fs/dlm/recover.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /******************************************************************************
   3 *******************************************************************************
   4 **
   5 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   6 **  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   7 **
   8 **
   9 *******************************************************************************
  10 ******************************************************************************/
  11
  12 #include "dlm_internal.h"
  13 #include "lockspace.h"
  14 #include "dir.h"
  15 #include "config.h"
  16 #include "ast.h"
  17 #include "memory.h"
  18 #include "rcom.h"
  19 #include "lock.h"
  20 #include "lowcomms.h"
  21 #include "member.h"
  22 #include "recover.h"
  23
  24
  25 /*
  26  * Recovery waiting routines: these functions wait for a particular reply from
  27  * a remote node, or for the remote node to report a certain status.  They need
  28  * to abort if the lockspace is stopped indicating a node has failed (perhaps
  29  * the one being waited for).
  30  */
  31
  32 /*
  33  * Wait until given function returns non-zero or lockspace is stopped
  34  * (LS_RECOVERY_STOP set due to failure of a node in ls_nodes).  When another
  35  * function thinks it could have completed the waited-on task, they should wake
  36  * up ls_wait_general to get an immediate response rather than waiting for the
  37  * timeout.  This uses a timeout so it can check periodically if the wait
  38  * should abort due to node failure (which doesn't cause a wake_up).
  39  * This should only be called by the dlm_recoverd thread.
  40  */
  41
  42 int dlm_wait_function(struct dlm_ls *ls, int (*testfn) (struct dlm_ls *ls))
  43 {
  44         int error = 0;
  45         int rv;
  46
  47         while (1) {
  48                 rv = wait_event_timeout(ls->ls_wait_general,
  49                                         testfn(ls) || dlm_recovery_stopped(ls),
  50                                         dlm_config.ci_recover_timer * HZ);
  51                 if (rv)
  52                         break;
  53                 if (test_bit(LSFL_RCOM_WAIT, &ls->ls_flags)) {
  54                         log_debug(ls, "dlm_wait_function timed out");
  55                         return -ETIMEDOUT;
  56                 }
  57         }
  58
  59         if (dlm_recovery_stopped(ls)) {
  60                 log_debug(ls, "dlm_wait_function aborted");
  61                 error = -EINTR;
  62         }
  63         return error;
  64 }
  65
  66 /*
  67  * An efficient way for all nodes to wait for all others to have a certain
  68  * status.  The node with the lowest nodeid polls all the others for their
  69  * status (wait_status_all) and all the others poll the node with the low id
  70  * for its accumulated result (wait_status_low).  When all nodes have set
  71  * status flag X, then status flag X_ALL will be set on the low nodeid.
  72  */
  73
  74 uint32_t dlm_recover_status(struct dlm_ls *ls)
  75 {
  76         uint32_t status;
  77         spin_lock(&ls->ls_recover_lock);
  78         status = ls->ls_recover_status;
  79         spin_unlock(&ls->ls_recover_lock);
  80         return status;
  81 }
  82
  83 static void _set_recover_status(struct dlm_ls *ls, uint32_t status)
  84 {
  85         ls->ls_recover_status |= status;
  86 }
  87
  88 void dlm_set_recover_status(struct dlm_ls *ls, uint32_t status)
  89 {
  90         spin_lock(&ls->ls_recover_lock);
  91         _set_recover_status(ls, status);
  92         spin_unlock(&ls->ls_recover_lock);
  93 }
  94
  95 static int wait_status_all(struct dlm_ls *ls, uint32_t wait_status,
  96                            int save_slots, uint64_t seq)
  97 {
  98         struct dlm_rcom *rc = ls->ls_recover_buf;
  99         struct dlm_member *memb;
 100         int error = 0, delay;
 101
 102         list_for_each_entry(memb, &ls->ls_nodes, list) {
 103                 delay = 0;
 104                 for (;;) {
 105                         if (dlm_recovery_stopped(ls)) {
 106                                 error = -EINTR;
 107                                 goto out;
 108                         }
 109
 110                         error = dlm_rcom_status(ls, memb->nodeid, 0, seq);
 111                         if (error)
 112                                 goto out;
 113
 114                         if (save_slots)
