diff --git a/vendor/go.etcd.io/etcd/wal/file_pipeline.go b/vendor/go.etcd.io/etcd/wal/file_pipeline.go
new file mode 100644
index 0000000..e1e1c55
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/file_pipeline.go
@@ -0,0 +1,106 @@
+// Copyright 2016 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 wal
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+
+	"go.uber.org/zap"
+)
+
+// filePipeline pipelines allocating disk space
+type filePipeline struct {
+	lg *zap.Logger
+
+	// dir to put files
+	dir string
+	// size of files to make, in bytes
+	size int64
+	// count number of files generated
+	count int
+
+	filec chan *fileutil.LockedFile
+	errc  chan error
+	donec chan struct{}
+}
+
+func newFilePipeline(lg *zap.Logger, dir string, fileSize int64) *filePipeline {
+	fp := &filePipeline{
+		lg:    lg,
+		dir:   dir,
+		size:  fileSize,
+		filec: make(chan *fileutil.LockedFile),
+		errc:  make(chan error, 1),
+		donec: make(chan struct{}),
+	}
+	go fp.run()
+	return fp
+}
+
+// Open returns a fresh file for writing. Rename the file before calling
+// Open again or there will be file collisions.
+func (fp *filePipeline) Open() (f *fileutil.LockedFile, err error) {
+	select {
+	case f = <-fp.filec:
+	case err = <-fp.errc:
+	}
+	return f, err
+}
+
+func (fp *filePipeline) Close() error {
+	close(fp.donec)
+	return <-fp.errc
+}
+
+func (fp *filePipeline) alloc() (f *fileutil.LockedFile, err error) {
+	// count % 2 so this file isn't the same as the one last published
+	fpath := filepath.Join(fp.dir, fmt.Sprintf("%d.tmp", fp.count%2))
+	if f, err = fileutil.LockFile(fpath, os.O_CREATE|os.O_WRONLY, fileutil.PrivateFileMode); err != nil {
+		return nil, err
+	}
+	if err = fileutil.Preallocate(f.File, fp.size, true); err != nil {
+		if fp.lg != nil {
+			fp.lg.Warn("failed to preallocate space when creating a new WAL", zap.Int64("size", fp.size), zap.Error(err))
+		} else {
+			plog.Errorf("failed to allocate space when creating new wal file (%v)", err)
+		}
+		f.Close()
+		return nil, err
+	}
+	fp.count++
+	return f, nil
+}
+
+func (fp *filePipeline) run() {
+	defer close(fp.errc)
+	for {
+		f, err := fp.alloc()
+		if err != nil {
+			fp.errc <- err
+			return
+		}
+		select {
+		case fp.filec <- f:
+		case <-fp.donec:
+			os.Remove(f.Name())
+			f.Close()
+			return
+		}
+	}
+}