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Commit 10b755f1 authored by David Anderson's avatar David Anderson
Browse files

libsnapshot: Add a test for when partitions shrink and grow simultaneously. 

Bug: 177935716
Test: vts_libsnapshot_test
Change-Id: Ie9415411b8450147d44c6e3b62f413c5aac993cc
parent f2d359cb

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+3 −0
Original line number Diff line number Diff line
@@ -379,6 +379,7 @@ class SnapshotManager final : public ISnapshotManager { 
    FRIEND_TEST(SnapshotUpdateTest, MergeCannotRemoveCow);

    FRIEND_TEST(SnapshotUpdateTest, MergeInRecovery);

    FRIEND_TEST(SnapshotUpdateTest, SnapshotStatusFileWithoutCow);

    FRIEND_TEST(SnapshotUpdateTest, SpaceSwapUpdate);

    friend class SnapshotTest;

    friend class SnapshotUpdateTest;

    friend class FlashAfterUpdateTest;
@@ -717,6 +718,8 @@ class SnapshotManager final : public ISnapshotManager { 
    bool PerformInitTransition(InitTransition transition,

                               std::vector<std::string>* snapuserd_argv = nullptr);



    SnapuserdClient* snapuserd_client() const { return snapuserd_client_.get(); }



    std::string gsid_dir_;

    std::string metadata_dir_;

    std::unique_ptr<IDeviceInfo> device_;

fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ void DeleteBackingImage(android::fiemap::IImageManager* manager, const std::stri 
bool WriteRandomData(const std::string& path, std::optional<size_t> expect_size = std::nullopt,

                     std::string* hash = nullptr);

bool WriteRandomData(ICowWriter* writer, std::string* hash = nullptr);

std::string HashSnapshot(ISnapshotWriter* writer);



std::optional<std::string> GetHash(const std::string& path);

fs_mgr/libsnapshot/snapshot_test.cpp

+177 −6
Original line number Diff line number Diff line
@@ -225,7 +225,7 @@ class SnapshotTest : public ::testing::Test { 
    }



    AssertionResult MapUpdateSnapshot(const std::string& name,

                                      std::unique_ptr<ICowWriter>* writer) {

                                      std::unique_ptr<ISnapshotWriter>* writer) {

        TestPartitionOpener opener(fake_super);

        CreateLogicalPartitionParams params{

                .block_device = fake_super,
@@ -279,6 +279,7 @@ class SnapshotTest : public ::testing::Test { 
            return AssertionFailure() << "Cannot unmap image " << snapshot << "-cow-img";

        }

        if (!(res = DeleteDevice(snapshot + "-base"))) return res;

        if (!(res = DeleteDevice(snapshot + "-src"))) return res;

        return AssertionSuccess();

    }
@@ -319,7 +320,7 @@ class SnapshotTest : public ::testing::Test { 


    // Prepare A/B slot for a partition named "test_partition".

    AssertionResult PrepareOneSnapshot(uint64_t device_size,

                                       std::unique_ptr<ICowWriter>* writer = nullptr) {

                                       std::unique_ptr<ISnapshotWriter>* writer = nullptr) {

        lock_ = nullptr;



        DeltaArchiveManifest manifest;
@@ -511,7 +512,7 @@ TEST_F(SnapshotTest, Merge) { 


    static const uint64_t kDeviceSize = 1024 * 1024;



    std::unique_ptr<ICowWriter> writer;

    std::unique_ptr<ISnapshotWriter> writer;

    ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize, &writer));



    // Release the lock.
@@ -827,11 +828,14 @@ class SnapshotUpdateTest : public SnapshotTest { 


        opener_ = std::make_unique<TestPartitionOpener>(fake_super);



        auto dynamic_partition_metadata = manifest_.mutable_dynamic_partition_metadata();

        dynamic_partition_metadata->set_vabc_enabled(IsCompressionEnabled());



        // Create a fake update package metadata.

        // Not using full name "system", "vendor", "product" because these names collide with the

        // mapped partitions on the running device.

        // Each test modifies manifest_ slightly to indicate changes to the partition layout.

        group_ = manifest_.mutable_dynamic_partition_metadata()->add_groups();

        group_ = dynamic_partition_metadata->add_groups();

        group_->set_name("group");

        group_->set_size(kGroupSize);

        group_->add_partition_names("sys");
@@ -945,7 +949,7 @@ class SnapshotUpdateTest : public SnapshotTest { 


    AssertionResult MapOneUpdateSnapshot(const std::string& name) {

        if (IsCompressionEnabled()) {

            std::unique_ptr<ICowWriter> writer;

            std::unique_ptr<ISnapshotWriter> writer;

            return MapUpdateSnapshot(name, &writer);

        } else {

            std::string path;
@@ -955,7 +959,7 @@ class SnapshotUpdateTest : public SnapshotTest { 


    AssertionResult WriteSnapshotAndHash(const std::string& name) {

        if (IsCompressionEnabled()) {

            std::unique_ptr<ICowWriter> writer;

            std::unique_ptr<ISnapshotWriter> writer;

            auto res = MapUpdateSnapshot(name, &writer);

            if (!res) {

                return res;
@@ -984,6 +988,42 @@ class SnapshotUpdateTest : public SnapshotTest { 
                                  << ", hash: " << hashes_[name];

    }



    // Generate a snapshot that moves all the upper blocks down to the start.

