Silence some alerts due to overly verbose warnings. (#3946)

* statement-distribution: Only warn on relevant stuff.

* Silence warnings in availability-distribution.

* Demote more warnings.

* More consistency.

* info -> debug

polkadot/node/network/statement-distribution/src/error.rs

@@ -87,8 +87,12 @@ pub enum NonFatal {
 	#[error("Relay parent could not be found in active heads")]
 	NoSuchHead(Hash),
 
+	/// Received message from actually disconnected peer.
+	#[error("Message from not connected peer")]
+	NoSuchPeer(PeerId),
+
 	/// Peer requested statement data for candidate that was never announced to it.
-	#[error("Peer requested data for candidate it never received a notification for")]
+	#[error("Peer requested data for candidate it never received a notification for (malicious?)")]
 	RequestedUnannouncedCandidate(PeerId, CandidateHash),
 
 	/// A large statement status was requested, which could not be found.
@@ -112,7 +116,11 @@ pub fn log_error(result: Result<()>, ctx: &'static str) -> std::result::Result<(
 	match result {
 		Err(Error::Fatal(f)) => Err(f),
 		Err(Error::NonFatal(error)) => {
-			tracing::warn!(target: LOG_TARGET, error = ?error, ctx);
+			match error {
+				NonFatal::RequestedUnannouncedCandidate(_, _) =>
+					tracing::warn!(target: LOG_TARGET, error = %error, ctx),
+				_ => tracing::debug!(target: LOG_TARGET, error = %error, ctx),
+			}
 			Ok(())
 		},
 		Ok(()) => Ok(()),

polkadot/node/network/statement-distribution/src/lib.rs

@@ -1625,7 +1625,7 @@ impl StatementDistribution {
 					&requesting_peer,
 					&relay_parent,
 					&candidate_hash,
-				) {
+				)? {
 					return Err(NonFatal::RequestedUnannouncedCandidate(
 						requesting_peer,
 						candidate_hash,
@@ -1896,27 +1896,15 @@ fn requesting_peer_knows_about_candidate(
 	requesting_peer: &PeerId,
 	relay_parent: &Hash,
 	candidate_hash: &CandidateHash,
-) -> bool {
-	requesting_peer_knows_about_candidate_inner(
-		peers,
-		requesting_peer,
-		relay_parent,
-		candidate_hash,
-	)
-	.is_some()
-}
-
-/// Helper function for `requesting_peer_knows_about_statement`.
-fn requesting_peer_knows_about_candidate_inner(
-	peers: &HashMap<PeerId, PeerData>,
-	requesting_peer: &PeerId,
-	relay_parent: &Hash,
-	candidate_hash: &CandidateHash,
-) -> Option<()> {
-	let peer_data = peers.get(requesting_peer)?;
-	let knowledge = peer_data.view_knowledge.get(relay_parent)?;
-	knowledge.sent_candidates.get(&candidate_hash)?;
-	Some(())
+) -> NonFatalResult<bool> {
+	let peer_data = peers
+		.get(requesting_peer)
+		.ok_or_else(|| NonFatal::NoSuchPeer(*requesting_peer))?;
+	let knowledge = peer_data
+		.view_knowledge
+		.get(relay_parent)
+		.ok_or_else(|| NonFatal::NoSuchHead(*relay_parent))?;
+	Ok(knowledge.sent_candidates.get(&candidate_hash).is_some())
 }
 
 #[derive(Clone)]