From owner-freebsd-bugs@FreeBSD.ORG Wed Nov 28 06:40:03 2007 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4A87A16A419 for ; Wed, 28 Nov 2007 06:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 3B09B13C465 for ; Wed, 28 Nov 2007 06:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id lAS6e3wg062828 for ; Wed, 28 Nov 2007 06:40:03 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id lAS6e3h5062827; Wed, 28 Nov 2007 06:40:03 GMT (envelope-from gnats) Date: Wed, 28 Nov 2007 06:40:03 GMT Message-Id: <200711280640.lAS6e3h5062827@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Yuri Cc: 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 Reply-To: Yuri List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Nov 2007 06:40:03 -0000 The following reply was made to PR bin/118160; it has been noted by GNATS. From: Yuri To: Bruce Evans Cc: Yuri , freebsd-gnats-submit@freebsd.org, freebsd-bugs@freebsd.org Subject: Re: misc/118160: unable to mount / rw while booting 7.0-BETA3 Date: Tue, 27 Nov 2007 22:36:28 -0800 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