Re: [PATCH net-next v2 2/5] rhashtable: add function to replace an element

From: Tom Herbert <redacted>
Date: Tue, 1 Dec 2015 15:11:09 -0800

+	lock = rht_bucket_lock(tbl, hash);
+
+	spin_lock_bh(lock);
+
+	pprev = &tbl->buckets[hash];
+	rht_for_each(he, tbl, hash) {
+		if (he != obj_old) {
+			pprev = &he->next;
+			continue;
+		}
+
+		rcu_assign_pointer(obj_new->next, obj_old->next);
+		rcu_assign_pointer(*pprev, obj_new);
+		err = 0;
+		break;

Are you sure this works fine in the presence of both parallel readers and
table expansion passes?