int uverbs_dealloc_mw(struct ib_mw *mw)
{
	struct ib_pd *pd = mw->pd;
	int ret;

	ret = mw->device->ops.dealloc_mw(mw);
	if (!ret)
		atomic_dec(&pd->usecnt);
	return ret;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.