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  2008 Sun Microsystems, Inc. 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 "ptlrpc_internal.h"
  50
  51 cfs_semaphore_t pinger_sem;
  52 static CFS_LIST_HEAD(pinger_imports);
  53 static cfs_list_t timeout_list = CFS_LIST_HEAD_INIT(timeout_list);
  54 struct ptlrpc_request *
  55 ptlrpc_prep_ping(struct obd_import *imp)
  56 {
  57         struct ptlrpc_request *req;
  58
  59         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING,
  60                                         LUSTRE_OBD_VERSION, OBD_PING);
  61         if (req) {
  62                 ptlrpc_request_set_replen(req);
  63                 req->rq_no_resend = req->rq_no_delay = 1;
  64         }
  65         return req;
  66 }
  67
  68 int ptlrpc_obd_ping(struct obd_device *obd)
  69 {
  70         int rc;
  71         struct ptlrpc_request *req;
  72         ENTRY;
  73
  74         req = ptlrpc_prep_ping(obd->u.cli.cl_import);
  75         if (req == NULL)
  76                 RETURN(-ENOMEM);
  77
  78         req->rq_send_state = LUSTRE_IMP_FULL;
  79
  80         rc = ptlrpc_queue_wait(req);
  81
  82         ptlrpc_req_finished(req);
  83
  84         RETURN(rc);
  85 }
  86 EXPORT_SYMBOL(ptlrpc_obd_ping);
  87
  88 int ptlrpc_ping(struct obd_import *imp)
  89 {
  90         struct ptlrpc_request *req;
  91         ENTRY;
  92
  93         req = ptlrpc_prep_ping(imp);
  94         if (req == NULL) {
  95                 CERROR("OOM trying to ping %s->%s\n",
  96                        imp->imp_obd->obd_uuid.uuid,
  97                        obd2cli_tgt(imp->imp_obd));
  98                 RETURN(-ENOMEM);
  99         }
 100
 101         DEBUG_REQ(D_INFO, req, "pinging %s->%s",
 102                   imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 103         ptlrpcd_add_req(req, PSCOPE_OTHER);
 104
 105         RETURN(0);
 106 }
 107
 108 void ptlrpc_update_next_ping(struct obd_import *imp)
 109 {
 110 #ifdef ENABLE_PINGER
 111         int time = PING_INTERVAL;
 112         if (imp->imp_state == LUSTRE_IMP_DISCON) {
 113                 int dtime = max_t(int, CONNECTION_SWITCH_MIN,
 114                                   AT_OFF ? 0 :
 115                                   at_get(&imp->imp_at.iat_net_latency));
 116                 time = min(time, dtime);
 117         }
 118         imp->imp_next_ping = cfs_time_shift(time);
 119 #endif /* ENABLE_PINGER */
 120 }
 121
 122 void ptlrpc_ping_import_soon(struct obd_import *imp)
 123 {
 124         imp->imp_next_ping = cfs_time_current();
 125 }
 126
 127 static inline int imp_is_deactive(struct obd_import *imp)
 128 {
 129         return (imp->imp_deactive ||
 130                 OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE));
 131 }
 132
 133 static inline int ptlrpc_next_reconnect(struct obd_import *imp)
 134 {
 135         if (imp->imp_server_timeout)
 136                 return cfs_time_shift(obd_timeout / 2);
 137         else
 138                 return cfs_time_shift(obd_timeout);
 139 }
 140
 141 static cfs_atomic_t suspend_timeouts = CFS_ATOMIC_INIT(0);
 142 static cfs_time_t suspend_wakeup_time = 0;
 143
 144 cfs_duration_t pinger_check_timeout(cfs_time_t time)
 145 {
 146         struct timeout_item *item;
 147         cfs_time_t timeout = PING_INTERVAL;
 148
 149         /* The timeout list is a increase order sorted list */
 150         cfs_mutex_down(&pinger_sem);
 151         cfs_list_for_each_entry(item, &timeout_list, ti_chain) {
 152                 int ti_timeout = item->ti_timeout;
 153                 if (timeout > ti_timeout)
 154                         timeout = ti_timeout;
 155                 break;
 156         }
 157         cfs_mutex_up(&pinger_sem);
 158
 159         return cfs_time_sub(cfs_time_add(time, cfs_time_seconds(timeout)),
 160                                          cfs_time_current());
 161 }
 162
 163 #ifdef __KERNEL__
 164 static cfs_waitq_t suspend_timeouts_waitq;
 165 #endif
 166
 167 cfs_time_t ptlrpc_suspend_wakeup_time(void)
 168 {
 169         return suspend_wakeup_time;
 170 }
 171
 172 void ptlrpc_deactivate_timeouts(struct obd_import *imp)
 173 {
 174         /*XXX: disabled for now, will be replaced by adaptive timeouts */
 175 #if 0
 176         if (imp->imp_no_timeout)
 177                 return;
 178         imp->imp_no_timeout = 1;
 179         cfs_atomic_inc(&suspend_timeouts);
 180         CDEBUG(D_HA|D_WARNING, "deactivate timeouts %u\n",
 181                cfs_atomic_read(&suspend_timeouts));
 182 #endif
 183 }
 184
 185 void ptlrpc_activate_timeouts(struct obd_import *imp)
 186 {
 187         /*XXX: disabled for now, will be replaced by adaptive timeouts */
 188 #if 0
 189         if (!imp->imp_no_timeout)
 190                 return;
 191         imp->imp_no_timeout = 0;
 192         LASSERT(cfs_atomic_read(&suspend_timeouts) > 0);
 193         if (cfs_atomic_dec_and_test(&suspend_timeouts)) {
