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Merge "libsnapshot: snaity check overflow bit at the end of update"

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am: babc293140

Change-Id: Ica15033799b3af1f226d7e784f8781d0c9b03907
This commit is contained in:
Yifan Hong 2019-12-13 19:07:32 -08:00 • committed by android-build-merger
commit f99af924e5
5 changed files with 159 additions and 65 deletions
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4
fs_mgr/libdm/dm.cpp
View file

@ -575,5 +575,9 @@ std::optional<std::string> DeviceMapper::GetParentBlockDeviceByPath(const std::s
return "/dev/block/" + sub_device_name;
}
bool DeviceMapper::TargetInfo::IsOverflowSnapshot() const {
return spec.target_type == "snapshot"s && data == "Overflow"s;
}
} // namespace dm
} // namespace android

2
fs_mgr/libdm/include/libdm/dm.h
View file

@ -205,6 +205,8 @@ class DeviceMapper final {
TargetInfo() {}
TargetInfo(const struct dm_target_spec& spec, const std::string& data)
: spec(spec), data(data) {}
bool IsOverflowSnapshot() const;
};
bool GetTableStatus(const std::string& name, std::vector<TargetInfo>* table);

6
fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
View file

@ -155,6 +155,7 @@ class SnapshotManager final {
// Mark snapshot writes as having completed. After this, new snapshots cannot
// be created, and the device must either cancel the OTA (either before
// rebooting or after rolling back), or merge the OTA.
// Before calling this function, all snapshots must be mapped.
bool FinishedSnapshotWrites();
private:
@ -490,6 +491,11 @@ class SnapshotManager final {
// This should only be called in recovery.
bool UnmapAllPartitions();
// Sanity check no snapshot overflows. Note that this returns false negatives if the snapshot
// overflows, then is remapped and not written afterwards. Hence, the function may only serve
// as a sanity check.
bool EnsureNoOverflowSnapshot(LockedFile* lock);
std::string gsid_dir_;
std::string metadata_dir_;
std::unique_ptr<IDeviceInfo> device_;

36
fs_mgr/libsnapshot/snapshot.cpp
View file

@ -214,6 +214,11 @@ bool SnapshotManager::FinishedSnapshotWrites() {
return false;
}
if (!EnsureNoOverflowSnapshot(lock.get())) {
LOG(ERROR) << "Cannot ensure there are no overflow snapshots.";
return false;
}
// This file acts as both a quick indicator for init (it can use access(2)
// to decide how to do first-stage mounts), and it stores the old slot, so
// we can tell whether or not we performed a rollback.
@ -2303,5 +2308,36 @@ bool SnapshotManager::HandleImminentDataWipe(const std::function<void()>& callba
return true;
}
bool SnapshotManager::EnsureNoOverflowSnapshot(LockedFile* lock) {
CHECK(lock);
std::vector<std::string> snapshots;
if (!ListSnapshots(lock, &snapshots)) {
LOG(ERROR) << "Could not list snapshots.";
return false;
}
auto& dm = DeviceMapper::Instance();
for (const auto& snapshot : snapshots) {
std::vector<DeviceMapper::TargetInfo> targets;
if (!dm.GetTableStatus(snapshot, &targets)) {
LOG(ERROR) << "Could not read snapshot device table: " << snapshot;
return false;
}
if (targets.size() != 1) {
LOG(ERROR) << "Unexpected device-mapper table for snapshot: " << snapshot
<< ", size = " << targets.size();
return false;
}
if (targets[0].IsOverflowSnapshot()) {
LOG(ERROR) << "Detected overflow in snapshot " << snapshot
<< ", CoW device size computation is wrong!";
return false;
}
}
return true;
}
} // namespace snapshot
} // namespace android

