fs/ocfs2/dlm/dlmdomain.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmdomain.c
   5  *
   6  * defines domain join / leave apis
   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 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31 #include <linux/utsname.h>
  32 #include <linux/init.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/delay.h>
  35 #include <linux/err.h>
  36
  37 #include "cluster/heartbeat.h"
  38 #include "cluster/nodemanager.h"
  39 #include "cluster/tcp.h"
  40
  41 #include "dlmapi.h"
  42 #include "dlmcommon.h"
  43
  44 #include "dlmdebug.h"
  45 #include "dlmdomain.h"
  46
  47 #include "dlmver.h"
  48
  49 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
  50 #include "cluster/masklog.h"
  51
  52 static void dlm_free_pagevec(void **vec, int pages)
  53 {
  54         while (pages--)
  55                 free_page((unsigned long)vec[pages]);
  56         kfree(vec);
  57 }
  58
  59 static void **dlm_alloc_pagevec(int pages)
  60 {
  61         void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
  62         int i;
  63
  64         if (!vec)
  65                 return NULL;
  66
  67         for (i = 0; i < pages; i++)
  68                 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
  69                         goto out_free;
  70
  71         mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
  72              pages, DLM_HASH_PAGES, (unsigned long)DLM_BUCKETS_PER_PAGE);
  73         return vec;
  74 out_free:
  75         dlm_free_pagevec(vec, i);
  76         return NULL;
  77 }
  78
  79 /*
  80  *
  81  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
  82  *    dlm_domain_lock
  83  *    struct dlm_ctxt->spinlock
  84  *    struct dlm_lock_resource->spinlock
  85  *    struct dlm_ctxt->master_lock
  86  *    struct dlm_ctxt->ast_lock
  87  *    dlm_master_list_entry->spinlock
  88  *    dlm_lock->spinlock
  89  *
  90  */
  91
  92 spinlock_t dlm_domain_lock = SPIN_LOCK_UNLOCKED;
  93 LIST_HEAD(dlm_domains);
  94 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
  95
  96 #define DLM_DOMAIN_BACKOFF_MS 200
  97
  98 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data);
  99 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data);
 100 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data);
 101 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data);
 102
 103 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 104
 105 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
 106 {
 107         hlist_del_init(&lockres->hash_node);
 108         dlm_lockres_put(lockres);
 109 }
 110
 111 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
 112                        struct dlm_lock_resource *res)
 113 {
 114         struct hlist_head *bucket;
 115         struct qstr *q;
 116
 117         assert_spin_locked(&dlm->spinlock);
 118
 119         q = &res->lockname;
 120         bucket = dlm_lockres_hash(dlm, q->hash);
 121
 122         /* get a reference for our hashtable */
 123         dlm_lockres_get(res);
 124
 125         hlist_add_head(&res->hash_node, bucket);
 126 }
 127
 128 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 129                                                 const char *name,
 130                                                 unsigned int len,
 131                                                 unsigned int hash)
 132 {
 133         struct hlist_head *bucket;
 134         struct hlist_node *list;
 135
 136         mlog_entry("%.*s\n", len, name);
 137
 138         assert_spin_locked(&dlm->spinlock);
 139
 140         bucket = dlm_lockres_hash(dlm, hash);
 141
 142         hlist_for_each(list, bucket) {
 143                 struct dlm_lock_resource *res = hlist_entry(list,
 144                         struct dlm_lock_resource, hash_node);
 145                 if (res->lockname.name[0] != name[0])
 146                         continue;
 147                 if (unlikely(res->lockname.len != len))
 148                         continue;
 149                 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
 150                         continue;
 151                 dlm_lockres_get(res);
 152                 return res;
 153         }
 154         return NULL;
 155 }
 156
 157 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 158                                     const char *name,
 159                                     unsigned int len)
 160 {
 161         struct dlm_lock_resource *res;
 162         unsigned int hash = dlm_lockid_hash(name, len);
 163
 164         spin_lock(&dlm->spinlock);
 165         res = __dlm_lookup_lockres(dlm, name, len, hash);
 166         spin_unlock(&dlm->spinlock);
 167         return res;
 168 }
 169
 170 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 171 {
 172         struct dlm_ctxt *tmp = NULL;
 173         struct list_head *iter;
 174
 175         assert_spin_locked(&dlm_domain_lock);
 176
 177         /* tmp->name here is always NULL terminated,
 178          * but domain may not be! */
 179         list_for_each(iter, &dlm_domains) {
 180                 tmp = list_entry (iter, struct dlm_ctxt, list);
 181                 if (strlen(tmp->name) == len &&
 182                     memcmp(tmp->name, domain, len)==0)
 183                         break;
 184                 tmp = NULL;
 185         }
 186
 187         return tmp;
 188 }
 189
 190 /* For null terminated domain strings ONLY */
 191 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
 192 {
 193         assert_spin_locked(&dlm_domain_lock);
 194
 195         return __dlm_lookup_domain_full(domain, strlen(domain));
 196 }
 197
 198
 199 /* returns true on one of two conditions:
 200  * 1) the domain does not exist
 201  * 2) the domain exists and it's state is "joined" */
 202 static int dlm_wait_on_domain_helper(const char *domain)
 203 {
 204         int ret = 0;
 205         struct dlm_ctxt *tmp = NULL;
 206
 207         spin_lock(&dlm_domain_lock);
 208
 209         tmp = __dlm_lookup_domain(domain);
 210         if (!tmp)
 211                 ret = 1;
 212         else if (tmp->dlm_state == DLM_CTXT_JOINED)
 213                 ret = 1;
 214
 215         spin_unlock(&dlm_domain_lock);
 216         return ret;
 217 }
 218
 219 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 220 {
 221         if (dlm->lockres_hash)
 222                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 223
 224         if (dlm->name)
 225                 kfree(dlm->name);
 226
 227         kfree(dlm);
 228 }
 229
 230 /* A little strange - this function will be called while holding
