auto import from //depot/cupcake/@135843
diff --git a/test_roots.c b/test_roots.c
new file mode 100644
index 0000000..f49f55e
--- /dev/null
+++ b/test_roots.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#include <sys/stat.h>
+#include "roots.h"
+#include "common.h"
+
+#define CANARY_FILE "/system/build.prop"
+#define CANARY_FILE_ROOT_PATH "SYSTEM:build.prop"
+
+int
+file_exists(const char *path)
+{
+ struct stat st;
+ int ret;
+ ret = stat(path, &st);
+ if (ret == 0) {
+ return S_ISREG(st.st_mode);
+ }
+ return 0;
+}
+
+int
+test_roots()
+{
+ int ret;
+
+ /* Make sure that /system isn't mounted yet.
+ */
+ if (file_exists(CANARY_FILE)) return -__LINE__;
+ if (is_root_path_mounted(CANARY_FILE_ROOT_PATH)) return -__LINE__;
+
+ /* Try to mount the root.
+ */
+ ret = ensure_root_path_mounted(CANARY_FILE_ROOT_PATH);
+ if (ret < 0) return -__LINE__;
+
+ /* Make sure we can see the file now and that we know the root is mounted.
+ */
+ if (!file_exists(CANARY_FILE)) return -__LINE__;
+ if (!is_root_path_mounted(CANARY_FILE_ROOT_PATH)) return -__LINE__;
+
+ /* Make sure that the root path corresponds to the regular path.
+ */
+ struct stat st1, st2;
+ char buf[128];
+ const char *path = translate_root_path(CANARY_FILE_ROOT_PATH,
+ buf, sizeof(buf));
+ if (path == NULL) return -__LINE__;
+ ret = stat(CANARY_FILE, &st1);
+ if (ret != 0) return -__LINE__;
+ ret = stat(path, &st2);
+ if (ret != 0) return -__LINE__;
+ if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) return -__LINE__;
+
+ /* Try to unmount the root.
+ */
+ ret = ensure_root_path_unmounted(CANARY_FILE_ROOT_PATH);
+ if (ret < 0) return -__LINE__;
+
+ /* Make sure that we can't see the file anymore and that
+ * we don't think the root is mounted.
+ */
+ if (file_exists(CANARY_FILE)) return -__LINE__;
+ if (is_root_path_mounted(CANARY_FILE_ROOT_PATH)) return -__LINE__;
+
+ return 0;
+}