Re: fs/bcachefs/bkey_methods.c:46:5-8: Unneeded variable: "ret". Return " 0" on line 53

[Kent Overstreet]

On Fri, Jan 19, 2024 at 09:31:24PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   9d1694dc91ce7b80bc96d6d8eaf1a1eca668d847
> commit: b65db750e2bb9252321fd54c284edd73c1595a09 bcachefs: Enumerate fsck errors
> date:   3 months ago
> config: hexagon-randconfig-r061-20240117 (https://download.01.org/0day-ci/archive/20240119/202401192156.IvrA7iSY-lkp@xxxxxxxxx/config)
> compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project 9bde5becb44ea071f5e1fa1f5d4071dc8788b18c)
> 
> 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@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202401192156.IvrA7iSY-lkp@xxxxxxxxx/
> 
> cocci warnings: (new ones prefixed by >>)
> >> fs/bcachefs/bkey_methods.c:46:5-8: Unneeded variable: "ret". Return "  0" on line 53
>    fs/bcachefs/bkey_methods.c:219:5-8: Unneeded variable: "ret". Return "  0" on line 229
> 
> vim +46 fs/bcachefs/bkey_methods.c
> 
>     42	
>     43	static int empty_val_key_invalid(struct bch_fs *c, struct bkey_s_c k,
>     44					 enum bkey_invalid_flags flags, struct printbuf *err)
>     45	{
>   > 46		int ret = 0;
>     47	
>     48		bkey_fsck_err_on(bkey_val_bytes(k.k), c, err,
>     49				 bkey_val_size_nonzero,
>     50				 "incorrect value size (%zu != 0)",
>     51				 bkey_val_bytes(k.k));
>     52	fsck_err:
>   > 53		return ret;
>     54	}
>     55	

This isn't an actual bug; ret and the fsck_err: labels are used by
fsck_err() and related macros - we need a way to annotate that ret isn't
unused if we want to silence this.