Shutdown errors and timeout

[Yasuhiro KIMURA]

From: Johan Hendriks <joh.hendriks at gmail.com>
Subject: Shutdown errors and timeout
Date: Fri, 13 Nov 2020 11:35:53 +0100

> Hello all, i have two FreeBSD 13 machines, one is a bare metal and one
> is virtualbox machine which i both update about once a week.
> 
> The vritual machine seems to fail stopping something and gives a
> timeout after 90 sec.
> 
> The console ends with
> 
> Writing entropy file: .
> Writing early boot entropy file: .
> 
> 90 second watchdog timeout expired. Shutdown terminated.
> Fri Nov13 11:20:40 CEST 2020
> Nov 13 11:20:40 test-head init[1]: /etc/rc.shutdown terminated
> abnormally, going to single user mode
> ...
> 
> On the bare metal machine i see the following.
> Writing entropy file: .
> Writing early boot entropy file: .
> cannot unmount '/var/run': umount failed
> cannot unmount '/var/log': umount failed
> cannot unmount '/var': umount failed
> cannot unmount '/usr/home': umount failed
> cannot unmount '/usr': umount failed
> cannot unmount '/': umount failed
> 
(snip)
> 
> The pools have not been upgraded after the latest openzfs import,
> maybe that is related?
> 
> FreeBSD test-freebsd-head 13.0-CURRENT FreeBSD 13.0-CURRENT #2
> r367585:
> 
> First thing i noticed is about a week ago.

I'm facing same problem with 13.0-CURRENT amd64 r367487 and
virtualbox. In my case I use autofs to mount remote file system of
12.2-RELEASE amd64 server with NFSv4. When there is still filesystem
mounted by autofs, then watchdog timeout happens while shutdown. The
watchdog timeout can be worked around by executing `automount -fu`
before shutting down. But 'cannot unmount ...' error messages are
still displayed.

I added 'rc_debug="YES"' to /etc/rc.conf and checked which rc script
causes this message. Then it is displayed when following `zfs_stop`
function of /etc/rc.d/zfs is executed.

----------------------------------------------------------------------
zfs_stop_main()
{
	zfs unshare -a
	zfs unmount -a
}
----------------------------------------------------------------------

At this point syslog process still running and it opens some files
under /var/log. So it make sence that `zfs unmount -a` results in the
message.

Probably order of executing each rc script in shutdown time should be
changed so `/etc/rc.d/zfs faststop` is executed after all processes
other than `init' are exited.

---
Yasuhiro KIMURA