Do not remove PVs from devices file if disabled or doesn't exists

When the file doesn't exists the 'lvmdevices --deldev' call will
fail but it will still create the devices file. This means we now
have an empty devices file and all subsequent LVM calls will fail.

Resolves: RHEL-65846

blivet/formats/lvmpv.py

@@ -171,6 +171,16 @@ def lvmdevices_remove(self):
         if not lvm.HAVE_LVMDEVICES:
             raise PhysicalVolumeError("LVM devices file feature is not supported")
 
+        if not os.path.exists(lvm.LVM_DEVICES_FILE):
+            log.debug("Not removing %s from devices file: %s doesn't exist",
+                      self.device, lvm.LVM_DEVICES_FILE)
+            return
+
+        if not flags.lvm_devices_file:
+            log.debug("Not removing %s from devices file: 'lvm_devices_file' flag is set to False",
+                      self.device)
+            return
+
         try:
             blockdev.lvm.devices_delete(self.device)
         except blockdev.LVMError as e:

tests/unit_tests/formats_tests/lvmpv_test.py

@@ -38,6 +38,11 @@ def test_lvm_devices(self):
 
             mock["blockdev"].lvm.devices_add.assert_not_called()
 
+            # LVM devices file not enabled/supported -> devices_delete should not be called
+            fmt._destroy()
+
+            mock["blockdev"].lvm.devices_delete.assert_not_called()
+
         with self.patches() as mock:
             # LVM devices file enabled and devices file exists -> devices_add should be called
             mock["lvm"].HAVE_LVMDEVICES = True
@@ -47,6 +52,11 @@ def test_lvm_devices(self):
 
             mock["blockdev"].lvm.devices_add.assert_called_with("/dev/test")
 
+            # LVM devices file enabled and devices file exists -> devices_delete should be called
+            fmt._destroy()
+
+            mock["blockdev"].lvm.devices_delete.assert_called_with("/dev/test")
+
         with self.patches() as mock:
             # LVM devices file enabled and devices file doesn't exist
             # and no existing VGs present -> devices_add should be called
@@ -58,6 +68,12 @@ def test_lvm_devices(self):
 
             mock["blockdev"].lvm.devices_add.assert_called_with("/dev/test")
 
+            # LVM devices file enabled but devices file doesn't exist
+            # -> devices_delete should not be called
+            fmt._destroy()
+
+            mock["blockdev"].lvm.devices_delete.assert_not_called()
+
         with self.patches() as mock:
             # LVM devices file enabled and devices file doesn't exist
             # and existing VGs present -> devices_add should not be called
@@ -69,6 +85,12 @@ def test_lvm_devices(self):
 
             mock["blockdev"].lvm.devices_add.assert_not_called()
 
+            # LVM devices file enabled but devices file doesn't exist
+            # -> devices_delete should not be called
+            fmt._destroy()
+
+            mock["blockdev"].lvm.devices_delete.assert_not_called()
+
         with self.patches() as mock:
             # LVM devices file enabled and devices file exists
             # but flag set to false -> devices_add should not be called
@@ -81,5 +103,11 @@ def test_lvm_devices(self):
 
             mock["blockdev"].lvm.devices_add.assert_not_called()
 
+            # LVM devices file enabled and devices file exists
+            # but flag set to false -> devices_delete should not be called
+            fmt._destroy()
+
+            mock["blockdev"].lvm.devices_delete.assert_not_called()
+
             # reset the flag back
             flags.lvm_devices_file = True