Add OptimizeSourceCopyOperation (d8a38e7c) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -74,7 +74,8 @@ class SnapshotStatus;

		static constexpr const std::string_view kCowGroupName = "cow";

		bool SourceCopyOperationIsClone(const chromeos_update_engine::InstallOperation& operation);
		bool OptimizeSourceCopyOperation(const chromeos_update_engine::InstallOperation& operation,
		chromeos_update_engine::InstallOperation* optimized);

		enum class CreateResult : unsigned int {
		ERROR,

fs_mgr/libsnapshot/partition_cow_creator.cpp

+67 −13

Original line number	Diff line number	Diff line
		@@ -62,17 +62,68 @@ bool PartitionCowCreator::HasExtent(Partition* p, Extent* e) {
		return false;
		}

		bool SourceCopyOperationIsClone(const InstallOperation& operation) {
		using ChromeOSExtent = chromeos_update_engine::Extent;
		if (operation.src_extents().size() != operation.dst_extents().size()) {
		bool OptimizeSourceCopyOperation(const InstallOperation& operation, InstallOperation* optimized) {
		if (operation.type() != InstallOperation::SOURCE_COPY) {
		return false;
		}
		return std::equal(operation.src_extents().begin(), operation.src_extents().end(),
		operation.dst_extents().begin(),
		[](const ChromeOSExtent& src, const ChromeOSExtent& dst) {
		return src.start_block() == dst.start_block() &&
		src.num_blocks() == dst.num_blocks();
		});

		optimized->Clear();
		optimized->set_type(InstallOperation::SOURCE_COPY);

		const auto& src_extents = operation.src_extents();
		const auto& dst_extents = operation.dst_extents();

		// If input is empty, skip by returning an empty result.
		if (src_extents.empty() && dst_extents.empty()) {
		return true;
		}

		auto s_it = src_extents.begin();
		auto d_it = dst_extents.begin();
		uint64_t s_offset = 0; // offset within *s_it
		uint64_t d_offset = 0; // offset within *d_it
		bool is_optimized = false;

		while (s_it != src_extents.end() \|\| d_it != dst_extents.end()) {
		if (s_it == src_extents.end() \|\| d_it == dst_extents.end()) {
		LOG(ERROR) << "number of blocks do not equal in src_extents and dst_extents";
		return false;
		}
		if (s_it->num_blocks() <= s_offset \|\| d_it->num_blocks() <= d_offset) {
		LOG(ERROR) << "Offset goes out of bounds.";
		return false;
		}

		// Check the next \|step\| blocks, where \|step\| is the min of remaining blocks in the current
		// source extent and current destination extent.
		auto s_step = s_it->num_blocks() - s_offset;
		auto d_step = d_it->num_blocks() - d_offset;
		auto step = std::min(s_step, d_step);

		bool moved = s_it->start_block() + s_offset != d_it->start_block() + d_offset;
		if (moved) {
		// If the next \|step\| blocks are not copied to the same location, add them to result.
		AppendExtent(optimized->mutable_src_extents(), s_it->start_block() + s_offset, step);
		AppendExtent(optimized->mutable_dst_extents(), d_it->start_block() + d_offset, step);
		} else {
		// The next \|step\| blocks are optimized out.
		is_optimized = true;
		}

		// Advance offsets by \|step\|, and go to the next non-empty extent if the current extent is
		// depleted.
		s_offset += step;
		d_offset += step;
		while (s_it != src_extents.end() && s_offset >= s_it->num_blocks()) {
		++s_it;
		s_offset = 0;
		}
		while (d_it != dst_extents.end() && d_offset >= d_it->num_blocks()) {
		++d_it;
		d_offset = 0;
		}
		}
		return is_optimized;
		}

		void WriteExtent(DmSnapCowSizeCalculator* sc, const chromeos_update_engine::Extent& de,
		@@ -101,12 +152,15 @@ uint64_t PartitionCowCreator::GetCowSize() {
		if (operations == nullptr) return sc.cow_size_bytes();

		for (const auto& iop : *operations) {
		// Do not allocate space for operations that are going to be skipped
		const InstallOperation* written_op = &iop;
		InstallOperation buf;
		// Do not allocate space for extents that are going to be skipped
		// during OTA application.
		if (iop.type() == InstallOperation::SOURCE_COPY && SourceCopyOperationIsClone(iop))
		continue;
		if (iop.type() == InstallOperation::SOURCE_COPY && OptimizeSourceCopyOperation(iop, &buf)) {
		written_op = &buf;
		}

		for (const auto& de : iop.dst_extents()) {
		for (const auto& de : written_op->dst_extents()) {
		WriteExtent(&sc, de, sectors_per_block);
		}
		}

fs_mgr/libsnapshot/partition_cow_creator_test.cpp

+81 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,9 @@
		// See the License for the specific language governing permissions and
		// limitations under the License.

