Merge "Helper function to mount snapshot devices in recovery" (94abcc5b) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+17 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,12 @@ static constexpr const std::string_view kCowGroupName = "cow";

		bool SourceCopyOperationIsClone(const chromeos_update_engine::InstallOperation& operation);

		enum class CreateResult : unsigned int {
		ERROR,
		CREATED,
		NOT_CREATED,
		};

		enum class UpdateState : unsigned int {
		// No update or merge is in progress.
		None,
		@@ -246,6 +252,17 @@ class SnapshotManager final {
		// optional callback fires periodically to query progress via GetUpdateState.
		bool HandleImminentDataWipe(const std::function<void()>& callback = {});

		// This method is only allowed in recovery and is used as a helper to
		// initialize the snapshot devices as a requirement to mount a snapshotted
		// /system in recovery.
		// This function returns:
		// - CreateResult::CREATED if snapshot devices were successfully created;
		// - CreateResult::NOT_CREATED if it was not necessary to create snapshot
		// devices;
		// - CreateResult::ERROR if a fatal error occurred, mounting /system should
		// be aborted.
		CreateResult RecoveryCreateSnapshotDevices();

		// Dump debug information.
		bool Dump(std::ostream& os);

+32 −0

Original line number	Diff line number	Diff line
		@@ -2356,5 +2356,37 @@ bool SnapshotManager::EnsureNoOverflowSnapshot(LockedFile* lock) {
		return true;
		}

		CreateResult SnapshotManager::RecoveryCreateSnapshotDevices() {
		if (!device_->IsRecovery()) {
		LOG(ERROR) << __func__ << " is only allowed in recovery.";
		return CreateResult::NOT_CREATED;
		}

		auto mount = EnsureMetadataMounted();
		if (!mount \|\| !mount->HasDevice()) {
		LOG(ERROR) << "Couldn't mount Metadata.";
		return CreateResult::NOT_CREATED;
		}

		auto state_file = GetStateFilePath();
		if (access(state_file.c_str(), F_OK) != 0 && errno == ENOENT) {
		LOG(ERROR) << "Couldn't access state file.";
		return CreateResult::NOT_CREATED;
		}

		if (!NeedSnapshotsInFirstStageMount()) {
		return CreateResult::NOT_CREATED;
		}

		auto slot_suffix = device_->GetOtherSlotSuffix();
		auto slot_number = SlotNumberForSlotSuffix(slot_suffix);
		auto super_path = device_->GetSuperDevice(slot_number);
		if (!CreateLogicalAndSnapshotPartitions(super_path)) {
		LOG(ERROR) << "Unable to map partitions.";
		return CreateResult::ERROR;
		}
		return CreateResult::CREATED;
		}

		} // namespace snapshot
		} // namespace android