linux/fs/ocfs2/dlm/dlmrecovery.c
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   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * dlmrecovery.c
   5 *
   6 * recovery stuff
   7 *
   8 * Copyright (C) 2004 Oracle.  All rights reserved.
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public
  12 * License as published by the Free Software Foundation; either
  13 * version 2 of the License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public
  21 * License along with this program; if not, write to the
  22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 * Boston, MA 021110-1307, USA.
  24 *
  25 */
  26
  27
  28#include <linux/module.h>
  29#include <linux/fs.h>
  30#include <linux/types.h>
  31#include <linux/slab.h>
  32#include <linux/highmem.h>
  33#include <linux/init.h>
  34#include <linux/sysctl.h>
  35#include <linux/random.h>
  36#include <linux/blkdev.h>
  37#include <linux/socket.h>
  38#include <linux/inet.h>
  39#include <linux/timer.h>
  40#include <linux/kthread.h>
  41#include <linux/delay.h>
  42
  43
  44#include "cluster/heartbeat.h"
  45#include "cluster/nodemanager.h"
  46#include "cluster/tcp.h"
  47
  48#include "dlmapi.h"
  49#include "dlmcommon.h"
  50#include "dlmdomain.h"
  51
  52#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
  53#include "cluster/masklog.h"
  54
  55static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
  56
  57static int dlm_recovery_thread(void *data);
  58static int dlm_do_recovery(struct dlm_ctxt *dlm);
  59
  60static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
  61static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
  62static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  63static int dlm_request_all_locks(struct dlm_ctxt *dlm,
  64                                 u8 request_from, u8 dead_node);
  65static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  66
  67static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
  68static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
  69                                        const char *lockname, int namelen,
  70                                        int total_locks, u64 cookie,
  71                                        u8 flags, u8 master);
  72static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
  73                                    struct dlm_migratable_lockres *mres,
  74                                    u8 send_to,
  75                                    struct dlm_lock_resource *res,
  76                                    int total_locks);
  77static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
  78                                     struct dlm_lock_resource *res,
  79                                     struct dlm_migratable_lockres *mres);
  80static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
  81static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
  82                                 u8 dead_node, u8 send_to);
  83static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
  84static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
  85                                        struct list_head *list, u8 dead_node);
  86static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
  87                                              u8 dead_node, u8 new_master);
  88static void dlm_reco_ast(void *astdata);
  89static void dlm_reco_bast(void *astdata, int blocked_type);
  90static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
  91static void dlm_request_all_locks_worker(struct dlm_work_item *item,
  92                                         void *data);
  93static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
  94static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
  95                                      struct dlm_lock_resource *res,
  96                                      u8 *real_master);
  97
  98static u64 dlm_get_next_mig_cookie(void);
  99
 100static DEFINE_SPINLOCK(dlm_reco_state_lock);
 101static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
 102static u64 dlm_mig_cookie = 1;
 103
 104static u64 dlm_get_next_mig_cookie(void)
 105{
 106        u64 c;
 107        spin_lock(&dlm_mig_cookie_lock);
 108        c = dlm_mig_cookie;
 109        if (dlm_mig_cookie == (~0ULL))
 110                dlm_mig_cookie = 1;
 111        else
 112                dlm_mig_cookie++;
 113        spin_unlock(&dlm_mig_cookie_lock);
 114        return c;
 115}
 116
 117static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
 118                                          u8 dead_node)
 119{
 120        assert_spin_locked(&dlm->spinlock);
 121        if (dlm->reco.dead_node != dead_node)
 122                mlog(0, "%s: changing dead_node from %u to %u\n",
 123                     dlm->name, dlm->reco.dead_node, dead_node);
 124        dlm->reco.dead_node = dead_node;
 125}
 126
 127static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
 128                                       u8 master)
 129{
 130        assert_spin_locked(&dlm->spinlock);
 131        mlog(0, "%s: changing new_master from %u to %u\n",
 132             dlm->name, dlm->reco.new_master, master);
 133        dlm->reco.new_master = master;
 134}
 135
 136static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
 137{
 138        assert_spin_locked(&dlm->spinlock);
 139        clear_bit(dlm->reco.dead_node, dlm->recovery_map);
 140        dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 141        dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 142}
 143
 144static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
 145{
 146        spin_lock(&dlm->spinlock);
 147        __dlm_reset_recovery(dlm);
 148        spin_unlock(&dlm->spinlock);
 149}
 150
 151/* Worker function used during recovery. */
 152void dlm_dispatch_work(struct work_struct *work)
 153{
 154        struct dlm_ctxt *dlm =
 155                container_of(work, struct dlm_ctxt, dispatched_work);
 156        LIST_HEAD(tmp_list);
 157        struct dlm_work_item *item, *next;
 158        dlm_workfunc_t *workfunc;
 159        int tot=0;
 160
 161        spin_lock(&dlm->work_lock);
 162        list_splice_init(&dlm->work_list, &tmp_list);
 163        spin_unlock(&dlm->work_lock);
 164
 165        list_for_each_entry(item, &tmp_list, list) {
 166                tot++;
 167        }
 168        mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
 169
 170        list_for_each_entry_safe(item, next, &tmp_list, list) {
 171                workfunc = item->func;
 172                list_del_init(&item->list);
 173
 174                /* already have ref on dlm to avoid having
 175                 * it disappear.  just double-check. */
 176                BUG_ON(item->dlm != dlm);
 177
 178                /* this is allowed to sleep and
 179                 * call network stuff */
 180                workfunc(item, item->data);
 181
 182                dlm_put(dlm);
 183                kfree(item);
 184        }
 185}
 186
 187/*
 188 * RECOVERY THREAD
 189 */
 190
 191void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
 192{
 193        /* wake the recovery thread
 194         * this will wake the reco thread in one of three places
 195         * 1) sleeping with no recovery happening
 196         * 2) sleeping with recovery mastered elsewhere
 197         * 3) recovery mastered here, waiting on reco data */
 198
 199        wake_up(&dlm->dlm_reco_thread_wq);
 200}
 201
 202/* Launch the recovery thread */
 203int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
 204{
 205        mlog(0, "starting dlm recovery thread...\n");
 206
 207        dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
 208                                                "dlm_reco_thread");
 209        if (IS_ERR(dlm->dlm_reco_thread_task)) {
 210                mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
 211                dlm->dlm_reco_thread_task = NULL;
 212                return -EINVAL;
 213        }
 214
 215        return 0;
 216}
 217
 218void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
 219{
 220        if (dlm->dlm_reco_thread_task) {
 221                mlog(0, "waiting for dlm recovery thread to exit\n");
 222                kthread_stop(dlm->dlm_reco_thread_task);
 223                dlm->dlm_reco_thread_task = NULL;
 224        }
 225}
 226
 227
 228
 229/*
 230 * this is lame, but here's how recovery works...
 231 * 1) all recovery threads cluster wide will work on recovering
 232 *    ONE node at a time
 233 * 2) negotiate who will take over all the locks for the dead node.
 234 *    thats right... ALL the locks.
 235 * 3) once a new master is chosen, everyone scans all locks
 236 *    and moves aside those mastered by the dead guy
 237 * 4) each of these locks should be locked until recovery is done
 238 * 5) the new master collects up all of secondary lock queue info
 239 *    one lock at a time, forcing each node to communicate back
 240 *    before continuing
 241 * 6) each secondary lock queue responds with the full known lock info
 242 * 7) once the new master has run all its locks, it sends a ALLDONE!
 243 *    message to everyone
 244 * 8) upon receiving this message, the secondary queue node unlocks
 245 *    and responds to the ALLDONE
 246 * 9) once the new master gets responses from everyone, he unlocks
 247 *    everything and recovery for this dead node is done
 248 *10) go back to 2) while there are still dead nodes
 249 *
 250 */
 251
 252static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
 253{
 254        struct dlm_reco_node_data *ndata;
 255        struct dlm_lock_resource *res;
 256
 257        mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
 258             dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
 259             dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
 260             dlm->reco.dead_node, dlm->reco.new_master);
 261
 262        list_for_each_entry(ndata, &dlm->reco.node_data, list) {
 263                char *st = "unknown";
 264                switch (ndata->state) {
 265                        case DLM_RECO_NODE_DATA_INIT:
 266                                st = "init";
 267                                break;
 268                        case DLM_RECO_NODE_DATA_REQUESTING:
 269                                st = "requesting";
 270                                break;
 271                        case DLM_RECO_NODE_DATA_DEAD:
 272                                st = "dead";
 273                                break;
 274                        case DLM_RECO_NODE_DATA_RECEIVING:
 275                                st = "receiving";
 276                                break;
 277                        case DLM_RECO_NODE_DATA_REQUESTED:
 278                                st = "requested";
 279                                break;
 280                        case DLM_RECO_NODE_DATA_DONE:
 281                                st = "done";
 282                                break;
 283                        case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 284                                st = "finalize-sent";
 285                                break;
 286                        default:
 287                                st = "bad";
 288                                break;
 289                }
 290                mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
 291                     dlm->name, ndata->node_num, st);
 292        }
 293        list_for_each_entry(res, &dlm->reco.resources, recovering) {
 294                mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
 295                     dlm->name, res->lockname.len, res->lockname.name);
 296        }
 297}
 298
 299#define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
 300
 301static int dlm_recovery_thread(void *data)
 302{
 303        int status;
 304        struct dlm_ctxt *dlm = data;
 305        unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
 306
 307        mlog(0, "dlm thread running for %s...\n", dlm->name);
 308
 309        while (!kthread_should_stop()) {
 310                if (dlm_domain_fully_joined(dlm)) {
 311                        status = dlm_do_recovery(dlm);
 312                        if (status == -EAGAIN) {
 313                                /* do not sleep, recheck immediately. */
 314                                continue;
 315                        }
 316                        if (status < 0)
 317                                mlog_errno(status);
 318                }
 319
 320                wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 321                                                 kthread_should_stop(),
 322                                                 timeout);
 323        }
 324
 325        mlog(0, "quitting DLM recovery thread\n");
 326        return 0;
 327}
 328
 329/* returns true when the recovery master has contacted us */
 330static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
 331{
 332        int ready;
 333        spin_lock(&dlm->spinlock);
 334        ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
 335        spin_unlock(&dlm->spinlock);
 336        return ready;
 337}
 338
 339/* returns true if node is no longer in the domain
 340 * could be dead or just not joined */
 341int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
 342{
 343        int dead;
 344        spin_lock(&dlm->spinlock);
 345        dead = !test_bit(node, dlm->domain_map);
 346        spin_unlock(&dlm->spinlock);
 347        return dead;
 348}
 349
 350/* returns true if node is no longer in the domain
 351 * could be dead or just not joined */
 352static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
 353{
 354        int recovered;
 355        spin_lock(&dlm->spinlock);
 356        recovered = !test_bit(node, dlm->recovery_map);
 357        spin_unlock(&dlm->spinlock);
 358        return recovered;
 359}
 360
 361
 362void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
 363{
 364        if (dlm_is_node_dead(dlm, node))
 365                return;
 366
 367        printk(KERN_NOTICE "o2dlm: Waiting on the death of node %u in "
 368               "domain %s\n", node, dlm->name);
 369
 370        if (timeout)
 371                wait_event_timeout(dlm->dlm_reco_thread_wq,
 372                                   dlm_is_node_dead(dlm, node),
 373                                   msecs_to_jiffies(timeout));
 374        else
 375                wait_event(dlm->dlm_reco_thread_wq,
 376                           dlm_is_node_dead(dlm, node));
 377}
 378
 379void dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
 380{
 381        if (dlm_is_node_recovered(dlm, node))
 382                return;
 383
 384        printk(KERN_NOTICE "o2dlm: Waiting on the recovery of node %u in "
 385               "domain %s\n", node, dlm->name);
 386
 387        if (timeout)
 388                wait_event_timeout(dlm->dlm_reco_thread_wq,
 389                                   dlm_is_node_recovered(dlm, node),
 390                                   msecs_to_jiffies(timeout));
 391        else
 392                wait_event(dlm->dlm_reco_thread_wq,
 393                           dlm_is_node_recovered(dlm, node));
 394}
 395
 396/* callers of the top-level api calls (dlmlock/dlmunlock) should
 397 * block on the dlm->reco.event when recovery is in progress.
