Merge "libsnapshot: Fix flaky low-space tests." (25613816) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h

+0 −23

Original line number	Diff line number	Diff line
		@@ -214,29 +214,6 @@ void SetSize(PartitionUpdate* partition_update, uint64_t size);
		// Get partition size from update package metadata.
		uint64_t GetSize(PartitionUpdate* partition_update);

		// Util class for test cases on low space scenario. These tests assumes image manager
		// uses /data as backup device.
		class LowSpaceUserdata {
		public:
		// Set the maximum free space allowed for this test. If /userdata has more space than the given
		// number, a file is allocated to consume space.
		AssertionResult Init(uint64_t max_free_space);

		uint64_t free_space() const;
		uint64_t available_space() const;
		uint64_t bsize() const;

		private:
		AssertionResult ReadUserdataStats();

		static constexpr const char* kUserDataDevice = "/data";
		std::unique_ptr<TemporaryFile> big_file_;
		bool initialized_ = false;
		uint64_t free_space_ = 0;
		uint64_t available_space_ = 0;
		uint64_t bsize_ = 0;
		};

		bool IsVirtualAbEnabled();

		#define SKIP_IF_NON_VIRTUAL_AB() \

fs_mgr/libsnapshot/snapshot.cpp

+9 −2

Original line number	Diff line number	Diff line
		@@ -3133,6 +3133,7 @@ static Return AddRequiredSpace(Return orig,
		for (auto&& [name, status] : all_snapshot_status) {
		sum += status.cow_file_size();
		}
		LOG(INFO) << "Calculated needed COW space: " << sum << " bytes";
		return Return::NoSpace(sum);
		}

		@@ -3279,7 +3280,10 @@ Return SnapshotManager::CreateUpdateSnapshots(const DeltaArchiveManifest& manife

		auto ret = CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
		&all_snapshot_status);
		if (!ret.is_ok()) return ret;
		if (!ret.is_ok()) {
		LOG(ERROR) << "CreateUpdateSnapshotsInternal failed: " << ret.string();
		return ret;
		}

		auto exported_target_metadata = target_metadata->Export();
		if (exported_target_metadata == nullptr) {
		@@ -3496,7 +3500,10 @@ Return SnapshotManager::CreateUpdateSnapshotsInternal(
		// Create the backing COW image if necessary.
		if (snapshot_status.cow_file_size() > 0) {
		auto ret = CreateCowImage(lock, name);
		if (!ret.is_ok()) return AddRequiredSpace(ret, *all_snapshot_status);
		if (!ret.is_ok()) {
		LOG(ERROR) << "CreateCowImage failed: " << ret.string();
		return AddRequiredSpace(ret, *all_snapshot_status);
		}
		}

		LOG(INFO) << "Successfully created snapshot for " << name;

fs_mgr/libsnapshot/snapshot_test.cpp

+46 −29

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@
		#include <signal.h>
		#include <sys/file.h>
		#include <sys/stat.h>
		#include <sys/statvfs.h>
		#include <sys/types.h>

		#include <chrono>
		@@ -2371,20 +2372,44 @@ TEST_F(SnapshotUpdateTest, Overflow) {
		<< "FinishedSnapshotWrites should detect overflow of CoW device.";
		}

		// Get max file size and free space.
		std::pair<uint64_t, uint64_t> GetBigFileLimit() {
		struct statvfs fs;
		if (statvfs("/data", &fs) < 0) {
		PLOG(ERROR) << "statfs failed";
		return {0, 0};
		}

		auto fs_limit = static_cast<uint64_t>(fs.f_blocks) * (fs.f_bsize - 1);
		auto fs_free = static_cast<uint64_t>(fs.f_bfree) * fs.f_bsize;

		LOG(INFO) << "Big file limit: " << fs_limit << ", free space: " << fs_free;

		return {fs_limit, fs_free};
		}

		TEST_F(SnapshotUpdateTest, LowSpace) {
		static constexpr auto kMaxFree = 10_MiB;
		auto userdata = std::make_unique<LowSpaceUserdata>();
		ASSERT_TRUE(userdata->Init(kMaxFree));
		// To make the low space test more reliable, we force a large cow estimate.
		// However legacy VAB ignores the COW estimate and uses InstallOperations
		// to compute the exact size required for dm-snapshot. It's difficult to
		// make this work reliably (we'd need to somehow fake an extremely large
		// super partition, and we don't have that level of dependency injection).
		//
		// For now, just skip this test on legacy VAB.
		if (!snapuserd_required_) {
		GTEST_SKIP() << "Skipping test on legacy VAB";
		}

		auto fs = GetBigFileLimit();
		ASSERT_NE(fs.first, 0);

		// Grow all partitions to 10_MiB, total 30_MiB. This requires 30 MiB of CoW space. After
		// using the empty space in super (< 1 MiB), it uses 30 MiB of /userdata space.
		constexpr uint64_t partition_size = 10_MiB;
		SetSize(sys_, partition_size);
		SetSize(vnd_, partition_size);
		SetSize(prd_, partition_size);
		sys_->set_estimate_cow_size(partition_size);
		vnd_->set_estimate_cow_size(partition_size);
		prd_->set_estimate_cow_size(partition_size);
		sys_->set_estimate_cow_size(fs.first);
		vnd_->set_estimate_cow_size(fs.first);
		prd_->set_estimate_cow_size(fs.first);

