lustre/ptlrpc/pinger.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/ptlrpc/pinger.c
  37  *
  38  * Portal-RPC reconnection and replay operations, for use in recovery.
  39  */
  40
  41 #ifndef __KERNEL__
  42 #include <liblustre.h>
  43 #else
  44 #define DEBUG_SUBSYSTEM S_RPC
  45 #endif
  46
  47 #include <obd_support.h>
  48 #include <obd_class.h>
  49 #include <lustre_net.h>
  50 #include "ptlrpc_internal.h"
  51
  52 #ifdef __KERNEL__
  53 /* What time pinger is supposed to wake up next.
  54  * pd_next_ping is the equivalent for liblustre. */
  55 cfs_time_t pinger_next_wake;
  56 #endif
  57
  58 struct semaphore pinger_sem;
  59 static struct list_head pinger_imports = CFS_LIST_HEAD_INIT(pinger_imports);
  60 static struct list_head timeout_list = CFS_LIST_HEAD_INIT(timeout_list);
  61
  62 struct ptlrpc_request *
  63 ptlrpc_prep_ping(struct obd_import *imp)
  64 {
  65         struct ptlrpc_request *req;
  66
  67         req = ptlrpc_prep_req(imp, LUSTRE_OBD_VERSION,
  68                               OBD_PING, 1, NULL, NULL);
  69         if (req) {
  70                 ptlrpc_req_set_repsize(req, 1, NULL);
  71                 req->rq_no_resend = req->rq_no_delay = 1;
  72         }
  73         return req;
  74 }
  75
  76 int ptlrpc_obd_ping(struct obd_device *obd)
  77 {
  78         int rc;
  79         struct ptlrpc_request *req;
  80         ENTRY;
  81
  82         req = ptlrpc_prep_ping(obd->u.cli.cl_import);
  83         if (req == NULL)
  84                 RETURN(-ENOMEM);
  85
  86         req->rq_send_state = LUSTRE_IMP_FULL;
  87
  88         rc = ptlrpc_queue_wait(req);
  89
  90         ptlrpc_req_finished(req);
  91
  92         RETURN(rc);
  93 }
  94 EXPORT_SYMBOL(ptlrpc_obd_ping);
  95
  96 int ptlrpc_ping(struct obd_import *imp)
  97 {
  98         struct ptlrpc_request *req;
  99         int rc = 0;
 100         ENTRY;
 101
 102         req = ptlrpc_prep_ping(imp);
 103         if (req) {
 104                 DEBUG_REQ(D_INFO, req, "pinging %s->%s",
 105                           imp->imp_obd->obd_uuid.uuid,
 106                           obd2cli_tgt(imp->imp_obd));
 107
 108                 /* To quickly detect server failure ping timeouts must be
 109                  * kept small.  Therefore we must override/ignore the server
 110                  * rpc completion estimate which may be very large since
 111                  * it includes non-ping service times.  The right long term
 112                  * fix will be to add a per-server (not per-service) thread
 113                  * in order to reduce the number of pings in the system in
 114                  * general (see bug 12471). */
 115                 if (!AT_OFF) {
 116                         req->rq_timeout = PING_SVC_TIMEOUT +
 117                                           at_get(&imp->imp_at.iat_net_latency);
 118                         lustre_msg_set_timeout(req->rq_reqmsg, req->rq_timeout);
 119                 }
 120
 121                 ptlrpcd_add_req(req);
 122         } else {
 123                 CERROR("OOM trying to ping %s->%s\n",
 124                        imp->imp_obd->obd_uuid.uuid,
 125                        obd2cli_tgt(imp->imp_obd));
 126                 rc = -ENOMEM;
 127         }
 128
 129         RETURN(rc);
 130 }
 131 EXPORT_SYMBOL(ptlrpc_ping);
 132
 133 static void ptlrpc_update_next_ping(struct obd_import *imp, int soon)
 134 {
 135 #ifdef ENABLE_PINGER
 136         cfs_time_t delay, dtime, ctime = cfs_time_current();
 137
 138         if (imp->imp_state == LUSTRE_IMP_DISCON ||
 139             imp->imp_state == LUSTRE_IMP_CONNECTING) {
 140                 /* In the disconnected case aggressively reconnect, for
 141                  * this request the AT service timeout will be set to
 142                  * INITIAL_CONNECT_TIMEOUT.  To ensure the request times
 143                  * out before we send another we add one extra second. */
 144                 dtime = cfs_time_seconds(max_t(int, CONNECTION_SWITCH_MIN,
 145                                 AT_OFF ? 0 : INITIAL_CONNECT_TIMEOUT + 1 +
 146                                 at_get(&imp->imp_at.iat_net_latency)));
 147         } else {
 148                 /* In the common case we want to cluster the pings at
 149                  * at regular intervals to minimize system noise. */
 150                 delay = cfs_time_seconds(soon ? PING_INTERVAL_SHORT :
 151                                          PING_INTERVAL);
 152                 dtime = delay - (ctime % delay);
 153         }
 154
 155         dtime = cfs_time_add(ctime, dtime);
 156
 157         if (soon && cfs_time_after(imp->imp_next_ping, ctime) &&
 158             cfs_time_after(dtime, imp->imp_next_ping)) {
 159                 /* if the next ping is due to be sent before the
 160                  * new deadline, don't delay it */
 161                  return;
 162         }
 163
 164         /* May harmlessly race with ptlrpc_update_next_ping() */
 165         imp->imp_next_ping = dtime;
 166
 167 #ifdef __KERNEL__
 168         if (pinger_next_wake != 0 && cfs_time_after(pinger_next_wake, dtime))
 169                 /* pinger is supposed to sleep until after the new ping
 170                  * deadline, wake it up to take into account our update.
