Re: [PATCH] iscsi-target: Add login_keys_workaround attribute for non RFC initiators

[Bart Van Assche <Bart.VanAssche@wdc.com>]

On Fri, 2017-07-07 at 22:24 +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch re-introduces part of a long standing login workaround that
> was recently dropped by:
> 
>   commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46
>   Author: Nicholas Bellinger <nab@linux-iscsi.org>
>   Date:   Sun Apr 2 13:36:44 2017 -0700
> 
>       iscsi-target: Drop work-around for legacy GlobalSAN initiator
> 
> Namely, the workaround for FirstBurstLength ended up being required by
> Mellanox Flexboot PXE boot ROMs as reported by Robert.
> 
> So this patch re-adds the work-around for FirstBurstLength within
> iscsi_check_proposer_for_optional_reply(), and makes the key optional
> to respond when the initiator does not propose, nor respond to it.
> 
> Also as requested by Arun, this patch introduces a new TPG attribute
> named 'login_keys_workaround' that controls the use of both the
> FirstBurstLength workaround, as well as the two other existing
> workarounds for gPXE iSCSI boot client.
> 
> By default, the workaround is enabled with login_keys_workaround=1,
> since Mellanox FlexBoot requires it, and Arun has verified the Qlogic
> MSFT initiator already proposes FirstBurstLength, so it's uneffected
> by this re-adding this part of the original work-around.

Hello Nick,

The new configfs attribute ("login_keys_workaround") may confuse users - for
someone who has not followed this e-mail thread it can take a long time
before they figure out that they need to set this configfs attribute. Have
you considered to let the iSCSI target driver figure out whether or not that
variable has to be set, e.g. by looking up the initiator IQN in a list?

Bart.