lustre/ptlrpc/pinger.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Portal-RPC reconnection and replay operations, for use in recovery.
   5  *
   6  *  Copyright (c) 2003 Cluster File Systems, Inc.
   7  *   Authors: Phil Schwan <phil@clusterfs.com>
   8  *            Mike Shaver <shaver@clusterfs.com>
   9  *
  10  *   This file is part of the Lustre file system, http://www.lustre.org
  11  *   Lustre is a trademark of Cluster File Systems, Inc.
  12  *
  13  *   You may have signed or agreed to another license before downloading
  14  *   this software.  If so, you are bound by the terms and conditions
  15  *   of that agreement, and the following does not apply to you.  See the
  16  *   LICENSE file included with this distribution for more information.
  17  *
  18  *   If you did not agree to a different license, then this copy of Lustre
  19  *   is open source software; you can redistribute it and/or modify it
  20  *   under the terms of version 2 of the GNU General Public License as
  21  *   published by the Free Software Foundation.
  22  *
  23  *   In either case, Lustre is distributed in the hope that it will be
  24  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  25  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *   license text for more details.
  27  */
  28
  29 #ifndef __KERNEL__
  30 #include <liblustre.h>
  31 #else
  32 #include <linux/version.h>
  33 #include <asm/semaphore.h>
  34 #define DEBUG_SUBSYSTEM S_RPC
  35 #endif
  36
  37 #include <linux/obd_support.h>
  38 #include <linux/obd_class.h>
  39 #include "ptlrpc_internal.h"
  40
  41 static DECLARE_MUTEX(pinger_sem);
  42 static struct list_head pinger_imports = LIST_HEAD_INIT(pinger_imports);
  43
  44 int ptlrpc_ping(struct obd_import *imp)
  45 {
  46         struct ptlrpc_request *req;
  47         int rc = 0;
  48         ENTRY;
  49
  50         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL,
  51                               NULL);
  52         if (req) {
  53                 DEBUG_REQ(D_INFO, req, "pinging %s->%s",
  54                           imp->imp_obd->obd_uuid.uuid,
  55                           imp->imp_target_uuid.uuid);
  56                 req->rq_no_resend = req->rq_no_delay = 1;
  57                 req->rq_replen = lustre_msg_size(0, NULL);
  58                 ptlrpcd_add_req(req);
  59         } else {
  60                 CERROR("OOM trying to ping %s->%s\n",
  61                        imp->imp_obd->obd_uuid.uuid,
  62                        imp->imp_target_uuid.uuid);
  63                 rc = -ENOMEM;
  64         }
  65
  66         RETURN(rc);
  67 }
  68
  69 static inline void ptlrpc_update_next_ping(struct obd_import *imp)
  70 {
  71         imp->imp_next_ping = jiffies + HZ *
  72                 (imp->imp_state == LUSTRE_IMP_DISCON ? 10 : PING_INTERVAL);
  73 }
  74
  75 void ptlrpc_ping_import_soon(struct obd_import *imp)
  76 {
  77         imp->imp_next_ping = jiffies;
  78 }
  79
  80 #ifdef __KERNEL__
  81 static int ptlrpc_pinger_main(void *arg)
  82 {
  83         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
  84         struct ptlrpc_thread *thread = data->thread;
  85         unsigned long flags;
  86         ENTRY;
  87
  88         lock_kernel();
  89         ptlrpc_daemonize();
  90
  91         SIGNAL_MASK_LOCK(current, flags);
  92         sigfillset(&current->blocked);
  93         RECALC_SIGPENDING;
  94         SIGNAL_MASK_UNLOCK(current, flags);
  95
  96         LASSERTF(strlen(data->name) < sizeof(current->comm),
  97                  "name %d > len %d\n",
  98                  (int)strlen(data->name), (int)sizeof(current->comm));
  99         THREAD_NAME(current->comm, sizeof(current->comm) - 1, "%s", data->name);
 100         unlock_kernel();
 101
 102         /* Record that the thread is running */
 103         thread->t_flags = SVC_RUNNING;
 104         wake_up(&thread->t_ctl_waitq);
 105
 106         /* And now, loop forever, pinging as needed. */
 107         while (1) {
 108                 unsigned long this_ping = jiffies;
 109                 long time_to_next_ping;
