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Date:      Mon, 26 Mar 2001 21:31:31 +0200
From:      Poul-Henning Kamp <phk@critter.freebsd.dk>
To:        John Baldwin <jhb@FreeBSD.org>
Cc:        Greg Lehey <grog@lemis.com>, leclercn@videotron.ca, freebsd-alpha@FreeBSD.org, Mike Smith <msmith@FreeBSD.org>
Subject:   Re: dev_t size mismatch kernel / userland 
Message-ID:  <66685.985635091@critter>
In-Reply-To: Your message of "Mon, 26 Mar 2001 10:57:55 -0800." <XFMail.010326105755.jhb@FreeBSD.org> 

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In message <XFMail.010326105755.jhb@FreeBSD.org>, John Baldwin writes:

>This will probably make Poul's head spin, but one idea might be to have a
>kdev_t type. :-P  In the kernel kdev_t == dev_t, and in userland, kdev_t is a
>void *.  This would work in this case I think because you never use the dev_t's
>while in userland.  I do like exporting trimmed down structures, however. 
>Please don't export mutexes while you are at it. :-P

Guys,

I'm net to this subject, so please fill me in: just what in the
(kernel) dev_t do you want to export to userland ?

Background:

I retained the dev_t name in the kernel to avoid a massive scale
source code incompatibility there.

In userland dev_t is defined in all sorts of standards as an
"arithmetic type", and code would break left right and center
if it wasn't one, so I maintained the "minor/major" integer.

To give access to the userland view of things in the kernel,
the type "udev_t" was introduced, but to avoid polluting things
I hid the definition of that type from userland.

--
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.

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