lustre/ptlrpc/import.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/ptlrpc/import.c
  33  *
  34  * Author: Mike Shaver <shaver@clusterfs.com>
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_RPC
  38
  39 #include <linux/kthread.h>
  40 #include <linux/delay.h>
  41 #include <obd_support.h>
  42 #include <lustre_ha.h>
  43 #include <lustre_net.h>
  44 #include <lustre_import.h>
  45 #include <lustre_export.h>
  46 #include <obd.h>
  47 #include <obd_cksum.h>
  48 #include <obd_class.h>
  49
  50 #include "ptlrpc_internal.h"
  51
  52 struct ptlrpc_connect_async_args {
  53          __u64 pcaa_peer_committed;
  54         int pcaa_initial_connect;
  55 };
  56
  57 /**
  58  * Updates import \a imp current state to provided \a state value
  59  * Helper function.
  60  */
  61 static void import_set_state_nolock(struct obd_import *imp,
  62                                     enum lustre_imp_state state)
  63 {
  64         switch (state) {
  65         case LUSTRE_IMP_CLOSED:
  66         case LUSTRE_IMP_NEW:
  67         case LUSTRE_IMP_DISCON:
  68         case LUSTRE_IMP_CONNECTING:
  69                 break;
  70         case LUSTRE_IMP_REPLAY_WAIT:
  71                 imp->imp_replay_state = LUSTRE_IMP_REPLAY_LOCKS;
  72                 break;
  73         default:
  74                 imp->imp_replay_state = LUSTRE_IMP_REPLAY;
  75                 break;
  76         }
  77
  78         /* A CLOSED import should remain so. */
  79         if (imp->imp_state == LUSTRE_IMP_CLOSED)
  80                 return;
  81
  82         if (imp->imp_state != LUSTRE_IMP_NEW) {
  83                 CDEBUG(D_HA, "%p %s: changing import state from %s to %s\n",
  84                        imp, obd2cli_tgt(imp->imp_obd),
  85                        ptlrpc_import_state_name(imp->imp_state),
  86                        ptlrpc_import_state_name(state));
  87         }
  88
  89         imp->imp_state = state;
  90         imp->imp_state_hist[imp->imp_state_hist_idx].ish_state = state;
  91         imp->imp_state_hist[imp->imp_state_hist_idx].ish_time =
  92                 ktime_get_real_seconds();
  93         imp->imp_state_hist_idx = (imp->imp_state_hist_idx + 1) %
  94                 IMP_STATE_HIST_LEN;
  95 }
  96
  97 static void import_set_state(struct obd_import *imp,
  98                              enum lustre_imp_state new_state)
  99 {
 100         spin_lock(&imp->imp_lock);
 101         import_set_state_nolock(imp, new_state);
 102         spin_unlock(&imp->imp_lock);
 103 }
 104
 105 void ptlrpc_import_enter_resend(struct obd_import *imp)
 106 {
 107         import_set_state(imp, LUSTRE_IMP_RECOVER);
 108 }
 109 EXPORT_SYMBOL(ptlrpc_import_enter_resend);
 110
 111
 112 static int ptlrpc_connect_interpret(const struct lu_env *env,
 113                                     struct ptlrpc_request *request,
 114                                     void *args, int rc);
 115 int ptlrpc_import_recovery_state_machine(struct obd_import *imp);
 116
 117 /* Only this function is allowed to change the import state when it is
 118  * CLOSED. I would rather refcount the import and free it after
 119  * disconnection like we do with exports. To do that, the client_obd
 120  * will need to save the peer info somewhere other than in the import,
 121  * though. */
 122 int ptlrpc_init_import(struct obd_import *imp)
 123 {
 124         spin_lock(&imp->imp_lock);
 125
 126         imp->imp_generation++;
 127         imp->imp_state =  LUSTRE_IMP_NEW;
 128
 129         spin_unlock(&imp->imp_lock);
 130
 131         return 0;
 132 }
 133 EXPORT_SYMBOL(ptlrpc_init_import);
 134
 135 #define UUID_STR "_UUID"
 136 void deuuidify(char *uuid, const char *prefix, char **uuid_start, int *uuid_len)
 137 {
 138         *uuid_start = !prefix || strncmp(uuid, prefix, strlen(prefix))
 139                 ? uuid : uuid + strlen(prefix);
 140
 141         *uuid_len = strlen(*uuid_start);
 142
 143         if (*uuid_len < strlen(UUID_STR))
 144                 return;
 145
 146         if (!strncmp(*uuid_start + *uuid_len - strlen(UUID_STR),
 147                     UUID_STR, strlen(UUID_STR)))
 148                 *uuid_len -= strlen(UUID_STR);
 149 }
 150
 151 /* Must be called with imp_lock held! */
 152 static void ptlrpc_deactivate_import_nolock(struct obd_import *imp)
 153 {
 154         ENTRY;
 155
 156         assert_spin_locked(&imp->imp_lock);
 157         CDEBUG(D_HA, "setting import %s INVALID\n", obd2cli_tgt(imp->imp_obd));
 158         imp->imp_invalid = 1;
 159         imp->imp_generation++;
 160
 161         ptlrpc_abort_inflight(imp);
 162
 163         EXIT;
 164 }
 165
 166 /**
 167  * Returns true if import was FULL, false if import was already not
 168  * connected.
 169  * @imp - import to be disconnected
 170  * @conn_cnt - connection count (epoch) of the request that timed out
 171  *             and caused the disconnection.  In some cases, multiple
 172  *             inflight requests can fail to a single target (e.g. OST
 173  *             bulk requests) and if one has already caused a reconnection
 174  *             (increasing the import->conn_cnt) the older failure should
 175  *             not also cause a reconnection.  If zero it forces a reconnect.
 176  * @invalid - set import invalid flag
 177  */
 178 int ptlrpc_set_import_discon(struct obd_import *imp,
 179                              __u32 conn_cnt, bool invalid)
 180 {
 181         int rc = 0;
 182
 183         spin_lock(&imp->imp_lock);
 184
 185         if (imp->imp_state == LUSTRE_IMP_FULL &&
 186             (conn_cnt == 0 || conn_cnt == imp->imp_conn_cnt)) {
 187                 char *target_start;
 188                 int   target_len;
 189                 bool  inact = false;
 190
 191                 deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
 192                           &target_start, &target_len);
 193
 194                 import_set_state_nolock(imp, LUSTRE_IMP_DISCON);
 195                 if (imp->imp_replayable) {
 196                         LCONSOLE_WARN("%s: Connection to %.*s (at %s) was "
 197                                "lost; in progress operations using this "
 198                                "service will wait for recovery to complete\n",
 199                                imp->imp_obd->obd_name, target_len, target_start,
 200                                obd_import_nid2str(imp));
 201                 } else {
 202                         LCONSOLE_ERROR_MSG(0x166, "%s: Connection to "
 203                                "%.*s (at %s) was lost; in progress "
 204                                "operations using this service will fail\n",
 205                                imp->imp_obd->obd_name, target_len, target_start,
 206                                obd_import_nid2str(imp));
 207                         if (invalid) {
 208                                 CDEBUG(D_HA, "import %s@%s for %s not "
 209                                        "replayable, auto-deactivating\n",
 210                                        obd2cli_tgt(imp->imp_obd),
 211                                        imp->imp_connection->c_remote_uuid.uuid,
 212                                        imp->imp_obd->obd_name);
 213                                 ptlrpc_deactivate_import_nolock(imp);
 214                                 inact = true;
 215                         }
 216                 }
 217                 spin_unlock(&imp->imp_lock);
 218
 219                 if (obd_dump_on_timeout)
 220                         libcfs_debug_dumplog();
 221
 222                 obd_import_event(imp->imp_obd, imp, IMP_EVENT_DISCON);
 223
 224                 if (inact)
 225                         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INACTIVE);
 226                 rc = 1;
 227         } else {
 228                 spin_unlock(&imp->imp_lock);
 229                 CDEBUG(D_HA, "%s: import %p already %s (conn %u, was %u): %s\n",
 230                        imp->imp_client->cli_name, imp,
 231                        (imp->imp_state == LUSTRE_IMP_FULL &&
 232                         imp->imp_conn_cnt > conn_cnt) ?
 233                        "reconnected" : "not connected", imp->imp_conn_cnt,
 234                        conn_cnt, ptlrpc_import_state_name(imp->imp_state));
 235         }
 236
 237         return rc;
 238 }
 239
 240 /*
 241  * This acts as a barrier; all existing requests are rejected, and
 242  * no new requests will be accepted until the import is valid again.
 243  */
 244 void ptlrpc_deactivate_import(struct obd_import *imp)
 245 {
 246         spin_lock(&imp->imp_lock);
 247         ptlrpc_deactivate_import_nolock(imp);
 248         spin_unlock(&imp->imp_lock);
 249
 250         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INACTIVE);
 251 }
 252 EXPORT_SYMBOL(ptlrpc_deactivate_import);
 253
 254 static time64_t ptlrpc_inflight_deadline(struct ptlrpc_request *req,
 255                                          time64_t now)
 256 {
 257         time64_t dl;
 258
 259         if (!(((req->rq_phase == RQ_PHASE_RPC) && !req->rq_waiting) ||
 260               (req->rq_phase == RQ_PHASE_BULK) ||
 261               (req->rq_phase == RQ_PHASE_NEW)))
 262                 return 0;
 263
 264         if (req->rq_timedout)
 265                 return 0;
 266
 267         if (req->rq_phase == RQ_PHASE_NEW)
 268                 dl = req->rq_sent;
 269         else
 270                 dl = req->rq_deadline;
 271
 272         if (dl <= now)
 273                 return 0;
 274
 275         return dl - now;
 276 }
 277
 278 static time64_t ptlrpc_inflight_timeout(struct obd_import *imp)
 279 {
 280         time64_t now = ktime_get_real_seconds();
 281         struct list_head *tmp, *n;
 282         struct ptlrpc_request *req;
 283         time64_t timeout = 0;
 284
 285         spin_lock(&imp->imp_lock);
 286         list_for_each_safe(tmp, n, &imp->imp_sending_list) {
 287                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 288                 timeout = max(ptlrpc_inflight_deadline(req, now), timeout);
 289         }
 290         spin_unlock(&imp->imp_lock);
 291         return timeout;
 292 }
 293
 294 /**
 295  * This function will invalidate the import, if necessary, then block
 296  * for all the RPC completions, and finally notify the obd to
 297  * invalidate its state (ie cancel locks, clear pending requests,
 298  * etc).
