From owner-freebsd-arch@FreeBSD.ORG  Wed Sep  1 17:02:00 2004
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 6109916A4CE
	for <freebsd-arch@freebsd.org>; Wed,  1 Sep 2004 17:02:00 +0000 (GMT)
Received: from green.homeunix.org (pcp04368961pcs.nrockv01.md.comcast.net
	[69.140.212.7])	by mx1.FreeBSD.org (Postfix) with ESMTP id 02C4843D45
	for <freebsd-arch@freebsd.org>; Wed,  1 Sep 2004 17:02:00 +0000 (GMT)
	(envelope-from green@green.homeunix.org)
Received: from green.homeunix.org (green@localhost [127.0.0.1])
	by green.homeunix.org (8.13.1/8.13.1) with ESMTP id i81H1xKF086046;
	Wed, 1 Sep 2004 13:01:59 -0400 (EDT)
	(envelope-from green@green.homeunix.org)
Received: (from green@localhost)
	by green.homeunix.org (8.13.1/8.13.1/Submit) id i81H1tnt086045;
	Wed, 1 Sep 2004 13:01:55 -0400 (EDT)
	(envelope-from green)
Date: Wed, 1 Sep 2004 13:01:54 -0400
From: Brian Fundakowski Feldman <green@freebsd.org>
To: Sam <sah@softcardsystems.com>
Message-ID: <20040901170154.GG45292@green.homeunix.org>
References: <Pine.LNX.4.60.0409011215400.13505@athena>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Pine.LNX.4.60.0409011215400.13505@athena>
User-Agent: Mutt/1.5.6i
cc: freebsd-arch@freebsd.org
Subject: Re: disk_create and cdevsw_add
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussion related to FreeBSD architecture
	<freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 01 Sep 2004 17:02:00 -0000

On Wed, Sep 01, 2004 at 12:32:58PM -0500, Sam wrote:
> 'lo again,
> 
> kern/subr_disk.c:/^disk_create/ takes
> two cdevsw types, and I only vaguely
> understand why.  Can someone explain it to me?
> 
> I'm generally confused about resolving
> entry points into the driver.  Does a
> block device only get an open() after
> registering it with disk_create?
> Supposing I want to set some ioctls for
> an aoecontrol utility (show all devices
> known, eg), what would aoecontrol open
> to ioctl?

Create /dev/aoectl which exists only to do global aoe things; alternately,
you could use a sysctl interface, but that's not really as clean.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green@FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\