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 static 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_lockres_master_requery(struct dlm_ctxt *dlm,
  82                                       struct dlm_lock_resource *res,
  83                                       u8 *real_master);
  84 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
  85                                      struct dlm_lock_resource *res,
  86                                      struct dlm_migratable_lockres *mres);
  87 static int dlm_do_master_requery(struct dlm_ctxt *dlm,
  88                                  struct dlm_lock_resource *res,
  89                                  u8 nodenum, u8 *real_master);
  90 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
  91 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
  92                                  u8 dead_node, u8 send_to);
  93 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
  94 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
  95                                         struct list_head *list, u8 dead_node);
  96 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
  97                                               u8 dead_node, u8 new_master);
  98 static void dlm_reco_ast(void *astdata);
  99 static void dlm_reco_bast(void *astdata, int blocked_type);
 100 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
 101 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
 102                                          void *data);
 103 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
 104
 105 static u64 dlm_get_next_mig_cookie(void);
 106
 107 static spinlock_t dlm_reco_state_lock = SPIN_LOCK_UNLOCKED;
 108 static spinlock_t dlm_mig_cookie_lock = SPIN_LOCK_UNLOCKED;
 109 static u64 dlm_mig_cookie = 1;
 110
 111 static u64 dlm_get_next_mig_cookie(void)
 112 {
 113         u64 c;
 114         spin_lock(&dlm_mig_cookie_lock);
 115         c = dlm_mig_cookie;
 116         if (dlm_mig_cookie == (~0ULL))
 117                 dlm_mig_cookie = 1;
 118         else
 119                 dlm_mig_cookie++;
 120         spin_unlock(&dlm_mig_cookie_lock);
 121         return c;
 122 }
 123
 124 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
 125 {
 126         spin_lock(&dlm->spinlock);
 127         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
 128         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
 129         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
 130         spin_unlock(&dlm->spinlock);
 131 }
 132
 133 /* Worker function used during recovery. */
 134 void dlm_dispatch_work(void *data)
 135 {
 136         struct dlm_ctxt *dlm = (struct dlm_ctxt *)data;
 137         LIST_HEAD(tmp_list);
 138         struct list_head *iter, *iter2;
 139         struct dlm_work_item *item;
 140         dlm_workfunc_t *workfunc;
 141
 142         spin_lock(&dlm->work_lock);
 143         list_splice_init(&dlm->work_list, &tmp_list);
 144         spin_unlock(&dlm->work_lock);
 145
 146         list_for_each_safe(iter, iter2, &tmp_list) {
 147                 item = list_entry(iter, struct dlm_work_item, list);
 148                 workfunc = item->func;
 149                 list_del_init(&item->list);
 150
 151                 /* already have ref on dlm to avoid having
 152                  * it disappear.  just double-check. */
 153                 BUG_ON(item->dlm != dlm);
 154
 155                 /* this is allowed to sleep and
 156                  * call network stuff */
 157                 workfunc(item, item->data);
 158
 159                 dlm_put(dlm);
 160                 kfree(item);
 161         }
 162 }
 163
 164 /*
 165  * RECOVERY THREAD
 166  */
 167
 168 static void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
 169 {
 170         /* wake the recovery thread
 171          * this will wake the reco thread in one of three places
 172          * 1) sleeping with no recovery happening
 173          * 2) sleeping with recovery mastered elsewhere
 174          * 3) recovery mastered here, waiting on reco data */
 175
 176         wake_up(&dlm->dlm_reco_thread_wq);
 177 }
 178
 179 /* Launch the recovery thread */
 180 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
 181 {
 182         mlog(0, "starting dlm recovery thread...\n");
 183
 184         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
 185                                                 "dlm_reco_thread");
 186         if (IS_ERR(dlm->dlm_reco_thread_task)) {
 187                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
 188                 dlm->dlm_reco_thread_task = NULL;
 189                 return -EINVAL;
 190         }
 191
 192         return 0;
 193 }
 194
 195 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
 196 {
 197         if (dlm->dlm_reco_thread_task) {
 198                 mlog(0, "waiting for dlm recovery thread to exit\n");
 199                 kthread_stop(dlm->dlm_reco_thread_task);
 200                 dlm->dlm_reco_thread_task = NULL;
 201         }
 202 }
 203
 204
 205
 206 /*
 207  * this is lame, but here's how recovery works...
 208  * 1) all recovery threads cluster wide will work on recovering
 209  *    ONE node at a time
 210  * 2) negotiate who will take over all the locks for the dead node.
 211  *    thats right... ALL the locks.
 212  * 3) once a new master is chosen, everyone scans all locks
 213  *    and moves aside those mastered by the dead guy
 214  * 4) each of these locks should be locked until recovery is done
 215  * 5) the new master collects up all of secondary lock queue info
 216  *    one lock at a time, forcing each node to communicate back
 217  *    before continuing
 218  * 6) each secondary lock queue responds with the full known lock info
 219  * 7) once the new master has run all its locks, it sends a ALLDONE!
 220  *    message to everyone
 221  * 8) upon receiving this message, the secondary queue node unlocks
 222  *    and responds to the ALLDONE
 223  * 9) once the new master gets responses from everyone, he unlocks
 224  *    everything and recovery for this dead node is done
 225  *10) go back to 2) while there are still dead nodes
 226  *
 227  */
 228
 229
 230 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
 231
 232 static int dlm_recovery_thread(void *data)
 233 {
 234         int status;
 235         struct dlm_ctxt *dlm = data;
 236         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
 237
 238         mlog(0, "dlm thread running for %s...\n", dlm->name);
 239
 240         while (!kthread_should_stop()) {
 241                 if (dlm_joined(dlm)) {
 242                         status = dlm_do_recovery(dlm);
 243                         if (status == -EAGAIN) {
 244                                 /* do not sleep, recheck immediately. */
 245                                 continue;
 246                         }
 247                         if (status < 0)
 248                                 mlog_errno(status);
 249                 }
 250
 251                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 252                                                  kthread_should_stop(),
 253                                                  timeout);
 254         }
 255
 256         mlog(0, "quitting DLM recovery thread\n");
 257         return 0;
 258 }
 259
 260 /* returns true when the recovery master has contacted us */
 261 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
 262 {
 263         int ready;
 264         spin_lock(&dlm->spinlock);
 265         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
 266         spin_unlock(&dlm->spinlock);
 267         return ready;
 268 }
 269
 270 /* returns true if node is no longer in the domain
 271  * could be dead or just not joined */
 272 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
 273 {
 274         int dead;
 275         spin_lock(&dlm->spinlock);
 276         dead = test_bit(node, dlm->domain_map);
 277         spin_unlock(&dlm->spinlock);
 278         return dead;
 279 }
 280
 281 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
 282 {
 283         if (timeout) {
 284                 mlog(ML_NOTICE, "%s: waiting %dms for notification of "
 285                      "death of node %u\n", dlm->name, timeout, node);
 286                 wait_event_timeout(dlm->dlm_reco_thread_wq,
 287                            dlm_is_node_dead(dlm, node),
 288                            msecs_to_jiffies(timeout));
 289         } else {
 290                 mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
 291                      "of death of node %u\n", dlm->name, node);
 292                 wait_event(dlm->dlm_reco_thread_wq,
 293                            dlm_is_node_dead(dlm, node));
 294         }
 295         /* for now, return 0 */
 296         return 0;
 297 }
 298
 299 /* callers of the top-level api calls (dlmlock/dlmunlock) should
 300  * block on the dlm->reco.event when recovery is in progress.
 301  * the dlm recovery thread will set this state when it begins
 302  * recovering a dead node (as the new master or not) and clear
 303  * the state and wake as soon as all affected lock resources have
 304  * been marked with the RECOVERY flag */
 305 static int dlm_in_recovery(struct dlm_ctxt *dlm)
 306 {
 307         int in_recovery;
 308         spin_lock(&dlm->spinlock);
 309         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 310         spin_unlock(&dlm->spinlock);
 311         return in_recovery;
 312 }
 313
 314
 315 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
 316 {
 317         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
 318 }
 319
 320 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
 321 {
 322         spin_lock(&dlm->spinlock);
 323         BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
 324         dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
 325         spin_unlock(&dlm->spinlock);
 326 }
 327
 328 static void dlm_end_recovery(struct dlm_ctxt *dlm)
 329 {
 330         spin_lock(&dlm->spinlock);
 331         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
 332         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
 333         spin_unlock(&dlm->spinlock);
 334         wake_up(&dlm->reco.event);
 335 }
 336
 337 static int dlm_do_recovery(struct dlm_ctxt *dlm)
 338 {
 339         int status = 0;
 340         int ret;
 341
 342         spin_lock(&dlm->spinlock);
 343
 344         /* check to see if the new master has died */
 345         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
 346             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
 347                 mlog(0, "new master %u died while recovering %u!\n",
 348                      dlm->reco.new_master, dlm->reco.dead_node);
 349                 /* unset the new_master, leave dead_node */
 350                 dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
 351         }
 352
 353         /* select a target to recover */
 354         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 355                 int bit;
 356
 357                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
 358                 if (bit >= O2NM_MAX_NODES || bit < 0)
 359                         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
 360                 else
 361                         dlm->reco.dead_node = bit;
 362         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
 363                 /* BUG? */
 364                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
 365                      dlm->reco.dead_node);
 366                 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
 367         }
 368
 369         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 370                 // mlog(0, "nothing to recover!  sleeping now!\n");
 371                 spin_unlock(&dlm->spinlock);
 372                 /* return to main thread loop and sleep. */
 373                 return 0;
 374         }
 375         mlog(0, "recovery thread found node %u in the recovery map!\n",
 376              dlm->reco.dead_node);
 377         spin_unlock(&dlm->spinlock);
 378
 379         /* take write barrier */
 380         /* (stops the list reshuffling thread, proxy ast handling) */
 381         dlm_begin_recovery(dlm);
 382
 383         if (dlm->reco.new_master == dlm->node_num)
 384                 goto master_here;
 385
 386         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
 387                 /* choose a new master, returns 0 if this node
 388                  * is the master, -EEXIST if it's another node.
