Re: [NFS] [PATCH 013 of 20] knfsd: nfsd: factor out code from show_expflags

["J. Bruce Fields" <bfields@fieldses.org>]

On Thu, Jul 19, 2007 at 10:16:14AM +1000, Neil Brown wrote:
> On Wednesday July 18, bfields@fieldses.org wrote:
> > On Fri, Jul 13, 2007 at 12:29:33AM -0700, Andrew Morton wrote:
> > > On Tue, 10 Jul 2007 12:27:37 +1000 NeilBrown <neilb@suse.de> wrote:
> > > 
> > > > +static void exp_flags(struct seq_file *m, int flag, int fsid,
> > > > +		uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fsloc)
> > > > +{
> > > > +	show_expflags(m, flag, NFSEXP_ALLFLAGS);
> > > >  	if (flag & NFSEXP_FSID)
> > > > -		seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
> > > > +		seq_printf(m, ",fsid=%d", fsid);
> > > >  	if (anonu != (uid_t)-2 && anonu != (0x10000-2))
> > > > -		seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
> > > > +		seq_printf(m, ",sanonuid=%d", anonu);
> > > 
> > > It's a bit presumptuous to print a uid_t with "%d".  Fortunately it
> > > will work OK with all the present architectures.
> > > 
> > > But in general: be cautious when feeding opaque types to printk.
> > 
> > OK, here I'm still confused--what should we be doing instead?
> 
> Cast the variable to a type that printf knows about.
>        seq_printf(m, ",anonuid=%d", (int)anonu);
> 
> Or maybe cast it to (long) and use %ld, just in case...

OK.  In the event that uid_t some day ceases to eventually become an
int, will the casts help, or will they just suppress useful warnings?

> Note the stray 's' in the current patch, after the comma!

Sharp eyes, thanks!  I'll make a patch.  Uh, any objection if I print
all those uid's as unsigned while I'm at it?

--b.
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