 231  * dlm_domain_lock and is expected to be holding it on the way out. We
 232  * will however drop and reacquire it multiple times */
 233 static void dlm_ctxt_release(struct kref *kref)
 234 {
 235         struct dlm_ctxt *dlm;
 236
 237         dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
 238
 239         BUG_ON(dlm->num_joins);
 240         BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
 241
 242         /* we may still be in the list if we hit an error during join. */
 243         list_del_init(&dlm->list);
 244
 245         spin_unlock(&dlm_domain_lock);
 246
 247         mlog(0, "freeing memory from domain %s\n", dlm->name);
 248
 249         wake_up(&dlm_domain_events);
 250
 251         dlm_free_ctxt_mem(dlm);
 252
 253         spin_lock(&dlm_domain_lock);
 254 }
 255
 256 void dlm_put(struct dlm_ctxt *dlm)
 257 {
 258         spin_lock(&dlm_domain_lock);
 259         kref_put(&dlm->dlm_refs, dlm_ctxt_release);
 260         spin_unlock(&dlm_domain_lock);
 261 }
 262
 263 static void __dlm_get(struct dlm_ctxt *dlm)
 264 {
 265         kref_get(&dlm->dlm_refs);
 266 }
 267
 268 /* given a questionable reference to a dlm object, gets a reference if
 269  * it can find it in the list, otherwise returns NULL in which case
 270  * you shouldn't trust your pointer. */
 271 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 272 {
 273         struct list_head *iter;
 274         struct dlm_ctxt *target = NULL;
 275
 276         spin_lock(&dlm_domain_lock);
 277
 278         list_for_each(iter, &dlm_domains) {
 279                 target = list_entry (iter, struct dlm_ctxt, list);
 280
 281                 if (target == dlm) {
 282                         __dlm_get(target);
 283                         break;
 284                 }
 285
 286                 target = NULL;
 287         }
 288
 289         spin_unlock(&dlm_domain_lock);
 290
 291         return target;
 292 }
 293
 294 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 295 {
 296         int ret;
 297
 298         spin_lock(&dlm_domain_lock);
 299         ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
 300                 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
 301         spin_unlock(&dlm_domain_lock);
 302
 303         return ret;
 304 }
 305
 306 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 307 {
 308         if (dlm->dlm_worker) {
 309                 flush_workqueue(dlm->dlm_worker);
 310                 destroy_workqueue(dlm->dlm_worker);
 311                 dlm->dlm_worker = NULL;
 312         }
 313 }
 314
 315 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 316 {
 317         dlm_unregister_domain_handlers(dlm);
 318         dlm_complete_thread(dlm);
 319         dlm_complete_recovery_thread(dlm);
 320         dlm_destroy_dlm_worker(dlm);
 321
 322         /* We've left the domain. Now we can take ourselves out of the
 323          * list and allow the kref stuff to help us free the
 324          * memory. */
 325         spin_lock(&dlm_domain_lock);
 326         list_del_init(&dlm->list);
 327         spin_unlock(&dlm_domain_lock);
 328
 329         /* Wake up anyone waiting for us to remove this domain */
 330         wake_up(&dlm_domain_events);
 331 }
 332
 333 static void dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 334 {
 335         int i;
 336         struct dlm_lock_resource *res;
 337
 338         mlog(0, "Migrating locks from domain %s\n", dlm->name);
 339 restart:
 340         spin_lock(&dlm->spinlock);
 341         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
 342                 while (!hlist_empty(dlm_lockres_hash(dlm, i))) {
 343                         res = hlist_entry(dlm_lockres_hash(dlm, i)->first,
 344                                           struct dlm_lock_resource, hash_node);
 345                         /* need reference when manually grabbing lockres */
 346                         dlm_lockres_get(res);
 347                         /* this should unhash the lockres
 348                          * and exit with dlm->spinlock */
 349                         mlog(0, "purging res=%p\n", res);
 350                         if (dlm_lockres_is_dirty(dlm, res)) {
 351                                 /* HACK!  this should absolutely go.
 352                                  * need to figure out why some empty
 353                                  * lockreses are still marked dirty */
 354                                 mlog(ML_ERROR, "lockres %.*s dirty!\n",
 355                                      res->lockname.len, res->lockname.name);
 356
 357                                 spin_unlock(&dlm->spinlock);
 358                                 dlm_kick_thread(dlm, res);
 359                                 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
 360                                 dlm_lockres_put(res);
 361                                 goto restart;
 362                         }
 363                         dlm_purge_lockres(dlm, res);
 364                         dlm_lockres_put(res);
 365                 }
 366         }
 367         spin_unlock(&dlm->spinlock);
 368
 369         mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
 370 }
 371
 372 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
 373 {
 374         int ret;
 375
 376         spin_lock(&dlm->spinlock);
 377         ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
 378         spin_unlock(&dlm->spinlock);
 379
 380         return ret;
 381 }
 382
 383 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
 384 {
 385         /* Yikes, a double spinlock! I need domain_lock for the dlm
 386          * state and the dlm spinlock for join state... Sorry! */
 387 again:
 388         spin_lock(&dlm_domain_lock);
 389         spin_lock(&dlm->spinlock);
 390
 391         if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 392                 mlog(0, "Node %d is joining, we wait on it.\n",
 393                           dlm->joining_node);
 394                 spin_unlock(&dlm->spinlock);
 395                 spin_unlock(&dlm_domain_lock);
 396
 397                 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
 398                 goto again;
 399         }
 400
 401         dlm->dlm_state = DLM_CTXT_LEAVING;
 402         spin_unlock(&dlm->spinlock);
 403         spin_unlock(&dlm_domain_lock);
 404 }
 405
 406 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
 407 {
 408         int node = -1;
 409
 410         assert_spin_locked(&dlm->spinlock);
 411
 412         mlog(ML_NOTICE, "Nodes in my domain (\"%s\"):\n", dlm->name);
 413