 110                 struct l_wait_info lwi = LWI_TIMEOUT(PING_INTERVAL * HZ,
 111                                                      NULL, NULL);
 112                 struct list_head *iter;
 113
 114                 down(&pinger_sem);
 115                 list_for_each(iter, &pinger_imports) {
 116                         struct obd_import *imp =
 117                                 list_entry(iter, struct obd_import,
 118                                            imp_pinger_chain);
 119                         int force, level;
 120                         unsigned long flags;
 121
 122
 123                         spin_lock_irqsave(&imp->imp_lock, flags);
 124                         level = imp->imp_state;
 125                         force = imp->imp_force_verify;
 126                         imp->imp_force_verify = 0;
 127                         spin_unlock_irqrestore(&imp->imp_lock, flags);
 128                         CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA,
 129                                "level %s/%u force %u deactive %u pingable %u\n",
 130                                ptlrpc_import_state_name(level), level,
 131                                force, imp->imp_deactive, imp->imp_pingable);
 132
 133                         if (force ||
 134                             /* if the next ping is within, say, 5 jiffies from
 135                                now, go ahead and ping. See note below. */
 136                             time_after_eq(this_ping, imp->imp_next_ping - 5)) {
 137                                 if (level == LUSTRE_IMP_DISCON &&
 138                                     !imp->imp_deactive) {
 139                                         /* wait at least a timeout before
 140                                            trying recovery again. */
 141                                         imp->imp_next_ping = jiffies +
 142                                                 obd_timeout * HZ;
 143                                         ptlrpc_initiate_recovery(imp);
 144                                 } else if (level != LUSTRE_IMP_FULL ||
 145                                          imp->imp_obd->obd_no_recov ||
 146                                          imp->imp_deactive) {
 147                                         CDEBUG(D_HA, "not pinging %s "
 148                                                "(in recovery: %s or recovery "
 149                                                "disabled: %u/%u)\n",
 150                                                imp->imp_target_uuid.uuid,
 151                                                ptlrpc_import_state_name(level),
 152                                                imp->imp_deactive,
 153                                                imp->imp_obd->obd_no_recov);
 154                                 } else if (imp->imp_pingable || force) {
 155                                         ptlrpc_ping(imp);
 156                                 }
 157                         } else {
 158                                 if (!imp->imp_pingable)
 159                                         continue;
 160                                 CDEBUG(D_INFO,
 161                                        "don't need to ping %s (%lu > %lu)\n",
 162                                        imp->imp_target_uuid.uuid,
 163                                        imp->imp_next_ping, this_ping);
 164                         }
 165
 166                         /* obd_timeout might have changed */
 167                         if (time_after(imp->imp_next_ping,
 168                                        this_ping + PING_INTERVAL * HZ))
 169                                 ptlrpc_update_next_ping(imp);
 170                 }
 171                 up(&pinger_sem);
 172
 173                 /* Wait until the next ping time, or until we're stopped. */
 174                 time_to_next_ping = this_ping + (PING_INTERVAL * HZ) - jiffies;
 175                 /* The ping sent by ptlrpc_send_rpc may get sent out
 176                    say .01 second after this.
