Re: [PATCH v3 0/2] nvme-fabrics: short-circuit connect retries

From: Sagi Grimberg
Date: Thu Mar 07 2024 - 06:30:11 EST




On 07/03/2024 12:37, Hannes Reinecke wrote:
On 3/7/24 09:00, Sagi Grimberg wrote:

On 05/03/2024 10:00, Daniel Wagner wrote:
I've picked up Hannes' DNR patches. In short the make the transports behave the same way when the DNR bit set on a re-connect attempt. We
had a discussion this
topic in the past and if I got this right we all agreed is that the host should honor the DNR bit on a connect attempt [1]
Umm, I don't recall this being conclusive though. The spec ought to be clearer here I think.

I've asked the NVMexpress fmds group, and the response was pretty unanimous that the DNR bit on connect should be evaluated.

OK.



The nvme/045 test case (authentication tests) in blktests is a good test case for this after extending it slightly. TCP and RDMA try to
reconnect with an
invalid key over and over again, while loop and FC stop after the first fail.

Who says that invalid key is a permanent failure though?

See the response to the other patchset.
'Invalid key' in this context means that the _client_ evaluated the key as invalid, ie the key is unusable for the client.
As the key is passed in via the commandline there is no way the client
can ever change the value here, and no amount of retry will change things here. That's what we try to fix.

Where is this retried today, I don't see where connect failure is retried, outside of a periodic reconnect.
Maybe I'm missing where what is the actual failure here.