--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_BTREE_KEY_CACHE_H
+#define _BCACHEFS_BTREE_KEY_CACHE_H
+
+static inline size_t bch2_nr_btree_keys_need_flush(struct bch_fs *c)
+{
+ size_t nr_dirty = atomic_long_read(&c->btree_key_cache.nr_dirty);
+ size_t nr_keys = atomic_long_read(&c->btree_key_cache.nr_keys);
+ size_t max_dirty = 1024 + nr_keys / 2;
+
+ return max_t(ssize_t, 0, nr_dirty - max_dirty);
+}
+
+static inline bool bch2_btree_key_cache_must_wait(struct bch_fs *c)
+{
+ size_t nr_dirty = atomic_long_read(&c->btree_key_cache.nr_dirty);
+ size_t nr_keys = atomic_long_read(&c->btree_key_cache.nr_keys);
+ size_t max_dirty = 4096 + (nr_keys * 3) / 4;
+
+ return nr_dirty > max_dirty;
+}
+
+int bch2_btree_key_cache_journal_flush(struct journal *,
+ struct journal_entry_pin *, u64);
+
+struct bkey_cached *
+bch2_btree_key_cache_find(struct bch_fs *, enum btree_id, struct bpos);
+
+int bch2_btree_path_traverse_cached(struct btree_trans *, struct btree_path *,
+ unsigned);
+
+bool bch2_btree_insert_key_cached(struct btree_trans *, unsigned,
+ struct btree_insert_entry *);
+void bch2_btree_key_cache_drop(struct btree_trans *,
+ struct btree_path *);
+
+void bch2_fs_btree_key_cache_exit(struct btree_key_cache *);
+void bch2_fs_btree_key_cache_init_early(struct btree_key_cache *);
+int bch2_fs_btree_key_cache_init(struct btree_key_cache *);
+
+void bch2_btree_key_cache_to_text(struct printbuf *, struct btree_key_cache *);
+
+void bch2_btree_key_cache_exit(void);
+int __init bch2_btree_key_cache_init(void);
+
+#endif /* _BCACHEFS_BTREE_KEY_CACHE_H */