fs/ocfs2/dlm/dlmrecovery.c

   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/utsname.h>
  34 #include <linux/init.h>
  35 #include <linux/sysctl.h>
  36 #include <linux/random.h>
  37 #include <linux/blkdev.h>
  38 #include <linux/socket.h>
  39 #include <linux/inet.h>
  40 #include <linux/timer.h>
  41 #include <linux/kthread.h>
  42 #include <linux/delay.h>
  43
  44
  45 #include "cluster/heartbeat.h"
  46 #include "cluster/nodemanager.h"
  47 #include "cluster/tcp.h"
  48
  49 #include "dlmapi.h"
  50 #include "dlmcommon.h"
  51 #include "dlmdomain.h"
  52
  53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
  54 #include "cluster/masklog.h"
  55
  56 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
  57
  58 static int dlm_recovery_thread(void *data);
  59 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
  60 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
  61 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
  62 static int dlm_do_recovery(struct dlm_ctxt *dlm);
  63
  64 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
  65 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
  66 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  67 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
  68                                  u8 request_from, u8 dead_node);
  69 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  70
  71 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
  72 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
  73                                         const char *lockname, int namelen,
  74                                         int total_locks, u64 cookie,
  75                                         u8 flags, u8 master);
  76 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
  77                                     struct dlm_migratable_lockres *mres,
  78                                     u8 send_to,
  79                                     struct dlm_lock_resource *res,
  80                                     int total_locks);
  81 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
  82                                      struct dlm_lock_resource *res,
  83                                      struct dlm_migratable_lockres *mres);
  84 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
  85 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
  86                                  u8 dead_node, u8 send_to);
  87 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
  88 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
  89                                         struct list_head *list, u8 dead_node);
  90 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
  91                                               u8 dead_node, u8 new_master);
  92 static void dlm_reco_ast(void *astdata);
  93 static void dlm_reco_bast(void *astdata, int blocked_type);
  94 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
  95 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
  96                                          void *data);
  97 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
  98 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
  99                                       struct dlm_lock_resource *res,
 100                                       u8 *real_master);
 101
 102 static u64 dlm_get_next_mig_cookie(void);
 103
 104 static DEFINE_SPINLOCK(dlm_reco_state_lock);
 105 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
 106 static u64 dlm_mig_cookie = 1;
 107
 108 static u64 dlm_get_next_mig_cookie(void)
 109 {
 110         u64 c;
 111         spin_lock(&dlm_mig_cookie_lock);
 112         c = dlm_mig_cookie;
 113         if (dlm_mig_cookie == (~0ULL))
 114                 dlm_mig_cookie = 1;
 115         else
 116                 dlm_mig_cookie++;
 117         spin_unlock(&dlm_mig_cookie_lock);
 118         return c;
 119 }
 120
 121 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
 122                                           u8 dead_node)
 123 {
 124         assert_spin_locked(&dlm->spinlock);
 125         if (dlm->reco.dead_node != dead_node)
 126                 mlog(0, "%s: changing dead_node from %u to %u\n",
 127                      dlm->name, dlm->reco.dead_node, dead_node);
 128         dlm->reco.dead_node = dead_node;
 129 }
 130
 131 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
 132                                        u8 master)
 133 {
 134         assert_spin_locked(&dlm->spinlock);
 135         mlog(0, "%s: changing new_master from %u to %u\n",
 136              dlm->name, dlm->reco.new_master, master);
 137         dlm->reco.new_master = master;
 138 }
 139
 140 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
 141 {
 142         assert_spin_locked(&dlm->spinlock);
 143         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
 144         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 145         dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 146 }
 147
 148 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
 149 {
 150         spin_lock(&dlm->spinlock);
 151         __dlm_reset_recovery(dlm);
 152         spin_unlock(&dlm->spinlock);
 153 }
 154
 155 /* Worker function used during recovery. */
 156 void dlm_dispatch_work(void *data)
 157 {
 158         struct dlm_ctxt *dlm = (struct dlm_ctxt *)data;
 159         LIST_HEAD(tmp_list);
 160         struct list_head *iter, *iter2;
 161         struct dlm_work_item *item;
 162         dlm_workfunc_t *workfunc;
 163         int tot=0;
 164
 165         if (!dlm_joined(dlm))
 166                 return;
 167
 168         spin_lock(&dlm->work_lock);
 169         list_splice_init(&dlm->work_list, &tmp_list);
 170         spin_unlock(&dlm->work_lock);
 171
 172         list_for_each_safe(iter, iter2, &tmp_list) {
 173                 tot++;
 174         }
 175         mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
 176
 177         list_for_each_safe(iter, iter2, &tmp_list) {
 178                 item = list_entry(iter, struct dlm_work_item, list);
 179                 workfunc = item->func;
 180                 list_del_init(&item->list);
 181
 182                 /* already have ref on dlm to avoid having
 183                  * it disappear.  just double-check. */
 184                 BUG_ON(item->dlm != dlm);
 185
 186                 /* this is allowed to sleep and
 187                  * call network stuff */
 188                 workfunc(item, item->data);
 189
 190                 dlm_put(dlm);
 191                 kfree(item);
 192         }
 193 }
 194
 195 /*
 196  * RECOVERY THREAD
 197  */
 198
 199 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
 200 {
 201         /* wake the recovery thread
 202          * this will wake the reco thread in one of three places
 203          * 1) sleeping with no recovery happening
 204          * 2) sleeping with recovery mastered elsewhere
 205          * 3) recovery mastered here, waiting on reco data */
 206
 207         wake_up(&dlm->dlm_reco_thread_wq);
 208 }
 209
 210 /* Launch the recovery thread */
 211 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
 212 {
 213         mlog(0, "starting dlm recovery thread...\n");
 214
 215         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
 216                                                 "dlm_reco_thread");
 217         if (IS_ERR(dlm->dlm_reco_thread_task)) {
 218                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
 219                 dlm->dlm_reco_thread_task = NULL;
 220                 return -EINVAL;
 221         }
 222
 223         return 0;
 224 }
 225
 226 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
 227 {
 228         if (dlm->dlm_reco_thread_task) {
 229                 mlog(0, "waiting for dlm recovery thread to exit\n");
 230                 kthread_stop(dlm->dlm_reco_thread_task);
 231                 dlm->dlm_reco_thread_task = NULL;
 232         }
 233 }
 234
 235
 236
 237 /*
 238  * this is lame, but here's how recovery works...
 239  * 1) all recovery threads cluster wide will work on recovering
 240  *    ONE node at a time
 241  * 2) negotiate who will take over all the locks for the dead node.
 242  *    thats right... ALL the locks.
 243  * 3) once a new master is chosen, everyone scans all locks
 244  *    and moves aside those mastered by the dead guy
 245  * 4) each of these locks should be locked until recovery is done
 246  * 5) the new master collects up all of secondary lock queue info
 247  *    one lock at a time, forcing each node to communicate back
 248  *    before continuing
 249  * 6) each secondary lock queue responds with the full known lock info
 250  * 7) once the new master has run all its locks, it sends a ALLDONE!
 251  *    message to everyone
 252  * 8) upon receiving this message, the secondary queue node unlocks
 253  *    and responds to the ALLDONE
 254  * 9) once the new master gets responses from everyone, he unlocks
 255  *    everything and recovery for this dead node is done
 256  *10) go back to 2) while there are still dead nodes
 257  *
 258  */
 259
 260 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
 261 {
 262         struct dlm_reco_node_data *ndata;
 263         struct dlm_lock_resource *res;
 264
 265         mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
 266              dlm->name, dlm->dlm_reco_thread_task->pid,
 267              dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
 268              dlm->reco.dead_node, dlm->reco.new_master);
 269
 270         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
 271                 char *st = "unknown";
 272                 switch (ndata->state) {
 273                         case DLM_RECO_NODE_DATA_INIT:
 274                                 st = "init";
 275                                 break;
 276                         case DLM_RECO_NODE_DATA_REQUESTING:
 277                                 st = "requesting";
 278                                 break;
 279                         case DLM_RECO_NODE_DATA_DEAD:
 280                                 st = "dead";
 281                                 break;
 282                         case DLM_RECO_NODE_DATA_RECEIVING:
 283                                 st = "receiving";
 284                                 break;
 285                         case DLM_RECO_NODE_DATA_REQUESTED:
 286                                 st = "requested";
 287                                 break;
 288                         case DLM_RECO_NODE_DATA_DONE:
 289                                 st = "done";
 290                                 break;
 291                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 292                                 st = "finalize-sent";
 293                                 break;
 294                         default:
 295                                 st = "bad";
 296                                 break;
 297                 }
 298                 mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
 299                      dlm->name, ndata->node_num, st);
 300         }
 301         list_for_each_entry(res, &dlm->reco.resources, recovering) {
 302                 mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
 303                      dlm->name, res->lockname.len, res->lockname.name);
 304         }
 305 }
 306
 307 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
 308
 309 static int dlm_recovery_thread(void *data)
 310 {
 311         int status;
 312         struct dlm_ctxt *dlm = data;
 313         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
 314
 315         mlog(0, "dlm thread running for %s...\n", dlm->name);
 316
 317         while (!kthread_should_stop()) {
 318                 if (dlm_joined(dlm)) {
 319                         status = dlm_do_recovery(dlm);
 320                         if (status == -EAGAIN) {
 321                                 /* do not sleep, recheck immediately. */
 322                                 continue;
 323                         }
 324                         if (status < 0)
 325                                 mlog_errno(status);
 326                 }
 327
 328                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 329                                                  kthread_should_stop(),
 330                                                  timeout);
 331         }
 332
 333         mlog(0, "quitting DLM recovery thread\n");
 334         return 0;
 335 }
 336
 337 /* returns true when the recovery master has contacted us */
 338 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
 339 {
 340         int ready;
 341         spin_lock(&dlm->spinlock);
 342         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
 343         spin_unlock(&dlm->spinlock);
 344         return ready;
 345 }
 346
 347 /* returns true if node is no longer in the domain
 348  * could be dead or just not joined */
 349 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
 350 {
 351         int dead;
 352         spin_lock(&dlm->spinlock);
 353         dead = !test_bit(node, dlm->domain_map);
 354         spin_unlock(&dlm->spinlock);
 355         return dead;
 356 }
 357
 358 /* returns true if node is no longer in the domain
 359  * could be dead or just not joined */
 360 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
 361 {
 362         int recovered;
 363         spin_lock(&dlm->spinlock);
 364         recovered = !test_bit(node, dlm->recovery_map);
 365         spin_unlock(&dlm->spinlock);
 366         return recovered;
 367 }
 368
 369
 370 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
 371 {
 372         if (timeout) {
 373                 mlog(ML_NOTICE, "%s: waiting %dms for notification of "
 374                      "death of node %u\n", dlm->name, timeout, node);
 375                 wait_event_timeout(dlm->dlm_reco_thread_wq,
 376                            dlm_is_node_dead(dlm, node),
 377                            msecs_to_jiffies(timeout));
 378         } else {
 379                 mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
 380                      "of death of node %u\n", dlm->name, node);
 381                 wait_event(dlm->dlm_reco_thread_wq,
 382                            dlm_is_node_dead(dlm, node));
 383         }
 384         /* for now, return 0 */
 385         return 0;
 386 }
 387
 388 int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
 389 {
 390         if (timeout) {
 391                 mlog(0, "%s: waiting %dms for notification of "
 392                      "recovery of node %u\n", dlm->name, timeout, node);
 393                 wait_event_timeout(dlm->dlm_reco_thread_wq,
 394                            dlm_is_node_recovered(dlm, node),
 395                            msecs_to_jiffies(timeout));
 396         } else {
 397                 mlog(0, "%s: waiting indefinitely for notification "
 398                      "of recovery of node %u\n", dlm->name, node);
 399                 wait_event(dlm->dlm_reco_thread_wq,
 400                            dlm_is_node_recovered(dlm, node));
 401         }
 402         /* for now, return 0 */
 403         return 0;
 404 }
 405
 406 /* callers of the top-level api calls (dlmlock/dlmunlock) should
 407  * block on the dlm->reco.event when recovery is in progress.
