--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-02-05  Jim Meyering  <meyering@redhat.com>
+
+	still avoid unused-parameter warnings, but do it cleanly
+	* lib/fsusage.c (UNUSED_PARAM): Remove definition.
+	(get_fs_usage): Cast to void instead.
+	* lib/mountlist.c (UNUSED_PARAM): Remove definition.
+	(dev_from_mount_options, read_file_system_list): Cast to void.
+	Prompted by Bruno Haible.
+
 2009-02-04  Jim Meyering  <meyering@redhat.com>
 
 	fsusage.c: correct copyright year

--- a/lib/fsusage.c
+++ b/lib/fsusage.c
@@ -84,12 +84,6 @@
    otherwise, use PROPAGATE_ALL_ONES.  */
 #define PROPAGATE_TOP_BIT(x) ((x) | ~ (EXTRACT_TOP_BIT (x) - 1))
 
-#ifdef STAT_READ_FILSYS
-# define UNUSED_PARAM /* empty */
-#else
-# define UNUSED_PARAM _UNUSED_PARAMETER_
-#endif
-
 /* Fill in the fields of FSP with information about space usage for
    the file system on which FILE resides.
    DISK is the device on which FILE is mounted, for space-getting
@@ -98,9 +92,9 @@
    ERRNO is either a system error value, or zero if DISK is NULL
    on a system that requires a non-NULL value.  */
 int
-get_fs_usage (char const *file, char const *disk UNUSED_PARAM,
-	      struct fs_usage *fsp)
+get_fs_usage (char const *file, char const *disk, struct fs_usage *fsp)
 {
+  (void) disk;  /* avoid argument-unused warning */
 #if defined STAT_STATVFS		/* POSIX */
 
   struct statvfs fsd;

--- a/lib/mountlist.c
+++ b/lib/mountlist.c
@@ -1,6 +1,6 @@
 /* mountlist.c -- return a list of mounted file systems
 
-   Copyright (C) 1991, 1992, 1997-2008 Free Software Foundation, Inc.
+   Copyright (C) 1991, 1992, 1997-2009 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -297,17 +297,10 @@
 
 #if defined MOUNTED_GETMNTENT1 || defined MOUNTED_GETMNTENT2
 
-#undef UNUSED_PARAM
-#ifdef __linux__
-# define UNUSED_PARAM _UNUSED_PARAMETER_
-#else
-# define UNUSED_PARAM
-#endif
-
 /* Return the device number from MOUNT_OPTIONS, if possible.
    Otherwise return (dev_t) -1.  */
 static dev_t
-dev_from_mount_options (char const *mount_options UNUSED_PARAM)
+dev_from_mount_options (char const *mount_options)
 {
   /* GNU/Linux allows file system implementations to define their own
      meaning for "dev=" mount options, so don't trust the meaning
@@ -332,30 +325,24 @@
     }
 
 # endif
-
+  (void) mount_options;
   return -1;
 }
 
 #endif
 
-#undef UNUSED_PARAM
-#ifdef GETFSTYP
-# define UNUSED_PARAM
-#else
-# define UNUSED_PARAM _UNUSED_PARAMETER_
-#endif
-
 /* Return a list of the currently mounted file systems, or NULL on error.
    Add each entry to the tail of the list so that they stay in order.
    If NEED_FS_TYPE is true, ensure that the file system type fields in
    the returned list are valid.  Otherwise, they might not be.  */
 
 struct mount_entry *
-read_file_system_list (bool need_fs_type UNUSED_PARAM)
+read_file_system_list (bool need_fs_type)
 {
   struct mount_entry *mount_list;
   struct mount_entry *me;
   struct mount_entry **mtail = &mount_list;
+  (void) need_fs_type;
 
 #ifdef MOUNTED_LISTMNTENT
   {