Move migrated data existence check into backend and add a new conditi…

…on for full sync node

core/blockchain.go

@@ -347,12 +347,6 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 	// Make sure the state associated with the block is available, or log out
 	// if there is no available state, waiting for state sync.
 	head := bc.CurrentBlock()
-	// Make sure Cel2 chain has migrated data from Celo1
-	if chainConfig.Cel2Time != nil && !chainConfig.IsCel2(head.Time) {
-		log.Error("Migrated data for Cel2 is missing, please ensure the migrated data from Celo1 can be properly loaded before starting the blockchain",
-			"current number", head.Number, "current hash", head.Hash())
-		return nil, fmt.Errorf("missing migrated data")
-	}
 	if !bc.HasState(head.Root) {
 		if head.Number.Uint64() == 0 {
 			// The genesis state is missing, which is only possible in the path-based

eth/backend.go

@@ -255,6 +255,13 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 	if err != nil {
 		return nil, err
 	}
+	// Make sure Cel2 full sync node has migrated data from Celo1
+	currentBlock := eth.blockchain.CurrentBlock()
+	if config.SyncMode == downloader.FullSync && chainConfig.Cel2Time != nil && !chainConfig.IsCel2(currentBlock.Number.Uint64()) {
+		log.Error("Migrated data for Cel2 is missing, please ensure the migrated data from Celo1 can be properly loaded before starting the blockchain",
+			"current number", currentBlock.Number.Uint64(), "current hash", currentBlock.Hash())
+		return nil, fmt.Errorf("missing migrated data")
+	}
 	if chainConfig := eth.blockchain.Config(); chainConfig.Optimism != nil { // config.Genesis.Config.ChainID cannot be used because it's based on CLI flags only, thus default to mainnet L1
 		config.NetworkId = chainConfig.ChainID.Uint64() // optimism defaults eth network ID to chain ID
 		eth.networkID = config.NetworkId