On Thu, Apr 30, 2020 at 03:18:26PM +0200, Hannes Reinecke wrote:
> Add function to check if a SCSI command originates from the reserved
> tag pool and update scsi_put_reserved_cmd() to only free commands if
> they originate from the reserved tag pool.
The SCSI bits should go into the previous patch. The block layer
bits should be a separate prep patch before that.
> +/**
> + * blk_mq_rq_is_reserved - Check for reserved request
> + *
> + * @rq: Request to check
No empty line before the parameter description, please.
> */
> void scsi_put_reserved_cmd(struct scsi_cmnd *scmd)
> {
> + struct request *rq;
>
> + if (scmd && scsi_cmd_is_reserved(scmd)) {
> + rq = blk_mq_rq_from_pdu(scmd);
> + blk_mq_free_request(rq);
> + }
The check looks weird. Passing a NULL cmnd here seems like an API
abuse to start with, and !scsi_cmd_is_reserved should at best be
a WARN_ON_ONCE.
So I think this should just be something like:
void scsi_put_reserved_cmd(struct scsi_cmnd *scmd)
{
WARN_ON_ONCE(!scsi_cmd_is_reserved(scmd));
blk_mq_free_request(blk_mq_rq_from_pdu(scmd));
}
> +/**
> + * scsi_cmd_is_reserved - check for reserved scsi command
> + * @scmd: command to check
> + *
> + * Returns true if @scmd originates from the reserved tag pool.
> + */
> +static inline bool scsi_cmd_is_reserved(struct scsi_cmnd *scmd)
> +{
> + struct request *rq = blk_mq_rq_from_pdu(scmd);
> +
> + return blk_mq_rq_is_reserved(rq);
Can be shortened to:
return blk_mq_rq_is_reserved(blk_mq_rq_from_pdu(scmd));