 194                 suspend_wakeup_time = cfs_time_current();
 195                 cfs_waitq_signal(&suspend_timeouts_waitq);
 196         }
 197         CDEBUG(D_HA|D_WARNING, "activate timeouts %u\n",
 198                cfs_atomic_read(&suspend_timeouts));
 199 #endif
 200 }
 201
 202 int ptlrpc_check_suspend(void)
 203 {
 204         if (cfs_atomic_read(&suspend_timeouts))
 205                 return 1;
 206         return 0;
 207 }
 208
 209 int ptlrpc_check_and_wait_suspend(struct ptlrpc_request *req)
 210 {
 211         struct l_wait_info lwi;
 212
 213         if (cfs_atomic_read(&suspend_timeouts)) {
 214                 DEBUG_REQ(D_NET, req, "-- suspend %d regular timeout",
 215                           cfs_atomic_read(&suspend_timeouts));
 216                 lwi = LWI_INTR(NULL, NULL);
 217                 l_wait_event(suspend_timeouts_waitq,
 218                              cfs_atomic_read(&suspend_timeouts) == 0, &lwi);
 219                 DEBUG_REQ(D_NET, req, "-- recharge regular timeout");
 220                 return 1;
 221         }
 222         return 0;
 223 }
 224
 225 #ifdef __KERNEL__
 226
 227 static void ptlrpc_pinger_process_import(struct obd_import *imp,
 228                                          unsigned long this_ping)
 229 {
 230         int force, level;
 231
 232         cfs_spin_lock(&imp->imp_lock);
 233         level = imp->imp_state;
 234         force = imp->imp_force_verify;
 235         if (force)
 236                 imp->imp_force_verify = 0;
 237         cfs_spin_unlock(&imp->imp_lock);
 238
 239         CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA,
 240                "level %s/%u force %u deactive %u pingable %u\n",
 241                ptlrpc_import_state_name(level), level,
 242                force, imp->imp_deactive, imp->imp_pingable);
 243
 244         if (cfs_time_aftereq(imp->imp_next_ping - 5 * CFS_TICK,
 245                              this_ping) && force == 0)
 246                 return;
 247
 248         if (level == LUSTRE_IMP_DISCON && !imp_is_deactive(imp)) {
 249                 /* wait at least a timeout before trying recovery again */
 250                 imp->imp_next_ping = ptlrpc_next_reconnect(imp);
 251                 ptlrpc_initiate_recovery(imp);
 252         } else if (level != LUSTRE_IMP_FULL ||
 253                    imp->imp_obd->obd_no_recov ||
 254                    imp_is_deactive(imp)) {
 255                 CDEBUG(D_HA, "not pinging %s (in recovery "
 256                        " or recovery disabled: %s)\n",
 257                        obd2cli_tgt(imp->imp_obd),
 258                        ptlrpc_import_state_name(level));
 259         } else if (imp->imp_pingable || force) {
 260                 ptlrpc_ping(imp);
 261         }
 262 }
 263
 264 static int ptlrpc_pinger_main(void *arg)
 265 {
 266         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
 267         struct ptlrpc_thread *thread = data->thread;
 268         ENTRY;
 269
 270         cfs_daemonize(data->name);
 271
 272         /* Record that the thread is running */
 273         thread->t_flags = SVC_RUNNING;
 274         cfs_waitq_signal(&thread->t_ctl_waitq);
 275
 276         /* And now, loop forever, pinging as needed. */
 277         while (1) {
 278                 cfs_time_t this_ping = cfs_time_current();
 279                 struct l_wait_info lwi;
 280                 cfs_duration_t time_to_next_wake;
 281                 struct timeout_item *item;
 282                 cfs_list_t *iter;
 283
 284                 cfs_mutex_down(&pinger_sem);
 285                 cfs_list_for_each_entry(item, &timeout_list, ti_chain) {
 286                         item->ti_cb(item, item->ti_cb_data);
 287                 }
 288                 cfs_list_for_each(iter, &pinger_imports) {
 289                         struct obd_import *imp =
 290                                 cfs_list_entry(iter, struct obd_import,
 291                                                imp_pinger_chain);
 292
 293                         ptlrpc_pinger_process_import(imp, this_ping);
 294                         /* obd_timeout might have changed */
 295                         if (imp->imp_pingable && imp->imp_next_ping &&
 296                             cfs_time_after(imp->imp_next_ping,
 297                                            cfs_time_add(this_ping,
 298                                                         cfs_time_seconds(PING_INTERVAL))))
 299                                 ptlrpc_update_next_ping(imp);
 300                 }
 301                 cfs_mutex_up(&pinger_sem);
 302                 /* update memory usage info */
 303                 obd_update_maxusage();
 304
 305                 /* Wait until the next ping time, or until we're stopped. */
 306                 time_to_next_wake = pinger_check_timeout(this_ping);
 307                 /* The ping sent by ptlrpc_send_rpc may get sent out
 308                    say .01 second after this.
