From nobody Mon Feb 9 21:12:17 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1623792231747345.1418043274705; Tue, 15 Jun 2021 14:23:51 -0700 (PDT) Received: from localhost ([::1]:46244 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltGXG-0006zZ-Dh for importer@patchew.org; Tue, 15 Jun 2021 17:23:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58656) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltFzN-0003Kc-TG for qemu-devel@nongnu.org; Tue, 15 Jun 2021 16:48:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49890) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltFzB-0001Hd-7d for qemu-devel@nongnu.org; Tue, 15 Jun 2021 16:48:49 -0400 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-234-IectG_BtOEK_QtK7Bw8eRg-1; Tue, 15 Jun 2021 16:48:34 -0400 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 CC8F3FC9E; Tue, 15 Jun 2021 20:48:33 +0000 (UTC) Received: from blue.redhat.com (ovpn-114-191.phx2.redhat.com [10.3.114.191]) by smtp.corp.redhat.com (Postfix) with ESMTP id 616805D9CA; Tue, 15 Jun 2021 20:48:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623790116; 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=U5lplDQFodWakYe4TIKYQfbPLYdG62Lnumqe7JGcOC0=; b=iKkGsoNcX4nhjld2m8H+SbCSrFA1kQR88UtnX65V86IBrt2ArjthW6DAFvP+eW1ULKULFe jmhZh/+lZnOSy58RjFNZhf3KvseJLaS6VFwTKA6xfmM/vzOHln82dLIJytM/cLwL1v5ahd NQV6ThZQ5KXlDx3tsUjZUc6lOaAZMTk= X-MC-Unique: IectG_BtOEK_QtK7Bw8eRg-1 From: Eric Blake To: qemu-devel@nongnu.org Subject: [PULL 34/34] block/nbd: safer transition to receiving request Date: Tue, 15 Jun 2021 15:47:56 -0500 Message-Id: <20210615204756.281505-35-eblake@redhat.com> In-Reply-To: <20210615204756.281505-1-eblake@redhat.com> References: <20210615204756.281505-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.197, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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 , Vladimir Sementsov-Ogievskiy , "open list:Network Block Dev..." , Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" From: Vladimir Sementsov-Ogievskiy req->receiving is a flag of request being in one concrete yield point in nbd_co_do_receive_one_chunk(). Such kind of boolean flag is always better to unset before scheduling the coroutine, to avoid double scheduling. So, let's be more careful. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Message-Id: <20210610100802.5888-33-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake --- block/nbd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/nbd.c b/block/nbd.c index 5cfb749e089d..3cbee762de8d 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -150,6 +150,7 @@ static void nbd_recv_coroutines_wake_all(BDRVNBDState *= s) NBDClientRequest *req =3D &s->requests[i]; if (req->coroutine && req->receiving) { + req->receiving =3D false; aio_co_wake(req->coroutine); } } @@ -548,6 +549,7 @@ static coroutine_fn void nbd_connection_entry(void *opa= que) * connection_co happens through a bottom half, which can only * run after we yield. */ + s->requests[i].receiving =3D false; aio_co_wake(s->requests[i].coroutine); qemu_coroutine_yield(); } @@ -934,7 +936,7 @@ static coroutine_fn int nbd_co_do_receive_one_chunk( /* Wait until we're woken up by nbd_connection_entry. */ s->requests[i].receiving =3D true; qemu_coroutine_yield(); - s->requests[i].receiving =3D false; + assert(!s->requests[i].receiving); if (!nbd_client_connected(s)) { error_setg(errp, "Connection closed"); return -EIO; --=20 2.31.1