From patchwork Fri May 10 16:16:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 10939233 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 59A4C1390 for ; Fri, 10 May 2019 16:37:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4948128C9C for ; Fri, 10 May 2019 16:37:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BE4728CC3; Fri, 10 May 2019 16:37:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id D16F628C9C for ; Fri, 10 May 2019 16:37:03 +0000 (UTC) Received: from localhost ([127.0.0.1]:46468 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP8W6-0007Op-Qb for patchwork-qemu-devel@patchwork.kernel.org; Fri, 10 May 2019 12:37:02 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40308) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hP8Cj-0004ZW-E2 for qemu-devel@nongnu.org; Fri, 10 May 2019 12:17:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hP8Ch-0000SM-HT for qemu-devel@nongnu.org; Fri, 10 May 2019 12:17:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48216) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hP8Cb-0000Fv-Nv; Fri, 10 May 2019 12:16:55 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CCE2D307DA31; Fri, 10 May 2019 16:16:51 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-116-183.ams2.redhat.com [10.36.116.183]) by smtp.corp.redhat.com (Postfix) with ESMTP id E0C6517797; Fri, 10 May 2019 16:16:50 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 10 May 2019 18:16:12 +0200 Message-Id: <20190510161614.23236-14-kwolf@redhat.com> In-Reply-To: <20190510161614.23236-1-kwolf@redhat.com> References: <20190510161614.23236-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Fri, 10 May 2019 16:16:51 +0000 (UTC) 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] [PULL 13/15] 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: kwolf@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Max Reitz 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 Signed-off-by: Kevin Wolf --- 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 = NULL; - if (bs->backing_format[0] != '\0') { - options = qdict_new(); - qdict_put_str(options, "driver", bs->backing_format); - } - - if (force_share) { - if (!options) { + if (bs->backing) { + if (bs->backing_format[0] != '\0') { options = 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 = 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 = -1; - goto out; + + if (force_share) { + if (!options) { + options = qdict_new(); + } + qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); + } + bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); + blk_old_backing = 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 = -1; + goto out; + } + } else { + blk_old_backing = NULL; } 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 = 0; int64_t new_backing_size = 0; uint64_t offset; int64_t n; @@ -3400,15 +3404,18 @@ static int img_rebase(int argc, char **argv) ret = -1; goto out; } - old_backing_size = blk_getlength(blk_old_backing); - if (old_backing_size < 0) { - char backing_name[PATH_MAX]; + if (blk_old_backing) { + old_backing_size = blk_getlength(blk_old_backing); + if (old_backing_size < 0) { + char backing_name[PATH_MAX]; - 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 = -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 = -1; + goto out; + } } if (blk_new_backing) { new_backing_size = blk_getlength(blk_new_backing);