iscsi-target: Add new TPG attribute

Add a new TPG attribute demo_mode_discovery which is enabled by default.

Signed-off-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
index 1ef5df0..98ccf0b 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -223,6 +223,7 @@
 	a->cache_dynamic_acls = TA_CACHE_DYNAMIC_ACLS;
 	a->demo_mode_write_protect = TA_DEMO_MODE_WRITE_PROTECT;
 	a->prod_mode_write_protect = TA_PROD_MODE_WRITE_PROTECT;
+	a->demo_mode_discovery = TA_DEMO_MODE_DISCOVERY;
 }
 
 int iscsit_tpg_add_portal_group(struct iscsi_tiqn *tiqn, struct iscsi_portal_group *tpg)
@@ -820,3 +821,22 @@
 
 	return 0;
 }
+
+int iscsit_ta_demo_mode_discovery(
+	struct iscsi_portal_group *tpg,
+	u32 flag)
+{
+	struct iscsi_tpg_attrib *a = &tpg->tpg_attrib;
+
+	if ((flag != 0) && (flag != 1)) {
+		pr_err("Illegal value %d\n", flag);
+		return -EINVAL;
+	}
+
+	a->demo_mode_discovery = flag;
+	pr_debug("iSCSI_TPG[%hu] - Demo Mode Discovery bit:"
+		" %s\n", tpg->tpgt, (a->demo_mode_discovery) ?
+		"ON" : "OFF");
+
+	return 0;
+}