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Subject: Re: linux-next: build warning after merge of the device-mapper tree
To:     Stephen Rothwell <sfr@canb.auug.org.au>,
        Alasdair G Kergon <agk@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>
CC:     Linux Next Mailing List <linux-next@vger.kernel.org>,
        "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
        Bryan Gurney <bgurney@redhat.com>
References: <20200709132609.6de53604@canb.auug.org.au>
From:   yangerkun <yangerkun@huawei.com>
Message-ID: <a6ff1a7c-628d-449e-f177-c4d23efbcd07@huawei.com>
Date:   Thu, 9 Jul 2020 12:38:30 +0800
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在 2020/7/9 11:26, Stephen Rothwell 写道:
> Hi all,
> 
> After merging the device-mapper tree, today's linux-next build (x86_64
> allmodconfig) produced this warning:
> 
> In file included from drivers/md/dm-dust.c:11:
> drivers/md/dm-dust.c: In function 'dust_list_badblocks':
> drivers/md/dm-dust.c:307:10: warning: zero-length gnu_printf format string [-Wformat-zero-length]
>    307 |   DMEMIT("");
Mike and Bryan,

Should we just use "DMEMIT("\n")"? Maybe it's bad since this lead a
blank line...


>        |          ^~
> include/linux/device-mapper.h:555:46: note: in definition of macro 'DMEMIT'
>    555 |      0 : scnprintf(result + sz, maxlen - sz, x))
>        |                                              ^
> 
> Introduced by commit
> 
>    20f93ea74f9c ("dm dust: add interface to list all badblocks")
>