Re: [PATCHv3] scsi: disable automatic target scan

[Benjamin Block <bblock@linux.vnet.ibm.com>]

Hello Hannes,

I am a bit late here, but as this got pulled and Steffen didn't have
time to give it a review, I did today.

On 08:39 Thu 17 Mar     , Hannes Reinecke wrote:
> On larger installations it is useful to disable automatic LUN
> scanning, and only add the required LUNs via udev rules.
> This can speed up bootup dramatically.
> 
> This patch introduces a new scan module parameter value 'manual',
> which works like 'none', but can be overriden by setting the 'rescan'
> value from scsi_scan_target to 'SCSI_SCAN_MANUAL'.
> And it updates all relevant callers to set the 'rescan' value
> to 'SCSI_SCAN_MANUAL' if invoked via the 'scan' option in sysfs.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---

[:snip:]

> 
> diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c
> index 157d3d2..08bba7c 100644
> --- a/drivers/s390/scsi/zfcp_unit.c
> +++ b/drivers/s390/scsi/zfcp_unit.c
> @@ -26,7 +26,8 @@ void zfcp_unit_scsi_scan(struct zfcp_unit *unit)
>  	lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
> 
>  	if (rport && rport->port_state == FC_PORTSTATE_ONLINE)
> -		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun, 1);
> +		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun,
> +				 SCSI_SCAN_RESCAN);

I'd rather use the new SCSI_SCAN_MANUAL here. We don't want this to be
"blocked" by an attribute set in a different (new) code-path and
config-location.

This path is used by both, zfcp-recovery and -userinterfaces (sysfs) and
in both cases we call it with the intend that the scan is really done -
hence the SCSI_SCAN_MANUAL to force a scan. I'd find it very weird if
suddenly our users would have to additionally use yet an other config to
get the old interfaces working properly.



                                                    Beste Grüße / Best regards,
                                                      - Benjamin Block
-- 
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