You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: srv_file.go
    path of file: ./repos/minikube/third_party/go9p
    
    the code of the file until where you have to start completion: // Copyright 2009 The Go9p Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package go9p

import (
	"log"
	"runtime"
	"sync"
	"time"
)

// The FStatOp interface provides a single operation (Stat) that will be
// called before a file stat is sent back to the client. If implemented,
// the operation should update the data in the srvFile struct.
type FStatOp interface {
	Stat(fid *FFid) error
}

// The FWst
    
func (*Fsrv) Walk(req *SrvReq) {
	fid := req.Fid.Aux.(*FFid)
	tc := req.Tc

	if req.Newfid.Aux == nil {
		nfid := new(FFid)
		nfid.Fid = req.Newfid
		req.Newfid.Aux = nfid
	}

	nfid := req.Newfid.Aux.(*FFid)
	wqids := make([]Qid, len(tc.Wname))
	i := 0
	f := fid.F
	for ; i < len(tc.Wname); i++ {
		if tc.Wname[i] == ".." {
			// handle dotdot
			f = f.Parent
			wqids[i] = f.Qid
			continue
		}
		if (wqids[i].Type & QTDIR) > 0 {
			if !f.CheckPerm(req.Fid.User, DMEXEC) {
				break
			}
		}

		p := f.Find(tc.Wname[i])
		if p == nil {
			break
		}

		f = p
		wqids[i] = f.Qid
	}

	if len(tc.Wname) > 0 && i == 0 {
		req.RespondError(Enoent)
		return
	}

	nfid.F = f
	req.RespondRwalk(wqids[0:i])
}