diff --git a/vendor/github.com/coreos/etcd/etcdserver/storage.go b/vendor/github.com/coreos/etcd/etcdserver/storage.go
new file mode 100644
index 0000000..2cddb5c
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/storage.go
@@ -0,0 +1,112 @@
+// 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"
+
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+	"github.com/coreos/etcd/pkg/pbutil"
+	"github.com/coreos/etcd/pkg/types"
+	"github.com/coreos/etcd/raft/raftpb"
+	"github.com/coreos/etcd/snap"
+	"github.com/coreos/etcd/wal"
+	"github.com/coreos/etcd/wal/walpb"
+)
+
+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
+	// Release releases the locked wal files older than the provided snapshot.
+	Release(snap raftpb.Snapshot) error
+	// Sync WAL
+	Sync() 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 file to disk and writes the WAL snapshot entry.
+func (st *storage) SaveSnap(snap raftpb.Snapshot) error {
+	walsnap := walpb.Snapshot{
+		Index: snap.Metadata.Index,
+		Term:  snap.Metadata.Term,
+	}
+
+	// save the snapshot file before writing the snapshot to the wal.
+	// This makes it possible for the snapshot file to become orphaned, but prevents
+	// a WAL snapshot entry from having no corresponding snapshot file.
+	err := st.Snapshotter.SaveSnap(snap)
+	if err != nil {
+		return err
+	}
+
+	return st.WAL.SaveSnapshot(walsnap)
+}
+
+// Release releases resources older than the given snap and are no longer needed:
+// - releases the locks to the wal files that are older than the provided wal for the given snap.
+// - deletes any .snap.db files that are older than the given snap.
+func (st *storage) Release(snap raftpb.Snapshot) error {
+	if err := st.WAL.ReleaseLockTo(snap.Metadata.Index); err != nil {
+		return err
+	}
+	return st.Snapshotter.ReleaseSnapDBs(snap)
+}
+
+func readWAL(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(waldir, snap); err != nil {
+			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 {
+				plog.Fatalf("read wal error (%v) and cannot be repaired", err)
+			}
+			if !wal.Repair(waldir) {
+				plog.Fatalf("WAL error (%v) cannot be repaired", 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
+}