Merge "libfiemap: Fix fallocate() usage." (42c86c76) · Commits · e / os / android_system_core

fs_mgr/libfiemap/fiemap_writer.cpp

+50 −37

Original line number	Original line	Diff line number	Diff line
	@@ -386,43 +386,12 @@ static bool PinFile(int file_fd, const std::string& file_path, uint32_t fs_type)
	return true;		return true;
	}		}

	// Reserve space for the file on the file system and write it out to make sure the extents
	// don't come back unwritten. Return from this function with the kernel file offset set to 0.
	// If the filesystem is f2fs, then we also PIN the file on disk to make sure the blocks
	// aren't moved around.
	static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blocksz,
	uint64_t file_size, unsigned int fs_type,
	std::function<bool(uint64_t, uint64_t)> on_progress) {
	switch (fs_type) {
	case EXT4_SUPER_MAGIC:
	break;
	case F2FS_SUPER_MAGIC: {
	bool supported;
	if (!F2fsPinBeforeAllocate(file_fd, &supported)) {
	return false;
	}
	if (supported && !PinFile(file_fd, file_path, fs_type)) {
	return false;
	}
	break;
	}
	case MSDOS_SUPER_MAGIC:
	// fallocate() is not supported, and not needed, since VFAT does not support holes.
	// Instead we can perform a much faster allocation.
	return FallocateFallback(file_fd, blocksz, file_size, file_path, on_progress);
	default:
	LOG(ERROR) << "Missing fallocate() support for file system " << fs_type;
	return false;
	}

	if (fallocate(file_fd, FALLOC_FL_ZERO_RANGE, 0, file_size)) {
	PLOG(ERROR) << "Failed to allocate space for file: " << file_path << " size: " << file_size;
	return false;
	}

	// write zeroes in 'blocksz' byte increments until we reach file_size to make sure the data		// write zeroes in 'blocksz' byte increments until we reach file_size to make sure the data
	// blocks are actually written to by the file system and thus getting rid of the holes in the		// blocks are actually written to by the file system and thus getting rid of the holes in the
	// file.		// file.
			static bool WriteZeroes(int file_fd, const std::string& file_path, size_t blocksz,
			uint64_t file_size,
			const std::function<bool(uint64_t, uint64_t)>& on_progress) {
	auto buffer = std::unique_ptr<void, decltype(&free)>(calloc(1, blocksz), free);		auto buffer = std::unique_ptr<void, decltype(&free)>(calloc(1, blocksz), free);
	if (buffer == nullptr) {		if (buffer == nullptr) {
	LOG(ERROR) << "failed to allocate memory for writing file";		LOG(ERROR) << "failed to allocate memory for writing file";
	@@ -460,6 +429,50 @@ static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blo
	PLOG(ERROR) << "Failed to reset offset at the beginning of : " << file_path;		PLOG(ERROR) << "Failed to reset offset at the beginning of : " << file_path;
	return false;		return false;
	}		}
			return true;
			}

			// Reserve space for the file on the file system and write it out to make sure the extents
			// don't come back unwritten. Return from this function with the kernel file offset set to 0.
			// If the filesystem is f2fs, then we also PIN the file on disk to make sure the blocks
			// aren't moved around.
			static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blocksz,
			uint64_t file_size, unsigned int fs_type,
			std::function<bool(uint64_t, uint64_t)> on_progress) {
			bool need_explicit_writes = true;
			switch (fs_type) {
			case EXT4_SUPER_MAGIC:
			break;
			case F2FS_SUPER_MAGIC: {
			bool supported;
			if (!F2fsPinBeforeAllocate(file_fd, &supported)) {
			return false;
			}
			if (supported) {
			if (!PinFile(file_fd, file_path, fs_type)) {
			return false;
			}
			need_explicit_writes = false;
			}
			break;
			}
			case MSDOS_SUPER_MAGIC:
			// fallocate() is not supported, and not needed, since VFAT does not support holes.
			// Instead we can perform a much faster allocation.
			return FallocateFallback(file_fd, blocksz, file_size, file_path, on_progress);
			default:
			LOG(ERROR) << "Missing fallocate() support for file system " << fs_type;
			return false;
			}

			if (fallocate(file_fd, 0, 0, file_size)) {
			PLOG(ERROR) << "Failed to allocate space for file: " << file_path << " size: " << file_size;
			return false;
			}

			if (need_explicit_writes && !WriteZeroes(file_fd, file_path, blocksz, file_size, on_progress)) {
			return false;
			}

	// flush all writes here ..		// flush all writes here ..
	if (fsync(file_fd)) {		if (fsync(file_fd)) {