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Commit 5576f7cc authored by Yifan Hong's avatar Yifan Hong
Browse files

libsnapshot: MapPartitionWithSnapshot: fix timeout 

The MapPartitionWithSnapshot call doesn't respect params.timeout.
Fix it.

Test: libsnapshot_test
Change-Id: I2c5a2889e4687449319bb2018e39405682b458a6
parent caaf9a61

fs_mgr/libsnapshot/snapshot.cpp

+32 −2
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ using android::fs_mgr::CreateLogicalPartitionParams; 
using android::fs_mgr::GetPartitionName;

using android::fs_mgr::LpMetadata;

using android::fs_mgr::SlotNumberForSlotSuffix;

using std::chrono::duration_cast;

using namespace std::chrono_literals;

using namespace std::string_literals;
@@ -1173,9 +1174,28 @@ bool SnapshotManager::CreateLogicalAndSnapshotPartitions(const std::string& supe 
    return true;

}



static std::chrono::milliseconds GetRemainingTime(

        const std::chrono::milliseconds& timeout,

        const std::chrono::time_point<std::chrono::steady_clock>& begin) {

    // If no timeout is specified, execute all commands without specifying any timeout.

    if (timeout.count() == 0) return std::chrono::milliseconds(0);

    auto passed_time = std::chrono::steady_clock::now() - begin;

    auto remaining_time = timeout - duration_cast<std::chrono::milliseconds>(passed_time);

    if (remaining_time.count() <= 0) {

        LOG(ERROR) << "MapPartitionWithSnapshot has reached timeout " << timeout.count() << "ms ("

                   << remaining_time.count() << "ms remaining)";

        // Return min() instead of remaining_time here because 0 is treated as a special value for

        // no timeout, where the rest of the commands will still be executed.

        return std::chrono::milliseconds::min();

    }

    return remaining_time;

}



bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock,

                                               CreateLogicalPartitionParams params,

                                               std::string* path) {

    auto begin = std::chrono::steady_clock::now();



    CHECK(lock);

    path->clear();
@@ -1246,15 +1266,25 @@ bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock, 
        return false;

    }



    // If there is a timeout specified, compute the remaining time to call Map* functions.

    // init calls CreateLogicalAndSnapshotPartitions, which has no timeout specified. Still call

    // Map* functions in this case.

    auto remaining_time = GetRemainingTime(params.timeout_ms, begin);

    if (remaining_time.count() < 0) return false;



    std::string cow_image_device;

    if (!MapCowImage(params.GetPartitionName(), {}, &cow_image_device)) {

    if (!MapCowImage(params.GetPartitionName(), remaining_time, &cow_image_device)) {

        LOG(ERROR) << "Could not map cow image for partition: " << params.GetPartitionName();

        return false;

    }

    // TODO: map cow linear device here

    std::string cow_device = cow_image_device;



    if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, {}, path)) {

    remaining_time = GetRemainingTime(params.timeout_ms, begin);

    if (remaining_time.count() < 0) return false;



    if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, remaining_time,

                     path)) {

        LOG(ERROR) << "Could not map snapshot for partition: " << params.GetPartitionName();

        return false;

    }