Re: XFS warning in 2.6.18-rc4

[David Chinner <dgc@sgi.com>]

On Fri, Aug 11, 2006 at 09:52:10AM +1000, Nathan Scott wrote:
> On Fri, Aug 11, 2006 at 01:47:43AM +0200, Jesper Juhl wrote:
> > On 10/08/06, Nathan Scott <nathans@sgi.com> wrote:
> > > On Wed, Aug 09, 2006 at 11:04:53PM +0300, Meelis Roos wrote:
> > > > fs/xfs/xfs_bmap.c: In function 'xfs_bmapi':
> > > > fs/xfs/xfs_bmap.c:2662: warning: 'rtx' is used uninitialized in this function
> > >
> > > You have a particularly dense compiler, unfortunately.  This code
> > > has always been this way, its just a false cc warning that can be
> > > safely ignored until you upgrade to a fixed compiler (unless I'm
> > > missing something - please enlighten me if so).  It does seem to
> > > be the case that there is no way 'rtx' will be used uninitialised
> > > when xfs_rtpick_extent() doesn't fail... no?
> > >
> > Ok, I may be reading something wrong here, but I think the warning is
> > actually not correct.
> 
> Thats how I read it too.  By "dense" I meant "buggy".
> 
> > Or am I missing something ?
> 
> Nope, thats my understanding too.  The compiler is wrong in this case.
> The only open issue I guess is whether its worh rearranging the code
> to stop people reporting it as a problem...  *shrug*.

No, the compiler needs to be fixed. There are other warnings caused by code
exactly like this that have not been fixed because it is an incorrect warning
(e.g. "idx" in bio_alloc_bioset()).

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group