[CentOS] Shutdown hangs on "Unmounting NFS filesystems"

Mon Aug 31 23:22:36 UTC 2015
Robert Nichols <rnicholsNOSPAM at comcast.net>

On 08/31/2015 10:32 AM, Robert Nichols wrote:
> On 08/30/2015 04:32 PM, Frank Cox wrote:
>> Perhaps you could unmount that share when you log off by putting a
>> umount command into the appropriate file.
>>
>> The definition of "appropriate file" varies depending on what DE
>> you're using.
>
> Thanks for the suggestion. I'm using Gnome, and created an
> executable file /etc/gdm/PostSession/autofsNFS containing:
>
>    #!/bin/bash
>    if grep -q ':.* nfs[234]\? ' /proc/mounts; then
>        if [ -r /var/run/autofs.pid ]; then
>        Pid=$(</var/run/autofs.pid)
>        [ -n "$Pid" ] && kill -USR1 $Pid
>        fi
>    fi
>
> That sends a SIGUSR1 to the automount process if there are any
> remote NFS mounts listed in /proc/mounts.  It seems to do the
> trick.

Weird!  That should not have worked since that file never gets
executed.  Apparently the problem is less repeatable than I thought.

I put that code into the /etc/gdm/PostSession/Default script,
where it actually gets executed and immediately runs into SELinux
issues.  I ran audit2allow on all the AVC denials, and now the
script runs properly and, again, seems to fix the issue.  Final
verdict on that is still pending, though.

Note that /etc/gdm/PostSession/Default is marked as a configuration
file in the gdm RPM, and so should not get wiped out by an update.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.