From 89d2d050a0c5784b7993eaaa08be21ef93084156 Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Tue, 15 Oct 2019 13:22:20 -0700
Subject: Force merges to complete before wiping data or metadata.

After an OTA is applied, a wipe in recovery may overwrite components of
dynamic partitions living in userdata. If the OTA has not yet begun
merging, we mark the current slot unbootable. If the OTA has begun
merging, we wait for the merge to complete. This logic is encapsulated
in libsnapshot.

Bug: 139156011
Test: manual test
Change-Id: Id6544a1b8583afcbba11559d46214ec2e68ffa40
---
 install/Android.bp                       |  2 ++
 install/include/install/snapshot_utils.h | 21 ++++++++++++++
 install/snapshot_utils.cpp               | 49 ++++++++++++++++++++++++++++++++
 install/wipe_data.cpp                    |  7 +++++
 4 files changed, 79 insertions(+)
 create mode 100644 install/include/install/snapshot_utils.h
 create mode 100644 install/snapshot_utils.cpp

(limited to 'install')

diff --git a/install/Android.bp b/install/Android.bp
index d4606e92c..be08506e5 100644
--- a/install/Android.bp
+++ b/install/Android.bp
@@ -39,6 +39,7 @@ cc_defaults {
     static_libs: [
         "librecovery_utils",
         "libotautil",
+        "libsnapshot_nobinder",
 
         // external dependencies
         "libvintf_recovery",
@@ -60,6 +61,7 @@ cc_library_static {
         "fuse_install.cpp",
         "install.cpp",
         "package.cpp",
+        "snapshot_utils.cpp",
         "verifier.cpp",
         "wipe_data.cpp",
         "wipe_device.cpp",
diff --git a/install/include/install/snapshot_utils.h b/install/include/install/snapshot_utils.h
new file mode 100644
index 000000000..00c3ef7e1
--- /dev/null
+++ b/install/include/install/snapshot_utils.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "recovery_ui/device.h"
+
+bool FinishPendingSnapshotMerges(Device* device);
diff --git a/install/snapshot_utils.cpp b/install/snapshot_utils.cpp
new file mode 100644
index 000000000..69da5eea0
--- /dev/null
+++ b/install/snapshot_utils.cpp
@@ -0,0 +1,49 @@
+
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/properties.h>
+#include <libsnapshot/snapshot.h>
+
+#include "recovery_ui/device.h"
+#include "recovery_ui/ui.h"
+#include "recovery_utils/roots.h"
+
+using android::snapshot::SnapshotManager;
+
+bool FinishPendingSnapshotMerges(Device* device) {
+  if (!android::base::GetBoolProperty("ro.virtual_ab.enabled", false)) {
+    return true;
+  }
+
+  RecoveryUI* ui = device->GetUI();
+  auto sm = SnapshotManager::NewForFirstStageMount();
+  if (!sm) {
+    ui->Print("Could not create SnapshotManager.\n");
+    return false;
+  }
+
+  auto callback = [&]() -> void {
+    double progress;
+    sm->GetUpdateState(&progress);
+    ui->Print("Waiting for merge to complete: %.2f\n", progress);
+  };
+  if (!sm->HandleImminentDataWipe(callback)) {
+    ui->Print("Unable to check merge status and/or complete update merge.\n");
+    return false;
+  }
+  return true;
+}
diff --git a/install/wipe_data.cpp b/install/wipe_data.cpp
index 82660bef0..287208583 100644
--- a/install/wipe_data.cpp
+++ b/install/wipe_data.cpp
@@ -27,6 +27,7 @@
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 
+#include "install/snapshot_utils.h"
 #include "otautil/dirutil.h"
 #include "recovery_ui/ui.h"
 #include "recovery_utils/logging.h"
@@ -104,6 +105,12 @@ bool WipeCache(RecoveryUI* ui, const std::function<bool()>& confirm_func) {
 bool WipeData(Device* device, bool convert_fbe) {
   RecoveryUI* ui = device->GetUI();
   ui->Print("\n-- Wiping data...\n");
+
+  if (!FinishPendingSnapshotMerges(device)) {
+    ui->Print("Unable to check update status or complete merge, cannot wipe partitions.\n");
+    return false;
+  }
+
   bool success = device->PreWipeData();
   if (success) {
     success &= EraseVolume(DATA_ROOT, ui, convert_fbe);
-- 
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