Merge changes I0ca6d083,I96d81313,I6010de4d,I608316d2

* changes:
  Record reason why the rollback is deleted (5/n)
  Delete committed rollbacks when they expire (4/n)
  Dump historical rollbacks for debugging purpose (3/n)
  Save deleted rollbacks for debugging purpose (2/n)

5 files changed, 128 insertions, 33 deletions

diff --git a/services/core/java/com/android/server/rollback/Rollback.java b/services/core/java/com/android/server/rollback/Rollback.java
index 2d51cf9a5083..63ed416f2859 100644
--- a/services/core/java/com/android/server/rollback/Rollback.java
+++ b/services/core/java/com/android/server/rollback/Rollback.java
@@ -141,11 +141,17 @@ class Rollback {
 
     /**
      * The current state of the rollback.
-     * ENABLING, AVAILABLE, or COMMITTED.
+     * ENABLING, AVAILABLE, DELETED, or COMMITTED.
      */
     private @RollbackState int mState;
 
     /**
+     * The detailed description of the current state. For a DELETED state, it describes
+     * the reason why the rollback is deleted.
+     */
+    private @NonNull String mStateDescription = "";
+
+    /**
      * True if we are expecting the package manager to call restoreUserData
      * for this rollback because it has just been committed but the rollback
      * has not yet been fully applied.
@@ -231,7 +237,7 @@ class Rollback {
      * Constructs a pre-populated Rollback instance.
      */
     Rollback(RollbackInfo info, File backupDir, Instant timestamp, int stagedSessionId,
-            @RollbackState int state, boolean restoreUserDataInProgress,
+            @RollbackState int state, String stateDescription, boolean restoreUserDataInProgress,
             int userId, String installerPackageName, SparseIntArray extensionVersions) {
         this.info = info;
         mUserId = userId;
@@ -240,6 +246,7 @@ class Rollback {
         mTimestamp = timestamp;
         mStagedSessionId = stagedSessionId;
         mState = state;
+        mStateDescription = stateDescription;
         mRestoreUserDataInProgress = restoreUserDataInProgress;
         mExtensionVersions = Objects.requireNonNull(extensionVersions);
         // TODO(b/120200473): Include this field during persistence. This field will be used to
@@ -478,7 +485,7 @@ class Rollback {
             Slog.w(TAG, "Cannot make deleted rollback available.");
             return;
         }
-        mState = ROLLBACK_STATE_AVAILABLE;
+        setState(ROLLBACK_STATE_AVAILABLE, "");
         mTimestamp = Instant.now();
         RollbackStore.saveRollback(this);
     }
@@ -598,7 +605,7 @@ class Rollback {
                         // Why would we expect commit not to fail again?
                         // TODO: Could this cause a rollback to be resurrected
                         // if it should otherwise have expired by now?
-                        mState = ROLLBACK_STATE_AVAILABLE;
+                        setState(ROLLBACK_STATE_AVAILABLE, "Commit failed");
                         mRestoreUserDataInProgress = false;
                         info.setCommittedSessionId(-1);
                         sendFailure(context, statusReceiver,
@@ -642,7 +649,7 @@ class Rollback {
             };
 
             final LocalIntentReceiver receiver = new LocalIntentReceiver(onResult);
-            mState = ROLLBACK_STATE_COMMITTED;
+            setState(ROLLBACK_STATE_COMMITTED, "");
             info.setCommittedSessionId(parentSessionId);
             mRestoreUserDataInProgress = true;
             parentSession.commit(receiver.getIntentSender());
@@ -691,7 +698,7 @@ class Rollback {
      * Deletes app data snapshots associated with this rollback, and moves to the DELETED state.
      */
     @WorkerThread
-    void delete(AppDataRollbackHelper dataHelper) {
+    void delete(AppDataRollbackHelper dataHelper, @NonNull String reason) {
         assertInWorkerThread();
         boolean containsApex = false;
         Set<Integer> apexUsers = new ArraySet<>();
@@ -717,7 +724,7 @@ class Rollback {
         }
 
         RollbackStore.deleteRollback(this);
-        mState = ROLLBACK_STATE_DELETED;
+        setState(ROLLBACK_STATE_DELETED, reason);
     }
 
