Merge "libfiemap_writer: Calculate FIBMAP blocks correctly." (9d3310c0) · Commits · e / os / android_system_core

fs_mgr/libfiemap_writer/fiemap_writer.cpp

+16 −7

Original line number	Diff line number	Diff line
		@@ -507,7 +507,17 @@ static bool ReadFibmap(int file_fd, const std::string& file_path,
		return false;
		}

		uint64_t num_blocks = (s.st_size + s.st_blksize - 1) / s.st_blksize;
		unsigned int blksize;
		if (ioctl(file_fd, FIGETBSZ, &blksize) < 0) {
		PLOG(ERROR) << "Failed to get FIGETBSZ for " << file_path;
		return false;
		}
		if (!blksize) {
		LOG(ERROR) << "Invalid filesystem block size: " << blksize;
		return false;
		}

		uint64_t num_blocks = (s.st_size + blksize - 1) / blksize;
		if (num_blocks > std::numeric_limits<uint32_t>::max()) {
		LOG(ERROR) << "Too many blocks for FIBMAP (" << num_blocks << ")";
		return false;
		@@ -525,12 +535,11 @@ static bool ReadFibmap(int file_fd, const std::string& file_path,
		}

		if (!extents->empty() && block == last_block + 1) {
		extents->back().fe_length += s.st_blksize;
		extents->back().fe_length += blksize;
		} else {
		extents->push_back(
		fiemap_extent{.fe_logical = block_number,
		.fe_physical = static_cast<uint64_t>(block) * s.st_blksize,
		.fe_length = static_cast<uint64_t>(s.st_blksize),
		extents->push_back(fiemap_extent{.fe_logical = block_number,
		.fe_physical = static_cast<uint64_t>(block) * blksize,
		.fe_length = static_cast<uint64_t>(blksize),
		.fe_flags = 0});
		}
		last_block = block;

fs_mgr/libfiemap_writer/fiemap_writer_test.cpp

+56 −1

Original line number	Diff line number	Diff line
		@@ -196,6 +196,61 @@ TEST_F(FiemapWriterTest, MaxBlockSize) {
		ASSERT_GT(DetermineMaximumFileSize(testfile), 0);
		}

		TEST_F(FiemapWriterTest, FibmapBlockAddressing) {
		FiemapUniquePtr fptr = FiemapWriter::Open(testfile, gBlockSize);
		ASSERT_NE(fptr, nullptr);

		switch (fptr->fs_type()) {
		case F2FS_SUPER_MAGIC:
		case EXT4_SUPER_MAGIC:
		// Skip the test for FIEMAP supported filesystems. This is really
		// because f2fs/ext4 have caches that seem to defeat reading back
		// directly from the block device, and writing directly is too
		// dangerous.
		std::cout << "Skipping test, filesystem does not use FIBMAP\n";
		return;
		}

		bool uses_dm;
		std::string bdev_path;
		ASSERT_TRUE(FiemapWriter::GetBlockDeviceForFile(testfile, &bdev_path, &uses_dm));

		if (uses_dm) {
		// We could use a device-mapper wrapper here to bypass encryption, but
		// really this test is for FIBMAP correctness on VFAT (where encryption
		// is never used), so we don't bother.
		std::cout << "Skipping test, block device is metadata encrypted\n";
		return;
		}

		std::string data(fptr->size(), '\0');
		for (size_t i = 0; i < data.size(); i++) {
		data[i] = 'A' + static_cast<char>(data.size() % 26);
		}

		{
		unique_fd fd(open(testfile.c_str(), O_WRONLY \| O_CLOEXEC));
		ASSERT_GE(fd, 0);
		ASSERT_TRUE(android::base::WriteFully(fd, data.data(), data.size()));
		ASSERT_EQ(fsync(fd), 0);
		}

		ASSERT_FALSE(fptr->extents().empty());
		const auto& first_extent = fptr->extents()[0];

		unique_fd bdev(open(fptr->bdev_path().c_str(), O_RDONLY \| O_CLOEXEC));
		ASSERT_GE(bdev, 0);

		off_t where = first_extent.fe_physical;
		ASSERT_EQ(lseek(bdev, where, SEEK_SET), where);

		// Note: this will fail on encrypted folders.
		std::string actual(data.size(), '\0');
		ASSERT_GE(first_extent.fe_length, data.size());
		ASSERT_TRUE(android::base::ReadFully(bdev, actual.data(), actual.size()));
		EXPECT_EQ(memcmp(actual.data(), data.data(), data.size()), 0);
		}

		TEST_F(SplitFiemapTest, Create) {
		auto ptr = SplitFiemap::Create(testfile, 1024 * 768, 1024 * 32);
		ASSERT_NE(ptr, nullptr);
		@@ -446,7 +501,7 @@ int main(int argc, char** argv) {
		if (argc <= 1) {
		cerr << "Usage: <test_dir> [file_size]\n";
		cerr << "\n";
		cerr << "Note: test_dir must be a writable directory.\n";
		cerr << "Note: test_dir must be a writable, unencrypted directory.\n";
		exit(EXIT_FAILURE);
		}
		::android::base::InitLogging(argv, ::android::base::StderrLogger);