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 <linux/kthread.h>
  40 #include <linux/workqueue.h>
  41 #include <obd_support.h>
  42 #include <obd_class.h>
  43 #include "ptlrpc_internal.h"
  44
  45 static int suppress_pings;
  46 module_param(suppress_pings, int, 0644);
  47 MODULE_PARM_DESC(suppress_pings, "Suppress pings");
  48
  49 struct mutex pinger_mutex;
  50 static struct list_head pinger_imports =
  51                 LIST_HEAD_INIT(pinger_imports);
  52
  53 int ptlrpc_pinger_suppress_pings(void)
  54 {
  55         return suppress_pings;
  56 }
  57 EXPORT_SYMBOL(ptlrpc_pinger_suppress_pings);
  58
  59 struct ptlrpc_request *
  60 ptlrpc_prep_ping(struct obd_import *imp)
  61 {
  62         struct ptlrpc_request *req;
  63
  64         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING,
  65                                         LUSTRE_OBD_VERSION, OBD_PING);
  66         if (req) {
  67                 ptlrpc_request_set_replen(req);
  68                 req->rq_no_resend = req->rq_no_delay = 1;
  69         }
  70         return req;
  71 }
  72
  73 int ptlrpc_obd_ping(struct obd_device *obd)
  74 {
  75         int rc;
  76         struct ptlrpc_request *req;
  77         struct obd_import *imp;
  78
  79         ENTRY;
  80
  81         with_imp_locked(obd, imp, rc) {
  82                 req = ptlrpc_prep_ping(imp);
  83                 if (!req) {
  84                         rc = -ENOMEM;
  85                         continue;
  86                 }
  87                 req->rq_send_state = LUSTRE_IMP_FULL;
  88                 rc = ptlrpc_queue_wait(req);
  89                 ptlrpc_req_finished(req);
  90         }
  91         RETURN(rc);
  92 }
  93 EXPORT_SYMBOL(ptlrpc_obd_ping);
  94
  95 static bool ptlrpc_check_import_is_idle(struct obd_import *imp)
  96 {
  97         struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
  98         time64_t now;
  99
 100         if (!imp->imp_idle_timeout)
 101                 return false;
 102
 103         if (atomic_read(&imp->imp_reqs) > 0)
 104                 return false;
 105
 106         /* any lock increases ns_bref being a resource holder */
 107         if (ns && atomic_read(&ns->ns_bref) > 0)
 108                 return false;
 109
 110         now = ktime_get_real_seconds();
 111         if (now - imp->imp_last_reply_time < imp->imp_idle_timeout)
 112                 return false;
 113
 114         return true;
 115 }
 116
 117 static void ptlrpc_update_next_ping(struct obd_import *imp, int soon)
 118 {
 119 #ifdef CONFIG_LUSTRE_FS_PINGER
 120         time64_t time = soon ? PING_INTERVAL_SHORT : PING_INTERVAL;
 121
 122         if (imp->imp_state == LUSTRE_IMP_DISCON) {
 123                 time64_t dtime = max_t(time64_t, CONNECTION_SWITCH_MIN,
 124                                        AT_OFF ? 0 :
 125                                        at_get(&imp->imp_at.iat_net_latency));
 126                 time = min(time, dtime);
 127         }
 128         imp->imp_next_ping = ktime_get_seconds() + time;
 129 #endif /* CONFIG_LUSTRE_FS_PINGER */
 130 }
 131
 132 static int ptlrpc_ping(struct obd_import *imp)
 133 {
 134         struct ptlrpc_request *req;
 135
 136         ENTRY;
 137
 138         if (ptlrpc_check_import_is_idle(imp))
 139                 RETURN(ptlrpc_disconnect_and_idle_import(imp));
 140
 141         req = ptlrpc_prep_ping(imp);
 142         if (!req) {
 143                 CERROR("OOM trying to ping %s->%s\n",
 144                        imp->imp_obd->obd_uuid.uuid,
 145                        obd2cli_tgt(imp->imp_obd));
 146                 RETURN(-ENOMEM);
 147         }
 148
 149         DEBUG_REQ(D_INFO, req, "pinging %s->%s",
 150                   imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 151         /* Updating imp_next_ping early, it allows pinger_check_timeout to
 152          * see an actual time for next awake. request_out_callback update
 153          * happens at another thread, and ptlrpc_pinger_main may sleep
 154          * already.
