Subject: Re: reboot hangs
To: <>
From: Ignatios Souvatzis <is@jocelyn.rhein.de>
List: tech-kern
Date: 05/01/2000 21:54:39
On Sat, Apr 29, 2000 at 05:06:07PM +1000, Simon Burge wrote:
> 
> I've seen this off-and-on since 1.4C.  It went away somewhere around
> 1.4H and reappeared somewhere around 1.4S.  With the debugging enabled
> in vfs_subr.c to print out busy vnodes, it's always a vnode on a MFS
> that's hung.  It seems to make sense that if the user-land mount_mfs has
etc.

So, I have a new observation to report.

I've seen the problem often, I use a MFS /tmp, so I finally tried to 
mount -u -r /tmp
before shutdown.

I now get a warning that wall cant open a temporary file, but otherwise all
(five or so) shutdowns that I did this way were ok.

So, my preliminary pretends-to-be-analysis is this:

- shutdown calls wall to print shutdown message.
- wall creates a temporary file for a preformatted version, thus creating a
  vnode with fresh pending writes.
- mfs fails to write those buffers out before mfs is terminated,
  and can't do so afterwards (because its address space is gone).

Some MFS expert please fix.

Regards,
	-is