target: Pass in transport supported PI at session initialization

In order to support local WRITE_INSERT + READ_STRIP operations for
non PI enabled fabrics, the fabric driver needs to be able signal
what protection offload operations are supported.

This is done at session initialization time so the modes can be
signaled by individual se_wwn + se_portal_group endpoints, as well
as optionally across different transports on the same endpoint.

For iser-target, set TARGET_PROT_ALL if the underlying ib_device
has already signaled PI offload support, and allow this to be
exposed via a new iscsit_transport->iscsit_get_sup_prot_ops()
callback.

For loopback, set TARGET_PROT_ALL to signal SCSI initiator mode
operation.

For all other drivers, set TARGET_PROT_NORMAL to disable fabric
level PI.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 96aee439c9fd..78cab13bbb1b 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -511,6 +511,11 @@ static void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 	__iscsit_free_cmd(cmd, scsi_cmd, true);
 }
 
+static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
+{
+	return TARGET_PROT_NORMAL;
+}
+
 static struct iscsit_transport iscsi_target_transport = {
 	.name			= "iSCSI/TCP",
 	.transport_type		= ISCSI_TCP,
@@ -526,6 +531,7 @@ static struct iscsit_transport iscsi_target_transport = {
 	.iscsit_queue_data_in	= iscsit_queue_rsp,
 	.iscsit_queue_status	= iscsit_queue_rsp,
 	.iscsit_aborted_task	= iscsit_aborted_task,
+	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
 };
 
 static int __init iscsi_target_init_module(void)