Re: [linux-next:master 14416/15220] fs/exportfs/expfs.c:357:5: error: expected identifier or '('

["Arnd Bergmann" <arnd@arndb.de>]

On Thu, Oct 26, 2023, at 15:49, kernel test robot wrote:
> tree:   
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 
> master
> head:   2ef7141596eed0b4b45ef18b3626f428a6b0a822
> commit: dfaf653dc41557548b2e75e6cd837071f7c63289 [14416/15220] 
> exportfs: make ->encode_fh() a mandatory method for NFS export
> config: hexagon-randconfig-r015-20211224 
> (https://download.01.org/0day-ci/archive/20231026/202310262151.renqMvme-lkp@intel.com/config)
> compiler: clang version 16.0.4 
> (https://github.com/llvm/llvm-project.git 
> ae42196bc493ffe877a7e3dff8be32035dea4d07)
> reproduce (this is a W=1 build): 
> (https://download.01.org/0day-ci/archive/20231026/202310262151.renqMvme-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new 
> version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: 
> https://lore.kernel.org/oe-kbuild-all/202310262151.renqMvme-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
>>> fs/exportfs/expfs.c:357:5: error: expected identifier or '('
>    int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int 
> *max_len,
>        ^
>    include/linux/exportfs.h:286:33: note: expanded from macro 

This bit is trivially fixed by allowing the protoype to
be visible for CONFIG_EXPORTFS=m

--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -314,7 +314,7 @@ extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 /*
  * Generic helpers for filesystems.
  */
-#ifdef CONFIG_EXPORTFS
+#if IS_ENABLED(CONFIG_EXPORTFS)
 int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len,
                            struct inode *parent);
 #else

but then we instead get link failures when the callers are
built-in:

x86_64-linux-ld: fs/ext4/super.o:(.rodata+0x11a0): undefined reference to `generic_encode_ino32_fh'
x86_64-linux-ld: fs/ext2/super.o:(.rodata+0x3a0): undefined reference to `generic_encode_ino32_fh'
x86_64-linux-ld: fs/fat/nfs.o:(.rodata+0x120): undefined reference to `generic_encode_ino32_fh'
x86_64-linux-ld: fs/ntfs3/super.o:(.rodata+0x2a0): undefined reference to `generic_encode_ino32_fh'
x86_64-linux-ld: fs/befs/linuxvfs.o:(.rodata+0x240): undefined reference to `generic_encode_ino32_fh'

Could this function just be move to fs/libfs.c or similar?

      Arnd