 115                                 dlm_slot_save(ls, rc, memb);
 116
 117                         if (le32_to_cpu(rc->rc_result) & wait_status)
 118                                 break;
 119                         if (delay < 1000)
 120                                 delay += 20;
 121                         msleep(delay);
 122                 }
 123         }
 124  out:
 125         return error;
 126 }
 127
 128 static int wait_status_low(struct dlm_ls *ls, uint32_t wait_status,
 129                            uint32_t status_flags, uint64_t seq)
 130 {
 131         struct dlm_rcom *rc = ls->ls_recover_buf;
 132         int error = 0, delay = 0, nodeid = ls->ls_low_nodeid;
 133
 134         for (;;) {
 135                 if (dlm_recovery_stopped(ls)) {
 136                         error = -EINTR;
 137                         goto out;
 138                 }
 139
 140                 error = dlm_rcom_status(ls, nodeid, status_flags, seq);
 141                 if (error)
 142                         break;
 143
 144                 if (le32_to_cpu(rc->rc_result) & wait_status)
 145                         break;
 146                 if (delay < 1000)
 147                         delay += 20;
 148                 msleep(delay);
 149         }
 150  out:
 151         return error;
 152 }
 153
 154 static int wait_status(struct dlm_ls *ls, uint32_t status, uint64_t seq)
 155 {
 156         uint32_t status_all = status << 1;
 157         int error;
 158
 159         if (ls->ls_low_nodeid == dlm_our_nodeid()) {
 160                 error = wait_status_all(ls, status, 0, seq);
 161                 if (!error)
 162                         dlm_set_recover_status(ls, status_all);
 163         } else
 164                 error = wait_status_low(ls, status_all, 0, seq);
 165
 166         return error;
 167 }
 168
 169 int dlm_recover_members_wait(struct dlm_ls *ls, uint64_t seq)
 170 {
 171         struct dlm_member *memb;
 172         struct dlm_slot *slots;
 173         int num_slots, slots_size;
 174         int error, rv;
 175         uint32_t gen;
 176
 177         list_for_each_entry(memb, &ls->ls_nodes, list) {
 178                 memb->slot = -1;
 179                 memb->generation = 0;
 180         }
 181
 182         if (ls->ls_low_nodeid == dlm_our_nodeid()) {
 183                 error = wait_status_all(ls, DLM_RS_NODES, 1, seq);
 184                 if (error)
 185                         goto out;
 186
 187                 /* slots array is sparse, slots_size may be > num_slots */
 188
 189                 rv = dlm_slots_assign(ls, &num_slots, &slots_size, &slots, &gen);
 190                 if (!rv) {
 191                         spin_lock(&ls->ls_recover_lock);
 192                         _set_recover_status(ls, DLM_RS_NODES_ALL);
 193                         ls->ls_num_slots = num_slots;
 194                         ls->ls_slots_size = slots_size;
 195                         ls->ls_slots = slots;
 196                         ls->ls_generation = gen;
 197                         spin_unlock(&ls->ls_recover_lock);
 198                 } else {
 199                         dlm_set_recover_status(ls, DLM_RS_NODES_ALL);
 200                 }
 201         } else {
 202                 error = wait_status_low(ls, DLM_RS_NODES_ALL,
 203                                         DLM_RSF_NEED_SLOTS, seq);
 204                 if (error)
 205                         goto out;
 206
 207                 dlm_slots_copy_in(ls);
 208         }
 209  out:
 210         return error;
 211 }
 212
 213 int dlm_recover_directory_wait(struct dlm_ls *ls, uint64_t seq)
 214 {
 215         return wait_status(ls, DLM_RS_DIR, seq);
 216 }
 217
 218 int dlm_recover_locks_wait(struct dlm_ls *ls, uint64_t seq)
 219 {
 220         return wait_status(ls, DLM_RS_LOCKS, seq);
 221 }
 222
 223 int dlm_recover_done_wait(struct dlm_ls *ls, uint64_t seq)
 224 {
 225         return wait_status(ls, DLM_RS_DONE, seq);
 226 }
 227
 228 /*
 229  * The recover_list contains all the rsb's for which we've requested the new
 230  * master nodeid.  As replies are returned from the resource directories the
 231  * rsb's are removed from the list.  When the list is empty we're done.
 232  *
 233  * The recover_list is later similarly used for all rsb's for which we've sent
 234  * new lkb's and need to receive new corresponding lkid's.
 235  *
 236  * We use the address of the rsb struct as a simple local identifier for the
 237  * rsb so we can match an rcom reply with the rsb it was sent for.
