lustre/ptlrpc/recover.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) 2002, 2003 Cluster File Systems, Inc.
   7  *   Author: Mike Shaver <shaver@clusterfs.com>
   8  *
   9  *   This file is part of Lustre, http://www.lustre.org.
  10  *
  11  *   Lustre is free software; you can redistribute it and/or
  12  *   modify it under the terms of version 2 of the GNU General Public
  13  *   License as published by the Free Software Foundation.
  14  *
  15  *   Lustre is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *   GNU General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU General Public License
  21  *   along with Lustre; if not, write to the Free Software
  22  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #define DEBUG_SUBSYSTEM S_RPC
  26 #ifdef __KERNEL__
  27 #include <linux/config.h>
  28 #include <linux/module.h>
  29 #include <linux/kmod.h>
  30 #else
  31 #include <liblustre.h>
  32 #endif
  33
  34 #include <linux/obd_support.h>
  35 #include <linux/lustre_ha.h>
  36 #include <linux/lustre_net.h>
  37 #include <linux/lustre_import.h>
  38 #include <linux/lustre_export.h>
  39 #include <linux/obd.h>
  40 #include <linux/obd_class.h>
  41 #include <linux/obd_lov.h> /* for IOC_LOV_SET_OSC_ACTIVE */
  42
  43 #include "ptlrpc_internal.h"
  44
  45 int ptlrpc_reconnect_import(struct obd_import *imp,
  46                             struct ptlrpc_request **reqptr)
  47 {
  48         struct obd_device *obd = imp->imp_obd;
  49         int flags, rc, size[] = {sizeof(imp->imp_target_uuid),
  50                                  sizeof(obd->obd_uuid),
  51                                  sizeof(imp->imp_dlm_handle)};
  52         char *tmp[] = {imp->imp_target_uuid.uuid,
  53                        obd->obd_uuid.uuid,
  54                        (char *)&imp->imp_dlm_handle};
  55         struct ptlrpc_connection *conn = imp->imp_connection;
  56         struct ptlrpc_request *req;
  57         struct lustre_handle old_hdl;
  58
  59         spin_lock_irqsave(&imp->imp_lock, flags);
  60         imp->imp_generation++;
  61         spin_unlock_irqrestore(&imp->imp_lock, flags);
  62
  63         CERROR("reconnect handle "LPX64"\n",
  64                imp->imp_dlm_handle.cookie);
  65
  66         req = ptlrpc_prep_req(imp, imp->imp_connect_op, 3, size, tmp);
  67         if (!req)
  68                 RETURN(-ENOMEM);
  69         req->rq_level = LUSTRE_CONN_NEW;
  70         req->rq_replen = lustre_msg_size(0, NULL);
  71         rc = ptlrpc_queue_wait(req);
  72         if (rc) {
  73                 CERROR("cannot connect to %s@%s: rc = %d\n",
  74                        imp->imp_target_uuid.uuid, conn->c_remote_uuid.uuid, rc);
  75                 GOTO(out_disc, rc);
  76         }
  77
  78         if (lustre_msg_get_op_flags(req->rq_repmsg) & MSG_CONNECT_RECONNECT) {
  79                 memset(&old_hdl, 0, sizeof(old_hdl));
  80                 if (!memcmp(&old_hdl, &req->rq_repmsg->handle,
  81                             sizeof (old_hdl))) {
  82                         CERROR("%s@%s didn't like our handle "LPX64
  83                                ", failed\n", imp->imp_target_uuid.uuid,
  84                                conn->c_remote_uuid.uuid,
  85                                imp->imp_dlm_handle.cookie);
  86                         GOTO(out_disc, rc = -ENOTCONN);
  87                 }
  88
  89                 if (memcmp(&imp->imp_remote_handle, &req->rq_repmsg->handle,
  90                            sizeof(imp->imp_remote_handle))) {
  91                         CERROR("%s@%s changed handle from "LPX64" to "LPX64