     /**
@@ -847,6 +854,7 @@ class Rollback {
             case Rollback.ROLLBACK_STATE_ENABLING: return "enabling";
             case Rollback.ROLLBACK_STATE_AVAILABLE: return "available";
             case Rollback.ROLLBACK_STATE_COMMITTED: return "committed";
+            case Rollback.ROLLBACK_STATE_DELETED: return "deleted";
         }
         throw new AssertionError("Invalid rollback state: " + state);
     }
@@ -858,6 +866,7 @@ class Rollback {
             case "enabling": return Rollback.ROLLBACK_STATE_ENABLING;
             case "available": return Rollback.ROLLBACK_STATE_AVAILABLE;
             case "committed": return Rollback.ROLLBACK_STATE_COMMITTED;
+            case "deleted": return Rollback.ROLLBACK_STATE_DELETED;
         }
         throw new ParseException("Invalid rollback state: " + state, 0);
     }
@@ -926,6 +935,7 @@ class Rollback {
         ipw.println(info.getRollbackId() + ":");
         ipw.increaseIndent();
         ipw.println("-state: " + getStateAsString());
+        ipw.println("-stateDescription: " + mStateDescription);
         ipw.println("-timestamp: " + getTimestamp());
         if (getStagedSessionId() != -1) {
             ipw.println("-stagedSessionId: " + getStagedSessionId());
@@ -955,4 +965,17 @@ class Rollback {
         }
         ipw.decreaseIndent();
     }
+
+    @WorkerThread
+    String getStateDescription() {
+        assertInWorkerThread();
+        return mStateDescription;
+    }
+
+    @VisibleForTesting
+    void setState(@RollbackState int state, String description) {
+        assertInWorkerThread();
+        mState = state;
+        mStateDescription = description;
+    }
 }
diff --git a/services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java b/services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java
index b34d46ff1a0c..192a00303a30 100644
--- a/services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java
+++ b/services/core/java/com/android/server/rollback/RollbackManagerServiceImpl.java
@@ -179,7 +179,9 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
         mInstaller = new Installer(mContext);
         mInstaller.onStart();
 
-        mRollbackStore = new RollbackStore(new File(Environment.getDataDirectory(), "rollback"));
+        mRollbackStore = new RollbackStore(
+                new File(Environment.getDataDirectory(), "rollback"),
+                new File(Environment.getDataDirectory(), "rollback-history"));
 
         mPackageHealthObserver = new RollbackPackageHealthObserver(mContext);
         mAppDataRollbackHelper = new AppDataRollbackHelper(mInstaller);
@@ -201,7 +203,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
             } else {
                 // Delete rollbacks when build fingerprint has changed.
                 for (Rollback rollback : mRollbacks) {
-                    rollback.delete(mAppDataRollbackHelper);
+                    deleteRollback(rollback, "Fingerprint changed");
                 }
                 mRollbacks.clear();
             }
@@ -271,7 +273,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
                     Rollback rollback = getRollbackForSession(sessionId);
                     if (rollback != null && rollback.isEnabling()) {
                         mRollbacks.remove(rollback);
-                        rollback.delete(mAppDataRollbackHelper);
+                        deleteRollback(rollback, "Rollback canceled");
                     }
                 }
             }
@@ -477,14 +479,14 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
     }
 
     @WorkerThread
-    private void expireRollbackForPackageInternal(String packageName) {
+    private void expireRollbackForPackageInternal(String packageName, String reason) {
         assertInWorkerThread();
         Iterator<Rollback> iter = mRollbacks.iterator();
         while (iter.hasNext()) {
             Rollback rollback = iter.next();
             if (rollback.includesPackage(packageName)) {
                 iter.remove();
-                rollback.delete(mAppDataRollbackHelper);
+                deleteRollback(rollback, reason);
             }
         }
     }
@@ -496,7 +498,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
         mContext.enforceCallingOrSelfPermission(
                 Manifest.permission.TEST_MANAGE_ROLLBACKS,
                 "expireRollbackForPackage");
-        awaitResult(() -> expireRollbackForPackageInternal(packageName));
+        awaitResult(() -> expireRollbackForPackageInternal(packageName, "Expired by API"));
     }
 
     @ExtThread
@@ -612,7 +614,8 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
                         .getPackageInstaller().getSessionInfo(rollback.getStagedSessionId());
                 if (session == null || session.isStagedSessionFailed()) {
                     iter.remove();
-                    rollback.delete(mAppDataRollbackHelper);
+                    deleteRollback(rollback,
+                            "Session " + session.getSessionId() + " not existed or failed");
                     continue;
                 }
 
