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

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

On Tue, 20 Oct 2015 21:18:51 +0100 (BST) Robert Swindells
<rjs%fdy2.co.uk@localhost> wrote:

> 
> "Ian D. Leroux" <idleroux%fastmail.fm@localhost> wrote:
> >With sources from Oct. 17th I get a repeatable hang whenever I
> >shutdown my laptop (NetBSD/amd64 current).  If X is running at
> >shutdown time, then I can't switch back to the console (Ctrl-Alt-F1
> >has no effect) and my only recourse is to kill the power.  If X is
> >not running I can switch to the console and see that the last
> >messages to the console are kernel (green) warnings of the form
> >
> >uid 0, pid 1, command init, on /var: file system full
> 
> Are any filesystems using tmpfs ?

/tmp, /dev and /var/shm are all tmpfs mounts.  If I manually
unmount /tmp and /var/shm before shutting down, I still see the hang.
I haven't tried unmounting /dev yet.

> I saw the same problem on one of my systems, I fixed it by backing out
> the last change to /etc/rc.d/swap1:
> 
> <http://mail-index.netbsd.org/source-changes/2015/04/20/msg065184.html>

I've commented out the relevant lines in swap1_stop() and now my laptop
reboots normally.  My guess is that swap1_stop() first forcibly
unmounts /dev, and then tries to remove block-type swap devices (and
generally carry on with shutdown) once /dev/wd0 no longer exists.  This
can't be sane.

I'm not sure what the right fix might be though, since I don't see how
to determine automatically and in general which tmpfs-mounted
filesystems are providing essential services (like /dev) and which ones
can be flushed to make space on swap (like /tmp).

--
IDL