fix: GoAhead signal from schedule_code_upgrade

Author: Daanvdplas

polkadot/runtime/parachains/src/inclusion/mod.rs

@@ -456,8 +456,9 @@ impl fmt::Debug for UmpAcceptanceCheckErr {
 				"the ump queue would have grown past the max size permitted by config ({} > {})",
 				total_size, limit,
 			),
-			UmpAcceptanceCheckErr::IsOffboarding =>
-				write!(fmt, "upward message rejected because the para is off-boarding",),
+			UmpAcceptanceCheckErr::IsOffboarding => {
+				write!(fmt, "upward message rejected because the para is off-boarding",)
+			},
 		}
 	}
 }
@@ -911,6 +912,7 @@ impl<T: Config> Pallet<T> {
 				new_code,
 				now,
 				&config,
+				true,
 			));
 		}
 

polkadot/runtime/parachains/src/inclusion/tests.rs

@@ -1259,7 +1259,13 @@ fn candidate_checks() {
 				let cfg = Configuration::config();
 				let expected_at = 10 + cfg.validation_upgrade_delay;
 				assert_eq!(expected_at, 12);
-				Paras::schedule_code_upgrade(chain_a, vec![1, 2, 3, 4].into(), expected_at, &cfg);
+				Paras::schedule_code_upgrade(
+					chain_a,
+					vec![1, 2, 3, 4].into(),
+					expected_at,
+					&cfg,
+					true,
+				);
 			}
 
 			assert_noop!(
@@ -2277,7 +2283,7 @@ fn para_upgrade_delay_scheduled_from_inclusion() {
 		let cause = &active_vote_state.causes()[0];
 		// Upgrade block is the block of inclusion, not candidate's parent.
 		assert_matches!(cause,
-			paras::PvfCheckCause::Upgrade { id, included_at }
+			paras::PvfCheckCause::Upgrade { id, included_at, set_go_ahead: true }
 				if id == &chain_a && included_at == &7
 		);
 	});

polkadot/runtime/parachains/src/paras/mod.rs

@@ -386,6 +386,8 @@ pub(crate) enum PvfCheckCause<BlockNumber> {
 		///
 		/// See https://github.com/paritytech/polkadot/issues/4601 for detailed explanation.
 		included_at: BlockNumber,
+		/// Whether or not the given para should be sent the `GoAhead` signal.
+		set_go_ahead: bool,
 	},
 }
 
@@ -723,7 +725,9 @@ pub mod pallet {
 		StorageMap<_, Twox64Concat, ParaId, ValidationCodeHash>;
 
 	/// This is used by the relay-chain to communicate to a parachain a go-ahead with in the upgrade
-	/// procedure.
+	/// procedure. The `GoAhead` is only set when it is assured the parachain is ready for the
+	/// upgrade, i.e. when the upgrade is enacted on the parachain side
+	/// (`enact_authorized_upgrade`).
 	///
 	/// This value is absent when there are no upgrades scheduled or during the time the relay chain
 	/// performs the checks. It is set at the first relay-chain block when the corresponding
@@ -869,7 +873,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			let config = configuration::Pallet::<T>::config();
-			Self::schedule_code_upgrade(para, new_code, relay_parent_number, &config);
+			Self::schedule_code_upgrade(para, new_code, relay_parent_number, &config, false);
 			Self::deposit_event(Event::CodeUpgradeScheduled(para));
 			Ok(())
 		}
@@ -1174,7 +1178,7 @@ impl<T: Config> Pallet<T> {
 		let current_block = frame_system::Pallet::<T>::block_number();
 		// Schedule the upgrade with a delay just like if a parachain triggered the upgrade.
 		let upgrade_block = current_block.saturating_add(config.validation_upgrade_delay);
-		Self::schedule_code_upgrade(id, new_code, upgrade_block, &config);
+		Self::schedule_code_upgrade(id, new_code, upgrade_block, &config, false);
 		Self::deposit_event(Event::CodeUpgradeScheduled(id));
 		Ok(())
 	}
@@ -1515,8 +1519,15 @@ impl<T: Config> Pallet<T> {
 				PvfCheckCause::Onboarding(id) => {
 					weight += Self::proceed_with_onboarding(*id, sessions_observed);
 				},
-				PvfCheckCause::Upgrade { id, included_at } => {
-					weight += Self::proceed_with_upgrade(*id, code_hash, now, *included_at, cfg);
+				PvfCheckCause::Upgrade { id, included_at, set_go_ahead } => {
+					weight += Self::proceed_with_upgrade(
+						*id,
+						code_hash,
+						now,
+						*included_at,
+						cfg,
+						*set_go_ahead,
+					);
 				},
 			}
 		}
@@ -1549,6 +1560,7 @@ impl<T: Config> Pallet<T> {
 		now: BlockNumberFor<T>,
 		relay_parent_number: BlockNumberFor<T>,
 		cfg: &configuration::HostConfiguration<BlockNumberFor<T>>,
+		set_go_ahead: bool,
 	) -> Weight {
 		let mut weight = Weight::zero();
 
@@ -1572,12 +1584,15 @@ impl<T: Config> Pallet<T> {
 		weight += T::DbWeight::get().reads_writes(1, 4);
 		FutureCodeUpgrades::<T>::insert(&id, expected_at);
 
-		UpcomingUpgrades::<T>::mutate(|upcoming_upgrades| {
-			let insert_idx = upcoming_upgrades
-				.binary_search_by_key(&expected_at, |&(_, b)| b)
-				.unwrap_or_else(|idx| idx);
-			upcoming_upgrades.insert(insert_idx, (id, expected_at));
-		});
+		// Only set an upcoming upgrade if `GoAhead` signal should be set for the respective para.
+		if set_go_ahead {
+			UpcomingUpgrades::<T>::mutate(|upcoming_upgrades| {
+				let insert_idx = upcoming_upgrades
+					.binary_search_by_key(&expected_at, |&(_, b)| b)
+					.unwrap_or_else(|idx| idx);
+				upcoming_upgrades.insert(insert_idx, (id, expected_at));
+			});
+		}
 
 		let expected_at = expected_at.saturated_into();
 		let log = ConsensusLog::ParaScheduleUpgradeCode(id, *code_hash, expected_at);
@@ -1816,6 +1831,7 @@ impl<T: Config> Pallet<T> {
 		new_code: ValidationCode,
 		inclusion_block_number: BlockNumberFor<T>,
 		cfg: &configuration::HostConfiguration<BlockNumberFor<T>>,
+		set_go_ahead: bool,
 	) -> Weight {
 		let mut weight = T::DbWeight::get().reads(1);
 
@@ -1865,7 +1881,7 @@ impl<T: Config> Pallet<T> {
 		});
 
 		weight += Self::kick_off_pvf_check(
-			PvfCheckCause::Upgrade { id, included_at: inclusion_block_number },
+			PvfCheckCause::Upgrade { id, included_at: inclusion_block_number, set_go_ahead },
 			code_hash,
 			new_code,
 			cfg,