git.oblomov.eu Git - linux-2.6/blob - fs/ocfs2/dlm/dlmrecovery.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmrecovery.c
   5  *
   6  * recovery stuff
   7  *
   8  * Copyright (C) 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  *
  25  */
  26
  27
  28 #include <linux/module.h>
  29 #include <linux/fs.h>
  30 #include <linux/types.h>
  31 #include <linux/slab.h>
  32 #include <linux/highmem.h>
  33 #include <linux/utsname.h>
  34 #include <linux/init.h>
  35 #include <linux/sysctl.h>
  36 #include <linux/random.h>
  37 #include <linux/blkdev.h>
  38 #include <linux/socket.h>
  39 #include <linux/inet.h>
  40 #include <linux/timer.h>
  41 #include <linux/kthread.h>
  42 #include <linux/delay.h>
  43
  44
  45 #include "cluster/heartbeat.h"
  46 #include "cluster/nodemanager.h"
  47 #include "cluster/tcp.h"
  48
  49 #include "dlmapi.h"
  50 #include "dlmcommon.h"
  51 #include "dlmdomain.h"
  52
  53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
  54 #include "cluster/masklog.h"
  55
  56 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
  57
  58 static int dlm_recovery_thread(void *data);
  59 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
  60 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
  61 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
  62 static int dlm_do_recovery(struct dlm_ctxt *dlm);
  63
  64 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
  65 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
  66 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  67 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
  68                                  u8 request_from, u8 dead_node);
  69 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
  70
  71 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
  72 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
  73                                         const char *lockname, int namelen,
  74                                         int total_locks, u64 cookie,
  75                                         u8 flags, u8 master);
  76 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
  77                                     struct dlm_migratable_lockres *mres,
  78                                     u8 send_to,
  79                                     struct dlm_lock_resource *res,
  80                                     int total_locks);
  81 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
  82                                      struct dlm_lock_resource *res,
  83                                      struct dlm_migratable_lockres *mres);
  84 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
  85 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
  86                                  u8 dead_node, u8 send_to);
  87 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
  88 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
  89                                         struct list_head *list, u8 dead_node);
  90 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
  91                                               u8 dead_node, u8 new_master);
  92 static void dlm_reco_ast(void *astdata);
  93 static void dlm_reco_bast(void *astdata, int blocked_type);
  94 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
  95 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
  96                                          void *data);
  97 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
  98 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
  99                                       struct dlm_lock_resource *res,
 100                                       u8 *real_master);
 101
 102 static u64 dlm_get_next_mig_cookie(void);
 103
 104 static DEFINE_SPINLOCK(dlm_reco_state_lock);
 105 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
 106 static u64 dlm_mig_cookie = 1;
 107
 108 static u64 dlm_get_next_mig_cookie(void)
 109 {
 110         u64 c;
 111         spin_lock(&dlm_mig_cookie_lock);
 112         c = dlm_mig_cookie;
 113         if (dlm_mig_cookie == (~0ULL))
 114                 dlm_mig_cookie = 1;
 115         else
 116                 dlm_mig_cookie++;
 117         spin_unlock(&dlm_mig_cookie_lock);
 118         return c;
 119 }
 120
 121 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
 122                                           u8 dead_node)
 123 {
 124         assert_spin_locked(&dlm->spinlock);
 125         if (dlm->reco.dead_node != dead_node)
 126                 mlog(0, "%s: changing dead_node from %u to %u\n",
 127                      dlm->name, dlm->reco.dead_node, dead_node);
 128         dlm->reco.dead_node = dead_node;
 129 }
 130
 131 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
 132                                        u8 master)
 133 {
 134         assert_spin_locked(&dlm->spinlock);
 135         mlog(0, "%s: changing new_master from %u to %u\n",
 136              dlm->name, dlm->reco.new_master, master);
 137         dlm->reco.new_master = master;
 138 }
 139
 140 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
 141 {
 142         assert_spin_locked(&dlm->spinlock);
 143         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
 144         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 145         dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 146 }
 147
 148 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
 149 {
 150         spin_lock(&dlm->spinlock);
 151         __dlm_reset_recovery(dlm);
 152         spin_unlock(&dlm->spinlock);
 153 }
 154
 155 /* Worker function used during recovery. */
 156 void dlm_dispatch_work(struct work_struct *work)
 157 {
 158         struct dlm_ctxt *dlm =
 159                 container_of(work, struct dlm_ctxt, dispatched_work);
 160         LIST_HEAD(tmp_list);
 161         struct list_head *iter, *iter2;
 162         struct dlm_work_item *item;
 163         dlm_workfunc_t *workfunc;
 164         int tot=0;
 165
 166         spin_lock(&dlm->work_lock);
 167         list_splice_init(&dlm->work_list, &tmp_list);
 168         spin_unlock(&dlm->work_lock);
 169
 170         list_for_each_safe(iter, iter2, &tmp_list) {
 171                 tot++;
 172         }
 173         mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
 174
 175         list_for_each_safe(iter, iter2, &tmp_list) {
 176                 item = list_entry(iter, struct dlm_work_item, list);
 177                 workfunc = item->func;
 178                 list_del_init(&item->list);
 179
 180                 /* already have ref on dlm to avoid having
 181                  * it disappear.  just double-check. */
 182                 BUG_ON(item->dlm != dlm);
 183
 184                 /* this is allowed to sleep and
 185                  * call network stuff */
 186                 workfunc(item, item->data);
 187
 188                 dlm_put(dlm);
 189                 kfree(item);
 190         }
 191 }
 192
 193 /*
 194  * RECOVERY THREAD
 195  */
 196
 197 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
 198 {
 199         /* wake the recovery thread
 200          * this will wake the reco thread in one of three places
 201          * 1) sleeping with no recovery happening
 202          * 2) sleeping with recovery mastered elsewhere
 203          * 3) recovery mastered here, waiting on reco data */
 204
 205         wake_up(&dlm->dlm_reco_thread_wq);
 206 }
 207
 208 /* Launch the recovery thread */
 209 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
 210 {
 211         mlog(0, "starting dlm recovery thread...\n");
 212
 213         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
 214                                                 "dlm_reco_thread");
 215         if (IS_ERR(dlm->dlm_reco_thread_task)) {
 216                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
 217                 dlm->dlm_reco_thread_task = NULL;
 218                 return -EINVAL;
 219         }
 220
 221         return 0;
 222 }
 223
 224 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
 225 {
 226         if (dlm->dlm_reco_thread_task) {
 227                 mlog(0, "waiting for dlm recovery thread to exit\n");
 228                 kthread_stop(dlm->dlm_reco_thread_task);
 229                 dlm->dlm_reco_thread_task = NULL;
 230         }
 231 }
 232
 233
 234
 235 /*
 236  * this is lame, but here's how recovery works...
 237  * 1) all recovery threads cluster wide will work on recovering
 238  *    ONE node at a time
 239  * 2) negotiate who will take over all the locks for the dead node.
 240  *    thats right... ALL the locks.
 241  * 3) once a new master is chosen, everyone scans all locks
 242  *    and moves aside those mastered by the dead guy
 243  * 4) each of these locks should be locked until recovery is done
 244  * 5) the new master collects up all of secondary lock queue info
 245  *    one lock at a time, forcing each node to communicate back
 246  *    before continuing
 247  * 6) each secondary lock queue responds with the full known lock info
 248  * 7) once the new master has run all its locks, it sends a ALLDONE!
 249  *    message to everyone
 250  * 8) upon receiving this message, the secondary queue node unlocks
 251  *    and responds to the ALLDONE
 252  * 9) once the new master gets responses from everyone, he unlocks
 253  *    everything and recovery for this dead node is done
 254  *10) go back to 2) while there are still dead nodes
 255  *
 256  */
 257
 258 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
 259 {
 260         struct dlm_reco_node_data *ndata;
 261         struct dlm_lock_resource *res;
 262
 263         mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
 264              dlm->name, dlm->dlm_reco_thread_task->pid,
 265              dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
 266              dlm->reco.dead_node, dlm->reco.new_master);
 267
 268         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
 269                 char *st = "unknown";
 270                 switch (ndata->state) {
 271                         case DLM_RECO_NODE_DATA_INIT:
 272                                 st = "init";
 273                                 break;
 274                         case DLM_RECO_NODE_DATA_REQUESTING:
 275                                 st = "requesting";
 276                                 break;
 277                         case DLM_RECO_NODE_DATA_DEAD:
 278                                 st = "dead";
 279                                 break;
 280                         case DLM_RECO_NODE_DATA_RECEIVING:
 281                                 st = "receiving";
 282                                 break;
 283                         case DLM_RECO_NODE_DATA_REQUESTED:
 284                                 st = "requested";
 285                                 break;
 286                         case DLM_RECO_NODE_DATA_DONE:
 287                                 st = "done";
 288                                 break;
 289                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 290                                 st = "finalize-sent";
 291                                 break;
 292                         default:
 293                                 st = "bad";
 294                                 break;
 295                 }
 296                 mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
 297                      dlm->name, ndata->node_num, st);
 298         }
 299         list_for_each_entry(res, &dlm->reco.resources, recovering) {
 300                 mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
 301                      dlm->name, res->lockname.len, res->lockname.name);
 302         }
 303 }
 304
 305 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
 306
 307 static int dlm_recovery_thread(void *data)
 308 {
 309         int status;
 310         struct dlm_ctxt *dlm = data;
 311         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
 312
 313         mlog(0, "dlm thread running for %s...\n", dlm->name);
 314
 315         while (!kthread_should_stop()) {
 316                 if (dlm_joined(dlm)) {
 317                         status = dlm_do_recovery(dlm);
 318                         if (status == -EAGAIN) {
 319                                 /* do not sleep, recheck immediately. */
 320                                 continue;
 321                         }
 322                         if (status < 0)
 323                                 mlog_errno(status);
 324                 }
 325
 326                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 327                                                  kthread_should_stop(),
 328                                                  timeout);
 329         }
 330
 331         mlog(0, "quitting DLM recovery thread\n");
 332         return 0;
 333 }
 334
 335 /* returns true when the recovery master has contacted us */
 336 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
 337 {
 338         int ready;
 339         spin_lock(&dlm->spinlock);
 340         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
 341         spin_unlock(&dlm->spinlock);
 342         return ready;
 343 }
 344
 345 /* returns true if node is no longer in the domain
 346  * could be dead or just not joined */
 347 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
 348 {
 349         int dead;
 350         spin_lock(&dlm->spinlock);
 351         dead = !test_bit(node, dlm->domain_map);
 352         spin_unlock(&dlm->spinlock);
 353         return dead;
 354 }
 355
 356 /* returns true if node is no longer in the domain
 357  * could be dead or just not joined */
 358 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
 359 {
 360         int recovered;
 361         spin_lock(&dlm->spinlock);
 362         recovered = !test_bit(node, dlm->recovery_map);
 363         spin_unlock(&dlm->spinlock);
 364         return recovered;
 365 }
 366
 367
 368 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
 369 {
 370         if (timeout) {
 371                 mlog(ML_NOTICE, "%s: waiting %dms for notification of "
 372                      "death of node %u\n", dlm->name, timeout, node);
 373                 wait_event_timeout(dlm->dlm_reco_thread_wq,
 374                            dlm_is_node_dead(dlm, node),
 375                            msecs_to_jiffies(timeout));
 376         } else {
 377                 mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
 378                      "of death of node %u\n", dlm->name, node);
 379                 wait_event(dlm->dlm_reco_thread_wq,
 380                            dlm_is_node_dead(dlm, node));
 381         }
 382         /* for now, return 0 */
 383         return 0;
 384 }
 385
 386 int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
 387 {
 388         if (timeout) {
 389                 mlog(0, "%s: waiting %dms for notification of "
 390                      "recovery of node %u\n", dlm->name, timeout, node);
 391                 wait_event_timeout(dlm->dlm_reco_thread_wq,
 392                            dlm_is_node_recovered(dlm, node),
 393                            msecs_to_jiffies(timeout));
 394         } else {
 395                 mlog(0, "%s: waiting indefinitely for notification "
 396                      "of recovery of node %u\n", dlm->name, node);
 397                 wait_event(dlm->dlm_reco_thread_wq,
 398                            dlm_is_node_recovered(dlm, node));
 399         }
 400         /* for now, return 0 */
 401         return 0;
 402 }
 403
 404 /* callers of the top-level api calls (dlmlock/dlmunlock) should
 405  * block on the dlm->reco.event when recovery is in progress.
