip_zone[j].dev_start>>1, 564 (unsigned long long)zone_size>>1); 565 zone_start = conf->strip_zone[j].zone_end; 566 } 567#endif 568 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); 569 return; 570} 571 572static void *raid0_takeover_raid45(mddev_t *mddev) 573{ 574 mdk_rdev_t *rdev; 575 raid0_conf_t *priv_conf; 576 577 if (mddev->degraded != 1) { 578 printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", 579 mdname(mddev), 580 mddev->degraded); 581 return ERR_PTR(-EINVAL); 582 } 583 584 list_for_each_entry(rdev, &mddev->disks, same_set) { 585 /* check slot number for a disk */ 586 if (rdev->raid_disk == mddev->raid_disks-1) { 587 printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", 588 mdname(mddev)); 589 return ERR_PTR(-EINVAL); 590 } 591 } 592 593 /* Set new parameters */ 594 mddev->new_level = 0; 595 mddev->new_layout = 0; 596 mddev->new_chunk_sectors = mddev->chunk_sectors; 597 mddev->raid_disks--; 598 mddev->delta_disks = -1; 599 /* make sure it will be not marked as dirty */ 600 mddev->recovery_cp = MaxSector; 601 602 create_strip_zones(mddev, &priv_conf); 603 return priv_conf; 604} 605 606static void *raid0_takeover_raid10(mddev_t *mddev) 607{ 608 raid0_conf_t *priv_conf; 609 610 /* Check layout: 611 * - far_copies must be 1 612 * - near_copies must be 2 613 * - disks number must be even 614 * - all mirrors must be already degraded 615 */ 616 if (mddev->layout != ((1 << 8) + 2)) { 617 printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", 618 mdname(mddev), 619 mddev->layout); 620 return ERR_PTR(-EINVAL); 621 } 622 if (mddev->raid_disks & 1) { 623 printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", 624 mdname(mddev)); 625 return ERR_PTR(-EINVAL); 626 } 627 if (mddev->degraded != (mddev->raid_disks>>1)) { 628 printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", 629 mdname(mddev)); 630 return ERR_PTR(-EINVAL); 631 } 632 633 /* Set new parameters */ 634 mddev->new_level = 0; 635 mddev->new_layout = 0; 636 mddev->new_chunk_sectors = mddev->chunk_sectors; 637 mddev->delta_disks = - mddev->raid_disks / 2; 638 mddev->raid_disks += mddev->delta_disks; 639 mddev->degraded = 0; 640 /* make sure it will be not marked as dirty */ 641 mddev->recovery_cp = MaxSector; 642 643 create_strip_zones(mddev, &priv_conf); 644 return priv_conf; 645} 646 647static void *raid0_takeover(mddev_t *mddev) 648{ 649 /* raid0 can take over: 650 * raid4 - if all data disks are active. 651 * raid5 - providing it is Raid4 layout and one disk is faulty 652 * raid10 - assuming we have all necessary active disks 653 */ 654 if (mddev->level == 4) 655 return raid0_takeover_raid45(mddev); 656 657 if (mddev->level == 5) { 658 if (mddev->layout == ALGORITHM_PARITY_N) 659 return raid0_takeover_raid45(mddev); 660 661 printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", 662 mdname(mddev), ALGORITHM_PARITY_N); 663 } 664 665 if (mddev->level == 10) 666 return raid0_takeover_raid10(mddev); 667 668 return ERR_PTR(-EINVAL); 669} 670 671static void raid0_quiesce(mddev_t *mddev, int state) 672{ 673} 674 675static struct mdk_personality raid0_personality= 676{ 677 .name = "raid0", 678 .level = 0, 679 .owner = THIS_MODULE, 680 .make_request = raid0_make_request, 681 .run = raid0_run, 682 .stop = raid0_stop, 683 .status = raid0_status, 684 .size = raid0_size, 685 .takeover = raid0_takeover, 686 .quiesce = raid0_quiesce, 687}; 688 689static int __init raid0_init (void) 690{ 691 return register_md_personality (&raid0_personality); 692} 693 694static void raid0_exit (void) 695{ 696 unregister_md_personality (&raid0_personality); 697} 698 699module_init(raid0_init); 700module_exit(raid0_exit); 701MODULE_LICENSE("GPL"); 702MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); 703MODULE_ALIAS("md-personality-2"); /* RAID0 */ 704MODULE_ALIAS("md-raid0"); 705MODULE_ALIAS("md-level-0"); 706