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>
This commit is contained in:
NeilBrown 2009-03-31 14:39:39 +11:00
commit d562b0c431