Bound some storage items for pallet staking and clean up deprecated…

… exposures (#7483)

Building from #6445 on top of #7282 

**Changes**

- [x] Bound `Invulnerables`, vector of validators invulnerable to
slashing.
- Add `MaxInvulnerables` to bound `Invulnerables` Vec -> `BoundedVec`.
- Set to constant 20 in the pallet (must be >= 17 for backward
compatibility with runtime `westend`).
- [x] Bound `Disabled Validators`, vector of validators that have
offended in a given era and have been disabled.
- Add `MaxDisabledValidators` to bound `DisabledValidators` Vec ->
`BoundedVec`.
- Set to constant 100 in the pallet (it should be <= 1/3 *
`MaxValidatorsCount` according to the current disabling strategy).
- [x] Remove `ErasStakers` and `ErasStakersClipped` (see #433 ),
non-paged validators exposures.
- They were deprecated in v14 and could have been removed since staking
era 1504 (now it's > 1700).
    - They are already empty on Polkadot and Kusama.
    - Completing the task from #5986.

Migrating pallet `staking` storage to v17 to apply all changes.  

**TO DO** (in a follow-up PR)
- [ ] Bound `ErasStakersPaged`
    - this needs bounding `ExposurePage.others` vector
- [ ] Bound `BondedEras` vector
- [ ] Bound `ClaimedRewards` pages vector
- [ ] Bound `ErasRewardPoints`
    - this needs bounding `EraRewardPoints.individual` BTreeMap 
- [ ] Bound `UnappliedSlashes`
- [ ] Bound `SlashingSpans` 
    - this needs bounding `SlashingSpans.prior` vector

---------

Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: kianenigma <kian@parity.io>

cumulus/parachains/integration-tests/emulated/chains/relays/westend/src/genesis.rs

@@ -19,7 +19,7 @@ use sp_authority_discovery::AuthorityId as AuthorityDiscoveryId;
 use sp_consensus_babe::AuthorityId as BabeId;
 use sp_consensus_beefy::ecdsa_crypto::AuthorityId as BeefyId;
 use sp_core::storage::Storage;
-use sp_runtime::Perbill;
+use sp_runtime::{BoundedVec, Perbill};
 
 // Polkadot
 use polkadot_primitives::{AssignmentId, ValidatorId};
@@ -87,7 +87,13 @@ pub fn genesis() -> Storage {
 				.iter()
 				.map(|x| (x.0.clone(), x.1.clone(), STASH, pallet_staking::StakerStatus::Validator))
 				.collect(),
-			invulnerables: validators::initial_authorities().iter().map(|x| x.0.clone()).collect(),
+			invulnerables: BoundedVec::try_from(
+				validators::initial_authorities()
+					.iter()
+					.map(|x| x.0.clone())
+					.collect::<Vec<_>>(),
+			)
+			.expect("Limit for staking invulnerables must be less than initial authorities."),
 			force_era: pallet_staking::Forcing::ForceNone,
 			slash_reward_fraction: Perbill::from_percent(10),
 			..Default::default()

polkadot/runtime/common/src/try_runtime.rs

@@ -36,7 +36,7 @@ where
 
 	let all_stakers = Ledger::<T>::iter().map(|(ctrl, l)| (ctrl, l.stash)).collect::<BTreeSet<_>>();
 	let mut all_exposed = BTreeSet::new();
-	ErasStakers::<T>::iter().for_each(|(_, val, expo)| {
+	ErasStakersPaged::<T>::iter().for_each(|((_era, val, _page), expo)| {
 		all_exposed.insert(val);
 		all_exposed.extend(expo.others.iter().map(|ie| ie.who.clone()))
 	});

polkadot/runtime/test-runtime/src/lib.rs

@@ -403,6 +403,8 @@ impl pallet_staking::Config for Runtime {
 	type WeightInfo = ();
 	type DisablingStrategy = pallet_staking::UpToLimitWithReEnablingDisablingStrategy;
 	type MaxValidatorSet = MaxAuthorities;
+	type MaxInvulnerables = ConstU32<20>;
+	type MaxDisabledValidators = ConstU32<100>;
 }
 
 parameter_types! {

polkadot/runtime/westend/src/genesis_config_presets.rs

@@ -33,7 +33,7 @@ use sp_consensus_grandpa::AuthorityId as GrandpaId;
 use sp_core::{crypto::get_public_from_string_or_panic, sr25519};
 use sp_genesis_builder::PresetId;
 use sp_keyring::Sr25519Keyring;
-use sp_runtime::Perbill;
+use sp_runtime::{BoundedVec, Perbill};
 use westend_runtime_constants::currency::UNITS as WND;
 
