Re: [PATCH v9 2/7] block/export: add blk_by_export_id()

[Markus Armbruster <armbru@redhat.com>]

Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> writes:

> We need it for further blockdev-replace functionality.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
>  block/export/export.c                       | 18 ++++++++++++++++++
>  include/sysemu/block-backend-global-state.h |  1 +
>  2 files changed, 19 insertions(+)
>
> diff --git a/block/export/export.c b/block/export/export.c
> index 6d51ae8ed7..57beae7982 100644
> --- a/block/export/export.c
> +++ b/block/export/export.c
> @@ -355,3 +355,21 @@ BlockExportInfoList *qmp_query_block_exports(Error **errp)
>  
>      return head;
>  }
> +
> +BlockBackend *blk_by_export_id(const char *id, Error **errp)
> +{
> +    BlockExport *exp;
> +
> +    exp = blk_exp_find(id);
> +    if (exp == NULL) {
> +        error_setg(errp, "Export '%s' not found", id);
> +        return NULL;
> +    }
> +
> +    if (!exp->blk) {
> +        error_setg(errp, "Export '%s' is empty", id);

Can this happen?

> +        return NULL;
> +    }
> +
> +    return exp->blk;
> +}
> diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h
> index ccb35546a1..410d0cc5c7 100644
> --- a/include/sysemu/block-backend-global-state.h
> +++ b/include/sysemu/block-backend-global-state.h
> @@ -74,6 +74,7 @@ void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
>  DeviceState *blk_get_attached_dev(BlockBackend *blk);
>  BlockBackend *blk_by_dev(void *dev);
>  BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
> +BlockBackend *blk_by_export_id(const char *id, Error **errp);
>  void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
>  
>  void blk_activate(BlockBackend *blk, Error **errp);