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Message-Id: <201106231859.p5NIx96V001280@red.freebsd.org>
Date: Thu, 23 Jun 2011 18:59:09 GMT
From: Paul B Mahol <onemda@gmail.com>
To: freebsd-gnats-submit@FreeBSD.org
Subject: panic on unmounting nullfs mounted over ufs on usb stick that got detached
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>Number:         158231
>Category:       kern
>Synopsis:       [nullfs] panic on unmounting nullfs mounted over ufs on usb stick that got detached
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-fs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jun 23 19:00:22 UTC 2011
>Closed-Date:    
>Last-Modified:  Fri Jun 24 00:33:41 UTC 2011
>Originator:     Paul B Mahol
>Release:        FreeBSD CURRENT
>Organization:
>Environment:
FreeBSD home 9.0-CURRENT FreeBSD 9.0-CURRENT #0 r223183+87c92c3: Sun Jun 19 04:19:19 UTC 2011     root@:/usr/obj/usr/src/sys/kernel  i386
>Description:
panic when umounting nullfs if target is gone.
>How-To-Repeat:
Mount usb stick, da0s1a (ufs fs) on /mnt mount point. Now use nullfs to mount usb file system directory onto / subdirectory on ada0s1a, for example:

mount_nullfs /mnt/path/to/dir /usr/some/stuff_on_hard_disk

Umount (force) or detach usb stick. Force umount of nullfs, kernel will panic.
>Fix:


>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: freebsd-bugs->freebsd-fs 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Fri Jun 24 00:33:29 UTC 2011 
Responsible-Changed-Why:  
Over to maintainer(s). 

http://www.freebsd.org/cgi/query-pr.cgi?pr=158231 
>Unformatted:
