Improve inactive fund tracking (paritytech#13009)

* Improve inactive fund tracking

* Resetting migration

* Fix

* Update frame/balances/src/migration.rs

bin/node/executor/tests/basic.rs

@@ -30,7 +30,7 @@ use sp_runtime::{
 use kitchensink_runtime::{
 	constants::{currency::*, time::SLOT_DURATION},
 	Balances, CheckedExtrinsic, Header, Runtime, RuntimeCall, RuntimeEvent, System,
-	TransactionPayment, UncheckedExtrinsic,
+	TransactionPayment, Treasury, UncheckedExtrinsic,
 };
 use node_primitives::{Balance, Hash};
 use node_testing::keyring::*;
@@ -398,6 +398,7 @@ fn full_native_block_import_works() {
 	});
 
 	fees = t.execute_with(|| transfer_fee(&xt()));
+	let pot = t.execute_with(|| Treasury::pot());
 
 	executor_call(&mut t, "Core_execute_block", &block2.0, true).0.unwrap();
 
@@ -408,6 +409,14 @@ fn full_native_block_import_works() {
 		);
 		assert_eq!(Balances::total_balance(&bob()), 179 * DOLLARS - fees);
 		let events = vec![
+			EventRecord {
+				phase: Phase::Initialization,
+				event: RuntimeEvent::Treasury(pallet_treasury::Event::UpdatedInactive {
+					reactivated: 0,
+					deactivated: pot,
+				}),
+				topics: vec![],
+			},
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(0),
 				event: RuntimeEvent::System(frame_system::Event::ExtrinsicSuccess {

frame/balances/src/migration.rs

@@ -69,3 +69,29 @@ impl<T: Config<I>, A: Get<Vec<T::AccountId>>, I: 'static> OnRuntimeUpgrade
 		migrate_v0_to_v1::<T, I>(&A::get())
 	}
 }
+
+pub struct ResetInactive<T, I = ()>(PhantomData<(T, I)>);
+impl<T: Config<I>, I: 'static> OnRuntimeUpgrade for ResetInactive<T, I> {
+	fn on_runtime_upgrade() -> Weight {
+		let onchain_version = Pallet::<T, I>::on_chain_storage_version();
+
+		if onchain_version == 1 {
+			// Remove the old `StorageVersion` type.
+			frame_support::storage::unhashed::kill(&frame_support::storage::storage_prefix(
+				Pallet::<T, I>::name().as_bytes(),
+				"StorageVersion".as_bytes(),
+			));
+
+			InactiveIssuance::<T, I>::kill();
+
+			// Set storage version to `0`.
+			StorageVersion::new(0).put::<Pallet<T, I>>();
+
+			log::info!(target: "runtime::balances", "Storage to version 0");
+			T::DbWeight::get().reads_writes(1, 2)
+		} else {
+			log::info!(target: "runtime::balances",  "Migration did not execute. This probably should be removed");
+			T::DbWeight::get().reads(1)
+		}
+	}
+}

frame/treasury/src/lib.rs

@@ -225,7 +225,8 @@ pub mod pallet {
 
 	/// The amount which has been reported as inactive to Currency.
 	#[pallet::storage]
-	pub type Inactive<T: Config<I>, I: 'static = ()> = StorageValue<_, BalanceOf<T, I>, ValueQuery>;
+	pub type Deactivated<T: Config<I>, I: 'static = ()> =
+		StorageValue<_, BalanceOf<T, I>, ValueQuery>;
 
 	/// Proposal indices that have been approved but not yet awarded.
 	#[pallet::storage]
@@ -292,6 +293,8 @@ pub mod pallet {
 			amount: BalanceOf<T, I>,
 			beneficiary: T::AccountId,
 		},
+		/// The inactive funds of the pallet have been updated.
+		UpdatedInactive { reactivated: BalanceOf<T, I>, deactivated: BalanceOf<T, I> },
 	}
 
 	/// Error for the treasury pallet.
@@ -321,13 +324,15 @@ pub mod pallet {
 		/// # </weight>
 		fn on_initialize(n: T::BlockNumber) -> Weight {
 			let pot = Self::pot();
-			let deactivated = Inactive::<T, I>::get();
+			let deactivated = Deactivated::<T, I>::get();
 			if pot != deactivated {
-				match (pot > deactivated, pot.max(deactivated) - pot.min(deactivated)) {
-					(true, delta) => T::Currency::deactivate(delta),
-					(false, delta) => T::Currency::reactivate(delta),
-				}
-				Inactive::<T, I>::put(&pot);
+				T::Currency::reactivate(deactivated);
+				T::Currency::deactivate(pot);
+				Deactivated::<T, I>::put(&pot);
+				Self::deposit_event(Event::<T, I>::UpdatedInactive {
+					reactivated: deactivated,
+					deactivated: pot,
+				});
 			}
 
 			// Check to see if we should spend some funds!