Store validator self-vote in bags-list, and allow them to be trimmed for election

frame/babe/src/mock.rs

@@ -197,7 +197,7 @@ impl pallet_staking::Config for Test {
 	type NextNewSession = Session;
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
 	type GenesisElectionProvider = Self::ElectionProvider;
-	type SortedListProvider = pallet_staking::UseNominatorsMap<Self>;
+	type SortedListProvider = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

frame/grandpa/src/mock.rs

@@ -205,7 +205,7 @@ impl pallet_staking::Config for Test {
 	type NextNewSession = Session;
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
 	type GenesisElectionProvider = Self::ElectionProvider;
-	type SortedListProvider = pallet_staking::UseNominatorsMap<Self>;
+	type SortedListProvider = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

frame/offences/benchmarking/src/mock.rs

@@ -175,7 +175,7 @@ impl pallet_staking::Config for Test {
 	type OffendingValidatorsThreshold = ();
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
 	type GenesisElectionProvider = Self::ElectionProvider;
-	type SortedListProvider = pallet_staking::UseNominatorsMap<Self>;
+	type SortedListProvider = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

frame/session/benchmarking/src/mock.rs

@@ -181,7 +181,7 @@ impl pallet_staking::Config for Test {
 	type OffendingValidatorsThreshold = ();
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
 	type GenesisElectionProvider = Self::ElectionProvider;
-	type SortedListProvider = pallet_staking::UseNominatorsMap<Self>;
+	type SortedListProvider = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

frame/staking/src/benchmarking.rs

@@ -332,24 +332,20 @@ benchmarks! {
 	}
 
 	validate {
-		// clean up any existing state.
-		clear_validators_and_nominators::<T>();
-
-		let origin_weight = MinNominatorBond::<T>::get().max(T::Currency::minimum_balance());
-
-		// setup a worst case scenario where the user calling validate was formerly a nominator so
-		// they must be removed from the list.
-		let scenario = ListScenario::<T>::new(origin_weight, true)?;
-		let controller = scenario.origin_controller1.clone();
-		let stash = scenario.origin_stash1.clone();
-		assert!(T::SortedListProvider::contains(&stash));
+		let (stash, controller) = create_stash_controller::<T>(
+			T::MaxNominations::get() - 1,
+			100,
+			Default::default(),
+		)?;
+		// because it is chilled.
+		assert!(!T::SortedListProvider::contains(&stash));
 
 		let prefs = ValidatorPrefs::default();
 		whitelist_account!(controller);
 	}: _(RawOrigin::Signed(controller), prefs)
 	verify {
 		assert!(Validators::<T>::contains_key(&stash));
-		assert!(!T::SortedListProvider::contains(&stash));
+		assert!(T::SortedListProvider::contains(&stash));
 	}
 
 	kick {

frame/staking/src/lib.rs

@@ -301,7 +301,7 @@ mod pallet;
 
 use codec::{Decode, Encode, HasCompact};
 use frame_support::{
-	traits::{ConstU32, Currency, Get},
+	traits::{Currency, Get},
 	weights::Weight,
 	BoundedVec, EqNoBound, PartialEqNoBound, RuntimeDebugNoBound,
 };
@@ -771,6 +771,7 @@ enum Releases {
 	V6_0_0, // removal of all storage associated with offchain phragmen.
 	V7_0_0, // keep track of number of nominators / validators in map
 	V8_0_0, // populate `SortedListProvider`.
+	V9_0_0, // inject validators into `SortedListProvider` as well.
 }
 
 impl Default for Releases {
@@ -851,6 +852,6 @@ pub struct TestBenchmarkingConfig;
 
 #[cfg(feature = "std")]
 impl BenchmarkingConfig for TestBenchmarkingConfig {
-	type MaxValidators = ConstU32<100>;
-	type MaxNominators = ConstU32<100>;
+	type MaxValidators = frame_support::traits::ConstU32<100>;
+	type MaxNominators = frame_support::traits::ConstU32<100>;
 }

frame/staking/src/migrations.rs

@@ -17,6 +17,53 @@
 //! Storage migrations for the Staking pallet.
 
 use super::*;
+use frame_election_provider_support::{SortedListProvider, VoteWeightProvider};
+use frame_support::traits::OnRuntimeUpgrade;
+
+/// Migration implementation that injects all validators into sorted list.
+///
+/// This is only useful for chains that started their `SortedListProvider` just based on nominators.
+pub struct InjectValidatorsIntoSortedListProvider<T>(sp_std::marker::PhantomData<T>);
+impl<T: Config> OnRuntimeUpgrade for InjectValidatorsIntoSortedListProvider<T> {
+	fn on_runtime_upgrade() -> Weight {
+		if StorageVersion::<T>::get() == Releases::V8_0_0 {
+			for (v, _) in Validators::<T>::iter() {
+				let weight = Pallet::<T>::vote_weight(&v);
+				let _ = T::SortedListProvider::on_insert(v.clone(), weight).map_err(|err| {
+					log!(warn, "failed to insert {:?} into SortedListProvider: {:?}", v, err)
+				});
+			}
+
+			T::BlockWeights::get().max_block
+		} else {
+			log!(warn, "InjectValidatorsIntoSortedListProvider being executed on the wrong storage version, expected Releases::V8_0_0");
+			T::DbWeight::get().reads(1)
+		}
+	}
+
+	#[cfg(feature = "try-runtime")]
+	fn pre_upgrade() -> Result<(), &'static str> {
+		use frame_support::traits::OnRuntimeUpgradeHelpersExt;
+		frame_support::ensure!(
+			StorageVersion::<T>::get() == crate::Releases::V8_0_0,
+			"must upgrade linearly"
+		);
+
+		let prev_count = T::SortedListProvider::count();
+		Self::set_temp_storage(prev_count, "prev");
+		Ok(())
+	}
+
+	#[cfg(feature = "try-runtime")]
+	fn post_upgrade() -> Result<(), &'static str> {
+		use frame_support::traits::OnRuntimeUpgradeHelpersExt;
+		let post_count = T::SortedListProvider::count();
+		let prev_count = Self::get_temp_storage::<u32>("prev").unwrap();
+		let validators = Validators::<T>::count();
+		assert!(post_count == prev_count + validators);
+		Ok(())
+	}
+}
 
 pub mod v8 {
 	use frame_election_provider_support::SortedListProvider;

frame/staking/src/mock.rs

@@ -269,7 +269,7 @@ impl crate::pallet::pallet::Config for Test {
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
 	type GenesisElectionProvider = Self::ElectionProvider;
-	// NOTE: consider a macro and use `UseNominatorsMap<Self>` as well.
+	// NOTE: consider a macro and use `UseNominatorsAndValidatorsMap<Self>` as well.
 	type SortedListProvider = BagsList;
 	type BenchmarkingConfig = TestBenchmarkingConfig;
 	type WeightInfo = ();
@@ -541,7 +541,7 @@ fn check_count() {
 
 	// the voters that the `SortedListProvider` list is storing for us.
 	let external_voters = <Test as Config>::SortedListProvider::count();
-	assert_eq!(external_voters, nominator_count);
+	assert_eq!(external_voters, nominator_count + validator_count);
 }
 
 fn check_ledgers() {