On Thu, Jul 20, 2023 at 04:00:24PM +0200, Hanna Czenczek wrote:
> For image creation code, we have central fallback code for protocols
> that do not support creating new images (like NBD or iscsi). So for
> them, you can only specify existing paths/exports that are overwritten
> to make clean new images. In such a case, if the given path cannot be
> opened (assuming a pre-existing image there), we print an error message
> that tries to describe what is going on: That with this protocol, you
> cannot create new images, but only overwrite existing ones; and the
> given path could not be opened as a pre-existing image.
>
> However, the current message is confusing, because it does not say that
> the protocol in question does not support creating new images, but
> instead that "image creation" is unsupported. This can be interpreted
> to mean that `qemu-img create` will not work in principle, which is not
> true. Be more verbose for clarity.
>
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2217204
> Signed-off-by: Hanna Czenczek <hre...@redhat.com>
> ---
> block.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
Definitely more vebose, but I don't see that as a bad thing.
Reviewed-by: Eric Blake <ebl...@redhat.com>
>
> diff --git a/block.c b/block.c
> index a307c151a8..f530dd9c02 100644
> --- a/block.c
> +++ b/block.c
> @@ -661,8 +661,10 @@ int coroutine_fn bdrv_co_create_opts_simple(BlockDriver
> *drv,
> blk = blk_co_new_open(filename, NULL, options,
> BDRV_O_RDWR | BDRV_O_RESIZE, errp);
> if (!blk) {
> - error_prepend(errp, "Protocol driver '%s' does not support image "
> - "creation, and opening the image failed: ",
> + error_prepend(errp, "Protocol driver '%s' does not support creating "
> + "new images, so an existing image must be selected as "
> + "the target; however, opening the given target as an "
> + "existing image failed: ",
> drv->format_name);
> return -EINVAL;
> }
> --
> 2.41.0
>
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