 408  * the dlm recovery thread will set this state when it begins
 409  * recovering a dead node (as the new master or not) and clear
 410  * the state and wake as soon as all affected lock resources have
 411  * been marked with the RECOVERY flag */
 412 static int dlm_in_recovery(struct dlm_ctxt *dlm)
 413 {
 414         int in_recovery;
 415         spin_lock(&dlm->spinlock);
 416         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 417         spin_unlock(&dlm->spinlock);
 418         return in_recovery;
 419 }
 420
 421
 422 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
 423 {
 424         if (dlm_in_recovery(dlm)) {
 425                 mlog(0, "%s: reco thread %d in recovery: "
 426                      "state=%d, master=%u, dead=%u\n",
 427                      dlm->name, dlm->dlm_reco_thread_task->pid,
 428                      dlm->reco.state, dlm->reco.new_master,
 429                      dlm->reco.dead_node);
 430         }
 431         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
 432 }
 433
 434 static void dlm_begin_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 }
 441
 442 static void dlm_end_recovery(struct dlm_ctxt *dlm)
 443 {
 444         spin_lock(&dlm->spinlock);
 445         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
 446         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
 447         spin_unlock(&dlm->spinlock);
 448         wake_up(&dlm->reco.event);
 449 }
 450
 451 static int dlm_do_recovery(struct dlm_ctxt *dlm)
 452 {
 453         int status = 0;
 454         int ret;
 455
 456         spin_lock(&dlm->spinlock);
 457
 458         /* check to see if the new master has died */
 459         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
 460             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
 461                 mlog(0, "new master %u died while recovering %u!\n",
 462                      dlm->reco.new_master, dlm->reco.dead_node);
 463                 /* unset the new_master, leave dead_node */
 464                 dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 465         }
 466
 467         /* select a target to recover */
 468         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 469                 int bit;
 470
 471                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
 472                 if (bit >= O2NM_MAX_NODES || bit < 0)
 473                         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 474                 else
 475                         dlm_set_reco_dead_node(dlm, bit);
 476         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
 477                 /* BUG? */
 478                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
 479                      dlm->reco.dead_node);
 480                 dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 481         }
 482
 483         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 484                 // mlog(0, "nothing to recover!  sleeping now!\n");
 485                 spin_unlock(&dlm->spinlock);
 486                 /* return to main thread loop and sleep. */
 487                 return 0;
 488         }
 489         mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
 490              dlm->name, dlm->dlm_reco_thread_task->pid,
 491              dlm->reco.dead_node);
 492         spin_unlock(&dlm->spinlock);
 493
 494         /* take write barrier */
 495         /* (stops the list reshuffling thread, proxy ast handling) */
 496         dlm_begin_recovery(dlm);
 497
 498         if (dlm->reco.new_master == dlm->node_num)
 499                 goto master_here;
 500
 501         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 502                 /* choose a new master, returns 0 if this node
 503                  * is the master, -EEXIST if it's another node.
 504                  * this does not return until a new master is chosen
 505                  * or recovery completes entirely. */
 506                 ret = dlm_pick_recovery_master(dlm);
 507                 if (!ret) {
 508                         /* already notified everyone.  go. */
 509                         goto master_here;
 510                 }
 511                 mlog(0, "another node will master this recovery session.\n");
 512         }
 513         mlog(0, "dlm=%s (%d), new_master=%u, this node=%u, dead_node=%u\n",
 514              dlm->name, dlm->dlm_reco_thread_task->pid, dlm->reco.new_master,
 515              dlm->node_num, dlm->reco.dead_node);
 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
 525 master_here:
 526         mlog(0, "(%d) mastering recovery of %s:%u here(this=%u)!\n",
 527              dlm->dlm_reco_thread_task->pid,
 528              dlm->name, dlm->reco.dead_node, dlm->node_num);
 529
 530         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
 531         if (status < 0) {
 532                 /* we should never hit this anymore */
 533                 mlog(ML_ERROR, "error %d remastering locks for node %u, "
 534                      "retrying.\n", status, dlm->reco.dead_node);
 535                 /* yield a bit to allow any final network messages
 536                  * to get handled on remaining nodes */
 537                 msleep(100);
 538         } else {
 539                 /* success!  see if any other nodes need recovery */
 540                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
 541                      dlm->name, dlm->reco.dead_node, dlm->node_num);
 542                 dlm_reset_recovery(dlm);
 543         }
 544         dlm_end_recovery(dlm);
 545
 546         /* continue and look for another dead node */
 547         return -EAGAIN;
 548 }
 549
 550 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
 551 {
 552         int status = 0;
 553         struct dlm_reco_node_data *ndata;
 554         struct list_head *iter;
 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(iter, &dlm->reco.node_data) {
 573                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 574                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
 575                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
 576
 577                 mlog(0, "requesting lock info from node %u\n",
 578                      ndata->node_num);
 579
 580                 if (ndata->node_num == dlm->node_num) {
 581                         ndata->state = DLM_RECO_NODE_DATA_DONE;
 582                         continue;
 583                 }
 584
 585                 do {
 586                         status = dlm_request_all_locks(dlm, ndata->node_num,
 587                                                        dead_node);
 588                         if (status < 0) {
 589                                 mlog_errno(status);
 590                                 if (dlm_is_host_down(status)) {
 591                                         /* node died, ignore it for recovery */
 592                                         status = 0;
 593                                         ndata->state = DLM_RECO_NODE_DATA_DEAD;
 594                                         /* wait for the domain map to catch up
 595                                          * with the network state. */
 596                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
 597                                                            dlm_is_node_dead(dlm,
 598                                                                 ndata->node_num),
 599                                                            msecs_to_jiffies(1000));
 600                                         mlog(0, "waited 1 sec for %u, "
 601                                              "dead? %s\n", ndata->node_num,
 602                                              dlm_is_node_dead(dlm, ndata->node_num) ?
 603                                              "yes" : "no");
 604                                 } else {
 605                                         /* -ENOMEM on the other node */
 606                                         mlog(0, "%s: node %u returned "
 607                                              "%d during recovery, retrying "
 608                                              "after a short wait\n",
 609                                              dlm->name, ndata->node_num,
 610                                              status);
 611                                         msleep(100);
 612                                 }
 613                         }
 614                 } while (status != 0);
 615
 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         }
 647
 648         mlog(0, "done requesting all lock info\n");
 649
 650         /* nodes should be sending reco data now
 651          * just need to wait */
 652
 653         while (1) {
 654                 /* check all the nodes now to see if we are
 655                  * done, or if anyone died */
 656                 all_nodes_done = 1;
 657                 spin_lock(&dlm_reco_state_lock);
 658                 list_for_each(iter, &dlm->reco.node_data) {
 659                         ndata = list_entry (iter, struct dlm_reco_node_data, list);
 660
 661                         mlog(0, "checking recovery state of node %u\n",
 662                              ndata->node_num);
 663                         switch (ndata->state) {
 664                                 case DLM_RECO_NODE_DATA_INIT:
 665                                 case DLM_RECO_NODE_DATA_REQUESTING:
 666                                         mlog(ML_ERROR, "bad ndata state for "
 667                                              "node %u: state=%d\n",
 668                                              ndata->node_num, ndata->state);
 669                                         BUG();
 670                                         break;
 671                                 case DLM_RECO_NODE_DATA_DEAD:
 672                                         mlog(0, "node %u died after "
 673                                              "requesting recovery info for "
 674                                              "node %u\n", ndata->node_num,
 675                                              dead_node);
 676                                         break;
 677                                 case DLM_RECO_NODE_DATA_RECEIVING:
 678                                 case DLM_RECO_NODE_DATA_REQUESTED:
 679                                         mlog(0, "%s: node %u still in state %s\n",
 680                                              dlm->name, ndata->node_num,
 681                                              ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
 682                                              "receiving" : "requested");
 683                                         all_nodes_done = 0;
 684                                         break;
 685                                 case DLM_RECO_NODE_DATA_DONE:
 686                                         mlog(0, "%s: node %u state is done\n",
 687                                              dlm->name, ndata->node_num);
 688                                         break;
 689                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 690                                         mlog(0, "%s: node %u state is finalize\n",
 691                                              dlm->name, ndata->node_num);
 692                                         break;
 693                         }
 694                 }
 695                 spin_unlock(&dlm_reco_state_lock);
 696
 697                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
 698                      all_nodes_done?"yes":"no");
 699                 if (all_nodes_done) {
 700                         int ret;
 701
 702                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
 703                          * just send a finalize message to everyone and
 704                          * clean up */
 705                         mlog(0, "all nodes are done! send finalize\n");
 706                         ret = dlm_send_finalize_reco_message(dlm);
 707                         if (ret < 0)
 708                                 mlog_errno(ret);
 709
 710                         spin_lock(&dlm->spinlock);
 711                         dlm_finish_local_lockres_recovery(dlm, dead_node,
 712                                                           dlm->node_num);
 713                         spin_unlock(&dlm->spinlock);
 714                         mlog(0, "should be done with recovery!\n");
 715
 716                         mlog(0, "finishing recovery of %s at %lu, "
 717                              "dead=%u, this=%u, new=%u\n", dlm->name,
 718                              jiffies, dlm->reco.dead_node,
 719                              dlm->node_num, dlm->reco.new_master);
 720                         destroy = 1;
 721                         status = 0;
 722                         /* rescan everything marked dirty along the way */
 723                         dlm_kick_thread(dlm, NULL);
 724                         break;
 725                 }
 726                 /* wait to be signalled, with periodic timeout
 727                  * to check for node death */
 728                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 729                                          kthread_should_stop(),
 730                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
 731
 732         }
 733
 734         if (destroy)
 735                 dlm_destroy_recovery_area(dlm, dead_node);
 736
 737         mlog_exit(status);
 738         return status;
 739 }
 740
 741 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 742 {
 743         int num=0;
 744         struct dlm_reco_node_data *ndata;
 745
 746         spin_lock(&dlm->spinlock);
 747         memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
 748         /* nodes can only be removed (by dying) after dropping
 749          * this lock, and death will be trapped later, so this should do */
 750         spin_unlock(&dlm->spinlock);
 751
 752         while (1) {
 753                 num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
 754                 if (num >= O2NM_MAX_NODES) {
 755                         break;
 756                 }
 757                 BUG_ON(num == dead_node);
 758
 759                 ndata = kcalloc(1, sizeof(*ndata), GFP_NOFS);
 760                 if (!ndata) {
 761                         dlm_destroy_recovery_area(dlm, dead_node);
 762                         return -ENOMEM;
 763                 }
 764                 ndata->node_num = num;
 765                 ndata->state = DLM_RECO_NODE_DATA_INIT;
 766                 spin_lock(&dlm_reco_state_lock);
 767                 list_add_tail(&ndata->list, &dlm->reco.node_data);
 768                 spin_unlock(&dlm_reco_state_lock);
 769                 num++;
 770         }
 771
 772         return 0;
 773 }
 774
 775 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 776 {
 777         struct list_head *iter, *iter2;
 778         struct dlm_reco_node_data *ndata;
 779         LIST_HEAD(tmplist);
 780
 781         spin_lock(&dlm_reco_state_lock);
 782         list_splice_init(&dlm->reco.node_data, &tmplist);
 783         spin_unlock(&dlm_reco_state_lock);
