diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index a02e569813d2..e517eaaa177b 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -1824,8 +1824,7 @@ int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler); int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler); int ip_vs_bind_scheduler(struct ip_vs_service *svc, struct ip_vs_scheduler *scheduler); -void ip_vs_unbind_scheduler(struct ip_vs_service *svc, - struct ip_vs_scheduler *sched); +void ip_vs_unbind_scheduler(struct ip_vs_service *svc); struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name); void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler); struct ip_vs_conn * diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index bd9cae44d214..16daba8cac83 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1898,7 +1898,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, if (ret_hooks >= 0) ip_vs_unregister_hooks(ipvs, u->af); if (svc != NULL) { - ip_vs_unbind_scheduler(svc, sched); + ip_vs_unbind_scheduler(svc); ip_vs_service_free(svc); } ip_vs_scheduler_put(sched); @@ -1962,9 +1962,8 @@ ip_vs_edit_service(struct ip_vs_service *svc, struct ip_vs_service_user_kern *u) old_sched = rcu_dereference_protected(svc->scheduler, 1); if (sched != old_sched) { if (old_sched) { - ip_vs_unbind_scheduler(svc, old_sched); - RCU_INIT_POINTER(svc->scheduler, NULL); - /* Wait all svc->sched_data users */ + ip_vs_unbind_scheduler(svc); + /* Wait all svc->scheduler/sched_data users */ synchronize_rcu(); } /* Bind the new scheduler */ @@ -1972,6 +1971,10 @@ ip_vs_edit_service(struct ip_vs_service *svc, struct ip_vs_service_user_kern *u) ret = ip_vs_bind_scheduler(svc, sched); if (ret) { ip_vs_scheduler_put(sched); + /* Try to restore the old_sched */ + if (old_sched && + !ip_vs_bind_scheduler(svc, old_sched)) + old_sched = NULL; goto out; } } @@ -2027,7 +2030,7 @@ static void __ip_vs_del_service(struct ip_vs_service *svc, bool cleanup) /* Unbind scheduler */ old_sched = rcu_dereference_protected(svc->scheduler, 1); - ip_vs_unbind_scheduler(svc, old_sched); + ip_vs_unbind_scheduler(svc); ip_vs_scheduler_put(old_sched); /* Unbind persistence engine, keep svc->pe */ diff --git a/net/netfilter/ipvs/ip_vs_sched.c b/net/netfilter/ipvs/ip_vs_sched.c index c6e421c4e299..24adc38942a0 100644 --- a/net/netfilter/ipvs/ip_vs_sched.c +++ b/net/netfilter/ipvs/ip_vs_sched.c @@ -56,19 +56,19 @@ int ip_vs_bind_scheduler(struct ip_vs_service *svc, /* * Unbind a service with its scheduler */ -void ip_vs_unbind_scheduler(struct ip_vs_service *svc, - struct ip_vs_scheduler *sched) +void ip_vs_unbind_scheduler(struct ip_vs_service *svc) { - struct ip_vs_scheduler *cur_sched; + struct ip_vs_scheduler *sched; - cur_sched = rcu_dereference_protected(svc->scheduler, 1); - /* This check proves that old 'sched' was installed */ - if (!cur_sched) + sched = rcu_dereference_protected(svc->scheduler, 1); + if (!sched) return; + /* Reset the scheduler before initiating any RCU callbacks */ + rcu_assign_pointer(svc->scheduler, NULL); + smp_wmb(); /* paired with smp_rmb() in ip_vs_schedule() */ if (sched->done_service) sched->done_service(svc); - /* svc->scheduler can be set to NULL only by caller */ }