[PATCH V2] nvme: Add module reference counting for multipath devices

[Sagi Grimberg]

On 23/08/2026 3:20, Sagi Grimberg wrote:
>
>
> On 13/08/2026 1:32, wenxiong at linux.ibm.com wrote:
>> From: Wen Xiong <wenxiong at linux.ibm.com>
>>
>> Add proper module reference counting to prevent premature unloading of
>> NVMe transport modules while multipath namespaces are still active.
>>
>> When a namespace is added to a multipath device via 
>> nvme_mpath_add_disk(),
>> the underlying transport module (PCIe, FC, RDMA, TCP, etc.) must remain
>> loaded as long as the multipath device references that namespace. 
>> Without
>> proper reference counting, the transport module could be unloaded while
>> the multipath device is still using resources from that module, leading
>> to the potential system crashes.
>>
>> This ensures the transport module remains loaded for the entire lifetime
>> of the multipath namespace association.
>
> Can you provide details about the issue that this patch is supposed to 
> address?
> (e.g. potential system crashes). The driver unload should be able to 
> disconnect all of the connected controllers when tearing down...

OK, I now read the original report regarding nvme root device. please 
disregard.