[Bug Report] nvme-cli commands fails to open head disk node and print error

[Nilay Shroff]

On 3/28/24 12:45, Christoph Hellwig wrote:
> On Thu, Mar 28, 2024 at 12:00:07PM +0530, Nilay Shroff wrote:
>> One of namespaces has zero disk capacity:
>>
>> # nvme id-ns /dev/nvme0 -n 0x3
>> NVME Identify Namespace 3:
>> nsze    : 0
>> ncap    : 0
>> nuse    : 0
>> nsfeat  : 0x14
>> nlbaf   : 4
>> flbas   : 0
>> <snip>
> 
> How can you have a namespace with a zero capacity?  NCAP is used
> as the check for legacy pre-ns scan controllers to check that
> the namespace exists.
> 
> 
I have this NVMe disk which has a namepsace with zero capacity.

# nvme list -v 
Subsystem        Subsystem-NQN                                                                                    Controllers
---------------- ------------------------------------------------------------------------------------------------ ----------------
nvme-subsys2     nqn.2019-10.com.kioxia:KCM7DRUG1T92:3D60A04906N1                                                 nvme0, nvme2

<snip>

Device       Generic      NSID       Usage                      Format           Controllers     
------------ ------------ ---------- -------------------------- ---------------- ----------------
/dev/nvme2n1 /dev/ng2n1   0x1          0.00   B /  46.01  GB      4 KiB +  0 B   nvme0
nvme2n2      /dev/ng2n2   0x3          0.00   B /   0.00   B    512   B +  0 B   nvme0

I didn't create that namespace with zero capacity and I didn't know about it until 
recently I upgraded to 6.9-rc1 kernel. It became only apparent with latest kernel. 
However as Daniel mentioned in another thread latest nvme-cli wouldn't exhibit the 
issue I reported. And I'm going to wipe this namespace anyways. 

Thanks,
--Nilay