req/resp: use IfDisconnected::ImmediateError (#4253)

* req/resp: use IfDisconnected::ImmediateError

* remove outdated comments

* fmt

polkadot/node/network/availability-distribution/src/pov_requester/mod.rs

@@ -64,10 +64,7 @@ where
 
 	ctx.send_message(NetworkBridgeMessage::SendRequests(
 		vec![full_req],
-		// We are supposed to be connected to validators of our group via `PeerSet`,
-		// but at session boundaries that is kind of racy, in case a connection takes
-		// longer to get established, so we try to connect in any case.
-		IfDisconnected::TryConnect,
+		IfDisconnected::ImmediateError,
 	))
 	.await;
 

polkadot/node/network/availability-distribution/src/requester/fetch_task/mod.rs

@@ -327,7 +327,7 @@ impl RunningTask {
 
 		self.sender
 			.send(FromFetchTask::Message(AllMessages::NetworkBridge(
-				NetworkBridgeMessage::SendRequests(vec![requests], IfDisconnected::TryConnect),
+				NetworkBridgeMessage::SendRequests(vec![requests], IfDisconnected::ImmediateError),
 			)))
 			.await
 			.map_err(|_| TaskError::ShuttingDown)?;

polkadot/node/network/availability-distribution/src/requester/fetch_task/tests.rs

@@ -230,7 +230,7 @@ impl TestRun {
 		match msg {
 			AllMessages::NetworkBridge(NetworkBridgeMessage::SendRequests(
 				reqs,
-				IfDisconnected::TryConnect,
+				IfDisconnected::ImmediateError,
 			)) => {
 				let mut valid_responses = 0;
 				for req in reqs {

polkadot/node/network/availability-distribution/src/tests/state.rs

@@ -216,7 +216,7 @@ impl TestState {
 			match msg {
 				AllMessages::NetworkBridge(NetworkBridgeMessage::SendRequests(
 					reqs,
-					IfDisconnected::TryConnect,
+					IfDisconnected::ImmediateError,
 				)) => {
 					for req in reqs {
 						// Forward requests:

polkadot/node/network/availability-recovery/src/lib.rs

@@ -201,7 +201,7 @@ impl RequestFromBackers {
 				.send_message(
 					NetworkBridgeMessage::SendRequests(
 						vec![Requests::AvailableDataFetching(req)],
-						IfDisconnected::TryConnect,
+						IfDisconnected::ImmediateError,
 					)
 					.into(),
 				)
@@ -345,7 +345,7 @@ impl RequestChunksFromValidators {
 
 		sender
 			.send_message(
-				NetworkBridgeMessage::SendRequests(requests, IfDisconnected::TryConnect).into(),
+				NetworkBridgeMessage::SendRequests(requests, IfDisconnected::ImmediateError).into(),
 			)
 			.await;
 	}

polkadot/node/network/availability-recovery/src/tests.rs

@@ -275,7 +275,7 @@ impl TestState {
 				AllMessages::NetworkBridge(
 					NetworkBridgeMessage::SendRequests(
 						requests,
-						IfDisconnected::TryConnect,
+						IfDisconnected::ImmediateError,
 					)
 				) => {
 					for req in requests {
@@ -324,7 +324,7 @@ impl TestState {
 				AllMessages::NetworkBridge(
 					NetworkBridgeMessage::SendRequests(
 						mut requests,
-						IfDisconnected::TryConnect,
+						IfDisconnected::ImmediateError,
 					)
 				) => {
 					assert_eq!(requests.len(), 1);

polkadot/node/network/dispute-distribution/src/sender/send_task.rs

@@ -304,11 +304,7 @@ async fn send_requests<Context: SubsystemContext>(
 		statuses.insert(receiver, DeliveryStatus::Pending(remote_handle));
 	}
 
-	let msg = NetworkBridgeMessage::SendRequests(
-		reqs,
-		// We should be connected, but the hell - if not, try!
-		IfDisconnected::TryConnect,
-	);
+	let msg = NetworkBridgeMessage::SendRequests(reqs, IfDisconnected::ImmediateError);
 	ctx.send_message(AllMessages::NetworkBridge(msg)).await;
 	Ok(statuses)
 }

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

@@ -663,7 +663,7 @@ async fn check_sent_requests(
 	assert_matches!(
 		handle.recv().await,
 		AllMessages::NetworkBridge(
-			NetworkBridgeMessage::SendRequests(reqs, IfDisconnected::TryConnect)
+			NetworkBridgeMessage::SendRequests(reqs, IfDisconnected::ImmediateError)
 		) => {
 			let reqs: Vec<_> = reqs.into_iter().map(|r|
 				assert_matches!(