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/init.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/delay.h>
  34 #include <linux/err.h>
  35 #include <linux/debugfs.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 #include "dlmdomain.h"
  44 #include "dlmdebug.h"
  45
  46 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
  47 #include "cluster/masklog.h"
  48
  49 /*
  50  * ocfs2 node maps are array of long int, which limits to send them freely
  51  * across the wire due to endianness issues. To workaround this, we convert
  52  * long ints to byte arrays. Following 3 routines are helper functions to
  53  * set/test/copy bits within those array of bytes
  54  */
  55 static inline void byte_set_bit(u8 nr, u8 map[])
  56 {
  57         map[nr >> 3] |= (1UL << (nr & 7));
  58 }
  59
  60 static inline int byte_test_bit(u8 nr, u8 map[])
  61 {
  62         return ((1UL << (nr & 7)) & (map[nr >> 3])) != 0;
  63 }
  64
  65 static inline void byte_copymap(u8 dmap[], unsigned long smap[],
  66                         unsigned int sz)
  67 {
  68         unsigned int nn;
  69
  70         if (!sz)
  71                 return;
  72
  73         memset(dmap, 0, ((sz + 7) >> 3));
  74         for (nn = 0 ; nn < sz; nn++)
  75                 if (test_bit(nn, smap))
  76                         byte_set_bit(nn, dmap);
  77 }
  78
  79 static void dlm_free_pagevec(void **vec, int pages)
  80 {
  81         while (pages--)
  82                 free_page((unsigned long)vec[pages]);
  83         kfree(vec);
  84 }
  85
  86 static void **dlm_alloc_pagevec(int pages)
  87 {
  88         void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
  89         int i;
  90
  91         if (!vec)
  92                 return NULL;
  93
  94         for (i = 0; i < pages; i++)
  95                 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
  96                         goto out_free;
  97
  98         mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
  99              pages, (unsigned long)DLM_HASH_PAGES,
 100              (unsigned long)DLM_BUCKETS_PER_PAGE);
 101         return vec;
 102 out_free:
 103         dlm_free_pagevec(vec, i);
 104         return NULL;
 105 }
 106
 107 /*
 108  *
 109  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
 110  *    dlm_domain_lock
 111  *    struct dlm_ctxt->spinlock
 112  *    struct dlm_lock_resource->spinlock
 113  *    struct dlm_ctxt->master_lock
 114  *    struct dlm_ctxt->ast_lock
 115  *    dlm_master_list_entry->spinlock
 116  *    dlm_lock->spinlock
 117  *
 118  */
 119
 120 DEFINE_SPINLOCK(dlm_domain_lock);
 121 LIST_HEAD(dlm_domains);
 122 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
 123
 124 /*
 125  * The supported protocol version for DLM communication.  Running domains
 126  * will have a negotiated version with the same major number and a minor
 127  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
 128  * be used to determine what a running domain is actually using.
 129  *
 130  * New in version 1.1:
 131  *      - Message DLM_QUERY_REGION added to support global heartbeat
 132  *      - Message DLM_QUERY_NODEINFO added to allow online node removes
 133  * New in version 1.2:
 134  *      - Message DLM_BEGIN_EXIT_DOMAIN_MSG added to mark start of exit domain
 135  */
 136 static const struct dlm_protocol_version dlm_protocol = {
 137         .pv_major = 1,
 138         .pv_minor = 2,
 139 };
 140
 141 #define DLM_DOMAIN_BACKOFF_MS 200
 142
 143 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 144                                   void **ret_data);
 145 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 146                                      void **ret_data);
 147 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
 148                                    void **ret_data);
 149 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
 150                                     void *data, void **ret_data);
 151 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 152                                    void **ret_data);
 153 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
 154                                 struct dlm_protocol_version *request);
 155
 156 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 157
 158 void __dlm_unhash_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 159 {
 160         if (hlist_unhashed(&res->hash_node))
 161                 return;
 162
 163         mlog(0, "%s: Unhash res %.*s\n", dlm->name, res->lockname.len,
 164              res->lockname.name);
 165         hlist_del_init(&res->hash_node);
 166         dlm_lockres_put(res);
 167 }
 168
 169 void __dlm_insert_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 170 {
 171         struct hlist_head *bucket;
 172         struct qstr *q;
 173
 174         assert_spin_locked(&dlm->spinlock);
 175
 176         q = &res->lockname;
 177         bucket = dlm_lockres_hash(dlm, q->hash);
 178
 179         /* get a reference for our hashtable */
 180         dlm_lockres_get(res);
 181
 182         hlist_add_head(&res->hash_node, bucket);
 183
 184         mlog(0, "%s: Hash res %.*s\n", dlm->name, res->lockname.len,
 185              res->lockname.name);
 186 }
 187
 188 struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
 189                                                      const char *name,
 190                                                      unsigned int len,
 191                                                      unsigned int hash)
 192 {
 193         struct hlist_head *bucket;
 194         struct dlm_lock_resource *res;
 195
 196         mlog(0, "%.*s\n", len, name);
 197
 198         assert_spin_locked(&dlm->spinlock);
 199
 200         bucket = dlm_lockres_hash(dlm, hash);
 201
 202         hlist_for_each_entry(res, bucket, hash_node) {
 203                 if (res->lockname.name[0] != name[0])
 204                         continue;
 205                 if (unlikely(res->lockname.len != len))
 206                         continue;
 207                 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
 208                         continue;
 209                 dlm_lockres_get(res);
 210                 return res;
 211         }
 212         return NULL;
 213 }
 214
 215 /* intended to be called by functions which do not care about lock
 216  * resources which are being purged (most net _handler functions).
 217  * this will return NULL for any lock resource which is found but
 218  * currently in the process of dropping its mastery reference.
 219  * use __dlm_lookup_lockres_full when you need the lock resource
 220  * regardless (e.g. dlm_get_lock_resource) */
 221 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 222                                                 const char *name,
 223                                                 unsigned int len,
 224                                                 unsigned int hash)
 225 {
 226         struct dlm_lock_resource *res = NULL;
 227
 228         mlog(0, "%.*s\n", len, name);
 229
 230         assert_spin_locked(&dlm->spinlock);
 231
 232         res = __dlm_lookup_lockres_full(dlm, name, len, hash);
 233         if (res) {
 234                 spin_lock(&res->spinlock);
 235                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
 236                         spin_unlock(&res->spinlock);
 237                         dlm_lockres_put(res);
 238                         return NULL;
 239                 }
 240                 spin_unlock(&res->spinlock);
 241         }
 242
 243         return res;
 244 }
 245
 246 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 247                                     const char *name,
 248                                     unsigned int len)
 249 {
 250         struct dlm_lock_resource *res;
 251         unsigned int hash = dlm_lockid_hash(name, len);
 252
 253         spin_lock(&dlm->spinlock);
 254         res = __dlm_lookup_lockres(dlm, name, len, hash);
 255         spin_unlock(&dlm->spinlock);
 256         return res;
 257 }
 258
 259 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 260 {
 261         struct dlm_ctxt *tmp;
 262
 263         assert_spin_locked(&dlm_domain_lock);
 264
 265         /* tmp->name here is always NULL terminated,
 266          * but domain may not be! */
 267         list_for_each_entry(tmp, &dlm_domains, list) {
 268                 if (strlen(tmp->name) == len &&
 269                     memcmp(tmp->name, domain, len)==0)
 270                         return tmp;
 271         }
 272
 273         return NULL;
 274 }
 275
 276 /* For null terminated domain strings ONLY */
 277 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
 278 {
 279         assert_spin_locked(&dlm_domain_lock);
 280
 281         return __dlm_lookup_domain_full(domain, strlen(domain));
 282 }
 283
 284
 285 /* returns true on one of two conditions:
 286  * 1) the domain does not exist
 287  * 2) the domain exists and it's state is "joined" */
 288 static int dlm_wait_on_domain_helper(const char *domain)
 289 {
 290         int ret = 0;
 291         struct dlm_ctxt *tmp = NULL;
 292
 293         spin_lock(&dlm_domain_lock);
 294
 295         tmp = __dlm_lookup_domain(domain);
 296         if (!tmp)
 297                 ret = 1;
 298         else if (tmp->dlm_state == DLM_CTXT_JOINED)
 299                 ret = 1;
 300
 301         spin_unlock(&dlm_domain_lock);
 302         return ret;
 303 }
 304
 305 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 306 {
 307         dlm_destroy_debugfs_subroot(dlm);
 308
 309         if (dlm->lockres_hash)
 310                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 311
 312         if (dlm->master_hash)
 313                 dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
 314
 315         kfree(dlm->name);
 316         kfree(dlm);
 317 }
 318
 319 /* A little strange - this function will be called while holding
 320  * dlm_domain_lock and is expected to be holding it on the way out. We
 321  * will however drop and reacquire it multiple times */
 322 static void dlm_ctxt_release(struct kref *kref)
 323 {
 324         struct dlm_ctxt *dlm;
 325
 326         dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
 327
 328         BUG_ON(dlm->num_joins);
 329         BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
 330
 331         /* we may still be in the list if we hit an error during join. */
 332         list_del_init(&dlm->list);
 333
 334         spin_unlock(&dlm_domain_lock);
 335
 336         mlog(0, "freeing memory from domain %s\n", dlm->name);
 337
 338         wake_up(&dlm_domain_events);
 339
 340         dlm_free_ctxt_mem(dlm);
 341
 342         spin_lock(&dlm_domain_lock);
