fs/dlm/member.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) 2005-2011 Red Hat, Inc.  All rights reserved.
   5 **
   6 **  This copyrighted material is made available to anyone wishing to use,
   7 **  modify, copy, or redistribute it subject to the terms and conditions
   8 **  of the GNU General Public License v.2.
   9 **
  10 *******************************************************************************
  11 ******************************************************************************/
  12
  13 #include "dlm_internal.h"
  14 #include "lockspace.h"
  15 #include "member.h"
  16 #include "recoverd.h"
  17 #include "recover.h"
  18 #include "rcom.h"
  19 #include "config.h"
  20 #include "lowcomms.h"
  21
  22 int dlm_slots_version(struct dlm_header *h)
  23 {
  24         if ((h->h_version & 0x0000FFFF) < DLM_HEADER_SLOTS)
  25                 return 0;
  26         return 1;
  27 }
  28
  29 void dlm_slot_save(struct dlm_ls *ls, struct dlm_rcom *rc,
  30                    struct dlm_member *memb)
  31 {
  32         struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
  33
  34         if (!dlm_slots_version(&rc->rc_header))
  35                 return;
  36
  37         memb->slot = le16_to_cpu(rf->rf_our_slot);
  38         memb->generation = le32_to_cpu(rf->rf_generation);
  39 }
  40
  41 void dlm_slots_copy_out(struct dlm_ls *ls, struct dlm_rcom *rc)
  42 {
  43         struct dlm_slot *slot;
  44         struct rcom_slot *ro;
  45         int i;
  46
  47         ro = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
  48
  49         /* ls_slots array is sparse, but not rcom_slots */
  50
  51         for (i = 0; i < ls->ls_slots_size; i++) {
  52                 slot = &ls->ls_slots[i];
  53                 if (!slot->nodeid)
  54                         continue;
  55                 ro->ro_nodeid = cpu_to_le32(slot->nodeid);
  56                 ro->ro_slot = cpu_to_le16(slot->slot);
  57                 ro++;
  58         }
  59 }
  60
  61 #define SLOT_DEBUG_LINE 128
  62
  63 static void log_slots(struct dlm_ls *ls, uint32_t gen, int num_slots,
  64                       struct rcom_slot *ro0, struct dlm_slot *array,
  65                       int array_size)
  66 {
  67         char line[SLOT_DEBUG_LINE];
  68         int len = SLOT_DEBUG_LINE - 1;
  69         int pos = 0;
  70         int ret, i;
  71
  72         memset(line, 0, sizeof(line));
  73
  74         if (array) {
  75                 for (i = 0; i < array_size; i++) {
  76                         if (!array[i].nodeid)
  77                                 continue;
  78
  79                         ret = snprintf(line + pos, len - pos, " %d:%d",
  80                                        array[i].slot, array[i].nodeid);
  81                         if (ret >= len - pos)
  82                                 break;
  83                         pos += ret;
  84                 }
  85         } else if (ro0) {
  86                 for (i = 0; i < num_slots; i++) {
  87                         ret = snprintf(line + pos, len - pos, " %d:%d",
  88                                        ro0[i].ro_slot, ro0[i].ro_nodeid);
  89                         if (ret >= len - pos)
  90                                 break;
  91                         pos += ret;
  92                 }
  93         }
  94
  95         log_rinfo(ls, "generation %u slots %d%s", gen, num_slots, line);
  96 }
  97
  98 int dlm_slots_copy_in(struct dlm_ls *ls)
  99 {
 100         struct dlm_member *memb;
 101         struct dlm_rcom *rc = ls->ls_recover_buf;
 102         struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
 103         struct rcom_slot *ro0, *ro;
 104         int our_nodeid = dlm_our_nodeid();
 105         int i, num_slots;
 106         uint32_t gen;
 107
 108         if (!dlm_slots_version(&rc->rc_header))
 109                 return -1;
 110
 111         gen = le32_to_cpu(rf->rf_generation);
 112         if (gen <= ls->ls_generation) {
 113                 log_error(ls, "dlm_slots_copy_in gen %u old %u",
 114                           gen, ls->ls_generation);
 115         }
 116         ls->ls_generation = gen;
 117
 118         num_slots = le16_to_cpu(rf->rf_num_slots);
 119         if (!num_slots)
 120                 return -1;
 121
