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);
154 * now since we have the hard sector sizes, we can make sure
155 * chunk size is a multiple of that sector size
157 if ((mddev->chunk_sectors << 9) % blksize) {
158 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
160 mddev->chunk_sectors << 9, blksize);
166 conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
167 conf->nr_strip_zones, GFP_KERNEL);
168 if (!conf->strip_zone)
170 conf->devlist = kzalloc(sizeof(struct md_rdev*)*
171 conf->nr_strip_zones*mddev->raid_disks,
176 /* The first zone must contain all devices, so here we check that
177 * there is a proper alignment of slots to devices and find them all
179 zone = &conf->strip_zone[0];
184 rdev_for_each(rdev1, mddev) {
185 int j = rdev1->raid_disk;
187 if (mddev->level == 10) {
188 /* taking over a raid10-n2 array */
190 rdev1->new_raid_disk = j;
193 if (mddev->level == 1) {
194 /* taiking over a raid1 array-
195 * we have only one active disk
198 rdev1->new_raid_disk = j;
202 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
206 if (j >= mddev->raid_disks) {
207 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
212 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
218 if (!smallest || (rdev1->sectors < smallest->sectors))
222 if (cnt != mddev->raid_disks) {
223 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
224 mdname(mddev), cnt, mddev->raid_disks);
228 zone->zone_end = smallest->sectors * cnt;
230 curr_zone_end = zone->zone_end;
232 /* now do the other zones */
233 for (i = 1; i < conf->nr_strip_zones; i++)
237 zone = conf->strip_zone + i;
238 dev = conf->devlist + i * mddev->raid_disks;
240 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
241 zone->dev_start = smallest->sectors;
245 for (j=0; j<cnt; j++) {
246 rdev = conf->devlist[j];
247 if (rdev->sectors <= zone->dev_start) {
248 pr_debug("md/raid0:%s: checking %s ... nope\n",
250 bdevname(rdev->bdev, b));
253 pr_debug("md/raid0:%s: checking %s ..."
254 " contained as device %d\n",
256 bdevname(rdev->bdev, b), c);
259 if (!smallest || rdev->sectors < smallest->sectors) {
261 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
263 (unsigned long long)rdev->sectors);
268 sectors = (smallest->sectors - zone->dev_start) * c;
269 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
271 zone->nb_dev, (unsigned long long)sectors);
273 curr_zone_end += sectors;
274 zone->zone_end = curr_zone_end;
276 pr_debug("md/raid0:%s: current zone start: %llu\n",
278 (unsigned long long)smallest->sectors);
281 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
282 conf->layout = RAID0_ORIG_LAYOUT;
283 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
284 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
285 conf->layout = mddev->layout;
286 } else if (default_layout == RAID0_ORIG_LAYOUT ||
287 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
288 conf->layout = default_layout;
290 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
292 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
297 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
298 *private_conf = conf;
302 kfree(conf->strip_zone);
303 kfree(conf->devlist);
305 *private_conf = ERR_PTR(err);
309 /* Find the zone which holds a particular offset
310 * Update *sectorp to be an offset in that zone
312 static struct strip_zone *find_zone(struct r0conf *conf,
316 struct strip_zone *z = conf->strip_zone;
317 sector_t sector = *sectorp;
319 for (i = 0; i < conf->nr_strip_zones; i++)
320 if (sector < z[i].zone_end) {
322 *sectorp = sector - z[i-1].zone_end;
329 * remaps the bio to the target device. we separate two flows.
