[PATCH 1/2] cpukit/jffs2: Set extracted nodes off-chain

[Kinsey Moore]

On Thu, Sep 21, 2023 at 9:47 AM Sebastian Huber <
sebastian.huber at embedded-brains.de> wrote:

> On 20.09.23 20:35, Kinsey Moore wrote:
> [...]
> > @@ -1306,8 +1307,22 @@ static void process_delayed_work(void)
> >       while (!rtems_chain_is_tail(&process_work_chain, node)) {
> >               work = (struct delayed_work*) node;
> >               rtems_chain_node* next_node = rtems_chain_next(node);
> > +
> > +             /*
> > +              * Don't leave extracted node exposed to other operations
> > +              * under RTEMS_DEBUG
> > +              */
> > +#ifdef RTEMS_DEBUG
> > +             mutex_lock(&delayed_work_mutex);
> > +#endif
> >               rtems_chain_extract(node);
> > +#ifdef RTEMS_DEBUG
> > +             node->next = node;
> > +             mutex_unlock(&delayed_work_mutex);
> > +#endif
> > +
> >               work->callback(&work->work);
> > +             rtems_chain_set_off_chain(node);
> >               node = next_node;
> >       }
> >   }
>
> This change makes no sense to me. The code should work regardless if
> RTEMS_DEBUG is defined or not.
>

RTEMS_DEBUG introduces a behavioral change in rtems_chain_extract() such
that extracted nodes are automatically set off-chain. When RTEMS_DEBUG is
not set, node->next is left untouched. This has to be managed because this
code needs the node to remain on-chain so that it is not re-queued during
the operation.

Kinsey
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