 122         ro0 = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
 123
 124         for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
 125                 ro->ro_nodeid = le32_to_cpu(ro->ro_nodeid);
 126                 ro->ro_slot = le16_to_cpu(ro->ro_slot);
 127         }
 128
 129         log_slots(ls, gen, num_slots, ro0, NULL, 0);
 130
 131         list_for_each_entry(memb, &ls->ls_nodes, list) {
 132                 for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
 133                         if (ro->ro_nodeid != memb->nodeid)
 134                                 continue;
 135                         memb->slot = ro->ro_slot;
 136                         memb->slot_prev = memb->slot;
 137                         break;
 138                 }
 139
 140                 if (memb->nodeid == our_nodeid) {
 141                         if (ls->ls_slot && ls->ls_slot != memb->slot) {
 142                                 log_error(ls, "dlm_slots_copy_in our slot "
 143                                           "changed %d %d", ls->ls_slot,
 144                                           memb->slot);
 145                                 return -1;
 146                         }
 147
 148                         if (!ls->ls_slot)
 149                                 ls->ls_slot = memb->slot;
 150                 }
 151
 152                 if (!memb->slot) {
 153                         log_error(ls, "dlm_slots_copy_in nodeid %d no slot",
 154                                    memb->nodeid);
 155                         return -1;
 156                 }
 157         }
 158
 159         return 0;
 160 }
 161
 162 /* for any nodes that do not support slots, we will not have set memb->slot
 163    in wait_status_all(), so memb->slot will remain -1, and we will not
 164    assign slots or set ls_num_slots here */
 165
 166 int dlm_slots_assign(struct dlm_ls *ls, int *num_slots, int *slots_size,
 167                      struct dlm_slot **slots_out, uint32_t *gen_out)
 168 {
 169         struct dlm_member *memb;
 170         struct dlm_slot *array;
 171         int our_nodeid = dlm_our_nodeid();
 172         int array_size, max_slots, i;
 173         int need = 0;
 174         int max = 0;
 175         int num = 0;
 176         uint32_t gen = 0;
 177
 178         /* our own memb struct will have slot -1 gen 0 */
 179
 180         list_for_each_entry(memb, &ls->ls_nodes, list) {
 181                 if (memb->nodeid == our_nodeid) {
 182                         memb->slot = ls->ls_slot;
 183                         memb->generation = ls->ls_generation;
 184                         break;
 185                 }
 186         }
 187
 188         list_for_each_entry(memb, &ls->ls_nodes, list) {
 189                 if (memb->generation > gen)
 190                         gen = memb->generation;
 191
 192                 /* node doesn't support slots */
 193
 194                 if (memb->slot == -1)
 195                         return -1;
 196
 197                 /* node needs a slot assigned */
 198
 199                 if (!memb->slot)
 200                         need++;
 201
 202                 /* node has a slot assigned */
 203
 204                 num++;
 205
 206                 if (!max || max < memb->slot)
 207                         max = memb->slot;
 208
 209                 /* sanity check, once slot is assigned it shouldn't change */
 210
 211                 if (memb->slot_prev && memb->slot && memb->slot_prev != memb->slot) {
 212                         log_error(ls, "nodeid %d slot changed %d %d",
 213                                   memb->nodeid, memb->slot_prev, memb->slot);
 214                         return -1;
 215                 }
 216                 memb->slot_prev = memb->slot;
 217         }
 218
 219         array_size = max + need;
 220
 221         array = kzalloc(array_size * sizeof(struct dlm_slot), GFP_NOFS);
 222         if (!array)
 223                 return -ENOMEM;
 224
 225         num = 0;
 226
 227         /* fill in slots (offsets) that are used */
 228
 229         list_for_each_entry(memb, &ls->ls_nodes, list) {
 230                 if (!memb->slot)
 231                         continue;
 232
 233                 if (memb->slot > array_size) {
 234                         log_error(ls, "invalid slot number %d", memb->slot);
