From c969006b559939fae0277c0f00330155eba17ce9 Mon Sep 17 00:00:00 2001
Message-Id: <c969006b559939fae0277c0f00330155eba17ce9.1369658547.git.minovotn@redhat.com>
In-Reply-To: <07146f8b79923c529fd93fa528e6fcbd6f571a02.1369658547.git.minovotn@redhat.com>
References: <07146f8b79923c529fd93fa528e6fcbd6f571a02.1369658547.git.minovotn@redhat.com>
From: Fam Zheng <famz@redhat.com>
Date: Mon, 20 May 2013 03:36:20 +0200
Subject: [PATCH 05/47] VMDK: bugfix, align offset to cluster in
get_whole_cluster
RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1369021022-22728-6-git-send-email-famz@redhat.com>
Patchwork-id: 51441
O-Subject: [PATCH RHEL-6.5 qemu-kvm v3 05/47] VMDK: bugfix, align offset to cluster in get_whole_cluster
Bugzilla: 960685
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
From: Fam Zheng <famcool@gmail.com>
In get_whole_cluster, the offset is not aligned to cluster when reading
from backing_hd. When the first write to child is not at the cluster
boundary, wrong address data from parent is copied to child.
Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 0e69c543946957fe8450ebb13874bb1ef280d55b)
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block/vmdk.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
block/vmdk.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index bbd2ca6..10b0f01 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -516,21 +516,23 @@ static int get_whole_cluster(BlockDriverState *bs,
/* 128 sectors * 512 bytes each = grain size 64KB */
uint8_t whole_grain[extent->cluster_sectors * 512];
- // we will be here if it's first write on non-exist grain(cluster).
- // try to read from parent image, if exist
+ /* we will be here if it's first write on non-exist grain(cluster).
+ * try to read from parent image, if exist */
if (bs->backing_hd) {
int ret;
if (!vmdk_is_cid_valid(bs))
return -1;
+ /* floor offset to cluster */
+ offset -= offset % (extent->cluster_sectors * 512);
ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
return -1;
}
- //Write grain only into the active image
+ /* Write grain only into the active image */
ret = bdrv_write(extent->file, cluster_offset, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
--
1.7.11.7