 343 }
 344
 345 void dlm_put(struct dlm_ctxt *dlm)
 346 {
 347         spin_lock(&dlm_domain_lock);
 348         kref_put(&dlm->dlm_refs, dlm_ctxt_release);
 349         spin_unlock(&dlm_domain_lock);
 350 }
 351
 352 static void __dlm_get(struct dlm_ctxt *dlm)
 353 {
 354         kref_get(&dlm->dlm_refs);
 355 }
 356
 357 /* given a questionable reference to a dlm object, gets a reference if
 358  * it can find it in the list, otherwise returns NULL in which case
 359  * you shouldn't trust your pointer. */
 360 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 361 {
 362         struct dlm_ctxt *target;
 363         struct dlm_ctxt *ret = NULL;
 364
 365         spin_lock(&dlm_domain_lock);
 366
 367         list_for_each_entry(target, &dlm_domains, list) {
 368                 if (target == dlm) {
 369                         __dlm_get(target);
 370                         ret = target;
 371                         break;
 372                 }
 373         }
 374
 375         spin_unlock(&dlm_domain_lock);
 376
 377         return ret;
 378 }
 379
 380 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 381 {
 382         int ret;
 383
 384         spin_lock(&dlm_domain_lock);
 385         ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
 386                 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
 387         spin_unlock(&dlm_domain_lock);
 388
 389         return ret;
 390 }
 391
 392 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 393 {
 394         if (dlm->dlm_worker) {
 395                 flush_workqueue(dlm->dlm_worker);
 396                 destroy_workqueue(dlm->dlm_worker);
 397                 dlm->dlm_worker = NULL;
 398         }
 399 }
 400
 401 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 402 {
 403         dlm_unregister_domain_handlers(dlm);
 404         dlm_debug_shutdown(dlm);
 405         dlm_complete_thread(dlm);
 406         dlm_complete_recovery_thread(dlm);
 407         dlm_destroy_dlm_worker(dlm);
 408
 409         /* We've left the domain. Now we can take ourselves out of the
 410          * list and allow the kref stuff to help us free the
 411          * memory. */
 412         spin_lock(&dlm_domain_lock);
 413         list_del_init(&dlm->list);
 414         spin_unlock(&dlm_domain_lock);
 415
 416         /* Wake up anyone waiting for us to remove this domain */
 417         wake_up(&dlm_domain_events);
 418 }
 419
 420 static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 421 {
 422         int i, num, n, ret = 0;
 423         struct dlm_lock_resource *res;
 424         struct hlist_node *iter;
 425         struct hlist_head *bucket;
 426         int dropped;
 427
 428         mlog(0, "Migrating locks from domain %s\n", dlm->name);
 429
 430         num = 0;
 431         spin_lock(&dlm->spinlock);
 432         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
 433 redo_bucket:
 434                 n = 0;
 435                 bucket = dlm_lockres_hash(dlm, i);
 436                 iter = bucket->first;
 437                 while (iter) {
 438                         n++;
 439                         res = hlist_entry(iter, struct dlm_lock_resource,
 440                                           hash_node);
 441                         dlm_lockres_get(res);
 442                         /* migrate, if necessary.  this will drop the dlm
 443                          * spinlock and retake it if it does migration. */
 444                         dropped = dlm_empty_lockres(dlm, res);
 445
 446                         spin_lock(&res->spinlock);
 447                         if (dropped)
 448                                 __dlm_lockres_calc_usage(dlm, res);
 449                         else
 450                                 iter = res->hash_node.next;
 451                         spin_unlock(&res->spinlock);
 452
 453                         dlm_lockres_put(res);
 454
 455                         if (dropped) {
 456                                 cond_resched_lock(&dlm->spinlock);
 457                                 goto redo_bucket;
 458                         }
 459                 }
 460                 cond_resched_lock(&dlm->spinlock);
 461                 num += n;
 462         }
 463         spin_unlock(&dlm->spinlock);
 464         wake_up(&dlm->dlm_thread_wq);
 465
 466         /* let the dlm thread take care of purging, keep scanning until
 467          * nothing remains in the hash */
 468         if (num) {
 469                 mlog(0, "%s: %d lock resources in hash last pass\n",
 470                      dlm->name, num);
 471                 ret = -EAGAIN;
 472         }
 473         mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
 474         return ret;
 475 }
 476
 477 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
 478 {
 479         int ret;
 480
 481         spin_lock(&dlm->spinlock);
 482         ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
 483         spin_unlock(&dlm->spinlock);
 484
 485         return ret;
 486 }
 487
 488 static int dlm_begin_exit_domain_handler(struct o2net_msg *msg, u32 len,
 489                                          void *data, void **ret_data)
 490 {
 491         struct dlm_ctxt *dlm = data;
 492         unsigned int node;
 493         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 494
 495         if (!dlm_grab(dlm))
 496                 return 0;
 497
 498         node = exit_msg->node_idx;
 499         mlog(0, "%s: Node %u sent a begin exit domain message\n", dlm->name, node);
 500
 501         spin_lock(&dlm->spinlock);
 502         set_bit(node, dlm->exit_domain_map);
 503         spin_unlock(&dlm->spinlock);
 504
 505         dlm_put(dlm);
 506
 507         return 0;
 508 }
 509
 510 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
 511 {
 512         /* Yikes, a double spinlock! I need domain_lock for the dlm
 513          * state and the dlm spinlock for join state... Sorry! */
 514 again:
 515         spin_lock(&dlm_domain_lock);
 516         spin_lock(&dlm->spinlock);
 517
 518         if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 519                 mlog(0, "Node %d is joining, we wait on it.\n",
 520                           dlm->joining_node);
 521                 spin_unlock(&dlm->spinlock);
 522                 spin_unlock(&dlm_domain_lock);
 523
 524                 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
 525                 goto again;
 526         }
 527
 528         dlm->dlm_state = DLM_CTXT_LEAVING;
 529         spin_unlock(&dlm->spinlock);
 530         spin_unlock(&dlm_domain_lock);
 531 }
 532
 533 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
 534 {
 535         int node = -1, num = 0;
 536
 537         assert_spin_locked(&dlm->spinlock);
 538
 539         printk("( ");
 540         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 541                                      node + 1)) < O2NM_MAX_NODES) {
 542                 printk("%d ", node);
 543                 ++num;
 544         }
 545         printk(") %u nodes\n", num);
 546 }
 547
 548 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 549                                    void **ret_data)
 550 {
 551         struct dlm_ctxt *dlm = data;
 552         unsigned int node;
 553         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 554
 555         mlog(0, "%p %u %p", msg, len, data);
 556
 557         if (!dlm_grab(dlm))
 558                 return 0;
 559
 560         node = exit_msg->node_idx;
 561
 562         spin_lock(&dlm->spinlock);
 563         clear_bit(node, dlm->domain_map);
 564         clear_bit(node, dlm->exit_domain_map);
 565         printk(KERN_NOTICE "o2dlm: Node %u leaves domain %s ", node, dlm->name);
 566         __dlm_print_nodes(dlm);
 567
 568         /* notify anything attached to the heartbeat events */
 569         dlm_hb_event_notify_attached(dlm, node, 0);
 570
 571         spin_unlock(&dlm->spinlock);
 572
 573         dlm_put(dlm);
 574
 575         return 0;
 576 }
 577
 578 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, u32 msg_type,
 579                                     unsigned int node)
 580 {
 581         int status;
 582         struct dlm_exit_domain leave_msg;
 583
 584         mlog(0, "%s: Sending domain exit message %u to node %u\n", dlm->name,
 585              msg_type, node);
 586
 587         memset(&leave_msg, 0, sizeof(leave_msg));
 588         leave_msg.node_idx = dlm->node_num;
 589
 590         status = o2net_send_message(msg_type, dlm->key, &leave_msg,
 591                                     sizeof(leave_msg), node, NULL);
 592         if (status < 0)
 593                 mlog(ML_ERROR, "Error %d sending domain exit message %u "
 594                      "to node %u on domain %s\n", status, msg_type, node,
 595                      dlm->name);
 596
 597         return status;
 598 }
 599
 600 static void dlm_begin_exit_domain(struct dlm_ctxt *dlm)
 601 {
 602         int node = -1;
 603
 604         /* Support for begin exit domain was added in 1.2 */
 605         if (dlm->dlm_locking_proto.pv_major == 1 &&
 606             dlm->dlm_locking_proto.pv_minor < 2)
 607                 return;
 608
 609         /*
 610          * Unlike DLM_EXIT_DOMAIN_MSG, DLM_BEGIN_EXIT_DOMAIN_MSG is purely
 611          * informational. Meaning if a node does not receive the message,
 612          * so be it.
 613          */
 614         spin_lock(&dlm->spinlock);
 615         while (1) {
 616                 node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, node + 1);
 617                 if (node >= O2NM_MAX_NODES)
 618                         break;
 619                 if (node == dlm->node_num)
 620                         continue;
 621
 622                 spin_unlock(&dlm->spinlock);
 623                 dlm_send_one_domain_exit(dlm, DLM_BEGIN_EXIT_DOMAIN_MSG, node);
 624                 spin_lock(&dlm->spinlock);
 625         }
 626         spin_unlock(&dlm->spinlock);
 627 }
 628
 629 static void dlm_leave_domain(struct dlm_ctxt *dlm)
 630 {
 631         int node, clear_node, status;
 632
 633         /* At this point we've migrated away all our locks and won't
 634          * accept mastership of new ones. The dlm is responsible for
 635          * almost nothing now. We make sure not to confuse any joining
 636          * nodes and then commence shutdown procedure. */
 637
 638         spin_lock(&dlm->spinlock);
 639         /* Clear ourselves from the domain map */
 640         clear_bit(dlm->node_num, dlm->domain_map);
 641         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 642                                      0)) < O2NM_MAX_NODES) {
 643                 /* Drop the dlm spinlock. This is safe wrt the domain_map.
