linux/drivers/md/raid0.c
Pascal Hambourg ea23994edc md/raid0: Ignore RAID0 layout if the second zone has only one device
The RAID0 layout is irrelevant if all members have the same size so the
array has only one zone. It is *also* irrelevant if the array has two
zones and the second zone has only one device, for example if the array
has two members of different sizes.

So in that case it makes sense to allow assembly even when the layout is
undefined, like what is done when the array has only one zone.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Pascal Hambourg <pascal@plouf.fr.eu.org>
Signed-off-by: Song Liu <song@kernel.org>
2022-04-25 14:00:37 -07:00

795 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
raid0.c : Multiple Devices driver for Linux
Copyright (C) 1994-96 Marc ZYNGIER
<zyngier@ufr-info-p7.ibp.fr> or
<maz@gloups.fdn.fr>
Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
RAID-0 management functions.
*/
#include <linux/blkdev.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid0.h"
#include "raid5.h"
static int default_layout = 0;
module_param(default_layout, int, 0644);
#define UNSUPPORTED_MDDEV_FLAGS \
((1L << MD_HAS_JOURNAL) | \
(1L << MD_JOURNAL_CLEAN) | \
(1L << MD_FAILFAST_SUPPORTED) |\
(1L << MD_HAS_PPL) | \
(1L << MD_HAS_MULTIPLE_PPLS))
/*
* inform the user of the raid configuration
*/
static void dump_zones(struct mddev *mddev)
{
int j, k;
sector_t zone_size = 0;
sector_t zone_start = 0;
char b[BDEVNAME_SIZE];
struct r0conf *conf = mddev->private;
int raid_disks = conf->strip_zone[0].nb_dev;
pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
mdname(mddev),
conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
for (j = 0; j < conf->nr_strip_zones; j++) {
char line[200];
int len = 0;
for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
bdevname(conf->devlist[j*raid_disks
+ k]->bdev, b));
pr_debug("md: zone%d=[%s]\n", j, line);
zone_size = conf->strip_zone[j].zone_end - zone_start;
pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
(unsigned long long)zone_start>>1,
(unsigned long long)conf->strip_zone[j].dev_start>>1,
(unsigned long long)zone_size>>1);
zone_start = conf->strip_zone[j].zone_end;
}
}
static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
{
int i, c, err;
sector_t curr_zone_end, sectors;
struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
struct strip_zone *zone;
int cnt;
char b[BDEVNAME_SIZE];
char b2[BDEVNAME_SIZE];
struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
unsigned blksize = 512;
*private_conf = ERR_PTR(-ENOMEM);
if (!conf)
return -ENOMEM;
rdev_for_each(rdev1, mddev) {
pr_debug("md/raid0:%s: looking at %s\n",
mdname(mddev),
bdevname(rdev1->bdev, b));
c = 0;
/* round size to chunk_size */
sectors = rdev1->sectors;
sector_div(sectors, mddev->chunk_sectors);
rdev1->sectors = sectors * mddev->chunk_sectors;
blksize = max(blksize, queue_logical_block_size(
rdev1->bdev->bd_disk->queue));
rdev_for_each(rdev2, mddev) {
pr_debug("md/raid0:%s: comparing %s(%llu)"
" with %s(%llu)\n",
mdname(mddev),
bdevname(rdev1->bdev,b),
(unsigned long long)rdev1->sectors,
bdevname(rdev2->bdev,b2),
(unsigned long long)rdev2->sectors);
if (rdev2 == rdev1) {
pr_debug("md/raid0:%s: END\n",
mdname(mddev));
break;
}
if (rdev2->sectors == rdev1->sectors) {
/*
* Not unique, don't count it as a new
* group
*/
pr_debug("md/raid0:%s: EQUAL\n",
mdname(mddev));
c = 1;
break;
}
pr_debug("md/raid0:%s: NOT EQUAL\n",
mdname(mddev));
}
if (!c) {
pr_debug("md/raid0:%s: ==> UNIQUE\n",
mdname(mddev));
conf->nr_strip_zones++;
pr_debug("md/raid0:%s: %d zones\n",
mdname(mddev), conf->nr_strip_zones);
}
}
pr_debug("md/raid0:%s: FINAL %d zones\n",
mdname(mddev), conf->nr_strip_zones);
/*
* now since we have the hard sector sizes, we can make sure
* chunk size is a multiple of that sector size
*/
if ((mddev->chunk_sectors << 9) % blksize) {
pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
mdname(mddev),
mddev->chunk_sectors << 9, blksize);
err = -EINVAL;
goto abort;
}
err = -ENOMEM;
conf->strip_zone = kcalloc(conf->nr_strip_zones,
sizeof(struct strip_zone),
GFP_KERNEL);
if (!conf->strip_zone)
goto abort;
conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
conf->nr_strip_zones,
mddev->raid_disks),
GFP_KERNEL);
if (!conf->devlist)
goto abort;
/* The first zone must contain all devices, so here we check that
* there is a proper alignment of slots to devices and find them all
*/
zone = &conf->strip_zone[0];
cnt = 0;
smallest = NULL;
dev = conf->devlist;
err = -EINVAL;
rdev_for_each(rdev1, mddev) {
int j = rdev1->raid_disk;
if (mddev->level == 10) {
/* taking over a raid10-n2 array */
j /= 2;
rdev1->new_raid_disk = j;
}
if (mddev->level == 1) {
/* taiking over a raid1 array-
* we have only one active disk
*/
j = 0;
rdev1->new_raid_disk = j;
}
if (j < 0) {
pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
mdname(mddev));
goto abort;
}
if (j >= mddev->raid_disks) {
pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
mdname(mddev), j);
goto abort;
}
if (dev[j]) {
pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
mdname(mddev), j);
goto abort;
}
dev[j] = rdev1;
if (!smallest || (rdev1->sectors < smallest->sectors))
smallest = rdev1;
cnt++;
}
if (cnt != mddev->raid_disks) {
pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
mdname(mddev), cnt, mddev->raid_disks);
goto abort;
}
zone->nb_dev = cnt;
zone->zone_end = smallest->sectors * cnt;
curr_zone_end = zone->zone_end;
/* now do the other zones */
for (i = 1; i < conf->nr_strip_zones; i++)
{
int j;
zone = conf->strip_zone + i;
dev = conf->devlist + i * mddev->raid_disks;
pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
zone->dev_start = smallest->sectors;
smallest = NULL;
c = 0;
for (j=0; j<cnt; j++) {
rdev = conf->devlist[j];
if (rdev->sectors <= zone->dev_start) {
pr_debug("md/raid0:%s: checking %s ... nope\n",
mdname(mddev),
bdevname(rdev->bdev, b));
continue;
}
pr_debug("md/raid0:%s: checking %s ..."
" contained as device %d\n",
mdname(mddev),
bdevname(rdev->bdev, b), c);
dev[c] = rdev;
c++;
if (!smallest || rdev->sectors < smallest->sectors) {
smallest = rdev;
pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
mdname(mddev),
(unsigned long long)rdev->sectors);
}
}
zone->nb_dev = c;
sectors = (smallest->sectors - zone->dev_start) * c;
pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
mdname(mddev),
zone->nb_dev, (unsigned long long)sectors);
curr_zone_end += sectors;
zone->zone_end = curr_zone_end;
pr_debug("md/raid0:%s: current zone start: %llu\n",
mdname(mddev),
(unsigned long long)smallest->sectors);
}
if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
conf->layout = RAID0_ORIG_LAYOUT;
} else if (mddev->layout == RAID0_ORIG_LAYOUT ||
mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
conf->layout = mddev->layout;
} else if (default_layout == RAID0_ORIG_LAYOUT ||
default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
conf->layout = default_layout;
} else {
pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
mdname(mddev));
pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
err = -EOPNOTSUPP;
goto abort;
}
pr_debug("md/raid0:%s: done.\n", mdname(mddev));
*private_conf = conf;
return 0;
abort:
kfree(conf->strip_zone);
kfree(conf->devlist);
kfree(conf);
*private_conf = ERR_PTR(err);
return err;
}
/* Find the zone which holds a particular offset
* Update *sectorp to be an offset in that zone
*/
static struct strip_zone *find_zone(struct r0conf *conf,
sector_t *sectorp)
{
int i;
struct strip_zone *z = conf->strip_zone;
sector_t sector = *sectorp;
for (i = 0; i < conf->nr_strip_zones; i++)
if (sector < z[i].zone_end) {
if (i)
*sectorp = sector - z[i-1].zone_end;
return z + i;
}
BUG();
}
/*
* remaps the bio to the target device. we separate two flows.
