Re: git: 9b967bd65de6 - main - domains: allow domains to be unloaded

On Sun, Aug 14, 2022 at 8:20 AM Alexander V. Chernikov <melifaro@ipfw.ru> wrote:
>
>
>
> > On 14 Aug 2022, at 15:51, Kyle Evans <kevans@FreeBSD.org> wrote:
> >
> > On Sun, Aug 14, 2022 at 2:22 AM Alexander V. Chernikov
> > <melifaro@freebsd.org> wrote:
> >>
> >> The branch main has been updated by melifaro:
> >>
> >> URL: https://cgit.FreeBSD.org/src/commit/?id=9b967bd65de6647aed68a141dc34f9b223a2593c
> >>
> >> commit 9b967bd65de6647aed68a141dc34f9b223a2593c
> >> Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
> >> AuthorDate: 2022-08-12 13:36:53 +0000
> >> Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
> >> CommitDate: 2022-08-14 09:22:33 +0000
> >>
> >>    domains: allow domains to be unloaded
> >>
> >>    Add domain_remove() SYSUNINT callback that removes the domain
> >>     from the domain list if it has DOMF_UNLOADABLE flag set.
> >>    This change is required to support netlink ( D36002 ).
> >>
> >>    Reviewed by:    glebius
> >>    Differential Revision: https://reviews.freebsd.org/D36173
> >> ---
> >> sys/kern/uipc_domain.c | 23 +++++++++++++++++++++++
> >> sys/sys/domain.h       |  4 ++++
> >> 2 files changed, 27 insertions(+)
> >>
> >> diff --git a/sys/kern/uipc_domain.c b/sys/kern/uipc_domain.c
> >> index c70b3150cbf0..2cae08be089a 100644
> >> --- a/sys/kern/uipc_domain.c
> >> +++ b/sys/kern/uipc_domain.c
> >> @@ -239,6 +239,29 @@ domain_add(void *data)
> >>        mtx_unlock(&dom_mtx);
> >> }
> >>
> >> +void
> >> +domain_remove(void *data)
> >> +{
> >> +       struct domain *dp = (struct domain *)data;
> >> +
> >> +       if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
> >> +               return;
> >> +
> >> +       mtx_lock(&dom_mtx);
> >> +       if (domains == dp) {
> >> +               domains = dp->dom_next;
> >> +       } else {
> >> +               struct domain *curr;
> >> +               for (curr = domains; curr != NULL; curr = curr->dom_next) {
> >> +                       if (curr->dom_next == dp) {
> >> +                               curr->dom_next = dp->dom_next;
> >> +                               break;
> >> +                       }
> >> +               }
> >> +       }
> >> +       mtx_unlock(&dom_mtx);
> >> +}
> >> +
> >> /* ARGSUSED*/
> >> static void
> >> domaininit(void *dummy)
> >
> > While it's not important for the one domain you care about, this
> > should likely also check if any contained protocols have
> > pr_fasttimo/pr_slowtimo and purge them from the appropriate list, just
> > to be technically correct. (Or at least assert under INVARIANTS that
> > they do not)
> That’s a good point!
> I should have provided more context in the commit message.
> There is some ongoing work glebius@ is doing in the domain space.
> Specifically, there are plans to remove this callbacks in the near future - https://reviews.freebsd.org/D36163 stack provides more reasoning and implementation details.
> Additionally, the KPI may be a bit fluid and may change in the near/mid-term future - that’s why the minimal working version was committed.
>

Aha, disregard then. Thanks! :-)