 644                  * -nodes cannot be added now as the
 645                  *   query_join_handlers knows to respond with OK_NO_MAP
 646                  * -we catch the right network errors if a node is
 647                  *   removed from the map while we're sending him the
 648                  *   exit message. */
 649                 spin_unlock(&dlm->spinlock);
 650
 651                 clear_node = 1;
 652
 653                 status = dlm_send_one_domain_exit(dlm, DLM_EXIT_DOMAIN_MSG,
 654                                                   node);
 655                 if (status < 0 &&
 656                     status != -ENOPROTOOPT &&
 657                     status != -ENOTCONN) {
 658                         mlog(ML_NOTICE, "Error %d sending domain exit message "
 659                              "to node %d\n", status, node);
 660
 661                         /* Not sure what to do here but lets sleep for
 662                          * a bit in case this was a transient
 663                          * error... */
 664                         msleep(DLM_DOMAIN_BACKOFF_MS);
 665                         clear_node = 0;
 666                 }
 667
 668                 spin_lock(&dlm->spinlock);
 669                 /* If we're not clearing the node bit then we intend
 670                  * to loop back around to try again. */
 671                 if (clear_node)
 672                         clear_bit(node, dlm->domain_map);
 673         }
 674         spin_unlock(&dlm->spinlock);
 675 }
 676
 677 int dlm_joined(struct dlm_ctxt *dlm)
 678 {
 679         int ret = 0;
 680
 681         spin_lock(&dlm_domain_lock);
 682
 683         if (dlm->dlm_state == DLM_CTXT_JOINED)
 684                 ret = 1;
 685
 686         spin_unlock(&dlm_domain_lock);
 687
 688         return ret;
 689 }
 690
 691 int dlm_shutting_down(struct dlm_ctxt *dlm)
 692 {
 693         int ret = 0;
 694
 695         spin_lock(&dlm_domain_lock);
 696
 697         if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
 698                 ret = 1;
 699
 700         spin_unlock(&dlm_domain_lock);
 701
 702         return ret;
 703 }
 704
 705 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 706 {
 707         int leave = 0;
 708         struct dlm_lock_resource *res;
 709
 710         spin_lock(&dlm_domain_lock);
 711         BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
 712         BUG_ON(!dlm->num_joins);
 713
 714         dlm->num_joins--;
 715         if (!dlm->num_joins) {
 716                 /* We mark it "in shutdown" now so new register
 717                  * requests wait until we've completely left the
 718                  * domain. Don't use DLM_CTXT_LEAVING yet as we still
 719                  * want new domain joins to communicate with us at
 720                  * least until we've completed migration of our
 721                  * resources. */
 722                 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
 723                 leave = 1;
 724         }
 725         spin_unlock(&dlm_domain_lock);
 726
 727         if (leave) {
 728                 mlog(0, "shutting down domain %s\n", dlm->name);
 729                 dlm_begin_exit_domain(dlm);
 730
 731                 /* We changed dlm state, notify the thread */
 732                 dlm_kick_thread(dlm, NULL);
 733
 734                 while (dlm_migrate_all_locks(dlm)) {
 735                         /* Give dlm_thread time to purge the lockres' */
 736                         msleep(500);
 737                         mlog(0, "%s: more migration to do\n", dlm->name);
 738                 }
 739
 740                 /* This list should be empty. If not, print remaining lockres */
 741                 if (!list_empty(&dlm->tracking_list)) {
 742                         mlog(ML_ERROR, "Following lockres' are still on the "
 743                              "tracking list:\n");
 744                         list_for_each_entry(res, &dlm->tracking_list, tracking)
 745                                 dlm_print_one_lock_resource(res);
 746                 }
 747
 748                 dlm_mark_domain_leaving(dlm);
 749                 dlm_leave_domain(dlm);
 750                 printk(KERN_NOTICE "o2dlm: Leaving domain %s\n", dlm->name);
 751                 dlm_force_free_mles(dlm);
 752                 dlm_complete_dlm_shutdown(dlm);
 753         }
 754         dlm_put(dlm);
 755 }
 756 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 757
 758 static int dlm_query_join_proto_check(char *proto_type, int node,
 759                                       struct dlm_protocol_version *ours,
 760                                       struct dlm_protocol_version *request)
 761 {
 762         int rc;
 763         struct dlm_protocol_version proto = *request;
 764
 765         if (!dlm_protocol_compare(ours, &proto)) {
 766                 mlog(0,
 767                      "node %u wanted to join with %s locking protocol "
 768                      "%u.%u, we respond with %u.%u\n",
 769                      node, proto_type,
 770                      request->pv_major,
 771                      request->pv_minor,
 772                      proto.pv_major, proto.pv_minor);
 773                 request->pv_minor = proto.pv_minor;
 774                 rc = 0;
 775         } else {
 776                 mlog(ML_NOTICE,
 777                      "Node %u wanted to join with %s locking "
 778                      "protocol %u.%u, but we have %u.%u, disallowing\n",
 779                      node, proto_type,
 780                      request->pv_major,
 781                      request->pv_minor,
 782                      ours->pv_major,
 783                      ours->pv_minor);
 784                 rc = 1;
 785         }
 786
 787         return rc;
 788 }
 789
 790 /*
 791  * struct dlm_query_join_packet is made up of four one-byte fields.  They
 792  * are effectively in big-endian order already.  However, little-endian
 793  * machines swap them before putting the packet on the wire (because
 794  * query_join's response is a status, and that status is treated as a u32
 795  * on the wire).  Thus, a big-endian and little-endian machines will treat
 796  * this structure differently.
 797  *
 798  * The solution is to have little-endian machines swap the structure when
 799  * converting from the structure to the u32 representation.  This will
 800  * result in the structure having the correct format on the wire no matter
 801  * the host endian format.
 802  */
 803 static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
 804                                           u32 *wire)
 805 {
 806         union dlm_query_join_response response;
 807
 808         response.packet = *packet;
 809         *wire = be32_to_cpu(response.intval);
 810 }
 811
 812 static void dlm_query_join_wire_to_packet(u32 wire,
 813                                           struct dlm_query_join_packet *packet)
 814 {
 815         union dlm_query_join_response response;
 816
 817         response.intval = cpu_to_be32(wire);
 818         *packet = response.packet;
 819 }
 820
 821 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 822                                   void **ret_data)
 823 {
 824         struct dlm_query_join_request *query;
 825         struct dlm_query_join_packet packet = {
 826                 .code = JOIN_DISALLOW,
 827         };
 828         struct dlm_ctxt *dlm = NULL;
 829         u32 response;
 830         u8 nodenum;
 831
 832         query = (struct dlm_query_join_request *) msg->buf;
 833
 834         mlog(0, "node %u wants to join domain %s\n", query->node_idx,
 835                   query->domain);
 836
 837         /*
 838          * If heartbeat doesn't consider the node live, tell it
 839          * to back off and try again.  This gives heartbeat a chance
 840          * to catch up.
 841          */
 842         if (!o2hb_check_node_heartbeating_no_sem(query->node_idx)) {
 843                 mlog(0, "node %u is not in our live map yet\n",
 844                      query->node_idx);
 845
 846                 packet.code = JOIN_DISALLOW;
 847                 goto respond;
 848         }
 849
 850         packet.code = JOIN_OK_NO_MAP;
 851
 852         spin_lock(&dlm_domain_lock);
 853         dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 854         if (!dlm)
 855                 goto unlock_respond;
 856
 857         /*
 858          * There is a small window where the joining node may not see the
 859          * node(s) that just left but still part of the cluster. DISALLOW
 860          * join request if joining node has different node map.
 861          */
 862         nodenum=0;
 863         while (nodenum < O2NM_MAX_NODES) {
 864                 if (test_bit(nodenum, dlm->domain_map)) {
 865                         if (!byte_test_bit(nodenum, query->node_map)) {
 866                                 mlog(0, "disallow join as node %u does not "
 867                                      "have node %u in its nodemap\n",
 868                                      query->node_idx, nodenum);
 869                                 packet.code = JOIN_DISALLOW;
 870                                 goto unlock_respond;
 871                         }
 872                 }
 873                 nodenum++;
 874         }
 875
 876         /* Once the dlm ctxt is marked as leaving then we don't want
 877          * to be put in someone's domain map.
