diff --git a/vendor/go.etcd.io/etcd/etcdserver/storage.go b/vendor/go.etcd.io/etcd/etcdserver/storage.go
new file mode 100644
index 0000000..d57b6f9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/storage.go
@@ -0,0 +1,116 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"io"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/wal"
+	"go.etcd.io/etcd/wal/walpb"
+
+	"go.uber.org/zap"
+)
+
+type Storage interface {
+	// Save function saves ents and state to the underlying stable storage.
+	// Save MUST block until st and ents are on stable storage.
+	Save(st raftpb.HardState, ents []raftpb.Entry) error
+	// SaveSnap function saves snapshot to the underlying stable storage.
+	SaveSnap(snap raftpb.Snapshot) error
+	// Close closes the Storage and performs finalization.
+	Close() error
+}
+
+type storage struct {
+	*wal.WAL
+	*snap.Snapshotter
+}
+
+func NewStorage(w *wal.WAL, s *snap.Snapshotter) Storage {
+	return &storage{w, s}
+}
+
+// SaveSnap saves the snapshot to disk and release the locked
+// wal files since they will not be used.
+func (st *storage) SaveSnap(snap raftpb.Snapshot) error {
+	walsnap := walpb.Snapshot{
+		Index: snap.Metadata.Index,
+		Term:  snap.Metadata.Term,
+	}
+	err := st.WAL.SaveSnapshot(walsnap)
+	if err != nil {
+		return err
+	}
+	err = st.Snapshotter.SaveSnap(snap)
+	if err != nil {
+		return err
+	}
+	return st.WAL.ReleaseLockTo(snap.Metadata.Index)
+}
+
+func readWAL(lg *zap.Logger, waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID, st raftpb.HardState, ents []raftpb.Entry) {
+	var (
+		err       error
+		wmetadata []byte
+	)
+
+	repaired := false
+	for {
+		if w, err = wal.Open(lg, waldir, snap); err != nil {
+			if lg != nil {
+				lg.Fatal("failed to open WAL", zap.Error(err))
+			} else {
+				plog.Fatalf("open wal error: %v", err)
+			}
+		}
+		if wmetadata, st, ents, err = w.ReadAll(); err != nil {
+			w.Close()
+			// we can only repair ErrUnexpectedEOF and we never repair twice.
+			if repaired || err != io.ErrUnexpectedEOF {
+				if lg != nil {
+					lg.Fatal("failed to read WAL, cannot be repaired", zap.Error(err))
+				} else {
+					plog.Fatalf("read wal error (%v) and cannot be repaired", err)
+				}
+			}
+			if !wal.Repair(lg, waldir) {
+				if lg != nil {
+					lg.Fatal("failed to repair WAL", zap.Error(err))
+				} else {
+					plog.Fatalf("WAL error (%v) cannot be repaired", err)
+				}
+			} else {
+				if lg != nil {
+					lg.Info("repaired WAL", zap.Error(err))
+				} else {
+					plog.Infof("repaired WAL error (%v)", err)
+				}
+				repaired = true
+			}
+			continue
+		}
+		break
+	}
+	var metadata pb.Metadata
+	pbutil.MustUnmarshal(&metadata, wmetadata)
+	id = types.ID(metadata.NodeID)
+	cid = types.ID(metadata.ClusterID)
+	return w, id, cid, st, ents
+}