 309                    ptlrpc_pinger_sending_on_import will then set the
 310                    next ping time to next_ping + .01 sec, which means
 311                    we will SKIP the next ping at next_ping, and the
 312                    ping will get sent 2 timeouts from now!  Beware. */
 313                 CDEBUG(D_INFO, "next wakeup in "CFS_DURATION_T" ("CFS_TIME_T")\n",
 314                                 time_to_next_wake,
 315                                 cfs_time_add(this_ping, cfs_time_seconds(PING_INTERVAL)));
 316                 if (time_to_next_wake > 0) {
 317                         lwi = LWI_TIMEOUT(max_t(cfs_duration_t, time_to_next_wake, cfs_time_seconds(1)),
 318                                             NULL, NULL);
 319                         l_wait_event(thread->t_ctl_waitq,
 320                                      thread->t_flags & (SVC_STOPPING|SVC_EVENT),
 321                                      &lwi);
 322                         if (thread->t_flags & SVC_STOPPING) {
 323                                 thread->t_flags &= ~SVC_STOPPING;
 324                                 EXIT;
 325                                 break;
 326                         } else if (thread->t_flags & SVC_EVENT) {
 327                                 /* woken after adding import to reset timer */
 328                                 thread->t_flags &= ~SVC_EVENT;
 329                         }
 330                 }
 331         }
 332
 333         thread->t_flags = SVC_STOPPED;
 334         cfs_waitq_signal(&thread->t_ctl_waitq);
 335
 336         CDEBUG(D_NET, "pinger thread exiting, process %d\n", cfs_curproc_pid());
 337         return 0;
 338 }
 339
 340 static struct ptlrpc_thread *pinger_thread = NULL;
 341
 342 int ptlrpc_start_pinger(void)
 343 {
 344         struct l_wait_info lwi = { 0 };
 345         struct ptlrpc_svc_data d;
 346         int rc;
 347 #ifndef ENABLE_PINGER
 348         return 0;
 349 #endif
 350         ENTRY;
 351
 352         if (pinger_thread != NULL)
 353                 RETURN(-EALREADY);
 354
 355         OBD_ALLOC_PTR(pinger_thread);
 356         if (pinger_thread == NULL)
 357                 RETURN(-ENOMEM);
 358         cfs_waitq_init(&pinger_thread->t_ctl_waitq);
 359         cfs_waitq_init(&suspend_timeouts_waitq);
 360
 361         d.name = "ll_ping";
 362         d.thread = pinger_thread;
 363
 364         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 365          * just drop the VM and FILES in cfs_daemonize_ctxt() right away. */
 366         rc = cfs_kernel_thread(ptlrpc_pinger_main, &d, CLONE_VM | CLONE_FILES);
 367         if (rc < 0) {
 368                 CERROR("cannot start thread: %d\n", rc);
 369                 OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 370                 pinger_thread = NULL;
 371                 RETURN(rc);
 372         }
 373         l_wait_event(pinger_thread->t_ctl_waitq,
 374                      pinger_thread->t_flags & SVC_RUNNING, &lwi);
 375
 376         RETURN(0);
 377 }
 378
 379 int ptlrpc_pinger_remove_timeouts(void);
 380
 381 int ptlrpc_stop_pinger(void)
 382 {
 383         struct l_wait_info lwi = { 0 };
 384         int rc = 0;
 385 #ifndef ENABLE_PINGER
 386         return 0;
 387 #endif
 388         ENTRY;
 389
 390         if (pinger_thread == NULL)
 391                 RETURN(-EALREADY);
 392
 393         ptlrpc_pinger_remove_timeouts();
 394         cfs_mutex_down(&pinger_sem);
 395         pinger_thread->t_flags = SVC_STOPPING;
 396         cfs_waitq_signal(&pinger_thread->t_ctl_waitq);
 397         cfs_mutex_up(&pinger_sem);
 398
 399         l_wait_event(pinger_thread->t_ctl_waitq,