 406  * the dlm recovery thread will set this state when it begins
 407  * recovering a dead node (as the new master or not) and clear
 408  * the state and wake as soon as all affected lock resources have
 409  * been marked with the RECOVERY flag */
 410 static int dlm_in_recovery(struct dlm_ctxt *dlm)
 411 {
 412         int in_recovery;
 413         spin_lock(&dlm->spinlock);
 414         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 415         spin_unlock(&dlm->spinlock);
 416         return in_recovery;
 417 }
 418
 419
 420 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
 421 {
 422         if (dlm_in_recovery(dlm)) {
 423                 mlog(0, "%s: reco thread %d in recovery: "
 424                      "state=%d, master=%u, dead=%u\n",
 425                      dlm->name, dlm->dlm_reco_thread_task->pid,
 426                      dlm->reco.state, dlm->reco.new_master,
 427                      dlm->reco.dead_node);
 428         }
 429         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
 430 }
 431
 432 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
 433 {
 434         spin_lock(&dlm->spinlock);
 435         BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 436         dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
 437         spin_unlock(&dlm->spinlock);
 438 }
 439
 440 static void dlm_end_recovery(struct dlm_ctxt *dlm)
 441 {
 442         spin_lock(&dlm->spinlock);
 443         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
 444         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
 445         spin_unlock(&dlm->spinlock);
 446         wake_up(&dlm->reco.event);
 447 }
 448
 449 static int dlm_do_recovery(struct dlm_ctxt *dlm)
 450 {
 451         int status = 0;
 452         int ret;
 453
 454         spin_lock(&dlm->spinlock);
 455
 456         /* check to see if the new master has died */
 457         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
 458             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
 459                 mlog(0, "new master %u died while recovering %u!\n",
 460                      dlm->reco.new_master, dlm->reco.dead_node);
 461                 /* unset the new_master, leave dead_node */
 462                 dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
 463         }
 464
 465         /* select a target to recover */
 466         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 467                 int bit;
 468
 469                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
 470                 if (bit >= O2NM_MAX_NODES || bit < 0)
 471                         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 472                 else
 473                         dlm_set_reco_dead_node(dlm, bit);
 474         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
 475                 /* BUG? */
 476                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
 477                      dlm->reco.dead_node);
 478                 dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 479         }
 480
 481         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 482                 // mlog(0, "nothing to recover!  sleeping now!\n");
 483                 spin_unlock(&dlm->spinlock);
 484                 /* return to main thread loop and sleep. */
 485                 return 0;
 486         }
 487         mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
 488              dlm->name, dlm->dlm_reco_thread_task->pid,
 489              dlm->reco.dead_node);
 490         spin_unlock(&dlm->spinlock);
 491
 492         /* take write barrier */
 493         /* (stops the list reshuffling thread, proxy ast handling) */
 494         dlm_begin_recovery(dlm);
 495
 496         if (dlm->reco.new_master == dlm->node_num)
 497                 goto master_here;
 498
 499         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 500                 /* choose a new master, returns 0 if this node
 501                  * is the master, -EEXIST if it's another node.
 502                  * this does not return until a new master is chosen
 503                  * or recovery completes entirely. */
 504                 ret = dlm_pick_recovery_master(dlm);
 505                 if (!ret) {
 506                         /* already notified everyone.  go. */
 507                         goto master_here;
 508                 }
 509                 mlog(0, "another node will master this recovery session.\n");
 510         }
 511         mlog(0, "dlm=%s (%d), new_master=%u, this node=%u, dead_node=%u\n",
 512              dlm->name, dlm->dlm_reco_thread_task->pid, dlm->reco.new_master,
 513              dlm->node_num, dlm->reco.dead_node);
 514
 515         /* it is safe to start everything back up here
 516          * because all of the dead node's lock resources
 517          * have been marked as in-recovery */
 518         dlm_end_recovery(dlm);
 519
 520         /* sleep out in main dlm_recovery_thread loop. */
 521         return 0;
 522
 523 master_here:
 524         mlog(0, "(%d) mastering recovery of %s:%u here(this=%u)!\n",
 525              dlm->dlm_reco_thread_task->pid,
 526              dlm->name, dlm->reco.dead_node, dlm->node_num);
 527
 528         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
 529         if (status < 0) {
 530                 /* we should never hit this anymore */
 531                 mlog(ML_ERROR, "error %d remastering locks for node %u, "
 532                      "retrying.\n", status, dlm->reco.dead_node);
 533                 /* yield a bit to allow any final network messages
 534                  * to get handled on remaining nodes */
 535                 msleep(100);
 536         } else {
 537                 /* success!  see if any other nodes need recovery */
 538                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
 539                      dlm->name, dlm->reco.dead_node, dlm->node_num);
 540                 dlm_reset_recovery(dlm);
 541         }
 542         dlm_end_recovery(dlm);
 543
 544         /* continue and look for another dead node */
 545         return -EAGAIN;
 546 }
 547
 548 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
 549 {
 550         int status = 0;
 551         struct dlm_reco_node_data *ndata;
 552         struct list_head *iter;
 553         int all_nodes_done;
 554         int destroy = 0;
 555         int pass = 0;
 556
 557         do {
 558                 /* we have become recovery master.  there is no escaping
 559                  * this, so just keep trying until we get it. */
 560                 status = dlm_init_recovery_area(dlm, dead_node);
 561                 if (status < 0) {
 562                         mlog(ML_ERROR, "%s: failed to alloc recovery area, "
 563                              "retrying\n", dlm->name);
 564                         msleep(1000);
 565                 }
 566         } while (status != 0);
 567
 568         /* safe to access the node data list without a lock, since this
 569          * process is the only one to change the list */
 570         list_for_each(iter, &dlm->reco.node_data) {
 571                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 572                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
 573                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
 574
 575                 mlog(0, "requesting lock info from node %u\n",
 576                      ndata->node_num);
 577
 578                 if (ndata->node_num == dlm->node_num) {
 579                         ndata->state = DLM_RECO_NODE_DATA_DONE;
 580                         continue;
 581                 }
 582
 583                 do {
 584                         status = dlm_request_all_locks(dlm, ndata->node_num,
 585                                                        dead_node);
 586                         if (status < 0) {
 587                                 mlog_errno(status);
 588                                 if (dlm_is_host_down(status)) {
 589                                         /* node died, ignore it for recovery */
 590                                         status = 0;
 591                                         ndata->state = DLM_RECO_NODE_DATA_DEAD;
 592                                         /* wait for the domain map to catch up
 593                                          * with the network state. */
 594                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
 595                                                            dlm_is_node_dead(dlm,
 596                                                                 ndata->node_num),
 597                                                            msecs_to_jiffies(1000));
 598                                         mlog(0, "waited 1 sec for %u, "
 599                                              "dead? %s\n", ndata->node_num,
 600                                              dlm_is_node_dead(dlm, ndata->node_num) ?
 601                                              "yes" : "no");
 602                                 } else {
 603                                         /* -ENOMEM on the other node */
 604                                         mlog(0, "%s: node %u returned "
 605                                              "%d during recovery, retrying "
 606                                              "after a short wait\n",
 607                                              dlm->name, ndata->node_num,
 608                                              status);
 609                                         msleep(100);
 610                                 }
 611                         }
 612                 } while (status != 0);
 613
 614                 switch (ndata->state) {
 615                         case DLM_RECO_NODE_DATA_INIT:
 616                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 617                         case DLM_RECO_NODE_DATA_REQUESTED:
 618                                 BUG();
 619                                 break;
 620                         case DLM_RECO_NODE_DATA_DEAD:
 621                                 mlog(0, "node %u died after requesting "
 622                                      "recovery info for node %u\n",
 623                                      ndata->node_num, dead_node);
 624                                 /* fine.  don't need this node's info.
 625                                  * continue without it. */
 626                                 break;
 627                         case DLM_RECO_NODE_DATA_REQUESTING:
 628                                 ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
 629                                 mlog(0, "now receiving recovery data from "
 630                                      "node %u for dead node %u\n",
 631                                      ndata->node_num, dead_node);
 632                                 break;
 633                         case DLM_RECO_NODE_DATA_RECEIVING:
 634                                 mlog(0, "already receiving recovery data from "
 635                                      "node %u for dead node %u\n",
 636                                      ndata->node_num, dead_node);
 637                                 break;
 638                         case DLM_RECO_NODE_DATA_DONE:
 639                                 mlog(0, "already DONE receiving recovery data "
 640                                      "from node %u for dead node %u\n",
 641                                      ndata->node_num, dead_node);
 642                                 break;
 643                 }
 644         }
 645
 646         mlog(0, "done requesting all lock info\n");
 647
 648         /* nodes should be sending reco data now
 649          * just need to wait */
 650
 651         while (1) {
 652                 /* check all the nodes now to see if we are
 653                  * done, or if anyone died */
 654                 all_nodes_done = 1;
 655                 spin_lock(&dlm_reco_state_lock);
 656                 list_for_each(iter, &dlm->reco.node_data) {
 657                         ndata = list_entry (iter, struct dlm_reco_node_data, list);
 658
 659                         mlog(0, "checking recovery state of node %u\n",
 660                              ndata->node_num);
 661                         switch (ndata->state) {
 662                                 case DLM_RECO_NODE_DATA_INIT:
 663                                 case DLM_RECO_NODE_DATA_REQUESTING:
 664                                         mlog(ML_ERROR, "bad ndata state for "
 665                                              "node %u: state=%d\n",
 666                                              ndata->node_num, ndata->state);
 667                                         BUG();
 668                                         break;
 669                                 case DLM_RECO_NODE_DATA_DEAD:
 670                                         mlog(0, "node %u died after "
 671                                              "requesting recovery info for "
 672                                              "node %u\n", ndata->node_num,
 673                                              dead_node);
 674                                         break;
 675                                 case DLM_RECO_NODE_DATA_RECEIVING:
 676                                 case DLM_RECO_NODE_DATA_REQUESTED:
 677                                         mlog(0, "%s: node %u still in state %s\n",
 678                                              dlm->name, ndata->node_num,
 679                                              ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
 680                                              "receiving" : "requested");
 681                                         all_nodes_done = 0;
 682                                         break;
 683                                 case DLM_RECO_NODE_DATA_DONE:
 684                                         mlog(0, "%s: node %u state is done\n",
 685                                              dlm->name, ndata->node_num);
 686                                         break;
 687                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 688                                         mlog(0, "%s: node %u state is finalize\n",
 689                                              dlm->name, ndata->node_num);
 690                                         break;
 691                         }
 692                 }
 693                 spin_unlock(&dlm_reco_state_lock);
 694
 695                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
 696                      all_nodes_done?"yes":"no");
 697                 if (all_nodes_done) {
 698                         int ret;
 699
 700                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
 701                          * just send a finalize message to everyone and
 702                          * clean up */
 703                         mlog(0, "all nodes are done! send finalize\n");
 704                         ret = dlm_send_finalize_reco_message(dlm);
 705                         if (ret < 0)
 706                                 mlog_errno(ret);
 707
 708                         spin_lock(&dlm->spinlock);
 709                         dlm_finish_local_lockres_recovery(dlm, dead_node,
 710                                                           dlm->node_num);
 711                         spin_unlock(&dlm->spinlock);
 712                         mlog(0, "should be done with recovery!\n");
 713
 714                         mlog(0, "finishing recovery of %s at %lu, "
 715                              "dead=%u, this=%u, new=%u\n", dlm->name,
 716                              jiffies, dlm->reco.dead_node,
 717                              dlm->node_num, dlm->reco.new_master);
 718                         destroy = 1;
 719                         status = 0;
 720                         /* rescan everything marked dirty along the way */
 721                         dlm_kick_thread(dlm, NULL);
 722                         break;
 723                 }
 724                 /* wait to be signalled, with periodic timeout
 725                  * to check for node death */
