device_part_info: do not recurse if we did not match anything (#5169)

First off, the recursion was bogus, because it called the wrong
function, but more importantly, it would lead to infinite recursion
anyway, even if we called the right one.

Throw a ValueError instead, because we've most likely been called with a
bogus value. Add a test to show that.

Sponsored by: The FreeBSD Foundation

cloudinit/distros/bsd.py

@@ -171,4 +171,5 @@ def device_part_info(devpath: str) -> tuple:
             if m:
                 return m["dev"], m["part_slice"]
 
-        return distros.Distro.device_part_info(devpath)
+        # the input is bogus and we need to bail
+        raise ValueError(f"Invalid value for devpath: '{devpath}'")

tests/unittests/config/test_cc_growpart.py

@@ -681,6 +681,12 @@ class TestDevicePartInfo:
                 does_not_raise(),
                 id="bsd_mbr_slice_and_partition",
             ),
+            pytest.param(
+                "zroot/ROOТ/default",
+                (),
+                pytest.raises(ValueError),
+                id="zfs_dataset",
+            ),
         ),
     )
     def test_device_part_info(self, devpath, expected, raised_exception):