 398 * the dlm recovery thread will set this state when it begins
 399 * recovering a dead node (as the new master or not) and clear
 400 * the state and wake as soon as all affected lock resources have
 401 * been marked with the RECOVERY flag */
 402static int dlm_in_recovery(struct dlm_ctxt *dlm)
 403{
 404        int in_recovery;
 405        spin_lock(&dlm->spinlock);
 406        in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 407        spin_unlock(&dlm->spinlock);
 408        return in_recovery;
 409}
 410
 411
 412void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
 413{
 414        if (dlm_in_recovery(dlm)) {
 415                mlog(0, "%s: reco thread %d in recovery: "
 416                     "state=%d, master=%u, dead=%u\n",
 417                     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
 418                     dlm->reco.state, dlm->reco.new_master,
 419                     dlm->reco.dead_node);
 420        }
 421        wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
 422}
 423
 424static void dlm_begin_recovery(struct dlm_ctxt *dlm)
 425{
 426        spin_lock(&dlm->spinlock);
 427        BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 428        printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n",
 429               dlm->name, dlm->reco.dead_node);
 430        dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
 431        spin_unlock(&dlm->spinlock);
 432}
 433
 434static void dlm_end_recovery(struct dlm_ctxt *dlm)
 435{
 436        spin_lock(&dlm->spinlock);
 437        BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
 438        dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
 439        spin_unlock(&dlm->spinlock);
 440        printk(KERN_NOTICE "o2dlm: End recovery on domain %s\n", dlm->name);
 441        wake_up(&dlm->reco.event);
 442}
 443
 444static void dlm_print_recovery_master(struct dlm_ctxt *dlm)
 445{
 446        printk(KERN_NOTICE "o2dlm: Node %u (%s) is the Recovery Master for the "
 447               "dead node %u in domain %s\n", dlm->reco.new_master,
 448               (dlm->node_num == dlm->reco.new_master ? "me" : "he"),
 449               dlm->reco.dead_node, dlm->name);
 450}
 451
 452static int dlm_do_recovery(struct dlm_ctxt *dlm)
 453{
 454        int status = 0;
 455        int ret;
 456
 457        spin_lock(&dlm->spinlock);
 458
 459        /* check to see if the new master has died */
 460        if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
 461            test_bit(dlm->reco.new_master, dlm->recovery_map)) {
 462                mlog(0, "new master %u died while recovering %u!\n",
 463                     dlm->reco.new_master, dlm->reco.dead_node);
 464                /* unset the new_master, leave dead_node */
 465                dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 466        }
 467
 468        /* select a target to recover */
 469        if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 470                int bit;
 471
 472                bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
 473                if (bit >= O2NM_MAX_NODES || bit < 0)
 474                        dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 475                else
 476                        dlm_set_reco_dead_node(dlm, bit);
 477        } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
 478                /* BUG? */
 479                mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
 480                     dlm->reco.dead_node);
 481                dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 482        }
 483
 484        if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 485                // mlog(0, "nothing to recover!  sleeping now!\n");
 486                spin_unlock(&dlm->spinlock);
 487                /* return to main thread loop and sleep. */
 488                return 0;
 489        }
 490        mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
 491             dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
 492             dlm->reco.dead_node);
 493        spin_unlock(&dlm->spinlock);
 494
 495        /* take write barrier */
 496        /* (stops the list reshuffling thread, proxy ast handling) */
 497        dlm_begin_recovery(dlm);
 498
 499        if (dlm->reco.new_master == dlm->node_num)
 500                goto master_here;
 501
 502        if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 503                /* choose a new master, returns 0 if this node
 504                 * is the master, -EEXIST if it's another node.
 505                 * this does not return until a new master is chosen
 506                 * or recovery completes entirely. */
 507                ret = dlm_pick_recovery_master(dlm);
 508                if (!ret) {
 509                        /* already notified everyone.  go. */
 510                        goto master_here;
 511                }
 512                mlog(0, "another node will master this recovery session.\n");
 513        }
 514
 515        dlm_print_recovery_master(dlm);
 516
 517        /* it is safe to start everything back up here
 518         * because all of the dead node's lock resources
 519         * have been marked as in-recovery */
 520        dlm_end_recovery(dlm);
 521
 522        /* sleep out in main dlm_recovery_thread loop. */
 523        return 0;
 524
 525master_here:
 526        dlm_print_recovery_master(dlm);
 527
 528        status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
 529        if (status < 0) {
 530                /* we should never hit this anymore */
 531                mlog(ML_ERROR, "%s: Error %d remastering locks for node %u, "
 532                     "retrying.\n", dlm->name, status, dlm->reco.dead_node);
 533                /* yield a bit to allow any final network messages
 534                 * to get handled on remaining nodes */
 535                msleep(100);
 536        } else {
 537                /* success!  see if any other nodes need recovery */
 538                mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
 539                     dlm->name, dlm->reco.dead_node, dlm->node_num);
 540                spin_lock(&dlm->spinlock);
 541                __dlm_reset_recovery(dlm);
 542                dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
 543                spin_unlock(&dlm->spinlock);
 544        }
 545        dlm_end_recovery(dlm);
 546
 547        /* continue and look for another dead node */
 548        return -EAGAIN;
 549}
 550
 551static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
 552{
 553        int status = 0;
 554        struct dlm_reco_node_data *ndata;
 555        int all_nodes_done;
 556        int destroy = 0;
 557        int pass = 0;
 558
 559        do {
 560                /* we have become recovery master.  there is no escaping
 561                 * this, so just keep trying until we get it. */
 562                status = dlm_init_recovery_area(dlm, dead_node);
 563                if (status < 0) {
 564                        mlog(ML_ERROR, "%s: failed to alloc recovery area, "
 565                             "retrying\n", dlm->name);
 566                        msleep(1000);
 567                }
 568        } while (status != 0);
 569
 570        /* safe to access the node data list without a lock, since this
 571         * process is the only one to change the list */
 572        list_for_each_entry(ndata, &dlm->reco.node_data, list) {
 573                BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
 574                ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
 575
 576                mlog(0, "%s: Requesting lock info from node %u\n", dlm->name,
 577                     ndata->node_num);
 578
 579                if (ndata->node_num == dlm->node_num) {
 580                        ndata->state = DLM_RECO_NODE_DATA_DONE;
 581                        continue;
 582                }
 583
 584                do {
 585                        status = dlm_request_all_locks(dlm, ndata->node_num,
 586                                                       dead_node);
 587                        if (status < 0) {
 588                                mlog_errno(status);
 589                                if (dlm_is_host_down(status)) {
 590                                        /* node died, ignore it for recovery */
 591                                        status = 0;
 592                                        ndata->state = DLM_RECO_NODE_DATA_DEAD;
 593                                        /* wait for the domain map to catch up
 594                                         * with the network state. */
 595                                        wait_event_timeout(dlm->dlm_reco_thread_wq,
 596                                                           dlm_is_node_dead(dlm,
 597                                                                ndata->node_num),
 598                                                           msecs_to_jiffies(1000));
 599                                        mlog(0, "waited 1 sec for %u, "
 600                                             "dead? %s\n", ndata->node_num,
 601                                             dlm_is_node_dead(dlm, ndata->node_num) ?
 602                                             "yes" : "no");
 603                                } else {
 604                                        /* -ENOMEM on the other node */
 605                                        mlog(0, "%s: node %u returned "
 606                                             "%d during recovery, retrying "
 607                                             "after a short wait\n",
 608                                             dlm->name, ndata->node_num,
 609                                             status);
 610                                        msleep(100);
 611                                }
 612                        }
 613                } while (status != 0);
 614
 615                spin_lock(&dlm_reco_state_lock);
 616                switch (ndata->state) {
 617                        case DLM_RECO_NODE_DATA_INIT:
 618                        case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 619                        case DLM_RECO_NODE_DATA_REQUESTED:
 620                                BUG();
 621                                break;
 622                        case DLM_RECO_NODE_DATA_DEAD:
 623                                mlog(0, "node %u died after requesting "
 624                                     "recovery info for node %u\n",
 625                                     ndata->node_num, dead_node);
 626                                /* fine.  don't need this node's info.
 627                                 * continue without it. */
 628                                break;
 629                        case DLM_RECO_NODE_DATA_REQUESTING:
 630                                ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
 631                                mlog(0, "now receiving recovery data from "
 632                                     "node %u for dead node %u\n",
 633                                     ndata->node_num, dead_node);
 634                                break;
 635                        case DLM_RECO_NODE_DATA_RECEIVING:
 636                                mlog(0, "already receiving recovery data from "
 637                                     "node %u for dead node %u\n",
 638                                     ndata->node_num, dead_node);
 639                                break;
 640                        case DLM_RECO_NODE_DATA_DONE:
 641                                mlog(0, "already DONE receiving recovery data "
 642                                     "from node %u for dead node %u\n",
 643                                     ndata->node_num, dead_node);
 644                                break;
 645                }
 646                spin_unlock(&dlm_reco_state_lock);
 647        }
 648
 649        mlog(0, "%s: Done requesting all lock info\n", dlm->name);
 650
 651        /* nodes should be sending reco data now
 652         * just need to wait */
 653
 654        while (1) {
 655                /* check all the nodes now to see if we are
 656                 * done, or if anyone died */
 657                all_nodes_done = 1;
 658                spin_lock(&dlm_reco_state_lock);
 659                list_for_each_entry(ndata, &dlm->reco.node_data, list) {
 660                        mlog(0, "checking recovery state of node %u\n",
 661                             ndata->node_num);
 662                        switch (ndata->state) {
 663                                case DLM_RECO_NODE_DATA_INIT:
 664                                case DLM_RECO_NODE_DATA_REQUESTING:
 665                                        mlog(ML_ERROR, "bad ndata state for "
 666                                             "node %u: state=%d\n",
 667                                             ndata->node_num, ndata->state);
 668                                        BUG();
 669                                        break;
 670                                case DLM_RECO_NODE_DATA_DEAD:
 671                                        mlog(0, "node %u died after "
 672                                             "requesting recovery info for "
 673                                             "node %u\n", ndata->node_num,
 674                                             dead_node);
 675                                        break;
 676                                case DLM_RECO_NODE_DATA_RECEIVING:
 677                                case DLM_RECO_NODE_DATA_REQUESTED:
 678                                        mlog(0, "%s: node %u still in state %s\n",
 679                                             dlm->name, ndata->node_num,
 680                                             ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
 681                                             "receiving" : "requested");
 682                                        all_nodes_done = 0;
 683                                        break;
 684                                case DLM_RECO_NODE_DATA_DONE:
 685                                        mlog(0, "%s: node %u state is done\n",
 686                                             dlm->name, ndata->node_num);
 687                                        break;
 688                                case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 689                                        mlog(0, "%s: node %u state is finalize\n",
 690                                             dlm->name, ndata->node_num);
 691                                        break;
 692                        }
 693                }
 694                spin_unlock(&dlm_reco_state_lock);
 695
 696                mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
 697                     all_nodes_done?"yes":"no");
 698                if (all_nodes_done) {
 699                        int ret;
 700
 701                        /* Set this flag on recovery master to avoid
 702                         * a new recovery for another dead node start
 703                         * before the recovery is not done. That may
 704                         * cause recovery hung.*/
 705                        spin_lock(&dlm->spinlock);
 706                        dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
 707                        spin_unlock(&dlm->spinlock);
 708
 709                        /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
 710                         * just send a finalize message to everyone and
 711                         * clean up */
 712                        mlog(0, "all nodes are done! send finalize\n");
 713                        ret = dlm_send_finalize_reco_message(dlm);
 714                        if (ret < 0)
 715                                mlog_errno(ret);
 716
 717                        spin_lock(&dlm->spinlock);
 718                        dlm_finish_local_lockres_recovery(dlm, dead_node,
 719                                                          dlm->node_num);
 720                        spin_unlock(&dlm->spinlock);
 721                        mlog(0, "should be done with recovery!\n");
 722
 723                        mlog(0, "finishing recovery of %s at %lu, "
 724                             "dead=%u, this=%u, new=%u\n", dlm->name,
 725                             jiffies, dlm->reco.dead_node,
 726                             dlm->node_num, dlm->reco.new_master);
 727                        destroy = 1;
 728                        status = 0;
 729                        /* rescan everything marked dirty along the way */
 730                        dlm_kick_thread(dlm, NULL);
 731                        break;
 732                }
 733                /* wait to be signalled, with periodic timeout
 734                 * to check for node death */
 735                wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 736                                         kthread_should_stop(),
