From nobody Mon Feb 9 12:09:57 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.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 (zoho.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 ARC-Seal: i=1; a=rsa-sha256; t=1573488339; cv=none; d=zoho.com; s=zohoarc; b=fhygbekNLqdLksTvnHBiNlsYI0a+oLru2D2F5LCxk2uGhSWog4sQH4q1NspZNXKgXYcR06SBFLKeurzxSW7vL12rTADupD+qwsZOv0k3WAVcAAQ/gsSAN0APU5Xp9H8QlC8j5Huneiwkk+wj3oyfaj5jrvnsf8yH32bnnNwYSCc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1573488339; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=JhPkULzpAKB6qvX8JHd2YYQL6Gxr+IDduoxSVeSIPns=; b=XOsUw6O4iA+T8d/dZAr6LNEZyXy3AaLa/bZ0NiyprG6u/VdD6tBaQi/VlD7J9zuq+9hTNGqOqsvM/+C1FyuQAelif2zmtb/ZRflfDDR6QMH7kr65mKaoPKLrwx5ejtlon8Cfq6gDMCVO4A43+01SAi2R9w4/AaCumFPb4S0UwDo= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=fail; spf=pass (zoho.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 header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1573488339018748.630558190926; Mon, 11 Nov 2019 08:05:39 -0800 (PST) Received: from localhost ([::1]:54514 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iUCC0-0001dK-Vk for importer@patchew.org; Mon, 11 Nov 2019 11:05:29 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38865) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iUC95-0007Wx-MI for qemu-devel@nongnu.org; Mon, 11 Nov 2019 11:02:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iUC94-0002bv-Ad for qemu-devel@nongnu.org; Mon, 11 Nov 2019 11:02:27 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:53346 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 1iUC94-0002bn-6V for qemu-devel@nongnu.org; Mon, 11 Nov 2019 11:02:26 -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-257-88TrCnz0N0G_8jV1Bn_KMg-1; Mon, 11 Nov 2019 11:02:23 -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 D21E5805D81; Mon, 11 Nov 2019 16:02:22 +0000 (UTC) Received: from localhost (ovpn-117-116.ams2.redhat.com [10.36.117.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 532FF600CC; Mon, 11 Nov 2019 16:02:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573488145; 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=JhPkULzpAKB6qvX8JHd2YYQL6Gxr+IDduoxSVeSIPns=; b=XDBjLTStd4oLn29iLQawYhFfHSff1m/tfIVAcLNdCu1TlNV+derus7qHv3Nzx8uKq78e/6 imj1mSWukEsWQmKQIxUVGvL8ZOWEo4csJfZdbrfG7aUyVjw0nnHrO9qybejsc5m4pp66QJ GJHRGQUWu2U6PHkSNFqUWSegNpqDpsM= From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH for-5.0 v2 01/23] blockdev: Allow external snapshots everywhere Date: Mon, 11 Nov 2019 17:01:54 +0100 Message-Id: <20191111160216.197086-2-mreitz@redhat.com> In-Reply-To: <20191111160216.197086-1-mreitz@redhat.com> References: <20191111160216.197086-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: 88TrCnz0N0G_8jV1Bn_KMg-1 X-Mimecast-Spam-Score: 0 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 , Alberto Garcia , 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 8e029e9c01..ab78230d23 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1595,11 +1595,6 @@ 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 2.23.0