 171                  * no needed for liblustre which updates pd_next_ping. */
 172                 ptlrpc_pinger_wake_up();
 173 #endif
 174
 175         CDEBUG(D_INFO, "Setting %s next ping to "CFS_TIME_T" ("CFS_TIME_T")\n",
 176                obd2cli_tgt(imp->imp_obd), imp->imp_next_ping, dtime);
 177
 178 #endif /* ENABLE_PINGER */
 179 }
 180
 181 static inline int imp_is_deactive(struct obd_import *imp)
 182 {
 183         return (imp->imp_deactive ||
 184                 OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE));
 185 }
 186
 187 cfs_duration_t pinger_check_timeout(cfs_time_t time)
 188 {
 189         struct timeout_item *item;
 190         cfs_time_t timeout = PING_INTERVAL;
 191
 192         /* The timeout list is a increase order sorted list */
 193         mutex_down(&pinger_sem);
 194         list_for_each_entry(item, &timeout_list, ti_chain) {
 195                 int ti_timeout = item->ti_timeout;
 196                 if (timeout > ti_timeout)
 197                          timeout = ti_timeout;
 198                 break;
 199         }
 200         mutex_up(&pinger_sem);
 201
 202         return cfs_time_sub(cfs_time_add(time, cfs_time_seconds(timeout)),
 203                                          cfs_time_current());
 204 }
 205
 206 #ifdef __KERNEL__
 207 static int ptlrpc_pinger_main(void *arg)
 208 {
 209         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
 210         struct ptlrpc_thread *thread = data->thread;
 211         ENTRY;
 212
 213         cfs_daemonize(data->name);
 214
 215         /* Record that the thread is running */
 216         thread->t_flags = SVC_RUNNING;
 217         cfs_waitq_signal(&thread->t_ctl_waitq);
 218
 219         /* And now, loop forever, pinging as needed. */
 220         while (1) {
 221                 cfs_time_t this_ping = cfs_time_current();
 222                 struct l_wait_info lwi;
 223                 cfs_duration_t time_to_next_wake;
 224                 cfs_time_t time_of_next_wake;
 225                 struct timeout_item *item;
 226                 struct list_head *iter;
 227
 228                 time_of_next_wake = cfs_time_shift(PING_INTERVAL);
 229
 230                 mutex_down(&pinger_sem);
 231                 list_for_each_entry(item, &timeout_list, ti_chain) {
 232                         item->ti_cb(item, item->ti_cb_data);
 233                 }
 234                 list_for_each(iter, &pinger_imports) {
 235                         struct obd_import *imp =
 236                                 list_entry(iter, struct obd_import,
 237                                            imp_pinger_chain);
 238                         int force, level;
 239
 240                         spin_lock(&imp->imp_lock);
 241                         level = imp->imp_state;
 242                         force = imp->imp_force_verify;
 243                         imp->imp_force_verify = 0;
 244                         spin_unlock(&imp->imp_lock);
 245
 246                         CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_RPCTRACE,
 247                                "level %s/%u force %u deactive %u pingable %u\n",
 248                                ptlrpc_import_state_name(level), level,
 249                                force, imp->imp_deactive, imp->imp_pingable);
 250
 251                         /* Include any ping which misses the deadline by up to
 252                          * 1/10 of a second.  The pings are designed to clump
 253                          * and this helps ensure the entire batch gets sent
 254                          * promptly, which minimizes system noise from pings */
 255
 256                         if (force ||
 257                             cfs_time_aftereq(this_ping, imp->imp_next_ping -
 258                                              (cfs_time_seconds(1) + 9) / 10)) {
 259                                 if (level == LUSTRE_IMP_DISCON &&
 260                                     !imp_is_deactive(imp)) {
 261                                         ptlrpc_update_next_ping(imp, 0);
 262                                         ptlrpc_initiate_recovery(imp);
 263                                 } else if (level != LUSTRE_IMP_FULL ||
 264                                          imp->imp_obd->obd_no_recov ||
 265                                          imp_is_deactive(imp)) {
 266                                         CDEBUG(D_HA, "not pinging %s "
 267                                                "(in recovery: %s or recovery "
 268                                                "disabled: %u/%u)\n",