 737                                         msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
 738
 739        }
 740
 741        if (destroy)
 742                dlm_destroy_recovery_area(dlm, dead_node);
 743
 744        return status;
 745}
 746
 747static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 748{
 749        int num=0;
 750        struct dlm_reco_node_data *ndata;
 751
 752        spin_lock(&dlm->spinlock);
 753        memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
 754        /* nodes can only be removed (by dying) after dropping
 755         * this lock, and death will be trapped later, so this should do */
 756        spin_unlock(&dlm->spinlock);
 757
 758        while (1) {
 759                num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
 760                if (num >= O2NM_MAX_NODES) {
 761                        break;
 762                }
 763                BUG_ON(num == dead_node);
 764
 765                ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
 766                if (!ndata) {
 767                        dlm_destroy_recovery_area(dlm, dead_node);
 768                        return -ENOMEM;
 769                }
 770                ndata->node_num = num;
 771                ndata->state = DLM_RECO_NODE_DATA_INIT;
 772                spin_lock(&dlm_reco_state_lock);
 773                list_add_tail(&ndata->list, &dlm->reco.node_data);
 774                spin_unlock(&dlm_reco_state_lock);
 775                num++;
 776        }
 777
 778        return 0;
 779}
 780
 781static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 782{
 783        struct dlm_reco_node_data *ndata, *next;
 784        LIST_HEAD(tmplist);
 785
 786        spin_lock(&dlm_reco_state_lock);
 787        list_splice_init(&dlm->reco.node_data, &tmplist);
 788        spin_unlock(&dlm_reco_state_lock);
 789
 790        list_for_each_entry_safe(ndata, next, &tmplist, list) {
 791                list_del_init(&ndata->list);
 792                kfree(ndata);
 793        }
 794}
 795
 796static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
 797                                 u8 dead_node)
 798{
 799        struct dlm_lock_request lr;
 800        int ret;
 801        int status;
 802
 803        mlog(0, "\n");
 804
 805
 806        mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
 807                  "to %u\n", dead_node, request_from);
 808
 809        memset(&lr, 0, sizeof(lr));
 810        lr.node_idx = dlm->node_num;
 811        lr.dead_node = dead_node;
 812
 813        // send message
 814        ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
 815                                 &lr, sizeof(lr), request_from, &status);
 816
 817        /* negative status is handled by caller */
 818        if (ret < 0)
 819                mlog(ML_ERROR, "%s: Error %d send LOCK_REQUEST to node %u "
 820                     "to recover dead node %u\n", dlm->name, ret,
 821                     request_from, dead_node);
 822        else
 823                ret = status;
 824        // return from here, then
 825        // sleep until all received or error
 826        return ret;
 827
 828}
 829
 830int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
 831                                  void **ret_data)
 832{
 833        struct dlm_ctxt *dlm = data;
 834        struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
 835        char *buf = NULL;
 836        struct dlm_work_item *item = NULL;
 837
 838        if (!dlm_grab(dlm))
 839                return -EINVAL;
 840
 841        if (lr->dead_node != dlm->reco.dead_node) {
 842                mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
 843                     "dead_node is %u\n", dlm->name, lr->node_idx,
 844                     lr->dead_node, dlm->reco.dead_node);
 845                dlm_print_reco_node_status(dlm);
 846                /* this is a hack */
 847                dlm_put(dlm);
 848                return -ENOMEM;
 849        }
 850        BUG_ON(lr->dead_node != dlm->reco.dead_node);
 851
 852        item = kzalloc(sizeof(*item), GFP_NOFS);
 853        if (!item) {
 854                dlm_put(dlm);
 855                return -ENOMEM;
 856        }
 857
 858        /* this will get freed by dlm_request_all_locks_worker */
 859        buf = (char *) __get_free_page(GFP_NOFS);
 860        if (!buf) {
 861                kfree(item);
 862                dlm_put(dlm);
 863                return -ENOMEM;
 864        }
 865
 866        /* queue up work for dlm_request_all_locks_worker */
 867        dlm_grab(dlm);  /* get an extra ref for the work item */
 868        dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
 869        item->u.ral.reco_master = lr->node_idx;
 870        item->u.ral.dead_node = lr->dead_node;
 871        spin_lock(&dlm->work_lock);
 872        list_add_tail(&item->list, &dlm->work_list);
 873        spin_unlock(&dlm->work_lock);
 874        queue_work(dlm->dlm_worker, &dlm->dispatched_work);
 875
 876        dlm_put(dlm);
 877        return 0;
 878}
 879
 880static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
 881{
 882        struct dlm_migratable_lockres *mres;
 883        struct dlm_lock_resource *res;
 884        struct dlm_ctxt *dlm;
 885        LIST_HEAD(resources);
 886        int ret;
 887        u8 dead_node, reco_master;
 888        int skip_all_done = 0;
 889
 890        dlm = item->dlm;
 891        dead_node = item->u.ral.dead_node;
 892        reco_master = item->u.ral.reco_master;
 893        mres = (struct dlm_migratable_lockres *)data;
 894
 895        mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
 896             dlm->name, dead_node, reco_master);
 897
 898        if (dead_node != dlm->reco.dead_node ||
 899            reco_master != dlm->reco.new_master) {
 900                /* worker could have been created before the recovery master
 901                 * died.  if so, do not continue, but do not error. */
 902                if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 903                        mlog(ML_NOTICE, "%s: will not send recovery state, "
 904                             "recovery master %u died, thread=(dead=%u,mas=%u)"
 905                             " current=(dead=%u,mas=%u)\n", dlm->name,
 906                             reco_master, dead_node, reco_master,
 907                             dlm->reco.dead_node, dlm->reco.new_master);
 908                } else {
 909                        mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
 910                             "master=%u), request(dead=%u, master=%u)\n",
 911                             dlm->name, dlm->reco.dead_node,
 912                             dlm->reco.new_master, dead_node, reco_master);
 913                }
 914                goto leave;
 915        }
 916
 917        /* lock resources should have already been moved to the
 918         * dlm->reco.resources list.  now move items from that list
 919         * to a temp list if the dead owner matches.  note that the
 920         * whole cluster recovers only one node at a time, so we
 921         * can safely move UNKNOWN lock resources for each recovery
 922         * session. */
 923        dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
 924
 925        /* now we can begin blasting lockreses without the dlm lock */
 926
 927        /* any errors returned will be due to the new_master dying,
 928         * the dlm_reco_thread should detect this */
 929        list_for_each_entry(res, &resources, recovering) {
 930                ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
 931                                        DLM_MRES_RECOVERY);
 932                if (ret < 0) {
 933                        mlog(ML_ERROR, "%s: node %u went down while sending "
 934                             "recovery state for dead node %u, ret=%d\n", dlm->name,
 935                             reco_master, dead_node, ret);
 936                        skip_all_done = 1;
 937                        break;
 938                }
 939        }
 940
 941        /* move the resources back to the list */
 942        spin_lock(&dlm->spinlock);
 943        list_splice_init(&resources, &dlm->reco.resources);
 944        spin_unlock(&dlm->spinlock);
 945
 946        if (!skip_all_done) {
 947                ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
 948                if (ret < 0) {
 949                        mlog(ML_ERROR, "%s: node %u went down while sending "
 950                             "recovery all-done for dead node %u, ret=%d\n",
 951                             dlm->name, reco_master, dead_node, ret);
 952                }
 953        }
 954leave:
 955        free_page((unsigned long)data);
 956}
 957
 958
 959static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
 960{
 961        int ret, tmpret;
 962        struct dlm_reco_data_done done_msg;
 963
 964        memset(&done_msg, 0, sizeof(done_msg));
 965        done_msg.node_idx = dlm->node_num;
 966        done_msg.dead_node = dead_node;
 967        mlog(0, "sending DATA DONE message to %u, "
 968             "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
 969             done_msg.dead_node);
 970
 971        ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
 972                                 sizeof(done_msg), send_to, &tmpret);
 973        if (ret < 0) {
 974                mlog(ML_ERROR, "%s: Error %d send RECO_DATA_DONE to node %u "
 975                     "to recover dead node %u\n", dlm->name, ret, send_to,
 976                     dead_node);
 977                if (!dlm_is_host_down(ret)) {
 978                        BUG();
 979                }
 980        } else
 981                ret = tmpret;
 982        return ret;
 983}
 984
 985
 986int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
 987                               void **ret_data)
 988{
 989        struct dlm_ctxt *dlm = data;
 990        struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
 991        struct dlm_reco_node_data *ndata = NULL;
 992        int ret = -EINVAL;
 993
 994        if (!dlm_grab(dlm))
 995                return -EINVAL;
 996
 997        mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 998             "node_idx=%u, this node=%u\n", done->dead_node,
 999             dlm->reco.dead_node, done->node_idx, dlm->node_num);
1000
1001        mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
1002                        "Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
1003                        "node_idx=%u, this node=%u\n", done->dead_node,
1004                        dlm->reco.dead_node, done->node_idx, dlm->node_num);
1005
1006        spin_lock(&dlm_reco_state_lock);
1007        list_for_each_entry(ndata, &dlm->reco.node_data, list) {
1008                if (ndata->node_num != done->node_idx)
1009                        continue;
1010
1011                switch (ndata->state) {
1012                        /* should have moved beyond INIT but not to FINALIZE yet */
1013                        case DLM_RECO_NODE_DATA_INIT:
1014                        case DLM_RECO_NODE_DATA_DEAD:
1015                        case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1016                                mlog(ML_ERROR, "bad ndata state for node %u:"
1017                                     " state=%d\n", ndata->node_num,
1018                                     ndata->state);
1019                                BUG();
1020                                break;
1021                        /* these states are possible at this point, anywhere along
1022                         * the line of recovery */
1023                        case DLM_RECO_NODE_DATA_DONE:
1024                        case DLM_RECO_NODE_DATA_RECEIVING:
1025                        case DLM_RECO_NODE_DATA_REQUESTED:
1026                        case DLM_RECO_NODE_DATA_REQUESTING:
1027                                mlog(0, "node %u is DONE sending "
1028                                          "recovery data!\n",
1029                                          ndata->node_num);
1030
1031                                ndata->state = DLM_RECO_NODE_DATA_DONE;
1032                                ret = 0;
1033                                break;
1034                }
1035        }
1036        spin_unlock(&dlm_reco_state_lock);
1037
1038        /* wake the recovery thread, some node is done */
1039        if (!ret)
1040                dlm_kick_recovery_thread(dlm);
1041
1042        if (ret < 0)
1043                mlog(ML_ERROR, "failed to find recovery node data for node "
1044                     "%u\n", done->node_idx);
1045        dlm_put(dlm);
1046
1047        mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1048        return ret;
1049}
1050
1051static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1052                                        struct list_head *list,
1053                                        u8 dead_node)
1054{
1055        struct dlm_lock_resource *res, *next;
1056        struct dlm_lock *lock;
1057
1058        spin_lock(&dlm->spinlock);
1059        list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
1060                /* always prune any $RECOVERY entries for dead nodes,
1061                 * otherwise hangs can occur during later recovery */
1062                if (dlm_is_recovery_lock(res->lockname.name,
1063                                         res->lockname.len)) {
1064                        spin_lock(&res->spinlock);
1065                        list_for_each_entry(lock, &res->granted, list) {
1066                                if (lock->ml.node == dead_node) {
1067                                        mlog(0, "AHA! there was "
1068                                             "a $RECOVERY lock for dead "
1069                                             "node %u (%s)!\n",
1070                                             dead_node, dlm->name);
1071                                        list_del_init(&lock->list);
1072                                        dlm_lock_put(lock);
1073                                        break;
1074                                }
1075                        }
1076                        spin_unlock(&res->spinlock);
1077                        continue;
1078                }
1079
1080                if (res->owner == dead_node) {
1081                        mlog(0, "found lockres owned by dead node while "
1082                                  "doing recovery for node %u. sending it.\n",
1083                                  dead_node);
1084                        list_move_tail(&res->recovering, list);
1085                } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1086                        mlog(0, "found UNKNOWN owner while doing recovery "
1087                                  "for node %u. sending it.\n", dead_node);
1088                        list_move_tail(&res->recovering, list);
1089                }
1090        }
1091        spin_unlock(&dlm->spinlock);
1092}
1093
1094static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1095{
1096        int total_locks = 0;
1097        struct list_head *iter, *queue = &res->granted;
1098        int i;
1099
1100        for (i=0; i<3; i++) {
1101                list_for_each(iter, queue)
1102                        total_locks++;
1103                queue++;
1104        }
1105        return total_locks;
1106}
1107
1108
1109static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1110                                      struct dlm_migratable_lockres *mres,
1111                                      u8 send_to,
1112                                      struct dlm_lock_resource *res,
1113                                      int total_locks)
1114{
1115        u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1116        int mres_total_locks = be32_to_cpu(mres->total_locks);
1117        int sz, ret = 0, status = 0;
1118        u8 orig_flags = mres->flags,
1119           orig_master = mres->master;
1120
1121        BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1122        if (!mres->num_locks)
1123                return 0;
1124
1125        sz = sizeof(struct dlm_migratable_lockres) +
1126                (mres->num_locks * sizeof(struct dlm_migratable_lock));
1127
1128        /* add an all-done flag if we reached the last lock */
1129        orig_flags = mres->flags;
1130        BUG_ON(total_locks > mres_total_locks);
1131        if (total_locks == mres_total_locks)
1132                mres->flags |= DLM_MRES_ALL_DONE;
1133
1134        mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
1135             dlm->name, res->lockname.len, res->lockname.name,
1136             orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
1137             send_to);
1138
1139        /* send it */
1140        ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1141                                 sz, send_to, &status);
1142        if (ret < 0) {
1143                /* XXX: negative status is not handled.
