iscsi/iser-target: Add fabric_prot_type attribute support

This patch updates iscsi/iser-target to add a new fabric_prot_type
TPG attribute for iser-target, used for controlling LLD level
protection into LIO when the backend device does not support T10-PI.

This is required for ib_isert to enable WRITE_STRIP + READ_INSERT
hardware offloads.

It's disabled by default and controls which se_sesion->sess_prot_type
are set at iscsi_target_locate_portal() session registration time.

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Martin Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
index bdd127c0e3ae..3076e6f3a831 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -228,6 +228,7 @@ static void iscsit_set_default_tpg_attribs(struct iscsi_portal_group *tpg)
 	a->demo_mode_discovery = TA_DEMO_MODE_DISCOVERY;
 	a->default_erl = TA_DEFAULT_ERL;
 	a->t10_pi = TA_DEFAULT_T10_PI;
+	a->fabric_prot_type = TA_DEFAULT_FABRIC_PROT_TYPE;
 }
 
 int iscsit_tpg_add_portal_group(struct iscsi_tiqn *tiqn, struct iscsi_portal_group *tpg)
@@ -878,3 +879,21 @@ int iscsit_ta_t10_pi(
 
 	return 0;
 }
+
+int iscsit_ta_fabric_prot_type(
+	struct iscsi_portal_group *tpg,
+	u32 prot_type)
+{
+	struct iscsi_tpg_attrib *a = &tpg->tpg_attrib;
+
+	if ((prot_type != 0) && (prot_type != 1) && (prot_type != 3)) {
+		pr_err("Illegal value for fabric_prot_type: %u\n", prot_type);
+		return -EINVAL;
+	}
+
+	a->fabric_prot_type = prot_type;
+	pr_debug("iSCSI_TPG[%hu] - T10 Fabric Protection Type: %u\n",
+		 tpg->tpgt, prot_type);
+
+	return 0;
+}