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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 1 Aug 2023 09:18:55 -0700
Message-ID: <CAKwvOdn2Qn219Ys6vyR0Xryi_32XTARBWsfmuc3zhdH8TLREWQ@mail.gmail.com>
Subject: Re: [PATCH v2] ext4: mballoc: avoid garbage value from err
To:     Su Hui <suhui@nfschina.com>
Cc:     tytso@mit.edu, adilger.kernel@dilger.ca, nathan@kernel.org,
        trix@redhat.com, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        kernel-janitors@vger.kernel.org
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On Mon, Jul 24, 2023 at 9:34=E2=80=AFPM Su Hui <suhui@nfschina.com> wrote:
>
> clang's static analysis warning: fs/ext4/mballoc.c
> line 4178, column 6, Branch condition evaluates to a garbage value.
>
> err is uninitialized and will be judged when 'len <=3D 0' or
> it first enters the loop while the condition "!ext4_sb_block_valid()"
> is true. Although this can't make problems now, it's better to
> correct it.
>
> Signed-off-by: Su Hui <suhui@nfschina.com>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
> v2:
>  - modify commit message
>
>  fs/ext4/mballoc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 21b903fe546e..769000c970b0 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -4084,7 +4084,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_f=
sblk_t block,
>         struct ext4_sb_info *sbi =3D EXT4_SB(sb);
>         ext4_group_t group;
>         ext4_grpblk_t blkoff;
> -       int i, err;
> +       int i, err =3D 0;
>         int already;
>         unsigned int clen, clen_changed, thisgrp_len;
>
> --
> 2.30.2
>


--=20
Thanks,
~Nick Desaulniers