 400                      (pinger_thread->t_flags & SVC_STOPPED), &lwi);
 401
 402         OBD_FREE_PTR(pinger_thread);
 403         pinger_thread = NULL;
 404         RETURN(rc);
 405 }
 406
 407 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 408 {
 409         ptlrpc_update_next_ping(imp);
 410 }
 411
 412 int ptlrpc_pinger_add_import(struct obd_import *imp)
 413 {
 414         ENTRY;
 415         if (!cfs_list_empty(&imp->imp_pinger_chain))
 416                 RETURN(-EALREADY);
 417
 418         cfs_mutex_down(&pinger_sem);
 419         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 420                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 421         /* if we add to pinger we want recovery on this import */
 422         imp->imp_obd->obd_no_recov = 0;
 423         ptlrpc_update_next_ping(imp);
 424         /* XXX sort, blah blah */
 425         cfs_list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 426         class_import_get(imp);
 427
 428         ptlrpc_pinger_wake_up();
 429         cfs_mutex_up(&pinger_sem);
 430
 431         RETURN(0);
 432 }
 433
 434 int ptlrpc_pinger_del_import(struct obd_import *imp)
 435 {
 436         ENTRY;
 437         if (cfs_list_empty(&imp->imp_pinger_chain))
 438                 RETURN(-ENOENT);
 439
 440         cfs_mutex_down(&pinger_sem);
 441         cfs_list_del_init(&imp->imp_pinger_chain);
 442         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 443                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 444         /* if we remove from pinger we don't want recovery on this import */
 445         imp->imp_obd->obd_no_recov = 1;
 446         class_import_put(imp);
 447         cfs_mutex_up(&pinger_sem);
 448         RETURN(0);
 449 }
 450
 451 /**
 452  * Register a timeout callback to the pinger list, and the callback will
 453  * be called when timeout happens.
 454  */
 455 struct timeout_item* ptlrpc_new_timeout(int time, enum timeout_event event,
 456                                         timeout_cb_t cb, void *data)
 457 {
 458         struct timeout_item *ti;
 459
 460         OBD_ALLOC_PTR(ti);
 461         if (!ti)
 462                 return(NULL);
 463
 464         CFS_INIT_LIST_HEAD(&ti->ti_obd_list);
 465         CFS_INIT_LIST_HEAD(&ti->ti_chain);
 466         ti->ti_timeout = time;
 467         ti->ti_event = event;
 468         ti->ti_cb = cb;
 469         ti->ti_cb_data = data;
 470
 471         return ti;
 472 }
 473
 474 /**
 475  * Register timeout event on the the pinger thread.
 476  * Note: the timeout list is an sorted list with increased timeout value.
 477  */
 478 static struct timeout_item*
 479 ptlrpc_pinger_register_timeout(int time, enum timeout_event event,
 480                                timeout_cb_t cb, void *data)
 481 {
 482         struct timeout_item *item, *tmp;
 483
 484         LASSERT_SEM_LOCKED(&pinger_sem);
 485
 486         cfs_list_for_each_entry(item, &timeout_list, ti_chain)
 487                 if (item->ti_event == event)
 488                         goto out;
 489
 490         item = ptlrpc_new_timeout(time, event, cb, data);
 491         if (item) {
 492                 cfs_list_for_each_entry_reverse(tmp, &timeout_list, ti_chain) {
 493                         if (tmp->ti_timeout < time) {
 494                                 cfs_list_add(&item->ti_chain, &tmp->ti_chain);
 495                                 goto out;
 496                         }
 497                 }
 498                 cfs_list_add(&item->ti_chain, &timeout_list);
 499         }
 500 out:
 501         return item;
 502 }
 503
 504 /* Add a client_obd to the timeout event list, when timeout(@time)
 505  * happens, the callback(@cb) will be called.
