From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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