From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin Schuster (IFKL IT OS DSM CD)" Subject: [NFS] re-exporting NFS-mounted dir over NFS Date: Wed, 4 Jun 2008 16:10:58 +0200 Message-ID: <4846A272.8040206@infineon.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" To: Return-path: Received: from smtp1.infineon.com ([217.10.60.22]:2010 "EHLO smtp1.infineon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753385AbYFDOVG (ORCPT ); Wed, 4 Jun 2008 10:21:06 -0400 Sender: linux-nfs-owner@vger.kernel.org List-ID: I am in the process of setting up an "NFS-proxy", a machine which mounts directories from an NetApp-filer using NFS3, and should re-export them using NFS4 (with Kerberos). But apparently nfsd doesn't support re-exporting NFS-mounted dirs: # mount | grep home netapp.example.com:/vol/home/schumar on /srv/nfs4/home/schumar type nfs # cat /etc/exports /srv/nfs4/home/schumar gss/krb5(rw,sync,fsid=0,secure,no_subtree_check) # exportfs -r exportfs: Warning: /srv/nfs4/home/schumar does not support NFS export. I traced this back to linux-2.6.25.1/fs/nfsd/export.c, where it says, starting in line 386: if (!inode->i_sb->s_export_op || !inode->i_sb->s_export_op->fh_to_dentry) { dprintk("exp_export: export of invalid fs type.\n"); return -EINVAL; } (and a quick look in fs/nfs/super.c confirmed that the nfs-client never sets an export_op) Is there a technical reason for this (i.e. is it simply theoretically impossible to re-export an NFS-mount), or is my use-case so strange that nobody has ever needed this until now, and thus it just wasn't coded? Or am I just stupid/blind? (wouldn't be the first time :) Thanks in advance, -- Infineon Technologies IT-Services GmbH Martin.Schuster1-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org Lakeside B05, 9020 Klagenfurt, Austria Martin Schuster FB: LG Klagenfurt, FN 246787y +43 5 1777 3517