kern/63605: Can't unmount DVDRAM with write protect

[Jason Bacon]

>Number:         63605
>Category:       kern
>Synopsis:       Can't unmount DVDRAM with write protect
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 01 10:50:13 PST 2004
>Closed-Date:
>Last-Modified:
>Originator:     Jason Bacon
>Release:        FreeBSD 5.1-RELEASE i386
>Organization:
Medical College of Wisconsin
>Environment:
System: FreeBSD smithers.neuro.mcw.edu 5.1-RELEASE FreeBSD 5.1-RELEASE #1: Thu Feb 19 13:09:05 CST 2004 bacon at smithers.neuro.mcw.edu:/usr/obj/usr/src/sys/smithers i386


>Description:
	If a DVDRAM is mounted with the write-protect enabled, attempts
	to unmount will produce the error:

	umount: umount of /dvdram failed: resource temporarily unavailable

	Presumably, there is some pending write operation that cannot be
	completed.  I think the system is missing the fact that the write
	protect is on, and mounting rw.  It should detect the write-protect
	upon mounting, and automatically mount read-only.

>How-To-Repeat:
	Set write protect on a DVDRAM and mount it.
>Fix:
	Workaround: camcontrol eject bus:target:lun will eject the disk,
	but will not update the mount table.
>Release-Note:
>Audit-Trail:
>Unformatted: