drivers/staging/lustre/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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2015, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/ptlrpc/import.c
  37  *
  38  * Author: Mike Shaver <shaver@clusterfs.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_RPC
  42
  43 #include "../include/obd_support.h"
  44 #include "../include/lustre_ha.h"
  45 #include "../include/lustre_net.h"
  46 #include "../include/lustre_import.h"
  47 #include "../include/lustre_export.h"
  48 #include "../include/obd.h"
  49 #include "../include/obd_cksum.h"
  50 #include "../include/obd_class.h"
  51
  52 #include "ptlrpc_internal.h"
  53
  54 struct ptlrpc_connect_async_args {
  55          __u64 pcaa_peer_committed;
  56         int pcaa_initial_connect;
  57 };
  58
  59 /**
  60  * Updates import \a imp current state to provided \a state value
  61  * Helper function. Must be called under imp_lock.
  62  */
  63 static void __import_set_state(struct obd_import *imp,
  64                                enum lustre_imp_state state)
  65 {
  66         switch (state) {
  67         case LUSTRE_IMP_CLOSED:
  68         case LUSTRE_IMP_NEW:
  69         case LUSTRE_IMP_DISCON:
  70         case LUSTRE_IMP_CONNECTING:
  71                 break;
  72         case LUSTRE_IMP_REPLAY_WAIT:
  73                 imp->imp_replay_state = LUSTRE_IMP_REPLAY_LOCKS;
  74                 break;
  75         default:
  76                 imp->imp_replay_state = LUSTRE_IMP_REPLAY;
  77         }
  78
  79         imp->imp_state = state;
  80         imp->imp_state_hist[imp->imp_state_hist_idx].ish_state = state;
  81         imp->imp_state_hist[imp->imp_state_hist_idx].ish_time =
  82                 ktime_get_real_seconds();
  83         imp->imp_state_hist_idx = (imp->imp_state_hist_idx + 1) %
  84                 IMP_STATE_HIST_LEN;
  85 }
  86
  87 /* A CLOSED import should remain so. */
  88 #define IMPORT_SET_STATE_NOLOCK(imp, state)                                    \
  89 do {                                                                           \
  90         if (imp->imp_state != LUSTRE_IMP_CLOSED) {                             \
  91                 CDEBUG(D_HA, "%p %s: changing import state from %s to %s\n",   \
  92                        imp, obd2cli_tgt(imp->imp_obd),                         \
  93                        ptlrpc_import_state_name(imp->imp_state),               \
  94                        ptlrpc_import_state_name(state));                       \
  95                 __import_set_state(imp, state);                                \
  96         }                                                                      \
  97 } while (0)
  98
  99 #define IMPORT_SET_STATE(imp, state)                                    \
 100 do {                                                                    \
 101         spin_lock(&imp->imp_lock);                                      \
 102         IMPORT_SET_STATE_NOLOCK(imp, state);                            \
 103         spin_unlock(&imp->imp_lock);                                    \
 104 } while (0)
 105
 106 static int ptlrpc_connect_interpret(const struct lu_env *env,
 107                                     struct ptlrpc_request *request,
 108                                     void *data, int rc);
 109 int ptlrpc_import_recovery_state_machine(struct obd_import *imp);
 110
 111 /* Only this function is allowed to change the import state when it is
 112  * CLOSED. I would rather refcount the import and free it after
 113  * disconnection like we do with exports. To do that, the client_obd
 114  * will need to save the peer info somewhere other than in the import,
 115  * though.
 116  */
 117 int ptlrpc_init_import(struct obd_import *imp)
 118 {
 119         spin_lock(&imp->imp_lock);
 120
 121         imp->imp_generation++;
 122         imp->imp_state = LUSTRE_IMP_NEW;
 123
 124         spin_unlock(&imp->imp_lock);
 125
 126         return 0;
 127 }
 128 EXPORT_SYMBOL(ptlrpc_init_import);
 129
 130 #define UUID_STR "_UUID"
 131 static void deuuidify(char *uuid, const char *prefix, char **uuid_start,
 132                       int *uuid_len)
 133 {
 134         *uuid_start = !prefix || strncmp(uuid, prefix, strlen(prefix))
 135                 ? uuid : uuid + strlen(prefix);
 136
 137         *uuid_len = strlen(*uuid_start);
 138
 139         if (*uuid_len < strlen(UUID_STR))
 140                 return;
 141
 142         if (!strncmp(*uuid_start + *uuid_len - strlen(UUID_STR),
 143                      UUID_STR, strlen(UUID_STR)))
 144                 *uuid_len -= strlen(UUID_STR);
 145 }
 146
 147 /**
 148  * Returns true if import was FULL, false if import was already not
 149  * connected.
 150  * @imp - import to be disconnected
 151  * @conn_cnt - connection count (epoch) of the request that timed out
 152  *           and caused the disconnection.  In some cases, multiple
 153  *           inflight requests can fail to a single target (e.g. OST
 154  *           bulk requests) and if one has already caused a reconnection
 155  *           (increasing the import->conn_cnt) the older failure should
 156  *           not also cause a reconnection.  If zero it forces a reconnect.
 157  */
 158 int ptlrpc_set_import_discon(struct obd_import *imp, __u32 conn_cnt)
 159 {
 160         int rc = 0;
 161
 162         spin_lock(&imp->imp_lock);
 163
 164         if (imp->imp_state == LUSTRE_IMP_FULL &&
 165             (conn_cnt == 0 || conn_cnt == imp->imp_conn_cnt)) {
 166                 char *target_start;
 167                 int   target_len;
 168
 169                 deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
 170                           &target_start, &target_len);
 171
 172                 if (imp->imp_replayable) {
 173                         LCONSOLE_WARN("%s: Connection to %.*s (at %s) was lost; in progress operations using this service will wait for recovery to complete\n",
 174                                       imp->imp_obd->obd_name, target_len, target_start,
 175                                       libcfs_nid2str(imp->imp_connection->c_peer.nid));
 176                 } else {
 177                         LCONSOLE_ERROR_MSG(0x166, "%s: Connection to %.*s (at %s) was lost; in progress operations using this service will fail\n",
 178                                            imp->imp_obd->obd_name,
 179                                            target_len, target_start,
 180                                            libcfs_nid2str(imp->imp_connection->c_peer.nid));
 181                 }
 182                 IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_DISCON);
 183                 spin_unlock(&imp->imp_lock);
 184
 185                 if (obd_dump_on_timeout)
 186                         libcfs_debug_dumplog();
 187
 188                 obd_import_event(imp->imp_obd, imp, IMP_EVENT_DISCON);
 189                 rc = 1;
 190         } else {
 191                 spin_unlock(&imp->imp_lock);
 192                 CDEBUG(D_HA, "%s: import %p already %s (conn %u, was %u): %s\n",
 193                        imp->imp_client->cli_name, imp,
 194                        (imp->imp_state == LUSTRE_IMP_FULL &&
 195                         imp->imp_conn_cnt > conn_cnt) ?
 196                        "reconnected" : "not connected", imp->imp_conn_cnt,
 197                        conn_cnt, ptlrpc_import_state_name(imp->imp_state));
 198         }
 199
 200         return rc;
 201 }
 202
 203 /*
 204  * This acts as a barrier; all existing requests are rejected, and
 205  * no new requests will be accepted until the import is valid again.
 206  */
 207 void ptlrpc_deactivate_import(struct obd_import *imp)
 208 {
 209         CDEBUG(D_HA, "setting import %s INVALID\n", obd2cli_tgt(imp->imp_obd));
 210
 211         spin_lock(&imp->imp_lock);
 212         imp->imp_invalid = 1;
 213         imp->imp_generation++;
 214         spin_unlock(&imp->imp_lock);
 215
 216         ptlrpc_abort_inflight(imp);
 217         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INACTIVE);
 218 }
 219 EXPORT_SYMBOL(ptlrpc_deactivate_import);
 220
 221 static unsigned int
 222 ptlrpc_inflight_deadline(struct ptlrpc_request *req, time64_t now)
 223 {
 224         long dl;
 225
 226         if (!(((req->rq_phase == RQ_PHASE_RPC) && !req->rq_waiting) ||
 227               (req->rq_phase == RQ_PHASE_BULK) ||
 228               (req->rq_phase == RQ_PHASE_NEW)))
 229                 return 0;
 230
 231         if (req->rq_timedout)
 232                 return 0;
 233
 234         if (req->rq_phase == RQ_PHASE_NEW)
 235                 dl = req->rq_sent;
 236         else
 237                 dl = req->rq_deadline;
 238
 239         if (dl <= now)
 240                 return 0;
 241
 242         return dl - now;
 243 }
 244
 245 static unsigned int ptlrpc_inflight_timeout(struct obd_import *imp)
 246 {
 247         time64_t now = ktime_get_real_seconds();
 248         struct list_head *tmp, *n;
 249         struct ptlrpc_request *req;
 250         unsigned int timeout = 0;
 251
 252         spin_lock(&imp->imp_lock);
 253         list_for_each_safe(tmp, n, &imp->imp_sending_list) {
 254                 req = list_entry(tmp, struct ptlrpc_request, rq_list);
 255                 timeout = max(ptlrpc_inflight_deadline(req, now), timeout);
 256         }
 257         spin_unlock(&imp->imp_lock);
 258         return timeout;
 259 }
 260
 261 /**
 262  * This function will invalidate the import, if necessary, then block
 263  * for all the RPC completions, and finally notify the obd to
 264  * invalidate its state (ie cancel locks, clear pending requests,
 265  * etc).
