Stop Celo L1 at a specific block

cmd/geth/main.go

@@ -74,6 +74,7 @@ var (
 		utils.USBFlag,
 		// utils.SmartCardDaemonPathFlag,
 		utils.OverrideHForkFlag,
+		utils.L2MigrationBlockFlag,
 		utils.TxPoolLocalsFlag,
 		utils.TxPoolNoLocalsFlag,
 		utils.TxPoolJournalFlag,

cmd/utils/flags.go

@@ -243,6 +243,11 @@ var (
 		Usage: "Manually specify the hfork block, overriding the bundled setting",
 	}
 
+	L2MigrationBlockFlag = cli.Uint64Flag{
+		Name:  "l2migrationblock",
+		Usage: "Block number at which to halt the network for Celo L2 migration. This is the first block of Celo as an L2, and one after the last block of Celo as an L1. If unset or set to 0, no halt will occur.",
+	}
+
 	BloomFilterSizeFlag = cli.Uint64Flag{
 		Name:  "bloomfilter.size",
 		Usage: "Megabytes of memory allocated to bloom-filter for pruning",
@@ -1723,6 +1728,9 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 	log.Debug("Sanitizing Go's GC trigger", "percent", int(gogc))
 	godebug.SetGCPercent(int(gogc))
 
+	if ctx.GlobalIsSet(L2MigrationBlockFlag.Name) {
+		cfg.L2MigrationBlock = new(big.Int).SetUint64(ctx.GlobalUint64(L2MigrationBlockFlag.Name))
+	}
 	if ctx.GlobalIsSet(SyncModeFlag.Name) {
 		cfg.SyncMode = *GlobalTextMarshaler(ctx, SyncModeFlag.Name).(*downloader.SyncMode)
 	}

consensus/istanbul/backend/backend.go

@@ -554,6 +554,12 @@ func (sb *Backend) Commit(proposal istanbul.Proposal, aggregatedSeal types.Istan
 		}
 	}
 	sb.onNewConsensusBlock(block, result.Receipts, result.Logs, result.State)
+
+	nextBlockNum := new(big.Int).Add(block.Number(), big.NewInt(1))
+	if sb.chain.Config().IsL2Migration(nextBlockNum) {
+		sb.logger.Info("The next block is the L2 migration block, stopping announce protocol and closing istanbul backend", "currentBlock", block.NumberU64(), "hash", block.Hash(), "nextBlock", nextBlockNum)
+		sb.StopAnnouncing()
+	}
 	return nil
 }
 

core/blockchain.go

@@ -811,6 +811,14 @@ func (bc *BlockChain) ExportN(w io.Writer, first uint64, last uint64) error {
 //
 // Note, this function assumes that the `mu` mutex is held!
 func (bc *BlockChain) writeHeadBlock(block *types.Block) {
+	// Normally the check at the end of the function will pass first, but if a node is restarted
+	// with the same l2-migration-block configured after already reaching and stopping on l2-migration-block,
+	// this check will pass first and log an error.
+	if bc.Config().IsL2Migration(block.Number()) {
+		log.Error("Attempt to insert block number >= l2MigrationBlock, stopping block insertion", "block", block.NumberU64(), "hash", block.Hash())
+		bc.StopInsert()
+		return
+	}
 	// If the block is on a side chain or an unknown one, force other heads onto it too
 	updateHeads := rawdb.ReadCanonicalHash(bc.db, block.NumberU64()) != block.Hash()
 
@@ -837,6 +845,13 @@ func (bc *BlockChain) writeHeadBlock(block *types.Block) {
 	}
 	bc.currentBlock.Store(block)
 	headBlockGauge.Update(int64(block.NumberU64()))
+
+	nextBlockNum := new(big.Int).Add(block.Number(), big.NewInt(1))
+	if bc.Config().IsL2Migration(nextBlockNum) {
+		log.Info("The next block is the L2 migration block, stopping block insertion", "currentBlock", block.NumberU64(), "hash", block.Hash(), "nextBlock", nextBlockNum.Uint64())
+		bc.StopInsert()
+		return
+	}
 }
 
