FILE_SETUP_READ_ONLY_FS
const int open_opt = setup == FILE_SETUP_READ_ONLY_FS ? O_RDONLY : O_RDWR;
const int mmap_prot = setup == FILE_SETUP_READ_ONLY_FS ? PROT_READ : (PROT_READ | PROT_WRITE);
setup == FILE_SETUP_READ_ONLY_FS ? "read-only" :
return file_setup_area_common(nr_hpages, FILE_SETUP_READ_ONLY_FS);