From 9d183632e4d14b88866548df81135fb10e246ccc Mon Sep 17 00:00:00 2001
From: Giulio rebuffo <giulio.rebuffo@gmail.com>
Date: Sun, 19 Jan 2025 16:56:03 +0100
Subject: [PATCH] Caplin: fix occassional loss of sync during `ForwardSync`
 (#13495)

---
 cl/cltypes/eth1_data.go                       |  7 +++-
 .../forkchoice/fork_graph/fork_graph_disk.go  |  3 ++
 .../fork_graph/fork_graph_disk_fs.go          | 42 ++++++++-----------
 cl/transition/machine/block.go                | 11 +----
 4 files changed, 27 insertions(+), 36 deletions(-)

diff --git a/cl/cltypes/eth1_data.go b/cl/cltypes/eth1_data.go
index b87c19d3445..18507ec9e24 100644
--- a/cl/cltypes/eth1_data.go
+++ b/cl/cltypes/eth1_data.go
@@ -35,8 +35,11 @@ func NewEth1Data() *Eth1Data {
 }
 
 func (e *Eth1Data) Copy() *Eth1Data {
-	copied := *e
-	return &copied
+	return &Eth1Data{
+		Root:         e.Root,
+		DepositCount: e.DepositCount,
+		BlockHash:    e.BlockHash,
+	}
 }
 
 func (e *Eth1Data) Equal(b *Eth1Data) bool {
diff --git a/cl/phase1/forkchoice/fork_graph/fork_graph_disk.go b/cl/phase1/forkchoice/fork_graph/fork_graph_disk.go
index d12500e4cff..51ab1b82c7b 100644
--- a/cl/phase1/forkchoice/fork_graph/fork_graph_disk.go
+++ b/cl/phase1/forkchoice/fork_graph/fork_graph_disk.go
@@ -395,6 +395,9 @@ func (f *forkGraphDisk) getState(blockRoot libcommon.Hash, alwaysCopy bool, addC
 	// Traverse the blocks from top to bottom.
 	for i := len(blocksInTheWay) - 1; i >= 0; i-- {
 		if err := transition.TransitionState(copyReferencedState, blocksInTheWay[i], nil, false); err != nil {
+			if addChainSegment {
+				f.currentState = nil // reset the state if it fails here.
+			}
 			return nil, err
 		}
 	}
diff --git a/cl/phase1/forkchoice/fork_graph/fork_graph_disk_fs.go b/cl/phase1/forkchoice/fork_graph/fork_graph_disk_fs.go
index 7f32c315129..f6f4d10a5d2 100644
--- a/cl/phase1/forkchoice/fork_graph/fork_graph_disk_fs.go
+++ b/cl/phase1/forkchoice/fork_graph/fork_graph_disk_fs.go
@@ -112,12 +112,7 @@ func (f *forkGraphDisk) DumpBeaconStateOnDisk(blockRoot libcommon.Hash, bs *stat
 		return
 	}
 	f.stateDumpLock.Lock()
-	unlockOnDefer := true
-	defer func() {
-		if unlockOnDefer {
-			f.stateDumpLock.Unlock()
-		}
-	}()
+	defer f.stateDumpLock.Unlock()
 	// Truncate and then grow the buffer to the size of the state.
 	f.sszBuffer, err = bs.EncodeSSZ(f.sszBuffer[:0])
 	if err != nil {
@@ -170,25 +165,22 @@ func (f *forkGraphDisk) DumpBeaconStateOnDisk(blockRoot libcommon.Hash, bs *stat
 		log.Error("failed to sync dumped file", "err", err)
 		return
 	}
-	unlockOnDefer = false
-	go func() {
-		cacheFile, err := f.fs.OpenFile(getBeaconStateCacheFilename(blockRoot), os.O_TRUNC|os.O_CREATE|os.O_RDWR, 0o755)
-		if err != nil {
-			log.Error("failed to open cache file", "err", err)
-			return
-		}
-		defer cacheFile.Close()
-		defer f.stateDumpLock.Unlock()
-
-		if _, err = cacheFile.Write(b.Bytes()); err != nil {
-			log.Error("failed to write cache file", "err", err)
-			return
-		}
-		if err = cacheFile.Sync(); err != nil {
-			log.Error("failed to sync cache file", "err", err)
-			return
-		}
-	}()
+
+	cacheFile, err := f.fs.OpenFile(getBeaconStateCacheFilename(blockRoot), os.O_TRUNC|os.O_CREATE|os.O_RDWR, 0o755)
+	if err != nil {
+		log.Error("failed to open cache file", "err", err)
+		return
+	}
+	defer cacheFile.Close()
+
+	if _, err = cacheFile.Write(b.Bytes()); err != nil {
+		log.Error("failed to write cache file", "err", err)
+		return
+	}
+	if err = cacheFile.Sync(); err != nil {
+		log.Error("failed to sync cache file", "err", err)
+		return
+	}
 
 	return
 }
diff --git a/cl/transition/machine/block.go b/cl/transition/machine/block.go
index 6f464fa8e3c..f94cbe0d0d6 100644
--- a/cl/transition/machine/block.go
+++ b/cl/transition/machine/block.go
@@ -117,8 +117,9 @@ func ProcessBlock(impl BlockProcessor, s abstract.BeaconState, block cltypes.Gen
 
 // ProcessOperations is called by ProcessBlock and processes the block body operations
 func ProcessOperations(impl BlockOperationProcessor, s abstract.BeaconState, blockBody cltypes.GenericBeaconBody) (signatures [][]byte, messages [][]byte, publicKeys [][]byte, err error) {
+	maxDepositsAllowed := int(min(s.BeaconConfig().MaxDeposits, s.Eth1Data().DepositCount-s.Eth1DepositIndex()))
 	if s.Version() <= clparams.DenebVersion {
-		if blockBody.GetDeposits().Len() != int(maximumDeposits(s)) {
+		if blockBody.GetDeposits().Len() != maxDepositsAllowed {
 			return nil, nil, nil, errors.New("outstanding deposits do not match maximum deposits")
 		}
 	} else if s.Version() >= clparams.ElectraVersion {
@@ -345,11 +346,3 @@ func processBlsToExecutionChanges(impl BlockOperationProcessor, s abstract.Beaco
 
 	return
 }
-
-func maximumDeposits(s abstract.BeaconState) (maxDeposits uint64) {
-	maxDeposits = s.Eth1Data().DepositCount - s.Eth1DepositIndex()
-	if maxDeposits > s.BeaconConfig().MaxDeposits {
-		maxDeposits = s.BeaconConfig().MaxDeposits
-	}
-	return
-}