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

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