Re: [PATCH 1/2] scsi: sd: Check physical sector alignment of sequential zone writes

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 3/4/23 03:03, Bart Van Assche wrote:
> On 3/2/23 17:44, Shin'ichiro Kawasaki wrote:
>> +	if (sdkp->device->type == TYPE_ZBC && blk_rq_zone_is_seq(rq) &&
>> +	    (req_op(rq) == REQ_OP_WRITE || req_op(rq) == REQ_OP_ZONE_APPEND) &&
>> +	    (!IS_ALIGNED(blk_rq_pos(rq), pb_sectors) ||
>> +	     !IS_ALIGNED(blk_rq_sectors(rq), pb_sectors))) {
>> +		scmd_printk(KERN_ERR, cmd,
>> +			    "Sequential write request not aligned to the physical block size\n");
>> +		goto fail;
>> +	}
> 
> I vote -1 for this patch because my opinion is that we should not 
> duplicate checks that must be performed by the storage controller anyway 
> inside the sd driver.

Sure, the drive will fail this request, so the end result is the same. But what
is the point of issuing such unaligned request that we know will fail ? The
error message also make it easier to debug as it clarifies that this is not a
write pointer violation. So while this change is not critical, it does have
merits in my opinion.

> 
> Thanks,
> 
> Bart.

-- 
Damien Le Moal
Western Digital Research