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Subject: Re: autoload rpcsec_gss_krb5
From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Boaz Harrosh <bharrosh@panasas.com>,
        Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>, linux-nfs@vger.kernel.org,
        Trond Myklebust <trond@netapp.com>
Date: Fri, 24 Jun 2011 10:34:30 -0400
In-Reply-To: <20110624140105.GA18829@fieldses.org>
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On Fri, 2011-06-24 at 10:01 -0400, J. Bruce Fields wrote: 
> On Thu, Jun 23, 2011 at 07:22:34PM -0700, Boaz Harrosh wrote:
> > On 06/23/2011 01:30 PM, J. Bruce Fields wrote:
> > > On Thu, Jun 23, 2011 at 04:11:17PM -0400, J. Bruce Fields wrote:
> > >> On Thu, Jun 23, 2011 at 10:06:14PM +0200, Tigran Mkrtchyan wrote:
> > >>> I recall a discussion at connectaton 2010, where Peter Staubach from
> > >>> RedHat ( at that time )
> > >>> requested a way to disable pNFS without rebuilding the kernel.
> > >>>
> > >>> Probably that's why autoload is not implemented.
> > >>
> > >> Well, autoload *is* implemented, you just have to add an alias command
> > >> to modprobe.conf before it'll work.
> > >>
> > >> And if we embed the alias in the module instead, it will still be
> > >> possible to disable autloading by adding a "backlist <modulename>" to
> > >> modproble.conf.
> > >>
> > >> So I don't *think* that's the issue, unless I've missed something.
> > > 
> > > So can we just do this?  (Untested.)
> > > 
> > > --b.
> > > 
> > > commit 8b3065071b5469c428d70052c80f1df3cb398da6
> > > Author: J. Bruce Fields <bfields@redhat.com>
> > > Date:   Thu Jun 23 16:15:39 2011 -0400
> > > 
> > >     pnfs: simplify pnfs files module autoloading
> > >     
> > >     Embed the necessary alias into the module rather than waiting for
> > >     someone to add it to /etc/modprobe.conf
> > >     
> > >     Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> > > 
> > > diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
> > > index 4269088..eb65f82 100644
> > > --- a/fs/nfs/nfs4filelayout.c
> > > +++ b/fs/nfs/nfs4filelayout.c
> > > @@ -896,5 +896,7 @@ static void __exit nfs4filelayout_exit(void)
> > >  	pnfs_unregister_layoutdriver(&filelayout_type);
> > >  }
> > >  
> > > +MODULE_ALIAS("nfs-layouttype4-1");
> > > +
> > >  module_init(nfs4filelayout_init);
> > >  module_exit(nfs4filelayout_exit);
> > diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
> > index 70272d5..dd6a453 100644
> > --- a/fs/nfs/objlayout/objio_osd.c
> > +++ b/fs/nfs/objlayout/objio_osd.c
> > @@ -1065,5 +1065,7 @@ objlayout_exit(void)
> >  	       __func__);
> >  }
> >  
> > +MODULE_ALIAS("nfs-layouttype4-2");
> > +
> >  module_init(objlayout_init);
> >  module_exit(objlayout_exit);
> > ---
> > 
> > nfs-layouttype4-1
> > nfs-layouttype4-2
> > ...
> > 
> > Can we use a name here or it must be the number?
> 
> Looks like it needs a number; see the request_module() call in
> set_pnfs_layoutdriver:
> 
> 	request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);

The title of the thread is "autoload rpcsec_gss_krb5", but the above
patch only deals with layouts.

Now I'm all confused...

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com