 /// Helper function to generate stash, controller and session key from seed
@@ -202,7 +202,10 @@ fn westend_testnet_genesis(
 				.iter()
 				.map(|x| (x.0.clone(), x.0.clone(), STASH, StakerStatus::<AccountId>::Validator))
 				.collect::<Vec<_>>(),
-			invulnerables: initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>(),
+			invulnerables: BoundedVec::try_from(
+					initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>()
+				)
+				.expect("Too many invulnerable validators: upper limit is MaxInvulnerables from pallet staking config"),
 			force_era: Forcing::NotForcing,
 			slash_reward_fraction: Perbill::from_percent(10),
 		},
@@ -373,7 +376,10 @@ fn westend_staging_testnet_config_genesis() -> serde_json::Value {
 				.iter()
 				.map(|x| (x.0.clone(), x.0.clone(), STASH, StakerStatus::<AccountId>::Validator))
 				.collect::<Vec<_>>(),
-			invulnerables: initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>(),
+			invulnerables: BoundedVec::try_from(
+					initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>()
+				)
+				.expect("Too many invulnerable validators: upper limit is MaxInvulnerables from pallet staking config"),
 			force_era: Forcing::ForceNone,
 			slash_reward_fraction: Perbill::from_percent(10),
 		},

polkadot/runtime/westend/src/lib.rs

@@ -769,6 +769,8 @@ impl pallet_staking::Config for Runtime {
 	type EventListeners = (NominationPools, DelegatedStaking);
 	type WeightInfo = weights::pallet_staking::WeightInfo<Runtime>;
 	type DisablingStrategy = pallet_staking::UpToLimitWithReEnablingDisablingStrategy;
+	type MaxInvulnerables = frame_support::traits::ConstU32<20>;
+	type MaxDisabledValidators = ConstU32<100>;
 }
 
 impl pallet_fast_unstake::Config for Runtime {
@@ -1867,7 +1869,6 @@ pub mod migrations {
 		parachains_shared::migration::MigrateToV1<Runtime>,
 		parachains_scheduler::migration::MigrateV2ToV3<Runtime>,
 		pallet_staking::migrations::v16::MigrateV15ToV16<Runtime>,
-		pallet_staking::migrations::v17::MigrateV16ToV17<Runtime>,
 		// permanent
 		pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>,
 	);

polkadot/runtime/westend/src/weights/pallet_fast_unstake.rs

@@ -108,8 +108,6 @@ impl<T: frame_system::Config> pallet_fast_unstake::WeightInfo for WeightInfo<T>
 	/// Proof Skipped: ElectionProviderMultiPhase CurrentPhase (max_values: Some(1), max_size: None, mode: Measured)
 	/// Storage: Staking CurrentEra (r:1 w:0)
 	/// Proof: Staking CurrentEra (max_values: Some(1), max_size: Some(4), added: 499, mode: MaxEncodedLen)
-	/// Storage: Staking ErasStakers (r:257 w:0)
-	/// Proof Skipped: Staking ErasStakers (max_values: None, max_size: None, mode: Measured)
 	/// The range of component `v` is `[1, 256]`.
 	/// The range of component `b` is `[1, 64]`.
 	fn on_idle_check(v: u32, b: u32, ) -> Weight {

