[Libguestfs] [PATCH nbdkit] server: Fix exit with parent behaviour if flag is not specified

[Richard W.M. Jones]

On Tue, Apr 18, 2023 at 12:00:22PM +0200, Laszlo Ersek wrote:
> On 4/18/23 09:25, Richard W.M. Jones wrote:
> > Commit 6b03ec8ad6 ("common: Move exit-with-parent code from include/
> > to utils/") was supposed to be a largely neutral refactoring of the
> > --exit-with-parent flag.  However I made a mistake in one hunk of that
> > patch:
> > 
> >     -#ifdef HAVE_EXIT_WITH_PARENT
> >     -  if (exit_with_parent) {
> >     -    if (set_exit_with_parent () == -1) {
> >     -      perror ("nbdkit: --exit-with-parent");
> >     -      exit (EXIT_FAILURE);
> >     -    }
> >     +  if (set_exit_with_parent () == -1) {
> >     +    perror ("nbdkit: --exit-with-parent");
> >     +    exit (EXIT_FAILURE);
> >        }
> >     -#endif
> > 
> > by removing the test for exit_with_parent.  The effect is similar to
> > if we always specified --exit-with-parent when nbdkit is running in
> > the foreground.
> > 
> > Somewhat surprisingly this didn't have any noticable effect.  That's
> > for a few of reasons: (1) Mostly if you don't fork then you should be
> > using --exit-with-parent (and the bulk of the tests do this).  (2) If
> > we do fork into the background then the PR_SET_PDEATHSIG flag is
> > cleared by Linux across the fork.  (3) It actually _did_ break Windows
> > because there set_exit_with_parent calls abort, but for unrelated
> > reasons our Windows CI was broken (and never tested running
> > nbdkit.exe).
> > 
> > Fix this with the obvious adjustment.
> > 
> > This broke nbdkit 1.32 and 1.34.
> > 
> > Fixes: commit 6b03ec8ad672e5956b41cbacae9c307e5acd786b
> > ---
> >  server/main.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/server/main.c b/server/main.c
> > index c3b9bf384..1df5d69ac 100644
> > --- a/server/main.c
> > +++ b/server/main.c
> > @@ -574,9 +574,11 @@ main (int argc, char *argv[])
> >    /* Implement --exit-with-parent early in case plugin initialization
> >     * takes a long time and the parent exits during that time.
> >     */
> > -  if (set_exit_with_parent () == -1) {
> > -    perror ("nbdkit: --exit-with-parent");
> > -    exit (EXIT_FAILURE);
> > +  if (exit_with_parent) {
> > +    if (set_exit_with_parent () == -1) {
> > +      perror ("nbdkit: --exit-with-parent");
> > +      exit (EXIT_FAILURE);
> > +    }
> >    }
> >  
> >    /* If the user has mixed up -p/--run/-s/-U/--vsock options, then
> 
> Reviewed-by: Laszlo Ersek <lersek at redhat.com>

Thanks, pushed as beae44398ddd5386add34b43353ed16e2df0f30e

I have nearly got all the tests passing on Wine (with my out of tree
AF_UNIX patch).  And in other news ...

https://www.winehq.org/mailman3/hyperkitty/list/wine-devel@winehq.org/thread/CWFIHT4ZP5WG7FKFZZWO4W7L477BFEKJ/
https://bugs.winehq.org/show_bug.cgi?id=52568

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
nbdkit - Flexible, fast NBD server with plugins
https://gitlab.com/nbdkit/nbdkit