 // Genesis retrieves the chain's genesis block.
@@ -1085,7 +1100,7 @@ func (bc *BlockChain) Stop() {
 		triedb := bc.stateCache.TrieDB()
 		triedb.SaveCache(bc.cacheConfig.TrieCleanJournal)
 	}
-	log.Info("Blockchain stopped")
+	log.Info("Blockchain stopped", "number", bc.CurrentBlock().NumberU64(), "hash", bc.CurrentBlock().Hash())
 }
 
 // StopInsert interrupts all insertion methods, causing them to return
@@ -1870,6 +1885,9 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals bool) (int, er
 		// If the chain is terminating, stop processing blocks
 		if bc.insertStopped() {
 			log.Debug("Abort during block processing")
+			if bc.Config().IsL2Migration(block.Number()) {
+				err = errInsertionInterrupted
+			}
 			break
 		}
 		// If the header is a banned one, straight out abort

core/blockchain_test.go

@@ -38,6 +38,7 @@ import (
 	"github.com/celo-org/celo-blockchain/ethdb"
 	"github.com/celo-org/celo-blockchain/params"
 	"github.com/celo-org/celo-blockchain/trie"
+	"github.com/stretchr/testify/require"
 )
 
 // So we can deterministically seed different blockchains
@@ -205,6 +206,28 @@ func TestLastBlock(t *testing.T) {
 	}
 }
 
+func TestNoInsertPastL2MigrationBlock(t *testing.T) {
+	_, blockchain, err := newCanonical(mockEngine.NewFaker(), 0, true)
+	if err != nil {
+		t.Fatalf("failed to create pristine chain: %v", err)
+	}
+	defer blockchain.Stop()
+
+	blockchain.chainConfig = blockchain.chainConfig.DeepCopy()
+	migrationBlock := 2
+	blockchain.chainConfig.L2MigrationBlock = big.NewInt(int64(migrationBlock))
+
+	blocks := makeBlockChain(blockchain.CurrentBlock(), 100000, mockEngine.NewFullFaker(), blockchain.db, 0)
+	failedBlock, err := blockchain.InsertChain(blocks)
+	require.EqualError(t, err, errInsertionInterrupted.Error())
+	// Compare with migrationBlock-1 because failedBlock is the index of the failed block in the blocks[] array, not in the actual blockchain.
+	require.EqualValues(t, migrationBlock-1, failedBlock)
+	// Only the first block in blocks[] should be inserted
+	if blocks[migrationBlock-2].Hash() != rawdb.ReadHeadBlockHash(blockchain.db) {
+		t.Fatalf("Write/Get HeadBlockHash failed")
+	}
+}
+
 // Tests that given a starting canonical chain of a given size, it can be extended
 // with various length chains.
 func TestExtendCanonicalHeaders(t *testing.T) { testExtendCanonical(t, false) }

core/forkid/forkid.go

@@ -224,6 +224,10 @@ func gatherForks(config *params.ChainConfig) []uint64 {
 		if !strings.HasSuffix(field.Name, "Block") {
 			continue
 		}
+		// Do not include L2MigrationBlock in forkid as doing so will prevent syncing with nodes that have not set the L2MigrationBlock flag
+		if field.Name == "L2MigrationBlock" {
+			continue
+		}
 		if field.Type != reflect.TypeOf(new(big.Int)) {
 			continue
 		}

e2e_test/e2e_bench_test.go

@@ -19,7 +19,7 @@ func BenchmarkNet100EmptyBlocks(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				ac := test.AccountConfig(n, 0)
 				gingerbreadBlock := common.Big0
-				gc, ec, err := test.BuildConfig(ac, gingerbreadBlock)
+				gc, ec, err := test.BuildConfig(ac, gingerbreadBlock, nil)
 				require.NoError(b, err)
 				network, shutdown, err := test.NewNetwork(ac, gc, ec)
 				require.NoError(b, err)
@@ -45,7 +45,7 @@ func BenchmarkNet1000Txs(b *testing.B) {
 
 				ac := test.AccountConfig(n, n)
 				gingerbreadBlock := common.Big0
-				gc, ec, err := test.BuildConfig(ac, gingerbreadBlock)
+				gc, ec, err := test.BuildConfig(ac, gingerbreadBlock, nil)
 				require.NoError(b, err)
 				accounts := test.Accounts(ac.DeveloperAccounts(), gc.ChainConfig())
 				network, shutdown, err := test.NewNetwork(ac, gc, ec)