[Qemu-devel] [PATCH v1 1/1] block/vmdk: Fix the endian problem of buf_len

[QingFeng Hao <haoqf@linux.vnet.ibm.com>]

The problem was triggered by qemu-iotests case 055. It failed when it
was comparing the compressed vmdk image with original test.img.

The cause is that buf_len in vmdk_write_extent wasn't converted to
little-endian before it was stored to disk. But later vmdk_read_extent
read it and converted it from little-endian to cpu endian.
If the cpu is big-endian like s390, the problem will happen and
the data length read by vmdk_read_extent will become invalid!
The fix is to add the conversion in vmdk_write_extent.

Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
---
 block/vmdk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index a11c27a..bf6667f 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1355,7 +1355,7 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
         }
 
         data->lba = offset >> BDRV_SECTOR_BITS;
-        data->size = buf_len;
+        data->size = cpu_to_le32(buf_len);
 
         n_bytes = buf_len + sizeof(VmdkGrainMarker);
         iov = (struct iovec) {
-- 
2.8.4