Re: [PATCH 10/13] scsi: alua: Add scsi_alua_prep_fn()

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

On 18/03/2026 08:01, Hannes Reinecke wrote:
>>   }
>> +static inline
>> +blk_status_t scsi_alua_prep_fn(struct scsi_device *sdev, struct 
>> request *req)
>> +{
>> +    return BLK_STS_OK;
>> +}
>>   static inline int scsi_alua_sdev_init(struct scsi_device *sdev)
>>   {
>>       return 0;
> 
> Hmm. The 'prep_fn' thingie was implemented such that other drivers (like 
> scsi_dh) could intercept the scsi prep function and inject their own
> stuff. But now with this patchset the functionality is in the scsi core,
> so really we should do away with the prep_fn here and call the functions
> directly.

ok, so I can just stop setting alua_dh.prep_fn and then have in 
scsi_prepare_cmd():


if (sdev->handler && sdev->handler->prep_fn) {
	blk_status_t ret = sdev->handler->prep_fn(sdev, req);

	if (ret != BLK_STS_OK)
		return ret;
} else if (sdev->alua) {
	/* We should be able to make this common for ALUA DH as well */
	blk_status_t ret = scsi_alua_prep_fn(sdev, req);

	if (ret != BLK_STS_OK)
		return ret;
}

Or even check sdev->alua first, as that is the most popular DH.

Thanks,
John