1. fix the damage type for single_mapping_tree_damage_visitor 2. walk_mapping_tree() now requires the device id 3. update metadata_dumper and thin_ls for the new walk_mapping_tree()
1. fix the damage type for single_mapping_tree_damage_visitor 2. walk_mapping_tree() now requires the device id 3. update metadata_dumper and thin_ls for the new walk_mapping_tree()