176
fs_mgr/libsnapshot/snapshot_test.cpp
View file

@ -273,6 +273,61 @@ class SnapshotTest : public ::testing::Test {
return AssertionSuccess();
}
// Prepare A/B slot for a partition named "test_partition".
AssertionResult PrepareOneSnapshot(uint64_t device_size,
std::string* out_snap_device = nullptr) {
std::string base_device, cow_device, snap_device;
if (!CreatePartition("test_partition_a", device_size)) {
return AssertionFailure();
}
if (!MapUpdatePartitions()) {
return AssertionFailure();
}
if (!dm_.GetDmDevicePathByName("test_partition_b-base", &base_device)) {
return AssertionFailure();
}
SnapshotStatus status;
status.set_name("test_partition_b");
status.set_device_size(device_size);
status.set_snapshot_size(device_size);
status.set_cow_file_size(device_size);
if (!sm->CreateSnapshot(lock_.get(), &status)) {
return AssertionFailure();
}
if (!CreateCowImage("test_partition_b")) {
return AssertionFailure();
}
if (!MapCowImage("test_partition_b", 10s, &cow_device)) {
return AssertionFailure();
}
if (!sm->MapSnapshot(lock_.get(), "test_partition_b", base_device, cow_device, 10s,
&snap_device)) {
return AssertionFailure();
}
if (out_snap_device) {
*out_snap_device = std::move(snap_device);
}
return AssertionSuccess();
}
// Simulate a reboot into the new slot.
AssertionResult SimulateReboot() {
lock_ = nullptr;
if (!sm->FinishedSnapshotWrites()) {
return AssertionFailure();
}
if (!dm_.DeleteDevice("test_partition_b")) {
return AssertionFailure();
}
if (!DestroyLogicalPartition("test_partition_b-base")) {
return AssertionFailure();
}
if (!sm->UnmapCowImage("test_partition_b")) {
return AssertionFailure();
}
return AssertionSuccess();
}
DeviceMapper& dm_;
std::unique_ptr<SnapshotManager::LockedFile> lock_;
android::fiemap::IImageManager* image_manager_ = nullptr;
@ -389,21 +444,8 @@ TEST_F(SnapshotTest, Merge) {
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
std::string base_device, cow_device, snap_device;
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
ASSERT_TRUE(dm_.GetDmDevicePathByName("test_partition_b-base", &base_device));
SnapshotStatus status;
status.set_name("test_partition_b");
status.set_device_size(kDeviceSize);
status.set_snapshot_size(kDeviceSize);
status.set_cow_file_size(kDeviceSize);
ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
ASSERT_TRUE(CreateCowImage("test_partition_b"));
ASSERT_TRUE(MapCowImage("test_partition_b", 10s, &cow_device));
ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test_partition_b", base_device, cow_device, 10s,
&snap_device));
std::string snap_device;
ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize, &snap_device));
std::string test_string = "This is a test string.";
{
@ -455,21 +497,8 @@ TEST_F(SnapshotTest, FirstStageMountAndMerge) {
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
SnapshotStatus status;
status.set_name("test_partition_b");
status.set_device_size(kDeviceSize);
status.set_snapshot_size(kDeviceSize);
status.set_cow_file_size(kDeviceSize);
ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
ASSERT_TRUE(CreateCowImage("test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
ASSERT_TRUE(sm->FinishedSnapshotWrites());
ASSERT_TRUE(DestroyLogicalPartition("test_partition_b-base"));
ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize));
ASSERT_TRUE(SimulateReboot());
auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
ASSERT_NE(init, nullptr);
@ -479,6 +508,7 @@ TEST_F(SnapshotTest, FirstStageMountAndMerge) {
ASSERT_TRUE(AcquireLock());
// Validate that we have a snapshot device.
SnapshotStatus status;
ASSERT_TRUE(init->ReadSnapshotStatus(lock_.get(), "test_partition_b", &status));
ASSERT_EQ(status.state(), SnapshotState::CREATED);
@ -492,21 +522,8 @@ TEST_F(SnapshotTest, FlashSuperDuringUpdate) {
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
SnapshotStatus status;
status.set_name("test_partition_b");
status.set_device_size(kDeviceSize);
status.set_snapshot_size(kDeviceSize);
status.set_cow_file_size(kDeviceSize);
ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
ASSERT_TRUE(CreateCowImage("test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
ASSERT_TRUE(sm->FinishedSnapshotWrites());
ASSERT_TRUE(DestroyLogicalPartition("test_partition_b-base"));
ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize));
