Merge "libsnapshot_cow: Prepare device to boot from pre-created snapshots" into main (6b78aac2) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+17 −1

Original line number	Diff line number	Diff line
		@@ -73,6 +73,9 @@ class ISnapshotMergeStats;
		class SnapshotMergeStats;
		class SnapshotStatus;

		using std::chrono::duration_cast;
		using namespace std::chrono_literals;

		static constexpr const std::string_view kCowGroupName = "cow";
		static constexpr char kVirtualAbCompressionProp[] = "ro.virtual_ab.compression.enabled";

		@@ -424,6 +427,7 @@ class SnapshotManager final : public ISnapshotManager {
		FRIEND_TEST(SnapshotTest, MergeFailureCode);
		FRIEND_TEST(SnapshotTest, NoMergeBeforeReboot);
		FRIEND_TEST(SnapshotTest, UpdateBootControlHal);
		FRIEND_TEST(SnapshotTest, BootSnapshotWithoutSlotSwitch);
		FRIEND_TEST(SnapshotUpdateTest, AddPartition);
		FRIEND_TEST(SnapshotUpdateTest, ConsistencyCheckResume);
		FRIEND_TEST(SnapshotUpdateTest, DaemonTransition);
		@@ -436,6 +440,7 @@ class SnapshotManager final : public ISnapshotManager {
		FRIEND_TEST(SnapshotUpdateTest, QueryStatusError);
		FRIEND_TEST(SnapshotUpdateTest, SnapshotStatusFileWithoutCow);
		FRIEND_TEST(SnapshotUpdateTest, SpaceSwapUpdate);
		FRIEND_TEST(SnapshotUpdateTest, MapAllSnapshotsWithoutSlotSwitch);
		friend class SnapshotTest;
		friend class SnapshotUpdateTest;
		friend class FlashAfterUpdateTest;
		@@ -456,7 +461,7 @@ class SnapshotManager final : public ISnapshotManager {
		bool EnsureImageManager();

		// Ensure we're connected to snapuserd.
		bool EnsureSnapuserdConnected();
		bool EnsureSnapuserdConnected(std::chrono::milliseconds timeout_ms = 10s);

		// Helpers for first-stage init.
		const std::unique_ptr<IDeviceInfo>& device() const { return device_; }
		@@ -549,6 +554,16 @@ class SnapshotManager final : public ISnapshotManager {
		// Unmap and remove all known snapshots.
		bool RemoveAllSnapshots(LockedFile* lock);

		// Boot device off snapshots without slot switch
		bool BootFromSnapshotsWithoutSlotSwitch();

		// Remove kBootSnapshotsWithoutSlotSwitch so that device can boot
		// without snapshots on the current slot
		bool PrepareDeviceToBootWithoutSnapshot();

		// Is the kBootSnapshotsWithoutSlotSwitch present
		bool IsSnapshotWithoutSlotSwitch();

		// List the known snapshot names.
		bool ListSnapshots(LockedFile* lock, std::vector<std::string>* snapshots,
		const std::string& suffix = "");
		@@ -663,6 +678,7 @@ class SnapshotManager final : public ISnapshotManager {
		std::string GetRollbackIndicatorPath();
		std::string GetForwardMergeIndicatorPath();
		std::string GetOldPartitionMetadataPath();
		std::string GetBootSnapshotsWithoutSlotSwitchPath();

		const LpMetadata* ReadOldPartitionMetadata(LockedFile* lock);

fs_mgr/libsnapshot/snapshot.cpp

+114 −8

Original line number	Diff line number	Diff line
		@@ -83,6 +83,8 @@ using std::chrono::duration_cast;
		using namespace std::chrono_literals;
		using namespace std::string_literals;

		static constexpr char kBootSnapshotsWithoutSlotSwitch[] =
		"/metadata/ota/snapshot-boot-without-slot-switch";
		static constexpr char kBootIndicatorPath[] = "/metadata/ota/snapshot-boot";
		static constexpr char kRollbackIndicatorPath[] = "/metadata/ota/rollback-indicator";
		static constexpr auto kUpdateStateCheckInterval = 2s;
		@@ -217,6 +219,12 @@ bool SnapshotManager::TryCancelUpdate(bool* needs_merge) {
		auto file = LockExclusive();
		if (!file) return false;

		if (IsSnapshotWithoutSlotSwitch()) {
		LOG(ERROR) << "Cannot cancel the snapshots as partitions are mounted off the snapshots on "
		"current slot.";
		return false;
		}

