From nobody Thu Nov 13 13:37:44 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1580421106724322.7291972274394; Thu, 30 Jan 2020 13:51:46 -0800 (PST) Received: from localhost ([::1]:39782 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixHiz-0005uQ-Jd for importer@patchew.org; Thu, 30 Jan 2020 16:51:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33019) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixHcB-0004JM-V0 for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:44:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ixHcA-00033i-Qp for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:44:43 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:52591 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ixHcA-00031a-Lk for qemu-devel@nongnu.org; Thu, 30 Jan 2020 16:44:42 -0500 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-249-0HVGktWTNBGa229sX_CK6g-1; Thu, 30 Jan 2020 16:44:37 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 39E348C3D06; Thu, 30 Jan 2020 21:44:36 +0000 (UTC) Received: from localhost (ovpn-204-145.brq.redhat.com [10.40.204.145]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9D2AE77939; Thu, 30 Jan 2020 21:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580420682; 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=TM4jM9Mqmd/WmtrFPjy3wXLYjWdFXzeHdwDDTFWk8Uk=; b=LzDN0i8d9PZ+F5JgBy3lqWi+ylAHGPAZ58pD2qA+hi1DBcEt392t7j0tyG+kek8G58cCA2 UGFslc+rqvTCKiinb36DKlYijYosm6/y7y0QGFUqtkVu+F8IobN8OLE/U++l+9umdbWcEN 7fVtFH+Lg9DxzLRdKr2JYpbVNUhONjA= From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v3 01/21] blockdev: Allow external snapshots everywhere Date: Thu, 30 Jan 2020 22:44:11 +0100 Message-Id: <20200130214431.333510-2-mreitz@redhat.com> In-Reply-To: <20200130214431.333510-1-mreitz@redhat.com> References: <20200130214431.333510-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: 0HVGktWTNBGa229sX_CK6g-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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: 207.211.31.81 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" 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 --- blockdev.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/blockdev.c b/blockdev.c index 4cd9a58d36..d47ed8e569 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1596,11 +1596,6 @@ 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 2.24.1