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: volume_create_linux.go
    path of file: ./repos/seaweedfs/weed/storage/backend
    
    the code of the file until where you have to start completion: //go:build linux
// +build linux

package backend

import (
	"os"
	"syscall"

	"github.com/seaweedfs/seaweedfs/weed/glog"
)

func CreateVolumeFile(fileName string, preallocate int64, memoryMapSizeMB uint32) (BackendSt
    
func CreateVolumeFile(fileName string, preallocate int64, memoryMapSizeMB uint32) (BackendStorageFile, error) {
	file, e := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	if e != nil {
		return nil, e
	}
	if preallocate != 0 {
		syscall.Fallocate(int(file.Fd()), 1, 0, preallocate)
		glog.V(1).Infof("Preallocated %d bytes disk space for %s", preallocate, fileName)
	}
	return NewDiskFile(file), nil
}