Hi Gao,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[cannot apply to v5.3-rc4 next-20190816]
[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/Gao-Xiang/staging-erofs-refuse-to-mount-images-with-malformed-volume-name/20190818-193037
config: sparc64-allmodconfig (attached as .config)
compiler: sparc64-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=sparc64 

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

All errors (new ones prefixed by >>):

   drivers/staging/erofs/super.c: In function 'superblock_read':
>> drivers/staging/erofs/super.c:153:10: error: 'EFSCORRUPTED' undeclared (first use in this function); did you mean 'FS_NRSUPER'?
      ret = -EFSCORRUPTED;
             ^~~~~~~~~~~~
             FS_NRSUPER
   drivers/staging/erofs/super.c:153:10: note: each undeclared identifier is reported only once for each function it appears in

vim +153 drivers/staging/erofs/super.c

   140	
   141		sbi->root_nid = le16_to_cpu(layout->root_nid);
   142		sbi->inos = le64_to_cpu(layout->inos);
   143	
   144		sbi->build_time = le64_to_cpu(layout->build_time);
   145		sbi->build_time_nsec = le32_to_cpu(layout->build_time_nsec);
   146	
   147		memcpy(&sb->s_uuid, layout->uuid, sizeof(layout->uuid));
   148	
   149		ret = strscpy(sbi->volume_name, layout->volume_name,
   150			      sizeof(layout->volume_name));
   151		if (ret < 0) {	/* -E2BIG */
   152			errln("bad volume name without NIL terminator");
 > 153			ret = -EFSCORRUPTED;
   154			goto out;
   155		}
   156		ret = 0;
   157	out:
   158		brelse(bh);
   159		return ret;
   160	}
   161	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation