Create subdirectories of misc_ce/misc_de when needed

Bug: 25861755
Test: Boot device, check directory exists as it should.
Change-Id: I413631452e8e0bdd869887091f8b077bd5f9297e
diff --git a/vold_prepare_subdirs b/vold_prepare_subdirs
new file mode 100644
index 0000000..f436ca2
--- /dev/null
+++ b/vold_prepare_subdirs
@@ -0,0 +1,44 @@
+#!/system/bin/sh
+#
+# Copyright (C) 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -e
+
+case "$3" in
+  *[!0-9]* | '')
+    echo "Invalid user id"
+    exit -1
+    ;;
+esac
+
+if [ x"$4" != x ] ; then
+    echo "Volume must be root volume"
+    exit -1;
+fi
+
+case "$1" in
+    misc_de|misc_ce)
+        computed_path="/data/$1/$3"
+        if [ x"$computed_path" != x"$2" ] ; then
+            echo "Parameter path didn't match computed path: " $computed_path
+            exit -1;
+        fi
+        /system/bin/prepare_dir --mode 700 --uid 0 --gid 0 -- "$computed_path"/vold
+        ;;
+    *)
+        echo "Unknown type: $1"
+        exit -1;
+        ;;
+esac