Re: [PATCH 2/2] block: stream: Allow users to request only format driver names in backing file format

[Vladimir Sementsov-Ogievskiy]

On 24.11.23 17:52, Peter Krempa wrote:
> Introduce a new flag 'backing_file_format_no_protocol' for the
> block-commit QMP command which instructs the internals to use 'raw'
> instead of the protocol driver in case when a image is used without a
> dummy 'raw' wrapper.
>
> The flag is designed such that it can be always asserted by management
> tools even when there isn't any update to backing files.
>
> The flag will be used by libvirt so that the backing images still
> reference the proper format even when libvirt will stop using the dummy
> raw driver (raw driver with no other config). Libvirt needs this so that
> the images stay compatible with older libvirt versions which didn't
> expect that a protocol driver name can appear in the backing file format
> field.
>
> Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> ---
>   block/monitor/block-hmp-cmds.c         |  2 +-
>   block/stream.c                         | 10 +++++++++-
>   blockdev.c                             |  7 +++++++
>   include/block/block_int-global-state.h |  3 +++
>   qapi/block-core.json                   | 11 ++++++++++-
>   5 files changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
> index c729cbf1eb..28e708a981 100644
> --- a/block/monitor/block-hmp-cmds.c
> +++ b/block/monitor/block-hmp-cmds.c
> @@ -509,7 +509,7 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict)
>       const char *base = qdict_get_try_str(qdict, "base");
>       int64_t speed = qdict_get_try_int(qdict, "speed", 0);
>
> -    qmp_block_stream(device, device, base, NULL, NULL, NULL,
> +    qmp_block_stream(device, device, base, NULL, NULL, NULL, false, false,

that should be

+    qmp_block_stream(device, device, base, NULL, NULL, false, false, NULL,


( definitely we lack named arguments of python in C :)


with that fixed:
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

>                        qdict_haskey(qdict, "speed"), speed,
>                        true, BLOCKDEV_ON_ERROR_REPORT, NULL,
>                        false, false, false, false, &error);

...

> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2408,6 +2408,8 @@ void qmp_block_stream(const char *job_id, const char 
> *device,
>                         const char *base,
>                         const char *base_node,
>                         const char *backing_file,
> +                      bool has_backing_file_format_no_protocol,
> +                      bool backing_file_format_no_protocol,
>                         const char *bottom,
>                         bool has_speed, int64_t speed,
>                         bool has_on_error, BlockdevOnError on_error,

--
Best regards,
Vladimir