From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: [GIT PULL] Squashfs pull request for 2.6.29 Date: Fri, 9 Jan 2009 22:19:38 +0100 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-Transfer-Encoding: QUOTED-PRINTABLE 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 To: David Brown Return-path: Content-Disposition: inline In-Reply-To: <20090109193738.GA9827@linode.davidb.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri, 9 January 2009 11:37:39 -0800, David Brown wrote: > On Fri, Jan 09, 2009 at 05:54:22PM +0100, J=C3=B6rn 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. >=20 > 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 hi= t 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. J=C3=B6rn --=20 Simplicity is prerequisite for reliability. -- Edsger W. Dijkstra