The Friday 07 Mar 2014 à 23:55:55 (+0100), Max Reitz wrote :
> bdrv_query_image_info() currently deduces the image filename and the
> format name from the top BDS. However, it is probably more reasonable to
> ignore as many filters as possible on top of the BDS chain since those
> neither change the type nor the filename of the underlying image.
>
> Filters like quorum which have multiple underlying BDS should not be
> removed, however, since the underlying BDS chains may lead to different
> image formats and most certainly to different filenames. Therefore, only
> simple filters with a single underlying BDS may be skipped.
>
> In addition, any "raw" BDS on top of such a simple filter should be
> removed, since they have probably been automatically created by
> bdrv_open() but basically function as a simple filter as well.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block/qapi.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/block/qapi.c b/block/qapi.c
> index 8f2b4db..84b3097 100644
> --- a/block/qapi.c
> +++ b/block/qapi.c
> @@ -171,11 +171,25 @@ void bdrv_query_image_info(BlockDriverState *bs,
> int ret;
> Error *err = NULL;
> ImageInfo *info = g_new0(ImageInfo, 1);
> + BlockDriverState *ubs;
>
> bdrv_get_geometry(bs, &total_sectors);
>
> - info->filename = g_strdup(bs->filename);
> - info->format = g_strdup(bdrv_get_format_name(bs));
> + /* Remove the top layer of filters; that is, remove every "raw" BDS on
> top
> + * of a single-child filter and every single-child filter itself until a
> BDS
> + * is encountered which cannot be removed through these rules */
> + ubs = bs;
> + while ((ubs->drv && ubs->drv->is_filter && ubs->drv->has_single_child) ||
> + (ubs->drv && !strcmp(ubs->drv->format_name, "raw") && ubs->file &&
> + ubs->file->drv && ubs->file->drv->is_filter &&
> + ubs->file->drv->has_single_child))
> + {
> + ubs = ubs->file;
> + }
> +
> + info->filename = g_strdup(ubs->filename);
> + info->format = g_strdup(bdrv_get_format_name(ubs));
> +
> info->virtual_size = total_sectors * 512;
> info->actual_size = bdrv_get_allocated_file_size(bs);
> info->has_actual_size = info->actual_size >= 0;
> --
> 1.9.0
>
>
Reviewed-by: Benoit Canet <ben...@irqsave.net>