Re: [PATCH v6 1/4] libata: Safely overwrite attached page in WRITE SAME xlat

From: Tom Yan
Date: Tue Aug 23 2016 - 03:54:47 EST


On 23 August 2016 at 06:20, Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx> wrote:
> On Tue, Aug 23, 2016 at 12:26 AM, Tom Yan <tom.ty89@xxxxxxxxx> wrote:
>
>> It is always 1 merely because we prefer sticking to that. Say we want
>> to enable multi-block payload now, it won't be 1 anymore.
>
> Sorry, I though that DSM TRIM is using 512 bytes here because
> WRITE_SAME_16 has a payload of a single logical sector.

Nope, SCSI Write Same commands does not have payload (or in SCSI
terms, parameter list / data-out buffer).

>
>> Also note that the payload is NOT always fully-filled.
>
> Oh, I was considering filling the remainder of the buffer
> with 0's using memset() as you described to be "filly-filled"
> in this case. Sorry for the confusion.

Well yeah _after_ memset() it should always be "fully-filled" (i.e.
512-byte aligned).

>
> --
> Shaun Tancheff