 269                                                obd2cli_tgt(imp->imp_obd),
 270                                                ptlrpc_import_state_name(level),
 271                                                imp->imp_deactive,
 272                                                imp->imp_obd->obd_no_recov);
 273                                 } else if (imp->imp_pingable || force) {
 274                                                 ptlrpc_ping(imp);
 275                                                 /* ptlrpc_pinger_sending_on_import()
 276                                                  * will asynch update imp_next_ping
 277                                                  * so it must not be used below to
 278                                                  * calculate minimum wait time. */
 279                                                 continue;
 280                                 }
 281                         } else {
 282                                 if (!imp->imp_pingable)
 283                                         continue;
 284                                 CDEBUG(D_INFO,
 285                                        "don't need to ping %s ("CFS_TIME_T
 286                                        " > "CFS_TIME_T")\n",
 287                                        obd2cli_tgt(imp->imp_obd),
 288                                        imp->imp_next_ping, this_ping);
 289                         }
 290
 291                         /* Wait time until next ping, or until we stopped. */
 292                         if (cfs_time_before(imp->imp_next_ping,
 293                                             time_of_next_wake))
 294                                 time_of_next_wake = imp->imp_next_ping;
 295                 }
 296                 pinger_next_wake = time_of_next_wake;
 297                 mutex_up(&pinger_sem);
 298                 obd_update_maxusage();
 299
 300                 time_to_next_wake = max_t(cfs_duration_t,
 301                                           cfs_time_seconds(1),
 302                                           cfs_time_sub(time_of_next_wake,
 303                                                        cfs_time_current()));
 304                 CDEBUG(D_INFO, "next ping in "CFS_DURATION_T" ("CFS_TIME_T")\n",
 305                                time_to_next_wake, time_of_next_wake);
 306
 307                 if (time_to_next_wake > 0) {
 308                         lwi = LWI_TIMEOUT(time_to_next_wake, NULL, NULL);
 309                         l_wait_event(thread->t_ctl_waitq,
 310                                      thread->t_flags & (SVC_STOPPING|SVC_EVENT),
 311                                      &lwi);
 312                         if (thread->t_flags & SVC_STOPPING) {
 313                                 thread->t_flags &= ~SVC_STOPPING;
 314                                 EXIT;
 315                                 break;
 316                         } else if (thread->t_flags & SVC_EVENT) {
 317                                 /* woken after adding import to reset timer */
 318                                 thread->t_flags &= ~SVC_EVENT;
 319                         }
 320                 }
 321         }
 322
 323         thread->t_flags = SVC_STOPPED;
 324         cfs_waitq_signal(&thread->t_ctl_waitq);
 325
 326         CDEBUG(D_NET, "pinger thread exiting, process %d\n", cfs_curproc_pid());
 327         return 0;
 328 }
 329
 330 static struct ptlrpc_thread *pinger_thread = NULL;
 331
 332 int ptlrpc_start_pinger(void)
 333 {
 334         struct l_wait_info lwi = { 0 };
 335         struct ptlrpc_svc_data d;
 336         int rc;
 337 #ifndef ENABLE_PINGER
 338         return 0;
 339 #endif
 340         ENTRY;
 341
 342         if (pinger_thread != NULL)
 343                 RETURN(-EALREADY);
 344
 345         OBD_ALLOC(pinger_thread, sizeof(*pinger_thread));
 346         if (pinger_thread == NULL)
 347                 RETURN(-ENOMEM);
 348         cfs_waitq_init(&pinger_thread->t_ctl_waitq);
 349
 350         d.name = "ll_ping";
 351         d.thread = pinger_thread;
 352
 353         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 354          * just drop the VM and FILES in cfs_daemonize_ctxt() right away. */
 355         rc = cfs_kernel_thread(ptlrpc_pinger_main, &d, CLONE_VM | CLONE_FILES);
 356         if (rc < 0) {
 357                 CERROR("cannot start thread: %d\n", rc);
 358                 OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 359                 pinger_thread = NULL;
 360                 RETURN(rc);
 361         }