 506  */
 507 int ptlrpc_add_timeout_client(int time, enum timeout_event event,
 508                               timeout_cb_t cb, void *data,
 509                               cfs_list_t *obd_list)
 510 {
 511         struct timeout_item *ti;
 512
 513         cfs_mutex_down(&pinger_sem);
 514         ti = ptlrpc_pinger_register_timeout(time, event, cb, data);
 515         if (!ti) {
 516                 cfs_mutex_up(&pinger_sem);
 517                 return (-EINVAL);
 518         }
 519         cfs_list_add(obd_list, &ti->ti_obd_list);
 520         cfs_mutex_up(&pinger_sem);
 521         return 0;
 522 }
 523
 524 int ptlrpc_del_timeout_client(cfs_list_t *obd_list,
 525                               enum timeout_event event)
 526 {
 527         struct timeout_item *ti = NULL, *item;
 528
 529         if (cfs_list_empty(obd_list))
 530                 return 0;
 531         cfs_mutex_down(&pinger_sem);
 532         cfs_list_del_init(obd_list);
 533         /**
 534          * If there are no obd attached to the timeout event
 535          * list, remove this timeout event from the pinger
 536          */
 537         cfs_list_for_each_entry(item, &timeout_list, ti_chain) {
 538                 if (item->ti_event == event) {
 539                         ti = item;
 540                         break;
 541                 }
 542         }
 543         LASSERTF(ti != NULL, "ti is NULL ! \n");
 544         if (cfs_list_empty(&ti->ti_obd_list)) {
 545                 cfs_list_del(&ti->ti_chain);
 546                 OBD_FREE_PTR(ti);
 547         }
 548         cfs_mutex_up(&pinger_sem);
 549         return 0;
 550 }
 551
 552 int ptlrpc_pinger_remove_timeouts(void)
 553 {
 554         struct timeout_item *item, *tmp;
 555
 556         cfs_mutex_down(&pinger_sem);
 557         cfs_list_for_each_entry_safe(item, tmp, &timeout_list, ti_chain) {
 558                 LASSERT(cfs_list_empty(&item->ti_obd_list));
 559                 cfs_list_del(&item->ti_chain);
 560                 OBD_FREE_PTR(item);
 561         }
 562         cfs_mutex_up(&pinger_sem);
 563         return 0;
 564 }
 565
 566 void ptlrpc_pinger_wake_up()
 567 {
 568 #ifdef ENABLE_PINGER
 569         pinger_thread->t_flags |= SVC_EVENT;
 570         cfs_waitq_signal(&pinger_thread->t_ctl_waitq);
 571 #endif
 572 }
 573
 574 /* Ping evictor thread */
 575 #define PET_READY     1
 576 #define PET_TERMINATE 2
 577
 578 static int               pet_refcount = 0;
 579 static int               pet_state;
 580 static cfs_waitq_t       pet_waitq;
 581 CFS_LIST_HEAD(pet_list);
 582 static cfs_spinlock_t    pet_lock = CFS_SPIN_LOCK_UNLOCKED;
 583
 584 int ping_evictor_wake(struct obd_export *exp)
 585 {
 586         struct obd_device *obd;
 587
 588         cfs_spin_lock(&pet_lock);
 589         if (pet_state != PET_READY) {
 590                 /* eventually the new obd will call here again. */
 591                 cfs_spin_unlock(&pet_lock);
 592                 return 1;
 593         }
 594
 595         obd = class_exp2obd(exp);
 596         if (cfs_list_empty(&obd->obd_evict_list)) {
 597                 class_incref(obd, __FUNCTION__, cfs_current());
 598                 cfs_list_add(&obd->obd_evict_list, &pet_list);
 599         }
 600         cfs_spin_unlock(&pet_lock);
 601
 602         cfs_waitq_signal(&pet_waitq);
 603         return 0;
 604 }
 605
 606 static int ping_evictor_main(void *arg)
 607 {
 608         struct obd_device *obd;
 609         struct obd_export *exp;
 610         struct l_wait_info lwi = { 0 };
 611         time_t expire_time;
 612         ENTRY;
 613
 614         cfs_daemonize_ctxt("ll_evictor");
 615
 616         CDEBUG(D_HA, "Starting Ping Evictor\n");
 617         pet_state = PET_READY;
 618         while (1) {
 619                 l_wait_event(pet_waitq, (!cfs_list_empty(&pet_list)) ||
 620                              (pet_state == PET_TERMINATE), &lwi);
 621
 622                 /* loop until all obd's will be removed */
 623                 if ((pet_state == PET_TERMINATE) && cfs_list_empty(&pet_list))
 624                         break;
 625
 626                 /* we only get here if pet_exp != NULL, and the end of this
 627                  * loop is the only place which sets it NULL again, so lock
 628                  * is not strictly necessary. */
 629                 cfs_spin_lock(&pet_lock);
 630                 obd = cfs_list_entry(pet_list.next, struct obd_device,
 631                                      obd_evict_list);
 632                 cfs_spin_unlock(&pet_lock);
 633
 634                 expire_time = cfs_time_current_sec() - PING_EVICT_TIMEOUT;
 635
 636                 CDEBUG(D_HA, "evicting all exports of obd %s older than %ld\n",
 637                        obd->obd_name, expire_time);
 638
 639                 /* Exports can't be deleted out of the list while we hold
 640                  * the obd lock (class_unlink_export), which means we can't