 155          */
 156         ptlrpc_update_next_ping(imp, 0);
 157         ptlrpcd_add_req(req);
 158
 159         RETURN(0);
 160 }
 161
 162 void ptlrpc_ping_import_soon(struct obd_import *imp)
 163 {
 164         imp->imp_next_ping = ktime_get_seconds();
 165 }
 166
 167 static inline int imp_is_deactive(struct obd_import *imp)
 168 {
 169         return imp->imp_deactive ||
 170                OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE);
 171 }
 172
 173 static inline time64_t ptlrpc_next_reconnect(struct obd_import *imp)
 174 {
 175         return ktime_get_seconds() + INITIAL_CONNECT_TIMEOUT;
 176 }
 177
 178 static timeout_t pinger_check_timeout(time64_t time)
 179 {
 180         timeout_t timeout = PING_INTERVAL;
 181         timeout_t next_timeout;
 182         time64_t now;
 183         struct list_head *iter;
 184         struct obd_import *imp;
 185
 186         mutex_lock(&pinger_mutex);
 187         now = ktime_get_seconds();
 188         /* Process imports to find a nearest next ping */
 189         list_for_each(iter, &pinger_imports) {
 190                 imp = list_entry(iter, struct obd_import, imp_pinger_chain);
 191                 if (!imp->imp_pingable || imp->imp_next_ping < now)
 192                         continue;
 193                 next_timeout = imp->imp_next_ping - now;
 194                 /* make sure imp_next_ping in the future from time */
 195                 if (next_timeout > (now - time) && timeout > next_timeout)
 196                         timeout = next_timeout;
 197         }
 198         mutex_unlock(&pinger_mutex);
 199
 200         return timeout - (now - time);
 201 }
 202
 203 static bool ir_up;
 204
 205 void ptlrpc_pinger_ir_up(void)
 206 {
 207         CDEBUG(D_HA, "IR up\n");
 208         ir_up = true;
 209 }
 210 EXPORT_SYMBOL(ptlrpc_pinger_ir_up);
 211
 212 void ptlrpc_pinger_ir_down(void)
 213 {
 214         CDEBUG(D_HA, "IR down\n");
 215         ir_up = false;
 216 }
 217 EXPORT_SYMBOL(ptlrpc_pinger_ir_down);
 218
 219 static void ptlrpc_pinger_process_import(struct obd_import *imp,
 220                                          time64_t this_ping)
 221 {
 222         int level;
 223         int force;
 224         int force_next;
 225         int suppress;
 226
 227         spin_lock(&imp->imp_lock);
 228
 229         level = imp->imp_state;
 230         force = imp->imp_force_verify;
 231         force_next = imp->imp_force_next_verify;
 232         /*
 233          * This will be used below only if the import is "FULL".