 878          * Also, explicitly disallow joining at certain troublesome
 879          * times (ie. during recovery). */
 880         if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
 881                 int bit = query->node_idx;
 882                 spin_lock(&dlm->spinlock);
 883
 884                 if (dlm->dlm_state == DLM_CTXT_NEW &&
 885                     dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
 886                         /*If this is a brand new context and we
 887                          * haven't started our join process yet, then
 888                          * the other node won the race. */
 889                         packet.code = JOIN_OK_NO_MAP;
 890                 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 891                         /* Disallow parallel joins. */
 892                         packet.code = JOIN_DISALLOW;
 893                 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 894                         mlog(0, "node %u trying to join, but recovery "
 895                              "is ongoing.\n", bit);
 896                         packet.code = JOIN_DISALLOW;
 897                 } else if (test_bit(bit, dlm->recovery_map)) {
 898                         mlog(0, "node %u trying to join, but it "
 899                              "still needs recovery.\n", bit);
 900                         packet.code = JOIN_DISALLOW;
 901                 } else if (test_bit(bit, dlm->domain_map)) {
 902                         mlog(0, "node %u trying to join, but it "
 903                              "is still in the domain! needs recovery?\n",
 904                              bit);
 905                         packet.code = JOIN_DISALLOW;
 906                 } else {
 907                         /* Alright we're fully a part of this domain
 908                          * so we keep some state as to who's joining
 909                          * and indicate to him that needs to be fixed
 910                          * up. */
 911
 912                         /* Make sure we speak compatible locking protocols.  */
 913                         if (dlm_query_join_proto_check("DLM", bit,
 914                                                        &dlm->dlm_locking_proto,
 915                                                        &query->dlm_proto)) {
 916                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 917                         } else if (dlm_query_join_proto_check("fs", bit,
 918                                                               &dlm->fs_locking_proto,
 919                                                               &query->fs_proto)) {
 920                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 921                         } else {
 922                                 packet.dlm_minor = query->dlm_proto.pv_minor;
 923                                 packet.fs_minor = query->fs_proto.pv_minor;
 924                                 packet.code = JOIN_OK;
 925                                 __dlm_set_joining_node(dlm, query->node_idx);
 926                         }
 927                 }
 928
 929                 spin_unlock(&dlm->spinlock);
 930         }
 931 unlock_respond:
 932         spin_unlock(&dlm_domain_lock);
 933
 934 respond:
 935         mlog(0, "We respond with %u\n", packet.code);
 936
 937         dlm_query_join_packet_to_wire(&packet, &response);
 938         return response;
 939 }
 940
 941 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 942                                      void **ret_data)
 943 {
 944         struct dlm_assert_joined *assert;
 945         struct dlm_ctxt *dlm = NULL;
 946
 947         assert = (struct dlm_assert_joined *) msg->buf;
 948
 949         mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
 950                   assert->domain);
 951
 952         spin_lock(&dlm_domain_lock);
 953         dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
 954         /* XXX should we consider no dlm ctxt an error? */
 955         if (dlm) {
 956                 spin_lock(&dlm->spinlock);
 957
 958                 /* Alright, this node has officially joined our
 959                  * domain. Set him in the map and clean up our
 960                  * leftover join state. */
 961                 BUG_ON(dlm->joining_node != assert->node_idx);
 962
 963                 if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 964                         mlog(0, "dlm recovery is ongoing, disallow join\n");
 965                         spin_unlock(&dlm->spinlock);
 966                         spin_unlock(&dlm_domain_lock);
 967                         return -EAGAIN;
 968                 }
 969
 970                 set_bit(assert->node_idx, dlm->domain_map);
 971                 clear_bit(assert->node_idx, dlm->exit_domain_map);
 972                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 973
 974                 printk(KERN_NOTICE "o2dlm: Node %u joins domain %s ",
 975                        assert->node_idx, dlm->name);
 976                 __dlm_print_nodes(dlm);
 977
 978                 /* notify anything attached to the heartbeat events */
 979                 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
 980
 981                 spin_unlock(&dlm->spinlock);
 982         }
 983         spin_unlock(&dlm_domain_lock);
 984
 985         return 0;
 986 }
 987
 988 static int dlm_match_regions(struct dlm_ctxt *dlm,
 989                              struct dlm_query_region *qr,
 990                              char *local, int locallen)
 991 {
 992         char *remote = qr->qr_regions;
 993         char *l, *r;
 994         int localnr, i, j, foundit;
 995         int status = 0;
 996
 997         if (!o2hb_global_heartbeat_active()) {
 998                 if (qr->qr_numregions) {
 999                         mlog(ML_ERROR, "Domain %s: Joining node %d has global "
1000                              "heartbeat enabled but local node %d does not\n",
1001                              qr->qr_domain, qr->qr_node, dlm->node_num);
1002                         status = -EINVAL;
1003                 }
1004                 goto bail;
1005         }
1006
1007         if (o2hb_global_heartbeat_active() && !qr->qr_numregions) {
1008                 mlog(ML_ERROR, "Domain %s: Local node %d has global "
1009                      "heartbeat enabled but joining node %d does not\n",
1010                      qr->qr_domain, dlm->node_num, qr->qr_node);
1011                 status = -EINVAL;
1012                 goto bail;
1013         }
1014
1015         r = remote;
1016         for (i = 0; i < qr->qr_numregions; ++i) {
1017                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, r);
1018                 r += O2HB_MAX_REGION_NAME_LEN;
1019         }
1020
1021         localnr = min(O2NM_MAX_REGIONS, locallen/O2HB_MAX_REGION_NAME_LEN);
1022         localnr = o2hb_get_all_regions(local, (u8)localnr);
1023
1024         /* compare local regions with remote */
1025         l = local;
1026         for (i = 0; i < localnr; ++i) {
1027                 foundit = 0;
1028                 r = remote;
1029                 for (j = 0; j <= qr->qr_numregions; ++j) {
1030                         if (!memcmp(l, r, O2HB_MAX_REGION_NAME_LEN)) {
1031                                 foundit = 1;
1032                                 break;
1033                         }
1034                         r += O2HB_MAX_REGION_NAME_LEN;
1035                 }
1036                 if (!foundit) {
1037                         status = -EINVAL;
1038                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1039                              "in local node %d but not in joining node %d\n",
1040                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, l,
1041                              dlm->node_num, qr->qr_node);
1042                         goto bail;
1043                 }
1044                 l += O2HB_MAX_REGION_NAME_LEN;
1045         }
1046
1047         /* compare remote with local regions */
1048         r = remote;
1049         for (i = 0; i < qr->qr_numregions; ++i) {
1050                 foundit = 0;
1051                 l = local;
1052                 for (j = 0; j < localnr; ++j) {
1053                         if (!memcmp(r, l, O2HB_MAX_REGION_NAME_LEN)) {
1054                                 foundit = 1;
1055                                 break;
1056                         }
1057                         l += O2HB_MAX_REGION_NAME_LEN;
1058                 }
1059                 if (!foundit) {
1060                         status = -EINVAL;
1061                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1062                              "in joining node %d but not in local node %d\n",
1063                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, r,
1064                              qr->qr_node, dlm->node_num);
1065                         goto bail;
1066                 }
1067                 r += O2HB_MAX_REGION_NAME_LEN;
1068         }
1069
1070 bail:
1071         return status;
1072 }
1073
1074 static int dlm_send_regions(struct dlm_ctxt *dlm, unsigned long *node_map)
1075 {
1076         struct dlm_query_region *qr = NULL;
1077         int status, ret = 0, i;
1078         char *p;
1079
1080         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1081                 goto bail;
1082
1083         qr = kzalloc(sizeof(struct dlm_query_region), GFP_KERNEL);
1084         if (!qr) {
1085                 ret = -ENOMEM;
1086                 mlog_errno(ret);
1087                 goto bail;
1088         }
1089
1090         qr->qr_node = dlm->node_num;
1091         qr->qr_namelen = strlen(dlm->name);
1092         memcpy(qr->qr_domain, dlm->name, qr->qr_namelen);
1093         /* if local hb, the numregions will be zero */
1094         if (o2hb_global_heartbeat_active())
1095                 qr->qr_numregions = o2hb_get_all_regions(qr->qr_regions,
1096                                                          O2NM_MAX_REGIONS);
1097
1098         p = qr->qr_regions;
1099         for (i = 0; i < qr->qr_numregions; ++i, p += O2HB_MAX_REGION_NAME_LEN)
1100                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, p);
1101
1102         i = -1;
1103         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1104                                   i + 1)) < O2NM_MAX_NODES) {
1105                 if (i == dlm->node_num)
1106                         continue;
1107
1108                 mlog(0, "Sending regions to node %d\n", i);
1109
1110                 ret = o2net_send_message(DLM_QUERY_REGION, DLM_MOD_KEY, qr,
1111                                          sizeof(struct dlm_query_region),
1112                                          i, &status);
1113                 if (ret >= 0)
1114                         ret = status;
1115                 if (ret) {
1116                         mlog(ML_ERROR, "Region mismatch %d, node %d\n",
1117                              ret, i);
1118                         break;
1119                 }
1120         }
1121
1122 bail:
1123         kfree(qr);
1124         return ret;
1125 }
1126
1127 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
1128                                     void *data, void **ret_data)
1129 {
1130         struct dlm_query_region *qr;
1131         struct dlm_ctxt *dlm = NULL;
1132         char *local = NULL;
1133         int status = 0;
1134
1135         qr = (struct dlm_query_region *) msg->buf;
1136
1137         mlog(0, "Node %u queries hb regions on domain %s\n", qr->qr_node,
1138              qr->qr_domain);
1139
1140         /* buffer used in dlm_mast_regions() */
1141         local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
1142         if (!local)
1143                 return -ENOMEM;
1144
1145         status = -EINVAL;
1146
1147         spin_lock(&dlm_domain_lock);
1148         dlm = __dlm_lookup_domain_full(qr->qr_domain, qr->qr_namelen);
1149         if (!dlm) {
1150                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1151                      "before join domain\n", qr->qr_node, qr->qr_domain);
1152                 goto out_domain_lock;
1153         }
1154
1155         spin_lock(&dlm->spinlock);
1156         if (dlm->joining_node != qr->qr_node) {
1157                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1158                      "but joining node is %d\n", qr->qr_node, qr->qr_domain,
1159                      dlm->joining_node);
1160                 goto out_dlm_lock;
1161         }
1162
1163         /* Support for global heartbeat was added in 1.1 */
1164         if (dlm->dlm_locking_proto.pv_major == 1 &&
1165             dlm->dlm_locking_proto.pv_minor == 0) {
