Another round of documentation.
Bug: N/A
Test: N/A
Change-Id: I1b818fbb36ddd6d084dee56828290c2717a0c9b0
diff --git a/libc/include/sys/fsuid.h b/libc/include/sys/fsuid.h
index bb7a58d..c1c8ebb 100644
--- a/libc/include/sys/fsuid.h
+++ b/libc/include/sys/fsuid.h
@@ -26,17 +26,36 @@
* SUCH DAMAGE.
*/
-#ifndef _SYS_FSUID_H_
-#define _SYS_FSUID_H_
+#pragma once
+
+/**
+ * @file sys/fsuid.h
+ * @brief Set UID/GID for filesystem checks.
+ */
#include <sys/cdefs.h>
#include <sys/types.h>
__BEGIN_DECLS
+/**
+ * [setfsuid(2)](http://man7.org/linux/man-pages/man2/setfsuid.2.html) sets the UID used for
+ * filesystem checks.
+ *
+ * Returns the previous UID.
+ *
+ * Available since API level 21.
+ */
int setfsuid(uid_t __uid) __INTRODUCED_IN(21);
+
+/**
+ * [setfsgid(2)](http://man7.org/linux/man-pages/man2/setfsgid.2.html) sets the GID used for
+ * filesystem checks.
+ *
+ * Returns the previous GID.
+ *
+ * Available since API level 21.
+ */
int setfsgid(gid_t __gid) __INTRODUCED_IN(21);
__END_DECLS
-
-#endif