ASSERT_TRUE(SimulateReboot());
// Reflash the super partition.
FormatFakeSuper();
@ -519,6 +536,7 @@ TEST_F(SnapshotTest, FlashSuperDuringUpdate) {
ASSERT_TRUE(AcquireLock());
SnapshotStatus status;
ASSERT_TRUE(init->ReadSnapshotStatus(lock_.get(), "test_partition_b", &status));
// We should not get a snapshot device now.
@ -535,21 +553,8 @@ TEST_F(SnapshotTest, FlashSuperDuringMerge) {
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
SnapshotStatus status;
status.set_name("test_partition_b");
status.set_device_size(kDeviceSize);
status.set_snapshot_size(kDeviceSize);
status.set_cow_file_size(kDeviceSize);
ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
ASSERT_TRUE(CreateCowImage("test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
ASSERT_TRUE(sm->FinishedSnapshotWrites());
ASSERT_TRUE(DestroyLogicalPartition("test_partition_b-base"));
ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize));
ASSERT_TRUE(SimulateReboot());
auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
ASSERT_NE(init, nullptr);
@ -905,6 +910,17 @@ class SnapshotUpdateTest : public SnapshotTest {
<< ", hash: " << hashes_[name];
}
AssertionResult MapUpdateSnapshots(const std::vector<std::string>& names = {"sys_b", "vnd_b",
"prd_b"}) {
for (const auto& name : names) {
auto res = MapUpdateSnapshot(name);
if (!res) {
return res;
}
}
return AssertionSuccess();
}
std::unique_ptr<TestPartitionOpener> opener_;
DeltaArchiveManifest manifest_;
std::unique_ptr<MetadataBuilder> src_;
@ -1064,9 +1080,7 @@ TEST_F(SnapshotUpdateTest, SnapshotStatusFileWithoutCow) {
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
// Check that target partitions can be mapped.
for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
EXPECT_TRUE(MapUpdateSnapshot(name));
}
EXPECT_TRUE(MapUpdateSnapshots());
}
// Test that the old partitions are not modified.
@ -1142,6 +1156,7 @@ TEST_F(SnapshotUpdateTest, ReclaimCow) {
// Execute the first update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.
@ -1277,6 +1292,7 @@ TEST_F(SnapshotUpdateTest, MergeCannotRemoveCow) {
// Execute the update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.
@ -1379,6 +1395,7 @@ TEST_F(SnapshotUpdateTest, MergeInRecovery) {
// Execute the first update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.
@ -1410,6 +1427,7 @@ TEST_F(SnapshotUpdateTest, DataWipeRollbackInRecovery) {
// Execute the first update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.
@ -1434,6 +1452,7 @@ TEST_F(SnapshotUpdateTest, DataWipeAfterRollback) {
// Execute the first update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.
@ -1480,7 +1499,8 @@ TEST_F(SnapshotUpdateTest, Hashtree) {
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
// Write some data to target partition.
// Map and write some data to target partition.
ASSERT_TRUE(MapUpdateSnapshots({"vnd_b", "prd_b"}));
ASSERT_TRUE(WriteSnapshotAndHash("sys_b", partition_size));
// Finish update.
@ -1500,6 +1520,32 @@ TEST_F(SnapshotUpdateTest, Hashtree) {
ASSERT_TRUE(IsPartitionUnchanged("sys_b"));
}
// Test for overflow bit after update
TEST_F(SnapshotUpdateTest, Overflow) {
const auto actual_write_size = GetSize(sys_);
const auto declared_write_size = actual_write_size - 1_MiB;
auto e = sys_->add_operations()->add_dst_extents();
e->set_start_block(0);
e->set_num_blocks(declared_write_size / manifest_.block_size());
// Execute the update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
// Map and write some data to target partitions.
ASSERT_TRUE(MapUpdateSnapshots({"vnd_b", "prd_b"}));
ASSERT_TRUE(WriteSnapshotAndHash("sys_b", actual_write_size));
std::vector<android::dm::DeviceMapper::TargetInfo> table;
ASSERT_TRUE(DeviceMapper::Instance().GetTableStatus("sys_b", &table));
ASSERT_EQ(1u, table.size());
EXPECT_TRUE(table[0].IsOverflowSnapshot());
ASSERT_FALSE(sm->FinishedSnapshotWrites())
<< "FinishedSnapshotWrites should detect overflow of CoW device.";
}
class FlashAfterUpdateTest : public SnapshotUpdateTest,
public WithParamInterface<std::tuple<uint32_t, bool>> {
public:
@ -1524,7 +1570,7 @@ TEST_P(FlashAfterUpdateTest, FlashSlotAfterUpdate) {
// Execute the update.
ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_TRUE(MapUpdateSnapshots());
ASSERT_TRUE(sm->FinishedSnapshotWrites());
// Simulate shutting down the device.