 414         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 415                                      node + 1)) < O2NM_MAX_NODES) {
 416                 mlog(ML_NOTICE, " node %d\n", node);
 417         }
 418 }
 419
 420 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data)
 421 {
 422         struct dlm_ctxt *dlm = data;
 423         unsigned int node;
 424         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 425
 426         mlog_entry("%p %u %p", msg, len, data);
 427
 428         if (!dlm_grab(dlm))
 429                 return 0;
 430
 431         node = exit_msg->node_idx;
 432
 433         mlog(0, "Node %u leaves domain %s\n", node, dlm->name);
 434
 435         spin_lock(&dlm->spinlock);
 436         clear_bit(node, dlm->domain_map);
 437         __dlm_print_nodes(dlm);
 438
 439         /* notify anything attached to the heartbeat events */
 440         dlm_hb_event_notify_attached(dlm, node, 0);
 441
 442         spin_unlock(&dlm->spinlock);
 443
 444         dlm_put(dlm);
 445
 446         return 0;
 447 }
 448
 449 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm,
 450                                     unsigned int node)
 451 {
 452         int status;
 453         struct dlm_exit_domain leave_msg;
 454
 455         mlog(0, "Asking node %u if we can leave the domain %s me = %u\n",
 456                   node, dlm->name, dlm->node_num);
 457
 458         memset(&leave_msg, 0, sizeof(leave_msg));
 459         leave_msg.node_idx = dlm->node_num;
 460
 461         status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key,
 462                                     &leave_msg, sizeof(leave_msg), node,
 463                                     NULL);
 464
 465         mlog(0, "status return %d from o2net_send_message\n", status);
 466
 467         return status;
 468 }
 469
 470
 471 static void dlm_leave_domain(struct dlm_ctxt *dlm)
 472 {
 473         int node, clear_node, status;
 474
 475         /* At this point we've migrated away all our locks and won't
 476          * accept mastership of new ones. The dlm is responsible for
 477          * almost nothing now. We make sure not to confuse any joining
 478          * nodes and then commence shutdown procedure. */
 479
 480         spin_lock(&dlm->spinlock);
 481         /* Clear ourselves from the domain map */
 482         clear_bit(dlm->node_num, dlm->domain_map);
 483         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 484                                      0)) < O2NM_MAX_NODES) {
 485                 /* Drop the dlm spinlock. This is safe wrt the domain_map.
 486                  * -nodes cannot be added now as the
 487                  *   query_join_handlers knows to respond with OK_NO_MAP
 488                  * -we catch the right network errors if a node is
 489                  *   removed from the map while we're sending him the
 490                  *   exit message. */
 491                 spin_unlock(&dlm->spinlock);
 492
 493                 clear_node = 1;
 494
 495                 status = dlm_send_one_domain_exit(dlm, node);
 496                 if (status < 0 &&
 497                     status != -ENOPROTOOPT &&
 498                     status != -ENOTCONN) {
 499                         mlog(ML_NOTICE, "Error %d sending domain exit message "
 500                              "to node %d\n", status, node);
 501
 502                         /* Not sure what to do here but lets sleep for
 503                          * a bit in case this was a transient
 504                          * error... */
 505                         msleep(DLM_DOMAIN_BACKOFF_MS);
 506                         clear_node = 0;
 507                 }
 508
 509                 spin_lock(&dlm->spinlock);
 510                 /* If we're not clearing the node bit then we intend
 511                  * to loop back around to try again. */
 512                 if (clear_node)
 513                         clear_bit(node, dlm->domain_map);
 514         }
 515         spin_unlock(&dlm->spinlock);
 516 }
 517
 518 int dlm_joined(struct dlm_ctxt *dlm)
 519 {
 520         int ret = 0;
 521
 522         spin_lock(&dlm_domain_lock);
 523
 524         if (dlm->dlm_state == DLM_CTXT_JOINED)
 525                 ret = 1;
 526
 527         spin_unlock(&dlm_domain_lock);
 528
 529         return ret;
 530 }
 531
 532 int dlm_shutting_down(struct dlm_ctxt *dlm)
 533 {
 534         int ret = 0;
 535
 536         spin_lock(&dlm_domain_lock);
 537
 538         if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
 539                 ret = 1;
 540
 541         spin_unlock(&dlm_domain_lock);
 542
 543         return ret;
 544 }
 545
 546 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 547 {
 548         int leave = 0;
 549
 550         spin_lock(&dlm_domain_lock);
 551         BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
 552         BUG_ON(!dlm->num_joins);
 553
 554         dlm->num_joins--;
 555         if (!dlm->num_joins) {
 556                 /* We mark it "in shutdown" now so new register
 557                  * requests wait until we've completely left the
 558                  * domain. Don't use DLM_CTXT_LEAVING yet as we still
 559                  * want new domain joins to communicate with us at
 560                  * least until we've completed migration of our
 561                  * resources. */
 562                 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
 563                 leave = 1;
 564         }
 565         spin_unlock(&dlm_domain_lock);
 566
 567         if (leave) {
 568                 mlog(0, "shutting down domain %s\n", dlm->name);
 569
 570                 /* We changed dlm state, notify the thread */
 571                 dlm_kick_thread(dlm, NULL);
 572
 573                 dlm_migrate_all_locks(dlm);
 574                 dlm_mark_domain_leaving(dlm);
 575                 dlm_leave_domain(dlm);
 576                 dlm_complete_dlm_shutdown(dlm);
 577         }
 578         dlm_put(dlm);
 579 }
 580 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 581
 582 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
 583 {
 584         struct dlm_query_join_request *query;
 585         enum dlm_query_join_response response;
 586         struct dlm_ctxt *dlm = NULL;
 587
 588         query = (struct dlm_query_join_request *) msg->buf;
 589
 590         mlog(0, "node %u wants to join domain %s\n", query->node_idx,
 591                   query->domain);
 592
 593         /*
 594          * If heartbeat doesn't consider the node live, tell it
 595          * to back off and try again.  This gives heartbeat a chance
 596          * to catch up.
