lustre/ptlrpc/service.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_RPC
  24 #ifndef __KERNEL__
  25 #include <liblustre.h>
  26 #include <linux/kp30.h>
  27 #endif
  28 #include <linux/obd_support.h>
  29 #include <linux/obd_class.h>
  30 #include <linux/lustre_net.h>
  31 #include <portals/types.h>
  32 #include "ptlrpc_internal.h"
  33
  34 extern int request_in_callback(ptl_event_t *ev);
  35
  36 static int ptlrpc_check_event(struct ptlrpc_service *svc,
  37                               struct ptlrpc_thread *thread, ptl_event_t *event)
  38 {
  39         struct ptlrpc_srv_ni *srv_ni;
  40         int i, idx, rc;
  41         ENTRY;
  42
  43         spin_lock(&svc->srv_lock);
  44
  45         if (thread->t_flags & SVC_STOPPING)
  46                 GOTO(out, rc = 1);
  47
  48         LASSERT ((thread->t_flags & SVC_EVENT) == 0);
  49         LASSERT (ptlrpc_ninterfaces > 0);
  50
  51         for (i = 0; i < ptlrpc_ninterfaces; i++) {
  52                 idx = (svc->srv_interface_rover + i) % ptlrpc_ninterfaces;
  53                 srv_ni = &svc->srv_interfaces[idx];
  54
  55                 LASSERT (!PtlHandleEqual (srv_ni->sni_eq_h, PTL_HANDLE_NONE));
  56
  57                 rc = PtlEQGet(srv_ni->sni_eq_h, event);
  58                 switch (rc) {
  59                 case PTL_OK:
  60                         /* next time start with the next interface */
  61                         svc->srv_interface_rover = (idx+1) % ptlrpc_ninterfaces;
  62                         thread->t_flags |= SVC_EVENT;
  63                         GOTO(out, rc = 1);
  64
  65                 case PTL_EQ_EMPTY:
  66                         continue;
  67
  68                 case PTL_EQ_DROPPED:
  69                         CWARN("Event queue overflow (bug 2125): timeouts will "
  70                               "follow.\n");
  71                         continue;
  72
  73                 default:
  74                         CERROR("BUG: PtlEQGet returned %d\n", rc);
  75                         LBUG();
  76                 }
  77         }
  78         rc = 0;
  79         EXIT;
  80  out:
  81         spin_unlock(&svc->srv_lock);
  82         return rc;
  83 }
  84
  85 struct ptlrpc_service * ptlrpc_init_svc(__u32 nevents, __u32 nbufs,
  86                                         __u32 bufsize, __u32 max_req_size,
  87                                         int req_portal, int rep_portal,
  88                                         svc_handler_t handler, char *name,
  89                                         struct proc_dir_entry *proc_entry)
  90 {
  91         int i, j, ssize, rc;
  92         struct ptlrpc_service *service;
  93         struct ptlrpc_srv_ni  *srv_ni;
  94         ENTRY;
  95
  96         LASSERT (ptlrpc_ninterfaces > 0);
  97
  98         ssize = offsetof (struct ptlrpc_service,
  99                           srv_interfaces[ptlrpc_ninterfaces]);
 100         OBD_ALLOC(service, ssize);
 101         if (service == NULL)
 102                 RETURN(NULL);
 103
 104         service->srv_name = name;
 105         spin_lock_init(&service->srv_lock);
 106         INIT_LIST_HEAD(&service->srv_threads);
 107         init_waitqueue_head(&service->srv_waitq);
 108
 109         service->srv_max_req_size = max_req_size;
 110         service->srv_buf_size = bufsize;
 111
 112         service->srv_rep_portal = rep_portal;
 113         service->srv_req_portal = req_portal;
 114         service->srv_handler = handler;
 115         service->srv_interface_rover = 0;
 116
 117         /* First initialise enough for early teardown */
 118         for (i = 0; i < ptlrpc_ninterfaces; i++) {
 119                 srv_ni = &service->srv_interfaces[i];
 120
 121                 srv_ni->sni_service = service;
 122                 srv_ni->sni_ni = &ptlrpc_interfaces[i];