		UpdateState state = ReadUpdateState(file.get());
		if (state == UpdateState::None) {
		RemoveInvalidSnapshots(file.get());
		@@ -299,10 +307,9 @@ bool SnapshotManager::RemoveAllUpdateState(LockedFile* lock, const std::function
		// - For ForwardMerge, FinishedSnapshotWrites asserts that the existence of the indicator
		// matches the incoming update.
		std::vector<std::string> files = {
		GetSnapshotBootIndicatorPath(),
		GetRollbackIndicatorPath(),
		GetForwardMergeIndicatorPath(),
		GetOldPartitionMetadataPath(),
		GetSnapshotBootIndicatorPath(), GetRollbackIndicatorPath(),
		GetForwardMergeIndicatorPath(), GetOldPartitionMetadataPath(),
		GetBootSnapshotsWithoutSlotSwitchPath(),
		};
		for (const auto& file : files) {
		RemoveFileIfExists(file);
		@@ -483,6 +490,32 @@ bool SnapshotManager::MapDmUserCow(LockedFile* lock, const std::string& name,
		LOG(ERROR) << "Failed to retrieve base_sectors from Snapuserd";
		return false;
		}
		} else if (IsSnapshotWithoutSlotSwitch()) {
		// When snapshots are on current slot, we determine the size
		// of block device based on the number of COW operations. We cannot
		// use base device as it will be from older image.
		size_t num_ops = 0;
		uint64_t dev_sz = 0;
		unique_fd fd(open(cow_file.c_str(), O_RDONLY \| O_CLOEXEC));
		if (fd < 0) {
		PLOG(ERROR) << "Failed to open " << cow_file;
		return false;
		}

		CowReader reader;
		if (!reader.Parse(std::move(fd))) {
		LOG(ERROR) << "Failed to parse cow " << cow_file;
		return false;
		}

		const auto& header = reader.GetHeader();
		if (header.prefix.major_version > 2) {
		LOG(ERROR) << "COW format not supported";
		return false;
		}
		num_ops = reader.get_num_total_data_ops();
		dev_sz = (num_ops * header.block_size);
		base_sectors = dev_sz >> 9;
		} else {
		// For userspace snapshots, the size of the base device is taken as the
		// size of the dm-user block device. Since there is no pseudo mapping
		@@ -1479,6 +1512,10 @@ MergeFailureCode SnapshotManager::MergeSecondPhaseSnapshots(LockedFile* lock) {
		return result;
		}

		std::string SnapshotManager::GetBootSnapshotsWithoutSlotSwitchPath() {
		return metadata_dir_ + "/" + android::base::Basename(kBootSnapshotsWithoutSlotSwitch);
		}

		std::string SnapshotManager::GetSnapshotBootIndicatorPath() {
		return metadata_dir_ + "/" + android::base::Basename(kBootIndicatorPath);
		}
		@@ -2120,6 +2157,10 @@ UpdateState SnapshotManager::GetUpdateState(double* progress) {
		return state;
		}

		bool SnapshotManager::IsSnapshotWithoutSlotSwitch() {
		return (access(GetBootSnapshotsWithoutSlotSwitchPath().c_str(), F_OK) == 0);
		}

		bool SnapshotManager::UpdateUsesCompression() {
		auto lock = LockShared();
		if (!lock) return false;
		@@ -2212,6 +2253,13 @@ std::string SnapshotManager::GetGlobalRollbackIndicatorPath() {
		}

		bool SnapshotManager::NeedSnapshotsInFirstStageMount() {
		if (IsSnapshotWithoutSlotSwitch()) {
		if (GetCurrentSlot() != Slot::Source) {
		LOG(ERROR) << "Snapshots marked to boot without slot switch; but slot is wrong";
		return false;
		}
		return true;
		}
		// If we fail to read, we'll wind up using CreateLogicalPartitions, which
		// will create devices that look like the old slot, except with extra
		// content at the end of each device. This will confuse dm-verity, and
		@@ -2347,7 +2395,8 @@ bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock,
		// completed, live_snapshot_status is set to nullopt.
		std::optional<SnapshotStatus> live_snapshot_status;
		do {
		if (!(params.partition->attributes & LP_PARTITION_ATTR_UPDATED)) {
		if (!IsSnapshotWithoutSlotSwitch() &&
		!(params.partition->attributes & LP_PARTITION_ATTR_UPDATED)) {
		LOG(INFO) << "Detected re-flashing of partition, will skip snapshot: "
		<< params.GetPartitionName();
		break;
		@@ -2703,7 +2752,7 @@ bool SnapshotManager::UnmapUserspaceSnapshotDevice(LockedFile* lock,
		// to unmap; hence, we can't be deleting the device
		// as the table would be mounted off partitions and will fail.
		if (snapshot_status.state() != SnapshotState::MERGE_COMPLETED) {
		if (!DeleteDeviceIfExists(dm_user_name)) {
		if (!DeleteDeviceIfExists(dm_user_name, 4000ms)) {
		LOG(ERROR) << "Cannot unmap " << dm_user_name;
		return false;
		}
		@@ -3098,7 +3147,7 @@ bool SnapshotManager::EnsureImageManager() {
		return true;
		}

