Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 12 Feb 2002 15:26:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 12 Feb 2002 15:25:56 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:12050 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Tue, 12 Feb 2002 15:25:53 -0500 Message-ID: <3C697A1D.4599DDE@zip.com.au> Date: Tue, 12 Feb 2002 12:25:01 -0800 From: Andrew Morton X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.18-pre9 i686) X-Accept-Language: en MIME-Version: 1.0 To: Jan Hudec CC: linux-kernel@vger.kernel.org, Matt Gauthier Subject: Re: secure erasure of files? In-Reply-To:

<20020212165504.A5915@devcon.net>, <20020212165504.A5915@devcon.net>; from aferber@techfak.uni-bielefeld.de on Tue, Feb 12, 2002 at 04:55:04PM +0100 <20020212204710.A7416@artax.karlin.mff.cuni.cz> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jan Hudec wrote: > > > I don't know if any filesystem currently relocates blocks if you > > overwrite a file, but it's certainly possible and allowed (everything > > else except the filesystem itself simply must not care where the data > > actually ends up on the disk). > > AFAIK, ext2 tries to defragment files when possible. We wish. > Thus if the file was > fragmented and the blocks after some fragment are free, it will use these > instead of the original ones somewhere far apart. Nope - if you're overwriting a part of the file which already has allocated blocks, ext2/3 will use the same blocks. Of course, the disk itself may decide to go and remap the block if it decides that part of the media is getting tired. - - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/