Subject: kern/26407: panic while updating async mount option
To: None <>
From: None <>
List: netbsd-bugs
Date: 07/22/2004 21:44:43
>Number:         26407
>Category:       kern
>Synopsis:       panic while updating async mount option
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 23 00:09:00 UTC 2004
>Originator:     Ken Raeburn
>Release:        2.0 branch as of several days ago, maybe the 17th
alpha xp1000, everything rebuilt out of cvs after a 1.6 install; GENERIC kernel config
I was running "top", a checkout of pkgsrc, and a build of the perl58-thread package from pkgsrc.  Out of curiousity for the difference it would make, I switched the "async" mount option on and off a few times while looking at the "top" output.

The last few lines of the slogin session:

   venix# mount -u -o noasync /usr
   venix# mount -u -o async /usr
   venix# mount -u -o noasync /usr

Since this is over a LAN, I assume from the lack of another prompt that it probably didn't finish the mount and didn't get to the "sync" command.

At this point, the kernel popped into the debugger:

panic: lockmgr: release of unlocked lock!

A traceback, quickly copied from the screen, includes:


I didn't get a crash dump.
Repeatedly turn async on and off while doing lots of file system updates?