@@ -666,7 +669,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
                     && rollback.includesPackageWithDifferentVersion(packageName,
                     installedVersion)) {
                 iter.remove();
-                rollback.delete(mAppDataRollbackHelper);
+                deleteRollback(rollback, "Package " + packageName + " replaced");
             }
         }
     }
@@ -678,7 +681,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
     @WorkerThread
     private void onPackageFullyRemoved(String packageName) {
         assertInWorkerThread();
-        expireRollbackForPackageInternal(packageName);
+        expireRollbackForPackageInternal(packageName, "Package " + packageName + " removed");
     }
 
     /**
@@ -713,14 +716,14 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
         Iterator<Rollback> iter = mRollbacks.iterator();
         while (iter.hasNext()) {
             Rollback rollback = iter.next();
-            if (!rollback.isAvailable()) {
+            if (!rollback.isAvailable() && !rollback.isCommitted()) {
                 continue;
             }
             Instant rollbackTimestamp = rollback.getTimestamp();
             if (!now.isBefore(rollbackTimestamp.plusMillis(mRollbackLifetimeDurationInMillis))) {
                 Slog.i(TAG, "runExpiration id=" + rollback.info.getRollbackId());
                 iter.remove();
-                rollback.delete(mAppDataRollbackHelper);
+                deleteRollback(rollback, "Expired by timeout");
             } else if (oldest == null || oldest.isAfter(rollbackTimestamp)) {
                 oldest = rollbackTimestamp;
             }
@@ -1132,7 +1135,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
                     Slog.w(TAG, "Delete rollback id=" + rollback.info.getRollbackId()
                             + " for failed session id=" + sessionId);
                     mRollbacks.remove(rollback);
-                    rollback.delete(mAppDataRollbackHelper);
+                    deleteRollback(rollback, "Session " + sessionId + " failed");
                 }
             }
         }
@@ -1159,7 +1162,7 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
         if (!rollback.allPackagesEnabled()) {
             Slog.e(TAG, "Failed to enable rollback for all packages in session.");
             mRollbacks.remove(rollback);
-            rollback.delete(mAppDataRollbackHelper);
+            deleteRollback(rollback, "Failed to enable rollback for all packages in session");
             return false;
         }
 
@@ -1240,6 +1243,18 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
                 rollback.dump(ipw);
             }
             ipw.println();
+
+            List<Rollback> historicalRollbacks = mRollbackStore.loadHistorialRollbacks();
+            if (!historicalRollbacks.isEmpty()) {
+                ipw.println("Historical rollbacks:");
+                ipw.increaseIndent();
+                for (Rollback rollback : historicalRollbacks) {
+                    rollback.dump(ipw);
+                }
+                ipw.decreaseIndent();
+                ipw.println();
+            }
+
             PackageWatchdog.getInstance(mContext).dump(ipw);
         });
     }
@@ -1329,4 +1344,11 @@ class RollbackManagerServiceImpl extends IRollbackManager.Stub implements Rollba
         }
         return null;
     }
+
+    @WorkerThread
+    private void deleteRollback(Rollback rollback, String reason) {
+        assertInWorkerThread();
+        rollback.delete(mAppDataRollbackHelper, reason);
+        mRollbackStore.saveRollbackToHistory(rollback);
+    }
 }
diff --git a/services/core/java/com/android/server/rollback/RollbackStore.java b/services/core/java/com/android/server/rollback/RollbackStore.java
index 2ee87e67e467..35c9f9ae6683 100644
--- a/services/core/java/com/android/server/rollback/RollbackStore.java
+++ b/services/core/java/com/android/server/rollback/RollbackStore.java
@@ -69,18 +69,20 @@ class RollbackStore {
     // * XXX, YYY are the rollbackIds for the corresponding rollbacks.
     // * rollback.json contains all relevant metadata for the rollback.
     private final File mRollbackDataDir;
+    private final File mRollbackHistoryDir;
 
-    RollbackStore(File rollbackDataDir) {
+    RollbackStore(File rollbackDataDir, File rollbackHistoryDir) {
         mRollbackDataDir = rollbackDataDir;
+        mRollbackHistoryDir = rollbackHistoryDir;
     }
 
     /**
      * Reads the rollbacks from persistent storage.
      */
-    List<Rollback> loadRollbacks() {
+    private static List<Rollback> loadRollbacks(File rollbackDataDir) {
         List<Rollback> rollbacks = new ArrayList<>();
-        mRollbackDataDir.mkdirs();
-        for (File rollbackDir : mRollbackDataDir.listFiles()) {
+        rollbackDataDir.mkdirs();
+        for (File rollbackDir : rollbackDataDir.listFiles()) {
             if (rollbackDir.isDirectory()) {
                 try {
                     rollbacks.add(loadRollback(rollbackDir));
@@ -93,6 +95,14 @@ class RollbackStore {
         return rollbacks;
     }
 