polkadot/runtime/westend/src/weights/pallet_staking.rs

@@ -500,8 +500,6 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	/// Proof: `Staking::Bonded` (`max_values`: None, `max_size`: Some(72), added: 2547, mode: `MaxEncodedLen`)
 	/// Storage: `Staking::Ledger` (r:65 w:65)
 	/// Proof: `Staking::Ledger` (`max_values`: None, `max_size`: Some(1091), added: 3566, mode: `MaxEncodedLen`)
-	/// Storage: `Staking::ErasStakersClipped` (r:1 w:0)
-	/// Proof: `Staking::ErasStakersClipped` (`max_values`: None, `max_size`: None, mode: `Measured`)
 	/// Storage: `Staking::ErasStakersOverview` (r:1 w:0)
 	/// Proof: `Staking::ErasStakersOverview` (`max_values`: None, `max_size`: Some(92), added: 2567, mode: `MaxEncodedLen`)
 	/// Storage: `Staking::ClaimedRewards` (r:1 w:1)

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

@@ -893,6 +893,8 @@ impl pallet_staking::Config for Runtime {
 	type WeightInfo = pallet_staking::weights::SubstrateWeight<Runtime>;
 	type BenchmarkingConfig = StakingBenchmarkingConfig;
 	type DisablingStrategy = pallet_staking::UpToLimitWithReEnablingDisablingStrategy;
+	type MaxInvulnerables = ConstU32<20>;
+	type MaxDisabledValidators = ConstU32<100>;
 }
 
 impl pallet_fast_unstake::Config for Runtime {

substrate/bin/node/testing/src/genesis.rs

@@ -24,7 +24,7 @@ use kitchensink_runtime::{
 	RuntimeGenesisConfig, SessionConfig, SocietyConfig, StakerStatus, StakingConfig,
 };
 use sp_keyring::Ed25519Keyring;
-use sp_runtime::Perbill;
+use sp_runtime::{BoundedVec, Perbill};
 
 /// Create genesis runtime configuration for tests.
 pub fn config() -> RuntimeGenesisConfig {
@@ -65,7 +65,8 @@ pub fn config_endowed(extra_endowed: Vec<AccountId>) -> RuntimeGenesisConfig {
 			validator_count: 3,
 			minimum_validator_count: 0,
 			slash_reward_fraction: Perbill::from_percent(10),
-			invulnerables: vec![alice(), bob(), charlie()],
+			invulnerables: BoundedVec::try_from(vec![alice(), bob(), charlie()])
+				.expect("Too many invulnerable validators: upper limit is MaxInvulnerables from pallet staking config"),
 			..Default::default()
 		},
 		society: SocietyConfig { pot: 0 },

substrate/frame/babe/src/mock.rs

@@ -39,7 +39,7 @@ use sp_runtime::{
 	impl_opaque_keys,
 	testing::{Digest, DigestItem, Header, TestXt},
 	traits::{Header as _, OpaqueKeys},
-	BuildStorage, Perbill,
+	BoundedVec, BuildStorage, Perbill,
 };
 use sp_staking::{EraIndex, SessionIndex};
 
@@ -345,7 +345,7 @@ pub fn new_test_ext_raw_authorities(authorities: Vec<AuthorityId>) -> sp_io::Tes
 		validator_count: 8,
 		force_era: pallet_staking::Forcing::ForceNew,
 		minimum_validator_count: 0,
-		invulnerables: vec![],
+		invulnerables: BoundedVec::new(),
 		..Default::default()
 	};
 

substrate/frame/beefy/src/mock.rs

@@ -36,7 +36,7 @@ use sp_runtime::{
 	impl_opaque_keys,
 	testing::TestXt,
 	traits::{Header as HeaderT, OpaqueKeys},
-	BuildStorage, Perbill,
+	BoundedVec, BuildStorage, Perbill,
 };
 use sp_staking::{EraIndex, SessionIndex};
 use sp_state_machine::BasicExternalities;
@@ -315,7 +315,7 @@ impl ExtBuilder {
 			validator_count: 2,
 			force_era: pallet_staking::Forcing::ForceNew,
 			minimum_validator_count: 0,
-			invulnerables: vec![],
+			invulnerables: BoundedVec::new(),
 			..Default::default()
 		};
 

substrate/frame/delegated-staking/src/mock.rs

@@ -24,7 +24,7 @@ use frame_support::{
 	PalletId,
 };
 
