v2.0: fix: borrow stakes delegation during snapshot serialization (ba…

…ckport of #2455) (#2500)

runtime/src/bank.rs

@@ -2296,8 +2296,7 @@ impl Bank {
                 .fold(
                     HashSet::default,
                     |mut voter_pubkeys, (_stake_pubkey, stake_account)| {
-                        let delegation = stake_account.delegation();
-                        voter_pubkeys.insert(delegation.voter_pubkey);
+                        voter_pubkeys.insert(stake_account.delegation().voter_pubkey);
                         voter_pubkeys
                     },
                 )
@@ -2361,7 +2360,7 @@ impl Bank {
             };
             if let Some(reward_calc_tracer) = reward_calc_tracer.as_ref() {
                 let delegation =
-                    InflationPointCalculationEvent::Delegation(delegation, solana_vote_program);
+                    InflationPointCalculationEvent::Delegation(*delegation, solana_vote_program);
                 let event = RewardCalculationEvent::Staking(stake_pubkey, &delegation);
                 reward_calc_tracer(&event);
             }

runtime/src/bank/partitioned_epoch_rewards/calculation.rs

@@ -378,10 +378,9 @@ impl Bank {
                     let stake_pubkey = **stake_pubkey;
                     let stake_account = (*stake_account).to_owned();
 
-                    let delegation = stake_account.delegation();
+                    let vote_pubkey = stake_account.delegation().voter_pubkey;
                     let (mut stake_account, stake_state) =
                         <(AccountSharedData, StakeStateV2)>::from(stake_account);
-                    let vote_pubkey = delegation.voter_pubkey;
                     let vote_account = get_vote_account(&vote_pubkey)?;
                     if vote_account.owner() != &solana_vote_program {
                         return None;
@@ -501,8 +500,7 @@ impl Bank {
             stake_delegations
                 .par_iter()
                 .map(|(_stake_pubkey, stake_account)| {
-                    let delegation = stake_account.delegation();
-                    let vote_pubkey = delegation.voter_pubkey;
+                    let vote_pubkey = stake_account.delegation().voter_pubkey;
 
                     let Some(vote_account) = get_vote_account(&vote_pubkey) else {
                         return 0;

runtime/src/bank/serde_snapshot.rs

@@ -488,7 +488,7 @@ mod tests {
         #[cfg_attr(
             feature = "frozen-abi",
             derive(AbiExample),
-            frozen_abi(digest = "6riNuebfnAUpS2e3GYb5G8udH5PoEtep48ULchLjRDCB")
+            frozen_abi(digest = "AzsxaiGEcf3Bxwna5DPS3w5DP4JjyxPDfHnYTvUfyZ5f")
         )]
         #[derive(Serialize)]
         pub struct BankAbiTestWrapper {

runtime/src/stake_account.rs

@@ -48,10 +48,10 @@ impl<T> StakeAccount<T> {
 
 impl StakeAccount<Delegation> {
     #[inline]
-    pub(crate) fn delegation(&self) -> Delegation {
+    pub(crate) fn delegation(&self) -> &Delegation {
         // Safe to unwrap here because StakeAccount<Delegation> will always
         // only wrap a stake-state which is a delegation.
-        self.stake_state.delegation().unwrap()
+        self.stake_state.delegation_ref().unwrap()
     }
 }
 

runtime/src/stakes.rs

@@ -26,6 +26,9 @@ use {
     thiserror::Error,
 };
 
+mod serde_stakes;
+pub(crate) use serde_stakes::serde_stakes_enum_compat;
+
 #[derive(Debug, Error)]
 pub enum Error {
     #[error("Invalid delegation: {0}")]
@@ -267,7 +270,7 @@ impl Stakes<StakeAccount> {
                 let stake_account = StakeAccount::try_from(stake_account)?;
                 // Sanity check that the delegation is consistent with what is
                 // stored in the account.
-                if stake_account.delegation() == *delegation {
+                if stake_account.delegation() == delegation {
                     map.insert(*pubkey, stake_account);
                     Ok(map)
                 } else {
@@ -499,12 +502,15 @@ impl StakesEnum {
     }
 }
 
+/// This conversion is very memory intensive so should only be used in
+/// development contexts.
+#[cfg(feature = "dev-context-only-utils")]
 impl From<Stakes<StakeAccount>> for Stakes<Delegation> {
     fn from(stakes: Stakes<StakeAccount>) -> Self {
         let stake_delegations = stakes
             .stake_delegations
             .into_iter()
-            .map(|(pubkey, stake_account)| (pubkey, stake_account.delegation()))
+            .map(|(pubkey, stake_account)| (pubkey, *stake_account.delegation()))
             .collect();
         Self {
             vote_accounts: stakes.vote_accounts,
@@ -516,6 +522,9 @@ impl From<Stakes<StakeAccount>> for Stakes<Delegation> {
     }
 }
 
