From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH iproute2] devlink: Ignore unknown attributes Date: Fri, 19 Jan 2018 14:02:31 -0800 Message-ID: <20180119140232.1191999c@xeon-e3> References: <1516195680-33683-1-git-send-email-arkadis@mellanox.com> <695fecfe-c45e-4a83-cee8-0476ee56d422@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Arkadi Sharshevsky , netdev@vger.kernel.org, davem@davemloft.net, mlxsw@mellanox.com To: David Ahern Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:41054 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756461AbeASWCf (ORCPT ); Fri, 19 Jan 2018 17:02:35 -0500 Received: by mail-pf0-f195.google.com with SMTP id j3so2338080pfh.8 for ; Fri, 19 Jan 2018 14:02:34 -0800 (PST) In-Reply-To: <695fecfe-c45e-4a83-cee8-0476ee56d422@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 18 Jan 2018 20:42:44 -0800 David Ahern wrote: > On 1/17/18 5:28 AM, Arkadi Sharshevsky wrote: > > In case of extending the UAPI old packages would break. > > > > Signed-off-by: Arkadi Sharshevsky > > --- > > devlink/devlink.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/devlink/devlink.c b/devlink/devlink.c > > index 39cda06..c9d1838 100644 > > --- a/devlink/devlink.c > > +++ b/devlink/devlink.c > > @@ -343,7 +343,7 @@ static int attr_cb(const struct nlattr *attr, void *data) > > int type; > > > > if (mnl_attr_type_valid(attr, DEVLINK_ATTR_MAX) < 0) > > - return MNL_CB_ERROR; > > + return MNL_CB_OK; > > > > type = mnl_attr_get_type(attr); > > if (mnl_attr_validate(attr, devlink_policy[type]) < 0) > > > > What's the point of calling mnl_attr_type_valid if you disregard a > failure? you might as well not call mnl_attr_type_valid at all. The way mnl handles attributes, you have to have a callback and it is up to the callback to copy the values it wants. The idea is that old code running against a newer kernel will have a smaller array of attributes it wants, and only copy those.