rculfhash: add assertion in path compression

Detects incorrect usage of path compression.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/rculfhash.c b/rculfhash.c
index 003ab0bd0236d39ee4c591c2dccec6a3266bfca9..2565099d2c12b633dce919e927363b10ff63912c 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -672,6 +672,13 @@ void _cds_lfht_gc_bucket(struct cds_lfht_node *dummy, struct cds_lfht_node *node
                /* We can always skip the dummy node initially */
                iter = rcu_dereference(iter_prev->p.next);
                assert(iter_prev->p.reverse_hash <= node->p.reverse_hash);
+               /*
+                * We should never be called with dummy (start of chain)
+                * and logically removed node (end of path compression
+                * marker) being the actual same node. This would be a
+                * bug in the algorithm implementation.
+                */
+               assert(dummy != node);
                for (;;) {
                        if (unlikely(!clear_flag(iter)))
                                return;