iSCSI Expected Data Transfer Length for T10-PI

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

Hey All,

Recently, iSER end-to-end T10-PI support maid it mainline.
I am wandering about the impact T10-PI should or shouldn't have on iSCSI 
header
field "Expected Data Transfer Length".

RFC-7143 states:
"the Expected Data Transfer Length field contains the number of bytes of 
data involved in this SCSI operation."
Since this field relates to *data bytes* I kept T10-PI implicit wrt this 
field. The iSCSI target calculates the
total transfer length (data + protection) from the cdb transfer length 
field and protect bits.

In FC, the fc_dl field was updated to relate to the total number of 
transfer bytes and includes
data and protection bytes. virtio_scsi was added with a header PI 
section (virtio_scsi_cmd_req_pi).

So my question is, should this field be updated to explicitly include 
T10-PI bytes like the FC equivalent fc_dl?
Or should T10-PI bytes be implicit?

I want to pin down this one to avoid a situation where the standard is 
open for interpretations.

Thanks,
Sagi.