Re: [PATCH 08/14] scsi: fnic: Add functionality in fnic to support FDLS

From: Hannes Reinecke
Date: Sat Jun 15 2024 - 05:07:30 EST


On 6/15/24 05:47, Karan Tilak Kumar (kartilak) wrote:
On Tuesday, June 11, 2024 11:57 PM, Hannes Reinecke <hare@xxxxxxx> wrote:

On 6/10/24 23:50, Karan Tilak Kumar wrote:
Add interfaces in fnic to use FDLS services.
Modify link up and link down functionality to use FDLS.
Replace existing interfaces to handle new functionality provided by
FDLS.
Modify data types of some data members to handle new functionality.
Add processing of tports and handling of tports.

Reviewed-by: Sesidhar Baddela <sebaddel@xxxxxxxxx>
Reviewed-by: Arulprabhu Ponnusamy <arulponn@xxxxxxxxx>
Reviewed-by: Gian Carlo Boffa <gcboffa@xxxxxxxxx>
Signed-off-by: Karan Tilak Kumar <kartilak@xxxxxxxxx>
---
drivers/scsi/fnic/fdls_disc.c | 74 +++++
drivers/scsi/fnic/fip.c | 27 +-
drivers/scsi/fnic/fnic.h | 20 +-
drivers/scsi/fnic/fnic_fcs.c | 498 ++++++++++++++++++++++++----------
drivers/scsi/fnic/fnic_main.c | 10 +-
drivers/scsi/fnic/fnic_scsi.c | 127 +++++++--
6 files changed, 587 insertions(+), 169 deletions(-)

This seems to not just _add_ the functionality to use FDLS, but rather _replace_ the existing
functionality with FDLS.
IE it seems that after this change the driver will always do FDLS, causing a possible service
interruption with existing setups.
Hmm?

Thanks for your review comments, Hannes.
As I mentioned in the other patch comments, Cisco has been shipping an async driver based on FDLS
for the past six years.
The async driver is backward compatible and supports all the adapters that are supported by the
existing upstream driver, and more.
The async driver in fact overrides the upstream driver on our installations.

Ah. Good to know. Ever more a reason to have your driver upstreamed, then...


On Cisco hardware, the best practice out in the field, is to update the driver to the async
driver during OS installation itself.
Due to this best practice, we have _not_ received any feedback from customers indicating an
abnormal service interruption specifically due to the driver update.

Ah. I wasn't aware of that.
So that's fine, then, and you can disregard my comments here.

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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