Re: [Nbd] [PATCH] Fix flags processing to avoid bogus read-only export

[Wouter Verhelst <w@...112...>]

On Wed, May 04, 2016 at 11:46:37AM +0100, Alex Bligh wrote:
> 
> On 4 May 2016, at 11:45, Alex Bligh <alex@...872...> wrote:
> 
> > As described here:
> >  https://www.mail-archive.com/nbd-general@lists.sourceforge.net/msg03878.html
> > 
> > NBD clients prior to 3.10 incorrectly attempt to merge the server flags
> > with the transmission flags. This means that any such client cannot connect
> > to a server (e.g. NBD server post 3.10, gonbdserver) which supports
> > NBD_FLAG_NO_ZEROES without making the export read-only.
> > 
> > This one line fix avoids the issue by simply passing the kernel the
> > transmission flags without an attempt to merge them. This is the
> > behaviour nbd-client (post 3.10) does, and also qemu's current behaviour.
> 
> This is against 3.7, obviously.
> 
> If people are OK about this, how do I get this upstream?

Well, I'm not going to release updated upstream versions of this, and
the most recent version of nbd doesn't expose the bug. However, having
that patch in distributions which still ships and older version of nbd
does sure sound like a good idea.

> I'm happy to file an Ubuntu bug but I'm wondering if Wouter is the
> Debian maintainer, and indeed whether we (I?) can simply push it as a
> branch.

I am the Debian maintainer, yes. What kind of branch do you mean,
though?

I'm thinking it does make sense to push an update to Debian Jessie for
this, too. It's a bit of an ugly bug.

-- 
< ron> I mean, the main *practical* problem with C++, is there's like a dozen
       people in the world who think they really understand all of its rules,
       and pretty much all of them are just lying to themselves too.
 -- #debian-devel, OFTC, 2016-02-12