Propagate old topologies only to approval-distribution

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>

polkadot/node/network/bridge/src/rx/mod.rs

@@ -57,6 +57,7 @@ use polkadot_primitives::{AuthorityDiscoveryId, BlockNumber, Hash, ValidatorInde
 use std::{
 	collections::{hash_map, HashMap},
 	iter::ExactSizeIterator,
+	u32,
 };
 
 use super::validator_discovery;
@@ -750,7 +751,7 @@ where
 	// This is kept sorted, descending, by block number.
 	let mut live_heads: Vec<ActivatedLeaf> = Vec::with_capacity(MAX_VIEW_HEADS);
 	let mut finalized_number = 0;
-
+	let mut newest_session = u32::MIN;
 	let mut mode = Mode::Syncing(sync_oracle);
 	loop {
 		match ctx.recv().fuse().await? {
@@ -775,15 +776,29 @@ where
 					flesh_out_topology_peers(&mut authority_discovery_service, canonical_shuffling)
 						.await;
 
-				dispatch_validation_event_to_all_unbounded(
-					NetworkBridgeEvent::NewGossipTopology(NewGossipTopology {
-						session,
-						topology: SessionGridTopology::new(shuffled_indices, topology_peers),
-						local_index,
-					}),
-					ctx.sender(),
-					approval_voting_parallel_enabled,
-				);
+				if session >= newest_session {
+					dispatch_validation_event_to_all_unbounded(
+						NetworkBridgeEvent::NewGossipTopology(NewGossipTopology {
+							session,
+							topology: SessionGridTopology::new(shuffled_indices, topology_peers),
+							local_index,
+						}),
+						ctx.sender(),
+						approval_voting_parallel_enabled,
+					);
+				} else {
+					dispatch_validation_event_to_approval_unbounded(
+						&NetworkBridgeEvent::NegowGossipTopology(NewGossipTopology {
+							session,
+							topology: SessionGridTopology::new(shuffled_indices, topology_peers),
+							local_index,
+						}),
+						ctx.sender(),
+						approval_voting_parallel_enabled,
+					);
+				}
+
+				newest_session = newest_session.max(session);
 			},
 			FromOrchestra::Communication {
 				msg: NetworkBridgeRxMessage::UpdatedAuthorityIds { peer_id, authority_ids },
@@ -1123,22 +1138,11 @@ async fn dispatch_collation_event_to_all(
 	dispatch_collation_events_to_all(std::iter::once(event), ctx).await
 }
 
-fn dispatch_validation_event_to_all_unbounded(
-	event: NetworkBridgeEvent<net_protocol::VersionedValidationProtocol>,
+fn dispatch_validation_event_to_approval_unbounded(
+	event: &NetworkBridgeEvent<net_protocol::VersionedValidationProtocol>,
 	sender: &mut impl overseer::NetworkBridgeRxSenderTrait,
 	approval_voting_parallel_enabled: bool,
 ) {
-	event
-		.focus()
-		.ok()
-		.map(StatementDistributionMessage::from)
-		.and_then(|msg| Some(sender.send_unbounded_message(msg)));
-	event
-		.focus()
-		.ok()
-		.map(BitfieldDistributionMessage::from)
-		.and_then(|msg| Some(sender.send_unbounded_message(msg)));
-
 	if approval_voting_parallel_enabled {
 		event
 			.focus()
@@ -1152,6 +1156,30 @@ fn dispatch_validation_event_to_all_unbounded(
 			.map(ApprovalDistributionMessage::from)
 			.and_then(|msg| Some(sender.send_unbounded_message(msg)));
 	}
+}
+
+fn dispatch_validation_event_to_all_unbounded(
+	event: NetworkBridgeEvent<net_protocol::VersionedValidationProtocol>,
+	sender: &mut impl overseer::NetworkBridgeRxSenderTrait,
+	approval_voting_parallel_enabled: bool,
+) {
+	event
+		.focus()
+		.ok()
+		.map(StatementDistributionMessage::from)
+		.and_then(|msg| Some(sender.send_unbounded_message(msg)));
+	event
+		.focus()
+		.ok()
+		.map(BitfieldDistributionMessage::from)
+		.and_then(|msg| Some(sender.send_unbounded_message(msg)));
+
+	dispatch_validation_event_to_approval_unbounded(
+		&event,
+		sender,
+		approval_voting_parallel_enabled,
+	);
+
 	event
 		.focus()
 		.ok()

polkadot/node/network/protocol/src/grid_topology.rs

@@ -477,10 +477,6 @@ impl SessionBoundGridTopologyStorage {
 		topology: SessionGridTopology,
 		local_index: Option<ValidatorIndex>,
 	) {
-		if self.current_topology.session_index > session_index {
-			return
-		}
-
 		let local_neighbors = local_index
 			.and_then(|l| topology.compute_grid_neighbors_for(l))
 			.unwrap_or_else(GridNeighbors::empty);