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=-2.3 required=3.0 tests=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 411C5C3A59B for ; Fri, 30 Aug 2019 23:12:53 +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 0B24623431 for ; Fri, 30 Aug 2019 23:12:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B24623431 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]:41588 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i3q4a-0007SN-9l for qemu-devel@archiver.kernel.org; Fri, 30 Aug 2019 19:12:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47194) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i3q2Q-0006uh-Sq for qemu-devel@nongnu.org; Fri, 30 Aug 2019 19:10:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i3q2O-0003ZW-LH for qemu-devel@nongnu.org; Fri, 30 Aug 2019 19:10:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33508) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i3q2I-0003Do-6Y; Fri, 30 Aug 2019 19:10:30 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id CB7F9308AA11; Fri, 30 Aug 2019 23:10:28 +0000 (UTC) Received: from [10.3.116.234] (ovpn-116-234.phx2.redhat.com [10.3.116.234]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AAAD060BF7; Fri, 30 Aug 2019 23:10:25 +0000 (UTC) To: Vladimir Sementsov-Ogievskiy , "qemu-devel@nongnu.org" References: <25ead363-4f37-5450-b985-1876374e314d@redhat.com> <20190823143726.27062-1-eblake@redhat.com> <20190823143726.27062-2-eblake@redhat.com> <92e9cfa2-fbaa-259d-7a04-91187cc809b6@virtuozzo.com> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: Date: Fri, 30 Aug 2019 18:10:24 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <92e9cfa2-fbaa-259d-7a04-91187cc809b6@virtuozzo.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PKFuRuvEDFdr4TIQr3NNeLmXHwWZulpQm" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Fri, 30 Aug 2019 23:10:28 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 1/5] nbd: Improve per-export flag handling in server 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: Kevin Wolf , "nbd@other.debian.org" , "libguestfs@redhat.com" , "open list:Network Block Dev..." , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --PKFuRuvEDFdr4TIQr3NNeLmXHwWZulpQm Content-Type: multipart/mixed; boundary="nkhkj5r1Hn4OmFY326cRQ1UABuL2Wam5l"; protected-headers="v1" From: Eric Blake To: Vladimir Sementsov-Ogievskiy , "qemu-devel@nongnu.org" Cc: Kevin Wolf , Max Reitz , "open list:Network Block Dev..." , "libguestfs@redhat.com" , "nbd@other.debian.org" Message-ID: Subject: Re: [Qemu-devel] [PATCH 1/5] nbd: Improve per-export flag handling in server References: <25ead363-4f37-5450-b985-1876374e314d@redhat.com> <20190823143726.27062-1-eblake@redhat.com> <20190823143726.27062-2-eblake@redhat.com> <92e9cfa2-fbaa-259d-7a04-91187cc809b6@virtuozzo.com> In-Reply-To: <92e9cfa2-fbaa-259d-7a04-91187cc809b6@virtuozzo.com> --nkhkj5r1Hn4OmFY326cRQ1UABuL2Wam5l Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 8/30/19 1:00 PM, Vladimir Sementsov-Ogievskiy wrote: > 23.08.2019 17:37, Eric Blake wrote: >> When creating a read-only image, we are still advertising support for >> TRIM and WRITE_ZEROES to the client, even though the client should not= >> be issuing those commands. But seeing this requires looking across >> multiple functions: >> >> @@ -458,10 +458,13 @@ static int nbd_negotiate_handle_export_name(NBDC= lient *client, >> return -EINVAL; >> } >> >> - trace_nbd_negotiate_new_style_size_flags(client->exp->size, >> - client->exp->nbdflags | = myflags); >> + myflags =3D client->exp->nbdflags; >> + if (client->structured_reply) { >> + myflags |=3D NBD_FLAG_SEND_DF; >> + } >=20 >=20 > why we cant do just > client->exp->nbdflags |=3D NBD_FLAG_SEND_DF ? Because myflags is the runtime flags for _this_ client, while client->exp->nbdflags are the base flags shared by _all_ clients. If client A requests structured reply, but client B does not, then we don't want to advertise DF to client B; but amending client->exp->nbdflags would have that effect. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --nkhkj5r1Hn4OmFY326cRQ1UABuL2Wam5l-- --PKFuRuvEDFdr4TIQr3NNeLmXHwWZulpQm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAl1prOAACgkQp6FrSiUn Q2pk2QgAri0azyBI4Bnz14RyFT+1/1LofTul86EY4+9yV3LgHamcDr/bq8hVV3t0 m7yaonFy9BqN14vRk8HW4xcNCi2dw6SRS4hkLxLzFs42nHnGspumIAjseqerAyPN q3WHQh9soKmpYCd63rcwOy9hM30/D72Ja2Yd9ahc3/EUEfeErTraYhM7Z+S1vSUH XYQGs27rFIb4Xg7Eog8NODucnbDDiMJOG0l04VwzqygCuaJ9cWeUMG/OrzHcplLM Jq5Rr9RQWLauU9RaqzyO92fArk45K9S1wApji5B52TgGghkvDdtYEvHlI+OHNbse /47ycql4cvVCXQ2coAgKcyadeKgHcQ== =bKIZ -----END PGP SIGNATURE----- --PKFuRuvEDFdr4TIQr3NNeLmXHwWZulpQm--