lustre/ptlrpc/import.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2002, 2003 Cluster File Systems, Inc.
   5  *   Author: Mike Shaver <shaver@clusterfs.com>
   6  *
   7  *   This file is part of Lustre, http://www.lustre.org.
   8  *
   9  *   Lustre is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Lustre is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Lustre; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_RPC
  24 #ifdef __KERNEL__
  25 # include <linux/config.h>
  26 # include <linux/module.h>
  27 # include <linux/kmod.h>
  28 #else
  29 # include <liblustre.h>
  30 #endif
  31
  32 #include <linux/obd_support.h>
  33 #include <linux/lustre_ha.h>
  34 #include <linux/lustre_net.h>
  35 #include <linux/lustre_import.h>
  36 #include <linux/lustre_export.h>
  37 #include <linux/obd.h>
  38 #include <linux/obd_class.h>
  39
  40 #include "ptlrpc_internal.h"
  41
  42 struct ptlrpc_connect_async_args {
  43          __u64 pcaa_peer_committed;
  44         int pcaa_initial_connect;
  45 };
  46
  47 /* A CLOSED import should remain so. */
  48 #define IMPORT_SET_STATE_NOLOCK(imp, state)                                    \
  49 do {                                                                           \
  50         if (imp->imp_state != LUSTRE_IMP_CLOSED) {                             \
  51                CDEBUG(D_HA, "%p %s: changing import state from %s to %s\n",    \
  52                       imp, imp->imp_target_uuid.uuid,                          \
  53                       ptlrpc_import_state_name(imp->imp_state),                \
  54                       ptlrpc_import_state_name(state));                        \
  55                imp->imp_state = state;                                         \
  56         }                                                                      \
  57 } while(0)
  58
  59 #define IMPORT_SET_STATE(imp, state)                    \
  60 do {                                                    \
  61         unsigned long flags;                            \
  62                                                         \
  63         spin_lock_irqsave(&imp->imp_lock, flags);       \
  64         IMPORT_SET_STATE_NOLOCK(imp, state);            \
  65         spin_unlock_irqrestore(&imp->imp_lock, flags);  \
  66 } while(0)
  67
  68
  69 static int ptlrpc_connect_interpret(struct ptlrpc_request *request,
  70                                     void * data, int rc);
  71 int ptlrpc_import_recovery_state_machine(struct obd_import *imp);
  72
  73 /* Only this function is allowed to change the import state when it is
  74  * CLOSED. I would rather refcount the import and free it after
  75  * disconnection like we do with exports. To do that, the client_obd
  76  * will need to save the peer info somewhere other than in the import,
  77  * though. */
  78 int ptlrpc_init_import(struct obd_import *imp)
  79 {
  80         unsigned long flags;
  81
  82         spin_lock_irqsave(&imp->imp_lock, flags);
  83
  84         imp->imp_generation++;
  85         imp->imp_state =  LUSTRE_IMP_NEW;
  86
  87         spin_unlock_irqrestore(&imp->imp_lock, flags);
  88
  89         return 0;
  90 }
  91
  92 /* Returns true if import was FULL, false if import was already not
  93  * connected.
  94  */
  95 int ptlrpc_set_import_discon(struct obd_import *imp)
  96 {
  97         unsigned long flags;
  98         int rc = 0;
  99
 100         spin_lock_irqsave(&imp->imp_lock, flags);
 101
 102         if (imp->imp_state == LUSTRE_IMP_FULL) {
 103                 CERROR("%s: connection lost to %s@%s\n",
 104                        imp->imp_obd->obd_name,
 105                        imp->imp_target_uuid.uuid,
 106                        imp->imp_connection->c_remote_uuid.uuid);
 107                 IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_DISCON);
 108                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 109                 obd_import_event(imp->imp_obd, imp, IMP_EVENT_DISCON);
 110                 rc = 1;
 111         } else {
 112                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 113                 CDEBUG(D_HA, "%p %s: import already not connected: %s\n",
 114                        imp,imp->imp_client->cli_name,
 115                        ptlrpc_import_state_name(imp->imp_state));
 116         }
 117
 118         return rc;
 119 }
 120
 121 /*
 122  * This acts as a barrier; all existing requests are rejected, and
 123  * no new requests will be accepted until the import is valid again.