 299  */
 300 void ptlrpc_invalidate_import(struct obd_import *imp)
 301 {
 302         struct list_head *tmp, *n;
 303         struct ptlrpc_request *req;
 304         time64_t timeout;
 305         int rc;
 306
 307         atomic_inc(&imp->imp_inval_count);
 308
 309         if (!imp->imp_invalid || imp->imp_obd->obd_no_recov)
 310                 ptlrpc_deactivate_import(imp);
 311
 312         if (OBD_FAIL_PRECHECK(OBD_FAIL_PTLRPC_CONNECT_RACE)) {
 313                 OBD_RACE(OBD_FAIL_PTLRPC_CONNECT_RACE);
 314                 msleep(10 * MSEC_PER_SEC);
 315         }
 316         CFS_FAIL_TIMEOUT(OBD_FAIL_MGS_CONNECT_NET, 3 * cfs_fail_val / 2);
 317         LASSERT(imp->imp_invalid);
 318
 319         /* Wait forever until inflight == 0. We really can't do it another
 320          * way because in some cases we need to wait for very long reply
 321          * unlink. We can't do anything before that because there is really
 322          * no guarantee that some rdma transfer is not in progress right now.
 323          */
 324         do {
 325                 long timeout_jiffies;
 326
 327                 /* Calculate max timeout for waiting on rpcs to error
 328                  * out. Use obd_timeout if calculated value is smaller
 329                  * than it.
 330                  */
 331                 if (!OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_LONG_REPL_UNLINK)) {
 332                         timeout = ptlrpc_inflight_timeout(imp);
 333                         timeout += div_u64(timeout, 3);
 334
 335                         if (timeout == 0)
 336                                 timeout = obd_timeout;
 337                 } else {
 338                         /* decrease the interval to increase race condition */
 339                         timeout = 1;
 340                 }
 341
 342                 CDEBUG(D_RPCTRACE, "Sleeping %llds for inflight to error out\n",
 343                        timeout);
 344
 345                 /* Wait for all requests to error out and call completion
 346                  * callbacks. Cap it at obd_timeout -- these should all
 347                  * have been locally cancelled by ptlrpc_abort_inflight.
 348                  */
 349                 timeout_jiffies = max_t(long, cfs_time_seconds(timeout), 1);
 350                 rc = wait_event_idle_timeout(
 351                                     imp->imp_recovery_waitq,
 352                                     (atomic_read(&imp->imp_inflight) == 0),
 353                                     timeout_jiffies);
 354
 355                 if (rc == 0) {
 356                         const char *cli_tgt = obd2cli_tgt(imp->imp_obd);
 357
 358                         CERROR("%s: timeout waiting for callback (%d != 0)\n",
 359                                cli_tgt, atomic_read(&imp->imp_inflight));
 360
 361                         spin_lock(&imp->imp_lock);
 362                         if (atomic_read(&imp->imp_inflight) == 0) {
 363                                 int count = atomic_read(&imp->imp_unregistering);
 364
 365                                 /* We know that "unregistering" rpcs only can
 366                                  * survive in sending or delaying lists (they
 367                                  * maybe waiting for long reply unlink in
 368                                  * sluggish nets). Let's check this. If there
 369                                  * is no inflight and unregistering != 0, this
 370                                  * is bug. */
 371                                 LASSERTF(count == 0, "Some RPCs are still "
 372                                          "unregistering: %d\n", count);
 373
 374                                 /* Let's save one loop as soon as inflight have
 375                                  * dropped to zero. No new inflights possible at
 376                                  * this point. */
 377                                 rc = 1;
 378                         } else {
 379                                 list_for_each_safe(tmp, n,
 380                                                    &imp->imp_sending_list) {
 381                                         req = list_entry(tmp,
 382                                                          struct ptlrpc_request,
 383                                                          rq_list);
 384                                         DEBUG_REQ(D_ERROR, req,
 385                                                   "still on sending list");
 386                                 }
 387                                 list_for_each_safe(tmp, n,
 388                                                    &imp->imp_delayed_list) {
 389                                         req = list_entry(tmp,
 390                                                          struct ptlrpc_request,
 391                                                          rq_list);
 392                                         DEBUG_REQ(D_ERROR, req,
 393                                                   "still on delayed list");
 394                                 }
 395
 396                                 CERROR("%s: Unregistering RPCs found (%d). "
 397                                        "Network is sluggish? Waiting for them "
 398                                        "to error out.\n", cli_tgt,
 399                                        atomic_read(&imp->imp_unregistering));
 400                         }
 401                         spin_unlock(&imp->imp_lock);
 402                 }
 403         } while (rc == 0);
 404
 405         /*
 406          * Let's additionally check that no new rpcs added to import in
 407          * "invalidate" state.
 408          */
 409         LASSERT(atomic_read(&imp->imp_inflight) == 0);
 410         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INVALIDATE);
 411         sptlrpc_import_flush_all_ctx(imp);
 412
 413         atomic_dec(&imp->imp_inval_count);
 414         wake_up(&imp->imp_recovery_waitq);
 415 }
 416 EXPORT_SYMBOL(ptlrpc_invalidate_import);
 417
 418 /* unset imp_invalid */
 419 void ptlrpc_activate_import(struct obd_import *imp, bool set_state_full)
 420 {
 421         struct obd_device *obd = imp->imp_obd;
 422
 423         spin_lock(&imp->imp_lock);
 424         if (imp->imp_deactive != 0) {
 425                 LASSERT(imp->imp_state != LUSTRE_IMP_FULL);
 426                 if (imp->imp_state != LUSTRE_IMP_DISCON)
 427                         import_set_state_nolock(imp, LUSTRE_IMP_DISCON);
 428                 spin_unlock(&imp->imp_lock);
 429                 return;
 430         }
 431         if (set_state_full)
 432                 import_set_state_nolock(imp, LUSTRE_IMP_FULL);
 433
 434         imp->imp_invalid = 0;
 435
 436         spin_unlock(&imp->imp_lock);
 437         obd_import_event(obd, imp, IMP_EVENT_ACTIVE);
 438 }
 439 EXPORT_SYMBOL(ptlrpc_activate_import);
 440
 441 void ptlrpc_pinger_force(struct obd_import *imp)
 442 {
 443         CDEBUG(D_HA, "%s: waking up pinger s:%s\n", obd2cli_tgt(imp->imp_obd),
 444                ptlrpc_import_state_name(imp->imp_state));
 445
 446         spin_lock(&imp->imp_lock);
 447         imp->imp_force_verify = 1;
 448         spin_unlock(&imp->imp_lock);
 449
 450         if (imp->imp_state != LUSTRE_IMP_CONNECTING)
 451                 ptlrpc_pinger_wake_up();
 452 }
 453 EXPORT_SYMBOL(ptlrpc_pinger_force);
 454
 455 void ptlrpc_fail_import(struct obd_import *imp, __u32 conn_cnt)
 456 {
 457         ENTRY;
 458
 459         LASSERT(!imp->imp_dlm_fake);
 460
 461         if (ptlrpc_set_import_discon(imp, conn_cnt, true))
 462                 ptlrpc_pinger_force(imp);
 463
 464         EXIT;
 465 }
 466
 467 int ptlrpc_reconnect_import(struct obd_import *imp)
 468 {
 469 #ifdef ENABLE_PINGER
 470         long timeout_jiffies = cfs_time_seconds(obd_timeout);
 471         int rc;
 472
 473         ptlrpc_pinger_force(imp);
 474
 475         CDEBUG(D_HA, "%s: recovery started, waiting %u seconds\n",
 476                obd2cli_tgt(imp->imp_obd), obd_timeout);
 477
 478         rc = wait_event_idle_timeout(imp->imp_recovery_waitq,
 479                                      !ptlrpc_import_in_recovery(imp),
 480                                      timeout_jiffies);
 481         if (rc == 0)
 482                 rc = -ETIMEDOUT;
 483         else
 484                 rc = 0;
 485         CDEBUG(D_HA, "%s: recovery finished s:%s\n", obd2cli_tgt(imp->imp_obd),
 486                ptlrpc_import_state_name(imp->imp_state));
 487         return rc;
 488 #else
 489         ptlrpc_set_import_discon(imp, 0, false);
 490         /* Force a new connect attempt */
 491         ptlrpc_invalidate_import(imp);
 492         /* Do a fresh connect next time by zeroing the handle */
 493         ptlrpc_disconnect_import(imp, 1);
 494         /* Wait for all invalidate calls to finish */
 495         if (atomic_read(&imp->imp_inval_count) > 0) {
 496                 int rc;
 497
 498                 rc = l_wait_event_abortable(
 499                         imp->imp_recovery_waitq,
 500                         (atomic_read(&imp->imp_inval_count) == 0));
 501                 if (rc)
 502                         CERROR("Interrupted, inval=%d\n",
 503                                atomic_read(&imp->imp_inval_count));
 504         }
 505
 506         /* Allow reconnect attempts */
 507         imp->imp_obd->obd_no_recov = 0;
 508         /* Remove 'invalid' flag */
 509         ptlrpc_activate_import(imp, false);
 510         /* Attempt a new connect */
 511         ptlrpc_recover_import(imp, NULL, 0);
 512         return 0;
 513 #endif
 514 }
 515 EXPORT_SYMBOL(ptlrpc_reconnect_import);
 516
 517 /**
 518  * Connection on import \a imp is changed to another one (if more than one is
 519  * present). We typically chose connection that we have not tried to connect to
 520  * the longest
 521  */
 522 static int import_select_connection(struct obd_import *imp)
 523 {
 524         struct obd_import_conn *imp_conn = NULL, *conn;
 525         struct obd_export *dlmexp;
 526         char *target_start;
 527         int target_len, tried_all = 1;
 528         int rc = 0;
 529         ENTRY;
 530
 531         spin_lock(&imp->imp_lock);
 532
 533         if (list_empty(&imp->imp_conn_list)) {
 534                 rc = -EINVAL;
 535                 CERROR("%s: no connections available: rc = %d\n",
 536                        imp->imp_obd->obd_name, rc);
 537                 GOTO(out_unlock, rc);
 538         }
 539
 540         list_for_each_entry(conn, &imp->imp_conn_list, oic_item) {
 541                 CDEBUG(D_HA, "%s: connect to NID %s last attempt %lld\n",
 542                        imp->imp_obd->obd_name,
 543                        libcfs_nid2str(conn->oic_conn->c_peer.nid),
 544                        conn->oic_last_attempt);
 545
 546                 /* If we have not tried this connection since
 547                  * the last successful attempt, go with this one
 548                  */
 549                 if ((conn->oic_last_attempt == 0) ||
 550                     conn->oic_last_attempt <= imp->imp_last_success_conn) {
 551                         imp_conn = conn;
 552                         tried_all = 0;
 553                         break;
 554                 }
 555
 556                 /* If all of the connections have already been tried
 557                  * since the last successful connection; just choose the
 558                  * least recently used
 559                  */
 560                 if (!imp_conn)
 561                         imp_conn = conn;
 562                 else if (imp_conn->oic_last_attempt > conn->oic_last_attempt)
 563                         imp_conn = conn;
 564         }
 565
 566         /* if not found, simply choose the current one */
 567         if (!imp_conn || imp->imp_force_reconnect) {
 568                 LASSERT(imp->imp_conn_current);
 569                 imp_conn = imp->imp_conn_current;
 570                 tried_all = 0;
 571         }
 572         LASSERT(imp_conn->oic_conn);
 573
 574         /* If we've tried everything, and we're back to the beginning of the
 575          * list, increase our timeout and try again. It will be reset when
 576          * we do finally connect. (FIXME: really we should wait for all network
 577          * state associated with the last connection attempt to drain before
 578          * trying to reconnect on it.)
