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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 CB988C433E2 for ; Mon, 31 Aug 2020 14:40:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A437720767 for ; Mon, 31 Aug 2020 14:40:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="d7ioD5Fx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728053AbgHaOkj (ORCPT ); Mon, 31 Aug 2020 10:40:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728014AbgHaOki (ORCPT ); Mon, 31 Aug 2020 10:40:38 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52FB6C061573 for ; Mon, 31 Aug 2020 07:40:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ecPIVKZPGvGK7Z99O1rOhMk/Zq7Bp/08RcPNGmkNUV0=; b=d7ioD5FxIjtL38bpXus7hzv0My lry3tAeHKNtI6BS3FnwHgI+AQfYSXH+8YyIN1bgcGtK9mPpruANatVuBMDpFOYx+cWDRlTcvy2wwF ASnsS0+01MbDZSXV3pMkl3dudWwnKs6FTDrle23sovgm+RlWbHAIHWBTFvxgcXJOU2ACPmE6QqRxT pNAh/Qzjztuv6cwonJJ2MjWlcHNfJL4hHdTkOsICKEQhY0bhdCa2FtjkQUZ/KNqpLOGTF08gagQQp 7gaOtkvuSSYudWe3HDCCx5cenK5xauleWfMQ/kii5iJjWuKIBqPA8kBRDjPY5+YOF4dTc+vGcwBgZ nMK83eQw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kCkyx-0004uo-LQ; Mon, 31 Aug 2020 14:40:27 +0000 Date: Mon, 31 Aug 2020 15:40:27 +0100 From: Matthew Wilcox To: "Theodore Y. Ts'o" Cc: Al Viro , Dave Chinner , Christian Schoenebeck , "Dr. David Alan Gilbert" , Greg Kurz , linux-fsdevel@vger.kernel.org, stefanha@redhat.com, mszeredi@redhat.com, vgoyal@redhat.com, gscrivan@redhat.com, dwalsh@redhat.com, chirantan@chromium.org Subject: Re: xattr names for unprivileged stacking? Message-ID: <20200831144027.GE14765@casper.infradead.org> References: <20200816230908.GI17456@casper.infradead.org> <20200817002930.GB28218@dread.disaster.area> <20200827152207.GJ14765@casper.infradead.org> <20200827222457.GB12096@dread.disaster.area> <20200829160717.GS14765@casper.infradead.org> <20200829161358.GP1236603@ZenIV.linux.org.uk> <20200829191751.GT14765@casper.infradead.org> <20200829194042.GT1236603@ZenIV.linux.org.uk> <20200829201245.GU14765@casper.infradead.org> <20200831142312.GB4267@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200831142312.GB4267@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Aug 31, 2020 at 10:23:12AM -0400, Theodore Y. Ts'o wrote: > On Sat, Aug 29, 2020 at 09:12:45PM +0100, Matthew Wilcox wrote: > > > 3) what happens to it if that underlying file is unlinked? > > > > Unlinking a file necessarily unlinks all the streams. So the file > > remains in existance until all fds on it are closed, including all > > the streams. > > That's a bad idea, because if the fds are closed silently, then they What? I think you completely misread me. I never said anything about closing file descriptors. I'm proprosing standard unix semantics; having a file descriptor open keeps a file in existance, even after it's unlinked.