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

[Wen Xiong]

On 2026-08-22 19:46, Sagi Grimberg wrote:

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

Hi Keith and Sagi,

For single port nvme device, I found out:
If NS does not have any filesystems configured and the root filesystem 
is located on another SCSI disk, the NVMe device's reference count is 0.
When a filesystem is created on NS, the NVMe device's reference count 
increases to 1.

With my V2 patch for multipath devices,
Nvme's reference count always increases if NS doesn't have any 
filesystem configured.
If nvme1 has 1 NS without any filesystem, reference count is 2 after 
system boots up.

Should Nvme's reference count increases if no filesystem configured on a 
NS?

Thanks,
Wendy