fix: reward callback failure unlock

contracts/linear/src/epoch_actions.rs

@@ -378,13 +378,25 @@ impl LiquidStakingContract {
     pub fn validator_get_balance_callback(
         &mut self,
         validator_id: AccountId,
-        #[callback] total_balance: U128,
+        #[callback_result] result: Result<U128, PromiseError>,
     ) {
         let mut validator = self
             .validator_pool
             .get_validator(&validator_id)
             .expect(ERR_VALIDATOR_NOT_EXIST);
 
+        let total_balance = match result {
+            Ok(total_balance) => total_balance,
+            Err(_) => {
+                validator.on_refresh_total_balance_failed(&mut self.validator_pool);
+                log!(
+                    "Failed to refresh total balance from validator {}",
+                    validator_id
+                );
+                return;
+            }
+        };
+
         let new_balance = total_balance.0;
         let rewards = new_balance - validator.total_balance();
         Event::EpochUpdateRewards {

contracts/linear/src/validator_pool.rs

@@ -1049,6 +1049,10 @@ impl Validator {
         pool.save_validator(self);
     }
 
+    pub fn on_refresh_total_balance_failed(&mut self, pool: &mut ValidatorPool) {
+        self.post_execution(pool);
+    }
+
     /// Due to shares calculation and rounding of staking pool contract,
     /// the amount of staked and unstaked balance might be a little bit
     /// different than we requested.

tests/__tests__/linear/epoch-action-failure.ava.ts

@@ -441,4 +441,22 @@ test('get balance failure', async (t) => {
 
   // balance should not change
   await assertValidator(v1, '60', '0');
+
+  await v1.call(v1, 'set_panic', {
+    panic: false,
+  });
+
+  // update reward should be retryable after the failed callback releases executing
+  await owner.call(
+    contract,
+    'epoch_update_rewards',
+    {
+      validator_id: v1.accountId,
+    },
+    {
+      gas: Gas.parse('200 Tgas'),
+    },
+  );
+
+  await assertValidator(v1, '61', '0');
 });