1144                 * this will end up killing this node. */
1145                mlog(ML_ERROR, "%s: res %.*s, Error %d send MIG_LOCKRES to "
1146                     "node %u (%s)\n", dlm->name, mres->lockname_len,
1147                     mres->lockname, ret, send_to,
1148                     (orig_flags & DLM_MRES_MIGRATION ?
1149                      "migration" : "recovery"));
1150        } else {
1151                /* might get an -ENOMEM back here */
1152                ret = status;
1153                if (ret < 0) {
1154                        mlog_errno(ret);
1155
1156                        if (ret == -EFAULT) {
1157                                mlog(ML_ERROR, "node %u told me to kill "
1158                                     "myself!\n", send_to);
1159                                BUG();
1160                        }
1161                }
1162        }
1163
1164        /* zero and reinit the message buffer */
1165        dlm_init_migratable_lockres(mres, res->lockname.name,
1166                                    res->lockname.len, mres_total_locks,
1167                                    mig_cookie, orig_flags, orig_master);
1168        return ret;
1169}
1170
1171static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1172                                        const char *lockname, int namelen,
1173                                        int total_locks, u64 cookie,
1174                                        u8 flags, u8 master)
1175{
1176        /* mres here is one full page */
1177        clear_page(mres);
1178        mres->lockname_len = namelen;
1179        memcpy(mres->lockname, lockname, namelen);
1180        mres->num_locks = 0;
1181        mres->total_locks = cpu_to_be32(total_locks);
1182        mres->mig_cookie = cpu_to_be64(cookie);
1183        mres->flags = flags;
1184        mres->master = master;
1185}
1186
1187static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
1188                                          struct dlm_migratable_lockres *mres,
1189                                          int queue)
1190{
1191        if (!lock->lksb)
1192               return;
1193
1194        /* Ignore lvb in all locks in the blocked list */
1195        if (queue == DLM_BLOCKED_LIST)
1196                return;
1197
1198        /* Only consider lvbs in locks with granted EX or PR lock levels */
1199        if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
1200                return;
1201
1202        if (dlm_lvb_is_empty(mres->lvb)) {
1203                memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1204                return;
1205        }
1206
1207        /* Ensure the lvb copied for migration matches in other valid locks */
1208        if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
1209                return;
1210
1211        mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
1212             "node=%u\n",
1213             dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
1214             dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
1215             lock->lockres->lockname.len, lock->lockres->lockname.name,
1216             lock->ml.node);
1217        dlm_print_one_lock_resource(lock->lockres);
1218        BUG();
1219}
1220
1221/* returns 1 if this lock fills the network structure,
1222 * 0 otherwise */
1223static int dlm_add_lock_to_array(struct dlm_lock *lock,
1224                                 struct dlm_migratable_lockres *mres, int queue)
1225{
1226        struct dlm_migratable_lock *ml;
1227        int lock_num = mres->num_locks;
1228
1229        ml = &(mres->ml[lock_num]);
1230        ml->cookie = lock->ml.cookie;
1231        ml->type = lock->ml.type;
1232        ml->convert_type = lock->ml.convert_type;
1233        ml->highest_blocked = lock->ml.highest_blocked;
1234        ml->list = queue;
1235        if (lock->lksb) {
1236                ml->flags = lock->lksb->flags;
1237                dlm_prepare_lvb_for_migration(lock, mres, queue);
1238        }
1239        ml->node = lock->ml.node;
1240        mres->num_locks++;
1241        /* we reached the max, send this network message */
1242        if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1243                return 1;
1244        return 0;
1245}
1246
1247static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1248                               struct dlm_migratable_lockres *mres)
1249{
1250        struct dlm_lock dummy;
1251        memset(&dummy, 0, sizeof(dummy));
1252        dummy.ml.cookie = 0;
1253        dummy.ml.type = LKM_IVMODE;
1254        dummy.ml.convert_type = LKM_IVMODE;
1255        dummy.ml.highest_blocked = LKM_IVMODE;
1256        dummy.lksb = NULL;
1257        dummy.ml.node = dlm->node_num;
1258        dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1259}
1260
1261static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1262                                    struct dlm_migratable_lock *ml,
1263                                    u8 *nodenum)
1264{
1265        if (unlikely(ml->cookie == 0 &&
1266            ml->type == LKM_IVMODE &&
1267            ml->convert_type == LKM_IVMODE &&
1268            ml->highest_blocked == LKM_IVMODE &&
1269            ml->list == DLM_BLOCKED_LIST)) {
1270                *nodenum = ml->node;
1271                return 1;
1272        }
1273        return 0;
1274}
1275
1276int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1277                         struct dlm_migratable_lockres *mres,
1278                         u8 send_to, u8 flags)
1279{
1280        struct list_head *queue;
1281        int total_locks, i;
1282        u64 mig_cookie = 0;
1283        struct dlm_lock *lock;
1284        int ret = 0;
1285
1286        BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1287
1288        mlog(0, "sending to %u\n", send_to);
1289
1290        total_locks = dlm_num_locks_in_lockres(res);
1291        if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1292                /* rare, but possible */
1293                mlog(0, "argh.  lockres has %d locks.  this will "
1294                          "require more than one network packet to "
1295                          "migrate\n", total_locks);
1296                mig_cookie = dlm_get_next_mig_cookie();
1297        }
1298
1299        dlm_init_migratable_lockres(mres, res->lockname.name,
1300                                    res->lockname.len, total_locks,
1301                                    mig_cookie, flags, res->owner);
1302
1303        total_locks = 0;
1304        for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1305                queue = dlm_list_idx_to_ptr(res, i);
1306                list_for_each_entry(lock, queue, list) {
1307                        /* add another lock. */
1308                        total_locks++;
1309                        if (!dlm_add_lock_to_array(lock, mres, i))
1310                                continue;
1311
1312                        /* this filled the lock message,
1313                         * we must send it immediately. */
1314                        ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1315                                                       res, total_locks);
1316                        if (ret < 0)
1317                                goto error;
1318                }
1319        }
1320        if (total_locks == 0) {
1321                /* send a dummy lock to indicate a mastery reference only */
1322                mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1323                     dlm->name, res->lockname.len, res->lockname.name,
1324                     send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1325                     "migration");
1326                dlm_add_dummy_lock(dlm, mres);
1327        }
1328        /* flush any remaining locks */
1329        ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1330        if (ret < 0)
1331                goto error;
1332        return ret;
1333
1334error:
1335        mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1336             dlm->name, ret);
1337        if (!dlm_is_host_down(ret))
1338                BUG();
1339        mlog(0, "%s: node %u went down while sending %s "
1340             "lockres %.*s\n", dlm->name, send_to,
1341             flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1342             res->lockname.len, res->lockname.name);
1343        return ret;
1344}
1345
1346
1347
1348/*
1349 * this message will contain no more than one page worth of
1350 * recovery data, and it will work on only one lockres.
1351 * there may be many locks in this page, and we may need to wait
1352 * for additional packets to complete all the locks (rare, but
1353 * possible).
1354 */
1355/*
1356 * NOTE: the allocation error cases here are scary
1357 * we really cannot afford to fail an alloc in recovery
1358 * do we spin?  returning an error only delays the problem really
1359 */
1360
1361int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1362                            void **ret_data)
1363{
1364        struct dlm_ctxt *dlm = data;
1365        struct dlm_migratable_lockres *mres =
1366                (struct dlm_migratable_lockres *)msg->buf;
1367        int ret = 0;
1368        u8 real_master;
1369        u8 extra_refs = 0;
1370        char *buf = NULL;
1371        struct dlm_work_item *item = NULL;
1372        struct dlm_lock_resource *res = NULL;
1373
1374        if (!dlm_grab(dlm))
1375                return -EINVAL;
1376
1377        BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1378
1379        real_master = mres->master;
1380        if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1381                /* cannot migrate a lockres with no master */
1382                BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1383        }
1384
1385        mlog(0, "%s message received from node %u\n",
1386                  (mres->flags & DLM_MRES_RECOVERY) ?
1387                  "recovery" : "migration", mres->master);
1388        if (mres->flags & DLM_MRES_ALL_DONE)
1389                mlog(0, "all done flag.  all lockres data received!\n");
1390
1391        ret = -ENOMEM;
1392        buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1393        item = kzalloc(sizeof(*item), GFP_NOFS);
1394        if (!buf || !item)
1395                goto leave;
1396
1397        /* lookup the lock to see if we have a secondary queue for this
1398         * already...  just add the locks in and this will have its owner
1399         * and RECOVERY flag changed when it completes. */
1400        res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1401        if (res) {
1402                /* this will get a ref on res */
1403                /* mark it as recovering/migrating and hash it */
1404                spin_lock(&res->spinlock);
1405                if (mres->flags & DLM_MRES_RECOVERY) {
1406                        res->state |= DLM_LOCK_RES_RECOVERING;
1407                } else {
1408                        if (res->state & DLM_LOCK_RES_MIGRATING) {
1409                                /* this is at least the second
1410                                 * lockres message */
1411                                mlog(0, "lock %.*s is already migrating\n",
1412                                          mres->lockname_len,
1413                                          mres->lockname);
1414                        } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1415                                /* caller should BUG */
1416                                mlog(ML_ERROR, "node is attempting to migrate "
1417                                     "lock %.*s, but marked as recovering!\n",
1418                                     mres->lockname_len, mres->lockname);
1419                                ret = -EFAULT;
1420                                spin_unlock(&res->spinlock);
1421                                dlm_lockres_put(res);
1422                                goto leave;
1423                        }
1424                        res->state |= DLM_LOCK_RES_MIGRATING;
1425                }
1426                spin_unlock(&res->spinlock);
1427        } else {
1428                /* need to allocate, just like if it was
1429                 * mastered here normally  */
1430                res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1431                if (!res)
1432                        goto leave;
1433
1434                /* to match the ref that we would have gotten if
1435                 * dlm_lookup_lockres had succeeded */
1436                dlm_lockres_get(res);
1437
1438                /* mark it as recovering/migrating and hash it */
1439                if (mres->flags & DLM_MRES_RECOVERY)
1440                        res->state |= DLM_LOCK_RES_RECOVERING;
1441                else
1442                        res->state |= DLM_LOCK_RES_MIGRATING;
1443
1444                spin_lock(&dlm->spinlock);
1445                __dlm_insert_lockres(dlm, res);
1446                spin_unlock(&dlm->spinlock);
1447
1448                /* Add an extra ref for this lock-less lockres lest the
1449                 * dlm_thread purges it before we get the chance to add
1450                 * locks to it */
1451                dlm_lockres_get(res);
1452
1453                /* There are three refs that need to be put.
1454                 * 1. Taken above.
