// flags and shouldn't be considered as replacement
// for os.OpenFile().
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, syscall.F_SETLKW)
}

// Open - Call os.OpenFile
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(path, flag, perm)

	return RenameSys(src, dst)
}

// OpenFile captures time taken to call os.OpenFile
func OpenFile(name string, flag int, perm os.FileMode) (f *os.File, err error) {
	switch flag & writeMode {
	case writeMode:
		defer updateOSMetrics(osMetricOpenFileW, name)(err)
	default:
		defer updateOSMetrics(osMetricOpenFileR, name)(err)
	}
	return os.OpenFile(name, flag, perm)
}

// flags and shouldn't be considered as replacement
// for os.OpenFile().
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, 0)
}

// Open - Call os.OpenFile
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(path, flag, perm)

func AppendFile(dst string, src string, osync bool) error {
	flags := os.O_WRONLY | os.O_APPEND | os.O_CREATE
	if osync {
		flags |= os.O_SYNC
	}
	appendFile, err := os.OpenFile(dst, flags, 0o666)
	if err != nil {
		return err
	}
	defer appendFile.Close()

	srcFile, err := os.Open(src)
	if err != nil {
		return err
	}
	defer srcFile.Close()

	OpenFileDirectIO = disk.OpenFileDirectIO
	// OsOpen allows overriding default function.
	OsOpen = os.Open
	// OsOpenFile allows overriding default function.
	OsOpenFile = os.OpenFile
)

// ReadFileWithFileInfo reads the named file and returns the contents.
// A successful call returns err == nil, not err == EOF.
// Because ReadFile reads the whole file, it does not treat an EOF from Read

// see this ZFS-on-Linux commit message:
// https://github.com/openzfs/zfs/commit/a584ef26053065f486d46a7335bea222cb03eeea

// OpenFileDirectIO wrapper around os.OpenFile nothing special
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(filePath, flag, perm)
}

// DisableDirectIO is a no-op
func DisableDirectIO(f *os.File) error {
	return nil
}

const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.
func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	_, err := unix.FcntlInt(fd, unix.F_NOCACHE, 0)
	return err
}

const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.
func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	flag, err := unix.FcntlInt(fd, unix.F_GETFL, 0)
	if err != nil {
		return err
	}

					// and check if that disk
					// appears in outDatedDisks.
					tamperedIndex = index
					filePath := pathJoin(erasureDisks[index].String(), bucket, object, fi.DataDir, "part.1")
					f, err := os.OpenFile(filePath, os.O_WRONLY|os.O_SYNC, 0)
					if err != nil {
						t.Fatalf("Failed to open %s: %s\n", filePath, err)
					}
					f.WriteString("oops") // Will cause bitrot error
					f.Close()
					break
				}

		}
	}

	return w, nil
}

func (s *xlStorage) openFileSync(filePath string, mode int, skipParent string) (f *os.File, err error) {
	return s.openFile(filePath, mode|writeMode, skipParent)
}

func (s *xlStorage) openFile(filePath string, mode int, skipParent string) (f *os.File, err error) {
	if skipParent == "" {
		skipParent = s.drivePath
	}