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=-2.4 required=3.0 tests=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 29DD7C2BB1D for ; Thu, 12 Mar 2020 21:49:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F15AD20674 for ; Thu, 12 Mar 2020 21:49:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (3072-bit key) header.d=samba.org header.i=@samba.org header.b="M0zd3UDi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbgCLVtH (ORCPT ); Thu, 12 Mar 2020 17:49:07 -0400 Received: from hr2.samba.org ([144.76.82.148]:24712 "EHLO hr2.samba.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726481AbgCLVtH (ORCPT ); Thu, 12 Mar 2020 17:49:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Message-ID:Cc:To:From:Date; bh=1JcRWJgIjBZEatikoz0G3mL9EJsdG0P/Ykm3OGVRQo4=; b=M0zd3UDimz2yegwwlZBWRu1Sjm Hb2a9sq9I/B2kDBeJsob+VR2XNQaYH9Iy1mlh80tLPM12bcDfMTE7Vl1rQta5McDePT92ZD8iJVx9 4tIkUFiaXRuJxqXRY1b3LYV5TT9y0Y51MUhnzpAXCmeCh50oytdBZauYcQ24b2HFNK/RLcTAtOrD5 hTBFgTzdVQ0ofrJuWOVAaffympfy8PogEB8b5bMOrBCYsIUxsV32VOqKq22+55Ix0JZtWjbxJNRV1 6vDfCbps6fckISnbwkJA83CC45iVr8ot0VEw954sESPpX3S08kajgNhTB7NTflfsu+IYxtRNf86CY b+xx302xd92v1CkKTYCFMBwqmCqn0RvpztruQ3/4/poqm41ia+R5OfQLbgustha/L4tkO0VQG5NXK fyDcx1FGbGK/vnFmBQd79m7VBcS1nIU1N2SRWXJu2fLt8wJuxfBAzUQjf6/twU2w9n5Gnq5D+R541 DWEaB6FUBoQZBsoGn8v9YsSo; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_RSA_CHACHA20_POLY1305:256) (Exim) id 1jCVhO-0001fg-IM; Thu, 12 Mar 2020 21:49:02 +0000 Date: Thu, 12 Mar 2020 14:48:54 -0700 From: Jeremy Allison To: Stefan Metzmacher Cc: Linus Torvalds , David Howells , Aleksa Sarai , Al Viro , Ian Kent , Miklos Szeredi , Christian Brauner , Jann Horn , "Darrick J. Wong" , Karel Zak , jlayton@redhat.com, Linux API , linux-fsdevel , LSM List , Linux Kernel Mailing List , Ralph =?iso-8859-1?Q?B=F6hme?= , Volker Lendecke Subject: Re: [PATCH 01/14] VFS: Add additional RESOLVE_* flags [ver #18] Message-ID: <20200312214854.GA19247@jeremy-acer> Reply-To: Jeremy Allison References: <158376244589.344135.12925590041630631412.stgit@warthog.procyon.org.uk> <158376245699.344135.7522994074747336376.stgit@warthog.procyon.org.uk> <20200310005549.adrn3yf4mbljc5f6@yavin> <580352.1583825105@warthog.procyon.org.uk> <3d209e29-e73d-23a6-5c6f-0267b1e669b6@samba.org> <8d24e9f6-8e90-96bb-6e98-035127af0327@samba.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8d24e9f6-8e90-96bb-6e98-035127af0327@samba.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Thu, Mar 12, 2020 at 06:11:09PM +0100, Stefan Metzmacher wrote: > Am 12.03.20 um 17:24 schrieb Linus Torvalds: > > On Thu, Mar 12, 2020 at 2:08 AM Stefan Metzmacher wrote: > >> > >> The whole discussion was triggered by the introduction of a completely > >> new fsinfo() call: > >> > >> Would you propose to have 'at_flags' and 'resolve_flags' passed in here? > > > > Yes, I think that would be the way to go. > > Ok, that's also fine for me:-) > > >>> If we need linkat2() and friends, so be it. Do we? > >> > >> Yes, I'm going to propose something like this, as it would make the life > >> much easier for Samba to have the new features available on all path > >> based syscalls. > > > > Will samba actually use them? I think we've had extensions before that > > weren't worth the non-portability pain? > > Yes, we're currently moving to the portable *at() calls as a start. > And we already make use of Linux only feature for performance reasons > in other places. Having the new resolve flags will make it possible to > move some of the performance intensive work into non-linux specific > modules as fallback. > > I hope that we'll use most of this through io_uring in the end, > that's the reason Jens added the IORING_REGISTER_PERSONALITY feature > used for IORING_OP_OPENAT2. > > > But yes, if we have a major package like samba use it, then by all > > means let's add linkat2(). How many things are we talking about? We > > have a number of system calls that do *not* take flags, but do do > > pathname walking. I'm thinking things like "mkdirat()"?) > > I haven't looked them up in detail yet. > Jeremy can you provide a list? Fixing the flags argument on fchmodat() to actually *implement* AT_SYMLINK_NOFOLLOW would be a good start :-). As for the syscalls that don't have flags I'm thinking of the things like: getxattr/setxattr/removexattr just off the top of my head. Jeremy.