1 // SPDX-License-Identifier: GPL-2.0-or-later
3 raid0.c : Multiple Devices driver for Linux
4 Copyright (C) 1994-96 Marc ZYNGIER
5 <zyngier@ufr-info-p7.ibp.fr> or
7 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
9 RAID-0 management functions.
13 #include <linux/blkdev.h>
14 #include <linux/seq_file.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <trace/events/block.h>
22 static int default_layout = 0;
23 module_param(default_layout, int, 0644);
25 #define UNSUPPORTED_MDDEV_FLAGS \
26 ((1L << MD_HAS_JOURNAL) | \
27 (1L << MD_JOURNAL_CLEAN) | \
28 (1L << MD_FAILFAST_SUPPORTED) |\
29 (1L << MD_HAS_PPL) | \
30 (1L << MD_HAS_MULTIPLE_PPLS))
32 static int raid0_congested(struct mddev *mddev, int bits)
34 struct r0conf *conf = mddev->private;
35 struct md_rdev **devlist = conf->devlist;
36 int raid_disks = conf->strip_zone[0].nb_dev;
39 for (i = 0; i < raid_disks && !ret ; i++) {
40 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
42 ret |= bdi_congested(q->backing_dev_info, bits);
48 * inform the user of the raid configuration
50 static void dump_zones(struct mddev *mddev)
53 sector_t zone_size = 0;
54 sector_t zone_start = 0;
55 char b[BDEVNAME_SIZE];
56 struct r0conf *conf = mddev->private;
57 int raid_disks = conf->strip_zone[0].nb_dev;
58 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
60 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
61 for (j = 0; j < conf->nr_strip_zones; j++) {
65 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
66 len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
67 bdevname(conf->devlist[j*raid_disks
69 pr_debug("md: zone%d=[%s]\n", j, line);
71 zone_size = conf->strip_zone[j].zone_end - zone_start;
72 pr_debug(" zone-offset=%10lluKB, 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;
80 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
83 sector_t curr_zone_end, sectors;
84 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
85 struct strip_zone *zone;
87 char b[BDEVNAME_SIZE];
88 char b2[BDEVNAME_SIZE];
89 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
90 unsigned blksize = 512;
92 *private_conf = ERR_PTR(-ENOMEM);
95 rdev_for_each(rdev1, mddev) {
96 pr_debug("md/raid0:%s: looking at %s\n",
98 bdevname(rdev1->bdev, b));
101 /* round size to chunk_size */
102 sectors = rdev1->sectors;
103 sector_div(sectors, mddev->chunk_sectors);
104 rdev1->sectors = sectors * mddev->chunk_sectors;
106 blksize = max(blksize, queue_logical_block_size(
107 rdev1->bdev->bd_disk->queue));
109 rdev_for_each(rdev2, mddev) {
110 pr_debug("md/raid0:%s: comparing %s(%llu)"
113 bdevname(rdev1->bdev,b),
114 (unsigned long long)rdev1->sectors,
115 bdevname(rdev2->bdev,b2),
116 (unsigned long long)rdev2->sectors);
117 if (rdev2 == rdev1) {
118 pr_debug("md/raid0:%s: END\n",
122 if (rdev2->sectors == rdev1->sectors) {
124 * Not unique, don't count it as a new
127 pr_debug("md/raid0:%s: EQUAL\n",
132 pr_debug("md/raid0:%s: NOT EQUAL\n",
136 pr_debug("md/raid0:%s: ==> UNIQUE\n",
138 conf->nr_strip_zones++;
139 pr_debug("md/raid0:%s: %d zones\n",
140 mdname(mddev), conf->nr_strip_zones);
143 pr_debug("md/raid0:%s: FINAL %d zones\n",
144 mdname(mddev), conf->nr_strip_zones);
146 if (conf->nr_strip_zones == 1) {
147 conf->layout = RAID0_ORIG_LAYOUT;
148 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
149 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
