From patchwork Wed Jun 9 15:46:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1489960 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=N2+LCiYE; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4G0Wty3Sr8z9sRK for ; Thu, 10 Jun 2021 01:56:42 +1000 (AEST) Received: from localhost ([::1]:42152 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lr0ZM-0002af-Eq for incoming@patchwork.ozlabs.org; Wed, 09 Jun 2021 11:56:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56374) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lr0QW-0007mf-Ex for qemu-devel@nongnu.org; Wed, 09 Jun 2021 11:47:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:20993) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lr0QR-0003b7-Jh for qemu-devel@nongnu.org; Wed, 09 Jun 2021 11:47:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623253647; 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=sorXIMPWrawIKyHExPP4hkOJoQqX3bYITQsH4ecnDV0=; b=N2+LCiYE0f4ulvdQSanm6QrLnDhPy7tGJYr9X9jQz6Kowt6dVQaPpPrENX09pL7dhBDDNI HTJ5KN7f29lNjWZ9CROc1tQf82XwGT+z1rk5RqteDJPV+JpjJ8rrUbSv1Geyistj0XI41+ /iWxTgVdm6V9tJbMuSBZ7GoVXcPUXE8= 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-592-65Us_LKMOSqtqUPFDMy_Uw-1; Wed, 09 Jun 2021 11:47:25 -0400 X-MC-Unique: 65Us_LKMOSqtqUPFDMy_Uw-1 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 C758A100A44B; Wed, 9 Jun 2021 15:47:24 +0000 (UTC) Received: from merkur.fritz.box (ovpn-114-230.ams2.redhat.com [10.36.114.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id AB3F160C04; Wed, 9 Jun 2021 15:47:23 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH 7/7] vhost-user-blk: Implement reconnection during realize Date: Wed, 9 Jun 2021 17:46:58 +0200 Message-Id: <20210609154658.350308-8-kwolf@redhat.com> In-Reply-To: <20210609154658.350308-1-kwolf@redhat.com> References: <20210609154658.350308-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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=-0.199, 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: kwolf@redhat.com, raphael.norwitz@nutanix.com, qemu-devel@nongnu.org, mst@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Commit dabefdd6 removed code that was supposed to try reconnecting during .realize(), but actually just crashed and had several design problems. This adds the feature back without the crash in simple cases while also fixing some design problems: Reconnection is now only tried if there was a problem with the connection and not an error related to the content (which would fail again the same way in the next attempt). Reconnection is limited to three attempts (four with the initial attempt) so that we won't end up in an infinite loop if a problem is permanent. If the backend restarts three times in the very short time window of device initialisation, we have bigger problems and erroring out is the right course of action. In the case that a connection error occurs and we reconnect, the error message is printed using error_report_err(), but otherwise ignored. Signed-off-by: Kevin Wolf Reviewed-by: Raphael Norwitz --- hw/block/vhost-user-blk.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index e49d2e4c83..f75a42bc62 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -455,8 +455,10 @@ static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) { + ERRP_GUARD(); VirtIODevice *vdev = VIRTIO_DEVICE(dev); VHostUserBlk *s = VHOST_USER_BLK(vdev); + int retries; int i, ret; if (!s->chardev.chr) { @@ -498,7 +500,17 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) s->inflight = g_new0(struct vhost_inflight, 1); s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); - ret = vhost_user_blk_realize_connect(s, errp); + retries = 3; + assert(!*errp); + do { + if (*errp) { + error_prepend(errp, "Reconnecting after error: "); + error_report_err(*errp); + *errp = NULL; + } + ret = vhost_user_blk_realize_connect(s, errp); + } while (ret == -EPROTO && retries--); + if (ret < 0) { goto virtio_err; }