Add ioengine.h header

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/ioengine.h b/ioengine.h
new file mode 100644
index 0000000..f293ab8
--- /dev/null
+++ b/ioengine.h
@@ -0,0 +1,142 @@
+#ifndef FIO_IOENGINE_H
+#define FIO_IOENGINE_H
+
+#define FIO_IOOPS_VERSION	10
+
+enum {
+	IO_U_F_FREE	= 1 << 0,
+	IO_U_F_FLIGHT	= 1 << 1,
+};
+
+/*
+ * The io unit
+ */
+struct io_u {
+	union {
+#ifdef FIO_HAVE_LIBAIO
+		struct iocb iocb;
+#endif
+#ifdef FIO_HAVE_POSIXAIO
+		struct aiocb aiocb;
+#endif
+#ifdef FIO_HAVE_SGIO
+		struct sg_io_hdr hdr;
+#endif
+#ifdef FIO_HAVE_GUASI
+		guasi_req_t greq;
+#endif
+#ifdef FIO_HAVE_SOLARISAIO
+		aio_result_t resultp;
+#endif
+		void *mmap_data;
+	};
+	struct timeval start_time;
+	struct timeval issue_time;
+
+	/*
+	 * Allocated/set buffer and length
+	 */
+	void *buf;
+	unsigned long buflen;
+	unsigned long long offset;
+
+	/*
+	 * IO engine state, may be different from above when we get
+	 * partial transfers / residual data counts
+	 */
+	void *xfer_buf;
+	unsigned long xfer_buflen;
+
+	unsigned int resid;
+	unsigned int error;
+
+	enum fio_ddir ddir;
+
+	/*
+	 * io engine private data
+	 */
+	union {
+		unsigned int index;
+		unsigned int seen;
+		void *engine_data;
+	};
+
+	unsigned int flags;
+
+	struct fio_file *file;
+
+	struct flist_head list;
+
+	/*
+	 * Callback for io completion
+	 */
+	int (*end_io)(struct thread_data *, struct io_u *);
+};
+
+/*
+ * io_ops->queue() return values
+ */
+enum {
+	FIO_Q_COMPLETED	= 0,		/* completed sync */
+	FIO_Q_QUEUED	= 1,		/* queued, will complete async */
+	FIO_Q_BUSY	= 2,		/* no more room, call ->commit() */
+};
+
+struct ioengine_ops {
+	struct flist_head list;
+	char name[16];
+	int version;
+	int flags;
+	int (*setup)(struct thread_data *);
+	int (*init)(struct thread_data *);
+	int (*prep)(struct thread_data *, struct io_u *);
+	int (*queue)(struct thread_data *, struct io_u *);
+	int (*commit)(struct thread_data *);
+	int (*getevents)(struct thread_data *, unsigned int, unsigned int, struct timespec *);
+	struct io_u *(*event)(struct thread_data *, int);
+	int (*cancel)(struct thread_data *, struct io_u *);
+	void (*cleanup)(struct thread_data *);
+	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 *);
+	void *data;
+	void *dlhandle;
+};
+
+
+/*
+ * io engine entry points
+ */
+extern int __must_check td_io_init(struct thread_data *);
+extern int __must_check td_io_prep(struct thread_data *, struct io_u *);
+extern int __must_check td_io_queue(struct thread_data *, struct io_u *);
+extern int __must_check td_io_sync(struct thread_data *, struct fio_file *);
+extern int __must_check td_io_getevents(struct thread_data *, unsigned int, unsigned int, struct timespec *);
+extern int __must_check td_io_commit(struct thread_data *);
+extern int __must_check td_io_open_file(struct thread_data *, struct fio_file *);
+extern int td_io_close_file(struct thread_data *, struct fio_file *);
+extern int __must_check td_io_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 void close_ioengine(struct thread_data *);
+
+/*
+ * io unit handling
+ */
+#define queue_full(td)	flist_empty(&(td)->io_u_freelist)
+extern struct io_u *__get_io_u(struct thread_data *);
+extern struct io_u *get_io_u(struct thread_data *);
+extern void put_io_u(struct thread_data *, struct io_u *);
+extern void requeue_io_u(struct thread_data *, struct io_u **);
+extern long __must_check io_u_sync_complete(struct thread_data *, struct io_u *);
+extern long __must_check io_u_queued_complete(struct thread_data *, int);
+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 io_u_fill_buffer(struct thread_data *td, struct io_u *, unsigned int);
+void io_u_mark_complete(struct thread_data *, unsigned int);
+void io_u_mark_submit(struct thread_data *, unsigned int);
+
+#endif