Don't attempt to refresh votes on non voting validators (#32315)

(cherry picked from commit e1576b5)

# Conflicts:
#	core/src/replay_stage.rs

core/src/consensus.rs

@@ -214,7 +214,8 @@ pub struct Tower {
     // blockhash of the voted block itself, depending if the vote slot was refreshed.
     // For instance, a vote for slot 5, may be refreshed/resubmitted for inclusion in
     //  block 10, in  which case `last_vote_tx_blockhash` equals the blockhash of 10, not 5.
-    last_vote_tx_blockhash: Hash,
+    // For non voting validators this is None
+    last_vote_tx_blockhash: Option<Hash>,
     last_timestamp: BlockTimestamp,
     #[serde(skip)]
     // Restored last voted slot which cannot be found in SlotHistory at replayed root
@@ -237,7 +238,7 @@ impl Default for Tower {
             vote_state: VoteState::default(),
             last_vote: VoteTransaction::from(VoteStateUpdate::default()),
             last_timestamp: BlockTimestamp::default(),
-            last_vote_tx_blockhash: Hash::default(),
+            last_vote_tx_blockhash: None,
             stray_restored_slot: Option::default(),
             last_switch_threshold_check: Option::default(),
         };
@@ -450,7 +451,7 @@ impl Tower {
         self.vote_state.tower()
     }
 
-    pub fn last_vote_tx_blockhash(&self) -> Hash {
+    pub fn last_vote_tx_blockhash(&self) -> Option<Hash> {
         self.last_vote_tx_blockhash
     }
 
@@ -494,7 +495,7 @@ impl Tower {
     }
 
     pub fn refresh_last_vote_tx_blockhash(&mut self, new_vote_tx_blockhash: Hash) {
-        self.last_vote_tx_blockhash = new_vote_tx_blockhash;
+        self.last_vote_tx_blockhash = Some(new_vote_tx_blockhash);
     }
 
     // Returns true if we have switched the new vote instruction that directly sets vote state

core/src/replay_stage.rs

@@ -2350,9 +2350,14 @@ impl ReplayStage {
                 last_voted_slot
             );
         }
+
+        // If we are a non voting validator or have an incorrect setup preventing us from
+        // generating vote txs, no need to refresh
+        let Some(last_vote_tx_blockhash) = tower.last_vote_tx_blockhash() else { return };
+
         if my_latest_landed_vote >= last_voted_slot
             || heaviest_bank_on_same_fork
-                .is_hash_valid_for_age(&tower.last_vote_tx_blockhash(), MAX_PROCESSING_AGE)
+                .is_hash_valid_for_age(&last_vote_tx_blockhash, MAX_PROCESSING_AGE)
             || {
                 // In order to avoid voting on multiple forks all past MAX_PROCESSING_AGE that don't
                 // include the last voted blockhash
@@ -6786,7 +6791,10 @@ pub(crate) mod tests {
         assert_eq!(votes.len(), 1);
         let vote_tx = &votes[0];
         assert_eq!(vote_tx.message.recent_blockhash, bank0.last_blockhash());
-        assert_eq!(tower.last_vote_tx_blockhash(), bank0.last_blockhash());
+        assert_eq!(
+            tower.last_vote_tx_blockhash().unwrap(),
+            bank0.last_blockhash()
+        );
         assert_eq!(tower.last_voted_slot().unwrap(), 0);
         bank1.process_transaction(vote_tx).unwrap();
         bank1.freeze();
@@ -6815,7 +6823,10 @@ pub(crate) mod tests {
             let votes = cluster_info.get_votes(&mut cursor);
             assert!(votes.is_empty());
             // Tower's latest vote tx blockhash hasn't changed either
-            assert_eq!(tower.last_vote_tx_blockhash(), bank0.last_blockhash());
+            assert_eq!(
+                tower.last_vote_tx_blockhash().unwrap(),
+                bank0.last_blockhash()
+            );
             assert_eq!(tower.last_voted_slot().unwrap(), 0);
         }
 