  92                                "; copying, but this may foreshadow disaster\n",
  93                                imp->imp_target_uuid.uuid,
  94                                conn->c_remote_uuid.uuid,
  95                                imp->imp_remote_handle.cookie,
  96                                req->rq_repmsg->handle.cookie);
  97                         imp->imp_remote_handle = req->rq_repmsg->handle;
  98                         GOTO(out_disc, rc = 0);
  99                 }
 100
 101                 CERROR("reconnected to %s@%s after partition\n",
 102                        imp->imp_target_uuid.uuid, conn->c_remote_uuid.uuid);
 103                 GOTO(out_disc, rc = 0);
 104         }
 105
 106         old_hdl = imp->imp_remote_handle;
 107         imp->imp_remote_handle = req->rq_repmsg->handle;
 108         CERROR("reconnected to %s@%s ("LPX64", was "LPX64")!\n",
 109                imp->imp_target_uuid.uuid, conn->c_remote_uuid.uuid,
 110                imp->imp_remote_handle.cookie, old_hdl.cookie);
 111         GOTO(out_disc, rc = 0);
 112
 113  out_disc:
 114         *reqptr = req;
 115         return rc;
 116 }
 117
 118 void ptlrpc_run_recovery_over_upcall(struct obd_device *obd)
 119 {
 120         char *argv[4];
 121         char *envp[3];
 122         int rc;
 123
 124         ENTRY;
 125         argv[0] = obd_lustre_upcall;
 126         argv[1] = "RECOVERY_OVER";
 127         argv[2] = obd->obd_uuid.uuid;
 128         argv[3] = NULL;
 129
 130         envp[0] = "HOME=/";
 131         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 132         envp[2] = NULL;
 133
 134         rc = USERMODEHELPER(argv[0], argv, envp);
 135         if (rc < 0) {
 136                 CERROR("Error invoking recovery upcall %s %s %s: %d; check "
 137                        "/proc/sys/lustre/upcall\n",
 138                        argv[0], argv[1], argv[2], rc);
 139
 140         } else {
 141                 CERROR("Invoked upcall %s %s %s",
 142                        argv[0], argv[1], argv[2]);
 143         }
 144 }
 145
 146 void ptlrpc_run_failed_import_upcall(struct obd_import* imp)
 147 {
 148         char *argv[6];
 149         char *envp[3];
 150         int rc;
 151
 152         ENTRY;
 153         argv[0] = obd_lustre_upcall;
 154         argv[1] = "FAILED_IMPORT";
 155         argv[2] = imp->imp_target_uuid.uuid;
 156         argv[3] = imp->imp_obd->obd_uuid.uuid;
 157         argv[4] = imp->imp_connection->c_remote_uuid.uuid;
 158         argv[5] = NULL;
 159
 160         envp[0] = "HOME=/";
 161         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 162         envp[2] = NULL;
 163
 164         rc = USERMODEHELPER(argv[0], argv, envp);
 165         if (rc < 0) {
 166                 CERROR("Error invoking recovery upcall %s %s %s %s %s: %d; check "
 167                        "/proc/sys/lustre/lustre_upcall\n",
 168                        argv[0], argv[1], argv[2], argv[3], argv[4],rc);
 169
 170         } else {
 171                 CERROR("Invoked upcall %s %s %s %s %s\n",
 172                        argv[0], argv[1], argv[2], argv[3], argv[4]);
 173         }
 174 }
 175
 176 int ptlrpc_replay(struct obd_import *imp)
 177 {
 178         int rc = 0;
 179         struct list_head *tmp, *pos;
 180         struct ptlrpc_request *req;
 181         unsigned long flags;
 182         __u64 committed = imp->imp_peer_committed_transno;
 183         ENTRY;
 184
 185         /* It might have committed some after we last spoke, so make sure we
 186          * get rid of them now.
