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author | NeilBrown <neilb@suse.de> | 2009-03-31 14:39:39 +1100 |
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committer | NeilBrown <neilb@suse.de> | 2009-03-31 14:39:39 +1100 |
commit | d562b0c4313e3ddea402a400371afa47ddf679f9 (patch) | |
tree | e895c3f1688493f6587ad61d9824e96994ca38d6 | |
parent | 245f46c2c221ef09c7db892f0e3fc2149be42052 (diff) | |
download | op-kernel-dev-d562b0c4313e3ddea402a400371afa47ddf679f9.zip op-kernel-dev-d562b0c4313e3ddea402a400371afa47ddf679f9.tar.gz |
md: add ->takeover method for raid5 to be able to take over raid1
The RAID1 must have two drives and be a suitable size to
be a multiple of a chunksize that isn't too small.
Signed-off-by: NeilBrown <neilb@suse.de>
-rw-r--r-- | drivers/md/raid5.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5b346b4..611ea7b 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4884,6 +4884,53 @@ static void raid5_quiesce(mddev_t *mddev, int state) } } + +static void *raid5_takeover_raid1(mddev_t *mddev) +{ + int chunksect; + + if (mddev->raid_disks != 2 || + mddev->degraded > 1) + return ERR_PTR(-EINVAL); + + /* Should check if there are write-behind devices? */ + + 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) < STRIPE_SIZE) + /* array size does not allow a suitable chunk size */ + return ERR_PTR(-EINVAL); + + mddev->new_level = 5; + mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC; + mddev->new_chunk = chunksect << 9; + + return setup_conf(mddev); +} + + +static void *raid5_takeover(mddev_t *mddev) +{ + /* raid5 can take over: + * raid0 - if all devices are the same - make it a raid4 layout + * raid1 - if there are two drives. We need to know the chunk size + * raid4 - trivial - just use a raid4 layout. + * raid6 - Providing it is a *_6 layout + * + * For now, just do raid1 + */ + + if (mddev->level == 1) + return raid5_takeover_raid1(mddev); + + return ERR_PTR(-EINVAL); +} + + static struct mdk_personality raid5_personality; static void *raid6_takeover(mddev_t *mddev) @@ -4975,6 +5022,7 @@ static struct mdk_personality raid5_personality = .start_reshape = raid5_start_reshape, #endif .quiesce = raid5_quiesce, + .takeover = raid5_takeover, }; static struct mdk_personality raid4_personality = |