panic: System call lstat returning with 1 locks held

[Attilio Rao]

2008/2/5, Attilio Rao <attilio at freebsd.org>:
> 2008/2/5, Yar Tikhiy <yar at comp.chem.msu.su>:
>
> > BTW, I seem to be hitting yet another lockmgr-related panic.
>  >
>  >  My system won't reboot under certain conditions: it'll panic instead
>  >  in vfs_unmountall().  Namely it will panic if I reboot from single-user
>  >  mode while it'll reboot OK from multi-user mode.  I have no idea
>  >  yet about the exact reason for the behaviour.  The output from kgdb
>  >  attached.
>  >
>  >  Note that this panic shouldn't be NTFS-related as I can trigger it
>  >  by typing `reboot' immediately after booting into single user.
>
>
> Yes, sorry for this.
>  I know of this and I alredy patched my tree.
>  I did the WITNESS stuff based on the assumption drained lock will
>  never be release while they are. Unmounting is currently the only one
>  consumer of LK_DRAIN I know of and I just need to do a WITNESS_LOCK()
>  over there.
>  I will provide you an updated patch about this problem and another one
>  found by kris at .
>
>  I will look later at the backtrace so we can go on.

More specifically, here is the "fixed" version:
http://www.freebsd.org/~attilio/witness_lockmgr2.diff

(against stock -CURRENT).
Kris and me tested (rather) this version and I found it reliable, so I
want to commit to CVS in a couple of hours.
If you can add any other feedback to it, I would be very happy.

Thanks,
Attilio

PS: this WITNESS patch reports 3-4 different LORs at boot-time and
other 3-4 at shutdown time...

-- 
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