More logs in is_potential_spam from dispute-coordinator (#5252)

Add more logs in `is_potential_spam` revealing why a statement was
marked as a spam.

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

polkadot/node/core/dispute-coordinator/src/initialized.rs

@@ -1351,6 +1351,12 @@ impl Initialized {
 				}
 			}
 			for validator_index in new_state.votes().invalid.keys() {
+				gum::debug!(
+					target: LOG_TARGET,
+					?candidate_hash,
+					?validator_index,
+					"Disabled offchain for voting invalid against a valid candidate",
+				);
 				self.offchain_disabled_validators
 					.insert_against_valid(session, *validator_index);
 			}
@@ -1375,6 +1381,13 @@ impl Initialized {
 			}
 			for (validator_index, (kind, _sig)) in new_state.votes().valid.raw() {
 				let is_backer = kind.is_backing();
+				gum::debug!(
+					target: LOG_TARGET,
+					?candidate_hash,
+					?validator_index,
+					?is_backer,
+					"Disabled offchain for voting valid for an invalid candidate",
+				);
 				self.offchain_disabled_validators.insert_for_invalid(
 					session,
 					*validator_index,

polkadot/node/core/dispute-coordinator/src/lib.rs

@@ -478,6 +478,18 @@ pub fn is_potential_spam(
 	let all_invalid_votes_disabled = vote_state.invalid_votes_all_disabled(is_disabled);
 	let ignore_disabled = !is_confirmed && all_invalid_votes_disabled;
 
+	gum::trace!(
+		target: LOG_TARGET,
+		?candidate_hash,
+		?is_disputed,
+		?is_included,
+		?is_backed,
+		?is_confirmed,
+		?all_invalid_votes_disabled,
+		?ignore_disabled,
+		"Checking for potential spam"
+	);
+
 	(is_disputed && !is_included && !is_backed && !is_confirmed) || ignore_disabled
 }
 

prdoc/pr_5252.prdoc

@@ -0,0 +1,11 @@
+title: Additional logging in `dispute-coordinator` subsystem
+
+doc:
+  - audience: Node Dev
+    description: |
+      Additional logging in `dispute-coordinator` subsystem tracing the list of offchain disabled
+      validators and the reason why an import statement is considered spam.
+
+crates:
+  - name: polkadot-node-core-dispute-coordinator
+    bump: patch