+    List<Rollback> loadRollbacks() {
+        return loadRollbacks(mRollbackDataDir);
+    }
+
+    List<Rollback> loadHistorialRollbacks() {
+        return loadRollbacks(mRollbackHistoryDir);
+    }
+
     /**
      * Converts a {@code JSONArray} of integers to a {@code List<Integer>}.
      */
@@ -258,15 +268,17 @@ class RollbackStore {
     /**
      * Saves the given rollback to persistent storage.
      */
-    static void saveRollback(Rollback rollback) {
+    private static void saveRollback(Rollback rollback, File backDir) {
         FileOutputStream fos = null;
-        AtomicFile file = new AtomicFile(new File(rollback.getBackupDir(), "rollback.json"));
+        AtomicFile file = new AtomicFile(new File(backDir, "rollback.json"));
         try {
+            backDir.mkdirs();
             JSONObject dataJson = new JSONObject();
             dataJson.put("info", rollbackInfoToJson(rollback.info));
             dataJson.put("timestamp", rollback.getTimestamp().toString());
             dataJson.put("stagedSessionId", rollback.getStagedSessionId());
             dataJson.put("state", rollback.getStateAsString());
+            dataJson.put("stateDescription", rollback.getStateDescription());
             dataJson.put("restoreUserDataInProgress", rollback.isRestoreUserDataInProgress());
             dataJson.put("userId", rollback.getUserId());
             dataJson.putOpt("installerPackageName", rollback.getInstallerPackageName());
@@ -286,6 +298,22 @@ class RollbackStore {
         }
     }
 
+    static void saveRollback(Rollback rollback) {
+        saveRollback(rollback, rollback.getBackupDir());
+    }
+
+    /**
+     * Saves the rollback to $mRollbackHistoryDir/ROLLBACKID-HEX for debugging purpose.
+     */
+    void saveRollbackToHistory(Rollback rollback) {
+        // The same id might be allocated to different historical rollbacks.
+        // Let's add a suffix to avoid naming collision.
+        String suffix = Long.toHexString(rollback.getTimestamp().getEpochSecond());
+        String dirName = Integer.toString(rollback.info.getRollbackId());
+        File backupDir = new File(mRollbackHistoryDir, dirName + "-" + suffix);
+        saveRollback(rollback, backupDir);
+    }
+
     /**
      * Removes all persistent storage associated with the given rollback.
      */
@@ -318,6 +346,7 @@ class RollbackStore {
                 Instant.parse(dataJson.getString("timestamp")),
                 dataJson.getInt("stagedSessionId"),
                 rollbackStateFromString(dataJson.getString("state")),
+                dataJson.optString("stateDescription"),
                 dataJson.getBoolean("restoreUserDataInProgress"),
                 dataJson.optInt("userId", UserHandle.SYSTEM.getIdentifier()),
                 dataJson.optString("installerPackageName", ""),
diff --git a/services/tests/servicestests/src/com/android/server/rollback/RollbackStoreTest.java b/services/tests/servicestests/src/com/android/server/rollback/RollbackStoreTest.java
index eedc9781aa40..c42f936d3ab4 100644
--- a/services/tests/servicestests/src/com/android/server/rollback/RollbackStoreTest.java
+++ b/services/tests/servicestests/src/com/android/server/rollback/RollbackStoreTest.java
@@ -110,6 +110,8 @@ public class RollbackStoreTest {
 
     @Rule
     public TemporaryFolder mFolder = new TemporaryFolder();
+    @Rule
+    public TemporaryFolder mHistoryDir = new TemporaryFolder();
 
     private File mRollbackDir;
 
@@ -117,7 +119,7 @@ public class RollbackStoreTest {
 
     @Before
     public void setUp() throws Exception {
-        mRollbackStore = new RollbackStore(mFolder.getRoot());
+        mRollbackStore = new RollbackStore(mFolder.getRoot(), mHistoryDir.getRoot());
         mRollbackDir = mFolder.newFolder(ID + "");
         mFolder.newFile("rollback.json");
     }
@@ -202,6 +204,8 @@ public class RollbackStoreTest {
         origRb.info.getPackages().add(pkgInfo1);
         origRb.info.getPackages().add(pkgInfo2);
 
+        origRb.setState(Rollback.ROLLBACK_STATE_AVAILABLE, "hello world");
+
         RollbackStore.saveRollback(origRb);
 