 579          */
 580         if (tried_all && (imp->imp_conn_list.next == &imp_conn->oic_item)) {
 581                 struct adaptive_timeout *at = &imp->imp_at.iat_net_latency;
 582                 if (at_get(at) < CONNECTION_SWITCH_MAX) {
 583                         at_measured(at, at_get(at) + CONNECTION_SWITCH_INC);
 584                         if (at_get(at) > CONNECTION_SWITCH_MAX)
 585                                 at_reset(at, CONNECTION_SWITCH_MAX);
 586                 }
 587                 LASSERT(imp_conn->oic_last_attempt);
 588                 CDEBUG(D_HA, "%s: tried all connections, increasing latency "
 589                        "to %ds\n", imp->imp_obd->obd_name, at_get(at));
 590         }
 591
 592         imp_conn->oic_last_attempt = ktime_get_seconds();
 593
 594         /* switch connection, don't mind if it's same as the current one */
 595         if (imp->imp_connection)
 596                 ptlrpc_connection_put(imp->imp_connection);
 597         imp->imp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
 598
 599         dlmexp = class_conn2export(&imp->imp_dlm_handle);
 600         if (!dlmexp)
 601                 GOTO(out_unlock, rc = -EINVAL);
 602         if (dlmexp->exp_connection)
 603                 ptlrpc_connection_put(dlmexp->exp_connection);
 604         dlmexp->exp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
 605         class_export_put(dlmexp);
 606
 607         if (imp->imp_conn_current != imp_conn) {
 608                 if (imp->imp_conn_current) {
 609                         deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
 610                                   &target_start, &target_len);
 611
 612                         CDEBUG(D_HA, "%s: Connection changing to"
 613                                " %.*s (at %s)\n",
 614                                imp->imp_obd->obd_name,
 615                                target_len, target_start,
 616                                libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
 617                 }
 618
 619                 imp->imp_conn_current = imp_conn;
 620         }
 621
 622         /* The below message is checked in conf-sanity.sh test_35[ab] */
 623         CDEBUG(D_HA, "%s: import %p using connection %s/%s\n",
 624                imp->imp_obd->obd_name, imp, imp_conn->oic_uuid.uuid,
 625                libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
 626
 627 out_unlock:
 628         spin_unlock(&imp->imp_lock);
 629         RETURN(rc);
 630 }
 631
 632 /*
 633  * must be called under imp_lock
 634  */
 635 static int ptlrpc_first_transno(struct obd_import *imp, __u64 *transno)
 636 {
 637         struct ptlrpc_request   *req;
 638         struct list_head        *tmp;
 639
 640         /* The requests in committed_list always have smaller transnos than
 641          * the requests in replay_list */
 642         if (!list_empty(&imp->imp_committed_list)) {
 643                 tmp = imp->imp_committed_list.next;
 644                 req = list_entry(tmp, struct ptlrpc_request, rq_replay_list);
 645                 *transno = req->rq_transno;
 646                 if (req->rq_transno == 0) {
 647                         DEBUG_REQ(D_ERROR, req,
 648                                   "zero transno in committed_list");
 649                         LBUG();
 650                 }
 651                 return 1;
 652         }
 653         if (!list_empty(&imp->imp_replay_list)) {
 654                 tmp = imp->imp_replay_list.next;
 655                 req = list_entry(tmp, struct ptlrpc_request, rq_replay_list);
 656                 *transno = req->rq_transno;
 657                 if (req->rq_transno == 0) {
 658                         DEBUG_REQ(D_ERROR, req, "zero transno in replay_list");
 659                         LBUG();
 660                 }
 661                 return 1;
 662         }
 663         return 0;
 664 }
 665
 666 int ptlrpc_connect_import(struct obd_import *imp)
 667 {
 668         spin_lock(&imp->imp_lock);
 669         return ptlrpc_connect_import_locked(imp);
 670 }
 671
 672 /**
 673  * Attempt to (re)connect import \a imp. This includes all preparations,
 674  * initializing CONNECT RPC request and passing it to ptlrpcd for
 675  * actual sending.
 676  *
 677  * Assumes imp->imp_lock is held, and releases it.
 678  *
 679  * Returns 0 on success or error code.
 680  */
 681 int ptlrpc_connect_import_locked(struct obd_import *imp)
 682 {
 683         struct obd_device *obd = imp->imp_obd;
 684         int initial_connect = 0;
 685         int set_transno = 0;
 686         __u64 committed_before_reconnect = 0;
 687         struct ptlrpc_request *request;
 688         struct obd_connect_data ocd;
 689         char *bufs[] = { NULL,
 690                          obd2cli_tgt(imp->imp_obd),
 691                          obd->obd_uuid.uuid,
 692                          (char *)&imp->imp_dlm_handle,
 693                          (char *)&ocd,
 694                          NULL };
 695         struct ptlrpc_connect_async_args *aa;
 696         int rc;
 697         ENTRY;
 698
 699         assert_spin_locked(&imp->imp_lock);
 700
 701         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
 702                 spin_unlock(&imp->imp_lock);
 703                 CERROR("can't connect to a closed import\n");
 704                 RETURN(-EINVAL);
 705         } else if (imp->imp_state == LUSTRE_IMP_FULL) {
 706                 spin_unlock(&imp->imp_lock);
 707                 CERROR("already connected\n");
 708                 RETURN(0);
 709         } else if (imp->imp_state == LUSTRE_IMP_CONNECTING ||
 710                    imp->imp_state == LUSTRE_IMP_EVICTED ||
 711                    imp->imp_connected) {
 712                 spin_unlock(&imp->imp_lock);
 713                 CERROR("already connecting\n");
 714                 RETURN(-EALREADY);
 715         }
 716
 717         import_set_state_nolock(imp, LUSTRE_IMP_CONNECTING);
 718
 719         imp->imp_conn_cnt++;
 720         imp->imp_resend_replay = 0;
 721
 722         if (!lustre_handle_is_used(&imp->imp_remote_handle))
 723                 initial_connect = 1;
 724         else
 725                 committed_before_reconnect = imp->imp_peer_committed_transno;
 726
 727         set_transno = ptlrpc_first_transno(imp,
 728                                            &imp->imp_connect_data.ocd_transno);
 729         spin_unlock(&imp->imp_lock);
 730
 731         rc = import_select_connection(imp);
 732         if (rc)
 733                 GOTO(out, rc);
 734
 735         rc = sptlrpc_import_sec_adapt(imp, NULL, NULL);
 736         if (rc)
 737                 GOTO(out, rc);
 738
 739         /* Reset connect flags to the originally requested flags, in case
 740          * the server is updated on-the-fly we will get the new features. */
 741         ocd = imp->imp_connect_data;
 742         ocd.ocd_connect_flags = imp->imp_connect_flags_orig;
 743         ocd.ocd_connect_flags2 = imp->imp_connect_flags2_orig;
 744         /* Reset ocd_version each time so the server knows the exact versions */
 745         ocd.ocd_version = LUSTRE_VERSION_CODE;
 746         imp->imp_msghdr_flags &= ~MSGHDR_AT_SUPPORT;
 747         imp->imp_msghdr_flags &= ~MSGHDR_CKSUM_INCOMPAT18;
 748
 749         rc = obd_reconnect(NULL, imp->imp_obd->obd_self_export, obd,
 750                            &obd->obd_uuid, &ocd, NULL);
 751         if (rc)
 752                 GOTO(out, rc);
 753
 754         request = ptlrpc_request_alloc(imp, &RQF_MDS_CONNECT);
 755         if (request == NULL)
 756                 GOTO(out, rc = -ENOMEM);
 757
 758         /* get SELinux policy info if any */
 759         rc = sptlrpc_get_sepol(request);
 760         if (rc < 0) {
 761                 ptlrpc_request_free(request);
 762                 GOTO(out, rc);
 763         }
 764
 765         bufs[5] = request->rq_sepol;
 766
 767         req_capsule_set_size(&request->rq_pill, &RMF_SELINUX_POL, RCL_CLIENT,
 768                              strlen(request->rq_sepol) ?
 769                              strlen(request->rq_sepol) + 1 : 0);
 770
 771         rc = ptlrpc_request_bufs_pack(request, LUSTRE_OBD_VERSION,
 772                                       imp->imp_connect_op, bufs, NULL);
 773         if (rc) {
 774                 ptlrpc_request_free(request);
 775                 GOTO(out, rc);
 776         }
 777
 778         /* Report the rpc service time to the server so that it knows how long
 779          * to wait for clients to join recovery */
 780         lustre_msg_set_service_time(request->rq_reqmsg,
 781                                     at_timeout2est(request->rq_timeout));
 782
 783         /* The amount of time we give the server to process the connect req.
 784          * import_select_connection will increase the net latency on
 785          * repeated reconnect attempts to cover slow networks.
