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 #include <linux/sched/signal.h>
  37
  38 #include "cluster/heartbeat.h"
  39 #include "cluster/nodemanager.h"
  40 #include "cluster/tcp.h"
  41
  42 #include "dlmapi.h"
  43 #include "dlmcommon.h"
  44 #include "dlmdomain.h"
  45 #include "dlmdebug.h"
  46
  47 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
  48 #include "cluster/masklog.h"
  49
  50 /*
  51  * ocfs2 node maps are array of long int, which limits to send them freely
  52  * across the wire due to endianness issues. To workaround this, we convert
  53  * long ints to byte arrays. Following 3 routines are helper functions to
  54  * set/test/copy bits within those array of bytes
  55  */
  56 static inline void byte_set_bit(u8 nr, u8 map[])
  57 {
  58         map[nr >> 3] |= (1UL << (nr & 7));
  59 }
  60
  61 static inline int byte_test_bit(u8 nr, u8 map[])
  62 {
  63         return ((1UL << (nr & 7)) & (map[nr >> 3])) != 0;
  64 }
  65
  66 static inline void byte_copymap(u8 dmap[], unsigned long smap[],
  67                         unsigned int sz)
  68 {
  69         unsigned int nn;
  70
  71         if (!sz)
  72                 return;
  73
  74         memset(dmap, 0, ((sz + 7) >> 3));
  75         for (nn = 0 ; nn < sz; nn++)
  76                 if (test_bit(nn, smap))
  77                         byte_set_bit(nn, dmap);
  78 }
  79
  80 static void dlm_free_pagevec(void **vec, int pages)
  81 {
  82         while (pages--)
  83                 free_page((unsigned long)vec[pages]);
  84         kfree(vec);
  85 }
  86
  87 static void **dlm_alloc_pagevec(int pages)
  88 {
  89         void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
  90         int i;
  91
  92         if (!vec)
  93                 return NULL;
  94
  95         for (i = 0; i < pages; i++)
  96                 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
  97                         goto out_free;
  98
  99         mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
 100              pages, (unsigned long)DLM_HASH_PAGES,
 101              (unsigned long)DLM_BUCKETS_PER_PAGE);
 102         return vec;
 103 out_free:
 104         dlm_free_pagevec(vec, i);
 105         return NULL;
 106 }
 107
 108 /*
 109  *
 110  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
 111  *    dlm_domain_lock
 112  *    struct dlm_ctxt->spinlock
 113  *    struct dlm_lock_resource->spinlock
 114  *    struct dlm_ctxt->master_lock
 115  *    struct dlm_ctxt->ast_lock
 116  *    dlm_master_list_entry->spinlock
 117  *    dlm_lock->spinlock
 118  *
 119  */
 120
 121 DEFINE_SPINLOCK(dlm_domain_lock);
 122 LIST_HEAD(dlm_domains);
 123 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
 124
 125 /*
 126  * The supported protocol version for DLM communication.  Running domains
 127  * will have a negotiated version with the same major number and a minor
 128  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
 129  * be used to determine what a running domain is actually using.
 130  *
 131  * New in version 1.1:
 132  *      - Message DLM_QUERY_REGION added to support global heartbeat
 133  *      - Message DLM_QUERY_NODEINFO added to allow online node removes
 134  * New in version 1.2:
 135  *      - Message DLM_BEGIN_EXIT_DOMAIN_MSG added to mark start of exit domain
 136  * New in version 1.3:
 137  *      - Message DLM_DEREF_LOCKRES_DONE added to inform non-master that the
 138  *        refmap is cleared
 139  */
 140 static const struct dlm_protocol_version dlm_protocol = {
 141         .pv_major = 1,
 142         .pv_minor = 3,
 143 };
 144
 145 #define DLM_DOMAIN_BACKOFF_MS 200
 146
 147 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 148                                   void **ret_data);
 149 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 150                                      void **ret_data);
 151 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
 152                                    void **ret_data);
 153 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
 154                                     void *data, void **ret_data);
 155 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 156                                    void **ret_data);
 157 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
 158                                 struct dlm_protocol_version *request);
 159
 160 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 161
 162 void __dlm_unhash_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 163 {
 164         if (hlist_unhashed(&res->hash_node))
 165                 return;
 166
 167         mlog(0, "%s: Unhash res %.*s\n", dlm->name, res->lockname.len,
 168              res->lockname.name);
 169         hlist_del_init(&res->hash_node);
 170         dlm_lockres_put(res);
 171 }
 172
 173 void __dlm_insert_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 174 {
 175         struct hlist_head *bucket;
 176
 177         assert_spin_locked(&dlm->spinlock);
 178
 179         bucket = dlm_lockres_hash(dlm, res->lockname.hash);
 180
 181         /* get a reference for our hashtable */
 182         dlm_lockres_get(res);
 183
 184         hlist_add_head(&res->hash_node, bucket);
 185
 186         mlog(0, "%s: Hash res %.*s\n", dlm->name, res->lockname.len,
 187              res->lockname.name);
 188 }
 189
 190 struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
 191                                                      const char *name,
 192                                                      unsigned int len,
 193                                                      unsigned int hash)
 194 {
 195         struct hlist_head *bucket;
 196         struct dlm_lock_resource *res;
 197
 198         mlog(0, "%.*s\n", len, name);
 199
 200         assert_spin_locked(&dlm->spinlock);
 201
 202         bucket = dlm_lockres_hash(dlm, hash);
 203
 204         hlist_for_each_entry(res, bucket, hash_node) {
 205                 if (res->lockname.name[0] != name[0])
 206                         continue;
 207                 if (unlikely(res->lockname.len != len))
 208                         continue;
 209                 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
 210                         continue;
 211                 dlm_lockres_get(res);
 212                 return res;
 213         }
 214         return NULL;
 215 }
 216
 217 /* intended to be called by functions which do not care about lock
 218  * resources which are being purged (most net _handler functions).
 219  * this will return NULL for any lock resource which is found but
 220  * currently in the process of dropping its mastery reference.
