Manage mounts in two stages to keep systemd cooperative.

tasks/main-blivet.yml

@@ -129,14 +129,34 @@
 #  changed options? (just add w/ new settings?)
 # add new mounts
 #
-- name: manage mounts to match the specified state
+# XXX Apparently we have to do the removals, then tell systemd to
+#     update its view, then set up the new mounts. Otherwise,
+#     systemd will forcibly prevent mounting a new volume to an
+#     existing mount point.
+- name: remove obsolete mounts
   mount:
     src: "{{ mount_info['src']|default(omit) }}"
     path: "{{ mount_info['path'] }}"
     fstype: "{{ mount_info['fstype']|default(omit) }}"
     opts: "{{ mount_info['opts']|default(omit) }}"
     state: "{{ mount_info['state'] }}"
-  loop: "{{ blivet_output.mounts }}"
+  loop: "{{ blivet_output.mounts|json_query('[?state==`absent`]') }}"
+  loop_control:
+    loop_var: mount_info
+
+- name: tell systemd to refresh its view of /etc/fstab
+  systemd:
+    daemon_reload: yes
+  when: blivet_output['mounts']
+
+- name: set up new/current mounts
+  mount:
+    src: "{{ mount_info['src']|default(omit) }}"
+    path: "{{ mount_info['path'] }}"
+    fstype: "{{ mount_info['fstype']|default(omit) }}"
+    opts: "{{ mount_info['opts']|default(omit) }}"
+    state: "{{ mount_info['state'] }}"
+  loop: "{{ blivet_output.mounts|json_query('[?state!=`absent`]') }}"
   loop_control:
     loop_var: mount_info