		AddOperationForPartitions();

		@@ -2393,8 +2418,12 @@ TEST_F(SnapshotUpdateTest, LowSpace) {
		auto res = sm->CreateUpdateSnapshots(manifest_);
		ASSERT_FALSE(res);
		ASSERT_EQ(Return::ErrorCode::NO_SPACE, res.error_code());
		ASSERT_GE(res.required_size(), 14_MiB);
		ASSERT_LT(res.required_size(), 40_MiB);

		// It's hard to predict exactly how much free space is needed, since /data
		// is writable and the test is not the only process running. Divide by two
		// as a rough lower bound, and adjust this in the future as necessary.
		auto expected_delta = fs.first - fs.second;
		ASSERT_GE(res.required_size(), expected_delta / 2);
		}

		TEST_F(SnapshotUpdateTest, AddPartition) {
		@@ -2776,6 +2805,7 @@ class ImageManagerTest : public SnapshotTest {
		void TearDown() override {
		RETURN_IF_NON_VIRTUAL_AB();
		CleanUp();
		SnapshotTest::TearDown();
		}
		void CleanUp() {
		if (!image_manager_) {
		@@ -2789,28 +2819,15 @@ class ImageManagerTest : public SnapshotTest {
		};

		TEST_F(ImageManagerTest, CreateImageNoSpace) {
		bool at_least_one_failure = false;
		for (uint64_t size = 1_MiB; size <= 512_MiB; size *= 2) {
		auto userdata = std::make_unique<LowSpaceUserdata>();
		ASSERT_TRUE(userdata->Init(size));

		uint64_t to_allocate = userdata->free_space() + userdata->bsize();
		auto fs = GetBigFileLimit();
		ASSERT_NE(fs.first, 0);

		auto res = image_manager_->CreateBackingImage(kImageName, to_allocate,
		auto res = image_manager_->CreateBackingImage(kImageName, fs.first,
		IImageManager::CREATE_IMAGE_DEFAULT);
		if (!res) {
		at_least_one_failure = true;
		} else {
		ASSERT_FALSE(res);
		ASSERT_EQ(res.error_code(), FiemapStatus::ErrorCode::NO_SPACE) << res.string();
		}

		CleanUp();
		}

		ASSERT_TRUE(at_least_one_failure)
		<< "We should have failed to allocate at least one over-sized image";
		}

		bool Mkdir(const std::string& path) {
		if (mkdir(path.c_str(), 0700) && errno != EEXIST) {
		std::cerr << "Could not mkdir " << path << ": " << strerror(errno) << std::endl;

fs_mgr/libsnapshot/test_helpers.cpp

+0 −62

Original line number	Diff line number	Diff line
		@@ -214,68 +214,6 @@ uint64_t GetSize(PartitionUpdate* partition_update) {
		return partition_update->mutable_new_partition_info()->size();
		}

		AssertionResult LowSpaceUserdata::Init(uint64_t max_free_space) {
		auto res = ReadUserdataStats();
		if (!res) return res;

		// Try to fill up the disk as much as possible until free_space_ <= max_free_space.
		big_file_ = std::make_unique<TemporaryFile>();
		if (big_file_->fd == -1) {
		return AssertionFailure() << strerror(errno);
		}
		if (!android::base::StartsWith(big_file_->path, kUserDataDevice)) {
		return AssertionFailure() << "Temp file allocated to " << big_file_->path << ", not in "
		<< kUserDataDevice;
		}
		uint64_t next_consume = std::min(std::max(available_space_, max_free_space) - max_free_space,
		(uint64_t)std::numeric_limits<off_t>::max());
		off_t allocated = 0;
		while (next_consume > 0 && free_space_ > max_free_space) {
		int status = fallocate(big_file_->fd, 0, allocated, next_consume);
		if (status == -1 && errno == ENOSPC) {
		next_consume /= 2;
		continue;
		}
		if (status == -1) {
		return AssertionFailure() << strerror(errno);
		}
		allocated += next_consume;

		res = ReadUserdataStats();
		if (!res) return res;
		}

		LOG(INFO) << allocated << " bytes allocated to " << big_file_->path;
		initialized_ = true;
		return AssertionSuccess();
		}

		AssertionResult LowSpaceUserdata::ReadUserdataStats() {
		struct statvfs buf;
		if (statvfs(kUserDataDevice, &buf) == -1) {
		return AssertionFailure() << strerror(errno);
		}
		bsize_ = buf.f_bsize;
		free_space_ = bsize_ * buf.f_bfree;
		available_space_ = bsize_ * buf.f_bavail;
		return AssertionSuccess();
		}

		uint64_t LowSpaceUserdata::free_space() const {
		CHECK(initialized_);
		return free_space_;
		}

		uint64_t LowSpaceUserdata::available_space() const {
		CHECK(initialized_);
		return available_space_;
		}

		uint64_t LowSpaceUserdata::bsize() const {
		CHECK(initialized_);
		return bsize_;
		}

		bool IsVirtualAbEnabled() {
		return android::base::GetBoolProperty("ro.virtual_ab.enabled", false);
		}