drivers/staging/lustre/lustre/ptlrpc/pinger.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/ptlrpc/pinger.c
  33  *
  34  * Portal-RPC reconnection and replay operations, for use in recovery.
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_RPC
  38
  39 #include "../include/obd_support.h"
  40 #include "../include/obd_class.h"
  41 #include "ptlrpc_internal.h"
  42
  43 struct mutex pinger_mutex;
  44 static LIST_HEAD(pinger_imports);
  45 static struct list_head timeout_list = LIST_HEAD_INIT(timeout_list);
  46
  47 struct ptlrpc_request *
  48 ptlrpc_prep_ping(struct obd_import *imp)
  49 {
  50         struct ptlrpc_request *req;
  51
  52         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING,
  53                                         LUSTRE_OBD_VERSION, OBD_PING);
  54         if (req) {
  55                 ptlrpc_request_set_replen(req);
  56                 req->rq_no_resend = 1;
  57                 req->rq_no_delay = 1;
  58         }
  59         return req;
  60 }
  61
  62 int ptlrpc_obd_ping(struct obd_device *obd)
  63 {
  64         int rc;
  65         struct ptlrpc_request *req;
  66
  67         req = ptlrpc_prep_ping(obd->u.cli.cl_import);
  68         if (!req)
  69                 return -ENOMEM;
  70
  71         req->rq_send_state = LUSTRE_IMP_FULL;
  72
  73         rc = ptlrpc_queue_wait(req);
  74
  75         ptlrpc_req_finished(req);
  76
  77         return rc;
  78 }
  79 EXPORT_SYMBOL(ptlrpc_obd_ping);
  80
  81 static int ptlrpc_ping(struct obd_import *imp)
  82 {
  83         struct ptlrpc_request *req;
  84
  85         req = ptlrpc_prep_ping(imp);
  86         if (!req) {
  87                 CERROR("OOM trying to ping %s->%s\n",
  88                        imp->imp_obd->obd_uuid.uuid,
  89                        obd2cli_tgt(imp->imp_obd));
  90                 return -ENOMEM;
  91         }
  92
  93         DEBUG_REQ(D_INFO, req, "pinging %s->%s",
  94                   imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
  95         ptlrpcd_add_req(req);
  96
  97         return 0;
  98 }
  99
 100 static void ptlrpc_update_next_ping(struct obd_import *imp, int soon)
 101 {
 102         int time = soon ? PING_INTERVAL_SHORT : PING_INTERVAL;
 103
 104         if (imp->imp_state == LUSTRE_IMP_DISCON) {
 105                 int dtime = max_t(int, CONNECTION_SWITCH_MIN,
 106                                   AT_OFF ? 0 :
 107                                   at_get(&imp->imp_at.iat_net_latency));
 108                 time = min(time, dtime);
 109         }
 110         imp->imp_next_ping = cfs_time_shift(time);
 111 }
 112
 113 static inline int imp_is_deactive(struct obd_import *imp)
 114 {
 115         return (imp->imp_deactive ||
 116                 OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE));
 117 }
 118
 119 static inline int ptlrpc_next_reconnect(struct obd_import *imp)
 120 {
 121         if (imp->imp_server_timeout)
 122                 return cfs_time_shift(obd_timeout / 2);
 123         else
 124                 return cfs_time_shift(obd_timeout);
 125 }
 126
 127 static long pinger_check_timeout(unsigned long time)
 128 {
 129         struct timeout_item *item;
 130         unsigned long timeout = PING_INTERVAL;
 131
 132         /* The timeout list is a increase order sorted list */
 133         mutex_lock(&pinger_mutex);
 134         list_for_each_entry(item, &timeout_list, ti_chain) {
 135                 int ti_timeout = item->ti_timeout;
 136
 137                 if (timeout > ti_timeout)
 138                         timeout = ti_timeout;
 139                 break;
 140         }
 141         mutex_unlock(&pinger_mutex);
 142
 143         return cfs_time_sub(cfs_time_add(time, cfs_time_seconds(timeout)),
 144                                          cfs_time_current());
 145 }
 146
 147 static bool ir_up;
 148
 149 void ptlrpc_pinger_ir_up(void)
 150 {
 151         CDEBUG(D_HA, "IR up\n");
 152         ir_up = true;
 153 }
 154 EXPORT_SYMBOL(ptlrpc_pinger_ir_up);
 155
 156 void ptlrpc_pinger_ir_down(void)
 157 {
 158         CDEBUG(D_HA, "IR down\n");
 159         ir_up = false;
 160 }
 161 EXPORT_SYMBOL(ptlrpc_pinger_ir_down);
 162
 163 static void ptlrpc_pinger_process_import(struct obd_import *imp,
 164                                          unsigned long this_ping)
 165 {
 166         int level;
 167         int force;
 168         int force_next;
 169         int suppress;
 170
 171         spin_lock(&imp->imp_lock);
 172
 173         level = imp->imp_state;
 174         force = imp->imp_force_verify;
 175         force_next = imp->imp_force_next_verify;
 176         /*
 177          * This will be used below only if the import is "FULL".
