extern void requeue_io_u(struct thread_data *, struct io_u **);
extern int __must_check io_u_sync_complete(struct thread_data *, struct io_u *, unsigned long *);
extern int __must_check io_u_queued_complete(struct thread_data *, int, unsigned long *);
extern void io_u_queued(struct thread_data *, struct io_u *);
extern void io_u_log_error(struct thread_data *, struct io_u *);
extern void io_u_mark_depth(struct thread_data *, unsigned int);
extern void requeue_io_u(struct thread_data *, struct io_u **);
extern int __must_check io_u_sync_complete(struct thread_data *, struct io_u *, unsigned long *);
extern int __must_check io_u_queued_complete(struct thread_data *, int, unsigned long *);
extern void io_u_queued(struct thread_data *, struct io_u *);
extern void io_u_log_error(struct thread_data *, struct io_u *);
extern void io_u_mark_depth(struct thread_data *, unsigned int);