150 conf->layout = mddev->layout;
151 } else if (default_layout == RAID0_ORIG_LAYOUT ||
152 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
153 conf->layout = default_layout;
155 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
157 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
162 * now since we have the hard sector sizes, we can make sure
163 * chunk size is a multiple of that sector size
165 if ((mddev->chunk_sectors << 9) % blksize) {
166 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
168 mddev->chunk_sectors << 9, blksize);
174 conf->strip_zone = kcalloc(conf->nr_strip_zones,
175 sizeof(struct strip_zone),
177 if (!conf->strip_zone)
179 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
180 conf->nr_strip_zones,
186 /* The first zone must contain all devices, so here we check that
187 * there is a proper alignment of slots to devices and find them all
189 zone = &conf->strip_zone[0];
194 rdev_for_each(rdev1, mddev) {
195 int j = rdev1->raid_disk;
197 if (mddev->level == 10) {
198 /* taking over a raid10-n2 array */
200 rdev1->new_raid_disk = j;
203 if (mddev->level == 1) {
204 /* taiking over a raid1 array-
205 * we have only one active disk
208 rdev1->new_raid_disk = j;
212 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
216 if (j >= mddev->raid_disks) {
217 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
222 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
228 if (!smallest || (rdev1->sectors < smallest->sectors))
232 if (cnt != mddev->raid_disks) {
233 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
234 mdname(mddev), cnt, mddev->raid_disks);
238 zone->zone_end = smallest->sectors * cnt;
240 curr_zone_end = zone->zone_end;
242 /* now do the other zones */
243 for (i = 1; i < conf->nr_strip_zones; i++)
247 zone = conf->strip_zone + i;
248 dev = conf->devlist + i * mddev->raid_disks;
250 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
251 zone->dev_start = smallest->sectors;
255 for (j=0; j<cnt; j++) {
256 rdev = conf->devlist[j];
257 if (rdev->sectors <= zone->dev_start) {
258 pr_debug("md/raid0:%s: checking %s ... nope\n",
260 bdevname(rdev->bdev, b));
263 pr_debug("md/raid0:%s: checking %s ..."
264 " contained as device %d\n",
266 bdevname(rdev->bdev, b), c);
269 if (!smallest || rdev->sectors < smallest->sectors) {
271 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
273 (unsigned long long)rdev->sectors);
278 sectors = (smallest->sectors - zone->dev_start) * c;
279 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
281 zone->nb_dev, (unsigned long long)sectors);
283 curr_zone_end += sectors;
284 zone->zone_end = curr_zone_end;
286 pr_debug("md/raid0:%s: current zone start: %llu\n",
288 (unsigned long long)smallest->sectors);
291 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
292 *private_conf = conf;
296 kfree(conf->strip_zone);
297 kfree(conf->devlist);
299 *private_conf = ERR_PTR(err);
303 /* Find the zone which holds a particular offset
304 * Update *sectorp to be an offset in that zone
306 static struct strip_zone *find_zone(struct r0conf *conf,
310 struct strip_zone *z = conf->strip_zone;
311 sector_t sector = *sectorp;
313 for (i = 0; i < conf->nr_strip_zones; i++)
314 if (sector < z[i].zone_end) {
316 *sectorp = sector - z[i-1].zone_end;
323 * remaps the bio to the target device. we separate two flows.
