2 raid0.c : Multiple Devices driver for Linux
3 Copyright (C) 1994-96 Marc ZYNGIER
4 <zyngier@ufr-info-p7.ibp.fr> or
6 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
8 RAID-0 management functions.
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)
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.
20 #include <linux/blkdev.h>
21 #include <linux/seq_file.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <trace/events/block.h>
29 static int default_layout = 0;
30 module_param(default_layout, int, 0644);
32 #define UNSUPPORTED_MDDEV_FLAGS \
33 ((1L << MD_HAS_JOURNAL) | \
34 (1L << MD_JOURNAL_CLEAN) | \
35 (1L << MD_FAILFAST_SUPPORTED) |\
36 (1L << MD_HAS_PPL) | \
37 (1L << MD_HAS_MULTIPLE_PPLS))
39 static int raid0_congested(struct mddev *mddev, int bits)
41 struct r0conf *conf = mddev->private;
42 struct md_rdev **devlist = conf->devlist;
43 int raid_disks = conf->strip_zone[0].nb_dev;
46 for (i = 0; i < raid_disks && !ret ; i++) {
47 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
49 ret |= bdi_congested(q->backing_dev_info, bits);
55 * inform the user of the raid configuration
57 static void dump_zones(struct mddev *mddev)
60 sector_t zone_size = 0;
61 sector_t zone_start = 0;
62 char b[BDEVNAME_SIZE];
63 struct r0conf *conf = mddev->private;
64 int raid_disks = conf->strip_zone[0].nb_dev;
65 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
67 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
68 for (j = 0; j < conf->nr_strip_zones; j++) {
72 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
73 len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
74 bdevname(conf->devlist[j*raid_disks
76 pr_debug("md: zone%d=[%s]\n", j, line);
78 zone_size = conf->strip_zone[j].zone_end - zone_start;
79 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
80 (unsigned long long)zone_start>>1,
81 (unsigned long long)conf->strip_zone[j].dev_start>>1,
82 (unsigned long long)zone_size>>1);
83 zone_start = conf->strip_zone[j].zone_end;
87 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
90 sector_t curr_zone_end, sectors;
91 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
92 struct strip_zone *zone;
94 char b[BDEVNAME_SIZE];
95 char b2[BDEVNAME_SIZE];
96 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
97 unsigned blksize = 512;
99 *private_conf = ERR_PTR(-ENOMEM);
102 rdev_for_each(rdev1, mddev) {
103 pr_debug("md/raid0:%s: looking at %s\n",
105 bdevname(rdev1->bdev, b));
108 /* round size to chunk_size */
109 sectors = rdev1->sectors;
110 sector_div(sectors, mddev->chunk_sectors);
111 rdev1->sectors = sectors * mddev->chunk_sectors;
113 blksize = max(blksize, queue_logical_block_size(
114 rdev1->bdev->bd_disk->queue));
116 rdev_for_each(rdev2, mddev) {
117 pr_debug("md/raid0:%s: comparing %s(%llu)"
120 bdevname(rdev1->bdev,b),
121 (unsigned long long)rdev1->sectors,
122 bdevname(rdev2->bdev,b2),
123 (unsigned long long)rdev2->sectors);
124 if (rdev2 == rdev1) {
125 pr_debug("md/raid0:%s: END\n",
129 if (rdev2->sectors == rdev1->sectors) {
131 * Not unique, don't count it as a new
134 pr_debug("md/raid0:%s: EQUAL\n",
139 pr_debug("md/raid0:%s: NOT EQUAL\n",
143 pr_debug("md/raid0:%s: ==> UNIQUE\n",
145 conf->nr_strip_zones++;
146 pr_debug("md/raid0:%s: %d zones\n",
147 mdname(mddev), conf->nr_strip_zones);
150 pr_debug("md/raid0:%s: FINAL %d zones\n",
151 mdname(mddev), conf->nr_strip_zones);
153 if (conf->nr_strip_zones == 1) {
154 conf->layout = RAID0_ORIG_LAYOUT;
155 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
156 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
157 conf->layout = mddev->layout;
158 } else if (default_layout == RAID0_ORIG_LAYOUT ||
159 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
160 conf->layout = default_layout;
162 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
164 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
169 * now since we have the hard sector sizes, we can make sure
170 * chunk size is a multiple of that sector size
172 if ((mddev->chunk_sectors << 9) % blksize) {
173 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
175 mddev->chunk_sectors << 9, blksize);
181 conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
182 conf->nr_strip_zones, GFP_KERNEL);
183 if (!conf->strip_zone)
185 conf->devlist = kzalloc(sizeof(struct md_rdev*)*
186 conf->nr_strip_zones*mddev->raid_disks,
191 /* The first zone must contain all devices, so here we check that
192 * there is a proper alignment of slots to devices and find them all
194 zone = &conf->strip_zone[0];
199 rdev_for_each(rdev1, mddev) {
200 int j = rdev1->raid_disk;
202 if (mddev->level == 10) {
203 /* taking over a raid10-n2 array */
205 rdev1->new_raid_disk = j;
208 if (mddev->level == 1) {
209 /* taiking over a raid1 array-
210 * we have only one active disk
213 rdev1->new_raid_disk = j;
217 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
221 if (j >= mddev->raid_disks) {
222 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
227 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
233 if (!smallest || (rdev1->sectors < smallest->sectors))
237 if (cnt != mddev->raid_disks) {
238 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
239 mdname(mddev), cnt, mddev->raid_disks);
243 zone->zone_end = smallest->sectors * cnt;
245 curr_zone_end = zone->zone_end;
247 /* now do the other zones */
248 for (i = 1; i < conf->nr_strip_zones; i++)
252 zone = conf->strip_zone + i;
253 dev = conf->devlist + i * mddev->raid_disks;
255 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
256 zone->dev_start = smallest->sectors;
260 for (j=0; j<cnt; j++) {
261 rdev = conf->devlist[j];
262 if (rdev->sectors <= zone->dev_start) {
263 pr_debug("md/raid0:%s: checking %s ... nope\n",
265 bdevname(rdev->bdev, b));
268 pr_debug("md/raid0:%s: checking %s ..."
