On Tue, Aug 23, 2016 at 2:53 AM, Tom Yan [off-list ref] wrote:

On 23 August 2016 at 06:20, Shaun Tancheff [off-list ref] wrote:

quoted

On Tue, Aug 23, 2016 at 12:26 AM, Tom Yan [off-list ref] wrote:

quoted

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).

Hmm. Not sure about T10, but that's not how I read
sd_setup_write_same_cmnd(), it always setups up a transfer of
sector_size for scsi_init_io().

As I understand things, this is how the cmd's sglist is populated and why
this should be using sg_copy_from_buffer() rather than open coding
to the page.
-- 
Shaun Tancheff