324 * power 2 flow and a general flow for the sake of performance
326 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
327 sector_t sector, sector_t *sector_offset)
329 unsigned int sect_in_chunk;
331 struct r0conf *conf = mddev->private;
332 int raid_disks = conf->strip_zone[0].nb_dev;
333 unsigned int chunk_sects = mddev->chunk_sectors;
335 if (is_power_of_2(chunk_sects)) {
336 int chunksect_bits = ffz(~chunk_sects);
337 /* find the sector offset inside the chunk */
338 sect_in_chunk = sector & (chunk_sects - 1);
339 sector >>= chunksect_bits;
341 chunk = *sector_offset;
342 /* quotient is the chunk in real device*/
343 sector_div(chunk, zone->nb_dev << chunksect_bits);
345 sect_in_chunk = sector_div(sector, chunk_sects);
346 chunk = *sector_offset;
347 sector_div(chunk, chunk_sects * zone->nb_dev);
350 * position the bio over the real device
351 * real sector = chunk in device + starting of zone
352 * + the position in the chunk
354 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
355 return conf->devlist[(zone - conf->strip_zone)*raid_disks
356 + sector_div(sector, zone->nb_dev)];
359 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
361 sector_t array_sectors = 0;
362 struct md_rdev *rdev;
364 WARN_ONCE(sectors || raid_disks,
365 "%s does not support generic reshape\n", __func__);
367 rdev_for_each(rdev, mddev)
368 array_sectors += (rdev->sectors &
369 ~(sector_t)(mddev->chunk_sectors-1));
371 return array_sectors;
374 static void raid0_free(struct mddev *mddev, void *priv);
376 static int raid0_run(struct mddev *mddev)
381 if (mddev->chunk_sectors == 0) {
382 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
385 if (md_check_no_bitmap(mddev))
388 /* if private is not null, we are here after takeover */
389 if (mddev->private == NULL) {
390 ret = create_strip_zones(mddev, &conf);
393 mddev->private = conf;
395 conf = mddev->private;
397 struct md_rdev *rdev;
398 bool discard_supported = false;
400 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
401 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
402 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
403 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
405 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
406 blk_queue_io_opt(mddev->queue,
407 (mddev->chunk_sectors << 9) * mddev->raid_disks);
409 rdev_for_each(rdev, mddev) {
410 disk_stack_limits(mddev->gendisk, rdev->bdev,
411 rdev->data_offset << 9);
412 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
413 discard_supported = true;
415 if (!discard_supported)
416 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue);
418 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
421 /* calculate array device size */
422 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
424 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
426 (unsigned long long)mddev->array_sectors);
429 /* calculate the max read-ahead size.
430 * For read-ahead of large files to be effective, we need to
431 * readahead at least twice a whole stripe. i.e. number of devices
432 * multiplied by chunk size times 2.
433 * If an individual device has an ra_pages greater than the
434 * chunk size, then we will not drive that device as hard as it
435 * wants. We consider this a configuration error: a larger
436 * chunksize should be used in that case.
438 int stripe = mddev->raid_disks *
439 (mddev->chunk_sectors << 9) / PAGE_SIZE;
440 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
441 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
446 ret = md_integrity_register(mddev);
451 static void raid0_free(struct mddev *mddev, void *priv)
453 struct r0conf *conf = priv;
455 kfree(conf->strip_zone);
456 kfree(conf->devlist);
461 * Is io distribute over 1 or more chunks ?
463 static inline int is_io_in_chunk_boundary(struct mddev *mddev,
464 unsigned int chunk_sects, struct bio *bio)
466 if (likely(is_power_of_2(chunk_sects))) {
467 return chunk_sects >=
468 ((bio->bi_iter.bi_sector & (chunk_sects-1))
471 sector_t sector = bio->bi_iter.bi_sector;
472 return chunk_sects >= (sector_div(sector, chunk_sects)
477 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
479 struct r0conf *conf = mddev->private;
480 struct strip_zone *zone;
481 sector_t start = bio->bi_iter.bi_sector;
483 unsigned int stripe_size;
