Add Force Unreserve to Balances (#9764)

* force unreserve

* add benchmark

* cargo run --quiet --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_balances --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/balances/src/weights.rs --template=./.maintain/frame-weight-template.hbs

Co-authored-by: Parity Bot <admin@parity.io>

substrate/frame/balances/src/benchmarking.rs

@@ -195,6 +195,26 @@ benchmarks_instance_pallet! {
 		assert!(Balances::<T, I>::free_balance(&caller).is_zero());
 		assert_eq!(Balances::<T, I>::free_balance(&recipient), balance);
 	}
+
+	force_unreserve {
+		let user: T::AccountId = account("user", 0, SEED);
+		let user_lookup: <T::Lookup as StaticLookup>::Source = T::Lookup::unlookup(user.clone());
+
+		// Give some multiple of the existential deposit
+		let existential_deposit = T::ExistentialDeposit::get();
+		let balance = existential_deposit.saturating_mul(ED_MULTIPLIER.into());
+		let _ = <Balances<T, I> as Currency<_>>::make_free_balance_be(&user, balance);
+
+		// Reserve the balance
+		<Balances<T, I> as ReservableCurrency<_>>::reserve(&user, balance)?;
+		assert_eq!(Balances::<T, I>::reserved_balance(&user), balance);
+		assert!(Balances::<T, I>::free_balance(&user).is_zero());
+
+	}: _(RawOrigin::Root, user_lookup, balance)
+	verify {
+		assert!(Balances::<T, I>::reserved_balance(&user).is_zero());
+		assert_eq!(Balances::<T, I>::free_balance(&user), balance);
+	}
 }
 
 impl_benchmark_test_suite!(

substrate/frame/balances/src/lib.rs

@@ -167,6 +167,7 @@ use codec::{Codec, Decode, Encode, MaxEncodedLen};
 use frame_support::traits::GenesisBuild;
 use frame_support::{
 	ensure,
+	pallet_prelude::DispatchResult,
 	traits::{
 		tokens::{fungible, BalanceStatus as Status, DepositConsequence, WithdrawConsequence},
 		Currency, ExistenceRequirement,
@@ -183,7 +184,7 @@ use sp_runtime::{
 		AtLeast32BitUnsigned, Bounded, CheckedAdd, CheckedSub, MaybeSerializeDeserialize,
 		Saturating, StaticLookup, Zero,
 	},
-	ArithmeticError, DispatchError, DispatchResult, RuntimeDebug,
+	ArithmeticError, DispatchError, RuntimeDebug,
 };
 use sp_std::{cmp, fmt::Debug, mem, ops::BitOr, prelude::*, result};
 pub use weights::WeightInfo;
@@ -419,7 +420,7 @@ pub mod pallet {
 			origin: OriginFor<T>,
 			dest: <T::Lookup as StaticLookup>::Source,
 			keep_alive: bool,
-		) -> DispatchResultWithPostInfo {
+		) -> DispatchResult {
 			use fungible::Inspect;
 			let transactor = ensure_signed(origin)?;
 			let reducible_balance = Self::reducible_balance(&transactor, keep_alive);
@@ -431,7 +432,22 @@ pub mod pallet {
 				reducible_balance,
 				keep_alive.into(),
 			)?;
-			Ok(().into())
+			Ok(())
+		}
+
+		/// Unreserve some balance from a user by force.
+		///
+		/// Can only be called by ROOT.
+		#[pallet::weight(T::WeightInfo::force_unreserve())]
+		pub fn force_unreserve(
+			origin: OriginFor<T>,
+			who: <T::Lookup as StaticLookup>::Source,
+			amount: T::Balance,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+			let who = T::Lookup::lookup(who)?;
+			let _leftover = <Self as ReservableCurrency<_>>::unreserve(&who, amount);
+			Ok(())
 		}
 	}
 

substrate/frame/balances/src/weights.rs

@@ -18,7 +18,7 @@
 //! Autogenerated weights for pallet_balances
 //!
 //! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
-//! DATE: 2021-08-07, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! DATE: 2021-09-13, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
 //! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("dev"), DB CACHE: 128
 
 // Executed Command:
@@ -51,6 +51,7 @@ pub trait WeightInfo {
 	fn set_balance_killing() -> Weight;
 	fn force_transfer() -> Weight;
 	fn transfer_all() -> Weight;
+	fn force_unreserve() -> Weight;
 }
 
 /// Weights for pallet_balances using the Substrate node and recommended hardware.
@@ -58,37 +59,43 @@ pub struct SubstrateWeight<T>(PhantomData<T>);
 impl<T: frame_system::Config> WeightInfo for SubstrateWeight<T> {
 	// Storage: System Account (r:1 w:1)
 	fn transfer() -> Weight {
-		(72_229_000 as Weight)
+		(70_952_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn transfer_keep_alive() -> Weight {
-		(55_013_000 as Weight)
+		(54_410_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn set_balance_creating() -> Weight {
-		(29_404_000 as Weight)
+		(29_176_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn set_balance_killing() -> Weight {
-		(36_311_000 as Weight)
+		(35_214_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:2 w:2)
 	fn force_transfer() -> Weight {
-		(73_125_000 as Weight)
+		(71_780_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(2 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn transfer_all() -> Weight {
-		(67_749_000 as Weight)
+		(66_475_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(1 as Weight))
+			.saturating_add(T::DbWeight::get().writes(1 as Weight))
+	}
+	// Storage: System Account (r:1 w:1)
+	fn force_unreserve() -> Weight {
+		(27_766_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
@@ -98,37 +105,43 @@ impl<T: frame_system::Config> WeightInfo for SubstrateWeight<T> {
 impl WeightInfo for () {
 	// Storage: System Account (r:1 w:1)
 	fn transfer() -> Weight {
-		(72_229_000 as Weight)
+		(70_952_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn transfer_keep_alive() -> Weight {
-		(55_013_000 as Weight)
+		(54_410_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn set_balance_creating() -> Weight {
-		(29_404_000 as Weight)
+		(29_176_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn set_balance_killing() -> Weight {
-		(36_311_000 as Weight)
+		(35_214_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}
 	// Storage: System Account (r:2 w:2)
 	fn force_transfer() -> Weight {
-		(73_125_000 as Weight)
+		(71_780_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(2 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(2 as Weight))
 	}
 	// Storage: System Account (r:1 w:1)
 	fn transfer_all() -> Weight {
-		(67_749_000 as Weight)
+		(66_475_000 as Weight)
+			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
+			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
+	}
+	// Storage: System Account (r:1 w:1)
+	fn force_unreserve() -> Weight {
+		(27_766_000 as Weight)
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}