[object spilling] Autocreate dir if not exists (#11999)

python/ray/external_storage.py

@@ -77,9 +77,10 @@ class FileSystemStorage(ExternalStorage):
     def __init__(self, directory_path):
         self.directory_path = directory_path
         self.prefix = "ray_spilled_object_"
+        os.makedirs(self.directory_path, exist_ok=True)
         if not os.path.exists(self.directory_path):
             raise ValueError("The given directory path to store objects, "
-                             f"{self.directory_path}, doesn't exist.")
+                             f"{self.directory_path}, could not be created.")
 
     def spill_objects(self, object_refs):
         keys = []

python/ray/tests/test_object_spilling.py

@@ -107,13 +107,6 @@ def test_invalid_config_raises_exception(shutdown_only):
             "object_spilling_config": json.dumps(copied_config),
         })
 
-    with pytest.raises(ValueError):
-        copied_config = copy.deepcopy(file_system_object_spilling_config)
-        copied_config["params"].update({"directory_path": "not_exist_path"})
-        ray.init(_system_config={
-            "object_spilling_config": json.dumps(copied_config),
-        })
-
 
 @pytest.mark.skipif(
     platform.system() == "Windows", reason="Failing on Windows.")