From patchwork Wed Aug 20 18:17:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 381784 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id D41681400D2 for ; Thu, 21 Aug 2014 05:09:34 +1000 (EST) Received: from localhost ([::1]:57099 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKBGG-0005NX-UG for incoming@patchwork.ozlabs.org; Wed, 20 Aug 2014 15:09:32 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKBFk-0004fK-NP for qemu-devel@nongnu.org; Wed, 20 Aug 2014 15:09:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XKBFe-00084d-Hn for qemu-devel@nongnu.org; Wed, 20 Aug 2014 15:09:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21289) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKBFe-00084P-Ap for qemu-devel@nongnu.org; Wed, 20 Aug 2014 15:08:54 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s7KJ8ror013579 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 20 Aug 2014 15:08:53 -0400 Received: from localhost (ovpn-116-40.ams2.redhat.com [10.36.116.40]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s7KIIUPd022260 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Wed, 20 Aug 2014 14:18:32 -0400 From: Max Reitz To: qemu-devel@nongnu.org Date: Wed, 20 Aug 2014 20:17:58 +0200 Message-Id: <1408558684-14162-9-git-send-email-mreitz@redhat.com> In-Reply-To: <1408558684-14162-1-git-send-email-mreitz@redhat.com> References: <1408558684-14162-1-git-send-email-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 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 v11 08/14] qemu-img: Empty image after 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 After the top image has been committed, it should be emptied unless specified otherwise. Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- qemu-img-cmds.hx | 4 ++-- qemu-img.c | 34 +++++++++++++++++++++++++++++++--- qemu-img.texi | 6 +++++- 3 files changed, 38 insertions(+), 6 deletions(-) diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index d029609..b31d81c 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] filename") + "commit [-q] [-f fmt] [-t cache] [-d] filename") STEXI -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] @var{filename} ETEXI DEF("compare", img_compare, diff --git a/qemu-img.c b/qemu-img.c index 1b2255b..302eb15 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -759,14 +759,14 @@ static int img_commit(int argc, char **argv) int c, ret, flags; const char *filename, *fmt, *cache; BlockDriverState *bs, *base_bs; - bool quiet = false; + bool quiet = false, drop = false; Error *local_err = NULL; CommonBlockJobCBInfo cbi; fmt = NULL; cache = BDRV_DEFAULT_CACHE; for(;;) { - c = getopt(argc, argv, "f:ht:q"); + c = getopt(argc, argv, "f:ht:dq"); if (c == -1) { break; } @@ -781,6 +781,9 @@ static int img_commit(int argc, char **argv) case 't': cache = optarg; break; + case 'd': + drop = true; + break; case 'q': quiet = true; break; @@ -791,7 +794,7 @@ static int img_commit(int argc, char **argv) } filename = argv[optind++]; - flags = BDRV_O_RDWR; + flags = BDRV_O_RDWR | BDRV_O_UNMAP; ret = bdrv_parse_cache_flags(cache, &flags); if (ret < 0) { error_report("Invalid cache option: %s", cache); @@ -823,7 +826,32 @@ static int img_commit(int argc, char **argv) goto done; } + /* The block job will swap base_bs and bs (which is not what we really want + * here, but okay) and unref base_bs (after the swap, i.e., the old top + * image). In order to still be able to empty that top image afterwards, + * increment the reference counter here preemptively. */ + if (!drop) { + bdrv_ref(base_bs); + } + run_block_job(bs->job, &local_err); + if (local_err) { + goto unref_backing; + } + + if (!drop && base_bs->drv->bdrv_make_empty) { + ret = base_bs->drv->bdrv_make_empty(base_bs); + if (ret) { + error_setg_errno(&local_err, -ret, "Could not empty %s", + filename); + goto unref_backing; + } + } + +unref_backing: + if (!drop) { + bdrv_unref(base_bs); + } done: bdrv_unref(bs); diff --git a/qemu-img.texi b/qemu-img.texi index 514be90..a709e92 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -163,7 +163,7 @@ 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 [-f @var{fmt}] [-t @var{cache}] @var{filename} +@item commit [-f @var{fmt}] [-t @var{cache}] [-d] @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 @@ -172,6 +172,10 @@ the backing file, the backing file will not be truncated. If you want the backing file to match the size of the smaller snapshot, you can safely truncate it yourself once the commit operation successfully completes. +The image @var{filename} is emptied after the operation has succeeded. If you do +not need @var{filename} afterwards and intend to drop it, you may skip emptying +@var{filename} by specifying the @code{-d} flag. + @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