 238  */
 239
 240 static int recover_list_empty(struct dlm_ls *ls)
 241 {
 242         int empty;
 243
 244         spin_lock(&ls->ls_recover_list_lock);
 245         empty = list_empty(&ls->ls_recover_list);
 246         spin_unlock(&ls->ls_recover_list_lock);
 247
 248         return empty;
 249 }
 250
 251 static void recover_list_add(struct dlm_rsb *r)
 252 {
 253         struct dlm_ls *ls = r->res_ls;
 254
 255         spin_lock(&ls->ls_recover_list_lock);
 256         if (list_empty(&r->res_recover_list)) {
 257                 list_add_tail(&r->res_recover_list, &ls->ls_recover_list);
 258                 ls->ls_recover_list_count++;
 259                 dlm_hold_rsb(r);
 260         }
 261         spin_unlock(&ls->ls_recover_list_lock);
 262 }
 263
 264 static void recover_list_del(struct dlm_rsb *r)
 265 {
 266         struct dlm_ls *ls = r->res_ls;
 267
 268         spin_lock(&ls->ls_recover_list_lock);
 269         list_del_init(&r->res_recover_list);
 270         ls->ls_recover_list_count--;
 271         spin_unlock(&ls->ls_recover_list_lock);
 272
 273         dlm_put_rsb(r);
 274 }
 275
 276 static void recover_list_clear(struct dlm_ls *ls)
 277 {
 278         struct dlm_rsb *r, *s;
 279
 280         spin_lock(&ls->ls_recover_list_lock);
 281         list_for_each_entry_safe(r, s, &ls->ls_recover_list, res_recover_list) {
 282                 list_del_init(&r->res_recover_list);
 283                 r->res_recover_locks_count = 0;
 284                 dlm_put_rsb(r);
 285                 ls->ls_recover_list_count--;
 286         }
 287
 288         if (ls->ls_recover_list_count != 0) {
 289                 log_error(ls, "warning: recover_list_count %d",
 290                           ls->ls_recover_list_count);
 291                 ls->ls_recover_list_count = 0;
 292         }
 293         spin_unlock(&ls->ls_recover_list_lock);
 294 }
 295
 296 static int recover_idr_empty(struct dlm_ls *ls)
 297 {
 298         int empty = 1;
 299
 300         spin_lock(&ls->ls_recover_idr_lock);
 301         if (ls->ls_recover_list_count)
 302                 empty = 0;
 303         spin_unlock(&ls->ls_recover_idr_lock);
 304
 305         return empty;
 306 }
 307
 308 static int recover_idr_add(struct dlm_rsb *r)
 309 {
 310         struct dlm_ls *ls = r->res_ls;
 311         int rv;
 312
 313         idr_preload(GFP_NOFS);
 314         spin_lock(&ls->ls_recover_idr_lock);
 315         if (r->res_id) {
 316                 rv = -1;
 317                 goto out_unlock;
 318         }
 319         rv = idr_alloc(&ls->ls_recover_idr, r, 1, 0, GFP_NOWAIT);
 320         if (rv < 0)
 321                 goto out_unlock;
 322
 323         r->res_id = rv;
 324         ls->ls_recover_list_count++;
 325         dlm_hold_rsb(r);
 326         rv = 0;
 327 out_unlock:
 328         spin_unlock(&ls->ls_recover_idr_lock);
 329         idr_preload_end();
 330         return rv;
 331 }
 332
 333 static void recover_idr_del(struct dlm_rsb *r)
 334 {
 335         struct dlm_ls *ls = r->res_ls;
 336
 337         spin_lock(&ls->ls_recover_idr_lock);
 338         idr_remove(&ls->ls_recover_idr, r->res_id);
 339         r->res_id = 0;
 340         ls->ls_recover_list_count--;
 341         spin_unlock(&ls->ls_recover_idr_lock);
 342
 343         dlm_put_rsb(r);
 344 }
 345
 346 static struct dlm_rsb *recover_idr_find(struct dlm_ls *ls, uint64_t id)
 347 {
 348         struct dlm_rsb *r;
 349
 350         spin_lock(&ls->ls_recover_idr_lock);
 351         r = idr_find(&ls->ls_recover_idr, (int)id);
 352         spin_unlock(&ls->ls_recover_idr_lock);
 353         return r;
 354 }
 355
 356 static void recover_idr_clear(struct dlm_ls *ls)
 357 {
 358         struct dlm_rsb *r;
 359         int id;
 360
 361         spin_lock(&ls->ls_recover_idr_lock);
 362
 363         idr_for_each_entry(&ls->ls_recover_idr, r, id) {
 364                 idr_remove(&ls->ls_recover_idr, id);
 365                 r->res_id = 0;
 366                 r->res_recover_locks_count = 0;
 367                 ls->ls_recover_list_count--;
 368
 369                 dlm_put_rsb(r);
 370         }
 371
 372         if (ls->ls_recover_list_count != 0) {
 373                 log_error(ls, "warning: recover_list_count %d",
 374                           ls->ls_recover_list_count);
 375                 ls->ls_recover_list_count = 0;
 376         }
 377         spin_unlock(&ls->ls_recover_idr_lock);
 378 }
 379
 380
 381 /* Master recovery: find new master node for rsb's that were
 382    mastered on nodes that have been removed.
