[systemd-devel] [SPAM]Re: Mount units with After=autofs.service cause ordering cycles

[John Florian]

On 10/31/19 1:08 PM, Lennart Poettering wrote:
> On Mo, 14.10.19 16:23, John Florian (john at doubledog.org) wrote:
>
>> So, I much prefer the expressiveness of systemd's mount units to the naive
>> era of /etc/fstab, but I've found one situation where I seem to always get
>> stuck and am never able to find a reliable solution that survives OS (Fedora
>> & CentOS) updates.  I have a NFS filesystem mounted by autofs at /pub that
>> needs to be bind mounted in various places such as /var/www/pub and
>> /var/ftp/pub. So I create a unit that looks like:
>>
>> ~~~
>>
>> # /etc/systemd/system/var-www-pub.mount
>> [Unit]
>> Description=mount /pub served via httpd
>> Requires=autofs.service
>> After=autofs.service
>>
>> [Mount]
>> What=/mnt/pub
>> Where=/var/www/pub
>> Options=bind,context=system_u:object_r:httpd_sys_content_t
>>
>> [Install]
>> WantedBy=multi-user.target
>>
>> ~~~
>>
>> The above worked for a long time, but once again a `dnf upgrade` seems to
>> have broken things because now I have a ordering cycle that systemd must
>> break.  Since I haven't changed my mount units, my ability to mesh with
>> those shipped by the OS proves fragile. I'm deliberately avoiding too much
>> detail here because it would seem that there should be a relatively simple
>> solution to this general sort of task -- I just can't seem to discover it.
>> Any recommendations that don't involve an entirely different approach?
> What precisely is the ordering cycle you are seeing? It's usually
> dumped along with the log message.

systemd[1]: local-fs.target: Found ordering cycle on var-www-pub.mount/start
systemd[1]: local-fs.target: Found dependency on autofs.service/start
systemd[1]: local-fs.target: Found dependency on rpc-statd.service/start
systemd[1]: local-fs.target: Found dependency on network-online.target/start
systemd[1]: local-fs.target: Found dependency on network.target/start
systemd[1]: local-fs.target: Found dependency on 
NetworkManager.service/start
systemd[1]: local-fs.target: Found dependency on sysinit.target/start
systemd[1]: local-fs.target: Found dependency on 
systemd-update-done.service/start
systemd[1]: local-fs.target: Found dependency on local-fs.target/start
systemd[1]: local-fs.target: Job var-www-pub.mount/start deleted to 
break ordering cycle starting with local-fs.target/start