    // It doesn't really matter the order, we just want copies that reference

    // blocks that won't exist if the partition shrinks.

    AssertionResult ShiftAllSnapshotBlocks(const std::string& name, uint64_t old_size) {

        std::unique_ptr<ISnapshotWriter> writer;

        if (auto res = MapUpdateSnapshot(name, &writer); !res) {

            return res;

        }

        if (!writer->options().max_blocks || !*writer->options().max_blocks) {

            return AssertionFailure() << "No max blocks set for " << name << " writer";

        }



        uint64_t src_block = (old_size / writer->options().block_size) - 1;

        uint64_t dst_block = 0;

        uint64_t max_blocks = *writer->options().max_blocks;

        while (dst_block < max_blocks && dst_block < src_block) {

            if (!writer->AddCopy(dst_block, src_block)) {

                return AssertionFailure() << "Unable to add copy for " << name << " for blocks "

                                          << src_block << ", " << dst_block;

            }

            dst_block++;

            src_block--;

        }

        if (!writer->Finalize()) {

            return AssertionFailure() << "Unable to finalize writer for " << name;

        }



        auto hash = HashSnapshot(writer.get());

        if (hash.empty()) {

            return AssertionFailure() << "Unable to hash snapshot writer for " << name;

        }

        hashes_[name] = hash;



        return AssertionSuccess();

    }



    AssertionResult MapUpdateSnapshots(const std::vector<std::string>& names = {"sys_b", "vnd_b",

                                                                                "prd_b"}) {

        for (const auto& name : names) {
@@ -1092,8 +1132,132 @@ TEST_F(SnapshotUpdateTest, FullUpdateFlow) { 
    // Initiate the merge and wait for it to be completed.

    ASSERT_TRUE(init->InitiateMerge());

    ASSERT_EQ(init->IsSnapuserdRequired(), IsCompressionEnabled());

    {

        // We should have started in SECOND_PHASE since nothing shrinks.

        ASSERT_TRUE(AcquireLock());

        auto local_lock = std::move(lock_);

        auto status = init->ReadSnapshotUpdateStatus(local_lock.get());

        ASSERT_EQ(status.merge_phase(), MergePhase::SECOND_PHASE);

    }

    ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());



    // Make sure the second phase ran and deleted snapshots.

    {

        ASSERT_TRUE(AcquireLock());

        auto local_lock = std::move(lock_);

        std::vector<std::string> snapshots;

        ASSERT_TRUE(init->ListSnapshots(local_lock.get(), &snapshots));

        ASSERT_TRUE(snapshots.empty());

    }



    // Check that the target partitions have the same content after the merge.

    for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {

        ASSERT_TRUE(IsPartitionUnchanged(name))

                << "Content of " << name << " changes after the merge";

    }

}



// Test that shrinking and growing partitions at the same time is handled

// correctly in VABC.

TEST_F(SnapshotUpdateTest, SpaceSwapUpdate) {

    // OTA client blindly unmaps all partitions that are possibly mapped.

    for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {

        ASSERT_TRUE(sm->UnmapUpdateSnapshot(name));

    }



    auto old_sys_size = GetSize(sys_);

    auto old_prd_size = GetSize(prd_);



    // Grow |sys| but shrink |prd|.

    SetSize(sys_, old_sys_size * 2);

    sys_->set_estimate_cow_size(8_MiB);

    SetSize(prd_, old_prd_size / 2);

    prd_->set_estimate_cow_size(1_MiB);



    AddOperationForPartitions();



    ASSERT_TRUE(sm->BeginUpdate());

    ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));



    // Check that the old partition sizes were saved correctly.

    {

        ASSERT_TRUE(AcquireLock());

        auto local_lock = std::move(lock_);



        SnapshotStatus status;

        ASSERT_TRUE(sm->ReadSnapshotStatus(local_lock.get(), "prd_b", &status));

        ASSERT_EQ(status.old_partition_size(), 3145728);

        ASSERT_TRUE(sm->ReadSnapshotStatus(local_lock.get(), "sys_b", &status));

        ASSERT_EQ(status.old_partition_size(), 3145728);

    }



    ASSERT_TRUE(WriteSnapshotAndHash("sys_b"));

    ASSERT_TRUE(WriteSnapshotAndHash("vnd_b"));

    ASSERT_TRUE(ShiftAllSnapshotBlocks("prd_b", old_prd_size));



    sync();



    // Assert that source partitions aren't affected.

    for (const auto& name : {"sys_a", "vnd_a", "prd_a"}) {

        ASSERT_TRUE(IsPartitionUnchanged(name));

    }



    ASSERT_TRUE(sm->FinishedSnapshotWrites(false));



    // Simulate shutting down the device.

