Re: [PATCH] fs: nfsd:xdr4.h: add missing conditional group CONFIG_NFSD_V3

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

On Thu, Feb 12, 2015 at 03:02:01PM -0800, Guenter Roeck wrote:
> On Thu, Feb 12, 2015 at 11:09:13PM +0100, Bas Peters wrote:
> > This patch adds a missing conditional group that has been causing build
> > breakages due to undefined struct members being referenced when
> > CONFIG_NFSD_v3 is not set.
> > 
> > This patch applies against linux-next.
> > 
> > Signed-off-by: Bas Peters <baspeters93@gmail.com>
> > ---
> >  fs/nfsd/xdr4.h | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> > index 0bda93e..5d1597f 100644
> > --- a/fs/nfsd/xdr4.h
> > +++ b/fs/nfsd/xdr4.h
> > @@ -630,9 +630,11 @@ void warn_on_nonidempotent_op(struct nfsd4_op *op);
> >  static inline void
> >  set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
> >  {
> > +	cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode);
> > +
> > +#ifdef CONFIG_NFSD_V3
> >  	BUG_ON(!fhp->fh_pre_saved);
> >  	cinfo->atomic = fhp->fh_post_saved;
> > -	cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode);
> >  
> >  	cinfo->before_change = fhp->fh_pre_change;
> >  	cinfo->after_change = fhp->fh_post_change;
> > @@ -640,7 +642,7 @@ set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
> >  	cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
> >  	cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
> >  	cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
> > -
> > +#endif
> >  }
> 
> You'll want to include and example of the build failure in the description,
> bisect results after the '---' line, and a Fixes: line pointing to the patch
> breaking the build.
> 
> In this case, I am not sure if the above really fixes the problem,
> or if it just hides it behind an #ifdef. To determine that, it will
> probably be necessary to know which patch actually caused the problem.
> This even more true since the code in question was not changed since 
> around 2010, so making it conditional looks really suspicious.
> 
> In the curent case, I suspect that the problem may have been introduced by
> commit 9cf514ccfac ("nfsd: implement pNFS operations"). That is just a guess,
> though; I didn't run bisect myself. The key really is to figure out why the
> code now fails to build, and not just to comment out the code that is causing
> the failure.

Yeah, when Jim Davis reported this I took a quick look at the history,
didn't see an obvious explanation, and figured well maybe this is just
the first time anyone's hit that particular config in a while.  Sounds
like this actually is a recent regression?

--b.