 221  * use __dlm_lookup_lockres_full when you need the lock resource
 222  * regardless (e.g. dlm_get_lock_resource) */
 223 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 224                                                 const char *name,
 225                                                 unsigned int len,
 226                                                 unsigned int hash)
 227 {
 228         struct dlm_lock_resource *res = NULL;
 229
 230         mlog(0, "%.*s\n", len, name);
 231
 232         assert_spin_locked(&dlm->spinlock);
 233
 234         res = __dlm_lookup_lockres_full(dlm, name, len, hash);
 235         if (res) {
 236                 spin_lock(&res->spinlock);
 237                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
 238                         spin_unlock(&res->spinlock);
 239                         dlm_lockres_put(res);
 240                         return NULL;
 241                 }
 242                 spin_unlock(&res->spinlock);
 243         }
 244
 245         return res;
 246 }
 247
 248 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 249                                     const char *name,
 250                                     unsigned int len)
 251 {
 252         struct dlm_lock_resource *res;
 253         unsigned int hash = dlm_lockid_hash(name, len);
 254
 255         spin_lock(&dlm->spinlock);
 256         res = __dlm_lookup_lockres(dlm, name, len, hash);
 257         spin_unlock(&dlm->spinlock);
 258         return res;
 259 }
 260
 261 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 262 {
 263         struct dlm_ctxt *tmp;
 264
 265         assert_spin_locked(&dlm_domain_lock);
 266
 267         /* tmp->name here is always NULL terminated,
 268          * but domain may not be! */
 269         list_for_each_entry(tmp, &dlm_domains, list) {
 270                 if (strlen(tmp->name) == len &&
 271                     memcmp(tmp->name, domain, len)==0)
 272                         return tmp;
 273         }
 274
 275         return NULL;
 276 }
 277
 278 /* For null terminated domain strings ONLY */
 279 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
 280 {
 281         assert_spin_locked(&dlm_domain_lock);
 282
 283         return __dlm_lookup_domain_full(domain, strlen(domain));
 284 }
 285
 286
 287 /* returns true on one of two conditions:
 288  * 1) the domain does not exist
 289  * 2) the domain exists and it's state is "joined" */
 290 static int dlm_wait_on_domain_helper(const char *domain)
 291 {
 292         int ret = 0;
 293         struct dlm_ctxt *tmp = NULL;
 294
 295         spin_lock(&dlm_domain_lock);
 296
 297         tmp = __dlm_lookup_domain(domain);
 298         if (!tmp)
 299                 ret = 1;
 300         else if (tmp->dlm_state == DLM_CTXT_JOINED)
 301                 ret = 1;
 302
 303         spin_unlock(&dlm_domain_lock);
 304         return ret;
 305 }
 306
 307 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 308 {
 309         dlm_destroy_debugfs_subroot(dlm);
 310
 311         if (dlm->lockres_hash)
 312                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 313
 314         if (dlm->master_hash)
 315                 dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
 316
 317         kfree(dlm->name);
 318         kfree(dlm);
 319 }
 320
 321 /* A little strange - this function will be called while holding
 322  * dlm_domain_lock and is expected to be holding it on the way out. We
 323  * will however drop and reacquire it multiple times */
 324 static void dlm_ctxt_release(struct kref *kref)
 325 {
 326         struct dlm_ctxt *dlm;
 327
 328         dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
 329
 330         BUG_ON(dlm->num_joins);
 331         BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
 332
 333         /* we may still be in the list if we hit an error during join. */
 334         list_del_init(&dlm->list);
 335
 336         spin_unlock(&dlm_domain_lock);
 337
 338         mlog(0, "freeing memory from domain %s\n", dlm->name);
 339
 340         wake_up(&dlm_domain_events);
 341
 342         dlm_free_ctxt_mem(dlm);
 343
 344         spin_lock(&dlm_domain_lock);
 345 }
 346
 347 void dlm_put(struct dlm_ctxt *dlm)
 348 {
 349         spin_lock(&dlm_domain_lock);
 350         kref_put(&dlm->dlm_refs, dlm_ctxt_release);
 351         spin_unlock(&dlm_domain_lock);
 352 }
 353
 354 static void __dlm_get(struct dlm_ctxt *dlm)
 355 {
 356         kref_get(&dlm->dlm_refs);
 357 }
 358
 359 /* given a questionable reference to a dlm object, gets a reference if
 360  * it can find it in the list, otherwise returns NULL in which case
 361  * you shouldn't trust your pointer. */
 362 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 363 {
 364         struct dlm_ctxt *target;
 365         struct dlm_ctxt *ret = NULL;
 366
 367         spin_lock(&dlm_domain_lock);
 368
 369         list_for_each_entry(target, &dlm_domains, list) {
 370                 if (target == dlm) {
 371                         __dlm_get(target);
 372                         ret = target;
 373                         break;
 374                 }
 375         }
 376
 377         spin_unlock(&dlm_domain_lock);
 378
 379         return ret;
 380 }
 381
 382 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 383 {
 384         int ret;
 385
 386         spin_lock(&dlm_domain_lock);
 387         ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
 388                 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
 389         spin_unlock(&dlm_domain_lock);
 390
 391         return ret;
 392 }
 393
 394 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 395 {
 396         if (dlm->dlm_worker) {
 397                 flush_workqueue(dlm->dlm_worker);
 398                 destroy_workqueue(dlm->dlm_worker);
 399                 dlm->dlm_worker = NULL;
 400         }
 401 }
 402
 403 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 404 {
 405         dlm_unregister_domain_handlers(dlm);
 406         dlm_debug_shutdown(dlm);
 407         dlm_complete_thread(dlm);
 408         dlm_complete_recovery_thread(dlm);
 409         dlm_destroy_dlm_worker(dlm);
 410
 411         /* We've left the domain. Now we can take ourselves out of the
 412          * list and allow the kref stuff to help us free the
 413          * memory. */
 414         spin_lock(&dlm_domain_lock);
 415         list_del_init(&dlm->list);
 416         spin_unlock(&dlm_domain_lock);
 417
 418         /* Wake up anyone waiting for us to remove this domain */
 419         wake_up(&dlm_domain_events);
 420 }
 421
 422 static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 423 {
 424         int i, num, n, ret = 0;
 425         struct dlm_lock_resource *res;
 426         struct hlist_node *iter;
 427         struct hlist_head *bucket;
 428         int dropped;
 429
 430         mlog(0, "Migrating locks from domain %s\n", dlm->name);
 431
 432         num = 0;
 433         spin_lock(&dlm->spinlock);
 434         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
 435 redo_bucket:
 436                 n = 0;
 437                 bucket = dlm_lockres_hash(dlm, i);
 438                 iter = bucket->first;
 439                 while (iter) {
 440                         n++;
 441                         res = hlist_entry(iter, struct dlm_lock_resource,
 442                                           hash_node);
 443                         dlm_lockres_get(res);
