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Date: Wed, 2 Oct 1996 22:39:33 -0700 (PDT)
From: Julian Elischer <julian>
Message-Id: <199610030539.WAA02269@freefall.freebsd.org>
To: current
Subject: HELP!! kernel deadlock found..
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Take the following 3 processes:

proc N, with a lock on file / (inode 2)
		wchan of that inode, waitstring of "ufslk2"
is waiting for inode for /mnt in the root filesystem (inode M)

proc N+1 with a lock on the inode M (/mnt in root filesystem)
is waiting for inode for / (inode 2) in  the mounted filesystem /mnt
it is showing "uihget" as a waitstring.

proc N+2 with a lock on inode 2 of the mnt filesystem (/ of that filesystem)
is waiting for the inode for / and is showing "ufslk2" as a waitstring.

It is my suspicion that process N+2 may be trying to unmount /mnt.

Unfortunatly though I have the system stopped in gdb
I don't know how to examine the stacktrace of arbitrary
processes so I can't say how those 3 processes got where
they are. All other processes on the system
that need to access the filesystem are locked in "ufslk2"

e.g. any new logins go there immediatly. :(

if anyone knows how to examine an arbitrary process stacktrace
I'd like to hear about it.......

I'll leave the system frozen in this state,
and I can arange to get other people with internet access
to be able to run gdb and examine whatever they want..

David?
Terry?
John?
any takers?

I'd love to be able to see what those 3 stack traces show.....


julian