xfs_btree_get_level
int level = xfs_btree_get_level(block);
xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
if (xfs_btree_get_level(left) > 0) {
int level = xfs_btree_get_level(block);
level = xfs_btree_get_level(block);
block_level = xfs_btree_get_level(btblock);