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 D0040ECDFB1 for ; Fri, 13 Jul 2018 15:40:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89BBA208B1 for ; Fri, 13 Jul 2018 15:40:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89BBA208B1 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 S1730017AbeGMPzk (ORCPT ); Fri, 13 Jul 2018 11:55:40 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60148 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729725AbeGMPzk (ORCPT ); Fri, 13 Jul 2018 11:55:40 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6C6E7DAC8; Fri, 13 Jul 2018 15:40:30 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-149.rdu2.redhat.com [10.10.120.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6ACD62156889; Fri, 13 Jul 2018 15:40:29 +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: <153126248868.14533.9751473662727327569.stgit@warthog.procyon.org.uk> <153126264966.14533.3388004240803696769.stgit@warthog.procyon.org.uk> <686E805C-81F3-43D0-A096-50C644C57EE3@amacapital.net> <22370.1531293761@warthog.procyon.org.uk> <7002.1531407244@warthog.procyon.org.uk> <338BC3C4-F3E7-48F0-A82E-2C7295B6640E@amacapital.net> <17749.1531429218@warthog.procyon.org.uk> <21131.1531488422@warthog.procyon.org.uk> To: Andy Lutomirski Cc: dhowells@redhat.com, Linus Torvalds , Andrew Lutomirski , Al Viro , Linux API , linux-fsdevel , Linux Kernel Mailing List , Jann Horn , Tycho Andersen Subject: Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for superblock creation [ver #9] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <26575.1531496428.1@warthog.procyon.org.uk> Date: Fri, 13 Jul 2018 16:40:28 +0100 Message-ID: <26576.1531496428@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 13 Jul 2018 15:40:30 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 13 Jul 2018 15:40:30 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 Andy Lutomirski wrote: > > Whilst I'm at it, do we want the option of doing the equivalent of > > mountat()? I.e. offering the option to open all the device files used by > > a superblock with dfd and AT_* flags in combination with the filename? > > > > Isn't that more or less what I was suggesting? Yes, you suggested that. I'm asking if we actually need that. > ... I also suggested just an fd and letting the caller open the file itself. I'm not entirely sure, but that might prevent the filesystem from being able to use it, since userspace might then prevent the filesystem getting exclusive holdership. David