 444                         /* migrate, if necessary.  this will drop the dlm
 445                          * spinlock and retake it if it does migration. */
 446                         dropped = dlm_empty_lockres(dlm, res);
 447
 448                         spin_lock(&res->spinlock);
 449                         if (dropped)
 450                                 __dlm_lockres_calc_usage(dlm, res);
 451                         else
 452                                 iter = res->hash_node.next;
 453                         spin_unlock(&res->spinlock);
 454
 455                         dlm_lockres_put(res);
 456
 457                         if (dropped) {
 458                                 cond_resched_lock(&dlm->spinlock);
 459                                 goto redo_bucket;
 460                         }
 461                 }
 462                 cond_resched_lock(&dlm->spinlock);
 463                 num += n;
 464         }
 465         spin_unlock(&dlm->spinlock);
 466         wake_up(&dlm->dlm_thread_wq);
 467
 468         /* let the dlm thread take care of purging, keep scanning until
 469          * nothing remains in the hash */
 470         if (num) {
 471                 mlog(0, "%s: %d lock resources in hash last pass\n",
 472                      dlm->name, num);
 473                 ret = -EAGAIN;
 474         }
 475         mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
 476         return ret;
 477 }
 478
 479 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
 480 {
 481         int ret;
 482
 483         spin_lock(&dlm->spinlock);
 484         ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
 485         spin_unlock(&dlm->spinlock);
 486
 487         return ret;
 488 }
 489
 490 static int dlm_begin_exit_domain_handler(struct o2net_msg *msg, u32 len,
 491                                          void *data, void **ret_data)
 492 {
 493         struct dlm_ctxt *dlm = data;
 494         unsigned int node;
 495         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 496
 497         if (!dlm_grab(dlm))
 498                 return 0;
 499
 500         node = exit_msg->node_idx;
 501         mlog(0, "%s: Node %u sent a begin exit domain message\n", dlm->name, node);
 502
 503         spin_lock(&dlm->spinlock);
 504         set_bit(node, dlm->exit_domain_map);
 505         spin_unlock(&dlm->spinlock);
 506
 507         dlm_put(dlm);
 508
 509         return 0;
 510 }
 511
 512 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
 513 {
 514         /* Yikes, a double spinlock! I need domain_lock for the dlm
 515          * state and the dlm spinlock for join state... Sorry! */
 516 again:
 517         spin_lock(&dlm_domain_lock);
 518         spin_lock(&dlm->spinlock);
 519
 520         if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 521                 mlog(0, "Node %d is joining, we wait on it.\n",
 522                           dlm->joining_node);
 523                 spin_unlock(&dlm->spinlock);
 524                 spin_unlock(&dlm_domain_lock);
 525
 526                 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
 527                 goto again;
 528         }
 529
 530         dlm->dlm_state = DLM_CTXT_LEAVING;
 531         spin_unlock(&dlm->spinlock);
 532         spin_unlock(&dlm_domain_lock);
 533 }
 534
 535 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
 536 {
 537         int node = -1, num = 0;
 538
 539         assert_spin_locked(&dlm->spinlock);
 540
 541         printk("( ");
 542         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 543                                      node + 1)) < O2NM_MAX_NODES) {
 544                 printk("%d ", node);
 545                 ++num;
 546         }
 547         printk(") %u nodes\n", num);
 548 }
 549
 550 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 551                                    void **ret_data)
 552 {
 553         struct dlm_ctxt *dlm = data;
 554         unsigned int node;
 555         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 556
 557         mlog(0, "%p %u %p", msg, len, data);
 558
 559         if (!dlm_grab(dlm))
 560                 return 0;
 561
 562         node = exit_msg->node_idx;
 563
 564         spin_lock(&dlm->spinlock);
 565         clear_bit(node, dlm->domain_map);
 566         clear_bit(node, dlm->exit_domain_map);
 567         printk(KERN_NOTICE "o2dlm: Node %u leaves domain %s ", node, dlm->name);
 568         __dlm_print_nodes(dlm);
 569
 570         /* notify anything attached to the heartbeat events */
 571         dlm_hb_event_notify_attached(dlm, node, 0);
 572
 573         spin_unlock(&dlm->spinlock);
 574
 575         dlm_put(dlm);
 576
 577         return 0;
 578 }
 579
 580 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, u32 msg_type,
 581                                     unsigned int node)
 582 {
 583         int status;
 584         struct dlm_exit_domain leave_msg;
 585
 586         mlog(0, "%s: Sending domain exit message %u to node %u\n", dlm->name,
 587              msg_type, node);
 588
 589         memset(&leave_msg, 0, sizeof(leave_msg));
 590         leave_msg.node_idx = dlm->node_num;
 591
 592         status = o2net_send_message(msg_type, dlm->key, &leave_msg,
 593                                     sizeof(leave_msg), node, NULL);
 594         if (status < 0)
 595                 mlog(ML_ERROR, "Error %d sending domain exit message %u "
 596                      "to node %u on domain %s\n", status, msg_type, node,
 597                      dlm->name);
 598
 599         return status;
 600 }
 601
 602 static void dlm_begin_exit_domain(struct dlm_ctxt *dlm)
 603 {
 604         int node = -1;
 605
 606         /* Support for begin exit domain was added in 1.2 */
 607         if (dlm->dlm_locking_proto.pv_major == 1 &&
 608             dlm->dlm_locking_proto.pv_minor < 2)
 609                 return;
 610
 611         /*
 612          * Unlike DLM_EXIT_DOMAIN_MSG, DLM_BEGIN_EXIT_DOMAIN_MSG is purely
 613          * informational. Meaning if a node does not receive the message,
 614          * so be it.
 615          */
 616         spin_lock(&dlm->spinlock);
 617         while (1) {
 618                 node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, node + 1);
 619                 if (node >= O2NM_MAX_NODES)
 620                         break;
 621                 if (node == dlm->node_num)
 622                         continue;
 623
 624                 spin_unlock(&dlm->spinlock);
 625                 dlm_send_one_domain_exit(dlm, DLM_BEGIN_EXIT_DOMAIN_MSG, node);
 626                 spin_lock(&dlm->spinlock);
 627         }
 628         spin_unlock(&dlm->spinlock);
 629 }
 630
 631 static void dlm_leave_domain(struct dlm_ctxt *dlm)
 632 {
 633         int node, clear_node, status;
 634
 635         /* At this point we've migrated away all our locks and won't
 636          * accept mastership of new ones. The dlm is responsible for
 637          * almost nothing now. We make sure not to confuse any joining
 638          * nodes and then commence shutdown procedure. */
 639
 640         spin_lock(&dlm->spinlock);
 641         /* Clear ourselves from the domain map */
 642         clear_bit(dlm->node_num, dlm->domain_map);
 643         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 644                                      0)) < O2NM_MAX_NODES) {
 645                 /* Drop the dlm spinlock. This is safe wrt the domain_map.