-use sp_runtime::{traits::IdentityLookup, BuildStorage, Perbill};
+use sp_runtime::{traits::IdentityLookup, BoundedVec, BuildStorage, Perbill};
 
 use frame_election_provider_support::{
 	bounds::{ElectionBounds, ElectionBoundsBuilder},
@@ -221,7 +221,7 @@ impl ExtBuilder {
 			// ideal validator count
 			validator_count: 2,
 			minimum_validator_count: 1,
-			invulnerables: vec![],
+			invulnerables: BoundedVec::new(),
 			slash_reward_fraction: Perbill::from_percent(10),
 			min_nominator_bond: ExistentialDeposit::get(),
 			min_validator_bond: ExistentialDeposit::get(),

substrate/frame/grandpa/src/mock.rs

@@ -39,7 +39,7 @@ use sp_runtime::{
 	impl_opaque_keys,
 	testing::{TestXt, UintAuthorityId},
 	traits::OpaqueKeys,
-	BuildStorage, DigestItem, Perbill,
+	BoundedVec, BuildStorage, DigestItem, Perbill,
 };
 use sp_staking::{EraIndex, SessionIndex};
 
@@ -261,7 +261,7 @@ pub fn new_test_ext_raw_authorities(authorities: AuthorityList) -> sp_io::TestEx
 		validator_count: 8,
 		force_era: pallet_staking::Forcing::ForceNew,
 		minimum_validator_count: 0,
-		invulnerables: vec![],
+		invulnerables: BoundedVec::new(),
 		..Default::default()
 	};
 

substrate/frame/root-offences/src/mock.rs

@@ -183,7 +183,7 @@ impl Config for Test {
 pub struct ExtBuilder {
 	validator_count: u32,
 	minimum_validator_count: u32,
-	invulnerables: Vec<AccountId>,
+	invulnerables: BoundedVec<AccountId, <Test as pallet_staking::Config>::MaxInvulnerables>,
 	balance_factor: Balance,
 }
 
@@ -192,7 +192,7 @@ impl Default for ExtBuilder {
 		Self {
 			validator_count: 2,
 			minimum_validator_count: 0,
-			invulnerables: vec![],
+			invulnerables: BoundedVec::new(),
 			balance_factor: 1,
 		}
 	}

substrate/frame/staking/src/benchmarking.rs

@@ -725,7 +725,7 @@ mod benchmarks {
 
 	#[benchmark]
 	// Worst case scenario, the list of invulnerables is very long.
-	fn set_invulnerables(v: Linear<0, { BenchMaxValidators::<T>::get() }>) {
+	fn set_invulnerables(v: Linear<0, { T::MaxInvulnerables::get() }>) {
 		let mut invulnerables = Vec::new();
 		for i in 0..v {
 			invulnerables.push(account("invulnerable", i, SEED));

substrate/frame/staking/src/lib.rs

@@ -1109,44 +1109,12 @@ where
 pub struct EraInfo<T>(core::marker::PhantomData<T>);
 impl<T: Config> EraInfo<T> {
 	/// Returns true if validator has one or more page of era rewards not claimed yet.
-	// Also looks at legacy storage that can be cleaned up after #433.
 	pub fn pending_rewards(era: EraIndex, validator: &T::AccountId) -> bool {
-		let page_count = if let Some(overview) = <ErasStakersOverview<T>>::get(&era, validator) {
-			overview.page_count
-		} else {
-			if <ErasStakers<T>>::contains_key(era, validator) {
-				// this means non paged exposure, and we treat them as single paged.
-				1
-			} else {
-				// if no exposure, then no rewards to claim.
-				return false
-			}
-		};
-
-		// check if era is marked claimed in legacy storage.
-		if <Ledger<T>>::get(validator)
-			.map(|l| l.legacy_claimed_rewards.contains(&era))
-			.unwrap_or_default()
-		{
-			return false
-		}
-
-		ClaimedRewards::<T>::get(era, validator).len() < page_count as usize
-	}
-
-	/// Temporary function which looks at both (1) passed param `T::StakingLedger` for legacy
-	/// non-paged rewards, and (2) `T::ClaimedRewards` for paged rewards. This function can be
-	/// removed once `T::HistoryDepth` eras have passed and none of the older non-paged rewards
-	/// are relevant/claimable.
-	// Refer tracker issue for cleanup: https://github.com/paritytech/polkadot-sdk/issues/433
-	pub(crate) fn is_rewards_claimed_with_legacy_fallback(
-		era: EraIndex,
-		ledger: &StakingLedger<T>,
-		validator: &T::AccountId,
-		page: Page,
-	) -> bool {
-		ledger.legacy_claimed_rewards.binary_search(&era).is_ok() ||
-			Self::is_rewards_claimed(era, validator, page)
+		<ErasStakersOverview<T>>::get(&era, validator)
+			.map(|overview| {
+				ClaimedRewards::<T>::get(era, validator).len() < overview.page_count as usize
+			})
+			.unwrap_or(false)
 	}
 
