Merge "Use target path when handling dm-bow" into main

};

std::string fs_mgr_find_bow_device(const std::string& block_device) {

    if (block_device.substr(0, 5) != "/dev/") {

        LOG(ERROR) << "Expected block device, got " << block_device;

        return std::string();

    // handle symlink such as "/dev/block/mapper/userdata"

    std::string real_path;

    if (!android::base::Realpath(block_device, &real_path)) {

        real_path = block_device;

    }

    std::string sys_dir = std::string("/sys/") + block_device.substr(5);

    struct stat st;

    if (stat(real_path.c_str(), &st) < 0) {

        PLOG(ERROR) << "stat failed: " << real_path;

        return std::string();

    }

    if (!S_ISBLK(st.st_mode)) {

        PLOG(ERROR) << real_path << " is not block device";

        return std::string();

    }

    std::string sys_dir = android::base::StringPrintf("/sys/dev/block/%u:%u", major(st.st_rdev),

                                                      minor(st.st_rdev));

    for (;;) {

        std::string name;

        if (!android::base::ReadFileToString(sys_dir + "/dm/name", &name)) {

            PLOG(ERROR) << block_device << " is not dm device";

            PLOG(ERROR) << real_path << " is not dm device";

            return std::string();

        }