tree 67757972da005990d619b810c3b75fb8b6c9969f
parent 911d4ee8536d89ea8a6cd3e96b1c95a3ebc5ea66
author NeilBrown <neilb@suse.de> 1238470778 +1100
committer NeilBrown <neilb@suse.de> 1238470778 +1100

md/raid5: Add support for new layouts for raid5 and raid6.

DDF uses different layouts for P and Q blocks than current md/raid6
so add those that are missing.
Also add support for RAID6 layouts that are identical to various
raid5 layouts with the simple addition of one device to hold all of
the 'Q' blocks.
Finally add 'raid5' layouts to match raid4.
These last to will allow online level conversion.

Note that this does not provide correct support for DDF/raid6 yet
as the order in which data blocks are summed to produce the Q block
is significant and different between current md code and DDF
requirements.

Signed-off-by: NeilBrown <neilb@suse.de>