[Libguestfs] [PATCH virt-v2v] v2v: -o rhv-upload: Enable multi-conn

[Nir Soffer]

On Tue, Aug 3, 2021 at 10:26 PM Eric Blake <eblake at redhat.com> wrote:
>
> On Mon, Aug 02, 2021 at 08:41:20AM +0100, Richard W.M. Jones wrote:
> > ---
> >  v2v/rhv-upload-plugin.py | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
> > index a3d578176..51e9b33f7 100644
> > --- a/v2v/rhv-upload-plugin.py
> > +++ b/v2v/rhv-upload-plugin.py
> > @@ -169,6 +169,10 @@ def open(readonly):
> >      }
> >
> >
> > +def can_multi_conn(h):
> > +    return True
>
> Should this be h['can_flush'] instead of True?
>
> Are we guaranteed that imageio guarantees a consistent image across
> all other http connections when a flush is received on a single http
> connection?

imageio keeps multiple connections to qemu-nbd, and pass all requests
to qemu-nbd. No caching is done in imageio.

But we don't do any synchronization, so we may have one flush command
in the middle of a write/write_zeros commands.

Does qemu-nbd wait until the write/wirte_zeros commands complete
before flushing?