Re: [PATCH 1/2] scsi: core: Extend struct scsi_exec_args

[John Garry <john.g.garry@oracle.com>]

On 02/02/2023 22:04, Bart Van Assche wrote:
> Allow SCSI LLDs to specify RQF_* and SCMD_* flags.

As I see, if BLK_MQ_REQ_PM is set for scsi_exec_args.req_flags, then 
RQF_PM gets set automatically in blk_mq_rq_ctx_init() for 
request.rq_flags. Christoph previously mentioned that we are required to 
set both (BLK_MQ_REQ_PM and RQF_PM). So where does it matter that we 
need to set RQF_PM (that setting BLK_MQ_REQ_PM doesn't cover)?

It would be nice to mention the reason in the commit description.

Thanks,
John

> 
> Cc: Mike Christie <michael.christie@oracle.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>   drivers/scsi/scsi_lib.c    | 3 ++-
>   include/scsi/scsi_device.h | 2 ++
>   2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index abe93ec8b7d0..5feb8be6d956 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -229,8 +229,9 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
>   	scmd->cmd_len = COMMAND_SIZE(cmd[0]);
>   	memcpy(scmd->cmnd, cmd, scmd->cmd_len);
>   	scmd->allowed = retries;
> +	scmd->flags |= args->scmd_flags;
>   	req->timeout = timeout;
> -	req->rq_flags |= RQF_QUIET;
> +	req->rq_flags |= args->rq_flags | RQF_QUIET;
>   
>   	/*
>   	 * head injection *required* here otherwise quiesce won't work
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 7e95ec45138f..79260e98774f 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -462,6 +462,8 @@ struct scsi_exec_args {
>   	unsigned int sense_len;		/* sense buffer len */
>   	struct scsi_sense_hdr *sshdr;	/* decoded sense header */
>   	blk_mq_req_flags_t req_flags;	/* BLK_MQ_REQ flags */
> +	req_flags_t rq_flags;		/* RQF flags */
> +	unsigned int scmd_flags;	/* SCMD flags */
>   	int *resid;			/* residual length */
>   };
>