 266  */
 267 void ptlrpc_invalidate_import(struct obd_import *imp)
 268 {
 269         struct list_head *tmp, *n;
 270         struct ptlrpc_request *req;
 271         struct l_wait_info lwi;
 272         unsigned int timeout;
 273         int rc;
 274
 275         atomic_inc(&imp->imp_inval_count);
 276
 277         if (!imp->imp_invalid || imp->imp_obd->obd_no_recov)
 278                 ptlrpc_deactivate_import(imp);
 279
 280         CFS_FAIL_TIMEOUT(OBD_FAIL_MGS_CONNECT_NET, 3 * cfs_fail_val / 2);
 281         LASSERT(imp->imp_invalid);
 282
 283         /* Wait forever until inflight == 0. We really can't do it another
 284          * way because in some cases we need to wait for very long reply
 285          * unlink. We can't do anything before that because there is really
 286          * no guarantee that some rdma transfer is not in progress right now.
 287          */
 288         do {
 289                 /* Calculate max timeout for waiting on rpcs to error
 290                  * out. Use obd_timeout if calculated value is smaller
 291                  * than it.
 292                  */
 293                 if (!OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_LONG_REPL_UNLINK)) {
 294                         timeout = ptlrpc_inflight_timeout(imp);
 295                         timeout += timeout / 3;
 296
 297                         if (timeout == 0)
 298                                 timeout = obd_timeout;
 299                 } else {
 300                         /* decrease the interval to increase race condition */
 301                         timeout = 1;
 302                 }
 303
 304                 CDEBUG(D_RPCTRACE,
 305                        "Sleeping %d sec for inflight to error out\n",
 306                        timeout);
 307
 308                 /* Wait for all requests to error out and call completion
 309                  * callbacks. Cap it at obd_timeout -- these should all
 310                  * have been locally cancelled by ptlrpc_abort_inflight.
 311                  */
 312                 lwi = LWI_TIMEOUT_INTERVAL(
 313                         cfs_timeout_cap(cfs_time_seconds(timeout)),
 314                         (timeout > 1)?cfs_time_seconds(1):cfs_time_seconds(1)/2,
 315                         NULL, NULL);
 316                 rc = l_wait_event(imp->imp_recovery_waitq,
 317                                   (atomic_read(&imp->imp_inflight) == 0),
 318                                   &lwi);
 319                 if (rc) {
 320                         const char *cli_tgt = obd2cli_tgt(imp->imp_obd);
 321
 322                         CERROR("%s: rc = %d waiting for callback (%d != 0)\n",
 323                                cli_tgt, rc,
 324                                atomic_read(&imp->imp_inflight));
 325
 326                         spin_lock(&imp->imp_lock);
 327                         if (atomic_read(&imp->imp_inflight) == 0) {
 328                                 int count = atomic_read(&imp->imp_unregistering);
 329
 330                                 /* We know that "unregistering" rpcs only can
 331                                  * survive in sending or delaying lists (they
 332                                  * maybe waiting for long reply unlink in
 333                                  * sluggish nets). Let's check this. If there
 334                                  * is no inflight and unregistering != 0, this
 335                                  * is bug.
 336                                  */
 337                                 LASSERTF(count == 0, "Some RPCs are still unregistering: %d\n",
 338                                          count);
 339
 340                                 /* Let's save one loop as soon as inflight have
 341                                  * dropped to zero. No new inflights possible at
 342                                  * this point.
 343                                  */
 344                                 rc = 0;
 345                         } else {
 346                                 list_for_each_safe(tmp, n,
 347                                                    &imp->imp_sending_list) {
 348                                         req = list_entry(tmp,
 349                                                          struct ptlrpc_request,
 350                                                          rq_list);
 351                                         DEBUG_REQ(D_ERROR, req,
 352                                                   "still on sending list");
 353                                 }
 354                                 list_for_each_safe(tmp, n,
 355                                                    &imp->imp_delayed_list) {
 356                                         req = list_entry(tmp,
 357                                                          struct ptlrpc_request,
 358                                                          rq_list);
 359                                         DEBUG_REQ(D_ERROR, req,
 360                                                   "still on delayed list");
 361                                 }
 362
 363                                 CERROR("%s: RPCs in \"%s\" phase found (%d). Network is sluggish? Waiting them to error out.\n",
 364                                        cli_tgt,
 365                                        ptlrpc_phase2str(RQ_PHASE_UNREGISTERING),
 366                                        atomic_read(&imp->
 367                                                    imp_unregistering));
 368                         }
 369                         spin_unlock(&imp->imp_lock);
 370                 }
 371         } while (rc != 0);
 372
 373         /*
 374          * Let's additionally check that no new rpcs added to import in
 375          * "invalidate" state.
 376          */
 377         LASSERT(atomic_read(&imp->imp_inflight) == 0);
 378         obd_import_event(imp->imp_obd, imp, IMP_EVENT_INVALIDATE);
 379         sptlrpc_import_flush_all_ctx(imp);
 380
 381         atomic_dec(&imp->imp_inval_count);
 382         wake_up_all(&imp->imp_recovery_waitq);
 383 }
 384 EXPORT_SYMBOL(ptlrpc_invalidate_import);
 385
 386 /* unset imp_invalid */
 387 void ptlrpc_activate_import(struct obd_import *imp)
 388 {
 389         struct obd_device *obd = imp->imp_obd;
 390
 391         spin_lock(&imp->imp_lock);
 392         if (imp->imp_deactive != 0) {
 393                 spin_unlock(&imp->imp_lock);
 394                 return;
 395         }
 396
 397         imp->imp_invalid = 0;
 398         spin_unlock(&imp->imp_lock);
 399         obd_import_event(obd, imp, IMP_EVENT_ACTIVE);
 400 }
 401 EXPORT_SYMBOL(ptlrpc_activate_import);
 402
 403 static void ptlrpc_pinger_force(struct obd_import *imp)
 404 {
 405         CDEBUG(D_HA, "%s: waking up pinger s:%s\n", obd2cli_tgt(imp->imp_obd),
 406                ptlrpc_import_state_name(imp->imp_state));
 407
 408         spin_lock(&imp->imp_lock);
 409         imp->imp_force_verify = 1;
 410         spin_unlock(&imp->imp_lock);
 411
 412         if (imp->imp_state != LUSTRE_IMP_CONNECTING)
 413                 ptlrpc_pinger_wake_up();
 414 }
 415
 416 void ptlrpc_fail_import(struct obd_import *imp, __u32 conn_cnt)
 417 {
 418         LASSERT(!imp->imp_dlm_fake);
 419
 420         if (ptlrpc_set_import_discon(imp, conn_cnt)) {
 421                 if (!imp->imp_replayable) {
 422                         CDEBUG(D_HA, "import %s@%s for %s not replayable, auto-deactivating\n",
 423                                obd2cli_tgt(imp->imp_obd),
 424                                imp->imp_connection->c_remote_uuid.uuid,
 425                                imp->imp_obd->obd_name);
 426                         ptlrpc_deactivate_import(imp);
 427                 }
 428
 429                 ptlrpc_pinger_force(imp);
 430         }
 431 }
 432 EXPORT_SYMBOL(ptlrpc_fail_import);
 433
 434 int ptlrpc_reconnect_import(struct obd_import *imp)
 435 {
 436         struct l_wait_info lwi;
 437         int secs = cfs_time_seconds(obd_timeout);
 438         int rc;
 439
 440         ptlrpc_pinger_force(imp);
 441
 442         CDEBUG(D_HA, "%s: recovery started, waiting %u seconds\n",
 443                obd2cli_tgt(imp->imp_obd), secs);
 444
 445         lwi = LWI_TIMEOUT(secs, NULL, NULL);
 446         rc = l_wait_event(imp->imp_recovery_waitq,
 447                           !ptlrpc_import_in_recovery(imp), &lwi);
 448         CDEBUG(D_HA, "%s: recovery finished s:%s\n", obd2cli_tgt(imp->imp_obd),
 449                ptlrpc_import_state_name(imp->imp_state));
 450         return rc;
 451 }
 452 EXPORT_SYMBOL(ptlrpc_reconnect_import);
 453
 454 /**
 455  * Connection on import \a imp is changed to another one (if more than one is
 456  * present). We typically chose connection that we have not tried to connect to