 786          * We override/ignore the server rpc completion estimate here,
 787          * which may be large if this is a reconnect attempt */
 788         request->rq_timeout = INITIAL_CONNECT_TIMEOUT;
 789         lustre_msg_set_timeout(request->rq_reqmsg, request->rq_timeout);
 790
 791         request->rq_no_resend = request->rq_no_delay = 1;
 792         request->rq_send_state = LUSTRE_IMP_CONNECTING;
 793         /* Allow a slightly larger reply for future growth compatibility */
 794         req_capsule_set_size(&request->rq_pill, &RMF_CONNECT_DATA, RCL_SERVER,
 795                              sizeof(struct obd_connect_data)+16*sizeof(__u64));
 796         ptlrpc_request_set_replen(request);
 797         request->rq_interpret_reply = ptlrpc_connect_interpret;
 798
 799         aa = ptlrpc_req_async_args(aa, request);
 800         memset(aa, 0, sizeof *aa);
 801
 802         aa->pcaa_peer_committed = committed_before_reconnect;
 803         aa->pcaa_initial_connect = initial_connect;
 804
 805         if (aa->pcaa_initial_connect) {
 806                 spin_lock(&imp->imp_lock);
 807                 imp->imp_replayable = 1;
 808                 spin_unlock(&imp->imp_lock);
 809                 lustre_msg_add_op_flags(request->rq_reqmsg,
 810                                         MSG_CONNECT_INITIAL);
 811         }
 812
 813         if (set_transno)
 814                 lustre_msg_add_op_flags(request->rq_reqmsg,
 815                                         MSG_CONNECT_TRANSNO);
 816
 817         DEBUG_REQ(D_RPCTRACE, request, "(re)connect request (timeout %ld)",
 818                   request->rq_timeout);
 819         ptlrpcd_add_req(request);
 820         rc = 0;
 821 out:
 822         if (rc != 0)
 823                 import_set_state(imp, LUSTRE_IMP_DISCON);
 824
 825         RETURN(rc);
 826 }
 827 EXPORT_SYMBOL(ptlrpc_connect_import);
 828
 829 static void ptlrpc_maybe_ping_import_soon(struct obd_import *imp)
 830 {
 831         int force_verify;
 832
 833         spin_lock(&imp->imp_lock);
 834         force_verify = imp->imp_force_verify != 0;
 835         spin_unlock(&imp->imp_lock);
 836
 837         if (force_verify)
 838                 ptlrpc_pinger_wake_up();
 839 }
 840
 841 static int ptlrpc_busy_reconnect(int rc)
 842 {
 843         return (rc == -EBUSY) || (rc == -EAGAIN);
 844 }
 845
 846 static int ptlrpc_connect_set_flags(struct obd_import *imp,
 847                                     struct obd_connect_data *ocd,
 848                                     __u64 old_connect_flags,
 849                                     struct obd_export *exp, int init_connect)
 850 {
 851         static bool warned;
 852         struct client_obd *cli = &imp->imp_obd->u.cli;
 853
 854         spin_lock(&imp->imp_lock);
 855         list_move(&imp->imp_conn_current->oic_item,
 856                   &imp->imp_conn_list);
 857         imp->imp_last_success_conn =
 858                 imp->imp_conn_current->oic_last_attempt;
 859
 860         spin_unlock(&imp->imp_lock);
 861
 862         if (!warned && (ocd->ocd_connect_flags & OBD_CONNECT_VERSION) &&
 863             (ocd->ocd_version > LUSTRE_VERSION_CODE +
 864                                 LUSTRE_VERSION_OFFSET_WARN ||
 865              ocd->ocd_version < LUSTRE_VERSION_CODE -
 866                                 LUSTRE_VERSION_OFFSET_WARN)) {
 867                 /* Sigh, some compilers do not like #ifdef in the middle
 868                    of macro arguments */
 869                 const char *older = "older than client. "
 870                                     "Consider upgrading server";
 871                 const char *newer = "newer than client. "
 872                                     "Consider upgrading client";
 873
 874                 LCONSOLE_WARN("Server %s version (%d.%d.%d.%d) "
 875                               "is much %s (%s)\n",
 876                               obd2cli_tgt(imp->imp_obd),
 877                               OBD_OCD_VERSION_MAJOR(ocd->ocd_version),
 878                               OBD_OCD_VERSION_MINOR(ocd->ocd_version),
 879                               OBD_OCD_VERSION_PATCH(ocd->ocd_version),
 880                               OBD_OCD_VERSION_FIX(ocd->ocd_version),
 881                               ocd->ocd_version > LUSTRE_VERSION_CODE ?
 882                               newer : older, LUSTRE_VERSION_STRING);
 883                 warned = true;
 884         }
 885
 886         if (ocd->ocd_connect_flags & OBD_CONNECT_CKSUM) {
 887                 /* We sent to the server ocd_cksum_types with bits set
 888                  * for algorithms we understand. The server masked off
 889                  * the checksum types it doesn't support */
 890                 if ((ocd->ocd_cksum_types &
 891                      obd_cksum_types_supported_client()) == 0) {
 892                         LCONSOLE_ERROR("The negotiation of the checksum "
 893                                        "alogrithm to use with server %s "
 894                                        "failed (%x/%x)\n",
 895                                        obd2cli_tgt(imp->imp_obd),
 896                                        ocd->ocd_cksum_types,
 897                                        obd_cksum_types_supported_client());
 898                         return -EPROTO;
 899                 } else {
 900                         cli->cl_supp_cksum_types = ocd->ocd_cksum_types;
 901                 }
 902         } else {
 903                 /* The server does not support OBD_CONNECT_CKSUM.
 904                  * Enforce ADLER for backward compatibility*/
 905                 cli->cl_supp_cksum_types = OBD_CKSUM_ADLER;
 906         }
 907         cli->cl_cksum_type = obd_cksum_type_select(imp->imp_obd->obd_name,
 908                                                   cli->cl_supp_cksum_types,
 909                                                   cli->cl_preferred_cksum_type);
 910
 911         if (ocd->ocd_connect_flags & OBD_CONNECT_BRW_SIZE)
 912                 cli->cl_max_pages_per_rpc =
 913                         min(ocd->ocd_brw_size >> PAGE_SHIFT,
 914                             cli->cl_max_pages_per_rpc);
 915         else if (imp->imp_connect_op == MDS_CONNECT ||
 916                  imp->imp_connect_op == MGS_CONNECT)
 917                 cli->cl_max_pages_per_rpc = 1;
 918
 919         LASSERT((cli->cl_max_pages_per_rpc <= PTLRPC_MAX_BRW_PAGES) &&
 920                 (cli->cl_max_pages_per_rpc > 0));
 921
 922         client_adjust_max_dirty(cli);
 923
 924         /* Update client max modify RPCs in flight with value returned
 925          * by the server */
 926         if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS)
 927                 cli->cl_max_mod_rpcs_in_flight = min(
 928                                         cli->cl_max_mod_rpcs_in_flight,
 929                                         ocd->ocd_maxmodrpcs);
 930         else
 931                 cli->cl_max_mod_rpcs_in_flight = 1;
 932
 933         /* Reset ns_connect_flags only for initial connect. It might be
 934          * changed in while using FS and if we reset it in reconnect
 935          * this leads to losing user settings done before such as
 936          * disable lru_resize, etc. */
 937         if (old_connect_flags != exp_connect_flags(exp) || init_connect) {
 938                 struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
 939                 __u64 changed_flags;
 940
 941                 changed_flags =
 942                         ns->ns_connect_flags ^ ns->ns_orig_connect_flags;
 943                 CDEBUG(D_HA, "%s: Resetting ns_connect_flags to server "
 944                              "flags: %#llx\n", imp->imp_obd->obd_name,
 945                              ocd->ocd_connect_flags);
 946                 ns->ns_connect_flags = (ns->ns_connect_flags & changed_flags) |
 947                                       (ocd->ocd_connect_flags & ~changed_flags);
 948                 ns->ns_orig_connect_flags = ocd->ocd_connect_flags;
 949         }
 950
 951         if (ocd->ocd_connect_flags & OBD_CONNECT_AT)
 952                 /* We need a per-message support flag, because
 953                  * a. we don't know if the incoming connect reply
 954                  *    supports AT or not (in reply_in_callback)
 955                  *    until we unpack it.
 956                  * b. failovered server means export and flags are gone
 957                  *    (in ptlrpc_send_reply).
 958                  *    Can only be set when we know AT is supported at
 959                  *    both ends */
 960                 imp->imp_msghdr_flags |= MSGHDR_AT_SUPPORT;
 961         else
 962                 imp->imp_msghdr_flags &= ~MSGHDR_AT_SUPPORT;
 963
 964         imp->imp_msghdr_flags |= MSGHDR_CKSUM_INCOMPAT18;
 965
 966         return 0;
 967 }
 968
 969 /**
 970  * Add all replay requests back to unreplied list before start replay,
 971  * so that we can make sure the known replied XID is always increased
 972  * only even if when replaying requests.
 973  */
 974 static void ptlrpc_prepare_replay(struct obd_import *imp)
 975 {
 976         struct ptlrpc_request *req;
 977
 978         if (imp->imp_state != LUSTRE_IMP_REPLAY ||
 979             imp->imp_resend_replay)
 980                 return;
 981
 982         /* If the server was restart during repaly, the requests may
 983          * have been added to the unreplied list in former replay. */
 984         spin_lock(&imp->imp_lock);
 985
 986         list_for_each_entry(req, &imp->imp_committed_list, rq_replay_list) {
 987                 if (list_empty(&req->rq_unreplied_list))
 988                         ptlrpc_add_unreplied(req);
 989         }
 990
 991         list_for_each_entry(req, &imp->imp_replay_list, rq_replay_list) {
 992                 if (list_empty(&req->rq_unreplied_list))
 993                         ptlrpc_add_unreplied(req);
 994         }
 995
 996         imp->imp_known_replied_xid = ptlrpc_known_replied_xid(imp);
 997         spin_unlock(&imp->imp_lock);
 998 }
 999
1000 /**
1001  * interpret_reply callback for connect RPCs.
1002  * Looks into returned status of connect operation and decides
1003  * what to do with the import - i.e enter recovery, promote it to
1004  * full state for normal operations of disconnect it due to an error.