 597          */
 598         if (!o2hb_check_node_heartbeating(query->node_idx)) {
 599                 mlog(0, "node %u is not in our live map yet\n",
 600                      query->node_idx);
 601
 602                 response = JOIN_DISALLOW;
 603                 goto respond;
 604         }
 605
 606         response = JOIN_OK_NO_MAP;
 607
 608         spin_lock(&dlm_domain_lock);
 609         dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 610         /* Once the dlm ctxt is marked as leaving then we don't want
 611          * to be put in someone's domain map.
 612          * Also, explicitly disallow joining at certain troublesome
 613          * times (ie. during recovery). */
 614         if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
 615                 int bit = query->node_idx;
 616                 spin_lock(&dlm->spinlock);
 617
 618                 if (dlm->dlm_state == DLM_CTXT_NEW &&
 619                     dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
 620                         /*If this is a brand new context and we
 621                          * haven't started our join process yet, then
 622                          * the other node won the race. */
 623                         response = JOIN_OK_NO_MAP;
 624                 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 625                         /* Disallow parallel joins. */
 626                         response = JOIN_DISALLOW;
 627                 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 628                         mlog(ML_NOTICE, "node %u trying to join, but recovery "
 629                              "is ongoing.\n", bit);
 630                         response = JOIN_DISALLOW;
 631                 } else if (test_bit(bit, dlm->recovery_map)) {
 632                         mlog(ML_NOTICE, "node %u trying to join, but it "
 633                              "still needs recovery.\n", bit);
 634                         response = JOIN_DISALLOW;
 635                 } else if (test_bit(bit, dlm->domain_map)) {
 636                         mlog(ML_NOTICE, "node %u trying to join, but it "
 637                              "is still in the domain! needs recovery?\n",
 638                              bit);
 639                         response = JOIN_DISALLOW;
 640                 } else {
 641                         /* Alright we're fully a part of this domain
 642                          * so we keep some state as to who's joining
 643                          * and indicate to him that needs to be fixed
 644                          * up. */
 645                         response = JOIN_OK;
 646                         __dlm_set_joining_node(dlm, query->node_idx);
 647                 }
 648
 649                 spin_unlock(&dlm->spinlock);
 650         }
 651         spin_unlock(&dlm_domain_lock);
 652
 653 respond:
 654         mlog(0, "We respond with %u\n", response);
 655
 656         return response;
 657 }
 658
 659 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data)
 660 {
 661         struct dlm_assert_joined *assert;
 662         struct dlm_ctxt *dlm = NULL;
 663
 664         assert = (struct dlm_assert_joined *) msg->buf;
 665
 666         mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
 667                   assert->domain);
 668
 669         spin_lock(&dlm_domain_lock);
 670         dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
 671         /* XXX should we consider no dlm ctxt an error? */
 672         if (dlm) {
 673                 spin_lock(&dlm->spinlock);
 674
 675                 /* Alright, this node has officially joined our
 676                  * domain. Set him in the map and clean up our
 677                  * leftover join state. */
 678                 BUG_ON(dlm->joining_node != assert->node_idx);
 679                 set_bit(assert->node_idx, dlm->domain_map);
 680                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 681
 682                 __dlm_print_nodes(dlm);
 683
 684                 /* notify anything attached to the heartbeat events */
 685                 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
 686
 687                 spin_unlock(&dlm->spinlock);
 688         }
 689         spin_unlock(&dlm_domain_lock);
 690
 691         return 0;
 692 }
 693
 694 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data)
 695 {
 696         struct dlm_cancel_join *cancel;
 697         struct dlm_ctxt *dlm = NULL;
 698
 699         cancel = (struct dlm_cancel_join *) msg->buf;
 700
 701         mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
 702                   cancel->domain);
 703
 704         spin_lock(&dlm_domain_lock);
 705         dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
 706
 707         if (dlm) {
 708                 spin_lock(&dlm->spinlock);
 709
 710                 /* Yikes, this guy wants to cancel his join. No
 711                  * problem, we simply cleanup our join state. */
 712                 BUG_ON(dlm->joining_node != cancel->node_idx);
 713                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 714
 715                 spin_unlock(&dlm->spinlock);
 716         }
 717         spin_unlock(&dlm_domain_lock);
 718
 719         return 0;
 720 }
 721
 722 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
 723                                     unsigned int node)
 724 {
 725         int status;
 726         struct dlm_cancel_join cancel_msg;
 727
 728         memset(&cancel_msg, 0, sizeof(cancel_msg));
 729         cancel_msg.node_idx = dlm->node_num;
 730         cancel_msg.name_len = strlen(dlm->name);
 731         memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
 732
 733         status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
 734                                     &cancel_msg, sizeof(cancel_msg), node,
 735                                     NULL);
 736         if (status < 0) {
 737                 mlog_errno(status);
 738                 goto bail;
 739         }
 740
 741 bail:
 742         return status;
 743 }
 744
 745 /* map_size should be in bytes. */
 746 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
 747                                  unsigned long *node_map,
 748                                  unsigned int map_size)
 749 {
 750         int status, tmpstat;
 751         unsigned int node;
 752
 753         if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
 754                          sizeof(unsigned long))) {
 755                 mlog(ML_ERROR,
 756                      "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
 757                      map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
 758                 return -EINVAL;
 759         }
 760
 761         status = 0;
 762         node = -1;
 763         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
 764                                      node + 1)) < O2NM_MAX_NODES) {
 765                 if (node == dlm->node_num)
 766                         continue;
 767
 768                 tmpstat = dlm_send_one_join_cancel(dlm, node);
 769                 if (tmpstat) {
 770                         mlog(ML_ERROR, "Error return %d cancelling join on "
 771                              "node %d\n", tmpstat, node);
 772                         if (!status)
 773                                 status = tmpstat;
 774                 }
 775         }
 776
 777         if (status)
 778                 mlog_errno(status);
 779         return status;
 780 }
 781
 782 static int dlm_request_join(struct dlm_ctxt *dlm,
 783                             int node,
 784                             enum dlm_query_join_response *response)
 785 {
 786         int status, retval;
 787         struct dlm_query_join_request join_msg;
 788
 789         mlog(0, "querying node %d\n", node);
 790
 791         memset(&join_msg, 0, sizeof(join_msg));
 792         join_msg.node_idx = dlm->node_num;
 793         join_msg.name_len = strlen(dlm->name);
 794         memcpy(join_msg.domain, dlm->name, join_msg.name_len);
