MQ_RQ_IDLE
WRITE_ONCE(flush_rq->state, MQ_RQ_IDLE);
[MQ_RQ_IDLE] = "idle",
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
return blk_mq_rq_state(rq) != MQ_RQ_IDLE;