struct bt_list_head siblings;
struct bt_list_head tmp_head;
unsigned int lineno;
+ /*
+ * We mark nodes visited in the generate-io-struct phase (last
+ * phase). We only mark the 1-depth level nodes as visited
+ * (never the root node, and not their sub-nodes). This allows
+ * skipping already visited nodes when doing incremental
+ * metadata append.
+ */
+ int visited;
enum node_type type;
union {