 383
 384    dlm_recover_masters
 385    recover_master
 386    dlm_send_rcom_lookup            ->  receive_rcom_lookup
 387                                        dlm_dir_lookup
 388    receive_rcom_lookup_reply       <-
 389    dlm_recover_master_reply
 390    set_new_master
 391    set_master_lkbs
 392    set_lock_master
 393 */
 394
 395 /*
 396  * Set the lock master for all LKBs in a lock queue
 397  * If we are the new master of the rsb, we may have received new
 398  * MSTCPY locks from other nodes already which we need to ignore
 399  * when setting the new nodeid.
 400  */
 401
 402 static void set_lock_master(struct list_head *queue, int nodeid)
 403 {
 404         struct dlm_lkb *lkb;
 405
 406         list_for_each_entry(lkb, queue, lkb_statequeue) {
 407                 if (!test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags)) {
 408                         lkb->lkb_nodeid = nodeid;
 409                         lkb->lkb_remid = 0;
 410                 }
 411         }
 412 }
 413
 414 static void set_master_lkbs(struct dlm_rsb *r)
 415 {
 416         set_lock_master(&r->res_grantqueue, r->res_nodeid);
 417         set_lock_master(&r->res_convertqueue, r->res_nodeid);
 418         set_lock_master(&r->res_waitqueue, r->res_nodeid);
 419 }
 420
 421 /*
 422  * Propagate the new master nodeid to locks
 423  * The NEW_MASTER flag tells dlm_recover_locks() which rsb's to consider.
 424  * The NEW_MASTER2 flag tells recover_lvb() and recover_grant() which
 425  * rsb's to consider.
 426  */
 427
 428 static void set_new_master(struct dlm_rsb *r)
 429 {
 430         set_master_lkbs(r);
 431         rsb_set_flag(r, RSB_NEW_MASTER);
 432         rsb_set_flag(r, RSB_NEW_MASTER2);
 433 }
 434
 435 /*
 436  * We do async lookups on rsb's that need new masters.  The rsb's
 437  * waiting for a lookup reply are kept on the recover_list.
 438  *
 439  * Another node recovering the master may have sent us a rcom lookup,
 440  * and our dlm_master_lookup() set it as the new master, along with
 441  * NEW_MASTER so that we'll recover it here (this implies dir_nodeid
 442  * equals our_nodeid below).
 443  */
 444
 445 static int recover_master(struct dlm_rsb *r, unsigned int *count, uint64_t seq)
 446 {
 447         struct dlm_ls *ls = r->res_ls;
 448         int our_nodeid, dir_nodeid;
 449         int is_removed = 0;
 450         int error;
 451
 452         if (is_master(r))
 453                 return 0;
 454
 455         is_removed = dlm_is_removed(ls, r->res_nodeid);
 456
 457         if (!is_removed && !rsb_flag(r, RSB_NEW_MASTER))
 458                 return 0;
 459
 460         our_nodeid = dlm_our_nodeid();
 461         dir_nodeid = dlm_dir_nodeid(r);
 462
 463         if (dir_nodeid == our_nodeid) {
 464                 if (is_removed) {
 465                         r->res_master_nodeid = our_nodeid;
 466                         r->res_nodeid = 0;
 467                 }
 468
 469                 /* set master of lkbs to ourself when is_removed, or to
 470                    another new master which we set along with NEW_MASTER
 471                    in dlm_master_lookup */
 472                 set_new_master(r);
 473                 error = 0;
 474         } else {
 475                 recover_idr_add(r);
 476                 error = dlm_send_rcom_lookup(r, dir_nodeid, seq);
 477         }
 478
 479         (*count)++;
 480         return error;
 481 }
 482
 483 /*
 484  * All MSTCPY locks are purged and rebuilt, even if the master stayed the same.
