Am 11.11.2019 um 17:02 hat Max Reitz geschrieben:
> Let check_to_replace_node() use the more specialized
> bdrv_recurse_can_replace() instead of
> bdrv_recurse_is_first_non_filter(), which is too restrictive.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/block.c b/block.c
> index de53addeb0..7608f21570 100644
> --- a/block.c
> +++ b/block.c
> @@ -6243,6 +6243,17 @@ bool bdrv_recurse_can_replace(BlockDriverState *bs,
> return false;
> }
>
> +/*
> + * Check whether the given @node_name can be replaced by a node that
> + * has the same data as @parent_bs. If so, return @node_name's BDS;
> + * NULL otherwise.
> + *
> + * @node_name must be a (recursive) *child of @parent_bs (or this
> + * function will return NULL).
> + *
> + * The result (whether the node can be replaced or not) is only valid
> + * for as long as no graph changes occur.
> + */
> BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
> const char *node_name, Error **errp)
> {
> @@ -6267,8 +6278,11 @@ BlockDriverState
> *check_to_replace_node(BlockDriverState *parent_bs,
> * Another benefit is that this tests exclude backing files which are
> * blocked by the backing blockers.
> */
> - if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
> - error_setg(errp, "Only top most non filter can be replaced");
> + if (!bdrv_recurse_can_replace(parent_bs, to_replace_bs)) {
> + error_setg(errp, "Cannot replace '%s' by a node mirrored from '%s', "
> + "because it cannot be guaranteed that doing so would not "
> + "lead to an abrupt change of visible data",
> + node_name, parent_bs->node_name);
If this function is only supposed to be used in the context of the
mirror job, moving it into block/mirror.c could be considered as a
cleanup on top.
Kevin
