Don't ask me why, but since 2.5.50 we need this forward-declaration
--- 1.2/include/linux/acct.h Tue Feb 5 16:23:04 2002
+++ edited/include/linux/acct.h Thu Nov 28 14:23:25 2002
@@ -75,6 +75,8 @@
#include <linux/config.h>
+struct super_block;
+
#ifdef CONFIG_BSD_PROCESS_ACCT
extern void acct_auto_close(struct super_block *sb);
extern int acct_process(long exitcode);