title: NFS volume created manually mounts but shows empty contents
body: <p>server: <code>docker ubuntu, 18.06.3-ce</code>
  local : <code>docker for mac, 19.03.13</code></p>
  <p>I have created a volume in the swarm manually, to a remote nfs server.  When I try to mount this volume in a service it appears to work, but the contents are empty and any writes <em>seem</em> to succeed (calling code doesn't crash), but the bytes are gone.  Maybe even to /dev/null.</p>
  <p>When I declare a similar volume inside the compose file it works.  The only difference I can find is the label &quot;com.docker.stack.namespace&quot;.</p>
  <pre><code>docker volume create --driver local \
      --opt type=nfs \
      --opt o=addr=10.0.1.100 \
      --opt device=:/data/ \
      my_nfs
  </code></pre>
  <pre><code>version: &quot;3.5&quot;
  
  services:
    my-api:
      volumes:
        - &quot;compose_nfs:/data1/&quot;  # works fine
        - &quot;externl_nfs:/data2/&quot;  # empty contents, forgotten writes
  
  volumes:
    externl_nfs: 
      external: true
    compose_nfs:
      driver: local
      driver_opts: 
        type: nfs
        o: addr=10.0.1.100
        device: &quot;:/data/&quot;
  </code></pre>
  <p>When inspecting the networks they are identical, except for that label.</p>
  <pre><code>{
      &quot;CreatedAt&quot;: &quot;2020-20-20T20:20:20Z&quot;,
      &quot;Driver&quot;: &quot;local&quot;,
      &quot;Labels&quot;: {
          # label missing on the manually created one
          &quot;com.docker.stack.namespace&quot;: &quot;stackie&quot;
      },
      &quot;Mountpoint&quot;: &quot;/var/lib/docker/volumes/externl_nfs/_data&quot;,
      &quot;Name&quot;: &quot;compose_nfs&quot;,
      &quot;Options&quot;: {
          &quot;device&quot;: &quot;:/data/&quot;,
          &quot;o&quot;: &quot;addr=10.0.1.100&quot;,
          &quot;type&quot;: &quot;nfs&quot;
      },
      &quot;Scope&quot;: &quot;local&quot;
  }
  </code></pre>