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 53D7FEFD237 for ; Wed, 25 Feb 2026 09:41:58 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vvBOW-0004uo-C7; Wed, 25 Feb 2026 04:41:24 -0500 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 1vvBOR-0004tk-4X for qemu-devel@nongnu.org; Wed, 25 Feb 2026 04:41:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vvBOO-0006Tf-CY for qemu-devel@nongnu.org; Wed, 25 Feb 2026 04:41:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772012474; 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=plVcXgmt44sllGFrE/IxZWE0NQ2BJUf3agMtN5GfDLg=; b=RgEXp/uunR04Zsy0zyaVnSKUhY6o+nHKtePdsEIkjUFF5S1QzjTU+hEhq+qtgoutDatqK+ RdexsK8ZP1XoJFASuMBKy507cALKe392WfRx7oVg8ZCn1EFSZJ2Jt0s8GXbY8Gnfd0s0Gg Y9+TZHnQQqwvyojykrvnDGGcNOfRXiE= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-284-m44EK2fyNj6Wr3tT5KfQlA-1; Wed, 25 Feb 2026 04:41:12 -0500 X-MC-Unique: m44EK2fyNj6Wr3tT5KfQlA-1 X-Mimecast-MFC-AGG-ID: m44EK2fyNj6Wr3tT5KfQlA_1772012471 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1C6D61956089; Wed, 25 Feb 2026 09:41:11 +0000 (UTC) Received: from redhat.com (unknown [10.45.225.165]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0DC391800352; Wed, 25 Feb 2026 09:41:07 +0000 (UTC) Date: Wed, 25 Feb 2026 09:41:04 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Ani Sinha Cc: Prasad Pandit , Peter Xu , Fabiano Rosas , Gerd Hoffmann , Paolo Bonzini , Ani Sinha , Prasad Pandit , qemu-devel Subject: Re: [PATCH v6 35/35] migration: return EEXIST when trying to add the same migration blocker Message-ID: References: <20260225035000.385950-1-anisinha@redhat.com> <20260225035000.385950-36-anisinha@redhat.com> <0F4C962C-7068-4F78-BC70-07F0731B1FEB@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0F4C962C-7068-4F78-BC70-07F0731B1FEB@redhat.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.358, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.659, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Feb 25, 2026 at 03:04:27PM +0530, Ani Sinha wrote: > > > > On 25 Feb 2026, at 2:37 PM, Daniel P. Berrangé wrote: > > > > On Wed, Feb 25, 2026 at 11:35:15AM +0530, Prasad Pandit wrote: > >> On Wed, 25 Feb 2026 at 09:23, Ani Sinha wrote: > >>> Currently the code that adds a migration blocker does not check if the same > >>> blocker already exists. Return an EEXIST error code if there is an attempt to > >>> add the same migration blocker again. This way the same migration blocker will > >>> not get added twice. > >>> > >>> Suggested-by: Prasad Pandit > >>> Signed-off-by: Ani Sinha > >>> --- > >>> migration/migration.c | 4 ++++ > >>> 1 file changed, 4 insertions(+) > >>> > >>> diff --git a/migration/migration.c b/migration/migration.c > >>> index a5b0465ed3..1eb75fb7fb 100644 > >>> --- a/migration/migration.c > >>> +++ b/migration/migration.c > >>> @@ -1702,6 +1702,10 @@ static int add_blockers(Error **reasonp, unsigned modes, Error **errp) > > > > This method has an '**errp' parameter..... > > > >>> { > >>> for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) { > >>> if (modes & BIT(mode)) { > >>> + if (g_slist_index(migration_blockers[mode], > >>> + *reasonp) >= 0) { > >>> + return -EEXIST; > > > > .... so using -errno for return values is not appropriate - it must > > set 'errp' and return -1. > > I see functions migrate_add_blocker_modes() or migrate_add_blocker_internal() > that do not do this. This is why I thought it was ok to just return -errno here. Yes they all set 'errp', but indirectly: if (is_only_migratable(reasonp, modes, errp)) { return -EACCES; } else if (is_busy(reasonp, errp)) { return -EBUSY; } In this case 'is_busy' and 'is_only_migratable' will be setting 'errp'. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|