scsi_dh: kill struct scsi_dh_data

Add a ->handler and a ->handler_data field to struct scsi_device and kill
this indirection.  Also move struct scsi_device_handler to scsi_dh.h so that
changes to it don't require rebuilding every SCSI LLDD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index 3a37b4c45..85d7317 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -55,6 +55,23 @@
 	SCSI_DH_NOSYS,
 	SCSI_DH_DRIVER_MAX,
 };
+
+typedef void (*activate_complete)(void *, int);
+struct scsi_device_handler {
+	/* Used by the infrastructure */
+	struct list_head list; /* list of scsi_device_handlers */
+
+	/* Filled by the hardware handler */
+	struct module *module;
+	const char *name;
+	int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
+	int (*attach)(struct scsi_device *);
+	void (*detach)(struct scsi_device *);
+	int (*activate)(struct scsi_device *, activate_complete, void *);
+	int (*prep_fn)(struct scsi_device *, struct request *);
+	int (*set_params)(struct scsi_device *, const char *);
+};
+
 #ifdef CONFIG_SCSI_DH
 extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
 extern int scsi_dh_attach(struct request_queue *, const char *);