shadow_parent
struct dm_block *shadow_parent(struct shadow_spine *s);
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
struct btree_node *parent = dm_block_data(shadow_parent(s));
memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
parent = shadow_parent(s);
parent = shadow_parent(s);
struct btree_node *left, *right, *parent = dm_block_data(shadow_parent(s));
struct btree_node *left, *right, *parent = dm_block_data(shadow_parent(s));