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Commit c0e5742c authored Jan 09, 2019 by Richard Uhler

Reorganize rollback data storage layout.

In preparation for supporting multi-package rollbacks.

The previous layout had a single directory used for a rollback and a
particular package. For example:

com.package.A-XXX/
    base.apk
    info.json
    enabled.txt

The new layout has separate directories to represent the rollback and
information about a package belonging to the rollback, so it's possible
to have multiple packages in a single rollback. For example:

XXX/
    com.package.A/
        base.apk
        info.json
    com.package.B/
        base.apk
        info.json
    enabled.txt

Where XXX is a random unique string generated by createTempDirectory.

Test: atest RollbackTest
Bug: 112431924
Change-Id: I6cc3b276d6f5f0c6d0852b183dd33c695f6a3fc1

parent 32f63a7e

services/core/java/com/android/server/rollback/RollbackData.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -30,7 +30,7 @@ class RollbackData {
		public final PackageRollbackInfo info;

		/**
		* The directory where the apk backup is stored.
		* The directory where the rollback data is stored.
		*/
		public final File backupDir;

services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java

+41 −23

Original line number	Diff line number	Diff line
		@@ -109,16 +109,19 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		// to store this data:
		// /data/rollback/
		// available/
		// com.package.A-XXX/
		// XXX/
		// com.package.A/
		// base.apk
		// info.json
		// enabled.txt
		// com.package.B-YYY/
		// YYY/
		// com.package.B/
		// base.apk
		// info.json
		// enabled.txt
		// recently_executed.json
		//
		// * XXX, YYY are random strings from Files.createTempDirectory
		// * info.json contains the package version to roll back from/to.
		// * enabled.txt contains a timestamp for when the rollback was first
		// made available. This file is not written until the rollback is made
		@@ -356,7 +359,8 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		session = packageInstaller.openSession(sessionId);

		// TODO: Will it always be called "base.apk"? What about splits?
		File baseApk = new File(data.backupDir, "base.apk");
		File packageDir = new File(data.backupDir, data.info.packageName);
		File baseApk = new File(packageDir, "base.apk");
		try (ParcelFileDescriptor fd = ParcelFileDescriptor.open(baseApk,
		ParcelFileDescriptor.MODE_READ_ONLY)) {
		final long token = Binder.clearCallingIdentity();
		@@ -472,18 +476,30 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		// be called.
		if (rollbackDir.isDirectory() && enabledFile.isFile()) {
		try {
		File jsonFile = new File(rollbackDir, "info.json");
		String jsonString = IoUtils.readFileAsString(jsonFile.getAbsolutePath());
		PackageRollbackInfo info = null;
		for (File packageDir : rollbackDir.listFiles()) {
		if (packageDir.isDirectory()) {
		File jsonFile = new File(packageDir, "info.json");
		String jsonString = IoUtils.readFileAsString(
		jsonFile.getAbsolutePath());
		JSONObject jsonObject = new JSONObject(jsonString);
		String packageName = jsonObject.getString("packageName");
		long higherVersionCode = jsonObject.getLong("higherVersionCode");
		long lowerVersionCode = jsonObject.getLong("lowerVersionCode");
		RollbackData data = new RollbackData(
		new PackageRollbackInfo(packageName,
		if (info != null) {
		throw new IOException("TODO: Support multi-package rollback");
		}
		info = new PackageRollbackInfo(packageName,
		new PackageRollbackInfo.PackageVersion(higherVersionCode),
		new PackageRollbackInfo.PackageVersion(lowerVersionCode)),
		rollbackDir);
		new PackageRollbackInfo.PackageVersion(lowerVersionCode));
		}
		}

		if (info == null) {
		throw new IOException("No package rollback info found");
		}

		RollbackData data = new RollbackData(info, rollbackDir);
		String enabledString = IoUtils.readFileAsString(enabledFile.getAbsolutePath());
		data.timestamp = Instant.parse(enabledString.trim());
		mAvailableRollbacks.add(data);
		@@ -771,33 +787,35 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub {
		File backupDir;
		try {
		backupDir = Files.createTempDirectory(
		mAvailableRollbacksDir.toPath(), packageName + "-").toFile();
		mAvailableRollbacksDir.toPath(), null).toFile();
		} catch (IOException e) {
		Log.e(TAG, "Unable to create rollback for " + packageName, e);
		return false;
		}

		File packageDir = new File(backupDir, packageName);
		packageDir.mkdirs();
		try {
		JSONObject json = new JSONObject();
		json.put("packageName", packageName);
		json.put("higherVersionCode", newVersion.versionCode);
		json.put("lowerVersionCode", installedVersion.versionCode);

		File jsonFile = new File(backupDir, "info.json");
		File jsonFile = new File(packageDir, "info.json");
		PrintWriter pw = new PrintWriter(jsonFile);
		pw.println(json.toString());
		pw.close();
		} catch (IOException \| JSONException e) {
		Log.e(TAG, "Unable to create rollback for " + packageName, e);
		removeFile(backupDir);
		removeFile(packageDir);
		return false;
		}

		// TODO: Copy by hard link instead to save on cpu and storage space?
		int status = PackageManagerServiceUtils.copyPackage(installedPackage.codePath, backupDir);
		int status = PackageManagerServiceUtils.copyPackage(installedPackage.codePath, packageDir);
		if (status != PackageManager.INSTALL_SUCCEEDED) {
		Log.e(TAG, "Unable to copy package for rollback for " + packageName);
		removeFile(backupDir);
		removeFile(packageDir);
		return false;
		}