 235                         kfree(array);
 236                         return -1;
 237                 }
 238
 239                 array[memb->slot - 1].nodeid = memb->nodeid;
 240                 array[memb->slot - 1].slot = memb->slot;
 241                 num++;
 242         }
 243
 244         /* assign new slots from unused offsets */
 245
 246         list_for_each_entry(memb, &ls->ls_nodes, list) {
 247                 if (memb->slot)
 248                         continue;
 249
 250                 for (i = 0; i < array_size; i++) {
 251                         if (array[i].nodeid)
 252                                 continue;
 253
 254                         memb->slot = i + 1;
 255                         memb->slot_prev = memb->slot;
 256                         array[i].nodeid = memb->nodeid;
 257                         array[i].slot = memb->slot;
 258                         num++;
 259
 260                         if (!ls->ls_slot && memb->nodeid == our_nodeid)
 261                                 ls->ls_slot = memb->slot;
 262                         break;
 263                 }
 264
 265                 if (!memb->slot) {
 266                         log_error(ls, "no free slot found");
 267                         kfree(array);
 268                         return -1;
 269                 }
 270         }
 271
 272         gen++;
 273
 274         log_slots(ls, gen, num, NULL, array, array_size);
 275
 276         max_slots = (dlm_config.ci_buffer_size - sizeof(struct dlm_rcom) -
 277                      sizeof(struct rcom_config)) / sizeof(struct rcom_slot);
 278
 279         if (num > max_slots) {
 280                 log_error(ls, "num_slots %d exceeds max_slots %d",
 281                           num, max_slots);
 282                 kfree(array);
 283                 return -1;
 284         }
 285
 286         *gen_out = gen;
 287         *slots_out = array;
 288         *slots_size = array_size;
 289         *num_slots = num;
 290         return 0;
 291 }
 292
 293 static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
 294 {
 295         struct dlm_member *memb = NULL;
 296         struct list_head *tmp;
 297         struct list_head *newlist = &new->list;
 298         struct list_head *head = &ls->ls_nodes;
 299
 300         list_for_each(tmp, head) {
 301                 memb = list_entry(tmp, struct dlm_member, list);
 302                 if (new->nodeid < memb->nodeid)
 303                         break;
 304         }
 305
 306         if (!memb)
 307                 list_add_tail(newlist, head);
 308         else {
 309                 /* FIXME: can use list macro here */
 310                 newlist->prev = tmp->prev;
 311                 newlist->next = tmp;
 312                 tmp->prev->next = newlist;
 313                 tmp->prev = newlist;
 314         }
 315 }
 316
 317 static int dlm_add_member(struct dlm_ls *ls, struct dlm_config_node *node)
 318 {
 319         struct dlm_member *memb;
 320         int error;
 321
 322         memb = kzalloc(sizeof(struct dlm_member), GFP_NOFS);
 323         if (!memb)
 324                 return -ENOMEM;
 325
 326         error = dlm_lowcomms_connect_node(node->nodeid);
 327         if (error < 0) {
 328                 kfree(memb);
 329                 return error;
 330         }
 331
 332         memb->nodeid = node->nodeid;
 333         memb->weight = node->weight;
 334         memb->comm_seq = node->comm_seq;
 335         add_ordered_member(ls, memb);
 336         ls->ls_num_nodes++;
 337         return 0;
 338 }
 339
 340 static struct dlm_member *find_memb(struct list_head *head, int nodeid)
 341 {
 342         struct dlm_member *memb;
 343
 344         list_for_each_entry(memb, head, list) {
 345                 if (memb->nodeid == nodeid)
 346                         return memb;
 347         }
 348         return NULL;
 349 }
 350
 351 int dlm_is_member(struct dlm_ls *ls, int nodeid)
 352 {
 353         if (find_memb(&ls->ls_nodes, nodeid))
 354                 return 1;
 355         return 0;
 356 }
 357
 358 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
 359 {
 360         if (find_memb(&ls->ls_nodes_gone, nodeid))
 361                 return 1;
 362         return 0;
 363 }
 364
 365 static void clear_memb_list(struct list_head *head)
