From patchwork Tue Apr 29 15:07:48 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 343876 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 022311400A0 for ; Wed, 30 Apr 2014 01:12:27 +1000 (EST) Received: from localhost ([::1]:50495 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wf9ho-0008Vg-OS for incoming@patchwork.ozlabs.org; Tue, 29 Apr 2014 11:12:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40302) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wf9f0-00049x-Eb for qemu-devel@nongnu.org; Tue, 29 Apr 2014 11:09:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wf9es-0003RD-CL for qemu-devel@nongnu.org; Tue, 29 Apr 2014 11:09:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10286) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wf9es-0003R6-4k for qemu-devel@nongnu.org; Tue, 29 Apr 2014 11:09:22 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s3TF9LWW022106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 29 Apr 2014 11:09:21 -0400 Received: from localhost (ovpn-116-17.ams2.redhat.com [10.36.116.17]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s3TF9IiC021493 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Tue, 29 Apr 2014 11:09:20 -0400 From: Max Reitz To: qemu-devel@nongnu.org Date: Tue, 29 Apr 2014 17:07:48 +0200 Message-Id: <1398784072-3319-11-git-send-email-mreitz@redhat.com> In-Reply-To: <1398784072-3319-1-git-send-email-mreitz@redhat.com> References: <1398784072-3319-1-git-send-email-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Stefan Hajnoczi , Max Reitz Subject: [Qemu-devel] [PATCH v6 10/14] qemu-img: Specify backing file for commit X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Introduce a new parameter for qemu-img commit which may be used to explicitly specify the backing file into which an image should be committed if the backing chain has more than a single layer. Signed-off-by: Max Reitz --- qemu-img-cmds.hx | 4 ++-- qemu-img.c | 24 +++++++++++++++++------- qemu-img.texi | 9 ++++++++- 3 files changed, 27 insertions(+), 10 deletions(-) diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index ea41d4f..4331949 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -22,9 +22,9 @@ STEXI ETEXI DEF("commit", img_commit, - "commit [-q] [-f fmt] [-t cache] [-d] [-p] filename") + "commit [-q] [-f fmt] [-t cache] [-b base] [-d] [-p] filename") STEXI -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] [-p] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename} ETEXI DEF("compare", img_compare, diff --git a/qemu-img.c b/qemu-img.c index 72b9384..e047fcb 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -741,7 +741,7 @@ static void run_block_job(BlockJob *job, Error **errp) static int img_commit(int argc, char **argv) { int c, ret, flags; - const char *filename, *fmt, *cache; + const char *filename, *fmt, *cache, *base; BlockDriverState *bs, *base_bs; bool progress = false, quiet = false, drop = false; Error *local_err = NULL; @@ -749,8 +749,9 @@ static int img_commit(int argc, char **argv) fmt = NULL; cache = BDRV_DEFAULT_CACHE; + base = NULL; for(;;) { - c = getopt(argc, argv, "f:ht:dpq"); + c = getopt(argc, argv, "f:ht:b:dpq"); if (c == -1) { break; } @@ -765,6 +766,11 @@ static int img_commit(int argc, char **argv) case 't': cache = optarg; break; + case 'b': + base = optarg; + /* -b implies -d */ + drop = true; + break; case 'd': drop = true; break; @@ -802,12 +808,16 @@ static int img_commit(int argc, char **argv) qemu_progress_init(progress, 1.f); qemu_progress_print(0.f, 100); - /* This is different from QMP, which by default uses the deepest file in the - * backing chain (i.e., the very base); however, the traditional behavior of - * qemu-img commit is using the immediate backing file. */ - base_bs = bs->backing_hd; + if (base) { + base_bs = bdrv_find_backing_image(bs, base); + } else { + /* This is different from QMP, which by default uses the deepest file in + * the backing chain (i.e., the very base); however, the traditional + * behavior of qemu-img commit is using the immediate backing file. */ + base_bs = bs->backing_hd; + } if (!base_bs) { - error_set(&local_err, QERR_BASE_NOT_FOUND, "NULL"); + error_set(&local_err, QERR_BASE_NOT_FOUND, base ?: "NULL"); goto done; } diff --git a/qemu-img.texi b/qemu-img.texi index 3639bea..95ed2e8 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -140,7 +140,7 @@ this case. @var{backing_file} will never be modified unless you use the The size can also be specified using the @var{size} option with @code{-o}, it doesn't need to be specified separately in this case. -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] [-p] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename} Commit the changes recorded in @var{filename} in its base image or backing file. If the backing file is smaller than the snapshot, then the backing file will be @@ -153,6 +153,13 @@ The image @var{filename} is emptied after the operation has been successful. If you do not need @var{filename} afterwards anymore and intend to drop it, you may skip this operation by specifying the @code{-d} flag. +If the backing chain of the given image file @var{filename} has more than one +layer, the backing file into which the changes will be committed may be +specified as @var{base} (which has to be part of @var{filename}'s backing +chain). If @var{base} is not specified, the immediate backing file of the top +image (which is @var{filename}) will be used. For reasons of consistency, +explicitly specifying @var{base} will always imply @code{-d}. + @item compare [-f @var{fmt}] [-F @var{fmt}] [-p] [-s] [-q] @var{filename1} @var{filename2} Check if two images have the same content. You can compare images with