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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47024 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9Pvk-0002kh-Vq for qemu-devel@archiver.kernel.org; Tue, 09 Feb 2021 05:07:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51312) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9Pu2-0001dX-Qf for qemu-devel@nongnu.org; Tue, 09 Feb 2021 05:05:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55968) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9Pty-0001fA-RZ for qemu-devel@nongnu.org; Tue, 09 Feb 2021 05:05:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612865145; h=from:from:reply-to: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=m1ATGORjSYoa5Irk7cab3sknr+41uFATDT/NQg6BQ5A=; b=ZmhzfDrVxEj5FpK1n3hWqeKVJFv4J+OTvu81jQMVEjabiHDuMjJDotDKKH8A7pYZRqWnlM 7eVKYKVzj4yfvY5l5NFixD8ohLG+tNn3nNLY05F+DuwPv1vxMeBMkQVNkLaJePOW55Os0Z QtCiJXR3sVCfq+S7NbbH3e6uh0Ws9O8= 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-445-gGjDTrAEMeCvqEgM2Fx1kQ-1; Tue, 09 Feb 2021 05:05:42 -0500 X-MC-Unique: gGjDTrAEMeCvqEgM2Fx1kQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A364284E244; Tue, 9 Feb 2021 10:05:40 +0000 (UTC) Received: from redhat.com (ovpn-115-66.ams2.redhat.com [10.36.115.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 568E061461; Tue, 9 Feb 2021 10:05:38 +0000 (UTC) Date: Tue, 9 Feb 2021 10:05:35 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Hao Wang Subject: Re: [PATCH] migration/tls: add error handling in multifd_tls_handshake_thread Message-ID: <20210209100535.GD1166421@redhat.com> References: <20210209075251.1428743-1-wanghao232@huawei.com> MIME-Version: 1.0 In-Reply-To: <20210209075251.1428743-1-wanghao232@huawei.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: yubihong@huawei.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, dgilbert@redhat.com, xiexiangyou@huawei.com, qemu-devel@nongnu.org, alex.chen@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Feb 09, 2021 at 03:52:51PM +0800, Hao Wang wrote: > If any error happens during multifd send thread creating (e.g. channel broke > because new domain is destroyed by the dst), multifd_tls_handshake_thread > may exit silently, leaving main migration thread hanging (ram_save_setup -> > multifd_send_sync_main -> qemu_sem_wait(&p->sem_sync)). > Fix that by adding error handling in multifd_tls_handshake_thread. > > Signed-off-by: Hao Wang > --- > migration/multifd.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/migration/multifd.c b/migration/multifd.c > index 45c690aa11..df29cdd26a 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -736,7 +736,16 @@ static void multifd_tls_outgoing_handshake(QIOTask *task, > } else { > trace_multifd_tls_outgoing_handshake_complete(ioc); > } > - multifd_channel_connect(p, ioc, err); > + > + if (multifd_channel_connect(p, ioc, err)) { Urgh, this method is rather confusing usng "true" to indicate failure. In include/qapi/error.h we document • bool-valued functions return true on success / false on failure, Admittedly this problem is pre-existing before this patch, but I would none the less like to see a patch that fixes thse inverted semantics first, and then this as a subsequent patch on top. > + /* > + * Error happen, mark multifd_send_thread status as 'quit' although it > + * is not created, and then tell who pay attention to me. > + */ > + p->quit = true; > + qemu_sem_post(&multifd_send_state->channels_ready); > + qemu_sem_post(&p->sem_sync); > + } > } > > static void *multifd_tls_handshake_thread(void *opaque) Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|