 726                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 727                                          kthread_should_stop(),
 728                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
 729
 730         }
 731
 732         if (destroy)
 733                 dlm_destroy_recovery_area(dlm, dead_node);
 734
 735         mlog_exit(status);
 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 list_head *iter, *iter2;
 776         struct dlm_reco_node_data *ndata;
 777         LIST_HEAD(tmplist);
 778
 779         spin_lock(&dlm_reco_state_lock);
 780         list_splice_init(&dlm->reco.node_data, &tmplist);
 781         spin_unlock(&dlm_reco_state_lock);
 782
 783         list_for_each_safe(iter, iter2, &tmplist) {
 784                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 785                 list_del_init(&ndata->list);
 786                 kfree(ndata);
 787         }
 788 }
 789
 790 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
 791                                  u8 dead_node)
 792 {
 793         struct dlm_lock_request lr;
 794         enum dlm_status ret;
 795
 796         mlog(0, "\n");
 797
 798
 799         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
 800                   "to %u\n", dead_node, request_from);
 801
 802         memset(&lr, 0, sizeof(lr));
 803         lr.node_idx = dlm->node_num;
 804         lr.dead_node = dead_node;
 805
 806         // send message
 807         ret = DLM_NOLOCKMGR;
 808         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
 809                                  &lr, sizeof(lr), request_from, NULL);
 810
 811         /* negative status is handled by caller */
 812         if (ret < 0)
 813                 mlog_errno(ret);
 814
 815         // return from here, then
 816         // sleep until all received or error
 817         return ret;
 818
 819 }
 820
 821 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
 822                                   void **ret_data)
 823 {
 824         struct dlm_ctxt *dlm = data;
 825         struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
 826         char *buf = NULL;
 827         struct dlm_work_item *item = NULL;
 828
 829         if (!dlm_grab(dlm))
 830                 return -EINVAL;
 831
 832         if (lr->dead_node != dlm->reco.dead_node) {
 833                 mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
 834                      "dead_node is %u\n", dlm->name, lr->node_idx,
 835                      lr->dead_node, dlm->reco.dead_node);
 836                 dlm_print_reco_node_status(dlm);
 837                 /* this is a hack */
 838                 dlm_put(dlm);
 839                 return -ENOMEM;
 840         }
 841         BUG_ON(lr->dead_node != dlm->reco.dead_node);
 842
 843         item = kzalloc(sizeof(*item), GFP_NOFS);
 844         if (!item) {
 845                 dlm_put(dlm);
 846                 return -ENOMEM;
 847         }
 848
 849         /* this will get freed by dlm_request_all_locks_worker */
 850         buf = (char *) __get_free_page(GFP_NOFS);
 851         if (!buf) {
 852                 kfree(item);
 853                 dlm_put(dlm);
 854                 return -ENOMEM;
 855         }
 856
 857         /* queue up work for dlm_request_all_locks_worker */
 858         dlm_grab(dlm);  /* get an extra ref for the work item */
 859         dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
 860         item->u.ral.reco_master = lr->node_idx;
 861         item->u.ral.dead_node = lr->dead_node;
 862         spin_lock(&dlm->work_lock);
 863         list_add_tail(&item->list, &dlm->work_list);
 864         spin_unlock(&dlm->work_lock);
 865         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
 866
 867         dlm_put(dlm);
 868         return 0;
 869 }
 870
 871 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
 872 {
 873         struct dlm_migratable_lockres *mres;
 874         struct dlm_lock_resource *res;
 875         struct dlm_ctxt *dlm;
 876         LIST_HEAD(resources);
 877         struct list_head *iter;
 878         int ret;
 879         u8 dead_node, reco_master;
 880         int skip_all_done = 0;
 881
 882         dlm = item->dlm;
 883         dead_node = item->u.ral.dead_node;
 884         reco_master = item->u.ral.reco_master;
 885         mres = (struct dlm_migratable_lockres *)data;
 886
 887         mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
 888              dlm->name, dead_node, reco_master);
 889
 890         if (dead_node != dlm->reco.dead_node ||
 891             reco_master != dlm->reco.new_master) {
 892                 /* worker could have been created before the recovery master
 893                  * died.  if so, do not continue, but do not error. */
 894                 if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 895                         mlog(ML_NOTICE, "%s: will not send recovery state, "
 896                              "recovery master %u died, thread=(dead=%u,mas=%u)"
 897                              " current=(dead=%u,mas=%u)\n", dlm->name,
 898                              reco_master, dead_node, reco_master,
 899                              dlm->reco.dead_node, dlm->reco.new_master);
 900                 } else {
 901                         mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
 902                              "master=%u), request(dead=%u, master=%u)\n",
 903                              dlm->name, dlm->reco.dead_node,
 904                              dlm->reco.new_master, dead_node, reco_master);
 905                 }
 906                 goto leave;
 907         }
 908
 909         /* lock resources should have already been moved to the
 910          * dlm->reco.resources list.  now move items from that list
 911          * to a temp list if the dead owner matches.  note that the
 912          * whole cluster recovers only one node at a time, so we
 913          * can safely move UNKNOWN lock resources for each recovery
 914          * session. */
 915         dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
 916
 917         /* now we can begin blasting lockreses without the dlm lock */
 918
 919         /* any errors returned will be due to the new_master dying,
 920          * the dlm_reco_thread should detect this */
 921         list_for_each(iter, &resources) {
 922                 res = list_entry (iter, struct dlm_lock_resource, recovering);
 923                 ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
 924                                         DLM_MRES_RECOVERY);
 925                 if (ret < 0) {
 926                         mlog(ML_ERROR, "%s: node %u went down while sending "
 927                              "recovery state for dead node %u, ret=%d\n", dlm->name,
 928                              reco_master, dead_node, ret);
 929                         skip_all_done = 1;
 930                         break;
 931                 }
 932         }
 933
 934         /* move the resources back to the list */
 935         spin_lock(&dlm->spinlock);
 936         list_splice_init(&resources, &dlm->reco.resources);
 937         spin_unlock(&dlm->spinlock);
 938
 939         if (!skip_all_done) {
 940                 ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
 941                 if (ret < 0) {
 942                         mlog(ML_ERROR, "%s: node %u went down while sending "
 943                              "recovery all-done for dead node %u, ret=%d\n",
 944                              dlm->name, reco_master, dead_node, ret);
 945                 }
 946         }
 947 leave:
 948         free_page((unsigned long)data);
 949 }
 950
 951
 952 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
 953 {
 954         int ret, tmpret;
 955         struct dlm_reco_data_done done_msg;
 956
 957         memset(&done_msg, 0, sizeof(done_msg));
 958         done_msg.node_idx = dlm->node_num;
 959         done_msg.dead_node = dead_node;
 960         mlog(0, "sending DATA DONE message to %u, "
 961              "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
 962              done_msg.dead_node);
 963
 964         ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
 965                                  sizeof(done_msg), send_to, &tmpret);
 966         if (ret < 0) {
 967                 if (!dlm_is_host_down(ret)) {
 968                         mlog_errno(ret);
 969                         mlog(ML_ERROR, "%s: unknown error sending data-done "
 970                              "to %u\n", dlm->name, send_to);
 971                         BUG();
 972                 }
 973         } else
 974                 ret = tmpret;
 975         return ret;
 976 }
 977
 978
 979 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
 980                                void **ret_data)
 981 {
 982         struct dlm_ctxt *dlm = data;
 983         struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
 984         struct list_head *iter;
 985         struct dlm_reco_node_data *ndata = NULL;
 986         int ret = -EINVAL;
 987
 988         if (!dlm_grab(dlm))
 989                 return -EINVAL;
 990
 991         mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 992              "node_idx=%u, this node=%u\n", done->dead_node,
 993              dlm->reco.dead_node, done->node_idx, dlm->node_num);
 994
 995         mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
 996                         "Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 997                         "node_idx=%u, this node=%u\n", done->dead_node,
 998                         dlm->reco.dead_node, done->node_idx, dlm->node_num);
 999
1000         spin_lock(&dlm_reco_state_lock);
1001         list_for_each(iter, &dlm->reco.node_data) {
1002                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
1003                 if (ndata->node_num != done->node_idx)
1004                         continue;
1005
1006                 switch (ndata->state) {
1007                         /* should have moved beyond INIT but not to FINALIZE yet */
1008                         case DLM_RECO_NODE_DATA_INIT:
1009                         case DLM_RECO_NODE_DATA_DEAD:
1010                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1011                                 mlog(ML_ERROR, "bad ndata state for node %u:"
1012                                      " state=%d\n", ndata->node_num,
1013                                      ndata->state);
1014                                 BUG();
1015                                 break;
1016                         /* these states are possible at this point, anywhere along
1017                          * the line of recovery */
1018                         case DLM_RECO_NODE_DATA_DONE:
1019                         case DLM_RECO_NODE_DATA_RECEIVING:
1020                         case DLM_RECO_NODE_DATA_REQUESTED:
1021                         case DLM_RECO_NODE_DATA_REQUESTING:
1022                                 mlog(0, "node %u is DONE sending "
1023                                           "recovery data!\n",
1024                                           ndata->node_num);
1025
1026                                 ndata->state = DLM_RECO_NODE_DATA_DONE;
1027                                 ret = 0;
1028                                 break;
1029                 }
1030         }
1031         spin_unlock(&dlm_reco_state_lock);
1032
1033         /* wake the recovery thread, some node is done */
1034         if (!ret)
1035                 dlm_kick_recovery_thread(dlm);
1036
1037         if (ret < 0)
1038                 mlog(ML_ERROR, "failed to find recovery node data for node "
1039                      "%u\n", done->node_idx);
1040         dlm_put(dlm);
1041
1042         mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1043         return ret;
1044 }
1045
1046 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1047                                         struct list_head *list,
1048                                         u8 dead_node)
1049 {
1050         struct dlm_lock_resource *res;
1051         struct list_head *iter, *iter2;
1052         struct dlm_lock *lock;
1053
1054         spin_lock(&dlm->spinlock);
1055         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
1056                 res = list_entry (iter, struct dlm_lock_resource, recovering);
1057                 /* always prune any $RECOVERY entries for dead nodes,
1058                  * otherwise hangs can occur during later recovery */
1059                 if (dlm_is_recovery_lock(res->lockname.name,
1060                                          res->lockname.len)) {
1061                         spin_lock(&res->spinlock);
1062                         list_for_each_entry(lock, &res->granted, list) {
1063                                 if (lock->ml.node == dead_node) {
1064                                         mlog(0, "AHA! there was "
1065                                              "a $RECOVERY lock for dead "
1066                                              "node %u (%s)!\n",
1067                                              dead_node, dlm->name);
1068                                         list_del_init(&lock->list);
1069                                         dlm_lock_put(lock);
1070                                         break;
1071                                 }
1072                         }
1073                         spin_unlock(&res->spinlock);
1074                         continue;
1075                 }
1076
1077                 if (res->owner == dead_node) {
1078                         mlog(0, "found lockres owned by dead node while "
1079                                   "doing recovery for node %u. sending it.\n",
1080                                   dead_node);
1081                         list_move_tail(&res->recovering, list);
1082                 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1083                         mlog(0, "found UNKNOWN owner while doing recovery "
1084                                   "for node %u. sending it.\n", dead_node);
1085                         list_move_tail(&res->recovering, list);
1086                 }
1087         }
1088         spin_unlock(&dlm->spinlock);
1089 }
1090
1091 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1092 {
1093         int total_locks = 0;
1094         struct list_head *iter, *queue = &res->granted;
1095         int i;
1096
1097         for (i=0; i<3; i++) {
1098                 list_for_each(iter, queue)
1099                         total_locks++;
1100                 queue++;
1101         }
1102         return total_locks;
1103 }
1104
1105
1106 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1107                                       struct dlm_migratable_lockres *mres,
1108                                       u8 send_to,
1109                                       struct dlm_lock_resource *res,
1110                                       int total_locks)
1111 {
1112         u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1113         int mres_total_locks = be32_to_cpu(mres->total_locks);
1114         int sz, ret = 0, status = 0;
1115         u8 orig_flags = mres->flags,
1116            orig_master = mres->master;
1117
1118         BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1119         if (!mres->num_locks)
1120                 return 0;
1121
1122         sz = sizeof(struct dlm_migratable_lockres) +
1123                 (mres->num_locks * sizeof(struct dlm_migratable_lock));
1124
1125         /* add an all-done flag if we reached the last lock */
1126         orig_flags = mres->flags;
1127         BUG_ON(total_locks > mres_total_locks);
1128         if (total_locks == mres_total_locks)
1129                 mres->flags |= DLM_MRES_ALL_DONE;
1130
1131         mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
1132              dlm->name, res->lockname.len, res->lockname.name,
1133              orig_flags & DLM_MRES_MIGRATION ? "migrate" : "recovery",
1134              send_to);
1135
1136         /* send it */
1137         ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1138                                  sz, send_to, &status);
1139         if (ret < 0) {
1140                 /* XXX: negative status is not handled.
