+
+/*
+ * Probe timer. We have an increment on fs_outstanding that we need to pass
+ * along to the work item.
+ */
+void afs_fs_probe_timer(struct timer_list *timer)
+{
+ struct afs_net *net = container_of(timer, struct afs_net, fs_probe_timer);
+
+ if (!queue_work(afs_wq, &net->fs_prober))
+ afs_dec_servers_outstanding(net);
+}
+
+/*
+ * Dispatch a probe to a server.
+ */
+static void afs_dispatch_fs_probe(struct afs_net *net, struct afs_server *server, bool all)
+ __releases(&net->fs_lock)
+{
+ struct key *key = NULL;
+
+ /* We remove it from the queues here - it will be added back to
+ * one of the queues on the completion of the probe.
+ */
+ list_del_init(&server->probe_link);
+
+ afs_get_server(server, afs_server_trace_get_probe);
+ write_sequnlock(&net->fs_lock);
+
+ afs_fs_probe_fileserver(net, server, key, all);
+ afs_put_server(net, server, afs_server_trace_put_probe);
+}
+
+/*
+ * Probe dispatcher to regularly dispatch probes to keep NAT alive.
+ */
+void afs_fs_probe_dispatcher(struct work_struct *work)
+{
+ struct afs_net *net = container_of(work, struct afs_net, fs_prober);
+ struct afs_server *fast, *slow, *server;
+ unsigned long nowj, timer_at, poll_at;
+ bool first_pass = true, set_timer = false;
+
+ if (!net->live)
+ return;
+
+ _enter("");
+
+ if (list_empty(&net->fs_probe_fast) && list_empty(&net->fs_probe_slow)) {
+ _leave(" [none]");
+ return;
+ }
+
+again:
+ write_seqlock(&net->fs_lock);
+
+ fast = slow = server = NULL;
+ nowj = jiffies;
+ timer_at = nowj + MAX_JIFFY_OFFSET;
+
+ if (!list_empty(&net->fs_probe_fast)) {
+ fast = list_first_entry(&net->fs_probe_fast, struct afs_server, probe_link);
+ poll_at = fast->probed_at + afs_fs_probe_fast_poll_interval;
+ if (time_before(nowj, poll_at)) {
+ timer_at = poll_at;
+ set_timer = true;
+ fast = NULL;
+ }
+ }
+
+ if (!list_empty(&net->fs_probe_slow)) {
+ slow = list_first_entry(&net->fs_probe_slow, struct afs_server, probe_link);
+ poll_at = slow->probed_at + afs_fs_probe_slow_poll_interval;
+ if (time_before(nowj, poll_at)) {
+ if (time_before(poll_at, timer_at))
+ timer_at = poll_at;
+ set_timer = true;
+ slow = NULL;
+ }
+ }
+
+ server = fast ?: slow;
+ if (server)
+ _debug("probe %pU", &server->uuid);
+
+ if (server && (first_pass || !need_resched())) {
+ afs_dispatch_fs_probe(net, server, server == fast);
+ first_pass = false;
+ goto again;
+ }
+
+ write_sequnlock(&net->fs_lock);
+
+ if (server) {
+ if (!queue_work(afs_wq, &net->fs_prober))
+ afs_dec_servers_outstanding(net);
+ _leave(" [requeue]");
+ } else if (set_timer) {
+ if (timer_reduce(&net->fs_probe_timer, timer_at))
+ afs_dec_servers_outstanding(net);
+ _leave(" [timer]");
+ } else {
+ afs_dec_servers_outstanding(net);
+ _leave(" [quiesce]");
+ }
+}