From owner-freebsd-hackers@FreeBSD.ORG  Wed Apr 27 04:58:19 2011
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 7162A1065670
	for <freebsd-hackers@freebsd.org>; Wed, 27 Apr 2011 04:58:19 +0000 (UTC)
	(envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85])
	by mx1.freebsd.org (Postfix) with ESMTP id 2E76B8FC16
	for <freebsd-hackers@freebsd.org>; Wed, 27 Apr 2011 04:58:19 +0000 (UTC)
Received: from [10.0.0.63] (63.imp.bsdimp.com [10.0.0.63])
	(authenticated bits=0)
	by harmony.bsdimp.com (8.14.4/8.14.3) with ESMTP id p3R4qbmr041966
	(version=TLSv1/SSLv3 cipher=DHE-DSS-AES128-SHA bits=128 verify=NO);
	Tue, 26 Apr 2011 22:52:38 -0600 (MDT) (envelope-from imp@bsdimp.com)
Mime-Version: 1.0 (Apple Message framework v1084)
Content-Type: text/plain; charset=us-ascii
From: Warner Losh <imp@bsdimp.com>
In-Reply-To: <4DB76085.4000402@chillt.de>
Date: Tue, 26 Apr 2011 22:52:37 -0600
Content-Transfer-Encoding: quoted-printable
Message-Id: <52F5A9FB-8771-4002-B6C0-563679CCB355@bsdimp.com>
References: <4DB695DB.1080505@chillt.de> <201104261217.23858.hselasky@c2i.net>
	<4DB6BCC6.5050001@chillt.de>
	<20110426124403.GQ48734@deviant.kiev.zoral.com.ua>
	<4DB76085.4000402@chillt.de>
To: Bartosz Fabianowski <freebsd@chillt.de>
X-Mailer: Apple Mail (2.1084)
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1
	(harmony.bsdimp.com [10.0.0.6]);
	Tue, 26 Apr 2011 22:52:39 -0600 (MDT)
Cc: Kostik Belousov <kostikbel@gmail.com>, freebsd-hackers@freebsd.org,
	Hans Petter Selasky <hselasky@c2i.net>
Subject: Re: Is there some implicit locking of device methods?
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 27 Apr 2011 04:58:19 -0000


On Apr 26, 2011, at 6:17 PM, Bartosz Fabianowski wrote:

>> If you needs per-file private data for cdev, you would be better =
served
>> by cdevpriv(9) KPI. Cloning is too hard to use correctly for such =
task.
>=20
> Thanks, I just got that working. To help those going down a similar =
path in the future, I would like to note quickly that the following must =
be added to the cdevsw structure to ensure proper clean-up:
>=20
> .d_flags =3D D_TRACKCLOSE
>=20
> I just spent hours debugging panics until I realized only the last =
close() was triggering a call to my .d_close method.

Traditional BSD behavior...

Warner