1141                  * this will end up killing this node. */
1142                 mlog_errno(ret);
1143         } else {
1144                 /* might get an -ENOMEM back here */
1145                 ret = status;
1146                 if (ret < 0) {
1147                         mlog_errno(ret);
1148
1149                         if (ret == -EFAULT) {
1150                                 mlog(ML_ERROR, "node %u told me to kill "
1151                                      "myself!\n", send_to);
1152                                 BUG();
1153                         }
1154                 }
1155         }
1156
1157         /* zero and reinit the message buffer */
1158         dlm_init_migratable_lockres(mres, res->lockname.name,
1159                                     res->lockname.len, mres_total_locks,
1160                                     mig_cookie, orig_flags, orig_master);
1161         return ret;
1162 }
1163
1164 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1165                                         const char *lockname, int namelen,
1166                                         int total_locks, u64 cookie,
1167                                         u8 flags, u8 master)
1168 {
1169         /* mres here is one full page */
1170         memset(mres, 0, PAGE_SIZE);
1171         mres->lockname_len = namelen;
1172         memcpy(mres->lockname, lockname, namelen);
1173         mres->num_locks = 0;
1174         mres->total_locks = cpu_to_be32(total_locks);
1175         mres->mig_cookie = cpu_to_be64(cookie);
1176         mres->flags = flags;
1177         mres->master = master;
1178 }
1179
1180
1181 /* returns 1 if this lock fills the network structure,
1182  * 0 otherwise */
1183 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1184                                  struct dlm_migratable_lockres *mres, int queue)
1185 {
1186         struct dlm_migratable_lock *ml;
1187         int lock_num = mres->num_locks;
1188
1189         ml = &(mres->ml[lock_num]);
1190         ml->cookie = lock->ml.cookie;
1191         ml->type = lock->ml.type;
1192         ml->convert_type = lock->ml.convert_type;
1193         ml->highest_blocked = lock->ml.highest_blocked;
1194         ml->list = queue;
1195         if (lock->lksb) {
1196                 ml->flags = lock->lksb->flags;
1197                 /* send our current lvb */
1198                 if (ml->type == LKM_EXMODE ||
1199                     ml->type == LKM_PRMODE) {
1200                         /* if it is already set, this had better be a PR
1201                          * and it has to match */
1202                         if (!dlm_lvb_is_empty(mres->lvb) &&
1203                             (ml->type == LKM_EXMODE ||
1204                              memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
1205                                 mlog(ML_ERROR, "mismatched lvbs!\n");
1206                                 __dlm_print_one_lock_resource(lock->lockres);
1207                                 BUG();
1208                         }
1209                         memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1210                 }
1211         }
1212         ml->node = lock->ml.node;
1213         mres->num_locks++;
1214         /* we reached the max, send this network message */
1215         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1216                 return 1;
1217         return 0;
1218 }
1219
1220 static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1221                                struct dlm_migratable_lockres *mres)
1222 {
1223         struct dlm_lock dummy;
1224         memset(&dummy, 0, sizeof(dummy));
1225         dummy.ml.cookie = 0;
1226         dummy.ml.type = LKM_IVMODE;
1227         dummy.ml.convert_type = LKM_IVMODE;
1228         dummy.ml.highest_blocked = LKM_IVMODE;
1229         dummy.lksb = NULL;
1230         dummy.ml.node = dlm->node_num;
1231         dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1232 }
1233
1234 static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1235                                     struct dlm_migratable_lock *ml,
1236                                     u8 *nodenum)
1237 {
1238         if (unlikely(ml->cookie == 0 &&
1239             ml->type == LKM_IVMODE &&
1240             ml->convert_type == LKM_IVMODE &&
1241             ml->highest_blocked == LKM_IVMODE &&
1242             ml->list == DLM_BLOCKED_LIST)) {
1243                 *nodenum = ml->node;
1244                 return 1;
1245         }
1246         return 0;
1247 }
1248
1249 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1250                          struct dlm_migratable_lockres *mres,
1251                          u8 send_to, u8 flags)
1252 {
1253         struct list_head *queue, *iter;
1254         int total_locks, i;
1255         u64 mig_cookie = 0;
1256         struct dlm_lock *lock;
1257         int ret = 0;
1258
1259         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1260
1261         mlog(0, "sending to %u\n", send_to);
1262
1263         total_locks = dlm_num_locks_in_lockres(res);
1264         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1265                 /* rare, but possible */
1266                 mlog(0, "argh.  lockres has %d locks.  this will "
1267                           "require more than one network packet to "
1268                           "migrate\n", total_locks);
1269                 mig_cookie = dlm_get_next_mig_cookie();
1270         }
1271
1272         dlm_init_migratable_lockres(mres, res->lockname.name,
1273                                     res->lockname.len, total_locks,
1274                                     mig_cookie, flags, res->owner);
1275
1276         total_locks = 0;
1277         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1278                 queue = dlm_list_idx_to_ptr(res, i);
1279                 list_for_each(iter, queue) {
1280                         lock = list_entry (iter, struct dlm_lock, list);
1281
1282                         /* add another lock. */
1283                         total_locks++;
1284                         if (!dlm_add_lock_to_array(lock, mres, i))
1285                                 continue;
1286
1287                         /* this filled the lock message,
1288                          * we must send it immediately. */
1289                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1290                                                        res, total_locks);
1291                         if (ret < 0)
1292                                 goto error;
1293                 }
1294         }
1295         if (total_locks == 0) {
1296                 /* send a dummy lock to indicate a mastery reference only */
1297                 mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1298                      dlm->name, res->lockname.len, res->lockname.name,
1299                      send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1300                      "migration");
1301                 dlm_add_dummy_lock(dlm, mres);
1302         }
1303         /* flush any remaining locks */
1304         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1305         if (ret < 0)
1306                 goto error;
1307         return ret;
1308
1309 error:
1310         mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1311              dlm->name, ret);
1312         if (!dlm_is_host_down(ret))
1313                 BUG();
1314         mlog(0, "%s: node %u went down while sending %s "
1315              "lockres %.*s\n", dlm->name, send_to,
1316              flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1317              res->lockname.len, res->lockname.name);
1318         return ret;
1319 }
1320
1321
1322
1323 /*
1324  * this message will contain no more than one page worth of
1325  * recovery data, and it will work on only one lockres.
1326  * there may be many locks in this page, and we may need to wait
1327  * for additional packets to complete all the locks (rare, but
1328  * possible).
1329  */
1330 /*
1331  * NOTE: the allocation error cases here are scary
1332  * we really cannot afford to fail an alloc in recovery
1333  * do we spin?  returning an error only delays the problem really
1334  */
1335
1336 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1337                             void **ret_data)
1338 {
1339         struct dlm_ctxt *dlm = data;
1340         struct dlm_migratable_lockres *mres =
1341                 (struct dlm_migratable_lockres *)msg->buf;
1342         int ret = 0;
1343         u8 real_master;
1344         char *buf = NULL;
1345         struct dlm_work_item *item = NULL;
1346         struct dlm_lock_resource *res = NULL;
1347
1348         if (!dlm_grab(dlm))
1349                 return -EINVAL;
1350
1351         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1352
1353         real_master = mres->master;
1354         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1355                 /* cannot migrate a lockres with no master */
1356                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1357         }
1358
1359         mlog(0, "%s message received from node %u\n",
1360                   (mres->flags & DLM_MRES_RECOVERY) ?
1361                   "recovery" : "migration", mres->master);
1362         if (mres->flags & DLM_MRES_ALL_DONE)
1363                 mlog(0, "all done flag.  all lockres data received!\n");
1364
1365         ret = -ENOMEM;
1366         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1367         item = kzalloc(sizeof(*item), GFP_NOFS);
1368         if (!buf || !item)
1369                 goto leave;
1370
1371         /* lookup the lock to see if we have a secondary queue for this
1372          * already...  just add the locks in and this will have its owner
1373          * and RECOVERY flag changed when it completes. */
1374         res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1375         if (res) {
1376                 /* this will get a ref on res */
1377                 /* mark it as recovering/migrating and hash it */
1378                 spin_lock(&res->spinlock);
1379                 if (mres->flags & DLM_MRES_RECOVERY) {
1380                         res->state |= DLM_LOCK_RES_RECOVERING;
1381                 } else {
1382                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1383                                 /* this is at least the second
1384                                  * lockres message */
1385                                 mlog(0, "lock %.*s is already migrating\n",
1386                                           mres->lockname_len,
1387                                           mres->lockname);
1388                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1389                                 /* caller should BUG */
1390                                 mlog(ML_ERROR, "node is attempting to migrate "
1391                                      "lock %.*s, but marked as recovering!\n",
1392                                      mres->lockname_len, mres->lockname);
1393                                 ret = -EFAULT;
1394                                 spin_unlock(&res->spinlock);
1395                                 goto leave;
1396                         }
1397                         res->state |= DLM_LOCK_RES_MIGRATING;
1398                 }
1399                 spin_unlock(&res->spinlock);
1400         } else {
1401                 /* need to allocate, just like if it was
1402                  * mastered here normally  */
1403                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1404                 if (!res)
1405                         goto leave;
1406
1407                 /* to match the ref that we would have gotten if
1408                  * dlm_lookup_lockres had succeeded */
1409                 dlm_lockres_get(res);
1410
1411                 /* mark it as recovering/migrating and hash it */
1412                 if (mres->flags & DLM_MRES_RECOVERY)
1413                         res->state |= DLM_LOCK_RES_RECOVERING;
1414                 else
1415                         res->state |= DLM_LOCK_RES_MIGRATING;
1416
1417                 spin_lock(&dlm->spinlock);
1418                 __dlm_insert_lockres(dlm, res);
1419                 spin_unlock(&dlm->spinlock);
1420
1421                 /* now that the new lockres is inserted,
1422                  * make it usable by other processes */
1423                 spin_lock(&res->spinlock);
1424                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1425                 spin_unlock(&res->spinlock);
1426                 wake_up(&res->wq);
1427
1428                 /* add an extra ref for just-allocated lockres
1429                  * otherwise the lockres will be purged immediately */
1430                 dlm_lockres_get(res);
1431         }
1432
1433         /* at this point we have allocated everything we need,
1434          * and we have a hashed lockres with an extra ref and
1435          * the proper res->state flags. */
1436         ret = 0;
1437         spin_lock(&res->spinlock);
1438         /* drop this either when master requery finds a different master
1439          * or when a lock is added by the recovery worker */
1440         dlm_lockres_grab_inflight_ref(dlm, res);
1441         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1442                 /* migration cannot have an unknown master */
1443                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1444                 mlog(0, "recovery has passed me a lockres with an "
1445                           "unknown owner.. will need to requery: "
1446                           "%.*s\n", mres->lockname_len, mres->lockname);
1447         } else {
1448                 /* take a reference now to pin the lockres, drop it
1449                  * when locks are added in the worker */
1450                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1451         }
1452         spin_unlock(&res->spinlock);
1453
1454         /* queue up work for dlm_mig_lockres_worker */
1455         dlm_grab(dlm);  /* get an extra ref for the work item */
1456         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1457         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1458         item->u.ml.lockres = res; /* already have a ref */
1459         item->u.ml.real_master = real_master;
1460         spin_lock(&dlm->work_lock);
1461         list_add_tail(&item->list, &dlm->work_list);
1462         spin_unlock(&dlm->work_lock);
1463         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1464
1465 leave:
1466         dlm_put(dlm);
1467         if (ret < 0) {
1468                 if (buf)
1469                         kfree(buf);
1470                 if (item)
1471                         kfree(item);
1472         }
1473
1474         mlog_exit(ret);
1475         return ret;
1476 }
1477
1478
1479 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1480 {
1481         struct dlm_ctxt *dlm = data;
1482         struct dlm_migratable_lockres *mres;
1483         int ret = 0;
1484         struct dlm_lock_resource *res;
1485         u8 real_master;
1486
1487         dlm = item->dlm;
1488         mres = (struct dlm_migratable_lockres *)data;
1489
1490         res = item->u.ml.lockres;
1491         real_master = item->u.ml.real_master;
1492
1493         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1494                 /* this case is super-rare. only occurs if
1495                  * node death happens during migration. */
1496 again:
1497                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1498                 if (ret < 0) {
1499                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1500                                   ret);
1501                         goto again;
1502                 }
1503                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1504                         mlog(0, "lockres %.*s not claimed.  "
1505                                    "this node will take it.\n",
1506                                    res->lockname.len, res->lockname.name);
1507                 } else {
1508                         spin_lock(&res->spinlock);
1509                         dlm_lockres_drop_inflight_ref(dlm, res);
1510                         spin_unlock(&res->spinlock);
1511                         mlog(0, "master needs to respond to sender "
1512                                   "that node %u still owns %.*s\n",
1513                                   real_master, res->lockname.len,
1514                                   res->lockname.name);
1515                         /* cannot touch this lockres */
1516                         goto leave;
1517                 }
1518         }
1519
1520         ret = dlm_process_recovery_data(dlm, res, mres);
1521         if (ret < 0)
1522                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1523         else
1524                 mlog(0, "dlm_process_recovery_data succeeded\n");
1525
1526         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1527                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1528                 ret = dlm_finish_migration(dlm, res, mres->master);
1529                 if (ret < 0)
1530                         mlog_errno(ret);
1531         }
1532
1533 leave:
1534         kfree(data);
1535         mlog_exit(ret);
1536 }
1537
1538
1539
1540 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1541                                       struct dlm_lock_resource *res,
1542                                       u8 *real_master)
1543 {
1544         struct dlm_node_iter iter;
1545         int nodenum;
1546         int ret = 0;
1547
1548         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1549
1550         /* we only reach here if one of the two nodes in a
1551          * migration died while the migration was in progress.