 485  * This is necessary because recovery can be started, aborted and restarted,
 486  * causing the master nodeid to briefly change during the aborted recovery, and
 487  * change back to the original value in the second recovery.  The MSTCPY locks
 488  * may or may not have been purged during the aborted recovery.  Another node
 489  * with an outstanding request in waiters list and a request reply saved in the
 490  * requestqueue, cannot know whether it should ignore the reply and resend the
 491  * request, or accept the reply and complete the request.  It must do the
 492  * former if the remote node purged MSTCPY locks, and it must do the later if
 493  * the remote node did not.  This is solved by always purging MSTCPY locks, in
 494  * which case, the request reply would always be ignored and the request
 495  * resent.
 496  */
 497
 498 static int recover_master_static(struct dlm_rsb *r, unsigned int *count)
 499 {
 500         int dir_nodeid = dlm_dir_nodeid(r);
 501         int new_master = dir_nodeid;
 502
 503         if (dir_nodeid == dlm_our_nodeid())
 504                 new_master = 0;
 505
 506         dlm_purge_mstcpy_locks(r);
 507         r->res_master_nodeid = dir_nodeid;
 508         r->res_nodeid = new_master;
 509         set_new_master(r);
 510         (*count)++;
 511         return 0;
 512 }
 513
 514 /*
 515  * Go through local root resources and for each rsb which has a master which
 516  * has departed, get the new master nodeid from the directory.  The dir will
 517  * assign mastery to the first node to look up the new master.  That means
 518  * we'll discover in this lookup if we're the new master of any rsb's.
 519  *
 520  * We fire off all the dir lookup requests individually and asynchronously to
 521  * the correct dir node.
 522  */
 523
 524 int dlm_recover_masters(struct dlm_ls *ls, uint64_t seq)
 525 {
 526         struct dlm_rsb *r;
 527         unsigned int total = 0;
 528         unsigned int count = 0;
 529         int nodir = dlm_no_directory(ls);
 530         int error;
 531
 532         log_rinfo(ls, "dlm_recover_masters");
 533
 534         down_read(&ls->ls_root_sem);
 535         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
 536                 if (dlm_recovery_stopped(ls)) {
 537                         up_read(&ls->ls_root_sem);
 538                         error = -EINTR;
 539                         goto out;
 540                 }
 541
 542                 lock_rsb(r);
 543                 if (nodir)
 544                         error = recover_master_static(r, &count);
 545                 else
 546                         error = recover_master(r, &count, seq);
 547                 unlock_rsb(r);
 548                 cond_resched();
 549                 total++;
 550
 551                 if (error) {
 552                         up_read(&ls->ls_root_sem);
 553                         goto out;
 554                 }
 555         }
 556         up_read(&ls->ls_root_sem);
 557
 558         log_rinfo(ls, "dlm_recover_masters %u of %u", count, total);
 559
 560         error = dlm_wait_function(ls, &recover_idr_empty);
 561  out:
 562         if (error)
 563                 recover_idr_clear(ls);
 564         return error;
 565 }
 566
 567 int dlm_recover_master_reply(struct dlm_ls *ls, const struct dlm_rcom *rc)
 568 {
 569         struct dlm_rsb *r;
 570         int ret_nodeid, new_master;
 571
 572         r = recover_idr_find(ls, le64_to_cpu(rc->rc_id));
 573         if (!r) {
 574                 log_error(ls, "dlm_recover_master_reply no id %llx",
 575                           (unsigned long long)le64_to_cpu(rc->rc_id));
 576                 goto out;
 577         }
 578
 579         ret_nodeid = le32_to_cpu(rc->rc_result);
 580
 581         if (ret_nodeid == dlm_our_nodeid())
 582                 new_master = 0;
 583         else
 584                 new_master = ret_nodeid;
 585
 586         lock_rsb(r);
 587         r->res_master_nodeid = ret_nodeid;
 588         r->res_nodeid = new_master;
 589         set_new_master(r);
 590         unlock_rsb(r);
 591         recover_idr_del(r);
 592
 593         if (recover_idr_empty(ls))
 594                 wake_up(&ls->ls_wait_general);
 595  out:
 596         return 0;
 597 }
 598
 599
 600 /* Lock recovery: rebuild the process-copy locks we hold on a
 601    remastered rsb on the new rsb master.
