Date: Mon, 9 Jan 2006 22:27:07 +0100 (CET) From: Simun Mikecin <sime@data.home.hr> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/91568: panic: writing to UFS/softupdates DVD media in DVD-ROM drive Message-ID: <20060109212707.839DD5F946@data.home.hr> Resent-Message-ID: <200601092130.k09LU4UU038402@freefall.freebsd.org>
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>Number: 91568 >Category: kern >Synopsis: panic: writing to UFS/softupdates DVD media in DVD-ROM drive >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon Jan 09 21:30:03 GMT 2006 >Closed-Date: >Last-Modified: >Originator: Simun Mikecin >Release: FreeBSD 6.0-STABLE amd64 >Organization: >Environment: System: FreeBSD data.home.hr 6.0-STABLE FreeBSD 6.0-STABLE #0: Mon Jan 9 18:11:29 CET 2006 root@data.home.hr:/var/obj/usr/src.6/sys/DATA amd64 acd0: DVDROM <Pioneer DVD-ROM ATAPIModel DVD-120S/1.01> at ata0-master UDMA66 acd1: DVDR <PIONEER DVD-RW DVR-110/1.22> at ata1-master UDMA66 >Description: Writing to DVD media mounted read-write with UFS2 filesystem (softupdates enabled) on a DVD-ROM drive unit (unit that can only read from the media) causes system panic after some time: initiate_write_filepage: already_started panic: initiate_write_inodeblock_ufs2: already started If softupdates were disabled, it does not panic, but the system will not allow you to dismount the media. You will have to reboot. This is not a real-world scenario, but I think it shows what could happen if you write to bad media or bad drive. System should not panic for these reasons. >How-To-Repeat: You need a DVD media (I used DVD+RW) that has UFS2 filesystem on it. softupdates have to be enabled on it. Insert the media in the DVD-ROM drive unit (unit that can only read from the media). Mount it with something like: mount_ufs /dev/acd0 /mnt/1 Softupdates should be listed as enabled if you use mount command to list mounted filesystems. Try to copy files to the newly mounted filesystems. System will allow you to do it, but you will get a bunch of errors on the console. After some time system panics. If softupdates were disabled system will not panic, but it will not allow you to dismount the media, and reboot will have to give up on some buffers while syncing. >Fix: disable softupdates to get rid of the panic. But it will not unmount. >Release-Note: >Audit-Trail: >Unformatted:
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