 457  * the longest
 458  */
 459 static int import_select_connection(struct obd_import *imp)
 460 {
 461         struct obd_import_conn *imp_conn = NULL, *conn;
 462         struct obd_export *dlmexp;
 463         char *target_start;
 464         int target_len, tried_all = 1;
 465
 466         spin_lock(&imp->imp_lock);
 467
 468         if (list_empty(&imp->imp_conn_list)) {
 469                 CERROR("%s: no connections available\n",
 470                        imp->imp_obd->obd_name);
 471                 spin_unlock(&imp->imp_lock);
 472                 return -EINVAL;
 473         }
 474
 475         list_for_each_entry(conn, &imp->imp_conn_list, oic_item) {
 476                 CDEBUG(D_HA, "%s: connect to NID %s last attempt %llu\n",
 477                        imp->imp_obd->obd_name,
 478                        libcfs_nid2str(conn->oic_conn->c_peer.nid),
 479                        conn->oic_last_attempt);
 480
 481                 /* If we have not tried this connection since
 482                  * the last successful attempt, go with this one
 483                  */
 484                 if ((conn->oic_last_attempt == 0) ||
 485                     cfs_time_beforeq_64(conn->oic_last_attempt,
 486                                         imp->imp_last_success_conn)) {
 487                         imp_conn = conn;
 488                         tried_all = 0;
 489                         break;
 490                 }
 491
 492                 /* If all of the connections have already been tried
 493                  * since the last successful connection; just choose the
 494                  * least recently used
 495                  */
 496                 if (!imp_conn)
 497                         imp_conn = conn;
 498                 else if (cfs_time_before_64(conn->oic_last_attempt,
 499                                             imp_conn->oic_last_attempt))
 500                         imp_conn = conn;
 501         }
 502
 503         /* if not found, simply choose the current one */
 504         if (!imp_conn || imp->imp_force_reconnect) {
 505                 LASSERT(imp->imp_conn_current);
 506                 imp_conn = imp->imp_conn_current;
 507                 tried_all = 0;
 508         }
 509         LASSERT(imp_conn->oic_conn);
 510
 511         /* If we've tried everything, and we're back to the beginning of the
 512          * list, increase our timeout and try again. It will be reset when
 513          * we do finally connect. (FIXME: really we should wait for all network
 514          * state associated with the last connection attempt to drain before
 515          * trying to reconnect on it.)
 516          */
 517         if (tried_all && (imp->imp_conn_list.next == &imp_conn->oic_item)) {
 518                 struct adaptive_timeout *at = &imp->imp_at.iat_net_latency;
 519
 520                 if (at_get(at) < CONNECTION_SWITCH_MAX) {
 521                         at_measured(at, at_get(at) + CONNECTION_SWITCH_INC);
 522                         if (at_get(at) > CONNECTION_SWITCH_MAX)
 523                                 at_reset(at, CONNECTION_SWITCH_MAX);
 524                 }
 525                 LASSERT(imp_conn->oic_last_attempt);
 526                 CDEBUG(D_HA, "%s: tried all connections, increasing latency to %ds\n",
 527                        imp->imp_obd->obd_name, at_get(at));
 528         }
 529
 530         imp_conn->oic_last_attempt = cfs_time_current_64();
 531
 532         /* switch connection, don't mind if it's same as the current one */
 533         ptlrpc_connection_put(imp->imp_connection);
 534         imp->imp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
 535
 536         dlmexp = class_conn2export(&imp->imp_dlm_handle);
 537         ptlrpc_connection_put(dlmexp->exp_connection);
 538         dlmexp->exp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
 539         class_export_put(dlmexp);
 540
 541         if (imp->imp_conn_current != imp_conn) {
 542                 if (imp->imp_conn_current) {
 543                         deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
 544                                   &target_start, &target_len);
 545
 546                         CDEBUG(D_HA, "%s: Connection changing to %.*s (at %s)\n",
 547                                imp->imp_obd->obd_name,
 548                                target_len, target_start,
 549                                libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
 550                 }
 551
 552                 imp->imp_conn_current = imp_conn;
 553         }
 554
 555         CDEBUG(D_HA, "%s: import %p using connection %s/%s\n",
 556                imp->imp_obd->obd_name, imp, imp_conn->oic_uuid.uuid,
 557                libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
 558
 559         spin_unlock(&imp->imp_lock);
 560
 561         return 0;
 562 }
 563
 564 /*
 565  * must be called under imp_lock
 566  */
 567 static int ptlrpc_first_transno(struct obd_import *imp, __u64 *transno)
 568 {
 569         struct ptlrpc_request *req;
 570         struct list_head *tmp;
 571
 572         /* The requests in committed_list always have smaller transnos than
 573          * the requests in replay_list
 574          */
 575         if (!list_empty(&imp->imp_committed_list)) {
 576                 tmp = imp->imp_committed_list.next;
 577                 req = list_entry(tmp, struct ptlrpc_request, rq_replay_list);
 578                 *transno = req->rq_transno;
 579                 if (req->rq_transno == 0) {
 580                         DEBUG_REQ(D_ERROR, req,
 581                                   "zero transno in committed_list");
 582                         LBUG();
 583                 }
 584                 return 1;
 585         }
 586         if (!list_empty(&imp->imp_replay_list)) {
 587                 tmp = imp->imp_replay_list.next;
 588                 req = list_entry(tmp, struct ptlrpc_request, rq_replay_list);
 589                 *transno = req->rq_transno;
 590                 if (req->rq_transno == 0) {
 591                         DEBUG_REQ(D_ERROR, req, "zero transno in replay_list");
 592                         LBUG();
 593                 }
 594                 return 1;
 595         }
 596         return 0;
 597 }
 598
 599 /**
 600  * Attempt to (re)connect import \a imp. This includes all preparations,
 601  * initializing CONNECT RPC request and passing it to ptlrpcd for
 602  * actual sending.
 603  * Returns 0 on success or error code.
 604  */
 605 int ptlrpc_connect_import(struct obd_import *imp)
 606 {
 607         struct obd_device *obd = imp->imp_obd;
 608         int initial_connect = 0;
 609         int set_transno = 0;
 610         __u64 committed_before_reconnect = 0;
 611         struct ptlrpc_request *request;
 612         char *bufs[] = { NULL,
 613                          obd2cli_tgt(imp->imp_obd),
 614                          obd->obd_uuid.uuid,
 615                          (char *)&imp->imp_dlm_handle,
 616                          (char *)&imp->imp_connect_data };
 617         struct ptlrpc_connect_async_args *aa;
 618         int rc;
 619
 620         spin_lock(&imp->imp_lock);
 621         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
 622                 spin_unlock(&imp->imp_lock);
 623                 CERROR("can't connect to a closed import\n");
 624                 return -EINVAL;
 625         } else if (imp->imp_state == LUSTRE_IMP_FULL) {
 626                 spin_unlock(&imp->imp_lock);
 627                 CERROR("already connected\n");
 628                 return 0;
 629         } else if (imp->imp_state == LUSTRE_IMP_CONNECTING) {
 630                 spin_unlock(&imp->imp_lock);
 631                 CERROR("already connecting\n");
 632                 return -EALREADY;
 633         }
 634
 635         IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_CONNECTING);
 636
 637         imp->imp_conn_cnt++;
 638         imp->imp_resend_replay = 0;
 639
 640         if (!lustre_handle_is_used(&imp->imp_remote_handle))
 641                 initial_connect = 1;
 642         else
 643                 committed_before_reconnect = imp->imp_peer_committed_transno;
 644
 645         set_transno = ptlrpc_first_transno(imp,
 646                                            &imp->imp_connect_data.ocd_transno);
 647         spin_unlock(&imp->imp_lock);
 648
 649         rc = import_select_connection(imp);
 650         if (rc)
 651                 goto out;
 652
 653         rc = sptlrpc_import_sec_adapt(imp, NULL, NULL);
 654         if (rc)
 655                 goto out;
 656
 657         /* Reset connect flags to the originally requested flags, in case
 658          * the server is updated on-the-fly we will get the new features.