 123                 srv_ni->sni_eq_h = PTL_HANDLE_NONE;
 124                 INIT_LIST_HEAD(&srv_ni->sni_rqbds);
 125                 srv_ni->sni_nrqbds = 0;
 126                 atomic_set(&srv_ni->sni_nrqbds_receiving, 0);
 127         }
 128
 129         /* Now allocate the event queue and request buffers, assuming all
 130          * interfaces require the same level of buffering. */
 131         for (i = 0; i < ptlrpc_ninterfaces; i++) {
 132                 srv_ni = &service->srv_interfaces[i];
 133                 CDEBUG (D_NET, "%s: initialising interface %s\n", name,
 134                         srv_ni->sni_ni->pni_name);
 135
 136                 rc = PtlEQAlloc(srv_ni->sni_ni->pni_ni_h, nevents,
 137                                 request_in_callback, &(srv_ni->sni_eq_h));
 138                 if (rc != PTL_OK) {
 139                         CERROR("%s.%d: PtlEQAlloc on %s failed: %d\n",
 140                                name, i, srv_ni->sni_ni->pni_name, rc);
 141                         GOTO (failed, NULL);
 142                 }
 143
 144                 for (j = 0; j < nbufs; j++) {
 145                         struct ptlrpc_request_buffer_desc *rqbd;
 146
 147                         OBD_ALLOC_WAIT(rqbd, sizeof(*rqbd));
 148                         if (rqbd == NULL) {
 149                                 CERROR ("%s.%d: Can't allocate request "
 150                                         "descriptor %d on %s\n",
 151                                         name, i, srv_ni->sni_nrqbds,
 152                                         srv_ni->sni_ni->pni_name);
 153                                 GOTO(failed, NULL);
 154                         }
 155
 156                         rqbd->rqbd_srv_ni = srv_ni;
 157                         rqbd->rqbd_me_h = PTL_HANDLE_NONE;
 158                         atomic_set(&rqbd->rqbd_refcount, 0);
 159
 160                         OBD_ALLOC_WAIT(rqbd->rqbd_buffer, service->srv_buf_size);
 161                         if (rqbd->rqbd_buffer == NULL) {
 162                                 CERROR ("%s.%d: Can't allocate request "
 163                                         "buffer %d on %s\n",
 164                                         name, i, srv_ni->sni_nrqbds,
 165                                         srv_ni->sni_ni->pni_name);
 166                                 OBD_FREE(rqbd, sizeof(*rqbd));
 167                                 GOTO(failed, NULL);
 168                         }
 169                         list_add(&rqbd->rqbd_list, &srv_ni->sni_rqbds);
 170                         srv_ni->sni_nrqbds++;
 171
 172                         ptlrpc_link_svc_me(rqbd);
 173                 }
 174         }
 175
 176         if (proc_entry != NULL)
 177                 ptlrpc_lprocfs_register_service(proc_entry, service);
 178
 179         CDEBUG(D_NET, "%s: Started on %d interfaces, listening on portal %d\n",
 180                service->srv_name, ptlrpc_ninterfaces, service->srv_req_portal);
 181
 182         RETURN(service);
 183 failed:
 184         ptlrpc_unregister_service(service);
 185         return NULL;
 186 }
 187
 188 static int handle_incoming_request(struct obd_device *obddev,
 189                                    struct ptlrpc_service *svc,
 190                                    ptl_event_t *event,
 191                                    struct ptlrpc_request *request)
 192 {
 193         struct ptlrpc_request_buffer_desc *rqbd = event->mem_desc.user_ptr;
 194         int rc;
 195
 196         /* FIXME: If we move to an event-driven model, we should put the request
 197          * on the stack of mds_handle instead. */
 198
 199         LASSERT (atomic_read (&rqbd->rqbd_refcount) > 0);
 200         LASSERT ((event->mem_desc.options & (PTL_MD_IOV | PTL_MD_KIOV)) == 0);