1005  */
1006 static int ptlrpc_connect_interpret(const struct lu_env *env,
1007                                     struct ptlrpc_request *request,
1008                                     void *data, int rc)
1009 {
1010         struct ptlrpc_connect_async_args *aa = data;
1011         struct obd_import *imp = request->rq_import;
1012         struct lustre_handle old_hdl;
1013         __u64 old_connect_flags;
1014         int msg_flags;
1015         struct obd_connect_data *ocd;
1016         struct obd_export *exp = NULL;
1017         int ret;
1018         ENTRY;
1019
1020         spin_lock(&imp->imp_lock);
1021         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
1022                 imp->imp_connect_tried = 1;
1023                 spin_unlock(&imp->imp_lock);
1024                 RETURN(0);
1025         }
1026
1027         imp->imp_connect_error = rc;
1028         if (rc) {
1029                 struct ptlrpc_request *free_req;
1030                 struct ptlrpc_request *tmp;
1031
1032                 /* abort all delayed requests initiated connection */
1033                 list_for_each_entry_safe(free_req, tmp, &imp->imp_delayed_list,
1034                                          rq_list) {
1035                         spin_lock(&free_req->rq_lock);
1036                         if (free_req->rq_no_resend) {
1037                                 free_req->rq_err = 1;
1038                                 free_req->rq_status = -EIO;
1039                                 ptlrpc_client_wake_req(free_req);
1040                         }
1041                         spin_unlock(&free_req->rq_lock);
1042                 }
1043
1044                 /* if this reconnect to busy export - not need select new target
1045                  * for connecting*/
1046                 imp->imp_force_reconnect = ptlrpc_busy_reconnect(rc);
1047                 spin_unlock(&imp->imp_lock);
1048                 ptlrpc_maybe_ping_import_soon(imp);
1049                 GOTO(out, rc);
1050         }
1051
1052         /* LU-7558: indicate that we are interpretting connect reply,
1053          * pltrpc_connect_import() will not try to reconnect until
1054          * interpret will finish. */
1055         imp->imp_connected = 1;
1056         spin_unlock(&imp->imp_lock);
1057
1058         LASSERT(imp->imp_conn_current);
1059
1060         msg_flags = lustre_msg_get_op_flags(request->rq_repmsg);
1061
1062         ret = req_capsule_get_size(&request->rq_pill, &RMF_CONNECT_DATA,
1063                                    RCL_SERVER);
1064         /* server replied obd_connect_data is always bigger */
1065         ocd = req_capsule_server_sized_get(&request->rq_pill,
1066                                            &RMF_CONNECT_DATA, ret);
1067
1068         if (ocd == NULL) {
1069                 CERROR("%s: no connect data from server\n",
1070                        imp->imp_obd->obd_name);
1071                 rc = -EPROTO;
1072                 GOTO(out, rc);
1073         }
1074
1075         spin_lock(&imp->imp_lock);
1076
1077         /* All imports are pingable */
1078         imp->imp_pingable = 1;
1079         imp->imp_force_reconnect = 0;
1080         imp->imp_force_verify = 0;
1081
1082         imp->imp_connect_data = *ocd;
1083
1084         CDEBUG(D_HA, "%s: connect to target with instance %u\n",
1085                imp->imp_obd->obd_name, ocd->ocd_instance);
1086         exp = class_conn2export(&imp->imp_dlm_handle);
1087
1088         spin_unlock(&imp->imp_lock);
1089
1090         if (!exp) {
1091                 /* This could happen if export is cleaned during the
1092                    connect attempt */
1093                 CERROR("%s: missing export after connect\n",
1094                        imp->imp_obd->obd_name);
1095                 GOTO(out, rc = -ENODEV);
1096         }
1097
1098         /* check that server granted subset of flags we asked for. */
1099         if ((ocd->ocd_connect_flags & imp->imp_connect_flags_orig) !=
1100             ocd->ocd_connect_flags) {
1101                 CERROR("%s: Server didn't grant requested subset of flags: "
1102                        "asked=%#llx granted=%#llx\n",
1103                        imp->imp_obd->obd_name, imp->imp_connect_flags_orig,
1104                        ocd->ocd_connect_flags);
1105                 GOTO(out, rc = -EPROTO);
1106         }
1107
1108         if ((ocd->ocd_connect_flags2 & imp->imp_connect_flags2_orig) !=
1109             ocd->ocd_connect_flags2) {
1110                 CERROR("%s: Server didn't grant requested subset of flags2: "
1111                        "asked=%#llx granted=%#llx\n",
1112                        imp->imp_obd->obd_name, imp->imp_connect_flags2_orig,
1113                        ocd->ocd_connect_flags2);
1114                 GOTO(out, rc = -EPROTO);
1115         }
1116
1117         if (!(imp->imp_connect_flags_orig & OBD_CONNECT_LIGHTWEIGHT) &&
1118             (imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS) &&
1119             (imp->imp_connect_flags_orig & OBD_CONNECT_FID) &&
1120             (ocd->ocd_connect_flags & OBD_CONNECT_VERSION)) {
1121                 __u32 major = OBD_OCD_VERSION_MAJOR(ocd->ocd_version);
1122                 __u32 minor = OBD_OCD_VERSION_MINOR(ocd->ocd_version);
1123                 __u32 patch = OBD_OCD_VERSION_PATCH(ocd->ocd_version);
1124
1125                 /* We do not support the MDT-MDT interoperations with
1126                  * different version MDT because of protocol changes. */
1127                 if (unlikely(major != LUSTRE_MAJOR ||
1128                              minor != LUSTRE_MINOR ||
1129                              abs(patch - LUSTRE_PATCH) > 3)) {
1130                         LCONSOLE_WARN("%s: import %p (%u.%u.%u.%u) tried the "
1131                                       "connection to different version MDT "
1132                                       "(%d.%d.%d.%d) %s\n",
1133                                       imp->imp_obd->obd_name, imp, LUSTRE_MAJOR,
1134                                       LUSTRE_MINOR, LUSTRE_PATCH, LUSTRE_FIX,
1135                                       major, minor, patch,
1136                                       OBD_OCD_VERSION_FIX(ocd->ocd_version),
1137                                       imp->imp_connection->c_remote_uuid.uuid);
1138
1139                         GOTO(out, rc = -EPROTO);
1140                 }
1141         }
1142
1143         old_connect_flags = exp_connect_flags(exp);
1144         exp->exp_connect_data = *ocd;
1145         imp->imp_obd->obd_self_export->exp_connect_data = *ocd;
1146
1147         /* The net statistics after (re-)connect is not valid anymore,
1148          * because may reflect other routing, etc. */
1149         at_reinit(&imp->imp_at.iat_net_latency, 0, 0);
1150         ptlrpc_at_adj_net_latency(request,
1151                                   lustre_msg_get_service_time(
1152                                           request->rq_repmsg));
1153
1154         /* Import flags should be updated before waking import at FULL state */
1155         rc = ptlrpc_connect_set_flags(imp, ocd, old_connect_flags, exp,
1156                                       aa->pcaa_initial_connect);
1157         class_export_put(exp);
1158         exp = NULL;
1159
1160         if (rc != 0)
1161                 GOTO(out, rc);
1162
1163         obd_import_event(imp->imp_obd, imp, IMP_EVENT_OCD);
1164
1165         if (aa->pcaa_initial_connect) {
1166                 spin_lock(&imp->imp_lock);
1167                 if (msg_flags & MSG_CONNECT_REPLAYABLE) {
1168                         imp->imp_replayable = 1;
1169                         CDEBUG(D_HA, "connected to replayable target: %s\n",
1170                                obd2cli_tgt(imp->imp_obd));
1171                 } else {
1172                         imp->imp_replayable = 0;
1173                 }
1174
1175                 /* if applies, adjust the imp->imp_msg_magic here
1176                  * according to reply flags
1177                  */
1178
1179                 imp->imp_remote_handle =
1180                         *lustre_msg_get_handle(request->rq_repmsg);
1181
1182                 /* Initial connects are allowed for clients with non-random
1183                  * uuids when servers are in recovery.  Simply signal the
1184                  * servers replay is complete and wait in REPLAY_WAIT.
1185                  */
1186                 if (msg_flags & MSG_CONNECT_RECOVERING) {
1187                         CDEBUG(D_HA, "connect to %s during recovery\n",
1188                                obd2cli_tgt(imp->imp_obd));
1189                         import_set_state_nolock(imp, LUSTRE_IMP_REPLAY_LOCKS);
1190                         spin_unlock(&imp->imp_lock);
1191                 } else {
1192                         spin_unlock(&imp->imp_lock);
1193                         ptlrpc_activate_import(imp, true);
1194                 }
1195
1196                 GOTO(finish, rc = 0);
1197         }
1198
1199         /* Determine what recovery state to move the import to. */
1200         if (MSG_CONNECT_RECONNECT & msg_flags) {
1201                 memset(&old_hdl, 0, sizeof(old_hdl));
1202                 if (!memcmp(&old_hdl, lustre_msg_get_handle(request->rq_repmsg),
1203                             sizeof(old_hdl))) {
1204                         LCONSOLE_WARN("Reconnect to %s (at @%s) failed due "
1205                                       "bad handle %#llx\n",
1206                                       obd2cli_tgt(imp->imp_obd),
1207                                       imp->imp_connection->c_remote_uuid.uuid,
1208                                       imp->imp_dlm_handle.cookie);
1209                         GOTO(out, rc = -ENOTCONN);
1210                 }
1211
1212                 if (memcmp(&imp->imp_remote_handle,
1213                            lustre_msg_get_handle(request->rq_repmsg),
1214                            sizeof(imp->imp_remote_handle))) {
1215                         int level = msg_flags & MSG_CONNECT_RECOVERING ?
1216                                 D_HA : D_WARNING;
1217
1218                         /* Bug 16611/14775: if server handle have changed,
1219                          * that means some sort of disconnection happened.
