From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Snitzer <snitzer@redhat.com>
Subject: Re: dm-raid: check for zero feature flags in metadata
Date: Fri, 29 Apr 2016 15:18:36 -0400
Message-ID: <20160429191835.GA22007@redhat.com>
References: <1461949196-17999-1-git-send-email-heinzm@redhat.com>
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On Fri, Apr 29 2016 at 12:59pm -0400,
heinzm@redhat.com <heinzm@redhat.com> wrote:

> From: Heinz Mauelshagen <heinzm@redhat.com>
> 
> Because we don't support any feature flags in the dm-raid ondisk
> metadata yet (see struct dm_raid_superblock, 'features' member), 
> this patch adds a check to ensure no flags are actually set or
> reject the activation of the RAID mapping.
> 
> This is to prevent possible data corruption in case of a
> kernel downgrade when there'll potentially be feature flags
> set by a future dm-raid target.
> 
> 
> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>

merged for 4.7, see:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-4.7&id=480375cd7ea3eed60381539dbfa96851b6174820