From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262846AbTDGSbi (for ); Mon, 7 Apr 2003 14:31:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262977AbTDGSbi (for ); Mon, 7 Apr 2003 14:31:38 -0400 Received: from almesberger.net ([63.105.73.239]:13062 "EHLO host.almesberger.net") by vger.kernel.org with ESMTP id S262846AbTDGSbh (for ); Mon, 7 Apr 2003 14:31:37 -0400 Date: Mon, 7 Apr 2003 15:43:03 -0300 From: Werner Almesberger To: Clayton Weaver Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] new syscall: flink Message-ID: <20030407154303.C19288@almesberger.net> References: <20030407165009.13596.qmail@email.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030407165009.13596.qmail@email.com>; from cgweav@email.com on Mon, Apr 07, 2003 at 11:50:08AM -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Clayton Weaver wrote: > If the client process subsequently flink()s to the inode, it is merely > a zerocopy file copy. As far as access to the data is concerned, yes. But there's also the location of the file. E.g. this might enable you to fill somebody else's quota, or, if distinct physical devices can be be covered by the same file system, to access a physical device that would otherwise not be available to you. Example: I write some kind of RAID mounted at /world, that contains my disk under /world/disk, and some Flash storage under /world/flash. I protect /world/flash against writes by other people. If a read-only FD could be turned into something writeable, some malicious creature could "wear out" my Flash by writing to it a lot of times. - Werner -- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina wa@almesberger.net / /_http://www.almesberger.net/____________________________________________/