Hello,
On Fri, 8 Jul 2022 00:53:16 +0300
Vitaliy Makkoveev <[email protected]> wrote:
> The `pipex_list_mtx' mutex(9) protects global pipex(4) lists so it need
> to be taken while we perform this foreach loop.
>
> The all sessions loop was reworked to make possible to drop the lock
> within. This is required because pipex_ppp_output() takes scheduler lock
> when performs ip_send().
>
> Index: sys/net/pipex.c
> ===================================================================
> RCS file: /cvs/src/sys/net/pipex.c,v
> retrieving revision 1.143
> diff -u -p -r1.143 pipex.c
> --- sys/net/pipex.c 2 Jul 2022 08:50:42 -0000 1.143
> +++ sys/net/pipex.c 7 Jul 2022 21:52:16 -0000
> @@ -842,20 +842,39 @@ pipex_ip_output(struct mbuf *m0, struct
>
> m0->m_flags &= ~(M_BCAST|M_MCAST);
>
> - LIST_FOREACH(session_tmp, &pipex_session_list, session_list) {
> + mtx_enter(&pipex_list_mtx);
> +
> + session_tmp = LIST_FIRST(&pipex_session_list);
> + while (session_tmp != NULL) {
> + struct pipex_session *session_save = NULL;
> +
> if (session_tmp->ownersc != session->ownersc)
> - continue;
> + goto next;
> if ((session->flags & (PIPEX_SFLAGS_IP_FORWARD |
> PIPEX_SFLAGS_IP6_FORWARD)) == 0)
> - continue;
> + goto next;
> m = m_copym(m0, 0, M_COPYALL, M_NOWAIT);
> if (m == NULL) {
> counters_inc(session->stat_counters,
> pxc_oerrors);
> - continue;
> + goto next;
> }
> +
> + refcnt_take(&session->pxs_refcnt);
this "session" should be session_tmp?
Also, isn't it needed to take reference count on top of the block?
session_ = LIST_FIRST(&pipex_session_list);
while (session_tmp != NULL) {
refcnt_take(&session_tmp->pxs_refcnt);
if (session_tmp->ownersc != session->ownersc)
goto next;
if ((session->flags & (PIPEX_SFLAGS_IP_FORWARD |
PIPEX_SFLAGS_IP6_FORWARD)) == 0)
goto next;
m = m_copym(m0, 0, M_COPYALL, M_NOWAIT);
if (m == NULL) {
counters_inc(session->stat_counters,
pxc_oerrors);
goto next;
}
mtx_leave(&pipex_list_mtx);
pipex_ppp_output(m, session_tmp, PPP_IP);
mtx_enter(&pipex_list_mtx);
next:
session_save = session_tmp;
session_tmp = LIST_NEXT(session_tmp, session_list);
pipex_rele_session(session_save);
}
> + mtx_leave(&pipex_list_mtx);
> +
> pipex_ppp_output(m, session_tmp, PPP_IP);
> +
> + mtx_enter(&pipex_list_mtx);
> + session_save = session_tmp;
> +next:
> + session_tmp = LIST_NEXT(session_tmp, session_list);
> + if (session_save != NULL)
> + pipex_rele_session(session_save);
> }
> +
> + mtx_leave(&pipex_list_mtx);
> +
> m_freem(m0);
> }
>