		bool SnapshotManager::EnsureSnapuserdConnected() {
		bool SnapshotManager::EnsureSnapuserdConnected(std::chrono::milliseconds timeout_ms) {
		if (snapuserd_client_) {
		return true;
		}
		@@ -3107,7 +3156,7 @@ bool SnapshotManager::EnsureSnapuserdConnected() {
		return false;
		}

		snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, 10s);
		snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, timeout_ms);
		if (!snapuserd_client_) {
		LOG(ERROR) << "Unable to connect to snapuserd";
		return false;
		@@ -4372,13 +4421,70 @@ std::string SnapshotManager::ReadSourceBuildFingerprint() {
		bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress() {
		auto slot = GetCurrentSlot();
		if (slot == Slot::Target) {
		// Merge in-progress
		if (IsSnapuserdRequired()) {
		return true;
		}
		}

		// Let's check more deeper to see if snapshots are mounted
		auto lock = LockExclusive();
		if (!lock) {
		return false;
		}

		std::vector<std::string> snapshots;
		if (!ListSnapshots(lock.get(), &snapshots)) {
		return false;
		}

		for (const auto& snapshot : snapshots) {
		// Active snapshot and daemon is alive
		if (IsSnapshotDevice(snapshot) && EnsureSnapuserdConnected(2s)) {
		return true;
		}
		}

		return false;
		}

		bool SnapshotManager::BootFromSnapshotsWithoutSlotSwitch() {
		auto lock = LockExclusive();
		if (!lock) return false;

		auto contents = device_->GetSlotSuffix();
		// This is the indicator which tells first-stage init
		// to boot from snapshots even though there was no slot-switch
		auto boot_file = GetBootSnapshotsWithoutSlotSwitchPath();
		if (!WriteStringToFileAtomic(contents, boot_file)) {
		PLOG(ERROR) << "write failed: " << boot_file;
		return false;
		}

		SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock.get());
		update_status.set_state(UpdateState::Initiated);
		update_status.set_userspace_snapshots(true);
		update_status.set_using_snapuserd(true);
		if (!WriteSnapshotUpdateStatus(lock.get(), update_status)) {
		return false;
		}
		return true;
		}

		bool SnapshotManager::PrepareDeviceToBootWithoutSnapshot() {
		auto lock = LockExclusive();
		if (!lock) return false;

		android::base::RemoveFileIfExists(GetSnapshotBootIndicatorPath());
		android::base::RemoveFileIfExists(GetBootSnapshotsWithoutSlotSwitchPath());

		SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock.get());
		update_status.set_state(UpdateState::Cancelled);
		if (!WriteSnapshotUpdateStatus(lock.get(), update_status)) {
		return false;
		}
		return true;
		}

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapshot_test.cpp

+50 −0

Original line number	Diff line number	Diff line
		@@ -2559,6 +2559,56 @@ TEST_F(SnapshotUpdateTest, DaemonTransition) {
		}
		}

		TEST_F(SnapshotUpdateTest, MapAllSnapshotsWithoutSlotSwitch) {
		MountMetadata();
		AddOperationForPartitions();
		// Execute the update.
		ASSERT_TRUE(sm->BeginUpdate());
		ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));

		if (!sm->UpdateUsesUserSnapshots()) {
		GTEST_SKIP() << "Test does not apply as UserSnapshots aren't enabled.";
		}

		ASSERT_TRUE(WriteSnapshots());
		ASSERT_TRUE(sm->FinishedSnapshotWrites(false));

		if (ShouldSkipLegacyMerging()) {
		GTEST_SKIP() << "Skipping legacy merge test";
		}
		// Mark the indicator
		ASSERT_TRUE(sm->BootFromSnapshotsWithoutSlotSwitch());

