Merge "Make partition metadata write atomic" into main (9c949326) · Commits · e / os / android_system_core

fs_mgr/libfiemap/metadata.cpp

+1 −7

Original line number	Diff line number	Diff line
		@@ -111,13 +111,7 @@ bool SaveMetadata(MetadataBuilder* builder, const std::string& metadata_dir) {
		return true;
		}

		unique_fd fd(open(metadata_file.c_str(), O_CREAT \| O_RDWR \| O_TRUNC \| O_CLOEXEC \| O_BINARY \| O_SYNC, 0644));
		if (fd < 0) {
		LOG(ERROR) << "open failed: " << metadata_file;
		return false;
		}

		if (!WriteToImageFile(fd, *exported.get())) {
		if (!WriteToImageFile(metadata_file, *exported.get())) {
		LOG(ERROR) << "Unable to save new metadata";
		return false;
		}

fs_mgr/liblp/images.cpp

+39 −5

Original line number	Diff line number	Diff line
		@@ -123,13 +123,46 @@ bool WriteToImageFile(borrowed_fd fd, const LpMetadata& input) {
		return true;
		}

		#if !defined(_WIN32)
		bool FsyncDirectory(const char* dirname) {
		android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(dirname, O_RDONLY \| O_CLOEXEC)));
		if (fd == -1) {
		PLOG(ERROR) << "Failed to open " << dirname;
		return false;
		}
		if (fsync(fd) == -1) {
		if (errno == EROFS \|\| errno == EINVAL) {
		PLOG(WARNING) << "Skip fsync " << dirname
		<< " on a file system does not support synchronization";
		} else {
		PLOG(ERROR) << "Failed to fsync " << dirname;
		return false;
		}
		}
		return true;
		}
		#endif

		bool WriteToImageFile(const std::string& file, const LpMetadata& input) {
		unique_fd fd(open(file.c_str(), O_CREAT \| O_RDWR \| O_TRUNC \| O_CLOEXEC \| O_BINARY, 0644));
		if (fd < 0) {
		PERROR << __PRETTY_FUNCTION__ << " open failed: " << file;
		const auto parent_dir = base::Dirname(file);
		TemporaryFile tmpfile(parent_dir);
		if (!WriteToImageFile(tmpfile.fd, input)) {
		PLOG(ERROR) << "Failed to write geometry data to tmpfile " << tmpfile.path;
		return false;
		}
		return WriteToImageFile(fd, input);

		#if !defined(_WIN32)
		fsync(tmpfile.fd);
		#endif
		const auto err = rename(tmpfile.path, file.c_str());
		if (err != 0) {
		PLOG(ERROR) << "Failed to rename tmp geometry file " << tmpfile.path << " to " << file;
		return false;
		}
		#if !defined(_WIN32)
		FsyncDirectory(parent_dir.c_str());
		#endif
		return true;
		}

		ImageBuilder::ImageBuilder(const LpMetadata& metadata, uint32_t block_size,
		@@ -208,7 +241,8 @@ bool ImageBuilder::ExportFiles(const std::string& output_dir) {
		std::string file_name = "super_" + name + ".img";
		std::string file_path = output_dir + "/" + file_name;

		static const int kOpenFlags = O_CREAT \| O_RDWR \| O_TRUNC \| O_CLOEXEC \| O_NOFOLLOW \| O_BINARY;
		static const int kOpenFlags =
		O_CREAT \| O_RDWR \| O_TRUNC \| O_CLOEXEC \| O_NOFOLLOW \| O_BINARY;
		unique_fd fd(open(file_path.c_str(), kOpenFlags, 0644));
		if (fd < 0) {
		PERROR << "open failed: " << file_path;