nvme: report capacity 0 for non supported ZNS SSDs

[Javier Gonzalez]

On 02.11.2020 16:30, Niklas Cassel wrote:
>On Mon, Nov 02, 2020 at 04:15:01PM +0000, Javier Gonzalez wrote:
>>
>> From: Keith Busch <kbusch at kernel.org>
>> Sent: Nov 2, 2020 16:45
>> To: Javier González <javier at javigon.com>
>> Cc: linux-nvme at lists.infradead.org; linux-block at vger.kernel.org; hch at lst.de; sagi at grimberg.me; axboe at kernel.dk; joshi.k at samsung.com; "Klaus B. Jensen" <k.jensen at samsung.com>; Niklas.Cassel at wdc.com; Javier Gonzalez <javier.gonz at samsung.com>
>> Subject: Re: [PATCH V2] nvme: report capacity 0 for non supported ZNS SSDs
>>
>> On Mon, Nov 02, 2020 at 02:22:14PM +0100, Javier González wrote:
>> > Changes since V1:
>> >    - Apply feedback from Niklas:
>> >        - Use IS_ENABLED() for checking config option
>>
>> Your v1 was correct. Using IS_ENBALED() attempts to use an undefined
>> symbol when the CONFIG is not enabled:
>>
>> Oh. Ok. Will return to that.
>
>Keith is correct, sorry for that.
>
>https://www.kernel.org/doc/html/latest/process/coding-style.html#conditional-compilation
>
>"Thus, you still have to use an #ifdef if the code inside the block
>references symbols that will not exist if the condition is not met."
>

No worries. Thanks for pointing this out - I had seen code with
IS_ENABLED(), but I had not done the necessary reading to determine if
it was something I should use or not. Now I know :)