int (*open_file)(struct thread_data *, struct fio_file *);
int (*close_file)(struct thread_data *, struct fio_file *);
int (*get_file_size)(struct thread_data *, struct fio_file *);
int (*open_file)(struct thread_data *, struct fio_file *);
int (*close_file)(struct thread_data *, struct fio_file *);
int (*get_file_size)(struct thread_data *, struct fio_file *);
extern struct ioengine_ops *load_ioengine(struct thread_data *, const char *);
extern void register_ioengine(struct ioengine_ops *);
extern void unregister_ioengine(struct ioengine_ops *);
extern struct ioengine_ops *load_ioengine(struct thread_data *, const char *);
extern void register_ioengine(struct ioengine_ops *);
extern void unregister_ioengine(struct ioengine_ops *);