 602
 603    dlm_recover_locks
 604    recover_locks
 605    recover_locks_queue
 606    dlm_send_rcom_lock              ->  receive_rcom_lock
 607                                        dlm_recover_master_copy
 608    receive_rcom_lock_reply         <-
 609    dlm_recover_process_copy
 610 */
 611
 612
 613 /*
 614  * keep a count of the number of lkb's we send to the new master; when we get
 615  * an equal number of replies then recovery for the rsb is done
 616  */
 617
 618 static int recover_locks_queue(struct dlm_rsb *r, struct list_head *head,
 619                                uint64_t seq)
 620 {
 621         struct dlm_lkb *lkb;
 622         int error = 0;
 623
 624         list_for_each_entry(lkb, head, lkb_statequeue) {
 625                 error = dlm_send_rcom_lock(r, lkb, seq);
 626                 if (error)
 627                         break;
 628                 r->res_recover_locks_count++;
 629         }
 630
 631         return error;
 632 }
 633
 634 static int recover_locks(struct dlm_rsb *r, uint64_t seq)
 635 {
 636         int error = 0;
 637
 638         lock_rsb(r);
 639
 640         DLM_ASSERT(!r->res_recover_locks_count, dlm_dump_rsb(r););
 641
 642         error = recover_locks_queue(r, &r->res_grantqueue, seq);
 643         if (error)
 644                 goto out;
 645         error = recover_locks_queue(r, &r->res_convertqueue, seq);
 646         if (error)
 647                 goto out;
 648         error = recover_locks_queue(r, &r->res_waitqueue, seq);
 649         if (error)
 650                 goto out;
 651
 652         if (r->res_recover_locks_count)
 653                 recover_list_add(r);
 654         else
 655                 rsb_clear_flag(r, RSB_NEW_MASTER);
 656  out:
 657         unlock_rsb(r);
 658         return error;
 659 }
 660
 661 int dlm_recover_locks(struct dlm_ls *ls, uint64_t seq)
 662 {
 663         struct dlm_rsb *r;
 664         int error, count = 0;
 665
 666         down_read(&ls->ls_root_sem);
 667         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
 668                 if (is_master(r)) {
 669                         rsb_clear_flag(r, RSB_NEW_MASTER);
 670                         continue;
 671                 }
 672
 673                 if (!rsb_flag(r, RSB_NEW_MASTER))
 674                         continue;
 675
 676                 if (dlm_recovery_stopped(ls)) {
 677                         error = -EINTR;
 678                         up_read(&ls->ls_root_sem);
 679                         goto out;
 680                 }
 681
 682                 error = recover_locks(r, seq);
 683                 if (error) {
 684                         up_read(&ls->ls_root_sem);
 685                         goto out;
 686                 }
 687
 688                 count += r->res_recover_locks_count;
 689         }
 690         up_read(&ls->ls_root_sem);
 691
 692         log_rinfo(ls, "dlm_recover_locks %d out", count);
 693
 694         error = dlm_wait_function(ls, &recover_list_empty);
 695  out:
 696         if (error)
 697                 recover_list_clear(ls);
 698         return error;
 699 }
 700
 701 void dlm_recovered_lock(struct dlm_rsb *r)
 702 {
 703         DLM_ASSERT(rsb_flag(r, RSB_NEW_MASTER), dlm_dump_rsb(r););
 704
 705         r->res_recover_locks_count--;
 706         if (!r->res_recover_locks_count) {
 707                 rsb_clear_flag(r, RSB_NEW_MASTER);
 708                 recover_list_del(r);
 709         }
 710
 711         if (recover_list_empty(r->res_ls))
 712                 wake_up(&r->res_ls->ls_wait_general);
 713 }
 714
 715 /*
 716  * The lvb needs to be recovered on all master rsb's.  This includes setting
 717  * the VALNOTVALID flag if necessary, and determining the correct lvb contents
 718  * based on the lvb's of the locks held on the rsb.
 719  *
 720  * RSB_VALNOTVALID is set in two cases:
 721  *
 722  * 1. we are master, but not new, and we purged an EX/PW lock held by a
 723  * failed node (in dlm_recover_purge which set RSB_RECOVER_LVB_INVAL)
 724  *
 725  * 2. we are a new master, and there are only NL/CR locks left.
 726  * (We could probably improve this by only invaliding in this way when
 727  * the previous master left uncleanly.  VMS docs mention that.)
