bcachefs: Ensure we wake up threads locking node when reusing it

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

fs/bcachefs/btree_cache.c

@@ -125,6 +125,8 @@ void bch2_btree_node_hash_remove(struct btree_cache *bc, struct btree *b)
 
 	/* Cause future lookups for this node to fail: */
 	b->hash_val = 0;
+
+	six_lock_wakeup_all(&b->c.lock);
 }
 
 int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b)

fs/bcachefs/btree_update_interior.c

@@ -138,8 +138,6 @@ static void __btree_node_free(struct bch_fs *c, struct btree *b)
 
 	bch2_btree_node_hash_remove(&c->btree_cache, b);
 
-	six_lock_wakeup_all(&b->c.lock);
-
 	mutex_lock(&c->btree_cache.lock);
 	list_move(&b->list, &c->btree_cache.freeable);
 	mutex_unlock(&c->btree_cache.lock);