[RFC PATCH 2/2] nvme-multipath: remove multipath module param

[Nilay Shroff]

On 4/7/25 8:15 PM, Christoph Hellwig wrote:
> On Fri, Mar 21, 2025 at 12:07:23PM +0530, Nilay Shroff wrote:
>> Remove the multipath module parameter from nvme-core and make native
>> NVMe multipath support explicit. Since we now always create a multipath
>> head disk node, even for single-port NVMe disks, when CONFIG_NVME_
>> MULTIPATH is enabled, this module parameter is no longer needed to
>> toggle the behavior.
>>
>> Users who prefer non-native multipath must disable CONFIG_NVME_MULTIPATH
>> at compile time.
> 
> Hmm, I actually missed that in the last patch.  I fear that is a huge
> change people don't expect.  I suspect we need to make the creation
> of the head node and the delayed removal an opt-in and not the default
> to keep existing behavior.
Okay, we can add an option to avoid making this behavior "the default".
So do you recommend adding a module option for opting in this behavior 
change or something else?

BTW, we're not removing nvme_core.multipath module option as we discussed
during LSFMM. Keith and others were against removing this option. So I'd
drop this second patch in the series.

Thanks,
--Nilay