 124  */
 125 void ptlrpc_deactivate_import(struct obd_import *imp)
 126 {
 127         unsigned long flags;
 128         ENTRY;
 129
 130         spin_lock_irqsave(&imp->imp_lock, flags);
 131         CDEBUG(D_HA, "setting import %s INVALID\n",
 132                imp->imp_target_uuid.uuid);
 133         imp->imp_invalid = 1;
 134         imp->imp_generation++;
 135         spin_unlock_irqrestore(&imp->imp_lock, flags);
 136
 137         ptlrpc_abort_inflight(imp);
 138         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INACTIVE);
 139 }
 140
 141 /*
 142  * This function will invalidate the import, if necessary, then block
 143  * for all the RPC completions, and finally notify the obd to
 144  * invalidate its state (ie cancel locks, clear pending requests,
 145  * etc).
 146  *
 147  * in_rpc: true if this is called while processing an rpc, like
 148  *    CONNECT. It will allow for one RPC to be inflight while
 149  *    waiting for requests to complete. Ugly, yes, but I don't see an
 150  *    cleaner way right now.
 151  */
 152 void ptlrpc_invalidate_import(struct obd_import *imp, int in_rpc)
 153 {
 154         struct l_wait_info lwi;
 155         unsigned long timeout;
 156         int inflight = 0;
 157         int rc;
 158
 159         if (!imp->imp_invalid)
 160                 ptlrpc_deactivate_import(imp);
 161
 162         LASSERT(imp->imp_invalid);
 163
 164         if (in_rpc)
 165                 inflight = 1;
 166
 167         /* wait for all requests to error out and call completion
 168            callbacks */
 169         if (imp->imp_server_timeout)
 170                 timeout = obd_timeout / 2;
 171         else
 172                 timeout = obd_timeout;
 173         timeout = MAX(timeout * HZ, 1);
 174         lwi = LWI_TIMEOUT_INTR(timeout, NULL, NULL, NULL);
 175         rc = l_wait_event(imp->imp_recovery_waitq,
 176                           (atomic_read(&imp->imp_inflight) == inflight),
 177                           &lwi);
 178
 179         if (rc)
 180                 CERROR("%s: rc = %d waiting for callback (%d != %d)\n",
 181                        imp->imp_target_uuid.uuid, rc,
 182                        atomic_read(&imp->imp_inflight), inflight);
 183
 184         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INVALIDATE);
 185 }
 186
 187 void ptlrpc_activate_import(struct obd_import *imp)
 188 {
 189         struct obd_device *obd = imp->imp_obd;
 190         unsigned long flags;
 191
 192         spin_lock_irqsave(&imp->imp_lock, flags);
 193         imp->imp_invalid = 0;
 194         spin_unlock_irqrestore(&imp->imp_lock, flags);
 195
 196         obd_import_event(obd, imp, IMP_EVENT_ACTIVE);
 197 }
 198
 199 void ptlrpc_fail_import(struct obd_import *imp, int generation)
 200 {
 201         ENTRY;
 202
 203         LASSERT (!imp->imp_dlm_fake);
 204
 205         if (ptlrpc_set_import_discon(imp)) {
 206                 unsigned long flags;
 207
 208                 if (!imp->imp_replayable) {
 209                         CDEBUG(D_HA, "import %s@%s for %s not replayable, "
 210                                "auto-deactivating\n",
 211                                imp->imp_target_uuid.uuid,
 212                                imp->imp_connection->c_remote_uuid.uuid,
 213                                imp->imp_obd->obd_name);
 214                         ptlrpc_deactivate_import(imp);
 215                 }
 216
 217                 CDEBUG(D_HA, "%s: waking up pinger\n",
 218                        imp->imp_target_uuid.uuid);
 219
 220                 spin_lock_irqsave(&imp->imp_lock, flags);
 221                 imp->imp_force_verify = 1;
 222                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 223
 224                 ptlrpc_pinger_wake_up();
 225         }
 226         EXIT;
 227 }
 228
 229 int ptlrpc_connect_import(struct obd_import *imp, char * new_uuid)
 230 {
 231         struct obd_device *obd = imp->imp_obd;
 232         int initial_connect = 0;
 233         int rc;
 234         __u64 committed_before_reconnect = 0;
 235         struct ptlrpc_request *request;
 236         int size[] = {sizeof(imp->imp_target_uuid),
 237                                  sizeof(obd->obd_uuid),
 238                                  sizeof(imp->imp_dlm_handle)};
 239         char *tmp[] = {imp->imp_target_uuid.uuid,
 240                        obd->obd_uuid.uuid,
 241                        (char *)&imp->imp_dlm_handle};
 242         struct ptlrpc_connect_async_args *aa;
 243         unsigned long flags;
 244
 245         spin_lock_irqsave(&imp->imp_lock, flags);
 246         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
 247                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 248                 CERROR("can't connect to a closed import\n");
 249                 RETURN(-EINVAL);
 250         } else if (imp->imp_state == LUSTRE_IMP_FULL) {
 251                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 252                 CERROR("already connected\n");
 253                 RETURN(0);
 254         } else if (imp->imp_state == LUSTRE_IMP_CONNECTING) {
 255                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 256                 CERROR("already connecting\n");
 257                 RETURN(-EALREADY);
 258         }
 259
 260         IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_CONNECTING);
 261
 262         imp->imp_resend_replay = 0;
 263
 264         if (imp->imp_remote_handle.cookie == 0) {
 265                 initial_connect = 1;
 266         } else {
 267                 committed_before_reconnect = imp->imp_peer_committed_transno;;
 268                 imp->imp_conn_cnt++;
 269         }
 270
 271
 272         spin_unlock_irqrestore(&imp->imp_lock, flags);
 273
 274         if (new_uuid) {
 275                 struct ptlrpc_connection *conn;
 276                 struct obd_uuid uuid;
 277                 struct obd_export *dlmexp;
 278
 279                 obd_str2uuid(&uuid, new_uuid);
 280
 281                 conn = ptlrpc_uuid_to_connection(&uuid);
 282                 if (!conn)
 283                         GOTO(out, rc = -ENOENT);
 284
 285                 CDEBUG(D_HA, "switching import %s/%s from %s to %s\n",
 286                        imp->imp_target_uuid.uuid, imp->imp_obd->obd_name,
 287                        imp->imp_connection->c_remote_uuid.uuid,
 288                        conn->c_remote_uuid.uuid);
 289
 290                 /* Switch the import's connection and the DLM export's
 291                  * connection (which are almost certainly the same, but we
 292                  * keep distinct refs just to make things clearer. I think. */
 293                 if (imp->imp_connection)
 294                         ptlrpc_put_connection(imp->imp_connection);
 295                 /* We hand off the ref from ptlrpc_get_connection. */
 296                 imp->imp_connection = conn;
 297
 298                 dlmexp = class_conn2export(&imp->imp_dlm_handle);
 299
 300                 LASSERT(dlmexp != NULL);
 301
 302                 if (dlmexp->exp_connection)
 303                         ptlrpc_put_connection(dlmexp->exp_connection);
 304                 dlmexp->exp_connection = ptlrpc_connection_addref(conn);
 305                 class_export_put(dlmexp);
 306
 307         }
 308
 309         request = ptlrpc_prep_req(imp, imp->imp_connect_op, 3, size, tmp);
 310         if (!request)
 311                 GOTO(out, rc = -ENOMEM);
 312
 313 #ifndef __KERNEL__
