// SPDX-License-Identifier: GPL-2.0-or-later
|
/* AFS fileserver probing
|
*
|
* Copyright (C) 2018, 2020 Red Hat, Inc. All Rights Reserved.
|
* Written by David Howells (dhowells@redhat.com)
|
*/
|
|
#include <linux/sched.h>
|
#include <linux/slab.h>
|
#include "afs_fs.h"
|
#include "internal.h"
|
#include "protocol_yfs.h"
|
|
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 {
|
server->rtt = UINT_MAX;
|
clear_bit(AFS_SERVER_FL_RESPONDING, &server->flags);
|
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)
|
{
|
struct afs_addr_list *alist = ac->alist;
|
unsigned int index = ac->index;
|
|
_enter("");
|
|
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);
|
}
|
|
/*
|
* Process the result of probing a fileserver. This is called after successful
|
* or failed delivery of an FS.GetCapabilities operation.
|
*/
|
void afs_fileserver_probe_result(struct afs_call *call)
|
{
|
struct afs_addr_list *alist = call->alist;
|
struct afs_server *server = call->server;
|
unsigned int index = call->addr_ix;
|
unsigned int rtt_us = 0;
|
int ret = call->error;
|
|
_enter("%pU,%u", &server->uuid, index);
|
|
spin_lock(&server->probe_lock);
|
|
switch (ret) {
|
case 0:
|
server->probe.error = 0;
|
goto responded;
|
case -ECONNABORTED:
|
if (!server->probe.responded) {
|
server->probe.abort_code = call->abort_code;
|
server->probe.error = ret;
|
}
|
goto responded;
|
case -ENOMEM:
|
case -ENONET:
|
clear_bit(index, &alist->responded);
|
server->probe.local_failure = true;
|
trace_afs_io_error(call->debug_id, ret, afs_io_error_fs_probe_fail);
|
goto out;
|
case -ECONNRESET: /* Responded, but call expired. */
|
case -ERFKILL:
|
case -EADDRNOTAVAIL:
|
case -ENETUNREACH:
|
case -EHOSTUNREACH:
|
case -EHOSTDOWN:
|
case -ECONNREFUSED:
|
case -ETIMEDOUT:
|
case -ETIME:
|
default:
|
clear_bit(index, &alist->responded);
|
set_bit(index, &alist->failed);
|
if (!server->probe.responded &&
|
(server->probe.error == 0 ||
|
server->probe.error == -ETIMEDOUT ||
|
server->probe.error == -ETIME))
|
server->probe.error = ret;
|
trace_afs_io_error(call->debug_id, ret, afs_io_error_fs_probe_fail);
|
goto out;
|
}
|
|
responded:
|
clear_bit(index, &alist->failed);
|
|
if (call->service_id == YFS_FS_SERVICE) {
|
server->probe.is_yfs = true;
|
set_bit(AFS_SERVER_FL_IS_YFS, &server->flags);
|
alist->addrs[index].srx_service = call->service_id;
|
} else {
|
server->probe.not_yfs = true;
|
if (!server->probe.is_yfs) {
|
clear_bit(AFS_SERVER_FL_IS_YFS, &server->flags);
|
alist->addrs[index].srx_service = call->service_id;
|
}
|
}
|
|
rxrpc_kernel_get_srtt(call->net->socket, call->rxcall, &rtt_us);
|
if (rtt_us < server->probe.rtt) {
|
server->probe.rtt = rtt_us;
|
server->rtt = rtt_us;
|
alist->preferred = index;
|
}
|
|
smp_wmb(); /* Set rtt before responded. */
|
server->probe.responded = true;
|
set_bit(index, &alist->responded);
|
set_bit(AFS_SERVER_FL_RESPONDING, &server->flags);
|
out:
|
spin_unlock(&server->probe_lock);
|
|
_debug("probe %pU [%u] %pISpc rtt=%u ret=%d",
|
&server->uuid, index, &alist->addrs[index].transport,
|
rtt_us, ret);
|
|
return afs_done_one_fs_probe(call->net, server);
|
}
|
|
/*
|
* Probe one or all of a fileserver's addresses to find out the best route and
|
* to query its capabilities.
|
*/
|
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,
|
};
|
|
_enter("%pU", &server->uuid);
|
|
read_lock(&server->fs_lock);
|
ac.alist = rcu_dereference_protected(server->addresses,
|
lockdep_is_held(&server->fs_lock));
|
afs_get_addrlist(ac.alist);
|
read_unlock(&server->fs_lock);
|
|
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;
|
|
ac.index = ac.alist->preferred;
|
if (ac.index < 0 || ac.index >= ac.alist->nr_addrs)
|
all = 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);
|
}
|
|
afs_put_addrlist(ac.alist);
|
}
|
|
/*
|
* Wait for the first as-yet untried fileserver to respond.