 795
 796         status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
 797                                     sizeof(join_msg), node, &retval);
 798         if (status < 0 && status != -ENOPROTOOPT) {
 799                 mlog_errno(status);
 800                 goto bail;
 801         }
 802
 803         /* -ENOPROTOOPT from the net code means the other side isn't
 804             listening for our message type -- that's fine, it means
 805             his dlm isn't up, so we can consider him a 'yes' but not
 806             joined into the domain.  */
 807         if (status == -ENOPROTOOPT) {
 808                 status = 0;
 809                 *response = JOIN_OK_NO_MAP;
 810         } else if (retval == JOIN_DISALLOW ||
 811                    retval == JOIN_OK ||
 812                    retval == JOIN_OK_NO_MAP) {
 813                 *response = retval;
 814         } else {
 815                 status = -EINVAL;
 816                 mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
 817                      node);
 818         }
 819
 820         mlog(0, "status %d, node %d response is %d\n", status, node,
 821                   *response);
 822
 823 bail:
 824         return status;
 825 }
 826
 827 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
 828                                     unsigned int node)
 829 {
 830         int status;
 831         struct dlm_assert_joined assert_msg;
 832
 833         mlog(0, "Sending join assert to node %u\n", node);
 834
 835         memset(&assert_msg, 0, sizeof(assert_msg));
 836         assert_msg.node_idx = dlm->node_num;
 837         assert_msg.name_len = strlen(dlm->name);
 838         memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
 839
 840         status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
 841                                     &assert_msg, sizeof(assert_msg), node,
 842                                     NULL);
 843         if (status < 0)
 844                 mlog_errno(status);
 845
 846         return status;
 847 }
 848
 849 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
 850                                   unsigned long *node_map)
 851 {
 852         int status, node, live;
 853
 854         status = 0;
 855         node = -1;
 856         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
 857                                      node + 1)) < O2NM_MAX_NODES) {
 858                 if (node == dlm->node_num)
 859                         continue;
 860
 861                 do {
 862                         /* It is very important that this message be
 863                          * received so we spin until either the node
 864                          * has died or it gets the message. */
 865                         status = dlm_send_one_join_assert(dlm, node);
 866
 867                         spin_lock(&dlm->spinlock);
 868                         live = test_bit(node, dlm->live_nodes_map);
 869                         spin_unlock(&dlm->spinlock);
 870
 871                         if (status) {
 872                                 mlog(ML_ERROR, "Error return %d asserting "
 873                                      "join on node %d\n", status, node);
 874
 875                                 /* give us some time between errors... */
 876                                 if (live)
 877                                         msleep(DLM_DOMAIN_BACKOFF_MS);
 878                         }
 879                 } while (status && live);
 880         }
 881 }
 882
 883 struct domain_join_ctxt {
 884         unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
 885         unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
 886 };
 887
 888 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
 889                                    struct domain_join_ctxt *ctxt,
 890                                    enum dlm_query_join_response response)
 891 {
 892         int ret;
 893
 894         if (response == JOIN_DISALLOW) {
 895                 mlog(0, "Latest response of disallow -- should restart\n");
 896                 return 1;
 897         }
 898
 899         spin_lock(&dlm->spinlock);
 900         /* For now, we restart the process if the node maps have
 901          * changed at all */
 902         ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
 903                      sizeof(dlm->live_nodes_map));
 904         spin_unlock(&dlm->spinlock);
 905
 906         if (ret)
 907                 mlog(0, "Node maps changed -- should restart\n");
 908
 909         return ret;
 910 }
 911
 912 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
 913 {
 914         int status = 0, tmpstat, node;
 915         struct domain_join_ctxt *ctxt;
 916         enum dlm_query_join_response response;
 917
 918         mlog_entry("%p", dlm);
 919
 920         ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL);
 921         if (!ctxt) {
 922                 status = -ENOMEM;
 923                 mlog_errno(status);
 924                 goto bail;
 925         }
 926
 927         /* group sem locking should work for us here -- we're already
 928          * registered for heartbeat events so filling this should be
 929          * atomic wrt getting those handlers called. */
 930         o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
 931
 932         spin_lock(&dlm->spinlock);
 933         memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
 934
 935         __dlm_set_joining_node(dlm, dlm->node_num);
 936
 937         spin_unlock(&dlm->spinlock);
 938
 939         node = -1;
 940         while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
 941                                      node + 1)) < O2NM_MAX_NODES) {
 942                 if (node == dlm->node_num)
 943                         continue;
 944
 945                 status = dlm_request_join(dlm, node, &response);
 946                 if (status < 0) {
 947                         mlog_errno(status);
 948                         goto bail;
 949                 }
 950
 951                 /* Ok, either we got a response or the node doesn't have a
 952                  * dlm up. */
 953                 if (response == JOIN_OK)
 954                         set_bit(node, ctxt->yes_resp_map);
 955
 956                 if (dlm_should_restart_join(dlm, ctxt, response)) {
 957                         status = -EAGAIN;
 958                         goto bail;
 959                 }
 960         }
 961
 962         mlog(0, "Yay, done querying nodes!\n");
 963
 964         /* Yay, everyone agree's we can join the domain. My domain is
 965          * comprised of all nodes who were put in the
 966          * yes_resp_map. Copy that into our domain map and send a join
 967          * assert message to clean up everyone elses state. */
 968         spin_lock(&dlm->spinlock);
 969         memcpy(dlm->domain_map, ctxt->yes_resp_map,
 970                sizeof(ctxt->yes_resp_map));
 971         set_bit(dlm->node_num, dlm->domain_map);
 972         spin_unlock(&dlm->spinlock);
 973
 974         dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
 975
 976         /* Joined state *must* be set before the joining node
 977          * information, otherwise the query_join handler may read no
 978          * current joiner but a state of NEW and tell joining nodes
 979          * we're not in the domain. */
 980         spin_lock(&dlm_domain_lock);
 981         dlm->dlm_state = DLM_CTXT_JOINED;
 982         dlm->num_joins++;
 983         spin_unlock(&dlm_domain_lock);
 984
 985 bail:
 986         spin_lock(&dlm->spinlock);
 987         __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 988         if (!status)
 989                 __dlm_print_nodes(dlm);
 990         spin_unlock(&dlm->spinlock);
 991
 992         if (ctxt) {
 993                 /* Do we need to send a cancel message to any nodes? */
 994                 if (status < 0) {
 995                         tmpstat = dlm_send_join_cancels(dlm,
 996                                                         ctxt->yes_resp_map,
