misc/110213: umount doesn't deallocate the md device after an mfs filesystem

[Gergely Czuczy]

>Number:         110213
>Category:       misc
>Synopsis:       umount doesn't deallocate the md device after an mfs filesystem
>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 12 10:10:01 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Gergely Czuczy
>Release:        6.2-RELEASE-p2
>Organization:
Publishing Factory
>Environment:
FreeBSD luggage.in.publishing.hu 6.2-RELEASE-p2 FreeBSD 6.2-RELEASE-p2 #0: Fri Mar  9 17:22:07 UTC 2007     toor at blinky:/usr/obj/usr/src/sys/LUGGAGE  i386

>Description:
i've played around with mount_mfs to have a pre-prepared mfs filesystem at startup, and i mounted/umounted it several times after modifying my fstab.
at the end, the result was:
# ls -lh /dev/md*
crw-r-----  1 root  operator    0, 103 Mar 12 09:55 /dev/md0
crw-r-----  1 root  operator    0, 104 Mar 12 09:55 /dev/md1
crw-r-----  1 root  operator    0, 105 Mar 12 09:55 /dev/md2
crw-r-----  1 root  operator    0, 106 Mar 12 09:55 /dev/md3
crw-r-----  1 root  operator    0, 107 Mar 12 09:58 /dev/md4
crw-------  1 root  wheel       0,  56 Mar 12 09:20 /dev/mdctl
# mount
/dev/md4 on /mnt/keys (ufs, local, soft-updates)

seems like after umounting an mfs filesystem the system leaves some dirt behind.
>How-To-Repeat:
1) make an mfs entry in fstab
2) mount it and umount it
3) repeat 2) a few times
4) check the allocated md devices by ls /dev/md*

>Fix:
i don't have.
but umount should handle it automaticly :)
>Release-Note:
>Audit-Trail:
>Unformatted: