1 files changed, 209 insertions, 68 deletions

diff --git a/fs/afs/fs_probe.c b/fs/afs/fs_probe.c
index d37d78eb84bd..442b5e7944ff 100644
--- a/fs/afs/fs_probe.c
+++ b/fs/afs/fs_probe.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /* AFS fileserver probing
  *
- * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2018, 2020 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  */
 
@@ -11,14 +11,83 @@
 #include "internal.h"
 #include "protocol_yfs.h"
 
-static bool afs_fs_probe_done(struct afs_server *server)
+static unsigned int afs_fs_probe_fast_poll_interval = 30 * HZ;
+static unsigned int afs_fs_probe_slow_poll_interval = 5 * 60 * HZ;
+
+/*
+ * Start the probe polling timer.  We have to supply it with an inc on the
+ * outstanding server count.
+ */
+static void afs_schedule_fs_probe(struct afs_net *net,
+				  struct afs_server *server, bool fast)
+{
+	unsigned long atj;
+
+	if (!net->live)
+		return;
+
+	atj = server->probed_at;
+	atj += fast ? afs_fs_probe_fast_poll_interval : afs_fs_probe_slow_poll_interval;
+
+	afs_inc_servers_outstanding(net);
+	if (timer_reduce(&net->fs_probe_timer, atj))
+		afs_dec_servers_outstanding(net);
+}
+
+/*
+ * Handle the completion of a set of probes.
+ */
+static void afs_finished_fs_probe(struct afs_net *net, struct afs_server *server)
+{
+	bool responded = server->probe.responded;
+
+	write_seqlock(&net->fs_lock);
+	if (responded)
+		list_add_tail(&server->probe_link, &net->fs_probe_slow);
+	else
+		list_add_tail(&server->probe_link, &net->fs_probe_fast);
+	write_sequnlock(&net->fs_lock);
+
+	afs_schedule_fs_probe(net, server, !responded);
+}
+
+/*
+ * Handle the completion of a probe.
+ */
+static void afs_done_one_fs_probe(struct afs_net *net, struct afs_server *server)
+{
+	_enter("");
+
+	if (atomic_dec_and_test(&server->probe_outstanding))
+		afs_finished_fs_probe(net, server);
+
+	wake_up_all(&server->probe_wq);
+}
+
+/*
+ * Handle inability to send a probe due to ENOMEM when trying to allocate a
+ * call struct.
+ */
+static void afs_fs_probe_not_done(struct afs_net *net,
+				  struct afs_server *server,
+				  struct afs_addr_cursor *ac)
 {
-	if (!atomic_dec_and_test(&server->probe_outstanding))
-		return false;
+	struct afs_addr_list *alist = ac->alist;
+	unsigned int index = ac->index;
+
+	_enter("");
 
-	clear_bit_unlock(AFS_SERVER_FL_PROBING, &server->flags);
-	wake_up_bit(&server->flags, AFS_SERVER_FL_PROBING);
-	return true;
+	trace_afs_io_error(0, -ENOMEM, afs_io_error_fs_probe_fail);
+	spin_lock(&server->probe_lock);
+
+	server->probe.local_failure = true;
+	if (server->probe.error == 0)
+		server->probe.error = -ENOMEM;
+
+	set_bit(index, &alist->failed);
+
+	spin_unlock(&server->probe_lock);
+	return afs_done_one_fs_probe(net, server);
 }
 
 /*
@@ -29,10 +98,8 @@ void afs_fileserver_probe_result(struct afs_call *call)
 {
 	struct afs_addr_list *alist = call->alist;
 	struct afs_server *server = call->server;
-	unsigned int server_index = call->server_index;
 	unsigned int index = call->addr_ix;
 	unsigned int rtt_us = 0;
-	bool have_result = false;
 	int ret = call->error;
 
 	_enter("%pU,%u", &server->uuid, index);
@@ -51,8 +118,9 @@ void afs_fileserver_probe_result(struct afs_call *call)
 		goto responded;
 	case -ENOMEM:
 	case -ENONET:
+		clear_bit(index, &alist->responded);
 		server->probe.local_failure = true;
-		afs_io_error(call, afs_io_error_fs_probe_fail);
+		trace_afs_io_error(call->debug_id, ret, afs_io_error_fs_probe_fail);
 		goto out;
 	case -ECONNRESET: /* Responded, but call expired. */
 	case -ERFKILL:
@@ -71,12 +139,11 @@ void afs_fileserver_probe_result(struct afs_call *call)
 		     server->probe.error == -ETIMEDOUT ||
 		     server->probe.error == -ETIME))
 			server->probe.error = ret;
-		afs_io_error(call, afs_io_error_fs_probe_fail);
+		trace_afs_io_error(call->debug_id, ret, afs_io_error_fs_probe_fail);
 		goto out;
 	}
 
 responded:
-	set_bit(index, &alist->responded);
 	clear_bit(index, &alist->failed);
 
 	if (call->service_id == YFS_FS_SERVICE) {
@@ -95,38 +162,31 @@ responded:
 	if (rtt_us < server->probe.rtt) {
 		server->probe.rtt = rtt_us;
 		alist->preferred = index;
-		have_result = true;
 	}
 
 	smp_wmb(); /* Set rtt before responded. */
 	server->probe.responded = true;
-	set_bit(AFS_SERVER_FL_PROBED, &server->flags);
+	set_bit(index, &alist->responded);
 out:
 	spin_unlock(&server->probe_lock);
 