 641                  * lose the last ref on the export.  If they've already been
 642                  * removed from the list, we won't find them here. */
 643                 cfs_spin_lock(&obd->obd_dev_lock);
 644                 while (!cfs_list_empty(&obd->obd_exports_timed)) {
 645                         exp = cfs_list_entry(obd->obd_exports_timed.next,
 646                                              struct obd_export,
 647                                              exp_obd_chain_timed);
 648                         if (expire_time > exp->exp_last_request_time) {
 649                                 class_export_get(exp);
 650                                 cfs_spin_unlock(&obd->obd_dev_lock);
 651                                  LCONSOLE_WARN("%s: haven't heard from client %s"
 652                                               " (at %s) in %ld seconds. I think"
 653                                               " it's dead, and I am evicting"
 654                                               " it. exp %p, cur %ld expire %ld"
 655                                               " last %ld\n",
 656                                               obd->obd_name,
 657                                               obd_uuid2str(&exp->exp_client_uuid),
 658                                               obd_export_nid2str(exp),
 659                                               (long)(cfs_time_current_sec() -
 660                                                      exp->exp_last_request_time),
 661                                               exp, (long)cfs_time_current_sec(),
 662                                               (long)expire_time,
 663                                               (long)exp->exp_last_request_time);
 664                                 CDEBUG(D_HA, "Last request was at %ld\n",
 665                                        exp->exp_last_request_time);
 666                                 class_fail_export(exp);
 667                                 class_export_put(exp);
 668                                 cfs_spin_lock(&obd->obd_dev_lock);
 669                         } else {
 670                                 /* List is sorted, so everyone below is ok */
 671                                 break;
 672                         }
 673                 }
 674                 cfs_spin_unlock(&obd->obd_dev_lock);
 675
 676                 cfs_spin_lock(&pet_lock);
 677                 cfs_list_del_init(&obd->obd_evict_list);
 678                 cfs_spin_unlock(&pet_lock);
 679
 680                 class_decref(obd, __FUNCTION__, cfs_current());
 681         }
 682         CDEBUG(D_HA, "Exiting Ping Evictor\n");
 683
 684         RETURN(0);
 685 }
 686
 687 void ping_evictor_start(void)
 688 {
 689         int rc;
 690
 691         if (++pet_refcount > 1)
 692                 return;
 693
 694         cfs_waitq_init(&pet_waitq);
 695
 696         rc = cfs_kernel_thread(ping_evictor_main, NULL, CLONE_VM | CLONE_FILES);
 697         if (rc < 0) {
 698                 pet_refcount--;
 699                 CERROR("Cannot start ping evictor thread: %d\n", rc);
 700         }
 701 }
 702 EXPORT_SYMBOL(ping_evictor_start);
 703
 704 void ping_evictor_stop(void)
 705 {
 706         if (--pet_refcount > 0)
 707                 return;
 708
 709         pet_state = PET_TERMINATE;
 710         cfs_waitq_signal(&pet_waitq);
 711 }
 712 EXPORT_SYMBOL(ping_evictor_stop);
 713 #else /* !__KERNEL__ */
 714
 715 /* XXX
 716  * the current implementation of pinger in liblustre is not optimized
 717  */
 718
 719 #ifdef ENABLE_PINGER
 720 static struct pinger_data {
 721         int             pd_recursion;
 722         cfs_time_t      pd_this_ping;   /* jiffies */
 723         cfs_time_t      pd_next_ping;   /* jiffies */
 724         struct ptlrpc_request_set *pd_set;
 725 } pinger_args;
 726
 727 static int pinger_check_rpcs(void *arg)
 728 {
 729         cfs_time_t curtime = cfs_time_current();
 730         struct ptlrpc_request *req;
 731         struct ptlrpc_request_set *set;
 732         cfs_list_t *iter;
 733         struct obd_import *imp;
 734         struct pinger_data *pd = &pinger_args;
 735         int rc;
 736
 737         /* prevent recursion */
 738         if (pd->pd_recursion++) {
 739                 CDEBUG(D_HA, "pinger: recursion! quit\n");
 740                 LASSERT(pd->pd_set);
 741                 pd->pd_recursion--;
 742                 return 0;
 743         }
 744
 745         /* have we reached ping point? */
 746         if (!pd->pd_set && cfs_time_before(curtime, pd->pd_next_ping)) {
 747                 pd->pd_recursion--;
 748                 return 0;
 749         }
 750
 751         /* if we have rpc_set already, continue processing it */
 752         if (pd->pd_set) {
 753                 LASSERT(pd->pd_this_ping);
 754                 set = pd->pd_set;
 755                 goto do_check_set;
