09.08.2019 19:13, Max Reitz wrote:
> If the driver does not implement bdrv_get_allocated_file_size(), we
> should fall back to cumulating the allocated size of all non-COW
> children instead of just bs->file.
>
> Suggested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/block.c b/block.c
> index 1070aa1ba9..6e1ddab056 100644
> --- a/block.c
> +++ b/block.c
> @@ -4650,9 +4650,27 @@ int64_t bdrv_get_allocated_file_size(BlockDriverState
> *bs)
> if (drv->bdrv_get_allocated_file_size) {
> return drv->bdrv_get_allocated_file_size(bs);
> }
> - if (bs->file) {
> - return bdrv_get_allocated_file_size(bs->file->bs);
> +
> + if (!QLIST_EMPTY(&bs->children)) {
> + BdrvChild *child;
> + int64_t child_size, total_size = 0;
> +
> + QLIST_FOREACH(child, &bs->children, next) {
> + if (child == bdrv_filtered_cow_child(bs)) {
> + /* Ignore COW backing files */
> + continue;
> + }
> +
> + child_size = bdrv_get_allocated_file_size(child->bs);
> + if (child_size < 0) {
> + return child_size;
> + }
> + total_size += child_size;
> + }
> +
> + return total_size;
> }
> +
> return -ENOTSUP;
> }
>
>
Hmm..
1. No children -> -ENOTSUP
2. Only cow child -> 0
3. Some non-cow children -> SUM
It's all arguable (the strictest way is -ENOTSUP in either case),
but if we want to fallback to SUM of non-cow children, 1. and 2. should return
the same.
--
Best regards,
Vladimir