269 " contained as device %d\n",
271 bdevname(rdev->bdev, b), c);
274 if (!smallest || rdev->sectors < smallest->sectors) {
276 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
278 (unsigned long long)rdev->sectors);
283 sectors = (smallest->sectors - zone->dev_start) * c;
284 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
286 zone->nb_dev, (unsigned long long)sectors);
288 curr_zone_end += sectors;
289 zone->zone_end = curr_zone_end;
291 pr_debug("md/raid0:%s: current zone start: %llu\n",
293 (unsigned long long)smallest->sectors);
296 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
297 *private_conf = conf;
301 kfree(conf->strip_zone);
302 kfree(conf->devlist);
304 *private_conf = ERR_PTR(err);
308 /* Find the zone which holds a particular offset
309 * Update *sectorp to be an offset in that zone
311 static struct strip_zone *find_zone(struct r0conf *conf,
315 struct strip_zone *z = conf->strip_zone;
316 sector_t sector = *sectorp;
318 for (i = 0; i < conf->nr_strip_zones; i++)
319 if (sector < z[i].zone_end) {
321 *sectorp = sector - z[i-1].zone_end;
328 * remaps the bio to the target device. we separate two flows.
329 * power 2 flow and a general flow for the sake of performance
331 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
332 sector_t sector, sector_t *sector_offset)
334 unsigned int sect_in_chunk;
336 struct r0conf *conf = mddev->private;
337 int raid_disks = conf->strip_zone[0].nb_dev;
338 unsigned int chunk_sects = mddev->chunk_sectors;
340 if (is_power_of_2(chunk_sects)) {
341 int chunksect_bits = ffz(~chunk_sects);
342 /* find the sector offset inside the chunk */
343 sect_in_chunk = sector & (chunk_sects - 1);
344 sector >>= chunksect_bits;
346 chunk = *sector_offset;
347 /* quotient is the chunk in real device*/
348 sector_div(chunk, zone->nb_dev << chunksect_bits);
350 sect_in_chunk = sector_div(sector, chunk_sects);
351 chunk = *sector_offset;
352 sector_div(chunk, chunk_sects * zone->nb_dev);
355 * position the bio over the real device
356 * real sector = chunk in device + starting of zone
357 * + the position in the chunk
359 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
360 return conf->devlist[(zone - conf->strip_zone)*raid_disks
361 + sector_div(sector, zone->nb_dev)];
364 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
366 sector_t array_sectors = 0;
367 struct md_rdev *rdev;
369 WARN_ONCE(sectors || raid_disks,
370 "%s does not support generic reshape\n", __func__);
372 rdev_for_each(rdev, mddev)
373 array_sectors += (rdev->sectors &
374 ~(sector_t)(mddev->chunk_sectors-1));
376 return array_sectors;
379 static void raid0_free(struct mddev *mddev, void *priv);
381 static int raid0_run(struct mddev *mddev)
386 if (mddev->chunk_sectors == 0) {
387 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
390 if (md_check_no_bitmap(mddev))
393 /* if private is not null, we are here after takeover */
394 if (mddev->private == NULL) {
395 ret = create_strip_zones(mddev, &conf);
398 mddev->private = conf;
400 conf = mddev->private;
402 struct md_rdev *rdev;
403 bool discard_supported = false;
405 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
406 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
407 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
408 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
410 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
411 blk_queue_io_opt(mddev->queue,
412 (mddev->chunk_sectors << 9) * mddev->raid_disks);
414 rdev_for_each(rdev, mddev) {
415 disk_stack_limits(mddev->gendisk, rdev->bdev,
416 rdev->data_offset << 9);
417 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
418 discard_supported = true;
420 if (!discard_supported)
421 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
423 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
426 /* calculate array device size */
427 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
429 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
431 (unsigned long long)mddev->array_sectors);
434 /* calculate the max read-ahead size.