 646                  * -nodes cannot be added now as the
 647                  *   query_join_handlers knows to respond with OK_NO_MAP
 648                  * -we catch the right network errors if a node is
 649                  *   removed from the map while we're sending him the
 650                  *   exit message. */
 651                 spin_unlock(&dlm->spinlock);
 652
 653                 clear_node = 1;
 654
 655                 status = dlm_send_one_domain_exit(dlm, DLM_EXIT_DOMAIN_MSG,
 656                                                   node);
 657                 if (status < 0 &&
 658                     status != -ENOPROTOOPT &&
 659                     status != -ENOTCONN) {
 660                         mlog(ML_NOTICE, "Error %d sending domain exit message "
 661                              "to node %d\n", status, node);
 662
 663                         /* Not sure what to do here but lets sleep for
 664                          * a bit in case this was a transient
 665                          * error... */
 666                         msleep(DLM_DOMAIN_BACKOFF_MS);
 667                         clear_node = 0;
 668                 }
 669
 670                 spin_lock(&dlm->spinlock);
 671                 /* If we're not clearing the node bit then we intend
 672                  * to loop back around to try again. */
 673                 if (clear_node)
 674                         clear_bit(node, dlm->domain_map);
 675         }
 676         spin_unlock(&dlm->spinlock);
 677 }
 678
 679 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 680 {
 681         int leave = 0;
 682         struct dlm_lock_resource *res;
 683
 684         spin_lock(&dlm_domain_lock);
 685         BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
 686         BUG_ON(!dlm->num_joins);
 687
 688         dlm->num_joins--;
 689         if (!dlm->num_joins) {
 690                 /* We mark it "in shutdown" now so new register
 691                  * requests wait until we've completely left the
 692                  * domain. Don't use DLM_CTXT_LEAVING yet as we still
 693                  * want new domain joins to communicate with us at
 694                  * least until we've completed migration of our
 695                  * resources. */
 696                 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
 697                 leave = 1;
 698         }
 699         spin_unlock(&dlm_domain_lock);
 700
 701         if (leave) {
 702                 mlog(0, "shutting down domain %s\n", dlm->name);
 703                 dlm_begin_exit_domain(dlm);
 704
 705                 /* We changed dlm state, notify the thread */
 706                 dlm_kick_thread(dlm, NULL);
 707
 708                 while (dlm_migrate_all_locks(dlm)) {
 709                         /* Give dlm_thread time to purge the lockres' */
 710                         msleep(500);
 711                         mlog(0, "%s: more migration to do\n", dlm->name);
 712                 }
 713
 714                 /* This list should be empty. If not, print remaining lockres */
 715                 if (!list_empty(&dlm->tracking_list)) {
 716                         mlog(ML_ERROR, "Following lockres' are still on the "
 717                              "tracking list:\n");
 718                         list_for_each_entry(res, &dlm->tracking_list, tracking)
 719                                 dlm_print_one_lock_resource(res);
 720                 }
 721
 722                 dlm_mark_domain_leaving(dlm);
 723                 dlm_leave_domain(dlm);
 724                 printk(KERN_NOTICE "o2dlm: Leaving domain %s\n", dlm->name);
 725                 dlm_force_free_mles(dlm);
 726                 dlm_complete_dlm_shutdown(dlm);
 727         }
 728         dlm_put(dlm);
 729 }
 730 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 731
 732 static int dlm_query_join_proto_check(char *proto_type, int node,
 733                                       struct dlm_protocol_version *ours,
 734                                       struct dlm_protocol_version *request)
 735 {
 736         int rc;
 737         struct dlm_protocol_version proto = *request;
 738
 739         if (!dlm_protocol_compare(ours, &proto)) {
 740                 mlog(0,
 741                      "node %u wanted to join with %s locking protocol "
 742                      "%u.%u, we respond with %u.%u\n",
 743                      node, proto_type,
 744                      request->pv_major,
 745                      request->pv_minor,
 746                      proto.pv_major, proto.pv_minor);
 747                 request->pv_minor = proto.pv_minor;
 748                 rc = 0;
 749         } else {
 750                 mlog(ML_NOTICE,
 751                      "Node %u wanted to join with %s locking "
 752                      "protocol %u.%u, but we have %u.%u, disallowing\n",
 753                      node, proto_type,
 754                      request->pv_major,
 755                      request->pv_minor,
 756                      ours->pv_major,
 757                      ours->pv_minor);
 758                 rc = 1;
 759         }
 760
 761         return rc;
 762 }
 763
 764 /*
 765  * struct dlm_query_join_packet is made up of four one-byte fields.  They
 766  * are effectively in big-endian order already.  However, little-endian
 767  * machines swap them before putting the packet on the wire (because
 768  * query_join's response is a status, and that status is treated as a u32
 769  * on the wire).  Thus, a big-endian and little-endian machines will treat
 770  * this structure differently.
 771  *
 772  * The solution is to have little-endian machines swap the structure when
 773  * converting from the structure to the u32 representation.  This will
 774  * result in the structure having the correct format on the wire no matter
 775  * the host endian format.
 776  */
 777 static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
 778                                           u32 *wire)
 779 {
 780         union dlm_query_join_response response;
 781
 782         response.packet = *packet;
 783         *wire = be32_to_cpu(response.intval);
 784 }
 785
 786 static void dlm_query_join_wire_to_packet(u32 wire,
 787                                           struct dlm_query_join_packet *packet)
 788 {
 789         union dlm_query_join_response response;
 790
 791         response.intval = cpu_to_be32(wire);
 792         *packet = response.packet;
 793 }
 794
 795 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 796                                   void **ret_data)
 797 {
 798         struct dlm_query_join_request *query;
 799         struct dlm_query_join_packet packet = {
 800                 .code = JOIN_DISALLOW,
 801         };
 802         struct dlm_ctxt *dlm = NULL;
 803         u32 response;
 804         u8 nodenum;
 805
 806         query = (struct dlm_query_join_request *) msg->buf;
 807
 808         mlog(0, "node %u wants to join domain %s\n", query->node_idx,
 809                   query->domain);
 810
 811         /*
 812          * If heartbeat doesn't consider the node live, tell it
 813          * to back off and try again.  This gives heartbeat a chance
 814          * to catch up.
 815          */
 816         if (!o2hb_check_node_heartbeating_no_sem(query->node_idx)) {
 817                 mlog(0, "node %u is not in our live map yet\n",
 818                      query->node_idx);
 819
 820                 packet.code = JOIN_DISALLOW;
 821                 goto respond;
 822         }
 823
 824         packet.code = JOIN_OK_NO_MAP;
 825
 826         spin_lock(&dlm_domain_lock);
 827         dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 828         if (!dlm)
 829                 goto unlock_respond;
 830
 831         /*
 832          * There is a small window where the joining node may not see the
 833          * node(s) that just left but still part of the cluster. DISALLOW
 834          * join request if joining node has different node map.
 835          */
 836         nodenum=0;
 837         while (nodenum < O2NM_MAX_NODES) {
 838                 if (test_bit(nodenum, dlm->domain_map)) {
 839                         if (!byte_test_bit(nodenum, query->node_map)) {
 840                                 mlog(0, "disallow join as node %u does not "
 841                                      "have node %u in its nodemap\n",
 842                                      query->node_idx, nodenum);
 843                                 packet.code = JOIN_DISALLOW;
 844                                 goto unlock_respond;
 845                         }
 846                 }
 847                 nodenum++;
 848         }
 849
 850         /* Once the dlm ctxt is marked as leaving then we don't want
 851          * to be put in someone's domain map.
