storage: More robust volume group polling

Previously the polling was done as part of the React component for the
volume group details. This of course means that no polling happens
when that component is not on the screen.

Do all the polling in the client, regardless of what is displayed.

pkg/storaged/client.js

@@ -835,11 +835,34 @@ function update_indices() {
     }
 }
 
+let lvm2_poll_timer = null;
+
+function update_lvm2_polling() {
+    const need_polling = !!Object.values(client.vgroups).find(vg => vg.NeedsPolling);
+
+    function poll() {
+        for (let path in client.vgroups) {
+            const vg = client.vgroups[path];
+            if (vg.NeedsPolling) {
+                vg.Poll();
+            }
+        }
+    }
+
+    if (need_polling && lvm2_poll_timer == null) {
+        lvm2_poll_timer = window.setInterval(poll, 2000);
+    } else if (!need_polling && lvm2_poll_timer) {
+        window.clearInterval(lvm2_poll_timer);
+        lvm2_poll_timer = null;
+    }
+}
+
 client.update = (first_time) => {
     if (first_time)
         client.ready = true;
     if (client.ready) {
         update_indices();
+        update_lvm2_polling();
         reset_pages();
         make_overview_page();
         export_mount_point_mapping();

pkg/storaged/lvm2/volume-group.jsx

@@ -273,23 +273,6 @@ export function make_lvm2_volume_group_page(parent, vgroup) {
     make_logical_volume_pages(vgroup_page, vgroup);
 }
 
-function vgroup_poller(vgroup) {
-    let timer = null;
-
-    if (vgroup.NeedsPolling) {
-        timer = window.setInterval(() => { vgroup.Poll() }, 2000);
-    }
-
-    function stop() {
-        if (timer)
-            window.clearInterval(timer);
-    }
-
-    return {
-        stop
-    };
-}
-
 const LVM2LogicalVolumesCard = ({ card, vgroup }) => {
     return (
         <StorageCard card={card}>
@@ -305,10 +288,6 @@ const LVM2LogicalVolumesCard = ({ card, vgroup }) => {
 const LVM2VolumeGroupCard = ({ card, vgroup }) => {
     const has_missing_pvs = vgroup.MissingPhysicalVolumes && vgroup.MissingPhysicalVolumes.length > 0;
 
-    useObject(() => vgroup_poller(vgroup),
-              poller => poller.stop(),
-              [vgroup]);
-
     function is_partial_linear_lvol(block) {
         const lvm2 = client.blocks_lvm2[block.path];
         const lvol = lvm2 && client.lvols[lvm2.LogicalVolume];