1166                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1167                      "but active dlm protocol is %d.%d\n", qr->qr_node,
1168                      qr->qr_domain, dlm->dlm_locking_proto.pv_major,
1169                      dlm->dlm_locking_proto.pv_minor);
1170                 goto out_dlm_lock;
1171         }
1172
1173         status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
1174
1175 out_dlm_lock:
1176         spin_unlock(&dlm->spinlock);
1177
1178 out_domain_lock:
1179         spin_unlock(&dlm_domain_lock);
1180
1181         kfree(local);
1182
1183         return status;
1184 }
1185
1186 static int dlm_match_nodes(struct dlm_ctxt *dlm, struct dlm_query_nodeinfo *qn)
1187 {
1188         struct o2nm_node *local;
1189         struct dlm_node_info *remote;
1190         int i, j;
1191         int status = 0;
1192
1193         for (j = 0; j < qn->qn_numnodes; ++j)
1194                 mlog(0, "Node %3d, %pI4:%u\n", qn->qn_nodes[j].ni_nodenum,
1195                      &(qn->qn_nodes[j].ni_ipv4_address),
1196                      ntohs(qn->qn_nodes[j].ni_ipv4_port));
1197
1198         for (i = 0; i < O2NM_MAX_NODES && !status; ++i) {
1199                 local = o2nm_get_node_by_num(i);
1200                 remote = NULL;
1201                 for (j = 0; j < qn->qn_numnodes; ++j) {
1202                         if (qn->qn_nodes[j].ni_nodenum == i) {
1203                                 remote = &(qn->qn_nodes[j]);
1204                                 break;
1205                         }
1206                 }
1207
1208                 if (!local && !remote)
1209                         continue;
1210
1211                 if ((local && !remote) || (!local && remote))
1212                         status = -EINVAL;
1213
1214                 if (!status &&
1215                     ((remote->ni_nodenum != local->nd_num) ||
1216                      (remote->ni_ipv4_port != local->nd_ipv4_port) ||
1217                      (remote->ni_ipv4_address != local->nd_ipv4_address)))
1218                         status = -EINVAL;
1219
1220                 if (status) {
1221                         if (remote && !local)
1222                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1223                                      "registered in joining node %d but not in "
1224                                      "local node %d\n", qn->qn_domain,
1225                                      remote->ni_nodenum,
1226                                      &(remote->ni_ipv4_address),
1227                                      ntohs(remote->ni_ipv4_port),
1228                                      qn->qn_nodenum, dlm->node_num);
1229                         if (local && !remote)
1230                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1231                                      "registered in local node %d but not in "
1232                                      "joining node %d\n", qn->qn_domain,
1233                                      local->nd_num, &(local->nd_ipv4_address),
1234                                      ntohs(local->nd_ipv4_port),
1235                                      dlm->node_num, qn->qn_nodenum);
1236                         BUG_ON((!local && !remote));
1237                 }
1238
1239                 if (local)
1240                         o2nm_node_put(local);
1241         }
1242
1243         return status;
1244 }
1245
1246 static int dlm_send_nodeinfo(struct dlm_ctxt *dlm, unsigned long *node_map)
1247 {
1248         struct dlm_query_nodeinfo *qn = NULL;
1249         struct o2nm_node *node;
1250         int ret = 0, status, count, i;
1251
1252         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1253                 goto bail;
1254
1255         qn = kzalloc(sizeof(struct dlm_query_nodeinfo), GFP_KERNEL);
1256         if (!qn) {
1257                 ret = -ENOMEM;
1258                 mlog_errno(ret);
1259                 goto bail;
1260         }
1261
1262         for (i = 0, count = 0; i < O2NM_MAX_NODES; ++i) {
1263                 node = o2nm_get_node_by_num(i);
1264                 if (!node)
1265                         continue;
1266                 qn->qn_nodes[count].ni_nodenum = node->nd_num;
1267                 qn->qn_nodes[count].ni_ipv4_port = node->nd_ipv4_port;
1268                 qn->qn_nodes[count].ni_ipv4_address = node->nd_ipv4_address;
1269                 mlog(0, "Node %3d, %pI4:%u\n", node->nd_num,
1270                      &(node->nd_ipv4_address), ntohs(node->nd_ipv4_port));
1271                 ++count;
1272                 o2nm_node_put(node);
1273         }
1274
1275         qn->qn_nodenum = dlm->node_num;
1276         qn->qn_numnodes = count;
1277         qn->qn_namelen = strlen(dlm->name);
1278         memcpy(qn->qn_domain, dlm->name, qn->qn_namelen);
1279
1280         i = -1;
1281         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1282                                   i + 1)) < O2NM_MAX_NODES) {
1283                 if (i == dlm->node_num)
1284                         continue;
1285
1286                 mlog(0, "Sending nodeinfo to node %d\n", i);
1287
1288                 ret = o2net_send_message(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
1289                                          qn, sizeof(struct dlm_query_nodeinfo),
1290                                          i, &status);
1291                 if (ret >= 0)
1292                         ret = status;
1293                 if (ret) {
1294                         mlog(ML_ERROR, "node mismatch %d, node %d\n", ret, i);
1295                         break;
1296                 }
1297         }
1298
1299 bail:
1300         kfree(qn);
1301         return ret;
1302 }
1303
1304 static int dlm_query_nodeinfo_handler(struct o2net_msg *msg, u32 len,
1305                                       void *data, void **ret_data)
1306 {
1307         struct dlm_query_nodeinfo *qn;
1308         struct dlm_ctxt *dlm = NULL;
1309         int locked = 0, status = -EINVAL;
1310
1311         qn = (struct dlm_query_nodeinfo *) msg->buf;
1312
1313         mlog(0, "Node %u queries nodes on domain %s\n", qn->qn_nodenum,
1314              qn->qn_domain);
1315
1316         spin_lock(&dlm_domain_lock);
1317         dlm = __dlm_lookup_domain_full(qn->qn_domain, qn->qn_namelen);
1318         if (!dlm) {
1319                 mlog(ML_ERROR, "Node %d queried nodes on domain %s before "
1320                      "join domain\n", qn->qn_nodenum, qn->qn_domain);
1321                 goto bail;
1322         }
1323
1324         spin_lock(&dlm->spinlock);
1325         locked = 1;
1326         if (dlm->joining_node != qn->qn_nodenum) {
1327                 mlog(ML_ERROR, "Node %d queried nodes on domain %s but "
1328                      "joining node is %d\n", qn->qn_nodenum, qn->qn_domain,
1329                      dlm->joining_node);
1330                 goto bail;
1331         }
1332
1333         /* Support for node query was added in 1.1 */
1334         if (dlm->dlm_locking_proto.pv_major == 1 &&
1335             dlm->dlm_locking_proto.pv_minor == 0) {
1336                 mlog(ML_ERROR, "Node %d queried nodes on domain %s "
1337                      "but active dlm protocol is %d.%d\n", qn->qn_nodenum,
1338                      qn->qn_domain, dlm->dlm_locking_proto.pv_major,
1339                      dlm->dlm_locking_proto.pv_minor);
1340                 goto bail;
1341         }
1342
1343         status = dlm_match_nodes(dlm, qn);
1344
1345 bail:
1346         if (locked)
1347                 spin_unlock(&dlm->spinlock);
1348         spin_unlock(&dlm_domain_lock);
1349
1350         return status;
1351 }
1352
1353 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
1354                                    void **ret_data)
1355 {
1356         struct dlm_cancel_join *cancel;
1357         struct dlm_ctxt *dlm = NULL;
1358
1359         cancel = (struct dlm_cancel_join *) msg->buf;
1360
1361         mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
1362                   cancel->domain);
1363
1364         spin_lock(&dlm_domain_lock);
1365         dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
1366
1367         if (dlm) {
1368                 spin_lock(&dlm->spinlock);
1369
1370                 /* Yikes, this guy wants to cancel his join. No
1371                  * problem, we simply cleanup our join state. */
1372                 BUG_ON(dlm->joining_node != cancel->node_idx);
1373                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1374
1375                 spin_unlock(&dlm->spinlock);
1376         }
1377         spin_unlock(&dlm_domain_lock);
1378
1379         return 0;
1380 }
1381
1382 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
1383                                     unsigned int node)
1384 {
1385         int status;
1386         struct dlm_cancel_join cancel_msg;
1387
1388         memset(&cancel_msg, 0, sizeof(cancel_msg));
1389         cancel_msg.node_idx = dlm->node_num;
1390         cancel_msg.name_len = strlen(dlm->name);
1391         memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
1392
1393         status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1394                                     &cancel_msg, sizeof(cancel_msg), node,
1395                                     NULL);
1396         if (status < 0) {
1397                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1398                      "node %u\n", status, DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1399                      node);
1400                 goto bail;
1401         }
1402
1403 bail:
1404         return status;
1405 }
1406
1407 /* map_size should be in bytes. */
1408 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
1409                                  unsigned long *node_map,
1410                                  unsigned int map_size)
1411 {
1412         int status, tmpstat;
1413         unsigned int node;
1414
1415         if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
1416                          sizeof(unsigned long))) {
1417                 mlog(ML_ERROR,
1418                      "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
1419                      map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
1420                 return -EINVAL;
1421         }
1422
1423         status = 0;
1424         node = -1;
1425         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1426                                      node + 1)) < O2NM_MAX_NODES) {
1427                 if (node == dlm->node_num)
1428                         continue;
1429
1430                 tmpstat = dlm_send_one_join_cancel(dlm, node);
1431                 if (tmpstat) {
1432                         mlog(ML_ERROR, "Error return %d cancelling join on "
1433                              "node %d\n", tmpstat, node);
1434                         if (!status)
1435                                 status = tmpstat;
1436                 }
1437         }
1438
1439         if (status)
1440                 mlog_errno(status);
1441         return status;
1442 }
1443
1444 static int dlm_request_join(struct dlm_ctxt *dlm,
1445                             int node,
1446                             enum dlm_query_join_response_code *response)
1447 {
1448         int status;
1449         struct dlm_query_join_request join_msg;
1450         struct dlm_query_join_packet packet;
1451         u32 join_resp;
1452
1453         mlog(0, "querying node %d\n", node);
1454
1455         memset(&join_msg, 0, sizeof(join_msg));
1456         join_msg.node_idx = dlm->node_num;
1457         join_msg.name_len = strlen(dlm->name);
1458         memcpy(join_msg.domain, dlm->name, join_msg.name_len);
1459         join_msg.dlm_proto = dlm->dlm_locking_proto;
1460         join_msg.fs_proto = dlm->fs_locking_proto;
1461
1462         /* copy live node map to join message */
1463         byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
1464
1465         status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
1466                                     sizeof(join_msg), node, &join_resp);
1467         if (status < 0 && status != -ENOPROTOOPT) {
1468                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1469                      "node %u\n", status, DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1470                      node);
1471                 goto bail;
1472         }
1473         dlm_query_join_wire_to_packet(join_resp, &packet);
1474
1475         /* -ENOPROTOOPT from the net code means the other side isn't
1476             listening for our message type -- that's fine, it means
1477             his dlm isn't up, so we can consider him a 'yes' but not
1478             joined into the domain.  */
1479         if (status == -ENOPROTOOPT) {