1220                          * If the server is not in recovery, that also means it
1221                          * already erased all of our state because of previous
1222                          * eviction. If it is in recovery - we are safe to
1223                          * participate since we can reestablish all of our state
1224                          * with server again
1225                          */
1226                         if ((MSG_CONNECT_RECOVERING & msg_flags)) {
1227                                 CDEBUG(level,
1228                                        "%s@%s changed server handle from "
1229                                        "%#llx to %#llx"
1230                                        " but is still in recovery\n",
1231                                        obd2cli_tgt(imp->imp_obd),
1232                                        imp->imp_connection->c_remote_uuid.uuid,
1233                                        imp->imp_remote_handle.cookie,
1234                                        lustre_msg_get_handle(
1235                                                request->rq_repmsg)->cookie);
1236                         } else {
1237                                 LCONSOLE_WARN("Evicted from %s (at %s) "
1238                                               "after server handle changed from "
1239                                               "%#llx to %#llx\n",
1240                                               obd2cli_tgt(imp->imp_obd),
1241                                               imp->imp_connection->
1242                                               c_remote_uuid.uuid,
1243                                               imp->imp_remote_handle.cookie,
1244                                               lustre_msg_get_handle(
1245                                                       request->rq_repmsg)->cookie);
1246                         }
1247
1248                         imp->imp_remote_handle =
1249                                 *lustre_msg_get_handle(request->rq_repmsg);
1250
1251                         if (!(MSG_CONNECT_RECOVERING & msg_flags)) {
1252                                 import_set_state(imp, LUSTRE_IMP_EVICTED);
1253                                 GOTO(finish, rc = 0);
1254                         }
1255                 } else {
1256                         CDEBUG(D_HA, "reconnected to %s@%s after partition\n",
1257                                obd2cli_tgt(imp->imp_obd),
1258                                imp->imp_connection->c_remote_uuid.uuid);
1259                 }
1260
1261                 if (imp->imp_invalid) {
1262                         CDEBUG(D_HA, "%s: reconnected but import is invalid; "
1263                                "marking evicted\n", imp->imp_obd->obd_name);
1264                         import_set_state(imp, LUSTRE_IMP_EVICTED);
1265                 } else if (MSG_CONNECT_RECOVERING & msg_flags) {
1266                         CDEBUG(D_HA, "%s: reconnected to %s during replay\n",
1267                                imp->imp_obd->obd_name,
1268                                obd2cli_tgt(imp->imp_obd));
1269
1270                         spin_lock(&imp->imp_lock);
1271                         imp->imp_resend_replay = 1;
1272                         spin_unlock(&imp->imp_lock);
1273
1274                         import_set_state(imp, imp->imp_replay_state);
1275                 } else {
1276                         import_set_state(imp, LUSTRE_IMP_RECOVER);
1277                 }
1278         } else if ((MSG_CONNECT_RECOVERING & msg_flags) && !imp->imp_invalid) {
1279                 LASSERT(imp->imp_replayable);
1280                 imp->imp_remote_handle =
1281                         *lustre_msg_get_handle(request->rq_repmsg);
1282                 imp->imp_last_replay_transno = 0;
1283                 imp->imp_replay_cursor = &imp->imp_committed_list;
1284                 import_set_state(imp, LUSTRE_IMP_REPLAY);
1285         } else if ((ocd->ocd_connect_flags & OBD_CONNECT_LIGHTWEIGHT) != 0 &&
1286                    !imp->imp_invalid) {
1287
1288                 obd_import_event(imp->imp_obd, imp, IMP_EVENT_INVALIDATE);
1289                 /* The below message is checked in recovery-small.sh test_106 */
1290                 DEBUG_REQ(D_HA, request, "%s: lwp recover",
1291                           imp->imp_obd->obd_name);
1292                 imp->imp_remote_handle =
1293                         *lustre_msg_get_handle(request->rq_repmsg);
1294                 import_set_state(imp, LUSTRE_IMP_RECOVER);
1295         } else {
1296                 DEBUG_REQ(D_HA, request,
1297                           "%s: evicting (reconnect/recover flags not set: %x)",
1298                           imp->imp_obd->obd_name, msg_flags);
1299                 imp->imp_remote_handle =
1300                         *lustre_msg_get_handle(request->rq_repmsg);
1301                 import_set_state(imp, LUSTRE_IMP_EVICTED);
1302         }
1303
1304         /* Sanity checks for a reconnected import. */
1305         if (!(imp->imp_replayable) != !(msg_flags & MSG_CONNECT_REPLAYABLE))
1306                 CERROR("imp_replayable flag does not match server after reconnect. We should LBUG right here.\n");
1307
1308         if (lustre_msg_get_last_committed(request->rq_repmsg) > 0 &&
1309             lustre_msg_get_last_committed(request->rq_repmsg) <
1310             aa->pcaa_peer_committed) {
1311                 static bool printed;
1312
1313                 /* The below message is checked in recovery-small.sh test_54 */
1314                 CERROR("%s: went back in time (transno %lld was previously committed, server now claims %lld)!\n",
1315                        obd2cli_tgt(imp->imp_obd), aa->pcaa_peer_committed,
1316                        lustre_msg_get_last_committed(request->rq_repmsg));
1317                 if (!printed) {
1318                         CERROR("For further information, see http://doc.lustre.org/lustre_manual.xhtml#went_back_in_time\n");
1319                         printed = true;
1320                 }
1321         }
1322
1323 finish:
1324         ptlrpc_prepare_replay(imp);
1325         rc = ptlrpc_import_recovery_state_machine(imp);
1326         if (rc == -ENOTCONN) {
1327                 CDEBUG(D_HA,
1328                        "evicted/aborted by %s@%s during recovery; invalidating and reconnecting\n",
1329                        obd2cli_tgt(imp->imp_obd),
1330                        imp->imp_connection->c_remote_uuid.uuid);
1331                 ptlrpc_connect_import(imp);
1332                 spin_lock(&imp->imp_lock);
1333                 imp->imp_connected = 0;
1334                 imp->imp_connect_tried = 1;
1335                 spin_unlock(&imp->imp_lock);
1336                 RETURN(0);
1337         }
1338
1339 out:
1340         if (exp != NULL)
1341                 class_export_put(exp);
1342
1343         spin_lock(&imp->imp_lock);
1344         imp->imp_connected = 0;
1345         imp->imp_connect_tried = 1;
1346
1347         if (rc != 0) {
1348                 bool inact = false;
1349
1350                 import_set_state_nolock(imp, LUSTRE_IMP_DISCON);
1351                 if (rc == -EACCES) {
1352                         /*
1353                          * Give up trying to reconnect
1354                          * EACCES means client has no permission for connection
1355                          */
1356                         imp->imp_obd->obd_no_recov = 1;
1357                         ptlrpc_deactivate_import_nolock(imp);
1358                         inact = true;
1359                 } else if (rc == -EPROTO) {
1360                         struct obd_connect_data *ocd;
1361
1362                         /* reply message might not be ready */
1363                         if (request->rq_repmsg == NULL) {
1364                                 spin_unlock(&imp->imp_lock);
1365                                 RETURN(-EPROTO);
1366                         }
1367
1368                         ocd = req_capsule_server_get(&request->rq_pill,
1369                                                      &RMF_CONNECT_DATA);
1370                         /* Servers are not supposed to refuse connections from
1371                          * clients based on version, only connection feature
1372                          * flags.  We should never see this from llite, but it
1373                          * may be useful for debugging in the future. */
1374                         if (ocd &&
1375                             (ocd->ocd_connect_flags & OBD_CONNECT_VERSION) &&
1376                             (ocd->ocd_version != LUSTRE_VERSION_CODE)) {
1377                                 LCONSOLE_ERROR_MSG(0x16a, "Server %s version "
1378                                                    "(%d.%d.%d.%d)"
1379                                                    " refused connection from this client "
1380                                                    "with an incompatible version (%s).  "
1381                                                    "Client must be recompiled\n",
1382                                                    obd2cli_tgt(imp->imp_obd),
1383                                                    OBD_OCD_VERSION_MAJOR(ocd->ocd_version),
1384                                                    OBD_OCD_VERSION_MINOR(ocd->ocd_version),
1385                                                    OBD_OCD_VERSION_PATCH(ocd->ocd_version),
1386                                                    OBD_OCD_VERSION_FIX(ocd->ocd_version),
1387                                                    LUSTRE_VERSION_STRING);
1388                                 ptlrpc_deactivate_import_nolock(imp);
1389                                 import_set_state_nolock(imp, LUSTRE_IMP_CLOSED);
1390                                 inact = true;
1391                         }
1392                 }
1393                 spin_unlock(&imp->imp_lock);
1394
1395                 if (inact)
1396                         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INACTIVE);
1397
1398                 if (rc == -EPROTO)
1399                         RETURN(rc);
1400
1401                 ptlrpc_maybe_ping_import_soon(imp);
1402
1403                 CDEBUG(D_HA, "recovery of %s on %s failed (%d)\n",
1404                        obd2cli_tgt(imp->imp_obd),
1405                        (char *)imp->imp_connection->c_remote_uuid.uuid, rc);
1406         } else {
1407                 spin_unlock(&imp->imp_lock);
1408         }
1409
1410         wake_up(&imp->imp_recovery_waitq);
1411         RETURN(rc);
1412 }
1413
1414 /**
1415  * interpret callback for "completed replay" RPCs.
1416  * \see signal_completed_replay
1417  */
1418 static int completed_replay_interpret(const struct lu_env *env,
1419                                       struct ptlrpc_request *req,
1420                                       void *args, int rc)
1421 {
1422         ENTRY;
1423         atomic_dec(&req->rq_import->imp_replay_inflight);
1424         if (req->rq_status == 0 && !req->rq_import->imp_vbr_failed) {
1425                 ptlrpc_import_recovery_state_machine(req->rq_import);
1426         } else {
1427                 if (req->rq_import->imp_vbr_failed) {
1428                         CDEBUG(D_WARNING,
1429                                "%s: version recovery fails, reconnecting\n",
1430                                req->rq_import->imp_obd->obd_name);
1431                 } else {
1432                         CDEBUG(D_HA, "%s: LAST_REPLAY message error: %d, "
1433                                      "reconnecting\n",
1434                                req->rq_import->imp_obd->obd_name,
1435                                req->rq_status);
1436                 }
1437                 ptlrpc_connect_import(req->rq_import);
1438         }
1439
1440         RETURN(0);
1441 }
1442
1443 /**
1444  * Let server know that we have no requests to replay anymore.
