kern/174969: unionfs and tmpfs can produce panic when mixed

[Volodymyr Kostyrko]

>Number:         174969
>Category:       kern
>Synopsis:       unionfs and tmpfs can produce panic when mixed
>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:   Fri Jan 04 14:00:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Volodymyr Kostyrko
>Release:        RELENG_9_1
>Organization:
None
>Environment:
FreeBSD urquan.xim.bz 9.1-RELEASE FreeBSD 9.1-RELEASE #3 r244839M: Sun Dec 30 00:34:33 EET 2012     arcade at urquan.xim.bz:/usr/obj/usr/src/sys/MINIMAL  amd64
>Description:
I'm doing this:

>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted:
 >>> /etc/fstab
 /tmp /some/other/dir unionfs ro,late,below 0 0
 
 cd /some/other/dir
 ls
 
 The system shows directory contents and I see shell prompt. Immediately after this panic occurs.
 
 https://docs.google.com/open?id=0Bxzr6h0p2pN8aU4xZ3E4ZkttSTA