 852          * Also, explicitly disallow joining at certain troublesome
 853          * times (ie. during recovery). */
 854         if (dlm->dlm_state != DLM_CTXT_LEAVING) {
 855                 int bit = query->node_idx;
 856                 spin_lock(&dlm->spinlock);
 857
 858                 if (dlm->dlm_state == DLM_CTXT_NEW &&
 859                     dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
 860                         /*If this is a brand new context and we
 861                          * haven't started our join process yet, then
 862                          * the other node won the race. */
 863                         packet.code = JOIN_OK_NO_MAP;
 864                 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 865                         /* Disallow parallel joins. */
 866                         packet.code = JOIN_DISALLOW;
 867                 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 868                         mlog(0, "node %u trying to join, but recovery "
 869                              "is ongoing.\n", bit);
 870                         packet.code = JOIN_DISALLOW;
 871                 } else if (test_bit(bit, dlm->recovery_map)) {
 872                         mlog(0, "node %u trying to join, but it "
 873                              "still needs recovery.\n", bit);
 874                         packet.code = JOIN_DISALLOW;
 875                 } else if (test_bit(bit, dlm->domain_map)) {
 876                         mlog(0, "node %u trying to join, but it "
 877                              "is still in the domain! needs recovery?\n",
 878                              bit);
 879                         packet.code = JOIN_DISALLOW;
 880                 } else {
 881                         /* Alright we're fully a part of this domain
 882                          * so we keep some state as to who's joining
 883                          * and indicate to him that needs to be fixed
 884                          * up. */
 885
 886                         /* Make sure we speak compatible locking protocols.  */
 887                         if (dlm_query_join_proto_check("DLM", bit,
 888                                                        &dlm->dlm_locking_proto,
 889                                                        &query->dlm_proto)) {
 890                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 891                         } else if (dlm_query_join_proto_check("fs", bit,
 892                                                               &dlm->fs_locking_proto,
 893                                                               &query->fs_proto)) {
 894                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 895                         } else {
 896                                 packet.dlm_minor = query->dlm_proto.pv_minor;
 897                                 packet.fs_minor = query->fs_proto.pv_minor;
 898                                 packet.code = JOIN_OK;
 899                                 __dlm_set_joining_node(dlm, query->node_idx);
 900                         }
 901                 }
 902
 903                 spin_unlock(&dlm->spinlock);
 904         }
 905 unlock_respond:
 906         spin_unlock(&dlm_domain_lock);
 907
 908 respond:
 909         mlog(0, "We respond with %u\n", packet.code);
 910
 911         dlm_query_join_packet_to_wire(&packet, &response);
 912         return response;
 913 }
 914
 915 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 916                                      void **ret_data)
 917 {
 918         struct dlm_assert_joined *assert;
 919         struct dlm_ctxt *dlm = NULL;
 920
 921         assert = (struct dlm_assert_joined *) msg->buf;
 922
 923         mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
 924                   assert->domain);
 925
 926         spin_lock(&dlm_domain_lock);
 927         dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
 928         /* XXX should we consider no dlm ctxt an error? */
 929         if (dlm) {
 930                 spin_lock(&dlm->spinlock);
 931
 932                 /* Alright, this node has officially joined our
 933                  * domain. Set him in the map and clean up our
 934                  * leftover join state. */
 935                 BUG_ON(dlm->joining_node != assert->node_idx);
 936
 937                 if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 938                         mlog(0, "dlm recovery is ongoing, disallow join\n");
 939                         spin_unlock(&dlm->spinlock);
 940                         spin_unlock(&dlm_domain_lock);
 941                         return -EAGAIN;
 942                 }
 943
 944                 set_bit(assert->node_idx, dlm->domain_map);
 945                 clear_bit(assert->node_idx, dlm->exit_domain_map);
 946                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 947
 948                 printk(KERN_NOTICE "o2dlm: Node %u joins domain %s ",
 949                        assert->node_idx, dlm->name);
 950                 __dlm_print_nodes(dlm);
 951
 952                 /* notify anything attached to the heartbeat events */
 953                 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
 954
 955                 spin_unlock(&dlm->spinlock);
 956         }
 957         spin_unlock(&dlm_domain_lock);
 958
 959         return 0;
 960 }
 961
 962 static int dlm_match_regions(struct dlm_ctxt *dlm,
 963                              struct dlm_query_region *qr,
 964                              char *local, int locallen)
 965 {
 966         char *remote = qr->qr_regions;
 967         char *l, *r;
 968         int localnr, i, j, foundit;
 969         int status = 0;
 970
 971         if (!o2hb_global_heartbeat_active()) {
 972                 if (qr->qr_numregions) {
 973                         mlog(ML_ERROR, "Domain %s: Joining node %d has global "
 974                              "heartbeat enabled but local node %d does not\n",
 975                              qr->qr_domain, qr->qr_node, dlm->node_num);
 976                         status = -EINVAL;
 977                 }
 978                 goto bail;
 979         }
 980
 981         if (o2hb_global_heartbeat_active() && !qr->qr_numregions) {
 982                 mlog(ML_ERROR, "Domain %s: Local node %d has global "
 983                      "heartbeat enabled but joining node %d does not\n",
 984                      qr->qr_domain, dlm->node_num, qr->qr_node);
 985                 status = -EINVAL;
 986                 goto bail;
 987         }
 988
 989         r = remote;
 990         for (i = 0; i < qr->qr_numregions; ++i) {
 991                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, r);
 992                 r += O2HB_MAX_REGION_NAME_LEN;
 993         }
 994
 995         localnr = min(O2NM_MAX_REGIONS, locallen/O2HB_MAX_REGION_NAME_LEN);
 996         localnr = o2hb_get_all_regions(local, (u8)localnr);
 997
 998         /* compare local regions with remote */
 999         l = local;
1000         for (i = 0; i < localnr; ++i) {
1001                 foundit = 0;
1002                 r = remote;
1003                 for (j = 0; j <= qr->qr_numregions; ++j) {
1004                         if (!memcmp(l, r, O2HB_MAX_REGION_NAME_LEN)) {
1005                                 foundit = 1;
1006                                 break;
1007                         }
1008                         r += O2HB_MAX_REGION_NAME_LEN;
1009                 }
1010                 if (!foundit) {
1011                         status = -EINVAL;
1012                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1013                              "in local node %d but not in joining node %d\n",
1014                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, l,
1015                              dlm->node_num, qr->qr_node);
1016                         goto bail;
1017                 }
1018                 l += O2HB_MAX_REGION_NAME_LEN;
1019         }
1020
1021         /* compare remote with local regions */
1022         r = remote;
1023         for (i = 0; i < qr->qr_numregions; ++i) {
1024                 foundit = 0;