 314         lustre_msg_add_op_flags(request->rq_reqmsg, MSG_CONNECT_LIBCLIENT);
 315 #endif
 316
 317         request->rq_send_state = LUSTRE_IMP_CONNECTING;
 318         request->rq_replen = lustre_msg_size(0, NULL);
 319         request->rq_interpret_reply = ptlrpc_connect_interpret;
 320
 321         LASSERT (sizeof (*aa) <= sizeof (request->rq_async_args));
 322         aa = (struct ptlrpc_connect_async_args *)&request->rq_async_args;
 323         memset(aa, 0, sizeof *aa);
 324
 325         aa->pcaa_peer_committed = committed_before_reconnect;
 326         aa->pcaa_initial_connect = initial_connect;
 327
 328         if (aa->pcaa_initial_connect) {
 329                 lustre_msg_add_op_flags(request->rq_reqmsg,
 330                                         MSG_CONNECT_INITIAL);
 331                 imp->imp_replayable = 1;
 332         }
 333
 334         ptlrpcd_add_req(request);
 335         rc = 0;
 336         imp->imp_connect_start = jiffies;
 337 out:
 338         if (rc != 0) {
 339                 IMPORT_SET_STATE(imp, LUSTRE_IMP_DISCON);
 340         }
 341
 342         RETURN(rc);
 343 }
 344
 345 static int ptlrpc_connect_interpret(struct ptlrpc_request *request,
 346                                     void * data, int rc)
 347 {
 348         struct ptlrpc_connect_async_args *aa = data;
 349         struct obd_import *imp = request->rq_import;
 350         struct lustre_handle old_hdl;
 351         unsigned long flags;
 352         int msg_flags;
 353         ENTRY;
 354
 355         spin_lock_irqsave(&imp->imp_lock, flags);
 356         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
 357                 spin_unlock_irqrestore(&imp->imp_lock, flags);
 358                 RETURN(0);
 359         }
 360         spin_unlock_irqrestore(&imp->imp_lock, flags);
 361
 362         if (rc)
 363                 GOTO(out, rc);
 364
 365         msg_flags = lustre_msg_get_op_flags(request->rq_repmsg);
 366
 367         if (aa->pcaa_initial_connect) {
 368                 if (msg_flags & MSG_CONNECT_REPLAYABLE) {
 369                         CDEBUG(D_HA, "connected to replayable target: %s\n",
 370                                imp->imp_target_uuid.uuid);
 371                         imp->imp_pingable = imp->imp_replayable = 1;
 372                 } else {
 373                         imp->imp_replayable = 0;
 374                 }
 375                 LASSERTF(imp->imp_conn_cnt < request->rq_repmsg->conn_cnt,
 376                          "imp conn_cnt %d req conn_cnt %d",
 377                          imp->imp_conn_cnt, request->rq_repmsg->conn_cnt);
 378                 imp->imp_conn_cnt = request->rq_repmsg->conn_cnt;
 379                 imp->imp_remote_handle = request->rq_repmsg->handle;
 380                 IMPORT_SET_STATE(imp, LUSTRE_IMP_FULL);
 381                 GOTO(finish, rc = 0);
 382         }
 383
 384         /* Determine what recovery state to move the import to. */
 385         if (MSG_CONNECT_RECONNECT & msg_flags) {
 386                 memset(&old_hdl, 0, sizeof(old_hdl));
 387                 if (!memcmp(&old_hdl, &request->rq_repmsg->handle,
 388                             sizeof (old_hdl))) {
 389                         CERROR("%s@%s didn't like our handle "LPX64
 390                                ", failed\n", imp->imp_target_uuid.uuid,
 391                                imp->imp_connection->c_remote_uuid.uuid,
 392                                imp->imp_dlm_handle.cookie);
 393                         GOTO(out, rc = -ENOTCONN);
 394                 }
 395
 396                 if (memcmp(&imp->imp_remote_handle, &request->rq_repmsg->handle,
 397                            sizeof(imp->imp_remote_handle))) {
 398                         CERROR("%s@%s changed handle from "LPX64" to "LPX64
