Re: [Qemu-devel] [PATCH 07/10] qcow2: Improve error handling in update_refcount

[Christoph Hellwig]

On Mon, Jan 18, 2010 at 01:11:33PM +0100, Kevin Wolf wrote:
> If update_refcount fails, try to undo any changes made so far to avoid
> inconsistencies in the image file.
> 
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  block/qcow2-refcount.c |   32 +++++++++++++++++++++++++-------
>  1 files changed, 25 insertions(+), 7 deletions(-)
> 

> +    /*
> +     * Try do undo any updates if an error is returned (This may succeed in
> +     * some cases like ENOSPC for allocating a new refcount block)
> +     */
> +    if (ret < 0) {
> +        int dummy;
> +        dummy = update_refcount(bs, offset, cluster_offset - offset, 
> -addend);

So we recursively call into update_refcount here.  What happens an error
causes all updates to fail?