 389                  * this does not return until a new master is chosen
 390                  * or recovery completes entirely. */
 391                 ret = dlm_pick_recovery_master(dlm);
 392                 if (!ret) {
 393                         /* already notified everyone.  go. */
 394                         goto master_here;
 395                 }
 396                 mlog(0, "another node will master this recovery session.\n");
 397         }
 398         mlog(0, "dlm=%s, new_master=%u, this node=%u, dead_node=%u\n",
 399              dlm->name, dlm->reco.new_master,
 400              dlm->node_num, dlm->reco.dead_node);
 401
 402         /* it is safe to start everything back up here
 403          * because all of the dead node's lock resources
 404          * have been marked as in-recovery */
 405         dlm_end_recovery(dlm);
 406
 407         /* sleep out in main dlm_recovery_thread loop. */
 408         return 0;
 409
 410 master_here:
 411         mlog(0, "mastering recovery of %s:%u here(this=%u)!\n",
 412              dlm->name, dlm->reco.dead_node, dlm->node_num);
 413
 414         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
 415         if (status < 0) {
 416                 mlog(ML_ERROR, "error %d remastering locks for node %u, "
 417                      "retrying.\n", status, dlm->reco.dead_node);
 418                 /* yield a bit to allow any final network messages
 419                  * to get handled on remaining nodes */
 420                 msleep(100);
 421         } else {
 422                 /* success!  see if any other nodes need recovery */
 423                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
 424                      dlm->name, dlm->reco.dead_node, dlm->node_num);
 425                 dlm_reset_recovery(dlm);
 426         }
 427         dlm_end_recovery(dlm);
 428
 429         /* continue and look for another dead node */
 430         return -EAGAIN;
 431 }
 432
 433 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
 434 {
 435         int status = 0;
 436         struct dlm_reco_node_data *ndata;
 437         struct list_head *iter;
 438         int all_nodes_done;
 439         int destroy = 0;
 440         int pass = 0;
 441
 442         status = dlm_init_recovery_area(dlm, dead_node);
 443         if (status < 0)
 444                 goto leave;
 445
 446         /* safe to access the node data list without a lock, since this
 447          * process is the only one to change the list */
 448         list_for_each(iter, &dlm->reco.node_data) {
 449                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 450                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
 451                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
 452
 453                 mlog(0, "requesting lock info from node %u\n",
 454                      ndata->node_num);
 455
 456                 if (ndata->node_num == dlm->node_num) {
 457                         ndata->state = DLM_RECO_NODE_DATA_DONE;
 458                         continue;
 459                 }
 460
 461                 status = dlm_request_all_locks(dlm, ndata->node_num, dead_node);
 462                 if (status < 0) {
 463                         mlog_errno(status);
 464                         if (dlm_is_host_down(status))
 465                                 ndata->state = DLM_RECO_NODE_DATA_DEAD;
 466                         else {
 467                                 destroy = 1;
 468                                 goto leave;
 469                         }
 470                 }
 471
 472                 switch (ndata->state) {
 473                         case DLM_RECO_NODE_DATA_INIT:
 474                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 475                         case DLM_RECO_NODE_DATA_REQUESTED:
 476                                 BUG();
 477                                 break;
 478                         case DLM_RECO_NODE_DATA_DEAD:
 479                                 mlog(0, "node %u died after requesting "
 480                                      "recovery info for node %u\n",
 481                                      ndata->node_num, dead_node);
 482                                 // start all over
 483                                 destroy = 1;
 484                                 status = -EAGAIN;
 485                                 goto leave;
 486                         case DLM_RECO_NODE_DATA_REQUESTING:
 487                                 ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
 488                                 mlog(0, "now receiving recovery data from "
 489                                      "node %u for dead node %u\n",
 490                                      ndata->node_num, dead_node);
 491                                 break;
 492                         case DLM_RECO_NODE_DATA_RECEIVING:
 493                                 mlog(0, "already receiving recovery data from "
 494                                      "node %u for dead node %u\n",
 495                                      ndata->node_num, dead_node);
 496                                 break;
 497                         case DLM_RECO_NODE_DATA_DONE:
 498                                 mlog(0, "already DONE receiving recovery data "
 499                                      "from node %u for dead node %u\n",
 500                                      ndata->node_num, dead_node);
 501                                 break;
 502                 }
 503         }
 504
 505         mlog(0, "done requesting all lock info\n");
 506
 507         /* nodes should be sending reco data now
 508          * just need to wait */
 509
 510         while (1) {
 511                 /* check all the nodes now to see if we are
 512                  * done, or if anyone died */
 513                 all_nodes_done = 1;
 514                 spin_lock(&dlm_reco_state_lock);
 515                 list_for_each(iter, &dlm->reco.node_data) {
 516                         ndata = list_entry (iter, struct dlm_reco_node_data, list);
 517
 518                         mlog(0, "checking recovery state of node %u\n",
 519                              ndata->node_num);
 520                         switch (ndata->state) {
 521                                 case DLM_RECO_NODE_DATA_INIT:
 522                                 case DLM_RECO_NODE_DATA_REQUESTING:
 523                                         mlog(ML_ERROR, "bad ndata state for "
 524                                              "node %u: state=%d\n",
 525                                              ndata->node_num, ndata->state);
 526                                         BUG();
 527                                         break;
 528                                 case DLM_RECO_NODE_DATA_DEAD:
 529                                         mlog(ML_NOTICE, "node %u died after "
 530                                              "requesting recovery info for "
 531                                              "node %u\n", ndata->node_num,
 532                                              dead_node);
 533                                         spin_unlock(&dlm_reco_state_lock);
 534                                         // start all over
 535                                         destroy = 1;
 536                                         status = -EAGAIN;
 537                                         /* instead of spinning like crazy here,
 538                                          * wait for the domain map to catch up
 539                                          * with the network state.  otherwise this
 540                                          * can be hit hundreds of times before
 541                                          * the node is really seen as dead. */
 542                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
 543                                                            dlm_is_node_dead(dlm,
 544                                                                 ndata->node_num),
 545                                                            msecs_to_jiffies(1000));
 546                                         mlog(0, "waited 1 sec for %u, "
 547                                              "dead? %s\n", ndata->node_num,
 548                                              dlm_is_node_dead(dlm, ndata->node_num) ?
 549                                              "yes" : "no");
 550                                         goto leave;
 551                                 case DLM_RECO_NODE_DATA_RECEIVING:
 552                                 case DLM_RECO_NODE_DATA_REQUESTED:
 553                                         all_nodes_done = 0;
 554                                         break;
 555                                 case DLM_RECO_NODE_DATA_DONE:
 556                                         break;
 557                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 558                                         break;
 559                         }
 560                 }
 561                 spin_unlock(&dlm_reco_state_lock);
 562
 563                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
 564                      all_nodes_done?"yes":"no");
 565                 if (all_nodes_done) {
 566                         int ret;
 567
 568                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
 569                          * just send a finalize message to everyone and
 570                          * clean up */
 571                         mlog(0, "all nodes are done! send finalize\n");
 572                         ret = dlm_send_finalize_reco_message(dlm);
 573                         if (ret < 0)
 574                                 mlog_errno(ret);
 575
 576                         spin_lock(&dlm->spinlock);
 577                         dlm_finish_local_lockres_recovery(dlm, dead_node,
 578                                                           dlm->node_num);
 579                         spin_unlock(&dlm->spinlock);
 580                         mlog(0, "should be done with recovery!\n");
 581
 582                         mlog(0, "finishing recovery of %s at %lu, "
 583                              "dead=%u, this=%u, new=%u\n", dlm->name,
 584                              jiffies, dlm->reco.dead_node,
 585                              dlm->node_num, dlm->reco.new_master);
 586                         destroy = 1;
 587                         status = ret;
 588                         /* rescan everything marked dirty along the way */
 589                         dlm_kick_thread(dlm, NULL);
 590                         break;
 591                 }
 592                 /* wait to be signalled, with periodic timeout
 593                  * to check for node death */
 594                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
 595                                          kthread_should_stop(),
 596                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
 597
 598         }
 599
 600 leave:
 601         if (destroy)
 602                 dlm_destroy_recovery_area(dlm, dead_node);
 603
 604         mlog_exit(status);
 605         return status;
 606 }
 607
 608 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 609 {
 610         int num=0;
 611         struct dlm_reco_node_data *ndata;
 612
 613         spin_lock(&dlm->spinlock);
 614         memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
 615         /* nodes can only be removed (by dying) after dropping
 616          * this lock, and death will be trapped later, so this should do */
 617         spin_unlock(&dlm->spinlock);
 618
 619         while (1) {
 620                 num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
 621                 if (num >= O2NM_MAX_NODES) {
 622                         break;
 623                 }
 624                 BUG_ON(num == dead_node);
 625
 626                 ndata = kcalloc(1, sizeof(*ndata), GFP_KERNEL);
 627                 if (!ndata) {
 628                         dlm_destroy_recovery_area(dlm, dead_node);
 629                         return -ENOMEM;
 630                 }
 631                 ndata->node_num = num;
 632                 ndata->state = DLM_RECO_NODE_DATA_INIT;
 633                 spin_lock(&dlm_reco_state_lock);
 634                 list_add_tail(&ndata->list, &dlm->reco.node_data);
 635                 spin_unlock(&dlm_reco_state_lock);
 636                 num++;
 637         }
 638
 639         return 0;
 640 }
 641
 642 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
 643 {
 644         struct list_head *iter, *iter2;
 645         struct dlm_reco_node_data *ndata;
 646         LIST_HEAD(tmplist);
 647
 648         spin_lock(&dlm_reco_state_lock);
 649         list_splice_init(&dlm->reco.node_data, &tmplist);
 650         spin_unlock(&dlm_reco_state_lock);
 651
 652         list_for_each_safe(iter, iter2, &tmplist) {
 653                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 654                 list_del_init(&ndata->list);
 655                 kfree(ndata);
 656         }
 657 }
 658
 659 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
 660                                  u8 dead_node)
