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=-1.0 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 CAE2DC46464 for ; Thu, 9 Aug 2018 16:33:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 754C921EB7 for ; Thu, 9 Aug 2018 16:33:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 754C921EB7 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 S1732499AbeHIS7C (ORCPT ); Thu, 9 Aug 2018 14:59:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57790 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730419AbeHIS7C (ORCPT ); Thu, 9 Aug 2018 14:59:02 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 08C797A7EB; Thu, 9 Aug 2018 16:33:22 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-78.rdu2.redhat.com [10.10.120.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id AFF2010F1BF9; Thu, 9 Aug 2018 16:33:20 +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: References: <153313703562.13253.5766498657900728120.stgit@warthog.procyon.org.uk> <153313723557.13253.9055982745313603422.stgit@warthog.procyon.org.uk> <87in4n9zg0.fsf@xmission.com> <27374.1533824694@warthog.procyon.org.uk> To: Miklos Szeredi Cc: dhowells@redhat.com, "Eric W. Biederman" , Al Viro , Linux API , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 28/33] vfs: syscall: Add fsconfig() for configuring and managing a context [ver #11] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <13159.1533832400.1@warthog.procyon.org.uk> Date: Thu, 09 Aug 2018 17:33:20 +0100 Message-ID: <13160.1533832400@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 09 Aug 2018 16:33:22 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 09 Aug 2018 16:33:22 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Miklos Szeredi wrote: > > However, as I have said, I *am* willing to add one of more flags to help > > with this, but I can't make any "legacy" fs honour them as this requires > > the fs_context to be passed down to sget_fc() and the filesystem - which > > is why I was considering leaving it for later. > > You can determine at fsopen() time whether the filesystem is able to > support the O_EXCL behavior? If so, then it's trivial to enable this > conditionally. I think that's what Eric is asking for, it's obviously > not fair to ask for a change in behavior of the legacy interface. What do you mean by "enable it conditionally"? It cannot be enabled for filesystems that don't pass fs_context down to sget(). mount(2) mustn't enable it lest it break userspace. fsopen(2) can let userspace set a flag to enable it. David