scheduler: update storage migration

runtime/kusama/src/lib.rs

@@ -1491,6 +1491,8 @@ pub type Migrations = (
 	// Unreleased - add new migrations here:
 	pallet_nomination_pools::migration::v5::MigrateToV5<Runtime>,
 	parachains_configuration::migration::v5::MigrateToV5<Runtime>,
+	/* Asynchronous backing mirgration */
+	parachains_scheduler::migration::v1::MigrateToV1<Runtime>,
 );
 
 /// Unchecked extrinsic type as expected by this runtime.

runtime/parachains/src/scheduler.rs

@@ -36,7 +36,6 @@
 //! over time.
 
 use frame_support::pallet_prelude::*;
-use frame_system::pallet_prelude::*;
 use primitives::{
 	CollatorId, CoreIndex, CoreOccupied, GroupIndex, GroupRotationInfo, Id as ParaId,
 	ParathreadClaim, ParathreadEntry, ScheduledCore, ValidatorIndex,
@@ -52,7 +51,9 @@ pub use pallet::*;
 #[cfg(test)]
 mod tests;
 
-mod migration;
+pub mod migration;
+
+const LOG_TARGET: &str = "runtime::scheduler";
 
 /// A queued parathread entry, pre-assigned to a core.
 #[derive(Encode, Decode, TypeInfo)]
@@ -166,13 +167,6 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config + configuration::Config + paras::Config {}
 
-	#[pallet::hooks]
-	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
-		fn on_runtime_upgrade() -> Weight {
-			migration::on_runtime_upgrade::<T>()
-		}
-	}
-
 	/// All the validator groups. One for each core. Indices are into `ActiveValidators` - not the
 	/// broader set of Polkadot validators, but instead just the subset used for parachains during
 	/// this session.

runtime/parachains/src/scheduler/migration.rs

@@ -16,29 +16,14 @@
 
 //! A module that is responsible for migration of storage.
 
-use crate::scheduler::{self, AssignmentKind, Config, Pallet, Scheduled};
-use frame_support::{pallet_prelude::*, traits::StorageVersion, weights::Weight};
-use parity_scale_codec::{Decode, Encode};
+use frame_support::traits::StorageVersion;
 
 /// The current storage version.
 pub const STORAGE_VERSION: StorageVersion = StorageVersion::new(1);
 
-/// Call this during the next runtime upgrade for this module.
-pub fn on_runtime_upgrade<T: Config>() -> Weight {
-	let mut weight: Weight = Weight::zero();
-
-	if StorageVersion::get::<Pallet<T>>() == 0 {
-		weight = weight
-			.saturating_add(v1::migrate::<T>())
-			.saturating_add(T::DbWeight::get().writes(1));
-		StorageVersion::new(1).put::<Pallet<T>>();
-	}
-
-	weight
-}
-
 mod v0 {
-	use super::*;
+	use crate::scheduler::{self, AssignmentKind};
+	use parity_scale_codec::{Decode, Encode};
 	use primitives::{CoreIndex, GroupIndex, Id as ParaId};
 
 	#[derive(Encode, Decode)]
@@ -58,11 +43,35 @@ mod v0 {
 
 /// V1: Group index is dropped from the core assignment, it's explicitly computed during
 /// candidates processing.
-mod v1 {
+pub mod v1 {
 	use super::*;
+	use crate::scheduler::{self, Config, Pallet, Scheduled};
+	use frame_support::{pallet_prelude::*, traits::OnRuntimeUpgrade, weights::Weight};
 	use sp_std::vec::Vec;
 
-	pub fn migrate<T: Config>() -> Weight {
+	pub struct MigrateToV1<T>(sp_std::marker::PhantomData<T>);
+	impl<T: Config> OnRuntimeUpgrade for MigrateToV1<T> {
+		fn on_runtime_upgrade() -> Weight {
+			let mut weight: Weight = T::DbWeight::get().reads(1);
+
+			if StorageVersion::get::<Pallet<T>>() < STORAGE_VERSION {
+				log::info!(target: scheduler::LOG_TARGET, "Migrating scheduler storage to v1");
+				weight = weight
+					.saturating_add(migrate::<T>())
+					.saturating_add(T::DbWeight::get().writes(1));
+				STORAGE_VERSION.put::<Pallet<T>>();
+			} else {
+				log::info!(
+					target: scheduler::LOG_TARGET,
+					"Scheduler storage up to date - no need for migration"
+				);
+			}
+
+			weight
+		}
+	}
+
+	fn migrate<T: Config>() -> Weight {
 		let _ = Scheduled::<T>::translate(|scheduled: Option<Vec<v0::CoreAssignment>>| {
 			scheduled.map(|scheduled| {
 				scheduled.into_iter().map(|old| scheduler::CoreAssignment::from(old)).collect()

runtime/polkadot/src/lib.rs

@@ -1427,6 +1427,8 @@ pub type Migrations = (
 	// Unreleased - add new migrations here:
 	pallet_nomination_pools::migration::v5::MigrateToV5<Runtime>,
 	parachains_configuration::migration::v5::MigrateToV5<Runtime>,
+	/* Asynchronous backing mirgration */
+	parachains_scheduler::migration::v1::MigrateToV1<Runtime>,
 );
 
 /// Unchecked extrinsic type as expected by this runtime.

runtime/rococo/src/lib.rs

@@ -1495,7 +1495,11 @@ pub type UncheckedExtrinsic =
 ///
 /// This contains the combined migrations of the last 10 releases. It allows to skip runtime
 /// upgrades in case governance decides to do so.
-pub type Migrations = parachains_configuration::migration::v5::MigrateToV5<Runtime>;
+pub type Migrations = (
+	parachains_configuration::migration::v5::MigrateToV5<Runtime>,
+	/* Asynchronous backing mirgration */
+	parachains_scheduler::migration::v1::MigrateToV1<Runtime>,
+);
 
 /// Executive: handles dispatch to the various modules.
 pub type Executive = frame_executive::Executive<

runtime/westend/src/lib.rs

@@ -1224,6 +1224,8 @@ pub type Migrations = (
 	// Unreleased - add new migrations here:
 	pallet_nomination_pools::migration::v5::MigrateToV5<Runtime>,
 	parachains_configuration::migration::v5::MigrateToV5<Runtime>,
+	/* Asynchronous backing mirgration */
+	parachains_scheduler::migration::v1::MigrateToV1<Runtime>,
 );
 
 /// Unchecked extrinsic type as expected by this runtime.