 362         l_wait_event(pinger_thread->t_ctl_waitq,
 363                      pinger_thread->t_flags & SVC_RUNNING, &lwi);
 364
 365         RETURN(0);
 366 }
 367
 368 int ptlrpc_pinger_remove_timeouts(void);
 369
 370 int ptlrpc_stop_pinger(void)
 371 {
 372         struct l_wait_info lwi = { 0 };
 373         int rc = 0;
 374 #ifndef ENABLE_PINGER
 375         return 0;
 376 #endif
 377         ENTRY;
 378
 379         if (pinger_thread == NULL)
 380                 RETURN(-EALREADY);
 381
 382         ptlrpc_pinger_remove_timeouts();
 383         mutex_down(&pinger_sem);
 384         pinger_thread->t_flags = SVC_STOPPING;
 385         cfs_waitq_signal(&pinger_thread->t_ctl_waitq);
 386         mutex_up(&pinger_sem);
 387
 388         l_wait_event(pinger_thread->t_ctl_waitq,
 389                      (pinger_thread->t_flags & SVC_STOPPED), &lwi);
 390
 391         OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 392         pinger_thread = NULL;
 393         RETURN(rc);
 394 }
 395
 396 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 397 {
 398         ptlrpc_update_next_ping(imp, 0);
 399 }
 400
 401 void ptlrpc_pinger_commit_expected(struct obd_import *imp)
 402 {
 403         ptlrpc_update_next_ping(imp, 1);
 404 }
 405
 406 int ptlrpc_pinger_add_import(struct obd_import *imp)
 407 {
 408         ENTRY;
 409         if (!list_empty(&imp->imp_pinger_chain))
 410                 RETURN(-EALREADY);
 411
 412         mutex_down(&pinger_sem);
 413         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 414                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 415         /* if we add to pinger we want recovery on this import */
 416         imp->imp_obd->obd_no_recov = 0;
 417
 418         ptlrpc_update_next_ping(imp, 0);
 419         /* XXX sort, blah blah */
 420         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 421         class_import_get(imp);
 422
 423         ptlrpc_pinger_wake_up();
 424         mutex_up(&pinger_sem);
 425
 426         RETURN(0);
 427 }
 428
 429 int ptlrpc_pinger_del_import(struct obd_import *imp)
 430 {
 431         ENTRY;
 432         if (list_empty(&imp->imp_pinger_chain))
 433                 RETURN(-ENOENT);
 434
 435         mutex_down(&pinger_sem);
 436         list_del_init(&imp->imp_pinger_chain);
 437         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 438                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 439         /* if we remove from pinger we don't want recovery on this import */
 440         imp->imp_obd->obd_no_recov = 1;
 441         class_import_put(imp);
 442         mutex_up(&pinger_sem);
 443         RETURN(0);
 444 }
 445
 446 /**
 447  * Register a timeout callback to the pinger list, and the callback will
 448  * be called when timeout happens.
 449  */
 450 struct timeout_item* ptlrpc_new_timeout(int time, enum timeout_event event,
 451                                         timeout_cb_t cb, void *data)
 452 {
 453         struct timeout_item *ti;
 454
 455         OBD_ALLOC_PTR(ti);
 456         if (!ti)
 457                 return(NULL);
 458
 459         CFS_INIT_LIST_HEAD(&ti->ti_obd_list);
 460         CFS_INIT_LIST_HEAD(&ti->ti_chain);
 461         ti->ti_timeout = time;
 462         ti->ti_event = event;
 463         ti->ti_cb = cb;
 464         ti->ti_cb_data = data;
 465
 466         return ti;
 467 }
 468
 469 /**
 470  * Register timeout event on the the pinger thread.
 471  * Note: the timeout list is an sorted list with increased timeout value.
 472  */
 473 static struct timeout_item*
 474 ptlrpc_pinger_register_timeout(int time, enum timeout_event event,
 475                                timeout_cb_t cb, void *data)
 476 {
 477         struct timeout_item *item, *tmp;
 478
 479         LASSERT_SEM_LOCKED(&pinger_sem);
 480
 481         list_for_each_entry(item, &timeout_list, ti_chain)
 482                 if (item->ti_event == event)
 483                         goto out;
 484
 485         item = ptlrpc_new_timeout(time, event, cb, data);
 486         if (item) {
 487                 list_for_each_entry_reverse(tmp, &timeout_list, ti_chain) {
 488                         if (tmp->ti_timeout < time) {
 489                                 list_add(&item->ti_chain, &tmp->ti_chain);
 490                                 goto out;
 491                         }
 492                 }
 493                 list_add(&item->ti_chain, &timeout_list);
 494         }
 495 out:
 496         return item;
 497 }
 498
 499 /* Add a client_obd to the timeout event list, when timeout(@time)
 500  * happens, the callback(@cb) will be called.
