diff --git a/include/cutils/fs.h b/include/cutils/fs.h
new file mode 100644
index 0000000..04c8839
--- /dev/null
+++ b/include/cutils/fs.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#ifndef __CUTILS_FS_H
+#define __CUTILS_FS_H
+
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Ensure that directory exists with given mode and owners.
+ */
+extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid);
+
+/*
+ * Read single plaintext integer from given file, correctly handling files
+ * partially written with fs_write_atomic_int().
+ */
+extern int fs_read_atomic_int(const char* path, int* value);
+
+/*
+ * Write single plaintext integer to given file, creating backup while
+ * in progress.
+ */
+extern int fs_write_atomic_int(const char* path, int value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __CUTILS_FS_H */
diff --git a/include/cutils/multiuser.h b/include/cutils/multiuser.h
index 0bf403c..635ddb1 100644
--- a/include/cutils/multiuser.h
+++ b/include/cutils/multiuser.h
@@ -30,9 +30,9 @@
 typedef uid_t userid_t;
 typedef uid_t appid_t;
 
-extern userid_t multiuser_getUserId(uid_t uid);
-extern appid_t multiuser_getAppId(uid_t uid);
-extern uid_t multiuser_getUid(userid_t userId, appid_t appId);
+extern userid_t multiuser_get_user_id(uid_t uid);
+extern appid_t multiuser_get_app_id(uid_t uid);
+extern uid_t multiuser_get_uid(userid_t userId, appid_t appId);
 
 #ifdef __cplusplus
 }