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 lists1p.gnu.org (lists1p.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 F17AAC624D0 for ; Wed, 2 Sep 2026 11:55:21 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x1jYI-0007Zy-Hw; Wed, 02 Sep 2026 07:54:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x1jYG-0007ZX-5w for qemu-devel@nongnu.org; Wed, 02 Sep 2026 07:54:48 -0400 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 1x1jYE-0004IB-QF for qemu-devel@nongnu.org; Wed, 02 Sep 2026 07:54:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1788350085; 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=ezt/sWGKwqisBAhESV1cl2GOKLFayu3inKaqXGM19Ys=; b=H3gM5sM0rMTvqKx7emr7vCWri00PbG+7OiMCgM51H/C3u3Du1PNa04P3U2W5fiKASEuF1R bztdCDZWZDzbZXFwgzH9D7B3UkOW2qcUjhJ+o+IicagZ7ABO18gpMJmdm6untzoQVI69Km bljxG7yu05fEzW7xUy49St7fVumy38w= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-460-IxenXDlmMmmNNHjbcZciPQ-1; Wed, 02 Sept 2026 07:54:42 -0400 X-MC-Unique: IxenXDlmMmmNNHjbcZciPQ-1 X-Mimecast-MFC-AGG-ID: IxenXDlmMmmNNHjbcZciPQ_1788350081 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3B736180884B; Wed, 2 Sep 2026 11:54:41 +0000 (UTC) Received: from localhost (unknown [10.2.16.27]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 692E11955F09; Wed, 2 Sep 2026 11:54:40 +0000 (UTC) Date: Wed, 2 Sep 2026 07:54:39 -0400 From: Stefan Hajnoczi To: Huiba Li Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Kevin Wolf , Hanna Reitz Subject: Re: [RFC] block: add an overlaybd image format driver Message-ID: <20260902115439.GA754231@fedora> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="V4Lv86iJw8wRF0DQ" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-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: qemu development 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 --V4Lv86iJw8wRF0DQ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Huiba, One thing I noticed is that the append-only format used for the upper write layer is not documented. I guess it's different from the read-only LSTM format since the index won't be kept in sorted order when appending. Do you want to document the append-only format? Stefan --V4Lv86iJw8wRF0DQ Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmqYDn8ACgkQnKSrs4Gr c8hOpQf+IEAN6rk9XOtCajGExOLv7QvTFhpsy1hWZR7m2PrQZM6c9zSdr2y6fXfT Zkkw7rGIjS06Y9LzepHh3xAVLm0g6/vDqOF6yfZn/Gdmq5XU3UogBqFtSiRxrTi5 37bJPTvj63ZyCpOtHJFwX+EYgNozZR0UXAXxEGqcHAt5SnolxPAECEZDFcCHRaEP arADqrtYMSNXE6YzCLuGGXbIlDraTRYlYsPrPND9UsVPnHrpKdbfVMxVwhR9bJBc e8zIZ4Ku6uusV56W6FfGj3Cpj1rc5k2wyGi87GLvb6XBoIQcQic+cgttwUvht3Ra c2pv7J8JED34EKReqm2pwTMYTwLwvQ== =LD76 -----END PGP SIGNATURE----- --V4Lv86iJw8wRF0DQ--