why can't include /sys/types and /linux/fs.h in the same file

Dear All:
I wrote a very small program as following :
#include <kernel/fs.h>
#include <sys/types.h>
int main ()
{
; // contains no C programs,
}
and give the command " cc -D__KERNEL__ -I/usr/src/linux/include to compiler the program .
A lot of parser error messages show on the screen .
Does anybody know why ?

You can't mix environments. Either you're building part of the kernel, in which case you need to use -D__KERNEL__ and <linux/*> headers, or you're building an application, in which case you need to use the headers from libc.

p.