Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210219210333.1439525-1-harshads@google.com> <20210219210333.1439525-4-harshads@google.com>
 <YDLpPr/DD/sSRuES@mit.edu>
In-Reply-To: <YDLpPr/DD/sSRuES@mit.edu>
From:   harshad shirwadkar <harshadshirwadkar@gmail.com>
Date:   Tue, 23 Feb 2021 09:41:05 -0800
Message-ID: <CAD+ocbwro-Zu9O60QQFTZ2CvQtdyZN19_X3bghFyxJS=hChStg@mail.gmail.com>
Subject: Re: [PATCH 4/4] e2fsck: initialize variable before first use in fast
 commit replay
To:     "Theodore Ts'o" <tytso@mit.edu>
Cc:     Ext4 Developers List <linux-ext4@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Thanks Ted, it makes sense, will fix this in V2.

- Harshad

On Sun, Feb 21, 2021 at 3:14 PM Theodore Ts'o <tytso@mit.edu> wrote:
>
> On Fri, Feb 19, 2021 at 01:03:33PM -0800, Harshad Shirwadkar wrote:
> > From: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> >
> > Initialize ext2fs_ex variable in ext4_fc_replay_scan() before first
> > use.
> >
> > Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
>
> I wonder if we should make the following change to
> ext2fs_decode_extent(), which will prevent other future bugs to
> potential users of the function:
>
>         to->e_pblk = ext2fs_le32_to_cpu(from->ee_start) +
>                 ((__u64) ext2fs_le16_to_cpu(from->ee_start_hi)
>                         << 32);
>         to->e_lblk = ext2fs_le32_to_cpu(from->ee_block);
>         to->e_len = ext2fs_le16_to_cpu(from->ee_len);
> -       to->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
> +       to->e_flags = EXT2_EXTENT_FLAGS_LEAF;
>
> ext2fs_decode_extent() overwrites all other members of the structure,
> so we might as well just initialize e_flags as opposed to depending
> the caller to initiaize *to just for the sake of to->e_flags.
>
> Cheers,
>
>                                         - Ted