 399                                "; copying, but this may foreshadow disaster\n",
 400                                imp->imp_target_uuid.uuid,
 401                                imp->imp_connection->c_remote_uuid.uuid,
 402                                imp->imp_remote_handle.cookie,
 403                                request->rq_repmsg->handle.cookie);
 404                         imp->imp_remote_handle = request->rq_repmsg->handle;
 405                 } else {
 406                         CERROR("reconnected to %s@%s after partition\n",
 407                                imp->imp_target_uuid.uuid,
 408                                imp->imp_connection->c_remote_uuid.uuid);
 409                 }
 410
 411                 if (imp->imp_invalid) {
 412                         IMPORT_SET_STATE(imp, LUSTRE_IMP_EVICTED);
 413                 } else if (MSG_CONNECT_RECOVERING & msg_flags) {
 414                         CDEBUG(D_HA, "%s: reconnected to %s during replay\n",
 415                                imp->imp_obd->obd_name,
 416                                imp->imp_target_uuid.uuid);
 417                         imp->imp_resend_replay = 1;
 418                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY);
 419                 } else {
 420                         IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
 421                 }
 422         } else if ((MSG_CONNECT_RECOVERING & msg_flags) && !imp->imp_invalid) {
 423                 LASSERT(imp->imp_replayable);
 424                 imp->imp_remote_handle = request->rq_repmsg->handle;
 425                 imp->imp_last_replay_transno = 0;
 426                 IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY);
 427         } else {
 428                 CWARN("oops! we get evicted from %s\n", imp->imp_target_uuid.uuid);
 429                 imp->imp_remote_handle = request->rq_repmsg->handle;
 430                 IMPORT_SET_STATE(imp, LUSTRE_IMP_EVICTED);
 431         }
 432
 433         /* Sanity checks for a reconnected import. */
 434         if (!(imp->imp_replayable) != !(msg_flags & MSG_CONNECT_REPLAYABLE)) {
 435                 CERROR("imp_replayable flag does not match server "
 436                        "after reconnect. We should LBUG right here.\n");
 437         }
 438
 439         if (request->rq_repmsg->last_committed < aa->pcaa_peer_committed) {
 440                 CERROR("%s went back in time (transno "LPD64
 441                        " was previously committed, server now claims "LPD64
 442                        ")! is shared storage not coherent?\n",
 443                        imp->imp_target_uuid.uuid,
 444                        aa->pcaa_peer_committed,
 445                        request->rq_repmsg->last_committed);
 446         }
 447
 448 finish:
 449         rc = ptlrpc_import_recovery_state_machine(imp);
 450         if (rc != 0) {
 451                 if (rc == -ENOTCONN) {
 452                         CDEBUG(D_HA, "evicted/aborted by %s@%s during recovery;"
 453                                "invalidating and reconnecting\n",
 454                                imp->imp_target_uuid.uuid,
 455                                imp->imp_connection->c_remote_uuid.uuid);
 456                         ptlrpc_connect_import(imp, NULL);
 457                         RETURN(0);
 458                 }
 459         }
 460  out:
 461         if (rc != 0) {
 462                 IMPORT_SET_STATE(imp, LUSTRE_IMP_DISCON);
 463                 if (aa->pcaa_initial_connect && !imp->imp_initial_recov) {
 464                         ptlrpc_deactivate_import(imp);
 465                 }
 466                 if (rc == -ETIMEDOUT && (jiffies - imp->imp_connect_start) > HZ) {
 467                         CDEBUG(D_ERROR, "recovery of %s on %s failed (timeout)\n",