484 sector_t first_stripe_index, last_stripe_index;
485 sector_t start_disk_offset;
486 unsigned int start_disk_index;
487 sector_t end_disk_offset;
488 unsigned int end_disk_index;
491 zone = find_zone(conf, &start);
493 if (bio_end_sector(bio) > zone->zone_end) {
494 struct bio *split = bio_split(bio,
495 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
497 bio_chain(split, bio);
498 generic_make_request(bio);
500 end = zone->zone_end;
502 end = bio_end_sector(bio);
504 if (zone != conf->strip_zone)
505 end = end - zone[-1].zone_end;
507 /* Now start and end is the offset in zone */
508 stripe_size = zone->nb_dev * mddev->chunk_sectors;
510 first_stripe_index = start;
511 sector_div(first_stripe_index, stripe_size);
512 last_stripe_index = end;
513 sector_div(last_stripe_index, stripe_size);
515 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
516 mddev->chunk_sectors;
517 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
518 mddev->chunk_sectors) +
519 first_stripe_index * mddev->chunk_sectors;
520 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
521 mddev->chunk_sectors;
522 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
523 mddev->chunk_sectors) +
524 last_stripe_index * mddev->chunk_sectors;
526 for (disk = 0; disk < zone->nb_dev; disk++) {
527 sector_t dev_start, dev_end;
528 struct bio *discard_bio = NULL;
529 struct md_rdev *rdev;
531 if (disk < start_disk_index)
532 dev_start = (first_stripe_index + 1) *
533 mddev->chunk_sectors;
534 else if (disk > start_disk_index)
535 dev_start = first_stripe_index * mddev->chunk_sectors;
537 dev_start = start_disk_offset;
539 if (disk < end_disk_index)
540 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
541 else if (disk > end_disk_index)
542 dev_end = last_stripe_index * mddev->chunk_sectors;
544 dev_end = end_disk_offset;
546 if (dev_end <= dev_start)
549 rdev = conf->devlist[(zone - conf->strip_zone) *
550 conf->strip_zone[0].nb_dev + disk];
551 if (__blkdev_issue_discard(rdev->bdev,
552 dev_start + zone->dev_start + rdev->data_offset,
553 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
556 bio_chain(discard_bio, bio);
557 bio_clone_blkg_association(discard_bio, bio);
559 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
560 discard_bio, disk_devt(mddev->gendisk),
561 bio->bi_iter.bi_sector);
562 generic_make_request(discard_bio);
567 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
569 struct r0conf *conf = mddev->private;
570 struct strip_zone *zone;
571 struct md_rdev *tmp_dev;
574 sector_t orig_sector;
575 unsigned chunk_sects;
578 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
579 && md_flush_request(mddev, bio))
582 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
583 raid0_handle_discard(mddev, bio);
587 bio_sector = bio->bi_iter.bi_sector;
589 chunk_sects = mddev->chunk_sectors;
591 sectors = chunk_sects -
592 (likely(is_power_of_2(chunk_sects))
593 ? (sector & (chunk_sects-1))
594 : sector_div(sector, chunk_sects));
596 /* Restore due to sector_div */
599 if (sectors < bio_sectors(bio)) {
600 struct bio *split = bio_split(bio, sectors, GFP_NOIO,
602 bio_chain(split, bio);
603 generic_make_request(bio);
607 orig_sector = sector;
608 zone = find_zone(mddev->private, §or);
609 switch (conf->layout) {
610 case RAID0_ORIG_LAYOUT:
611 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
613 case RAID0_ALT_MULTIZONE_LAYOUT:
614 tmp_dev = map_sector(mddev, zone, sector, §or);
617 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
622 if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) {
627 bio_set_dev(bio, tmp_dev->bdev);
628 bio->bi_iter.bi_sector = sector + zone->dev_start +
629 tmp_dev->data_offset;
632 trace_block_bio_remap(bio->bi_disk->queue, bio,
633 disk_devt(mddev->gendisk), bio_sector);
634 mddev_check_writesame(mddev, bio);
635 mddev_check_write_zeroes(mddev, bio);
636 generic_make_request(bio);
640 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
642 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
646 static void *raid0_takeover_raid45(struct mddev *mddev)
648 struct md_rdev *rdev;
649 struct r0conf *priv_conf;
651 if (mddev->degraded != 1) {
652 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
655 return ERR_PTR(-EINVAL);
658 rdev_for_each(rdev, mddev) {
659 /* check slot number for a disk */
