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 056D6C433F4 for ; Mon, 24 Sep 2018 12:37:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3C0921486 for ; Mon, 24 Sep 2018 12:37:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3C0921486 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 S2387675AbeIXSjo (ORCPT ); Mon, 24 Sep 2018 14:39:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728937AbeIXSjn (ORCPT ); Mon, 24 Sep 2018 14:39:43 -0400 Received: from smtp.corp.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 52C9E30DF6E7; Mon, 24 Sep 2018 12:37:47 +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 EA5ED30A605C; Mon, 24 Sep 2018 12:37:45 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20180924094755.lkwdbrrayfrp45uu@brauner.io> References: <20180924094755.lkwdbrrayfrp45uu@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> <30364.1537771838@warthog.procyon.org.uk> To: Christian Brauner Cc: dhowells@redhat.com, Miklos Szeredi , Al Viro , aviro@redhat.com, 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: <29955.1537792665.1@warthog.procyon.org.uk> Date: Mon, 24 Sep 2018 13:37:45 +0100 Message-ID: <29956.1537792665@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 24 Sep 2018 12:37:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christian Brauner wrote: > I have thought a little more about splitting up the mount flags into > sensible sets. I think the following four sets make sense: > > enum { > MOUNT_ATTR_PROPAGATION = 1, > MOUNT_ATTR_SECURITY, > MOUNT_ATTR_SYNC, > MOUNT_ATTR_TIME, > }; Al (I think it was) has been against splitting them up before (I've previously proposed splitting the topology propagation flags from the mount attributes). > #define MOUNT_ATTR_NOATIME (1<<1) > #define MOUNT_ATTR_RELATIME (1<<3) > #define MOUNT_ATTR_STRICTATIME (1<<4) These aren't independent, but are actually settings on the same dial, so I would suggest that they shouldn't be separate flags. I'm not sure about LAZYTIME though. > enum { > MOUNT_ATTR_PROPAGATION = 1, > MOUNT_ATTR_SECURITY, > MOUNT_ATTR_SECURITY_1 = MOUNT_ATTR_SECURITY, > MOUNT_ATTR_SYNC, > MOUNT_ATTR_TIME, > MOUNT_ATTR_SECURITY_2, > }; In UAPI headers, always explicitly number your symbols, even in an enum, just to make sure that the numbers don't get transparently changed by accident. > These flags will likely become AT_* flags or be tied to a syscall > afaict. > > #define MS_REMOUNT 32 > #define MS_BIND 4096 > #define MS_MOVE 8192 > #define MS_REC 16384 MS_REMOUNT: fd = fspick(); fscommand(fd, FSCONFIG_CMD_RECONFIGURE); MS_REMOUNT|MS_BIND: mount_setattr(). MS_BIND: fd = open_tree(..., OPEN_TREE_CLONE); move_mount(fd, "", ...); MS_MOVE: fd = open_tree(..., 0); move_mount(fd, "", ...); MS_REC: AT_RECURSIVE > Internal sb flags will not be part of the new mount attr sets. (They > should - imho - not be exposed to userspace at all.): Agreed. > What remains is an odd duck that probably could be thrown into security > but also *shrug* > > #define MS_I_VERSION (1<<23) Um. I think it would probably belong with atime settings. David