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Commit adb91b0e authored by David Anderson's avatar David Anderson
Browse files

remount: Detect when flashall has happened in the bootloader. 

This adds a new metadata header flag to the super partition. This flag
is set when "adb remount" is used, and is implicitly cleared when
flashing.

If there is a scratch partition present on /data, we require that the
flag be set in order to proceed using overlays. If not set, scratch is
not mapped in first-stage init, and scratch images are removed later
during startup.

Bug: 297923468
Test: adb remount -R, touch file in out/, sync, flashall
Change-Id: I9cc411a1632101b5fc043193b38db8ffb9c20e7f
parent e2c6171f

fastboot/fastboot.cpp

+1 −1
Original line number Diff line number Diff line
@@ -1675,7 +1675,7 @@ bool AddResizeTasks(const FlashingPlan* fp, std::vector<std::unique_ptr<Task>>* 
    }

    for (size_t i = 0; i < tasks->size(); i++) {

        if (auto flash_task = tasks->at(i)->AsFlashTask()) {

            if (FlashTask::IsDynamicParitition(fp->source.get(), flash_task)) {

            if (FlashTask::IsDynamicPartition(fp->source.get(), flash_task)) {

                if (!loc) {

                    loc = i;

                }

fastboot/task.cpp

+2 −2
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ FlashTask::FlashTask(const std::string& slot, const std::string& pname, const st 
                     const bool apply_vbmeta, const FlashingPlan* fp)

    : pname_(pname), fname_(fname), slot_(slot), apply_vbmeta_(apply_vbmeta), fp_(fp) {}



bool FlashTask::IsDynamicParitition(const ImageSource* source, const FlashTask* task) {

bool FlashTask::IsDynamicPartition(const ImageSource* source, const FlashTask* task) {

    std::vector<char> contents;

    if (!source->ReadFile("super_empty.img", &contents)) {

        return false;
@@ -152,7 +152,7 @@ bool OptimizedFlashSuperTask::CanOptimize(const ImageSource* source, 
            continue;

        }

        auto flash_task = tasks[i + 2]->AsFlashTask();

        if (!FlashTask::IsDynamicParitition(source, flash_task)) {

        if (!FlashTask::IsDynamicPartition(source, flash_task)) {

            continue;

        }

        return true;

fastboot/task.h

+1 −1
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ class FlashTask : public Task { 
              const bool apply_vbmeta, const FlashingPlan* fp);

    virtual FlashTask* AsFlashTask() override { return this; }



    static bool IsDynamicParitition(const ImageSource* source, const FlashTask* task);

    static bool IsDynamicPartition(const ImageSource* source, const FlashTask* task);

    void Run() override;

    std::string ToString() const override;

    std::string GetPartition() const { return pname_; }

fastboot/task_test.cpp

+3 −3
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ TEST_F(ParseTest, CorrectTaskLists) { 
            << "size of fastboot-info task list: " << fastboot_info_tasks.size()

            << " size of hardcoded task list: " << hardcoded_tasks.size();

}

TEST_F(ParseTest, IsDynamicParitiontest) {

TEST_F(ParseTest, IsDynamicPartitiontest) {

    if (!get_android_product_out()) {

        GTEST_SKIP();

    }
@@ -258,7 +258,7 @@ TEST_F(ParseTest, IsDynamicParitiontest) { 
                ParseFastbootInfoLine(fp.get(), android::base::Tokenize(test.first, " "));

        auto flash_task = task->AsFlashTask();

        ASSERT_FALSE(flash_task == nullptr);

        ASSERT_EQ(FlashTask::IsDynamicParitition(fp->source.get(), flash_task), test.second);

        ASSERT_EQ(FlashTask::IsDynamicPartition(fp->source.get(), flash_task), test.second);

    }

}
@@ -358,7 +358,7 @@ TEST_F(ParseTest, OptimizedFlashSuperPatternMatchTest) { 
                    contains_optimized_task = true;

                }

                if (auto flash_task = task->AsFlashTask()) {

                    if (FlashTask::IsDynamicParitition(fp->source.get(), flash_task)) {

                    if (FlashTask::IsDynamicPartition(fp->source.get(), flash_task)) {

                        return false;

                    }

                }

fs_mgr/fs_mgr_overlayfs_control.cpp

+46 −0
Original line number Diff line number Diff line
@@ -219,6 +219,35 @@ OverlayfsTeardownResult TeardownDataScratch(IImageManager* images, 
    return OverlayfsTeardownResult::Ok;

}



bool GetOverlaysActiveFlag() {

    auto slot_number = fs_mgr_overlayfs_slot_number();

    const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();



    auto metadata = ReadMetadata(super_device, slot_number);

    if (!metadata) {

        return false;

    }

    return !!(metadata->header.flags & LP_HEADER_FLAG_OVERLAYS_ACTIVE);

}



bool SetOverlaysActiveFlag(bool flag) {

    // Mark overlays as active in the partition table, to detect re-flash.

    auto slot_number = fs_mgr_overlayfs_slot_number();

    const auto super_device = kPhysicalDevice + fs_mgr_get_super_partition_name();

    auto builder = MetadataBuilder::New(super_device, slot_number);

    if (!builder) {

        LERROR << "open " << super_device << " metadata";

        return false;

    }

    builder->SetOverlaysActiveFlag(flag);

    auto metadata = builder->Export();

    if (!metadata || !UpdatePartitionTable(super_device, *metadata.get(), slot_number)) {

        LERROR << "update super metadata";

        return false;

    }

    return true;

}



OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& overlay,

                                                          bool* change) {

    // umount and delete kScratchMountPoint storage if we have logical partitions
@@ -232,6 +261,10 @@ OverlayfsTeardownResult fs_mgr_overlayfs_teardown_scratch(const std::string& ove 
        return OverlayfsTeardownResult::Error;

    }



    // Note: we don't care if SetOverlaysActiveFlag fails, since

    // the overlays are removed no matter what.

    SetOverlaysActiveFlag(false);



    bool was_mounted = fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false);

    if (was_mounted) {

        fs_mgr_overlayfs_umount_scratch();
@@ -448,6 +481,7 @@ static bool CreateDynamicScratch(std::string* scratch_device, bool* partition_ex 
            }

        }

    }



    // land the update back on to the partition

    if (changed) {

        auto metadata = builder->Export();
@@ -592,6 +626,12 @@ bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab) { 
        return false;

    }



    if (!SetOverlaysActiveFlag(true)) {

        LOG(ERROR) << "Failed to update dynamic partition data";

        fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, nullptr);

        return false;

    }



    // If the partition exists, assume first that it can be mounted.

    if (partition_exists) {

        if (MountScratch(scratch_device)) {
@@ -856,6 +896,9 @@ void MapScratchPartitionIfNeeded(Fstab* fstab, 
        return;

    }



    if (!GetOverlaysActiveFlag()) {

        return;

    }

    if (ScratchIsOnData()) {

        if (auto images = IImageManager::Open("remount", 0ms)) {

            images->MapAllImages(init);
@@ -879,6 +922,9 @@ void CleanupOldScratchFiles() { 
    }

    if (auto images = IImageManager::Open("remount", 0ms)) {

        images->RemoveDisabledImages();

        if (!GetOverlaysActiveFlag()) {

            fs_mgr_overlayfs_teardown_scratch(kScratchMountPoint, nullptr);

        }

    }

}