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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 92897E7E626 for ; Tue, 26 Sep 2023 11:53:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ql6cW-0002fl-HQ; Tue, 26 Sep 2023 07:52:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ql6cU-0002fO-JK for qemu-devel@nongnu.org; Tue, 26 Sep 2023 07:52:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ql6cS-0003i1-Qt for qemu-devel@nongnu.org; Tue, 26 Sep 2023 07:52:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695729166; 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: in-reply-to:in-reply-to:references:references; bh=UHCrGxetD81Cc8eChcC/bSpplPB9Zt/YuYRBomfNjGA=; b=YaUtd0RMMHfdyFiPRAtC8GXDm1ImV2Z1vV0eDJb74RB7PON8IecKHpVH2YlwFisfOUbjSb BxMkJOnCOSxPVQxUsJqsxEyLysdyxMUHaak5ixAo0J8WbWn4XIqKhE8MOFIf7o7/WnXIJt gl96zljuHVCIWiofn2xcyOzz2Le7W34= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-671-KCOlYtw2NZ6fPTWJRXhoLg-1; Tue, 26 Sep 2023 07:52:43 -0400 X-MC-Unique: KCOlYtw2NZ6fPTWJRXhoLg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 98B6C185A790; Tue, 26 Sep 2023 11:52:42 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.25]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7067C40C6EA8; Tue, 26 Sep 2023 11:52:42 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1053921E6900; Tue, 26 Sep 2023 13:52:41 +0200 (CEST) From: Markus Armbruster To: "Zhijian Li (Fujitsu)" Cc: "qemu-devel@nongnu.org" , "quintela@redhat.com" , "peterx@redhat.com" , "leobras@redhat.com" Subject: Re: [PATCH 50/52] migration/rdma: Silence qemu_rdma_cleanup() References: <20230918144206.560120-1-armbru@redhat.com> <20230918144206.560120-51-armbru@redhat.com> <2f697774-aea3-6f09-e781-cc1634021933@fujitsu.com> Date: Tue, 26 Sep 2023 13:52:41 +0200 In-Reply-To: <2f697774-aea3-6f09-e781-cc1634021933@fujitsu.com> (Zhijian Li's message of "Tue, 26 Sep 2023 10:12:50 +0000") Message-ID: <87y1gt40dy.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org "Zhijian Li (Fujitsu)" writes: > On 18/09/2023 22:42, Markus Armbruster wrote: >> Functions that use an Error **errp parameter to return errors should >> not also report them to the user, because reporting is the caller's >> job. When the caller does, the error is reported twice. When it >> doesn't (because it recovered from the error), there is no error to >> report, i.e. the report is bogus. >> >> qemu_rdma_source_init(), qemu_rdma_connect(), >> rdma_start_incoming_migration(), and rdma_start_outgoing_migration() >> violate this principle: they call error_report() via >> qemu_rdma_cleanup(). >> >> Moreover, qemu_rdma_cleanup() can't fail. It is called on error >> paths, and QIOChannel close and finalization. Are the conditions it >> reports really errors? I doubt it. > > I'm not very sure, it's fine if it's call from the error path. but when > the caller is migration_cancle from HMP/QMP, shall we report something more > though we know QEMU can recover. > > maybe change to warning etc... The part I'm sure about is that reporting an error to the user is wrong when we actually recover from the error. Which qemu_rdma_cleanup() does. I'm not sure whether the (complicated!) condition that triggers qemu_rdma_cleanup()'s ill-advised error report needs to be reported in some other form. The remainder of the function ignores failure... If you think we should to downgrade the error to a warning, and no maintainer disagrees, then I'll downgrade. Do you? >> Clean this up: silence qemu_rdma_cleanup(). I believe that's fine for >> all these callers. If it isn't, we need to convert to Error instead. >> >> Signed-off-by: Markus Armbruster >> --- >> migration/rdma.c | 6 +----- >> 1 file changed, 1 insertion(+), 5 deletions(-) >> >> diff --git a/migration/rdma.c b/migration/rdma.c >> index d9f80ef390..be2db7946d 100644 >> --- a/migration/rdma.c >> +++ b/migration/rdma.c >> @@ -2330,7 +2330,6 @@ static int qemu_rdma_write(QEMUFile *f, RDMAContext *rdma, >> >> static void qemu_rdma_cleanup(RDMAContext *rdma) >> { >> - Error *err = NULL; >> int idx; >> >> if (rdma->cm_id && rdma->connected) { >> @@ -2341,10 +2340,7 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) >> .type = RDMA_CONTROL_ERROR, >> .repeat = 1, >> }; >> - error_report("Early error. Sending error."); >> - if (qemu_rdma_post_send_control(rdma, NULL, &head, &err) < 0) { >> - error_report_err(err); >> - } >> + qemu_rdma_post_send_control(rdma, NULL, &head, NULL); >> } >> >> rdma_disconnect(rdma->cm_id);