Add better description to bad blocks

Track original cause of blocks being marked as bad.

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

chain/badtscache.go

@@ -1,6 +1,8 @@
 package chain
 
 import (
+	"fmt"
+
 	"github.com/filecoin-project/lotus/build"
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/ipfs/go-cid"
@@ -10,6 +12,35 @@ type BadBlockCache struct {
 	badBlocks *lru.ARCCache
 }
 
+type BadBlockReason struct {
+	Reason         string
+	TipSet         []cid.Cid
+	OriginalReason *BadBlockReason
+}
+
+func NewBadBlockReason(cid []cid.Cid, format string, i ...interface{}) BadBlockReason {
+	return BadBlockReason{
+		TipSet: cid,
+		Reason: fmt.Sprintf(format, i...),
+	}
+}
+
+func (bbr BadBlockReason) Linked(reason string, i ...interface{}) BadBlockReason {
+	or := &bbr
+	if bbr.OriginalReason != nil {
+		or = bbr.OriginalReason
+	}
+	return BadBlockReason{Reason: reason, OriginalReason: or}
+}
+
+func (bbr BadBlockReason) String() string {
+	res := bbr.Reason
+	if bbr.OriginalReason != nil {
+		res += " caused by: " + bbr.OriginalReason.String()
+	}
+	return res
+}
+
 func NewBadBlockCache() *BadBlockCache {
 	cache, err := lru.NewARC(build.BadBlockCacheSize)
 	if err != nil {
@@ -21,15 +52,15 @@ func NewBadBlockCache() *BadBlockCache {
 	}
 }
 
-func (bts *BadBlockCache) Add(c cid.Cid, reason string) {
-	bts.badBlocks.Add(c, reason)
+func (bts *BadBlockCache) Add(c cid.Cid, bbr BadBlockReason) {
+	bts.badBlocks.Add(c, bbr)
 }
 
-func (bts *BadBlockCache) Has(c cid.Cid) (string, bool) {
+func (bts *BadBlockCache) Has(c cid.Cid) (BadBlockReason, bool) {
 	rval, ok := bts.badBlocks.Get(c)
 	if !ok {
-		return "", false
+		return BadBlockReason{}, false
 	}
 
-	return rval.(string), true
+	return rval.(BadBlockReason), true
 }

chain/sync.go

@@ -536,7 +536,7 @@ func (syncer *Syncer) ValidateTipSet(ctx context.Context, fts *store.FullTipSet)
 		futures = append(futures, async.Err(func() error {
 			if err := syncer.ValidateBlock(ctx, b); err != nil {
 				if isPermanent(err) {
-					syncer.bad.Add(b.Cid(), err.Error())
+					syncer.bad.Add(b.Cid(), BadBlockReason{Reason: err.Error()})
 				}
 				return xerrors.Errorf("validating block %s: %w", b.Cid(), err)
 			}
@@ -1110,17 +1110,14 @@ func (syncer *Syncer) collectHeaders(ctx context.Context, from *types.TipSet, to
 		trace.Int64Attribute("toHeight", int64(to.Height())),
 	)
 
-	markBad := func(fmts string, args ...interface{}) {
-		for _, b := range from.Cids() {
-			syncer.bad.Add(b, fmt.Sprintf(fmts, args...))
-		}
-	}
-
 	// Check if the parents of the from block are in the denylist.
 	// i.e. if a fork of the chain has been requested that we know to be bad.
 	for _, pcid := range from.Parents().Cids() {
 		if reason, ok := syncer.bad.Has(pcid); ok {
-			markBad("linked to %s", pcid)
+			newReason := reason.Linked("linked to %s", pcid)
+			for _, b := range from.Cids() {
+				syncer.bad.Add(b, newReason)
+			}
 			return nil, xerrors.Errorf("chain linked to block marked previously as bad (%s, %s) (reason: %s)", from.Cids(), pcid, reason)
 		}
 	}
@@ -1132,7 +1129,7 @@ func (syncer *Syncer) collectHeaders(ctx context.Context, from *types.TipSet, to
 			return targetBE[i].Round < targetBE[j].Round
 		})
 		if !sorted {
-			syncer.bad.Add(from.Cids()[0], "wrong order of beacon entires")
+			syncer.bad.Add(from.Cids()[0], NewBadBlockReason(from.Cids(), "wrong order of beacon entires"))
 			return nil, xerrors.Errorf("wrong order of beacon entires")
 		}
 
@@ -1166,8 +1163,9 @@ loop:
 	for blockSet[len(blockSet)-1].Height() > untilHeight {
 		for _, bc := range at.Cids() {
 			if reason, ok := syncer.bad.Has(bc); ok {
+				newReason := reason.Linked("change contained %s", bc)
 				for _, b := range acceptedBlocks {
-					syncer.bad.Add(b, fmt.Sprintf("chain contained %s", bc))
+					syncer.bad.Add(b, newReason)
 				}
 
 				return nil, xerrors.Errorf("chain contained block marked previously as bad (%s, %s) (reason: %s)", from.Cids(), bc, reason)
@@ -1214,8 +1212,9 @@ loop:
 			}
 			for _, bc := range b.Cids() {
 				if reason, ok := syncer.bad.Has(bc); ok {
+					newReason := reason.Linked("change contained %s", bc)
 					for _, b := range acceptedBlocks {
-						syncer.bad.Add(b, fmt.Sprintf("chain contained %s", bc))
+						syncer.bad.Add(b, newReason)
 					}
 
 					return nil, xerrors.Errorf("chain contained block marked previously as bad (%s, %s) (reason: %s)", from.Cids(), bc, reason)
@@ -1246,7 +1245,7 @@ loop:
 				// TODO: we're marking this block bad in the same way that we mark invalid blocks bad. Maybe distinguish?
 				log.Warn("adding forked chain to our bad tipset cache")
 				for _, b := range from.Blocks() {
-					syncer.bad.Add(b.Cid(), "fork past finality")
+					syncer.bad.Add(b.Cid(), NewBadBlockReason(from.Cids(), "fork past finality"))
 				}
 			}
 			return nil, xerrors.Errorf("failed to sync fork: %w", err)
@@ -1499,12 +1498,14 @@ func (syncer *Syncer) State() []SyncerState {
 
 // MarkBad manually adds a block to the "bad blocks" cache.
 func (syncer *Syncer) MarkBad(blk cid.Cid) {
-	syncer.bad.Add(blk, "manually marked bad")
+	syncer.bad.Add(blk, NewBadBlockReason([]cid.Cid{blk}, "manually marked bad"))
 }
 
 func (syncer *Syncer) CheckBadBlockCache(blk cid.Cid) (string, bool) {
-	return syncer.bad.Has(blk)
+	bbr, ok := syncer.bad.Has(blk)
+	return bbr.String(), ok
 }
+
 func (syncer *Syncer) getLatestBeaconEntry(_ context.Context, ts *types.TipSet) (*types.BeaconEntry, error) {
 	cur := ts
 	for i := 0; i < 20; i++ {