 997                                                         sizeof(ctxt->yes_resp_map));
 998                         if (tmpstat < 0)
 999                                 mlog_errno(tmpstat);
1000                 }
1001                 kfree(ctxt);
1002         }
1003
1004         mlog(0, "returning %d\n", status);
1005         return status;
1006 }
1007
1008 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1009 {
1010         o2hb_unregister_callback(&dlm->dlm_hb_up);
1011         o2hb_unregister_callback(&dlm->dlm_hb_down);
1012         o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1013 }
1014
1015 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1016 {
1017         int status;
1018
1019         mlog(0, "registering handlers.\n");
1020
1021         o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1022                             dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1023         status = o2hb_register_callback(&dlm->dlm_hb_down);
1024         if (status)
1025                 goto bail;
1026
1027         o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1028                             dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1029         status = o2hb_register_callback(&dlm->dlm_hb_up);
1030         if (status)
1031                 goto bail;
1032
1033         status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1034                                         sizeof(struct dlm_master_request),
1035                                         dlm_master_request_handler,
1036                                         dlm, &dlm->dlm_domain_handlers);
1037         if (status)
1038                 goto bail;
1039
1040         status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1041                                         sizeof(struct dlm_assert_master),
1042                                         dlm_assert_master_handler,
1043                                         dlm, &dlm->dlm_domain_handlers);
1044         if (status)
1045                 goto bail;
1046
1047         status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1048                                         sizeof(struct dlm_create_lock),
1049                                         dlm_create_lock_handler,
1050                                         dlm, &dlm->dlm_domain_handlers);
1051         if (status)
1052                 goto bail;
1053
1054         status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1055                                         DLM_CONVERT_LOCK_MAX_LEN,
1056                                         dlm_convert_lock_handler,
1057                                         dlm, &dlm->dlm_domain_handlers);
1058         if (status)
1059                 goto bail;
1060
1061         status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1062                                         DLM_UNLOCK_LOCK_MAX_LEN,
1063                                         dlm_unlock_lock_handler,
1064                                         dlm, &dlm->dlm_domain_handlers);
1065         if (status)
1066                 goto bail;
1067
1068         status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1069                                         DLM_PROXY_AST_MAX_LEN,
1070                                         dlm_proxy_ast_handler,
1071                                         dlm, &dlm->dlm_domain_handlers);
1072         if (status)
1073                 goto bail;
1074
1075         status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1076                                         sizeof(struct dlm_exit_domain),
1077                                         dlm_exit_domain_handler,
1078                                         dlm, &dlm->dlm_domain_handlers);
1079         if (status)
1080                 goto bail;
1081
1082         status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1083                                         sizeof(struct dlm_migrate_request),
1084                                         dlm_migrate_request_handler,
1085                                         dlm, &dlm->dlm_domain_handlers);
1086         if (status)
1087                 goto bail;
1088
1089         status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1090                                         DLM_MIG_LOCKRES_MAX_LEN,
1091                                         dlm_mig_lockres_handler,
1092                                         dlm, &dlm->dlm_domain_handlers);
1093         if (status)
1094                 goto bail;
1095
1096         status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1097                                         sizeof(struct dlm_master_requery),
1098                                         dlm_master_requery_handler,
1099                                         dlm, &dlm->dlm_domain_handlers);
1100         if (status)
1101                 goto bail;
1102
1103         status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1104                                         sizeof(struct dlm_lock_request),
1105                                         dlm_request_all_locks_handler,
1106                                         dlm, &dlm->dlm_domain_handlers);
1107         if (status)
1108                 goto bail;
1109
1110         status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1111                                         sizeof(struct dlm_reco_data_done),
1112                                         dlm_reco_data_done_handler,
1113                                         dlm, &dlm->dlm_domain_handlers);
1114         if (status)
1115                 goto bail;
1116
1117         status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1118                                         sizeof(struct dlm_begin_reco),
1119                                         dlm_begin_reco_handler,
1120                                         dlm, &dlm->dlm_domain_handlers);
1121         if (status)
1122                 goto bail;
1123
1124         status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1125                                         sizeof(struct dlm_finalize_reco),
1126                                         dlm_finalize_reco_handler,
1127                                         dlm, &dlm->dlm_domain_handlers);
1128         if (status)
1129                 goto bail;
1130
1131 bail:
1132         if (status)
1133                 dlm_unregister_domain_handlers(dlm);
1134
1135         return status;
1136 }
1137
1138 static int dlm_join_domain(struct dlm_ctxt *dlm)
1139 {
1140         int status;
1141
1142         BUG_ON(!dlm);
1143
1144         mlog(0, "Join domain %s\n", dlm->name);
1145
1146         status = dlm_register_domain_handlers(dlm);
1147         if (status) {
1148                 mlog_errno(status);
1149                 goto bail;
1150         }
1151
1152         status = dlm_launch_thread(dlm);
1153         if (status < 0) {
1154                 mlog_errno(status);
1155                 goto bail;
1156         }
1157
1158         status = dlm_launch_recovery_thread(dlm);
1159         if (status < 0) {
1160                 mlog_errno(status);
1161                 goto bail;
1162         }
1163
1164         dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1165         if (!dlm->dlm_worker) {
1166                 status = -ENOMEM;
1167                 mlog_errno(status);
1168                 goto bail;
1169         }
1170
1171         do {
1172                 unsigned int backoff;
1173                 status = dlm_try_to_join_domain(dlm);
1174
1175                 /* If we're racing another node to the join, then we
1176                  * need to back off temporarily and let them
1177                  * complete. */
1178                 if (status == -EAGAIN) {
1179                         if (signal_pending(current)) {
1180                                 status = -ERESTARTSYS;
1181                                 goto bail;
1182                         }
1183
1184                         /*
1185                          * <chip> After you!
