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 5A7C9C3601E for ; Mon, 14 Apr 2025 05:07:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u4C2H-0006qv-TH; Mon, 14 Apr 2025 01:07:09 -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 1u4C2F-0006qT-SR for qemu-devel@nongnu.org; Mon, 14 Apr 2025 01:07:07 -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 1u4C2D-0004HG-H4 for qemu-devel@nongnu.org; Mon, 14 Apr 2025 01:07:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744607221; 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=Ll6IniNpU4hfdSdOBDEEkawbwEous11xak5FPHlaBaQ=; b=PWyjzSMpwYJfr9qztnCJjyXZK2mR1opS31RSI5SvjAqCseHBUljc+5dS5aDRcHC0ril93b HX2K7K8LLrUFG3cyS0t3SdYh/RtMTRU8xJoSgXcjd0whpahJtYb6npd/MBqgtt6ZUtmylN kd35GZ0MKeXbbQ/oqLQ/NPH+oYWAFNA= 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-625-yF8-s-smOwGRMPXKFxj3Hw-1; Mon, 14 Apr 2025 01:06:59 -0400 X-MC-Unique: yF8-s-smOwGRMPXKFxj3Hw-1 X-Mimecast-MFC-AGG-ID: yF8-s-smOwGRMPXKFxj3Hw_1744607218 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 CA37A1956089; Mon, 14 Apr 2025 05:06:56 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.3]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8692619560AD; Mon, 14 Apr 2025 05:06:55 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id D8EEA21E66C2; Mon, 14 Apr 2025 07:06:52 +0200 (CEST) From: Markus Armbruster To: Raman Dzehtsiar Cc: qemu-devel@nongnu.org, Wen Congyang , Hanna Reitz , Kevin Wolf , Vladimir Sementsov-Ogievskiy , John Snow , Xie Changlong , Eric Blake , qemu-block@nongnu.org Subject: Re: [PATCH v3] blockdev-backup: Add error handling option for copy-before-write jobs In-Reply-To: <20250414011817.671328-1-Raman.Dzehtsiar@gmail.com> (Raman Dzehtsiar's message of "Mon, 14 Apr 2025 03:18:17 +0200") References: <20250414011817.671328-1-Raman.Dzehtsiar@gmail.com> Date: Mon, 14 Apr 2025 07:06:52 +0200 Message-ID: <87r01v1gcz.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 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_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 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 Raman Dzehtsiar writes: > This patch extends the blockdev-backup QMP command to allow users to spec= ify > how to behave when IO errors occur during copy-before-write operations. > Previously, the behavior was fixed and could not be controlled by the use= r. > > The new 'on-cbw-error' option can be set to one of two values: > - 'break-guest-write': Forwards the IO error to the guest and triggers > the on-source-error policy. This preserves snapshot integrity at the > expense of guest IO operations. > - 'break-snapshot': Allows the guest OS to continue running normally, > but invalidates the snapshot and aborts related jobs. This prioritizes > guest operation over backup consistency. > > This enhancement provides more flexibility for backup operations in diffe= rent > environments where requirements for guest availability versus backup > consistency may vary. > > The default behavior remains unchanged to maintain backward compatibility. > > Signed-off-by: Raman Dzehtsiar [...] > diff --git a/qapi/block-core.json b/qapi/block-core.json > index b1937780e1..d35326167d 100644 > --- a/qapi/block-core.json > +++ b/qapi/block-core.json > @@ -1622,6 +1622,9 @@ > # @discard-source: Discard blocks on source which have already been > # copied to the target. (Since 9.1) > # > +# @on-cbw-error: optional policy defining behavior on I/O errors in > +# copy-before-write jobs; defaults to break-guest-write. (Since 10.= 0) > +# This will come out like =E2=80=A2 on-cbw-error (OnCbwError, optional) =E2=80=93 optional policy= defining behavior on I/O errors in copy-before-write jobs; defaults to break-guest-write. (Since 10.0) Scratch "optional", please. Also, make it 10.1, and keep the member documentation ordered like ... > # @x-perf: Performance options. (Since 6.0) > # > # Features: > @@ -1641,6 +1644,7 @@ > '*compress': 'bool', > '*on-source-error': 'BlockdevOnError', > '*on-target-error': 'BlockdevOnError', > + '*on-cbw-error': 'OnCbwError', > '*auto-finalize': 'bool', '*auto-dismiss': 'bool', > '*filter-node-name': 'str', > '*discard-source': 'bool', ... the actual members. [...]