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 75E06C433E6 for ; Sun, 30 Aug 2020 19:10:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43C0C206F0 for ; Sun, 30 Aug 2020 19:10:31 +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="n3NzOi3P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgH3TKa (ORCPT ); Sun, 30 Aug 2020 15:10:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726178AbgH3TKa (ORCPT ); Sun, 30 Aug 2020 15:10:30 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70909C061573 for ; Sun, 30 Aug 2020 12:10:28 -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=J1cbLJ8F4WGYQkL5gnov6H5FbEcaOkn/XAlRvPP0Z7Q=; b=n3NzOi3PjZt2/X6wydSB721ero sWqXXAejB4W60L+Cs2/TWLtK2JXs7f2ktFuKbsCGLFN8/lDIv2ftG8V7UuauWv/Czl00KIP8WmSeq nSGryHdMDqoXXKRUqWJbulJwyObE0q1ku1VHCFjrNEE92d/uiYiCZWo9SZcdHIn1D8q1WJ47djwRW 8WjkjgX7DHvNGhsXC38d4bNi1/ZkzgQkHlhhIlVGRn/IOXLXnXBR/UUI/xuyDyVdAAD1y21qL87lZ 3xP3xc9SGt2LqnPSPaCB0x4ccCAFriOj1X7M8BHVhFU6XfcKPhbuZIkF+XmEba/tgiw+fO96F6SxC pWitJJig==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kCSiX-0000FI-1l; Sun, 30 Aug 2020 19:10:17 +0000 Date: Sun, 30 Aug 2020 20:10:16 +0100 From: Matthew Wilcox To: Miklos Szeredi Cc: Al Viro , Dave Chinner , Christian Schoenebeck , "Dr. David Alan Gilbert" , Greg Kurz , linux-fsdevel@vger.kernel.org, Stefan Hajnoczi , Miklos Szeredi , Vivek Goyal , Giuseppe Scrivano , Daniel J Walsh , Chirantan Ekbote Subject: Re: xattr names for unprivileged stacking? Message-ID: <20200830191016.GZ14765@casper.infradead.org> References: <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> <20200829180448.GQ1236603@ZenIV.linux.org.uk> <20200829192522.GS1236603@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Aug 30, 2020 at 09:05:40PM +0200, Miklos Szeredi wrote: > Yes, open(..., O_ALT) would be special. Let's call it open_alt(2) to > avoid confusion with normal open on a normal filesystem. No special > casing anywhere at all. It's a completely new interface that returns > a file which either has ->read/write() or ->iterate() and which points > to an inode with empty i_ops. I think fiemap() should be allowed on a stream. After all, these extents do exist. But I'm opposed to allowing getdents(); it'll only encourage people to think they can have non-files as streams.