 177                    ptlrpc_pinger_sending_on_import will then set the
 178                    next ping time to next_ping + .01 sec, which means
 179                    we will SKIP the next ping at next_ping, and the
 180                    ping will get sent 2 timeouts from now!  Beware. */
 181                 CDEBUG(D_INFO, "next ping in %lu (%lu)\n", time_to_next_ping,
 182                        this_ping + PING_INTERVAL * HZ);
 183                 if (time_to_next_ping > 0) {
 184                         lwi = LWI_TIMEOUT(max_t(long, time_to_next_ping, HZ),
 185                                           NULL, NULL);
 186                         l_wait_event(thread->t_ctl_waitq,
 187                                      thread->t_flags & (SVC_STOPPING|SVC_EVENT),
 188                                      &lwi);
 189                         if (thread->t_flags & SVC_STOPPING) {
 190                                 thread->t_flags &= ~SVC_STOPPING;
 191                                 EXIT;
 192                                 break;
 193                         } else if (thread->t_flags & SVC_EVENT) {
 194                                 /* woken after adding import to reset timer */
 195                                 thread->t_flags &= ~SVC_EVENT;
 196                         }
 197                 }
 198         }
 199
 200         thread->t_flags = SVC_STOPPED;
 201         wake_up(&thread->t_ctl_waitq);
 202
 203         CDEBUG(D_NET, "pinger thread exiting, process %d\n", current->pid);
 204         return 0;
 205 }
 206
 207 static struct ptlrpc_thread *pinger_thread = NULL;
 208
 209 int ptlrpc_start_pinger(void)
 210 {
 211         struct l_wait_info lwi = { 0 };
 212         struct ptlrpc_svc_data d;
 213         int rc;
 214 #ifndef ENABLE_PINGER
 215         return 0;
 216 #endif
 217         ENTRY;
 218
 219         if (pinger_thread != NULL)
 220                 RETURN(-EALREADY);
 221
 222         OBD_ALLOC(pinger_thread, sizeof(*pinger_thread));
 223         if (pinger_thread == NULL)
 224                 RETURN(-ENOMEM);
 225         init_waitqueue_head(&pinger_thread->t_ctl_waitq);
 226
 227         d.name = "ll_ping";
 228         d.thread = pinger_thread;
 229
 230         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 231          * just drop the VM and FILES in ptlrpc_daemonize() right away. */
 232         rc = kernel_thread(ptlrpc_pinger_main, &d, CLONE_VM | CLONE_FILES);
 233         if (rc < 0) {
 234                 CERROR("cannot start thread: %d\n", rc);
 235                 OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 236                 RETURN(rc);
 237         }
 238         l_wait_event(pinger_thread->t_ctl_waitq,
 239                      pinger_thread->t_flags & SVC_RUNNING, &lwi);
 240
 241         RETURN(rc);
 242 }
 243
 244 int ptlrpc_stop_pinger(void)
 245 {
 246         struct l_wait_info lwi = { 0 };
 247         int rc = 0;
 248 #ifndef ENABLE_PINGER
 249         return 0;
 250 #endif
 251         ENTRY;
 252
 253         if (pinger_thread == NULL)
 254                 RETURN(-EALREADY);
 255         down(&pinger_sem);
 256         pinger_thread->t_flags = SVC_STOPPING;
 257         wake_up(&pinger_thread->t_ctl_waitq);
 258         up(&pinger_sem);
 259
 260         l_wait_event(pinger_thread->t_ctl_waitq,
 261                      (pinger_thread->t_flags & SVC_STOPPED), &lwi);
 262
 263         OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 264         pinger_thread = NULL;
 265         RETURN(rc);
 266 }
 267
 268 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 269 {
 270         ptlrpc_update_next_ping(imp);
 271 }
 272
 273 int ptlrpc_pinger_add_import(struct obd_import *imp)
 274 {
 275         ENTRY;
 276         if (!list_empty(&imp->imp_pinger_chain))
 277                 RETURN(-EALREADY);
 278
 279         down(&pinger_sem);
 280         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 281                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 282         ptlrpc_update_next_ping(imp);
 283         /* XXX sort, blah blah */
 284         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 285         class_import_get(imp);
 286
 287         ptlrpc_pinger_wake_up();
 288         up(&pinger_sem);
 289
 290         RETURN(0);
 291 }
 292
 293 int ptlrpc_pinger_del_import(struct obd_import *imp)
 294 {
 295         ENTRY;
 296         if (list_empty(&imp->imp_pinger_chain))
