Hi Gao,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[cannot apply to v5.3 next-20190920]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Gao-Xiang/erofs-fix-erofs_get_meta_page-locking-by-a-cleanup/20190921-173503
config: s390-allmodconfig (attached as .config)
compiler: s390-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=s390 
:::::: branch date: 57 minutes ago
:::::: commit date: 57 minutes ago

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

All warnings (new ones prefixed by >>):

   fs//erofs/data.c: In function 'erofs_get_meta_page':
>> fs//erofs/data.c:43:10: warning: return makes pointer from integer without a cast [-Wint-conversion]
      return PTR_ERR(page);
             ^~~~~~~~~~~~~

# https://github.com/0day-ci/linux/commit/e21cd9836355e16fdb49ff36d5492ed35b2abe5c
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout e21cd9836355e16fdb49ff36d5492ed35b2abe5c
vim +43 fs//erofs/data.c

81781b02f9845b drivers/staging/erofs/data.c Gao Xiang 2018-07-26  34  
e655b5b3a29c5a fs/erofs/data.c              Gao Xiang 2019-09-04  35  struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)
81781b02f9845b drivers/staging/erofs/data.c Gao Xiang 2018-07-26  36  {
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  37  	struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  38  	struct page *page;
81781b02f9845b drivers/staging/erofs/data.c Gao Xiang 2018-07-26  39  
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  40  	page = read_cache_page_gfp(mapping, blkaddr,
618f40ea026bda fs/erofs/data.c              Gao Xiang 2019-09-04  41  				   mapping_gfp_constraint(mapping, ~__GFP_FS));
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  42  	if (IS_ERR(page))
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21 @43  		return PTR_ERR(page);
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  44  
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  45  	/* should already be PageUptodate */
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  46  	lock_page(page);
e21cd9836355e1 fs/erofs/data.c              Gao Xiang 2019-09-21  47  	return page;
81781b02f9845b drivers/staging/erofs/data.c Gao Xiang 2018-07-26  48  }
81781b02f9845b drivers/staging/erofs/data.c Gao Xiang 2018-07-26  49  

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