Re: [PATCH] qemu-nbd: Document benefit of --pid-file

[Eric Blake]

On 10/8/19 8:53 AM, Vladimir Sementsov-Ogievskiy wrote:

> I've already implemented loop of attempting to connect in my series (patch 4/3).
> It's a bit more difficult to implement, but it's done. And it's a bit better,
> as it test exactly what we want to test. Can we proceed with it?

For test purposes, yes, that's fine (a test doesn't have to be clean, 
just work).

> > We shouldn't need todo any of those tricks IIUC.  The --fork argument is
> > supposed to only let the parent process exit once the server is running.
> >
> > IOW, if you run qemu-nbd --fork, in the foreground, then when execution
> > continues the sockets should be present & accepting connections. No need
> > to check for existance of any files or check connecting, etc.
> >
> >
> > Except that AFAICT, --fork isn't actually implemented with this semantics
> > in qemu-nbd. It looks like we only listen on the sockets after the parent
> > has already exited :-( Can we fix that to synchronize wrt socket listeners ?

Yes, sounds like something good to have.  I'll take a look at doing that.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org