linux-kernel - Re: [PATCH 6/9] nfsd: fix empty-body warning in nfs4state.c

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Message-ID: <6c796219ea79d87093409f2dd1d3bf8e4a157ed7.camel@perches.com>
Date:   Sat, 18 Apr 2020 11:53:44 -0700
From:   Joe Perches <joe@...ches.com>
To:     Chuck Lever <chuck.lever@...cle.com>,
        Randy Dunlap <rdunlap@...radead.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        linux-fsdevel@...r.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        linux-input@...r.kernel.org, Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, alsa-devel@...a-project.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, Bruce Fields <bfields@...ldses.org>,
        Linux NFS Mailing List <linux-nfs@...r.kernel.org>,
        Johannes Berg <johannes@...solutions.net>,
        Dan Williams <dan.j.williams@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        Dave Jiang <dave.jiang@...el.com>, linux-nvdimm@...ts.01.org,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        linux-scsi@...r.kernel.org, target-devel@...r.kernel.org,
        Zzy Wysm <zzy@...wysm.com>
Subject: Re: [PATCH 6/9] nfsd: fix empty-body warning in nfs4state.c

On Sat, 2020-04-18 at 14:45 -0400, Chuck Lever wrote:
> > On Apr 18, 2020, at 2:41 PM, Randy Dunlap <rdunlap@...radead.org> wrote:
> > 
> > Fix gcc empty-body warning when -Wextra is used:
> > 
> > ../fs/nfsd/nfs4state.c:3898:3: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]
> > 
> > Signed-off-by: Randy Dunlap <rdunlap@...radead.org>
> > Cc: Linus Torvalds <torvalds@...ux-foundation.org>
> > Cc: Andrew Morton <akpm@...ux-foundation.org>
> > Cc: "J. Bruce Fields" <bfields@...ldses.org>
> > Cc: Chuck Lever <chuck.lever@...cle.com>
> > Cc: linux-nfs@...r.kernel.org
> 
> I have a patch in my queue that addresses this particular warning,
> but your change works for me too.
> 
> Acked-by: Chuck Lever <chuck.lever@...cle.com>
> 
> Unless Bruce objects.
> 
> 
> > ---
> > fs/nfsd/nfs4state.c |    3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > --- linux-next-20200417.orig/fs/nfsd/nfs4state.c
> > +++ linux-next-20200417/fs/nfsd/nfs4state.c
> > @@ -34,6 +34,7 @@
> > 
> > #include <linux/file.h>
> > #include <linux/fs.h>
> > +#include <linux/kernel.h>
> > #include <linux/slab.h>
> > #include <linux/namei.h>
> > #include <linux/swap.h>
> > @@ -3895,7 +3896,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp
> > 		copy_clid(new, conf);
> > 		gen_confirm(new, nn);
> > 	} else /* case 4 (new client) or cases 2, 3 (client reboot): */
> > -		;
> > +		do_empty();
> > 	new->cl_minorversion = 0;
> > 	gen_callback(new, setclid, rqstp);
> > 	add_to_unconfirmed(new);

This empty else seems silly and could likely be better handled by
a comment above the first if, something like:

	/* for now only handle case 1: probable callback update */
	if (conf && same_verf(&conf->cl_verifier, &clverifier)) {
		copy_clid(new, conf);
		gen_confirm(new, nn);
	}

with no else use.