Hi Xu, > Hi Petr > I think detecting file_handle struct(it is in fcntl.h) in configure.ac is > correct instead of using HAVE_NAME_TO_HANDLE_AT macro directly. You're right, using AC_CHECK_TYPES([struct, ],,,[#include <fcntl.h>]) is probably safer. I'll send v2. Kind regards, Petr Vorel > Best Regards > Yang Xu