1455                 * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
1456                 * 3. dlm_lookup_lockres()
1457                 * The first one is handled at the end of this function. The
1458                 * other two are handled in the worker thread after locks have
1459                 * been attached. Yes, we don't wait for purge time to match
1460                 * kref_init. The lockres will still have atleast one ref
1461                 * added because it is in the hash __dlm_insert_lockres() */
1462                extra_refs++;
1463
1464                /* now that the new lockres is inserted,
1465                 * make it usable by other processes */
1466                spin_lock(&res->spinlock);
1467                res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1468                spin_unlock(&res->spinlock);
1469                wake_up(&res->wq);
1470        }
1471
1472        /* at this point we have allocated everything we need,
1473         * and we have a hashed lockres with an extra ref and
1474         * the proper res->state flags. */
1475        ret = 0;
1476        spin_lock(&res->spinlock);
1477        /* drop this either when master requery finds a different master
1478         * or when a lock is added by the recovery worker */
1479        dlm_lockres_grab_inflight_ref(dlm, res);
1480        if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1481                /* migration cannot have an unknown master */
1482                BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1483                mlog(0, "recovery has passed me a lockres with an "
1484                          "unknown owner.. will need to requery: "
1485                          "%.*s\n", mres->lockname_len, mres->lockname);
1486        } else {
1487                /* take a reference now to pin the lockres, drop it
1488                 * when locks are added in the worker */
1489                dlm_change_lockres_owner(dlm, res, dlm->node_num);
1490        }
1491        spin_unlock(&res->spinlock);
1492
1493        /* queue up work for dlm_mig_lockres_worker */
1494        dlm_grab(dlm);  /* get an extra ref for the work item */
1495        memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1496        dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1497        item->u.ml.lockres = res; /* already have a ref */
1498        item->u.ml.real_master = real_master;
1499        item->u.ml.extra_ref = extra_refs;
1500        spin_lock(&dlm->work_lock);
1501        list_add_tail(&item->list, &dlm->work_list);
1502        spin_unlock(&dlm->work_lock);
1503        queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1504
1505leave:
1506        /* One extra ref taken needs to be put here */
1507        if (extra_refs)
1508                dlm_lockres_put(res);
1509
1510        dlm_put(dlm);
1511        if (ret < 0) {
1512                kfree(buf);
1513                kfree(item);
1514                mlog_errno(ret);
1515        }
1516
1517        return ret;
1518}
1519
1520
1521static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1522{
1523        struct dlm_ctxt *dlm;
1524        struct dlm_migratable_lockres *mres;
1525        int ret = 0;
1526        struct dlm_lock_resource *res;
1527        u8 real_master;
1528        u8 extra_ref;
1529
1530        dlm = item->dlm;
1531        mres = (struct dlm_migratable_lockres *)data;
1532
1533        res = item->u.ml.lockres;
1534        real_master = item->u.ml.real_master;
1535        extra_ref = item->u.ml.extra_ref;
1536
1537        if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1538                /* this case is super-rare. only occurs if
1539                 * node death happens during migration. */
1540again:
1541                ret = dlm_lockres_master_requery(dlm, res, &real_master);
1542                if (ret < 0) {
1543                        mlog(0, "dlm_lockres_master_requery ret=%d\n",
1544                                  ret);
1545                        goto again;
1546                }
1547                if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1548                        mlog(0, "lockres %.*s not claimed.  "
1549                                   "this node will take it.\n",
1550                                   res->lockname.len, res->lockname.name);
1551                } else {
1552                        spin_lock(&res->spinlock);
1553                        dlm_lockres_drop_inflight_ref(dlm, res);
1554                        spin_unlock(&res->spinlock);
1555                        mlog(0, "master needs to respond to sender "
1556                                  "that node %u still owns %.*s\n",
1557                                  real_master, res->lockname.len,
1558                                  res->lockname.name);
1559                        /* cannot touch this lockres */
1560                        goto leave;
1561                }
1562        }
1563
1564        ret = dlm_process_recovery_data(dlm, res, mres);
1565        if (ret < 0)
1566                mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1567        else
1568                mlog(0, "dlm_process_recovery_data succeeded\n");
1569
1570        if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1571                           (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1572                ret = dlm_finish_migration(dlm, res, mres->master);
1573                if (ret < 0)
1574                        mlog_errno(ret);
1575        }
1576
1577leave:
1578        /* See comment in dlm_mig_lockres_handler() */
1579        if (res) {
1580                if (extra_ref)
1581                        dlm_lockres_put(res);
1582                dlm_lockres_put(res);
1583        }
1584        kfree(data);
1585}
1586
1587
1588
1589static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1590                                      struct dlm_lock_resource *res,
1591                                      u8 *real_master)
1592{
1593        struct dlm_node_iter iter;
1594        int nodenum;
1595        int ret = 0;
1596
1597        *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1598
1599        /* we only reach here if one of the two nodes in a
1600         * migration died while the migration was in progress.
1601         * at this point we need to requery the master.  we
1602         * know that the new_master got as far as creating
1603         * an mle on at least one node, but we do not know
1604         * if any nodes had actually cleared the mle and set
1605         * the master to the new_master.  the old master
1606         * is supposed to set the owner to UNKNOWN in the
1607         * event of a new_master death, so the only possible
1608         * responses that we can get from nodes here are
1609         * that the master is new_master, or that the master
1610         * is UNKNOWN.
1611         * if all nodes come back with UNKNOWN then we know
1612         * the lock needs remastering here.
1613         * if any node comes back with a valid master, check
1614         * to see if that master is the one that we are
1615         * recovering.  if so, then the new_master died and
1616         * we need to remaster this lock.  if not, then the
1617         * new_master survived and that node will respond to
1618         * other nodes about the owner.
1619         * if there is an owner, this node needs to dump this
1620         * lockres and alert the sender that this lockres
1621         * was rejected. */
1622        spin_lock(&dlm->spinlock);
1623        dlm_node_iter_init(dlm->domain_map, &iter);
1624        spin_unlock(&dlm->spinlock);
1625
1626        while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1627                /* do not send to self */
1628                if (nodenum == dlm->node_num)
1629                        continue;
1630                ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1631                if (ret < 0) {
1632                        mlog_errno(ret);
1633                        if (!dlm_is_host_down(ret))
1634                                BUG();
1635                        /* host is down, so answer for that node would be
1636                         * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1637                }
1638                if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1639                        mlog(0, "lock master is %u\n", *real_master);
1640                        break;
1641                }
1642        }
1643        return ret;
1644}
1645
1646
1647int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1648                          u8 nodenum, u8 *real_master)
1649{
1650        int ret = -EINVAL;
1651        struct dlm_master_requery req;
1652        int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1653
1654        memset(&req, 0, sizeof(req));
1655        req.node_idx = dlm->node_num;
1656        req.namelen = res->lockname.len;
1657        memcpy(req.name, res->lockname.name, res->lockname.len);
1658
1659resend:
1660        ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1661                                 &req, sizeof(req), nodenum, &status);
1662        if (ret < 0)
1663                mlog(ML_ERROR, "Error %d when sending message %u (key "
1664                     "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
1665                     dlm->key, nodenum);
1666        else if (status == -ENOMEM) {
1667                mlog_errno(status);
1668                msleep(50);
1669                goto resend;
1670        } else {
1671                BUG_ON(status < 0);
1672                BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1673                *real_master = (u8) (status & 0xff);
1674                mlog(0, "node %u responded to master requery with %u\n",
1675                          nodenum, *real_master);
1676                ret = 0;
1677        }
1678        return ret;
1679}
1680
1681
1682/* this function cannot error, so unless the sending
1683 * or receiving of the message failed, the owner can
1684 * be trusted */
1685int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1686                               void **ret_data)
1687{
1688        struct dlm_ctxt *dlm = data;
1689        struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1690        struct dlm_lock_resource *res = NULL;
1691        unsigned int hash;
1692        int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1693        u32 flags = DLM_ASSERT_MASTER_REQUERY;
1694
1695        if (!dlm_grab(dlm)) {
1696                /* since the domain has gone away on this
1697                 * node, the proper response is UNKNOWN */
1698                return master;
1699        }
1700
1701        hash = dlm_lockid_hash(req->name, req->namelen);
1702
1703        spin_lock(&dlm->spinlock);
1704        res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1705        if (res) {
1706                spin_lock(&res->spinlock);
1707                master = res->owner;
1708                if (master == dlm->node_num) {
1709                        int ret = dlm_dispatch_assert_master(dlm, res,
1710                                                             0, 0, flags);
1711                        if (ret < 0) {
1712                                mlog_errno(ret);
1713                                spin_unlock(&res->spinlock);
1714                                dlm_lockres_put(res);
1715                                spin_unlock(&dlm->spinlock);
1716                                dlm_put(dlm);
1717                                /* sender will take care of this and retry */
1718                                return ret;
1719                        } else
1720                                __dlm_lockres_grab_inflight_worker(dlm, res);
1721                        spin_unlock(&res->spinlock);
1722                } else {
1723                        /* put.. incase we are not the master */
1724                        spin_unlock(&res->spinlock);
1725                        dlm_lockres_put(res);
1726                }
1727        }
1728        spin_unlock(&dlm->spinlock);
1729
1730        dlm_put(dlm);
1731        return master;
1732}
1733
1734static inline struct list_head *
1735dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1736{
1737        struct list_head *ret;
1738        BUG_ON(list_num < 0);
1739        BUG_ON(list_num > 2);
1740        ret = &(res->granted);
1741        ret += list_num;
1742        return ret;
1743}
1744/* TODO: do ast flush business
1745 * TODO: do MIGRATING and RECOVERING spinning
1746 */
1747
1748/*
1749* NOTE about in-flight requests during migration:
1750*
1751* Before attempting the migrate, the master has marked the lockres as
1752* MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1753* requests either got queued before the MIGRATING flag got set, in which
1754* case the lock data will reflect the change and a return message is on
1755* the way, or the request failed to get in before MIGRATING got set.  In
1756* this case, the caller will be told to spin and wait for the MIGRATING
1757* flag to be dropped, then recheck the master.
1758* This holds true for the convert, cancel and unlock cases, and since lvb
1759* updates are tied to these same messages, it applies to lvb updates as
1760* well.  For the lock case, there is no way a lock can be on the master
1761* queue and not be on the secondary queue since the lock is always added
1762* locally first.  This means that the new target node will never be sent
1763* a lock that he doesn't already have on the list.
1764* In total, this means that the local lock is correct and should not be
1765* updated to match the one sent by the master.  Any messages sent back
1766* from the master before the MIGRATING flag will bring the lock properly
1767* up-to-date, and the change will be ordered properly for the waiter.
1768* We will *not* attempt to modify the lock underneath the waiter.
1769*/
1770
1771static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1772                                     struct dlm_lock_resource *res,
1773                                     struct dlm_migratable_lockres *mres)
1774{
1775        struct dlm_migratable_lock *ml;
1776        struct list_head *queue, *iter;
1777        struct list_head *tmpq = NULL;
1778        struct dlm_lock *newlock = NULL;
1779        struct dlm_lockstatus *lksb = NULL;
1780        int ret = 0;
1781        int i, j, bad;
1782        struct dlm_lock *lock;
1783        u8 from = O2NM_MAX_NODES;
1784        unsigned int added = 0;
1785        __be64 c;
1786
1787        mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1788        for (i=0; i<mres->num_locks; i++) {
1789                ml = &(mres->ml[i]);
1790
1791                if (dlm_is_dummy_lock(dlm, ml, &from)) {
1792                        /* placeholder, just need to set the refmap bit */
1793                        BUG_ON(mres->num_locks != 1);
1794                        mlog(0, "%s:%.*s: dummy lock for %u\n",
1795                             dlm->name, mres->lockname_len, mres->lockname,
1796                             from);
1797                        spin_lock(&res->spinlock);
1798                        dlm_lockres_set_refmap_bit(dlm, res, from);
1799                        spin_unlock(&res->spinlock);
1800                        added++;
1801                        break;
1802                }
1803                BUG_ON(ml->highest_blocked != LKM_IVMODE);
1804                newlock = NULL;
1805                lksb = NULL;
1806
1807                queue = dlm_list_num_to_pointer(res, ml->list);
1808                tmpq = NULL;
1809
1810                /* if the lock is for the local node it needs to
1811                 * be moved to the proper location within the queue.
