Suppress lock errors from concurrent tx processing (MystenLabs#2378)

* In case of lock error, check if the tx effects already exist

* Revert temp fix from 2091

crates/sui-core/src/authority/authority_store.rs

@@ -773,8 +773,17 @@ impl<
             // 2. Not all validators lock, just 2f+1, so transaction should proceed regardless
             //    (But the lock should exist which means previous transactions finished)
             // 3. Equivocation possible (different TX) but as long as 2f+1 approves current TX its fine
+            // 4. Locks may have existed when we started processing this tx, but could have since
+            //    been deleted by a concurrent tx that finished first. In that case, check if the tx effects exist.
             if USE_LOCKS {
-                self.lock_service.locks_exist(owned_inputs.clone()).await?;
+                if let Err(e) = self.lock_service.locks_exist(owned_inputs.clone()).await {
+                    if self.effects_exists(&transaction_digest)? {
+                        debug!(digest = ?transaction_digest, "locks were deleted due to concurrent processing of tx");
+                        return Ok(());
+                    } else {
+                        return Err(e);
+                    }
+                }
             }
 
             if let Some(next_seq) = seq_opt {

crates/sui-core/src/authority_active/gossip/mod.rs

@@ -270,14 +270,7 @@ where
                     if !self.state.database.effects_exists(&digest)? {
                         // Download the certificate
                         let response = self.client.handle_transaction_info_request(TransactionInfoRequest::from(digest)).await?;
-                        if let Err(err) = self.process_response(response).await {
-                            // Check again whether the failure is due to a concurrent execution.
-                            // TODO: a concurrent execution should not really have returned an
-                            //       error but it seems it does? Check correctness?
-                            if !self.state.database.effects_exists(&digest)?{
-                                return Err(err);
-                            }
-                        }
+                        self.process_response(response).await?;
                     }
                 }
             };