1480                 status = 0;
1481                 *response = JOIN_OK_NO_MAP;
1482         } else if (packet.code == JOIN_DISALLOW ||
1483                    packet.code == JOIN_OK_NO_MAP) {
1484                 *response = packet.code;
1485         } else if (packet.code == JOIN_PROTOCOL_MISMATCH) {
1486                 mlog(ML_NOTICE,
1487                      "This node requested DLM locking protocol %u.%u and "
1488                      "filesystem locking protocol %u.%u.  At least one of "
1489                      "the protocol versions on node %d is not compatible, "
1490                      "disconnecting\n",
1491                      dlm->dlm_locking_proto.pv_major,
1492                      dlm->dlm_locking_proto.pv_minor,
1493                      dlm->fs_locking_proto.pv_major,
1494                      dlm->fs_locking_proto.pv_minor,
1495                      node);
1496                 status = -EPROTO;
1497                 *response = packet.code;
1498         } else if (packet.code == JOIN_OK) {
1499                 *response = packet.code;
1500                 /* Use the same locking protocol as the remote node */
1501                 dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
1502                 dlm->fs_locking_proto.pv_minor = packet.fs_minor;
1503                 mlog(0,
1504                      "Node %d responds JOIN_OK with DLM locking protocol "
1505                      "%u.%u and fs locking protocol %u.%u\n",
1506                      node,
1507                      dlm->dlm_locking_proto.pv_major,
1508                      dlm->dlm_locking_proto.pv_minor,
1509                      dlm->fs_locking_proto.pv_major,
1510                      dlm->fs_locking_proto.pv_minor);
1511         } else {
1512                 status = -EINVAL;
1513                 mlog(ML_ERROR, "invalid response %d from node %u\n",
1514                      packet.code, node);
1515         }
1516
1517         mlog(0, "status %d, node %d response is %d\n", status, node,
1518              *response);
1519
1520 bail:
1521         return status;
1522 }
1523
1524 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
1525                                     unsigned int node)
1526 {
1527         int status;
1528         int ret;
1529         struct dlm_assert_joined assert_msg;
1530
1531         mlog(0, "Sending join assert to node %u\n", node);
1532
1533         memset(&assert_msg, 0, sizeof(assert_msg));
1534         assert_msg.node_idx = dlm->node_num;
1535         assert_msg.name_len = strlen(dlm->name);
1536         memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
1537
1538         status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1539                                     &assert_msg, sizeof(assert_msg), node,
1540                                     &ret);
1541         if (status < 0)
1542                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1543                      "node %u\n", status, DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1544                      node);
1545         else
1546                 status = ret;
1547
1548         return status;
1549 }
1550
1551 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
1552                                   unsigned long *node_map)
1553 {
1554         int status, node, live;
1555
1556         status = 0;
1557         node = -1;
1558         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1559                                      node + 1)) < O2NM_MAX_NODES) {
1560                 if (node == dlm->node_num)
1561                         continue;
1562
1563                 do {
1564                         /* It is very important that this message be
1565                          * received so we spin until either the node
1566                          * has died or it gets the message. */
1567                         status = dlm_send_one_join_assert(dlm, node);
1568
1569                         spin_lock(&dlm->spinlock);
1570                         live = test_bit(node, dlm->live_nodes_map);
1571                         spin_unlock(&dlm->spinlock);
1572
1573                         if (status) {
1574                                 mlog(ML_ERROR, "Error return %d asserting "
1575                                      "join on node %d\n", status, node);
1576
1577                                 /* give us some time between errors... */
1578                                 if (live)
1579                                         msleep(DLM_DOMAIN_BACKOFF_MS);
1580                         }
1581                 } while (status && live);
1582         }
1583 }
1584
1585 struct domain_join_ctxt {
1586         unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1587         unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1588 };
1589
1590 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
1591                                    struct domain_join_ctxt *ctxt,
1592                                    enum dlm_query_join_response_code response)
1593 {
1594         int ret;
1595
1596         if (response == JOIN_DISALLOW) {
1597                 mlog(0, "Latest response of disallow -- should restart\n");
1598                 return 1;
1599         }
1600
1601         spin_lock(&dlm->spinlock);
1602         /* For now, we restart the process if the node maps have
1603          * changed at all */
1604         ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
1605                      sizeof(dlm->live_nodes_map));
1606         spin_unlock(&dlm->spinlock);
1607
1608         if (ret)
1609                 mlog(0, "Node maps changed -- should restart\n");
1610
1611         return ret;
1612 }
1613
1614 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
1615 {
1616         int status = 0, tmpstat, node;
1617         struct domain_join_ctxt *ctxt;
1618         enum dlm_query_join_response_code response = JOIN_DISALLOW;
1619
1620         mlog(0, "%p", dlm);
1621
1622         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
1623         if (!ctxt) {
1624                 status = -ENOMEM;
1625                 mlog_errno(status);
1626                 goto bail;
1627         }
1628
1629         /* group sem locking should work for us here -- we're already
1630          * registered for heartbeat events so filling this should be
1631          * atomic wrt getting those handlers called. */
1632         o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
1633
1634         spin_lock(&dlm->spinlock);
1635         memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
1636
1637         __dlm_set_joining_node(dlm, dlm->node_num);
1638
1639         spin_unlock(&dlm->spinlock);
1640
1641         node = -1;
1642         while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
1643                                      node + 1)) < O2NM_MAX_NODES) {
1644                 if (node == dlm->node_num)
1645                         continue;
1646
1647                 status = dlm_request_join(dlm, node, &response);
1648                 if (status < 0) {
1649                         mlog_errno(status);
1650                         goto bail;
1651                 }
1652
1653                 /* Ok, either we got a response or the node doesn't have a
1654                  * dlm up. */
1655                 if (response == JOIN_OK)
1656                         set_bit(node, ctxt->yes_resp_map);
1657
1658                 if (dlm_should_restart_join(dlm, ctxt, response)) {
1659                         status = -EAGAIN;
1660                         goto bail;
1661                 }
1662         }
1663
1664         mlog(0, "Yay, done querying nodes!\n");
1665
1666         /* Yay, everyone agree's we can join the domain. My domain is
1667          * comprised of all nodes who were put in the
1668          * yes_resp_map. Copy that into our domain map and send a join
1669          * assert message to clean up everyone elses state. */
1670         spin_lock(&dlm->spinlock);
1671         memcpy(dlm->domain_map, ctxt->yes_resp_map,
1672                sizeof(ctxt->yes_resp_map));
1673         set_bit(dlm->node_num, dlm->domain_map);
1674         spin_unlock(&dlm->spinlock);
1675
1676         /* Support for global heartbeat and node info was added in 1.1 */
1677         if (dlm->dlm_locking_proto.pv_major > 1 ||
1678             dlm->dlm_locking_proto.pv_minor > 0) {
1679                 status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
1680                 if (status) {
1681                         mlog_errno(status);
1682                         goto bail;
1683                 }
1684                 status = dlm_send_regions(dlm, ctxt->yes_resp_map);
1685                 if (status) {
1686                         mlog_errno(status);
1687                         goto bail;
1688                 }
1689         }
1690
1691         dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
1692
1693         /* Joined state *must* be set before the joining node
1694          * information, otherwise the query_join handler may read no
1695          * current joiner but a state of NEW and tell joining nodes
1696          * we're not in the domain. */
1697         spin_lock(&dlm_domain_lock);
1698         dlm->dlm_state = DLM_CTXT_JOINED;
1699         dlm->num_joins++;
1700         spin_unlock(&dlm_domain_lock);
1701
1702 bail:
1703         spin_lock(&dlm->spinlock);
1704         __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1705         if (!status) {
1706                 printk(KERN_NOTICE "o2dlm: Joining domain %s ", dlm->name);
1707                 __dlm_print_nodes(dlm);
1708         }
1709         spin_unlock(&dlm->spinlock);
1710
1711         if (ctxt) {
1712                 /* Do we need to send a cancel message to any nodes? */
1713                 if (status < 0) {
1714                         tmpstat = dlm_send_join_cancels(dlm,
1715                                                         ctxt->yes_resp_map,
1716                                                         sizeof(ctxt->yes_resp_map));
1717                         if (tmpstat < 0)
1718                                 mlog_errno(tmpstat);
1719                 }
1720                 kfree(ctxt);
1721         }
1722
1723         mlog(0, "returning %d\n", status);
1724         return status;
1725 }
1726
1727 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1728 {
1729         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_up);
1730         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_down);
1731         o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1732 }
1733
1734 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1735 {
1736         int status;
1737
1738         mlog(0, "registering handlers.\n");
1739
1740         o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1741                             dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1742         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
1743         if (status)
1744                 goto bail;
1745
1746         o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1747                             dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1748         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
1749         if (status)
1750                 goto bail;
1751
1752         status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1753                                         sizeof(struct dlm_master_request),
1754                                         dlm_master_request_handler,
1755                                         dlm, NULL, &dlm->dlm_domain_handlers);
1756         if (status)
1757                 goto bail;
1758
1759         status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1760                                         sizeof(struct dlm_assert_master),
1761                                         dlm_assert_master_handler,
1762                                         dlm, dlm_assert_master_post_handler,
1763                                         &dlm->dlm_domain_handlers);
1764         if (status)
1765                 goto bail;
1766
1767         status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1768                                         sizeof(struct dlm_create_lock),
1769                                         dlm_create_lock_handler,
1770                                         dlm, NULL, &dlm->dlm_domain_handlers);
1771         if (status)
1772                 goto bail;
1773
1774         status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1775                                         DLM_CONVERT_LOCK_MAX_LEN,
1776                                         dlm_convert_lock_handler,
1777                                         dlm, NULL, &dlm->dlm_domain_handlers);
