diff --git a/substrate/bin/node-template/runtime/src/lib.rs b/substrate/bin/node-template/runtime/src/lib.rs
index baba5d9b05e592d861efe71ad3fee8c59ccf0820..48404598166326a1265d3cd5aea88450253497c4 100644
--- a/substrate/bin/node-template/runtime/src/lib.rs
+++ b/substrate/bin/node-template/runtime/src/lib.rs
@@ -230,6 +230,7 @@ impl pallet_grandpa::Config for Runtime {
type WeightInfo = ();
type MaxAuthorities = ConstU32<32>;
+ type MaxSetIdSessionEntries = ConstU64<0>;
}
impl pallet_timestamp::Config for Runtime {
diff --git a/substrate/bin/node/runtime/src/lib.rs b/substrate/bin/node/runtime/src/lib.rs
index 30165cdb6f6c7cf49359ec5049a3e152704dd99a..8e8ecc125dba4780af9485cd703cab4606a3a5c7 100644
--- a/substrate/bin/node/runtime/src/lib.rs
+++ b/substrate/bin/node/runtime/src/lib.rs
@@ -1310,6 +1310,10 @@ impl pallet_authority_discovery::Config for Runtime {
type MaxAuthorities = MaxAuthorities;
}
+parameter_types! {
+ pub const MaxSetIdSessionEntries: u32 = BondingDuration::get() * SessionsPerEra::get();
+}
+
impl pallet_grandpa::Config for Runtime {
type RuntimeEvent = RuntimeEvent;
@@ -1331,6 +1335,7 @@ impl pallet_grandpa::Config for Runtime {
type WeightInfo = ();
type MaxAuthorities = MaxAuthorities;
+ type MaxSetIdSessionEntries = MaxSetIdSessionEntries;
}
parameter_types! {
diff --git a/substrate/frame/grandpa/src/lib.rs b/substrate/frame/grandpa/src/lib.rs
index aa09b445c6bdd5c791b29376055336d36b96a8a1..ea534947ddd37caeef0ab130fc2875062fc60f8f 100644
--- a/substrate/frame/grandpa/src/lib.rs
+++ b/substrate/frame/grandpa/src/lib.rs
@@ -121,6 +121,15 @@ pub mod pallet {
/// Max Authorities in use
#[pallet::constant]
type MaxAuthorities: Get<u32>;
+
+ /// The maximum number of entries to keep in the set id to session index mapping.
+ ///
+ /// Since the `SetIdSession` map is only used for validating equivocations this
+ /// value should relate to the bonding duration of whatever staking system is
+ /// being used (if any). If equivocation handling is not enabled then this value
+ /// can be zero.
+ #[pallet::constant]
+ type MaxSetIdSessionEntries: Get<u64>;
}
#[pallet::hooks]
@@ -323,6 +332,12 @@ pub mod pallet {
/// A mapping from grandpa set ID to the index of the *most recent* session for which its
/// members were responsible.
///
+ /// This is only used for validating equivocation proofs. An equivocation proof must
+ /// contains a key-ownership proof for a given session, therefore we need a way to tie
+ /// together sessions and GRANDPA set ids, i.e. we need to validate that a validator
+ /// was the owner of a given key on a given session, and what the active set ID was
+ /// during that session.
+ ///
/// TWOX-NOTE: `SetId` is not under user control.
#[pallet::storage]
#[pallet::getter(fn session_for_set)]
@@ -643,10 +658,17 @@ where
};
if res.is_ok() {
- CurrentSetId::<T>::mutate(|s| {
+ let current_set_id = CurrentSetId::<T>::mutate(|s| {
*s += 1;
*s
- })
+ });
+
+ let max_set_id_session_entries = T::MaxSetIdSessionEntries::get().max(1);
+ if current_set_id >= max_set_id_session_entries {
+ SetIdSession::<T>::remove(current_set_id - max_set_id_session_entries);
+ }
+
+ current_set_id
} else {
// either the session module signalled that the validators have changed
// or the set was stalled. but since we didn't successfully schedule
@@ -659,8 +681,8 @@ where
Self::current_set_id()
};
- // if we didn't issue a change, we update the mapping to note that the current
- // set corresponds to the latest equivalent session (i.e. now).
+ // update the mapping to note that the current set corresponds to the
+ // latest equivalent session (i.e. now).
let session_index = <pallet_session::Pallet<T>>::current_index();
SetIdSession::<T>::insert(current_set_id, &session_index);
}
diff --git a/substrate/frame/grandpa/src/migrations.rs b/substrate/frame/grandpa/src/migrations.rs
index 7795afcd8034f438f6e41e031702ac2a23cbc0cc..f4a28fff139745a9998844342189ddaa69434668 100644
--- a/substrate/frame/grandpa/src/migrations.rs
+++ b/substrate/frame/grandpa/src/migrations.rs
@@ -15,5 +15,51 @@
// See the License for the specific language governing permissions and
// limitations under the License.