 178          */
 179         suppress = ir_up && OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS);
 180
 181         imp->imp_force_verify = 0;
 182
 183         if (cfs_time_aftereq(imp->imp_next_ping - 5 * CFS_TICK, this_ping) &&
 184             !force) {
 185                 spin_unlock(&imp->imp_lock);
 186                 return;
 187         }
 188
 189         imp->imp_force_next_verify = 0;
 190
 191         spin_unlock(&imp->imp_lock);
 192
 193         CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA, "%s->%s: level %s/%u force %u force_next %u deactive %u pingable %u suppress %u\n",
 194                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
 195                ptlrpc_import_state_name(level), level, force, force_next,
 196                imp->imp_deactive, imp->imp_pingable, suppress);
 197
 198         if (level == LUSTRE_IMP_DISCON && !imp_is_deactive(imp)) {
 199                 /* wait for a while before trying recovery again */
 200                 imp->imp_next_ping = ptlrpc_next_reconnect(imp);
 201                 if (!imp->imp_no_pinger_recover)
 202                         ptlrpc_initiate_recovery(imp);
 203         } else if (level != LUSTRE_IMP_FULL ||
 204                    imp->imp_obd->obd_no_recov ||
 205                    imp_is_deactive(imp)) {
 206                 CDEBUG(D_HA, "%s->%s: not pinging (in recovery or recovery disabled: %s)\n",
 207                        imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
 208                        ptlrpc_import_state_name(level));
 209                 if (force) {
 210                         spin_lock(&imp->imp_lock);
 211                         imp->imp_force_verify = 1;
 212                         spin_unlock(&imp->imp_lock);
 213                 }
 214         } else if ((imp->imp_pingable && !suppress) || force_next || force) {
 215                 ptlrpc_ping(imp);
 216         }
 217 }
 218
 219 static int ptlrpc_pinger_main(void *arg)
 220 {
 221         struct ptlrpc_thread *thread = arg;
 222
 223         /* Record that the thread is running */
 224         thread_set_flags(thread, SVC_RUNNING);
 225         wake_up(&thread->t_ctl_waitq);
 226
 227         /* And now, loop forever, pinging as needed. */
 228         while (1) {
 229                 unsigned long this_ping = cfs_time_current();
 230                 struct l_wait_info lwi;
 231                 long time_to_next_wake;
 232                 struct timeout_item *item;
 233                 struct list_head *iter;
 234
 235                 mutex_lock(&pinger_mutex);
 236                 list_for_each_entry(item, &timeout_list, ti_chain) {
 237                         item->ti_cb(item, item->ti_cb_data);
 238                 }
 239                 list_for_each(iter, &pinger_imports) {
 240                         struct obd_import *imp =
 241                                 list_entry(iter, struct obd_import,
 242                                            imp_pinger_chain);
 243
 244                         ptlrpc_pinger_process_import(imp, this_ping);
 245                         /* obd_timeout might have changed */
 246                         if (imp->imp_pingable && imp->imp_next_ping &&
 247                             cfs_time_after(imp->imp_next_ping,
 248                                            cfs_time_add(this_ping,
 249                                                         cfs_time_seconds(PING_INTERVAL))))
 250                                 ptlrpc_update_next_ping(imp, 0);
 251                 }
 252                 mutex_unlock(&pinger_mutex);
 253
 254                 /* Wait until the next ping time, or until we're stopped. */
 255                 time_to_next_wake = pinger_check_timeout(this_ping);
 256                 /* The ping sent by ptlrpc_send_rpc may get sent out
 257                  * say .01 second after this.
 258                  * ptlrpc_pinger_sending_on_import will then set the
 259                  * next ping time to next_ping + .01 sec, which means
 260                  * we will SKIP the next ping at next_ping, and the
 261                  * ping will get sent 2 timeouts from now!  Beware.
