Re: [PATCH v2 22/33] qapi: publish copy-before-write filter

[Max Reitz]

On 20.05.21 16:21, Vladimir Sementsov-Ogievskiy wrote:
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>   qapi/block-core.json | 30 ++++++++++++++++++++++++++----
>   1 file changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 2ea294129e..8c4801a13d 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -2808,15 +2808,17 @@
>   # @blklogwrites: Since 3.0
>   # @blkreplay: Since 4.2
>   # @compress: Since 5.0
> +# @copy-before-write: Since 6.1
>   #
>   # Since: 2.9
>   ##
>   { 'enum': 'BlockdevDriver',
>     'data': [ 'blkdebug', 'blklogwrites', 'blkreplay', 'blkverify', 'bochs',
> -            'cloop', 'compress', 'copy-on-read', 'dmg', 'file', 'ftp', 'ftps',
> -            'gluster', 'host_cdrom', 'host_device', 'http', 'https', 'iscsi',
> -            'luks', 'nbd', 'nfs', 'null-aio', 'null-co', 'nvme', 'parallels',
> -            'preallocate', 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'rbd',
> +            'cloop', 'compress', 'copy-before-write', 'copy-on-read', 'dmg',
> +            'file', 'ftp', 'ftps', 'gluster', 'host_cdrom', 'host_device',
> +            'http', 'https', 'iscsi', 'luks', 'nbd', 'nfs', 'null-aio',
> +            'null-co', 'nvme', 'parallels', 'preallocate', 'qcow', 'qcow2',
> +            'qed', 'quorum', 'raw', 'rbd',
>               { 'name': 'replication', 'if': 'defined(CONFIG_REPLICATION)' },
>               'ssh', 'throttle', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
>   
> @@ -3937,6 +3939,25 @@
>     'base': 'BlockdevOptionsGenericFormat',
>     'data': { '*bottom': 'str' } }
>   
> +##
> +# @BlockdevOptionsCbw:
> +#
> +# Driver specific block device options for the copy-before-write driver,
> +# which does so called copy-before-write operations: when data is
> +# written to the filter, the filter firstly reads corresponding blocks
> +# from its file child and copies them to @target child. After successful
> +# copying the write request is propagated to file child. If copying
> +# filed, the original write request is failed too and no data is written

s/filed/failed/

With that fixed:

Reviewed-by: Max Reitz <mreitz@redhat.com>

> +# to file child.
> +#
> +# @target: The target for copy-before-write operations.
> +#
> +# Since: 6.1
> +##
> +{ 'struct': 'BlockdevOptionsCbw',
> +  'base': 'BlockdevOptionsGenericFormat',
> +  'data': { 'target': 'BlockdevRef' } }
> +
>   ##
>   # @BlockdevOptions:
>   #
> @@ -3989,6 +4010,7 @@
>         'bochs':      'BlockdevOptionsGenericFormat',
>         'cloop':      'BlockdevOptionsGenericFormat',
>         'compress':   'BlockdevOptionsGenericFormat',
> +      'copy-before-write':'BlockdevOptionsCbw',
>         'copy-on-read':'BlockdevOptionsCor',
>         'dmg':        'BlockdevOptionsGenericFormat',
>         'file':       'BlockdevOptionsFile',