Merge "libdm: Make ExtractBlockDeviceName() return its result" into sc-dev (232ec664) · Commits · e / os / android_system_core

fs_mgr/libdm/dm.cpp

+13 −17

Original line number	Diff line number	Diff line
		@@ -560,34 +560,30 @@ std::string DeviceMapper::GetTargetType(const struct dm_target_spec& spec) {
		return std::string{spec.target_type, sizeof(spec.target_type)};
		}

		static bool ExtractBlockDeviceName(const std::string& path, std::string* name) {
		static std::optional<std::string> ExtractBlockDeviceName(const std::string& path) {
		static constexpr std::string_view kDevBlockPrefix("/dev/block/");
		if (android::base::StartsWith(path, kDevBlockPrefix)) {
		*name = path.substr(kDevBlockPrefix.length());
		return true;
		return path.substr(kDevBlockPrefix.length());
		}
		return false;
		return {};
		}

		bool DeviceMapper::IsDmBlockDevice(const std::string& path) {
		std::string name;
		if (!ExtractBlockDeviceName(path, &name)) {
		return false;
		}
		return android::base::StartsWith(name, "dm-");
		std::optional<std::string> name = ExtractBlockDeviceName(path);
		return name && android::base::StartsWith(*name, "dm-");
		}

		std::optional<std::string> DeviceMapper::GetDmDeviceNameByPath(const std::string& path) {
		std::string name;
		if (!ExtractBlockDeviceName(path, &name)) {
		std::optional<std::string> name = ExtractBlockDeviceName(path);
		if (!name) {
		LOG(WARNING) << path << " is not a block device";
		return std::nullopt;
		}
		if (!android::base::StartsWith(name, "dm-")) {
		if (!android::base::StartsWith(*name, "dm-")) {
		LOG(WARNING) << path << " is not a dm device";
		return std::nullopt;
		}
		std::string dm_name_file = "/sys/block/" + name + "/dm/name";
		std::string dm_name_file = "/sys/block/" + *name + "/dm/name";
		std::string dm_name;
		if (!android::base::ReadFileToString(dm_name_file, &dm_name)) {
		PLOG(ERROR) << "Failed to read file " << dm_name_file;
		@@ -598,16 +594,16 @@ std::optional<std::string> DeviceMapper::GetDmDeviceNameByPath(const std::string
		}

		std::optional<std::string> DeviceMapper::GetParentBlockDeviceByPath(const std::string& path) {
		std::string name;
		if (!ExtractBlockDeviceName(path, &name)) {
		std::optional<std::string> name = ExtractBlockDeviceName(path);
		if (!name) {
		LOG(WARNING) << path << " is not a block device";
		return std::nullopt;
		}
		if (!android::base::StartsWith(name, "dm-")) {
		if (!android::base::StartsWith(*name, "dm-")) {
		// Reached bottom of the device mapper stack.
		return std::nullopt;
		}
		auto slaves_dir = "/sys/block/" + name + "/slaves";
		auto slaves_dir = "/sys/block/" + *name + "/slaves";
		auto dir = std::unique_ptr<DIR, decltype(&closedir)>(opendir(slaves_dir.c_str()), closedir);
		if (dir == nullptr) {
		PLOG(ERROR) << "Failed to open: " << slaves_dir;