core, eth: fix dependency cycle (#17720)

1 files changed, 39 insertions, 9 deletions

diff --git a/eth/backend.go b/eth/backend.go
index 90d185ed4..ca0b13eed 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -156,7 +156,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		}
 		cacheConfig = &core.CacheConfig{Disabled: config.NoPruning, TrieNodeLimit: config.TrieCache, TrieTimeLimit: config.TrieTimeout}
 	)
-	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, eth.chainConfig, eth.engine, vmConfig, eth.isMinerAccount)
+	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, eth.chainConfig, eth.engine, vmConfig, eth.shouldPreserve)
 	if err != nil {
 		return nil, err
 	}
@@ -334,30 +334,60 @@ func (s *Ethereum) Etherbase() (eb common.Address, err error) {
 	return common.Address{}, fmt.Errorf("etherbase must be explicitly specified")
 }
 
-// isMinerAccount checks whether the specified address is a miner account.
+// isLocalBlock checks whether the specified block is mined
+// by local miner accounts.
 //
-// This function is used during block chain reorg checking to determine
-// whether a block is mined by local accounts. We regard two types of
-// accounts as local account: etherbase and accounts specified via
-// `txpool.locals` flag.
-func (s *Ethereum) isMinerAccount(addr common.Address) bool {
+// We regard two types of accounts as local miner account: etherbase
+// and accounts specified via `txpool.locals` flag.
+func (s *Ethereum) isLocalBlock(block *types.Block) bool {
+	author, err := s.engine.Author(block.Header())
+	if err != nil {
+		log.Warn("Failed to retrieve block author", "number", block.NumberU64(), "hash", block.Hash(), "err", err)
+		return false
+	}
 	// Check whether the given address is etherbase.
 	s.lock.RLock()
 	etherbase := s.etherbase
 	s.lock.RUnlock()
-	if addr == etherbase {
+	if author == etherbase {
 		return true
 	}
 	// Check whether the given address is specified by `txpool.local`
 	// CLI flag.
 	for _, account := range s.config.TxPool.Locals {
-		if account == addr {
+		if account == author {
 			return true
 		}
 	}
 	return false
 }
 
+// shouldPreserve checks whether we should preserve the given block
+// during the chain reorg depending on whether the author of block
+// is a local account.
+func (s *Ethereum) shouldPreserve(block *types.Block) bool {
+	// The reason we need to disable the self-reorg preserving for clique
+	// is it can be probable to introduce a deadlock.
+	//
+	// e.g. If there are 7 available signers
+	//
+	// r1   A
+	// r2     B
+	// r3       C
+	// r4         D
+	// r5   A      [X] F G
+	// r6    [X]
+	//
+	// In the round5, the inturn signer E is offline, so the worst case
+	// is A, F and G sign the block of round5 and reject the block of opponents
+	// and in the round6, the last available signer B is offline, the whole
+	// network is stuck.
+	if _, ok := s.engine.(*clique.Clique); ok {
+		return false
+	}
+	return s.isLocalBlock(block)
+}
+
 // SetEtherbase sets the mining reward address.
 func (s *Ethereum) SetEtherbase(etherbase common.Address) {
 	s.lock.Lock()