[SCSI] scsi_transport_fc: Introduce disable_target_scan flag

This change has already been discussed on linux-scsi:
http://marc.info/?t=118771096400003
http://marc.info/?t=118760913100005

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Acked-by: James Smart <James.Smart@Emulex.Com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_fc.c

@@ -2988,10 +2988,12 @@ fc_scsi_scan_rport(struct work_struct *work)
 	struct fc_rport *rport =
 		container_of(work, struct fc_rport, scan_work);
 	struct Scsi_Host *shost = rport_to_shost(rport);
+	struct fc_internal *i = to_fc_internal(shost->transportt);
 	unsigned long flags;
 
 	if ((rport->port_state == FC_PORTSTATE_ONLINE) &&
-	    (rport->roles & FC_PORT_ROLE_FCP_TARGET)) {
+	    (rport->roles & FC_PORT_ROLE_FCP_TARGET) &&
+	    !(i->f->disable_target_scan)) {
 		scsi_scan_target(&rport->dev, rport->channel,
 			rport->scsi_target_id, SCAN_WILD_CARD, 1);
 	}

include/scsi/scsi_transport_fc.h

@@ -632,6 +632,8 @@ struct fc_function_template {
 	unsigned long	show_host_fabric_name:1;
 	unsigned long	show_host_symbolic_name:1;
 	unsigned long	show_host_system_hostname:1;
+
+	unsigned long	disable_target_scan:1;
 };