* power 2 flow and a general flow for the sake of performance
*/
static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
sector_t sector, sector_t *sector_offset)
{
unsigned int sect_in_chunk;
sector_t chunk;
struct r0conf *conf = mddev->private;
int raid_disks = conf->strip_zone[0].nb_dev;
unsigned int chunk_sects = mddev->chunk_sectors;
if (is_power_of_2(chunk_sects)) {
int chunksect_bits = ffz(~chunk_sects);
/* find the sector offset inside the chunk */
sect_in_chunk = sector & (chunk_sects - 1);
sector >>= chunksect_bits;
/* chunk in zone */
chunk = *sector_offset;
/* quotient is the chunk in real device*/
sector_div(chunk, zone->nb_dev << chunksect_bits);
} else{
sect_in_chunk = sector_div(sector, chunk_sects);
chunk = *sector_offset;
sector_div(chunk, chunk_sects * zone->nb_dev);
}
/*
* position the bio over the real device
* real sector = chunk in device + starting of zone
* + the position in the chunk
*/
*sector_offset = (chunk * chunk_sects) + sect_in_chunk;
return conf->devlist[(zone - conf->strip_zone)*raid_disks
+ sector_div(sector, zone->nb_dev)];
}
static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
sector_t array_sectors = 0;
struct md_rdev *rdev;
WARN_ONCE(sectors || raid_disks,
"%s does not support generic reshape\n", __func__);
rdev_for_each(rdev, mddev)
array_sectors += (rdev->sectors &
~(sector_t)(mddev->chunk_sectors-1));
return array_sectors;
}
static void free_conf(struct mddev *mddev, struct r0conf *conf)
{
kfree(conf->strip_zone);
kfree(conf->devlist);
kfree(conf);
mddev->private = NULL;
}
static void raid0_free(struct mddev *mddev, void *priv)
{
struct r0conf *conf = priv;
free_conf(mddev, conf);
acct_bioset_exit(mddev);
}
static int raid0_run(struct mddev *mddev)
{
struct r0conf *conf;
int ret;
if (mddev->chunk_sectors == 0) {
pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
return -EINVAL;
}
if (md_check_no_bitmap(mddev))
return -EINVAL;
if (acct_bioset_init(mddev)) {
pr_err("md/raid0:%s: alloc acct bioset failed.\n", mdname(mddev));
return -ENOMEM;
}
/* if private is not null, we are here after takeover */
if (mddev->private == NULL) {
ret = create_strip_zones(mddev, &conf);
if (ret < 0)
goto exit_acct_set;
mddev->private = conf;
}
conf = mddev->private;
if (mddev->queue) {
struct md_rdev *rdev;
blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
blk_queue_io_opt(mddev->queue,
(mddev->chunk_sectors << 9) * mddev->raid_disks);
rdev_for_each(rdev, mddev) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
}
}
/* calculate array device size */
md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
mdname(mddev),
(unsigned long long)mddev->array_sectors);
dump_zones(mddev);
ret = md_integrity_register(mddev);
if (ret)
goto free;
return ret;
free:
free_conf(mddev, conf);
exit_acct_set:
acct_bioset_exit(mddev);
return ret;
}
static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r0conf *conf = mddev->private;
struct strip_zone *zone;
sector_t start = bio->bi_iter.bi_sector;
sector_t end;
unsigned int stripe_size;
sector_t first_stripe_index, last_stripe_index;
sector_t start_disk_offset;
unsigned int start_disk_index;
sector_t end_disk_offset;
unsigned int end_disk_index;
unsigned int disk;
zone = find_zone(conf, &start);
if (bio_end_sector(bio) > zone->zone_end) {
struct bio *split = bio_split(bio,
zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
&mddev->bio_set);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
end = zone->zone_end;
} else
