kern/115645: lockmgr: thread 0xc4c00d80, not exclusive lock holder 0xc4dd7c00 unlocking

[postmaster at uni-bielefeld.de]

>Number:         115645
>Category:       kern
>Synopsis:       lockmgr: thread 0xc4c00d80, not exclusive lock holder 0xc4dd7c00 unlocking
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Aug 20 14:00:01 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Lars Köller & Jens Pönninghaus
>Release:        FreeBSD 6.1-RELEASE-p12 i386
>Organization:
Computing Center, Bielefeld University, Germany
>Environment:

System: FreeBSD rx300.hrz.uni-bielefeld.de 6.1-RELEASE-p12 FreeBSD 6.1-RELEASE-p12 #0: Tue Jan 16 16:58:07 CET 2007 root at rx300.hrz.uni-bielefeld.de:/opt/tmp/obj/usr/src/sys/PMX i386


>Description:

  We use the snapshot creation toolkit from rse at FreeBSD.org
  http://people.freebsd.org/~rse/snapshot/ on our Sophos PureMessage
  Server Farm (six FSC rx300 server). Cause PMX only supports FreeBSD-6.1,
  we can't upgrade to 6.2 at the moment.

  During creation of an snapshot the system panics from time to time
  Perhaps this is correlated with PR kern/68757.


115573 : cat /var/crash/info.13 
Dump header from device /dev/da0s1b
  Architecture: i386
  Architecture Version: 2
  Dump Length: 1073242112B (1023 MB)
  Blocksize: 512
  Dumptime: Fri Aug 17 13:01:36 2007
  Hostname: rx300.hrz.uni-bielefeld.de
  Magic: FreeBSD Kernel Dump
  Version String: FreeBSD 6.1-RELEASE-p12 #0: Tue Jan 16 16:58:07 CET 2007
    root at rx300.hrz.uni-bielefeld.de:/opt/tmp/obj/usr/src/sys/PMX
  Panic String: lockmgr: thread 0xc4c00d80, not exclusive lock holder 0xc4dd7c00 unlocking
  Dump Parity: 1320559640
  Bounds: 13
  Dump Status: good


115570 : df -kl
Filesystem  1K-blocks     Used    Avail Capacity  Mounted on
/dev/da0s1a    507630   185360   281660    40%    /
devfs               1        1        0   100%    /dev
procfs              4        4        0   100%    /proc
/dev/da0s1d  16244334  2434562 12510226    16%    /var
/dev/da0s1e   4058062       32  3733386     0%    /tmp
/dev/da0s1f   9499186  2032248  6707004    23%    /usr
/dev/da1s1a  68825650 10008236 53311362    16%    /opt


115572 : mount   
/dev/da0s1a on / (ufs, local)
devfs on /dev (devfs, local)
procfs on /proc (procfs, local)
/dev/da0s1d on /var (ufs, local, soft-updates)
/dev/da0s1e on /tmp (ufs, local, soft-updates)
/dev/da0s1f on /usr (ufs, local, soft-updates)
/dev/da1s1a on /opt (ufs, local, soft-updates)
pid906 at rx300:/snap on /snap (nfs)



115569 : snapshot list
Filesystem          User   User%     Snap   Snap%  Snapshot       
/                  181MB   36.5%      3MB    0.7%  daily.0        
/                  181MB   36.5%      3MB    0.7%  weekly.0       
/var              2377MB   15.0%     40MB    0.3%  daily.0        
/var              2377MB   15.0%      9MB    0.1%  hourly.0       
/var              2377MB   15.0%     10MB    0.1%  hourly.1       
/var              2377MB   15.0%     10MB    0.1%  hourly.2       
/var              2377MB   15.0%     10MB    0.1%  hourly.3       
/var              2377MB   15.0%     10MB    0.1%  hourly.4       
/var              2377MB   15.0%     10MB    0.1%  hourly.5       
/var              2377MB   15.0%     10MB    0.1%  hourly.6       
/var              2377MB   15.0%     10MB    0.1%  hourly.7       
/var              2377MB   15.0%     44MB    0.3%  weekly.0       
/usr              1984MB   21.4%     61MB    0.7%  daily.1        
/usr              1984MB   21.4%     67MB    0.7%  daily.2        
/usr              1984MB   21.4%     11MB    0.1%  weekly.0       
/opt              9773MB   14.5%    361MB    0.5%  daily.0        
/opt              9773MB   14.5%    757MB    1.1%  daily.2        
/opt              9773MB   14.5%    142MB    0.2%  hourly.0       
/opt              9773MB   14.5%    156MB    0.2%  hourly.1       
/opt              9773MB   14.5%    171MB    0.3%  hourly.2       
/opt              9773MB   14.5%    187MB    0.3%  hourly.3       
/opt              9773MB   14.5%    204MB    0.3%  hourly.4       
/opt              9773MB   14.5%    218MB    0.3%  hourly.5       
/opt              9773MB   14.5%    231MB    0.3%  hourly.6       
/opt              9773MB   14.5%    717MB    1.1%  weekly.0       


>How-To-Repeat:

  Keep periodically snapshots.
  Perhaps the creation of files on the snapshotted filesystem is
  a prerequisite to trigger the crash (compare PR kern/68757).


>Fix:

  Don't know!



>Release-Note:
>Audit-Trail:
>Unformatted: