On Sun, Jan 10, 1999 at 11:36:28PM -0800, Matthew Jacob wrote:
> 
> Although the details in 4907 are somewhat vague, I'd have guessed it
> was different.

  See also PR 5476 and 5239.  Nullfs apparently can cause panics
with "already locked" (as you submitted), "lockmgr: locking against
myself", and "lockmgr: pid ..., not exclusive lock holder".  So
it appears that nullfs currently has at least one major lock bug,
and probably more.
  
  5239 has a patch that helps a lot in getting rid of "locking
against myself", but didn't fix all the bugs.  You might want to
try it to see if it helps decrease the frequency of the panics.

  Yes, nullfs really is cool, and it's a shame it doesn't work, but
unfortunately all the people so far who are experiencing it do
not have the skills to debug and fix it!  Is there anyone out
there that is an FS locking guru, and has a bit of free time?  :)

  Brian