Workaround: Request non-incremental backup to include @pm@

The fake package manager package is essential for the backup, but when its data doesn't change and we request a normal incremental backup, it doesn't get included, because our transport doesn't even get called for it. Only the BackupMonitor gets a hint that it had no (new?) data via LOG_EVENT_ID_NO_DATA_TO_SEND. This behavior started with Android 15.
seedvault-app · Oct 2, 2024 · a406e18 · a406e18
1 parent 1dee14f
commit a406e18
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Showing 4 changed files with 12 additions and 6 deletions.
diff --git a/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotCreator.kt b/app/src/main/java/com/stevesoltys/seedvault/repo/SnapshotCreator.kt
@@ -16,6 +16,7 @@ import android.provider.Settings
 import android.provider.Settings.Secure.ANDROID_ID
 import com.google.protobuf.ByteString
 import com.stevesoltys.seedvault.Clock
+import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.metadata.BackupType
 import com.stevesoltys.seedvault.metadata.MetadataManager
@@ -134,6 +135,8 @@ internal class SnapshotCreator(
             putAllApps(appBuilderMap.mapValues { it.value.build() })
             putAllBlobs(this@SnapshotCreator.blobsMap)
         }.build()
+        // may as well fail the backup, if @pm@ isn't in it
+        check(MAGIC_PACKAGE_MANAGER in snapshot.appsMap) { "No metadata for @pm@" }
         appBuilderMap.clear()
         snapshotBuilder.clear()
         blobsMap.clear()

diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackup.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackup.kt
@@ -14,6 +14,7 @@ import android.app.backup.BackupTransport.TRANSPORT_OK
 import android.content.pm.PackageInfo
 import android.os.ParcelFileDescriptor
 import android.util.Log
+import com.stevesoltys.seedvault.NO_DATA_END_SENTINEL
 import com.stevesoltys.seedvault.repo.BackupData
 import com.stevesoltys.seedvault.repo.BackupReceiver
 import java.io.IOException
@@ -52,6 +53,8 @@ internal class KVBackup(
             else -> Log.i(TAG, "Performing K/V backup for $packageName")
         }
         check(state == null) { "Have unexpected state for ${state?.packageInfo?.packageName}" }
+        // This fake package name just signals that we've seen all packages without new data
+        if (packageName == NO_DATA_END_SENTINEL) return TRANSPORT_OK
 
         // initialize state
         state = KVBackupState(packageInfo = packageInfo, db = dbManager.getDb(packageName))

diff --git a/app/src/main/java/com/stevesoltys/seedvault/transport/backup/PackageService.kt b/app/src/main/java/com/stevesoltys/seedvault/transport/backup/PackageService.kt
@@ -59,18 +59,17 @@ internal class PackageService(
                 logPackages(packages)
             }
 
-            val eligibleApps = packages.filter(::shouldIncludeAppInBackup).toTypedArray()
+            val eligibleApps = packages.filter(::shouldIncludeAppInBackup).toMutableList()
             // log eligible packages
             if (Log.isLoggable(TAG, INFO)) {
                 Log.i(TAG, "Filtering left ${eligibleApps.size} eligible packages:")
-                logPackages(eligibleApps.toList())
+                logPackages(eligibleApps)
             }
 
             // add magic @pm@ package (PACKAGE_MANAGER_SENTINEL) which holds package manager data
-            val packageArray = eligibleApps.toMutableList()
-            packageArray.add(MAGIC_PACKAGE_MANAGER)
+            eligibleApps.add(0, MAGIC_PACKAGE_MANAGER)
 
-            return packageArray
+            return eligibleApps
         }
 
     /**

diff --git a/app/src/main/java/com/stevesoltys/seedvault/worker/BackupRequester.kt b/app/src/main/java/com/stevesoltys/seedvault/worker/BackupRequester.kt
@@ -6,6 +6,7 @@
 package com.stevesoltys.seedvault.worker
 
 import android.app.backup.BackupManager
+import android.app.backup.BackupManager.FLAG_NON_INCREMENTAL_BACKUP
 import android.app.backup.IBackupManager
 import android.content.Context
 import android.os.RemoteException
@@ -82,7 +83,7 @@ internal class BackupRequester(
     private fun request(chunk: Array<String>): Boolean {
         Log.i(TAG, "${chunk.toList()}")
         val result = try {
-            backupManager.requestBackup(chunk, observer, monitor, 0)
+            backupManager.requestBackup(chunk, observer, monitor, FLAG_NON_INCREMENTAL_BACKUP)
         } catch (e: RemoteException) {
             Log.e(TAG, "Error during backup: ", e)
             val nm: BackupNotificationManager = GlobalContext.get().get()