 201         LASSERT (rqbd->rqbd_srv_ni->sni_service == svc);
 202         LASSERT (rqbd->rqbd_buffer == event->mem_desc.start);
 203         LASSERT (event->offset + event->mlength <= svc->srv_buf_size);
 204
 205         memset(request, 0, sizeof(*request));
 206         spin_lock_init (&request->rq_lock);
 207         INIT_LIST_HEAD(&request->rq_list);
 208         request->rq_svc = svc;
 209         request->rq_xid = event->match_bits;
 210         request->rq_reqmsg = event->mem_desc.start + event->offset;
 211         request->rq_reqlen = event->mlength;
 212
 213 #if SWAB_PARANOIA
 214         /* Clear request swab mask; this is a new request */
 215         request->rq_req_swab_mask = 0;
 216 #endif
 217         rc = lustre_unpack_msg (request->rq_reqmsg, request->rq_reqlen);
 218         if (rc != 0) {
 219                 CERROR ("error unpacking request: ptl %d from "LPX64
 220                         " xid "LPU64"\n", svc->srv_req_portal,
 221                        event->initiator.nid, request->rq_xid);
 222                 goto out;
 223         }
 224         rc = -EINVAL;
 225         if (request->rq_reqmsg->type != PTL_RPC_MSG_REQUEST) {
 226                 CERROR("wrong packet type received (type=%u)\n",
 227                        request->rq_reqmsg->type);
 228                 goto out;
 229         }
 230
 231         CDEBUG(D_NET, "got req "LPD64" (md: %p + %d)\n", request->rq_xid,
 232                event->mem_desc.start, event->offset);
 233
 234         request->rq_peer.peer_nid = event->initiator.nid;
 235         request->rq_peer.peer_ni = rqbd->rqbd_srv_ni->sni_ni;
 236
 237         request->rq_export = class_conn2export(&request->rq_reqmsg->handle);
 238
 239         if (request->rq_export) {
 240                 request->rq_connection = request->rq_export->exp_connection;
 241                 ptlrpc_connection_addref(request->rq_connection);
 242                 if (request->rq_reqmsg->conn_cnt <
 243                     request->rq_export->exp_conn_cnt) {
 244                         DEBUG_REQ(D_ERROR, request,
 245                                   "DROPPING req from old connection %d < %d",
 246                                   request->rq_reqmsg->conn_cnt,
 247                                   request->rq_export->exp_conn_cnt);
 248                         goto put_conn;
 249                 }
 250
 251                 request->rq_export->exp_last_request_time =
 252                         LTIME_S(CURRENT_TIME);
 253         } else {
 254                 /* create a (hopefully temporary) connection that will be used
 255                  * to send the reply if this call doesn't create an export.
 256                  * XXX revisit this when we revamp ptlrpc */
 257                 request->rq_connection =
 258                         ptlrpc_get_connection(&request->rq_peer, NULL);
 259         }
 260
 261         CDEBUG(D_RPCTRACE, "Handling RPC pname:cluuid+ref:pid:xid:ni:nid:opc "
 262                "%s:%s+%d:%d:"LPU64":%s:"LPX64":%d\n", current->comm,
 263                (request->rq_export ?
 264                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
 265                (request->rq_export ?
 266                 atomic_read(&request->rq_export->exp_refcount) : -99),
 267                request->rq_reqmsg->status, request->rq_xid,
 268                rqbd->rqbd_srv_ni->sni_ni->pni_name, event->initiator.nid,
 269                request->rq_reqmsg->opc);
 270
 271         rc = svc->srv_handler(request);
 272         CDEBUG(D_RPCTRACE, "Handled RPC pname:cluuid+ref:pid:xid:ni:nid:opc "
 273                "%s:%s+%d:%d:"LPU64":%s:"LPX64":%d\n", current->comm,
 274                (request->rq_export ?
 275                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
 276                (request->rq_export ?