 661 {
 662         struct dlm_lock_request lr;
 663         enum dlm_status ret;
 664
 665         mlog(0, "\n");
 666
 667
 668         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
 669                   "to %u\n", dead_node, request_from);
 670
 671         memset(&lr, 0, sizeof(lr));
 672         lr.node_idx = dlm->node_num;
 673         lr.dead_node = dead_node;
 674
 675         // send message
 676         ret = DLM_NOLOCKMGR;
 677         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
 678                                  &lr, sizeof(lr), request_from, NULL);
 679
 680         /* negative status is handled by caller */
 681         if (ret < 0)
 682                 mlog_errno(ret);
 683
 684         // return from here, then
 685         // sleep until all received or error
 686         return ret;
 687
 688 }
 689
 690 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data)
 691 {
 692         struct dlm_ctxt *dlm = data;
 693         struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
 694         char *buf = NULL;
 695         struct dlm_work_item *item = NULL;
 696
 697         if (!dlm_grab(dlm))
 698                 return -EINVAL;
 699
 700         BUG_ON(lr->dead_node != dlm->reco.dead_node);
 701
 702         item = kcalloc(1, sizeof(*item), GFP_KERNEL);
 703         if (!item) {
 704                 dlm_put(dlm);
 705                 return -ENOMEM;
 706         }
 707
 708         /* this will get freed by dlm_request_all_locks_worker */
 709         buf = (char *) __get_free_page(GFP_KERNEL);
 710         if (!buf) {
 711                 kfree(item);
 712                 dlm_put(dlm);
 713                 return -ENOMEM;
 714         }
 715
 716         /* queue up work for dlm_request_all_locks_worker */
 717         dlm_grab(dlm);  /* get an extra ref for the work item */
 718         dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
 719         item->u.ral.reco_master = lr->node_idx;
 720         item->u.ral.dead_node = lr->dead_node;
 721         spin_lock(&dlm->work_lock);
 722         list_add_tail(&item->list, &dlm->work_list);
 723         spin_unlock(&dlm->work_lock);
 724         schedule_work(&dlm->dispatched_work);
 725
 726         dlm_put(dlm);
 727         return 0;
 728 }
 729
 730 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
 731 {
 732         struct dlm_migratable_lockres *mres;
 733         struct dlm_lock_resource *res;
 734         struct dlm_ctxt *dlm;
 735         LIST_HEAD(resources);
 736         struct list_head *iter;
 737         int ret;
 738         u8 dead_node, reco_master;
 739
 740         dlm = item->dlm;
 741         dead_node = item->u.ral.dead_node;
 742         reco_master = item->u.ral.reco_master;
 743         mres = (struct dlm_migratable_lockres *)data;
 744
 745         if (dead_node != dlm->reco.dead_node ||
 746             reco_master != dlm->reco.new_master) {
 747                 /* show extra debug info if the recovery state is messed */
 748                 mlog(ML_ERROR, "%s: bad reco state: reco(dead=%u, master=%u), "
 749                      "request(dead=%u, master=%u)\n",
 750                      dlm->name, dlm->reco.dead_node, dlm->reco.new_master,
 751                      dead_node, reco_master);
 752                 mlog(ML_ERROR, "%s: name=%.*s master=%u locks=%u/%u flags=%u "
 753                      "entry[0]={c=%"MLFu64",l=%u,f=%u,t=%d,ct=%d,hb=%d,n=%u}\n",
 754                      dlm->name, mres->lockname_len, mres->lockname, mres->master,
 755                      mres->num_locks, mres->total_locks, mres->flags,
 756                      mres->ml[0].cookie, mres->ml[0].list, mres->ml[0].flags,
 757                      mres->ml[0].type, mres->ml[0].convert_type,
 758                      mres->ml[0].highest_blocked, mres->ml[0].node);
 759                 BUG();
 760         }
 761         BUG_ON(dead_node != dlm->reco.dead_node);
 762         BUG_ON(reco_master != dlm->reco.new_master);
 763
 764         /* lock resources should have already been moved to the
 765          * dlm->reco.resources list.  now move items from that list
 766          * to a temp list if the dead owner matches.  note that the
 767          * whole cluster recovers only one node at a time, so we
 768          * can safely move UNKNOWN lock resources for each recovery
 769          * session. */
 770         dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
 771
 772         /* now we can begin blasting lockreses without the dlm lock */
 773         list_for_each(iter, &resources) {
 774                 res = list_entry (iter, struct dlm_lock_resource, recovering);
 775                 ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
 776                                         DLM_MRES_RECOVERY);
 777                 if (ret < 0)
 778                         mlog_errno(ret);
 779         }
 780
 781         /* move the resources back to the list */
 782         spin_lock(&dlm->spinlock);
 783         list_splice_init(&resources, &dlm->reco.resources);
 784         spin_unlock(&dlm->spinlock);
 785
 786         ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
 787         if (ret < 0)
 788                 mlog_errno(ret);
 789
 790         free_page((unsigned long)data);
 791 }
 792
 793
 794 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
 795 {
 796         int ret, tmpret;
 797         struct dlm_reco_data_done done_msg;
 798
 799         memset(&done_msg, 0, sizeof(done_msg));
 800         done_msg.node_idx = dlm->node_num;
 801         done_msg.dead_node = dead_node;
 802         mlog(0, "sending DATA DONE message to %u, "
 803              "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
 804              done_msg.dead_node);
 805
 806         ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
 807                                  sizeof(done_msg), send_to, &tmpret);
 808         /* negative status is ignored by the caller */
 809         if (ret >= 0)
 810                 ret = tmpret;
 811         return ret;
 812 }
 813
 814
 815 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data)
 816 {
 817         struct dlm_ctxt *dlm = data;
 818         struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
 819         struct list_head *iter;
 820         struct dlm_reco_node_data *ndata = NULL;
 821         int ret = -EINVAL;
 822
 823         if (!dlm_grab(dlm))
 824                 return -EINVAL;
 825
 826         mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
 827              "node_idx=%u, this node=%u\n", done->dead_node,
 828              dlm->reco.dead_node, done->node_idx, dlm->node_num);
 829         BUG_ON(done->dead_node != dlm->reco.dead_node);
 830
 831         spin_lock(&dlm_reco_state_lock);
 832         list_for_each(iter, &dlm->reco.node_data) {
 833                 ndata = list_entry (iter, struct dlm_reco_node_data, list);
 834                 if (ndata->node_num != done->node_idx)
 835                         continue;
 836
 837                 switch (ndata->state) {
 838                         /* should have moved beyond INIT but not to FINALIZE yet */
 839                         case DLM_RECO_NODE_DATA_INIT:
 840                         case DLM_RECO_NODE_DATA_DEAD:
 841                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
 842                                 mlog(ML_ERROR, "bad ndata state for node %u:"
 843                                      " state=%d\n", ndata->node_num,
 844                                      ndata->state);
 845                                 BUG();
 846                                 break;
 847                         /* these states are possible at this point, anywhere along
 848                          * the line of recovery */
 849                         case DLM_RECO_NODE_DATA_DONE:
 850                         case DLM_RECO_NODE_DATA_RECEIVING:
 851                         case DLM_RECO_NODE_DATA_REQUESTED:
 852                         case DLM_RECO_NODE_DATA_REQUESTING:
 853                                 mlog(0, "node %u is DONE sending "
 854                                           "recovery data!\n",
 855                                           ndata->node_num);
 856
 857                                 ndata->state = DLM_RECO_NODE_DATA_DONE;
 858                                 ret = 0;
 859                                 break;
 860                 }
 861         }
 862         spin_unlock(&dlm_reco_state_lock);
 863
 864         /* wake the recovery thread, some node is done */
 865         if (!ret)
 866                 dlm_kick_recovery_thread(dlm);
 867
 868         if (ret < 0)
 869                 mlog(ML_ERROR, "failed to find recovery node data for node "
 870                      "%u\n", done->node_idx);
 871         dlm_put(dlm);
 872
 873         mlog(0, "leaving reco data done handler, ret=%d\n", ret);
 874         return ret;
 875 }
 876
 877 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
 878                                         struct list_head *list,
 879                                         u8 dead_node)
 880 {
 881         struct dlm_lock_resource *res;
 882         struct list_head *iter, *iter2;
 883         struct dlm_lock *lock;
 884
 885         spin_lock(&dlm->spinlock);
 886         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
 887                 res = list_entry (iter, struct dlm_lock_resource, recovering);
 888                 /* always prune any $RECOVERY entries for dead nodes,
 889                  * otherwise hangs can occur during later recovery */
 890                 if (dlm_is_recovery_lock(res->lockname.name,
 891                                          res->lockname.len)) {
 892                         spin_lock(&res->spinlock);
 893                         list_for_each_entry(lock, &res->granted, list) {
 894                                 if (lock->ml.node == dead_node) {
 895                                         mlog(0, "AHA! there was "
 896                                              "a $RECOVERY lock for dead "
 897                                              "node %u (%s)!\n",
 898                                              dead_node, dlm->name);
 899                                         list_del_init(&lock->list);
 900                                         dlm_lock_put(lock);
 901                                         break;
 902                                 }
 903                         }
 904                         spin_unlock(&res->spinlock);
 905                         continue;
 906                 }
 907
 908                 if (res->owner == dead_node) {
 909                         mlog(0, "found lockres owned by dead node while "
 910                                   "doing recovery for node %u. sending it.\n",
 911                                   dead_node);
 912                         list_del_init(&res->recovering);
 913                         list_add_tail(&res->recovering, list);
 914                 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
 915                         mlog(0, "found UNKNOWN owner while doing recovery "
 916                                   "for node %u. sending it.\n", dead_node);
 917                         list_del_init(&res->recovering);
 918                         list_add_tail(&res->recovering, list);
 919                 }
 920         }
 921         spin_unlock(&dlm->spinlock);
 922 }
 923
 924 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
 925 {
 926         int total_locks = 0;
 927         struct list_head *iter, *queue = &res->granted;
 928         int i;
 929
 930         for (i=0; i<3; i++) {
 931                 list_for_each(iter, queue)
 932                         total_locks++;
 933                 queue++;
 934         }
 935         return total_locks;
 936 }
 937
 938
 939 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
 940                                       struct dlm_migratable_lockres *mres,
 941                                       u8 send_to,
 942                                       struct dlm_lock_resource *res,
 943                                       int total_locks)
 944 {
 945         u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
 946         int mres_total_locks = be32_to_cpu(mres->total_locks);
 947         int sz, ret = 0, status = 0;
 948         u8 orig_flags = mres->flags,
 949            orig_master = mres->master;
 950
 951         BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
 952         if (!mres->num_locks)
 953                 return 0;
 954
 955         sz = sizeof(struct dlm_migratable_lockres) +
 956                 (mres->num_locks * sizeof(struct dlm_migratable_lock));
 957
 958         /* add an all-done flag if we reached the last lock */
 959         orig_flags = mres->flags;
 960         BUG_ON(total_locks > mres_total_locks);
 961         if (total_locks == mres_total_locks)
 962                 mres->flags |= DLM_MRES_ALL_DONE;
 963
 964         /* send it */
 965         ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
 966                                  sz, send_to, &status);
 967         if (ret < 0) {
 968                 /* XXX: negative status is not handled.
