From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263568AbTLON1l (ORCPT ); Mon, 15 Dec 2003 08:27:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263571AbTLON1k (ORCPT ); Mon, 15 Dec 2003 08:27:40 -0500 Received: from mail.fh-wedel.de ([213.39.232.194]:34244 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S263568AbTLON1k (ORCPT ); Mon, 15 Dec 2003 08:27:40 -0500 Date: Mon, 15 Dec 2003 14:26:21 +0100 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Rob Landley Cc: Vladimir Saveliev , linux-kernel@vger.kernel.org Subject: Re: Is there a "make hole" (truncate in middle) syscall? Message-ID: <20031215132621.GB1286@wohnheim.fh-wedel.de> References: <20031211125806.B2422@hexapodia.org> <200312121535.22375.rob@landley.net> <1071482402.11042.36.camel@tribesman.namesys.com> <200312150552.22805.rob@landley.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200312150552.22805.rob@landley.net> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 December 2003 05:52:22 -0600, Rob Landley wrote: > > The earlier suggestion I was disagreeing with would automatically create holes > in any file that wrote a sufficiently large range of zero bytes. Hence the > cache poisoning and general defeating the purpose of DMA and such. Neither > truncate, nor a punch syscall, would mess with the normal "write" path > (beyond locking so write and truncate/punch didn't stomp each other). And the suggestor remains convinced that this is a good idea. It would be perfectly ok to defer actually looking at the data to later, move that functionality to a journald or gcd or so, but the principle mains unchanged. Jörn -- And spam is a useful source of entropy for /dev/random too! -- Jasmine Strong