 277                 atomic_read(&request->rq_export->exp_refcount) : -99),
 278                request->rq_reqmsg->status, request->rq_xid,
 279                rqbd->rqbd_srv_ni->sni_ni->pni_name, event->initiator.nid,
 280                request->rq_reqmsg->opc);
 281
 282 put_conn:
 283         ptlrpc_put_connection(request->rq_connection);
 284         if (request->rq_export != NULL)
 285                 class_export_put(request->rq_export);
 286
 287  out:
 288         if (atomic_dec_and_test (&rqbd->rqbd_refcount)) /* last reference? */
 289                 ptlrpc_link_svc_me (rqbd);
 290
 291         return rc;
 292 }
 293
 294 /* Don't use daemonize, it removes fs struct from new thread (bug 418) */
 295 void ptlrpc_daemonize(void)
 296 {
 297         exit_mm(current);
 298         lustre_daemonize_helper();
 299         exit_files(current);
 300         reparent_to_init();
 301 }
 302
 303 static long timeval_sub(struct timeval *large, struct timeval *small)
 304 {
 305         return (large->tv_sec - small->tv_sec) * 1000000 +
 306                 (large->tv_usec - small->tv_usec);
 307 }
 308
 309 static int ptlrpc_main(void *arg)
 310 {
 311         struct ptlrpc_svc_data *data = arg;
 312         struct obd_device *obddev = data->dev;
 313         struct ptlrpc_service *svc = data->svc;
 314         struct ptlrpc_thread *thread = data->thread;
 315         struct ptlrpc_request *request;
 316         ptl_event_t *event;
 317         unsigned long flags;
 318         struct timeval start_time, finish_time;
 319         long total;
 320         int rc = 0;
 321         ENTRY;
 322
 323         lock_kernel();
 324         ptlrpc_daemonize();
 325
 326         SIGNAL_MASK_LOCK(current, flags);
 327         sigfillset(&current->blocked);
 328         RECALC_SIGPENDING;
 329         SIGNAL_MASK_UNLOCK(current, flags);
 330
 331         THREAD_NAME(current->comm, "%s", data->name);
 332         unlock_kernel();
 333
 334         OBD_ALLOC(event, sizeof(*event));
 335         if (event == NULL)
 336                 GOTO(out, rc = -ENOMEM);
 337         OBD_ALLOC(request, sizeof(*request));
 338         if (request == NULL)
 339                 GOTO(out_event, rc = -ENOMEM);
 340
 341         /* Record that the thread is running */
 342         thread->t_flags = SVC_RUNNING;
 343         wake_up(&thread->t_ctl_waitq);
 344
 345         /* XXX maintain a list of all managed devices: insert here */
 346
 347         do_gettimeofday(&finish_time);
 348         /* And now, loop forever on requests */
 349         while (1) {
 350                 struct l_wait_info lwi = { 0 };
 351                 l_wait_event_exclusive(svc->srv_waitq,
 352                                        ptlrpc_check_event(svc, thread, event),
 353                                        &lwi);
 354
 355                 spin_lock(&svc->srv_lock);
 356                 if (thread->t_flags & SVC_STOPPING) {
 357                         thread->t_flags &= ~SVC_STOPPING;
 358                         spin_unlock(&svc->srv_lock);
 359
 360                         EXIT;
 361                         break;
 362                 }
 363
 364                 if (!(thread->t_flags & SVC_EVENT)) {
 365                         CERROR("unknown flag in service");
 366                         spin_unlock(&svc->srv_lock);
 367                         LBUG();
 368                         EXIT;
 369                         break;
 370                 }
 371
 372                 thread->t_flags &= ~SVC_EVENT;
 373                 spin_unlock(&svc->srv_lock);
 374
 375                 do_gettimeofday(&start_time);
 376                 total = timeval_sub(&start_time, &event->arrival_time);
 377                 if (svc->srv_stats != NULL) {
 378                         lprocfs_counter_add(svc->srv_stats, PTLRPC_REQWAIT_CNTR,
 379                                             total);
 380                         lprocfs_counter_add(svc->srv_stats,
 381                                             PTLRPC_SVCIDLETIME_CNTR,
 382                                             timeval_sub(&start_time,
 383                                                         &finish_time));
 384 #if 0 /* Wait for b_eq branch */
 385                         lprocfs_counter_add(svc->srv_stats,
 386                                             PTLRPC_SVCEQDEPTH_CNTR, 0);
 387 #endif
 388                 }
 389
 390                 if (total / 1000000 > (long)obd_timeout) {
 391                         CERROR("Dropping request from NID "LPX64" because it's "
 392                                "%ld seconds old.\n", event->initiator.nid,
 393                                total / 1000000); /* bug 1502 */
