From patchwork Thu Apr 5 15:42:58 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 151017 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)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 69EDAB703F for ; Fri, 6 Apr 2012 06:21:30 +1000 (EST) Received: from localhost ([::1]:43947 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SFor4-0001M3-5h for incoming@patchwork.ozlabs.org; Thu, 05 Apr 2012 11:44:10 -0400 Received: from eggs.gnu.org ([208.118.235.92]:58006) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SFoqZ-0000g5-BY for qemu-devel@nongnu.org; Thu, 05 Apr 2012 11:43:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SFoqN-0005Y9-3L for qemu-devel@nongnu.org; Thu, 05 Apr 2012 11:43:36 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:34338) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SFoqM-0005WY-QU for qemu-devel@nongnu.org; Thu, 05 Apr 2012 11:43:27 -0400 Received: by mail-pz0-f46.google.com with SMTP id z9so2115338dad.33 for ; Thu, 05 Apr 2012 08:43:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=Eer4Da2l7kEsIkqKMaPovszixFG/q3ERyu1cCRMFRXs=; b=jjaM6CRPwn8gLVUhhngTpL27pWEaUavjw1bVVPCzLeQNJCrhLk+RoFFRZn5/6V9XAG 6dMZ4cCUbBJ7ZtHHy3EB2EjNaxfJ3t77cMP6dnySTdMKreH3hwIdEn/84p2z8T4Vn2Jd pmEDoCM0quf9u9eS+5VhCowyD61eACfuY0nKEVTX4wXDOM/xO+KThVEXD7BM/StR2qIu xfS0PcpvxnTCbFAcXe41gX7g2zcorLHotHqzL+ujasGzw8nxYTTPV+lrIoqa/3g5Rzso VCdj9sz4C63YkGDKs8wAUDcANvjEynEuT8vLr3VeQWmQFfdvALsLzeypEAe5Frbd50Zc JeNw== Received: by 10.68.218.228 with SMTP id pj4mr5886753pbc.167.1333640602205; Thu, 05 Apr 2012 08:43:22 -0700 (PDT) Received: from yakj.usersys.redhat.com (93-34-182-16.ip50.fastwebnet.it. [93.34.182.16]) by mx.google.com with ESMTPS id y3sm3552971pbh.59.2012.04.05.08.43.19 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 05 Apr 2012 08:43:21 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Thu, 5 Apr 2012 17:42:58 +0200 Message-Id: <1333640581-25649-5-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.7.9.3 In-Reply-To: <1333640581-25649-1-git-send-email-pbonzini@redhat.com> References: <1333640581-25649-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.210.46 Cc: Federico Simoncelli , Marcelo Tosatti Subject: [Qemu-devel] [PATCH 4/7] block: close unused image files at the end of streaming 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 From: Marcelo Tosatti Close the now unused images that were part of the previous backing file chain and adjust ->backing_hd properly. Note that this only works with relative paths. Given the images: /tmp/a/base.raw /tmp/a/snap1.qcow2 /tmp/b/snap2.qcow2 chained as: base(bak:"") <- snap1(bak:"base.raw") <- snap2(bak:"../a/snap1.qcow2") merging snap1 and snap2 we will obtain: base(bak:"") <- snap2(bak:"base.raw") However this should be maintained by the user/admin: one can also screw up relative paths using qemu-img manually. Signed-off-by: Marcelo Tosatti Cc: Federico Simoncelli Signed-off-by: Paolo Bonzini --- block/stream.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/block/stream.c b/block/stream.c index 61ff7a2..54f2b39 100644 --- a/block/stream.c +++ b/block/stream.c @@ -76,6 +76,28 @@ static int coroutine_fn stream_populate(BlockDriverState *bs, return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov); } +static void close_unused_images(BlockDriverState *top, BlockDriverState *base, + const char *base_id) +{ + BlockDriverState *intermediate; + intermediate = top->backing_hd; + + while (intermediate) { + BlockDriverState *unused; + + /* reached base */ + if (intermediate == base) { + break; + } + + unused = intermediate; + intermediate = intermediate->backing_hd; + unused->backing_hd = NULL; + bdrv_delete(unused); + } + top->backing_hd = base; +} + /* * Given an image chain: [BASE] -> [INTER1] -> [INTER2] -> [TOP] * @@ -223,6 +245,7 @@ retry: base_id = s->backing_file_id; } ret = bdrv_change_backing_file(bs, base_id, NULL); + close_unused_images(bs, base, base_id); } qemu_vfree(buf);