Re: [PATCH 3/4] scsi: Support scsi_devices without a device wide limit

[Hannes Reinecke <hare@suse.de>]

On 4/23/26 12:02, John Garry wrote:
> On 22/04/2026 14:15, Hannes Reinecke wrote:
>>> --- a/drivers/scsi/scsi_scan.c
>>> +++ b/drivers/scsi/scsi_scan.c
>>> @@ -352,18 +352,20 @@ static struct scsi_device 
>>> *scsi_alloc_sdev(struct scsi_target *starget,
>>>       if (scsi_device_is_pseudo_dev(sdev))
>>>           return sdev;
>>> -    depth = sdev->host->cmd_per_lun ?: 1;
>>> +    if (sdev->host->cmd_per_lun != SCSI_UNLIMITED_CMD_PER_LUN) {
>>> +        depth = sdev->host->cmd_per_lun ?: 1;
>> Why don't we use a simple flag in the host (or host template) to
>> indicate that cmd_per_lun should be ignored?
>> I'm not in favour of using magic values for a setting which
>> otherwise is a limit.
>> Look to dev_loss_tmo as a bad example ...
> 
> I think it's better to not have a flag and also keep cmd_per_lun, as 
> then we need to sanitize one vs the other. As mentioned in the cover 
> letter response, cmd_per_lun could be got rid off / reworked.
> 
> Personally I also dislike how the scsi budget code checks for a budget 
> map being non-NULL (which is for reserved scsi devices, which doesn't 
> need a per-sdev budget map).

Let's see if we can schedule a session at LSF; I really would like to
get this one sorted out.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
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