Golang fails to write header to tar package？

code show as below

    fInfo, err := os.Stat(fp)
	if err != nil {
        fmt.Println(err.Error())
		return
	}
	header, err := tar.FileInfoHeader(fInfo, "")
	if err != nil {
		fmt.Println(err.Error())
		return
	}
	header.Name = name
	if header.Format == tar.FormatUnknown {
		header.Format = tar.FormatGNU
	}

	err = this.writer.WriteHeader(header)
	if err != nil {
		fmt.Println(err.Error())
		return
	}

	f, err := os.Open(fp)
	if err != nil {
		fmt.Println(err.Error())
		return
	}
	defer f.Close()
	_, err = io.Copy(this.writer, f)
	fmt.Println(err.Error())
	return

Reporting an error in the diverted code

this.writer.WriteHeader(header)

The error is as follows

archive/tar: missed writing 15251 bytes

I have tested many times, I don't know why this error occurs in this way.

It should be noted that the content I packaged is the content in the U disk.

As it is mentioned in the documentation, WriteHeader implicitly calls Flush, which in turn checks is there any number of remaining bytes to write. If so it will return an error that you got.

The number of remaining bytes is stored in nb variable and initialised when you write header first time. Then every time when you write some content it will be decreased by a number of bytes written.

If nb is more then zero and you try to call WriteHeader second time you will get this error.