 784
 785         list_for_each_safe(iter, iter2, &tmplist) {
 786                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 787                 list_del_init(&ndata->list);
 788                 kfree(ndata);
 789         }
 790 }
 791
 792 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
 793                                  u8 dead_node)
 794 {
 795         struct dlm_lock_request lr;
 796         enum dlm_status ret;
 797
 798         mlog(0, "\n");
 799
 800
 801         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
 802                   "to %u\n", dead_node, request_from);
 803
 804         memset(&lr, 0, sizeof(lr));
 805         lr.node_idx = dlm->node_num;
 806         lr.dead_node = dead_node;
 807
 808         // send message
 809         ret = DLM_NOLOCKMGR;
 810         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
 811                                  &lr, sizeof(lr), request_from, NULL);
 812
 813         /* negative status is handled by caller */
 814         if (ret < 0)
 815                 mlog_errno(ret);
 816
 817         // return from here, then
 818         // sleep until all received or error
 819         return ret;
 820
 821 }
 822
 823 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data)
 824 {
 825         struct dlm_ctxt *dlm = data;
 826         struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
 827         char *buf = NULL;
 828         struct dlm_work_item *item = NULL;
 829
 830         if (!dlm_grab(dlm))
 831                 return -EINVAL;
 832
 833         if (lr->dead_node != dlm->reco.dead_node) {
 834                 mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
 835                      "dead_node is %u\n", dlm->name, lr->node_idx,
 836                      lr->dead_node, dlm->reco.dead_node);
 837                 dlm_print_reco_node_status(dlm);
 838                 /* this is a hack */
 839                 dlm_put(dlm);
 840                 return -ENOMEM;
 841         }
 842         BUG_ON(lr->dead_node != dlm->reco.dead_node);
 843
 844         item = kcalloc(1, sizeof(*item), GFP_NOFS);
 845         if (!item) {
 846                 dlm_put(dlm);
 847                 return -ENOMEM;
 848         }
 849
 850         /* this will get freed by dlm_request_all_locks_worker */
 851         buf = (char *) __get_free_page(GFP_NOFS);
 852         if (!buf) {
 853                 kfree(item);
 854                 dlm_put(dlm);
 855                 return -ENOMEM;
 856         }
 857
 858         /* queue up work for dlm_request_all_locks_worker */
 859         dlm_grab(dlm);  /* get an extra ref for the work item */
 860         dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
 861         item->u.ral.reco_master = lr->node_idx;
 862         item->u.ral.dead_node = lr->dead_node;
 863         spin_lock(&dlm->work_lock);
 864         list_add_tail(&item->list, &dlm->work_list);
 865         spin_unlock(&dlm->work_lock);
 866         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
 867
 868         dlm_put(dlm);
 869         return 0;
 870 }
 871
 872 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
 873 {
 874         struct dlm_migratable_lockres *mres;
 875         struct dlm_lock_resource *res;
 876         struct dlm_ctxt *dlm;
 877         LIST_HEAD(resources);
 878         struct list_head *iter;
 879         int ret;
 880         u8 dead_node, reco_master;
 881         int skip_all_done = 0;
 882
 883         dlm = item->dlm;
 884         dead_node = item->u.ral.dead_node;
 885         reco_master = item->u.ral.reco_master;
 886         mres = (struct dlm_migratable_lockres *)data;
 887
 888         mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
 889              dlm->name, dead_node, reco_master);
 890
 891         if (dead_node != dlm->reco.dead_node ||
 892             reco_master != dlm->reco.new_master) {
 893                 /* worker could have been created before the recovery master
 894                  * died.  if so, do not continue, but do not error. */
 895                 if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 896                         mlog(ML_NOTICE, "%s: will not send recovery state, "
 897                              "recovery master %u died, thread=(dead=%u,mas=%u)"
 898                              " current=(dead=%u,mas=%u)\n", dlm->name,
 899                              reco_master, dead_node, reco_master,
 900                              dlm->reco.dead_node, dlm->reco.new_master);
 901                 } else {
 902                         mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
 903                              "master=%u), request(dead=%u, master=%u)\n",
 904                              dlm->name, dlm->reco.dead_node,
 905                              dlm->reco.new_master, dead_node, reco_master);
 906                 }
 907                 goto leave;
 908         }
 909
 910         /* lock resources should have already been moved to the
 911          * dlm->reco.resources list.  now move items from that list
 912          * to a temp list if the dead owner matches.  note that the
 913          * whole cluster recovers only one node at a time, so we
 914          * can safely move UNKNOWN lock resources for each recovery
 915          * session. */
 916         dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
 917
 918         /* now we can begin blasting lockreses without the dlm lock */
 919
 920         /* any errors returned will be due to the new_master dying,
 921          * the dlm_reco_thread should detect this */
 922         list_for_each(iter, &resources) {
 923                 res = list_entry (iter, struct dlm_lock_resource, recovering);
 924                 ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
 925                                         DLM_MRES_RECOVERY);
 926                 if (ret < 0) {
 927                         mlog(ML_ERROR, "%s: node %u went down while sending "
 928                              "recovery state for dead node %u, ret=%d\n", dlm->name,
 929                              reco_master, dead_node, ret);
 930                         skip_all_done = 1;
 931                         break;
 932                 }
 933         }
 934
 935         /* move the resources back to the list */
 936         spin_lock(&dlm->spinlock);
 937         list_splice_init(&resources, &dlm->reco.resources);
 938         spin_unlock(&dlm->spinlock);
 939
 940         if (!skip_all_done) {
 941                 ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
 942                 if (ret < 0) {
 943                         mlog(ML_ERROR, "%s: node %u went down while sending "
 944                              "recovery all-done for dead node %u, ret=%d\n",
 945                              dlm->name, reco_master, dead_node, ret);
 946                 }
 947         }
 948 leave:
 949         free_page((unsigned long)data);
 950 }
 951
 952
 953 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
 954 {
 955         int ret, tmpret;
 956         struct dlm_reco_data_done done_msg;
 957
 958         memset(&done_msg, 0, sizeof(done_msg));
 959         done_msg.node_idx = dlm->node_num;
 960         done_msg.dead_node = dead_node;
 961         mlog(0, "sending DATA DONE message to %u, "
 962              "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
 963              done_msg.dead_node);
 964
 965         ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
 966                                  sizeof(done_msg), send_to, &tmpret);
 967         if (ret < 0) {
 968                 if (!dlm_is_host_down(ret)) {
 969                         mlog_errno(ret);
 970                         mlog(ML_ERROR, "%s: unknown error sending data-done "
 971                              "to %u\n", dlm->name, send_to);
 972                         BUG();
 973                 }
 974         } else
 975                 ret = tmpret;
 976         return ret;
 977 }
 978
 979
 980 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data)
 981 {
 982         struct dlm_ctxt *dlm = data;
 983         struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
 984         struct list_head *iter;
 985         struct dlm_reco_node_data *ndata = NULL;
 986         int ret = -EINVAL;
 987
 988         if (!dlm_grab(dlm))
 989                 return -EINVAL;
 990
 991         mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 992              "node_idx=%u, this node=%u\n", done->dead_node,
 993              dlm->reco.dead_node, done->node_idx, dlm->node_num);
 994
 995         mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
 996                         "Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 997                         "node_idx=%u, this node=%u\n", done->dead_node,
 998                         dlm->reco.dead_node, done->node_idx, dlm->node_num);
 999
1000         spin_lock(&dlm_reco_state_lock);
1001         list_for_each(iter, &dlm->reco.node_data) {
1002                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
1003                 if (ndata->node_num != done->node_idx)
1004                         continue;
1005
1006                 switch (ndata->state) {
1007                         /* should have moved beyond INIT but not to FINALIZE yet */
1008                         case DLM_RECO_NODE_DATA_INIT:
1009                         case DLM_RECO_NODE_DATA_DEAD:
1010                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1011                                 mlog(ML_ERROR, "bad ndata state for node %u:"
1012                                      " state=%d\n", ndata->node_num,
1013                                      ndata->state);
1014                                 BUG();
1015                                 break;
1016                         /* these states are possible at this point, anywhere along
1017                          * the line of recovery */
1018                         case DLM_RECO_NODE_DATA_DONE:
1019                         case DLM_RECO_NODE_DATA_RECEIVING:
1020                         case DLM_RECO_NODE_DATA_REQUESTED:
1021                         case DLM_RECO_NODE_DATA_REQUESTING:
1022                                 mlog(0, "node %u is DONE sending "
1023                                           "recovery data!\n",
1024                                           ndata->node_num);
1025
1026                                 ndata->state = DLM_RECO_NODE_DATA_DONE;
1027                                 ret = 0;
1028                                 break;
1029                 }
1030         }
1031         spin_unlock(&dlm_reco_state_lock);
1032
1033         /* wake the recovery thread, some node is done */
1034         if (!ret)
1035                 dlm_kick_recovery_thread(dlm);
1036
1037         if (ret < 0)
1038                 mlog(ML_ERROR, "failed to find recovery node data for node "
1039                      "%u\n", done->node_idx);
1040         dlm_put(dlm);
1041
1042         mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1043         return ret;
1044 }
1045
1046 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1047                                         struct list_head *list,
1048                                         u8 dead_node)
1049 {
1050         struct dlm_lock_resource *res;
1051         struct list_head *iter, *iter2;
1052         struct dlm_lock *lock;
1053
1054         spin_lock(&dlm->spinlock);
1055         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
1056                 res = list_entry (iter, struct dlm_lock_resource, recovering);
1057                 /* always prune any $RECOVERY entries for dead nodes,
1058                  * otherwise hangs can occur during later recovery */
1059                 if (dlm_is_recovery_lock(res->lockname.name,
1060                                          res->lockname.len)) {
1061                         spin_lock(&res->spinlock);
1062                         list_for_each_entry(lock, &res->granted, list) {
1063                                 if (lock->ml.node == dead_node) {
1064                                         mlog(0, "AHA! there was "
1065                                              "a $RECOVERY lock for dead "
1066                                              "node %u (%s)!\n",
1067                                              dead_node, dlm->name);
1068                                         list_del_init(&lock->list);
1069                                         dlm_lock_put(lock);
1070                                         break;
1071                                 }
1072                         }
1073                         spin_unlock(&res->spinlock);
1074                         continue;
1075                 }
1076
1077                 if (res->owner == dead_node) {
1078                         mlog(0, "found lockres owned by dead node while "
1079                                   "doing recovery for node %u. sending it.\n",
1080                                   dead_node);
1081                         list_move_tail(&res->recovering, list);
1082                 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1083                         mlog(0, "found UNKNOWN owner while doing recovery "
1084                                   "for node %u. sending it.\n", dead_node);
1085                         list_move_tail(&res->recovering, list);
1086                 }
1087         }
1088         spin_unlock(&dlm->spinlock);
1089 }
1090
1091 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1092 {
1093         int total_locks = 0;
1094         struct list_head *iter, *queue = &res->granted;
1095         int i;
1096
1097         for (i=0; i<3; i++) {
1098                 list_for_each(iter, queue)
1099                         total_locks++;
1100                 queue++;
1101         }
1102         return total_locks;
1103 }
1104
1105
1106 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1107                                       struct dlm_migratable_lockres *mres,
1108                                       u8 send_to,
1109                                       struct dlm_lock_resource *res,
1110                                       int total_locks)
1111 {
1112         u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1113         int mres_total_locks = be32_to_cpu(mres->total_locks);
1114         int sz, ret = 0, status = 0;
1115         u8 orig_flags = mres->flags,
1116            orig_master = mres->master;
1117
1118         BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1119         if (!mres->num_locks)
1120                 return 0;
1121
1122         sz = sizeof(struct dlm_migratable_lockres) +
1123                 (mres->num_locks * sizeof(struct dlm_migratable_lock));
1124
1125         /* add an all-done flag if we reached the last lock */
1126         orig_flags = mres->flags;
1127         BUG_ON(total_locks > mres_total_locks);
1128         if (total_locks == mres_total_locks)
1129                 mres->flags |= DLM_MRES_ALL_DONE;
1130
1131         /* send it */
1132         ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1133                                  sz, send_to, &status);
1134         if (ret < 0) {
1135                 /* XXX: negative status is not handled.