330 * power 2 flow and a general flow for the sake of performance
332 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
333 sector_t sector, sector_t *sector_offset)
335 unsigned int sect_in_chunk;
337 struct r0conf *conf = mddev->private;
338 int raid_disks = conf->strip_zone[0].nb_dev;
339 unsigned int chunk_sects = mddev->chunk_sectors;
341 if (is_power_of_2(chunk_sects)) {
342 int chunksect_bits = ffz(~chunk_sects);
343 /* find the sector offset inside the chunk */
344 sect_in_chunk = sector & (chunk_sects - 1);
345 sector >>= chunksect_bits;
347 chunk = *sector_offset;
348 /* quotient is the chunk in real device*/
349 sector_div(chunk, zone->nb_dev << chunksect_bits);
351 sect_in_chunk = sector_div(sector, chunk_sects);
352 chunk = *sector_offset;
353 sector_div(chunk, chunk_sects * zone->nb_dev);
356 * position the bio over the real device
357 * real sector = chunk in device + starting of zone
358 * + the position in the chunk
360 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
361 return conf->devlist[(zone - conf->strip_zone)*raid_disks
362 + sector_div(sector, zone->nb_dev)];
365 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
367 sector_t array_sectors = 0;
368 struct md_rdev *rdev;
370 WARN_ONCE(sectors || raid_disks,
371 "%s does not support generic reshape\n", __func__);
373 rdev_for_each(rdev, mddev)
374 array_sectors += (rdev->sectors &
375 ~(sector_t)(mddev->chunk_sectors-1));
377 return array_sectors;
380 static void raid0_free(struct mddev *mddev, void *priv);
382 static int raid0_run(struct mddev *mddev)
387 if (mddev->chunk_sectors == 0) {
388 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
391 if (md_check_no_bitmap(mddev))
394 /* if private is not null, we are here after takeover */
395 if (mddev->private == NULL) {
396 ret = create_strip_zones(mddev, &conf);
399 mddev->private = conf;
401 conf = mddev->private;
403 struct md_rdev *rdev;
404 bool discard_supported = false;
406 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
407 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
408 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
409 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
411 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
412 blk_queue_io_opt(mddev->queue,
413 (mddev->chunk_sectors << 9) * mddev->raid_disks);
415 rdev_for_each(rdev, mddev) {
416 disk_stack_limits(mddev->gendisk, rdev->bdev,
417 rdev->data_offset << 9);
418 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
419 discard_supported = true;
421 if (!discard_supported)
422 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
424 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
427 /* calculate array device size */
428 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
430 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
432 (unsigned long long)mddev->array_sectors);
435 /* calculate the max read-ahead size.
436 * For read-ahead of large files to be effective, we need to
437 * readahead at least twice a whole stripe. i.e. number of devices
438 * multiplied by chunk size times 2.
439 * If an individual device has an ra_pages greater than the
440 * chunk size, then we will not drive that device as hard as it
441 * wants. We consider this a configuration error: a larger
442 * chunksize should be used in that case.
444 int stripe = mddev->raid_disks *
445 (mddev->chunk_sectors << 9) / PAGE_SIZE;
446 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
447 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
452 ret = md_integrity_register(mddev);
457 static void raid0_free(struct mddev *mddev, void *priv)
459 struct r0conf *conf = priv;
461 kfree(conf->strip_zone);
462 kfree(conf->devlist);
467 * Is io distribute over 1 or more chunks ?
469 static inline int is_io_in_chunk_boundary(struct mddev *mddev,
470 unsigned int chunk_sects, struct bio *bio)
472 if (likely(is_power_of_2(chunk_sects))) {
473 return chunk_sects >=
474 ((bio->bi_iter.bi_sector & (chunk_sects-1))
477 sector_t sector = bio->bi_iter.bi_sector;
478 return chunk_sects >= (sector_div(sector, chunk_sects)
483 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
485 struct r0conf *conf = mddev->private;
486 struct strip_zone *zone;
487 sector_t start = bio->bi_iter.bi_sector;
489 unsigned int stripe_size;
