Target/transport: Allocate protection sg if needed

In case protection information is involved, allocate
protection SG-list for transport.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_transport.c

@@ -2039,6 +2039,10 @@ static inline void transport_free_pages(struct se_cmd *cmd)
 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
 	cmd->t_bidi_data_sg = NULL;
 	cmd->t_bidi_data_nents = 0;
+
+	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
+	cmd->t_prot_sg = NULL;
+	cmd->t_prot_nents = 0;
 }
 
 /**
@@ -2202,6 +2206,14 @@ transport_generic_new_cmd(struct se_cmd *cmd)
 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 		}
 
+		if (cmd->prot_type != TARGET_PROT_NORMAL) {
+			ret = target_alloc_sgl(&cmd->t_prot_sg,
+					       &cmd->t_prot_nents,
+					       cmd->prot_length, true);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+
 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
 				       cmd->data_length, zero_flag);
 		if (ret < 0)