 756         }
 757
 758         pd->pd_this_ping = curtime;
 759         pd->pd_set = ptlrpc_prep_set();
 760         if (pd->pd_set == NULL)
 761                 goto out;
 762         set = pd->pd_set;
 763
 764         /* add rpcs into set */
 765         cfs_mutex_down(&pinger_sem);
 766         cfs_list_for_each(iter, &pinger_imports) {
 767                 struct obd_import *imp = cfs_list_entry(iter, struct obd_import,
 768                                                         imp_pinger_chain);
 769                 int generation, level;
 770
 771                 if (cfs_time_aftereq(pd->pd_this_ping,
 772                                      imp->imp_next_ping - 5 * CFS_TICK)) {
 773                         /* Add a ping. */
 774                         cfs_spin_lock(&imp->imp_lock);
 775                         generation = imp->imp_generation;
 776                         level = imp->imp_state;
 777                         cfs_spin_unlock(&imp->imp_lock);
 778
 779                         if (level != LUSTRE_IMP_FULL) {
 780                                 CDEBUG(D_HA,
 781                                        "not pinging %s (in recovery)\n",
 782                                        obd2cli_tgt(imp->imp_obd));
 783                                 continue;
 784                         }
 785
 786                         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING,
 787                                                         LUSTRE_OBD_VERSION,
 788                                                         OBD_PING);
 789                         if (req == NULL) {
 790                                 CERROR("OOM trying to ping %s->%s\n",
 791                                        imp->imp_obd->obd_uuid.uuid,
 792                                        obd2cli_tgt(imp->imp_obd));
 793                                 break;
 794                         }
 795
 796                         req->rq_no_resend = 1;
 797                         ptlrpc_request_set_replen(req);
 798                         req->rq_send_state = LUSTRE_IMP_FULL;
 799                         ptlrpc_rqphase_move(req, RQ_PHASE_RPC);
 800                         req->rq_import_generation = generation;
 801                         ptlrpc_set_add_req(set, req);
 802                 } else {
 803                         CDEBUG(D_INFO, "don't need to ping %s ("CFS_TIME_T
 804                                " > "CFS_TIME_T")\n", obd2cli_tgt(imp->imp_obd),
 805                                imp->imp_next_ping, pd->pd_this_ping);
 806                 }
 807         }
 808         pd->pd_this_ping = curtime;
 809         cfs_mutex_up(&pinger_sem);
 810
 811         /* Might be empty, that's OK. */
 812         if (set->set_remaining == 0)
 813                 CDEBUG(D_RPCTRACE, "nothing to ping\n");
 814
 815         cfs_list_for_each(iter, &set->set_requests) {
 816                 struct ptlrpc_request *req =
 817                         cfs_list_entry(iter, struct ptlrpc_request,
 818                                        rq_set_chain);
 819                 DEBUG_REQ(D_RPCTRACE, req, "pinging %s->%s",
 820                           req->rq_import->imp_obd->obd_uuid.uuid,
 821                           obd2cli_tgt(req->rq_import->imp_obd));
 822                 (void)ptl_send_rpc(req, 0);
 823         }
 824
 825 do_check_set:
 826         rc = ptlrpc_check_set(NULL, set);
 827
 828         /* not finished, and we are not expired, simply return */
 829         if (!rc && cfs_time_before(curtime, cfs_time_add(pd->pd_this_ping,
 830                                             cfs_time_seconds(PING_INTERVAL)))) {
 831                 CDEBUG(D_RPCTRACE, "not finished, but also not expired\n");
 832                 pd->pd_recursion--;
 833                 return 0;
 834         }
 835
 836         /* Expire all the requests that didn't come back. */
 837         cfs_mutex_down(&pinger_sem);
 838         cfs_list_for_each(iter, &set->set_requests) {
 839                 req = cfs_list_entry(iter, struct ptlrpc_request,
 840                                      rq_set_chain);
 841
 842                 if (req->rq_phase == RQ_PHASE_COMPLETE)
 843                         continue;
 844
 845                 CDEBUG(D_RPCTRACE, "Pinger initiate expire request(%p)\n",
 846                        req);
 847
 848                 /* This will also unregister reply. */
 849                 ptlrpc_expire_one_request(req, 0);
 850
 851                 /* We're done with this req, let's finally move it to complete
 852                  * phase and take care of inflights. */
 853                 ptlrpc_rqphase_move(req, RQ_PHASE_COMPLETE);
 854                 imp = req->rq_import;
 855                 cfs_spin_lock(&imp->imp_lock);
 856                 if (!cfs_list_empty(&req->rq_list)) {
 857                         cfs_list_del_init(&req->rq_list);