1812                 * do not allocate a new lock structure. */
1813                if (ml->node == dlm->node_num) {
1814                        /* MIGRATION ONLY! */
1815                        BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1816
1817                        lock = NULL;
1818                        spin_lock(&res->spinlock);
1819                        for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1820                                tmpq = dlm_list_idx_to_ptr(res, j);
1821                                list_for_each(iter, tmpq) {
1822                                        lock = list_entry(iter,
1823                                                  struct dlm_lock, list);
1824                                        if (lock->ml.cookie == ml->cookie)
1825                                                break;
1826                                        lock = NULL;
1827                                }
1828                                if (lock)
1829                                        break;
1830                        }
1831
1832                        /* lock is always created locally first, and
1833                         * destroyed locally last.  it must be on the list */
1834                        if (!lock) {
1835                                c = ml->cookie;
1836                                mlog(ML_ERROR, "Could not find local lock "
1837                                               "with cookie %u:%llu, node %u, "
1838                                               "list %u, flags 0x%x, type %d, "
1839                                               "conv %d, highest blocked %d\n",
1840                                     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1841                                     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1842                                     ml->node, ml->list, ml->flags, ml->type,
1843                                     ml->convert_type, ml->highest_blocked);
1844                                __dlm_print_one_lock_resource(res);
1845                                BUG();
1846                        }
1847
1848                        if (lock->ml.node != ml->node) {
1849                                c = lock->ml.cookie;
1850                                mlog(ML_ERROR, "Mismatched node# in lock "
1851                                     "cookie %u:%llu, name %.*s, node %u\n",
1852                                     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1853                                     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1854                                     res->lockname.len, res->lockname.name,
1855                                     lock->ml.node);
1856                                c = ml->cookie;
1857                                mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
1858                                     "node %u, list %u, flags 0x%x, type %d, "
1859                                     "conv %d, highest blocked %d\n",
1860                                     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1861                                     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1862                                     ml->node, ml->list, ml->flags, ml->type,
1863                                     ml->convert_type, ml->highest_blocked);
1864                                __dlm_print_one_lock_resource(res);
1865                                BUG();
1866                        }
1867
1868                        if (tmpq != queue) {
1869                                c = ml->cookie;
1870                                mlog(0, "Lock cookie %u:%llu was on list %u "
1871                                     "instead of list %u for %.*s\n",
1872                                     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1873                                     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1874                                     j, ml->list, res->lockname.len,
1875                                     res->lockname.name);
1876                                __dlm_print_one_lock_resource(res);
1877                                spin_unlock(&res->spinlock);
1878                                continue;
1879                        }
1880
1881                        /* see NOTE above about why we do not update
1882                         * to match the master here */
1883
1884                        /* move the lock to its proper place */
1885                        /* do not alter lock refcount.  switching lists. */
1886                        list_move_tail(&lock->list, queue);
1887                        spin_unlock(&res->spinlock);
1888                        added++;
1889
1890                        mlog(0, "just reordered a local lock!\n");
1891                        continue;
1892                }
1893
1894                /* lock is for another node. */
1895                newlock = dlm_new_lock(ml->type, ml->node,
1896                                       be64_to_cpu(ml->cookie), NULL);
1897                if (!newlock) {
1898                        ret = -ENOMEM;
1899                        goto leave;
1900                }
1901                lksb = newlock->lksb;
1902                dlm_lock_attach_lockres(newlock, res);
1903
1904                if (ml->convert_type != LKM_IVMODE) {
1905                        BUG_ON(queue != &res->converting);
1906                        newlock->ml.convert_type = ml->convert_type;
1907                }
1908                lksb->flags |= (ml->flags &
1909                                (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1910
1911                if (ml->type == LKM_NLMODE)
1912                        goto skip_lvb;
1913
1914                /*
1915                 * If the lock is in the blocked list it can't have a valid lvb,
1916                 * so skip it
1917                 */
1918                if (ml->list == DLM_BLOCKED_LIST)
1919                        goto skip_lvb;
1920
1921                if (!dlm_lvb_is_empty(mres->lvb)) {
1922                        if (lksb->flags & DLM_LKSB_PUT_LVB) {
1923                                /* other node was trying to update
1924                                 * lvb when node died.  recreate the
1925                                 * lksb with the updated lvb. */
1926                                memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1927                                /* the lock resource lvb update must happen
1928                                 * NOW, before the spinlock is dropped.
1929                                 * we no longer wait for the AST to update
1930                                 * the lvb. */
1931                                memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1932                        } else {
1933                                /* otherwise, the node is sending its
1934                                 * most recent valid lvb info */
1935                                BUG_ON(ml->type != LKM_EXMODE &&
1936                                       ml->type != LKM_PRMODE);
1937                                if (!dlm_lvb_is_empty(res->lvb) &&
1938                                    (ml->type == LKM_EXMODE ||
1939                                     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1940                                        int i;
1941                                        mlog(ML_ERROR, "%s:%.*s: received bad "
1942                                             "lvb! type=%d\n", dlm->name,
1943                                             res->lockname.len,
1944                                             res->lockname.name, ml->type);
1945                                        printk("lockres lvb=[");
1946                                        for (i=0; i<DLM_LVB_LEN; i++)
1947                                                printk("%02x", res->lvb[i]);
1948                                        printk("]\nmigrated lvb=[");
1949                                        for (i=0; i<DLM_LVB_LEN; i++)
1950                                                printk("%02x", mres->lvb[i]);
1951                                        printk("]\n");
1952                                        dlm_print_one_lock_resource(res);
1953                                        BUG();
1954                                }
1955                                memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1956                        }
1957                }
1958skip_lvb:
1959
1960                /* NOTE:
1961                 * wrt lock queue ordering and recovery:
1962                 *    1. order of locks on granted queue is
1963                 *       meaningless.
1964                 *    2. order of locks on converting queue is
1965                 *       LOST with the node death.  sorry charlie.
1966                 *    3. order of locks on the blocked queue is
1967                 *       also LOST.
1968                 * order of locks does not affect integrity, it
1969                 * just means that a lock request may get pushed
1970                 * back in line as a result of the node death.
1971                 * also note that for a given node the lock order
1972                 * for its secondary queue locks is preserved
1973                 * relative to each other, but clearly *not*
1974                 * preserved relative to locks from other nodes.
1975                 */
1976                bad = 0;
1977                spin_lock(&res->spinlock);
1978                list_for_each_entry(lock, queue, list) {
1979                        if (lock->ml.cookie == ml->cookie) {
1980                                c = lock->ml.cookie;
1981                                mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1982                                     "exists on this lockres!\n", dlm->name,
1983                                     res->lockname.len, res->lockname.name,
1984                                     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1985                                     dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1986
1987                                mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1988                                     "node=%u, cookie=%u:%llu, queue=%d\n",
1989                                     ml->type, ml->convert_type, ml->node,
1990                                     dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
1991                                     dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
1992                                     ml->list);
1993
1994                                __dlm_print_one_lock_resource(res);
1995                                bad = 1;
1996                                break;
1997                        }
1998                }
1999                if (!bad) {
2000                        dlm_lock_get(newlock);
2001                        if (mres->flags & DLM_MRES_RECOVERY &&
2002                                        ml->list == DLM_CONVERTING_LIST &&
2003                                        newlock->ml.type >
2004                                        newlock->ml.convert_type) {
2005                                /* newlock is doing downconvert, add it to the
2006                                 * head of converting list */
2007                                list_add(&newlock->list, queue);
2008                        } else
2009                                list_add_tail(&newlock->list, queue);
2010                        mlog(0, "%s:%.*s: added lock for node %u, "
2011                             "setting refmap bit\n", dlm->name,
2012                             res->lockname.len, res->lockname.name, ml->node);
2013                        dlm_lockres_set_refmap_bit(dlm, res, ml->node);
2014                        added++;
2015                }
2016                spin_unlock(&res->spinlock);
2017        }
2018        mlog(0, "done running all the locks\n");
2019
2020leave:
2021        /* balance the ref taken when the work was queued */
2022        spin_lock(&res->spinlock);
2023        dlm_lockres_drop_inflight_ref(dlm, res);
2024        spin_unlock(&res->spinlock);
2025
2026        if (ret < 0)
2027                mlog_errno(ret);
2028
2029        return ret;
2030}
2031
2032void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
2033                                       struct dlm_lock_resource *res)
2034{
2035        int i;
2036        struct list_head *queue;
2037        struct dlm_lock *lock, *next;
2038
2039        assert_spin_locked(&dlm->spinlock);
2040        assert_spin_locked(&res->spinlock);
2041        res->state |= DLM_LOCK_RES_RECOVERING;
2042        if (!list_empty(&res->recovering)) {
2043                mlog(0,
2044                     "Recovering res %s:%.*s, is already on recovery list!\n",
2045                     dlm->name, res->lockname.len, res->lockname.name);
2046                list_del_init(&res->recovering);
2047                dlm_lockres_put(res);
2048        }
2049        /* We need to hold a reference while on the recovery list */
2050        dlm_lockres_get(res);
2051        list_add_tail(&res->recovering, &dlm->reco.resources);
2052
2053        /* find any pending locks and put them back on proper list */
2054        for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
2055                queue = dlm_list_idx_to_ptr(res, i);
2056                list_for_each_entry_safe(lock, next, queue, list) {
2057                        dlm_lock_get(lock);
2058                        if (lock->convert_pending) {
2059                                /* move converting lock back to granted */
2060                                BUG_ON(i != DLM_CONVERTING_LIST);
2061                                mlog(0, "node died with convert pending "
2062                                     "on %.*s. move back to granted list.\n",
2063                                     res->lockname.len, res->lockname.name);
2064                                dlm_revert_pending_convert(res, lock);
2065                                lock->convert_pending = 0;
2066                        } else if (lock->lock_pending) {
2067                                /* remove pending lock requests completely */
2068                                BUG_ON(i != DLM_BLOCKED_LIST);
2069                                mlog(0, "node died with lock pending "
2070                                     "on %.*s. remove from blocked list and skip.\n",
2071                                     res->lockname.len, res->lockname.name);
2072                                /* lock will be floating until ref in
2073                                 * dlmlock_remote is freed after the network
2074                                 * call returns.  ok for it to not be on any
2075                                 * list since no ast can be called
2076                                 * (the master is dead). */
2077                                dlm_revert_pending_lock(res, lock);
2078                                lock->lock_pending = 0;
2079                        } else if (lock->unlock_pending) {
2080                                /* if an unlock was in progress, treat as
2081                                 * if this had completed successfully
2082                                 * before sending this lock state to the
2083                                 * new master.  note that the dlm_unlock
2084                                 * call is still responsible for calling
2085                                 * the unlockast.  that will happen after
2086                                 * the network call times out.  for now,
2087                                 * just move lists to prepare the new
2088                                 * recovery master.  */
2089                                BUG_ON(i != DLM_GRANTED_LIST);
2090                                mlog(0, "node died with unlock pending "
2091                                     "on %.*s. remove from blocked list and skip.\n",
2092                                     res->lockname.len, res->lockname.name);
2093                                dlm_commit_pending_unlock(res, lock);
2094                                lock->unlock_pending = 0;
2095                        } else if (lock->cancel_pending) {
2096                                /* if a cancel was in progress, treat as
2097                                 * if this had completed successfully
2098                                 * before sending this lock state to the
2099                                 * new master */
2100                                BUG_ON(i != DLM_CONVERTING_LIST);
2101                                mlog(0, "node died with cancel pending "
2102                                     "on %.*s. move back to granted list.\n",
2103                                     res->lockname.len, res->lockname.name);
2104                                dlm_commit_pending_cancel(res, lock);
2105                                lock->cancel_pending = 0;
2106                        }
2107                        dlm_lock_put(lock);
2108                }
2109        }
2110}
2111
2112
2113
2114/* removes all recovered locks from the recovery list.
2115 * sets the res->owner to the new master.