 187          */
 188         spin_lock_irqsave(&imp->imp_lock, flags);
 189         ptlrpc_free_committed(imp);
 190         spin_unlock_irqrestore(&imp->imp_lock, flags);
 191
 192         CDEBUG(D_HA, "import %p from %s has committed "LPD64"\n",
 193                imp, imp->imp_target_uuid.uuid, committed);
 194
 195         list_for_each(tmp, &imp->imp_replay_list) {
 196                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 197                 DEBUG_REQ(D_HA, req, "RETAINED: ");
 198         }
 199
 200         /* Do I need to hold a lock across this iteration?  We shouldn't be
 201          * racing with any additions to the list, because we're in recovery
 202          * and are therefore not processing additional requests to add.  Calls
 203          * to ptlrpc_free_committed might commit requests, but nothing "newer"
 204          * than the one we're replaying (it can't be committed until it's
 205          * replayed, and we're doing that here).  l_f_e_safe protects against
 206          * problems with the current request being committed, in the unlikely
 207          * event of that race.  So, in conclusion, I think that it's safe to
 208          * perform this list-walk without the imp_lock held.
 209          *
 210          * But, the {mdc,osc}_replay_open callbacks both iterate
 211          * request lists, and have comments saying they assume the
 212          * imp_lock is being held by ptlrpc_replay, but it's not. it's
 213          * just a little race...
 214          */
 215         list_for_each_safe(tmp, pos, &imp->imp_replay_list) {
 216                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 217
 218                 DEBUG_REQ(D_HA, req, "REPLAY:");
 219
 220                 rc = ptlrpc_replay_req(req);
 221
 222                 if (rc) {
 223                         CERROR("recovery replay error %d for req "LPD64"\n",
 224                                rc, req->rq_xid);
 225                         RETURN(rc);
 226                 }
 227         }
 228
 229         RETURN(0);
 230 }
 231
 232 int ptlrpc_resend(struct obd_import *imp)
 233 {
 234         struct list_head *tmp, *pos;
 235         struct ptlrpc_request *req;
 236         unsigned long flags;
 237
 238         ENTRY;
 239
 240         /* As long as we're in recovery, nothing should be added to the sending
 241          * list, so we don't need to hold the lock during this iteration and
 242          * resend process.
 243          */
 244         spin_lock_irqsave(&imp->imp_lock, flags);
 245         LASSERT(imp->imp_level < LUSTRE_CONN_FULL);
 246         spin_unlock_irqrestore(&imp->imp_lock, flags);
 247
 248         list_for_each_safe(tmp, pos, &imp->imp_sending_list) {
 249                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 250                 ptlrpc_resend_req(req);
 251         }
 252
 253         RETURN(0);
 254 }
 255
 256 void ptlrpc_wake_delayed(struct obd_import *imp)
 257 {
 258         unsigned long flags;
 259         struct list_head *tmp, *pos;
 260         struct ptlrpc_request *req;
 261
 262         spin_lock_irqsave(&imp->imp_lock, flags);
 263         list_for_each_safe(tmp, pos, &imp->imp_delayed_list) {
 264                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 265
 266                 ptlrpc_put_connection(req->rq_connection);
 267                 req->rq_connection =
 268                        ptlrpc_connection_addref(req->rq_import->imp_connection);
 269
 270                 if (req->rq_set) {
 271                         DEBUG_REQ(D_HA, req, "waking (set %p):", req->rq_set);
 272                         wake_up(&req->rq_set->set_waitq);
 273                 } else {
 274                         DEBUG_REQ(D_HA, req, "waking:");
 275                         wake_up(&req->rq_wait_for_rep);
 276                 }
 277         }
 278         spin_unlock_irqrestore(&imp->imp_lock, flags);
 279 }
 280
 281 inline void ptlrpc_invalidate_import_state(struct obd_import *imp)
 282 {