 468                                imp->imp_target_uuid.uuid,
 469                                (char *)imp->imp_connection->c_remote_uuid.uuid);
 470                         ptlrpc_connect_import(imp, NULL);
 471                         RETURN(0);
 472                 }
 473                 CDEBUG(D_ERROR, "recovery of %s on %s failed (%d)\n",
 474                        imp->imp_target_uuid.uuid,
 475                        (char *)imp->imp_connection->c_remote_uuid.uuid, rc);
 476         }
 477
 478         wake_up(&imp->imp_recovery_waitq);
 479         RETURN(rc);
 480 }
 481
 482 static int completed_replay_interpret(struct ptlrpc_request *req,
 483                                     void * data, int rc)
 484 {
 485         atomic_dec(&req->rq_import->imp_replay_inflight);
 486         if (req->rq_status == 0) {
 487                 ptlrpc_import_recovery_state_machine(req->rq_import);
 488         } else {
 489                 CDEBUG(D_HA, "%s: LAST_REPLAY message error: %d, "
 490                        "reconnecting\n",
 491                        req->rq_import->imp_obd->obd_name, req->rq_status);
 492                 ptlrpc_connect_import(req->rq_import, NULL);
 493         }
 494
 495         RETURN(0);
 496 }
 497
 498 static int signal_completed_replay(struct obd_import *imp)
 499  {
 500         struct ptlrpc_request *req;
 501         ENTRY;
 502
 503         LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
 504         atomic_inc(&imp->imp_replay_inflight);
 505
 506         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL, NULL);
 507         if (!req)
 508                 RETURN(-ENOMEM);
 509
 510         req->rq_replen = lustre_msg_size(0, NULL);
 511         req->rq_send_state = LUSTRE_IMP_REPLAY_WAIT;
 512         req->rq_reqmsg->flags |= MSG_LAST_REPLAY;
 513         req->rq_timeout *= 3;
 514         req->rq_interpret_reply = completed_replay_interpret;
 515
 516         ptlrpcd_add_req(req);
 517         RETURN(0);
 518 }
 519
 520 int ptlrpc_import_recovery_state_machine(struct obd_import *imp)
 521 {
 522         int rc = 0;
 523         int inflight;
 524
 525         if (imp->imp_state == LUSTRE_IMP_EVICTED) {
 526                 CDEBUG(D_HA, "evicted from %s@%s; invalidating\n",
 527                        imp->imp_target_uuid.uuid,
 528                        imp->imp_connection->c_remote_uuid.uuid);
 529
 530                 ptlrpc_invalidate_import(imp, 1);
 531
 532                 IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
 533         }
 534
 535         if (imp->imp_state == LUSTRE_IMP_REPLAY) {
 536                 CDEBUG(D_HA, "replay requested by %s\n",
 537                        imp->imp_target_uuid.uuid);
 538                 rc = ptlrpc_replay_next(imp, &inflight);
 539                 if (inflight == 0 &&
 540                     atomic_read(&imp->imp_replay_inflight) == 0) {
 541                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY_LOCKS);
 542                         rc = ldlm_replay_locks(imp);
 543                         if (rc)
 544                                 GOTO(out, rc);
 545                 }
 546                 rc = 0;
 547         }
 548
 549         if (imp->imp_state == LUSTRE_IMP_REPLAY_LOCKS) {
 550                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
 551                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY_WAIT);
 552                         rc = signal_completed_replay(imp);
 553                         if (rc)
 554                                 GOTO(out, rc);
 555                 }
 556
 557         }
 558
 559         if (imp->imp_state == LUSTRE_IMP_REPLAY_WAIT) {
 560                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
