leaf_data_end
push_space -= leaf_data_end(left);
data_end = leaf_data_end(right);
leaf_data_end(left), push_space);
copy_leaf_data(left, right, leaf_data_end(left) - push_space,
leaf_data_end(right);
leaf_data_end(right), push_space);
data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l);
leaf_data_end(l), data_copy_size);
data_end = leaf_data_end(leaf);
data_end = leaf_data_end(leaf);
data_end = leaf_data_end(leaf);
const int data_end = leaf_data_end(leaf);