2116 * unsets the RECOVERY flag and wakes waiters. */
2117static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
2118                                              u8 dead_node, u8 new_master)
2119{
2120        int i;
2121        struct hlist_head *bucket;
2122        struct dlm_lock_resource *res, *next;
2123
2124        assert_spin_locked(&dlm->spinlock);
2125
2126        list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
2127                if (res->owner == dead_node) {
2128                        mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
2129                             dlm->name, res->lockname.len, res->lockname.name,
2130                             res->owner, new_master);
2131                        list_del_init(&res->recovering);
2132                        spin_lock(&res->spinlock);
2133                        /* new_master has our reference from
2134                         * the lock state sent during recovery */
2135                        dlm_change_lockres_owner(dlm, res, new_master);
2136                        res->state &= ~DLM_LOCK_RES_RECOVERING;
2137                        if (__dlm_lockres_has_locks(res))
2138                                __dlm_dirty_lockres(dlm, res);
2139                        spin_unlock(&res->spinlock);
2140                        wake_up(&res->wq);
2141                        dlm_lockres_put(res);
2142                }
2143        }
2144
2145        /* this will become unnecessary eventually, but
2146         * for now we need to run the whole hash, clear
2147         * the RECOVERING state and set the owner
2148         * if necessary */
2149        for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2150                bucket = dlm_lockres_hash(dlm, i);
2151                hlist_for_each_entry(res, bucket, hash_node) {
2152                        if (!(res->state & DLM_LOCK_RES_RECOVERING))
2153                                continue;
2154
2155                        if (res->owner != dead_node &&
2156                            res->owner != dlm->node_num)
2157                                continue;
2158
2159                        if (!list_empty(&res->recovering)) {
2160                                list_del_init(&res->recovering);
2161                                dlm_lockres_put(res);
2162                        }
2163
2164                        /* new_master has our reference from
2165                         * the lock state sent during recovery */
2166                        mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
2167                             dlm->name, res->lockname.len, res->lockname.name,
2168                             res->owner, new_master);
2169                        spin_lock(&res->spinlock);
2170                        dlm_change_lockres_owner(dlm, res, new_master);
2171                        res->state &= ~DLM_LOCK_RES_RECOVERING;
2172                        if (__dlm_lockres_has_locks(res))
2173                                __dlm_dirty_lockres(dlm, res);
2174                        spin_unlock(&res->spinlock);
2175                        wake_up(&res->wq);
2176                }
2177        }
2178}
2179
2180static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2181{
2182        if (local) {
2183                if (lock->ml.type != LKM_EXMODE &&
2184                    lock->ml.type != LKM_PRMODE)
2185                        return 1;
2186        } else if (lock->ml.type == LKM_EXMODE)
2187                return 1;
2188        return 0;
2189}
2190
2191static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2192                               struct dlm_lock_resource *res, u8 dead_node)
2193{
2194        struct list_head *queue;
2195        struct dlm_lock *lock;
2196        int blank_lvb = 0, local = 0;
2197        int i;
2198        u8 search_node;
2199
2200        assert_spin_locked(&dlm->spinlock);
2201        assert_spin_locked(&res->spinlock);
2202
2203        if (res->owner == dlm->node_num)
2204                /* if this node owned the lockres, and if the dead node
2205                 * had an EX when he died, blank out the lvb */
2206                search_node = dead_node;
2207        else {
2208                /* if this is a secondary lockres, and we had no EX or PR
2209                 * locks granted, we can no longer trust the lvb */
2210                search_node = dlm->node_num;
2211                local = 1;  /* check local state for valid lvb */
2212        }
2213
2214        for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2215                queue = dlm_list_idx_to_ptr(res, i);
2216                list_for_each_entry(lock, queue, list) {
2217                        if (lock->ml.node == search_node) {
2218                                if (dlm_lvb_needs_invalidation(lock, local)) {
2219                                        /* zero the lksb lvb and lockres lvb */
2220                                        blank_lvb = 1;
2221                                        memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2222                                }
2223                        }
2224                }
2225        }
2226
2227        if (blank_lvb) {
2228                mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2229                     res->lockname.len, res->lockname.name, dead_node);
2230                memset(res->lvb, 0, DLM_LVB_LEN);
2231        }
2232}
2233
2234static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2235                                struct dlm_lock_resource *res, u8 dead_node)
2236{
2237        struct dlm_lock *lock, *next;
2238        unsigned int freed = 0;
2239
2240        /* this node is the lockres master:
2241         * 1) remove any stale locks for the dead node
2242         * 2) if the dead node had an EX when he died, blank out the lvb
2243         */
2244        assert_spin_locked(&dlm->spinlock);
2245        assert_spin_locked(&res->spinlock);
2246
2247        /* We do two dlm_lock_put(). One for removing from list and the other is
2248         * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
2249
2250        /* TODO: check pending_asts, pending_basts here */
2251        list_for_each_entry_safe(lock, next, &res->granted, list) {
2252                if (lock->ml.node == dead_node) {
2253                        list_del_init(&lock->list);
2254                        dlm_lock_put(lock);
2255                        /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2256                        dlm_lock_put(lock);
2257                        freed++;
2258                }
2259        }
2260        list_for_each_entry_safe(lock, next, &res->converting, list) {
2261                if (lock->ml.node == dead_node) {
2262                        list_del_init(&lock->list);
2263                        dlm_lock_put(lock);
2264                        /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2265                        dlm_lock_put(lock);
2266                        freed++;
2267                }
2268        }
2269        list_for_each_entry_safe(lock, next, &res->blocked, list) {
2270                if (lock->ml.node == dead_node) {
2271                        list_del_init(&lock->list);
2272                        dlm_lock_put(lock);
2273                        /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2274                        dlm_lock_put(lock);
2275                        freed++;
2276                }
2277        }
2278
2279        if (freed) {
2280                mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2281                     "dropping ref from lockres\n", dlm->name,
2282                     res->lockname.len, res->lockname.name, freed, dead_node);
2283                if(!test_bit(dead_node, res->refmap)) {
2284                        mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
2285                             "but ref was not set\n", dlm->name,
2286                             res->lockname.len, res->lockname.name, freed, dead_node);
2287                        __dlm_print_one_lock_resource(res);
2288                }
2289                dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2290        } else if (test_bit(dead_node, res->refmap)) {
2291                mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2292                     "no locks and had not purged before dying\n", dlm->name,
2293                     res->lockname.len, res->lockname.name, dead_node);
2294                dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2295        }
2296
2297        /* do not kick thread yet */
2298        __dlm_dirty_lockres(dlm, res);
2299}
2300
2301/* if this node is the recovery master, and there are no
2302 * locks for a given lockres owned by this node that are in
2303 * either PR or EX mode, zero out the lvb before requesting.
2304 *
2305 */
2306
2307
2308static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2309{
2310        struct dlm_lock_resource *res;
2311        int i;
2312        struct hlist_head *bucket;
2313        struct dlm_lock *lock;
2314
2315
2316        /* purge any stale mles */
2317        dlm_clean_master_list(dlm, dead_node);
2318
2319        /*
2320         * now clean up all lock resources.  there are two rules:
2321         *
2322         * 1) if the dead node was the master, move the lockres
2323         *    to the recovering list.  set the RECOVERING flag.
2324         *    this lockres needs to be cleaned up before it can
2325         *    be used further.
2326         *
2327         * 2) if this node was the master, remove all locks from
2328         *    each of the lockres queues that were owned by the
2329         *    dead node.  once recovery finishes, the dlm thread
2330         *    can be kicked again to see if any ASTs or BASTs
2331         *    need to be fired as a result.
2332         */
2333        for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2334                bucket = dlm_lockres_hash(dlm, i);
2335                hlist_for_each_entry(res, bucket, hash_node) {
2336                        /* always prune any $RECOVERY entries for dead nodes,
2337                         * otherwise hangs can occur during later recovery */
2338                        if (dlm_is_recovery_lock(res->lockname.name,
2339                                                 res->lockname.len)) {
2340                                spin_lock(&res->spinlock);
2341                                list_for_each_entry(lock, &res->granted, list) {
2342                                        if (lock->ml.node == dead_node) {
2343                                                mlog(0, "AHA! there was "
2344                                                     "a $RECOVERY lock for dead "
2345                                                     "node %u (%s)!\n",
2346                                                     dead_node, dlm->name);
2347                                                list_del_init(&lock->list);
2348                                                dlm_lock_put(lock);
2349                                                break;
2350                                        }
2351                                }
2352                                spin_unlock(&res->spinlock);
2353                                continue;
2354                        }
2355                        spin_lock(&res->spinlock);
2356                        /* zero the lvb if necessary */
2357                        dlm_revalidate_lvb(dlm, res, dead_node);
2358                        if (res->owner == dead_node) {
2359                                if (res->state & DLM_LOCK_RES_DROPPING_REF) {
2360                                        mlog(ML_NOTICE, "%s: res %.*s, Skip "
2361                                             "recovery as it is being freed\n",
2362                                             dlm->name, res->lockname.len,
2363                                             res->lockname.name);
2364                                } else
2365                                        dlm_move_lockres_to_recovery_list(dlm,
2366                                                                          res);
2367
2368                        } else if (res->owner == dlm->node_num) {
2369                                dlm_free_dead_locks(dlm, res, dead_node);
2370                                __dlm_lockres_calc_usage(dlm, res);
2371                        } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2372                                if (test_bit(dead_node, res->refmap)) {
2373                                        mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2374                                                "no locks and had not purged before dying\n",
2375                                                dlm->name, res->lockname.len,
2376                                                res->lockname.name, dead_node);
2377                                        dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2378                                }
2379                        }
2380                        spin_unlock(&res->spinlock);
2381                }
2382        }
2383
2384}
2385
2386static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2387{
2388        assert_spin_locked(&dlm->spinlock);
2389
2390        if (dlm->reco.new_master == idx) {
2391                mlog(0, "%s: recovery master %d just died\n",
2392                     dlm->name, idx);
2393                if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2394                        /* finalize1 was reached, so it is safe to clear
2395                         * the new_master and dead_node.  that recovery
2396                         * is complete. */
2397                        mlog(0, "%s: dead master %d had reached "
2398                             "finalize1 state, clearing\n", dlm->name, idx);
2399                        dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2400                        __dlm_reset_recovery(dlm);
2401                }
2402        }
2403
2404        /* Clean up join state on node death. */
2405        if (dlm->joining_node == idx) {
2406                mlog(0, "Clearing join state for node %u\n", idx);
2407                __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2408        }
2409
2410        /* check to see if the node is already considered dead */
2411        if (!test_bit(idx, dlm->live_nodes_map)) {
2412                mlog(0, "for domain %s, node %d is already dead. "
2413                     "another node likely did recovery already.\n",
2414                     dlm->name, idx);
2415                return;
2416        }
2417
2418        /* check to see if we do not care about this node */
2419        if (!test_bit(idx, dlm->domain_map)) {
2420                /* This also catches the case that we get a node down
2421                 * but haven't joined the domain yet. */
2422                mlog(0, "node %u already removed from domain!\n", idx);
2423                return;
2424        }
2425
2426        clear_bit(idx, dlm->live_nodes_map);
2427
2428        /* make sure local cleanup occurs before the heartbeat events */
2429        if (!test_bit(idx, dlm->recovery_map))
2430                dlm_do_local_recovery_cleanup(dlm, idx);
2431
2432        /* notify anything attached to the heartbeat events */
2433        dlm_hb_event_notify_attached(dlm, idx, 0);
2434
2435        mlog(0, "node %u being removed from domain map!\n", idx);
2436        clear_bit(idx, dlm->domain_map);
2437        clear_bit(idx, dlm->exit_domain_map);
2438        /* wake up migration waiters if a node goes down.
2439         * perhaps later we can genericize this for other waiters. */
2440        wake_up(&dlm->migration_wq);
2441
2442        if (test_bit(idx, dlm->recovery_map))
2443                mlog(0, "domain %s, node %u already added "
2444                     "to recovery map!\n", dlm->name, idx);
2445        else
2446                set_bit(idx, dlm->recovery_map);
2447}
2448
2449void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2450{
2451        struct dlm_ctxt *dlm = data;
2452
2453        if (!dlm_grab(dlm))
2454                return;
2455
2456        /*
2457         * This will notify any dlm users that a node in our domain
2458         * went away without notifying us first.
2459         */
2460        if (test_bit(idx, dlm->domain_map))
2461                dlm_fire_domain_eviction_callbacks(dlm, idx);
2462
2463        spin_lock(&dlm->spinlock);
2464        __dlm_hb_node_down(dlm, idx);
2465        spin_unlock(&dlm->spinlock);
2466
2467        dlm_put(dlm);
2468}
2469
2470void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2471{
2472        struct dlm_ctxt *dlm = data;
2473
2474        if (!dlm_grab(dlm))
2475                return;
2476
2477        spin_lock(&dlm->spinlock);
2478        set_bit(idx, dlm->live_nodes_map);
2479        /* do NOT notify mle attached to the heartbeat events.
