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 D8A52C33CB1 for ; Tue, 14 Jan 2020 08:30:49 +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 A708B207FD for ; Tue, 14 Jan 2020 08:30:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="X+4fBSRL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A708B207FD 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]:34454 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irHb6-0000Os-R2 for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 03:30:48 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:49343) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irHaP-0008LQ-0c for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:30:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irHaL-0000XX-6Q for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:30:03 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:37045 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irHaJ-0000X0-Gw for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:30:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578990598; h=from:from:reply-to: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=4BNggyF8hWS8lOjf9K2N79gC4qZrBpdt4d4H03Wh3Dc=; b=X+4fBSRLcJrXN3riaNe0gsYXJFninDm0Ni+uHyEr+89beA8+HU95HIlFzCvxVVU3VPlJzL G1pcNknNAJCSmi3Dt+5Arphl7l4rXaYTcdZlEhaiBA4PwDLtAFBqwW10vn2hkWXHoVTQKP 0O1Bv7Yih1r6ZHZT0kqTS79ovL55xOw= 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-404-zohDXdFMMAmm3eVUSwJyCg-1; Tue, 14 Jan 2020 03:29:56 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0738D8024DC for ; Tue, 14 Jan 2020 08:29:56 +0000 (UTC) Received: from redhat.com (ovpn-112-42.ams2.redhat.com [10.36.112.42]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 30C4560BE2; Tue, 14 Jan 2020 08:29:51 +0000 (UTC) Date: Tue, 14 Jan 2020 08:29:49 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Dr. David Alan Gilbert" Subject: Re: [PATCH 066/104] virtiofsd: passthrough_ll: add renameat2 support Message-ID: <20200114082949.GB4071034@redhat.com> 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> MIME-Version: 1.0 In-Reply-To: <20200113200624.GB87499@work-vm> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: zohDXdFMMAmm3eVUSwJyCg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 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: 205.139.110.120 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= 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" 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=C3=A9 (berrange@redhat.com) wrote: > > > On Thu, Dec 12, 2019 at 04:38:26PM +0000, Dr. David Alan Gilbert (git= ) 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/pas= sthrough_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_i= no_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 it > 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. 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_.. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberrange= :| |: https://libvirt.org -o- https://fstop138.berrange.com= :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange= :|