Eric Blake <ebl...@redhat.com> writes:
> On 12/13/19 8:11 AM, Peter Krempa wrote:
>> When a management application manages node names there's no reason to
>> recurse into backing images in the output of query-named-block-nodes.
>>
>> Add a parameter to the command which will return just the top level
>> structs.
>
> At one point, Kevin was working on a saner command that tried to cut
> out on more than just the redundant nesting. But this is certainly a
> quick-and-easy fix to ease libvirt's use of the existing command,
> while we decide whether to add a saner new command.
What exactly is the problem libvirt is having with the existing
query-named-block-nodes?
>>
>> Signed-off-by: Peter Krempa <pkre...@redhat.com>
>> ---
>> block.c | 5 +++--
>> block/qapi.c | 10 ++++++++--
>> blockdev.c | 12 ++++++++++--
>> include/block/block.h | 2 +-
>> include/block/qapi.h | 4 +++-
>> monitor/hmp-cmds.c | 2 +-
>> qapi/block-core.json | 6 +++++-
>> 7 files changed, 31 insertions(+), 10 deletions(-)
>>
>
>> +++ b/blockdev.c
>> @@ -3707,9 +3707,17 @@ void qmp_drive_backup(DriveBackup *arg, Error **errp)
>> }
>> }
>>
>> -BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
>> +BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
>> + bool flat,
>> + Error **errp)
>> {
>> - return bdrv_named_nodes_list(errp);
>> + bool return_flat = false;
>> +
>> + if (has_flat) {
>> + return_flat = flat;
>> + }
>
> This could be shortened as 'bool return_flat = has_flat && flat;', but
> that's not essential.
I'd prefer that.
Even return_flat = flat would do, because !has_flat implies !flat when
flat is bool. Matter of taste.
>> +
>> + return bdrv_named_nodes_list(return_flat, errp);
>> }
>>
>
> Reviewed-by: Eric Blake <ebl...@redhat.com>
Un-snipping the QAPI schema change:
>> diff --git a/qapi/block-core.json b/qapi/block-core.json
>> index 0cf68fea14..bd651106bd 100644
>> --- a/qapi/block-core.json
>> +++ b/qapi/block-core.json
>> @@ -1752,6 +1752,8 @@
>> #
>> # Get the named block driver list
>> #
>> +# @flat: don't recurse into backing images if true. Default is false (Since
>> 5.0)
>> +#
>> # Returns: the list of BlockDeviceInfo
>> #
>> # Since: 2.0
What does it mean not to recurse? Sounds like flat: false asks for a
subset of the full set. How exactly is the subset defined?
>> @@ -1805,7 +1807,9 @@
>> # } } ] }
>> #
>> ##
>> -{ 'command': 'query-named-block-nodes', 'returns': [ 'BlockDeviceInfo' ] }
>> +{ 'command': 'query-named-block-nodes',
>> + 'returns': [ 'BlockDeviceInfo' ],
>> + 'data': { '*flat': 'bool' } }
>>
>> ##
>> # @XDbgBlockGraphNodeType:
