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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E9678C04AB1 for ; Thu, 9 May 2019 17:56:49 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C0A3F2085A for ; Thu, 9 May 2019 17:56:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0A3F2085A 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 ([127.0.0.1]:58861 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hOnHk-0006Aw-QZ for qemu-devel@archiver.kernel.org; Thu, 09 May 2019 13:56:48 -0400 Received: from eggs.gnu.org ([209.51.188.92]:34721) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hOnDp-0002jY-Ma for qemu-devel@nongnu.org; Thu, 09 May 2019 13:52:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hOnDo-0006CO-Kv for qemu-devel@nongnu.org; Thu, 09 May 2019 13:52:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39408) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hOnDm-0006Ac-C0; Thu, 09 May 2019 13:52:42 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AFC2B80082; Thu, 9 May 2019 17:52:41 +0000 (UTC) Received: from localhost (ovpn-204-168.brq.redhat.com [10.40.204.168]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 475D160CC0; Thu, 9 May 2019 17:52:41 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Thu, 9 May 2019 19:52:35 +0200 Message-Id: <20190509175237.19363-2-mreitz@redhat.com> In-Reply-To: <20190509175237.19363-1-mreitz@redhat.com> References: <20190509175237.19363-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 09 May 2019 17:52:41 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 1/3] qemu-img: Allow rebase with no input base X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Currently, without -u, you cannot add a backing file to an image when it currently has none: $ qemu-img rebase -b base.qcow2 foo.qcow2 qemu-img: Could not open old backing file '': The 'file' block driver requires a file name It is really simple to allow this, though (effectively by setting old_backing_size to 0), so this patch does just that. Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- qemu-img.c | 61 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 27 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 71c92f142a..cfa44b4153 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3312,26 +3312,30 @@ static int img_rebase(int argc, char **argv) char backing_name[PATH_MAX]; QDict *options =3D NULL; =20 - if (bs->backing_format[0] !=3D '\0') { - options =3D qdict_new(); - qdict_put_str(options, "driver", bs->backing_format); - } - - if (force_share) { - if (!options) { + if (bs->backing) { + if (bs->backing_format[0] !=3D '\0') { options =3D qdict_new(); + qdict_put_str(options, "driver", bs->backing_format); } - qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); - } - bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)= ); - blk_old_backing =3D blk_new_open(backing_name, NULL, - options, src_flags, &local_err); - if (!blk_old_backing) { - error_reportf_err(local_err, - "Could not open old backing file '%s': ", - backing_name); - ret =3D -1; - goto out; + + if (force_share) { + if (!options) { + options =3D qdict_new(); + } + qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); + } + bdrv_get_backing_filename(bs, backing_name, sizeof(backing_n= ame)); + blk_old_backing =3D blk_new_open(backing_name, NULL, + options, src_flags, &local_er= r); + if (!blk_old_backing) { + error_reportf_err(local_err, + "Could not open old backing file '%s':= ", + backing_name); + ret =3D -1; + goto out; + } + } else { + blk_old_backing =3D NULL; } =20 if (out_baseimg[0]) { @@ -3384,7 +3388,7 @@ static int img_rebase(int argc, char **argv) */ if (!unsafe) { int64_t size; - int64_t old_backing_size; + int64_t old_backing_size =3D 0; int64_t new_backing_size =3D 0; uint64_t offset; int64_t n; @@ -3400,15 +3404,18 @@ static int img_rebase(int argc, char **argv) ret =3D -1; goto out; } - old_backing_size =3D blk_getlength(blk_old_backing); - if (old_backing_size < 0) { - char backing_name[PATH_MAX]; + if (blk_old_backing) { + old_backing_size =3D blk_getlength(blk_old_backing); + if (old_backing_size < 0) { + char backing_name[PATH_MAX]; =20 - bdrv_get_backing_filename(bs, backing_name, sizeof(backing_n= ame)); - error_report("Could not get size of '%s': %s", - backing_name, strerror(-old_backing_size)); - ret =3D -1; - goto out; + bdrv_get_backing_filename(bs, backing_name, + sizeof(backing_name)); + error_report("Could not get size of '%s': %s", + backing_name, strerror(-old_backing_size)); + ret =3D -1; + goto out; + } } if (blk_new_backing) { new_backing_size =3D blk_getlength(blk_new_backing); --=20 2.21.0