Migrate Currency trait to Fungible in Multisig pallet

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs

@@ -449,11 +449,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = MaxSignatories;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs

@@ -403,11 +403,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = MaxSignatories;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs

@@ -483,11 +483,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs

@@ -448,11 +448,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs

@@ -240,11 +240,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/contracts/contracts-rococo/src/lib.rs

@@ -247,11 +247,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = pallet_multisig::weights::SubstrateWeight<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs

@@ -414,11 +414,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs

@@ -402,11 +402,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/people/people-rococo/src/lib.rs

@@ -380,11 +380,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

cumulus/parachains/runtimes/people/people-westend/src/lib.rs

@@ -380,11 +380,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 impl pallet_utility::Config for Runtime {

polkadot/runtime/rococo/src/lib.rs

@@ -692,11 +692,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = MaxSignatories;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 parameter_types! {

polkadot/runtime/westend/src/lib.rs

@@ -905,11 +905,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = MaxSignatories;
 	type WeightInfo = weights::pallet_multisig::WeightInfo<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 parameter_types! {

substrate/bin/node/runtime/src/lib.rs

@@ -335,11 +335,12 @@ parameter_types! {
 impl pallet_multisig::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = DepositBase;
 	type DepositFactor = DepositFactor;
 	type MaxSignatories = ConstU32<100>;
 	type WeightInfo = pallet_multisig::weights::SubstrateWeight<Runtime>;
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 parameter_types! {

substrate/frame/multisig/src/benchmarking.rs

@@ -23,6 +23,7 @@ use super::*;
 use frame_benchmarking::v1::{account, benchmarks};
 use frame_system::RawOrigin;
 use sp_runtime::traits::Bounded;
+use frame_support::traits::fungible::Unbalanced;
 
 use crate::Pallet as Multisig;
 
@@ -37,7 +38,7 @@ fn setup_multi<T: Config>(
 		let signatory = account("signatory", i, SEED);
 		// Give them some balance for a possible deposit
 		let balance = BalanceOf::<T>::max_value();
-		T::Currency::make_free_balance_be(&signatory, balance);
+		let _ = T::NativeBalance::write_balance(&signatory, balance);
 		signatories.push(signatory);
 	}
 	signatories.sort();

substrate/frame/multisig/src/lib.rs

@@ -55,15 +55,19 @@ use frame_support::{
 		PostDispatchInfo,
 	},
 	ensure,
-	traits::{Currency, Get, ReservableCurrency},
+	traits::{
+		fungible::{Inspect, MutateHold},
+		tokens::Precision::BestEffort,
+		Get,
+	},
 	weights::Weight,
 	BoundedVec,
 };
 use frame_system::{self as system, pallet_prelude::BlockNumberFor, RawOrigin};
 use scale_info::TypeInfo;
 use sp_io::hashing::blake2_256;
 use sp_runtime::{
-	traits::{Dispatchable, TrailingZeroInput, Zero},
+	traits::{Dispatchable, TrailingZeroInput},
 	DispatchError, RuntimeDebug,
 };
 use sp_std::prelude::*;
@@ -85,8 +89,8 @@ macro_rules! log {
 	};
 }
 
-type BalanceOf<T> =
-	<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;
+pub type BalanceOf<T> =
+	<<T as Config>::NativeBalance as Inspect<<T as frame_system::Config>::AccountId>>::Balance;
 
 /// A global extrinsic index, formed as the extrinsic index within a block, together with that
 /// block's height. This allows a transaction in which a multisig operation of a particular
@@ -142,8 +146,9 @@ pub mod pallet {
 			+ GetDispatchInfo
 			+ From<frame_system::Call<Self>>;
 
-		/// The currency mechanism.
-		type Currency: ReservableCurrency<Self::AccountId>;
+		/// The fungible in which multisig balances are held.
+		type NativeBalance: Inspect<Self::AccountId>
+			+ MutateHold<Self::AccountId, Reason = Self::RuntimeHoldReason>;
 