@@ -6848,7 +6859,10 @@ pub(crate) mod tests {
         assert_eq!(votes.len(), 1);
         let vote_tx = &votes[0];
         assert_eq!(vote_tx.message.recent_blockhash, bank1.last_blockhash());
-        assert_eq!(tower.last_vote_tx_blockhash(), bank1.last_blockhash());
+        assert_eq!(
+            tower.last_vote_tx_blockhash().unwrap(),
+            bank1.last_blockhash()
+        );
         assert_eq!(tower.last_voted_slot().unwrap(), 1);
 
         // Trying to refresh the vote for bank 1 in bank 2 won't succeed because
@@ -6870,7 +6884,10 @@ pub(crate) mod tests {
         // No new votes have been submitted to gossip
         let votes = cluster_info.get_votes(&mut cursor);
         assert!(votes.is_empty());
-        assert_eq!(tower.last_vote_tx_blockhash(), bank1.last_blockhash());
+        assert_eq!(
+            tower.last_vote_tx_blockhash().unwrap(),
+            bank1.last_blockhash()
+        );
         assert_eq!(tower.last_voted_slot().unwrap(), 1);
 
         // Create a bank where the last vote transaction will have expired
@@ -6929,7 +6946,7 @@ pub(crate) mod tests {
             expired_bank.last_blockhash()
         );
         assert_eq!(
-            tower.last_vote_tx_blockhash(),
+            tower.last_vote_tx_blockhash().unwrap(),
             expired_bank.last_blockhash()
         );
         assert_eq!(tower.last_voted_slot().unwrap(), 1);
@@ -6985,7 +7002,7 @@ pub(crate) mod tests {
             expired_bank.last_blockhash()
         );
         assert_eq!(
-            tower.last_vote_tx_blockhash(),
+            tower.last_vote_tx_blockhash().unwrap(),
             expired_bank.last_blockhash()
         );
         assert_eq!(tower.last_voted_slot().unwrap(), 1);

core/src/tower1_14_11.rs

@@ -19,7 +19,7 @@ pub struct Tower1_14_11 {
     // blockhash of the voted block itself, depending if the vote slot was refreshed.
     // For instance, a vote for slot 5, may be refreshed/resubmitted for inclusion in
     //  block 10, in  which case `last_vote_tx_blockhash` equals the blockhash of 10, not 5.
-    pub(crate) last_vote_tx_blockhash: Hash,
+    pub(crate) last_vote_tx_blockhash: Option<Hash>,
     pub(crate) last_timestamp: BlockTimestamp,
     #[serde(skip)]
     // Restored last voted slot which cannot be found in SlotHistory at replayed root

core/src/tower1_7_14.rs

@@ -22,7 +22,7 @@ pub struct Tower1_7_14 {
     // blockhash of the voted block itself, depending if the vote slot was refreshed.
     // For instance, a vote for slot 5, may be refreshed/resubmitted for inclusion in
     //  block 10, in  which case `last_vote_tx_blockhash` equals the blockhash of 10, not 5.
-    pub(crate) last_vote_tx_blockhash: Hash,
+    pub(crate) last_vote_tx_blockhash: Option<Hash>,
     pub(crate) last_timestamp: BlockTimestamp,
     #[serde(skip)]
     // Restored last voted slot which cannot be found in SlotHistory at replayed root

core/src/tower_storage.rs

@@ -404,7 +404,7 @@ pub mod test {
             vote_state: VoteState1_14_11::from(vote_state),
             last_vote: vote.clone(),
             last_timestamp: BlockTimestamp::default(),
-            last_vote_tx_blockhash: Hash::default(),
+            last_vote_tx_blockhash: None,
             stray_restored_slot: Some(2),
             last_switch_threshold_check: Option::default(),
         };