 728  *
 729  * The LVB contents are only considered for changing when this is a new master
 730  * of the rsb (NEW_MASTER2).  Then, the rsb's lvb is taken from any lkb with
 731  * mode > CR.  If no lkb's exist with mode above CR, the lvb contents are taken
 732  * from the lkb with the largest lvb sequence number.
 733  */
 734
 735 static void recover_lvb(struct dlm_rsb *r)
 736 {
 737         struct dlm_lkb *big_lkb = NULL, *iter, *high_lkb = NULL;
 738         uint32_t high_seq = 0;
 739         int lock_lvb_exists = 0;
 740         int lvblen = r->res_ls->ls_lvblen;
 741
 742         if (!rsb_flag(r, RSB_NEW_MASTER2) &&
 743             rsb_flag(r, RSB_RECOVER_LVB_INVAL)) {
 744                 /* case 1 above */
 745                 rsb_set_flag(r, RSB_VALNOTVALID);
 746                 return;
 747         }
 748
 749         if (!rsb_flag(r, RSB_NEW_MASTER2))
 750                 return;
 751
 752         /* we are the new master, so figure out if VALNOTVALID should
 753            be set, and set the rsb lvb from the best lkb available. */
 754
 755         list_for_each_entry(iter, &r->res_grantqueue, lkb_statequeue) {
 756                 if (!(iter->lkb_exflags & DLM_LKF_VALBLK))
 757                         continue;
 758
 759                 lock_lvb_exists = 1;
 760
 761                 if (iter->lkb_grmode > DLM_LOCK_CR) {
 762                         big_lkb = iter;
 763                         goto setflag;
 764                 }
 765
 766                 if (((int)iter->lkb_lvbseq - (int)high_seq) >= 0) {
 767                         high_lkb = iter;
 768                         high_seq = iter->lkb_lvbseq;
 769                 }
 770         }
 771
 772         list_for_each_entry(iter, &r->res_convertqueue, lkb_statequeue) {
 773                 if (!(iter->lkb_exflags & DLM_LKF_VALBLK))
 774                         continue;
 775
 776                 lock_lvb_exists = 1;
 777
 778                 if (iter->lkb_grmode > DLM_LOCK_CR) {
 779                         big_lkb = iter;
 780                         goto setflag;
 781                 }
 782
 783                 if (((int)iter->lkb_lvbseq - (int)high_seq) >= 0) {
 784                         high_lkb = iter;
 785                         high_seq = iter->lkb_lvbseq;
 786                 }
 787         }
 788
 789  setflag:
 790         if (!lock_lvb_exists)
 791                 goto out;
 792
 793         /* lvb is invalidated if only NL/CR locks remain */
 794         if (!big_lkb)
 795                 rsb_set_flag(r, RSB_VALNOTVALID);
 796
 797         if (!r->res_lvbptr) {
 798                 r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
 799                 if (!r->res_lvbptr)
 800                         goto out;
 801         }
 802
 803         if (big_lkb) {
 804                 r->res_lvbseq = big_lkb->lkb_lvbseq;
 805                 memcpy(r->res_lvbptr, big_lkb->lkb_lvbptr, lvblen);
 806         } else if (high_lkb) {
 807                 r->res_lvbseq = high_lkb->lkb_lvbseq;
 808                 memcpy(r->res_lvbptr, high_lkb->lkb_lvbptr, lvblen);
 809         } else {
 810                 r->res_lvbseq = 0;
 811                 memset(r->res_lvbptr, 0, lvblen);
 812         }
 813  out:
 814         return;
 815 }
 816
 817 /* All master rsb's flagged RECOVER_CONVERT need to be looked at.  The locks
 818    converting PR->CW or CW->PR need to have their lkb_grmode set. */
 819
 820 static void recover_conversion(struct dlm_rsb *r)
 821 {
 822         struct dlm_ls *ls = r->res_ls;
 823         struct dlm_lkb *lkb;
 824         int grmode = -1;
 825
 826         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
 827                 if (lkb->lkb_grmode == DLM_LOCK_PR ||
 828                     lkb->lkb_grmode == DLM_LOCK_CW) {
 829                         grmode = lkb->lkb_grmode;
 830                         break;
 831                 }
 832         }
 833
 834         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
 835                 if (lkb->lkb_grmode != DLM_LOCK_IV)
 836                         continue;
 837                 if (grmode == -1) {
 838                         log_debug(ls, "recover_conversion %x set gr to rq %d",
 839                                   lkb->lkb_id, lkb->lkb_rqmode);
 840                         lkb->lkb_grmode = lkb->lkb_rqmode;
 841                 } else {
