Hi,

[auto build test ERROR on next-20160517]
[cannot apply to v4.6-rc7 v4.6-rc6 v4.6-rc5 v4.6]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Arnd-Bergmann/remove-unused-blkdev_dax_capable-function/20160518-155729
config: m68k-allyesconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 4.9.0
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=m68k 

All errors (new ones prefixed by >>):

   fs/block_dev.c: In function '__blkdev_get':

quoted

fs/block_dev.c:1242:5: error: implicit declaration of function 'blkdev_dax_capable' [-Werror=implicit-function-declaration]

        if (!blkdev_dax_capable(bdev))
        ^
   cc1: some warnings being treated as errors

vim +/blkdev_dax_capable +1242 fs/block_dev.c

d3374825 NeilBrown    2009-01-09  1236  					goto restart;
d3374825 NeilBrown    2009-01-09  1237  				}
1196f8b8 Tejun Heo    2011-04-21  1238  			}
7e69723f Tejun Heo    2011-05-23  1239  
5a023cdb Dan Williams 2015-11-30  1240  			if (!ret) {
7e69723f Tejun Heo    2011-05-23  1241  				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
5a023cdb Dan Williams 2015-11-30 @1242  				if (!blkdev_dax_capable(bdev))
5a023cdb Dan Williams 2015-11-30  1243  					bdev->bd_inode->i_flags &= ~S_DAX;
5a023cdb Dan Williams 2015-11-30  1244  			}
7e69723f Tejun Heo    2011-05-23  1245  

:::::: The code at line 1242 was first introduced by commit
:::::: 5a023cdba50c5f5f2bc351783b3131699deb3937 block: enable dax for raw block devices

:::::: TO: Dan Williams [off-list ref]
:::::: CC: Dan Williams [off-list ref]

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