 858                         cfs_atomic_dec(&imp->imp_inflight);
 859                 }
 860                 cfs_spin_unlock(&imp->imp_lock);
 861                 set->set_remaining--;
 862         }
 863         cfs_mutex_up(&pinger_sem);
 864
 865         ptlrpc_set_destroy(set);
 866         pd->pd_set = NULL;
 867
 868 out:
 869         pd->pd_next_ping = cfs_time_add(pd->pd_this_ping,
 870                                         cfs_time_seconds(PING_INTERVAL));
 871         pd->pd_this_ping = 0; /* XXX for debug */
 872
 873         CDEBUG(D_INFO, "finished a round ping\n");
 874         pd->pd_recursion--;
 875         return 0;
 876 }
 877
 878 static void *pinger_callback = NULL;
 879 #endif /* ENABLE_PINGER */
 880
 881 int ptlrpc_start_pinger(void)
 882 {
 883 #ifdef ENABLE_PINGER
 884         memset(&pinger_args, 0, sizeof(pinger_args));
 885         pinger_callback = liblustre_register_wait_callback("pinger_check_rpcs",
 886                                                            &pinger_check_rpcs,
 887                                                            &pinger_args);
 888 #endif
 889         return 0;
 890 }
 891
 892 int ptlrpc_stop_pinger(void)
 893 {
 894 #ifdef ENABLE_PINGER
 895         if (pinger_callback)
 896                 liblustre_deregister_wait_callback(pinger_callback);
 897 #endif
 898         return 0;
 899 }
 900
 901 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 902 {
 903 #ifdef ENABLE_PINGER
 904         cfs_mutex_down(&pinger_sem);
 905         ptlrpc_update_next_ping(imp);
 906         if (pinger_args.pd_set == NULL &&
 907             cfs_time_before(imp->imp_next_ping, pinger_args.pd_next_ping)) {
 908                 CDEBUG(D_HA, "set next ping to "CFS_TIME_T"(cur "CFS_TIME_T")\n",
 909                         imp->imp_next_ping, cfs_time_current());
 910                 pinger_args.pd_next_ping = imp->imp_next_ping;
 911         }
 912         cfs_mutex_up(&pinger_sem);
 913 #endif
 914 }
 915
 916 int ptlrpc_add_timeout_client(int time, enum timeout_event event,
 917                               timeout_cb_t cb, void *data,
 918                               cfs_list_t *obd_list)
 919 {
 920         return 0;
 921 }
 922
 923 int ptlrpc_del_timeout_client(cfs_list_t *obd_list,
 924                               enum timeout_event event)
 925 {
 926         return 0;
 927 }
 928
 929 int ptlrpc_pinger_add_import(struct obd_import *imp)
 930 {
 931         ENTRY;
 932         if (!cfs_list_empty(&imp->imp_pinger_chain))
 933                 RETURN(-EALREADY);
 934
 935         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 936                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 937         ptlrpc_pinger_sending_on_import(imp);
 938
 939         cfs_mutex_down(&pinger_sem);
 940         cfs_list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 941         class_import_get(imp);
 942         cfs_mutex_up(&pinger_sem);
 943
 944         RETURN(0);
 945 }
 946
 947 int ptlrpc_pinger_del_import(struct obd_import *imp)
 948 {
 949         ENTRY;
 950         if (cfs_list_empty(&imp->imp_pinger_chain))
 951                 RETURN(-ENOENT);
 952
 953         cfs_mutex_down(&pinger_sem);
 954         cfs_list_del_init(&imp->imp_pinger_chain);
 955         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 956                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 957         class_import_put(imp);
 958         cfs_mutex_up(&pinger_sem);
 959         RETURN(0);
 960 }
 961
 962 void ptlrpc_pinger_wake_up()
 963 {
 964 #ifdef ENABLE_PINGER
 965         /* XXX force pinger to run, if needed */
 966         struct obd_import *imp;
 967         ENTRY;
 968         cfs_list_for_each_entry(imp, &pinger_imports, imp_pinger_chain) {
 969                 CDEBUG(D_RPCTRACE, "checking import %s->%s\n",
 970                        imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 971 #ifdef ENABLE_LIBLUSTRE_RECOVERY
 972                 if (imp->imp_state == LUSTRE_IMP_DISCON &&
 973                     !imp_is_deactive(imp))
 974 #else
 975                 /*XXX only recover for the initial connection */
 976                 if (!lustre_handle_is_used(&imp->imp_remote_handle) &&
 977                     imp->imp_state == LUSTRE_IMP_DISCON &&
 978                     !imp_is_deactive(imp))
 979 #endif
 980                         ptlrpc_initiate_recovery(imp);
 981                 else if (imp->imp_state != LUSTRE_IMP_FULL)
 982                         CDEBUG(D_HA, "Refused to recover import %s->%s "
 983                                      "state %d, deactive %d\n",
 984                                      imp->imp_obd->obd_uuid.uuid,
 985                                      obd2cli_tgt(imp->imp_obd), imp->imp_state,
 986                                      imp_is_deactive(imp));
 987         }
 988         EXIT;
 989 #endif
 990 }
 991 #endif /* !__KERNEL__ */