 842                         log_debug(ls, "recover_conversion %x set gr %d",
 843                                   lkb->lkb_id, grmode);
 844                         lkb->lkb_grmode = grmode;
 845                 }
 846         }
 847 }
 848
 849 /* We've become the new master for this rsb and waiting/converting locks may
 850    need to be granted in dlm_recover_grant() due to locks that may have
 851    existed from a removed node. */
 852
 853 static void recover_grant(struct dlm_rsb *r)
 854 {
 855         if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
 856                 rsb_set_flag(r, RSB_RECOVER_GRANT);
 857 }
 858
 859 void dlm_recover_rsbs(struct dlm_ls *ls)
 860 {
 861         struct dlm_rsb *r;
 862         unsigned int count = 0;
 863
 864         down_read(&ls->ls_root_sem);
 865         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
 866                 lock_rsb(r);
 867                 if (is_master(r)) {
 868                         if (rsb_flag(r, RSB_RECOVER_CONVERT))
 869                                 recover_conversion(r);
 870
 871                         /* recover lvb before granting locks so the updated
 872                            lvb/VALNOTVALID is presented in the completion */
 873                         recover_lvb(r);
 874
 875                         if (rsb_flag(r, RSB_NEW_MASTER2))
 876                                 recover_grant(r);
 877                         count++;
 878                 } else {
 879                         rsb_clear_flag(r, RSB_VALNOTVALID);
 880                 }
 881                 rsb_clear_flag(r, RSB_RECOVER_CONVERT);
 882                 rsb_clear_flag(r, RSB_RECOVER_LVB_INVAL);
 883                 rsb_clear_flag(r, RSB_NEW_MASTER2);
 884                 unlock_rsb(r);
 885         }
 886         up_read(&ls->ls_root_sem);
 887
 888         if (count)
 889                 log_rinfo(ls, "dlm_recover_rsbs %d done", count);
 890 }
 891
 892 /* Create a single list of all root rsb's to be used during recovery */
 893
 894 int dlm_create_root_list(struct dlm_ls *ls)
 895 {
 896         struct rb_node *n;
 897         struct dlm_rsb *r;
 898         int i, error = 0;
 899
 900         down_write(&ls->ls_root_sem);
 901         if (!list_empty(&ls->ls_root_list)) {
 902                 log_error(ls, "root list not empty");
 903                 error = -EINVAL;
 904                 goto out;
 905         }
 906
 907         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
 908                 spin_lock(&ls->ls_rsbtbl[i].lock);
 909                 for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
 910                         r = rb_entry(n, struct dlm_rsb, res_hashnode);
 911                         list_add(&r->res_root_list, &ls->ls_root_list);
 912                         dlm_hold_rsb(r);
 913                 }
 914
 915                 if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[i].toss))
 916                         log_error(ls, "dlm_create_root_list toss not empty");
 917                 spin_unlock(&ls->ls_rsbtbl[i].lock);
 918         }
 919  out:
 920         up_write(&ls->ls_root_sem);
 921         return error;
 922 }
 923
 924 void dlm_release_root_list(struct dlm_ls *ls)
 925 {
 926         struct dlm_rsb *r, *safe;
 927
 928         down_write(&ls->ls_root_sem);
 929         list_for_each_entry_safe(r, safe, &ls->ls_root_list, res_root_list) {
 930                 list_del_init(&r->res_root_list);
 931                 dlm_put_rsb(r);
 932         }
 933         up_write(&ls->ls_root_sem);
 934 }
 935
 936 void dlm_clear_toss(struct dlm_ls *ls)
 937 {
 938         struct rb_node *n, *next;
 939         struct dlm_rsb *r;
 940         unsigned int count = 0;
 941         int i;
 942
 943         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
 944                 spin_lock(&ls->ls_rsbtbl[i].lock);
 945                 for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = next) {
 946                         next = rb_next(n);
 947                         r = rb_entry(n, struct dlm_rsb, res_hashnode);
 948                         rb_erase(n, &ls->ls_rsbtbl[i].toss);
 949                         dlm_free_rsb(r);
 950                         count++;
 951                 }
 952                 spin_unlock(&ls->ls_rsbtbl[i].lock);
 953         }
 954
 955         if (count)
 956                 log_rinfo(ls, "dlm_clear_toss %u done", count);
 957 }
 958