Re: xfs_iomap.c:undefined reference to `put_dax'

[Arnd Bergmann]

On Sun, May 14, 2017 at 1:21 AM, kbuild test robot
<fengguang.wu@xxxxxxxxx> wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   cd636458904a04de2349c728323c5d2af1203bdf
> commit: ef51042472f55b325fd7f2b26a2e29fd89757234 block, dax: move "select DAX" from BLOCK to FS_DAX
> date:   5 days ago
> config: ia64-bigsur_defconfig (attached as .config)
> compiler: ia64-linux-gcc (GCC) 6.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         git checkout ef51042472f55b325fd7f2b26a2e29fd89757234
>         # save the attached .config to linux build tree
>         make.cross ARCH=ia64
>
> All errors (new ones prefixed by >>):
>
>    fs/built-in.o: In function `xfs_file_iomap_end':
>>> xfs_iomap.c:(.text+0x2e3022): undefined reference to `put_dax'
>    fs/built-in.o: In function `xfs_file_iomap_begin':
>>> xfs_iomap.c:(.text+0x2e4502): undefined reference to `dax_get_by_host'

This is caused by CONFIG_DAX now being allowed to be '=m' while used by
a built-in file system. This only happens for XFS at the moment though, as the
other file systems check for CONFIG_FS_DAX already.

I have a patch that I'm testing at the moment.

       Arnd