 394                 } else {
 395                         CDEBUG(D_HA, "request from NID "LPX64" noticed after "
 396                                "%ldus\n", event->initiator.nid, total);
 397                         rc = handle_incoming_request(obddev, svc, event,
 398                                                      request);
 399                 }
 400                 do_gettimeofday(&finish_time);
 401                 total = timeval_sub(&finish_time, &start_time);
 402
 403                 CDEBUG((total / 1000000 > (long)obd_timeout) ? D_ERROR : D_HA,
 404                        "request "LPU64" from NID "LPX64" processed in %ldus "
 405                        "(%ldus total)\n", request->rq_xid, event->initiator.nid,
 406                        total, timeval_sub(&finish_time, &event->arrival_time));
 407
 408                 if (svc->srv_stats != NULL) {
 409                         int opc = opcode_offset(request->rq_reqmsg->opc);
 410                         if (opc > 0) {
 411                                 LASSERT(opc < LUSTRE_MAX_OPCODES);
 412                                 lprocfs_counter_add(svc->srv_stats,
 413                                                     opc + PTLRPC_LAST_CNTR,
 414                                                     total);
 415                         }
 416                 }
 417         }
 418
 419         /* NB should wait for all SENT callbacks to complete before exiting
 420          * here.  Unfortunately at this time there is no way to track this
 421          * state. */
 422         OBD_FREE(request, sizeof(*request));
 423 out_event:
 424         OBD_FREE(event, sizeof(*event));
 425 out:
 426         thread->t_flags = SVC_STOPPED;
 427         wake_up(&thread->t_ctl_waitq);
 428
 429         CDEBUG(D_NET, "service thread exiting, process %d: rc = %d\n",
 430                current->pid, rc);
 431         return rc;
 432 }
 433
 434 static void ptlrpc_stop_thread(struct ptlrpc_service *svc,
 435                                struct ptlrpc_thread *thread)
 436 {
 437         struct l_wait_info lwi = { 0 };
 438
 439         spin_lock(&svc->srv_lock);
 440         thread->t_flags = SVC_STOPPING;
 441         spin_unlock(&svc->srv_lock);
 442
 443         wake_up_all(&svc->srv_waitq);
 444         l_wait_event(thread->t_ctl_waitq, (thread->t_flags & SVC_STOPPED),
 445                      &lwi);
 446 }
 447
 448 void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
 449 {
 450         spin_lock(&svc->srv_lock);
 451         while (!list_empty(&svc->srv_threads)) {
 452                 struct ptlrpc_thread *thread;
 453                 thread = list_entry(svc->srv_threads.next, struct ptlrpc_thread,
 454                                     t_link);
 455                 spin_unlock(&svc->srv_lock);
 456                 ptlrpc_stop_thread(svc, thread);
 457                 spin_lock(&svc->srv_lock);
 458                 list_del(&thread->t_link);
 459                 OBD_FREE(thread, sizeof(*thread));
 460         }
 461         spin_unlock(&svc->srv_lock);
 462 }
 463
 464 int ptlrpc_start_n_threads(struct obd_device *dev, struct ptlrpc_service *svc,
 465                            int num_threads, char *base_name)
 466 {
 467         int i, rc = 0;
 468         ENTRY;
 469
 470         for (i = 0; i < num_threads; i++) {
 471                 char name[32];
 472                 sprintf(name, "%s_%02d", base_name, i);
 473                 rc = ptlrpc_start_thread(dev, svc, name);
 474                 if (rc) {
 475                         CERROR("cannot start %s thread #%d: rc %d\n", base_name,
 476                                i, rc);
 477                         ptlrpc_stop_all_threads(svc);
 478                 }
 479         }
 480         RETURN(rc);
 481 }
 482
 483 int ptlrpc_start_thread(struct obd_device *dev, struct ptlrpc_service *svc,
 484                         char *name)
 485 {
 486         struct l_wait_info lwi = { 0 };
 487         struct ptlrpc_svc_data d;
 488         struct ptlrpc_thread *thread;
 489         int rc;
 490         ENTRY;
 491
 492         OBD_ALLOC(thread, sizeof(*thread));
 493         if (thread == NULL)
 494                 RETURN(-ENOMEM);
 495         init_waitqueue_head(&thread->t_ctl_waitq);
 496
 497         d.dev = dev;
 498         d.svc = svc;
 499         d.name = name;
 500         d.thread = thread;
 501
 502         spin_lock(&svc->srv_lock);
 503         list_add(&thread->t_link, &svc->srv_threads);
 504         spin_unlock(&svc->srv_lock);
 505
 506         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 507          * just drop the VM and FILES in ptlrpc_daemonize() right away.