1186                          * <dale> No, after you!
1187                          * <chip> I insist!
1188                          * <dale> But you first!
1189                          * ...
1190                          */
1191                         backoff = (unsigned int)(jiffies & 0x3);
1192                         backoff *= DLM_DOMAIN_BACKOFF_MS;
1193                         mlog(0, "backoff %d\n", backoff);
1194                         msleep(backoff);
1195                 }
1196         } while (status == -EAGAIN);
1197
1198         if (status < 0) {
1199                 mlog_errno(status);
1200                 goto bail;
1201         }
1202
1203         status = 0;
1204 bail:
1205         wake_up(&dlm_domain_events);
1206
1207         if (status) {
1208                 dlm_unregister_domain_handlers(dlm);
1209                 dlm_complete_thread(dlm);
1210                 dlm_complete_recovery_thread(dlm);
1211                 dlm_destroy_dlm_worker(dlm);
1212         }
1213
1214         return status;
1215 }
1216
1217 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1218                                 u32 key)
1219 {
1220         int i;
1221         struct dlm_ctxt *dlm = NULL;
1222
1223         dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL);
1224         if (!dlm) {
1225                 mlog_errno(-ENOMEM);
1226                 goto leave;
1227         }
1228
1229         dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL);
1230         if (dlm->name == NULL) {
1231                 mlog_errno(-ENOMEM);
1232                 kfree(dlm);
1233                 dlm = NULL;
1234                 goto leave;
1235         }
1236
1237         dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1238         if (!dlm->lockres_hash) {
1239                 mlog_errno(-ENOMEM);
1240                 kfree(dlm->name);
1241                 kfree(dlm);
1242                 dlm = NULL;
1243                 goto leave;
1244         }
1245
1246         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1247                 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1248
1249         strcpy(dlm->name, domain);
1250         dlm->key = key;
1251         dlm->node_num = o2nm_this_node();
1252
1253         spin_lock_init(&dlm->spinlock);
1254         spin_lock_init(&dlm->master_lock);
1255         spin_lock_init(&dlm->ast_lock);
1256         INIT_LIST_HEAD(&dlm->list);
1257         INIT_LIST_HEAD(&dlm->dirty_list);
1258         INIT_LIST_HEAD(&dlm->reco.resources);
1259         INIT_LIST_HEAD(&dlm->reco.received);
1260         INIT_LIST_HEAD(&dlm->reco.node_data);
1261         INIT_LIST_HEAD(&dlm->purge_list);
1262         INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
1263         dlm->reco.state = 0;
1264
1265         INIT_LIST_HEAD(&dlm->pending_asts);
1266         INIT_LIST_HEAD(&dlm->pending_basts);
1267
1268         mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
1269                   dlm->recovery_map, &(dlm->recovery_map[0]));
1270
1271         memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
1272         memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
1273         memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
1274
1275         dlm->dlm_thread_task = NULL;
1276         dlm->dlm_reco_thread_task = NULL;
1277         dlm->dlm_worker = NULL;
1278         init_waitqueue_head(&dlm->dlm_thread_wq);
1279         init_waitqueue_head(&dlm->dlm_reco_thread_wq);
1280         init_waitqueue_head(&dlm->reco.event);
1281         init_waitqueue_head(&dlm->ast_wq);
1282         init_waitqueue_head(&dlm->migration_wq);
1283         INIT_LIST_HEAD(&dlm->master_list);
1284         INIT_LIST_HEAD(&dlm->mle_hb_events);
1285
1286         dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
1287         init_waitqueue_head(&dlm->dlm_join_events);
1288
1289         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
1290         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
1291         atomic_set(&dlm->local_resources, 0);
1292         atomic_set(&dlm->remote_resources, 0);
1293         atomic_set(&dlm->unknown_resources, 0);
1294
1295         spin_lock_init(&dlm->work_lock);
1296         INIT_LIST_HEAD(&dlm->work_list);
1297         INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm);
1298
1299         kref_init(&dlm->dlm_refs);
1300         dlm->dlm_state = DLM_CTXT_NEW;
1301
1302         INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
1303
1304         mlog(0, "context init: refcount %u\n",
1305                   atomic_read(&dlm->dlm_refs.refcount));
1306
1307 leave:
1308         return dlm;
1309 }
1310
1311 /*
1312  * dlm_register_domain: one-time setup per "domain"
1313  */
1314 struct dlm_ctxt * dlm_register_domain(const char *domain,
1315                                u32 key)
1316 {
1317         int ret;
1318         struct dlm_ctxt *dlm = NULL;
1319         struct dlm_ctxt *new_ctxt = NULL;
1320
1321         if (strlen(domain) > O2NM_MAX_NAME_LEN) {
1322                 ret = -ENAMETOOLONG;
1323                 mlog(ML_ERROR, "domain name length too long\n");
1324                 goto leave;
1325         }
1326
1327         if (!o2hb_check_local_node_heartbeating()) {
1328                 mlog(ML_ERROR, "the local node has not been configured, or is "
1329                      "not heartbeating\n");
1330                 ret = -EPROTO;
1331                 goto leave;
1332         }
1333
1334         mlog(0, "register called for domain \"%s\"\n", domain);
1335
1336 retry:
1337         dlm = NULL;
1338         if (signal_pending(current)) {
1339                 ret = -ERESTARTSYS;
1340                 mlog_errno(ret);
1341                 goto leave;
1342         }
1343
1344         spin_lock(&dlm_domain_lock);
1345
1346         dlm = __dlm_lookup_domain(domain);
1347         if (dlm) {
1348                 if (dlm->dlm_state != DLM_CTXT_JOINED) {