end = bio_end_sector(bio);
if (zone != conf->strip_zone)
end = end - zone[-1].zone_end;
/* Now start and end is the offset in zone */
stripe_size = zone->nb_dev * mddev->chunk_sectors;
first_stripe_index = start;
sector_div(first_stripe_index, stripe_size);
last_stripe_index = end;
sector_div(last_stripe_index, stripe_size);
start_disk_index = (int)(start - first_stripe_index * stripe_size) /
mddev->chunk_sectors;
start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
mddev->chunk_sectors) +
first_stripe_index * mddev->chunk_sectors;
end_disk_index = (int)(end - last_stripe_index * stripe_size) /
mddev->chunk_sectors;
end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
mddev->chunk_sectors) +
last_stripe_index * mddev->chunk_sectors;
for (disk = 0; disk < zone->nb_dev; disk++) {
sector_t dev_start, dev_end;
struct md_rdev *rdev;
if (disk < start_disk_index)
dev_start = (first_stripe_index + 1) *
mddev->chunk_sectors;
else if (disk > start_disk_index)
dev_start = first_stripe_index * mddev->chunk_sectors;
else
dev_start = start_disk_offset;
if (disk < end_disk_index)
dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
else if (disk > end_disk_index)
dev_end = last_stripe_index * mddev->chunk_sectors;
else
dev_end = end_disk_offset;
if (dev_end <= dev_start)
continue;
rdev = conf->devlist[(zone - conf->strip_zone) *
conf->strip_zone[0].nb_dev + disk];
md_submit_discard_bio(mddev, rdev, bio,
dev_start + zone->dev_start + rdev->data_offset,
dev_end - dev_start);
}
bio_endio(bio);
}
static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
{
struct r0conf *conf = mddev->private;
struct strip_zone *zone;
struct md_rdev *tmp_dev;
sector_t bio_sector;
sector_t sector;
sector_t orig_sector;
unsigned chunk_sects;
unsigned sectors;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
raid0_handle_discard(mddev, bio);
return true;
}
bio_sector = bio->bi_iter.bi_sector;
sector = bio_sector;
chunk_sects = mddev->chunk_sectors;
sectors = chunk_sects -
(likely(is_power_of_2(chunk_sects))
? (sector & (chunk_sects-1))
: sector_div(sector, chunk_sects));
/* Restore due to sector_div */
sector = bio_sector;
if (sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, sectors, GFP_NOIO,
&mddev->bio_set);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
}
if (bio->bi_pool != &mddev->bio_set)
md_account_bio(mddev, &bio);
orig_sector = sector;
zone = find_zone(mddev->private, &sector);
switch (conf->layout) {
case RAID0_ORIG_LAYOUT:
tmp_dev = map_sector(mddev, zone, orig_sector, &sector);
break;
case RAID0_ALT_MULTIZONE_LAYOUT:
tmp_dev = map_sector(mddev, zone, sector, &sector);
break;
default:
WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
bio_io_error(bio);
return true;
}
if (unlikely(is_mddev_broken(tmp_dev, "raid0"))) {
bio_io_error(bio);
return true;
}
bio_set_dev(bio, tmp_dev->bdev);
bio->bi_iter.bi_sector = sector + zone->dev_start +
tmp_dev->data_offset;
if (mddev->gendisk)
trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
bio_sector);
mddev_check_write_zeroes(mddev, bio);
submit_bio_noacct(bio);
return true;
}
static void raid0_status(struct seq_file *seq, struct mddev *mddev)
{
seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
return;
}
static void *raid0_takeover_raid45(struct mddev *mddev)
{
struct md_rdev *rdev;
struct r0conf *priv_conf;
if (mddev->degraded != 1) {
pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
mdname(mddev),
mddev->degraded);
return ERR_PTR(-EINVAL);