    ASSERT_TRUE(UnmapAll());



    // After reboot, init does first stage mount.

    auto init = NewManagerForFirstStageMount("_b");

    ASSERT_NE(init, nullptr);

    ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());

    ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));



    auto indicator = sm->GetRollbackIndicatorPath();

    ASSERT_NE(access(indicator.c_str(), R_OK), 0);



    // Check that the target partitions have the same content.

    for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {

        ASSERT_TRUE(IsPartitionUnchanged(name));

    }



    // Initiate the merge and wait for it to be completed.

    ASSERT_TRUE(init->InitiateMerge());

    ASSERT_EQ(init->IsSnapuserdRequired(), IsCompressionEnabled());

    {

        // Check that the merge phase is FIRST_PHASE until at least one call

        // to ProcessUpdateState() occurs.

        ASSERT_TRUE(AcquireLock());

        auto local_lock = std::move(lock_);

        auto status = init->ReadSnapshotUpdateStatus(local_lock.get());

        ASSERT_EQ(status.merge_phase(), MergePhase::FIRST_PHASE);

    }



    // Simulate shutting down the device and creating partitions again.

    ASSERT_TRUE(UnmapAll());

    ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));



    // Check that we used the correct types after rebooting mid-merge.

    DeviceMapper::TargetInfo target;

    ASSERT_TRUE(init->IsSnapshotDevice("prd_b", &target));

    ASSERT_EQ(DeviceMapper::GetTargetType(target.spec), "snapshot-merge");

    ASSERT_TRUE(init->IsSnapshotDevice("sys_b", &target));

    ASSERT_EQ(DeviceMapper::GetTargetType(target.spec), "snapshot");

    ASSERT_TRUE(init->IsSnapshotDevice("vnd_b", &target));

    ASSERT_EQ(DeviceMapper::GetTargetType(target.spec), "snapshot");



    // Complete the merge.

    ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());



    // Make sure the second phase ran and deleted snapshots.

    {

        ASSERT_TRUE(AcquireLock());

        auto local_lock = std::move(lock_);

        std::vector<std::string> snapshots;

        ASSERT_TRUE(init->ListSnapshots(local_lock.get(), &snapshots));

        ASSERT_TRUE(snapshots.empty());

    }



    // Check that the target partitions have the same content after the merge.

    for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {

        ASSERT_TRUE(IsPartitionUnchanged(name))
@@ -1814,6 +1978,13 @@ TEST_F(SnapshotUpdateTest, DaemonTransition) { 


    ASSERT_TRUE(init->PerformInitTransition(SnapshotManager::InitTransition::SECOND_STAGE));



    // :TODO: this is a workaround to ensure the handler list stays empty. We

    // should make this test more like actual init, and spawn two copies of

    // snapuserd, given how many other tests we now have for normal snapuserd.

    ASSERT_TRUE(init->snapuserd_client()->WaitForDeviceDelete("sys_b-user-cow-init"));

    ASSERT_TRUE(init->snapuserd_client()->WaitForDeviceDelete("vnd_b-user-cow-init"));

    ASSERT_TRUE(init->snapuserd_client()->WaitForDeviceDelete("prd_b-user-cow-init"));



    // The control device should have been renamed.

    ASSERT_TRUE(android::fs_mgr::WaitForFileDeleted("/dev/dm-user/sys_b-user-cow-init", 10s));

    ASSERT_EQ(access("/dev/dm-user/sys_b-user-cow", F_OK), 0);

fs_mgr/libsnapshot/test_helpers.cpp

+32 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <android-base/unique_fd.h>

#include <gtest/gtest.h>

#include <openssl/sha.h>

#include <payload_consumer/file_descriptor.h>



namespace android {

namespace snapshot {
@@ -169,6 +170,37 @@ bool WriteRandomData(ICowWriter* writer, std::string* hash) { 
    return true;

}



std::string HashSnapshot(ISnapshotWriter* writer) {

    auto reader = writer->OpenReader();

    if (!reader) {

        return {};

    }



    SHA256_CTX ctx;

    SHA256_Init(&ctx);



    uint64_t remaining = reader->BlockDevSize();

    char buffer[4096];

    while (remaining) {

        size_t to_read =

                static_cast<size_t>(std::min(remaining, static_cast<uint64_t>(sizeof(buffer))));

        ssize_t read = reader->Read(&buffer, to_read);

        if (read <= 0) {

            if (read < 0) {

                LOG(ERROR) << "Failed to read from snapshot writer";

                return {};

            }

            break;

        }

        SHA256_Update(&ctx, buffer, to_read);

        remaining -= static_cast<size_t>(read);

    }



    uint8_t out[32];

    SHA256_Final(out, &ctx);

    return ToHexString(out, sizeof(out));

}



std::optional<std::string> GetHash(const std::string& path) {

    std::string content;

    if (!android::base::ReadFileToString(path, &content, true)) {