From patchwork Thu May 20 14:48:43 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 53075 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id D6B3AB7D4A for ; Fri, 21 May 2010 00:51:31 +1000 (EST) Received: from localhost ([127.0.0.1]:52998 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OF75q-0007nA-Gq for incoming@patchwork.ozlabs.org; Thu, 20 May 2010 10:51:26 -0400 Received: from [140.186.70.92] (port=36236 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OF73g-0006lz-SZ for qemu-devel@nongnu.org; Thu, 20 May 2010 10:49:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OF73Z-0007FA-D2 for qemu-devel@nongnu.org; Thu, 20 May 2010 10:49:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54759) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OF73Z-0007Ez-5u for qemu-devel@nongnu.org; Thu, 20 May 2010 10:49:05 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o4KEn43g009703 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 20 May 2010 10:49:04 -0400 Received: from localhost.localdomain (dhcp-5-217.str.redhat.com [10.32.5.217]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o4KEn1TS020672; Thu, 20 May 2010 10:49:03 -0400 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Thu, 20 May 2010 16:48:43 +0200 Message-Id: <1274366923-30095-2-git-send-email-kwolf@redhat.com> In-Reply-To: <1274366923-30095-1-git-send-email-kwolf@redhat.com> References: <1274366923-30095-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: kwolf@redhat.com Subject: [Qemu-devel] [PATCH 2/2] qcow2: Fix error handling in l2_allocate X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org l2_allocate has some intermediate states in which the image is inconsistent. Change the order to write to the L1 table only after the new L2 table has successfully been initialized. Also reset the L2 cache in failure case, it's very likely wrong. Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 23 +++++++++++++---------- 1 files changed, 13 insertions(+), 10 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index ed5c4b2..244b4a7 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -239,14 +239,6 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) return l2_offset; } - /* update the L1 entry */ - - s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; - ret = write_l1_entry(bs, l1_index); - if (ret < 0) { - return ret; - } - /* allocate a new entry in the l2 cache */ min_index = l2_cache_new_entry(bs); @@ -261,7 +253,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) ret = bdrv_pread(bs->file, old_l2_offset, l2_table, s->l2_size * sizeof(uint64_t)); if (ret < 0) { - return ret; + goto fail; } } /* write the l2 table to the file */ @@ -269,7 +261,14 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) ret = bdrv_pwrite(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)); if (ret < 0) { - return ret; + goto fail; + } + + /* update the L1 entry */ + s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; + ret = write_l1_entry(bs, l1_index); + if (ret < 0) { + goto fail; } /* update the l2 cache entry */ @@ -279,6 +278,10 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) *table = l2_table; return 0; + +fail: + qcow2_l2_cache_reset(bs); + return ret; } static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,