fix: Correctly check PVs for grow_to_fill feature

We need to check the size of the PV format and compare it to the
size of the underlying block device when deciding if the format
size should be grown. The size of the VG (self._device here) is
not relevant for this operation.
This code used to work because of a bug in blivet where size of
the VG was incorrectly calculated for PVs with size not matching
the underlying block device size, this was fixed in blivet (see
storaged-project/blivet#1334) so the
grow_to_fill feature no longer works without this fix.

Author: vojtechtrefny

library/blivet.py

@@ -1854,17 +1854,16 @@ def _manage_members(self):
             grow_pv_candidates = [pv for pv in self._device.pvs if pv not in remove_pvs and pv not in add_disks]
 
             for pv in grow_pv_candidates:
-                if abs(self._device.size - self._device.current_size) < 2 * self._device.pe_size:
-                    continue
-
                 pv.format.update_size_info()  # set pv to be resizable
 
-                if pv.format.resizable:
+                if not pv.format.resizable:
+                    log.warning("cannot grow/resize PV '%s', format is not resizable", pv.name)
+                    continue
+
+                if abs(pv.size - pv.format.size) > 2 * self._device.pe_size:
                     pv.format.grow_to_fill = True
                     ac = ActionResizeFormat(pv, pv.size)
                     self._blivet.devicetree.actions.add(ac)
-                else:
-                    log.warning("cannot grow/resize PV '%s', format is not resizable", pv.name)
 
         if not (add_disks or remove_pvs):
             return