         List<Rollback> loadedRollbacks = mRollbackStore.loadRollbacks();
@@ -324,10 +328,26 @@ public class RollbackStoreTest {
         assertThat(expectedFile.exists()).isFalse();
     }
 
-    private void assertRollbacksAreEquivalent(Rollback b, Rollback a) {
-        assertThat(b.info.getRollbackId()).isEqualTo(ID);
+    @Test
+    public void saveToHistoryAndLoad() {
+        Rollback origRb = mRollbackStore.createNonStagedRollback(
+                ID, USER, INSTALLER, null, new SparseIntArray(0));
+        mRollbackStore.saveRollbackToHistory(origRb);
+
+        List<Rollback> loadedRollbacks = mRollbackStore.loadHistorialRollbacks();
+        assertThat(loadedRollbacks).hasSize(1);
+        Rollback loadedRb = loadedRollbacks.get(0);
+
+        assertRollbacksAreEquivalentExcludingBackupDir(loadedRb, origRb);
+    }
 
+    private void assertRollbacksAreEquivalent(Rollback b, Rollback a) {
         assertThat(b.getBackupDir()).isEqualTo(a.getBackupDir());
+        assertRollbacksAreEquivalentExcludingBackupDir(b, a);
+    }
+
+    private void assertRollbacksAreEquivalentExcludingBackupDir(Rollback b, Rollback a) {
+        assertThat(b.info.getRollbackId()).isEqualTo(ID);
 
         assertThat(b.isRestoreUserDataInProgress())
                 .isEqualTo(a.isRestoreUserDataInProgress());
@@ -337,6 +357,7 @@ public class RollbackStoreTest {
         assertThat(b.isEnabling()).isEqualTo(a.isEnabling());
         assertThat(b.isAvailable()).isEqualTo(a.isAvailable());
         assertThat(b.isCommitted()).isEqualTo(a.isCommitted());
+        assertThat(b.getStateDescription()).isEqualTo(a.getStateDescription());
 
         assertThat(b.isStaged()).isEqualTo(a.isStaged());
 
diff --git a/services/tests/servicestests/src/com/android/server/rollback/RollbackUnitTest.java b/services/tests/servicestests/src/com/android/server/rollback/RollbackUnitTest.java
index cd2c9230221c..cf1ed4815a74 100644
--- a/services/tests/servicestests/src/com/android/server/rollback/RollbackUnitTest.java
+++ b/services/tests/servicestests/src/com/android/server/rollback/RollbackUnitTest.java
@@ -123,7 +123,7 @@ public class RollbackUnitTest {
     public void deletedRollbackCannotBeMadeAvailable() {
         Rollback rollback = new Rollback(123, new File("/test/testing"), -1, USER, INSTALLER);
 
-        rollback.delete(mMockDataHelper);
+        rollback.delete(mMockDataHelper, "test");
 
         assertThat(rollback.isDeleted()).isTrue();
 
@@ -221,7 +221,7 @@ public class RollbackUnitTest {
         PackageRollbackInfo pkgInfo2 = newPkgInfoFor(PKG_2, 18, 12, true);
         rollback.info.getPackages().addAll(Arrays.asList(pkgInfo1, pkgInfo2));
 
-        rollback.delete(mMockDataHelper);
+        rollback.delete(mMockDataHelper, "test");
 
         assertThat(rollback.isDeleted()).isTrue();
 
@@ -247,7 +247,7 @@ public class RollbackUnitTest {
 
         verify(mMockDataHelper).snapshotAppData(eq(123), pkgRollbackInfoFor(PKG_2), eq(userIds));
 
-        rollback.delete(mMockDataHelper);
+        rollback.delete(mMockDataHelper, "test");
 
         verify(mMockDataHelper).destroyAppDataSnapshot(eq(123), pkgRollbackInfoFor(PKG_2), eq(111));
         verify(mMockDataHelper).destroyAppDataSnapshot(eq(123), pkgRollbackInfoFor(PKG_2), eq(222));
@@ -269,7 +269,7 @@ public class RollbackUnitTest {
 
         verify(mMockDataHelper).snapshotAppData(eq(123), pkgRollbackInfoFor(PKG_2), eq(userIds));
 
-        rollback.delete(mMockDataHelper);
+        rollback.delete(mMockDataHelper, "test");
 
         verify(mMockDataHelper, never())
                 .destroyAppDataSnapshot(anyInt(), pkgRollbackInfoFor(PKG_2), anyInt());