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=-6.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 3A319C433E5 for ; Mon, 27 Jul 2020 22:05:39 +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 079392072E for ; Mon, 27 Jul 2020 22:05:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EBD4hYL8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 079392072E 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]:40048 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k0BFa-0005um-68 for qemu-devel@archiver.kernel.org; Mon, 27 Jul 2020 18:05:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48428) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0BC7-0002Qy-Rj for qemu-devel@nongnu.org; Mon, 27 Jul 2020 18:02:03 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:41576 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k0BC1-0004sk-AI for qemu-devel@nongnu.org; Mon, 27 Jul 2020 18:02:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595887315; 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=nb1kFPazJv+IWfagIPDZL6tVyCO7pbbpzAUfvLlaI/c=; b=EBD4hYL8ABgr/I7Z7dEBck1HaVppzTTYPQcW0a4SubgW7QEiF/dqr6P2jAxSQIb2kKMHee 6q5z0a6ketZPkqxSJwYm1rPRTFG+TBppngA5mJmCC33tSQJpUrmiGf+6KGWN5BpA5ZI81n uJeFH4HIULjfq0NMRuE7tDXZmu3U9jE= 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-239-5hbpZKezPdyouisREZ7EcQ-1; Mon, 27 Jul 2020 18:01:51 -0400 X-MC-Unique: 5hbpZKezPdyouisREZ7EcQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 461BF100CC89; Mon, 27 Jul 2020 22:01:50 +0000 (UTC) Received: from [10.10.118.248] (ovpn-118-248.rdu2.redhat.com [10.10.118.248]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4B0F610013C4; Mon, 27 Jul 2020 22:01:49 +0000 (UTC) Subject: Re: [PATCH v2 for-5.1? 0/5] Fix nbd reconnect dead-locks To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20200727184751.15704-1-vsementsov@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Mon, 27 Jul 2020 17:01:48 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200727184751.15704-1-vsementsov@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/27 03:37:14 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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, den@openvz.org, berrange@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/27/20 1:47 PM, Vladimir Sementsov-Ogievskiy wrote: > Hi all! > > v2: it's a bit updated "[PATCH for-5.1? 0/3] Fix nbd reconnect dead-locks" > plus completely rewritten "[PATCH for-5.1? 0/4] non-blocking connect" > (which is now the only one patch 05) > > 01: new > 02: rebased on 01, fix (add outer "if") > 03-04: add Eric's r-b: > 05: new > > If 05 is too big for 5.1, it's OK to take only 01-04 or less, as well as > postponing everything to 5.2, as it's all not a degradation of 5.1 > (it's a degradation of 4.2, together with the whole reconnect feature). I think I like where 5/5 is headed, but am not sure yet whether all paths are thread-safe or if there is anything we can reuse to make its implementation smaller. You are right that it's probably best to defer that to 5.2. In the meantime, I'll queue 1-4 for my NBD pull request for -rc2. > > Vladimir Sementsov-Ogievskiy (5): > block/nbd: split nbd_establish_connection out of nbd_client_connect > block/nbd: allow drain during reconnect attempt > block/nbd: on shutdown terminate connection attempt > block/nbd: nbd_co_reconnect_loop(): don't sleep if drained > block/nbd: use non-blocking connect: fix vm hang on connect() > > block/nbd.c | 360 +++++++++++++++++++++++++++++++++++++++++---- > block/trace-events | 4 +- > 2 files changed, 331 insertions(+), 33 deletions(-) > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org