1136                  * this will end up killing this node. */
1137                 mlog_errno(ret);
1138         } else {
1139                 /* might get an -ENOMEM back here */
1140                 ret = status;
1141                 if (ret < 0) {
1142                         mlog_errno(ret);
1143
1144                         if (ret == -EFAULT) {
1145                                 mlog(ML_ERROR, "node %u told me to kill "
1146                                      "myself!\n", send_to);
1147                                 BUG();
1148                         }
1149                 }
1150         }
1151
1152         /* zero and reinit the message buffer */
1153         dlm_init_migratable_lockres(mres, res->lockname.name,
1154                                     res->lockname.len, mres_total_locks,
1155                                     mig_cookie, orig_flags, orig_master);
1156         return ret;
1157 }
1158
1159 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1160                                         const char *lockname, int namelen,
1161                                         int total_locks, u64 cookie,
1162                                         u8 flags, u8 master)
1163 {
1164         /* mres here is one full page */
1165         memset(mres, 0, PAGE_SIZE);
1166         mres->lockname_len = namelen;
1167         memcpy(mres->lockname, lockname, namelen);
1168         mres->num_locks = 0;
1169         mres->total_locks = cpu_to_be32(total_locks);
1170         mres->mig_cookie = cpu_to_be64(cookie);
1171         mres->flags = flags;
1172         mres->master = master;
1173 }
1174
1175
1176 /* returns 1 if this lock fills the network structure,
1177  * 0 otherwise */
1178 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1179                                  struct dlm_migratable_lockres *mres, int queue)
1180 {
1181         struct dlm_migratable_lock *ml;
1182         int lock_num = mres->num_locks;
1183
1184         ml = &(mres->ml[lock_num]);
1185         ml->cookie = lock->ml.cookie;
1186         ml->type = lock->ml.type;
1187         ml->convert_type = lock->ml.convert_type;
1188         ml->highest_blocked = lock->ml.highest_blocked;
1189         ml->list = queue;
1190         if (lock->lksb) {
1191                 ml->flags = lock->lksb->flags;
1192                 /* send our current lvb */
1193                 if (ml->type == LKM_EXMODE ||
1194                     ml->type == LKM_PRMODE) {
1195                         /* if it is already set, this had better be a PR
1196                          * and it has to match */
1197                         if (!dlm_lvb_is_empty(mres->lvb) &&
1198                             (ml->type == LKM_EXMODE ||
1199                              memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
1200                                 mlog(ML_ERROR, "mismatched lvbs!\n");
1201                                 __dlm_print_one_lock_resource(lock->lockres);
1202                                 BUG();
1203                         }
1204                         memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1205                 }
1206         }
1207         ml->node = lock->ml.node;
1208         mres->num_locks++;
1209         /* we reached the max, send this network message */
1210         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1211                 return 1;
1212         return 0;
1213 }
1214
1215
1216 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1217                          struct dlm_migratable_lockres *mres,
1218                          u8 send_to, u8 flags)
1219 {
1220         struct list_head *queue, *iter;
1221         int total_locks, i;
1222         u64 mig_cookie = 0;
1223         struct dlm_lock *lock;
1224         int ret = 0;
1225
1226         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1227
1228         mlog(0, "sending to %u\n", send_to);
1229
1230         total_locks = dlm_num_locks_in_lockres(res);
1231         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1232                 /* rare, but possible */
1233                 mlog(0, "argh.  lockres has %d locks.  this will "
1234                           "require more than one network packet to "
1235                           "migrate\n", total_locks);
1236                 mig_cookie = dlm_get_next_mig_cookie();
1237         }
1238
1239         dlm_init_migratable_lockres(mres, res->lockname.name,
1240                                     res->lockname.len, total_locks,
1241                                     mig_cookie, flags, res->owner);
1242
1243         total_locks = 0;
1244         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1245                 queue = dlm_list_idx_to_ptr(res, i);
1246                 list_for_each(iter, queue) {
1247                         lock = list_entry (iter, struct dlm_lock, list);
1248
1249                         /* add another lock. */
1250                         total_locks++;
1251                         if (!dlm_add_lock_to_array(lock, mres, i))
1252                                 continue;
1253
1254                         /* this filled the lock message,
1255                          * we must send it immediately. */
1256                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1257                                                        res, total_locks);
1258                         if (ret < 0)
1259                                 goto error;
1260                 }
1261         }
1262         /* flush any remaining locks */
1263         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1264         if (ret < 0)
1265                 goto error;
1266         return ret;
1267
1268 error:
1269         mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1270              dlm->name, ret);
1271         if (!dlm_is_host_down(ret))
1272                 BUG();
1273         mlog(0, "%s: node %u went down while sending %s "
1274              "lockres %.*s\n", dlm->name, send_to,
1275              flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1276              res->lockname.len, res->lockname.name);
1277         return ret;
1278 }
1279
1280
1281
1282 /*
1283  * this message will contain no more than one page worth of
1284  * recovery data, and it will work on only one lockres.
1285  * there may be many locks in this page, and we may need to wait
1286  * for additional packets to complete all the locks (rare, but
1287  * possible).
1288  */
1289 /*
1290  * NOTE: the allocation error cases here are scary
1291  * we really cannot afford to fail an alloc in recovery
1292  * do we spin?  returning an error only delays the problem really
1293  */
1294
1295 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data)
1296 {
1297         struct dlm_ctxt *dlm = data;
1298         struct dlm_migratable_lockres *mres =
1299                 (struct dlm_migratable_lockres *)msg->buf;
1300         int ret = 0;
1301         u8 real_master;
1302         char *buf = NULL;
1303         struct dlm_work_item *item = NULL;
1304         struct dlm_lock_resource *res = NULL;
1305
1306         if (!dlm_grab(dlm))
1307                 return -EINVAL;
1308
1309         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1310
1311         real_master = mres->master;
1312         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1313                 /* cannot migrate a lockres with no master */
1314                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1315         }
1316
1317         mlog(0, "%s message received from node %u\n",
1318                   (mres->flags & DLM_MRES_RECOVERY) ?
1319                   "recovery" : "migration", mres->master);
1320         if (mres->flags & DLM_MRES_ALL_DONE)
1321                 mlog(0, "all done flag.  all lockres data received!\n");
1322
1323         ret = -ENOMEM;
1324         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1325         item = kcalloc(1, sizeof(*item), GFP_NOFS);
1326         if (!buf || !item)
1327                 goto leave;
1328
1329         /* lookup the lock to see if we have a secondary queue for this
1330          * already...  just add the locks in and this will have its owner
1331          * and RECOVERY flag changed when it completes. */
1332         res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1333         if (res) {
1334                 /* this will get a ref on res */
1335                 /* mark it as recovering/migrating and hash it */
1336                 spin_lock(&res->spinlock);
1337                 if (mres->flags & DLM_MRES_RECOVERY) {
1338                         res->state |= DLM_LOCK_RES_RECOVERING;
1339                 } else {
1340                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1341                                 /* this is at least the second
1342                                  * lockres message */
1343                                 mlog(0, "lock %.*s is already migrating\n",
1344                                           mres->lockname_len,
1345                                           mres->lockname);
1346                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1347                                 /* caller should BUG */
1348                                 mlog(ML_ERROR, "node is attempting to migrate "
1349                                      "lock %.*s, but marked as recovering!\n",
1350                                      mres->lockname_len, mres->lockname);
1351                                 ret = -EFAULT;
1352                                 spin_unlock(&res->spinlock);
1353                                 goto leave;
1354                         }
1355                         res->state |= DLM_LOCK_RES_MIGRATING;
1356                 }
1357                 spin_unlock(&res->spinlock);
1358         } else {
1359                 /* need to allocate, just like if it was
1360                  * mastered here normally  */
1361                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1362                 if (!res)
1363                         goto leave;
1364
1365                 /* to match the ref that we would have gotten if
1366                  * dlm_lookup_lockres had succeeded */
1367                 dlm_lockres_get(res);
1368
1369                 /* mark it as recovering/migrating and hash it */
1370                 if (mres->flags & DLM_MRES_RECOVERY)
1371                         res->state |= DLM_LOCK_RES_RECOVERING;
1372                 else
1373                         res->state |= DLM_LOCK_RES_MIGRATING;
1374
1375                 spin_lock(&dlm->spinlock);
1376                 __dlm_insert_lockres(dlm, res);
1377                 spin_unlock(&dlm->spinlock);
1378
1379                 /* now that the new lockres is inserted,
1380                  * make it usable by other processes */
1381                 spin_lock(&res->spinlock);
1382                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1383                 spin_unlock(&res->spinlock);
1384
1385                 /* add an extra ref for just-allocated lockres
1386                  * otherwise the lockres will be purged immediately */
1387                 dlm_lockres_get(res);
1388
1389         }
1390
1391         /* at this point we have allocated everything we need,
1392          * and we have a hashed lockres with an extra ref and
1393          * the proper res->state flags. */
1394         ret = 0;
1395         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1396                 /* migration cannot have an unknown master */
1397                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1398                 mlog(0, "recovery has passed me a lockres with an "
1399                           "unknown owner.. will need to requery: "
1400                           "%.*s\n", mres->lockname_len, mres->lockname);
1401         } else {
1402                 spin_lock(&res->spinlock);
1403                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1404                 spin_unlock(&res->spinlock);
1405         }
1406
1407         /* queue up work for dlm_mig_lockres_worker */
1408         dlm_grab(dlm);  /* get an extra ref for the work item */
1409         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1410         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1411         item->u.ml.lockres = res; /* already have a ref */
1412         item->u.ml.real_master = real_master;
1413         spin_lock(&dlm->work_lock);
1414         list_add_tail(&item->list, &dlm->work_list);
1415         spin_unlock(&dlm->work_lock);
1416         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1417
1418 leave:
1419         dlm_put(dlm);
1420         if (ret < 0) {
1421                 if (buf)
1422                         kfree(buf);
1423                 if (item)
1424                         kfree(item);
1425         }
1426
1427         mlog_exit(ret);
1428         return ret;
1429 }
1430
1431
1432 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1433 {
1434         struct dlm_ctxt *dlm = data;
1435         struct dlm_migratable_lockres *mres;
1436         int ret = 0;
1437         struct dlm_lock_resource *res;
1438         u8 real_master;
1439
1440         dlm = item->dlm;
1441         mres = (struct dlm_migratable_lockres *)data;
1442
1443         res = item->u.ml.lockres;
1444         real_master = item->u.ml.real_master;
1445
1446         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1447                 /* this case is super-rare. only occurs if
1448                  * node death happens during migration. */
1449 again:
1450                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1451                 if (ret < 0) {
1452                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1453                                   ret);
1454                         goto again;
1455                 }
1456                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1457                         mlog(0, "lockres %.*s not claimed.  "
1458                                    "this node will take it.\n",
1459                                    res->lockname.len, res->lockname.name);
1460                 } else {
1461                         mlog(0, "master needs to respond to sender "
1462                                   "that node %u still owns %.*s\n",
1463                                   real_master, res->lockname.len,
1464                                   res->lockname.name);
1465                         /* cannot touch this lockres */
1466                         goto leave;
1467                 }
1468         }
1469
1470         ret = dlm_process_recovery_data(dlm, res, mres);
1471         if (ret < 0)
1472                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1473         else
1474                 mlog(0, "dlm_process_recovery_data succeeded\n");
1475
1476         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1477                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1478                 ret = dlm_finish_migration(dlm, res, mres->master);
1479                 if (ret < 0)
1480                         mlog_errno(ret);
1481         }
1482
1483 leave:
1484         kfree(data);
1485         mlog_exit(ret);
1486 }
1487
1488
1489
1490 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1491                                       struct dlm_lock_resource *res,
1492                                       u8 *real_master)
1493 {
1494         struct dlm_node_iter iter;
1495         int nodenum;
1496         int ret = 0;
1497
1498         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1499
1500         /* we only reach here if one of the two nodes in a
1501          * migration died while the migration was in progress.