 501  */
 502 int ptlrpc_add_timeout_client(int time, enum timeout_event event,
 503                               timeout_cb_t cb, void *data,
 504                               struct list_head *obd_list)
 505 {
 506         struct timeout_item *ti;
 507
 508         mutex_down(&pinger_sem);
 509         ti = ptlrpc_pinger_register_timeout(time, event, cb, data);
 510         if (!ti) {
 511                 mutex_up(&pinger_sem);
 512                 return (-EINVAL);
 513         }
 514         list_add(obd_list, &ti->ti_obd_list);
 515         mutex_up(&pinger_sem);
 516         return 0;
 517 }
 518
 519 int ptlrpc_del_timeout_client(struct list_head *obd_list,
 520                               enum timeout_event event)
 521 {
 522         struct timeout_item *ti = NULL, *item;
 523
 524         if (list_empty(obd_list))
 525                 return 0;
 526         mutex_down(&pinger_sem);
 527         list_del_init(obd_list);
 528         /**
 529          * If there are no obd attached to the timeout event
 530          * list, remove this timeout event from the pinger
 531          */
 532         list_for_each_entry(item, &timeout_list, ti_chain) {
 533                 if (item->ti_event == event) {
 534                         ti = item;
 535                         break;
 536                 }
 537         }
 538         LASSERTF(ti != NULL, "ti is NULL ! \n");
 539         if (list_empty(&ti->ti_obd_list)) {
 540                 list_del(&ti->ti_chain);
 541                 OBD_FREE_PTR(ti);
 542         }
 543         mutex_up(&pinger_sem);
 544         return 0;
 545 }
 546
 547 int ptlrpc_pinger_remove_timeouts(void)
 548 {
 549         struct timeout_item *item, *tmp;
 550
 551         mutex_down(&pinger_sem);
 552         list_for_each_entry_safe(item, tmp, &timeout_list, ti_chain) {
 553                 LASSERT(list_empty(&item->ti_obd_list));
 554                 list_del(&item->ti_chain);
 555                 OBD_FREE_PTR(item);
 556         }
 557         mutex_up(&pinger_sem);
 558         return 0;
 559 }
 560
 561 void ptlrpc_pinger_wake_up()
 562 {
 563 #ifdef ENABLE_PINGER
 564         pinger_thread->t_flags |= SVC_EVENT;
 565         cfs_waitq_signal(&pinger_thread->t_ctl_waitq);
 566 #endif
 567 }
 568
 569 /* Ping evictor thread */
 570 #define PET_READY     1
 571 #define PET_TERMINATE 2
 572
 573 static int               pet_refcount = 0;
 574 static int               pet_state;
 575 static wait_queue_head_t pet_waitq;
 576 CFS_LIST_HEAD(pet_list);
 577 static spinlock_t        pet_lock = SPIN_LOCK_UNLOCKED;
 578
 579 int ping_evictor_wake(struct obd_export *exp)
 580 {
 581         struct obd_device *obd;
 582
 583         spin_lock(&pet_lock);
 584         if (pet_state != PET_READY) {
 585                 /* eventually the new obd will call here again. */
 586                 spin_unlock(&pet_lock);
 587                 return 1;
 588         }
 589
 590         obd = class_exp2obd(exp);
 591         if (list_empty(&obd->obd_evict_list)) {
 592                 class_incref(obd);
 593                 list_add(&obd->obd_evict_list, &pet_list);
 594         }
 595         spin_unlock(&pet_lock);
 596
 597         wake_up(&pet_waitq);
 598         return 0;
 599 }
 600
 601 static int ping_evictor_main(void *arg)
 602 {
 603         struct obd_device *obd;
 604         struct obd_export *exp;
 605         struct l_wait_info lwi = { 0 };
 606         time_t expire_time;
 607         ENTRY;
 608
 609         cfs_daemonize_ctxt("ll_evictor");
 610
 611         CDEBUG(D_HA, "Starting Ping Evictor\n");
 612         pet_state = PET_READY;
 613         while (1) {
 614                 l_wait_event(pet_waitq, (!list_empty(&pet_list)) ||
 615                              (pet_state == PET_TERMINATE), &lwi);
 616
 617                 /* loop until all obd's will be removed */
 618                 if ((pet_state == PET_TERMINATE) && list_empty(&pet_list))
 619                         break;
 620
 621                 /* we only get here if pet_exp != NULL, and the end of this
 622                  * loop is the only place which sets it NULL again, so lock
 623                  * is not strictly necessary. */
 624                 spin_lock(&pet_lock);
 625                 obd = list_entry(pet_list.next, struct obd_device,
 626                                  obd_evict_list);
 627                 spin_unlock(&pet_lock);
 628
 629                 if (obd->obd_recovering) {
 630                         /* bug 18948: ensure recovery is aborted in a timely fashion */
 631                         target_recovery_check_and_stop(obd);
 632                         /* no evictor during recovery */
 633                         GOTO(skip, 0);
 634                 }
 635
 636                 expire_time = cfs_time_current_sec() - PING_EVICT_TIMEOUT;
 637
 638                 CDEBUG(D_HA, "evicting all exports of obd %s older than %ld\n",