 		/// The base amount of currency needed to reserve for creating a multisig execution or to
 		/// store a dispatch call for later.
@@ -166,6 +171,9 @@ pub mod pallet {
 
 		/// Weight information for extrinsics in this pallet.
 		type WeightInfo: WeightInfo;
+
+		/// The hold reason when holding funds for starting a multisig operation.
+		type RuntimeHoldReason: From<HoldReason>;
 	}
 
 	/// The current storage version.
@@ -247,6 +255,13 @@ pub mod pallet {
 		},
 	}
 
+	/// A reason for this pallet placing a hold on funds.
+	#[pallet::composite_enum]
+	pub enum HoldReason {
+		/// The funds are held as deposit for the multisig
+		MultisigHold,
+	}
+
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
 
@@ -481,8 +496,12 @@ pub mod pallet {
 			ensure!(m.when == timepoint, Error::<T>::WrongTimepoint);
 			ensure!(m.depositor == who, Error::<T>::NotOwner);
 
-			let err_amount = T::Currency::unreserve(&m.depositor, m.deposit);
-			debug_assert!(err_amount.is_zero());
+			T::NativeBalance::release(
+				&HoldReason::MultisigHold.into(),
+				&m.depositor,
+				m.deposit,
+				BestEffort,
+			)?;
 			<Multisigs<T>>::remove(&id, &call_hash);
 
 			Self::deposit_event(Event::MultisigCancelled {
@@ -559,7 +578,12 @@ impl<T: Config> Pallet<T> {
 				// Clean up storage before executing call to avoid an possibility of reentrancy
 				// attack.
 				<Multisigs<T>>::remove(&id, call_hash);
-				T::Currency::unreserve(&m.depositor, m.deposit);
+				T::NativeBalance::release(
+					&HoldReason::MultisigHold.into(),
+					&m.depositor,
+					m.deposit,
+					BestEffort,
+				)?;
 
 				let result = call.dispatch(RawOrigin::Signed(id.clone()).into());
 				Self::deposit_event(Event::MultisigExecuted {
@@ -612,7 +636,7 @@ impl<T: Config> Pallet<T> {
 			// Just start the operation by recording it in storage.
 			let deposit = T::DepositBase::get() + T::DepositFactor::get() * threshold.into();
 
-			T::Currency::reserve(&who, deposit)?;
+			T::NativeBalance::hold(&HoldReason::MultisigHold.into(), &who, deposit)?;
 
 			let initial_approvals =
 				vec![who.clone()].try_into().map_err(|_| Error::<T>::TooManySignatories)?;

substrate/frame/multisig/src/migrations.rs

@@ -56,12 +56,17 @@ pub mod v1 {
 
 			if onchain > 0 {
 				log!(info, "MigrateToV1 should be removed");
-				return T::DbWeight::get().reads(1)
+				return T::DbWeight::get().reads(1);
 			}
 
 			let mut call_count = 0u64;
 			Calls::<T>::drain().for_each(|(_call_hash, (_data, caller, deposit))| {
-				T::Currency::unreserve(&caller, deposit);
+				let _ = T::NativeBalance::release(
+					&HoldReason::MultisigHold.into(),
+					&caller,
+					deposit,
+					BestEffort,
+				);
 				call_count.saturating_inc();
 			});
 

substrate/frame/multisig/src/tests.rs

@@ -67,11 +67,12 @@ impl Contains<RuntimeCall> for TestBaseCallFilter {
 impl Config for Test {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
-	type Currency = Balances;
+	type NativeBalance = Balances;
 	type DepositBase = ConstU64<1>;
 	type DepositFactor = ConstU64<1>;
 	type MaxSignatories = ConstU32<3>;
 	type WeightInfo = ();
+	type RuntimeHoldReason = RuntimeHoldReason;
 }
 
 use pallet_balances::Call as BalancesCall;