bcachefs: Ensure intent locks are marked before taking write locks

Locks must be correctly marked for the cycle detector to work.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_key_cache.c

@@ -214,9 +214,13 @@ bkey_cached_alloc(struct btree_trans *trans, struct btree_path *path)
 			return ERR_PTR(ret);
 		}
 
-		ret = btree_node_lock_nopath(trans, &ck->c, SIX_LOCK_write);
+		path->l[0].b = (void *) ck;
+		path->l[0].lock_seq = ck->c.lock.state.seq;
+		mark_btree_node_locked(trans, path, 0, SIX_LOCK_intent);
+
+		ret = bch2_btree_node_lock_write(trans, path, &ck->c);
 		if (unlikely(ret)) {
-			six_unlock_intent(&ck->c.lock);
+			btree_node_unlock(trans, path, 0);
 			bkey_cached_move_to_freelist(bc, ck);
 			return ERR_PTR(ret);
 		}
@@ -285,6 +289,7 @@ btree_key_cache_create(struct btree_trans *trans, struct btree_path *path)
 			return ERR_PTR(-ENOMEM);
 		}
 
+		mark_btree_node_locked(trans, path, 0, SIX_LOCK_intent);
 		was_new = false;
 	} else {
 		if (path->btree_id == BTREE_ID_subvolumes)
@@ -311,6 +316,7 @@ btree_key_cache_create(struct btree_trans *trans, struct btree_path *path)
 			bkey_cached_free_fast(bc, ck);
 		}
 
+		mark_btree_node_locked(trans, path, 0, BTREE_NODE_UNLOCKED);
 		return NULL;
 	}