From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wedgwood Subject: Re: enforcing DB immutability Date: Wed, 20 Apr 2005 01:58:22 -0700 Message-ID: <20050420085822.GC3263@taniwha.stupidest.org> References: <20050413182909.GA25221@elte.hu> <20050413200237.GA26635@elte.hu> <425D7C0F.2050109@zytor.com> <20050413201523.GC27088@elte.hu> <20050420074053.GA22436@elte.hu> <20050420074948.GA22620@elte.hu> <20050420075320.GA22676@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , "H. Peter Anvin" , git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Apr 20 10:55:12 2005 Return-path: Received: from vger.kernel.org ([12.107.209.244]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DOAym-0000Kx-Fs for gcvg-git@gmane.org; Wed, 20 Apr 2005 10:54:40 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261498AbVDTI6q (ORCPT ); Wed, 20 Apr 2005 04:58:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261515AbVDTI6q (ORCPT ); Wed, 20 Apr 2005 04:58:46 -0400 Received: from ylpvm29-ext.prodigy.net ([207.115.57.60]:43404 "EHLO ylpvm29.prodigy.net") by vger.kernel.org with ESMTP id S261498AbVDTI6m (ORCPT ); Wed, 20 Apr 2005 04:58:42 -0400 Received: from pimout2-ext.prodigy.net (pimout2-ext.prodigy.net [207.115.63.101]) by ylpvm29.prodigy.net (8.12.10 outbound/8.12.10) with ESMTP id j3K8w3D9021966 for ; Wed, 20 Apr 2005 04:58:06 -0400 X-ORBL: [67.124.119.21] Received: from taniwha.stupidest.org (adsl-67-124-119-21.dsl.snfc21.pacbell.net [67.124.119.21]) by pimout2-ext.prodigy.net (8.12.10 milter /8.12.10) with ESMTP id j3K8wPcU440696; Wed, 20 Apr 2005 04:58:31 -0400 Received: by taniwha.stupidest.org (Postfix, from userid 38689) id D14C2115C85B; Wed, 20 Apr 2005 01:58:22 -0700 (PDT) To: Ingo Molnar Content-Disposition: inline In-Reply-To: <20050420075320.GA22676@elte.hu> Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org On Wed, Apr 20, 2005 at 09:53:20AM +0200, Ingo Molnar wrote: > so the only sensible thing the editor/tool can do when it wants to > change the file is precisely what we want: it will copy the > hardlinked files's contents to a new file, and will replace the old > file with the new file - a copy on write. No accidental corruption > of the DB's contents. editors that have SCM smarts and know about the files different states can do this i really like the way this works under BK btw --- files are RO until i do the magic thing which will do a 'bk edit' and i can then do checkins or similar as needed (this assumes you can do per-file deltas)