1778         if (status)
1779                 goto bail;
1780
1781         status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1782                                         DLM_UNLOCK_LOCK_MAX_LEN,
1783                                         dlm_unlock_lock_handler,
1784                                         dlm, NULL, &dlm->dlm_domain_handlers);
1785         if (status)
1786                 goto bail;
1787
1788         status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1789                                         DLM_PROXY_AST_MAX_LEN,
1790                                         dlm_proxy_ast_handler,
1791                                         dlm, NULL, &dlm->dlm_domain_handlers);
1792         if (status)
1793                 goto bail;
1794
1795         status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1796                                         sizeof(struct dlm_exit_domain),
1797                                         dlm_exit_domain_handler,
1798                                         dlm, NULL, &dlm->dlm_domain_handlers);
1799         if (status)
1800                 goto bail;
1801
1802         status = o2net_register_handler(DLM_DEREF_LOCKRES_MSG, dlm->key,
1803                                         sizeof(struct dlm_deref_lockres),
1804                                         dlm_deref_lockres_handler,
1805                                         dlm, NULL, &dlm->dlm_domain_handlers);
1806         if (status)
1807                 goto bail;
1808
1809         status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1810                                         sizeof(struct dlm_migrate_request),
1811                                         dlm_migrate_request_handler,
1812                                         dlm, NULL, &dlm->dlm_domain_handlers);
1813         if (status)
1814                 goto bail;
1815
1816         status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1817                                         DLM_MIG_LOCKRES_MAX_LEN,
1818                                         dlm_mig_lockres_handler,
1819                                         dlm, NULL, &dlm->dlm_domain_handlers);
1820         if (status)
1821                 goto bail;
1822
1823         status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1824                                         sizeof(struct dlm_master_requery),
1825                                         dlm_master_requery_handler,
1826                                         dlm, NULL, &dlm->dlm_domain_handlers);
1827         if (status)
1828                 goto bail;
1829
1830         status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1831                                         sizeof(struct dlm_lock_request),
1832                                         dlm_request_all_locks_handler,
1833                                         dlm, NULL, &dlm->dlm_domain_handlers);
1834         if (status)
1835                 goto bail;
1836
1837         status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1838                                         sizeof(struct dlm_reco_data_done),
1839                                         dlm_reco_data_done_handler,
1840                                         dlm, NULL, &dlm->dlm_domain_handlers);
1841         if (status)
1842                 goto bail;
1843
1844         status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1845                                         sizeof(struct dlm_begin_reco),
1846                                         dlm_begin_reco_handler,
1847                                         dlm, NULL, &dlm->dlm_domain_handlers);
1848         if (status)
1849                 goto bail;
1850
1851         status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1852                                         sizeof(struct dlm_finalize_reco),
1853                                         dlm_finalize_reco_handler,
1854                                         dlm, NULL, &dlm->dlm_domain_handlers);
1855         if (status)
1856                 goto bail;
1857
1858         status = o2net_register_handler(DLM_BEGIN_EXIT_DOMAIN_MSG, dlm->key,
1859                                         sizeof(struct dlm_exit_domain),
1860                                         dlm_begin_exit_domain_handler,
1861                                         dlm, NULL, &dlm->dlm_domain_handlers);
1862         if (status)
1863                 goto bail;
1864
1865 bail:
1866         if (status)
1867                 dlm_unregister_domain_handlers(dlm);
1868
1869         return status;
1870 }
1871
1872 static int dlm_join_domain(struct dlm_ctxt *dlm)
1873 {
1874         int status;
1875         unsigned int backoff;
1876         unsigned int total_backoff = 0;
1877
1878         BUG_ON(!dlm);
1879
1880         mlog(0, "Join domain %s\n", dlm->name);
1881
1882         status = dlm_register_domain_handlers(dlm);
1883         if (status) {
1884                 mlog_errno(status);
1885                 goto bail;
1886         }
1887
1888         status = dlm_launch_thread(dlm);
1889         if (status < 0) {
1890                 mlog_errno(status);
1891                 goto bail;
1892         }
1893
1894         status = dlm_launch_recovery_thread(dlm);
1895         if (status < 0) {
1896                 mlog_errno(status);
1897                 goto bail;
1898         }
1899
1900         status = dlm_debug_init(dlm);
1901         if (status < 0) {
1902                 mlog_errno(status);
1903                 goto bail;
1904         }
1905
1906         dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1907         if (!dlm->dlm_worker) {
1908                 status = -ENOMEM;
1909                 mlog_errno(status);
1910                 goto bail;
1911         }
1912
1913         do {
1914                 status = dlm_try_to_join_domain(dlm);
1915
1916                 /* If we're racing another node to the join, then we
1917                  * need to back off temporarily and let them
1918                  * complete. */
1919 #define DLM_JOIN_TIMEOUT_MSECS  90000
1920                 if (status == -EAGAIN) {
1921                         if (signal_pending(current)) {
1922                                 status = -ERESTARTSYS;
1923                                 goto bail;
1924                         }
1925
1926                         if (total_backoff > DLM_JOIN_TIMEOUT_MSECS) {
1927                                 status = -ERESTARTSYS;
1928                                 mlog(ML_NOTICE, "Timed out joining dlm domain "
1929                                      "%s after %u msecs\n", dlm->name,
1930                                      total_backoff);
1931                                 goto bail;
1932                         }
1933
1934                         /*
1935                          * <chip> After you!
1936                          * <dale> No, after you!
1937                          * <chip> I insist!
1938                          * <dale> But you first!
1939                          * ...
1940                          */
1941                         backoff = (unsigned int)(jiffies & 0x3);
1942                         backoff *= DLM_DOMAIN_BACKOFF_MS;
1943                         total_backoff += backoff;
1944                         mlog(0, "backoff %d\n", backoff);
1945                         msleep(backoff);
1946                 }
1947         } while (status == -EAGAIN);
1948
1949         if (status < 0) {
1950                 mlog_errno(status);
1951                 goto bail;
1952         }
1953
1954         status = 0;
1955 bail:
1956         wake_up(&dlm_domain_events);
1957
1958         if (status) {
1959                 dlm_unregister_domain_handlers(dlm);
1960                 dlm_debug_shutdown(dlm);
1961                 dlm_complete_thread(dlm);
1962                 dlm_complete_recovery_thread(dlm);
1963                 dlm_destroy_dlm_worker(dlm);
1964         }
1965
1966         return status;
1967 }
1968
1969 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1970                                 u32 key)
1971 {
1972         int i;
1973         int ret;
1974         struct dlm_ctxt *dlm = NULL;
1975
1976         dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1977         if (!dlm) {
1978                 ret = -ENOMEM;
1979                 mlog_errno(ret);
1980                 goto leave;
1981         }
1982
1983         dlm->name = kstrdup(domain, GFP_KERNEL);
1984         if (dlm->name == NULL) {
1985                 ret = -ENOMEM;
1986                 mlog_errno(ret);
1987                 goto leave;
1988         }
1989
1990         dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1991         if (!dlm->lockres_hash) {
1992                 ret = -ENOMEM;
1993                 mlog_errno(ret);
1994                 goto leave;
1995         }
1996
1997         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1998                 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1999
2000         dlm->master_hash = (struct hlist_head **)
2001                                 dlm_alloc_pagevec(DLM_HASH_PAGES);
2002         if (!dlm->master_hash) {
2003                 ret = -ENOMEM;
2004                 mlog_errno(ret);
2005                 goto leave;
2006         }
2007
2008         for (i = 0; i < DLM_HASH_BUCKETS; i++)
2009                 INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
2010
2011         dlm->key = key;
2012         dlm->node_num = o2nm_this_node();
2013
2014         ret = dlm_create_debugfs_subroot(dlm);
2015         if (ret < 0)
2016                 goto leave;
2017
2018         spin_lock_init(&dlm->spinlock);
2019         spin_lock_init(&dlm->master_lock);
2020         spin_lock_init(&dlm->ast_lock);
2021         spin_lock_init(&dlm->track_lock);
2022         INIT_LIST_HEAD(&dlm->list);
2023         INIT_LIST_HEAD(&dlm->dirty_list);
2024         INIT_LIST_HEAD(&dlm->reco.resources);
2025         INIT_LIST_HEAD(&dlm->reco.node_data);
2026         INIT_LIST_HEAD(&dlm->purge_list);
2027         INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
2028         INIT_LIST_HEAD(&dlm->tracking_list);
2029         dlm->reco.state = 0;
2030
2031         INIT_LIST_HEAD(&dlm->pending_asts);
2032         INIT_LIST_HEAD(&dlm->pending_basts);
2033
2034         mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
2035                   dlm->recovery_map, &(dlm->recovery_map[0]));
2036
2037         memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
2038         memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
2039         memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
2040
2041         dlm->dlm_thread_task = NULL;
2042         dlm->dlm_reco_thread_task = NULL;
2043         dlm->dlm_worker = NULL;
2044         init_waitqueue_head(&dlm->dlm_thread_wq);
2045         init_waitqueue_head(&dlm->dlm_reco_thread_wq);
2046         init_waitqueue_head(&dlm->reco.event);
2047         init_waitqueue_head(&dlm->ast_wq);
2048         init_waitqueue_head(&dlm->migration_wq);
2049         INIT_LIST_HEAD(&dlm->mle_hb_events);
2050
2051         dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
2052         init_waitqueue_head(&dlm->dlm_join_events);
2053
2054         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
2055         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
2056
2057         atomic_set(&dlm->res_tot_count, 0);
2058         atomic_set(&dlm->res_cur_count, 0);
2059         for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
2060                 atomic_set(&dlm->mle_tot_count[i], 0);
2061                 atomic_set(&dlm->mle_cur_count[i], 0);
2062         }
2063
2064         spin_lock_init(&dlm->work_lock);
2065         INIT_LIST_HEAD(&dlm->work_list);
2066         INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
2067
2068         kref_init(&dlm->dlm_refs);
2069         dlm->dlm_state = DLM_CTXT_NEW;
2070
2071         INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
2072
2073         mlog(0, "context init: refcount %u\n",
2074                   atomic_read(&dlm->dlm_refs.refcount));
2075
2076 leave:
2077         if (ret < 0 && dlm) {
2078                 if (dlm->master_hash)
2079                         dlm_free_pagevec((void **)dlm->master_hash,
2080                                         DLM_HASH_PAGES);
2081
2082                 if (dlm->lockres_hash)
2083                         dlm_free_pagevec((void **)dlm->lockres_hash,
2084                                         DLM_HASH_PAGES);
2085
2086                 kfree(dlm->name);
2087                 kfree(dlm);
2088                 dlm = NULL;
2089         }
2090         return dlm;
2091 }
2092
2093 /*
2094  * Compare a requested locking protocol version against the current one.