 366 {
 367         struct dlm_member *memb;
 368
 369         while (!list_empty(head)) {
 370                 memb = list_entry(head->next, struct dlm_member, list);
 371                 list_del(&memb->list);
 372                 kfree(memb);
 373         }
 374 }
 375
 376 void dlm_clear_members(struct dlm_ls *ls)
 377 {
 378         clear_memb_list(&ls->ls_nodes);
 379         ls->ls_num_nodes = 0;
 380 }
 381
 382 void dlm_clear_members_gone(struct dlm_ls *ls)
 383 {
 384         clear_memb_list(&ls->ls_nodes_gone);
 385 }
 386
 387 static void make_member_array(struct dlm_ls *ls)
 388 {
 389         struct dlm_member *memb;
 390         int i, w, x = 0, total = 0, all_zero = 0, *array;
 391
 392         kfree(ls->ls_node_array);
 393         ls->ls_node_array = NULL;
 394
 395         list_for_each_entry(memb, &ls->ls_nodes, list) {
 396                 if (memb->weight)
 397                         total += memb->weight;
 398         }
 399
 400         /* all nodes revert to weight of 1 if all have weight 0 */
 401
 402         if (!total) {
 403                 total = ls->ls_num_nodes;
 404                 all_zero = 1;
 405         }
 406
 407         ls->ls_total_weight = total;
 408
 409         array = kmalloc(sizeof(int) * total, GFP_NOFS);
 410         if (!array)
 411                 return;
 412
 413         list_for_each_entry(memb, &ls->ls_nodes, list) {
 414                 if (!all_zero && !memb->weight)
 415                         continue;
 416
 417                 if (all_zero)
 418                         w = 1;
 419                 else
 420                         w = memb->weight;
 421
 422                 DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
 423
 424                 for (i = 0; i < w; i++)
 425                         array[x++] = memb->nodeid;
 426         }
 427
 428         ls->ls_node_array = array;
 429 }
 430
 431 /* send a status request to all members just to establish comms connections */
 432
 433 static int ping_members(struct dlm_ls *ls)
 434 {
 435         struct dlm_member *memb;
 436         int error = 0;
 437
 438         list_for_each_entry(memb, &ls->ls_nodes, list) {
 439                 error = dlm_recovery_stopped(ls);
 440                 if (error)
 441                         break;
 442                 error = dlm_rcom_status(ls, memb->nodeid, 0);
 443                 if (error)
 444                         break;
 445         }
 446         if (error)
 447                 log_rinfo(ls, "ping_members aborted %d last nodeid %d",
 448                           error, ls->ls_recover_nodeid);
 449         return error;
 450 }
 451
 452 static void dlm_lsop_recover_prep(struct dlm_ls *ls)
 453 {
 454         if (!ls->ls_ops || !ls->ls_ops->recover_prep)
 455                 return;
 456         ls->ls_ops->recover_prep(ls->ls_ops_arg);
 457 }
 458
 459 static void dlm_lsop_recover_slot(struct dlm_ls *ls, struct dlm_member *memb)
 460 {
 461         struct dlm_slot slot;
 462         uint32_t seq;
 463         int error;
 464
 465         if (!ls->ls_ops || !ls->ls_ops->recover_slot)
 466                 return;
 467
 468         /* if there is no comms connection with this node
 469            or the present comms connection is newer
 470            than the one when this member was added, then
 471            we consider the node to have failed (versus
 472            being removed due to dlm_release_lockspace) */
 473
 474         error = dlm_comm_seq(memb->nodeid, &seq);
 475
 476         if (!error && seq == memb->comm_seq)
 477                 return;
 478
 479         slot.nodeid = memb->nodeid;
 480         slot.slot = memb->slot;
 481
 482         ls->ls_ops->recover_slot(ls->ls_ops_arg, &slot);
 483 }
 484
 485 void dlm_lsop_recover_done(struct dlm_ls *ls)
 486 {
 487         struct dlm_member *memb;
 488         struct dlm_slot *slots;
 489         int i, num;
 490
 491         if (!ls->ls_ops || !ls->ls_ops->recover_done)
 492                 return;
 493
 494         num = ls->ls_num_nodes;
 495
 496         slots = kzalloc(num * sizeof(struct dlm_slot), GFP_KERNEL);
 497         if (!slots)
 498                 return;
 499
 500         i = 0;
 501         list_for_each_entry(memb, &ls->ls_nodes, list) {
 502                 if (i == num) {