1502          * at this point we need to requery the master.  we
1503          * know that the new_master got as far as creating
1504          * an mle on at least one node, but we do not know
1505          * if any nodes had actually cleared the mle and set
1506          * the master to the new_master.  the old master
1507          * is supposed to set the owner to UNKNOWN in the
1508          * event of a new_master death, so the only possible
1509          * responses that we can get from nodes here are
1510          * that the master is new_master, or that the master
1511          * is UNKNOWN.
1512          * if all nodes come back with UNKNOWN then we know
1513          * the lock needs remastering here.
1514          * if any node comes back with a valid master, check
1515          * to see if that master is the one that we are
1516          * recovering.  if so, then the new_master died and
1517          * we need to remaster this lock.  if not, then the
1518          * new_master survived and that node will respond to
1519          * other nodes about the owner.
1520          * if there is an owner, this node needs to dump this
1521          * lockres and alert the sender that this lockres
1522          * was rejected. */
1523         spin_lock(&dlm->spinlock);
1524         dlm_node_iter_init(dlm->domain_map, &iter);
1525         spin_unlock(&dlm->spinlock);
1526
1527         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1528                 /* do not send to self */
1529                 if (nodenum == dlm->node_num)
1530                         continue;
1531                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1532                 if (ret < 0) {
1533                         mlog_errno(ret);
1534                         if (!dlm_is_host_down(ret))
1535                                 BUG();
1536                         /* host is down, so answer for that node would be
1537                          * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1538                 }
1539                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1540                         mlog(0, "lock master is %u\n", *real_master);
1541                         break;
1542                 }
1543         }
1544         return ret;
1545 }
1546
1547
1548 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1549                           u8 nodenum, u8 *real_master)
1550 {
1551         int ret = -EINVAL;
1552         struct dlm_master_requery req;
1553         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1554
1555         memset(&req, 0, sizeof(req));
1556         req.node_idx = dlm->node_num;
1557         req.namelen = res->lockname.len;
1558         memcpy(req.name, res->lockname.name, res->lockname.len);
1559
1560         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1561                                  &req, sizeof(req), nodenum, &status);
1562         /* XXX: negative status not handled properly here. */
1563         if (ret < 0)
1564                 mlog_errno(ret);
1565         else {
1566                 BUG_ON(status < 0);
1567                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1568                 *real_master = (u8) (status & 0xff);
1569                 mlog(0, "node %u responded to master requery with %u\n",
1570                           nodenum, *real_master);
1571                 ret = 0;
1572         }
1573         return ret;
1574 }
1575
1576
1577 /* this function cannot error, so unless the sending
1578  * or receiving of the message failed, the owner can
1579  * be trusted */
1580 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data)
1581 {
1582         struct dlm_ctxt *dlm = data;
1583         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1584         struct dlm_lock_resource *res = NULL;
1585         unsigned int hash;
1586         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1587         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1588
1589         if (!dlm_grab(dlm)) {
1590                 /* since the domain has gone away on this
1591                  * node, the proper response is UNKNOWN */
1592                 return master;
1593         }
1594
1595         hash = dlm_lockid_hash(req->name, req->namelen);
1596
1597         spin_lock(&dlm->spinlock);
1598         res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1599         if (res) {
1600                 spin_lock(&res->spinlock);
1601                 master = res->owner;
1602                 if (master == dlm->node_num) {
1603                         int ret = dlm_dispatch_assert_master(dlm, res,
1604                                                              0, 0, flags);
1605                         if (ret < 0) {
1606                                 mlog_errno(-ENOMEM);
1607                                 /* retry!? */
1608                                 BUG();
1609                         }
1610                 }
1611                 spin_unlock(&res->spinlock);
1612         }
1613         spin_unlock(&dlm->spinlock);
1614
1615         dlm_put(dlm);
1616         return master;
1617 }
1618
1619 static inline struct list_head *
1620 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1621 {
1622         struct list_head *ret;
1623         BUG_ON(list_num < 0);
1624         BUG_ON(list_num > 2);
1625         ret = &(res->granted);
1626         ret += list_num;
1627         return ret;
1628 }
1629 /* TODO: do ast flush business
1630  * TODO: do MIGRATING and RECOVERING spinning
1631  */
1632
1633 /*
1634 * NOTE about in-flight requests during migration:
1635 *
1636 * Before attempting the migrate, the master has marked the lockres as
1637 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1638 * requests either got queued before the MIGRATING flag got set, in which
1639 * case the lock data will reflect the change and a return message is on
1640 * the way, or the request failed to get in before MIGRATING got set.  In
1641 * this case, the caller will be told to spin and wait for the MIGRATING
1642 * flag to be dropped, then recheck the master.
1643 * This holds true for the convert, cancel and unlock cases, and since lvb
1644 * updates are tied to these same messages, it applies to lvb updates as
1645 * well.  For the lock case, there is no way a lock can be on the master
1646 * queue and not be on the secondary queue since the lock is always added
1647 * locally first.  This means that the new target node will never be sent
1648 * a lock that he doesn't already have on the list.
1649 * In total, this means that the local lock is correct and should not be
1650 * updated to match the one sent by the master.  Any messages sent back
1651 * from the master before the MIGRATING flag will bring the lock properly
1652 * up-to-date, and the change will be ordered properly for the waiter.
1653 * We will *not* attempt to modify the lock underneath the waiter.
1654 */
1655
1656 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1657                                      struct dlm_lock_resource *res,
1658                                      struct dlm_migratable_lockres *mres)
1659 {
1660         struct dlm_migratable_lock *ml;
1661         struct list_head *queue;
1662         struct dlm_lock *newlock = NULL;
1663         struct dlm_lockstatus *lksb = NULL;
1664         int ret = 0;
1665         int i, bad;
1666         struct list_head *iter;
1667         struct dlm_lock *lock = NULL;
1668
1669         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1670         for (i=0; i<mres->num_locks; i++) {
1671                 ml = &(mres->ml[i]);
1672                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1673                 newlock = NULL;
1674                 lksb = NULL;
1675
1676                 queue = dlm_list_num_to_pointer(res, ml->list);
1677
1678                 /* if the lock is for the local node it needs to
1679                  * be moved to the proper location within the queue.
1680                  * do not allocate a new lock structure. */
1681                 if (ml->node == dlm->node_num) {
1682                         /* MIGRATION ONLY! */
1683                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1684
1685                         spin_lock(&res->spinlock);
1686                         list_for_each(iter, queue) {
1687                                 lock = list_entry (iter, struct dlm_lock, list);
1688                                 if (lock->ml.cookie != ml->cookie)
1689                                         lock = NULL;
1690                                 else
1691                                         break;
1692                         }
1693
1694                         /* lock is always created locally first, and
1695                          * destroyed locally last.  it must be on the list */
1696                         if (!lock) {
1697                                 u64 c = ml->cookie;
1698                                 mlog(ML_ERROR, "could not find local lock "
1699                                                "with cookie %u:%llu!\n",
1700                                                dlm_get_lock_cookie_node(c),
1701                                                dlm_get_lock_cookie_seq(c));
1702                                 BUG();
1703                         }
1704                         BUG_ON(lock->ml.node != ml->node);
1705
1706                         /* see NOTE above about why we do not update
1707                          * to match the master here */
1708
1709                         /* move the lock to its proper place */
1710                         /* do not alter lock refcount.  switching lists. */
1711                         list_move_tail(&lock->list, queue);
1712                         spin_unlock(&res->spinlock);
1713
1714                         mlog(0, "just reordered a local lock!\n");
1715                         continue;
1716                 }
1717
1718                 /* lock is for another node. */
1719                 newlock = dlm_new_lock(ml->type, ml->node,
1720                                        be64_to_cpu(ml->cookie), NULL);
1721                 if (!newlock) {
1722                         ret = -ENOMEM;
1723                         goto leave;
1724                 }
1725                 lksb = newlock->lksb;
1726                 dlm_lock_attach_lockres(newlock, res);
1727
1728                 if (ml->convert_type != LKM_IVMODE) {
1729                         BUG_ON(queue != &res->converting);
1730                         newlock->ml.convert_type = ml->convert_type;
1731                 }
1732                 lksb->flags |= (ml->flags &
1733                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1734
1735                 if (ml->type == LKM_NLMODE)
1736                         goto skip_lvb;
1737
1738                 if (!dlm_lvb_is_empty(mres->lvb)) {
1739                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1740                                 /* other node was trying to update
1741                                  * lvb when node died.  recreate the
1742                                  * lksb with the updated lvb. */
1743                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1744                                 /* the lock resource lvb update must happen
1745                                  * NOW, before the spinlock is dropped.