 969                  * this will end up killing this node. */
 970                 mlog_errno(ret);
 971         } else {
 972                 /* might get an -ENOMEM back here */
 973                 ret = status;
 974                 if (ret < 0) {
 975                         mlog_errno(ret);
 976
 977                         if (ret == -EFAULT) {
 978                                 mlog(ML_ERROR, "node %u told me to kill "
 979                                      "myself!\n", send_to);
 980                                 BUG();
 981                         }
 982                 }
 983         }
 984
 985         /* zero and reinit the message buffer */
 986         dlm_init_migratable_lockres(mres, res->lockname.name,
 987                                     res->lockname.len, mres_total_locks,
 988                                     mig_cookie, orig_flags, orig_master);
 989         return ret;
 990 }
 991
 992 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
 993                                         const char *lockname, int namelen,
 994                                         int total_locks, u64 cookie,
 995                                         u8 flags, u8 master)
 996 {
 997         /* mres here is one full page */
 998         memset(mres, 0, PAGE_SIZE);
 999         mres->lockname_len = namelen;
1000         memcpy(mres->lockname, lockname, namelen);
1001         mres->num_locks = 0;
1002         mres->total_locks = cpu_to_be32(total_locks);
1003         mres->mig_cookie = cpu_to_be64(cookie);
1004         mres->flags = flags;
1005         mres->master = master;
1006 }
1007
1008
1009 /* returns 1 if this lock fills the network structure,
1010  * 0 otherwise */
1011 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1012                                  struct dlm_migratable_lockres *mres, int queue)
1013 {
1014         struct dlm_migratable_lock *ml;
1015         int lock_num = mres->num_locks;
1016
1017         ml = &(mres->ml[lock_num]);
1018         ml->cookie = lock->ml.cookie;
1019         ml->type = lock->ml.type;
1020         ml->convert_type = lock->ml.convert_type;
1021         ml->highest_blocked = lock->ml.highest_blocked;
1022         ml->list = queue;
1023         if (lock->lksb) {
1024                 ml->flags = lock->lksb->flags;
1025                 /* send our current lvb */
1026                 if (ml->type == LKM_EXMODE ||
1027                     ml->type == LKM_PRMODE) {
1028                         /* if it is already set, this had better be a PR
1029                          * and it has to match */
1030                         if (mres->lvb[0] && (ml->type == LKM_EXMODE ||
1031                             memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
1032                                 mlog(ML_ERROR, "mismatched lvbs!\n");
1033                                 __dlm_print_one_lock_resource(lock->lockres);
1034                                 BUG();
1035                         }
1036                         memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1037                 }
1038         }
1039         ml->node = lock->ml.node;
1040         mres->num_locks++;
1041         /* we reached the max, send this network message */
1042         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1043                 return 1;
1044         return 0;
1045 }
1046
1047
1048 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1049                          struct dlm_migratable_lockres *mres,
1050                          u8 send_to, u8 flags)
1051 {
1052         struct list_head *queue, *iter;
1053         int total_locks, i;
1054         u64 mig_cookie = 0;
1055         struct dlm_lock *lock;
1056         int ret = 0;
1057
1058         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1059
1060         mlog(0, "sending to %u\n", send_to);
1061
1062         total_locks = dlm_num_locks_in_lockres(res);
1063         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1064                 /* rare, but possible */
1065                 mlog(0, "argh.  lockres has %d locks.  this will "
1066                           "require more than one network packet to "
1067                           "migrate\n", total_locks);
1068                 mig_cookie = dlm_get_next_mig_cookie();
1069         }
1070
1071         dlm_init_migratable_lockres(mres, res->lockname.name,
1072                                     res->lockname.len, total_locks,
1073                                     mig_cookie, flags, res->owner);
1074
1075         total_locks = 0;
1076         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1077                 queue = dlm_list_idx_to_ptr(res, i);
1078                 list_for_each(iter, queue) {
1079                         lock = list_entry (iter, struct dlm_lock, list);
1080
1081                         /* add another lock. */
1082                         total_locks++;
1083                         if (!dlm_add_lock_to_array(lock, mres, i))
1084                                 continue;
1085
1086                         /* this filled the lock message,
1087                          * we must send it immediately. */
1088                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1089                                                        res, total_locks);
1090                         if (ret < 0) {
1091                                 // TODO
1092                                 mlog(ML_ERROR, "dlm_send_mig_lockres_msg "
1093                                      "returned %d, TODO\n", ret);
1094                                 BUG();
1095                         }
1096                 }
1097         }
1098         /* flush any remaining locks */
1099         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1100         if (ret < 0) {
1101                 // TODO
1102                 mlog(ML_ERROR, "dlm_send_mig_lockres_msg returned %d, "
1103                      "TODO\n", ret);
1104                 BUG();
1105         }
1106         return ret;
1107 }
1108
1109
1110
1111 /*
1112  * this message will contain no more than one page worth of
1113  * recovery data, and it will work on only one lockres.
1114  * there may be many locks in this page, and we may need to wait
1115  * for additional packets to complete all the locks (rare, but
1116  * possible).
1117  */
1118 /*
1119  * NOTE: the allocation error cases here are scary
1120  * we really cannot afford to fail an alloc in recovery
1121  * do we spin?  returning an error only delays the problem really
1122  */
1123
1124 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data)
1125 {
1126         struct dlm_ctxt *dlm = data;
1127         struct dlm_migratable_lockres *mres =
1128                 (struct dlm_migratable_lockres *)msg->buf;
1129         int ret = 0;
1130         u8 real_master;
1131         char *buf = NULL;
1132         struct dlm_work_item *item = NULL;
1133         struct dlm_lock_resource *res = NULL;
1134
1135         if (!dlm_grab(dlm))
1136                 return -EINVAL;
1137
1138         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1139
1140         real_master = mres->master;
1141         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1142                 /* cannot migrate a lockres with no master */
1143                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1144         }
1145
1146         mlog(0, "%s message received from node %u\n",
1147                   (mres->flags & DLM_MRES_RECOVERY) ?
