Merge changes from topic "snapuserd-selinux" (270c98f1) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+27 −7

Original line number	Diff line number	Diff line
		@@ -306,13 +306,17 @@ class SnapshotManager final : public ISnapshotManager {
		// Helper function for second stage init to restorecon on the rollback indicator.
		static std::string GetGlobalRollbackIndicatorPath();

		// Initiate the transition from first-stage to second-stage snapuserd. This
		// process involves re-creating the dm-user table entries for each device,
		// so that they connect to the new daemon. Once all new tables have been
		// activated, we ask the first-stage daemon to cleanly exit.
		//
		// The caller must pass a function which starts snapuserd.
		bool PerformSecondStageTransition();
		// Detach dm-user devices from the current snapuserd, and populate
		// \|snapuserd_argv\| with the necessary arguments to restart snapuserd
		// and reattach them.
		bool DetachSnapuserdForSelinux(std::vector<std::string>* snapuserd_argv);

		// Perform the transition from the selinux stage of snapuserd into the
		// second-stage of snapuserd. This process involves re-creating the dm-user
		// table entries for each device, so that they connect to the new daemon.
		// Once all new tables have been activated, we ask the first-stage daemon
		// to cleanly exit.
		bool PerformSecondStageInitTransition();

		// ISnapshotManager overrides.
		bool BeginUpdate() override;
		@@ -626,6 +630,9 @@ class SnapshotManager final : public ISnapshotManager {
		// The reverse of MapPartitionWithSnapshot.
		bool UnmapPartitionWithSnapshot(LockedFile* lock, const std::string& target_partition_name);

		// Unmap a dm-user device through snapuserd.
		bool UnmapDmUserDevice(const std::string& snapshot_name);

		// If there isn't a previous update, return true. \|needs_merge\| is set to false.
		// If there is a previous update but the device has not boot into it, tries to cancel the
		// update and delete any snapshots. Return true if successful. \|needs_merge\| is set to false.
		@@ -693,6 +700,19 @@ class SnapshotManager final : public ISnapshotManager {
		// returns true.
		bool WaitForDevice(const std::string& device, std::chrono::milliseconds timeout_ms);

		enum class InitTransition { SELINUX_DETACH, SECOND_STAGE };

		// Initiate the transition from first-stage to second-stage snapuserd. This
		// process involves re-creating the dm-user table entries for each device,
		// so that they connect to the new daemon. Once all new tables have been
		// activated, we ask the first-stage daemon to cleanly exit.
		//
		// If the mode is SELINUX_DETACH, snapuserd_argv must be non-null and will
		// be populated with a list of snapuserd arguments to pass to execve(). It
		// is otherwise ignored.
		bool PerformInitTransition(InitTransition transition,
		std::vector<std::string>* snapuserd_argv = nullptr);

		std::string gsid_dir_;
		std::string metadata_dir_;
		std::unique_ptr<IDeviceInfo> device_;

fs_mgr/libsnapshot/include/libsnapshot/snapuserd_client.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -32,8 +32,6 @@ static constexpr uint32_t PACKET_SIZE = 512;

		static constexpr char kSnapuserdSocket[] = "snapuserd";

		static constexpr char kSnapuserdFirstStagePidVar[] = "FIRST_STAGE_SNAPUSERD_PID";

		// Ensure that the second-stage daemon for snapuserd is running.
		bool EnsureSnapuserdStarted();

fs_mgr/libsnapshot/snapshot.cpp

+63 −24

Original line number	Diff line number	Diff line
		@@ -1247,6 +1247,10 @@ bool SnapshotManager::CollapseSnapshotDevice(const std::string& name,
		return false;
		}

		if (status.compression_enabled()) {
		UnmapDmUserDevice(name);
		}

		// Cleanup the base device as well, since it is no longer used. This does
		// not block cleanup.
		auto base_name = GetBaseDeviceName(name);
		@@ -1291,12 +1295,13 @@ bool SnapshotManager::HandleCancelledUpdate(LockedFile* lock,
		return RemoveAllUpdateState(lock, before_cancel);
		}

		bool SnapshotManager::PerformSecondStageTransition() {
		LOG(INFO) << "Performing second-stage transition for snapuserd.";
		bool SnapshotManager::PerformInitTransition(InitTransition transition,
		std::vector<std::string>* snapuserd_argv) {
		LOG(INFO) << "Performing transition for snapuserd.";