2095  *
2096  * If the major numbers are different, they are incompatible.
2097  * If the current minor is greater than the request, they are incompatible.
2098  * If the current minor is less than or equal to the request, they are
2099  * compatible, and the requester should run at the current minor version.
2100  */
2101 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
2102                                 struct dlm_protocol_version *request)
2103 {
2104         if (existing->pv_major != request->pv_major)
2105                 return 1;
2106
2107         if (existing->pv_minor > request->pv_minor)
2108                 return 1;
2109
2110         if (existing->pv_minor < request->pv_minor)
2111                 request->pv_minor = existing->pv_minor;
2112
2113         return 0;
2114 }
2115
2116 /*
2117  * dlm_register_domain: one-time setup per "domain".
2118  *
2119  * The filesystem passes in the requested locking version via proto.
2120  * If registration was successful, proto will contain the negotiated
2121  * locking protocol.
2122  */
2123 struct dlm_ctxt * dlm_register_domain(const char *domain,
2124                                u32 key,
2125                                struct dlm_protocol_version *fs_proto)
2126 {
2127         int ret;
2128         struct dlm_ctxt *dlm = NULL;
2129         struct dlm_ctxt *new_ctxt = NULL;
2130
2131         if (strlen(domain) >= O2NM_MAX_NAME_LEN) {
2132                 ret = -ENAMETOOLONG;
2133                 mlog(ML_ERROR, "domain name length too long\n");
2134                 goto leave;
2135         }
2136
2137         mlog(0, "register called for domain \"%s\"\n", domain);
2138
2139 retry:
2140         dlm = NULL;
2141         if (signal_pending(current)) {
2142                 ret = -ERESTARTSYS;
2143                 mlog_errno(ret);
2144                 goto leave;
2145         }
2146
2147         spin_lock(&dlm_domain_lock);
2148
2149         dlm = __dlm_lookup_domain(domain);
2150         if (dlm) {
2151                 if (dlm->dlm_state != DLM_CTXT_JOINED) {
2152                         spin_unlock(&dlm_domain_lock);
2153
2154                         mlog(0, "This ctxt is not joined yet!\n");
2155                         wait_event_interruptible(dlm_domain_events,
2156                                                  dlm_wait_on_domain_helper(
2157                                                          domain));
2158                         goto retry;
2159                 }
2160
2161                 if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
2162                         spin_unlock(&dlm_domain_lock);
2163                         mlog(ML_ERROR,
2164                              "Requested locking protocol version is not "
2165                              "compatible with already registered domain "
2166                              "\"%s\"\n", domain);
2167                         ret = -EPROTO;
2168                         goto leave;
2169                 }
2170
2171                 __dlm_get(dlm);
2172                 dlm->num_joins++;
2173
2174                 spin_unlock(&dlm_domain_lock);
2175
2176                 ret = 0;
2177                 goto leave;
2178         }
2179
2180         /* doesn't exist */
2181         if (!new_ctxt) {
2182                 spin_unlock(&dlm_domain_lock);
2183
2184                 new_ctxt = dlm_alloc_ctxt(domain, key);
2185                 if (new_ctxt)
2186                         goto retry;
2187
2188                 ret = -ENOMEM;
2189                 mlog_errno(ret);
2190                 goto leave;
2191         }
2192
2193         /* a little variable switch-a-roo here... */
2194         dlm = new_ctxt;
2195         new_ctxt = NULL;
2196
2197         /* add the new domain */
2198         list_add_tail(&dlm->list, &dlm_domains);
2199         spin_unlock(&dlm_domain_lock);
2200
2201         /*
2202          * Pass the locking protocol version into the join.  If the join
2203          * succeeds, it will have the negotiated protocol set.
2204          */
2205         dlm->dlm_locking_proto = dlm_protocol;
2206         dlm->fs_locking_proto = *fs_proto;
2207
2208         ret = dlm_join_domain(dlm);
2209         if (ret) {
2210                 mlog_errno(ret);
2211                 dlm_put(dlm);
2212                 goto leave;
2213         }
2214
2215         /* Tell the caller what locking protocol we negotiated */
2216         *fs_proto = dlm->fs_locking_proto;
2217
2218         ret = 0;
2219 leave:
2220         if (new_ctxt)
2221                 dlm_free_ctxt_mem(new_ctxt);
2222
2223         if (ret < 0)
2224                 dlm = ERR_PTR(ret);
2225
2226         return dlm;
2227 }
2228 EXPORT_SYMBOL_GPL(dlm_register_domain);
2229
2230 static LIST_HEAD(dlm_join_handlers);
2231
2232 static void dlm_unregister_net_handlers(void)
2233 {
2234         o2net_unregister_handler_list(&dlm_join_handlers);
2235 }
2236
2237 static int dlm_register_net_handlers(void)
2238 {
2239         int status = 0;
2240
2241         status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
2242                                         sizeof(struct dlm_query_join_request),
2243                                         dlm_query_join_handler,
2244                                         NULL, NULL, &dlm_join_handlers);
2245         if (status)
2246                 goto bail;
2247
2248         status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
2249                                         sizeof(struct dlm_assert_joined),
2250                                         dlm_assert_joined_handler,
2251                                         NULL, NULL, &dlm_join_handlers);
2252         if (status)
2253                 goto bail;
2254
2255         status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
2256                                         sizeof(struct dlm_cancel_join),
2257                                         dlm_cancel_join_handler,
2258                                         NULL, NULL, &dlm_join_handlers);
2259         if (status)
2260                 goto bail;
2261
2262         status = o2net_register_handler(DLM_QUERY_REGION, DLM_MOD_KEY,
2263                                         sizeof(struct dlm_query_region),
2264                                         dlm_query_region_handler,
2265                                         NULL, NULL, &dlm_join_handlers);
2266
2267         if (status)
2268                 goto bail;
2269
2270         status = o2net_register_handler(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
2271                                         sizeof(struct dlm_query_nodeinfo),
2272                                         dlm_query_nodeinfo_handler,
2273                                         NULL, NULL, &dlm_join_handlers);
2274 bail:
2275         if (status < 0)
2276                 dlm_unregister_net_handlers();
2277
2278         return status;
2279 }
2280
2281 /* Domain eviction callback handling.
2282  *
2283  * The file system requires notification of node death *before* the
2284  * dlm completes it's recovery work, otherwise it may be able to
2285  * acquire locks on resources requiring recovery. Since the dlm can
2286  * evict a node from it's domain *before* heartbeat fires, a similar
2287  * mechanism is required. */
2288
2289 /* Eviction is not expected to happen often, so a per-domain lock is
2290  * not necessary. Eviction callbacks are allowed to sleep for short
2291  * periods of time. */
2292 static DECLARE_RWSEM(dlm_callback_sem);
2293
2294 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
2295                                         int node_num)
2296 {
2297         struct dlm_eviction_cb *cb;
2298
2299         down_read(&dlm_callback_sem);
2300         list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
2301                 cb->ec_func(node_num, cb->ec_data);
2302         }
2303         up_read(&dlm_callback_sem);
2304 }
2305
2306 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
2307                            dlm_eviction_func *f,
2308                            void *data)
2309 {
2310         INIT_LIST_HEAD(&cb->ec_item);
2311         cb->ec_func = f;
2312         cb->ec_data = data;
2313 }
2314 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
2315
2316 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
2317                               struct dlm_eviction_cb *cb)
2318 {
2319         down_write(&dlm_callback_sem);
2320         list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
2321         up_write(&dlm_callback_sem);
2322 }
2323 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
2324
2325 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
2326 {
2327         down_write(&dlm_callback_sem);
2328         list_del_init(&cb->ec_item);
2329         up_write(&dlm_callback_sem);
2330 }
2331 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
2332
2333 static int __init dlm_init(void)
2334 {
2335         int status;
2336
2337         status = dlm_init_mle_cache();
2338         if (status) {
2339                 mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
2340                 goto error;
2341         }
2342
2343         status = dlm_init_master_caches();
2344         if (status) {
2345                 mlog(ML_ERROR, "Could not create o2dlm_lockres and "
2346                      "o2dlm_lockname slabcaches\n");
2347                 goto error;
2348         }
2349
2350         status = dlm_init_lock_cache();
2351         if (status) {
2352                 mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
2353                 goto error;
2354         }
2355
2356         status = dlm_register_net_handlers();
2357         if (status) {
2358                 mlog(ML_ERROR, "Unable to register network handlers\n");
2359                 goto error;
2360         }
2361
2362         status = dlm_create_debugfs_root();
2363         if (status)
2364                 goto error;
2365
2366         return 0;
2367 error:
2368         dlm_unregister_net_handlers();
2369         dlm_destroy_lock_cache();
2370         dlm_destroy_master_caches();
2371         dlm_destroy_mle_cache();
2372         return -1;
2373 }
2374
2375 static void __exit dlm_exit (void)
2376 {
2377         dlm_destroy_debugfs_root();
2378         dlm_unregister_net_handlers();
2379         dlm_destroy_lock_cache();
2380         dlm_destroy_master_caches();
2381         dlm_destroy_mle_cache();
2382 }
2383
2384 MODULE_AUTHOR("Oracle");
2385 MODULE_LICENSE("GPL");
2386 MODULE_DESCRIPTION("OCFS2 Distributed Lock Management");
2387
2388 module_init(dlm_init);
2389 module_exit(dlm_exit);