[Cluster-devel] Re: mmotm 2009-01-14-20-31 uploaded (gfs2)

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Fri, 2009-01-16 at 08:43 -0800, Andrew Morton wrote:
> On Fri, 16 Jan 2009 10:20:03 +0000 Steven Whitehouse <swhiteho@redhat.com> wrote:
> 
> > Hi,
> > 
> > On Thu, 2009-01-15 at 11:13 -0800, Randy Dunlap wrote:
> > > akpm at linux-foundation.org wrote:
> > > > The mm-of-the-moment snapshot 2009-01-14-20-31 has been uploaded to
> > > > 
> > > >    http://userweb.kernel.org/~akpm/mmotm/
> > > > 
> > > > and will soon be available at
> > > > 
> > > >    git://git.zen-sources.org/zen/mmotm.git
> > > 
> > > 
> > > when CONFIG_FILE_LOCKING=n:
> > > 
> > > mmotm-2009-0114-2031/fs/gfs2/ops_file.c:746: error: 'generic_setlease' undeclared here (not in a function)
> > > 
> > > 
> > > since generic_setlease() is a macro/define in that case.
> > > 
> > Hmm, it looks like I'll have to do this, in that case:
> > 
> > diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
> > index 99d726f..4580335 100644
> > --- a/fs/gfs2/ops_file.c
> > +++ b/fs/gfs2/ops_file.c
> > @@ -743,7 +743,9 @@ const struct file_operations *gfs2_file_fops_nolock = &(const struct file_operat
> >  	.fsync		= gfs2_fsync,
> >  	.splice_read	= generic_file_splice_read,
> >  	.splice_write	= generic_file_splice_write,
> > +#ifdef CONFIG_FILE_LOCKING
> >  	.setlease	= generic_setlease,
> > +#endif /* CONFIG_FILE_LOCKING */
> >  };
> >  
> >  const struct file_operations *gfs2_dir_fops_nolock = &(const struct file_operations){
> > 
> > 
> > which is not ideal, but I don't see any easy way to avoid the #ifdef,
> > 
> 
> Take a look in fs.h:
> 
> #define generic_setlease(a, b, c) ({ -EINVAL; })
> 
> If that wasn't a stupid macro, your code would have compiled and ran
> just as intended.
> 
There doesn't seem to be an easy answer though. If I #define it to NULL,
that upsets other parts of the code that rely on that macro, and if I
turn it into a inline function which returns -EINVAL, then presumably I
can't take its address for my file_operations.

I could create a small function which then calls generic_setlease I
suppose, but is that any better than this? Its not really very neat
which ever I choose :(

Steve.