 659          */
 660         imp->imp_connect_data.ocd_connect_flags = imp->imp_connect_flags_orig;
 661         /* Reset ocd_version each time so the server knows the exact versions */
 662         imp->imp_connect_data.ocd_version = LUSTRE_VERSION_CODE;
 663         imp->imp_msghdr_flags &= ~MSGHDR_AT_SUPPORT;
 664         imp->imp_msghdr_flags &= ~MSGHDR_CKSUM_INCOMPAT18;
 665
 666         rc = obd_reconnect(NULL, imp->imp_obd->obd_self_export, obd,
 667                            &obd->obd_uuid, &imp->imp_connect_data, NULL);
 668         if (rc)
 669                 goto out;
 670
 671         request = ptlrpc_request_alloc(imp, &RQF_MDS_CONNECT);
 672         if (!request) {
 673                 rc = -ENOMEM;
 674                 goto out;
 675         }
 676
 677         rc = ptlrpc_request_bufs_pack(request, LUSTRE_OBD_VERSION,
 678                                       imp->imp_connect_op, bufs, NULL);
 679         if (rc) {
 680                 ptlrpc_request_free(request);
 681                 goto out;
 682         }
 683
 684         /* Report the rpc service time to the server so that it knows how long
 685          * to wait for clients to join recovery
 686          */
 687         lustre_msg_set_service_time(request->rq_reqmsg,
 688                                     at_timeout2est(request->rq_timeout));
 689
 690         /* The amount of time we give the server to process the connect req.
 691          * import_select_connection will increase the net latency on
 692          * repeated reconnect attempts to cover slow networks.
 693          * We override/ignore the server rpc completion estimate here,
 694          * which may be large if this is a reconnect attempt
 695          */
 696         request->rq_timeout = INITIAL_CONNECT_TIMEOUT;
 697         lustre_msg_set_timeout(request->rq_reqmsg, request->rq_timeout);
 698
 699         lustre_msg_add_op_flags(request->rq_reqmsg, MSG_CONNECT_NEXT_VER);
 700
 701         request->rq_no_resend = request->rq_no_delay = 1;
 702         request->rq_send_state = LUSTRE_IMP_CONNECTING;
 703         /* Allow a slightly larger reply for future growth compatibility */
 704         req_capsule_set_size(&request->rq_pill, &RMF_CONNECT_DATA, RCL_SERVER,
 705                              sizeof(struct obd_connect_data)+16*sizeof(__u64));
 706         ptlrpc_request_set_replen(request);
 707         request->rq_interpret_reply = ptlrpc_connect_interpret;
 708
 709         CLASSERT(sizeof(*aa) <= sizeof(request->rq_async_args));
 710         aa = ptlrpc_req_async_args(request);
 711         memset(aa, 0, sizeof(*aa));
 712
 713         aa->pcaa_peer_committed = committed_before_reconnect;
 714         aa->pcaa_initial_connect = initial_connect;
 715
 716         if (aa->pcaa_initial_connect) {
 717                 spin_lock(&imp->imp_lock);
 718                 imp->imp_replayable = 1;
 719                 spin_unlock(&imp->imp_lock);
 720                 lustre_msg_add_op_flags(request->rq_reqmsg,
 721                                         MSG_CONNECT_INITIAL);
 722         }
 723
 724         if (set_transno)
 725                 lustre_msg_add_op_flags(request->rq_reqmsg,
 726                                         MSG_CONNECT_TRANSNO);
 727
 728         DEBUG_REQ(D_RPCTRACE, request, "(re)connect request (timeout %d)",
 729                   request->rq_timeout);
 730         ptlrpcd_add_req(request);
 731         rc = 0;
 732 out:
 733         if (rc != 0)
 734                 IMPORT_SET_STATE(imp, LUSTRE_IMP_DISCON);
 735
 736         return rc;
 737 }
 738 EXPORT_SYMBOL(ptlrpc_connect_import);
 739
 740 static void ptlrpc_maybe_ping_import_soon(struct obd_import *imp)
 741 {
 742         int force_verify;
 743
 744         spin_lock(&imp->imp_lock);
 745         force_verify = imp->imp_force_verify != 0;
 746         spin_unlock(&imp->imp_lock);
 747
 748         if (force_verify)
 749                 ptlrpc_pinger_wake_up();
 750 }
 751
 752 static int ptlrpc_busy_reconnect(int rc)
 753 {
 754         return (rc == -EBUSY) || (rc == -EAGAIN);
 755 }
 756
 757 /**
 758  * interpret_reply callback for connect RPCs.
 759  * Looks into returned status of connect operation and decides
 760  * what to do with the import - i.e enter recovery, promote it to
 761  * full state for normal operations of disconnect it due to an error.
 762  */
 763 static int ptlrpc_connect_interpret(const struct lu_env *env,
 764                                     struct ptlrpc_request *request,
 765                                     void *data, int rc)
 766 {
 767         struct ptlrpc_connect_async_args *aa = data;
 768         struct obd_import *imp = request->rq_import;
 769         struct client_obd *cli = &imp->imp_obd->u.cli;
 770         struct lustre_handle old_hdl;
 771         __u64 old_connect_flags;
 772         int msg_flags;
 773         struct obd_connect_data *ocd;
 774         struct obd_export *exp;
 775         int ret;
 776
 777         spin_lock(&imp->imp_lock);
 778         if (imp->imp_state == LUSTRE_IMP_CLOSED) {
 779                 imp->imp_connect_tried = 1;
 780                 spin_unlock(&imp->imp_lock);
 781                 return 0;
 782         }
 783
 784         if (rc) {
 785                 /* if this reconnect to busy export - not need select new target
 786                  * for connecting
 787                  */
 788                 imp->imp_force_reconnect = ptlrpc_busy_reconnect(rc);
 789                 spin_unlock(&imp->imp_lock);
 790                 ptlrpc_maybe_ping_import_soon(imp);
 791                 goto out;
 792         }
 793         spin_unlock(&imp->imp_lock);
 794
 795         LASSERT(imp->imp_conn_current);
 796
 797         msg_flags = lustre_msg_get_op_flags(request->rq_repmsg);
 798
 799         ret = req_capsule_get_size(&request->rq_pill, &RMF_CONNECT_DATA,
 800                                    RCL_SERVER);
 801         /* server replied obd_connect_data is always bigger */
 802         ocd = req_capsule_server_sized_get(&request->rq_pill,
 803                                            &RMF_CONNECT_DATA, ret);
 804
 805         if (!ocd) {
 806                 CERROR("%s: no connect data from server\n",
 807                        imp->imp_obd->obd_name);
 808                 rc = -EPROTO;
 809                 goto out;
 810         }
 811
 812         spin_lock(&imp->imp_lock);
 813
 814         /* All imports are pingable */
 815         imp->imp_pingable = 1;
 816         imp->imp_force_reconnect = 0;
 817         imp->imp_force_verify = 0;
 818
 819         imp->imp_connect_data = *ocd;
 820
 821         CDEBUG(D_HA, "%s: connect to target with instance %u\n",
 822                imp->imp_obd->obd_name, ocd->ocd_instance);
 823         exp = class_conn2export(&imp->imp_dlm_handle);
 824
 825         spin_unlock(&imp->imp_lock);
 826
 827         /* check that server granted subset of flags we asked for. */
 828         if ((ocd->ocd_connect_flags & imp->imp_connect_flags_orig) !=
 829             ocd->ocd_connect_flags) {
 830                 CERROR("%s: Server didn't granted asked subset of flags: asked=%#llx grranted=%#llx\n",
 831                        imp->imp_obd->obd_name, imp->imp_connect_flags_orig,
 832                        ocd->ocd_connect_flags);
 833                 rc = -EPROTO;
 834                 goto out;
 835         }
 836
 837         if (!exp) {
 838                 /* This could happen if export is cleaned during the
 839                  * connect attempt
 840                  */
 841                 CERROR("%s: missing export after connect\n",
 842                        imp->imp_obd->obd_name);
 843                 rc = -ENODEV;
 844                 goto out;
 845         }
 846         old_connect_flags = exp_connect_flags(exp);
 847         exp->exp_connect_data = *ocd;
 848         imp->imp_obd->obd_self_export->exp_connect_data = *ocd;
 849         class_export_put(exp);
 850
 851         obd_import_event(imp->imp_obd, imp, IMP_EVENT_OCD);
 852
 853         if (aa->pcaa_initial_connect) {
 854                 spin_lock(&imp->imp_lock);
 855                 if (msg_flags & MSG_CONNECT_REPLAYABLE) {
 856                         imp->imp_replayable = 1;
 857                         spin_unlock(&imp->imp_lock);
 858                         CDEBUG(D_HA, "connected to replayable target: %s\n",
 859                                obd2cli_tgt(imp->imp_obd));
 860                 } else {
 861                         imp->imp_replayable = 0;
 862                         spin_unlock(&imp->imp_lock);
 863                 }
 864
 865                 /* if applies, adjust the imp->imp_msg_magic here
 866                  * according to reply flags
 867                  */
 868
 869                 imp->imp_remote_handle =
 870                                 *lustre_msg_get_handle(request->rq_repmsg);
 871
 872                 /* Initial connects are allowed for clients with non-random
 873                  * uuids when servers are in recovery.  Simply signal the
 874                  * servers replay is complete and wait in REPLAY_WAIT.
