fs/ocfs2/dlm/dlmrecovery.c

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