target: Move cmd->prot_op check into target_write_prot_action

This patch moves the existing target_execute_cmd() check for
cmd->prot_op into it's own function, so it's easier to add
future support for WRITE STRIP.

(Use better target_write_prot_action name - Sagi)

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

drivers/target/target_core_transport.c

@@ -1738,6 +1738,25 @@ void __target_execute_cmd(struct se_cmd *cmd)
 	}
 }
 
+static int target_write_prot_action(struct se_cmd *cmd)
+{
+	/*
+	 * Perform WRITE_INSERT of PI using software emulation when backend
+	 * device has PI enabled, if the transport has not already generated
+	 * PI using hardware WRITE_INSERT offload.
+	 */
+	switch (cmd->prot_op) {
+	case TARGET_PROT_DOUT_INSERT:
+		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
+			sbc_dif_generate(cmd);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static bool target_handle_task_attr(struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
@@ -1817,15 +1836,9 @@ void target_execute_cmd(struct se_cmd *cmd)
 	cmd->t_state = TRANSPORT_PROCESSING;
 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 	spin_unlock_irq(&cmd->t_state_lock);
-	/*
-	 * Perform WRITE_INSERT of PI using software emulation when backend
-	 * device has PI enabled, if the transport has not already generated
-	 * PI using hardware WRITE_INSERT offload.
-	 */
-	if (cmd->prot_op == TARGET_PROT_DOUT_INSERT) {
-		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
-			sbc_dif_generate(cmd);
-	}
+
+	if (target_write_prot_action(cmd))
+		return;
 
 	if (target_handle_task_attr(cmd)) {
 		spin_lock_irq(&cmd->t_state_lock);