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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AC2FBC3A5A2 for ; Fri, 23 Aug 2019 14:49:45 +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 82CBC2166E for ; Fri, 23 Aug 2019 14:49:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82CBC2166E 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]:57278 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i1Asp-00088F-Gi for qemu-devel@archiver.kernel.org; Fri, 23 Aug 2019 10:49:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51386) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i1AhD-00043I-0T for qemu-devel@nongnu.org; Fri, 23 Aug 2019 10:37:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i1AhB-0004gt-Vx for qemu-devel@nongnu.org; Fri, 23 Aug 2019 10:37:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44266) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i1Ah6-0004dc-S6; Fri, 23 Aug 2019 10:37:36 -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 462F989AC9; Fri, 23 Aug 2019 14:37:36 +0000 (UTC) Received: from blue.redhat.com (ovpn-116-234.phx2.redhat.com [10.3.116.234]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC1856CE58; Fri, 23 Aug 2019 14:37:33 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Fri, 23 Aug 2019 09:37:24 -0500 Message-Id: <20190823143726.27062-4-eblake@redhat.com> In-Reply-To: <20190823143726.27062-1-eblake@redhat.com> References: <25ead363-4f37-5450-b985-1876374e314d@redhat.com> <20190823143726.27062-1-eblake@redhat.com> MIME-Version: 1.0 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 [10.5.110.26]); Fri, 23 Aug 2019 14:37:36 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 3/5] nbd: Implement client use of NBD FAST_ZERO 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 , Max Reitz , "open list:Network Block Dev..." , libguestfs@redhat.com, nbd@other.debian.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The client side is fairly straightforward: if the server advertised fast zero support, then we can map that to BDRV_REQ_NO_FALLBACK support. A server that advertises FAST_ZERO but not WRITE_ZEROES is technically broken, but we can ignore that situation as it does not change our behavior. Signed-off-by: Eric Blake --- Perhaps this is worth merging with the previous patch. --- block/nbd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/nbd.c b/block/nbd.c index beed46fb3414..8339d7106366 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -1044,6 +1044,10 @@ static int nbd_client_co_pwrite_zeroes(BlockDriver= State *bs, int64_t offset, if (!(flags & BDRV_REQ_MAY_UNMAP)) { request.flags |=3D NBD_CMD_FLAG_NO_HOLE; } + if (flags & BDRV_REQ_NO_FALLBACK) { + assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); + request.flags |=3D NBD_CMD_FLAG_FAST_ZERO; + } if (!bytes) { return 0; @@ -1239,6 +1243,9 @@ static int nbd_client_connect(BlockDriverState *bs,= Error **errp) } if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { bs->supported_zero_flags |=3D BDRV_REQ_MAY_UNMAP; + if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { + bs->supported_zero_flags |=3D BDRV_REQ_NO_FALLBACK; + } } s->sioc =3D sioc; --=20 2.21.0