tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git afs-operation head: 1fa49979d472daf24a62cc4cba698f33e70b0045 commit: 38d3c676670ff9a446fce98c7a66cbd264c2c614 [8/13] vfs: Make the inode hash table RCU searchable config: i386-allyesconfig (attached as .config) compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 reproduce: git checkout 38d3c676670ff9a446fce98c7a66cbd264c2c614 # save the attached .config to linux build tree make ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): fs/f2fs/node.c: In function 'flush_dirty_inode': fs/f2fs/node.c:1793:10: error: implicit declaration of function 'find_inode_nowait'; did you mean 'find_inode_rcu'? [-Werror=implicit-function-declaration] inode = find_inode_nowait(sbi->sb, ino, f2fs_match_ino, NULL); ^~~~~~~~~~~~~~~~~ find_inode_rcu inode = find_inode_nowait(sbi->sb, ino, f2fs_match_ino, NULL); ^ cc1: some warnings being treated as errors vim +1793 fs/f2fs/node.c 052a82d85a3b3e Chao Yu 2019-08-22 1786 052a82d85a3b3e Chao Yu 2019-08-22 1787 static bool flush_dirty_inode(struct page *page) 052a82d85a3b3e Chao Yu 2019-08-22 1788 { 052a82d85a3b3e Chao Yu 2019-08-22 1789 struct f2fs_sb_info *sbi = F2FS_P_SB(page); 052a82d85a3b3e Chao Yu 2019-08-22 1790 struct inode *inode; 052a82d85a3b3e Chao Yu 2019-08-22 1791 nid_t ino = ino_of_node(page); 052a82d85a3b3e Chao Yu 2019-08-22 1792 052a82d85a3b3e Chao Yu 2019-08-22 @1793 inode = find_inode_nowait(sbi->sb, ino, f2fs_match_ino, NULL); 052a82d85a3b3e Chao Yu 2019-08-22 1794 if (!inode) 052a82d85a3b3e Chao Yu 2019-08-22 1795 return false; 052a82d85a3b3e Chao Yu 2019-08-22 1796 052a82d85a3b3e Chao Yu 2019-08-22 1797 f2fs_update_inode(inode, page); 052a82d85a3b3e Chao Yu 2019-08-22 1798 unlock_page(page); 052a82d85a3b3e Chao Yu 2019-08-22 1799 052a82d85a3b3e Chao Yu 2019-08-22 1800 iput(inode); 052a82d85a3b3e Chao Yu 2019-08-22 1801 return true; 052a82d85a3b3e Chao Yu 2019-08-22 1802 } 052a82d85a3b3e Chao Yu 2019-08-22 1803 :::::: The code at line 1793 was first introduced by commit :::::: 052a82d85a3b3eee6a386be2ba3b82278cf277ce f2fs: fix to writeout dirty inode during node flush :::::: TO: Chao Yu <yuchao0(a)huawei.com&gt; :::::: CC: Jaegeuk Kim <jaegeuk(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org