2480         * new nodes are not interesting in mastery until joined. */
2481        spin_unlock(&dlm->spinlock);
2482
2483        dlm_put(dlm);
2484}
2485
2486static void dlm_reco_ast(void *astdata)
2487{
2488        struct dlm_ctxt *dlm = astdata;
2489        mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2490             dlm->node_num, dlm->name);
2491}
2492static void dlm_reco_bast(void *astdata, int blocked_type)
2493{
2494        struct dlm_ctxt *dlm = astdata;
2495        mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2496             dlm->node_num, dlm->name);
2497}
2498static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2499{
2500        mlog(0, "unlockast for recovery lock fired!\n");
2501}
2502
2503/*
2504 * dlm_pick_recovery_master will continually attempt to use
2505 * dlmlock() on the special "$RECOVERY" lockres with the
2506 * LKM_NOQUEUE flag to get an EX.  every thread that enters
2507 * this function on each node racing to become the recovery
2508 * master will not stop attempting this until either:
2509 * a) this node gets the EX (and becomes the recovery master),
2510 * or b) dlm->reco.new_master gets set to some nodenum
2511 * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2512 * so each time a recovery master is needed, the entire cluster
2513 * will sync at this point.  if the new master dies, that will
2514 * be detected in dlm_do_recovery */
2515static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2516{
2517        enum dlm_status ret;
2518        struct dlm_lockstatus lksb;
2519        int status = -EINVAL;
2520
2521        mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2522             dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2523again:
2524        memset(&lksb, 0, sizeof(lksb));
2525
2526        ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2527                      DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2528                      dlm_reco_ast, dlm, dlm_reco_bast);
2529
2530        mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2531             dlm->name, ret, lksb.status);
2532
2533        if (ret == DLM_NORMAL) {
2534                mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2535                     dlm->name, dlm->node_num);
2536
2537                /* got the EX lock.  check to see if another node
2538                 * just became the reco master */
2539                if (dlm_reco_master_ready(dlm)) {
2540                        mlog(0, "%s: got reco EX lock, but %u will "
2541                             "do the recovery\n", dlm->name,
2542                             dlm->reco.new_master);
2543                        status = -EEXIST;
2544                } else {
2545                        status = 0;
2546
2547                        /* see if recovery was already finished elsewhere */
2548                        spin_lock(&dlm->spinlock);
2549                        if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2550                                status = -EINVAL;
2551                                mlog(0, "%s: got reco EX lock, but "
2552                                     "node got recovered already\n", dlm->name);
2553                                if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2554                                        mlog(ML_ERROR, "%s: new master is %u "
2555                                             "but no dead node!\n",
2556                                             dlm->name, dlm->reco.new_master);
2557                                        BUG();
2558                                }
2559                        }
2560                        spin_unlock(&dlm->spinlock);
2561                }
2562
2563                /* if this node has actually become the recovery master,
2564                 * set the master and send the messages to begin recovery */
2565                if (!status) {
2566                        mlog(0, "%s: dead=%u, this=%u, sending "
2567                             "begin_reco now\n", dlm->name,
2568                             dlm->reco.dead_node, dlm->node_num);
2569                        status = dlm_send_begin_reco_message(dlm,
2570                                      dlm->reco.dead_node);
2571                        /* this always succeeds */
2572                        BUG_ON(status);
2573
2574                        /* set the new_master to this node */
2575                        spin_lock(&dlm->spinlock);
2576                        dlm_set_reco_master(dlm, dlm->node_num);
2577                        spin_unlock(&dlm->spinlock);
2578                }
2579
2580                /* recovery lock is a special case.  ast will not get fired,
2581                 * so just go ahead and unlock it. */
2582                ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2583                if (ret == DLM_DENIED) {
2584                        mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2585                        ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2586                }
2587                if (ret != DLM_NORMAL) {
2588                        /* this would really suck. this could only happen
2589                         * if there was a network error during the unlock
2590                         * because of node death.  this means the unlock
2591                         * is actually "done" and the lock structure is
2592                         * even freed.  we can continue, but only
2593                         * because this specific lock name is special. */
2594                        mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2595                }
2596        } else if (ret == DLM_NOTQUEUED) {
2597                mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2598                     dlm->name, dlm->node_num);
2599                /* another node is master. wait on
2600                 * reco.new_master != O2NM_INVALID_NODE_NUM
2601                 * for at most one second */
2602                wait_event_timeout(dlm->dlm_reco_thread_wq,
2603                                         dlm_reco_master_ready(dlm),
2604                                         msecs_to_jiffies(1000));
2605                if (!dlm_reco_master_ready(dlm)) {
2606                        mlog(0, "%s: reco master taking awhile\n",
2607                             dlm->name);
2608                        goto again;
2609                }
2610                /* another node has informed this one that it is reco master */
2611                mlog(0, "%s: reco master %u is ready to recover %u\n",
2612                     dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2613                status = -EEXIST;
2614        } else if (ret == DLM_RECOVERING) {
2615                mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2616                     dlm->name, dlm->node_num);
2617                goto again;
2618        } else {
2619                struct dlm_lock_resource *res;
2620
2621                /* dlmlock returned something other than NOTQUEUED or NORMAL */
2622                mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2623                     "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2624                     dlm_errname(lksb.status));
2625                res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2626                                         DLM_RECOVERY_LOCK_NAME_LEN);
2627                if (res) {
2628                        dlm_print_one_lock_resource(res);
2629                        dlm_lockres_put(res);
2630                } else {
2631                        mlog(ML_ERROR, "recovery lock not found\n");
2632                }
2633                BUG();
2634        }
2635
2636        return status;
2637}
2638
2639static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2640{
2641        struct dlm_begin_reco br;
2642        int ret = 0;
2643        struct dlm_node_iter iter;
2644        int nodenum;
2645        int status;
2646
2647        mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2648
2649        spin_lock(&dlm->spinlock);
2650        dlm_node_iter_init(dlm->domain_map, &iter);
2651        spin_unlock(&dlm->spinlock);
2652
2653        clear_bit(dead_node, iter.node_map);
2654
2655        memset(&br, 0, sizeof(br));
2656        br.node_idx = dlm->node_num;
2657        br.dead_node = dead_node;
2658
2659        while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2660                ret = 0;
2661                if (nodenum == dead_node) {
2662                        mlog(0, "not sending begin reco to dead node "
2663                                  "%u\n", dead_node);
2664                        continue;
2665                }
2666                if (nodenum == dlm->node_num) {
2667                        mlog(0, "not sending begin reco to self\n");
2668                        continue;
2669                }
2670retry:
2671                ret = -EINVAL;
2672                mlog(0, "attempting to send begin reco msg to %d\n",
2673                          nodenum);
2674                ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2675                                         &br, sizeof(br), nodenum, &status);
2676                /* negative status is handled ok by caller here */
2677                if (ret >= 0)
2678                        ret = status;
2679                if (dlm_is_host_down(ret)) {
2680                        /* node is down.  not involved in recovery
2681                         * so just keep going */
2682                        mlog(ML_NOTICE, "%s: node %u was down when sending "
2683                             "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2684                        ret = 0;
2685                }
2686
2687                /*
2688                 * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
2689                 * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
2690                 * We are handling both for compatibility reasons.
2691                 */
2692                if (ret == -EAGAIN || ret == EAGAIN) {
2693                        mlog(0, "%s: trying to start recovery of node "
2694                             "%u, but node %u is waiting for last recovery "
2695                             "to complete, backoff for a bit\n", dlm->name,
2696                             dead_node, nodenum);
2697                        msleep(100);
2698                        goto retry;
2699                }
2700                if (ret < 0) {
2701                        struct dlm_lock_resource *res;
2702
2703                        /* this is now a serious problem, possibly ENOMEM
2704                         * in the network stack.  must retry */
2705                        mlog_errno(ret);
2706                        mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2707                             "returned %d\n", dlm->name, nodenum, ret);
2708                        res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2709                                                 DLM_RECOVERY_LOCK_NAME_LEN);
2710                        if (res) {
2711                                dlm_print_one_lock_resource(res);
2712                                dlm_lockres_put(res);
2713                        } else {
2714                                mlog(ML_ERROR, "recovery lock not found\n");
2715                        }
2716                        /* sleep for a bit in hopes that we can avoid
2717                         * another ENOMEM */
2718                        msleep(100);
2719                        goto retry;
2720                }
2721        }
2722
2723        return ret;
2724}
2725
2726int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2727                           void **ret_data)
2728{
2729        struct dlm_ctxt *dlm = data;
2730        struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2731
2732        /* ok to return 0, domain has gone away */
2733        if (!dlm_grab(dlm))
2734                return 0;
2735
2736        spin_lock(&dlm->spinlock);
2737        if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2738                mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2739                     "but this node is in finalize state, waiting on finalize2\n",
2740                     dlm->name, br->node_idx, br->dead_node,
2741                     dlm->reco.dead_node, dlm->reco.new_master);
2742                spin_unlock(&dlm->spinlock);
2743                dlm_put(dlm);
2744                return -EAGAIN;
2745        }
2746        spin_unlock(&dlm->spinlock);
2747
2748        mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2749             dlm->name, br->node_idx, br->dead_node,
2750             dlm->reco.dead_node, dlm->reco.new_master);
2751
2752        dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2753
2754        spin_lock(&dlm->spinlock);
2755        if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2756                if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2757                        mlog(0, "%s: new_master %u died, changing "
2758                             "to %u\n", dlm->name, dlm->reco.new_master,
2759                             br->node_idx);
2760                } else {
2761                        mlog(0, "%s: new_master %u NOT DEAD, changing "
2762                             "to %u\n", dlm->name, dlm->reco.new_master,
2763                             br->node_idx);
2764                        /* may not have seen the new master as dead yet */
2765                }
2766        }
2767        if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2768                mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2769                     "node %u changing it to %u\n", dlm->name,
2770                     dlm->reco.dead_node, br->node_idx, br->dead_node);
2771        }
2772        dlm_set_reco_master(dlm, br->node_idx);
2773        dlm_set_reco_dead_node(dlm, br->dead_node);
2774        if (!test_bit(br->dead_node, dlm->recovery_map)) {
2775                mlog(0, "recovery master %u sees %u as dead, but this "
2776                     "node has not yet.  marking %u as dead\n",
2777                     br->node_idx, br->dead_node, br->dead_node);
2778                if (!test_bit(br->dead_node, dlm->domain_map) ||
2779                    !test_bit(br->dead_node, dlm->live_nodes_map))
2780                        mlog(0, "%u not in domain/live_nodes map "
2781                             "so setting it in reco map manually\n",
2782                             br->dead_node);
2783                /* force the recovery cleanup in __dlm_hb_node_down
2784                 * both of these will be cleared in a moment */
2785                set_bit(br->dead_node, dlm->domain_map);
2786                set_bit(br->dead_node, dlm->live_nodes_map);
2787                __dlm_hb_node_down(dlm, br->dead_node);
2788        }
2789        spin_unlock(&dlm->spinlock);
2790
2791        dlm_kick_recovery_thread(dlm);
2792
2793        mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2794             dlm->name, br->node_idx, br->dead_node,
2795             dlm->reco.dead_node, dlm->reco.new_master);
2796
2797        dlm_put(dlm);
2798        return 0;
2799}
2800
2801#define DLM_FINALIZE_STAGE2  0x01
2802static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2803{
2804        int ret = 0;
2805        struct dlm_finalize_reco fr;
2806        struct dlm_node_iter iter;
2807        int nodenum;
2808        int status;
2809        int stage = 1;
2810
2811        mlog(0, "finishing recovery for node %s:%u, "
2812             "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2813
2814        spin_lock(&dlm->spinlock);
2815        dlm_node_iter_init(dlm->domain_map, &iter);
2816        spin_unlock(&dlm->spinlock);
2817
2818stage2:
2819        memset(&fr, 0, sizeof(fr));
2820        fr.node_idx = dlm->node_num;
2821        fr.dead_node = dlm->reco.dead_node;
2822        if (stage == 2)
2823                fr.flags |= DLM_FINALIZE_STAGE2;
2824
2825        while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2826                if (nodenum == dlm->node_num)
2827                        continue;
2828                ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2829                                         &fr, sizeof(fr), nodenum, &status);
2830                if (ret >= 0)
2831                        ret = status;
2832                if (ret < 0) {
2833                        mlog(ML_ERROR, "Error %d when sending message %u (key "
2834                             "0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
2835                             dlm->key, nodenum);
2836                        if (dlm_is_host_down(ret)) {
2837                                /* this has no effect on this recovery
2838                                 * session, so set the status to zero to
2839                                 * finish out the last recovery */
2840                                mlog(ML_ERROR, "node %u went down after this "
2841                                     "node finished recovery.\n", nodenum);
2842                                ret = 0;
2843                                continue;
2844                        }
2845                        break;
2846                }
2847        }
2848        if (stage == 1) {
2849                /* reset the node_iter back to the top and send finalize2 */
2850                iter.curnode = -1;
2851                stage = 2;
2852                goto stage2;
2853        }
2854
2855        return ret;
2856}
2857
2858int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2859                              void **ret_data)
2860{
2861        struct dlm_ctxt *dlm = data;
2862        struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2863        int stage = 1;
2864
2865        /* ok to return 0, domain has gone away */
2866        if (!dlm_grab(dlm))
2867                return 0;
2868
2869        if (fr->flags & DLM_FINALIZE_STAGE2)
2870                stage = 2;
2871
2872        mlog(0, "%s: node %u finalizing recovery stage%d of "
2873             "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2874             fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2875
2876        spin_lock(&dlm->spinlock);
2877
2878        if (dlm->reco.new_master != fr->node_idx) {
2879                mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2880                     "%u is supposed to be the new master, dead=%u\n",
2881                     fr->node_idx, dlm->reco.new_master, fr->dead_node);
2882                BUG();
2883        }
2884        if (dlm->reco.dead_node != fr->dead_node) {
2885                mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2886                     "node %u, but node %u is supposed to be dead\n",
2887                     fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2888                BUG();
2889        }
2890
2891        switch (stage) {
2892                case 1:
2893                        dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2894                        if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2895                                mlog(ML_ERROR, "%s: received finalize1 from "
2896                                     "new master %u for dead node %u, but "
2897                                     "this node has already received it!\n",
2898                                     dlm->name, fr->node_idx, fr->dead_node);
2899                                dlm_print_reco_node_status(dlm);
2900                                BUG();
2901                        }
2902                        dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2903                        spin_unlock(&dlm->spinlock);
2904                        break;
2905                case 2:
2906                        if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2907                                mlog(ML_ERROR, "%s: received finalize2 from "
2908                                     "new master %u for dead node %u, but "
2909                                     "this node did not have finalize1!\n",
2910                                     dlm->name, fr->node_idx, fr->dead_node);
2911                                dlm_print_reco_node_status(dlm);
2912                                BUG();
2913                        }
2914                        dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2915                        __dlm_reset_recovery(dlm);
2916                        spin_unlock(&dlm->spinlock);
2917                        dlm_kick_recovery_thread(dlm);
2918                        break;
2919                default:
2920                        BUG();
2921        }
2922
2923        mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2924             dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2925
2926        dlm_put(dlm);
2927        return 0;
2928}
2929