On 2020-04-30 06:18, Hannes Reinecke wrote:
> +/**
> + * scsi_get_reserved_cmd - allocate a SCSI command from reserved tags
> + * @sdev: SCSI device from which to allocate the command
> + * @data_direction: Data direction for the allocated command
> + */
> +struct scsi_cmnd *scsi_get_reserved_cmd(struct scsi_device *sdev,
> + int data_direction)
> +{
> + struct request *rq;
> + struct scsi_cmnd *scmd;
> +
> + rq = blk_mq_alloc_request(sdev->request_queue,
> + data_direction == DMA_TO_DEVICE ?
> + REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN | REQ_NOWAIT,
> + BLK_MQ_REQ_RESERVED);
> + if (IS_ERR(rq))
> + return NULL;
> + scmd = blk_mq_rq_to_pdu(rq);
> + scmd->request = rq;
> + return scmd;
> +}
Isn't REQ_NOWAIT something the caller should decide about instead of
always setting that flag? Additionally, I think some parentheses are
missing. I think the compiler will interpret the blk_mq_alloc_request()
call as follows, which is probably not what was intended:
rq = blk_mq_alloc_request(sdev->request_queue,
data_direction == DMA_TO_DEVICE ?
REQ_OP_SCSI_OUT : (REQ_OP_SCSI_IN | REQ_NOWAIT),
BLK_MQ_REQ_RESERVED);
Thanks,
Bart.
