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. Fix: disable softupdates to get rid of the panic. But it will not unmount. 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.
In the PR I forgot to write my real e-mail address, which is sime@logos.hr. Please send all followups to sime@logos.hr instead of above address. -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/
State Changed From-To: open->feedback To submitter: is this still a problem on 7.2?
Responsible Changed From-To: freebsd-bugs->freebsd-fs Over to maintainer(s).
State Changed From-To: feedback->closed Feedback timeout.