From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gerd Hoffmann <kraxel@suse.de>
Subject: Re: building blktap as a module
Date: Mon, 16 Oct 2006 13:45:31 +0200
Message-ID: <453370DB.8090902@suse.de>
References: <C1591E06.28FE%Keir.Fraser@cl.cam.ac.uk>
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To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: Andrew Warfield <Andrew.Warfield@xensource.com>, xen-devel@lists.xensource.com, Jan Beulich <jbeulich@novell.com>
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  Hi,

>  1. The one in blktap_release() - why? Standard semantics is for mmap
> regions to exist beyond the closing of the mapping device. Doesn't make much
> sense to do that here, but then again not really any need to explicitly
> disallow it (and add extra code to enforce).

The linux kernel does call the drivers release() method when the last
reference is gone.  If you call close() with mappings still being
active, then ->release() is _not_ called when you close the file handle
but when the last mapping is unmapped.  Thus there is no point in trying
to handle active mappings there ;)

cheers,

  Gerd

-- 
Gerd Hoffmann <kraxel@suse.de>
http://www.suse.de/~kraxel/julika-dora.jpeg