1552          * at this point we need to requery the master.  we
1553          * know that the new_master got as far as creating
1554          * an mle on at least one node, but we do not know
1555          * if any nodes had actually cleared the mle and set
1556          * the master to the new_master.  the old master
1557          * is supposed to set the owner to UNKNOWN in the
1558          * event of a new_master death, so the only possible
1559          * responses that we can get from nodes here are
1560          * that the master is new_master, or that the master
1561          * is UNKNOWN.
1562          * if all nodes come back with UNKNOWN then we know
1563          * the lock needs remastering here.
1564          * if any node comes back with a valid master, check
1565          * to see if that master is the one that we are
1566          * recovering.  if so, then the new_master died and
1567          * we need to remaster this lock.  if not, then the
1568          * new_master survived and that node will respond to
1569          * other nodes about the owner.
1570          * if there is an owner, this node needs to dump this
1571          * lockres and alert the sender that this lockres
1572          * was rejected. */
1573         spin_lock(&dlm->spinlock);
1574         dlm_node_iter_init(dlm->domain_map, &iter);
1575         spin_unlock(&dlm->spinlock);
1576
1577         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1578                 /* do not send to self */
1579                 if (nodenum == dlm->node_num)
1580                         continue;
1581                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1582                 if (ret < 0) {
1583                         mlog_errno(ret);
1584                         if (!dlm_is_host_down(ret))
1585                                 BUG();
1586                         /* host is down, so answer for that node would be
1587                          * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1588                 }
1589                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1590                         mlog(0, "lock master is %u\n", *real_master);
1591                         break;
1592                 }
1593         }
1594         return ret;
1595 }
1596
1597
1598 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1599                           u8 nodenum, u8 *real_master)
1600 {
1601         int ret = -EINVAL;
1602         struct dlm_master_requery req;
1603         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1604
1605         memset(&req, 0, sizeof(req));
1606         req.node_idx = dlm->node_num;
1607         req.namelen = res->lockname.len;
1608         memcpy(req.name, res->lockname.name, res->lockname.len);
1609
1610         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1611                                  &req, sizeof(req), nodenum, &status);
1612         /* XXX: negative status not handled properly here. */
1613         if (ret < 0)
1614                 mlog_errno(ret);
1615         else {
1616                 BUG_ON(status < 0);
1617                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1618                 *real_master = (u8) (status & 0xff);
1619                 mlog(0, "node %u responded to master requery with %u\n",
1620                           nodenum, *real_master);
1621                 ret = 0;
1622         }
1623         return ret;
1624 }
1625
1626
1627 /* this function cannot error, so unless the sending
1628  * or receiving of the message failed, the owner can
1629  * be trusted */
1630 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1631                                void **ret_data)
1632 {
1633         struct dlm_ctxt *dlm = data;
1634         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1635         struct dlm_lock_resource *res = NULL;
1636         unsigned int hash;
1637         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1638         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1639
1640         if (!dlm_grab(dlm)) {
1641                 /* since the domain has gone away on this
1642                  * node, the proper response is UNKNOWN */
1643                 return master;
1644         }
1645
1646         hash = dlm_lockid_hash(req->name, req->namelen);
1647
1648         spin_lock(&dlm->spinlock);
1649         res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1650         if (res) {
1651                 spin_lock(&res->spinlock);
1652                 master = res->owner;
1653                 if (master == dlm->node_num) {
1654                         int ret = dlm_dispatch_assert_master(dlm, res,
1655                                                              0, 0, flags);
1656                         if (ret < 0) {
1657                                 mlog_errno(-ENOMEM);
1658                                 /* retry!? */
1659                                 BUG();
1660                         }
1661                 }
1662                 spin_unlock(&res->spinlock);
1663         }
1664         spin_unlock(&dlm->spinlock);
1665
1666         dlm_put(dlm);
1667         return master;
1668 }
1669
1670 static inline struct list_head *
1671 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1672 {
1673         struct list_head *ret;
1674         BUG_ON(list_num < 0);
1675         BUG_ON(list_num > 2);
1676         ret = &(res->granted);
1677         ret += list_num;
1678         return ret;
1679 }
1680 /* TODO: do ast flush business
1681  * TODO: do MIGRATING and RECOVERING spinning
1682  */
1683
1684 /*
1685 * NOTE about in-flight requests during migration:
1686 *
1687 * Before attempting the migrate, the master has marked the lockres as
1688 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1689 * requests either got queued before the MIGRATING flag got set, in which
1690 * case the lock data will reflect the change and a return message is on
1691 * the way, or the request failed to get in before MIGRATING got set.  In
1692 * this case, the caller will be told to spin and wait for the MIGRATING
1693 * flag to be dropped, then recheck the master.
1694 * This holds true for the convert, cancel and unlock cases, and since lvb
1695 * updates are tied to these same messages, it applies to lvb updates as
1696 * well.  For the lock case, there is no way a lock can be on the master
1697 * queue and not be on the secondary queue since the lock is always added
1698 * locally first.  This means that the new target node will never be sent
1699 * a lock that he doesn't already have on the list.
1700 * In total, this means that the local lock is correct and should not be
1701 * updated to match the one sent by the master.  Any messages sent back
1702 * from the master before the MIGRATING flag will bring the lock properly
1703 * up-to-date, and the change will be ordered properly for the waiter.
1704 * We will *not* attempt to modify the lock underneath the waiter.
1705 */
1706
1707 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1708                                      struct dlm_lock_resource *res,
1709                                      struct dlm_migratable_lockres *mres)
1710 {
1711         struct dlm_migratable_lock *ml;
1712         struct list_head *queue;
1713         struct list_head *tmpq = NULL;
1714         struct dlm_lock *newlock = NULL;
1715         struct dlm_lockstatus *lksb = NULL;
1716         int ret = 0;
1717         int i, j, bad;
1718         struct list_head *iter;
1719         struct dlm_lock *lock = NULL;
1720         u8 from = O2NM_MAX_NODES;
1721         unsigned int added = 0;
1722
1723         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1724         for (i=0; i<mres->num_locks; i++) {
1725                 ml = &(mres->ml[i]);
1726
1727                 if (dlm_is_dummy_lock(dlm, ml, &from)) {
1728                         /* placeholder, just need to set the refmap bit */
1729                         BUG_ON(mres->num_locks != 1);
1730                         mlog(0, "%s:%.*s: dummy lock for %u\n",
1731                              dlm->name, mres->lockname_len, mres->lockname,
1732                              from);
1733                         spin_lock(&res->spinlock);
1734                         dlm_lockres_set_refmap_bit(from, res);
1735                         spin_unlock(&res->spinlock);
1736                         added++;
1737                         break;
1738                 }
1739                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1740                 newlock = NULL;
1741                 lksb = NULL;
1742
1743                 queue = dlm_list_num_to_pointer(res, ml->list);
1744                 tmpq = NULL;
1745
1746                 /* if the lock is for the local node it needs to
1747                  * be moved to the proper location within the queue.
1748                  * do not allocate a new lock structure. */
1749                 if (ml->node == dlm->node_num) {
1750                         /* MIGRATION ONLY! */
1751                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1752
1753                         spin_lock(&res->spinlock);
1754                         for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1755                                 tmpq = dlm_list_idx_to_ptr(res, j);
1756                                 list_for_each(iter, tmpq) {
1757                                         lock = list_entry (iter, struct dlm_lock, list);
1758                                         if (lock->ml.cookie != ml->cookie)
1759                                                 lock = NULL;
1760                                         else
1761                                                 break;
1762                                 }
1763                                 if (lock)
1764                                         break;
1765                         }
1766
1767                         /* lock is always created locally first, and
1768                          * destroyed locally last.  it must be on the list */
1769                         if (!lock) {
1770                                 u64 c = ml->cookie;
1771                                 mlog(ML_ERROR, "could not find local lock "
1772                                                "with cookie %u:%llu!\n",
1773                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1774                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1775                                 __dlm_print_one_lock_resource(res);
1776                                 BUG();
1777                         }
1778                         BUG_ON(lock->ml.node != ml->node);
1779
1780                         if (tmpq != queue) {
1781                                 mlog(0, "lock was on %u instead of %u for %.*s\n",
1782                                      j, ml->list, res->lockname.len, res->lockname.name);
1783                                 spin_unlock(&res->spinlock);
1784                                 continue;
1785                         }
1786
1787                         /* see NOTE above about why we do not update
1788                          * to match the master here */
1789
1790                         /* move the lock to its proper place */
1791                         /* do not alter lock refcount.  switching lists. */
1792                         list_move_tail(&lock->list, queue);
1793                         spin_unlock(&res->spinlock);
1794                         added++;
1795
1796                         mlog(0, "just reordered a local lock!\n");
1797                         continue;
1798                 }
1799
1800                 /* lock is for another node. */
1801                 newlock = dlm_new_lock(ml->type, ml->node,
1802                                        be64_to_cpu(ml->cookie), NULL);
1803                 if (!newlock) {
1804                         ret = -ENOMEM;
1805                         goto leave;
1806                 }
1807                 lksb = newlock->lksb;
1808                 dlm_lock_attach_lockres(newlock, res);
1809
1810                 if (ml->convert_type != LKM_IVMODE) {
1811                         BUG_ON(queue != &res->converting);
1812                         newlock->ml.convert_type = ml->convert_type;
1813                 }
1814                 lksb->flags |= (ml->flags &
1815                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1816
1817                 if (ml->type == LKM_NLMODE)
1818                         goto skip_lvb;
1819
1820                 if (!dlm_lvb_is_empty(mres->lvb)) {
1821                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1822                                 /* other node was trying to update
1823                                  * lvb when node died.  recreate the
1824                                  * lksb with the updated lvb. */
1825                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1826                                 /* the lock resource lvb update must happen
1827                                  * NOW, before the spinlock is dropped.
