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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C4C82C433E0 for ; Mon, 1 Mar 2021 19:07:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92AE764E45 for ; Mon, 1 Mar 2021 19:07:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240993AbhCATGr (ORCPT ); Mon, 1 Mar 2021 14:06:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236001AbhCATEO (ORCPT ); Mon, 1 Mar 2021 14:04:14 -0500 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 146F6C061756; Mon, 1 Mar 2021 11:03:00 -0800 (PST) Received: by fieldses.org (Postfix, from userid 2815) id 1177725FE; Mon, 1 Mar 2021 14:02:59 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 1177725FE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1614625379; bh=mxaTekYNEqDdiYO9bMH3o6RRL26uXiJHF5SOuD+r1Sc=; h=Date:To:Cc:Subject:References:In-Reply-To:From:From; b=fWmjUM4x73v2iYzV6qOdYURZOkzE7G3TZ5AsCJrbp49BX7PtAKjVHoknZLjDHApgr lmIGmjISuJGcvyJsNAVtcGj/jwYrriVsJfinvv/u6DFiTgPnhHl2CidBkMx5DGUkxO xtbRF3uSxFKFU2yI0EwnZHjydFlEI6gaxHZNK770= Date: Mon, 1 Mar 2021 14:02:59 -0500 To: Al Viro Cc: Drew DeVault , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Aleksa Sarai Subject: Re: [RFC PATCH] fs: introduce mkdirat2 syscall for atomic mkdir Message-ID: <20210301190259.GC14881@fieldses.org> References: <20210228002500.11483-1-sir@cmpwn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Sun, Feb 28, 2021 at 02:58:22AM +0000, Al Viro wrote: > TBH, I don't understand what are you trying to achieve - > what will that mkdir+open combination buy you, especially > since that atomicity goes straight out of window if you try > to use that on e.g. NFS. How is the userland supposed to make > use of that thing? For what it's worth, the RPC that creates a directory can also get a filehandle of the new directory, so I don't think there's anything in the NFS protocol that would *prevent* implementing this. (Whether that's useful, I don't know.) --b.