extern int fio_gf_get_file_size(struct thread_data *td, struct fio_file *f);
extern int fio_gf_open_file(struct thread_data *td, struct fio_file *f);
extern int fio_gf_close_file(struct thread_data *td, struct fio_file *f);
extern int fio_gf_get_file_size(struct thread_data *td, struct fio_file *f);
extern int fio_gf_open_file(struct thread_data *td, struct fio_file *f);
extern int fio_gf_close_file(struct thread_data *td, struct fio_file *f);