 875                  */
 876                 if (msg_flags & MSG_CONNECT_RECOVERING) {
 877                         CDEBUG(D_HA, "connect to %s during recovery\n",
 878                                obd2cli_tgt(imp->imp_obd));
 879                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY_LOCKS);
 880                 } else {
 881                         IMPORT_SET_STATE(imp, LUSTRE_IMP_FULL);
 882                         ptlrpc_activate_import(imp);
 883                 }
 884
 885                 rc = 0;
 886                 goto finish;
 887         }
 888
 889         /* Determine what recovery state to move the import to. */
 890         if (msg_flags & MSG_CONNECT_RECONNECT) {
 891                 memset(&old_hdl, 0, sizeof(old_hdl));
 892                 if (!memcmp(&old_hdl, lustre_msg_get_handle(request->rq_repmsg),
 893                             sizeof(old_hdl))) {
 894                         LCONSOLE_WARN("Reconnect to %s (at @%s) failed due bad handle %#llx\n",
 895                                       obd2cli_tgt(imp->imp_obd),
 896                                       imp->imp_connection->c_remote_uuid.uuid,
 897                                       imp->imp_dlm_handle.cookie);
 898                         rc = -ENOTCONN;
 899                         goto out;
 900                 }
 901
 902                 if (memcmp(&imp->imp_remote_handle,
 903                            lustre_msg_get_handle(request->rq_repmsg),
 904                            sizeof(imp->imp_remote_handle))) {
 905                         int level = msg_flags & MSG_CONNECT_RECOVERING ?
 906                                 D_HA : D_WARNING;
 907
 908                         /* Bug 16611/14775: if server handle have changed,
 909                          * that means some sort of disconnection happened.
 910                          * If the server is not in recovery, that also means it
 911                          * already erased all of our state because of previous
 912                          * eviction. If it is in recovery - we are safe to
 913                          * participate since we can reestablish all of our state
 914                          * with server again
 915                          */
 916                         if ((msg_flags & MSG_CONNECT_RECOVERING)) {
 917                                 CDEBUG(level, "%s@%s changed server handle from %#llx to %#llx but is still in recovery\n",
 918                                        obd2cli_tgt(imp->imp_obd),
 919                                        imp->imp_connection->c_remote_uuid.uuid,
 920                                        imp->imp_remote_handle.cookie,
 921                                        lustre_msg_get_handle(
 922                                        request->rq_repmsg)->cookie);
 923                         } else {
 924                                 LCONSOLE_WARN("Evicted from %s (at %s) after server handle changed from %#llx to %#llx\n",
 925                                               obd2cli_tgt(imp->imp_obd),
 926                                               imp->imp_connection-> \
 927                                               c_remote_uuid.uuid,
 928                                               imp->imp_remote_handle.cookie,
 929                                               lustre_msg_get_handle(
 930                                                       request->rq_repmsg)->cookie);
 931                         }
 932
 933                         imp->imp_remote_handle =
 934                                      *lustre_msg_get_handle(request->rq_repmsg);
 935
 936                         if (!(msg_flags & MSG_CONNECT_RECOVERING)) {
 937                                 IMPORT_SET_STATE(imp, LUSTRE_IMP_EVICTED);
 938                                 rc = 0;
 939                                 goto finish;
 940                         }
 941
 942                 } else {
 943                         CDEBUG(D_HA, "reconnected to %s@%s after partition\n",
 944                                obd2cli_tgt(imp->imp_obd),
 945                                imp->imp_connection->c_remote_uuid.uuid);
 946                 }
 947
 948                 if (imp->imp_invalid) {
 949                         CDEBUG(D_HA, "%s: reconnected but import is invalid; marking evicted\n",
 950                                imp->imp_obd->obd_name);
 951                         IMPORT_SET_STATE(imp, LUSTRE_IMP_EVICTED);
 952                 } else if (msg_flags & MSG_CONNECT_RECOVERING) {
 953                         CDEBUG(D_HA, "%s: reconnected to %s during replay\n",
 954                                imp->imp_obd->obd_name,
 955                                obd2cli_tgt(imp->imp_obd));
 956
 957                         spin_lock(&imp->imp_lock);
 958                         imp->imp_resend_replay = 1;
 959                         spin_unlock(&imp->imp_lock);
 960
 961                         IMPORT_SET_STATE(imp, imp->imp_replay_state);
 962                 } else {
 963                         IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
 964                 }
 965         } else if ((msg_flags & MSG_CONNECT_RECOVERING) && !imp->imp_invalid) {
 966                 LASSERT(imp->imp_replayable);
 967                 imp->imp_remote_handle =
 968                                 *lustre_msg_get_handle(request->rq_repmsg);
 969                 imp->imp_last_replay_transno = 0;
 970                 IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY);
 971         } else {
 972                 DEBUG_REQ(D_HA, request, "%s: evicting (reconnect/recover flags not set: %x)",
 973                           imp->imp_obd->obd_name, msg_flags);
 974                 imp->imp_remote_handle =
 975                                 *lustre_msg_get_handle(request->rq_repmsg);
 976                 IMPORT_SET_STATE(imp, LUSTRE_IMP_EVICTED);
 977         }
 978
 979         /* Sanity checks for a reconnected import. */
 980         if (!(imp->imp_replayable) != !(msg_flags & MSG_CONNECT_REPLAYABLE)) {
 981                 CERROR("imp_replayable flag does not match server after reconnect. We should LBUG right here.\n");
 982         }
 983
 984         if (lustre_msg_get_last_committed(request->rq_repmsg) > 0 &&
 985             lustre_msg_get_last_committed(request->rq_repmsg) <
 986             aa->pcaa_peer_committed) {
 987                 CERROR("%s went back in time (transno %lld was previously committed, server now claims %lld)!  See https://bugzilla.lustre.org/show_bug.cgi?id=9646\n",
 988                        obd2cli_tgt(imp->imp_obd), aa->pcaa_peer_committed,
 989                        lustre_msg_get_last_committed(request->rq_repmsg));
 990         }
 991
 992 finish:
 993         rc = ptlrpc_import_recovery_state_machine(imp);
 994         if (rc != 0) {
 995                 if (rc == -ENOTCONN) {
 996                         CDEBUG(D_HA, "evicted/aborted by %s@%s during recovery; invalidating and reconnecting\n",
 997                                obd2cli_tgt(imp->imp_obd),
 998                                imp->imp_connection->c_remote_uuid.uuid);
 999                         ptlrpc_connect_import(imp);
1000                         imp->imp_connect_tried = 1;
1001                         return 0;
1002                 }
1003         } else {
1004
1005                 spin_lock(&imp->imp_lock);
1006                 list_del(&imp->imp_conn_current->oic_item);
1007                 list_add(&imp->imp_conn_current->oic_item, &imp->imp_conn_list);
1008                 imp->imp_last_success_conn =
1009                         imp->imp_conn_current->oic_last_attempt;
1010
1011                 spin_unlock(&imp->imp_lock);
1012
1013                 if ((imp->imp_connect_flags_orig & OBD_CONNECT_IBITS) &&
1014                     !(ocd->ocd_connect_flags & OBD_CONNECT_IBITS)) {
1015                         LCONSOLE_WARN("%s: MDS %s does not support ibits lock, either very old or invalid: requested %llx, replied %llx\n",
1016                                       imp->imp_obd->obd_name,
1017                                       imp->imp_connection->c_remote_uuid.uuid,
1018                                       imp->imp_connect_flags_orig,
1019                                       ocd->ocd_connect_flags);
1020                         rc = -EPROTO;
1021                         goto out;
1022                 }
1023
1024                 if ((ocd->ocd_connect_flags & OBD_CONNECT_VERSION) &&
1025                     (ocd->ocd_version > LUSTRE_VERSION_CODE +
1026                                         LUSTRE_VERSION_OFFSET_WARN ||
1027                      ocd->ocd_version < LUSTRE_VERSION_CODE -
1028                                         LUSTRE_VERSION_OFFSET_WARN)) {
1029                         /* Sigh, some compilers do not like #ifdef in the middle
1030                          * of macro arguments
1031                          */
1032                         const char *older = "older. Consider upgrading server or downgrading client"
1033                                 ;
1034                         const char *newer = "newer than client version. Consider upgrading client"
1035                                             ;
1036
1037                         LCONSOLE_WARN("Server %s version (%d.%d.%d.%d) is much %s (%s)\n",
1038                                       obd2cli_tgt(imp->imp_obd),
1039                                       OBD_OCD_VERSION_MAJOR(ocd->ocd_version),
1040                                       OBD_OCD_VERSION_MINOR(ocd->ocd_version),
1041                                       OBD_OCD_VERSION_PATCH(ocd->ocd_version),
1042                                       OBD_OCD_VERSION_FIX(ocd->ocd_version),
1043                                       ocd->ocd_version > LUSTRE_VERSION_CODE ?