		ASSERT_TRUE(sm->EnsureSnapuserdConnected());
		sm->set_use_first_stage_snapuserd(true);

		ASSERT_TRUE(sm->NeedSnapshotsInFirstStageMount());

		// Map snapshots
		ASSERT_TRUE(sm->MapAllSnapshots(10s));

		// New updates should fail
		ASSERT_FALSE(sm->BeginUpdate());

		// Snapshots cannot be cancelled
		ASSERT_FALSE(sm->CancelUpdate());

		// Merge cannot start
		ASSERT_FALSE(sm->InitiateMerge());

		// Read bytes back and verify they match the cache.
		ASSERT_TRUE(IsPartitionUnchanged("sys_b"));

		// Remove the indicators
		ASSERT_TRUE(sm->PrepareDeviceToBootWithoutSnapshot());

		// Ensure snapshots are still mounted
		ASSERT_TRUE(sm->IsUserspaceSnapshotUpdateInProgress());

		// Cleanup snapshots
		ASSERT_TRUE(sm->UnmapAllSnapshots());
		}

		TEST_F(SnapshotUpdateTest, MapAllSnapshots) {
		AddOperationForPartitions();
		// Execute the update.

fs_mgr/libsnapshot/snapshotctl.cpp

+69 −23

Original line number	Diff line number	Diff line
		@@ -75,7 +75,11 @@ int Usage() {
		" unmap-snapshots\n"
		" Unmap all pre-created snapshots\n"
		" delete-snapshots\n"
		" Delete all pre-created snapshots\n";
		" Delete all pre-created snapshots\n"
		" revert-snapshots\n"
		" Prepares devices to boot without snapshots on next boot.\n"
		" This does not delete the snapshot. It only removes the indicators\n"
		" so that first stage init will not mount from snapshots.\n";
		return EX_USAGE;
		}

		@@ -87,9 +91,11 @@ class MapSnapshots {
		MapSnapshots(std::string path = "");
		bool CreateSnapshotDevice(std::string& partition_name, std::string& patch);
		bool InitiateThreadedSnapshotWrite(std::string& pname, std::string& snapshot_patch);
		bool WaitForSnapshotWritesToComplete();
		bool FinishSnapshotWrites();
		bool UnmapCowImagePath(std::string& name);
		bool DeleteCowImage(std::string& name);
		bool DeleteSnapshots();
		bool CleanupSnapshot() { return sm_->PrepareDeviceToBootWithoutSnapshot(); }
		bool BeginUpdate();

		private:
		std::optional<std::string> GetCowImagePath(std::string& name);
		@@ -107,7 +113,24 @@ MapSnapshots::MapSnapshots(std::string path) {
		exit(1);
		}
		snapshot_dir_path_ = path + "/";
		}

		bool MapSnapshots::BeginUpdate() {
		lock_ = sm_->LockExclusive();
		std::vector<std::string> snapshots;
		sm_->ListSnapshots(lock_.get(), &snapshots);
		if (!snapshots.empty()) {
		// Snapshots are already present.
		return true;
		}

		lock_ = nullptr;
		if (!sm_->BeginUpdate()) {
		LOG(ERROR) << "BeginUpdate failed";
		return false;
		}
		lock_ = sm_->LockExclusive();
		return true;
		}

		bool MapSnapshots::CreateSnapshotDevice(std::string& partition_name, std::string& patchfile) {
		@@ -130,6 +153,9 @@ bool MapSnapshots::CreateSnapshotDevice(std::string& partition_name, std::string
		dev_sz &= ~(block_sz - 1);

		SnapshotStatus status;
		status.set_state(SnapshotState::CREATED);
		status.set_using_snapuserd(true);
		status.set_old_partition_size(0);
		status.set_name(partition_name);
		status.set_cow_file_size(dev_sz);
		status.set_cow_partition_size(0);
		@@ -216,27 +242,33 @@ bool MapSnapshots::InitiateThreadedSnapshotWrite(std::string& pname, std::string
		return true;
		}

		bool MapSnapshots::WaitForSnapshotWritesToComplete() {
		bool MapSnapshots::FinishSnapshotWrites() {
		bool ret = true;
		for (auto& t : threads_) {
		ret = t.get() && ret;
		}

		lock_ = nullptr;
		if (ret) {
		LOG(INFO) << "Pre-created snapshots successfully copied";
		} else {
		LOG(ERROR) << "Snapshot copy failed";
		if (!sm_->FinishedSnapshotWrites(false)) {
		return false;
		}
		return sm_->BootFromSnapshotsWithoutSlotSwitch();
		}
		return ret;