 234          */
 235         suppress = ir_up && OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS);
 236
 237         imp->imp_force_verify = 0;
 238
 239         if (imp->imp_next_ping - 5 >= this_ping && !force) {
 240                 spin_unlock(&imp->imp_lock);
 241                 return;
 242         }
 243
 244         imp->imp_force_next_verify = 0;
 245
 246         CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA,
 247                "%s->%s: level %s/%u force %u force_next %u deactive %u pingable %u suppress %u\n",
 248                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
 249                ptlrpc_import_state_name(level), level, force, force_next,
 250                imp->imp_deactive, imp->imp_pingable, suppress);
 251
 252         if (level == LUSTRE_IMP_DISCON && !imp_is_deactive(imp)) {
 253                 /* wait for a while before trying recovery again */
 254                 imp->imp_next_ping = ptlrpc_next_reconnect(imp);
 255                 spin_unlock(&imp->imp_lock);
 256                 if (!imp->imp_no_pinger_recover ||
 257                     imp->imp_connect_error == -EAGAIN)
 258                         ptlrpc_initiate_recovery(imp);
 259         } else if (level != LUSTRE_IMP_FULL || imp->imp_obd->obd_no_recov ||
 260                    imp_is_deactive(imp)) {
 261                 CDEBUG(D_HA,
 262                        "%s->%s: not pinging (in recovery or recovery disabled: %s)\n",
 263                        imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
 264                        ptlrpc_import_state_name(level));
 265                 if (force)
 266                         imp->imp_force_verify = 1;
 267                 spin_unlock(&imp->imp_lock);
 268         } else if ((imp->imp_pingable && !suppress) || force_next || force) {
 269                 spin_unlock(&imp->imp_lock);
 270                 ptlrpc_ping(imp);
 271         } else {
 272                 spin_unlock(&imp->imp_lock);
 273         }
 274 }
 275
 276 static struct workqueue_struct *pinger_wq;
 277 static void ptlrpc_pinger_main(struct work_struct *ws);
 278 static DECLARE_DELAYED_WORK(ping_work, ptlrpc_pinger_main);
 279
 280 static void ptlrpc_pinger_main(struct work_struct *ws)
 281 {
 282         time64_t this_ping, time_after_ping;
 283         timeout_t time_to_next_wake;
 284         struct obd_import *imp;
 285
 286         do {
 287                 this_ping = ktime_get_seconds();
 288
 289                 mutex_lock(&pinger_mutex);
 290
 291                 list_for_each_entry(imp, &pinger_imports, imp_pinger_chain) {
 292                         ptlrpc_pinger_process_import(imp, this_ping);
 293                         /* obd_timeout might have changed */
 294                         if (imp->imp_pingable && imp->imp_next_ping &&
 295                             imp->imp_next_ping > this_ping + PING_INTERVAL)
 296                                 ptlrpc_update_next_ping(imp, 0);
 297                 }
 298                 mutex_unlock(&pinger_mutex);
 299
 300                 time_after_ping = ktime_get_seconds();
 301                 /* update memory usage info */
 302                 obd_update_maxusage();
 303
 304                 if ((ktime_get_seconds() - this_ping - 3) > PING_INTERVAL)
 305                         CDEBUG(D_HA, "long time to ping: %lld, %lld, %lld\n",
 306                                this_ping, time_after_ping, ktime_get_seconds());
 307
 308                 /* Wait until the next ping time, or until we're stopped. */
 309                 time_to_next_wake = pinger_check_timeout(this_ping);
 310                 /*
 311                  * The ping sent by ptlrpc_send_rpc may get sent out
 312                  * say .01 second after this.
 313                  * ptlrpc_pinger_sending_on_import will then set the
 314                  * next ping time to next_ping + .01 sec, which means
 315                  * we will SKIP the next ping at next_ping, and the
 316                  * ping will get sent 2 timeouts from now!  Beware.
 317                  */
 318                 CDEBUG(D_INFO, "next wakeup in %d (%lld)\n",
 319                        time_to_next_wake, this_ping + PING_INTERVAL);
 320         } while (time_to_next_wake <= 0);
 321
 322         queue_delayed_work(pinger_wq, &ping_work,
 323                            cfs_time_seconds(max(time_to_next_wake, 1)));
 324 }
 325
 326 int ptlrpc_start_pinger(void)
 327 {
 328 #ifdef CONFIG_LUSTRE_FS_PINGER
 329         if (pinger_wq)
 330                 return -EALREADY;
 331
 332         pinger_wq = cfs_cpt_bind_workqueue("ptlrpc_pinger", cfs_cpt_tab,
 333                                            0, CFS_CPT_ANY, 1);
 334         if (IS_ERR(pinger_wq)) {
 335                 CERROR("cannot start pinger workqueue\n");
 336                 return PTR_ERR(pinger_wq);
 337         }
 338
 339         queue_delayed_work(pinger_wq, &ping_work, 0);
 340
 341         if (suppress_pings)
 342                 CWARN("Pings will be suppressed at the request of the administrator. The configuration shall meet the additional requirements described in the manual. (Search for the \"suppress_pings\" kernel module parameter.)\n");
 343 #endif
 344         return 0;
 345 }
 346
 347 int ptlrpc_stop_pinger(void)
 348 {
 349 #ifdef CONFIG_LUSTRE_FS_PINGER
 350         if (!pinger_wq)
 351                 return -EALREADY;
 352
 353         cancel_delayed_work_sync(&ping_work);
 354         destroy_workqueue(pinger_wq);
 355         pinger_wq = NULL;
 356 #endif
 357         return 0;
 358 }
 359
 360 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 361 {
 362         ptlrpc_update_next_ping(imp, 0);
 363 }
 364
 365 void ptlrpc_pinger_commit_expected(struct obd_import *imp)
 366 {
 367         ptlrpc_update_next_ping(imp, 1);
 368         assert_spin_locked(&imp->imp_lock);
 369         /*
 370          * Avoid reading stale imp_connect_data.  When not sure if pings are
 371          * expected or not on next connection, we assume they are not and force
 372          * one anyway to guarantee the chance of updating
 373          * imp_peer_committed_transno.
