qcow2: Assign bs->file->bs to file in qcow2_co_get_block_status

Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Message-id: 1453780743-16806-4-git-send-email-famz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

block/qcow2.c

@@ -1349,6 +1349,7 @@ static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
         !s->cipher) {
         index_in_cluster = sector_num & (s->cluster_sectors - 1);
         cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
+        *file = bs->file->bs;
         status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset;
     }
     if (ret == QCOW2_CLUSTER_ZERO) {