Allow StakingAdmin to set min_commission

bin/node/runtime/src/lib.rs

@@ -567,7 +567,7 @@ impl pallet_staking::Config for Runtime {
 	type BondingDuration = BondingDuration;
 	type SlashDeferDuration = SlashDeferDuration;
 	/// A super-majority of the council can cancel the slash.
-	type SlashCancelOrigin = EitherOfDiverse<
+	type AdminOrigin = EitherOfDiverse<
 		EnsureRoot<AccountId>,
 		pallet_collective::EnsureProportionAtLeast<AccountId, CouncilCollective, 3, 4>,
 	>;

frame/babe/src/mock.rs

@@ -195,7 +195,7 @@ impl pallet_staking::Config for Test {
 	type SessionsPerEra = SessionsPerEra;
 	type BondingDuration = BondingDuration;
 	type SlashDeferDuration = SlashDeferDuration;
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type SessionInterface = Self;
 	type UnixTime = pallet_timestamp::Pallet<Test>;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/fast-unstake/src/mock.rs

@@ -140,7 +140,7 @@ impl pallet_staking::Config for Runtime {
 	type Reward = ();
 	type SessionsPerEra = ();
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = BondingDuration;
 	type SessionInterface = ();
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/grandpa/src/mock.rs

@@ -199,7 +199,7 @@ impl pallet_staking::Config for Test {
 	type SessionsPerEra = SessionsPerEra;
 	type BondingDuration = BondingDuration;
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type SessionInterface = Self;
 	type UnixTime = pallet_timestamp::Pallet<Test>;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/nomination-pools/benchmarking/src/mock.rs

@@ -102,7 +102,7 @@ impl pallet_staking::Config for Runtime {
 	type Reward = ();
 	type SessionsPerEra = ();
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = ConstU32<3>;
 	type SessionInterface = ();
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/nomination-pools/test-staking/src/mock.rs

@@ -116,7 +116,7 @@ impl pallet_staking::Config for Runtime {
 	type Reward = ();
 	type SessionsPerEra = ();
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = BondingDuration;
 	type SessionInterface = ();
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/offences/benchmarking/src/mock.rs

@@ -173,7 +173,7 @@ impl pallet_staking::Config for Test {
 	type Reward = ();
 	type SessionsPerEra = ();
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = ();
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/root-offences/src/mock.rs

@@ -184,7 +184,7 @@ impl pallet_staking::Config for Test {
 	type Reward = ();
 	type SessionsPerEra = SessionsPerEra;
 	type SlashDeferDuration = SlashDeferDuration;
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = BondingDuration;
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/session/benchmarking/src/mock.rs

@@ -167,7 +167,7 @@ impl pallet_staking::Config for Test {
 	type Reward = ();
 	type SessionsPerEra = ();
 	type SlashDeferDuration = ();
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type BondingDuration = ();
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;

frame/staking/src/benchmarking.rs

@@ -922,6 +922,13 @@ benchmarks! {
 		);
 	}
 
+	set_min_commission {
+		let min_commission = Perbill::max_value();
+	}: _(RawOrigin::Root, min_commission)
+	verify {
+		assert_eq!(MinCommission::<T>::get(), Perbill::from_percent(100));
+	}
+
 	impl_benchmark_test_suite!(
 		Staking,
 		crate::mock::ExtBuilder::default().has_stakers(true),

frame/staking/src/mock.rs

@@ -20,13 +20,14 @@
 use crate::{self as pallet_staking, *};
 use frame_election_provider_support::{onchain, SequentialPhragmen, VoteWeight};
 use frame_support::{
-	assert_ok, parameter_types,
+	assert_ok, ord_parameter_types, parameter_types,
 	traits::{
-		ConstU32, ConstU64, Currency, FindAuthor, GenesisBuild, Get, Hooks, Imbalance,
-		OnUnbalanced, OneSessionHandler,
+		ConstU32, ConstU64, Currency, EitherOfDiverse, FindAuthor, GenesisBuild, Get, Hooks,
+		Imbalance, OnUnbalanced, OneSessionHandler,
 	},
 	weights::constants::RocksDbWeight,
 };
+use frame_system::{EnsureRoot, EnsureSignedBy};
 use sp_core::H256;
 use sp_io;
 use sp_runtime::{
@@ -292,7 +293,7 @@ impl crate::pallet::pallet::Config for Test {
 	type Reward = MockReward;
 	type SessionsPerEra = SessionsPerEra;
 	type SlashDeferDuration = SlashDeferDuration;
-	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type AdminOrigin = EnsureOneOrRoot;
 	type BondingDuration = BondingDuration;
 	type SessionInterface = Self;
 	type EraPayout = ConvertCurve<RewardCurve>;
@@ -797,6 +798,11 @@ pub(crate) fn staking_events() -> Vec<crate::Event<Test>> {
 parameter_types! {
 	static StakingEventsIndex: usize = 0;
 }
+ord_parameter_types! {
+	pub const One: u64 = 1;
+}
+
+type EnsureOneOrRoot = EitherOfDiverse<EnsureRoot<AccountId>, EnsureSignedBy<One, AccountId>>;
 
 pub(crate) fn staking_events_since_last_call() -> Vec<crate::Event<Test>> {
 	let all: Vec<_> = System::events()

frame/staking/src/pallet/mod.rs

@@ -183,8 +183,10 @@ pub mod pallet {
 		#[pallet::constant]
 		type SlashDeferDuration: Get<EraIndex>;
 