 297                 RETURN(-ENOENT);
 298
 299         down(&pinger_sem);
 300         list_del_init(&imp->imp_pinger_chain);
 301         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 302                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 303         class_import_put(imp);
 304         up(&pinger_sem);
 305         RETURN(0);
 306 }
 307
 308 void ptlrpc_pinger_wake_up()
 309 {
 310 #ifdef ENABLE_PINGER
 311         pinger_thread->t_flags |= SVC_EVENT;
 312         wake_up(&pinger_thread->t_ctl_waitq);
 313 #endif
 314 }
 315
 316 #else /* !__KERNEL__ */
 317
 318 /* XXX
 319  * the current implementation of pinger in liblustre is not optimized
 320  */
 321
 322 static struct pinger_data {
 323         int             pd_recursion;
 324         unsigned long   pd_this_ping;   /* jiffies */
 325         unsigned long   pd_next_ping;   /* jiffies */
 326         struct ptlrpc_request_set *pd_set;
 327 } pinger_args;
 328
 329 static int pinger_check_rpcs(void *arg)
 330 {
 331         unsigned long curtime = jiffies;
 332         struct ptlrpc_request *req;
 333         struct ptlrpc_request_set *set;
 334         struct list_head *iter;
 335         struct pinger_data *pd = &pinger_args;
 336         int rc;
 337
 338         /* prevent recursion */
 339         if (pd->pd_recursion++) {
 340                 CDEBUG(D_HA, "pinger: recursion! quit\n");
 341                 LASSERT(pd->pd_set);
 342                 pd->pd_recursion--;
 343                 return 0;
 344         }
 345
 346         /* have we reached ping point? */
 347         if (!pd->pd_set && time_before(curtime, pd->pd_next_ping)) {
 348                 pd->pd_recursion--;
 349                 return 0;
 350         }
 351
 352         /* if we have rpc_set already, continue processing it */
 353         if (pd->pd_set) {
 354                 LASSERT(pd->pd_this_ping);
 355                 set = pd->pd_set;
 356                 goto do_check_set;
 357         }
 358
 359         pd->pd_this_ping = curtime;
 360         pd->pd_set = ptlrpc_prep_set();
 361         if (pd->pd_set == NULL)
 362                 goto out;
 363         set = pd->pd_set;
 364
 365         /* add rpcs into set */
 366         down(&pinger_sem);
 367         list_for_each(iter, &pinger_imports) {
 368                 struct obd_import *imp =
 369                         list_entry(iter, struct obd_import, imp_pinger_chain);
 370                 int generation, level;
 371                 unsigned long flags;
 372
 373                 if (time_after_eq(pd->pd_this_ping, imp->imp_next_ping - 5)) {
 374                         /* Add a ping. */
 375                         spin_lock_irqsave(&imp->imp_lock, flags);
 376                         generation = imp->imp_generation;
 377                         level = imp->imp_state;
 378                         spin_unlock_irqrestore(&imp->imp_lock, flags);
 379
 380                         if (level != LUSTRE_IMP_FULL) {
 381                                 CDEBUG(D_HA,
 382                                        "not pinging %s (in recovery)\n",
 383                                        imp->imp_target_uuid.uuid);
 384                                 continue;
 385                         }
 386
 387                         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL,
 388                                               NULL);
 389                         if (!req) {
 390                                 CERROR("out of memory\n");
 391                                 break;
 392                         }
 393                         req->rq_no_resend = 1;
 394                         req->rq_replen = lustre_msg_size(0, NULL);
 395                         req->rq_send_state = LUSTRE_IMP_FULL;
 396                         req->rq_phase = RQ_PHASE_RPC;
 397                         req->rq_import_generation = generation;
 398                         ptlrpc_set_add_req(set, req);
 399                 } else {
 400                         CDEBUG(D_HA, "don't need to ping %s (%lu > "
 401                                "%lu)\n", imp->imp_target_uuid.uuid,
 402                                imp->imp_next_ping, pd->pd_this_ping);
 403                 }
 404         }
 405         pd->pd_this_ping = curtime;
 406         up(&pinger_sem);
 407
 408         /* Might be empty, that's OK. */
 409         if (set->set_remaining == 0)
 410                 CDEBUG(D_HA, "nothing to ping\n");
