[stable2503] Backport #8447 (#8448)

Backport #8447 into `stable2503` from eskimor.

See the
[documentation](https://github.com/paritytech/polkadot-sdk/blob/master/docs/BACKPORT.md)
on how to use this bot.

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---------

Co-authored-by: eskimor <[email protected]>
Co-authored-by: Robert <[email protected]>
Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: 3 people

polkadot/node/network/dispute-distribution/src/receiver/mod.rs

@@ -72,12 +72,6 @@ const COST_NOT_A_VALIDATOR: Rep = Rep::CostMajor("Reporting peer was not a valid
 const COST_INVALID_IMPORT: Rep =
 	Rep::CostMinor("Import was deemed invalid by dispute-coordinator.");
 
-/// Mildly punish peers exceeding their rate limit.
-///
-/// For honest peers this should rarely happen, but if it happens we would not want to disconnect
-/// too quickly. Minor cost should suffice for disconnecting any real flooder.
-const COST_APPARENT_FLOOD: Rep = Rep::CostMinor("Peer exceeded the rate limit.");
-
 /// How many votes must have arrived in the last `BATCH_COLLECTING_INTERVAL`
 ///
 /// in order for a batch to stay alive and not get flushed/imported to the dispute-coordinator.
@@ -311,7 +305,7 @@ where
 			);
 			req.send_outgoing_response(OutgoingResponse {
 				result: Err(()),
-				reputation_changes: vec![COST_APPARENT_FLOOD],
+				reputation_changes: vec![],
 				sent_feedback: None,
 			})
 			.map_err(|_| JfyiError::SendResponses(vec![peer]))?;

polkadot/node/network/dispute-distribution/src/tests/mod.rs

@@ -390,17 +390,12 @@ fn receive_rate_limit_is_enforced() {
 			rx_response_flood.await,
 			Ok(resp) => {
 				let sc_network::config::OutgoingResponse {
-					result: _,
-					reputation_changes,
+					result,
+					reputation_changes: _,
 					sent_feedback: _,
 				} = resp;
-				gum::trace!(
-					target: LOG_TARGET,
-					?reputation_changes,
-					"Received reputation changes."
-				);
-				// Received punishment for flood:
-				assert_eq!(reputation_changes.len(), 1);
+				// Received error because of flood.
+				assert!(!result.is_ok());
 			}
 		);
 		gum::trace!("Need to wait 2 patch intervals:");

prdoc/pr_8447.prdoc

@@ -0,0 +1,7 @@
+title: Fix a potential cause of slow parachain blocks
+doc:
+- audience: Node Operator
+  description: This fix removes a needless reputation change, which might be causing the longer parachain block times on Polkadot.
+crates:
+- name: polkadot-dispute-distribution
+  bump: minor