-ssize_t btget(struct store *st, struct btnode *tree, block_t bl, void *buf, size_t len);
-int btputmany(struct store *st, struct btnode *tree, struct btop *ops, int numops);
-int btput(struct store *st, struct btnode *tree, block_t bl, void *buf, size_t len);
-block_t btcount(struct store *st, struct btnode *tree);
+ssize_t btget(struct store *st, struct btnode *tree, block_t bl, void *buf, size_t len, size_t blsize);
+int btputmany(struct store *st, struct btnode *tree, struct btop *ops, int numops, size_t blsize);
+int btput(struct store *st, struct btnode *tree, block_t bl, void *buf, size_t len, size_t blsize);
+block_t btcount(struct store *st, struct btnode *tree, size_t blsize);