 508          */
 509         rc = kernel_thread(ptlrpc_main, &d, CLONE_VM | CLONE_FILES);
 510         if (rc < 0) {
 511                 CERROR("cannot start thread: %d\n", rc);
 512                 OBD_FREE(thread, sizeof(*thread));
 513                 RETURN(rc);
 514         }
 515         l_wait_event(thread->t_ctl_waitq, thread->t_flags & SVC_RUNNING, &lwi);
 516
 517         RETURN(0);
 518 }
 519
 520 int ptlrpc_unregister_service(struct ptlrpc_service *service)
 521 {
 522         int i, rc;
 523         struct ptlrpc_srv_ni *srv_ni;
 524
 525         LASSERT (list_empty (&service->srv_threads));
 526
 527         /* XXX We could reply (with failure) to all buffered requests
 528          * _after_ unlinking _all_ the request buffers, but _before_
 529          * freeing them.
 530          */
 531
 532         for (i = 0; i < ptlrpc_ninterfaces; i++) {
 533                 srv_ni = &service->srv_interfaces[i];
 534                 CDEBUG (D_NET, "%s: tearing down interface %s\n",
 535                         service->srv_name, srv_ni->sni_ni->pni_name);
 536
 537                 while (!list_empty (&srv_ni->sni_rqbds)) {
 538                         struct ptlrpc_request_buffer_desc *rqbd =
 539                                 list_entry (srv_ni->sni_rqbds.next,
 540                                             struct ptlrpc_request_buffer_desc,
 541                                             rqbd_list);
 542
 543                         list_del (&rqbd->rqbd_list);
 544
 545                         LASSERT (atomic_read (&rqbd->rqbd_refcount) > 0);
 546                         /* refcount could be anything; it's possible for
 547                          * the buffers to continued to get filled after all
 548                          * the server threads exited.  But we know they
 549                          * _have_ exited.
 550                          */
 551
 552                         (void) PtlMEUnlink(rqbd->rqbd_me_h);
 553                         /* The callback handler could have unlinked this ME
 554                          * already (we're racing with her) but it's safe to
 555                          * ensure it _has_ been unlinked.
 556                          */
 557
 558                         OBD_FREE (rqbd->rqbd_buffer, service->srv_buf_size);
 559                         OBD_FREE (rqbd, sizeof (*rqbd));
 560                         srv_ni->sni_nrqbds--;
 561                 }
 562
 563                 LASSERT (srv_ni->sni_nrqbds == 0);
 564
 565                 if (!PtlHandleEqual (srv_ni->sni_eq_h, PTL_HANDLE_NONE)) {
 566                         rc = PtlEQFree(srv_ni->sni_eq_h);
 567                         if (rc)
 568                                 CERROR("%s.%d: PtlEQFree failed on %s: %d\n",
 569                                        service->srv_name, i,
 570                                        srv_ni->sni_ni->pni_name, rc);
 571                 }
 572         }
 573
 574         ptlrpc_lprocfs_unregister_service(service);
 575
 576         OBD_FREE(service,
 577                  offsetof (struct ptlrpc_service,
 578                            srv_interfaces[ptlrpc_ninterfaces]));
 579         return 0;
 580 }