only enter ST_OPEN subtrees which we own

src/vdp_pesi.c

@@ -1349,12 +1349,24 @@ bytes_unpend_worklist(struct req *req, struct bytes_tree *tree,
 		return;
 	}
 
-	/* XXX what if we are a different worker and within a tree ?*/
+	/*
+	 * if unpending changes between threads, we need to make sure that we
+	 * only descend into ST_OPEN T_NEXUS which we own, so re-start at the
+	 * root
+	 *
+	 * this might seem inefficient, but we skip over any delivered subtrees,
+	 * so we will not walk the whole tree each time
+	 */
+	AN(tree->front);
+
+	if (tree->front_owner == req->wrk)
+		node = tree->front;
+	else
+		node = tree->root;
 
 	/* when starting, we do not want to see any ST_UNPENDING nodes */
 	check = CHK_DELI;
 
-	node = tree->front;
 	while (node != NULL) {
 		assert_node(node, CHK_ANY);
 
@@ -1405,16 +1417,27 @@ bytes_unpend_worklist(struct req *req, struct bytes_tree *tree,
 
 		assert_node(node, CHK_PEND);
 
-		/* XXX only enter ST_OPEN if we own it */
+		/* for ST_OPEN, only descend if we own it */
 		if (node->type == T_NEXUS) {
-			node = VSTAILQ_FIRST(&node->nexus.children);
-			continue;
-		}
+			next = VSTAILQ_FIRST(&node->nexus.children);
 
-		if (node->state == ST_OPEN) {
-			VSLdbg(req, "bytes_unpend: init node no children");
+			switch (node->state) {
+			case ST_CLOSED:
+				// closed node with no children must not exist
+				AN(next);
+				node = next;
+				continue;
+			case ST_OPEN:
 				set_front(tree, node, req->wrk);
+				AN(node->nexus.owner);
+				if (node->nexus.owner == req->wrk) {
+					node = next;
+					continue;
+				}
 				return;
+			default:
+				INCOMPL();
+			}
 		}
 
 		assert(node->state == ST_DATA);