Re: [PATCH v4 1/7] nbd: allow reconnect on open, with corresponding new options

[Eric Blake]

On Mon, Dec 13, 2021 at 04:32:34PM +0100, Vladimir Sementsov-Ogievskiy wrote:
> It is useful when start of vm and start of nbd server are not
> simple to sync.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  qapi/block-core.json |  9 ++++++++-
>  block/nbd.c          | 45 +++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 52 insertions(+), 2 deletions(-)
> 
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 1d3dd9cb48..8cf82417a6 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -4096,6 +4096,12 @@
>  #                   future requests before a successful reconnect will
>  #                   immediately fail. Default 0 (Since 4.2)
>  #
> +# @open-timeout: In seconds. If zero, the nbd driver tries the connection
> +#                only once, and fails to open if the connection fails.
> +#                If non-zero, the nbd driver will repeat connection attempts
> +#                until successful or until @open-timeout seconds have 
> elapsed.
> +#                Default 0 (Since 6.2)

We'll have to tweak this to be since 7.0, now.  Easy to do on top, and
not worth a respin by itself.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org