1349                         spin_unlock(&dlm_domain_lock);
1350
1351                         mlog(0, "This ctxt is not joined yet!\n");
1352                         wait_event_interruptible(dlm_domain_events,
1353                                                  dlm_wait_on_domain_helper(
1354                                                          domain));
1355                         goto retry;
1356                 }
1357
1358                 __dlm_get(dlm);
1359                 dlm->num_joins++;
1360
1361                 spin_unlock(&dlm_domain_lock);
1362
1363                 ret = 0;
1364                 goto leave;
1365         }
1366
1367         /* doesn't exist */
1368         if (!new_ctxt) {
1369                 spin_unlock(&dlm_domain_lock);
1370
1371                 new_ctxt = dlm_alloc_ctxt(domain, key);
1372                 if (new_ctxt)
1373                         goto retry;
1374
1375                 ret = -ENOMEM;
1376                 mlog_errno(ret);
1377                 goto leave;
1378         }
1379
1380         /* a little variable switch-a-roo here... */
1381         dlm = new_ctxt;
1382         new_ctxt = NULL;
1383
1384         /* add the new domain */
1385         list_add_tail(&dlm->list, &dlm_domains);
1386         spin_unlock(&dlm_domain_lock);
1387
1388         ret = dlm_join_domain(dlm);
1389         if (ret) {
1390                 mlog_errno(ret);
1391                 dlm_put(dlm);
1392                 goto leave;
1393         }
1394
1395         ret = 0;
1396 leave:
1397         if (new_ctxt)
1398                 dlm_free_ctxt_mem(new_ctxt);
1399
1400         if (ret < 0)
1401                 dlm = ERR_PTR(ret);
1402
1403         return dlm;
1404 }
1405 EXPORT_SYMBOL_GPL(dlm_register_domain);
1406
1407 static LIST_HEAD(dlm_join_handlers);
1408
1409 static void dlm_unregister_net_handlers(void)
1410 {
1411         o2net_unregister_handler_list(&dlm_join_handlers);
1412 }
1413
1414 static int dlm_register_net_handlers(void)
1415 {
1416         int status = 0;
1417
1418         status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1419                                         sizeof(struct dlm_query_join_request),
1420                                         dlm_query_join_handler,
1421                                         NULL, &dlm_join_handlers);
1422         if (status)
1423                 goto bail;
1424
1425         status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1426                                         sizeof(struct dlm_assert_joined),
1427                                         dlm_assert_joined_handler,
1428                                         NULL, &dlm_join_handlers);
1429         if (status)
1430                 goto bail;
1431
1432         status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1433                                         sizeof(struct dlm_cancel_join),
1434                                         dlm_cancel_join_handler,
1435                                         NULL, &dlm_join_handlers);
1436
1437 bail:
1438         if (status < 0)
1439                 dlm_unregister_net_handlers();
1440
1441         return status;
1442 }
1443
1444 /* Domain eviction callback handling.
1445  *
1446  * The file system requires notification of node death *before* the
1447  * dlm completes it's recovery work, otherwise it may be able to
1448  * acquire locks on resources requiring recovery. Since the dlm can
1449  * evict a node from it's domain *before* heartbeat fires, a similar
1450  * mechanism is required. */
1451
1452 /* Eviction is not expected to happen often, so a per-domain lock is
1453  * not necessary. Eviction callbacks are allowed to sleep for short
1454  * periods of time. */
1455 static DECLARE_RWSEM(dlm_callback_sem);
1456
1457 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
1458                                         int node_num)
1459 {
1460         struct list_head *iter;
1461         struct dlm_eviction_cb *cb;
1462
1463         down_read(&dlm_callback_sem);
1464         list_for_each(iter, &dlm->dlm_eviction_callbacks) {
1465                 cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
1466
1467                 cb->ec_func(node_num, cb->ec_data);
1468         }
1469         up_read(&dlm_callback_sem);
1470 }
1471
1472 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
1473                            dlm_eviction_func *f,
1474                            void *data)
1475 {
1476         INIT_LIST_HEAD(&cb->ec_item);
1477         cb->ec_func = f;
1478         cb->ec_data = data;
1479 }
1480 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
1481
1482 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
1483                               struct dlm_eviction_cb *cb)
1484 {
1485         down_write(&dlm_callback_sem);
1486         list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
1487         up_write(&dlm_callback_sem);
1488 }
1489 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
1490
1491 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
1492 {
1493         down_write(&dlm_callback_sem);
1494         list_del_init(&cb->ec_item);
1495         up_write(&dlm_callback_sem);
1496 }
1497 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
1498
1499 static int __init dlm_init(void)
1500 {
1501         int status;
1502
1503         dlm_print_version();
1504
1505         status = dlm_init_mle_cache();
1506         if (status)
1507                 return -1;
1508
1509         status = dlm_register_net_handlers();
1510         if (status) {
1511                 dlm_destroy_mle_cache();
1512                 return -1;
1513         }
1514
1515         return 0;
1516 }
1517
1518 static void __exit dlm_exit (void)
1519 {
1520         dlm_unregister_net_handlers();
1521         dlm_destroy_mle_cache();
1522 }
1523
1524 MODULE_AUTHOR("Oracle");
1525 MODULE_LICENSE("GPL");
1526
1527 module_init(dlm_init);
1528 module_exit(dlm_exit);