target: add helper to copy sense to se_cmd buffer

This adds a helper to copy sense from backend module buffer to
the se_cmd's sense buffer.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_transport.c

@@ -704,6 +704,24 @@ static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 	return cmd->sense_buffer;
 }
 
+void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
+{
+	unsigned char *cmd_sense_buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	cmd_sense_buf = transport_get_sense_buffer(cmd);
+	if (!cmd_sense_buf) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return;
+	}
+
+	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
+	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+}
+EXPORT_SYMBOL(transport_copy_sense_to_cmd);
+
 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 {
 	struct se_device *dev = cmd->se_dev;

include/target/target_core_backend.h

@@ -73,6 +73,8 @@ void	target_backend_unregister(const struct target_backend_ops *);
 void	target_complete_cmd(struct se_cmd *, u8);
 void	target_complete_cmd_with_length(struct se_cmd *, u8, int);
 
+void	transport_copy_sense_to_cmd(struct se_cmd *, unsigned char *);
+
 sense_reason_t	spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
 sense_reason_t	spc_emulate_report_luns(struct se_cmd *cmd);
 sense_reason_t	spc_emulate_inquiry_std(struct se_cmd *, unsigned char *);