 639                        obd->obd_name, expire_time);
 640
 641                 /* Exports can't be deleted out of the list while we hold
 642                  * the obd lock (class_unlink_export), which means we can't
 643                  * lose the last ref on the export.  If they've already been
 644                  * removed from the list, we won't find them here. */
 645                 spin_lock(&obd->obd_dev_lock);
 646                 while (!list_empty(&obd->obd_exports_timed)) {
 647                         exp = list_entry(obd->obd_exports_timed.next,
 648                                          struct obd_export,exp_obd_chain_timed);
 649                         if (expire_time > exp->exp_last_request_time) {
 650                                 class_export_get(exp);
 651                                 spin_unlock(&obd->obd_dev_lock);
 652                                 LCONSOLE_WARN("%s: haven't heard from client %s"
 653                                               " (at %s) in %ld seconds. I think"
 654                                               " it's dead, and I am evicting"
 655                                               " it.\n", obd->obd_name,
 656                                               obd_uuid2str(&exp->exp_client_uuid),
 657                                               obd_export_nid2str(exp),
 658                                               (long)(cfs_time_current_sec() -
 659                                                      exp->exp_last_request_time));
 660                                 CDEBUG(D_HA, "Last request was at %ld\n",
 661                                        exp->exp_last_request_time);
 662                                 class_fail_export(exp);
 663                                 class_export_put(exp);
 664                                 spin_lock(&obd->obd_dev_lock);
 665                         } else {
 666                                 /* List is sorted, so everyone below is ok */
 667                                 break;
 668                         }
 669                 }
 670                 spin_unlock(&obd->obd_dev_lock);
 671 skip:
 672                 spin_lock(&pet_lock);
 673                 list_del_init(&obd->obd_evict_list);
 674                 spin_unlock(&pet_lock);
 675
 676                 class_decref(obd);
 677         }
 678
 679         CDEBUG(D_HA, "Exiting Ping Evictor\n");
 680
 681         RETURN(0);
 682 }
 683
 684 void ping_evictor_start(void)
 685 {
 686         int rc;
 687
 688         if (++pet_refcount > 1)
 689                 return;
 690
 691         init_waitqueue_head(&pet_waitq);
 692
 693         rc = cfs_kernel_thread(ping_evictor_main, NULL, CLONE_VM | CLONE_FILES);
 694         if (rc < 0) {
 695                 pet_refcount--;
 696                 CERROR("Cannot start ping evictor thread: %d\n", rc);
 697         }
 698 }
 699 EXPORT_SYMBOL(ping_evictor_start);
 700
 701 void ping_evictor_stop(void)
 702 {
 703         if (--pet_refcount > 0)
 704                 return;
 705
 706         pet_state = PET_TERMINATE;
 707         wake_up(&pet_waitq);
 708 }
 709 EXPORT_SYMBOL(ping_evictor_stop);
 710 #else /* !__KERNEL__ */
 711
 712 /* XXX
 713  * the current implementation of pinger in liblustre is not optimized
 714  */
 715
 716 #ifdef ENABLE_PINGER
 717 static struct pinger_data {
 718         int             pd_recursion;
 719         cfs_time_t      pd_this_ping;   /* jiffies */
 720         cfs_time_t      pd_next_ping;   /* jiffies */
 721         struct ptlrpc_request_set *pd_set;
 722 } pinger_args;
 723
 724 static int pinger_check_rpcs(void *arg)
 725 {
 726         cfs_time_t curtime = cfs_time_current();
 727         struct ptlrpc_request *req;
 728         struct ptlrpc_request_set *set;
 729         struct list_head *iter;
 730         struct obd_import *imp;
 731         struct pinger_data *pd = &pinger_args;
 732         int rc;
 733
 734         /* prevent recursion */
 735         if (pd->pd_recursion++) {
 736                 CDEBUG(D_HA, "pinger: recursion! quit\n");
 737                 LASSERT(pd->pd_set);
 738                 pd->pd_recursion--;
 739                 return 0;
 740         }
 741
 742         /* have we reached ping point? */
 743         if (!pd->pd_set && time_before(curtime, pd->pd_next_ping)) {
 744                 pd->pd_recursion--;
 745                 return 0;
 746         }
 747
 748         /* if we have rpc_set already, continue processing it */
 749         if (pd->pd_set) {
 750                 LASSERT(pd->pd_this_ping);
 751                 set = pd->pd_set;
 752                 goto do_check_set;
 753         }
 754
 755         pd->pd_this_ping = curtime;
 756         pd->pd_set = ptlrpc_prep_set();
 757         if (pd->pd_set == NULL)
 758                 goto out;
 759         set = pd->pd_set;
 760
 761         /* add rpcs into set */
 762         mutex_down(&pinger_sem);
