[dm-devel] dm-raid: check for zero feature flags in metadata

[Mike Snitzer]

On Fri, Apr 29 2016 at  3:18pm -0400,
Mike Snitzer <snitzer at redhat.com> wrote:

> On Fri, Apr 29 2016 at 12:59pm -0400,
> heinzm at redhat.com <heinzm at redhat.com> wrote:
> 
> > From: Heinz Mauelshagen <heinzm at 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 at 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

Actually, I revised the header and patch content, see:

https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-4.7&id=ecdb57d205b98b656ab3ea0412f7a15ec003357f