1025                 l = local;
1026                 for (j = 0; j < localnr; ++j) {
1027                         if (!memcmp(r, l, O2HB_MAX_REGION_NAME_LEN)) {
1028                                 foundit = 1;
1029                                 break;
1030                         }
1031                         l += O2HB_MAX_REGION_NAME_LEN;
1032                 }
1033                 if (!foundit) {
1034                         status = -EINVAL;
1035                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1036                              "in joining node %d but not in local node %d\n",
1037                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, r,
1038                              qr->qr_node, dlm->node_num);
1039                         goto bail;
1040                 }
1041                 r += O2HB_MAX_REGION_NAME_LEN;
1042         }
1043
1044 bail:
1045         return status;
1046 }
1047
1048 static int dlm_send_regions(struct dlm_ctxt *dlm, unsigned long *node_map)
1049 {
1050         struct dlm_query_region *qr = NULL;
1051         int status, ret = 0, i;
1052         char *p;
1053
1054         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1055                 goto bail;
1056
1057         qr = kzalloc(sizeof(struct dlm_query_region), GFP_KERNEL);
1058         if (!qr) {
1059                 ret = -ENOMEM;
1060                 mlog_errno(ret);
1061                 goto bail;
1062         }
1063
1064         qr->qr_node = dlm->node_num;
1065         qr->qr_namelen = strlen(dlm->name);
1066         memcpy(qr->qr_domain, dlm->name, qr->qr_namelen);
1067         /* if local hb, the numregions will be zero */
1068         if (o2hb_global_heartbeat_active())
1069                 qr->qr_numregions = o2hb_get_all_regions(qr->qr_regions,
1070                                                          O2NM_MAX_REGIONS);
1071
1072         p = qr->qr_regions;
1073         for (i = 0; i < qr->qr_numregions; ++i, p += O2HB_MAX_REGION_NAME_LEN)
1074                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, p);
1075
1076         i = -1;
1077         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1078                                   i + 1)) < O2NM_MAX_NODES) {
1079                 if (i == dlm->node_num)
1080                         continue;
1081
1082                 mlog(0, "Sending regions to node %d\n", i);
1083
1084                 ret = o2net_send_message(DLM_QUERY_REGION, DLM_MOD_KEY, qr,
1085                                          sizeof(struct dlm_query_region),
1086                                          i, &status);
1087                 if (ret >= 0)
1088                         ret = status;
1089                 if (ret) {
1090                         mlog(ML_ERROR, "Region mismatch %d, node %d\n",
1091                              ret, i);
1092                         break;
1093                 }
1094         }
1095
1096 bail:
1097         kfree(qr);
1098         return ret;
1099 }
1100
1101 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
1102                                     void *data, void **ret_data)
1103 {
1104         struct dlm_query_region *qr;
1105         struct dlm_ctxt *dlm = NULL;
1106         char *local = NULL;
1107         int status = 0;
1108
1109         qr = (struct dlm_query_region *) msg->buf;
1110
1111         mlog(0, "Node %u queries hb regions on domain %s\n", qr->qr_node,
1112              qr->qr_domain);
1113
1114         /* buffer used in dlm_mast_regions() */
1115         local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
1116         if (!local)
1117                 return -ENOMEM;
1118
1119         status = -EINVAL;
1120
1121         spin_lock(&dlm_domain_lock);
1122         dlm = __dlm_lookup_domain_full(qr->qr_domain, qr->qr_namelen);
1123         if (!dlm) {
1124                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1125                      "before join domain\n", qr->qr_node, qr->qr_domain);
1126                 goto out_domain_lock;
1127         }
1128
1129         spin_lock(&dlm->spinlock);
1130         if (dlm->joining_node != qr->qr_node) {
1131                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1132                      "but joining node is %d\n", qr->qr_node, qr->qr_domain,
1133                      dlm->joining_node);
1134                 goto out_dlm_lock;
1135         }
1136
1137         /* Support for global heartbeat was added in 1.1 */
1138         if (dlm->dlm_locking_proto.pv_major == 1 &&
1139             dlm->dlm_locking_proto.pv_minor == 0) {
1140                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1141                      "but active dlm protocol is %d.%d\n", qr->qr_node,
1142                      qr->qr_domain, dlm->dlm_locking_proto.pv_major,
1143                      dlm->dlm_locking_proto.pv_minor);
1144                 goto out_dlm_lock;
1145         }
1146
1147         status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
1148
1149 out_dlm_lock:
1150         spin_unlock(&dlm->spinlock);
1151
1152 out_domain_lock:
1153         spin_unlock(&dlm_domain_lock);
1154
1155         kfree(local);
1156
1157         return status;
1158 }
1159
1160 static int dlm_match_nodes(struct dlm_ctxt *dlm, struct dlm_query_nodeinfo *qn)
1161 {
1162         struct o2nm_node *local;
1163         struct dlm_node_info *remote;
1164         int i, j;
1165         int status = 0;
1166
1167         for (j = 0; j < qn->qn_numnodes; ++j)
1168                 mlog(0, "Node %3d, %pI4:%u\n", qn->qn_nodes[j].ni_nodenum,
1169                      &(qn->qn_nodes[j].ni_ipv4_address),
1170                      ntohs(qn->qn_nodes[j].ni_ipv4_port));
1171
1172         for (i = 0; i < O2NM_MAX_NODES && !status; ++i) {
1173                 local = o2nm_get_node_by_num(i);
1174                 remote = NULL;
1175                 for (j = 0; j < qn->qn_numnodes; ++j) {
1176                         if (qn->qn_nodes[j].ni_nodenum == i) {
1177                                 remote = &(qn->qn_nodes[j]);
1178                                 break;
1179                         }
1180                 }
1181
1182                 if (!local && !remote)
1183                         continue;
1184
1185                 if ((local && !remote) || (!local && remote))
1186                         status = -EINVAL;
1187
1188                 if (!status &&
1189                     ((remote->ni_nodenum != local->nd_num) ||
1190                      (remote->ni_ipv4_port != local->nd_ipv4_port) ||
1191                      (remote->ni_ipv4_address != local->nd_ipv4_address)))
1192                         status = -EINVAL;
1193
1194                 if (status) {
1195                         if (remote && !local)
1196                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1197                                      "registered in joining node %d but not in "
1198                                      "local node %d\n", qn->qn_domain,
1199                                      remote->ni_nodenum,
1200                                      &(remote->ni_ipv4_address),
1201                                      ntohs(remote->ni_ipv4_port),
1202                                      qn->qn_nodenum, dlm->node_num);
1203                         if (local && !remote)
1204                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1205                                      "registered in local node %d but not in "
1206                                      "joining node %d\n", qn->qn_domain,
1207                                      local->nd_num, &(local->nd_ipv4_address),
1208                                      ntohs(local->nd_ipv4_port),
1209                                      dlm->node_num, qn->qn_nodenum);
1210                         BUG_ON((!local && !remote));
1211                 }
1212
1213                 if (local)
1214                         o2nm_node_put(local);
1215         }
1216
1217         return status;
1218 }
1219
1220 static int dlm_send_nodeinfo(struct dlm_ctxt *dlm, unsigned long *node_map)
1221 {
1222         struct dlm_query_nodeinfo *qn = NULL;
1223         struct o2nm_node *node;
1224         int ret = 0, status, count, i;