 262                  */
 263                 CDEBUG(D_INFO, "next wakeup in " CFS_DURATION_T " (%ld)\n",
 264                        time_to_next_wake,
 265                        cfs_time_add(this_ping,
 266                                     cfs_time_seconds(PING_INTERVAL)));
 267                 if (time_to_next_wake > 0) {
 268                         lwi = LWI_TIMEOUT(max_t(long, time_to_next_wake,
 269                                                 cfs_time_seconds(1)),
 270                                           NULL, NULL);
 271                         l_wait_event(thread->t_ctl_waitq,
 272                                      thread_is_stopping(thread) ||
 273                                      thread_is_event(thread),
 274                                      &lwi);
 275                         if (thread_test_and_clear_flags(thread, SVC_STOPPING))
 276                                 break;
 277                         /* woken after adding import to reset timer */
 278                         thread_test_and_clear_flags(thread, SVC_EVENT);
 279                 }
 280         }
 281
 282         thread_set_flags(thread, SVC_STOPPED);
 283         wake_up(&thread->t_ctl_waitq);
 284
 285         CDEBUG(D_NET, "pinger thread exiting, process %d\n", current_pid());
 286         return 0;
 287 }
 288
 289 static struct ptlrpc_thread pinger_thread;
 290
 291 int ptlrpc_start_pinger(void)
 292 {
 293         struct l_wait_info lwi = { 0 };
 294         struct task_struct *task;
 295         int rc;
 296
 297         if (!thread_is_init(&pinger_thread) &&
 298             !thread_is_stopped(&pinger_thread))
 299                 return -EALREADY;
 300
 301         init_waitqueue_head(&pinger_thread.t_ctl_waitq);
 302
 303         strcpy(pinger_thread.t_name, "ll_ping");
 304
 305         task = kthread_run(ptlrpc_pinger_main, &pinger_thread,
 306                            pinger_thread.t_name);
 307         if (IS_ERR(task)) {
 308                 rc = PTR_ERR(task);
 309                 CERROR("cannot start pinger thread: rc = %d\n", rc);
 310                 return rc;
 311         }
 312         l_wait_event(pinger_thread.t_ctl_waitq,
 313                      thread_is_running(&pinger_thread), &lwi);
 314
 315         return 0;
 316 }
 317
 318 static int ptlrpc_pinger_remove_timeouts(void);
 319
 320 int ptlrpc_stop_pinger(void)
 321 {
 322         struct l_wait_info lwi = { 0 };
 323         int rc = 0;
 324
 325         if (thread_is_init(&pinger_thread) ||
 326             thread_is_stopped(&pinger_thread))
 327                 return -EALREADY;
 328
 329         ptlrpc_pinger_remove_timeouts();
 330         thread_set_flags(&pinger_thread, SVC_STOPPING);
 331         wake_up(&pinger_thread.t_ctl_waitq);
 332
 333         l_wait_event(pinger_thread.t_ctl_waitq,
 334                      thread_is_stopped(&pinger_thread), &lwi);
 335
 336         return rc;
 337 }
 338
 339 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 340 {
 341         ptlrpc_update_next_ping(imp, 0);
 342 }
 343 EXPORT_SYMBOL(ptlrpc_pinger_sending_on_import);
 344
 345 void ptlrpc_pinger_commit_expected(struct obd_import *imp)
 346 {
 347         ptlrpc_update_next_ping(imp, 1);
 348         assert_spin_locked(&imp->imp_lock);
 349         /*
 350          * Avoid reading stale imp_connect_data.  When not sure if pings are
 351          * expected or not on next connection, we assume they are not and force
 352          * one anyway to guarantee the chance of updating
 353          * imp_peer_committed_transno.
 354          */
 355         if (imp->imp_state != LUSTRE_IMP_FULL ||
 356             OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS))
 357                 imp->imp_force_next_verify = 1;
 358 }
 359
 360 int ptlrpc_pinger_add_import(struct obd_import *imp)
 361 {
 362         if (!list_empty(&imp->imp_pinger_chain))
 363                 return -EALREADY;
 364
 365         mutex_lock(&pinger_mutex);
 366         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 367                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 368         /* if we add to pinger we want recovery on this import */
 369         imp->imp_obd->obd_no_recov = 0;
 370         ptlrpc_update_next_ping(imp, 0);
 371         /* XXX sort, blah blah */
 372         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 373         class_import_get(imp);
 374
 375         ptlrpc_pinger_wake_up();
 376         mutex_unlock(&pinger_mutex);
 377
 378         return 0;
 379 }
 380 EXPORT_SYMBOL(ptlrpc_pinger_add_import);
 381
 382 int ptlrpc_pinger_del_import(struct obd_import *imp)
 383 {
 384         if (list_empty(&imp->imp_pinger_chain))
 385                 return -ENOENT;
 386
 387         mutex_lock(&pinger_mutex);
 388         list_del_init(&imp->imp_pinger_chain);
 389         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 390                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 391         /* if we remove from pinger we don't want recovery on this import */
 392         imp->imp_obd->obd_no_recov = 1;
 393         class_import_put(imp);
 394         mutex_unlock(&pinger_mutex);
 395         return 0;
 396 }
 397 EXPORT_SYMBOL(ptlrpc_pinger_del_import);
 398
 399 /**
 400  * Register a timeout callback to the pinger list, and the callback will
 401  * be called when timeout happens.
