Hi Dan, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.16-rc5 next-20180316] [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/Dan-Williams/dax-fix-dma-vs-truncate-hole-punch/20180318-050250 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) >> fs/ext2/inode.c:992:39: sparse: symbol 'ext2_dax_aops' was not declared. Should it be static? Please review and possibly fold the followup patch. --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation