Re: iSCSI: DataACK SNACK

["Mallikarjun C." <cbm@rose.hp.com>]

Julian,

Since the DataACK mechanism is based on DataSNs and
hence per-task, I think Chuck is suggesting changing:

"For a Data/R2T SNACK, the Initiator Task Tag MUST be set to the Initi-
ator Task Tag of the referenced Command. Otherwise, it is reserved."

to something like:

"For Status SNACK, the Initiator Task Tag is reserved.  In all other
cases,
the Initiator Task Tag field MUST be set to the Initiator Task Tag of
the 
referenced command."

I think the change is required. 
-- 
Mallikarjun 


Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions Organization
MS 5668	Hewlett-Packard, Roseville.
cbm@rose.hp.com


Julian Satran wrote:
> 
> DataACK is a "bulk ack". Answering the last (in case of several) is
> good enough.
> I fail to see your point.
> 
> Julo
> 
>   "Chuck Micalizzi"
>   <chuck.micalizzi@qlogic.com>                   To:
>   Sent by: owner-ips@ece.cmu.edu          <ips@ece.cmu.edu>
>                                                  cc:
>   14-02-02 21:02                                 Subject:
>                                           iSCSI: DataACK SNACK
> 
> 
> 
> All,
> 
>    I have a question regarding DataACK.
> 
>    Rev. 10 section 10.16.1 states:
> 
>    For a Data/R2T SNACK, the Initiator Task Tag MUST be set
>    to the Initiator Task Tag of the referenced Command.
>    Otherwise, it is reserved.
> 
>    it also states:
> 
>    The DataACK is used to free resources at the target and
>    not to request or imply data retransmission.
> 
>    Is the target allowed to have more than one DataACK
>    outstanding on a connection?
> 
>    If multiple outstanding DataACKs are allowed per connection
>    then in my opinion the DataACK must have a valid task tag
>    inorder for the target to associate the DataACK with the
>    appropriate resources to be freed.
> 
> 
> chuck micalizzi
> Qlogic Corp.