1828                                  * we no longer wait for the AST to update
1829                                  * the lvb. */
1830                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1831                         } else {
1832                                 /* otherwise, the node is sending its
1833                                  * most recent valid lvb info */
1834                                 BUG_ON(ml->type != LKM_EXMODE &&
1835                                        ml->type != LKM_PRMODE);
1836                                 if (!dlm_lvb_is_empty(res->lvb) &&
1837                                     (ml->type == LKM_EXMODE ||
1838                                      memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1839                                         int i;
1840                                         mlog(ML_ERROR, "%s:%.*s: received bad "
1841                                              "lvb! type=%d\n", dlm->name,
1842                                              res->lockname.len,
1843                                              res->lockname.name, ml->type);
1844                                         printk("lockres lvb=[");
1845                                         for (i=0; i<DLM_LVB_LEN; i++)
1846                                                 printk("%02x", res->lvb[i]);
1847                                         printk("]\nmigrated lvb=[");
1848                                         for (i=0; i<DLM_LVB_LEN; i++)
1849                                                 printk("%02x", mres->lvb[i]);
1850                                         printk("]\n");
1851                                         dlm_print_one_lock_resource(res);
1852                                         BUG();
1853                                 }
1854                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1855                         }
1856                 }
1857 skip_lvb:
1858
1859                 /* NOTE:
1860                  * wrt lock queue ordering and recovery:
1861                  *    1. order of locks on granted queue is
1862                  *       meaningless.
1863                  *    2. order of locks on converting queue is
1864                  *       LOST with the node death.  sorry charlie.
1865                  *    3. order of locks on the blocked queue is
1866                  *       also LOST.
1867                  * order of locks does not affect integrity, it
1868                  * just means that a lock request may get pushed
1869                  * back in line as a result of the node death.
1870                  * also note that for a given node the lock order
1871                  * for its secondary queue locks is preserved
1872                  * relative to each other, but clearly *not*
1873                  * preserved relative to locks from other nodes.
1874                  */
1875                 bad = 0;
1876                 spin_lock(&res->spinlock);
1877                 list_for_each_entry(lock, queue, list) {
1878                         if (lock->ml.cookie == ml->cookie) {
1879                                 u64 c = lock->ml.cookie;
1880                                 mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1881                                      "exists on this lockres!\n", dlm->name,
1882                                      res->lockname.len, res->lockname.name,
1883                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1884                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1885
1886                                 mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1887                                      "node=%u, cookie=%u:%llu, queue=%d\n",
1888                                      ml->type, ml->convert_type, ml->node,
1889                                      dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
1890                                      dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
1891                                      ml->list);
1892
1893                                 __dlm_print_one_lock_resource(res);
1894                                 bad = 1;
1895                                 break;
1896                         }
1897                 }
1898                 if (!bad) {
1899                         dlm_lock_get(newlock);
1900                         list_add_tail(&newlock->list, queue);
1901                         mlog(0, "%s:%.*s: added lock for node %u, "
1902                              "setting refmap bit\n", dlm->name,
1903                              res->lockname.len, res->lockname.name, ml->node);
1904                         dlm_lockres_set_refmap_bit(ml->node, res);
1905                         added++;
1906                 }
1907                 spin_unlock(&res->spinlock);
1908         }
1909         mlog(0, "done running all the locks\n");
1910
1911 leave:
1912         /* balance the ref taken when the work was queued */
1913         spin_lock(&res->spinlock);
1914         dlm_lockres_drop_inflight_ref(dlm, res);
1915         spin_unlock(&res->spinlock);
1916
1917         if (ret < 0) {
1918                 mlog_errno(ret);
1919                 if (newlock)
1920                         dlm_lock_put(newlock);
1921         }
1922
1923         mlog_exit(ret);
1924         return ret;
1925 }
1926
1927 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1928                                        struct dlm_lock_resource *res)
1929 {
1930         int i;
1931         struct list_head *queue, *iter, *iter2;
1932         struct dlm_lock *lock;
1933
1934         res->state |= DLM_LOCK_RES_RECOVERING;
1935         if (!list_empty(&res->recovering)) {
1936                 mlog(0,
1937                      "Recovering res %s:%.*s, is already on recovery list!\n",
1938                      dlm->name, res->lockname.len, res->lockname.name);
1939                 list_del_init(&res->recovering);
1940         }
1941         /* We need to hold a reference while on the recovery list */
1942         dlm_lockres_get(res);
1943         list_add_tail(&res->recovering, &dlm->reco.resources);
1944
1945         /* find any pending locks and put them back on proper list */
1946         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
1947                 queue = dlm_list_idx_to_ptr(res, i);
1948                 list_for_each_safe(iter, iter2, queue) {
1949                         lock = list_entry (iter, struct dlm_lock, list);
1950                         dlm_lock_get(lock);
1951                         if (lock->convert_pending) {
1952                                 /* move converting lock back to granted */
1953                                 BUG_ON(i != DLM_CONVERTING_LIST);
1954                                 mlog(0, "node died with convert pending "
1955                                      "on %.*s. move back to granted list.\n",
1956                                      res->lockname.len, res->lockname.name);
1957                                 dlm_revert_pending_convert(res, lock);
1958                                 lock->convert_pending = 0;
1959                         } else if (lock->lock_pending) {
1960                                 /* remove pending lock requests completely */
1961                                 BUG_ON(i != DLM_BLOCKED_LIST);
1962                                 mlog(0, "node died with lock pending "
1963                                      "on %.*s. remove from blocked list and skip.\n",
1964                                      res->lockname.len, res->lockname.name);
1965                                 /* lock will be floating until ref in
1966                                  * dlmlock_remote is freed after the network
1967                                  * call returns.  ok for it to not be on any
1968                                  * list since no ast can be called
1969                                  * (the master is dead). */
1970                                 dlm_revert_pending_lock(res, lock);
1971                                 lock->lock_pending = 0;
1972                         } else if (lock->unlock_pending) {
1973                                 /* if an unlock was in progress, treat as
1974                                  * if this had completed successfully
1975                                  * before sending this lock state to the
1976                                  * new master.  note that the dlm_unlock
1977                                  * call is still responsible for calling
1978                                  * the unlockast.  that will happen after
1979                                  * the network call times out.  for now,
1980                                  * just move lists to prepare the new
1981                                  * recovery master.  */
1982                                 BUG_ON(i != DLM_GRANTED_LIST);
1983                                 mlog(0, "node died with unlock pending "
1984                                      "on %.*s. remove from blocked list and skip.\n",
1985                                      res->lockname.len, res->lockname.name);
1986                                 dlm_commit_pending_unlock(res, lock);
1987                                 lock->unlock_pending = 0;
1988                         } else if (lock->cancel_pending) {
1989                                 /* if a cancel was in progress, treat as
1990                                  * if this had completed successfully
1991                                  * before sending this lock state to the
1992                                  * new master */
1993                                 BUG_ON(i != DLM_CONVERTING_LIST);
1994                                 mlog(0, "node died with cancel pending "
1995                                      "on %.*s. move back to granted list.\n",
1996                                      res->lockname.len, res->lockname.name);
1997                                 dlm_commit_pending_cancel(res, lock);
1998                                 lock->cancel_pending = 0;
1999                         }
2000                         dlm_lock_put(lock);
2001                 }
2002         }
2003 }
2004
2005
2006
2007 /* removes all recovered locks from the recovery list.
2008  * sets the res->owner to the new master.
2009  * unsets the RECOVERY flag and wakes waiters. */
2010 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
2011                                               u8 dead_node, u8 new_master)
2012 {
2013         int i;
2014         struct list_head *iter, *iter2;
2015         struct hlist_node *hash_iter;
2016         struct hlist_head *bucket;
2017
2018         struct dlm_lock_resource *res;
2019
2020         mlog_entry_void();
2021
2022         assert_spin_locked(&dlm->spinlock);
2023
2024         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
2025                 res = list_entry (iter, struct dlm_lock_resource, recovering);
2026                 if (res->owner == dead_node) {
2027                         list_del_init(&res->recovering);
2028                         spin_lock(&res->spinlock);
2029                         /* new_master has our reference from
2030                          * the lock state sent during recovery */
2031                         dlm_change_lockres_owner(dlm, res, new_master);
2032                         res->state &= ~DLM_LOCK_RES_RECOVERING;
2033                         if (__dlm_lockres_has_locks(res))
2034                                 __dlm_dirty_lockres(dlm, res);
2035                         spin_unlock(&res->spinlock);
2036                         wake_up(&res->wq);
2037                         dlm_lockres_put(res);
2038                 }
2039         }
2040
2041         /* this will become unnecessary eventually, but
2042          * for now we need to run the whole hash, clear
2043          * the RECOVERING state and set the owner
2044          * if necessary */
2045         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2046                 bucket = dlm_lockres_hash(dlm, i);
2047                 hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
2048                         if (res->state & DLM_LOCK_RES_RECOVERING) {
2049                                 if (res->owner == dead_node) {
2050                                         mlog(0, "(this=%u) res %.*s owner=%u "
2051                                              "was not on recovering list, but "
2052                                              "clearing state anyway\n",
2053                                              dlm->node_num, res->lockname.len,
2054                                              res->lockname.name, new_master);
2055                                 } else if (res->owner == dlm->node_num) {
2056                                         mlog(0, "(this=%u) res %.*s owner=%u "
2057                                              "was not on recovering list, "
2058                                              "owner is THIS node, clearing\n",
2059                                              dlm->node_num, res->lockname.len,
2060                                              res->lockname.name, new_master);
2061                                 } else
2062                                         continue;
2063
2064                                 if (!list_empty(&res->recovering)) {
2065                                         mlog(0, "%s:%.*s: lockres was "
2066                                              "marked RECOVERING, owner=%u\n",
2067                                              dlm->name, res->lockname.len,
2068                                              res->lockname.name, res->owner);
2069                                         list_del_init(&res->recovering);
2070                                         dlm_lockres_put(res);
2071                                 }
2072                                 spin_lock(&res->spinlock);
2073                                 /* new_master has our reference from
2074                                  * the lock state sent during recovery */
2075                                 dlm_change_lockres_owner(dlm, res, new_master);
2076                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
2077                                 if (__dlm_lockres_has_locks(res))
2078                                         __dlm_dirty_lockres(dlm, res);
2079                                 spin_unlock(&res->spinlock);
2080                                 wake_up(&res->wq);
2081                         }
2082                 }
2083         }
2084 }
2085
2086 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2087 {
2088         if (local) {
2089                 if (lock->ml.type != LKM_EXMODE &&
2090                     lock->ml.type != LKM_PRMODE)
2091                         return 1;
2092         } else if (lock->ml.type == LKM_EXMODE)
2093                 return 1;
2094         return 0;
2095 }
2096
2097 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2098                                struct dlm_lock_resource *res, u8 dead_node)
2099 {
2100         struct list_head *iter, *queue;
2101         struct dlm_lock *lock;
2102         int blank_lvb = 0, local = 0;
2103         int i;
2104         u8 search_node;
2105
2106         assert_spin_locked(&dlm->spinlock);
2107         assert_spin_locked(&res->spinlock);
2108
2109         if (res->owner == dlm->node_num)
2110                 /* if this node owned the lockres, and if the dead node
2111                  * had an EX when he died, blank out the lvb */
2112                 search_node = dead_node;
2113         else {
2114                 /* if this is a secondary lockres, and we had no EX or PR
2115                  * locks granted, we can no longer trust the lvb */
2116                 search_node = dlm->node_num;
2117                 local = 1;  /* check local state for valid lvb */
2118         }
2119
2120         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2121                 queue = dlm_list_idx_to_ptr(res, i);
2122                 list_for_each(iter, queue) {
2123                         lock = list_entry (iter, struct dlm_lock, list);
2124                         if (lock->ml.node == search_node) {
2125                                 if (dlm_lvb_needs_invalidation(lock, local)) {
2126                                         /* zero the lksb lvb and lockres lvb */
2127                                         blank_lvb = 1;
2128                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2129                                 }
2130                         }
2131                 }
2132         }
2133
2134         if (blank_lvb) {
2135                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2136                      res->lockname.len, res->lockname.name, dead_node);
2137                 memset(res->lvb, 0, DLM_LVB_LEN);
2138         }
2139 }
2140
2141 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2142                                 struct dlm_lock_resource *res, u8 dead_node)
2143 {
2144         struct list_head *iter, *tmpiter;
2145         struct dlm_lock *lock;
2146         unsigned int freed = 0;
2147
2148         /* this node is the lockres master:
2149          * 1) remove any stale locks for the dead node
2150          * 2) if the dead node had an EX when he died, blank out the lvb
2151          */
2152         assert_spin_locked(&dlm->spinlock);
2153         assert_spin_locked(&res->spinlock);
2154
2155         /* TODO: check pending_asts, pending_basts here */
2156         list_for_each_safe(iter, tmpiter, &res->granted) {
2157                 lock = list_entry (iter, struct dlm_lock, list);
2158                 if (lock->ml.node == dead_node) {
2159                         list_del_init(&lock->list);
2160                         dlm_lock_put(lock);
2161                         freed++;
2162                 }
2163         }
2164         list_for_each_safe(iter, tmpiter, &res->converting) {
2165                 lock = list_entry (iter, struct dlm_lock, list);
2166                 if (lock->ml.node == dead_node) {
2167                         list_del_init(&lock->list);
2168                         dlm_lock_put(lock);
2169                         freed++;
2170                 }
2171         }
2172         list_for_each_safe(iter, tmpiter, &res->blocked) {
2173                 lock = list_entry (iter, struct dlm_lock, list);
2174                 if (lock->ml.node == dead_node) {
2175                         list_del_init(&lock->list);
2176                         dlm_lock_put(lock);
2177                         freed++;
2178                 }
2179         }
2180
2181         if (freed) {
2182                 mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2183                      "dropping ref from lockres\n", dlm->name,
2184                      res->lockname.len, res->lockname.name, freed, dead_node);
2185                 BUG_ON(!test_bit(dead_node, res->refmap));
2186                 dlm_lockres_clear_refmap_bit(dead_node, res);
2187         } else if (test_bit(dead_node, res->refmap)) {
2188                 mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2189                      "no locks and had not purged before dying\n", dlm->name,
2190                      res->lockname.len, res->lockname.name, dead_node);
2191                 dlm_lockres_clear_refmap_bit(dead_node, res);
2192         }
2193
2194         /* do not kick thread yet */
2195         __dlm_dirty_lockres(dlm, res);
2196 }
2197
2198 /* if this node is the recovery master, and there are no
2199  * locks for a given lockres owned by this node that are in
2200  * either PR or EX mode, zero out the lvb before requesting.
2201  *
2202  */
2203
2204
2205 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2206 {
2207         struct hlist_node *iter;
2208         struct dlm_lock_resource *res;
2209         int i;
2210         struct hlist_head *bucket;
2211         struct dlm_lock *lock;
2212
2213
2214         /* purge any stale mles */
2215         dlm_clean_master_list(dlm, dead_node);
2216
2217         /*
2218          * now clean up all lock resources.  there are two rules:
2219          *
2220          * 1) if the dead node was the master, move the lockres
2221          *    to the recovering list.  set the RECOVERING flag.
2222          *    this lockres needs to be cleaned up before it can
2223          *    be used further.
2224          *
2225          * 2) if this node was the master, remove all locks from
2226          *    each of the lockres queues that were owned by the
2227          *    dead node.  once recovery finishes, the dlm thread
2228          *    can be kicked again to see if any ASTs or BASTs
2229          *    need to be fired as a result.
2230          */
2231         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2232                 bucket = dlm_lockres_hash(dlm, i);
2233                 hlist_for_each_entry(res, iter, bucket, hash_node) {
2234                         /* always prune any $RECOVERY entries for dead nodes,
2235                          * otherwise hangs can occur during later recovery */
2236                         if (dlm_is_recovery_lock(res->lockname.name,
2237                                                  res->lockname.len)) {
2238                                 spin_lock(&res->spinlock);
2239                                 list_for_each_entry(lock, &res->granted, list) {
2240                                         if (lock->ml.node == dead_node) {
2241                                                 mlog(0, "AHA! there was "
2242                                                      "a $RECOVERY lock for dead "
2243                                                      "node %u (%s)!\n",
2244                                                      dead_node, dlm->name);
2245                                                 list_del_init(&lock->list);
2246                                                 dlm_lock_put(lock);
2247                                                 break;
2248                                         }
2249                                 }
2250                                 spin_unlock(&res->spinlock);
2251                                 continue;
2252                         }
2253                         spin_lock(&res->spinlock);
2254                         /* zero the lvb if necessary */
2255                         dlm_revalidate_lvb(dlm, res, dead_node);
2256                         if (res->owner == dead_node) {
2257                                 if (res->state & DLM_LOCK_RES_DROPPING_REF)
2258                                         mlog(0, "%s:%.*s: owned by "
2259                                              "dead node %u, this node was "
2260                                              "dropping its ref when it died. "
2261                                              "continue, dropping the flag.\n",
2262                                              dlm->name, res->lockname.len,
2263                                              res->lockname.name, dead_node);
2264
2265                                 /* the wake_up for this will happen when the
2266                                  * RECOVERING flag is dropped later */
2267                                 res->state &= ~DLM_LOCK_RES_DROPPING_REF;
2268
2269                                 dlm_move_lockres_to_recovery_list(dlm, res);
2270                         } else if (res->owner == dlm->node_num) {
2271                                 dlm_free_dead_locks(dlm, res, dead_node);
2272                                 __dlm_lockres_calc_usage(dlm, res);
2273                         }
2274                         spin_unlock(&res->spinlock);
2275                 }
2276         }
2277
2278 }
2279
2280 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2281 {
2282         assert_spin_locked(&dlm->spinlock);
2283
2284         if (dlm->reco.new_master == idx) {
2285                 mlog(0, "%s: recovery master %d just died\n",
2286                      dlm->name, idx);
2287                 if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2288                         /* finalize1 was reached, so it is safe to clear
2289                          * the new_master and dead_node.  that recovery
2290                          * is complete. */
2291                         mlog(0, "%s: dead master %d had reached "
2292                              "finalize1 state, clearing\n", dlm->name, idx);
2293                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2294                         __dlm_reset_recovery(dlm);
2295                 }
2296         }
2297
2298         /* check to see if the node is already considered dead */
2299         if (!test_bit(idx, dlm->live_nodes_map)) {
2300                 mlog(0, "for domain %s, node %d is already dead. "
2301                      "another node likely did recovery already.\n",
2302                      dlm->name, idx);
2303                 return;
2304         }
2305
2306         /* check to see if we do not care about this node */
2307         if (!test_bit(idx, dlm->domain_map)) {
2308                 /* This also catches the case that we get a node down
2309                  * but haven't joined the domain yet. */
2310                 mlog(0, "node %u already removed from domain!\n", idx);
2311                 return;
2312         }
2313
2314         clear_bit(idx, dlm->live_nodes_map);
2315
2316         /* Clean up join state on node death. */
2317         if (dlm->joining_node == idx) {
2318                 mlog(0, "Clearing join state for node %u\n", idx);
2319                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2320         }
2321
2322         /* make sure local cleanup occurs before the heartbeat events */
2323         if (!test_bit(idx, dlm->recovery_map))
2324                 dlm_do_local_recovery_cleanup(dlm, idx);
2325
2326         /* notify anything attached to the heartbeat events */
2327         dlm_hb_event_notify_attached(dlm, idx, 0);
2328
2329         mlog(0, "node %u being removed from domain map!\n", idx);
2330         clear_bit(idx, dlm->domain_map);
2331         /* wake up migration waiters if a node goes down.
2332          * perhaps later we can genericize this for other waiters. */
2333         wake_up(&dlm->migration_wq);
2334
2335         if (test_bit(idx, dlm->recovery_map))
2336                 mlog(0, "domain %s, node %u already added "
2337                      "to recovery map!\n", dlm->name, idx);
2338         else
2339                 set_bit(idx, dlm->recovery_map);
2340 }
2341
2342 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2343 {
2344         struct dlm_ctxt *dlm = data;
2345
2346         if (!dlm_grab(dlm))
2347                 return;
2348
2349         spin_lock(&dlm->spinlock);
2350         __dlm_hb_node_down(dlm, idx);
2351         spin_unlock(&dlm->spinlock);
2352
2353         dlm_put(dlm);
2354 }
2355
2356 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2357 {
2358         struct dlm_ctxt *dlm = data;
2359
2360         if (!dlm_grab(dlm))
2361                 return;
2362
2363         spin_lock(&dlm->spinlock);
2364         set_bit(idx, dlm->live_nodes_map);
2365         /* do NOT notify mle attached to the heartbeat events.