1148                   "recovery" : "migration", mres->master);
1149         if (mres->flags & DLM_MRES_ALL_DONE)
1150                 mlog(0, "all done flag.  all lockres data received!\n");
1151
1152         ret = -ENOMEM;
1153         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_KERNEL);
1154         item = kcalloc(1, sizeof(*item), GFP_KERNEL);
1155         if (!buf || !item)
1156                 goto leave;
1157
1158         /* lookup the lock to see if we have a secondary queue for this
1159          * already...  just add the locks in and this will have its owner
1160          * and RECOVERY flag changed when it completes. */
1161         res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1162         if (res) {
1163                 /* this will get a ref on res */
1164                 /* mark it as recovering/migrating and hash it */
1165                 spin_lock(&res->spinlock);
1166                 if (mres->flags & DLM_MRES_RECOVERY) {
1167                         res->state |= DLM_LOCK_RES_RECOVERING;
1168                 } else {
1169                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1170                                 /* this is at least the second
1171                                  * lockres message */
1172                                 mlog(0, "lock %.*s is already migrating\n",
1173                                           mres->lockname_len,
1174                                           mres->lockname);
1175                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1176                                 /* caller should BUG */
1177                                 mlog(ML_ERROR, "node is attempting to migrate "
1178                                      "lock %.*s, but marked as recovering!\n",
1179                                      mres->lockname_len, mres->lockname);
1180                                 ret = -EFAULT;
1181                                 spin_unlock(&res->spinlock);
1182                                 goto leave;
1183                         }
1184                         res->state |= DLM_LOCK_RES_MIGRATING;
1185                 }
1186                 spin_unlock(&res->spinlock);
1187         } else {
1188                 /* need to allocate, just like if it was
1189                  * mastered here normally  */
1190                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1191                 if (!res)
1192                         goto leave;
1193
1194                 /* to match the ref that we would have gotten if
1195                  * dlm_lookup_lockres had succeeded */
1196                 dlm_lockres_get(res);
1197
1198                 /* mark it as recovering/migrating and hash it */
1199                 if (mres->flags & DLM_MRES_RECOVERY)
1200                         res->state |= DLM_LOCK_RES_RECOVERING;
1201                 else
1202                         res->state |= DLM_LOCK_RES_MIGRATING;
1203
1204                 spin_lock(&dlm->spinlock);
1205                 __dlm_insert_lockres(dlm, res);
1206                 spin_unlock(&dlm->spinlock);
1207
1208                 /* now that the new lockres is inserted,
1209                  * make it usable by other processes */
1210                 spin_lock(&res->spinlock);
1211                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1212                 spin_unlock(&res->spinlock);
1213
1214                 /* add an extra ref for just-allocated lockres
1215                  * otherwise the lockres will be purged immediately */
1216                 dlm_lockres_get(res);
1217
1218         }
1219
1220         /* at this point we have allocated everything we need,
1221          * and we have a hashed lockres with an extra ref and
1222          * the proper res->state flags. */
1223         ret = 0;
1224         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1225                 /* migration cannot have an unknown master */
1226                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1227                 mlog(0, "recovery has passed me a lockres with an "
1228                           "unknown owner.. will need to requery: "
1229                           "%.*s\n", mres->lockname_len, mres->lockname);
1230         } else {
1231                 spin_lock(&res->spinlock);
1232                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1233                 spin_unlock(&res->spinlock);
1234         }
1235
1236         /* queue up work for dlm_mig_lockres_worker */
1237         dlm_grab(dlm);  /* get an extra ref for the work item */
1238         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1239         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1240         item->u.ml.lockres = res; /* already have a ref */
1241         item->u.ml.real_master = real_master;
1242         spin_lock(&dlm->work_lock);
1243         list_add_tail(&item->list, &dlm->work_list);
1244         spin_unlock(&dlm->work_lock);
1245         schedule_work(&dlm->dispatched_work);
1246
1247 leave:
1248         dlm_put(dlm);
1249         if (ret < 0) {
1250                 if (buf)
1251                         kfree(buf);
1252                 if (item)
1253                         kfree(item);
1254         }
1255
1256         mlog_exit(ret);
1257         return ret;
1258 }
1259
1260
1261 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1262 {
1263         struct dlm_ctxt *dlm = data;
1264         struct dlm_migratable_lockres *mres;
1265         int ret = 0;
1266         struct dlm_lock_resource *res;
1267         u8 real_master;
1268
1269         dlm = item->dlm;
1270         mres = (struct dlm_migratable_lockres *)data;
1271
1272         res = item->u.ml.lockres;
1273         real_master = item->u.ml.real_master;
1274
1275         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1276                 /* this case is super-rare. only occurs if
1277                  * node death happens during migration. */
1278 again:
1279                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1280                 if (ret < 0) {
1281                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1282                                   ret);
1283                         goto again;
1284                 }
1285                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1286                         mlog(0, "lockres %.*s not claimed.  "
1287                                    "this node will take it.\n",
1288                                    res->lockname.len, res->lockname.name);
1289                 } else {
1290                         mlog(0, "master needs to respond to sender "
1291                                   "that node %u still owns %.*s\n",
1292                                   real_master, res->lockname.len,
1293                                   res->lockname.name);
1294                         /* cannot touch this lockres */
1295                         goto leave;
1296                 }
1297         }
1298
1299         ret = dlm_process_recovery_data(dlm, res, mres);
1300         if (ret < 0)
1301                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1302         else
1303                 mlog(0, "dlm_process_recovery_data succeeded\n");
1304
1305         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1306                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1307                 ret = dlm_finish_migration(dlm, res, mres->master);
1308                 if (ret < 0)
1309                         mlog_errno(ret);
1310         }
1311
1312 leave:
1313         kfree(data);
1314         mlog_exit(ret);
1315 }
1316
1317
1318
1319 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1320                                       struct dlm_lock_resource *res,
1321                                       u8 *real_master)
1322 {
1323         struct dlm_node_iter iter;
1324         int nodenum;
1325         int ret = 0;
1326
1327         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1328
1329         /* we only reach here if one of the two nodes in a
1330          * migration died while the migration was in progress.
1331          * at this point we need to requery the master.  we
1332          * know that the new_master got as far as creating
1333          * an mle on at least one node, but we do not know
1334          * if any nodes had actually cleared the mle and set
1335          * the master to the new_master.  the old master
1336          * is supposed to set the owner to UNKNOWN in the
1337          * event of a new_master death, so the only possible
1338          * responses that we can get from nodes here are
1339          * that the master is new_master, or that the master
1340          * is UNKNOWN.
1341          * if all nodes come back with UNKNOWN then we know
1342          * the lock needs remastering here.
1343          * if any node comes back with a valid master, check
1344          * to see if that master is the one that we are
1345          * recovering.  if so, then the new_master died and
1346          * we need to remaster this lock.  if not, then the
1347          * new_master survived and that node will respond to
1348          * other nodes about the owner.
1349          * if there is an owner, this node needs to dump this
1350          * lockres and alert the sender that this lockres
1351          * was rejected. */
1352         spin_lock(&dlm->spinlock);
1353         dlm_node_iter_init(dlm->domain_map, &iter);
1354         spin_unlock(&dlm->spinlock);
1355
1356         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1357                 /* do not send to self */
1358                 if (nodenum == dlm->node_num)
1359                         continue;
1360                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1361                 if (ret < 0) {
1362                         mlog_errno(ret);
1363                         BUG();
1364                         /* TODO: need to figure a way to restart this */
1365                 }
1366                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1367                         mlog(0, "lock master is %u\n", *real_master);
1368                         break;
1369                 }
1370         }
1371         return ret;
1372 }
1373
1374
1375 static int dlm_do_master_requery(struct dlm_ctxt *dlm,
1376                                  struct dlm_lock_resource *res,
1377                                  u8 nodenum, u8 *real_master)
1378 {
1379         int ret = -EINVAL;
1380         struct dlm_master_requery req;
1381         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1382
1383         memset(&req, 0, sizeof(req));
1384         req.node_idx = dlm->node_num;
1385         req.namelen = res->lockname.len;
1386         memcpy(req.name, res->lockname.name, res->lockname.len);
1387
1388         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1389                                  &req, sizeof(req), nodenum, &status);
1390         /* XXX: negative status not handled properly here. */
1391         if (ret < 0)
1392                 mlog_errno(ret);
1393         else {
1394                 BUG_ON(status < 0);
1395                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1396                 *real_master = (u8) (status & 0xff);
1397                 mlog(0, "node %u responded to master requery with %u\n",
1398                           nodenum, *real_master);
1399                 ret = 0;
1400         }
1401         return ret;
1402 }
1403
1404
1405 /* this function cannot error, so unless the sending
1406  * or receiving of the message failed, the owner can
1407  * be trusted */
1408 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data)
1409 {
1410         struct dlm_ctxt *dlm = data;
1411         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1412         struct dlm_lock_resource *res = NULL;
1413         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1414         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1415
1416         if (!dlm_grab(dlm)) {
1417                 /* since the domain has gone away on this
1418                  * node, the proper response is UNKNOWN */
1419                 return master;
1420         }
1421
1422         spin_lock(&dlm->spinlock);
1423         res = __dlm_lookup_lockres(dlm, req->name, req->namelen);
1424         if (res) {
1425                 spin_lock(&res->spinlock);
1426                 master = res->owner;
1427                 if (master == dlm->node_num) {
1428                         int ret = dlm_dispatch_assert_master(dlm, res,
1429                                                              0, 0, flags);
1430                         if (ret < 0) {
1431                                 mlog_errno(-ENOMEM);
1432                                 /* retry!? */
1433                                 BUG();
1434                         }
1435                 }
1436                 spin_unlock(&res->spinlock);
1437         }
1438         spin_unlock(&dlm->spinlock);
1439
1440         dlm_put(dlm);
1441         return master;
1442 }
1443
1444 static inline struct list_head *
1445 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1446 {
1447         struct list_head *ret;
1448         BUG_ON(list_num < 0);
1449         BUG_ON(list_num > 2);
1450         ret = &(res->granted);
1451         ret += list_num;
1452         return ret;
1453 }
1454 /* TODO: do ast flush business
1455  * TODO: do MIGRATING and RECOVERING spinning
1456  */
1457
1458 /*
1459 * NOTE about in-flight requests during migration:
1460 *
1461 * Before attempting the migrate, the master has marked the lockres as
1462 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1463 * requests either got queued before the MIGRATING flag got set, in which
1464 * case the lock data will reflect the change and a return message is on
1465 * the way, or the request failed to get in before MIGRATING got set.  In
1466 * this case, the caller will be told to spin and wait for the MIGRATING
1467 * flag to be dropped, then recheck the master.
1468 * This holds true for the convert, cancel and unlock cases, and since lvb
1469 * updates are tied to these same messages, it applies to lvb updates as
1470 * well.  For the lock case, there is no way a lock can be on the master
1471 * queue and not be on the secondary queue since the lock is always added
1472 * locally first.  This means that the new target node will never be sent
1473 * a lock that he doesn't already have on the list.
1474 * In total, this means that the local lock is correct and should not be
1475 * updated to match the one sent by the master.  Any messages sent back
1476 * from the master before the MIGRATING flag will bring the lock properly
1477 * up-to-date, and the change will be ordered properly for the waiter.
1478 * We will *not* attempt to modify the lock underneath the waiter.
1479 */
1480
1481 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1482                                      struct dlm_lock_resource *res,
1483                                      struct dlm_migratable_lockres *mres)
1484 {
1485         struct dlm_migratable_lock *ml;
1486         struct list_head *queue;
1487         struct dlm_lock *newlock = NULL;
1488         struct dlm_lockstatus *lksb = NULL;
1489         int ret = 0;
1490         int i;
1491         struct list_head *iter;
1492         struct dlm_lock *lock = NULL;
1493
1494         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1495         for (i=0; i<mres->num_locks; i++) {
1496                 ml = &(mres->ml[i]);
1497                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1498                 newlock = NULL;
1499                 lksb = NULL;
1500
1501                 queue = dlm_list_num_to_pointer(res, ml->list);
1502
1503                 /* if the lock is for the local node it needs to
1504                  * be moved to the proper location within the queue.