 374          */
 375         if (imp->imp_state != LUSTRE_IMP_FULL ||
 376             OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS))
 377                 imp->imp_force_next_verify = 1;
 378 }
 379
 380 int ptlrpc_pinger_add_import(struct obd_import *imp)
 381 {
 382         ENTRY;
 383         if (!list_empty(&imp->imp_pinger_chain))
 384                 RETURN(-EALREADY);
 385
 386         mutex_lock(&pinger_mutex);
 387         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 388                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 389         /* if we add to pinger we want recovery on this import */
 390         imp->imp_obd->obd_no_recov = 0;
 391         ptlrpc_update_next_ping(imp, 0);
 392         /* XXX sort, blah blah */
 393         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 394         class_import_get(imp);
 395
 396         ptlrpc_pinger_wake_up();
 397         mutex_unlock(&pinger_mutex);
 398
 399         RETURN(0);
 400 }
 401 EXPORT_SYMBOL(ptlrpc_pinger_add_import);
 402
 403 int ptlrpc_pinger_del_import(struct obd_import *imp)
 404 {
 405         ENTRY;
 406
 407         if (list_empty(&imp->imp_pinger_chain))
 408                 RETURN(-ENOENT);
 409
 410         mutex_lock(&pinger_mutex);
 411         list_del_init(&imp->imp_pinger_chain);
 412         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 413                imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
 414         /* if we remove from pinger we don't want recovery on this import */
 415         imp->imp_obd->obd_no_recov = 1;
 416         class_import_put(imp);
 417         mutex_unlock(&pinger_mutex);
 418         RETURN(0);
 419 }
 420 EXPORT_SYMBOL(ptlrpc_pinger_del_import);
 421
 422 void ptlrpc_pinger_wake_up(void)
 423 {
 424 #ifdef CONFIG_LUSTRE_FS_PINGER
 425         mod_delayed_work(pinger_wq, &ping_work, 0);
 426 #endif
 427 }
 428
 429 /* Ping evictor thread */
 430 #define PET_READY     1
 431 #define PET_TERMINATE 2
 432
 433 static int pet_refcount;
 434 static int pet_state;
 435 static wait_queue_head_t pet_waitq;
 436 static LIST_HEAD(pet_list);
 437 static DEFINE_SPINLOCK(pet_lock);
 438
 439 int ping_evictor_wake(struct obd_export *exp)
 440 {
 441         struct obd_device *obd;
 442
 443         spin_lock(&pet_lock);
 444         if (pet_state != PET_READY) {
 445                 /* eventually the new obd will call here again. */
 446                 spin_unlock(&pet_lock);
 447                 return 1;
 448         }
 449
 450         obd = class_exp2obd(exp);
 451         if (list_empty(&obd->obd_evict_list)) {
 452                 class_incref(obd, "evictor", obd);
 453                 list_add(&obd->obd_evict_list, &pet_list);
 454         }
 455         spin_unlock(&pet_lock);
 456
 457         wake_up(&pet_waitq);
 458         return 0;
 459 }
 460
 461 static int ping_evictor_main(void *arg)
 462 {
 463         struct obd_device *obd;
 464         struct obd_export *exp;
 465         time64_t expire_time;
 466
 467         ENTRY;
 468         CDEBUG(D_HA, "Starting Ping Evictor\n");
 469         pet_state = PET_READY;
 470         while (1) {
 471                 wait_event_idle(pet_waitq,
 472                                 (!list_empty(&pet_list)) ||
 473                                 (pet_state == PET_TERMINATE));
 474
 475                 /* loop until all obd's will be removed */
 476                 if ((pet_state == PET_TERMINATE) && list_empty(&pet_list))
 477                         break;
 478
 479                 /*
 480                  * we only get here if pet_exp != NULL, and the end of this
 481                  * loop is the only place which sets it NULL again, so lock
 482                  * is not strictly necessary.