 	/// Check if the rewards for the given era and page index have been claimed.
@@ -1167,20 +1135,7 @@ impl<T: Config> EraInfo<T> {
 		validator: &T::AccountId,
 		page: Page,
 	) -> Option<PagedExposure<T::AccountId, BalanceOf<T>>> {
-		let overview = <ErasStakersOverview<T>>::get(&era, validator);
-
-		// return clipped exposure if page zero and paged exposure does not exist
-		// exists for backward compatibility and can be removed as part of #13034
-		if overview.is_none() && page == 0 {
-			return Some(PagedExposure::from_clipped(<ErasStakersClipped<T>>::get(era, validator)))
-		}
-
-		// no exposure for this validator
-		if overview.is_none() {
-			return None
-		}
-
-		let overview = overview.expect("checked above; qed");
+		let overview = <ErasStakersOverview<T>>::get(&era, validator)?;
 
 		// validator stake is added only in page zero
 		let validator_stake = if page == 0 { overview.own } else { Zero::zero() };
@@ -1201,13 +1156,9 @@ impl<T: Config> EraInfo<T> {
 		era: EraIndex,
 		validator: &T::AccountId,
 	) -> Exposure<T::AccountId, BalanceOf<T>> {
-		let overview = <ErasStakersOverview<T>>::get(&era, validator);
-
-		if overview.is_none() {
-			return ErasStakers::<T>::get(era, validator)
-		}
-
-		let overview = overview.expect("checked above; qed");
+		let Some(overview) = <ErasStakersOverview<T>>::get(&era, validator) else {
+			return Exposure::default();
+		};
 
 		let mut others = Vec::with_capacity(overview.nominator_count as usize);
 		for page in 0..overview.page_count {
@@ -1238,20 +1189,7 @@ impl<T: Config> EraInfo<T> {
 	}
 
 	/// Returns the next page that can be claimed or `None` if nothing to claim.
-	pub(crate) fn get_next_claimable_page(
-		era: EraIndex,
-		validator: &T::AccountId,
-		ledger: &StakingLedger<T>,
-	) -> Option<Page> {
-		if Self::is_non_paged_exposure(era, validator) {
-			return match ledger.legacy_claimed_rewards.binary_search(&era) {
-				// already claimed
-				Ok(_) => None,
-				// Non-paged exposure is considered as a single page
-				Err(_) => Some(0),
-			}
-		}
-
+	pub(crate) fn get_next_claimable_page(era: EraIndex, validator: &T::AccountId) -> Option<Page> {
 		// Find next claimable page of paged exposure.
 		let page_count = Self::get_page_count(era, validator);
 		let all_claimable_pages: Vec<Page> = (0..page_count).collect();
@@ -1260,11 +1198,6 @@ impl<T: Config> EraInfo<T> {
 		all_claimable_pages.into_iter().find(|p| !claimed_pages.contains(p))
 	}
 
-	/// Checks if exposure is paged or not.
-	fn is_non_paged_exposure(era: EraIndex, validator: &T::AccountId) -> bool {
-		<ErasStakersClipped<T>>::contains_key(&era, validator)
-	}
-
 	/// Returns validator commission for this era and page.
 	pub(crate) fn get_validator_commission(
 		era: EraIndex,