		#include <optional>
		#include <tuple>

		#include <gmock/gmock.h>
		#include <gtest/gtest.h>
		#include <libdm/dm.h>
		@@ -26,6 +29,13 @@

		using namespace android::fs_mgr;

		using chromeos_update_engine::InstallOperation;
		using UeExtent = chromeos_update_engine::Extent;
		using google::protobuf::RepeatedPtrField;
		using ::testing::Matches;
		using ::testing::Pointwise;
		using ::testing::Truly;

		namespace android {
		namespace snapshot {

		@@ -213,5 +223,76 @@ TEST(DmSnapshotInternals, CowSizeCalculator) {
		}
		}

		void BlocksToExtents(const std::vector<uint64_t>& blocks,
		google::protobuf::RepeatedPtrField<UeExtent>* extents) {
		for (uint64_t block : blocks) {
		AppendExtent(extents, block, 1);
		}
		}

		template <typename T>
		std::vector<uint64_t> ExtentsToBlocks(const T& extents) {
		std::vector<uint64_t> blocks;
		for (const auto& extent : extents) {
		for (uint64_t offset = 0; offset < extent.num_blocks(); ++offset) {
		blocks.push_back(extent.start_block() + offset);
		}
		}
		return blocks;
		}

		InstallOperation CreateCopyOp(const std::vector<uint64_t>& src_blocks,
		const std::vector<uint64_t>& dst_blocks) {
		InstallOperation op;
		op.set_type(InstallOperation::SOURCE_COPY);
		BlocksToExtents(src_blocks, op.mutable_src_extents());
		BlocksToExtents(dst_blocks, op.mutable_dst_extents());
		return op;
		}

		// ExtentEqual(tuple<UeExtent, UeExtent>)
		MATCHER(ExtentEqual, "") {
		auto&& [a, b] = arg;
		return a.start_block() == b.start_block() && a.num_blocks() == b.num_blocks();
		}

		struct OptimizeOperationTestParam {
		InstallOperation input;
		std::optional<InstallOperation> expected_output;
		};

		class OptimizeOperationTest : public ::testing::TestWithParam<OptimizeOperationTestParam> {};
		TEST_P(OptimizeOperationTest, Test) {
		InstallOperation actual_output;
		EXPECT_EQ(GetParam().expected_output.has_value(),
		OptimizeSourceCopyOperation(GetParam().input, &actual_output))
		<< "OptimizeSourceCopyOperation should "
		<< (GetParam().expected_output.has_value() ? "succeed" : "fail");
		if (!GetParam().expected_output.has_value()) return;
		EXPECT_THAT(actual_output.src_extents(),
		Pointwise(ExtentEqual(), GetParam().expected_output->src_extents()));
		EXPECT_THAT(actual_output.dst_extents(),
		Pointwise(ExtentEqual(), GetParam().expected_output->dst_extents()));
		}

		std::vector<OptimizeOperationTestParam> GetOptimizeOperationTestParams() {
		return {
		{CreateCopyOp({}, {}), CreateCopyOp({}, {})},
		{CreateCopyOp({1, 2, 4}, {1, 2, 4}), CreateCopyOp({}, {})},
		{CreateCopyOp({1, 2, 3}, {4, 5, 6}), std::nullopt},
		{CreateCopyOp({3, 2}, {1, 2}), CreateCopyOp({3}, {1})},
		{CreateCopyOp({5, 6, 3, 4, 1, 2}, {1, 2, 3, 4, 5, 6}),
		CreateCopyOp({5, 6, 1, 2}, {1, 2, 5, 6})},
		{CreateCopyOp({1, 2, 3, 5, 5, 6}, {5, 6, 3, 4, 1, 2}),
		CreateCopyOp({1, 2, 5, 5, 6}, {5, 6, 4, 1, 2})},
		{CreateCopyOp({1, 2, 5, 6, 9, 10}, {1, 4, 5, 6, 7, 8}),
		CreateCopyOp({2, 9, 10}, {4, 7, 8})},
		{CreateCopyOp({2, 3, 3, 4, 4}, {1, 2, 3, 4, 5}), CreateCopyOp({2, 3, 4}, {1, 2, 5})},
		};
		}

		INSTANTIATE_TEST_CASE_P(Snapshot, OptimizeOperationTest,
		::testing::ValuesIn(GetOptimizeOperationTestParams()));

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/utility.cpp

+16 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@ using android::fs_mgr::GetEntryForPath;
		using android::fs_mgr::MetadataBuilder;
		using android::fs_mgr::Partition;
		using android::fs_mgr::ReadDefaultFstab;
		using google::protobuf::RepeatedPtrField;

		namespace android {
		namespace snapshot {
		@@ -166,5 +167,20 @@ std::ostream& operator<<(std::ostream& os, const Now&) {
		return os << std::put_time(&now, "%Y%m%d-%H%M%S");
		}

		void AppendExtent(RepeatedPtrField<chromeos_update_engine::Extent>* extents, uint64_t start_block,
		uint64_t num_blocks) {
		if (extents->size() > 0) {
		auto last_extent = extents->rbegin();
		auto next_block = last_extent->start_block() + last_extent->num_blocks();
		if (start_block == next_block) {
		last_extent->set_num_blocks(last_extent->num_blocks() + num_blocks);
		return;
		}
		}
		auto* new_extent = extents->Add();
		new_extent->set_start_block(start_block);
		new_extent->set_num_blocks(num_blocks);
		}

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/utility.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -125,5 +125,9 @@ bool WriteStringToFileAtomic(const std::string& content, const std::string& path
		struct Now {};
		std::ostream& operator<<(std::ostream& os, const Now&);

		// Append to \|extents\|. Merged into the last element if possible.
		void AppendExtent(google::protobuf::RepeatedPtrField<chromeos_update_engine::Extent>* extents,
		uint64_t start_block, uint64_t num_blocks);

		} // namespace snapshot
		} // namespace android