[ammarfaizi2-block:dhowells/linux-fs/netfs-lib 14/24] fs/netfs/read_helper.c:979:14: warning: variable 'folio' is uninitialized when used here

[kernel test robot]

tree:   https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/netfs-lib
head:   e450b62f32df4384c141a6a382811b3fe5723bad
commit: e6b340ed3634bb80396afb564c499eebdeff601f [14/24] netfs: Use a buffer in netfs_read_request and add pages to it
config: x86_64-randconfig-a001-20220117 (https://download.01.org/0day-ci/archive/20220118/202201180514.gVYTloyy-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 5f782d25a742302d25ef3c8b84b54f7483c2deb9)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/ammarfaizi2/linux-block/commit/e6b340ed3634bb80396afb564c499eebdeff601f
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block dhowells/linux-fs/netfs-lib
        git checkout e6b340ed3634bb80396afb564c499eebdeff601f
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/netfs/

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

All warnings (new ones prefixed by >>):

>> fs/netfs/read_helper.c:979:14: warning: variable 'folio' is uninitialized when used here [-Wuninitialized]
                           folio_put(folio);
                                     ^~~~~
   fs/netfs/read_helper.c:928:21: note: initialize the variable 'folio' to silence this warning
           struct folio *folio;
                              ^
                               = NULL
   1 warning generated.


vim +/folio +979 fs/netfs/read_helper.c

   943	
   944		ret = netfs_rreq_add_folios_to_buffer(rreq, want_index, have_index - 1,
   945						      gfp_mask);
   946		if (ret < 0)
   947			return ret;
   948		have_folios += have_index - want_index;
   949	
   950		ret = netfs_rreq_add_folios_to_buffer(rreq, have_index + have_folios,
   951						      want_index + want_folios - 1,
   952						      gfp_mask);
   953		if (ret < 0)
   954			return ret;
   955	
   956		/* Transfer the folios proposed by the VM into the buffer and take refs
   957		 * on them.  The locks will be dropped in netfs_rreq_unlock().
   958		 */
   959		if (ractl) {
   960			while ((folio = readahead_folio(ractl))) {
   961				folio_get(folio);
   962				if (folio == keep)
   963					folio_get(folio);
   964				ret = xa_insert_set_mark(&rreq->buffer,
   965							 folio_index(folio), folio,
   966							 XA_MARK_0, gfp_mask);
   967				if (ret < 0) {
   968					if (folio != keep)
   969						folio_unlock(folio);
   970					folio_put(folio);
   971					return ret;
   972				}
   973			}
   974		} else {
   975			folio_get(keep);
   976			ret = xa_insert_set_mark(&rreq->buffer, keep->index, keep,
   977						 XA_MARK_0, gfp_mask);
   978			if (ret < 0) {
 > 979				folio_put(folio);
   980				return ret;
   981			}
   982		}
   983		return 0;
   984	}
   985	

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