From: Heinz Mauelshagen Date: Wed, 24 Sep 2014 15:47:19 +0000 (+0200) Subject: dm raid: add discard support for RAID levels 4, 5 and 6 X-Git-Tag: fixes-against-v3.18-rc2~51^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48cf06bc5f508d5f71bc0fd7530daebb12a48428;p=pandora-kernel.git dm raid: add discard support for RAID levels 4, 5 and 6 In case of RAID levels 4, 5 and 6 we have to verify each RAID members' ability to zero data on discards to avoid stripe data corruption -- if discard_zeroes_data is not set for each RAID member discard support must be disabled. But given the uncertainty of whether or not a RAID member properly supports zeroing data on discard we require the user to explicitly allow discard support on RAID levels 4, 5, and 6 by setting a dm-raid module paramter, e.g.: dm-raid.devices_handle_discard_safely=Y Otherwise, discards could cause data corruption on RAID4/5/6. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- Reading git-diff-tree failed