}
rdev_for_each(rdev, mddev) {
/* check slot number for a disk */
if (rdev->raid_disk == mddev->raid_disks-1) {
pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
rdev->sectors = mddev->dev_sectors;
}
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->raid_disks--;
mddev->delta_disks = -1;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover_raid10(struct mddev *mddev)
{
struct r0conf *priv_conf;
/* Check layout:
* - far_copies must be 1
* - near_copies must be 2
* - disks number must be even
* - all mirrors must be already degraded
*/
if (mddev->layout != ((1 << 8) + 2)) {
pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
mdname(mddev),
mddev->layout);
return ERR_PTR(-EINVAL);
}
if (mddev->raid_disks & 1) {
pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
if (mddev->degraded != (mddev->raid_disks>>1)) {
pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = - mddev->raid_disks / 2;
mddev->raid_disks += mddev->delta_disks;
mddev->degraded = 0;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover_raid1(struct mddev *mddev)
{
struct r0conf *priv_conf;
int chunksect;
/* Check layout:
* - (N - 1) mirror drives must be already faulty
*/
if ((mddev->raid_disks - 1) != mddev->degraded) {
pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
/*
* a raid1 doesn't have the notion of chunk size, so
* figure out the largest suitable size we can use.
*/
chunksect = 64 * 2; /* 64K by default */
/* The array must be an exact multiple of chunksize */
while (chunksect && (mddev->array_sectors & (chunksect - 1)))
chunksect >>= 1;
if ((chunksect << 9) < PAGE_SIZE)
/* array size does not allow a suitable chunk size */
return ERR_PTR(-EINVAL);
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = chunksect;
mddev->chunk_sectors = chunksect;
mddev->delta_disks = 1 - mddev->raid_disks;
mddev->raid_disks = 1;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover(struct mddev *mddev)
{
/* raid0 can take over:
* raid4 - if all data disks are active.
* raid5 - providing it is Raid4 layout and one disk is faulty
* raid10 - assuming we have all necessary active disks
* raid1 - with (N -1) mirror drives faulty
*/
if (mddev->bitmap) {
pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
mdname(mddev));
return ERR_PTR(-EBUSY);
}
if (mddev->level == 4)
return raid0_takeover_raid45(mddev);
if (mddev->level == 5) {
if (mddev->layout == ALGORITHM_PARITY_N)
return raid0_takeover_raid45(mddev);
pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
mdname(mddev), ALGORITHM_PARITY_N);
}
if (mddev->level == 10)
return raid0_takeover_raid10(mddev);
if (mddev->level == 1)
return raid0_takeover_raid1(mddev);
pr_warn("Takeover from raid%i to raid0 not supported\n",
mddev->level);
return ERR_PTR(-EINVAL);
}
static void raid0_quiesce(struct mddev *mddev, int quiesce)
{
}
static struct md_personality raid0_personality=
{
.name = "raid0",
.level = 0,
.owner = THIS_MODULE,
.make_request = raid0_make_request,
.run = raid0_run,
.free = raid0_free,
.status = raid0_status,
.size = raid0_size,
.takeover = raid0_takeover,
.quiesce = raid0_quiesce,
};
static int __init raid0_init (void)
{
return register_md_personality (&raid0_personality);
}
static void raid0_exit (void)
{
unregister_md_personality (&raid0_personality);
}
module_init(raid0_init);
module_exit(raid0_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
MODULE_ALIAS("md-personality-2"); /* RAID0 */
MODULE_ALIAS("md-raid0");
MODULE_ALIAS("md-level-0");