 561                         IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
 562                 }
 563         }
 564
 565         if (imp->imp_state == LUSTRE_IMP_RECOVER) {
 566                 CDEBUG(D_HA, "reconnected to %s@%s\n",
 567                        imp->imp_target_uuid.uuid,
 568                        imp->imp_connection->c_remote_uuid.uuid);
 569
 570                 rc = ptlrpc_resend(imp);
 571                 if (rc)
 572                         GOTO(out, rc);
 573                 IMPORT_SET_STATE(imp, LUSTRE_IMP_FULL);
 574                 ptlrpc_activate_import(imp);
 575                 CERROR("%s: connection restored to %s@%s\n",
 576                        imp->imp_obd->obd_name,
 577                        imp->imp_target_uuid.uuid,
 578                        imp->imp_connection->c_remote_uuid.uuid);
 579         }
 580
 581         if (imp->imp_state == LUSTRE_IMP_FULL) {
 582                 wake_up(&imp->imp_recovery_waitq);
 583                 ptlrpc_wake_delayed(imp);
 584         }
 585
 586  out:
 587         RETURN(rc);
 588 }
 589
 590 static int back_to_sleep(void *unused)
 591 {
 592         return 0;
 593 }
 594
 595 int ptlrpc_disconnect_import(struct obd_import *imp)
 596 {
 597         struct ptlrpc_request *request;
 598         int rq_opc;
 599         int rc = 0;
 600         unsigned long flags;
 601         ENTRY;
 602
 603         switch (imp->imp_connect_op) {
 604         case OST_CONNECT: rq_opc = OST_DISCONNECT; break;
 605         case MDS_CONNECT: rq_opc = MDS_DISCONNECT; break;
 606         case MGMT_CONNECT:rq_opc = MGMT_DISCONNECT;break;
 607         default:
 608                 CERROR("don't know how to disconnect from %s (connect_op %d)\n",
 609                        imp->imp_target_uuid.uuid, imp->imp_connect_op);
 610                 RETURN(-EINVAL);
 611         }
 612
 613
 614         if (ptlrpc_import_in_recovery(imp)) {
 615                 struct l_wait_info lwi;
 616                 unsigned long timeout;
 617                 if (imp->imp_server_timeout)
 618                         timeout = obd_timeout / 2;
 619                 else
 620                         timeout = obd_timeout;
 621                 timeout = MAX(timeout * HZ, 1);
 622                 lwi = LWI_TIMEOUT_INTR(obd_timeout, back_to_sleep, NULL, NULL);
 623                 rc = l_wait_event(imp->imp_recovery_waitq,
 624                                   !ptlrpc_import_in_recovery(imp), &lwi);
 625
 626         }
 627
 628         spin_lock_irqsave(&imp->imp_lock, flags);
 629         if (imp->imp_state != LUSTRE_IMP_FULL) {
 630                 GOTO(out, 0);
 631         }
 632         spin_unlock_irqrestore(&imp->imp_lock, flags);
 633
 634         request = ptlrpc_prep_req(imp, rq_opc, 0, NULL, NULL);
 635         if (request) {
 636                 /* For non-replayable connections, don't attempt
 637                    reconnect if this fails */
 638                 if (!imp->imp_replayable) {
 639                         request->rq_no_resend = 1;
 640                         IMPORT_SET_STATE(imp, LUSTRE_IMP_CONNECTING);
 641                         request->rq_send_state =  LUSTRE_IMP_CONNECTING;
 642                 }
 643                 request->rq_replen = lustre_msg_size(0, NULL);
 644                 rc = ptlrpc_queue_wait(request);
 645                 ptlrpc_req_finished(request);
 646         }
 647
 648         spin_lock_irqsave(&imp->imp_lock, flags);
 649 out:
 650         IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_CLOSED);
 651         memset(&imp->imp_remote_handle, 0, sizeof(imp->imp_remote_handle));
 652         imp->imp_conn_cnt = 0;
 653         spin_unlock_irqrestore(&imp->imp_lock, flags);
 654
 655         RETURN(rc);
 656 }
 657