#ifdef IAMSUID
#ifdef I_SYS_STATVFS
-# include <sys/statvfs.h>
-#else
-# ifdef I_SYS_MOUNT
-# include <sys/mount.h>
-# else
-# ifdef I_MNTENT
-# include <mntent.h>
-# endif
-# endif
+# include <sys/statvfs.h> /* for f?statvfs() */
+#endif
+#ifdef I_SYS_MOUNT
+# include <sys/mount.h> /* for *BSD f?statfs() */
+#endif
+#ifdef I_MNTENT
+# include <mntent.h> /* for getmntent() */
#endif
#endif /* IAMSUID */