 483                  */
 484                 spin_lock(&pet_lock);
 485                 obd = list_entry(pet_list.next, struct obd_device,
 486                                  obd_evict_list);
 487                 spin_unlock(&pet_lock);
 488
 489                 expire_time = ktime_get_real_seconds() - PING_EVICT_TIMEOUT;
 490
 491                 CDEBUG(D_HA, "evicting all exports of obd %s older than %lld\n",
 492                        obd->obd_name, expire_time);
 493
 494                 /*
 495                  * Exports can't be deleted out of the list while we hold
 496                  * the obd lock (class_unlink_export), which means we can't
 497                  * lose the last ref on the export.  If they've already been
 498                  * removed from the list, we won't find them here.
 499                  */
 500                 spin_lock(&obd->obd_dev_lock);
 501                 while (!list_empty(&obd->obd_exports_timed)) {
 502                         exp = list_entry(obd->obd_exports_timed.next,
 503                                          struct obd_export,
 504                                          exp_obd_chain_timed);
 505                         if (expire_time > exp->exp_last_request_time) {
 506                                 struct obd_uuid *client_uuid;
 507
 508                                 class_export_get(exp);
 509                                 client_uuid = &exp->exp_client_uuid;
 510                                 spin_unlock(&obd->obd_dev_lock);
 511                                 LCONSOLE_WARN("%s: haven't heard from client %s (at %s) in %lld seconds. I think it's dead, and I am evicting it. exp %p, cur %lld expire %lld last %lld\n",
 512                                               obd->obd_name,
 513                                               obd_uuid2str(client_uuid),
 514                                               obd_export_nid2str(exp),
 515                                               ktime_get_real_seconds() -
 516                                               exp->exp_last_request_time,
 517                                               exp, ktime_get_real_seconds(),
 518                                               expire_time,
 519                                               exp->exp_last_request_time);
 520                                 CDEBUG(D_HA, "Last request was at %lld\n",
 521                                        exp->exp_last_request_time);
 522                                 class_fail_export(exp);
 523                                 class_export_put(exp);
 524                                 spin_lock(&obd->obd_dev_lock);
 525                         } else {
 526                                 /* List is sorted, so everyone below is ok */
 527                                 break;
 528                         }
 529                 }
 530                 spin_unlock(&obd->obd_dev_lock);
 531
 532                 spin_lock(&pet_lock);
 533                 list_del_init(&obd->obd_evict_list);
 534                 spin_unlock(&pet_lock);
 535
 536                 class_decref(obd, "evictor", obd);
 537         }
 538         CDEBUG(D_HA, "Exiting Ping Evictor\n");
 539
 540         RETURN(0);
 541 }
 542
 543 void ping_evictor_start(void)
 544 {
 545         struct task_struct *task;
 546
 547         if (++pet_refcount > 1)
 548                 return;
 549
 550         init_waitqueue_head(&pet_waitq);
 551
 552         task = kthread_run(ping_evictor_main, NULL, "ll_evictor");
 553         if (IS_ERR(task)) {
 554                 pet_refcount--;
 555                 CERROR("Cannot start ping evictor thread: %ld\n",
 556                         PTR_ERR(task));
 557         }
 558 }
 559 EXPORT_SYMBOL(ping_evictor_start);
 560
 561 void ping_evictor_stop(void)
 562 {
 563         if (--pet_refcount > 0)
 564                 return;
 565
 566         pet_state = PET_TERMINATE;
 567         wake_up(&pet_waitq);
 568 }
 569 EXPORT_SYMBOL(ping_evictor_stop);