Merge "libfiemap: Disable loop mapping code." into main

    // If there is no intermediate device-mapper node, then partitions cannot be

    // opened writable due to sepolicy and exclusivity of having a mounted

    // filesystem. This should only happen on devices with no encryption, or

    // devices with FBE and no metadata encryption. For these cases it suffices

    // to perform normal file writes to /data/gsi (which is unencrypted).

    // devices with FBE and no metadata encryption. For these cases we COULD

    // perform normal writes to /data/gsi (which is unencrypted), but given that

    // metadata encryption has been mandated since Android R, we don't actually

    // support or test this.

    //

    // Note: this is not gated on DeviceInfo, because the recovery-specific path

    // must only be used in actual recovery.

    // So, we validate here that /data is backed by device-mapper. This code

    // isn't needed in recovery since there is no /data.

    //

    // If this logic sticks for a release, we can remove MapWithLoopDevice, as

    // well as WrapUserdataIfNeeded in fs_mgr.

    std::string block_device;

    bool can_use_devicemapper;

    if (!FiemapWriter::GetBlockDeviceForFile(image_header, &block_device, &can_use_devicemapper)) {

        return false;

    }

    if (can_use_devicemapper) {

        if (!MapWithDmLinear(*partition_opener_.get(), name, timeout_ms, path)) {

            return false;

        }

    } else if (!MapWithLoopDevice(name, timeout_ms, path)) {

    if (!can_use_devicemapper) {

        LOG(ERROR) << "Cannot map image: /data must be mounted on top of device-mapper.";

        return false;

    }

#else

    // In recovery, we can *only* use device-mapper, since partitions aren't

    // mounted. That also means we cannot call GetBlockDeviceForFile.

#endif

    if (!MapWithDmLinear(*partition_opener_.get(), name, timeout_ms, path)) {

        return false;

    }

#endif

    // Set a property so we remember this is mapped.

    auto prop_name = GetStatusPropertyName(name);