From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262909AbTJPRlc (ORCPT ); Thu, 16 Oct 2003 13:41:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263052AbTJPRlc (ORCPT ); Thu, 16 Oct 2003 13:41:32 -0400 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:52107 "EHLO velociraptor.random") by vger.kernel.org with ESMTP id S262909AbTJPRlb (ORCPT ); Thu, 16 Oct 2003 13:41:31 -0400 Date: Thu, 16 Oct 2003 19:41:53 +0200 From: Andrea Arcangeli To: Jeff Garzik Cc: Erik Mouw , Josh Litherland , linux-kernel@vger.kernel.org Subject: Re: Transparent compression in the FS Message-ID: <20031016174153.GI1663@velociraptor.random> References: <1066163449.4286.4.camel@Borogove> <20031015133305.GF24799@bitwizard.nl> <3F8D6417.8050409@pobox.com> <20031016162926.GF1663@velociraptor.random> <3F8ED0FC.9070706@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F8ED0FC.9070706@pobox.com> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 16, 2003 at 01:10:20PM -0400, Jeff Garzik wrote: > As Andre H and Larry McVoy love to point out, data isn't _really_ secure > until it's been checksummed, and that checksum data is verified on > reads. LM has an anecdote (doesn't he always? ) about how BitKeeper > -- which checksums its data inside the app -- has found data-corrupting > kernel bugs, in days long past. yes, even a fs checksum won't protect against kernel bugs randomly corrupting pagacache, and that's why having it in userspace is preferable IMHO (though in userspace it's more difficult to switch it off transparently unless the app is designed for that).