btree_keys_ops
void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
const struct btree_keys_ops *ops;
void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
const struct btree_keys_ops bch_btree_keys_ops = {
const struct btree_keys_ops bch_extent_keys_ops = {
extern const struct btree_keys_ops bch_btree_keys_ops;
extern const struct btree_keys_ops bch_extent_keys_ops;