1044                                       newer : older, LUSTRE_VERSION_STRING);
1045                 }
1046
1047 #if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 2, 50, 0)
1048                 /* Check if server has LU-1252 fix applied to not always swab
1049                  * the IR MNE entries. Do this only once per connection.  This
1050                  * fixup is version-limited, because we don't want to carry the
1051                  * OBD_CONNECT_MNE_SWAB flag around forever, just so long as we
1052                  * need interop with unpatched 2.2 servers.  For newer servers,
1053                  * the client will do MNE swabbing only as needed.  LU-1644
1054                  */
1055                 if (unlikely((ocd->ocd_connect_flags & OBD_CONNECT_VERSION) &&
1056                              !(ocd->ocd_connect_flags & OBD_CONNECT_MNE_SWAB) &&
1057                              OBD_OCD_VERSION_MAJOR(ocd->ocd_version) == 2 &&
1058                              OBD_OCD_VERSION_MINOR(ocd->ocd_version) == 2 &&
1059                              OBD_OCD_VERSION_PATCH(ocd->ocd_version) < 55 &&
1060                              strcmp(imp->imp_obd->obd_type->typ_name,
1061                                     LUSTRE_MGC_NAME) == 0))
1062                         imp->imp_need_mne_swab = 1;
1063                 else /* clear if server was upgraded since last connect */
1064                         imp->imp_need_mne_swab = 0;
1065 #else
1066 #warning "LU-1644: Remove old OBD_CONNECT_MNE_SWAB fixup and imp_need_mne_swab"
1067 #endif
1068
1069                 if (ocd->ocd_connect_flags & OBD_CONNECT_CKSUM) {
1070                         /* We sent to the server ocd_cksum_types with bits set
1071                          * for algorithms we understand. The server masked off
1072                          * the checksum types it doesn't support
1073                          */
1074                         if ((ocd->ocd_cksum_types &
1075                              cksum_types_supported_client()) == 0) {
1076                                 LCONSOLE_WARN("The negotiation of the checksum algorithm to use with server %s failed (%x/%x), disabling checksums\n",
1077                                               obd2cli_tgt(imp->imp_obd),
1078                                               ocd->ocd_cksum_types,
1079                                               cksum_types_supported_client());
1080                                 cli->cl_checksum = 0;
1081                                 cli->cl_supp_cksum_types = OBD_CKSUM_ADLER;
1082                         } else {
1083                                 cli->cl_supp_cksum_types = ocd->ocd_cksum_types;
1084                         }
1085                 } else {
1086                         /* The server does not support OBD_CONNECT_CKSUM.
1087                          * Enforce ADLER for backward compatibility
1088                          */
1089                         cli->cl_supp_cksum_types = OBD_CKSUM_ADLER;
1090                 }
1091                 cli->cl_cksum_type = cksum_type_select(cli->cl_supp_cksum_types);
1092
1093                 if (ocd->ocd_connect_flags & OBD_CONNECT_BRW_SIZE)
1094                         cli->cl_max_pages_per_rpc =
1095                                 min(ocd->ocd_brw_size >> PAGE_CACHE_SHIFT,
1096                                     cli->cl_max_pages_per_rpc);
1097                 else if (imp->imp_connect_op == MDS_CONNECT ||
1098                          imp->imp_connect_op == MGS_CONNECT)
1099                         cli->cl_max_pages_per_rpc = 1;
1100
1101                 /* Reset ns_connect_flags only for initial connect. It might be
1102                  * changed in while using FS and if we reset it in reconnect
1103                  * this leads to losing user settings done before such as
1104                  * disable lru_resize, etc.
1105                  */
1106                 if (old_connect_flags != exp_connect_flags(exp) ||
1107                     aa->pcaa_initial_connect) {
1108                         CDEBUG(D_HA, "%s: Resetting ns_connect_flags to server flags: %#llx\n",
1109                                imp->imp_obd->obd_name, ocd->ocd_connect_flags);
1110                         imp->imp_obd->obd_namespace->ns_connect_flags =
1111                                 ocd->ocd_connect_flags;
1112                         imp->imp_obd->obd_namespace->ns_orig_connect_flags =
1113                                 ocd->ocd_connect_flags;
1114                 }
1115
1116                 if ((ocd->ocd_connect_flags & OBD_CONNECT_AT) &&
1117                     (imp->imp_msg_magic == LUSTRE_MSG_MAGIC_V2))
1118                         /* We need a per-message support flag, because
1119                          * a. we don't know if the incoming connect reply
1120                          *    supports AT or not (in reply_in_callback)
1121                          *    until we unpack it.
1122                          * b. failovered server means export and flags are gone
1123                          *    (in ptlrpc_send_reply).
1124                          * Can only be set when we know AT is supported at
1125                          * both ends
1126                          */
1127                         imp->imp_msghdr_flags |= MSGHDR_AT_SUPPORT;
1128                 else
1129                         imp->imp_msghdr_flags &= ~MSGHDR_AT_SUPPORT;
1130
1131                 if ((ocd->ocd_connect_flags & OBD_CONNECT_FULL20) &&
1132                     (imp->imp_msg_magic == LUSTRE_MSG_MAGIC_V2))
1133                         imp->imp_msghdr_flags |= MSGHDR_CKSUM_INCOMPAT18;
1134                 else
1135                         imp->imp_msghdr_flags &= ~MSGHDR_CKSUM_INCOMPAT18;
1136
1137                 LASSERT((cli->cl_max_pages_per_rpc <= PTLRPC_MAX_BRW_PAGES) &&
1138                         (cli->cl_max_pages_per_rpc > 0));
1139         }
1140
1141 out:
1142         imp->imp_connect_tried = 1;
1143
1144         if (rc != 0) {
1145                 IMPORT_SET_STATE(imp, LUSTRE_IMP_DISCON);
1146                 if (rc == -EACCES) {
1147                         /*
1148                          * Give up trying to reconnect
1149                          * EACCES means client has no permission for connection
1150                          */
1151                         imp->imp_obd->obd_no_recov = 1;
1152                         ptlrpc_deactivate_import(imp);
1153                 }
1154
1155                 if (rc == -EPROTO) {
1156                         struct obd_connect_data *ocd;
1157
1158                         /* reply message might not be ready */
1159                         if (!request->rq_repmsg)
1160                                 return -EPROTO;
1161
1162                         ocd = req_capsule_server_get(&request->rq_pill,
1163                                                      &RMF_CONNECT_DATA);
1164                         if (ocd &&
1165                             (ocd->ocd_connect_flags & OBD_CONNECT_VERSION) &&
1166                             (ocd->ocd_version != LUSTRE_VERSION_CODE)) {
1167                                 /*
1168                                  * Actually servers are only supposed to refuse
1169                                  * connection from liblustre clients, so we
1170                                  * should never see this from VFS context
1171                                  */
1172                                 LCONSOLE_ERROR_MSG(0x16a, "Server %s version (%d.%d.%d.%d) refused connection from this client with an incompatible version (%s).  Client must be recompiled\n",
1173                                                    obd2cli_tgt(imp->imp_obd),
1174                                                    OBD_OCD_VERSION_MAJOR(ocd->ocd_version),
1175                                                    OBD_OCD_VERSION_MINOR(ocd->ocd_version),
1176                                                    OBD_OCD_VERSION_PATCH(ocd->ocd_version),
1177                                                    OBD_OCD_VERSION_FIX(ocd->ocd_version),
1178                                                    LUSTRE_VERSION_STRING);
1179                                 ptlrpc_deactivate_import(imp);
1180                                 IMPORT_SET_STATE(imp, LUSTRE_IMP_CLOSED);
1181                         }
1182                         return -EPROTO;
1183                 }
1184
1185                 ptlrpc_maybe_ping_import_soon(imp);
1186
1187                 CDEBUG(D_HA, "recovery of %s on %s failed (%d)\n",
1188                        obd2cli_tgt(imp->imp_obd),
1189                        (char *)imp->imp_connection->c_remote_uuid.uuid, rc);
1190         }
1191
1192         wake_up_all(&imp->imp_recovery_waitq);
1193         return rc;
1194 }
1195
1196 /**
1197  * interpret callback for "completed replay" RPCs.
