diff --git a/block/stream.c b/block/stream.c index 61ff7a236e..0efe1adfd5 100644 --- a/block/stream.c +++ b/block/stream.c @@ -76,6 +76,39 @@ static int coroutine_fn stream_populate(BlockDriverState *bs, return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov); } +static void close_unused_images(BlockDriverState *top, BlockDriverState *base, + const char *base_id) +{ + BlockDriverState *intermediate; + intermediate = top->backing_hd; + + while (intermediate) { + BlockDriverState *unused; + + /* reached base */ + if (intermediate == base) { + break; + } + + unused = intermediate; + intermediate = intermediate->backing_hd; + unused->backing_hd = NULL; + bdrv_delete(unused); + } + top->backing_hd = base; + + pstrcpy(top->backing_file, sizeof(top->backing_file), ""); + pstrcpy(top->backing_format, sizeof(top->backing_format), ""); + if (base_id) { + pstrcpy(top->backing_file, sizeof(top->backing_file), base_id); + if (base->drv) { + pstrcpy(top->backing_format, sizeof(top->backing_format), + base->drv->format_name); + } + } + +} + /* * Given an image chain: [BASE] -> [INTER1] -> [INTER2] -> [TOP] * @@ -223,6 +256,7 @@ retry: base_id = s->backing_file_id; } ret = bdrv_change_backing_file(bs, base_id, NULL); + close_unused_images(bs, base, base_id); } qemu_vfree(buf);