scsi: scsi_transport_fc: Add dummy initiator role to rport

This patch allows scsi drivers that expose virturalized fibre channel
devices but that do not expose rports to successfully rescan the scsi
bus via echo "- - -" > /sys/class/scsi_host/hostX/scan.  Drivers can
create a pseudo rport and indicate FC_PORT_ROLE_FCP_DUMMY_INITIATOR as
the rport's role in fc_rport_identifiers. This insures that a valid
scsi_target_id is assigned to the newly created rport and it can meet
the requirements of fc_user_scan_tgt calling scsi_scan_target.

Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_transport_fc.c

@@ -289,9 +289,10 @@ static const struct {
 	u32 			value;
 	char			*name;
 } fc_port_role_names[] = {
-	{ FC_PORT_ROLE_FCP_TARGET,	"FCP Target" },
-	{ FC_PORT_ROLE_FCP_INITIATOR,	"FCP Initiator" },
-	{ FC_PORT_ROLE_IP_PORT,		"IP Port" },
+	{ FC_PORT_ROLE_FCP_TARGET,		"FCP Target" },
+	{ FC_PORT_ROLE_FCP_INITIATOR,		"FCP Initiator" },
+	{ FC_PORT_ROLE_IP_PORT,			"IP Port" },
+	{ FC_PORT_ROLE_FCP_DUMMY_INITIATOR,	"FCP Dummy Initiator" },
 };
 fc_bitfield_name_search(port_roles, fc_port_role_names)
 
@@ -2628,7 +2629,8 @@ fc_remote_port_create(struct Scsi_Host *shost, int channel,
 	spin_lock_irqsave(shost->host_lock, flags);
 
 	rport->number = fc_host->next_rport_number++;
-	if (rport->roles & FC_PORT_ROLE_FCP_TARGET)
+	if ((rport->roles & FC_PORT_ROLE_FCP_TARGET) ||
+	    (rport->roles & FC_PORT_ROLE_FCP_DUMMY_INITIATOR))
 		rport->scsi_target_id = fc_host->next_target_id++;
 	else
 		rport->scsi_target_id = -1;

include/scsi/scsi_transport_fc.h

@@ -162,6 +162,7 @@ enum fc_tgtid_binding_type  {
 #define FC_PORT_ROLE_FCP_TARGET			0x01
 #define FC_PORT_ROLE_FCP_INITIATOR		0x02
 #define FC_PORT_ROLE_IP_PORT			0x04
+#define FC_PORT_ROLE_FCP_DUMMY_INITIATOR	0x08
 
 /* The following are for compatibility */
 #define FC_RPORT_ROLE_UNKNOWN			FC_PORT_ROLE_UNKNOWN