1505                  * do not allocate a new lock structure. */
1506                 if (ml->node == dlm->node_num) {
1507                         /* MIGRATION ONLY! */
1508                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1509
1510                         spin_lock(&res->spinlock);
1511                         list_for_each(iter, queue) {
1512                                 lock = list_entry (iter, struct dlm_lock, list);
1513                                 if (lock->ml.cookie != ml->cookie)
1514                                         lock = NULL;
1515                                 else
1516                                         break;
1517                         }
1518
1519                         /* lock is always created locally first, and
1520                          * destroyed locally last.  it must be on the list */
1521                         if (!lock) {
1522                                 mlog(ML_ERROR, "could not find local lock "
1523                                                "with cookie %"MLFu64"!\n",
1524                                      ml->cookie);
1525                                 BUG();
1526                         }
1527                         BUG_ON(lock->ml.node != ml->node);
1528
1529                         /* see NOTE above about why we do not update
1530                          * to match the master here */
1531
1532                         /* move the lock to its proper place */
1533                         /* do not alter lock refcount.  switching lists. */
1534                         list_del_init(&lock->list);
1535                         list_add_tail(&lock->list, queue);
1536                         spin_unlock(&res->spinlock);
1537
1538                         mlog(0, "just reordered a local lock!\n");
1539                         continue;
1540                 }
1541
1542                 /* lock is for another node. */
1543                 newlock = dlm_new_lock(ml->type, ml->node,
1544                                        be64_to_cpu(ml->cookie), NULL);
1545                 if (!newlock) {
1546                         ret = -ENOMEM;
1547                         goto leave;
1548                 }
1549                 lksb = newlock->lksb;
1550                 dlm_lock_attach_lockres(newlock, res);
1551
1552                 if (ml->convert_type != LKM_IVMODE) {
1553                         BUG_ON(queue != &res->converting);
1554                         newlock->ml.convert_type = ml->convert_type;
1555                 }
1556                 lksb->flags |= (ml->flags &
1557                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1558
1559                 if (mres->lvb[0]) {
1560                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1561                                 /* other node was trying to update
1562                                  * lvb when node died.  recreate the
1563                                  * lksb with the updated lvb. */
1564                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1565                         } else {
1566                                 /* otherwise, the node is sending its
1567                                  * most recent valid lvb info */
1568                                 BUG_ON(ml->type != LKM_EXMODE &&
1569                                        ml->type != LKM_PRMODE);
1570                                 if (res->lvb[0] && (ml->type == LKM_EXMODE ||
1571                                     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1572                                         mlog(ML_ERROR, "received bad lvb!\n");
1573                                         __dlm_print_one_lock_resource(res);
1574                                         BUG();
1575                                 }
1576                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1577                         }
1578                 }
1579
1580
1581                 /* NOTE:
1582                  * wrt lock queue ordering and recovery:
1583                  *    1. order of locks on granted queue is
1584                  *       meaningless.
1585                  *    2. order of locks on converting queue is
1586                  *       LOST with the node death.  sorry charlie.
1587                  *    3. order of locks on the blocked queue is
1588                  *       also LOST.
1589                  * order of locks does not affect integrity, it
1590                  * just means that a lock request may get pushed
1591                  * back in line as a result of the node death.
1592                  * also note that for a given node the lock order
1593                  * for its secondary queue locks is preserved
1594                  * relative to each other, but clearly *not*
1595                  * preserved relative to locks from other nodes.
1596                  */
1597                 spin_lock(&res->spinlock);
1598                 dlm_lock_get(newlock);
1599                 list_add_tail(&newlock->list, queue);
1600                 spin_unlock(&res->spinlock);
1601         }
1602         mlog(0, "done running all the locks\n");
1603
1604 leave:
1605         if (ret < 0) {
1606                 mlog_errno(ret);
1607                 if (newlock)
1608                         dlm_lock_put(newlock);
1609         }
1610
1611         mlog_exit(ret);
1612         return ret;
1613 }
1614
1615 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1616                                        struct dlm_lock_resource *res)
1617 {
1618         int i;
1619         struct list_head *queue, *iter, *iter2;
1620         struct dlm_lock *lock;
1621
1622         res->state |= DLM_LOCK_RES_RECOVERING;
1623         if (!list_empty(&res->recovering))
1624                 list_del_init(&res->recovering);
1625         list_add_tail(&res->recovering, &dlm->reco.resources);
1626
1627         /* find any pending locks and put them back on proper list */
1628         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
1629                 queue = dlm_list_idx_to_ptr(res, i);
1630                 list_for_each_safe(iter, iter2, queue) {
1631                         lock = list_entry (iter, struct dlm_lock, list);
1632                         dlm_lock_get(lock);
1633                         if (lock->convert_pending) {
1634                                 /* move converting lock back to granted */
1635                                 BUG_ON(i != DLM_CONVERTING_LIST);
1636                                 mlog(0, "node died with convert pending "
1637                                      "on %.*s. move back to granted list.\n",
1638                                      res->lockname.len, res->lockname.name);
1639                                 dlm_revert_pending_convert(res, lock);
1640                                 lock->convert_pending = 0;
1641                         } else if (lock->lock_pending) {
1642                                 /* remove pending lock requests completely */
1643                                 BUG_ON(i != DLM_BLOCKED_LIST);
1644                                 mlog(0, "node died with lock pending "
1645                                      "on %.*s. remove from blocked list and skip.\n",
1646                                      res->lockname.len, res->lockname.name);
1647                                 /* lock will be floating until ref in
1648                                  * dlmlock_remote is freed after the network
1649                                  * call returns.  ok for it to not be on any
1650                                  * list since no ast can be called
1651                                  * (the master is dead). */
1652                                 dlm_revert_pending_lock(res, lock);
1653                                 lock->lock_pending = 0;
1654                         } else if (lock->unlock_pending) {
1655                                 /* if an unlock was in progress, treat as
1656                                  * if this had completed successfully
1657                                  * before sending this lock state to the
1658                                  * new master.  note that the dlm_unlock
1659                                  * call is still responsible for calling
1660                                  * the unlockast.  that will happen after
1661                                  * the network call times out.  for now,
1662                                  * just move lists to prepare the new
1663                                  * recovery master.  */
1664                                 BUG_ON(i != DLM_GRANTED_LIST);
1665                                 mlog(0, "node died with unlock pending "
1666                                      "on %.*s. remove from blocked list and skip.\n",
1667                                      res->lockname.len, res->lockname.name);
1668                                 dlm_commit_pending_unlock(res, lock);
1669                                 lock->unlock_pending = 0;
1670                         } else if (lock->cancel_pending) {
1671                                 /* if a cancel was in progress, treat as
1672                                  * if this had completed successfully
1673                                  * before sending this lock state to the
1674                                  * new master */
1675                                 BUG_ON(i != DLM_CONVERTING_LIST);
1676                                 mlog(0, "node died with cancel pending "
1677                                      "on %.*s. move back to granted list.\n",
1678                                      res->lockname.len, res->lockname.name);
1679                                 dlm_commit_pending_cancel(res, lock);
1680                                 lock->cancel_pending = 0;
1681                         }
1682                         dlm_lock_put(lock);
1683                 }
1684         }
1685 }
1686
1687
1688
1689 /* removes all recovered locks from the recovery list.
1690  * sets the res->owner to the new master.
