From patchwork Mon Dec 30 05:29:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hu Tao X-Patchwork-Id: 305702 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 87D862C022C for ; Mon, 30 Dec 2013 16:32:20 +1100 (EST) Received: from localhost ([::1]:57209 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVSb-0006ye-Qq for incoming@patchwork.ozlabs.org; Mon, 30 Dec 2013 00:32:17 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVRy-0006qw-6s for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VxVRp-00019d-Pw for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:38 -0500 Received: from [222.73.24.84] (port=11779 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVRp-00015n-ER for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:29 -0500 X-IronPort-AV: E=Sophos;i="4.95,571,1384272000"; d="scan'208";a="9349127" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 30 Dec 2013 13:27:38 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id rBU5V9Jw005710; Mon, 30 Dec 2013 13:31:12 +0800 Received: from G08FNSTD100614.fnst.cn.fujitsu.com ([10.167.226.102]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2013123013302281-761720 ; Mon, 30 Dec 2013 13:30:22 +0800 From: Hu Tao To: qemu-devel@nongnu.org Date: Mon, 30 Dec 2013 13:29:09 +0800 Message-Id: <33b97a2f2e4860e69e658143d1e63927fa12a92e.1388381026.git.hutao@cn.fujitsu.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: References: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/12/30 13:30:22, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/12/30 13:30:25, Serialize complete at 2013/12/30 13:30:25 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 222.73.24.84 Cc: Kevin Wolf , Stefan Hajnoczi Subject: [Qemu-devel] [PATCH v1 3/3] qcow2: check for NULL l2meta 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 In case of do preallocating metadata with a large cluster size, qcow2_alloc_cluster_offset() can allocate nothing and returns a NULL l2meta. This patch checks for it and link2 l2 with only valid l2meta. Signed-off-by: Hu Tao Reviewed-by: Max Reitz --- block/qcow2.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 46860d5..380c240 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1399,18 +1399,20 @@ static int preallocate(BlockDriverState *bs) offset = 0; while (nb_sectors) { - num = MIN(nb_sectors, INT_MAX >> 9); + num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS); ret = qcow2_alloc_cluster_offset(bs, offset, &num, &host_offset, &meta); if (ret < 0) { return ret; } - ret = qcow2_alloc_cluster_link_l2(bs, meta); - if (ret < 0) { - qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters, - QCOW2_DISCARD_NEVER); - return ret; + if (meta) { + ret = qcow2_alloc_cluster_link_l2(bs, meta); + if (ret < 0) { + qcow2_free_any_clusters(bs, meta->alloc_offset, + meta->nb_clusters, QCOW2_DISCARD_NEVER); + return ret; + } } /* There are no dependent requests, but we need to remove our request