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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B6F32C33CB1 for ; Tue, 14 Jan 2020 10:07:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 85D8C24681 for ; Tue, 14 Jan 2020 10:07:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OYTu6lmW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85D8C24681 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36052 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irJ72-0008W9-My for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 05:07:52 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:37858) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irJ6Q-0007yR-Jx for qemu-devel@nongnu.org; Tue, 14 Jan 2020 05:07:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irJ6P-00011f-7p for qemu-devel@nongnu.org; Tue, 14 Jan 2020 05:07:14 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:46909 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irJ6P-00011V-3C for qemu-devel@nongnu.org; Tue, 14 Jan 2020 05:07:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578996432; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=stfsFp75i47VJlVqquXOjIbx9Xx8xj92dO692LzjoVE=; b=OYTu6lmWq7BXkljrhDLP28vLmB/8acWMlX891LqHPZ3PLYdPprCRjZO0bMFleOsAT4nhk0 76ikN24MC72Cw0P1HqsZ02GYtWYvh46epx2zqOVf6keIlRy2GRS30X0SkirLkx6o2U3hw8 GWp2mdA8tT9XL0mL10isBTmo/8SyYFA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-423-Vk5_zMxPN1OnpwE8SNlYbg-1; Tue, 14 Jan 2020 05:07:10 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A5B2A18C8C2C for ; Tue, 14 Jan 2020 10:07:09 +0000 (UTC) Received: from work-vm (ovpn-117-209.ams2.redhat.com [10.36.117.209]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 071485DA70; Tue, 14 Jan 2020 10:07:05 +0000 (UTC) Date: Tue, 14 Jan 2020 10:07:03 +0000 From: "Dr. David Alan Gilbert" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Subject: Re: [PATCH 066/104] virtiofsd: passthrough_ll: add renameat2 support Message-ID: <20200114100703.GC2812@work-vm> References: <20191212163904.159893-1-dgilbert@redhat.com> <20191212163904.159893-67-dgilbert@redhat.com> <20200107112143.GJ3368802@redhat.com> <20200110095228.GC3901@work-vm> <20200113200624.GB87499@work-vm> <20200114082949.GB4071034@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200114082949.GB4071034@redhat.com> User-Agent: Mutt/1.13.0 (2019-11-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: Vk5_zMxPN1OnpwE8SNlYbg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mszeredi@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > On Mon, Jan 13, 2020 at 08:06:24PM +0000, Dr. David Alan Gilbert wrote: > > * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > > > * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > > > > On Thu, Dec 12, 2019 at 04:38:26PM +0000, Dr. David Alan Gilbert (g= it) wrote: > > > > > From: Miklos Szeredi > > > > >=20 > > > > > No glibc support yet, so use syscall(). > > > >=20 > > > > It exists in glibc in my Fedora 31 install. > > > >=20 > > > > Presumably this is related to an older version > > > >=20 > > > > > Signed-off-by: Miklos Szeredi > > > > > --- > > > > > tools/virtiofsd/passthrough_ll.c | 10 ++++++++++ > > > > > 1 file changed, 10 insertions(+) > > > > >=20 > > > > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/p= assthrough_ll.c > > > > > index 91d3120033..bed2270141 100644 > > > > > --- a/tools/virtiofsd/passthrough_ll.c > > > > > +++ b/tools/virtiofsd/passthrough_ll.c > > > > > @@ -1083,7 +1083,17 @@ static void lo_rename(fuse_req_t req, fuse= _ino_t parent, const char *name, > > > > > } > > > > > =20 > > > > > if (flags) { > > > > > +#ifndef SYS_renameat2 > > > > > fuse_reply_err(req, EINVAL); > > > > > +#else > > > > > + res =3D syscall(SYS_renameat2, lo_fd(req, parent), name, > > > > > + lo_fd(req, newparent), newname, flags); > > > > > + if (res =3D=3D -1 && errno =3D=3D ENOSYS) { > > > > > + fuse_reply_err(req, EINVAL); > > > > > + } else { > > > > > + fuse_reply_err(req, res =3D=3D -1 ? errno : 0); > > > > > + } > > > > > +#endif > > > >=20 > > > > We should use the formal API if available as first choice > > >=20 > > > OK, done - I've kept the 'ifndef SYS_renameat2' that drops back to an > > > error for truly ancient cases; although I doubt everything else will > > > build on something that old. > >=20 > > Hmm, and this breaks on middle age distros; older distros don't have i= t > > at all, new ones have both the syscall and the wrapper; but for the > > middle age ones they have the syscall but not the wrapper. > > > > Dan: What's your preference here; should I add a config fragment to > > detect the wrapper - it seems overkill rather than just reverting it > > until it becomes common. >=20 > What specific middle age distro in particular is affected ? My general > thought would be to /not/ support such distros. Focus on modern distros > since this is a brand new feature in QEMU, where we should try to > minimize support for legacy stuff at the start. But depending on the > distro impacted, the might be a reason to stay with SYS_.. The report came from Ubuntu 18.04 (which Intel uses on CI); that's not that old, so I think it sohuld be supported. I don't really see the justification for insisting on using the wrapper. Dave > Regards, > Daniel > --=20 > |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| > |: https://libvirt.org -o- https://fstop138.berrange.c= om :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK