RE: [PATCH] iscsi_iser: Re-enable 'iser_pi_guard' module parameter

Schremmer, Steven
2018-01-11T00:04:27Z

> From: Jason Gunthorpe [mailto:jgg-uk2M96/98Pc@public.gmane.org]
> Sent: Wednesday, January 10, 2018 5:03 PM
>
> On Wed, Jan 10, 2018 at 10:07:36AM +0100, Hannes Reinecke wrote:
> > The module parameter 'iser_pi_guard' has been disabled by commit
> > 5bb6e543d2a7d58 ("IB/iser: DIX update"), but the functionality
> > to select the guard algorithm is still required.
>
> Commit should explain why it is still required? What is the actual bug here?
>
> Someone who understands this is going to have to Ack it for it to go
> through the rdma tree..
>
Without the module parameter, there is no way to actually use the CRC guard format.
Currently, iscsi_iser_session_create() indicates support for both IP and CRC formats, but
sd_dif_config_host() always checks for IP support first, so CRC guard won't be used.