From owner-freebsd-hackers@FreeBSD.ORG Mon May 21 10:58:41 2007 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 8CBFD16A400 for ; Mon, 21 May 2007 10:58:41 +0000 (UTC) (envelope-from des@des.no) Received: from tim.des.no (tim.des.no [194.63.250.121]) by mx1.freebsd.org (Postfix) with ESMTP id 4D8CC13C43E for ; Mon, 21 May 2007 10:58:41 +0000 (UTC) (envelope-from des@des.no) Received: from tim.des.no (localhost [127.0.0.1]) by spam.des.no (Postfix) with ESMTP id 7E2722084; Mon, 21 May 2007 12:58:35 +0200 (CEST) X-Spam-Tests: AWL X-Spam-Learn: disabled X-Spam-Score: 0.0/3.0 X-Spam-Checker-Version: SpamAssassin 3.1.7 (2006-10-05) on tim.des.no Received: from dwp.des.no (des.no [80.203.243.180]) by smtp.des.no (Postfix) with ESMTP id 011892083; Mon, 21 May 2007 12:58:35 +0200 (CEST) Received: by dwp.des.no (Postfix, from userid 1001) id DD2355747; Mon, 21 May 2007 12:58:34 +0200 (CEST) From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= To: Lawrence Stewart References: <4649349D.4060101@room52.net> <200705150847.38838.marc.loerner@hob.de> <46499491.2010205@room52.net> <46515DE0.20209@room52.net> Date: Mon, 21 May 2007 12:58:34 +0200 In-Reply-To: <46515DE0.20209@room52.net> (Lawrence Stewart's message of "Mon\, 21 May 2007 18\:52\:48 +1000") Message-ID: <86sl9qtpd1.fsf@dwp.des.no> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.3 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-hackers@freebsd.org, Ivan Voras Subject: Re: Writing a plain text file to disk from kernel space X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 May 2007 10:58:41 -0000 Lawrence Stewart writes: > I suspect that you can't use a file descriptor that was opened in one > thread in a completely different thread, but I'm not sure if this is > true, and if it is true, how to get around it. A file descriptor is an index into a file table. Different threads have different file tables. If you want to read from or write to files within the kernel, you need to operate directly on vnodes, not on file descriptors. DES --=20 Dag-Erling Sm=C3=B8rgrav - des@des.no