		// Don't use EnsuerSnapuserdConnected() because this is called from init,
		// and attempting to do so will deadlock.
		if (!snapuserd_client_) {
		if (!snapuserd_client_ && transition != InitTransition::SELINUX_DETACH) {
		snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, 10s);
		if (!snapuserd_client_) {
		LOG(ERROR) << "Unable to connect to snapuserd";
		@@ -1343,6 +1348,9 @@ bool SnapshotManager::PerformSecondStageTransition() {
		}

		auto misc_name = user_cow_name;
		if (transition == InitTransition::SELINUX_DETACH) {
		misc_name += "-selinux";
		}

		DmTable table;
		table.Emplace<DmTargetUser>(0, target.spec.length, misc_name);
		@@ -1378,6 +1386,17 @@ bool SnapshotManager::PerformSecondStageTransition() {
		continue;
		}

		if (transition == InitTransition::SELINUX_DETACH) {
		auto message = misc_name + "," + cow_image_device + "," + backing_device;
		snapuserd_argv->emplace_back(std::move(message));

		// Do not attempt to connect to the new snapuserd yet, it hasn't
		// been started. We do however want to wait for the misc device
		// to have been created.
		ok_cows++;
		continue;
		}

		uint64_t base_sectors =
		snapuserd_client_->InitDmUserCow(misc_name, cow_image_device, backing_device);
		if (base_sectors == 0) {
		@@ -2048,11 +2067,36 @@ bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name)

		auto& dm = DeviceMapper::Instance();

		auto dm_user_name = GetDmUserCowName(name);
		if (IsCompressionEnabled() && dm.GetState(dm_user_name) != DmDeviceState::INVALID) {
		if (IsCompressionEnabled() && !UnmapDmUserDevice(name)) {
		return false;
		}

		auto cow_name = GetCowName(name);
		if (!dm.DeleteDeviceIfExists(cow_name)) {
		LOG(ERROR) << "Cannot unmap " << cow_name;
		return false;
		}

		std::string cow_image_name = GetCowImageDeviceName(name);
		if (!images_->UnmapImageIfExists(cow_image_name)) {
		LOG(ERROR) << "Cannot unmap image " << cow_image_name;
		return false;
		}
		return true;
		}

		bool SnapshotManager::UnmapDmUserDevice(const std::string& snapshot_name) {
		auto& dm = DeviceMapper::Instance();

		if (!EnsureSnapuserdConnected()) {
		return false;
		}

		auto dm_user_name = GetDmUserCowName(snapshot_name);
		if (dm.GetState(dm_user_name) == DmDeviceState::INVALID) {
		return true;
		}

		if (!dm.DeleteDeviceIfExists(dm_user_name)) {
		LOG(ERROR) << "Cannot unmap " << dm_user_name;
		return false;
		@@ -2069,19 +2113,6 @@ bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name)
		LOG(ERROR) << "Timed out waiting for " << control_device << " to unlink";
		return false;
		}
		}

		auto cow_name = GetCowName(name);
		if (!dm.DeleteDeviceIfExists(cow_name)) {
		LOG(ERROR) << "Cannot unmap " << cow_name;
		return false;
		}

		std::string cow_image_name = GetCowImageDeviceName(name);
		if (!images_->UnmapImageIfExists(cow_image_name)) {
		LOG(ERROR) << "Cannot unmap image " << cow_image_name;
		return false;
		}
		return true;
		}

		@@ -3311,5 +3342,13 @@ bool SnapshotManager::IsSnapuserdRequired() {
		return status.state() != UpdateState::None && status.compression_enabled();
		}

		bool SnapshotManager::DetachSnapuserdForSelinux(std::vector<std::string>* snapuserd_argv) {
		return PerformInitTransition(InitTransition::SELINUX_DETACH, snapuserd_argv);
		}

		bool SnapshotManager::PerformSecondStageInitTransition() {
		return PerformInitTransition(InitTransition::SECOND_STAGE);
		}

		} // namespace snapshot
		} // namespace android