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

[Dan Williams]

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.