+/// This conversion is memory intensive so should only be used in development
+/// contexts.
+#[cfg(feature = "dev-context-only-utils")]
 impl From<Stakes<Stake>> for Stakes<Delegation> {
     fn from(stakes: Stakes<Stake>) -> Self {
         let stake_delegations = stakes
@@ -533,6 +542,9 @@ impl From<Stakes<Stake>> for Stakes<Delegation> {
     }
 }
 
+/// This conversion is memory intensive so should only be used in development
+/// contexts.
+#[cfg(feature = "dev-context-only-utils")]
 impl From<StakesEnum> for Stakes<Delegation> {
     fn from(stakes: StakesEnum) -> Self {
         match stakes {
@@ -576,36 +588,6 @@ impl PartialEq<StakesEnum> for StakesEnum {
     }
 }
 
-// In order to maintain backward compatibility, the StakesEnum in EpochStakes
-// and SerializableVersionedBank should be serialized as Stakes<Delegation>.
-pub(crate) mod serde_stakes_enum_compat {
-    use {
-        super::*,
-        serde::{Deserialize, Deserializer, Serialize, Serializer},
-    };
-
-    pub(crate) fn serialize<S>(stakes: &StakesEnum, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        match stakes {
-            StakesEnum::Delegations(stakes) => stakes.serialize(serializer),
-            stakes => {
-                let stakes = Stakes::<Delegation>::from(stakes.clone());
-                stakes.serialize(serializer)
-            }
-        }
-    }
-
-    pub(crate) fn deserialize<'de, D>(deserializer: D) -> Result<Arc<StakesEnum>, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        let stakes = Stakes::<Delegation>::deserialize(deserializer)?;
-        Ok(Arc::new(StakesEnum::Delegations(stakes)))
-    }
-}
-
 fn refresh_vote_accounts(
     thread_pool: &ThreadPool,
     epoch: Epoch,
@@ -651,7 +633,6 @@ fn refresh_vote_accounts(
 pub(crate) mod tests {
     use {
         super::*,
-        rand::Rng,
         rayon::ThreadPoolBuilder,
         solana_sdk::{account::WritableAccount, pubkey::Pubkey, rent::Rent, stake},
         solana_stake_program::stake_state,
@@ -1078,63 +1059,4 @@ pub(crate) mod tests {
             );
         }
     }
-
-    #[test]
-    fn test_serde_stakes_enum_compat() {
-        #[derive(Debug, PartialEq, Deserialize, Serialize)]
-        struct Dummy {
-            head: String,
-            #[serde(with = "serde_stakes_enum_compat")]
-            stakes: Arc<StakesEnum>,
-            tail: String,
-        }
-        let mut rng = rand::thread_rng();
-        let stakes_cache = StakesCache::new(Stakes {
-            unused: rng.gen(),
-            epoch: rng.gen(),
-            ..Stakes::default()
-        });
-        for _ in 0..rng.gen_range(5usize..10) {
-            let vote_pubkey = solana_sdk::pubkey::new_rand();
-            let vote_account = vote_state::create_account(
-                &vote_pubkey,
-                &solana_sdk::pubkey::new_rand(), // node_pubkey
-                rng.gen_range(0..101),           // commission
-                rng.gen_range(0..1_000_000),     // lamports
-            );
-            stakes_cache.check_and_store(&vote_pubkey, &vote_account, None);
-            for _ in 0..rng.gen_range(10usize..20) {
-                let stake_pubkey = solana_sdk::pubkey::new_rand();
-                let rent = Rent::with_slots_per_epoch(rng.gen());
-                let stake_account = stake_state::create_account(
-                    &stake_pubkey, // authorized
-                    &vote_pubkey,
-                    &vote_account,
-                    &rent,
-                    rng.gen_range(0..1_000_000), // lamports
-                );
-                stakes_cache.check_and_store(&stake_pubkey, &stake_account, None);
-            }
-        }
-        let stakes: Stakes<StakeAccount> = stakes_cache.stakes().clone();
-        assert!(stakes.vote_accounts.as_ref().len() >= 5);
-        assert!(stakes.stake_delegations.len() >= 50);
-        let dummy = Dummy {
-            head: String::from("dummy-head"),
-            stakes: Arc::new(StakesEnum::from(stakes.clone())),
-            tail: String::from("dummy-tail"),
-        };
-        assert!(dummy.stakes.vote_accounts().as_ref().len() >= 5);
-        let data = bincode::serialize(&dummy).unwrap();
-        let other: Dummy = bincode::deserialize(&data).unwrap();
-        assert_eq!(other, dummy);
-        let stakes = Stakes::<Delegation>::from(stakes);
-        assert!(stakes.vote_accounts.as_ref().len() >= 5);
-        assert!(stakes.stake_delegations.len() >= 50);
-        let other = match &*other.stakes {
-            StakesEnum::Accounts(_) | StakesEnum::Stakes(_) => panic!("wrong type!"),
-            StakesEnum::Delegations(delegations) => delegations,
-        };
-        assert_eq!(other, &stakes)
-    }
 }