|
*/
|
int afs_wait_for_fs_probes(struct afs_server_list *slist, unsigned long untried)
|
{
|
struct wait_queue_entry *waits;
|
struct afs_server *server;
|
unsigned int rtt = UINT_MAX, rtt_s;
|
bool have_responders = false;
|
int pref = -1, i;
|
|
_enter("%u,%lx", slist->nr_servers, untried);
|
|
/* Only wait for servers that have a probe outstanding. */
|
for (i = 0; i < slist->nr_servers; i++) {
|
if (test_bit(i, &untried)) {
|
server = slist->servers[i].server;
|
if (!atomic_read(&server->probe_outstanding))
|
__clear_bit(i, &untried);
|
if (server->probe.responded)
|
have_responders = true;
|
}
|
}
|
if (have_responders || !untried)
|
return 0;
|
|
waits = kmalloc(array_size(slist->nr_servers, sizeof(*waits)), GFP_KERNEL);
|
if (!waits)
|
return -ENOMEM;
|
|
for (i = 0; i < slist->nr_servers; i++) {
|
if (test_bit(i, &untried)) {
|
server = slist->servers[i].server;
|
init_waitqueue_entry(&waits[i], current);
|
add_wait_queue(&server->probe_wq, &waits[i]);
|
}
|
}
|
|
for (;;) {
|
bool still_probing = false;
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
for (i = 0; i < slist->nr_servers; i++) {
|
if (test_bit(i, &untried)) {
|
server = slist->servers[i].server;
|
if (server->probe.responded)
|
goto stop;
|
if (atomic_read(&server->probe_outstanding))
|
still_probing = true;
|
}
|
}
|
|
if (!still_probing || signal_pending(current))
|
goto stop;
|
schedule();
|
}
|
|
stop:
|
set_current_state(TASK_RUNNING);
|
|
for (i = 0; i < slist->nr_servers; i++) {
|
if (test_bit(i, &untried)) {
|
server = slist->servers[i].server;
|
rtt_s = READ_ONCE(server->rtt);
|
if (test_bit(AFS_SERVER_FL_RESPONDING, &server->flags) &&
|
rtt_s < rtt) {
|
pref = i;
|
rtt = rtt_s;
|
}
|
|
remove_wait_queue(&server->probe_wq, &waits[i]);
|
}
|
}
|
|
kfree(waits);
|
|
if (pref == -1 && signal_pending(current))
|
return -ERESTARTSYS;
|
|
if (pref >= 0)
|
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 (!net->live || !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 a server immediately without waiting for its due time to come
|
* round. This is used when all of the addresses have been tried.
|
*/
|
void afs_probe_fileserver(struct afs_net *net, struct afs_server *server)
|
{
|
write_seqlock(&net->fs_lock);
|
if (!list_empty(&server->probe_link))
|
return afs_dispatch_fs_probe(net, server, true);
|
write_sequnlock(&net->fs_lock);
|
}
|
|
/*
|
* 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]");
|
}
|
}
|
|
/*
|
* Wait for a probe on a particular fileserver to complete for 2s.
|
*/
|
int afs_wait_for_one_fs_probe(struct afs_server *server, bool is_intr)
|
{
|
struct wait_queue_entry wait;
|
unsigned long timo = 2 * HZ;
|
|
if (atomic_read(&server->probe_outstanding) == 0)
|
goto dont_wait;
|
|
init_wait_entry(&wait, 0);
|
for (;;) {
|
prepare_to_wait_event(&server->probe_wq, &wait,
|
is_intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
|
if (timo == 0 ||
|
server->probe.responded ||
|
atomic_read(&server->probe_outstanding) == 0 ||
|
(is_intr && signal_pending(current)))
|
break;
|
timo = schedule_timeout(timo);
|
}
|
|
finish_wait(&server->probe_wq, &wait);
|
|
dont_wait:
|
if (server->probe.responded)
|
return 0;
|
if (is_intr && signal_pending(current))
|
return -ERESTARTSYS;
|
if (timo == 0)
|
return -ETIME;
|
return -EDESTADDRREQ;
|
}
|
|
/*
|
* Clean up the probing when the namespace is killed off.
|
*/
|
void afs_fs_probe_cleanup(struct afs_net *net)
|
{
|
if (del_timer_sync(&net->fs_probe_timer))
|
afs_dec_servers_outstanding(net);
|
}
|