1746                                  * we no longer wait for the AST to update
1747                                  * the lvb. */
1748                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1749                         } else {
1750                                 /* otherwise, the node is sending its
1751                                  * most recent valid lvb info */
1752                                 BUG_ON(ml->type != LKM_EXMODE &&
1753                                        ml->type != LKM_PRMODE);
1754                                 if (!dlm_lvb_is_empty(res->lvb) &&
1755                                     (ml->type == LKM_EXMODE ||
1756                                      memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1757                                         int i;
1758                                         mlog(ML_ERROR, "%s:%.*s: received bad "
1759                                              "lvb! type=%d\n", dlm->name,
1760                                              res->lockname.len,
1761                                              res->lockname.name, ml->type);
1762                                         printk("lockres lvb=[");
1763                                         for (i=0; i<DLM_LVB_LEN; i++)
1764                                                 printk("%02x", res->lvb[i]);
1765                                         printk("]\nmigrated lvb=[");
1766                                         for (i=0; i<DLM_LVB_LEN; i++)
1767                                                 printk("%02x", mres->lvb[i]);
1768                                         printk("]\n");
1769                                         dlm_print_one_lock_resource(res);
1770                                         BUG();
1771                                 }
1772                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1773                         }
1774                 }
1775 skip_lvb:
1776
1777                 /* NOTE:
1778                  * wrt lock queue ordering and recovery:
1779                  *    1. order of locks on granted queue is
1780                  *       meaningless.
1781                  *    2. order of locks on converting queue is
1782                  *       LOST with the node death.  sorry charlie.
1783                  *    3. order of locks on the blocked queue is
1784                  *       also LOST.
1785                  * order of locks does not affect integrity, it
1786                  * just means that a lock request may get pushed
1787                  * back in line as a result of the node death.
1788                  * also note that for a given node the lock order
1789                  * for its secondary queue locks is preserved
1790                  * relative to each other, but clearly *not*
1791                  * preserved relative to locks from other nodes.
1792                  */
1793                 bad = 0;
1794                 spin_lock(&res->spinlock);
1795                 list_for_each_entry(lock, queue, list) {
1796                         if (lock->ml.cookie == ml->cookie) {
1797                                 u64 c = lock->ml.cookie;
1798                                 mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1799                                      "exists on this lockres!\n", dlm->name,
1800                                      res->lockname.len, res->lockname.name,
1801                                      dlm_get_lock_cookie_node(c),
1802                                      dlm_get_lock_cookie_seq(c));
1803
1804                                 mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1805                                      "node=%u, cookie=%u:%llu, queue=%d\n",
1806                                      ml->type, ml->convert_type, ml->node,
1807                                      dlm_get_lock_cookie_node(ml->cookie),
1808                                      dlm_get_lock_cookie_seq(ml->cookie),
1809                                      ml->list);
1810
1811                                 __dlm_print_one_lock_resource(res);
1812                                 bad = 1;
1813                                 break;
1814                         }
1815                 }
1816                 if (!bad) {
1817                         dlm_lock_get(newlock);
1818                         list_add_tail(&newlock->list, queue);
1819                 }
1820                 spin_unlock(&res->spinlock);
1821         }
1822         mlog(0, "done running all the locks\n");
1823
1824 leave:
1825         if (ret < 0) {
1826                 mlog_errno(ret);
1827                 if (newlock)
1828                         dlm_lock_put(newlock);
1829         }
1830
1831         mlog_exit(ret);
1832         return ret;
1833 }
1834
1835 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1836                                        struct dlm_lock_resource *res)
1837 {
1838         int i;
1839         struct list_head *queue, *iter, *iter2;
1840         struct dlm_lock *lock;
1841
1842         res->state |= DLM_LOCK_RES_RECOVERING;
1843         if (!list_empty(&res->recovering)) {
1844                 mlog(0,
1845                      "Recovering res %s:%.*s, is already on recovery list!\n",
1846                      dlm->name, res->lockname.len, res->lockname.name);
1847                 list_del_init(&res->recovering);
1848         }
1849         /* We need to hold a reference while on the recovery list */
1850         dlm_lockres_get(res);
1851         list_add_tail(&res->recovering, &dlm->reco.resources);
1852
1853         /* find any pending locks and put them back on proper list */
1854         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
1855                 queue = dlm_list_idx_to_ptr(res, i);
1856                 list_for_each_safe(iter, iter2, queue) {
1857                         lock = list_entry (iter, struct dlm_lock, list);
1858                         dlm_lock_get(lock);
1859                         if (lock->convert_pending) {
1860                                 /* move converting lock back to granted */
1861                                 BUG_ON(i != DLM_CONVERTING_LIST);
1862                                 mlog(0, "node died with convert pending "
1863                                      "on %.*s. move back to granted list.\n",
1864                                      res->lockname.len, res->lockname.name);
1865                                 dlm_revert_pending_convert(res, lock);
1866                                 lock->convert_pending = 0;
1867                         } else if (lock->lock_pending) {
1868                                 /* remove pending lock requests completely */
1869                                 BUG_ON(i != DLM_BLOCKED_LIST);
1870                                 mlog(0, "node died with lock pending "
1871                                      "on %.*s. remove from blocked list and skip.\n",
1872                                      res->lockname.len, res->lockname.name);
1873                                 /* lock will be floating until ref in
1874                                  * dlmlock_remote is freed after the network
1875                                  * call returns.  ok for it to not be on any
1876                                  * list since no ast can be called
1877                                  * (the master is dead). */
1878                                 dlm_revert_pending_lock(res, lock);
1879                                 lock->lock_pending = 0;
1880                         } else if (lock->unlock_pending) {
1881                                 /* if an unlock was in progress, treat as
1882                                  * if this had completed successfully
1883                                  * before sending this lock state to the
1884                                  * new master.  note that the dlm_unlock
1885                                  * call is still responsible for calling
1886                                  * the unlockast.  that will happen after
1887                                  * the network call times out.  for now,
1888                                  * just move lists to prepare the new
1889                                  * recovery master.  */
1890                                 BUG_ON(i != DLM_GRANTED_LIST);
1891                                 mlog(0, "node died with unlock pending "
1892                                      "on %.*s. remove from blocked list and skip.\n",
1893                                      res->lockname.len, res->lockname.name);
1894                                 dlm_commit_pending_unlock(res, lock);
1895                                 lock->unlock_pending = 0;
1896                         } else if (lock->cancel_pending) {
1897                                 /* if a cancel was in progress, treat as
1898                                  * if this had completed successfully
1899                                  * before sending this lock state to the
1900                                  * new master */
1901                                 BUG_ON(i != DLM_CONVERTING_LIST);
1902                                 mlog(0, "node died with cancel pending "
1903                                      "on %.*s. move back to granted list.\n",
1904                                      res->lockname.len, res->lockname.name);
1905                                 dlm_commit_pending_cancel(res, lock);
1906                                 lock->cancel_pending = 0;
1907                         }
1908                         dlm_lock_put(lock);
1909                 }
1910         }
1911 }
1912
1913
1914
1915 /* removes all recovered locks from the recovery list.
1916  * sets the res->owner to the new master.
1917  * unsets the RECOVERY flag and wakes waiters. */
1918 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
1919                                               u8 dead_node, u8 new_master)
1920 {
1921         int i;
1922         struct list_head *iter, *iter2;
1923         struct hlist_node *hash_iter;
1924         struct hlist_head *bucket;
1925
1926         struct dlm_lock_resource *res;
1927
1928         mlog_entry_void();
1929
1930         assert_spin_locked(&dlm->spinlock);
1931
1932         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
1933                 res = list_entry (iter, struct dlm_lock_resource, recovering);
1934                 if (res->owner == dead_node) {
1935                         list_del_init(&res->recovering);
1936                         spin_lock(&res->spinlock);
1937                         dlm_change_lockres_owner(dlm, res, new_master);
1938                         res->state &= ~DLM_LOCK_RES_RECOVERING;
1939                         if (!__dlm_lockres_unused(res))
1940                                 __dlm_dirty_lockres(dlm, res);
1941                         spin_unlock(&res->spinlock);
1942                         wake_up(&res->wq);
1943                         dlm_lockres_put(res);
1944                 }
1945         }
1946
1947         /* this will become unnecessary eventually, but
1948          * for now we need to run the whole hash, clear
1949          * the RECOVERING state and set the owner
1950          * if necessary */
1951         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
1952                 bucket = dlm_lockres_hash(dlm, i);
1953                 hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
1954                         if (res->state & DLM_LOCK_RES_RECOVERING) {
1955                                 if (res->owner == dead_node) {
1956                                         mlog(0, "(this=%u) res %.*s owner=%u "
1957                                              "was not on recovering list, but "
1958                                              "clearing state anyway\n",
1959                                              dlm->node_num, res->lockname.len,
1960                                              res->lockname.name, new_master);
1961                                 } else if (res->owner == dlm->node_num) {
1962                                         mlog(0, "(this=%u) res %.*s owner=%u "
1963                                              "was not on recovering list, "
1964                                              "owner is THIS node, clearing\n",
1965                                              dlm->node_num, res->lockname.len,
1966                                              res->lockname.name, new_master);
1967                                 } else
1968                                         continue;
1969
1970                                 if (!list_empty(&res->recovering)) {
1971                                         mlog(0, "%s:%.*s: lockres was "
1972                                              "marked RECOVERING, owner=%u\n",
1973                                              dlm->name, res->lockname.len,
1974                                              res->lockname.name, res->owner);
1975                                         list_del_init(&res->recovering);
1976                                         dlm_lockres_put(res);
1977                                 }
1978                                 spin_lock(&res->spinlock);
1979                                 dlm_change_lockres_owner(dlm, res, new_master);
1980                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
1981                                 if (!__dlm_lockres_unused(res))
1982                                         __dlm_dirty_lockres(dlm, res);
1983                                 spin_unlock(&res->spinlock);
1984                                 wake_up(&res->wq);
1985                         }
1986                 }
1987         }
1988 }
1989
1990 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
1991 {
1992         if (local) {
1993                 if (lock->ml.type != LKM_EXMODE &&
1994                     lock->ml.type != LKM_PRMODE)
1995                         return 1;
1996         } else if (lock->ml.type == LKM_EXMODE)
1997                 return 1;
1998         return 0;
1999 }
2000
2001 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2002                                struct dlm_lock_resource *res, u8 dead_node)
2003 {
2004         struct list_head *iter, *queue;
2005         struct dlm_lock *lock;
2006         int blank_lvb = 0, local = 0;
2007         int i;
2008         u8 search_node;
2009
2010         assert_spin_locked(&dlm->spinlock);
2011         assert_spin_locked(&res->spinlock);
2012
2013         if (res->owner == dlm->node_num)
2014                 /* if this node owned the lockres, and if the dead node
2015                  * had an EX when he died, blank out the lvb */
2016                 search_node = dead_node;
2017         else {
2018                 /* if this is a secondary lockres, and we had no EX or PR
2019                  * locks granted, we can no longer trust the lvb */
2020                 search_node = dlm->node_num;
2021                 local = 1;  /* check local state for valid lvb */
2022         }
2023
2024         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2025                 queue = dlm_list_idx_to_ptr(res, i);
2026                 list_for_each(iter, queue) {
2027                         lock = list_entry (iter, struct dlm_lock, list);
2028                         if (lock->ml.node == search_node) {
2029                                 if (dlm_lvb_needs_invalidation(lock, local)) {
2030                                         /* zero the lksb lvb and lockres lvb */
2031                                         blank_lvb = 1;
2032                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2033                                 }
2034                         }
2035                 }
2036         }
2037
2038         if (blank_lvb) {
2039                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2040                      res->lockname.len, res->lockname.name, dead_node);
2041                 memset(res->lvb, 0, DLM_LVB_LEN);
2042         }
2043 }
2044
2045 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2046                                 struct dlm_lock_resource *res, u8 dead_node)
2047 {
2048         struct list_head *iter, *tmpiter;
2049         struct dlm_lock *lock;
2050
2051         /* this node is the lockres master:
2052          * 1) remove any stale locks for the dead node
2053          * 2) if the dead node had an EX when he died, blank out the lvb
2054          */
2055         assert_spin_locked(&dlm->spinlock);
2056         assert_spin_locked(&res->spinlock);
2057
2058         /* TODO: check pending_asts, pending_basts here */
2059         list_for_each_safe(iter, tmpiter, &res->granted) {
2060                 lock = list_entry (iter, struct dlm_lock, list);
2061                 if (lock->ml.node == dead_node) {
2062                         list_del_init(&lock->list);
2063                         dlm_lock_put(lock);
2064                 }
2065         }
2066         list_for_each_safe(iter, tmpiter, &res->converting) {
2067                 lock = list_entry (iter, struct dlm_lock, list);
2068                 if (lock->ml.node == dead_node) {
2069                         list_del_init(&lock->list);
2070                         dlm_lock_put(lock);
2071                 }
2072         }
2073         list_for_each_safe(iter, tmpiter, &res->blocked) {
2074                 lock = list_entry (iter, struct dlm_lock, list);
2075                 if (lock->ml.node == dead_node) {
2076                         list_del_init(&lock->list);
2077                         dlm_lock_put(lock);
2078                 }
2079         }
2080
2081         /* do not kick thread yet */
2082         __dlm_dirty_lockres(dlm, res);
2083 }
2084
2085 /* if this node is the recovery master, and there are no
2086  * locks for a given lockres owned by this node that are in
2087  * either PR or EX mode, zero out the lvb before requesting.
