From owner-freebsd-arch@FreeBSD.ORG  Wed Jul 21 09:22:14 2004
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To: Doug Rabson <dfr@nlsystems.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Wed, 21 Jul 2004 10:10:07 BST."
             <200407211010.08159.dfr@nlsystems.com> 
Date: Wed, 21 Jul 2004 11:21:39 +0200
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cc: arch@freebsd.org
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Subject: Re: kldunload DIAGNOSTIC idea... 
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In message <200407211010.08159.dfr@nlsystems.com>, Doug Rabson writes:

>The original intention was that drivers use the 
>device_busy()/device_unbusy() counter to handle these things. In some 
>cases, just calling device_busy() from fooopen() and device_unbusy() 
>from fooclose() is sufficient.

That is not enough.  All methods in cdevsw, and things not in cdevsw
(clone handlers, call backs, etc etc) needs to refcount.

I have a lot of this working in a tree here, and will commit it once
I have gone over it a few more times.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.