Rewrite chain export walker function to actually do the right thing

node/impl/full/chain.go

@@ -20,11 +20,11 @@ import (
 	offline "github.com/ipfs/go-ipfs-exchange-offline"
 	cbor "github.com/ipfs/go-ipld-cbor"
 	ipld "github.com/ipfs/go-ipld-format"
+	logging "github.com/ipfs/go-log"
 	"github.com/ipfs/go-merkledag"
 	"github.com/ipfs/go-path"
 	"github.com/ipfs/go-path/resolver"
 	mh "github.com/multiformats/go-multihash"
-	"github.com/prometheus/common/log"
 	"go.uber.org/fx"
 	"golang.org/x/xerrors"
 
@@ -35,6 +35,8 @@ import (
 	"github.com/filecoin-project/lotus/chain/types"
 )
 
+var log = logging.Logger("fullnode")
+
 type ChainAPI struct {
 	fx.In
 
@@ -424,7 +426,7 @@ func (a *ChainAPI) ChainExport(ctx context.Context, tsk types.TipSetKey) (<-chan
 		for {
 			buf := make([]byte, 4096)
 			n, err := r.Read(buf)
-			if err != nil {
+			if err != nil && err != io.EOF {
 				log.Errorf("chain export pipe read failed: %s", err)
 				return
 			}
@@ -433,6 +435,9 @@ func (a *ChainAPI) ChainExport(ctx context.Context, tsk types.TipSetKey) (<-chan
 			case <-ctx.Done():
 				log.Warnf("export writer failed: %s", ctx.Err())
 			}
+			if err == io.EOF {
+				return
+			}
 		}
 	}()
 

node/impl/full/state.go

@@ -10,7 +10,6 @@ import (
 	"github.com/ipfs/go-hamt-ipld"
 	cbor "github.com/ipfs/go-ipld-cbor"
 	"github.com/libp2p/go-libp2p-core/peer"
-	"github.com/prometheus/common/log"
 	cbg "github.com/whyrusleeping/cbor-gen"
 	"go.uber.org/fx"
 	"golang.org/x/xerrors"

node/impl/full/sync.go

@@ -8,7 +8,6 @@ import (
 	"github.com/filecoin-project/lotus/chain"
 	"github.com/filecoin-project/lotus/chain/types"
 	cid "github.com/ipfs/go-cid"
-	"github.com/prometheus/common/log"
 
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"go.uber.org/fx"