2088  *
2089  */
2090
2091
2092 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2093 {
2094         struct hlist_node *iter;
2095         struct dlm_lock_resource *res;
2096         int i;
2097         struct hlist_head *bucket;
2098         struct dlm_lock *lock;
2099
2100
2101         /* purge any stale mles */
2102         dlm_clean_master_list(dlm, dead_node);
2103
2104         /*
2105          * now clean up all lock resources.  there are two rules:
2106          *
2107          * 1) if the dead node was the master, move the lockres
2108          *    to the recovering list.  set the RECOVERING flag.
2109          *    this lockres needs to be cleaned up before it can
2110          *    be used further.
2111          *
2112          * 2) if this node was the master, remove all locks from
2113          *    each of the lockres queues that were owned by the
2114          *    dead node.  once recovery finishes, the dlm thread
2115          *    can be kicked again to see if any ASTs or BASTs
2116          *    need to be fired as a result.
2117          */
2118         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2119                 bucket = dlm_lockres_hash(dlm, i);
2120                 hlist_for_each_entry(res, iter, bucket, hash_node) {
2121                         /* always prune any $RECOVERY entries for dead nodes,
2122                          * otherwise hangs can occur during later recovery */
2123                         if (dlm_is_recovery_lock(res->lockname.name,
2124                                                  res->lockname.len)) {
2125                                 spin_lock(&res->spinlock);
2126                                 list_for_each_entry(lock, &res->granted, list) {
2127                                         if (lock->ml.node == dead_node) {
2128                                                 mlog(0, "AHA! there was "
2129                                                      "a $RECOVERY lock for dead "
2130                                                      "node %u (%s)!\n",
2131                                                      dead_node, dlm->name);
2132                                                 list_del_init(&lock->list);
2133                                                 dlm_lock_put(lock);
2134                                                 break;
2135                                         }
2136                                 }
2137                                 spin_unlock(&res->spinlock);
2138                                 continue;
2139                         }
2140                         spin_lock(&res->spinlock);
2141                         /* zero the lvb if necessary */
2142                         dlm_revalidate_lvb(dlm, res, dead_node);
2143                         if (res->owner == dead_node)
2144                                 dlm_move_lockres_to_recovery_list(dlm, res);
2145                         else if (res->owner == dlm->node_num) {
2146                                 dlm_free_dead_locks(dlm, res, dead_node);
2147                                 __dlm_lockres_calc_usage(dlm, res);
2148                         }
2149                         spin_unlock(&res->spinlock);
2150                 }
2151         }
2152
2153 }
2154
2155 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2156 {
2157         assert_spin_locked(&dlm->spinlock);
2158
2159         if (dlm->reco.new_master == idx) {
2160                 mlog(0, "%s: recovery master %d just died\n",
2161                      dlm->name, idx);
2162                 if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2163                         /* finalize1 was reached, so it is safe to clear
2164                          * the new_master and dead_node.  that recovery
2165                          * is complete. */
2166                         mlog(0, "%s: dead master %d had reached "
2167                              "finalize1 state, clearing\n", dlm->name, idx);
2168                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2169                         __dlm_reset_recovery(dlm);
2170                 }
2171         }
2172
2173         /* check to see if the node is already considered dead */
2174         if (!test_bit(idx, dlm->live_nodes_map)) {
2175                 mlog(0, "for domain %s, node %d is already dead. "
2176                      "another node likely did recovery already.\n",
2177                      dlm->name, idx);
2178                 return;
2179         }
2180
2181         /* check to see if we do not care about this node */
2182         if (!test_bit(idx, dlm->domain_map)) {
2183                 /* This also catches the case that we get a node down
2184                  * but haven't joined the domain yet. */
2185                 mlog(0, "node %u already removed from domain!\n", idx);
2186                 return;
2187         }
2188
2189         clear_bit(idx, dlm->live_nodes_map);
2190
2191         /* Clean up join state on node death. */
2192         if (dlm->joining_node == idx) {
2193                 mlog(0, "Clearing join state for node %u\n", idx);
2194                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2195         }
2196
2197         /* make sure local cleanup occurs before the heartbeat events */
2198         if (!test_bit(idx, dlm->recovery_map))
2199                 dlm_do_local_recovery_cleanup(dlm, idx);
2200
2201         /* notify anything attached to the heartbeat events */
2202         dlm_hb_event_notify_attached(dlm, idx, 0);
2203
2204         mlog(0, "node %u being removed from domain map!\n", idx);
2205         clear_bit(idx, dlm->domain_map);
2206         /* wake up migration waiters if a node goes down.
2207          * perhaps later we can genericize this for other waiters. */
2208         wake_up(&dlm->migration_wq);
2209
2210         if (test_bit(idx, dlm->recovery_map))
2211                 mlog(0, "domain %s, node %u already added "
2212                      "to recovery map!\n", dlm->name, idx);
2213         else
2214                 set_bit(idx, dlm->recovery_map);
2215 }
2216
2217 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2218 {
2219         struct dlm_ctxt *dlm = data;
2220
2221         if (!dlm_grab(dlm))
2222                 return;
2223
2224         spin_lock(&dlm->spinlock);
2225         __dlm_hb_node_down(dlm, idx);
2226         spin_unlock(&dlm->spinlock);
2227
2228         dlm_put(dlm);
2229 }
2230
2231 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2232 {
2233         struct dlm_ctxt *dlm = data;
2234
2235         if (!dlm_grab(dlm))
2236                 return;
2237
2238         spin_lock(&dlm->spinlock);
2239         set_bit(idx, dlm->live_nodes_map);
2240         /* do NOT notify mle attached to the heartbeat events.