-	_debug("probe [%u][%u] %pISpc rtt=%u ret=%d",
-	       server_index, index, &alist->addrs[index].transport, rtt_us, ret);
+	_debug("probe %pU [%u] %pISpc rtt=%u ret=%d",
+	       &server->uuid, index, &alist->addrs[index].transport,
+	       rtt_us, ret);
 
-	have_result |= afs_fs_probe_done(server);
-	if (have_result)
-		wake_up_all(&server->probe_wq);
+	return afs_done_one_fs_probe(call->net, server);
 }
 
 /*
- * Probe all of a fileserver's addresses to find out the best route and to
- * query its capabilities.
+ * Probe one or all of a fileserver's addresses to find out the best route and
+ * to query its capabilities.
  */
-static int afs_do_probe_fileserver(struct afs_net *net,
-				   struct afs_server *server,
-				   struct key *key,
-				   unsigned int server_index,
-				   struct afs_error *_e)
+void afs_fs_probe_fileserver(struct afs_net *net, struct afs_server *server,
+			     struct key *key, bool all)
 {
 	struct afs_addr_cursor ac = {
 		.index = 0,
 	};
-	struct afs_call *call;
-	bool in_progress = false;
 
 	_enter("%pU", &server->uuid);
 
@@ -136,50 +196,25 @@ static int afs_do_probe_fileserver(struct afs_net *net,
 	afs_get_addrlist(ac.alist);
 	read_unlock(&server->fs_lock);
 
-	atomic_set(&server->probe_outstanding, ac.alist->nr_addrs);
+	server->probed_at = jiffies;
+	atomic_set(&server->probe_outstanding, all ? ac.alist->nr_addrs : 1);
 	memset(&server->probe, 0, sizeof(server->probe));
 	server->probe.rtt = UINT_MAX;
 
-	for (ac.index = 0; ac.index < ac.alist->nr_addrs; ac.index++) {
-		call = afs_fs_get_capabilities(net, server, &ac, key, server_index);
-		if (!IS_ERR(call)) {
-			afs_put_call(call);
-			in_progress = true;
-		} else {
-			afs_prioritise_error(_e, PTR_ERR(call), ac.abort_code);
-		}
-	}
-
-	if (!in_progress)
-		afs_fs_probe_done(server);
-	afs_put_addrlist(ac.alist);
-	return in_progress;
-}
+	ac.index = ac.alist->preferred;
+	if (ac.index < 0 || ac.index >= ac.alist->nr_addrs)
+		all = true;
 
-/*
- * Send off probes to all unprobed servers.
- */
-int afs_probe_fileservers(struct afs_net *net, struct key *key,
-			  struct afs_server_list *list)
-{
-	struct afs_server *server;
-	struct afs_error e;
-	bool in_progress = false;
-	int i;
-
-	e.error = 0;
-	e.responded = false;
-	for (i = 0; i < list->nr_servers; i++) {
-		server = list->servers[i].server;
-		if (test_bit(AFS_SERVER_FL_PROBED, &server->flags))
-			continue;
-
-		if (!test_and_set_bit_lock(AFS_SERVER_FL_PROBING, &server->flags) &&
-		    afs_do_probe_fileserver(net, server, key, i, &e))
-			in_progress = true;
+	if (all) {
+		for (ac.index = 0; ac.index < ac.alist->nr_addrs; ac.index++)
+			if (!afs_fs_get_capabilities(net, server, &ac, key))
+				afs_fs_probe_not_done(net, server, &ac);
+	} else {
+		if (!afs_fs_get_capabilities(net, server, &ac, key))
+			afs_fs_probe_not_done(net, server, &ac);
 	}
 
-	return in_progress ? 0 : e.error;
+	afs_put_addrlist(ac.alist);
 }
 
 /*
@@ -199,7 +234,7 @@ int afs_wait_for_fs_probes(struct afs_server_list *slist, unsigned long untried)
 	for (i = 0; i < slist->nr_servers; i++) {
 		if (test_bit(i, &untried)) {
 			server = slist->servers[i].server;
-			if (!test_bit(AFS_SERVER_FL_PROBING, &server->flags))
+			if (!atomic_read(&server->probe_outstanding))
 				__clear_bit(i, &untried);
 			if (server->probe.responded)
 				have_responders = true;
@@ -229,7 +264,7 @@ int afs_wait_for_fs_probes(struct afs_server_list *slist, unsigned long untried)
 				server = slist->servers[i].server;
 				if (server->probe.responded)
 					goto stop;
-				if (test_bit(AFS_SERVER_FL_PROBING, &server->flags))
+				if (atomic_read(&server->probe_outstanding))
 					still_probing = true;
 			}
 		}
@@ -264,3 +299,109 @@ stop:
 		slist->preferred = pref;
 	return 0;
 }
+
+/*
+ * 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]");
+	}
+}