1445  * Achieved by just sending a PING request
1446  */
1447 static int signal_completed_replay(struct obd_import *imp)
1448 {
1449         struct ptlrpc_request *req;
1450         ENTRY;
1451
1452         if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_FINISH_REPLAY)))
1453                 RETURN(0);
1454
1455         LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
1456         atomic_inc(&imp->imp_replay_inflight);
1457
1458         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING, LUSTRE_OBD_VERSION,
1459                                         OBD_PING);
1460         if (req == NULL) {
1461                 atomic_dec(&imp->imp_replay_inflight);
1462                 RETURN(-ENOMEM);
1463         }
1464
1465         ptlrpc_request_set_replen(req);
1466         req->rq_send_state = LUSTRE_IMP_REPLAY_WAIT;
1467         lustre_msg_add_flags(req->rq_reqmsg,
1468                              MSG_LOCK_REPLAY_DONE | MSG_REQ_REPLAY_DONE);
1469         if (AT_OFF)
1470                 req->rq_timeout *= 3;
1471         req->rq_interpret_reply = completed_replay_interpret;
1472
1473         ptlrpcd_add_req(req);
1474         RETURN(0);
1475 }
1476
1477 /**
1478  * In kernel code all import invalidation happens in its own
1479  * separate thread, so that whatever application happened to encounter
1480  * a problem could still be killed or otherwise continue
1481  */
1482 static int ptlrpc_invalidate_import_thread(void *data)
1483 {
1484         struct obd_import *imp = data;
1485
1486         ENTRY;
1487
1488         unshare_fs_struct();
1489
1490         CDEBUG(D_HA, "thread invalidate import %s to %s@%s\n",
1491                imp->imp_obd->obd_name, obd2cli_tgt(imp->imp_obd),
1492                imp->imp_connection->c_remote_uuid.uuid);
1493
1494         ptlrpc_invalidate_import(imp);
1495
1496         if (obd_dump_on_eviction) {
1497                 CERROR("dump the log upon eviction\n");
1498                 libcfs_debug_dumplog();
1499         }
1500
1501         import_set_state(imp, LUSTRE_IMP_RECOVER);
1502         ptlrpc_import_recovery_state_machine(imp);
1503
1504         class_import_put(imp);
1505         RETURN(0);
1506 }
1507
1508 /**
1509  * This is the state machine for client-side recovery on import.
1510  *
1511  * Typicaly we have two possibly paths. If we came to server and it is not
1512  * in recovery, we just enter IMP_EVICTED state, invalidate our import
1513  * state and reconnect from scratch.
1514  * If we came to server that is in recovery, we enter IMP_REPLAY import state.
1515  * We go through our list of requests to replay and send them to server one by
1516  * one.
1517  * After sending all request from the list we change import state to
1518  * IMP_REPLAY_LOCKS and re-request all the locks we believe we have from server
1519  * and also all the locks we don't yet have and wait for server to grant us.
1520  * After that we send a special "replay completed" request and change import
1521  * state to IMP_REPLAY_WAIT.
1522  * Upon receiving reply to that "replay completed" RPC we enter IMP_RECOVER
1523  * state and resend all requests from sending list.
1524  * After that we promote import to FULL state and send all delayed requests
1525  * and import is fully operational after that.
1526  *
1527  */
1528 int ptlrpc_import_recovery_state_machine(struct obd_import *imp)
1529 {
1530         int rc = 0;
1531         int inflight;
1532         char *target_start;
1533         int target_len;
1534
1535         ENTRY;
1536         if (imp->imp_state == LUSTRE_IMP_EVICTED) {
1537                 deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
1538                           &target_start, &target_len);
1539                 /* Don't care about MGC eviction */
1540                 if (strcmp(imp->imp_obd->obd_type->typ_name,
1541                            LUSTRE_MGC_NAME) != 0) {
1542                         LCONSOLE_ERROR_MSG(0x167, "%s: This client was evicted "
1543                                            "by %.*s; in progress operations "
1544                                            "using this service will fail.\n",
1545                                            imp->imp_obd->obd_name, target_len,
1546                                            target_start);
1547                         LASSERTF(!obd_lbug_on_eviction, "LBUG upon eviction");
1548                 }
1549                 CDEBUG(D_HA, "evicted from %s@%s; invalidating\n",
1550                        obd2cli_tgt(imp->imp_obd),
1551                        imp->imp_connection->c_remote_uuid.uuid);
1552                 /* reset vbr_failed flag upon eviction */
1553                 spin_lock(&imp->imp_lock);
1554                 imp->imp_vbr_failed = 0;
1555                 spin_unlock(&imp->imp_lock);
1556
1557                 {
1558                 struct task_struct *task;
1559                 /* bug 17802:  XXX client_disconnect_export vs connect request
1560                  * race. if client is evicted at this time then we start
1561                  * invalidate thread without reference to import and import can
1562                  * be freed at same time. */
1563                 class_import_get(imp);
1564                 task = kthread_run(ptlrpc_invalidate_import_thread, imp,
1565                                      "ll_imp_inval");
1566                 if (IS_ERR(task)) {
1567                         class_import_put(imp);
1568                         CERROR("error starting invalidate thread: %d\n", rc);
1569                         rc = PTR_ERR(task);
1570                 } else {
1571                         rc = 0;
1572                 }
1573                 RETURN(rc);
1574                 }
1575         }
1576
1577         if (imp->imp_state == LUSTRE_IMP_REPLAY) {
1578                 CDEBUG(D_HA, "replay requested by %s\n",
1579                        obd2cli_tgt(imp->imp_obd));
1580                 rc = ptlrpc_replay_next(imp, &inflight);
1581                 if (inflight == 0 &&
1582                     atomic_read(&imp->imp_replay_inflight) == 0) {
1583                         import_set_state(imp, LUSTRE_IMP_REPLAY_LOCKS);
1584                         rc = ldlm_replay_locks(imp);
1585                         if (rc)
1586                                 GOTO(out, rc);
1587                 }
1588                 rc = 0;
1589         }
1590
1591         if (imp->imp_state == LUSTRE_IMP_REPLAY_LOCKS) {
1592                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
1593                         import_set_state(imp, LUSTRE_IMP_REPLAY_WAIT);
1594                         rc = signal_completed_replay(imp);
1595                         if (rc)
1596                                 GOTO(out, rc);
1597                 }
1598         }
1599
1600         if (imp->imp_state == LUSTRE_IMP_REPLAY_WAIT) {
1601                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
1602                         import_set_state(imp, LUSTRE_IMP_RECOVER);
1603                 }
1604         }
1605
1606         if (imp->imp_state == LUSTRE_IMP_RECOVER) {
1607                 struct ptlrpc_connection *conn = imp->imp_connection;
1608
1609                 rc = ptlrpc_resend(imp);
1610                 if (rc)
1611                         GOTO(out, rc);
1612                 ptlrpc_activate_import(imp, true);
1613
1614                 CDEBUG_LIMIT(imp->imp_was_idle ?
1615                                 imp->imp_idle_debug : D_CONSOLE,
1616                              "%s: Connection restored to %s (at %s)\n",
1617                              imp->imp_obd->obd_name,
1618                              obd_uuid2str(&conn->c_remote_uuid),
1619                              obd_import_nid2str(imp));
1620                 spin_lock(&imp->imp_lock);
1621                 imp->imp_was_idle = 0;
1622                 spin_unlock(&imp->imp_lock);
1623         }
1624
1625         if (imp->imp_state == LUSTRE_IMP_FULL) {
1626                 wake_up(&imp->imp_recovery_waitq);
1627                 ptlrpc_wake_delayed(imp);
1628         }
1629
1630 out:
1631         RETURN(rc);
1632 }
1633
1634 static struct ptlrpc_request *ptlrpc_disconnect_prep_req(struct obd_import *imp)
1635 {
1636         struct ptlrpc_request *req;
1637         int rq_opc, rc = 0;
1638         ENTRY;
1639
1640         switch (imp->imp_connect_op) {
1641         case OST_CONNECT:
1642                 rq_opc = OST_DISCONNECT;
1643                 break;
1644         case MDS_CONNECT:
1645                 rq_opc = MDS_DISCONNECT;
1646                 break;
1647         case MGS_CONNECT:
1648                 rq_opc = MGS_DISCONNECT;
1649                 break;
1650         default:
1651                 rc = -EINVAL;
1652                 CERROR("%s: don't know how to disconnect from %s "
1653                        "(connect_op %d): rc = %d\n",
1654                        imp->imp_obd->obd_name, obd2cli_tgt(imp->imp_obd),
1655                        imp->imp_connect_op, rc);
1656                 RETURN(ERR_PTR(rc));
1657         }
1658
1659         req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_DISCONNECT,
1660                                         LUSTRE_OBD_VERSION, rq_opc);
1661         if (req == NULL)
1662                 RETURN(ERR_PTR(-ENOMEM));
1663
1664         /* We are disconnecting, do not retry a failed DISCONNECT rpc if
1665          * it fails.  We can get through the above with a down server
1666          * if the client doesn't know the server is gone yet. */
1667         req->rq_no_resend = 1;
1668
1669         /* We want client umounts to happen quickly, no matter the
1670            server state... */
1671         req->rq_timeout = min_t(int, req->rq_timeout,
1672                                 INITIAL_CONNECT_TIMEOUT);
1673
1674         import_set_state(imp, LUSTRE_IMP_CONNECTING);
1675         req->rq_send_state =  LUSTRE_IMP_CONNECTING;
1676         ptlrpc_request_set_replen(req);
1677
1678         RETURN(req);
1679 }
1680
1681 int ptlrpc_disconnect_import(struct obd_import *imp, int noclose)
1682 {
1683         struct ptlrpc_request *req;
1684         int rc = 0;
1685         ENTRY;
1686
1687         if (imp->imp_obd->obd_force)
1688                 GOTO(set_state, rc);
1689
1690         /* probably the import has been disconnected already being idle */
1691         spin_lock(&imp->imp_lock);
1692         if (imp->imp_state == LUSTRE_IMP_IDLE)
1693                 GOTO(out, rc);
1694         spin_unlock(&imp->imp_lock);
1695
1696         if (ptlrpc_import_in_recovery(imp)) {
1697                 long timeout_jiffies;
1698                 time64_t timeout;
1699
1700                 if (AT_OFF) {
1701                         if (imp->imp_server_timeout)
1702                                 timeout = obd_timeout >> 1;
1703                         else
1704                                 timeout = obd_timeout;
1705                 } else {
1706                         u32 req_portal;
1707                         int idx;
1708
1709                         req_portal = imp->imp_client->cli_request_portal;
