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Date: Fri, 16 Oct 2009 11:32:00 +0300
From: Andriy Gapon <avg@icyb.net.ua>
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To: Pawel Jakub Dawidek <pjd@FreeBSD.org>
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Cc: Alexander Best <alexbestms@math.uni-muenster.de>,
	freebsd-current@FreeBSD.org
Subject: Re: panic when mounting device >= 2 times
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on 14/10/2009 23:46 Pawel Jakub Dawidek said the following:
> I've this patch that is suppose to fix it:
> 
> 	http://people.freebsd.org/~pjd/patches/geom_vfs.c.patch
> 
> But AFAIR its not complete. I think it is still possible to remount one
> of the read-only mounts to read-write.
> 
> Another possibility that comes to my mind is to keep list/array of
> consumers in bo_private instead of using one consumer only. This would
> be better in terms of access management.

This looks very good for at least preventing the most common accidents.
I've been thinking about something like creating a cloned vnode for the device
vnode and giving a private copy to each filesystem. But I currently lack a lot
knowledge in this area, so I can't even say if it could be feasible, let alone
implement it.


-- 
Andriy Gapon