 503                         log_error(ls, "dlm_lsop_recover_done bad num %d", num);
 504                         goto out;
 505                 }
 506                 slots[i].nodeid = memb->nodeid;
 507                 slots[i].slot = memb->slot;
 508                 i++;
 509         }
 510
 511         ls->ls_ops->recover_done(ls->ls_ops_arg, slots, num,
 512                                  ls->ls_slot, ls->ls_generation);
 513  out:
 514         kfree(slots);
 515 }
 516
 517 static struct dlm_config_node *find_config_node(struct dlm_recover *rv,
 518                                                 int nodeid)
 519 {
 520         int i;
 521
 522         for (i = 0; i < rv->nodes_count; i++) {
 523                 if (rv->nodes[i].nodeid == nodeid)
 524                         return &rv->nodes[i];
 525         }
 526         return NULL;
 527 }
 528
 529 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 530 {
 531         struct dlm_member *memb, *safe;
 532         struct dlm_config_node *node;
 533         int i, error, neg = 0, low = -1;
 534
 535         /* previously removed members that we've not finished removing need to
 536            count as a negative change so the "neg" recovery steps will happen */
 537
 538         list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
 539                 log_rinfo(ls, "prev removed member %d", memb->nodeid);
 540                 neg++;
 541         }
 542
 543         /* move departed members from ls_nodes to ls_nodes_gone */
 544
 545         list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
 546                 node = find_config_node(rv, memb->nodeid);
 547                 if (node && !node->new)
 548                         continue;
 549
 550                 if (!node) {
 551                         log_rinfo(ls, "remove member %d", memb->nodeid);
 552                 } else {
 553                         /* removed and re-added */
 554                         log_rinfo(ls, "remove member %d comm_seq %u %u",
 555                                   memb->nodeid, memb->comm_seq, node->comm_seq);
 556                 }
 557
 558                 neg++;
 559                 list_move(&memb->list, &ls->ls_nodes_gone);
 560                 ls->ls_num_nodes--;
 561                 dlm_lsop_recover_slot(ls, memb);
 562         }
 563
 564         /* add new members to ls_nodes */
 565
 566         for (i = 0; i < rv->nodes_count; i++) {
 567                 node = &rv->nodes[i];
 568                 if (dlm_is_member(ls, node->nodeid))
 569                         continue;
 570                 dlm_add_member(ls, node);
 571                 log_rinfo(ls, "add member %d", node->nodeid);
 572         }
 573
 574         list_for_each_entry(memb, &ls->ls_nodes, list) {
 575                 if (low == -1 || memb->nodeid < low)
 576                         low = memb->nodeid;
 577         }
 578         ls->ls_low_nodeid = low;
 579
 580         make_member_array(ls);
 581         *neg_out = neg;
 582
 583         error = ping_members(ls);
 584         if (!error || error == -EPROTO) {
 585                 /* new_lockspace() may be waiting to know if the config
 586                    is good or bad */
 587                 ls->ls_members_result = error;
 588                 complete(&ls->ls_members_done);
 589         }
 590
 591         log_rinfo(ls, "dlm_recover_members %d nodes", ls->ls_num_nodes);
 592         return error;
 593 }
 594
 595 /* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
 596    dlm_ls_start() is called on any of them to start the new recovery. */
 597
 598 int dlm_ls_stop(struct dlm_ls *ls)
 599 {
 600         int new;
 601
 602         /*
 603          * Prevent dlm_recv from being in the middle of something when we do
 604          * the stop.  This includes ensuring dlm_recv isn't processing a
 605          * recovery message (rcom), while dlm_recoverd is aborting and
 606          * resetting things from an in-progress recovery.  i.e. we want
 607          * dlm_recoverd to abort its recovery without worrying about dlm_recv
 608          * processing an rcom at the same time.  Stopping dlm_recv also makes
 609          * it easy for dlm_receive_message() to check locking stopped and add a
 610          * message to the requestqueue without races.
