Hi Goldwyn,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on kdave/for-next]
[also build test WARNING on v5.10 next-20201215]
[cannot apply to xfs-linux/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Goldwyn-Rodrigues/Fix-locking-for-btrfs-direct-writes/20201216-021312
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next
config: sparc-randconfig-s031-20201215 (attached as .config)
compiler: sparc-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-184-g1b896707-dirty
        # https://github.com/0day-ci/linux/commit/4706fd8a8832b4948c25abc5fec38a017704d828
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Goldwyn-Rodrigues/Fix-locking-for-btrfs-direct-writes/20201216-021312
        git checkout 4706fd8a8832b4948c25abc5fec38a017704d828
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=sparc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> fs/iomap/direct-io.c:127:9: warning: no previous prototype for 'iomap_dio_complete' [-Wmissing-prototypes]
     127 | ssize_t iomap_dio_complete(struct iomap_dio *dio)
         |         ^~~~~~~~~~~~~~~~~~

"sparse warnings: (new ones prefixed by >>)"


vim +/iomap_dio_complete +127 fs/iomap/direct-io.c

   126	
 > 127	ssize_t iomap_dio_complete(struct iomap_dio *dio)
   128	{
   129		ssize_t ret;
   130	
   131		ret = __iomap_dio_complete(dio);
   132		/*
   133		 * If this is a DSYNC write, make sure we push it to stable storage now
   134		 * that we've written data.
   135		 */
   136		if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC))
   137			ret = generic_write_sync(dio->iocb, ret);
   138	
   139		kfree(dio);
   140	
   141		return ret;
   142	}
   143	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org