misc/61400: Unmount md from CD fails.

[Tim J. Robbins]

Synopsis: Unmount md from CD fails.

State-Changed-From-To: open->closed
State-Changed-By: tjr
State-Changed-When: Tue Aug 24 04:42:01 GMT 2004
State-Changed-Why: 
You should mount the md filesystem readonly. The incorrect handling of
read/write mounts on write-protected media (CD-ROM in your case, floppy
disks in other cases) is well known.

http://www.freebsd.org/cgi/query-pr.cgi?pr=61400