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