Merge "libfiemap_writer: Allow callers to query the block device of a file." (281a0f21) · Commits · e / os / android_system_core

fs_mgr/libfiemap_writer/fiemap_writer.cpp

+7 −2

Original line number	Diff line number	Diff line
		@@ -126,7 +126,8 @@ static bool DeviceMapperStackPop(const std::string& bdev, std::string* bdev_raw)
		return DeviceMapperStackPop(bdev_next, bdev_raw);
		}

		static bool FileToBlockDevicePath(const std::string& file_path, std::string* bdev_path) {
		bool FiemapWriter::GetBlockDeviceForFile(const std::string& file_path, std::string* bdev_path,
		bool* uses_dm) {
		struct stat sb;
		if (stat(file_path.c_str(), &sb)) {
		PLOG(ERROR) << "Failed to get stat for: " << file_path;
		@@ -146,6 +147,10 @@ static bool FileToBlockDevicePath(const std::string& file_path, std::string* bde
		return false;
		}

		if (uses_dm) {
		*uses_dm = (bdev_raw != bdev);
		}

		LOG(DEBUG) << "Popped device (" << bdev_raw << ") from device mapper stack starting with ("
		<< bdev << ")";

		@@ -458,7 +463,7 @@ FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_s
		}

		std::string bdev_path;
		if (!FileToBlockDevicePath(abs_path, &bdev_path)) {
		if (!GetBlockDeviceForFile(abs_path, &bdev_path)) {
		LOG(ERROR) << "Failed to get block dev path for file: " << file_path;
		cleanup(abs_path, create);
		return nullptr;

+7 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,13 @@ class FiemapWriter final {
		// FiemapWriter::Open).
		static bool HasPinnedExtents(const std::string& file_path);

		// Returns the underlying block device of a file. This will look past device-mapper layers.
		// If an intermediate device-mapper layer would not maintain a 1:1 mapping (i.e. is a non-
		// trivial dm-linear), then this will fail. If device-mapper nodes are encountered, then
		// \|uses_dm\| will be set to true.
		static bool GetBlockDeviceForFile(const std::string& file_path, std::string* bdev_path,
		bool* uses_dm = nullptr);

		// The counter part of Write(). It is an error for the offset to be unaligned with
		// the block device's block size.
		// In case of error, the contents of buffer MUST be discarded.