[dm-devel] [PATCH 2/3] dm: Start pr_reserve from the same starting path

[michael.christie at oracle.com]

On 7/18/22 12:39 PM, Mike Christie wrote:
> On 7/18/22 12:55 AM, Christoph Hellwig wrote:
>> On Thu, Jul 14, 2022 at 07:34:57PM -0500, Mike Christie wrote:
>>> I also ran the libiscsi PGR tests. We pass all of those tests except the
>>> Write Exclusive and Exclusive Access tests. I don't think those reservation
>>> types make sense for multipath devices though. And as I write this I'm
>>> thinking we should add a check for these types and just return failure).
>>
>> Why would any reservation type make less sense for multipath vs
>> non-multipath setups/
> 
> I think those 2 types only work for really specific use cases in multipath
> setups.
> 

...

>>  2) the target actually has a useful concept of the Linux system being
>>     a single initiator, which outside of a few setups like software
>>     only iSCSI are rarely true
>>
Oh yeah, if we are talking about the same type of thing then I've seen a
target that has some smarts and treats Write Exclusive and Exclusive Access like
a All Reg or Reg Only variants when it detects or is setup for linux and it sees
all an initiator's paths registered.

So yeah I guess we should not fail those reservations types.