// Do the interface allocations only once for common
// Errno values.
const (
	errnoERROR_IO_PENDING = 997
)

var (
	errERROR_IO_PENDING error = Errno(errnoERROR_IO_PENDING)
	errERROR_EINVAL     error = EINVAL
)

// errnoErr returns common boxed Errno values, to prevent
// allocations at runtime.
func errnoErr(e Errno) error {
	switch e {
	case 0:
		return errERROR_EINVAL
	case errnoERROR_IO_PENDING:

		{0, io.SeekCurrent, 2<<32 - 1},
	}
	for i, tt := range tests {
		off, err := f.Seek(tt.in, tt.whence)
		if off != tt.out || err != nil {
			if e, ok := err.(*PathError); ok && e.Err == syscall.EINVAL && tt.out > 1<<32 && runtime.GOOS == "linux" {
				mounts, _ := ReadFile("/proc/mounts")
				if strings.Contains(string(mounts), "reiserfs") {
					// Reiserfs rejects the big seeks.