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