kubernetes/vendor/go.etcd.io/etcd/client/pkg/v3/fileutil/sync_linux.go

// Fsync is a wrapper around file.Sync(). Special handling is needed on darwin platform.
func Fsync(f *os.File) error { … }

// Fdatasync is similar to fsync(), but does not flush modified metadata
// unless that metadata is needed in order to allow a subsequent data retrieval
// to be correctly handled.
func Fdatasync(f *os.File) error { … }