Re: [PATCH 1/2] dax: hide block device code in #ifdef

From: Arnd Bergmann
Date: Mon May 15 2017 - 10:20:21 EST


On Mon, May 15, 2017 at 4:11 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> On Mon, May 15, 2017 at 6:44 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> We allow configurations with CONFIG_BLOCK=n and CONFIG_DAX=y, which now
>> results in a link error:
>>
>> drivers/dax/super.c: In function 'bdev_dax_pgoff':
>> drivers/dax/super.c:50:26: error: implicit declaration of function 'get_start_sect'; did you mean 'get_task_cred'? [-Werror=implicit-function-declaration]
>>
>> The two obvious ways to avoid the link error are to either add an #ifdef
>> around the code that was moved from fs/block_dev.c, or to disallow the
>> configuration. I could not see if there is or is not a reason to support
>> this combination of options, but in case there is, the #ifdef is the
>> safer choice.
>>
>> Fixes: ef51042472f5 ("block, dax: move "select DAX" from BLOCK to FS_DAX")
>> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Yup, the same one I came up with:
>
> https://patchwork.kernel.org/patch/9725513/
>
> If you have a a pull request coming up soon you can add my Acked-by to
> both of these patches, otherwise I'll send what I have along at the
> end of the week.

I didn't plan to send a pull request, please use whatever you have.

Arnd