Re: [PATCH] block: remove format defaults from QemuOpts in bdrv_create_file()

[Kevin Wolf]

Am 08.03.2021 um 17:12 hat Stefano Garzarella geschrieben:
> QemuOpts is usually created merging the QemuOptsList of format
> and protocol. So, when the format calls bdr_create_file(), the 'opts'
> parameter contains a QemuOptsList with a combination of format and
> protocol default values.
> 
> The format properly removes its options before calling
> bdr_create_file(), but the default values remain in 'opts->list'.
> So if the protocol has options with the same name (e.g. rbd has
> 'cluster_size' as qcow2), it will see the default values of the format,
> since for overlapping options, the format wins.
> 
> To avoid this issue, lets convert QemuOpts to QDict, in this way we take
> only the set options, and then convert it back to QemuOpts, using the
> 'create_opts' of the protocol. So the new QemuOpts, will contain only the
> protocol defaults.
> 
> Suggested-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>

Thanks, applied to the block branch.

Kevin