From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Tue, 19 Mar 2013 11:23:47 -0400
From: David Teigland <teigland@redhat.com>
Message-ID: <20130319152347.GA986@redhat.com>
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Subject: Re: [linux-lvm] [PATCH 01/10] lvchange: Allow cluster lock
	conversion
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To: Vladislav Bogdanov <bubble@hoster-ok.com>
Cc: linux-lvm@redhat.com

On Tue, Mar 19, 2013 at 01:32:41PM +0000, Vladislav Bogdanov wrote:
> Allow clvm locks to be converted shared <-> exclusive with corosync/dlm.
> 
> Without this it is impossible to alow both
> * VM migration (shared lock is required)
> * host-side snapshots of VM disks (exlusive lock is required)
> 
> Locks are only converted if --force parameter passed to lvchange.
> 
> Internally LKF_CONVERT flag is passed to dlm, so that is a real lock
> conversion.
> 
> Also deny release of an exclusive lock on a remote note without --force
> flag to lvchange -an.

I'm trying to figure out why the code doesn't already use CONVERT when
possible; I would have expected it to.  (It has to be combined with
NOQUEUE to avoid deadlocks.)  What happens now without this force/CONVERT
patch? a new lock created/requested?