Iterate expired components from the da_checker (#5895)

* Iterate expired components from the da_checker

* Fix rebase

beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

@@ -269,6 +269,26 @@ impl<E: EthSpec> PendingComponents<E> {
             AvailableExecutedBlock::new(available_block, import_data, payload_verification_outcome),
         )))
     }
+
+    /// Returns the epoch of the block if it is cached, otherwise returns the epoch of the first blob.
+    pub fn epoch(&self) -> Option<Epoch> {
+        self.executed_block
+            .as_ref()
+            .map(|pending_block| pending_block.as_block().epoch())
+            .or_else(|| {
+                for maybe_blob in self.verified_blobs.iter() {
+                    if maybe_blob.is_some() {
+                        return maybe_blob.as_ref().map(|kzg_verified_blob| {
+                            kzg_verified_blob
+                                .as_blob()
+                                .slot()
+                                .epoch(E::slots_per_epoch())
+                        });
+                    }
+                }
+                None
+            })
+    }
 }
 
 /// This is the main struct for this module. Outside methods should
@@ -475,6 +495,22 @@ impl<T: BeaconChainTypes> DataAvailabilityCheckerInner<T> {
     pub fn do_maintenance(&self, cutoff_epoch: Epoch) -> Result<(), AvailabilityCheckError> {
         // clean up any lingering states in the state cache
         self.state_cache.do_maintenance(cutoff_epoch);
+
+        // Collect keys of pending blocks from a previous epoch to cutoff
+        let mut write_lock = self.critical.write();
+        let mut keys_to_remove = vec![];
+        for (key, value) in write_lock.iter() {
+            if let Some(epoch) = value.epoch() {
+                if epoch < cutoff_epoch {
+                    keys_to_remove.push(*key);
+                }
+            }
+        }
+        // Now remove keys
+        for key in keys_to_remove {
+            write_lock.pop(&key);
+        }
+
         Ok(())
     }