490 sector_t first_stripe_index, last_stripe_index;
491 sector_t start_disk_offset;
492 unsigned int start_disk_index;
493 sector_t end_disk_offset;
494 unsigned int end_disk_index;
497 zone = find_zone(conf, &start);
499 if (bio_end_sector(bio) > zone->zone_end) {
500 struct bio *split = bio_split(bio,
501 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
503 bio_chain(split, bio);
504 generic_make_request(bio);
506 end = zone->zone_end;
508 end = bio_end_sector(bio);
510 if (zone != conf->strip_zone)
511 end = end - zone[-1].zone_end;
513 /* Now start and end is the offset in zone */
514 stripe_size = zone->nb_dev * mddev->chunk_sectors;
516 first_stripe_index = start;
517 sector_div(first_stripe_index, stripe_size);
518 last_stripe_index = end;
519 sector_div(last_stripe_index, stripe_size);
521 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
522 mddev->chunk_sectors;
523 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
524 mddev->chunk_sectors) +
525 first_stripe_index * mddev->chunk_sectors;
526 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
527 mddev->chunk_sectors;
528 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
529 mddev->chunk_sectors) +
530 last_stripe_index * mddev->chunk_sectors;
532 for (disk = 0; disk < zone->nb_dev; disk++) {
533 sector_t dev_start, dev_end;
534 struct bio *discard_bio = NULL;
535 struct md_rdev *rdev;
537 if (disk < start_disk_index)
538 dev_start = (first_stripe_index + 1) *
539 mddev->chunk_sectors;
540 else if (disk > start_disk_index)
541 dev_start = first_stripe_index * mddev->chunk_sectors;
543 dev_start = start_disk_offset;
545 if (disk < end_disk_index)
546 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
547 else if (disk > end_disk_index)
548 dev_end = last_stripe_index * mddev->chunk_sectors;
550 dev_end = end_disk_offset;
552 if (dev_end <= dev_start)
555 rdev = conf->devlist[(zone - conf->strip_zone) *
556 conf->strip_zone[0].nb_dev + disk];
557 if (__blkdev_issue_discard(rdev->bdev,
558 dev_start + zone->dev_start + rdev->data_offset,
559 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
562 bio_chain(discard_bio, bio);
563 bio_clone_blkcg_association(discard_bio, bio);
565 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
566 discard_bio, disk_devt(mddev->gendisk),
567 bio->bi_iter.bi_sector);
568 generic_make_request(discard_bio);
573 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
575 struct r0conf *conf = mddev->private;
576 struct strip_zone *zone;
577 struct md_rdev *tmp_dev;
580 sector_t orig_sector;
581 unsigned chunk_sects;
584 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
585 md_flush_request(mddev, bio);
589 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
590 raid0_handle_discard(mddev, bio);
594 bio_sector = bio->bi_iter.bi_sector;
596 chunk_sects = mddev->chunk_sectors;
598 sectors = chunk_sects -
599 (likely(is_power_of_2(chunk_sects))
600 ? (sector & (chunk_sects-1))
601 : sector_div(sector, chunk_sects));
603 /* Restore due to sector_div */
606 if (sectors < bio_sectors(bio)) {
607 struct bio *split = bio_split(bio, sectors, GFP_NOIO, mddev->bio_set);
608 bio_chain(split, bio);
609 generic_make_request(bio);
613 orig_sector = sector;
614 zone = find_zone(mddev->private, §or);
615 switch (conf->layout) {
616 case RAID0_ORIG_LAYOUT:
617 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
619 case RAID0_ALT_MULTIZONE_LAYOUT:
620 tmp_dev = map_sector(mddev, zone, sector, §or);
623 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
628 bio_set_dev(bio, tmp_dev->bdev);
629 bio->bi_iter.bi_sector = sector + zone->dev_start +
630 tmp_dev->data_offset;
633 trace_block_bio_remap(bio->bi_disk->queue, bio,
634 disk_devt(mddev->gendisk), bio_sector);
635 mddev_check_writesame(mddev, bio);
636 mddev_check_write_zeroes(mddev, bio);
637 generic_make_request(bio);
641 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
643 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
647 static void *raid0_takeover_raid45(struct mddev *mddev)
649 struct md_rdev *rdev;
650 struct r0conf *priv_conf;
652 if (mddev->degraded != 1) {
653 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
656 return ERR_PTR(-EINVAL);
659 rdev_for_each(rdev, mddev) {
660 /* check slot number for a disk */