2366          * new nodes are not interesting in mastery until joined. */
2367         spin_unlock(&dlm->spinlock);
2368
2369         dlm_put(dlm);
2370 }
2371
2372 static void dlm_reco_ast(void *astdata)
2373 {
2374         struct dlm_ctxt *dlm = astdata;
2375         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2376              dlm->node_num, dlm->name);
2377 }
2378 static void dlm_reco_bast(void *astdata, int blocked_type)
2379 {
2380         struct dlm_ctxt *dlm = astdata;
2381         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2382              dlm->node_num, dlm->name);
2383 }
2384 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2385 {
2386         mlog(0, "unlockast for recovery lock fired!\n");
2387 }
2388
2389 /*
2390  * dlm_pick_recovery_master will continually attempt to use
2391  * dlmlock() on the special "$RECOVERY" lockres with the
2392  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2393  * this function on each node racing to become the recovery
2394  * master will not stop attempting this until either:
2395  * a) this node gets the EX (and becomes the recovery master),
2396  * or b) dlm->reco.new_master gets set to some nodenum
2397  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2398  * so each time a recovery master is needed, the entire cluster
2399  * will sync at this point.  if the new master dies, that will
2400  * be detected in dlm_do_recovery */
2401 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2402 {
2403         enum dlm_status ret;
2404         struct dlm_lockstatus lksb;
2405         int status = -EINVAL;
2406
2407         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2408              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2409 again:
2410         memset(&lksb, 0, sizeof(lksb));
2411
2412         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2413                       DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2414                       dlm_reco_ast, dlm, dlm_reco_bast);
2415
2416         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2417              dlm->name, ret, lksb.status);
2418
2419         if (ret == DLM_NORMAL) {
2420                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2421                      dlm->name, dlm->node_num);
2422
2423                 /* got the EX lock.  check to see if another node
2424                  * just became the reco master */
2425                 if (dlm_reco_master_ready(dlm)) {
2426                         mlog(0, "%s: got reco EX lock, but %u will "
2427                              "do the recovery\n", dlm->name,
2428                              dlm->reco.new_master);
2429                         status = -EEXIST;
2430                 } else {
2431                         status = 0;
2432
2433                         /* see if recovery was already finished elsewhere */
2434                         spin_lock(&dlm->spinlock);
2435                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2436                                 status = -EINVAL;
2437                                 mlog(0, "%s: got reco EX lock, but "
2438                                      "node got recovered already\n", dlm->name);
2439                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2440                                         mlog(ML_ERROR, "%s: new master is %u "
2441                                              "but no dead node!\n",
2442                                              dlm->name, dlm->reco.new_master);
2443                                         BUG();
2444                                 }
2445                         }
2446                         spin_unlock(&dlm->spinlock);
2447                 }
2448
2449                 /* if this node has actually become the recovery master,
2450                  * set the master and send the messages to begin recovery */
2451                 if (!status) {
2452                         mlog(0, "%s: dead=%u, this=%u, sending "
2453                              "begin_reco now\n", dlm->name,
2454                              dlm->reco.dead_node, dlm->node_num);
2455                         status = dlm_send_begin_reco_message(dlm,
2456                                       dlm->reco.dead_node);
2457                         /* this always succeeds */
2458                         BUG_ON(status);
2459
2460                         /* set the new_master to this node */
2461                         spin_lock(&dlm->spinlock);
2462                         dlm_set_reco_master(dlm, dlm->node_num);
2463                         spin_unlock(&dlm->spinlock);
2464                 }
2465
2466                 /* recovery lock is a special case.  ast will not get fired,
2467                  * so just go ahead and unlock it. */
2468                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2469                 if (ret == DLM_DENIED) {
2470                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2471                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2472                 }
2473                 if (ret != DLM_NORMAL) {
2474                         /* this would really suck. this could only happen
2475                          * if there was a network error during the unlock
2476                          * because of node death.  this means the unlock
2477                          * is actually "done" and the lock structure is
2478                          * even freed.  we can continue, but only
2479                          * because this specific lock name is special. */
2480                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2481                 }
2482         } else if (ret == DLM_NOTQUEUED) {
2483                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2484                      dlm->name, dlm->node_num);
2485                 /* another node is master. wait on
2486                  * reco.new_master != O2NM_INVALID_NODE_NUM
2487                  * for at most one second */
2488                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2489                                          dlm_reco_master_ready(dlm),
2490                                          msecs_to_jiffies(1000));
2491                 if (!dlm_reco_master_ready(dlm)) {
2492                         mlog(0, "%s: reco master taking awhile\n",
2493                              dlm->name);
2494                         goto again;
2495                 }
2496                 /* another node has informed this one that it is reco master */
2497                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2498                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2499                 status = -EEXIST;
2500         } else if (ret == DLM_RECOVERING) {
2501                 mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2502                      dlm->name, dlm->node_num);
2503                 goto again;
2504         } else {
2505                 struct dlm_lock_resource *res;
2506
2507                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2508                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2509                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2510                      dlm_errname(lksb.status));
2511                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2512                                          DLM_RECOVERY_LOCK_NAME_LEN);
2513                 if (res) {
2514                         dlm_print_one_lock_resource(res);
2515                         dlm_lockres_put(res);
2516                 } else {
2517                         mlog(ML_ERROR, "recovery lock not found\n");
2518                 }
2519                 BUG();
2520         }
2521
2522         return status;
2523 }
2524
2525 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2526 {
2527         struct dlm_begin_reco br;
2528         int ret = 0;
2529         struct dlm_node_iter iter;
2530         int nodenum;
2531         int status;
2532
2533         mlog_entry("%u\n", dead_node);
2534
2535         mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2536
2537         spin_lock(&dlm->spinlock);
2538         dlm_node_iter_init(dlm->domain_map, &iter);
2539         spin_unlock(&dlm->spinlock);
2540
2541         clear_bit(dead_node, iter.node_map);
2542
2543         memset(&br, 0, sizeof(br));
2544         br.node_idx = dlm->node_num;
2545         br.dead_node = dead_node;
2546
2547         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2548                 ret = 0;
2549                 if (nodenum == dead_node) {
2550                         mlog(0, "not sending begin reco to dead node "
2551                                   "%u\n", dead_node);
2552                         continue;
2553                 }
2554                 if (nodenum == dlm->node_num) {
2555                         mlog(0, "not sending begin reco to self\n");
2556                         continue;
2557                 }
2558 retry:
2559                 ret = -EINVAL;
2560                 mlog(0, "attempting to send begin reco msg to %d\n",
2561                           nodenum);
2562                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2563                                          &br, sizeof(br), nodenum, &status);
2564                 /* negative status is handled ok by caller here */
2565                 if (ret >= 0)
2566                         ret = status;
2567                 if (dlm_is_host_down(ret)) {
2568                         /* node is down.  not involved in recovery
2569                          * so just keep going */
2570                         mlog(0, "%s: node %u was down when sending "
2571                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2572                         ret = 0;
2573                 }
2574                 if (ret < 0) {
2575                         struct dlm_lock_resource *res;
2576                         /* this is now a serious problem, possibly ENOMEM
2577                          * in the network stack.  must retry */
2578                         mlog_errno(ret);
2579                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2580                             " returned %d\n", dlm->name, nodenum, ret);
2581                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2582                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2583                         if (res) {
2584                                 dlm_print_one_lock_resource(res);
2585                                 dlm_lockres_put(res);
2586                         } else {
2587                                 mlog(ML_ERROR, "recovery lock not found\n");
2588                         }
2589                         /* sleep for a bit in hopes that we can avoid
2590                          * another ENOMEM */
2591                         msleep(100);
2592                         goto retry;
2593                 } else if (ret == EAGAIN) {
2594                         mlog(0, "%s: trying to start recovery of node "
2595                              "%u, but node %u is waiting for last recovery "
2596                              "to complete, backoff for a bit\n", dlm->name,
2597                              dead_node, nodenum);
2598                         /* TODO Look into replacing msleep with cond_resched() */
2599                         msleep(100);
2600                         goto retry;
2601                 }
2602         }
2603
2604         return ret;
2605 }
2606
2607 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2608                            void **ret_data)
2609 {
2610         struct dlm_ctxt *dlm = data;
2611         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2612
2613         /* ok to return 0, domain has gone away */
2614         if (!dlm_grab(dlm))
2615                 return 0;
2616
2617         spin_lock(&dlm->spinlock);
2618         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2619                 mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2620                      "but this node is in finalize state, waiting on finalize2\n",
2621                      dlm->name, br->node_idx, br->dead_node,
2622                      dlm->reco.dead_node, dlm->reco.new_master);
2623                 spin_unlock(&dlm->spinlock);
2624                 return EAGAIN;
2625         }
2626         spin_unlock(&dlm->spinlock);
2627
2628         mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2629              dlm->name, br->node_idx, br->dead_node,
2630              dlm->reco.dead_node, dlm->reco.new_master);
2631
2632         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2633
2634         spin_lock(&dlm->spinlock);
2635         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2636                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2637                         mlog(0, "%s: new_master %u died, changing "
2638                              "to %u\n", dlm->name, dlm->reco.new_master,
2639                              br->node_idx);
2640                 } else {
2641                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2642                              "to %u\n", dlm->name, dlm->reco.new_master,
2643                              br->node_idx);
2644                         /* may not have seen the new master as dead yet */
2645                 }
2646         }
2647         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2648                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2649                      "node %u changing it to %u\n", dlm->name,
2650                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2651         }
2652         dlm_set_reco_master(dlm, br->node_idx);
2653         dlm_set_reco_dead_node(dlm, br->dead_node);
2654         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2655                 mlog(0, "recovery master %u sees %u as dead, but this "
2656                      "node has not yet.  marking %u as dead\n",
2657                      br->node_idx, br->dead_node, br->dead_node);
2658                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2659                     !test_bit(br->dead_node, dlm->live_nodes_map))
2660                         mlog(0, "%u not in domain/live_nodes map "
2661                              "so setting it in reco map manually\n",
2662                              br->dead_node);
2663                 /* force the recovery cleanup in __dlm_hb_node_down
2664                  * both of these will be cleared in a moment */
2665                 set_bit(br->dead_node, dlm->domain_map);
2666                 set_bit(br->dead_node, dlm->live_nodes_map);
2667                 __dlm_hb_node_down(dlm, br->dead_node);
2668         }
2669         spin_unlock(&dlm->spinlock);
2670
2671         dlm_kick_recovery_thread(dlm);
2672
2673         mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2674              dlm->name, br->node_idx, br->dead_node,
2675              dlm->reco.dead_node, dlm->reco.new_master);
2676
2677         dlm_put(dlm);
2678         return 0;
2679 }
2680
2681 #define DLM_FINALIZE_STAGE2  0x01
2682 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2683 {
2684         int ret = 0;
2685         struct dlm_finalize_reco fr;
2686         struct dlm_node_iter iter;
2687         int nodenum;
2688         int status;
2689         int stage = 1;
2690
2691         mlog(0, "finishing recovery for node %s:%u, "
2692              "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2693
2694         spin_lock(&dlm->spinlock);
2695         dlm_node_iter_init(dlm->domain_map, &iter);
2696         spin_unlock(&dlm->spinlock);
2697
2698 stage2:
2699         memset(&fr, 0, sizeof(fr));
2700         fr.node_idx = dlm->node_num;
2701         fr.dead_node = dlm->reco.dead_node;
2702         if (stage == 2)
2703                 fr.flags |= DLM_FINALIZE_STAGE2;
2704
2705         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2706                 if (nodenum == dlm->node_num)
2707                         continue;
2708                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2709                                          &fr, sizeof(fr), nodenum, &status);
2710                 if (ret >= 0)
2711                         ret = status;
2712                 if (ret < 0) {
2713                         mlog_errno(ret);
2714                         if (dlm_is_host_down(ret)) {
2715                                 /* this has no effect on this recovery
2716                                  * session, so set the status to zero to
2717                                  * finish out the last recovery */
2718                                 mlog(ML_ERROR, "node %u went down after this "
2719                                      "node finished recovery.\n", nodenum);
2720                                 ret = 0;
2721                                 continue;
2722                         }
2723                         break;
2724                 }
2725         }
2726         if (stage == 1) {
2727                 /* reset the node_iter back to the top and send finalize2 */
2728                 iter.curnode = -1;
2729                 stage = 2;
2730                 goto stage2;
2731         }
2732
2733         return ret;
2734 }
2735
2736 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2737                               void **ret_data)
2738 {
2739         struct dlm_ctxt *dlm = data;
2740         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2741         int stage = 1;
2742
2743         /* ok to return 0, domain has gone away */
2744         if (!dlm_grab(dlm))
2745                 return 0;
2746
2747         if (fr->flags & DLM_FINALIZE_STAGE2)
2748                 stage = 2;
2749
2750         mlog(0, "%s: node %u finalizing recovery stage%d of "
2751              "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2752              fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2753
2754         spin_lock(&dlm->spinlock);
2755
2756         if (dlm->reco.new_master != fr->node_idx) {
2757                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2758                      "%u is supposed to be the new master, dead=%u\n",
2759                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2760                 BUG();
2761         }
2762         if (dlm->reco.dead_node != fr->dead_node) {
2763                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2764                      "node %u, but node %u is supposed to be dead\n",
2765                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2766                 BUG();
2767         }
2768
2769         switch (stage) {
2770                 case 1:
2771                         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2772                         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2773                                 mlog(ML_ERROR, "%s: received finalize1 from "
2774                                      "new master %u for dead node %u, but "
2775                                      "this node has already received it!\n",
2776                                      dlm->name, fr->node_idx, fr->dead_node);
2777                                 dlm_print_reco_node_status(dlm);
2778                                 BUG();
2779                         }
2780                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2781                         spin_unlock(&dlm->spinlock);
2782                         break;
2783                 case 2:
2784                         if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2785                                 mlog(ML_ERROR, "%s: received finalize2 from "
2786                                      "new master %u for dead node %u, but "
2787                                      "this node did not have finalize1!\n",
2788                                      dlm->name, fr->node_idx, fr->dead_node);
2789                                 dlm_print_reco_node_status(dlm);
2790                                 BUG();
2791                         }
2792                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2793                         spin_unlock(&dlm->spinlock);
2794                         dlm_reset_recovery(dlm);
2795                         dlm_kick_recovery_thread(dlm);
2796                         break;
2797                 default:
2798                         BUG();
2799         }
2800
2801         mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2802              dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2803
2804         dlm_put(dlm);
2805         return 0;
2806 }