[Libguestfs] [nbdkit PATCH] sh: Add exit status triggers for nbdkit_{shutdown, disconnect}

[Eric Blake]

On Wed, Nov 02, 2022 at 01:43:13PM +0000, Richard W.M. Jones wrote:
> On Tue, Nov 01, 2022 at 02:56:09PM -0500, Eric Blake wrote:
> ...
> > +=item S<6>
> > +
> > +Triggers a call to the C function C<nbdkit_disconnect> with C<force>
> > +set to false, which requests a soft disconnect of the current client
> > +(future client requests are rejected with C<ESHUTDOWN> without calling
> > +into the plugin, but current requests may complete).  Since the client
> > +will likely get the response to this command, nbdkit then treats empty
> > +stderr as success for the current callback, and parses non-empty
> > +stderr as if the script had exited with code S<1>.
> 
> OK .. seems like complicated behaviour, but I can sort of see the
> reasoning behind it.
> 
> I do wonder if we just want to use separate codes for the "soft
> disconnect + OK" and the "soft disconnect + error" cases.  We have
> reserved more so we won't run out :-)

Given that both you and Laszlo requested it, I will respin along those
lines.

> 
> > +=item 7-15
> > +
> > +These exit codes are reserved for future use.  Note that versions of
> > +nbdkit E<lt> 1.34 documented that codes S<8> through S<15> behaved
> 
> This is actually a case where S<> around the nbdkit E<lt> 1.34 makes
> sense.  But it should be removed around S<8> etc and in the next line
> below.

I'll fix the pre-existing inconsistent use of S<> as part of the respin.

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