1691  * unsets the RECOVERY flag and wakes waiters. */
1692 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
1693                                               u8 dead_node, u8 new_master)
1694 {
1695         int i;
1696         struct list_head *iter, *iter2;
1697         struct hlist_node *hash_iter;
1698         struct hlist_head *bucket;
1699
1700         struct dlm_lock_resource *res;
1701
1702         mlog_entry_void();
1703
1704         assert_spin_locked(&dlm->spinlock);
1705
1706         list_for_each_safe(iter, iter2, &dlm->reco.resources) {
1707                 res = list_entry (iter, struct dlm_lock_resource, recovering);
1708                 if (res->owner == dead_node) {
1709                         list_del_init(&res->recovering);
1710                         spin_lock(&res->spinlock);
1711                         dlm_change_lockres_owner(dlm, res, new_master);
1712                         res->state &= ~DLM_LOCK_RES_RECOVERING;
1713                         __dlm_dirty_lockres(dlm, res);
1714                         spin_unlock(&res->spinlock);
1715                         wake_up(&res->wq);
1716                 }
1717         }
1718
1719         /* this will become unnecessary eventually, but
1720          * for now we need to run the whole hash, clear
1721          * the RECOVERING state and set the owner
1722          * if necessary */
1723         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
1724                 bucket = &(dlm->lockres_hash[i]);
1725                 hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
1726                         if (res->state & DLM_LOCK_RES_RECOVERING) {
1727                                 if (res->owner == dead_node) {
1728                                         mlog(0, "(this=%u) res %.*s owner=%u "
1729                                              "was not on recovering list, but "
1730                                              "clearing state anyway\n",
1731                                              dlm->node_num, res->lockname.len,
1732                                              res->lockname.name, new_master);
1733                                 } else if (res->owner == dlm->node_num) {
1734                                         mlog(0, "(this=%u) res %.*s owner=%u "
1735                                              "was not on recovering list, "
1736                                              "owner is THIS node, clearing\n",
1737                                              dlm->node_num, res->lockname.len,
1738                                              res->lockname.name, new_master);
1739                                 } else
1740                                         continue;
1741
1742                                 spin_lock(&res->spinlock);
1743                                 dlm_change_lockres_owner(dlm, res, new_master);
1744                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
1745                                 __dlm_dirty_lockres(dlm, res);
1746                                 spin_unlock(&res->spinlock);
1747                                 wake_up(&res->wq);
1748                         }
1749                 }
1750         }
1751 }
1752
1753 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
1754 {
1755         if (local) {
1756                 if (lock->ml.type != LKM_EXMODE &&
1757                     lock->ml.type != LKM_PRMODE)
1758                         return 1;
1759         } else if (lock->ml.type == LKM_EXMODE)
1760                 return 1;
1761         return 0;
1762 }
1763
1764 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
1765                                struct dlm_lock_resource *res, u8 dead_node)
1766 {
1767         struct list_head *iter, *queue;
1768         struct dlm_lock *lock;
1769         int blank_lvb = 0, local = 0;
1770         int i;
1771         u8 search_node;
1772
1773         assert_spin_locked(&dlm->spinlock);
1774         assert_spin_locked(&res->spinlock);
1775
1776         if (res->owner == dlm->node_num)
1777                 /* if this node owned the lockres, and if the dead node
1778                  * had an EX when he died, blank out the lvb */
1779                 search_node = dead_node;
1780         else {
1781                 /* if this is a secondary lockres, and we had no EX or PR
1782                  * locks granted, we can no longer trust the lvb */
1783                 search_node = dlm->node_num;
1784                 local = 1;  /* check local state for valid lvb */
1785         }
1786
1787         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
1788                 queue = dlm_list_idx_to_ptr(res, i);
1789                 list_for_each(iter, queue) {
1790                         lock = list_entry (iter, struct dlm_lock, list);
1791                         if (lock->ml.node == search_node) {
1792                                 if (dlm_lvb_needs_invalidation(lock, local)) {
1793                                         /* zero the lksb lvb and lockres lvb */
1794                                         blank_lvb = 1;
1795                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
1796                                 }
1797                         }
1798                 }
1799         }
1800
1801         if (blank_lvb) {
1802                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
1803                      res->lockname.len, res->lockname.name, dead_node);
1804                 memset(res->lvb, 0, DLM_LVB_LEN);
1805         }
1806 }
1807
1808 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
1809                                 struct dlm_lock_resource *res, u8 dead_node)
1810 {
1811         struct list_head *iter, *tmpiter;
1812         struct dlm_lock *lock;
1813
1814         /* this node is the lockres master:
1815          * 1) remove any stale locks for the dead node
1816          * 2) if the dead node had an EX when he died, blank out the lvb
1817          */
1818         assert_spin_locked(&dlm->spinlock);
1819         assert_spin_locked(&res->spinlock);
1820
1821         /* TODO: check pending_asts, pending_basts here */
1822         list_for_each_safe(iter, tmpiter, &res->granted) {
1823                 lock = list_entry (iter, struct dlm_lock, list);
1824                 if (lock->ml.node == dead_node) {
1825                         list_del_init(&lock->list);
1826                         dlm_lock_put(lock);
1827                 }
1828         }
1829         list_for_each_safe(iter, tmpiter, &res->converting) {
1830                 lock = list_entry (iter, struct dlm_lock, list);
1831                 if (lock->ml.node == dead_node) {
1832                         list_del_init(&lock->list);
1833                         dlm_lock_put(lock);
1834                 }
1835         }
1836         list_for_each_safe(iter, tmpiter, &res->blocked) {
1837                 lock = list_entry (iter, struct dlm_lock, list);
1838                 if (lock->ml.node == dead_node) {
1839                         list_del_init(&lock->list);
1840                         dlm_lock_put(lock);
1841                 }
1842         }
1843
1844         /* do not kick thread yet */
1845         __dlm_dirty_lockres(dlm, res);
1846 }
1847
1848 /* if this node is the recovery master, and there are no
1849  * locks for a given lockres owned by this node that are in
1850  * either PR or EX mode, zero out the lvb before requesting.
1851  *
1852  */
1853
1854
1855 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
1856 {
1857         struct hlist_node *iter;
1858         struct dlm_lock_resource *res;
1859         int i;
1860         struct hlist_head *bucket;
1861         struct dlm_lock *lock;
1862
1863
1864         /* purge any stale mles */
1865         dlm_clean_master_list(dlm, dead_node);
1866
1867         /*
1868          * now clean up all lock resources.  there are two rules:
1869          *
1870          * 1) if the dead node was the master, move the lockres
1871          *    to the recovering list.  set the RECOVERING flag.
1872          *    this lockres needs to be cleaned up before it can
1873          *    be used further.
1874          *
1875          * 2) if this node was the master, remove all locks from
1876          *    each of the lockres queues that were owned by the
1877          *    dead node.  once recovery finishes, the dlm thread
1878          *    can be kicked again to see if any ASTs or BASTs
1879          *    need to be fired as a result.
1880          */
1881         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
1882                 bucket = &(dlm->lockres_hash[i]);
1883                 hlist_for_each_entry(res, iter, bucket, hash_node) {
1884                         /* always prune any $RECOVERY entries for dead nodes,
1885                          * otherwise hangs can occur during later recovery */
1886                         if (dlm_is_recovery_lock(res->lockname.name,
1887                                                  res->lockname.len)) {
1888                                 spin_lock(&res->spinlock);
1889                                 list_for_each_entry(lock, &res->granted, list) {
1890                                         if (lock->ml.node == dead_node) {
1891                                                 mlog(0, "AHA! there was "
1892                                                      "a $RECOVERY lock for dead "
1893                                                      "node %u (%s)!\n",
1894                                                      dead_node, dlm->name);
1895                                                 list_del_init(&lock->list);
1896                                                 dlm_lock_put(lock);
1897                                                 break;
1898                                         }
1899                                 }
1900                                 spin_unlock(&res->spinlock);
1901                                 continue;
1902                         }
1903                         spin_lock(&res->spinlock);
1904                         /* zero the lvb if necessary */
1905                         dlm_revalidate_lvb(dlm, res, dead_node);
1906                         if (res->owner == dead_node)
1907                                 dlm_move_lockres_to_recovery_list(dlm, res);
1908                         else if (res->owner == dlm->node_num) {
1909                                 dlm_free_dead_locks(dlm, res, dead_node);
1910                                 __dlm_lockres_calc_usage(dlm, res);
1911                         }
1912                         spin_unlock(&res->spinlock);
1913                 }
1914         }
1915
1916 }
1917
1918 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
1919 {
1920         assert_spin_locked(&dlm->spinlock);
1921
1922         /* check to see if the node is already considered dead */
1923         if (!test_bit(idx, dlm->live_nodes_map)) {
1924                 mlog(0, "for domain %s, node %d is already dead. "
1925                      "another node likely did recovery already.\n",
1926                      dlm->name, idx);
1927                 return;
1928         }
1929
1930         /* check to see if we do not care about this node */
1931         if (!test_bit(idx, dlm->domain_map)) {
1932                 /* This also catches the case that we get a node down
1933                  * but haven't joined the domain yet. */
1934                 mlog(0, "node %u already removed from domain!\n", idx);
1935                 return;
1936         }
1937
1938         clear_bit(idx, dlm->live_nodes_map);
1939
1940         /* Clean up join state on node death. */
1941         if (dlm->joining_node == idx) {
1942                 mlog(0, "Clearing join state for node %u\n", idx);
1943                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1944         }
1945
1946         /* make sure local cleanup occurs before the heartbeat events */
1947         if (!test_bit(idx, dlm->recovery_map))
1948                 dlm_do_local_recovery_cleanup(dlm, idx);
1949
1950         /* notify anything attached to the heartbeat events */
1951         dlm_hb_event_notify_attached(dlm, idx, 0);
1952
1953         mlog(0, "node %u being removed from domain map!\n", idx);
1954         clear_bit(idx, dlm->domain_map);
1955         /* wake up migration waiters if a node goes down.
1956          * perhaps later we can genericize this for other waiters. */
1957         wake_up(&dlm->migration_wq);
1958
1959         if (test_bit(idx, dlm->recovery_map))
1960                 mlog(0, "domain %s, node %u already added "
1961                      "to recovery map!\n", dlm->name, idx);
1962         else
1963                 set_bit(idx, dlm->recovery_map);
1964 }
1965
1966 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
1967 {
1968         struct dlm_ctxt *dlm = data;
1969
1970         if (!dlm_grab(dlm))
1971                 return;
1972
1973         spin_lock(&dlm->spinlock);
1974         __dlm_hb_node_down(dlm, idx);
1975         spin_unlock(&dlm->spinlock);
1976
1977         dlm_put(dlm);
1978 }
1979
1980 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
1981 {
1982         struct dlm_ctxt *dlm = data;
1983
1984         if (!dlm_grab(dlm))
1985                 return;
1986
1987         spin_lock(&dlm->spinlock);
1988         set_bit(idx, dlm->live_nodes_map);
1989         /* do NOT notify mle attached to the heartbeat events.