 402  */
 403 static struct timeout_item *ptlrpc_new_timeout(int time,
 404                                                enum timeout_event event,
 405                                                timeout_cb_t cb, void *data)
 406 {
 407         struct timeout_item *ti;
 408
 409         ti = kzalloc(sizeof(*ti), GFP_NOFS);
 410         if (!ti)
 411                 return NULL;
 412
 413         INIT_LIST_HEAD(&ti->ti_obd_list);
 414         INIT_LIST_HEAD(&ti->ti_chain);
 415         ti->ti_timeout = time;
 416         ti->ti_event = event;
 417         ti->ti_cb = cb;
 418         ti->ti_cb_data = data;
 419
 420         return ti;
 421 }
 422
 423 /**
 424  * Register timeout event on the pinger thread.
 425  * Note: the timeout list is an sorted list with increased timeout value.
 426  */
 427 static struct timeout_item*
 428 ptlrpc_pinger_register_timeout(int time, enum timeout_event event,
 429                                timeout_cb_t cb, void *data)
 430 {
 431         struct timeout_item *item, *tmp;
 432
 433         LASSERT(mutex_is_locked(&pinger_mutex));
 434
 435         list_for_each_entry(item, &timeout_list, ti_chain)
 436                 if (item->ti_event == event)
 437                         goto out;
 438
 439         item = ptlrpc_new_timeout(time, event, cb, data);
 440         if (item) {
 441                 list_for_each_entry_reverse(tmp, &timeout_list, ti_chain) {
 442                         if (tmp->ti_timeout < time) {
 443                                 list_add(&item->ti_chain, &tmp->ti_chain);
 444                                 goto out;
 445                         }
 446                 }
 447                 list_add(&item->ti_chain, &timeout_list);
 448         }
 449 out:
 450         return item;
 451 }
 452
 453 /* Add a client_obd to the timeout event list, when timeout(@time)
 454  * happens, the callback(@cb) will be called.
 455  */
 456 int ptlrpc_add_timeout_client(int time, enum timeout_event event,
 457                               timeout_cb_t cb, void *data,
 458                               struct list_head *obd_list)
 459 {
 460         struct timeout_item *ti;
 461
 462         mutex_lock(&pinger_mutex);
 463         ti = ptlrpc_pinger_register_timeout(time, event, cb, data);
 464         if (!ti) {
 465                 mutex_unlock(&pinger_mutex);
 466                 return -EINVAL;
 467         }
 468         list_add(obd_list, &ti->ti_obd_list);
 469         mutex_unlock(&pinger_mutex);
 470         return 0;
 471 }
 472 EXPORT_SYMBOL(ptlrpc_add_timeout_client);
 473
 474 int ptlrpc_del_timeout_client(struct list_head *obd_list,
 475                               enum timeout_event event)
 476 {
 477         struct timeout_item *ti = NULL, *item;
 478
 479         if (list_empty(obd_list))
 480                 return 0;
 481         mutex_lock(&pinger_mutex);
 482         list_del_init(obd_list);
 483         /**
 484          * If there are no obd attached to the timeout event
 485          * list, remove this timeout event from the pinger
 486          */
 487         list_for_each_entry(item, &timeout_list, ti_chain) {
 488                 if (item->ti_event == event) {
 489                         ti = item;
 490                         break;
 491                 }
 492         }
 493         if (list_empty(&ti->ti_obd_list)) {
 494                 list_del(&ti->ti_chain);
 495                 kfree(ti);
 496         }
 497         mutex_unlock(&pinger_mutex);
 498         return 0;
 499 }
 500 EXPORT_SYMBOL(ptlrpc_del_timeout_client);
 501
 502 static int ptlrpc_pinger_remove_timeouts(void)
 503 {
 504         struct timeout_item *item, *tmp;
 505
 506         mutex_lock(&pinger_mutex);
 507         list_for_each_entry_safe(item, tmp, &timeout_list, ti_chain) {
 508                 LASSERT(list_empty(&item->ti_obd_list));
 509                 list_del(&item->ti_chain);
 510                 kfree(item);
 511         }
 512         mutex_unlock(&pinger_mutex);
 513         return 0;
 514 }
 515
 516 void ptlrpc_pinger_wake_up(void)
 517 {
 518         thread_add_flags(&pinger_thread, SVC_EVENT);
 519         wake_up(&pinger_thread.t_ctl_waitq);
 520 }