LU-14945 lnet: don't use hops to determine the route state

[fs/lustre-release.git] / lnet / lnet / router.c

diff --git a/lnet/lnet/router.c b/lnet/lnet/router.c
index c297959..f46627e 100644 (file)
--- a/lnet/lnet/router.c
+++ b/lnet/lnet/router.c
@@ -329,7 +329,7 @@ bool lnet_is_route_alive(struct lnet_route *route)
         * routes the next-hop will not have the remote net.
         */
        if (avoid_asym_router_failure &&
-           (route->lr_hops == 1 || route->lr_hops == LNET_UNDEFINED_HOPS)) {
+           (route->lr_hops == 1 || route->lr_single_hop)) {
                rlpn = lnet_peer_get_net_locked(gw, route->lr_net);
                if (!rlpn)
                        return false;
@@ -483,8 +483,7 @@ lnet_router_discovery_ping_reply(struct lnet_peer *lp)
 
                route->lr_single_hop = single_hop;
                if (avoid_asym_router_failure &&
-                   (route->lr_hops == 1 ||
-                    route->lr_hops == LNET_UNDEFINED_HOPS))
+                   (route->lr_hops == 1 || route->lr_single_hop))
                        lnet_set_route_aliveness(route, net_up);
                else
                        lnet_set_route_aliveness(route, true);
@@ -790,6 +789,14 @@ lnet_add_route(__u32 net, __u32 hops, struct lnet_nid *gateway,
        lnet_peer_ni_decref_locked(lpni);
        lnet_net_unlock(LNET_LOCK_EX);
 
+       /* If avoid_asym_router_failure is enabled and hop count is not
+        * set to 1 for a route that is actually single-hop, then the
+        * feature will fail to prevent the router from being selected
+        * if it is missing a NI on the remote network due to misconfiguration.
+        */
+       if (avoid_asym_router_failure && hops == LNET_UNDEFINED_HOPS)
+               CWARN("Use hops = 1 for a single-hop route when avoid_asym_router_failure feature is enabled");
+
        rc = 0;
 
        if (!add_route) {