Re: [Qemu-block] [Qemu-devel] [PATCH v2] nbd: Flip qemu-nbd to prefer newstyle; add -O for old behavior

[Eric Blake]

On 10/3/18 12:55 PM, Eric Blake wrote:
> Oldstyle NBD negotiation cannot perform any of the extensions that
> we have recently been relying on.  While you can always pass -x ""
> to get newstyle negotiation, these days, it is better to just default
> to newstyle (with an empty export name) and fall back to oldstyle
> only on an explicit request.
>
> qemu as client can manage either style since 2.6.0, commit 69b49502d8
>
> For comparison:
>
> nbdkit 1.3 switched its default to newstyle (Jan 2018):
> https://github.com/libguestfs/nbdkit/commit/b2a8aecc
> https://github.com/libguestfs/nbdkit/commit/8158e773
>
> nbd 3.10 dropped oldstyle long ago (Mar 2015):
> https://github.com/NetworkBlockDevice/nbd/commit/36940193
>
> Signed-off-by: Eric Blake <address@hidden>
> ---
> v2: improve 'qemu-nbd --help', drop redundant variable 'newproto'
> ---
>   qemu-nbd.c | 37 +++++++++++++++++++++++--------------
>   1 file changed, 23 insertions(+), 14 deletions(-)

But I still forgot to document it in qemu-nbd.texi.

I'm dropping this patch in favor of Vladimir's stronger series, now that 
Rich has agreed with my observation that nbdkit can bridge the needs of 
any non-qemu client that still only talks oldstyle.

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