1225
1226         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1227                 goto bail;
1228
1229         qn = kzalloc(sizeof(struct dlm_query_nodeinfo), GFP_KERNEL);
1230         if (!qn) {
1231                 ret = -ENOMEM;
1232                 mlog_errno(ret);
1233                 goto bail;
1234         }
1235
1236         for (i = 0, count = 0; i < O2NM_MAX_NODES; ++i) {
1237                 node = o2nm_get_node_by_num(i);
1238                 if (!node)
1239                         continue;
1240                 qn->qn_nodes[count].ni_nodenum = node->nd_num;
1241                 qn->qn_nodes[count].ni_ipv4_port = node->nd_ipv4_port;
1242                 qn->qn_nodes[count].ni_ipv4_address = node->nd_ipv4_address;
1243                 mlog(0, "Node %3d, %pI4:%u\n", node->nd_num,
1244                      &(node->nd_ipv4_address), ntohs(node->nd_ipv4_port));
1245                 ++count;
1246                 o2nm_node_put(node);
1247         }
1248
1249         qn->qn_nodenum = dlm->node_num;
1250         qn->qn_numnodes = count;
1251         qn->qn_namelen = strlen(dlm->name);
1252         memcpy(qn->qn_domain, dlm->name, qn->qn_namelen);
1253
1254         i = -1;
1255         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1256                                   i + 1)) < O2NM_MAX_NODES) {
1257                 if (i == dlm->node_num)
1258                         continue;
1259
1260                 mlog(0, "Sending nodeinfo to node %d\n", i);
1261
1262                 ret = o2net_send_message(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
1263                                          qn, sizeof(struct dlm_query_nodeinfo),
1264                                          i, &status);
1265                 if (ret >= 0)
1266                         ret = status;
1267                 if (ret) {
1268                         mlog(ML_ERROR, "node mismatch %d, node %d\n", ret, i);
1269                         break;
1270                 }
1271         }
1272
1273 bail:
1274         kfree(qn);
1275         return ret;
1276 }
1277
1278 static int dlm_query_nodeinfo_handler(struct o2net_msg *msg, u32 len,
1279                                       void *data, void **ret_data)
1280 {
1281         struct dlm_query_nodeinfo *qn;
1282         struct dlm_ctxt *dlm = NULL;
1283         int locked = 0, status = -EINVAL;
1284
1285         qn = (struct dlm_query_nodeinfo *) msg->buf;
1286
1287         mlog(0, "Node %u queries nodes on domain %s\n", qn->qn_nodenum,
1288              qn->qn_domain);
1289
1290         spin_lock(&dlm_domain_lock);
1291         dlm = __dlm_lookup_domain_full(qn->qn_domain, qn->qn_namelen);
1292         if (!dlm) {
1293                 mlog(ML_ERROR, "Node %d queried nodes on domain %s before "
1294                      "join domain\n", qn->qn_nodenum, qn->qn_domain);
1295                 goto bail;
1296         }
1297
1298         spin_lock(&dlm->spinlock);
1299         locked = 1;
1300         if (dlm->joining_node != qn->qn_nodenum) {
1301                 mlog(ML_ERROR, "Node %d queried nodes on domain %s but "
1302                      "joining node is %d\n", qn->qn_nodenum, qn->qn_domain,
1303                      dlm->joining_node);
1304                 goto bail;
1305         }
1306
1307         /* Support for node query was added in 1.1 */
1308         if (dlm->dlm_locking_proto.pv_major == 1 &&
1309             dlm->dlm_locking_proto.pv_minor == 0) {
1310                 mlog(ML_ERROR, "Node %d queried nodes on domain %s "
1311                      "but active dlm protocol is %d.%d\n", qn->qn_nodenum,
1312                      qn->qn_domain, dlm->dlm_locking_proto.pv_major,
1313                      dlm->dlm_locking_proto.pv_minor);
1314                 goto bail;
1315         }
1316
1317         status = dlm_match_nodes(dlm, qn);
1318
1319 bail:
1320         if (locked)
1321                 spin_unlock(&dlm->spinlock);
1322         spin_unlock(&dlm_domain_lock);
1323
1324         return status;
1325 }
1326
1327 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
1328                                    void **ret_data)
1329 {
1330         struct dlm_cancel_join *cancel;
1331         struct dlm_ctxt *dlm = NULL;
1332
1333         cancel = (struct dlm_cancel_join *) msg->buf;
1334
1335         mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
1336                   cancel->domain);
1337
1338         spin_lock(&dlm_domain_lock);
1339         dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
1340
1341         if (dlm) {
1342                 spin_lock(&dlm->spinlock);
1343
1344                 /* Yikes, this guy wants to cancel his join. No
1345                  * problem, we simply cleanup our join state. */
1346                 BUG_ON(dlm->joining_node != cancel->node_idx);
1347                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1348
1349                 spin_unlock(&dlm->spinlock);
1350         }
1351         spin_unlock(&dlm_domain_lock);
1352
1353         return 0;
1354 }
1355
1356 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
1357                                     unsigned int node)
1358 {
1359         int status;
1360         struct dlm_cancel_join cancel_msg;
1361
1362         memset(&cancel_msg, 0, sizeof(cancel_msg));
1363         cancel_msg.node_idx = dlm->node_num;
1364         cancel_msg.name_len = strlen(dlm->name);
1365         memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
1366
1367         status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1368                                     &cancel_msg, sizeof(cancel_msg), node,
1369                                     NULL);
1370         if (status < 0) {
1371                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1372                      "node %u\n", status, DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1373                      node);
1374                 goto bail;
1375         }
1376
1377 bail:
1378         return status;
1379 }
1380
1381 /* map_size should be in bytes. */
1382 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
1383                                  unsigned long *node_map,
1384                                  unsigned int map_size)
1385 {
1386         int status, tmpstat;
1387         int node;
1388
1389         if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
1390                          sizeof(unsigned long))) {
1391                 mlog(ML_ERROR,
1392                      "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
1393                      map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
1394                 return -EINVAL;
1395         }
1396
1397         status = 0;
1398         node = -1;
1399         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1400                                      node + 1)) < O2NM_MAX_NODES) {
1401                 if (node == dlm->node_num)
1402                         continue;
1403
1404                 tmpstat = dlm_send_one_join_cancel(dlm, node);
1405                 if (tmpstat) {
1406                         mlog(ML_ERROR, "Error return %d cancelling join on "
1407                              "node %d\n", tmpstat, node);
1408                         if (!status)
1409                                 status = tmpstat;
1410                 }
1411         }
1412
1413         if (status)
1414                 mlog_errno(status);
1415         return status;
1416 }
1417
1418 static int dlm_request_join(struct dlm_ctxt *dlm,
1419                             int node,
1420                             enum dlm_query_join_response_code *response)
1421 {
1422         int status;
1423         struct dlm_query_join_request join_msg;
1424         struct dlm_query_join_packet packet;
1425         u32 join_resp;
1426
1427         mlog(0, "querying node %d\n", node);
1428
1429         memset(&join_msg, 0, sizeof(join_msg));
1430         join_msg.node_idx = dlm->node_num;
1431         join_msg.name_len = strlen(dlm->name);
1432         memcpy(join_msg.domain, dlm->name, join_msg.name_len);
1433         join_msg.dlm_proto = dlm->dlm_locking_proto;
1434         join_msg.fs_proto = dlm->fs_locking_proto;
1435