 763         list_for_each(iter, &pinger_imports) {
 764                 struct obd_import *imp =
 765                         list_entry(iter, struct obd_import, imp_pinger_chain);
 766                 int generation, level;
 767
 768                 /* Include any ping within 1/10 of a second of the deadline */
 769                 if (cfs_time_aftereq(pd->pd_this_ping, imp->imp_next_ping -
 770                                      (cfs_time_seconds(1) + 9) / 10)) {
 771                         /* Add a ping. */
 772                         spin_lock(&imp->imp_lock);
 773                         generation = imp->imp_generation;
 774                         level = imp->imp_state;
 775                         spin_unlock(&imp->imp_lock);
 776
 777                         if (level != LUSTRE_IMP_FULL) {
 778                                 CDEBUG(D_HA,
 779                                        "not pinging %s (in recovery)\n",
 780                                        obd2cli_tgt(imp->imp_obd));
 781                                 continue;
 782                         }
 783
 784                         req = ptlrpc_prep_req(imp, LUSTRE_OBD_VERSION, OBD_PING,
 785                                               1, NULL, NULL);
 786                         if (!req) {
 787                                 CERROR("out of memory\n");
 788                                 break;
 789                         }
 790                         req->rq_no_resend = 1;
 791                         ptlrpc_req_set_repsize(req, 1, NULL);
 792                         req->rq_send_state = LUSTRE_IMP_FULL;
 793                         ptlrpc_rqphase_move(req, RQ_PHASE_RPC);
 794                         req->rq_import_generation = generation;
 795                         ptlrpc_set_add_req(set, req);
 796                 } else {
 797                         CDEBUG(D_INFO, "don't need to ping %s ("CFS_TIME_T
 798                                " > "CFS_TIME_T")\n", obd2cli_tgt(imp->imp_obd),
 799                                imp->imp_next_ping, pd->pd_this_ping);
 800                 }
 801         }
 802         pd->pd_this_ping = curtime;
 803         mutex_up(&pinger_sem);
 804
 805         /* Might be empty, that's OK. */
 806         if (atomic_read(&set->set_remaining) == 0)
 807                 CDEBUG(D_RPCTRACE, "nothing to ping\n");
 808
 809         list_for_each(iter, &set->set_requests) {
 810                 struct ptlrpc_request *req =
 811                         list_entry(iter, struct ptlrpc_request,
 812                                    rq_set_chain);
 813                 DEBUG_REQ(D_RPCTRACE, req, "pinging %s->%s",
 814                           req->rq_import->imp_obd->obd_uuid.uuid,
 815                           obd2cli_tgt(req->rq_import->imp_obd));
 816                 (void)ptl_send_rpc(req, 0);
 817         }
 818
 819 do_check_set:
 820         rc = ptlrpc_check_set(set);
 821
 822         /* not finished, and we are not expired, simply return */
 823         if (!rc && cfs_time_before(curtime, cfs_time_add(pd->pd_this_ping,
 824                                             cfs_time_seconds(PING_INTERVAL)))) {
 825                 CDEBUG(D_RPCTRACE, "not finished, but also not expired\n");
 826                 pd->pd_recursion--;
 827                 return 0;
 828         }
 829
 830         /* Expire all the requests that didn't come back. */
 831         mutex_down(&pinger_sem);
 832         list_for_each(iter, &set->set_requests) {
 833                 req = list_entry(iter, struct ptlrpc_request,
 834                                  rq_set_chain);
 835
 836                 if (req->rq_phase == RQ_PHASE_COMPLETE)
 837                         continue;
 838
 839                 CDEBUG(D_RPCTRACE, "Pinger initiate expire request(%p)\n",
 840                        req);
 841
 842                 /* This will also unregister reply. */
 843                 ptlrpc_expire_one_request(req, 0);
 844
 845                 /* We're done with this req, let's finally move it to complete
 846                  * phase and take care of inflights. */
 847                 ptlrpc_rqphase_move(req, RQ_PHASE_COMPLETE);
 848                 imp = req->rq_import;
 849                 spin_lock(&imp->imp_lock);
 850                 if (!list_empty(&req->rq_list)) {
 851                         list_del_init(&req->rq_list);
 852                         atomic_dec(&imp->imp_inflight);
 853                 }
 854                 spin_unlock(&imp->imp_lock);
 855                 atomic_dec(&set->set_remaining);
 856         }
 857         mutex_up(&pinger_sem);
 858
 859         ptlrpc_set_destroy(set);
 860         pd->pd_set = NULL;
 861
 862 out:
 863         pd->pd_next_ping = cfs_time_add(pd->pd_this_ping,
 864                                         cfs_time_seconds(PING_INTERVAL));
 865         pd->pd_this_ping = 0; /* XXX for debug */
 866
 867         CDEBUG(D_INFO, "finished a round ping\n");