		LOG(ERROR) << "Snapshot copy failed";
		return false;
		}

		bool MapSnapshots::UnmapCowImagePath(std::string& name) {
		return sm_->UnmapCowImage(name);
		}

		bool MapSnapshots::DeleteCowImage(std::string& name) {
		if (!sm_->DeleteSnapshot(lock_.get(), name)) {
		LOG(ERROR) << "Delete snapshot failed";
		bool MapSnapshots::DeleteSnapshots() {
		lock_ = sm_->LockExclusive();
		if (!sm_->RemoveAllUpdateState(lock_.get())) {
		LOG(ERROR) << "Remove All Update State failed";
		return false;
		}
		return true;
		@@ -281,7 +313,8 @@ bool GetVerityPartitions(std::vector<std::string>& partitions) {
		return true;
		}

		bool UnMapPrecreatedSnapshots(int, char**) {
		bool UnMapPrecreatedSnapshots(int, char** argv) {
		android::base::InitLogging(argv, &android::base::KernelLogger);
		// Make sure we are root.
		if (::getuid() != 0) {
		LOG(ERROR) << "Not running as root. Try \"adb root\" first.";
		@@ -302,29 +335,36 @@ bool UnMapPrecreatedSnapshots(int, char**) {
		return true;
		}

		bool DeletePrecreatedSnapshots(int, char**) {
		bool RemovePrecreatedSnapshots(int, char** argv) {
		android::base::InitLogging(argv, &android::base::KernelLogger);
		// Make sure we are root.
		if (::getuid() != 0) {
		LOG(ERROR) << "Not running as root. Try \"adb root\" first.";
		return EXIT_FAILURE;
		}

		std::vector<std::string> partitions;
		if (!GetVerityPartitions(partitions)) {
		return false;
		}

		MapSnapshots snapshot;
		for (auto partition : partitions) {
		if (!snapshot.DeleteCowImage(partition)) {
		LOG(ERROR) << "DeleteCowImage failed: " << partition;
		}
		if (!snapshot.CleanupSnapshot()) {
		LOG(ERROR) << "CleanupSnapshot failed";
		return false;
		}
		return true;
		}

		bool DeletePrecreatedSnapshots(int, char** argv) {
		android::base::InitLogging(argv, &android::base::KernelLogger);
		// Make sure we are root.
		if (::getuid() != 0) {
		LOG(ERROR) << "Not running as root. Try \"adb root\" first.";
		return EXIT_FAILURE;
		}

		MapSnapshots snapshot;
		return snapshot.DeleteSnapshots();
		}

		bool MapPrecreatedSnapshots(int argc, char** argv) {
		android::base::InitLogging(argv, &android::base::StderrLogger);
		android::base::InitLogging(argv, &android::base::KernelLogger);

		// Make sure we are root.
		if (::getuid() != 0) {
		@@ -365,6 +405,11 @@ bool MapPrecreatedSnapshots(int argc, char** argv) {
		}

		MapSnapshots cow(path);
		if (!cow.BeginUpdate()) {
		LOG(ERROR) << "BeginUpdate failed";
		return false;
		}

		for (auto& pair : partitions) {
		if (!cow.CreateSnapshotDevice(pair.first, pair.second)) {
		LOG(ERROR) << "CreateSnapshotDevice failed for: " << pair.first;
		@@ -376,7 +421,7 @@ bool MapPrecreatedSnapshots(int argc, char** argv) {
		}
		}

		return cow.WaitForSnapshotWritesToComplete();
		return cow.FinishSnapshotWrites();
		}

		#ifdef SNAPSHOTCTL_USERDEBUG_OR_ENG
		@@ -508,6 +553,7 @@ static std::map<std::string, std::function<bool(int, char**)>> kCmdMap = {
		{"map-snapshots", MapPrecreatedSnapshots},
		{"unmap-snapshots", UnMapPrecreatedSnapshots},
		{"delete-snapshots", DeletePrecreatedSnapshots},
		{"revert-snapshots", RemovePrecreatedSnapshots},
		// clang-format on
		};