From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Christie <michaelc@cs.wisc.edu>
Subject: Re: [patch] dm-mpath pg_init could race with destructor
Date: Wed, 15 Jun 2005 13:21:34 -0500
Message-ID: <42B071AE.4040305@cs.wisc.edu>
References: <20050615071946.GA765@marowsky-bree.de>
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Lars Marowsky-Bree wrote:
> Why send a pg_init request at this point if there are no queued ios?
> This was in fact my solution, to only send a pg_init io if there are
> queued ios.
> 

Are there management situations where some admin wants to manually 
switch. If he was going to take a controller temporarily offline for 
maitnenance for example? Will multipath tools and dm-mutlipath be used 
to do this type of management, or will it be some vendor specific tool 
that sends a SG_IO directly?

It would not be possible to just have dm-multipath increment some 
refcount like pending so you cannot destroy things while a pg_init IO is 
in flight would it?