660 if (rdev->raid_disk == mddev->raid_disks-1) {
661 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
663 return ERR_PTR(-EINVAL);
665 rdev->sectors = mddev->dev_sectors;
668 /* Set new parameters */
669 mddev->new_level = 0;
670 mddev->new_layout = 0;
671 mddev->new_chunk_sectors = mddev->chunk_sectors;
673 mddev->delta_disks = -1;
674 /* make sure it will be not marked as dirty */
675 mddev->recovery_cp = MaxSector;
676 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
678 create_strip_zones(mddev, &priv_conf);
683 static void *raid0_takeover_raid10(struct mddev *mddev)
685 struct r0conf *priv_conf;
688 * - far_copies must be 1
689 * - near_copies must be 2
690 * - disks number must be even
691 * - all mirrors must be already degraded
693 if (mddev->layout != ((1 << 8) + 2)) {
694 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
697 return ERR_PTR(-EINVAL);
699 if (mddev->raid_disks & 1) {
700 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
702 return ERR_PTR(-EINVAL);
704 if (mddev->degraded != (mddev->raid_disks>>1)) {
705 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
707 return ERR_PTR(-EINVAL);
710 /* Set new parameters */
711 mddev->new_level = 0;
712 mddev->new_layout = 0;
713 mddev->new_chunk_sectors = mddev->chunk_sectors;
714 mddev->delta_disks = - mddev->raid_disks / 2;
715 mddev->raid_disks += mddev->delta_disks;
717 /* make sure it will be not marked as dirty */
718 mddev->recovery_cp = MaxSector;
719 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
721 create_strip_zones(mddev, &priv_conf);
725 static void *raid0_takeover_raid1(struct mddev *mddev)
727 struct r0conf *priv_conf;
731 * - (N - 1) mirror drives must be already faulty
733 if ((mddev->raid_disks - 1) != mddev->degraded) {
734 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
736 return ERR_PTR(-EINVAL);
740 * a raid1 doesn't have the notion of chunk size, so
741 * figure out the largest suitable size we can use.
743 chunksect = 64 * 2; /* 64K by default */
745 /* The array must be an exact multiple of chunksize */
746 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
749 if ((chunksect << 9) < PAGE_SIZE)
750 /* array size does not allow a suitable chunk size */
751 return ERR_PTR(-EINVAL);
753 /* Set new parameters */
754 mddev->new_level = 0;
755 mddev->new_layout = 0;
756 mddev->new_chunk_sectors = chunksect;
757 mddev->chunk_sectors = chunksect;
758 mddev->delta_disks = 1 - mddev->raid_disks;
759 mddev->raid_disks = 1;
760 /* make sure it will be not marked as dirty */
761 mddev->recovery_cp = MaxSector;
762 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
764 create_strip_zones(mddev, &priv_conf);
768 static void *raid0_takeover(struct mddev *mddev)
770 /* raid0 can take over:
771 * raid4 - if all data disks are active.
772 * raid5 - providing it is Raid4 layout and one disk is faulty
773 * raid10 - assuming we have all necessary active disks
774 * raid1 - with (N -1) mirror drives faulty
778 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
780 return ERR_PTR(-EBUSY);
782 if (mddev->level == 4)
783 return raid0_takeover_raid45(mddev);
785 if (mddev->level == 5) {
786 if (mddev->layout == ALGORITHM_PARITY_N)
787 return raid0_takeover_raid45(mddev);
789 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
790 mdname(mddev), ALGORITHM_PARITY_N);
793 if (mddev->level == 10)
794 return raid0_takeover_raid10(mddev);
796 if (mddev->level == 1)
797 return raid0_takeover_raid1(mddev);
799 pr_warn("Takeover from raid%i to raid0 not supported\n",
802 return ERR_PTR(-EINVAL);
805 static void raid0_quiesce(struct mddev *mddev, int quiesce)
809 static struct md_personality raid0_personality=
813 .owner = THIS_MODULE,
814 .make_request = raid0_make_request,
817 .status = raid0_status,
819 .takeover = raid0_takeover,
820 .quiesce = raid0_quiesce,
821 .congested = raid0_congested,
824 static int __init raid0_init (void)
826 return register_md_personality (&raid0_personality);
829 static void raid0_exit (void)
831 unregister_md_personality (&raid0_personality);
834 module_init(raid0_init);
835 module_exit(raid0_exit);
836 MODULE_LICENSE("GPL");
837 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
838 MODULE_ALIAS("md-personality-2"); /* RAID0 */
839 MODULE_ALIAS("md-raid0");
840 MODULE_ALIAS("md-level-0");