Re: Hanging at shutdown with mystery "file system full" error

["Ian D. Leroux" <idleroux%fastmail.fm@localhost>]

On Wed, Oct 21, 2015, at 08:35, Robert Elz wrote:
> Not sane perhaps, but most likely not as bad as it sounds, the kernel
> shouldn't be using pathname lookups to find anything it is trying to
> remove, it has vnodes for the devices already, which is all that's
> needed to close them.
>
> So, while the problem you're seeing is probably all bound up in that
> mess somewhere, I doubt it is quite as simple as "/dev/wd0x doesn't
> exist, help"...

I agree that my guess (which is all it was) was a crude
oversimplication.

This implies, incidentally, that I could manually unmount all tmpfs
filesystems (including /dev) before shutting down.  I'll try that
tonight and see what happens.

Is /dev a tmpfs on the other machines that are seeing this hang?  If
not, that would rule out my crude oversimplified guess completely, which
would be good to know.

> That said, I really don't understand the desire to cleanly disengage
> everything.  As soon as userland is done (when init will no longer run
> again) the kernel should just sync & mark clean all of the
> filesystems, force stopped (or into a tight loop, whatever is
> appropriate for the hardware) all but one of the cpus, then exit to
> the bios (or whatever) to reset/halt/reboot or whatever is wanted.

I'm not sure if you're discussing what ought to be happening now or what
ought to be happening in a better design, but note that I'm pretty sure
that the current hang happens before "userland is done".  For one thing,
when I activate ddb it shows that I'm interrupting a userland daemon
(syslogd or estd).

--
IDL