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 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 191ECECDE30 for ; Wed, 17 Oct 2018 13:15:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4BBD20645 for ; Wed, 17 Oct 2018 13:15:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4BBD20645 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 S1727214AbeJQVKw convert rfc822-to-8bit (ORCPT ); Wed, 17 Oct 2018 17:10:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33376 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727000AbeJQVKw (ORCPT ); Wed, 17 Oct 2018 17:10:52 -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 CB974317C40B; Wed, 17 Oct 2018 13:15:13 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-250.rdu2.redhat.com [10.10.120.250]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3EED519E26; Wed, 17 Oct 2018 13:15:02 +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: <68a2107f-bf70-055b-86cf-1ba2ba9422bf@gmail.com> References: <68a2107f-bf70-055b-86cf-1ba2ba9422bf@gmail.com> <153754740781.17872.7869536526927736855.stgit@warthog.procyon.org.uk> <153754766004.17872.9829232103614083565.stgit@warthog.procyon.org.uk> <9b8bf436-65de-13b9-0002-0479d11c18ca@gmail.com> <20181013061141.GR32577@ZenIV.linux.org.uk> To: Alan Jenkins Cc: dhowells@redhat.com, Al Viro , linux-api@vger.kernel.org, torvalds@linux-foundation.org, ebiederm@xmission.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, mszeredi@redhat.com Subject: Re: [PATCH 31/34] vfs: syscall: Add fspick() to select a superblock for reconfiguration [ver #12] MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Date: Wed, 17 Oct 2018 14:15:01 +0100 Message-ID: <19866.1539782101@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 [10.5.110.41]); Wed, 17 Oct 2018 13:15:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alan Jenkins wrote: > Sorry, I guess SB_NOUSER was the wrong word.  I was trying find if anything > stopped things like > > int memfd = memfd_create("foo", 0); > int fsfd = fspick(memfd, "", FSPICK_EMPTY_PATH); > > fsconfig(fsfd, FSCONFIG_SET_FLAG, "ro", NULL, 0); > fsconfig(fsfd, FSCONFIG_SET_STRING, "size", "100M", 0); > fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0); > > So far I'm getting -EBUSY if I try to apply the "ro", -EINVAL if I try to > apply the "size=100M".  But if I don't apply either, then > FSCONFIG_CMD_RECONFIGURE succeeds. I should probably check that the picked point is actually a mountpoint. David