1990          * new nodes are not interesting in mastery until joined. */
1991         spin_unlock(&dlm->spinlock);
1992
1993         dlm_put(dlm);
1994 }
1995
1996 static void dlm_reco_ast(void *astdata)
1997 {
1998         struct dlm_ctxt *dlm = astdata;
1999         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2000              dlm->node_num, dlm->name);
2001 }
2002 static void dlm_reco_bast(void *astdata, int blocked_type)
2003 {
2004         struct dlm_ctxt *dlm = astdata;
2005         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2006              dlm->node_num, dlm->name);
2007 }
2008 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2009 {
2010         mlog(0, "unlockast for recovery lock fired!\n");
2011 }
2012
2013 /*
2014  * dlm_pick_recovery_master will continually attempt to use
2015  * dlmlock() on the special "$RECOVERY" lockres with the
2016  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2017  * this function on each node racing to become the recovery
2018  * master will not stop attempting this until either:
2019  * a) this node gets the EX (and becomes the recovery master),
2020  * or b) dlm->reco.new_master gets set to some nodenum
2021  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2022  * so each time a recovery master is needed, the entire cluster
2023  * will sync at this point.  if the new master dies, that will
2024  * be detected in dlm_do_recovery */
2025 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2026 {
2027         enum dlm_status ret;
2028         struct dlm_lockstatus lksb;
2029         int status = -EINVAL;
2030
2031         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2032              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2033 again:
2034         memset(&lksb, 0, sizeof(lksb));
2035
2036         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2037                       DLM_RECOVERY_LOCK_NAME, dlm_reco_ast, dlm, dlm_reco_bast);
2038
2039         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2040              dlm->name, ret, lksb.status);
2041
2042         if (ret == DLM_NORMAL) {
2043                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2044                      dlm->name, dlm->node_num);
2045
2046                 /* got the EX lock.  check to see if another node
2047                  * just became the reco master */
2048                 if (dlm_reco_master_ready(dlm)) {
2049                         mlog(0, "%s: got reco EX lock, but %u will "
2050                              "do the recovery\n", dlm->name,
2051                              dlm->reco.new_master);
2052                         status = -EEXIST;
2053                 } else {
2054                         status = 0;
2055
2056                         /* see if recovery was already finished elsewhere */
2057                         spin_lock(&dlm->spinlock);
2058                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2059                                 status = -EINVAL;
2060                                 mlog(0, "%s: got reco EX lock, but "
2061                                      "node got recovered already\n", dlm->name);
2062                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2063                                         mlog(ML_ERROR, "%s: new master is %u "
2064                                              "but no dead node!\n",
2065                                              dlm->name, dlm->reco.new_master);
2066                                         BUG();
2067                                 }
2068                         }
2069                         spin_unlock(&dlm->spinlock);
2070                 }
2071
2072                 /* if this node has actually become the recovery master,
2073                  * set the master and send the messages to begin recovery */
2074                 if (!status) {
2075                         mlog(0, "%s: dead=%u, this=%u, sending "
2076                              "begin_reco now\n", dlm->name,
2077                              dlm->reco.dead_node, dlm->node_num);
2078                         status = dlm_send_begin_reco_message(dlm,
2079                                       dlm->reco.dead_node);
2080                         /* this always succeeds */
2081                         BUG_ON(status);
2082
2083                         /* set the new_master to this node */
2084                         spin_lock(&dlm->spinlock);
2085                         dlm->reco.new_master = dlm->node_num;
2086                         spin_unlock(&dlm->spinlock);
2087                 }
2088
2089                 /* recovery lock is a special case.  ast will not get fired,
2090                  * so just go ahead and unlock it. */
2091                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2092                 if (ret == DLM_DENIED) {
2093                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2094                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2095                 }
2096                 if (ret != DLM_NORMAL) {
2097                         /* this would really suck. this could only happen
2098                          * if there was a network error during the unlock
2099                          * because of node death.  this means the unlock
2100                          * is actually "done" and the lock structure is
2101                          * even freed.  we can continue, but only
2102                          * because this specific lock name is special. */
2103                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2104                 }
2105         } else if (ret == DLM_NOTQUEUED) {
2106                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2107                      dlm->name, dlm->node_num);
2108                 /* another node is master. wait on
2109                  * reco.new_master != O2NM_INVALID_NODE_NUM
2110                  * for at most one second */
2111                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2112                                          dlm_reco_master_ready(dlm),
2113                                          msecs_to_jiffies(1000));
2114                 if (!dlm_reco_master_ready(dlm)) {
2115                         mlog(0, "%s: reco master taking awhile\n",
2116                              dlm->name);
2117                         goto again;
2118                 }
2119                 /* another node has informed this one that it is reco master */
2120                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2121                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2122                 status = -EEXIST;
2123         } else {
2124                 struct dlm_lock_resource *res;
2125
2126                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2127                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2128                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2129                      dlm_errname(lksb.status));
2130                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2131                                          DLM_RECOVERY_LOCK_NAME_LEN);
2132                 if (res) {
2133                         dlm_print_one_lock_resource(res);
2134                         dlm_lockres_put(res);
2135                 } else {
2136                         mlog(ML_ERROR, "recovery lock not found\n");
2137                 }
2138                 BUG();
2139         }
2140
2141         return status;
2142 }
2143
2144 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2145 {
2146         struct dlm_begin_reco br;
2147         int ret = 0;
2148         struct dlm_node_iter iter;
2149         int nodenum;
2150         int status;
2151
2152         mlog_entry("%u\n", dead_node);
2153
2154         mlog(0, "dead node is %u\n", dead_node);
2155
2156         spin_lock(&dlm->spinlock);
2157         dlm_node_iter_init(dlm->domain_map, &iter);
2158         spin_unlock(&dlm->spinlock);
2159
2160         clear_bit(dead_node, iter.node_map);
2161
2162         memset(&br, 0, sizeof(br));
2163         br.node_idx = dlm->node_num;
2164         br.dead_node = dead_node;
2165
2166         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2167                 ret = 0;
2168                 if (nodenum == dead_node) {
2169                         mlog(0, "not sending begin reco to dead node "
2170                                   "%u\n", dead_node);
2171                         continue;
2172                 }
2173                 if (nodenum == dlm->node_num) {
2174                         mlog(0, "not sending begin reco to self\n");
2175                         continue;
2176                 }
2177 retry:
2178                 ret = -EINVAL;
2179                 mlog(0, "attempting to send begin reco msg to %d\n",
2180                           nodenum);
2181                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2182                                          &br, sizeof(br), nodenum, &status);
2183                 /* negative status is handled ok by caller here */
2184                 if (ret >= 0)
2185                         ret = status;
2186                 if (dlm_is_host_down(ret)) {
2187                         /* node is down.  not involved in recovery
2188                          * so just keep going */
2189                         mlog(0, "%s: node %u was down when sending "
2190                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2191                         ret = 0;
2192                 }
2193                 if (ret < 0) {
2194                         struct dlm_lock_resource *res;
2195                         /* this is now a serious problem, possibly ENOMEM
2196                          * in the network stack.  must retry */
2197                         mlog_errno(ret);
2198                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2199                             " returned %d\n", dlm->name, nodenum, ret);
2200                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2201                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2202                         if (res) {
2203                                 dlm_print_one_lock_resource(res);
2204                                 dlm_lockres_put(res);
2205                         } else {
2206                                 mlog(ML_ERROR, "recovery lock not found\n");
2207                         }
2208                         /* sleep for a bit in hopes that we can avoid
2209                          * another ENOMEM */
2210                         msleep(100);
2211                         goto retry;
2212                 }
2213         }
2214
2215         return ret;
2216 }
2217
2218 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data)
2219 {
2220         struct dlm_ctxt *dlm = data;
2221         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2222
2223         /* ok to return 0, domain has gone away */
2224         if (!dlm_grab(dlm))
2225                 return 0;
2226
2227         mlog(0, "node %u wants to recover node %u\n",
2228                   br->node_idx, br->dead_node);
2229
2230         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2231
2232         spin_lock(&dlm->spinlock);
2233         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2234                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2235                         mlog(0, "%s: new_master %u died, changing "
2236                              "to %u\n", dlm->name, dlm->reco.new_master,
2237                              br->node_idx);
2238                 } else {
2239                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2240                              "to %u\n", dlm->name, dlm->reco.new_master,
2241                              br->node_idx);
2242                         /* may not have seen the new master as dead yet */
2243                 }
2244         }
2245         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2246                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2247                      "node %u changing it to %u\n", dlm->name,
2248                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2249         }
2250         dlm->reco.new_master = br->node_idx;
2251         dlm->reco.dead_node = br->dead_node;
2252         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2253                 mlog(0, "recovery master %u sees %u as dead, but this "
2254                      "node has not yet.  marking %u as dead\n",
2255                      br->node_idx, br->dead_node, br->dead_node);
2256                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2257                     !test_bit(br->dead_node, dlm->live_nodes_map))
2258                         mlog(0, "%u not in domain/live_nodes map "
2259                              "so setting it in reco map manually\n",
2260                              br->dead_node);
2261                 set_bit(br->dead_node, dlm->recovery_map);
2262                 __dlm_hb_node_down(dlm, br->dead_node);
2263         }
2264         spin_unlock(&dlm->spinlock);
2265
2266         dlm_kick_recovery_thread(dlm);
2267         dlm_put(dlm);
2268         return 0;
2269 }
2270
2271 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2272 {
2273         int ret = 0;
2274         struct dlm_finalize_reco fr;
2275         struct dlm_node_iter iter;
2276         int nodenum;
2277         int status;
2278
2279         mlog(0, "finishing recovery for node %s:%u\n",
2280              dlm->name, dlm->reco.dead_node);
2281
2282         spin_lock(&dlm->spinlock);
2283         dlm_node_iter_init(dlm->domain_map, &iter);
2284         spin_unlock(&dlm->spinlock);
2285
2286         memset(&fr, 0, sizeof(fr));
2287         fr.node_idx = dlm->node_num;
2288         fr.dead_node = dlm->reco.dead_node;
2289
2290         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2291                 if (nodenum == dlm->node_num)
2292                         continue;
2293                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2294                                          &fr, sizeof(fr), nodenum, &status);
2295                 if (ret >= 0) {
2296                         ret = status;
2297                         if (dlm_is_host_down(ret)) {
2298                                 /* this has no effect on this recovery
2299                                  * session, so set the status to zero to
2300                                  * finish out the last recovery */
2301                                 mlog(ML_ERROR, "node %u went down after this "
2302                                      "node finished recovery.\n", nodenum);
2303                                 ret = 0;
2304                         }
2305                 }
2306                 if (ret < 0) {
2307                         mlog_errno(ret);
2308                         break;
2309                 }
2310         }
2311
2312         return ret;
2313 }
2314
2315 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data)
2316 {
2317         struct dlm_ctxt *dlm = data;
2318         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2319
2320         /* ok to return 0, domain has gone away */
2321         if (!dlm_grab(dlm))
2322                 return 0;
2323
2324         mlog(0, "node %u finalizing recovery of node %u\n",
2325              fr->node_idx, fr->dead_node);
2326
2327         spin_lock(&dlm->spinlock);
2328
2329         if (dlm->reco.new_master != fr->node_idx) {
2330                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2331                      "%u is supposed to be the new master, dead=%u\n",
2332                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2333                 BUG();
2334         }
2335         if (dlm->reco.dead_node != fr->dead_node) {
2336                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2337                      "node %u, but node %u is supposed to be dead\n",
2338                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2339                 BUG();
2340         }
2341
2342         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2343
2344         spin_unlock(&dlm->spinlock);
2345
2346         dlm_reset_recovery(dlm);
2347
2348         dlm_kick_recovery_thread(dlm);
2349         dlm_put(dlm);
2350         return 0;
2351 }