 283         struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
 284         if (ptlrpc_ldlm_namespace_cleanup == NULL)
 285                 CERROR("ptlrpc/ldlm hook is NULL!  Please tell phil\n");
 286         else
 287                 ptlrpc_ldlm_namespace_cleanup(ns, 1 /* no network ops */);
 288         ptlrpc_abort_inflight(imp);
 289 }
 290
 291 int ptlrpc_request_handle_eviction(struct ptlrpc_request *failed_req)
 292 {
 293         int rc = 0, in_recovery = 0;
 294         struct obd_import *imp= failed_req->rq_import;
 295         unsigned long flags;
 296         struct ptlrpc_request *req;
 297
 298         spin_lock_irqsave(&imp->imp_lock, flags);
 299
 300         if (imp->imp_level == LUSTRE_CONN_NOTCONN)
 301                 in_recovery = 1;
 302
 303         if (failed_req->rq_import_generation == imp->imp_generation)
 304                 imp->imp_level = LUSTRE_CONN_NOTCONN;
 305         else
 306                 in_recovery = 1;
 307
 308         spin_unlock_irqrestore(&imp->imp_lock, flags);
 309
 310         if (in_recovery) {
 311                 ptlrpc_resend_req(failed_req);
 312                 RETURN(rc);
 313         }
 314
 315         CDEBUG(D_HA, "import %s of %s@%s evicted: reconnecting\n",
 316                imp->imp_obd->obd_name,
 317                imp->imp_target_uuid.uuid,
 318                imp->imp_connection->c_remote_uuid.uuid);
 319         rc = ptlrpc_reconnect_import(imp, &req);
 320         if (rc) {
 321                 ptlrpc_resend_req(failed_req);
 322                 ptlrpc_fail_import(imp, imp->imp_generation);
 323         } else {
 324                 spin_lock_irqsave (&failed_req->rq_lock, flags);
 325                 failed_req->rq_err = 1;
 326                 spin_unlock_irqrestore (&failed_req->rq_lock, flags);
 327                 spin_lock_irqsave(&imp->imp_lock, flags);
 328                 imp->imp_level = LUSTRE_CONN_FULL;
 329                 imp->imp_invalid = 0;
 330                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 331                 ptlrpc_invalidate_import_state(imp/*, req->rq_import_generation*/);
 332         }
 333         ptlrpc_req_finished(req);
 334         RETURN(rc);
 335 }
 336
 337 int ptlrpc_set_import_active(struct obd_import *imp, int active)
 338 {
 339         struct obd_device *notify_obd;
 340         unsigned long flags;
 341         int rc;
 342
 343         LASSERT(imp->imp_obd);
 344
 345         notify_obd = imp->imp_obd->u.cli.cl_containing_lov;
 346
 347         /* When deactivating, mark import invalid, and
 348            abort in-flight requests. */
 349         if (!active) {
 350                 spin_lock_irqsave(&imp->imp_lock, flags);
 351                 imp->imp_invalid = 1;
 352                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 353
 354                 ptlrpc_abort_inflight(imp);
 355         }
 356
 357         imp->imp_invalid = !active;
 358
 359         if (notify_obd == NULL)
 360                 GOTO(out, rc = 0);
 361
 362         /* How gross is _this_? */
 363         if (!list_empty(&notify_obd->obd_exports)) {
 364                 struct lustre_handle fakeconn;
 365                 struct obd_ioctl_data ioc_data = { 0 };
 366                 struct obd_export *exp =
 367                         list_entry(notify_obd->obd_exports.next,
 368                                    struct obd_export, exp_obd_chain);
 369
 370                 fakeconn.cookie = exp->exp_handle.h_cookie;
 371                 ioc_data.ioc_inlbuf1 = (char *)&imp->imp_target_uuid;
 372                 ioc_data.ioc_offset = active;
 373                 rc = obd_iocontrol(IOC_LOV_SET_OSC_ACTIVE, &fakeconn,
 374                                    sizeof ioc_data, &ioc_data, NULL);
 375                 if (rc)
 376                         CERROR("error %sabling %s on LOV %p/%s: %d\n",
 377                                active ? "en" : "dis",
 378                                imp->imp_target_uuid.uuid, notify_obd,