1198  * \see signal_completed_replay
1199  */
1200 static int completed_replay_interpret(const struct lu_env *env,
1201                                       struct ptlrpc_request *req,
1202                                       void *data, int rc)
1203 {
1204         atomic_dec(&req->rq_import->imp_replay_inflight);
1205         if (req->rq_status == 0 &&
1206             !req->rq_import->imp_vbr_failed) {
1207                 ptlrpc_import_recovery_state_machine(req->rq_import);
1208         } else {
1209                 if (req->rq_import->imp_vbr_failed) {
1210                         CDEBUG(D_WARNING,
1211                                "%s: version recovery fails, reconnecting\n",
1212                                req->rq_import->imp_obd->obd_name);
1213                 } else {
1214                         CDEBUG(D_HA, "%s: LAST_REPLAY message error: %d, reconnecting\n",
1215                                req->rq_import->imp_obd->obd_name,
1216                                req->rq_status);
1217                 }
1218                 ptlrpc_connect_import(req->rq_import);
1219         }
1220
1221         return 0;
1222 }
1223
1224 /**
1225  * Let server know that we have no requests to replay anymore.
1226  * Achieved by just sending a PING request
1227  */
1228 static int signal_completed_replay(struct obd_import *imp)
1229 {
1230         struct ptlrpc_request *req;
1231
1232         if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_FINISH_REPLAY)))
1233                 return 0;
1234
1235         LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
1236         atomic_inc(&imp->imp_replay_inflight);
1237
1238         req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING, LUSTRE_OBD_VERSION,
1239                                         OBD_PING);
1240         if (!req) {
1241                 atomic_dec(&imp->imp_replay_inflight);
1242                 return -ENOMEM;
1243         }
1244
1245         ptlrpc_request_set_replen(req);
1246         req->rq_send_state = LUSTRE_IMP_REPLAY_WAIT;
1247         lustre_msg_add_flags(req->rq_reqmsg,
1248                              MSG_LOCK_REPLAY_DONE | MSG_REQ_REPLAY_DONE);
1249         if (AT_OFF)
1250                 req->rq_timeout *= 3;
1251         req->rq_interpret_reply = completed_replay_interpret;
1252
1253         ptlrpcd_add_req(req);
1254         return 0;
1255 }
1256
1257 /**
1258  * In kernel code all import invalidation happens in its own
1259  * separate thread, so that whatever application happened to encounter
1260  * a problem could still be killed or otherwise continue
1261  */
1262 static int ptlrpc_invalidate_import_thread(void *data)
1263 {
1264         struct obd_import *imp = data;
1265
1266         unshare_fs_struct();
1267
1268         CDEBUG(D_HA, "thread invalidate import %s to %s@%s\n",
1269                imp->imp_obd->obd_name, obd2cli_tgt(imp->imp_obd),
1270                imp->imp_connection->c_remote_uuid.uuid);
1271
1272         ptlrpc_invalidate_import(imp);
1273
1274         if (obd_dump_on_eviction) {
1275                 CERROR("dump the log upon eviction\n");
1276                 libcfs_debug_dumplog();
1277         }
1278
1279         IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
1280         ptlrpc_import_recovery_state_machine(imp);
1281
1282         class_import_put(imp);
1283         return 0;
1284 }
1285
1286 /**
1287  * This is the state machine for client-side recovery on import.
1288  *
1289  * Typically we have two possibly paths. If we came to server and it is not
1290  * in recovery, we just enter IMP_EVICTED state, invalidate our import
1291  * state and reconnect from scratch.
1292  * If we came to server that is in recovery, we enter IMP_REPLAY import state.
1293  * We go through our list of requests to replay and send them to server one by
1294  * one.
1295  * After sending all request from the list we change import state to
1296  * IMP_REPLAY_LOCKS and re-request all the locks we believe we have from server
1297  * and also all the locks we don't yet have and wait for server to grant us.
1298  * After that we send a special "replay completed" request and change import
1299  * state to IMP_REPLAY_WAIT.
1300  * Upon receiving reply to that "replay completed" RPC we enter IMP_RECOVER
1301  * state and resend all requests from sending list.
1302  * After that we promote import to FULL state and send all delayed requests
1303  * and import is fully operational after that.
1304  *
1305  */
1306 int ptlrpc_import_recovery_state_machine(struct obd_import *imp)
1307 {
1308         int rc = 0;
1309         int inflight;
1310         char *target_start;
1311         int target_len;
1312
1313         if (imp->imp_state == LUSTRE_IMP_EVICTED) {
1314                 deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
1315                           &target_start, &target_len);
1316                 /* Don't care about MGC eviction */
1317                 if (strcmp(imp->imp_obd->obd_type->typ_name,
1318                            LUSTRE_MGC_NAME) != 0) {
1319                         LCONSOLE_ERROR_MSG(0x167, "%s: This client was evicted by %.*s; in progress operations using this service will fail.\n",
1320                                            imp->imp_obd->obd_name, target_len,
1321                                            target_start);
1322                 }
1323                 CDEBUG(D_HA, "evicted from %s@%s; invalidating\n",
1324                        obd2cli_tgt(imp->imp_obd),
1325                        imp->imp_connection->c_remote_uuid.uuid);
1326                 /* reset vbr_failed flag upon eviction */
1327                 spin_lock(&imp->imp_lock);
1328                 imp->imp_vbr_failed = 0;
1329                 spin_unlock(&imp->imp_lock);
1330
1331                 {
1332                 struct task_struct *task;
1333                 /* bug 17802:  XXX client_disconnect_export vs connect request
1334                  * race. if client is evicted at this time, we start
1335                  * invalidate thread without reference to import and import can
1336                  * be freed at same time.
1337                  */
1338                 class_import_get(imp);
1339                 task = kthread_run(ptlrpc_invalidate_import_thread, imp,
1340                                    "ll_imp_inval");
1341                 if (IS_ERR(task)) {
1342                         class_import_put(imp);
1343                         CERROR("error starting invalidate thread: %d\n", rc);
1344                         rc = PTR_ERR(task);
1345                 } else {
1346                         rc = 0;
1347                 }
1348                 return rc;
1349                 }
1350         }
1351
1352         if (imp->imp_state == LUSTRE_IMP_REPLAY) {
1353                 CDEBUG(D_HA, "replay requested by %s\n",
1354                        obd2cli_tgt(imp->imp_obd));
1355                 rc = ptlrpc_replay_next(imp, &inflight);
1356                 if (inflight == 0 &&
1357                     atomic_read(&imp->imp_replay_inflight) == 0) {
1358                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY_LOCKS);
1359                         rc = ldlm_replay_locks(imp);
1360                         if (rc)
1361                                 goto out;
1362                 }
1363                 rc = 0;
1364         }
1365
1366         if (imp->imp_state == LUSTRE_IMP_REPLAY_LOCKS) {
1367                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
1368                         IMPORT_SET_STATE(imp, LUSTRE_IMP_REPLAY_WAIT);
1369                         rc = signal_completed_replay(imp);
1370                         if (rc)
1371                                 goto out;
1372                 }
1373
1374         }
1375
1376         if (imp->imp_state == LUSTRE_IMP_REPLAY_WAIT) {
1377                 if (atomic_read(&imp->imp_replay_inflight) == 0) {
1378                         IMPORT_SET_STATE(imp, LUSTRE_IMP_RECOVER);
1379                 }
1380         }
1381
1382         if (imp->imp_state == LUSTRE_IMP_RECOVER) {
1383                 CDEBUG(D_HA, "reconnected to %s@%s\n",
1384                        obd2cli_tgt(imp->imp_obd),
1385                        imp->imp_connection->c_remote_uuid.uuid);
1386
1387                 rc = ptlrpc_resend(imp);
1388                 if (rc)
1389                         goto out;
1390                 IMPORT_SET_STATE(imp, LUSTRE_IMP_FULL);
1391                 ptlrpc_activate_import(imp);
1392
1393                 deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
1394                           &target_start, &target_len);
1395                 LCONSOLE_INFO("%s: Connection restored to %.*s (at %s)\n",
1396                               imp->imp_obd->obd_name,
1397                               target_len, target_start,
1398                               libcfs_nid2str(imp->imp_connection->c_peer.nid));
1399         }
1400
