Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 11 Nov 2019 19:31:58 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>
Cc:     Qu Wenruo <wqu@suse.com>, David Sterba <dsterba@suse.com>,
        Johannes Thumshirn <jthumshirn@suse.de>,
        Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
        linux-btrfs@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH next 1/2] btrfs: tree-checker: Fix error format string
Message-ID: <20191111183158.GT3001@twin.jikos.cz>
Reply-To: dsterba@suse.cz
Mail-Followup-To: dsterba@suse.cz,
        Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>,
        Qu Wenruo <wqu@suse.com>, David Sterba <dsterba@suse.com>,
        Johannes Thumshirn <jthumshirn@suse.de>, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>, linux-btrfs@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20191108213853.16635-1-afaerber@suse.de>
 <20191108213853.16635-2-afaerber@suse.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20191108213853.16635-2-afaerber@suse.de>
User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Nov 08, 2019 at 10:38:52PM +0100, Andreas F?rber wrote:
> From: Andreas F?rber <afaerber@suse.com>
> 
> Argument BTRFS_FILE_EXTENT_INLINE_DATA_START is defined as offsetof(),
> which returns type size_t, so we need %zu instead of %lu.
> 
> This fixes a build warning on 32-bit arm:
> 
>   ../fs/btrfs/tree-checker.c: In function 'check_extent_data_item':
>   ../fs/btrfs/tree-checker.c:230:43: warning: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'unsigned int' [-Wformat=]
>     230 |     "invalid item size, have %u expect [%lu, %u)",
>         |                                         ~~^
>         |                                           |
>         |                                           long unsigned int
>         |                                         %u

Is there a gcc warning option that can catch that on 64bit too?
-Wformat=2 does not and I don't see any other of the option family to do
that. We've had fixups of the size_t printk formats and I'd like to
catch that when the patches are added to the devel branches. I can't run
32bit build check each time but this seems to be the only way so far.

> Fixes: a31ccb4b7ba2 ("btrfs: tree-checker: Check item size before reading file extent type")

As the patch is still in the devel branch, the commit id is not stable
and I'll fold the change to to the patch. Thanks.