From owner-freebsd-bugs@FreeBSD.ORG Wed Nov 28 06:36:32 2007 Return-Path: Delivered-To: freebsd-bugs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1DD4F16A419; Wed, 28 Nov 2007 06:36:32 +0000 (UTC) (envelope-from yuri@rawbw.com) Received: from mail0.rawbw.com (mail0.rawbw.com [198.144.192.41]) by mx1.freebsd.org (Postfix) with ESMTP id 0326313C457; Wed, 28 Nov 2007 06:36:31 +0000 (UTC) (envelope-from yuri@rawbw.com) Received: from mail0.rawbw.com (localhost [127.0.0.1]) by mail0.rawbw.com (8.13.8/8.13.8) with ESMTP id lAS6aSOM043510; Tue, 27 Nov 2007 22:36:28 -0800 (PST) Received: (from www@localhost) by mail0.rawbw.com (8.13.8/8.13.8/Submit) id lAS6aSDY043506; Tue, 27 Nov 2007 22:36:28 -0800 (PST) X-Authentication-Warning: mail0.rawbw.com: www set sender to yuri@rawbw.com using -f Received: from ip224.carlyle.sfo.ygnition.net (ip224.carlyle.sfo.ygnition.net [24.219.144.224]) by webmail.rawbw.com (IMP) with HTTP for ; Tue, 27 Nov 2007 22:36:28 -0800 Message-ID: <1196231788.474d0c6c67e9b@webmail.rawbw.com> Date: Tue, 27 Nov 2007 22:36:28 -0800 From: Yuri To: Bruce Evans References: <200711210234.lAL2Y7cU041129@www.freebsd.org> <20071121170349.X81263@delplex.bde.org> <1196219512.474cdc78837c1@webmail.rawbw.com> <20071128144615.T745@besplex.bde.org> In-Reply-To: <20071128144615.T745@besplex.bde.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.2.1 X-Originating-IP: 24.219.144.224 Cc: Yuri , freebsd-gnats-submit@freebsd.org, freebsd-bugs@freebsd.org Subject: Re: misc/118160: unable to mount / rw while booting 7.0-BETA3 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Nov 2007 06:36:32 -0000 Quoting Bruce Evans : > Using the 'c' partition is normally an error. Here it is a very large > error. ad12s1b overlaps ad12s1c, so if swap on ad12s1b is actually > used then it will normally clobber the file system on ad12s1c. It > might be possible to make the clobbering harmless, e.g., by putting > ad12s1b at the end of ad12s1c and not using all of ad12s1c for the > file system, but this is harder to configure than a normal configuration > and is supposed to be disallowed. > Having root mounted on ad12s1c is probably a result of my typo. > > This misbehaviour seems to be a result of the disallowment not being > complete. Mounted file systems normally have exclusive write access > to their device. However, for early root mounts, while the mount is > only r/o, exclusive write access is given up so that fsck can work. > There seems to be no exclusivity at all, so swapon on a different but > overlapping device is granted write access. Then while swapon is on, > it holds exclusive write access and r/w mounts of root are denied > (correctly except for the wrong errno and other misleading things in > the error message). Also, after the root mount becomes r/w, swapon > fails (correctly except for the wrong errno). > Should this situation generate system log message, not only EPERM? If it would have said: 'Attempt to mount already exclusively locked partition' it would have been clear what the problem is right away. So I would suggest such message to be added, otherwise this PR can be closed. Yuri