1401         if (imp->imp_state == LUSTRE_IMP_FULL) {
1402                 wake_up_all(&imp->imp_recovery_waitq);
1403                 ptlrpc_wake_delayed(imp);
1404         }
1405
1406 out:
1407         return rc;
1408 }
1409
1410 int ptlrpc_disconnect_import(struct obd_import *imp, int noclose)
1411 {
1412         struct ptlrpc_request *req;
1413         int rq_opc, rc = 0;
1414
1415         if (imp->imp_obd->obd_force)
1416                 goto set_state;
1417
1418         switch (imp->imp_connect_op) {
1419         case OST_CONNECT:
1420                 rq_opc = OST_DISCONNECT;
1421                 break;
1422         case MDS_CONNECT:
1423                 rq_opc = MDS_DISCONNECT;
1424                 break;
1425         case MGS_CONNECT:
1426                 rq_opc = MGS_DISCONNECT;
1427                 break;
1428         default:
1429                 rc = -EINVAL;
1430                 CERROR("%s: don't know how to disconnect from %s (connect_op %d): rc = %d\n",
1431                        imp->imp_obd->obd_name, obd2cli_tgt(imp->imp_obd),
1432                        imp->imp_connect_op, rc);
1433                 return rc;
1434         }
1435
1436         if (ptlrpc_import_in_recovery(imp)) {
1437                 struct l_wait_info lwi;
1438                 long timeout;
1439
1440                 if (AT_OFF) {
1441                         if (imp->imp_server_timeout)
1442                                 timeout = cfs_time_seconds(obd_timeout / 2);
1443                         else
1444                                 timeout = cfs_time_seconds(obd_timeout);
1445                 } else {
1446                         int idx = import_at_get_index(imp,
1447                                 imp->imp_client->cli_request_portal);
1448                         timeout = cfs_time_seconds(
1449                                 at_get(&imp->imp_at.iat_service_estimate[idx]));
1450                 }
1451
1452                 lwi = LWI_TIMEOUT_INTR(cfs_timeout_cap(timeout),
1453                                        back_to_sleep, LWI_ON_SIGNAL_NOOP, NULL);
1454                 rc = l_wait_event(imp->imp_recovery_waitq,
1455                                   !ptlrpc_import_in_recovery(imp), &lwi);
1456
1457         }
1458
1459         spin_lock(&imp->imp_lock);
1460         if (imp->imp_state != LUSTRE_IMP_FULL)
1461                 goto out;
1462         spin_unlock(&imp->imp_lock);
1463
1464         req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_DISCONNECT,
1465                                         LUSTRE_OBD_VERSION, rq_opc);
1466         if (req) {
1467                 /* We are disconnecting, do not retry a failed DISCONNECT rpc if
1468                  * it fails.  We can get through the above with a down server
1469                  * if the client doesn't know the server is gone yet.
1470                  */
1471                 req->rq_no_resend = 1;
1472
1473                 /* We want client umounts to happen quickly, no matter the
1474                  * server state...
1475                  */
1476                 req->rq_timeout = min_t(int, req->rq_timeout,
1477                                         INITIAL_CONNECT_TIMEOUT);
1478
1479                 IMPORT_SET_STATE(imp, LUSTRE_IMP_CONNECTING);
1480                 req->rq_send_state = LUSTRE_IMP_CONNECTING;
1481                 ptlrpc_request_set_replen(req);
1482                 rc = ptlrpc_queue_wait(req);
1483                 ptlrpc_req_finished(req);
1484         }
1485
1486 set_state:
1487         spin_lock(&imp->imp_lock);
1488 out:
1489         if (noclose)
1490                 IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_DISCON);
1491         else
1492                 IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_CLOSED);
1493         memset(&imp->imp_remote_handle, 0, sizeof(imp->imp_remote_handle));
1494         spin_unlock(&imp->imp_lock);
1495
1496         if (rc == -ETIMEDOUT || rc == -ENOTCONN || rc == -ESHUTDOWN)
1497                 rc = 0;
1498
1499         return rc;
1500 }
1501 EXPORT_SYMBOL(ptlrpc_disconnect_import);
1502
1503 /* Adaptive Timeout utils */
1504 extern unsigned int at_min, at_max, at_history;
1505
1506 /* Bin into timeslices using AT_BINS bins.
1507  * This gives us a max of the last binlimit*AT_BINS secs without the storage,
1508  * but still smoothing out a return to normalcy from a slow response.
1509  * (E.g. remember the maximum latency in each minute of the last 4 minutes.)
1510  */
1511 int at_measured(struct adaptive_timeout *at, unsigned int val)
1512 {
1513         unsigned int old = at->at_current;
1514         time64_t now = ktime_get_real_seconds();
1515         long binlimit = max_t(long, at_history / AT_BINS, 1);
1516
1517         LASSERT(at);
1518         CDEBUG(D_OTHER, "add %u to %p time=%lu v=%u (%u %u %u %u)\n",
1519                val, at, (long)(now - at->at_binstart), at->at_current,
1520                at->at_hist[0], at->at_hist[1], at->at_hist[2], at->at_hist[3]);
1521
1522         if (val == 0)
1523                 /* 0's don't count, because we never want our timeout to
1524                  * drop to 0, and because 0 could mean an error
1525                  */
1526                 return 0;
1527
1528         spin_lock(&at->at_lock);
1529
1530         if (unlikely(at->at_binstart == 0)) {
1531                 /* Special case to remove default from history */
1532                 at->at_current = val;
1533                 at->at_worst_ever = val;
1534                 at->at_worst_time = now;
1535                 at->at_hist[0] = val;
1536                 at->at_binstart = now;
1537         } else if (now - at->at_binstart < binlimit) {
1538                 /* in bin 0 */
1539                 at->at_hist[0] = max(val, at->at_hist[0]);
1540                 at->at_current = max(val, at->at_current);
1541         } else {
1542                 int i, shift;
1543                 unsigned int maxv = val;
1544                 /* move bins over */
1545                 shift = (u32)(now - at->at_binstart) / binlimit;
1546                 LASSERT(shift > 0);
1547                 for (i = AT_BINS - 1; i >= 0; i--) {
1548                         if (i >= shift) {
1549                                 at->at_hist[i] = at->at_hist[i - shift];
1550                                 maxv = max(maxv, at->at_hist[i]);
1551                         } else {
1552                                 at->at_hist[i] = 0;
1553                         }
1554                 }
1555                 at->at_hist[0] = val;
1556                 at->at_current = maxv;
1557                 at->at_binstart += shift * binlimit;
1558         }
1559
1560         if (at->at_current > at->at_worst_ever) {
1561                 at->at_worst_ever = at->at_current;
1562                 at->at_worst_time = now;
1563         }
1564
1565         if (at->at_flags & AT_FLG_NOHIST)
1566                 /* Only keep last reported val; keeping the rest of the history
1567                  * for debugfs only
1568                  */
1569                 at->at_current = val;
1570
1571         if (at_max > 0)
1572                 at->at_current =  min(at->at_current, at_max);
1573         at->at_current =  max(at->at_current, at_min);
1574
1575         if (at->at_current != old)
1576                 CDEBUG(D_OTHER, "AT %p change: old=%u new=%u delta=%d (val=%u) hist %u %u %u %u\n",
1577                        at,
1578                        old, at->at_current, at->at_current - old, val,
1579                        at->at_hist[0], at->at_hist[1], at->at_hist[2],
1580                        at->at_hist[3]);
1581
1582         /* if we changed, report the old value */
1583         old = (at->at_current != old) ? old : 0;
1584
1585         spin_unlock(&at->at_lock);
1586         return old;
1587 }
1588
1589 /* Find the imp_at index for a given portal; assign if space available */
1590 int import_at_get_index(struct obd_import *imp, int portal)
1591 {
1592         struct imp_at *at = &imp->imp_at;
1593         int i;
1594
1595         for (i = 0; i < IMP_AT_MAX_PORTALS; i++) {
1596                 if (at->iat_portal[i] == portal)
1597                         return i;
1598                 if (at->iat_portal[i] == 0)
1599                         /* unused */
1600                         break;
1601         }
1602
1603         /* Not found in list, add it under a lock */
1604         spin_lock(&imp->imp_lock);
1605
1606         /* Check unused under lock */
1607         for (; i < IMP_AT_MAX_PORTALS; i++) {
1608                 if (at->iat_portal[i] == portal)
1609                         goto out;
1610                 if (at->iat_portal[i] == 0)
1611                         /* unused */
1612                         break;
1613         }
1614
1615         /* Not enough portals? */
1616         LASSERT(i < IMP_AT_MAX_PORTALS);
1617
1618         at->iat_portal[i] = portal;
1619 out:
1620         spin_unlock(&imp->imp_lock);
1621         return i;
1622 }