435 * For read-ahead of large files to be effective, we need to
436 * readahead at least twice a whole stripe. i.e. number of devices
437 * multiplied by chunk size times 2.
438 * If an individual device has an ra_pages greater than the
439 * chunk size, then we will not drive that device as hard as it
440 * wants. We consider this a configuration error: a larger
441 * chunksize should be used in that case.
443 int stripe = mddev->raid_disks *
444 (mddev->chunk_sectors << 9) / PAGE_SIZE;
445 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
446 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
451 ret = md_integrity_register(mddev);
456 static void raid0_free(struct mddev *mddev, void *priv)
458 struct r0conf *conf = priv;
460 kfree(conf->strip_zone);
461 kfree(conf->devlist);
466 * Is io distribute over 1 or more chunks ?
468 static inline int is_io_in_chunk_boundary(struct mddev *mddev,
469 unsigned int chunk_sects, struct bio *bio)
471 if (likely(is_power_of_2(chunk_sects))) {
472 return chunk_sects >=
473 ((bio->bi_iter.bi_sector & (chunk_sects-1))
476 sector_t sector = bio->bi_iter.bi_sector;
477 return chunk_sects >= (sector_div(sector, chunk_sects)
482 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
484 struct r0conf *conf = mddev->private;
485 struct strip_zone *zone;
486 sector_t start = bio->bi_iter.bi_sector;
488 unsigned int stripe_size;
489 sector_t first_stripe_index, last_stripe_index;
490 sector_t start_disk_offset;
491 unsigned int start_disk_index;
492 sector_t end_disk_offset;
493 unsigned int end_disk_index;
496 zone = find_zone(conf, &start);
498 if (bio_end_sector(bio) > zone->zone_end) {
499 struct bio *split = bio_split(bio,
500 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
502 bio_chain(split, bio);
503 generic_make_request(bio);
505 end = zone->zone_end;
507 end = bio_end_sector(bio);
509 if (zone != conf->strip_zone)
510 end = end - zone[-1].zone_end;
512 /* Now start and end is the offset in zone */
513 stripe_size = zone->nb_dev * mddev->chunk_sectors;
515 first_stripe_index = start;
516 sector_div(first_stripe_index, stripe_size);
517 last_stripe_index = end;
518 sector_div(last_stripe_index, stripe_size);
520 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
521 mddev->chunk_sectors;
522 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
523 mddev->chunk_sectors) +
524 first_stripe_index * mddev->chunk_sectors;
525 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
526 mddev->chunk_sectors;
527 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
528 mddev->chunk_sectors) +
529 last_stripe_index * mddev->chunk_sectors;
531 for (disk = 0; disk < zone->nb_dev; disk++) {
532 sector_t dev_start, dev_end;
533 struct bio *discard_bio = NULL;
534 struct md_rdev *rdev;
536 if (disk < start_disk_index)
537 dev_start = (first_stripe_index + 1) *
538 mddev->chunk_sectors;
539 else if (disk > start_disk_index)
540 dev_start = first_stripe_index * mddev->chunk_sectors;
542 dev_start = start_disk_offset;
544 if (disk < end_disk_index)
545 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
546 else if (disk > end_disk_index)
547 dev_end = last_stripe_index * mddev->chunk_sectors;
549 dev_end = end_disk_offset;
551 if (dev_end <= dev_start)
554 rdev = conf->devlist[(zone - conf->strip_zone) *
555 conf->strip_zone[0].nb_dev + disk];
556 if (__blkdev_issue_discard(rdev->bdev,
557 dev_start + zone->dev_start + rdev->data_offset,
558 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
561 bio_chain(discard_bio, bio);
562 bio_clone_blkcg_association(discard_bio, bio);
564 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
565 discard_bio, disk_devt(mddev->gendisk),
566 bio->bi_iter.bi_sector);
567 generic_make_request(discard_bio);
572 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
574 struct r0conf *conf = mddev->private;
575 struct strip_zone *zone;
576 struct md_rdev *tmp_dev;
579 sector_t orig_sector;
580 unsigned chunk_sects;
583 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
584 md_flush_request(mddev, bio);
588 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
589 raid0_handle_discard(mddev, bio);
593 bio_sector = bio->bi_iter.bi_sector;
595 chunk_sects = mddev->chunk_sectors;
597 sectors = chunk_sects -
598 (likely(is_power_of_2(chunk_sects))
599 ? (sector & (chunk_sects-1))
600 : sector_div(sector, chunk_sects));
602 /* Restore due to sector_div */
605 if (sectors < bio_sectors(bio)) {
606 struct bio *split = bio_split(bio, sectors, GFP_NOIO, mddev->bio_set);
607 bio_chain(split, bio);
608 generic_make_request(bio);
612 orig_sector = sector;
613 zone = find_zone(mddev->private, §or);
614 switch (conf->layout) {
615 case RAID0_ORIG_LAYOUT:
616 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
618 case RAID0_ALT_MULTIZONE_LAYOUT:
619 tmp_dev = map_sector(mddev, zone, sector, §or);
622 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
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");