Re: Stackable Filesystems/deadlock/VI_DOOMED

On Fri, Apr 15, 2005 at 02:02:02PM +0200, Gunther Thiel wrote:
> Had posted this one to freebsd-fs but there is apparently not too much going on.
> So, am retrying it here.
> 
> I am working on stackable filesystems using 5.3-STABLE and figured that 
> there are still deadlock problems when using the nullfs template on a
> busy, stressed machine.
> >From what I have experienced, apparently the deadlock occurs when trying
> to get a new node while it's being recycled.
> 
> What I have seen in the VFS code of the CURRENT branch looks very
> promising (VI_DOOMED instead of VI_XLOCK!), but as I have no clue when
> new VFS stuff will be in a solid state, I wanted to ask if the problem
> is at all solveable with the VFS concept under 5.3 and if so, how.
> If it is not solveable (which is my personal guess) would someone mind
> giving me a hint on dependencies when I would only like to use as much
> stuff from CURRENT to move to new VFS concept (with all the ostentatious
> risks)?

You should probably just start developing on 6.0-CURRENT; it is slated to
become -STABLE not too far in the future.  Someone else should tell me
if I'm wrong, but I don't think these changes are remotely small enough
to merge back into 5.x.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green_at_FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\