Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:47734 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551Ab3LQDiv (ORCPT ); Mon, 16 Dec 2013 22:38:51 -0500 Date: Mon, 16 Dec 2013 22:38:49 -0500 From: "J. Bruce Fields" To: Joakim Tjernlund Cc: linux-nfs@vger.kernel.org, steved@redhat.com Subject: Re: nfs-utils-1.2.9 does not play well with linux 3.10.x Message-ID: <20131217033849.GA3490@fieldses.org> References: <20131216185419.GB31816@fieldses.org> <20131216200301.GD31816@fieldses.org> <20131216202345.GF31816@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Dec 16, 2013 at 11:24:03PM +0100, Joakim Tjernlund wrote: > "J. Bruce Fields" wrote on 2013/12/16 21:23:45: > > > From: "J. Bruce Fields" > > To: Joakim Tjernlund , > > Cc: linux-nfs@vger.kernel.org, steved@redhat.com > > Date: 2013/12/16 21:23 > > Subject: Re: nfs-utils-1.2.9 does not play well with linux 3.10.x > > > > On Mon, Dec 16, 2013 at 09:21:15PM +0100, Joakim Tjernlund wrote: > > > "J. Bruce Fields" wrote on 2013/12/16 21:03:01: > > > > > > > From: "J. Bruce Fields" > > > > To: Joakim Tjernlund , > > > > Cc: linux-nfs@vger.kernel.org, steved@redhat.com > > > > Date: 2013/12/16 21:03 > > > > Subject: Re: nfs-utils-1.2.9 does not play well with linux 3.10.x > > > > > > > > On Mon, Dec 16, 2013 at 01:54:19PM -0500, bfields wrote: > > > > > On Mon, Dec 16, 2013 at 07:16:00PM +0100, Joakim Tjernlund wrote: > > > > > > rpc.nfsd insists on adding "-4.2" when writing > > > /proc/fs/nfsd/versions : > > > > > > rpc.nfsd: Writing version string to kernel: +4.1 -4.2 -2 +3 +4 > > > > > > Which causes Linux to return an EIVAL error as 3.10 has no > support > > > for 4.2 > > > > > > and > > > > > > does not accept any reference to 4.2 > > > > > > > > > > > > It seems reasonable to me that Linux should accpect -4.2 as a > noop > > > and > > > > > > continue > > > > > > processing the rest of the options but I am just guessing. > > > > > > Anyhow, just to test I applied this commit to my 3.10.24 kernel: > > > > > > > > > > > > > > > > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4bdc33ed5bd9fbaa243bda6fdccb22674aed6305 > > > > > > > > > > and now it accepts the "-4.2" but I have no idea if this messes > up > > > > > > something else. > > > > > > > > > > That should be perfectly safe. > > > > > > Thanks, I will keep this then until nfs-utils is working. > > > > > > > > > > > > > I agree that we should teach the kernel to treat "-4.x" at least > as a > > > > > no-op for unknown .x. But nfs-utils also has to keep working with > > > > older > > > > > kernels which don't do that. > > > > > > > > > > The problem was introduced by > 12a590f8d556c00a9502eeebaa763d906222d521 > > > > > "rpc.nfsd: Allow v4.2 server support with the -V option". That > should > > > > > be using an array of ints not a bit array, so it can make the > > > > > distinction between "off", "on", and "don't care". > > > > > > > > So, something like this (untested).--b. > > > > > > I tested this on my system(which has the above kernel patch) and I > noticed > > > a difference: > > > > Thanks! > > > > > rpc.nfsd: Writing version string to kernel: -2 +3 +4 > > > which is different than previous > > > rpc.nfsd: Writing version string to kernel: +4.1 -4.2 -2 +3 +4 > > > > > > The "+4.1" is missing. > > > > Yes, that's intentional. Is it causing you any problem? > > I don't know yet, but I don't think it would be a problem for me. > However, are you not changing the defaults here? In that > case someone else relying on 4.1 might have a problem I guess. That's just restoring the behavior we had before 12a590f8d556c00a9502eeebaa763d906222d521, and will still result in 4.1 being turned on if the kernel is recent enough. --b.