IsReadOnlyVolume
if (Utility::IsReadOnlyVolume("/boot")) {
fIsReadOnly = Utility::IsReadOnlyVolume(fPath);
fReadOnlyBootVolume = Utility::IsReadOnlyVolume("/boot");
return IsReadOnlyVolume(dev_for_path(path));
bool IsReadOnlyVolume(dev_t device);
bool IsReadOnlyVolume(const char* path);