From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/afs/fs_probe.c | 478 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 478 insertions(+) create mode 100644 fs/afs/fs_probe.c (limited to 'fs/afs/fs_probe.c') diff --git a/fs/afs/fs_probe.c b/fs/afs/fs_probe.c new file mode 100644 index 000000000..daaf3810c --- /dev/null +++ b/fs/afs/fs_probe.c @@ -0,0 +1,478 @@ +// 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 +#include +#include "afs_fs.h" +#include "internal.h" +#include "protocol_afs.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, cap0; + 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; + } + cap0 = ntohl(call->tmp); + if (cap0 & AFS3_VICED_CAPABILITY_64BITFILES) + set_bit(AFS_SERVER_FL_HAS_FS64, &server->flags); + else + clear_bit(AFS_SERVER_FL_HAS_FS64, &server->flags); + } + + 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) { + afs_dec_servers_outstanding(net); + return; + } + + _enter(""); + + if (list_empty(&net->fs_probe_fast) && list_empty(&net->fs_probe_slow)) { + afs_dec_servers_outstanding(net); + _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); +} -- cgit v1.2.3