+use frame_support::{
+ traits::{Get, OnRuntimeUpgrade},
+ weights::Weight,
+};
+
+use crate::{Config, CurrentSetId, SetIdSession, LOG_TARGET};
+
/// Version 4.
pub mod v4;
+
+/// This migration will clean up all stale set id -> session entries from the
+/// `SetIdSession` storage map, only the latest `max_set_id_session_entries`
+/// will be kept.
+///
+/// This migration should be added with a runtime upgrade that introduces the
+/// `MaxSetIdSessionEntries` constant to the pallet (although it could also be
+/// done later on).
+pub struct CleanupSetIdSessionMap<T>(sp_std::marker::PhantomData<T>);
+impl<T: Config> OnRuntimeUpgrade for CleanupSetIdSessionMap<T> {
+ fn on_runtime_upgrade() -> Weight {
+ // NOTE: since this migration will loop over all stale entries in the
+ // map we need to set some cutoff value, otherwise the migration might
+ // take too long to run. for scenarios where there are that many entries
+ // to cleanup a multiblock migration will be needed instead.
+ if CurrentSetId::<T>::get() > 25_000 {
+ log::warn!(
+ target: LOG_TARGET,
+ "CleanupSetIdSessionMap migration was aborted since there are too many entries to cleanup."
+ );
+
+ return T::DbWeight::get().reads(1)
+ }
+
+ cleanup_set_id_sesion_map::<T>()
+ }
+}
+
+fn cleanup_set_id_sesion_map<T: Config>() -> Weight {
+ let until_set_id = CurrentSetId::<T>::get().saturating_sub(T::MaxSetIdSessionEntries::get());
+
+ for set_id in 0..=until_set_id {
+ SetIdSession::<T>::remove(set_id);
+ }
+
+ T::DbWeight::get()
+ .reads(1)
+ .saturating_add(T::DbWeight::get().writes(until_set_id + 1))
+}
diff --git a/substrate/frame/grandpa/src/mock.rs b/substrate/frame/grandpa/src/mock.rs
index 54f34008abc5660dc3a80ad36546e478ad61ca76..7d54966a498a6f30f45f4cd877aba648df5c64c8 100644
--- a/substrate/frame/grandpa/src/mock.rs
+++ b/substrate/frame/grandpa/src/mock.rs
@@ -219,6 +219,7 @@ impl pallet_offences::Config for Test {
parameter_types! {
pub const ReportLongevity: u64 =
BondingDuration::get() as u64 * SessionsPerEra::get() as u64 * Period::get();
+ pub const MaxSetIdSessionEntries: u32 = BondingDuration::get() * SessionsPerEra::get();
}
impl Config for Test {
@@ -239,6 +240,7 @@ impl Config for Test {
type WeightInfo = ();
type MaxAuthorities = ConstU32<100>;
+ type MaxSetIdSessionEntries = MaxSetIdSessionEntries;
}
pub fn grandpa_log(log: ConsensusLog<u64>) -> DigestItem {
diff --git a/substrate/frame/grandpa/src/tests.rs b/substrate/frame/grandpa/src/tests.rs
index 626decd12821e8fda0a2c5f9a390ebfc317f92c2..e090dcebb60bf1f2ee9447d6f5c4770b9303eda6 100644
--- a/substrate/frame/grandpa/src/tests.rs
+++ b/substrate/frame/grandpa/src/tests.rs
@@ -781,6 +781,33 @@ fn on_new_session_doesnt_start_new_set_if_schedule_change_failed() {
});
}
+#[test]
+fn cleans_up_old_set_id_session_mappings() {
+ new_test_ext(vec![(1, 1), (2, 1), (3, 1)]).execute_with(|| {
+ let max_set_id_session_entries = MaxSetIdSessionEntries::get();
+
+ start_era(max_set_id_session_entries);
+
+ // we should have a session id mapping for all the set ids from
+ // `max_set_id_session_entries` eras we have observed
+ for i in 1..=max_set_id_session_entries {
+ assert!(Grandpa::session_for_set(i as u64).is_some());
+ }
+
+ start_era(max_set_id_session_entries * 2);
+
+ // we should keep tracking the new mappings for new eras
+ for i in max_set_id_session_entries + 1..=max_set_id_session_entries * 2 {
+ assert!(Grandpa::session_for_set(i as u64).is_some());
+ }
+
+ // but the old ones should have been pruned by now
+ for i in 1..=max_set_id_session_entries {
+ assert!(Grandpa::session_for_set(i as u64).is_none());
+ }
+ });
+}
+
#[test]
fn always_schedules_a_change_on_new_session_when_stalled() {
new_test_ext(vec![(1, 1), (2, 1), (3, 1)]).execute_with(|| {