[bug report][libnvme/nvme-cli] "nvme smart-log" fails with liburing

[Daniel Wagner]

On Tue, May 27, 2025 at 10:31:18AM +0000, Shinichiro Kawasaki wrote:
> Hi Daniel, I think I found a problem in libnvme as below. Is this a
> known issue?

No, it's new to me.

> - When libnvme is built with liburing, the failure happens. When libnvme
>   is built without liburing, the failure does not happen.
>
> I took a look in the kernel code. The io_uring_setup ioctl for namespace
> devices falls into blkdev_uring_cmd() in block layer. It does not reach to
> nvme driver and just fails. So I guess the kernel does not support nvme
> admin commands for namespace devices through io_uring. Assuming this guess is
> correct, I think libnvme should use regular ioctl instead for io_uring for
> namespace devices. What do you think?

Thanks for the detailed bug report. I'll fix libnvme so it only use the
uring interface for char devices.

Cheers,
Daniel