Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757440AbZAIVUT (ORCPT ); Fri, 9 Jan 2009 16:20:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756094AbZAIVUA (ORCPT ); Fri, 9 Jan 2009 16:20:00 -0500 Received: from lazybastard.de ([212.112.238.170]:49131 "EHLO longford.logfs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759AbZAIVT7 (ORCPT ); Fri, 9 Jan 2009 16:19:59 -0500 Date: Fri, 9 Jan 2009 22:19:38 +0100 From: =?utf-8?B?SsO2cm4=?= Engel To: David Brown Cc: Phil Oester , Kay Sievers , Phillip Lougher , Andrew Morton , Christoph Hellwig , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [GIT PULL] Squashfs pull request for 2.6.29 Message-ID: <20090109211937.GA14342@logfs.org> References: <20090108165029.GA10951@infradead.org> <20090108175338.2abbee16.akpm@linux-foundation.org> <4966B24E.1050700@lougher.demon.co.uk> <20090109023629.GA29520@linuxace.com> <20090109165422.GF24884@logfs.org> <20090109193738.GA9827@linode.davidb.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20090109193738.GA9827@linode.davidb.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1303 Lines: 31 On Fri, 9 January 2009 11:37:39 -0800, David Brown wrote: > On Fri, Jan 09, 2009 at 05:54:22PM +0100, Jörn Engel wrote: > > > >In general, filesystems and ABI changes are special because stupid > >mistakes are eternal. If some device driver has a bug, you can fix it, > >reboot and be done with it. Not so with filesystems. > > Squashfs is readonly from the kernel. The images are created with > userspace tools. While true, it doesn't make a difference. If, for example, your structures members are not naturally aligned, you take a performance hit for no good reason. Simply moving fields around would make the code go faster. But the format is fixed and prevents you from making this change. You have to get those things right from the beginning or pay for your mistakes everafter. In general (and I stress "In general") filesystems want more review than ordinary device drivers. And just to stress that again, this is not an argument against merging squashfs now. Jörn -- Simplicity is prerequisite for reliability. -- Edsger W. Dijkstra -- 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/