 611          */
 612
 613         down_write(&ls->ls_recv_active);
 614
 615         /*
 616          * Abort any recovery that's in progress (see RECOVER_STOP,
 617          * dlm_recovery_stopped()) and tell any other threads running in the
 618          * dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
 619          */
 620
 621         spin_lock(&ls->ls_recover_lock);
 622         set_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
 623         new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
 624         ls->ls_recover_seq++;
 625         spin_unlock(&ls->ls_recover_lock);
 626
 627         /*
 628          * Let dlm_recv run again, now any normal messages will be saved on the
 629          * requestqueue for later.
 630          */
 631
 632         up_write(&ls->ls_recv_active);
 633
 634         /*
 635          * This in_recovery lock does two things:
 636          * 1) Keeps this function from returning until all threads are out
 637          *    of locking routines and locking is truly stopped.
 638          * 2) Keeps any new requests from being processed until it's unlocked
 639          *    when recovery is complete.
 640          */
 641
 642         if (new) {
 643                 set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags);
 644                 wake_up_process(ls->ls_recoverd_task);
 645                 wait_event(ls->ls_recover_lock_wait,
 646                            test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
 647         }
 648
 649         /*
 650          * The recoverd suspend/resume makes sure that dlm_recoverd (if
 651          * running) has noticed RECOVER_STOP above and quit processing the
 652          * previous recovery.
 653          */
 654
 655         dlm_recoverd_suspend(ls);
 656
 657         spin_lock(&ls->ls_recover_lock);
 658         kfree(ls->ls_slots);
 659         ls->ls_slots = NULL;
 660         ls->ls_num_slots = 0;
 661         ls->ls_slots_size = 0;
 662         ls->ls_recover_status = 0;
 663         spin_unlock(&ls->ls_recover_lock);
 664
 665         dlm_recoverd_resume(ls);
 666
 667         if (!ls->ls_recover_begin)
 668                 ls->ls_recover_begin = jiffies;
 669
 670         dlm_lsop_recover_prep(ls);
 671         return 0;
 672 }
 673
 674 int dlm_ls_start(struct dlm_ls *ls)
 675 {
 676         struct dlm_recover *rv = NULL, *rv_old;
 677         struct dlm_config_node *nodes;
 678         int error, count;
 679
 680         rv = kzalloc(sizeof(struct dlm_recover), GFP_NOFS);
 681         if (!rv)
 682                 return -ENOMEM;
 683
 684         error = dlm_config_nodes(ls->ls_name, &nodes, &count);
 685         if (error < 0)
 686                 goto fail;
 687
 688         spin_lock(&ls->ls_recover_lock);
 689
 690         /* the lockspace needs to be stopped before it can be started */
 691
 692         if (!dlm_locking_stopped(ls)) {
 693                 spin_unlock(&ls->ls_recover_lock);
 694                 log_error(ls, "start ignored: lockspace running");
 695                 error = -EINVAL;
 696                 goto fail;
 697         }
 698
 699         rv->nodes = nodes;
 700         rv->nodes_count = count;
 701         rv->seq = ++ls->ls_recover_seq;
 702         rv_old = ls->ls_recover_args;
 703         ls->ls_recover_args = rv;
 704         spin_unlock(&ls->ls_recover_lock);
 705
 706         if (rv_old) {
 707                 log_error(ls, "unused recovery %llx %d",
 708                           (unsigned long long)rv_old->seq, rv_old->nodes_count);
 709                 kfree(rv_old->nodes);
 710                 kfree(rv_old);
 711         }
 712
 713         set_bit(LSFL_RECOVER_WORK, &ls->ls_flags);
 714         wake_up_process(ls->ls_recoverd_task);
 715         return 0;
 716
 717  fail:
 718         kfree(rv);
 719         kfree(nodes);
 720         return error;
 721 }
 722