From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E7A5ECE561 for ; Mon, 24 Sep 2018 06:50:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E95AC206B6 for ; Mon, 24 Sep 2018 06:50:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E95AC206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727573AbeIXMvQ (ORCPT ); Mon, 24 Sep 2018 08:51:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45961 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725992AbeIXMvQ (ORCPT ); Mon, 24 Sep 2018 08:51:16 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C58E23081247; Mon, 24 Sep 2018 06:50:40 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-123-84.rdu2.redhat.com [10.10.123.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id 72651CDBE2; Mon, 24 Sep 2018 06:50:39 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20180923230150.32qbjhnnzy56x3yy@brauner.io> References: <20180923230150.32qbjhnnzy56x3yy@brauner.io> <20180922161406.6beo2ob6ki2otrjx@brauner.io> <20180922132106.wfa6xaxwbu276qka@brauner.io> <20180921155455.flkf5vdrm3vgn6do@brauner.io> <20180920151214.15484-6-mszeredi@redhat.com> <20180920151214.15484-1-mszeredi@redhat.com> <17157.1537542475@warthog.procyon.org.uk> <20311.1537548756@warthog.procyon.org.uk> <8221.1537631312@warthog.procyon.org.uk> <3868.1537742717@warthog.procyon.org.uk> To: Christian Brauner Cc: dhowells@redhat.com, Miklos Szeredi , Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/6] fsmount: do not use legacy MS_ flags MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <30363.1537771838.1@warthog.procyon.org.uk> Date: Mon, 24 Sep 2018 07:50:38 +0100 Message-ID: <30364.1537771838@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 24 Sep 2018 06:50:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christian Brauner wrote: > Ok, understood. What about passing the different attrs as a struct? > > struct mount_attr { > unsigned int attr_cmd, > unsigned int attr_values, > unsigned int attr_mask, > > }; > > mount_setattr(int dfd, const char *path, unsigned int atflags, > struct mount_attr *attr); > > I find that to be a little cleaner in all honesty. > One could also add a version argument similar to what we currently do > for vfs fcaps so that kernel and userspace can easily navigate > compabitility when a new member gets added or removed in later releases. Yeah, we could do that - it's not like I expect mount_setattr() to have to be particularly performant in the user interface. I would put the attr_cmd in the argument list, probably, so that you can use that to vary the struct in future (say we run out of attribute bits). David