 379                                notify_obd->obd_uuid.uuid, rc);
 380         } else {
 381                 CDEBUG(D_HA, "No exports for obd %p/%s, can't notify about "
 382                        "%p\n", notify_obd, notify_obd->obd_uuid.uuid,
 383                        imp->imp_obd->obd_uuid.uuid);
 384                 rc = -ENOENT;
 385         }
 386
 387 out:
 388         /* When activating, mark import valid */
 389         if (active) {
 390                 spin_lock_irqsave(&imp->imp_lock, flags);
 391                 imp->imp_invalid = 0;
 392                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 393         }
 394
 395         RETURN(rc);
 396 }
 397
 398 void ptlrpc_fail_import(struct obd_import *imp, int generation)
 399 {
 400         unsigned long flags;
 401         int in_recovery = 0;
 402         ENTRY;
 403
 404         LASSERT (!imp->imp_dlm_fake);
 405
 406         /* If we were already in recovery, or if the import's connection to its
 407          * service is newer than the failing operation's original attempt, then
 408          * we don't want to recover again. */
 409         spin_lock_irqsave(&imp->imp_lock, flags);
 410
 411         if (imp->imp_level == LUSTRE_CONN_RECOVD)
 412                 in_recovery = 1;
 413
 414         if (generation == imp->imp_generation) {
 415                 imp->imp_level = LUSTRE_CONN_RECOVD;
 416                 imp->imp_generation++;
 417         } else {
 418                 in_recovery = 1;
 419         }
 420
 421         spin_unlock_irqrestore(&imp->imp_lock, flags);
 422
 423         if (in_recovery) {
 424                 EXIT;
 425                 return;
 426         }
 427
 428         if (!imp->imp_replayable) {
 429                 CDEBUG(D_HA,
 430                        "import %s@%s for %s not replayable, deactivating\n",
 431                        imp->imp_target_uuid.uuid,
 432                        imp->imp_connection->c_remote_uuid.uuid,
 433                        imp->imp_obd->obd_name);
 434                 ptlrpc_set_import_active(imp, 0);
 435         }
 436
 437         ptlrpc_run_failed_import_upcall(imp);
 438         EXIT;
 439 }
 440
 441 static int signal_completed_replay(struct obd_import *imp)
 442 {
 443         struct ptlrpc_request *req;
 444         int rc;
 445         ENTRY;
 446
 447         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL, NULL);
 448         if (!req)
 449                 RETURN(-ENOMEM);
 450
 451         req->rq_replen = lustre_msg_size(0, NULL);
 452         req->rq_level = LUSTRE_CONN_RECOVD;
 453         req->rq_reqmsg->flags |= MSG_LAST_REPLAY;
 454
 455         rc = ptlrpc_queue_wait(req);
 456
 457         ptlrpc_req_finished(req);
 458         RETURN(rc);
 459 }
 460
 461 int ptlrpc_recover_import(struct obd_import *imp, char *new_uuid)
 462 {
 463         int msg_flags = 0, rc;
 464         unsigned long flags;
 465         struct ptlrpc_request *req;
 466         ENTRY;
 467
 468         spin_lock_irqsave(&imp->imp_lock, flags);
 469         if (imp->imp_level == LUSTRE_CONN_FULL) {
 470                 imp->imp_level = LUSTRE_CONN_RECOVD;
 471                 imp->imp_generation++;
 472         }
 473         spin_unlock_irqrestore(&imp->imp_lock, flags);
 474
 475         if (new_uuid) {
 476                 struct ptlrpc_connection *conn;
 477                 struct obd_uuid uuid;
 478                 struct ptlrpc_peer peer;
 479                 struct obd_export *dlmexp;
 480
 481                 obd_str2uuid(&uuid, new_uuid);
 482                 if (ptlrpc_uuid_to_peer(&uuid, &peer)) {
 483                         CERROR("no connection found for UUID %s\n", new_uuid);
 484                         RETURN(-EINVAL);
 485                 }
 486
 487                 conn = ptlrpc_get_connection(&peer, &uuid);
 488                 if (!conn)
 489                         RETURN(-ENOMEM);
 490
 491                 CDEBUG(D_HA, "switching import %s/%s from %s to %s\n",
