From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:41712 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964990AbeFRJbY (ORCPT ); Mon, 18 Jun 2018 05:31:24 -0400 Subject: Re: [PATCH] btrfs: Fix a C compliance issue To: dsterba@suse.cz, Bart Van Assche , Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, Jeff Mahoney References: <20180615223659.32420-1-bart.vanassche@wdc.com> <838e73e8-e9b8-6075-1d69-79bc65c15b0c@suse.com> <20180618092633.GH24375@twin.jikos.cz> From: Nikolay Borisov Message-ID: <14645aca-930b-2d7d-a7d6-6893f7cfcbbd@suse.com> Date: Mon, 18 Jun 2018 12:31:21 +0300 MIME-Version: 1.0 In-Reply-To: <20180618092633.GH24375@twin.jikos.cz> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 18.06.2018 12:26, David Sterba wrote: > On Sat, Jun 16, 2018 at 01:28:13PM +0300, Nikolay Borisov wrote: >> >> >> On 16.06.2018 01:36, Bart Van Assche wrote: >>> The C programming language does not allow to use preprocessor statements >>> inside macro arguments (pr_info() is defined as a macro). Hence rework >>> the pr_info() statement in btrfs_print_mod_info() such that it becomes >>> compliant. This patch allows tools like sparse to analyze the BTRFS >>> source code. >>> >>> Fixes: 62e855771dac ("btrfs: convert printk(KERN_* to use pr_* calls") >>> Signed-off-by: Bart Van Assche >>> Cc: Jeff Mahoney >>> Cc: David Sterba >>> --- >>> fs/btrfs/super.c | 6 +++--- >>> 1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c >>> index 81107ad49f3a..dd4980df5b8e 100644 >>> --- a/fs/btrfs/super.c >>> +++ b/fs/btrfs/super.c >>> @@ -2369,7 +2369,7 @@ static __cold void btrfs_interface_exit(void) >>> >>> static void __init btrfs_print_mod_info(void) >>> { >>> - pr_info("Btrfs loaded, crc32c=%s" >>> + static const char fmt[] = KERN_INFO "Btrfs loaded, crc32c=%s" >>> #ifdef CONFIG_BTRFS_DEBUG >>> ", debug=on" >>> #endif >>> @@ -2382,8 +2382,8 @@ static void __init btrfs_print_mod_info(void) >>> #ifdef CONFIG_BTRFS_FS_REF_VERIFY >>> ", ref-verify=on" >>> #endif >>> - "\n", >>> - crc32c_impl()); >>> + "\n"; >>> + printk(fmt, crc32c_impl()); >> >> I'd rather not see more printk being added. Nothing prevents from having >> the fmt string being passed to pr_info. > > So you mean to do > > + static const char fmt[] = "Btrfs loaded, crc32c=%s" > + pr_info(fmt); Pretty much, something along the lines of pr_info(fmt, crc32c_impl). printk requires having the KERN_INFO in the format string, which I see no point in doing, correct me if I'm wrong? > > ? >