 411
 412         list_for_each(iter, &set->set_requests) {
 413                 struct ptlrpc_request *req =
 414                         list_entry(iter, struct ptlrpc_request,
 415                                    rq_set_chain);
 416                 DEBUG_REQ(D_HA, req, "pinging %s->%s",
 417                           req->rq_import->imp_obd->obd_uuid.uuid,
 418                           req->rq_import->imp_target_uuid.uuid);
 419                 (void)ptl_send_rpc(req);
 420         }
 421
 422 do_check_set:
 423         rc = ptlrpc_check_set(set);
 424
 425         /* not finished, and we are not expired, simply return */
 426         if (!rc && time_before(curtime, pd->pd_this_ping + PING_INTERVAL * HZ)) {
 427                 CDEBUG(D_HA, "not finished, but also not expired\n");
 428                 pd->pd_recursion--;
 429                 return 0;
 430         }
 431
 432         /* Expire all the requests that didn't come back. */
 433         down(&pinger_sem);
 434         list_for_each(iter, &set->set_requests) {
 435                 req = list_entry(iter, struct ptlrpc_request,
 436                                  rq_set_chain);
 437
 438                 if (req->rq_replied)
 439                         continue;
 440
 441                 req->rq_phase = RQ_PHASE_COMPLETE;
 442                 set->set_remaining--;
 443                 /* If it was disconnected, don't sweat it. */
 444                 if (list_empty(&req->rq_import->imp_pinger_chain)) {
 445                         ptlrpc_unregister_reply(req);
 446                         continue;
 447                 }
 448
 449                 CDEBUG(D_HA, "pinger initiate expire_one_request\n");
 450                 ptlrpc_expire_one_request(req);
 451         }
 452         up(&pinger_sem);
 453
 454         ptlrpc_set_destroy(set);
 455         pd->pd_set = NULL;
 456
 457 out:
 458         pd->pd_next_ping = pd->pd_this_ping + PING_INTERVAL * HZ;
 459         pd->pd_this_ping = 0; /* XXX for debug */
 460
 461         CDEBUG(D_HA, "finished a round ping\n");
 462         pd->pd_recursion--;
 463         return 0;
 464 }
 465
 466 static void *pinger_callback = NULL;
 467
 468 int ptlrpc_start_pinger(void)
 469 {
 470         memset(&pinger_args, 0, sizeof(pinger_args));
 471 #ifdef ENABLE_PINGER
 472         pinger_callback =
 473                 liblustre_register_wait_callback(&pinger_check_rpcs, &pinger_args);
 474 #endif
 475         return 0;
 476 }
 477
 478 int ptlrpc_stop_pinger(void)
 479 {
 480 #ifdef ENABLE_PINGER
 481         if (pinger_callback)
 482                 liblustre_deregister_wait_callback(pinger_callback);
 483 #endif
 484         return 0;
 485 }
 486
 487 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 488 {
 489         down(&pinger_sem);
 490         ptlrpc_update_next_ping(imp);
 491         if (pinger_args.pd_set == NULL &&
 492             time_before(imp->imp_next_ping, pinger_args.pd_next_ping)) {
 493                 CDEBUG(D_HA, "set next ping to %ld(cur %ld)\n",
 494                         imp->imp_next_ping, jiffies);
 495                 pinger_args.pd_next_ping = imp->imp_next_ping;
 496         }
 497         up(&pinger_sem);
 498 }
 499
 500 int ptlrpc_pinger_add_import(struct obd_import *imp)
 501 {
 502         ENTRY;
 503         if (!list_empty(&imp->imp_pinger_chain))
 504                 RETURN(-EALREADY);
 505
 506         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 507                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 508         ptlrpc_pinger_sending_on_import(imp);
 509
 510         down(&pinger_sem);
 511         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 512         class_import_get(imp);
 513         up(&pinger_sem);
 514
 515         RETURN(0);
 516 }
 517
 518 int ptlrpc_pinger_del_import(struct obd_import *imp)
 519 {
 520         ENTRY;
 521         if (list_empty(&imp->imp_pinger_chain))
 522                 RETURN(-ENOENT);
 523
 524         down(&pinger_sem);
 525         list_del_init(&imp->imp_pinger_chain);
 526         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 527                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 528         class_import_put(imp);
 529         up(&pinger_sem);
 530         RETURN(0);
 531 }
 532
 533 void ptlrpc_pinger_wake_up()
 534 {
 535 #ifdef ENABLE_PINGER
 536         /* XXX force pinger to run, if needed */
 537 #endif
 538 }
 539 #endif /* !__KERNEL__ */