Re: [Qemu-devel] [PATCH v3 3/5] block/null: Implement bdrv_refresh_filename()

[Fam Zheng <famz@redhat.com>]

On Fri, 06/10 20:57, Max Reitz wrote:
> Signed-off-by: Max Reitz <mreitz@redhat.com>

The commit message could go a little more informative. Seems nothing special in
the added callback, aren't things supposed to just work without this patch?
What is missing?

> ---
>  block/null.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/block/null.c b/block/null.c
> index 396500b..b511010 100644
> --- a/block/null.c
> +++ b/block/null.c
> @@ -12,6 +12,8 @@
>  
>  #include "qemu/osdep.h"
>  #include "qapi/error.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/qmp/qstring.h"
>  #include "block/block_int.h"
>  
>  #define NULL_OPT_LATENCY "latency-ns"
> @@ -223,6 +225,20 @@ static int64_t coroutine_fn null_co_get_block_status(BlockDriverState *bs,
>      }
>  }
>  
> +static void null_refresh_filename(BlockDriverState *bs, QDict *opts)
> +{
> +    QINCREF(opts);
> +    qdict_del(opts, "filename");

Why is this qdict_del necessary?

> +
> +    if (!qdict_size(opts)) {
> +        snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
> +                 bs->drv->format_name);
> +    }
> +
> +    qdict_put(opts, "driver", qstring_from_str(bs->drv->format_name));
> +    bs->full_open_options = opts;
> +}
> +
>  static BlockDriver bdrv_null_co = {
>      .format_name            = "null-co",
>      .protocol_name          = "null-co",
> @@ -238,6 +254,8 @@ static BlockDriver bdrv_null_co = {
>      .bdrv_reopen_prepare    = null_reopen_prepare,
>  
>      .bdrv_co_get_block_status   = null_co_get_block_status,
> +
> +    .bdrv_refresh_filename  = null_refresh_filename,
>  };
>  
>  static BlockDriver bdrv_null_aio = {
> @@ -255,6 +273,8 @@ static BlockDriver bdrv_null_aio = {
>      .bdrv_reopen_prepare    = null_reopen_prepare,
>  
>      .bdrv_co_get_block_status   = null_co_get_block_status,
> +
> +    .bdrv_refresh_filename  = null_refresh_filename,
>  };
>  
>  static void bdrv_null_init(void)
> -- 
> 2.8.3
>