Merge "libsnapshot: Check for valid snapshots based on current slot" into main (acdc4848) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/snapshot.cpp

+13 −5

Original line number	Diff line number	Diff line
		@@ -729,6 +729,14 @@ bool SnapshotManager::DeleteSnapshot(LockedFile* lock, const std::string& name)
		LOG(ERROR) << "Failed to remove status file " << file_path << ": " << error;
		return false;
		}

		// This path may never exist. If it is present, then it's a stale
		// snapshot status file. Just remove the file and log the message.
		const std::string tmp_path = file_path + ".tmp";
		if (!android::base::RemoveFileIfExists(tmp_path, &error)) {
		LOG(ERROR) << "Failed to remove stale snapshot file " << tmp_path;
		}

		return true;
		}

		@@ -754,10 +762,10 @@ bool SnapshotManager::InitiateMerge() {
		return false;
		}

		auto other_suffix = device_->GetOtherSlotSuffix();
		auto current_slot_suffix = device_->GetSlotSuffix();

		for (const auto& snapshot : snapshots) {
		if (android::base::EndsWith(snapshot, other_suffix)) {
		if (!android::base::EndsWith(snapshot, current_slot_suffix)) {
		// Allow the merge to continue, but log this unexpected case.
		LOG(ERROR) << "Unexpected snapshot found during merge: " << snapshot;
		continue;
		@@ -1123,7 +1131,7 @@ auto SnapshotManager::CheckMergeState(LockedFile* lock, const std::function<bool
		return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ListSnapshots);
		}

		auto other_suffix = device_->GetOtherSlotSuffix();
		auto current_slot_suffix = device_->GetSlotSuffix();

		bool cancelled = false;
		bool merging = false;
		@@ -1131,9 +1139,9 @@ auto SnapshotManager::CheckMergeState(LockedFile* lock, const std::function<bool
		bool wrong_phase = false;
		MergeFailureCode failure_code = MergeFailureCode::Ok;
		for (const auto& snapshot : snapshots) {
		if (android::base::EndsWith(snapshot, other_suffix)) {
		if (!android::base::EndsWith(snapshot, current_slot_suffix)) {
		// This will have triggered an error message in InitiateMerge already.
		LOG(INFO) << "Skipping merge validation of unexpected snapshot: " << snapshot;
		LOG(ERROR) << "Skipping merge validation of unexpected snapshot: " << snapshot;
		continue;
		}

fs_mgr/libsnapshot/snapshot_test.cpp

+22 −1

Original line number	Diff line number	Diff line
		@@ -685,6 +685,17 @@ TEST_F(SnapshotTest, Merge) {
		}
		ASSERT_TRUE(sm->InitiateMerge());

		// Create stale files in snapshot directory. Merge should skip these files
		// as the suffix doesn't match the current slot.
		auto tmp_path = test_device->GetMetadataDir() + "/snapshots/test_partition_b.tmp";
		auto other_slot = test_device->GetMetadataDir() + "/snapshots/test_partition_a";

		unique_fd fd(open(tmp_path.c_str(), O_RDWR \| O_CLOEXEC \| O_CREAT, 0644));
		ASSERT_GE(fd, 0);

		fd.reset(open(other_slot.c_str(), O_RDWR \| O_CLOEXEC \| O_CREAT, 0644));
		ASSERT_GE(fd, 0);

		// The device should have been switched to a snapshot-merge target.
		DeviceMapper::TargetInfo target;
		ASSERT_TRUE(sm->IsSnapshotDevice("test_partition_b", &target));
		@@ -700,13 +711,23 @@ TEST_F(SnapshotTest, Merge) {
		ASSERT_EQ(sm->ProcessUpdateState(), UpdateState::MergeCompleted);
		ASSERT_EQ(sm->GetUpdateState(), UpdateState::None);

		// Make sure that snapshot states are cleared and all stale files
		// are deleted
		{
		ASSERT_TRUE(AcquireLock());
		auto local_lock = std::move(lock_);
		std::vector<std::string> snapshots;
		ASSERT_TRUE(sm->ListSnapshots(local_lock.get(), &snapshots));
		ASSERT_TRUE(snapshots.empty());
		}

		// The device should no longer be a snapshot or snapshot-merge.
		ASSERT_FALSE(sm->IsSnapshotDevice("test_partition_b"));

		// Test that we can read back the string we wrote to the snapshot. Note
		// that the base device is gone now. \|snap_device\| contains the correct
		// partition.
		unique_fd fd(open("/dev/block/mapper/test_partition_b", O_RDONLY \| O_CLOEXEC));
		fd.reset(open("/dev/block/mapper/test_partition_b", O_RDONLY \| O_CLOEXEC));
		ASSERT_GE(fd, 0);

		std::string buffer(test_string.size(), '\0');