tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git fscache-rewrite head: 82abe23a0865faea23cf06ac51f2303f26b9bb53 commit: f6770459bb519747a01e91834f88ac82299a47de [65/69] nfs: Implement cache I/O by accessing the cache directly config: nds32-defconfig (https://download.01.org/0day-ci/archive/20211210/202112100957.2oEDT20W-lk...) compiler: nds32le-linux-gcc (GCC) 11.2.0 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://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/com... git remote add dhowells-fs https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git git fetch --no-tags dhowells-fs fscache-rewrite git checkout f6770459bb519747a01e91834f88ac82299a47de # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=nds32 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): fs/nfs/file.c: In function 'nfs_file_release': fs/nfs/file.c:87:9: error: implicit declaration of function 'nfs_fscache_release_file'; did you mean 'nfs_fscache_open_file'? [-Werror=implicit-function-declaration] 87 | nfs_fscache_release_file(inode, filp); | ^~~~~~~~~~~~~~~~~~~~~~~~ | nfs_fscache_open_file fs/nfs/file.c: In function 'nfs_release_page': 435 | return nfs_fscache_release_page(page, gfp); | ^~~~~~~~~~~~~~~~~~~~~~~~ | nfs_release_page cc1: some warnings being treated as errors vim +435 fs/nfs/file.c cd52ed35535ef4 Trond Myklebust 2006-03-20 421 6b9b3514aa1881 David Howells 2009-04-03 422 /* 6b9b3514aa1881 David Howells 2009-04-03 423 * Attempt to release the private state associated with a page 545db45f0fc0d4 David Howells 2009-04-03 424 * - Called if either PG_private or PG_fscache is set on the page 6b9b3514aa1881 David Howells 2009-04-03 425 * - Caller holds page lock 6b9b3514aa1881 David Howells 2009-04-03 426 * - Return true (may release page) or false (may not) 6b9b3514aa1881 David Howells 2009-04-03 427 */ cd52ed35535ef4 Trond Myklebust 2006-03-20 428 static int nfs_release_page(struct page *page, gfp_t gfp) cd52ed35535ef4 Trond Myklebust 2006-03-20 429 { b7eaefaa8722fd Chuck Lever 2008-06-11 430 dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); b7eaefaa8722fd Chuck Lever 2008-06-11 431 e3db7691e9f3df Trond Myklebust 2007-01-10 432 /* If PagePrivate() is set, then the page is not freeable */ 545db45f0fc0d4 David Howells 2009-04-03 433 if (PagePrivate(page)) ddeff520f02b92 Nikita Danilov 2006-08-09 434 return 0; 545db45f0fc0d4 David Howells 2009-04-03 @435 return nfs_fscache_release_page(page, gfp); e3db7691e9f3df Trond Myklebust 2007-01-10 436 } e3db7691e9f3df Trond Myklebust 2007-01-10 437 :::::: The code at line 435 was first introduced by commit :::::: 545db45f0fc0d4203b045047798ce156972a3056 NFS: FS-Cache page management :::::: TO: David Howells <dhowells(a)redhat.com&gt; :::::: CC: David Howells <dhowells(a)redhat.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org