2241          * new nodes are not interesting in mastery until joined. */
2242         spin_unlock(&dlm->spinlock);
2243
2244         dlm_put(dlm);
2245 }
2246
2247 static void dlm_reco_ast(void *astdata)
2248 {
2249         struct dlm_ctxt *dlm = astdata;
2250         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2251              dlm->node_num, dlm->name);
2252 }
2253 static void dlm_reco_bast(void *astdata, int blocked_type)
2254 {
2255         struct dlm_ctxt *dlm = astdata;
2256         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2257              dlm->node_num, dlm->name);
2258 }
2259 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2260 {
2261         mlog(0, "unlockast for recovery lock fired!\n");
2262 }
2263
2264 /*
2265  * dlm_pick_recovery_master will continually attempt to use
2266  * dlmlock() on the special "$RECOVERY" lockres with the
2267  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2268  * this function on each node racing to become the recovery
2269  * master will not stop attempting this until either:
2270  * a) this node gets the EX (and becomes the recovery master),
2271  * or b) dlm->reco.new_master gets set to some nodenum
2272  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2273  * so each time a recovery master is needed, the entire cluster
2274  * will sync at this point.  if the new master dies, that will
2275  * be detected in dlm_do_recovery */
2276 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2277 {
2278         enum dlm_status ret;
2279         struct dlm_lockstatus lksb;
2280         int status = -EINVAL;
2281
2282         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2283              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2284 again:
2285         memset(&lksb, 0, sizeof(lksb));
2286
2287         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2288                       DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2289                       dlm_reco_ast, dlm, dlm_reco_bast);
2290
2291         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2292              dlm->name, ret, lksb.status);
2293
2294         if (ret == DLM_NORMAL) {
2295                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2296                      dlm->name, dlm->node_num);
2297
2298                 /* got the EX lock.  check to see if another node
2299                  * just became the reco master */
2300                 if (dlm_reco_master_ready(dlm)) {
2301                         mlog(0, "%s: got reco EX lock, but %u will "
2302                              "do the recovery\n", dlm->name,
2303                              dlm->reco.new_master);
2304                         status = -EEXIST;
2305                 } else {
2306                         status = 0;
2307
2308                         /* see if recovery was already finished elsewhere */
2309                         spin_lock(&dlm->spinlock);
2310                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2311                                 status = -EINVAL;
2312                                 mlog(0, "%s: got reco EX lock, but "
2313                                      "node got recovered already\n", dlm->name);
2314                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2315                                         mlog(ML_ERROR, "%s: new master is %u "
2316                                              "but no dead node!\n",
2317                                              dlm->name, dlm->reco.new_master);
2318                                         BUG();
2319                                 }
2320                         }
2321                         spin_unlock(&dlm->spinlock);
2322                 }
2323
2324                 /* if this node has actually become the recovery master,
2325                  * set the master and send the messages to begin recovery */
2326                 if (!status) {
2327                         mlog(0, "%s: dead=%u, this=%u, sending "
2328                              "begin_reco now\n", dlm->name,
2329                              dlm->reco.dead_node, dlm->node_num);
2330                         status = dlm_send_begin_reco_message(dlm,
2331                                       dlm->reco.dead_node);
2332                         /* this always succeeds */
2333                         BUG_ON(status);
2334
2335                         /* set the new_master to this node */
2336                         spin_lock(&dlm->spinlock);
2337                         dlm_set_reco_master(dlm, dlm->node_num);
2338                         spin_unlock(&dlm->spinlock);
2339                 }
2340
2341                 /* recovery lock is a special case.  ast will not get fired,
2342                  * so just go ahead and unlock it. */
2343                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2344                 if (ret == DLM_DENIED) {
2345                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2346                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2347                 }
2348                 if (ret != DLM_NORMAL) {
2349                         /* this would really suck. this could only happen
2350                          * if there was a network error during the unlock
2351                          * because of node death.  this means the unlock
2352                          * is actually "done" and the lock structure is
2353                          * even freed.  we can continue, but only
2354                          * because this specific lock name is special. */
2355                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2356                 }
2357         } else if (ret == DLM_NOTQUEUED) {
2358                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2359                      dlm->name, dlm->node_num);
2360                 /* another node is master. wait on
2361                  * reco.new_master != O2NM_INVALID_NODE_NUM
2362                  * for at most one second */
2363                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2364                                          dlm_reco_master_ready(dlm),
2365                                          msecs_to_jiffies(1000));
2366                 if (!dlm_reco_master_ready(dlm)) {
2367                         mlog(0, "%s: reco master taking awhile\n",
2368                              dlm->name);
2369                         goto again;
2370                 }
2371                 /* another node has informed this one that it is reco master */
2372                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2373                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2374                 status = -EEXIST;
2375         } else if (ret == DLM_RECOVERING) {
2376                 mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2377                      dlm->name, dlm->node_num);
2378                 goto again;
2379         } else {
2380                 struct dlm_lock_resource *res;
2381
2382                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2383                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2384                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2385                      dlm_errname(lksb.status));
2386                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2387                                          DLM_RECOVERY_LOCK_NAME_LEN);
2388                 if (res) {
2389                         dlm_print_one_lock_resource(res);
2390                         dlm_lockres_put(res);
2391                 } else {
2392                         mlog(ML_ERROR, "recovery lock not found\n");
2393                 }
2394                 BUG();
2395         }
2396
2397         return status;
2398 }
2399
2400 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2401 {
2402         struct dlm_begin_reco br;
2403         int ret = 0;
2404         struct dlm_node_iter iter;
2405         int nodenum;
2406         int status;
2407
2408         mlog_entry("%u\n", dead_node);
2409
2410         mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2411
2412         spin_lock(&dlm->spinlock);
2413         dlm_node_iter_init(dlm->domain_map, &iter);
2414         spin_unlock(&dlm->spinlock);
2415
2416         clear_bit(dead_node, iter.node_map);
2417
2418         memset(&br, 0, sizeof(br));
2419         br.node_idx = dlm->node_num;
2420         br.dead_node = dead_node;
2421
2422         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2423                 ret = 0;
2424                 if (nodenum == dead_node) {
2425                         mlog(0, "not sending begin reco to dead node "
2426                                   "%u\n", dead_node);
2427                         continue;
2428                 }
2429                 if (nodenum == dlm->node_num) {
2430                         mlog(0, "not sending begin reco to self\n");
2431                         continue;
2432                 }
2433 retry:
2434                 ret = -EINVAL;
2435                 mlog(0, "attempting to send begin reco msg to %d\n",
2436                           nodenum);
2437                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2438                                          &br, sizeof(br), nodenum, &status);
2439                 /* negative status is handled ok by caller here */
2440                 if (ret >= 0)
2441                         ret = status;
2442                 if (dlm_is_host_down(ret)) {
2443                         /* node is down.  not involved in recovery
2444                          * so just keep going */
2445                         mlog(0, "%s: node %u was down when sending "
2446                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2447                         ret = 0;
2448                 }
2449                 if (ret < 0) {
2450                         struct dlm_lock_resource *res;
2451                         /* this is now a serious problem, possibly ENOMEM
2452                          * in the network stack.  must retry */
2453                         mlog_errno(ret);
2454                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2455                             " returned %d\n", dlm->name, nodenum, ret);
2456                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2457                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2458                         if (res) {
2459                                 dlm_print_one_lock_resource(res);
2460                                 dlm_lockres_put(res);
2461                         } else {
2462                                 mlog(ML_ERROR, "recovery lock not found\n");
2463                         }
2464                         /* sleep for a bit in hopes that we can avoid
2465                          * another ENOMEM */
2466                         msleep(100);
2467                         goto retry;
2468                 } else if (ret == EAGAIN) {
2469                         mlog(0, "%s: trying to start recovery of node "
2470                              "%u, but node %u is waiting for last recovery "
2471                              "to complete, backoff for a bit\n", dlm->name,
2472                              dead_node, nodenum);
2473                         /* TODO Look into replacing msleep with cond_resched() */
2474                         msleep(100);
2475                         goto retry;
2476                 }
2477         }
2478
2479         return ret;
2480 }
2481
2482 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data)
2483 {
2484         struct dlm_ctxt *dlm = data;
2485         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2486
2487         /* ok to return 0, domain has gone away */
2488         if (!dlm_grab(dlm))
2489                 return 0;
2490
2491         spin_lock(&dlm->spinlock);
2492         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2493                 mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2494                      "but this node is in finalize state, waiting on finalize2\n",
2495                      dlm->name, br->node_idx, br->dead_node,
2496                      dlm->reco.dead_node, dlm->reco.new_master);
2497                 spin_unlock(&dlm->spinlock);
2498                 return EAGAIN;
2499         }
2500         spin_unlock(&dlm->spinlock);
2501
2502         mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2503              dlm->name, br->node_idx, br->dead_node,
2504              dlm->reco.dead_node, dlm->reco.new_master);
2505
2506         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2507
2508         spin_lock(&dlm->spinlock);
2509         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2510                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2511                         mlog(0, "%s: new_master %u died, changing "
2512                              "to %u\n", dlm->name, dlm->reco.new_master,
2513                              br->node_idx);
2514                 } else {
2515                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2516                              "to %u\n", dlm->name, dlm->reco.new_master,
2517                              br->node_idx);
2518                         /* may not have seen the new master as dead yet */
2519                 }
2520         }
2521         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2522                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2523                      "node %u changing it to %u\n", dlm->name,
2524                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2525         }
2526         dlm_set_reco_master(dlm, br->node_idx);
2527         dlm_set_reco_dead_node(dlm, br->dead_node);
2528         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2529                 mlog(0, "recovery master %u sees %u as dead, but this "
2530                      "node has not yet.  marking %u as dead\n",
2531                      br->node_idx, br->dead_node, br->dead_node);
2532                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2533                     !test_bit(br->dead_node, dlm->live_nodes_map))
2534                         mlog(0, "%u not in domain/live_nodes map "
2535                              "so setting it in reco map manually\n",
2536                              br->dead_node);
2537                 /* force the recovery cleanup in __dlm_hb_node_down
2538                  * both of these will be cleared in a moment */
2539                 set_bit(br->dead_node, dlm->domain_map);
2540                 set_bit(br->dead_node, dlm->live_nodes_map);
2541                 __dlm_hb_node_down(dlm, br->dead_node);
2542         }
2543         spin_unlock(&dlm->spinlock);
2544
2545         dlm_kick_recovery_thread(dlm);
2546
2547         mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2548              dlm->name, br->node_idx, br->dead_node,
2549              dlm->reco.dead_node, dlm->reco.new_master);
2550
2551         dlm_put(dlm);
2552         return 0;
2553 }
2554
2555 #define DLM_FINALIZE_STAGE2  0x01
2556 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2557 {
2558         int ret = 0;
2559         struct dlm_finalize_reco fr;
2560         struct dlm_node_iter iter;
2561         int nodenum;
2562         int status;
2563         int stage = 1;
2564
2565         mlog(0, "finishing recovery for node %s:%u, "
2566              "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2567
2568         spin_lock(&dlm->spinlock);
2569         dlm_node_iter_init(dlm->domain_map, &iter);
2570         spin_unlock(&dlm->spinlock);
2571
2572 stage2:
2573         memset(&fr, 0, sizeof(fr));
2574         fr.node_idx = dlm->node_num;
2575         fr.dead_node = dlm->reco.dead_node;
2576         if (stage == 2)
2577                 fr.flags |= DLM_FINALIZE_STAGE2;
2578
2579         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2580                 if (nodenum == dlm->node_num)
2581                         continue;
2582                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2583                                          &fr, sizeof(fr), nodenum, &status);
2584                 if (ret >= 0)
2585                         ret = status;
2586                 if (ret < 0) {
2587                         mlog_errno(ret);
2588                         if (dlm_is_host_down(ret)) {
2589                                 /* this has no effect on this recovery
2590                                  * session, so set the status to zero to
2591                                  * finish out the last recovery */
2592                                 mlog(ML_ERROR, "node %u went down after this "
2593                                      "node finished recovery.\n", nodenum);
2594                                 ret = 0;
2595                                 continue;
2596                         }
2597                         break;
2598                 }
2599         }
2600         if (stage == 1) {
2601                 /* reset the node_iter back to the top and send finalize2 */
2602                 iter.curnode = -1;
2603                 stage = 2;
2604                 goto stage2;
2605         }
2606
2607         return ret;
2608 }
2609
2610 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data)
2611 {
2612         struct dlm_ctxt *dlm = data;
2613         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2614         int stage = 1;
2615
2616         /* ok to return 0, domain has gone away */
2617         if (!dlm_grab(dlm))
2618                 return 0;
2619
2620         if (fr->flags & DLM_FINALIZE_STAGE2)
2621                 stage = 2;
2622
2623         mlog(0, "%s: node %u finalizing recovery stage%d of "
2624              "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2625              fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2626
2627         spin_lock(&dlm->spinlock);
2628
2629         if (dlm->reco.new_master != fr->node_idx) {
2630                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2631                      "%u is supposed to be the new master, dead=%u\n",
2632                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2633                 BUG();
2634         }
2635         if (dlm->reco.dead_node != fr->dead_node) {
2636                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2637                      "node %u, but node %u is supposed to be dead\n",
2638                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2639                 BUG();
2640         }
2641
2642         switch (stage) {
2643                 case 1:
2644                         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2645                         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2646                                 mlog(ML_ERROR, "%s: received finalize1 from "
2647                                      "new master %u for dead node %u, but "
2648                                      "this node has already received it!\n",
2649                                      dlm->name, fr->node_idx, fr->dead_node);
2650                                 dlm_print_reco_node_status(dlm);
2651                                 BUG();
2652                         }
2653                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2654                         spin_unlock(&dlm->spinlock);
2655                         break;
2656                 case 2:
2657                         if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2658                                 mlog(ML_ERROR, "%s: received finalize2 from "
2659                                      "new master %u for dead node %u, but "
2660                                      "this node did not have finalize1!\n",
2661                                      dlm->name, fr->node_idx, fr->dead_node);
2662                                 dlm_print_reco_node_status(dlm);
2663                                 BUG();
2664                         }
2665                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2666                         spin_unlock(&dlm->spinlock);
2667                         dlm_reset_recovery(dlm);
2668                         dlm_kick_recovery_thread(dlm);
2669                         break;
2670                 default:
2671                         BUG();
2672         }
2673
2674         mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2675              dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2676
2677         dlm_put(dlm);
2678         return 0;
2679 }