-		/// The origin which can cancel a deferred slash. Root can always do this.
-		type SlashCancelOrigin: EnsureOrigin<Self::RuntimeOrigin>;
+		/// The origin which can manage less critical staking parameters that does not require root.
+		///
+		/// Supported actions: (1) cancel deferred slash, (2) set minimum commission.
+		type AdminOrigin: EnsureOrigin<Self::RuntimeOrigin>;
 
 		/// Interface for interacting with a session pallet.
 		type SessionInterface: SessionInterface<Self::AccountId>;
@@ -1452,7 +1454,7 @@ pub mod pallet {
 
 		/// Cancel enactment of a deferred slash.
 		///
-		/// Can be called by the `T::SlashCancelOrigin`.
+		/// Can be called by the `T::AdminOrigin`.
 		///
 		/// Parameters: era and indices of the slashes for that era to kill.
 		#[pallet::call_index(17)]
@@ -1462,7 +1464,7 @@ pub mod pallet {
 			era: EraIndex,
 			slash_indices: Vec<u32>,
 		) -> DispatchResult {
-			T::SlashCancelOrigin::ensure_origin(origin)?;
+			T::AdminOrigin::ensure_origin(origin)?;
 
 			ensure!(!slash_indices.is_empty(), Error::<T>::EmptyTargets);
 			ensure!(is_sorted_and_unique(&slash_indices), Error::<T>::NotSortedAndUnique);
@@ -1683,7 +1685,6 @@ pub mod pallet {
 			config_op_exp!(MinCommission<T>, min_commission);
 			Ok(())
 		}
-
 		/// Declare a `controller` to stop participating as either a validator or nominator.
 		///
 		/// Effects will be felt at the beginning of the next era.
@@ -1792,6 +1793,20 @@ pub mod pallet {
 			})?;
 			Ok(())
 		}
+
+		/// Sets the minimum amount of commission that each validators must maintain.
+		///
+		/// This call has lower privilege requirements than `set_staking_config` and can be called
+		/// by the `T::AdminOrigin`. Root can always call this.
+		///
+		/// Weight: `O(1)`
+		#[pallet::call_index(25)]
+		#[pallet::weight(T::WeightInfo::set_min_commission())]
+		pub fn set_min_commission(origin: OriginFor<T>, new: Perbill) -> DispatchResult {
+			T::AdminOrigin::ensure_origin(origin)?;
+			MinCommission::<T>::put(new);
+			Ok(())
+		}
 	}
 }
 

frame/staking/src/tests.rs

@@ -5726,6 +5726,46 @@ fn scale_validator_count_errors() {
 	})
 }
 
+#[test]
+fn set_min_commission_works_with_admin_origin() {
+	ExtBuilder::default().build_and_execute(|| {
+		// no minimum commission set initially
+		assert_eq!(MinCommission::<Test>::get(), Perbill::from_percent(0));
+
+		// root can set min commission
+		assert_ok!(Staking::set_min_commission(RuntimeOrigin::root(), Perbill::from_percent(10),));
+
+		assert_eq!(MinCommission::<Test>::get(), Perbill::from_percent(10));
+
+		// Non privileged origin can not set min_commission
+		assert_noop!(
+			Staking::set_min_commission(RuntimeOrigin::signed(2), Perbill::from_percent(15)),
+			BadOrigin
+		);
+
+		// Admin Origin can set min commission
+		assert_ok!(Staking::set_min_commission(
+			RuntimeOrigin::signed(1),
+			Perbill::from_percent(15),
+		));
+
+		// setting commission below min_commission fails
+		assert_noop!(
+			Staking::validate(
+				RuntimeOrigin::signed(10),
+				ValidatorPrefs { commission: Perbill::from_percent(14), blocked: false }
+			),
+			Error::<Test>::CommissionTooLow
+		);
+
+		// setting commission >= min_commission works
+		assert_ok!(Staking::validate(
+			RuntimeOrigin::signed(10),
+			ValidatorPrefs { commission: Perbill::from_percent(15), blocked: false }
+		));
+	})
+}
+
 mod staking_interface {
 	use frame_support::storage::with_storage_layer;
 	use sp_staking::StakingInterface;