661 if (rdev->raid_disk == mddev->raid_disks-1) {
662 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
664 return ERR_PTR(-EINVAL);
666 rdev->sectors = mddev->dev_sectors;
669 /* Set new parameters */
670 mddev->new_level = 0;
671 mddev->new_layout = 0;
672 mddev->new_chunk_sectors = mddev->chunk_sectors;
674 mddev->delta_disks = -1;
675 /* make sure it will be not marked as dirty */
676 mddev->recovery_cp = MaxSector;
677 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
679 create_strip_zones(mddev, &priv_conf);
684 static void *raid0_takeover_raid10(struct mddev *mddev)
686 struct r0conf *priv_conf;
689 * - far_copies must be 1
690 * - near_copies must be 2
691 * - disks number must be even
692 * - all mirrors must be already degraded
694 if (mddev->layout != ((1 << 8) + 2)) {
695 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
698 return ERR_PTR(-EINVAL);
700 if (mddev->raid_disks & 1) {
701 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
703 return ERR_PTR(-EINVAL);
705 if (mddev->degraded != (mddev->raid_disks>>1)) {
706 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
708 return ERR_PTR(-EINVAL);
711 /* Set new parameters */
712 mddev->new_level = 0;
713 mddev->new_layout = 0;
714 mddev->new_chunk_sectors = mddev->chunk_sectors;
715 mddev->delta_disks = - mddev->raid_disks / 2;
716 mddev->raid_disks += mddev->delta_disks;
718 /* make sure it will be not marked as dirty */
719 mddev->recovery_cp = MaxSector;
720 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
722 create_strip_zones(mddev, &priv_conf);
726 static void *raid0_takeover_raid1(struct mddev *mddev)
728 struct r0conf *priv_conf;
732 * - (N - 1) mirror drives must be already faulty
734 if ((mddev->raid_disks - 1) != mddev->degraded) {
735 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
737 return ERR_PTR(-EINVAL);
741 * a raid1 doesn't have the notion of chunk size, so
742 * figure out the largest suitable size we can use.
744 chunksect = 64 * 2; /* 64K by default */
746 /* The array must be an exact multiple of chunksize */
747 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
750 if ((chunksect << 9) < PAGE_SIZE)
751 /* array size does not allow a suitable chunk size */
752 return ERR_PTR(-EINVAL);
754 /* Set new parameters */
755 mddev->new_level = 0;
756 mddev->new_layout = 0;
757 mddev->new_chunk_sectors = chunksect;
758 mddev->chunk_sectors = chunksect;
759 mddev->delta_disks = 1 - mddev->raid_disks;
760 mddev->raid_disks = 1;
761 /* make sure it will be not marked as dirty */
762 mddev->recovery_cp = MaxSector;
763 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
765 create_strip_zones(mddev, &priv_conf);
769 static void *raid0_takeover(struct mddev *mddev)
771 /* raid0 can take over:
772 * raid4 - if all data disks are active.
773 * raid5 - providing it is Raid4 layout and one disk is faulty
774 * raid10 - assuming we have all necessary active disks
775 * raid1 - with (N -1) mirror drives faulty
779 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
781 return ERR_PTR(-EBUSY);
783 if (mddev->level == 4)
784 return raid0_takeover_raid45(mddev);
786 if (mddev->level == 5) {
787 if (mddev->layout == ALGORITHM_PARITY_N)
788 return raid0_takeover_raid45(mddev);
790 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
791 mdname(mddev), ALGORITHM_PARITY_N);
794 if (mddev->level == 10)
795 return raid0_takeover_raid10(mddev);
797 if (mddev->level == 1)
798 return raid0_takeover_raid1(mddev);
800 pr_warn("Takeover from raid%i to raid0 not supported\n",
803 return ERR_PTR(-EINVAL);
806 static void raid0_quiesce(struct mddev *mddev, int quiesce)
810 static struct md_personality raid0_personality=
814 .owner = THIS_MODULE,
815 .make_request = raid0_make_request,
818 .status = raid0_status,
820 .takeover = raid0_takeover,
821 .quiesce = raid0_quiesce,
822 .congested = raid0_congested,
825 static int __init raid0_init (void)
827 return register_md_personality (&raid0_personality);
830 static void raid0_exit (void)
832 unregister_md_personality (&raid0_personality);
835 module_init(raid0_init);
836 module_exit(raid0_exit);
837 MODULE_LICENSE("GPL");
838 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
839 MODULE_ALIAS("md-personality-2"); /* RAID0 */
840 MODULE_ALIAS("md-raid0");
841 MODULE_ALIAS("md-level-0");