Merge "Respect `namespace mnt`"

    return success;

}

// Switch the mount namespace of the current process from bootstrap to default OR from default to

// bootstrap. If the current mount namespace is neither bootstrap nor default, keep it that way.

Result<void> SwitchToMountNamespaceIfNeeded(MountNamespace target_mount_namespace) {

    if (IsRecoveryMode() || !IsApexUpdatable()) {

        // we don't have multiple namespaces in recovery mode or if apex is not updatable

        return {};

    }

    const auto& ns_id = target_mount_namespace == NS_BOOTSTRAP ? bootstrap_ns_id : default_ns_id;

    const std::string current_namespace_id = GetMountNamespaceId();

    MountNamespace current_mount_namespace;

    if (current_namespace_id == bootstrap_ns_id) {

        current_mount_namespace = NS_BOOTSTRAP;

    } else if (current_namespace_id == default_ns_id) {

        current_mount_namespace = NS_DEFAULT;

    } else {

        // services with `namespace mnt` start in its own mount namespace. So we need to keep it.

        return {};

    }

    // We're already in the target mount namespace.

    if (current_mount_namespace == target_mount_namespace) {

        return {};

    }

    const auto& ns_fd = target_mount_namespace == NS_BOOTSTRAP ? bootstrap_ns_fd : default_ns_fd;

    const auto& ns_name = target_mount_namespace == NS_BOOTSTRAP ? "bootstrap" : "default";

    if (ns_id != GetMountNamespaceId() && ns_fd.get() != -1) {

    if (ns_fd.get() != -1) {

        if (setns(ns_fd.get(), CLONE_NEWNS) == -1) {

            return ErrnoError() << "Failed to switch to " << ns_name << " mount namespace.";

        }