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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C9B0C34026 for ; Tue, 18 Feb 2020 14:14:31 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 28EE421D56 for ; Tue, 18 Feb 2020 14:14:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hRHq9VU9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28EE421D56 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35852 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j43du-0004Z9-A7 for qemu-devel@archiver.kernel.org; Tue, 18 Feb 2020 09:14:30 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53066) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j43Xx-0007Um-BI for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j43Xw-0001Yz-7D for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:21 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:46010 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j43Xw-0001Yj-2d for qemu-devel@nongnu.org; Tue, 18 Feb 2020 09:08:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582034899; 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=h8Md0x14UjaweuuaHfsB7Kl/vSv+NPI3OnXqts0iVnA=; b=hRHq9VU99xewey8qFGKCKGwLCGA3rfK4vDhqODazpzBRWnwgD7EnREAQVuIxgmlcwlhGAB nrERB6/C8pUPpud+eGMkuC200og5xkNiRcNAuBvFkGhfMIK1wxBPwteRJO6dvVn6ZQDqy5 6ZdFN3tyjreDIrNKR+sP7RP4DJnAY2c= 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-387-QjLdp11tO5qvb7f3zs2v0A-1; Tue, 18 Feb 2020 09:08:17 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D9F811005516; Tue, 18 Feb 2020 14:08:15 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-181.ams2.redhat.com [10.36.117.181]) by smtp.corp.redhat.com (Postfix) with ESMTP id D703019E9C; Tue, 18 Feb 2020 14:08:14 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 18/36] blockdev: Allow external snapshots everywhere Date: Tue, 18 Feb 2020 15:07:04 +0100 Message-Id: <20200218140722.23876-19-kwolf@redhat.com> In-Reply-To: <20200218140722.23876-1-kwolf@redhat.com> References: <20200218140722.23876-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: QjLdp11tO5qvb7f3zs2v0A-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Max Reitz There is no good reason why we would allow external snapshots only on the first non-filter node in a chain. Parent BDSs should not care whether their child is replaced by a snapshot. (If they do care, they should announce that via freezing the chain, which is checked in bdrv_append() through bdrv_set_backing_hd().) Before we had bdrv_is_first_non_filter() here (since 212a5a8f095), there was a special function bdrv_check_ext_snapshot() that allowed snapshots by default, but block drivers could override this. Only blkverify did so, however. It is not clear to me why blkverify would do so; maybe just so that the testee block driver would not be replaced. The introducing commit f6186f49e2c does not explain why. Maybe because 08b24cfe376 would have been the correct solution? (Which adds a .supports_backing check.) Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20200218103454.296704-2-mreitz@redhat.com> Signed-off-by: Kevin Wolf --- blockdev.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/blockdev.c b/blockdev.c index 374189a426..d83bb2beda 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1592,11 +1592,6 @@ static void external_snapshot_prepare(BlkActionState= *common, } } =20 - if (!bdrv_is_first_non_filter(state->old_bs)) { - error_setg(errp, QERR_FEATURE_DISABLED, "snapshot"); - goto out; - } - if (action->type =3D=3D TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC= ) { BlockdevSnapshotSync *s =3D action->u.blockdev_snapshot_sync.data; const char *format =3D s->has_format ? s->format : "qcow2"; --=20 2.20.1