TB_CFG_REQUEST_ACTIVE
WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));
set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
if (!test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags)) {
clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);