[SCSI] zfcp: Dont block zfcp_wq with scan

When running the scsi_scan from the zfcp workqueue and the target
device does not respond, the zfcp workqueue can block until the
scsi_scan hits a timeout. Move the work to the scsi host workqueue,
since this one is also used for the scan from the SCSI midlayer.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 58201e1..5b11386 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -583,6 +583,23 @@
 }
 
 
+void zfcp_scsi_scan(struct work_struct *work)
+{
+	struct zfcp_unit *unit = container_of(work, struct zfcp_unit,
+					      scsi_work);
+	struct fc_rport *rport;
+
+	flush_work(&unit->port->rport_work);
+	rport = unit->port->rport;
+
+	if (rport && rport->port_state == FC_PORTSTATE_ONLINE)
+		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id,
+				 scsilun_to_int((struct scsi_lun *)
+						&unit->fcp_lun), 0);
+
+	zfcp_unit_put(unit);
+}
+
 struct fc_function_template zfcp_transport_functions = {
 	.show_starget_port_id = 1,
 	.show_starget_port_name = 1,