 868         pd->pd_recursion--;
 869         return 0;
 870 }
 871
 872 static void *pinger_callback = NULL;
 873 #endif /* ENABLE_PINGER */
 874
 875 int ptlrpc_start_pinger(void)
 876 {
 877 #ifdef ENABLE_PINGER
 878         memset(&pinger_args, 0, sizeof(pinger_args));
 879         pinger_callback = liblustre_register_wait_callback("pinger_check_rpcs",
 880                                                            &pinger_check_rpcs,
 881                                                            &pinger_args);
 882 #endif
 883         return 0;
 884 }
 885
 886 int ptlrpc_stop_pinger(void)
 887 {
 888 #ifdef ENABLE_PINGER
 889         if (pinger_callback)
 890                 liblustre_deregister_wait_callback(pinger_callback);
 891 #endif
 892         return 0;
 893 }
 894
 895 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 896 {
 897 #ifdef ENABLE_PINGER
 898         mutex_down(&pinger_sem);
 899         ptlrpc_update_next_ping(imp, 0);
 900         if (pinger_args.pd_set == NULL &&
 901             time_before(imp->imp_next_ping, pinger_args.pd_next_ping)) {
 902                 CDEBUG(D_HA, "set next ping to "CFS_TIME_T"(cur "CFS_TIME_T")\n",
 903                         imp->imp_next_ping, cfs_time_current());
 904                 pinger_args.pd_next_ping = imp->imp_next_ping;
 905         }
 906         mutex_up(&pinger_sem);
 907 #endif
 908 }
 909
 910 void ptlrpc_pinger_commit_expected(struct obd_import *imp)
 911 {
 912 #ifdef ENABLE_PINGER
 913         mutex_down(&pinger_sem);
 914         ptlrpc_update_next_ping(imp, 1);
 915         if (pinger_args.pd_set == NULL &&
 916             time_before(imp->imp_next_ping, pinger_args.pd_next_ping)) {
 917                 CDEBUG(D_HA, "set next ping to "CFS_TIME_T"(cur "CFS_TIME_T")\n",
 918                         imp->imp_next_ping, cfs_time_current());
 919                 pinger_args.pd_next_ping = imp->imp_next_ping;
 920         }
 921         mutex_up(&pinger_sem);
 922 #endif
 923 }
 924
 925 int ptlrpc_add_timeout_client(int time, enum timeout_event event,
 926                               timeout_cb_t cb, void *data,
 927                               struct list_head *obd_list)
 928 {
 929         return 0;
 930 }
 931
 932 int ptlrpc_del_timeout_client(struct list_head *obd_list,
 933                               enum timeout_event event)
 934 {
 935         return 0;
 936 }
 937
 938 int ptlrpc_pinger_add_import(struct obd_import *imp)
 939 {
 940         ENTRY;
 941         if (!list_empty(&imp->imp_pinger_chain))
 942                 RETURN(-EALREADY);
 943
 944         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 945                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 946         ptlrpc_pinger_sending_on_import(imp);
 947
 948         mutex_down(&pinger_sem);
 949         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 950         class_import_get(imp);
 951         mutex_up(&pinger_sem);
 952
 953         RETURN(0);
 954 }
 955
 956 int ptlrpc_pinger_del_import(struct obd_import *imp)
 957 {
 958         ENTRY;
 959         if (list_empty(&imp->imp_pinger_chain))
 960                 RETURN(-ENOENT);
 961
 962         mutex_down(&pinger_sem);
 963         list_del_init(&imp->imp_pinger_chain);
 964         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 965                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 966         class_import_put(imp);
 967         mutex_up(&pinger_sem);
 968         RETURN(0);
 969 }
 970
 971 void ptlrpc_pinger_wake_up()
 972 {
 973 #ifdef ENABLE_PINGER
 974         ENTRY;
 975         /* XXX force pinger to run, if needed */
 976         struct obd_import *imp;
 977         list_for_each_entry(imp, &pinger_imports, imp_pinger_chain) {
 978                 CDEBUG(D_RPCTRACE, "checking import %s->%s\n",
 979                        imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 980 #ifdef ENABLE_LIBLUSTRE_RECOVERY
 981                 if (imp->imp_state == LUSTRE_IMP_DISCON &&
 982                     !imp_is_deactive(imp))
 983 #else
 984                 /*XXX only recover for the initial connection */
 985                 if (!lustre_handle_is_used(&imp->imp_remote_handle) &&
 986                     imp->imp_state == LUSTRE_IMP_DISCON &&
 987                     !imp_is_deactive(imp))
 988 #endif
 989                         ptlrpc_initiate_recovery(imp);
 990                 else if (imp->imp_state != LUSTRE_IMP_FULL)
 991                         CDEBUG(D_HA, "Refused to recover import %s->%s "
 992                                      "state %d, deactive %d\n",
 993                                      imp->imp_obd->obd_uuid.uuid,
 994                                      obd2cli_tgt(imp->imp_obd), imp->imp_state,
 995                                      imp_is_deactive(imp));
 996         }
 997 #endif
 998         EXIT;
 999 }
1000 #endif /* !__KERNEL__ */