[SCSI] zfcp: Add allow_lun_scan module parameter

The zfcpdump tool requires a method to attach exactly one LUN. The
easiest way to achieve this is to add a new zfcp module parameter.
When allow_lun_scan is set to "false", zfcp only accepts LUNs that
have been configured through the unit_add sysfs interface.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 59a653d15a19..ddb5800823a9 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -30,6 +30,10 @@ module_param_named(dif, enable_dif, bool, 0600);
 MODULE_PARM_DESC(dif, "Enable DIF/DIX data integrity support");
 #endif
 
+static bool allow_lun_scan = 1;
+module_param(allow_lun_scan, bool, 0600);
+MODULE_PARM_DESC(allow_lun_scan, "For NPIV, scan and attach all storage LUNs");
+
 static int zfcp_scsi_change_queue_depth(struct scsi_device *sdev, int depth,
                                         int reason)
 {
@@ -130,6 +134,7 @@ static int zfcp_scsi_slave_alloc(struct scsi_device *sdev)
         struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
         struct zfcp_port *port;
         struct zfcp_unit *unit;
+        int npiv = adapter->connection_features & FSF_FEATURE_NPIV_MODE;
 
         port = zfcp_get_port_by_wwpn(adapter, rport->port_name);
         if (!port)
@@ -139,7 +144,7 @@ static int zfcp_scsi_slave_alloc(struct scsi_device *sdev)
         if (unit)
                 put_device(&unit->dev);
 
-        if (!unit && !(adapter->connection_features & FSF_FEATURE_NPIV_MODE)) {
+        if (!unit && !(allow_lun_scan && npiv)) {
                 put_device(&port->dev);
                 return -ENXIO;
         }