From nobody Sun Feb 8 22:18:27 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1486980974649374.0814348731295; Mon, 13 Feb 2017 02:16:14 -0800 (PST) Received: from localhost ([::1]:55539 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdDg5-0005cg-AN for importer@patchew.org; Mon, 13 Feb 2017 05:16:13 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53437) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdDZJ-0007qq-9d for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cdDZH-0007Xn-Pp for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48442) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cdDZH-0007Xc-KP for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:11 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D3991C057FA6 for ; Mon, 13 Feb 2017 10:09:11 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-196.ams2.redhat.com [10.36.117.196]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1DA934e009201; Mon, 13 Feb 2017 05:09:10 -0500 From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 13 Feb 2017 11:08:51 +0100 Message-Id: <20170213100906.23486-4-pbonzini@redhat.com> In-Reply-To: <20170213100906.23486-1-pbonzini@redhat.com> References: <20170213100906.23486-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 13 Feb 2017 10:09:11 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 03/18] block-backend: allow blk_prw from coroutine context X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: famz@redhat.com, stefanha@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" qcow2_create2 calls this. Do not run a nested event loop, as that breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup list of the currently running one. Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini --- block/block-backend.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index efbf398..1177598 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -880,7 +880,6 @@ static int blk_prw(BlockBackend *blk, int64_t offset, u= int8_t *buf, { QEMUIOVector qiov; struct iovec iov; - Coroutine *co; BlkRwCo rwco; =20 iov =3D (struct iovec) { @@ -897,9 +896,14 @@ static int blk_prw(BlockBackend *blk, int64_t offset, = uint8_t *buf, .ret =3D NOT_DONE, }; =20 - co =3D qemu_coroutine_create(co_entry, &rwco); - qemu_coroutine_enter(co); - BDRV_POLL_WHILE(blk_bs(blk), rwco.ret =3D=3D NOT_DONE); + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + co_entry(&rwco); + } else { + Coroutine *co =3D qemu_coroutine_create(co_entry, &rwco); + qemu_coroutine_enter(co); + BDRV_POLL_WHILE(blk_bs(blk), rwco.ret =3D=3D NOT_DONE); + } =20 return rwco.ret; } --=20 2.9.3