Re: fs/ext4/super.c:5649:3: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]

[Lukas Czerner]

The following patch on the list is going to fix it

https://lore.kernel.org/linux-ext4/20220119130209.40112-1-lczerner@xxxxxxxxxx/T/#u

Thanks!
-Lukas

On Thu, Jan 27, 2022 at 02:40:58PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   0280e3c58f92b2fe0e8fbbdf8d386449168de4a8
> commit: cebe85d570cf84804e848332d6721bc9e5300e07 ext4: switch to the new mount api
> date:   7 weeks ago
> config: x86_64-randconfig-c007 (https://download.01.org/0day-ci/archive/20220126/202201261659.dZZOrgxb-lkp@xxxxxxxxx/config)
> compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f7b7138a62648f4019c55e4671682af1f851f295)
> 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/torvalds/linux.git/commit/?id=cebe85d570cf84804e848332d6721bc9e5300e07
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout cebe85d570cf84804e848332d6721bc9e5300e07
>         # save the config file to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <yujie.liu@xxxxxxxxx>
> 
> 
> clang-analyzer warnings: (new ones prefixed by >>)
> 
> >> fs/ext4/super.c:5649:3: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
>                    ret = -ENOMEM;
>                    ^     ~~~~~~~
> 
> vim +/ret +5649 fs/ext4/super.c
> 
> ac27a0ec112a08 Dave Kleikamp 2006-10-11  5639
> cebe85d570cf84 Lukas Czerner 2021-10-27  5640  static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5641  {
> cebe85d570cf84 Lukas Czerner 2021-10-27  5642  	struct ext4_fs_context *ctx = fc->fs_private;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5643  	struct ext4_sb_info *sbi;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5644  	const char *descr;
> cebe85d570cf84 Lukas Czerner 2021-10-27  5645  	int ret;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5646
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5647  	sbi = ext4_alloc_sbi(sb);
> cebe85d570cf84 Lukas Czerner 2021-10-27  5648  	if (!sbi)
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27 @5649  		ret = -ENOMEM;
> 
> can use "return -ENOMEM;" here
> 
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5650
> cebe85d570cf84 Lukas Czerner 2021-10-27  5651  	fc->s_fs_info = sbi;
> cebe85d570cf84 Lukas Czerner 2021-10-27  5652
> cebe85d570cf84 Lukas Czerner 2021-10-27  5653  	/* Cleanup superblock name */
> cebe85d570cf84 Lukas Czerner 2021-10-27  5654  	strreplace(sb->s_id, '/', '!');
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5655
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5656  	sbi->s_sb_block = 1;	/* Default super block location */
> cebe85d570cf84 Lukas Czerner 2021-10-27  5657  	if (ctx->spec & EXT4_SPEC_s_sb_block)
> cebe85d570cf84 Lukas Czerner 2021-10-27  5658  		sbi->s_sb_block = ctx->s_sb_block;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5659
> cebe85d570cf84 Lukas Czerner 2021-10-27  5660  	ret = __ext4_fill_super(fc, sb, fc->sb_flags & SB_SILENT);
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5661  	if (ret < 0)
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5662  		goto free_sbi;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5663
> cebe85d570cf84 Lukas Czerner 2021-10-27  5664  	if (sbi->s_journal) {
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5665  		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5666  			descr = " journalled data mode";
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5667  		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5668  			descr = " ordered data mode";
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5669  		else
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5670  			descr = " writeback data mode";
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5671  	} else
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5672  		descr = "out journal";
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5673
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5674  	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5675  		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
> cebe85d570cf84 Lukas Czerner 2021-10-27  5676  			 "Quota mode: %s.", descr, ext4_quota_mode(sb));
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5677
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5678  	return 0;
> cebe85d570cf84 Lukas Czerner 2021-10-27  5679
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5680  free_sbi:
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5681  	ext4_free_sbi(sbi);
> cebe85d570cf84 Lukas Czerner 2021-10-27  5682  	fc->s_fs_info = NULL;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5683  	return ret;
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5684  }
> 7edfd85b1ffd36 Lukas Czerner 2021-10-27  5685
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
>