1710                         idx = import_at_get_index(imp, req_portal);
1711                         timeout = at_get(&imp->imp_at.iat_service_estimate[idx]);
1712                 }
1713
1714                 timeout_jiffies = cfs_time_seconds(timeout);
1715                 if (wait_event_idle_timeout(imp->imp_recovery_waitq,
1716                                             !ptlrpc_import_in_recovery(imp),
1717                                             timeout_jiffies) == 0 &&
1718                     l_wait_event_abortable(imp->imp_recovery_waitq,
1719                                            !ptlrpc_import_in_recovery(imp)) < 0)
1720                         rc = -EINTR;
1721         }
1722
1723         spin_lock(&imp->imp_lock);
1724         if (imp->imp_state != LUSTRE_IMP_FULL)
1725                 GOTO(out, rc);
1726         spin_unlock(&imp->imp_lock);
1727
1728         req = ptlrpc_disconnect_prep_req(imp);
1729         if (IS_ERR(req))
1730                 GOTO(set_state, rc = PTR_ERR(req));
1731         rc = ptlrpc_queue_wait(req);
1732         ptlrpc_req_finished(req);
1733
1734 set_state:
1735         spin_lock(&imp->imp_lock);
1736 out:
1737         if (noclose)
1738                 import_set_state_nolock(imp, LUSTRE_IMP_DISCON);
1739         else
1740                 import_set_state_nolock(imp, LUSTRE_IMP_CLOSED);
1741         memset(&imp->imp_remote_handle, 0, sizeof(imp->imp_remote_handle));
1742         spin_unlock(&imp->imp_lock);
1743
1744         if (rc == -ETIMEDOUT || rc == -ENOTCONN || rc == -ESHUTDOWN)
1745                 rc = 0;
1746         RETURN(rc);
1747 }
1748 EXPORT_SYMBOL(ptlrpc_disconnect_import);
1749
1750 static void ptlrpc_reset_reqs_generation(struct obd_import *imp)
1751 {
1752         struct ptlrpc_request *old, *tmp;
1753
1754         /* tag all resendable requests generated before disconnection
1755          * notice this code is part of disconnect-at-idle path only */
1756         list_for_each_entry_safe(old, tmp, &imp->imp_delayed_list,
1757                         rq_list) {
1758                 spin_lock(&old->rq_lock);
1759                 if (old->rq_import_generation == imp->imp_generation - 1 &&
1760                     ((imp->imp_initiated_at == imp->imp_generation) ||
1761                      !old->rq_no_resend))
1762                         old->rq_import_generation = imp->imp_generation;
1763                 spin_unlock(&old->rq_lock);
1764         }
1765 }
1766
1767 static int ptlrpc_disconnect_idle_interpret(const struct lu_env *env,
1768                                             struct ptlrpc_request *req,
1769                                             void *args, int rc)
1770 {
1771         struct obd_import *imp = req->rq_import;
1772         int connect = 0;
1773
1774         DEBUG_REQ(D_HA, req, "inflight=%d, refcount=%d: rc = %d",
1775                   atomic_read(&imp->imp_inflight),
1776                   refcount_read(&imp->imp_refcount), rc);
1777
1778         spin_lock(&imp->imp_lock);
1779         /* DISCONNECT reply can be late and another connection can just
1780          * be initiated. so we have to abort disconnection. */
1781         if (req->rq_import_generation == imp->imp_generation &&
1782             imp->imp_state != LUSTRE_IMP_CLOSED) {
1783                 LASSERTF(imp->imp_state == LUSTRE_IMP_CONNECTING,
1784                          "%s\n", ptlrpc_import_state_name(imp->imp_state));
1785                 memset(&imp->imp_remote_handle, 0,
1786                        sizeof(imp->imp_remote_handle));
1787                 /* take our DISCONNECT into account */
1788                 if (atomic_read(&imp->imp_inflight) > 1) {
1789                         imp->imp_generation++;
1790                         imp->imp_initiated_at = imp->imp_generation;
1791                         import_set_state_nolock(imp, LUSTRE_IMP_NEW);
1792                         ptlrpc_reset_reqs_generation(imp);
1793                         connect = 1;
1794                 } else {
1795                         /* do not expose transient IDLE state */
1796                         import_set_state_nolock(imp, LUSTRE_IMP_IDLE);
1797                 }
1798         }
1799
1800         if (connect) {
1801                 rc = ptlrpc_connect_import_locked(imp);
1802                 if (rc >= 0)
1803                         ptlrpc_pinger_add_import(imp);
1804         } else {
1805                 spin_unlock(&imp->imp_lock);
1806         }
1807
1808         return 0;
1809 }
1810
1811 int ptlrpc_disconnect_and_idle_import(struct obd_import *imp)
1812 {
1813         struct ptlrpc_request *req;
1814         ENTRY;
1815
1816         if (imp->imp_obd->obd_force)
1817                 RETURN(0);
1818
1819         if (ptlrpc_import_in_recovery(imp))
1820                 RETURN(0);
1821
1822         spin_lock(&imp->imp_lock);
1823         if (imp->imp_state != LUSTRE_IMP_FULL) {
1824                 spin_unlock(&imp->imp_lock);
1825                 RETURN(0);
1826         }
1827         spin_unlock(&imp->imp_lock);
1828
1829         req = ptlrpc_disconnect_prep_req(imp);
1830         if (IS_ERR(req))
1831                 RETURN(PTR_ERR(req));
1832
1833         CDEBUG_LIMIT(imp->imp_idle_debug, "%s: disconnect after %llus idle\n",
1834                      imp->imp_obd->obd_name,
1835                      ktime_get_real_seconds() - imp->imp_last_reply_time);
1836
1837         /* don't make noise at reconnection */
1838         spin_lock(&imp->imp_lock);
1839         imp->imp_was_idle = 1;
1840         spin_unlock(&imp->imp_lock);
1841
1842         req->rq_interpret_reply = ptlrpc_disconnect_idle_interpret;
1843         ptlrpcd_add_req(req);
1844
1845         RETURN(0);
1846 }
1847 EXPORT_SYMBOL(ptlrpc_disconnect_and_idle_import);
1848
1849 void ptlrpc_cleanup_imp(struct obd_import *imp)
1850 {
1851         ENTRY;
1852
1853         spin_lock(&imp->imp_lock);
1854
1855         import_set_state_nolock(imp, LUSTRE_IMP_CLOSED);
1856         imp->imp_generation++;
1857         ptlrpc_abort_inflight(imp);
1858
1859         spin_unlock(&imp->imp_lock);
1860
1861         EXIT;
1862 }
1863
1864 /* Adaptive Timeout utils */
1865
1866 /* Update at_current with the specified value (bounded by at_min and at_max),
1867  * as well as the AT history "bins".
1868  *  - Bin into timeslices using AT_BINS bins.
1869  *  - This gives us a max of the last at_history seconds without the storage,
1870  *    but still smoothing out a return to normalcy from a slow response.
1871  *  - (E.g. remember the maximum latency in each minute of the last 4 minutes.)
1872  */
1873 int at_measured(struct adaptive_timeout *at, unsigned int val)
1874 {
1875         unsigned int old = at->at_current;
1876         time64_t now = ktime_get_real_seconds();
1877         long binlimit = max_t(long, at_history / AT_BINS, 1);
1878
1879         LASSERT(at);
1880         CDEBUG(D_OTHER, "add %u to %p time=%lu v=%u (%u %u %u %u)\n",
1881                val, at, (long)(now - at->at_binstart), at->at_current,
1882                at->at_hist[0], at->at_hist[1], at->at_hist[2], at->at_hist[3]);
1883
1884         if (val == 0)
1885                 /* 0's don't count, because we never want our timeout to
1886                    drop to 0, and because 0 could mean an error */
1887                 return 0;
1888
1889         spin_lock(&at->at_lock);
1890
1891         if (unlikely(at->at_binstart == 0)) {
1892                 /* Special case to remove default from history */
1893                 at->at_current = val;
1894                 at->at_worst_ever = val;
1895                 at->at_worst_time = now;
1896                 at->at_hist[0] = val;
1897                 at->at_binstart = now;
1898         } else if (now - at->at_binstart < binlimit ) {
1899                 /* in bin 0 */
1900                 at->at_hist[0] = max(val, at->at_hist[0]);
1901                 at->at_current = max(val, at->at_current);
1902         } else {
1903                 int i, shift;
1904                 unsigned int maxv = val;
1905
1906                 /* move bins over */
1907                 shift = (u32)(now - at->at_binstart) / binlimit;
1908                 LASSERT(shift > 0);
1909                 for(i = AT_BINS - 1; i >= 0; i--) {
1910                         if (i >= shift) {
1911                                 at->at_hist[i] = at->at_hist[i - shift];
1912                                 maxv = max(maxv, at->at_hist[i]);
1913                         } else {
1914                                 at->at_hist[i] = 0;
1915                         }
1916                 }
1917                 at->at_hist[0] = val;
1918                 at->at_current = maxv;
1919                 at->at_binstart += shift * binlimit;
1920         }
1921
1922         if (at->at_current > at->at_worst_ever) {
1923                 at->at_worst_ever = at->at_current;
1924                 at->at_worst_time = now;
1925         }
1926
1927         if (at->at_flags & AT_FLG_NOHIST)
1928                 /* Only keep last reported val; keeping the rest of the history
1929                    for proc only */
1930                 at->at_current = val;
1931
1932         if (at_max > 0)
1933                 at->at_current =  min(at->at_current, at_max);
1934         at->at_current =  max(at->at_current, at_min);
1935
1936         if (at->at_current != old)
1937                 CDEBUG(D_OTHER, "AT %p change: old=%u new=%u delta=%d "
1938                        "(val=%u) hist %u %u %u %u\n", at,
1939                        old, at->at_current, at->at_current - old, val,
1940                        at->at_hist[0], at->at_hist[1], at->at_hist[2],
1941                        at->at_hist[3]);
1942
1943         /* if we changed, report the old value */
1944         old = (at->at_current != old) ? old : 0;
1945
1946         spin_unlock(&at->at_lock);
1947         return old;
1948 }
1949
1950 /* Find the imp_at index for a given portal; assign if space available */
1951 int import_at_get_index(struct obd_import *imp, int portal)
1952 {
1953         struct imp_at *at = &imp->imp_at;
1954         int i;
1955
1956         for (i = 0; i < IMP_AT_MAX_PORTALS; i++) {
1957                 if (at->iat_portal[i] == portal)
1958                         return i;
1959                 if (at->iat_portal[i] == 0)
1960                         /* unused */
1961                         break;
1962         }
1963
1964         /* Not found in list, add it under a lock */
1965         spin_lock(&imp->imp_lock);
1966
1967         /* Check unused under lock */
1968         for (; i < IMP_AT_MAX_PORTALS; i++) {
1969                 if (at->iat_portal[i] == portal)
1970                         goto out;
1971                 if (at->iat_portal[i] == 0)
1972                         /* unused */
1973                         break;
1974         }
1975
1976         /* Not enough portals? */
1977         LASSERT(i < IMP_AT_MAX_PORTALS);
1978
1979         at->iat_portal[i] = portal;
1980 out:
1981         spin_unlock(&imp->imp_lock);
1982         return i;
1983 }