bcachefs: Add accounting for dirty btree nodes/keys

This lets us improve journal reclaim, so that it now tries to make sure
no more than 3/4s of the btree node cache and btree key cache are dirty
- ensuring the shrinkers can free memory.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 17 insertions, 0 deletions

diff --git a/fs/bcachefs/btree_io.h b/fs/bcachefs/btree_io.h
index 626d0f071b70..1a4b11e99cc4 100644
--- a/fs/bcachefs/btree_io.h
+++ b/fs/bcachefs/btree_io.h
@@ -14,6 +14,23 @@ struct btree_write;
 struct btree;
 struct btree_iter;
 
+static inline bool btree_node_dirty(struct btree *b)
+{
+	return test_bit(BTREE_NODE_dirty, &b->flags);
+}
+
+static inline void set_btree_node_dirty(struct bch_fs *c, struct btree *b)
+{
+	if (!test_and_set_bit(BTREE_NODE_dirty, &b->flags))
+		atomic_inc(&c->btree_cache.dirty);
+}
+
+static inline void clear_btree_node_dirty(struct bch_fs *c, struct btree *b)
+{
+	if (test_and_clear_bit(BTREE_NODE_dirty, &b->flags))
+		atomic_dec(&c->btree_cache.dirty);
+}
+
 struct btree_read_bio {
 	struct bch_fs		*c;
 	u64			start_time;