 492                        imp->imp_target_uuid.uuid, imp->imp_obd->obd_name,
 493                        imp->imp_connection->c_remote_uuid.uuid,
 494                        conn->c_remote_uuid.uuid);
 495
 496                 /* Switch the import's connection and the DLM export's
 497                  * connection (which are almost certainly the same, but we
 498                  * keep distinct refs just to make things clearer. I think. */
 499                 if (imp->imp_connection)
 500                         ptlrpc_put_connection(imp->imp_connection);
 501                 /* We hand off the ref from ptlrpc_get_connection. */
 502                 imp->imp_connection = conn;
 503
 504                 dlmexp = class_conn2export(&imp->imp_dlm_handle);
 505                 if (dlmexp->exp_connection)
 506                         ptlrpc_put_connection(dlmexp->exp_connection);
 507                 dlmexp->exp_connection = ptlrpc_connection_addref(conn);
 508                 class_export_put(dlmexp);
 509
 510         }
 511
 512         rc = ptlrpc_reconnect_import(imp, &req);
 513
 514         if (rc) {
 515                 CERROR("failed to reconnect to %s@%s: %d\n",
 516                        imp->imp_target_uuid.uuid,
 517                        imp->imp_connection->c_remote_uuid.uuid, rc);
 518                 RETURN(rc);
 519         }
 520
 521         if (req->rq_repmsg)
 522                 msg_flags = lustre_msg_get_op_flags(req->rq_repmsg);
 523
 524         if (msg_flags & MSG_CONNECT_RECOVERING) {
 525                 CDEBUG(D_HA, "replay requested by %s\n",
 526                        imp->imp_target_uuid.uuid);
 527                 rc = ptlrpc_replay(imp);
 528                 if (rc)
 529                         GOTO(out, rc);
 530
 531                 if (ptlrpc_ldlm_replay_locks == NULL)
 532                         CERROR("ptlrpc/ldlm hook is NULL!  Please tell phil\n");
 533                 else
 534                         rc = ptlrpc_ldlm_replay_locks(imp);
 535                 if (rc)
 536                         GOTO(out, rc);
 537
 538                 rc = signal_completed_replay(imp);
 539                 if (rc)
 540                         GOTO(out, rc);
 541         } else if (msg_flags & MSG_CONNECT_RECONNECT) {
 542                 CDEBUG(D_HA, "reconnected to %s@%s\n",
 543                        imp->imp_target_uuid.uuid,
 544                        imp->imp_connection->c_remote_uuid.uuid);
 545         } else {
 546                 CDEBUG(D_HA, "evicted from %s@%s; invalidating\n",
 547                        imp->imp_target_uuid.uuid,
 548                        imp->imp_connection->c_remote_uuid.uuid);
 549                 ptlrpc_invalidate_import_state(imp);
 550         }
 551
 552         rc = ptlrpc_resend(imp);
 553
 554         spin_lock_irqsave(&imp->imp_lock, flags);
 555         imp->imp_level = LUSTRE_CONN_FULL;
 556         imp->imp_invalid = 0;
 557         spin_unlock_irqrestore(&imp->imp_lock, flags);
 558
 559         ptlrpc_wake_delayed(imp);
 560         EXIT;
 561  out:
 562         ptlrpc_req_finished(req);
 563         return rc;
 564 }
 565
 566 void ptlrpc_fail_export(struct obd_export *exp)
 567 {
 568         int rc, already_failed;
 569         struct lustre_handle hdl;
 570         unsigned long flags;
 571
 572         spin_lock_irqsave(&exp->exp_lock, flags);
 573         already_failed = exp->exp_failed;
 574         exp->exp_failed = 1;
 575         spin_unlock_irqrestore(&exp->exp_lock, flags);
 576
 577         if (already_failed) {
 578                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
 579                        exp, exp->exp_client_uuid.uuid);
 580                 return;
 581         }
 582
 583         CDEBUG(D_HA, "disconnecting export %p/%s\n",
 584                exp, exp->exp_client_uuid.uuid);
 585         hdl.cookie = exp->exp_handle.h_cookie;
 586         rc = obd_disconnect(&hdl, 0);
 587         if (rc)
 588                 CERROR("disconnecting export %p failed: %d\n", exp, rc);
 589 }