From c969006b559939fae0277c0f00330155eba17ce9 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: <07146f8b79923c529fd93fa528e6fcbd6f571a02.1369658547.git.minovotn@redhat.com> References: <07146f8b79923c529fd93fa528e6fcbd6f571a02.1369658547.git.minovotn@redhat.com> From: Fam Zheng 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 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 RH-Acked-by: Jeffrey Cody RH-Acked-by: Kevin Wolf From: Fam Zheng 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 Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf (cherry picked from commit 0e69c543946957fe8450ebb13874bb1ef280d55b) Signed-off-by: Fam Zheng --- block/vmdk.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) Signed-off-by: Michal Novotny --- 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