1436         /* copy live node map to join message */
1437         byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
1438
1439         status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
1440                                     sizeof(join_msg), node, &join_resp);
1441         if (status < 0 && status != -ENOPROTOOPT) {
1442                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1443                      "node %u\n", status, DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1444                      node);
1445                 goto bail;
1446         }
1447         dlm_query_join_wire_to_packet(join_resp, &packet);
1448
1449         /* -ENOPROTOOPT from the net code means the other side isn't
1450             listening for our message type -- that's fine, it means
1451             his dlm isn't up, so we can consider him a 'yes' but not
1452             joined into the domain.  */
1453         if (status == -ENOPROTOOPT) {
1454                 status = 0;
1455                 *response = JOIN_OK_NO_MAP;
1456         } else {
1457                 *response = packet.code;
1458                 switch (packet.code) {
1459                 case JOIN_DISALLOW:
1460                 case JOIN_OK_NO_MAP:
1461                         break;
1462                 case JOIN_PROTOCOL_MISMATCH:
1463                         mlog(ML_NOTICE,
1464                              "This node requested DLM locking protocol %u.%u and "
1465                              "filesystem locking protocol %u.%u.  At least one of "
1466                              "the protocol versions on node %d is not compatible, "
1467                              "disconnecting\n",
1468                              dlm->dlm_locking_proto.pv_major,
1469                              dlm->dlm_locking_proto.pv_minor,
1470                              dlm->fs_locking_proto.pv_major,
1471                              dlm->fs_locking_proto.pv_minor,
1472                              node);
1473                         status = -EPROTO;
1474                         break;
1475                 case JOIN_OK:
1476                         /* Use the same locking protocol as the remote node */
1477                         dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
1478                         dlm->fs_locking_proto.pv_minor = packet.fs_minor;
1479                         mlog(0,
1480                              "Node %d responds JOIN_OK with DLM locking protocol "
1481                              "%u.%u and fs locking protocol %u.%u\n",
1482                              node,
1483                              dlm->dlm_locking_proto.pv_major,
1484                              dlm->dlm_locking_proto.pv_minor,
1485                              dlm->fs_locking_proto.pv_major,
1486                              dlm->fs_locking_proto.pv_minor);
1487                         break;
1488                 default:
1489                         status = -EINVAL;
1490                         mlog(ML_ERROR, "invalid response %d from node %u\n",
1491                              packet.code, node);
1492                         /* Reset response to JOIN_DISALLOW */
1493                         *response = JOIN_DISALLOW;
1494                         break;
1495                 }
1496         }
1497
1498         mlog(0, "status %d, node %d response is %d\n", status, node,
1499              *response);
1500
1501 bail:
1502         return status;
1503 }
1504
1505 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
1506                                     unsigned int node)
1507 {
1508         int status;
1509         int ret;
1510         struct dlm_assert_joined assert_msg;
1511
1512         mlog(0, "Sending join assert to node %u\n", node);
1513
1514         memset(&assert_msg, 0, sizeof(assert_msg));
1515         assert_msg.node_idx = dlm->node_num;
1516         assert_msg.name_len = strlen(dlm->name);
1517         memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
1518
1519         status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1520                                     &assert_msg, sizeof(assert_msg), node,
1521                                     &ret);
1522         if (status < 0)
1523                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1524                      "node %u\n", status, DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1525                      node);
1526         else
1527                 status = ret;
1528
1529         return status;
1530 }
1531
1532 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
1533                                   unsigned long *node_map)
1534 {
1535         int status, node, live;
1536
1537         status = 0;
1538         node = -1;
1539         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1540                                      node + 1)) < O2NM_MAX_NODES) {
1541                 if (node == dlm->node_num)
1542                         continue;
1543
1544                 do {
1545                         /* It is very important that this message be
1546                          * received so we spin until either the node
1547                          * has died or it gets the message. */
1548                         status = dlm_send_one_join_assert(dlm, node);
1549
1550                         spin_lock(&dlm->spinlock);
1551                         live = test_bit(node, dlm->live_nodes_map);
1552                         spin_unlock(&dlm->spinlock);
1553
1554                         if (status) {
1555                                 mlog(ML_ERROR, "Error return %d asserting "
1556                                      "join on node %d\n", status, node);
1557
1558                                 /* give us some time between errors... */
1559                                 if (live)
1560                                         msleep(DLM_DOMAIN_BACKOFF_MS);
1561                         }
1562                 } while (status && live);
1563         }
1564 }
1565
1566 struct domain_join_ctxt {
1567         unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1568         unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1569 };
1570
1571 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
1572                                    struct domain_join_ctxt *ctxt,
1573                                    enum dlm_query_join_response_code response)
1574 {
1575         int ret;
1576
1577         if (response == JOIN_DISALLOW) {
1578                 mlog(0, "Latest response of disallow -- should restart\n");
1579                 return 1;
1580         }
1581
1582         spin_lock(&dlm->spinlock);
1583         /* For now, we restart the process if the node maps have
1584          * changed at all */
1585         ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
1586                      sizeof(dlm->live_nodes_map));
1587         spin_unlock(&dlm->spinlock);
1588
1589         if (ret)
1590                 mlog(0, "Node maps changed -- should restart\n");
1591
1592         return ret;
1593 }
1594
1595 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
1596 {
1597         int status = 0, tmpstat, node;
1598         struct domain_join_ctxt *ctxt;
1599         enum dlm_query_join_response_code response = JOIN_DISALLOW;
1600
1601         mlog(0, "%p", dlm);
1602
1603         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
1604         if (!ctxt) {
1605                 status = -ENOMEM;
1606                 mlog_errno(status);
1607                 goto bail;
1608         }
1609
1610         /* group sem locking should work for us here -- we're already
1611          * registered for heartbeat events so filling this should be
1612          * atomic wrt getting those handlers called. */
1613         o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
1614
1615         spin_lock(&dlm->spinlock);
1616         memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
1617
1618         __dlm_set_joining_node(dlm, dlm->node_num);
1619
1620         spin_unlock(&dlm->spinlock);
1621
1622         node = -1;
1623         while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
1624                                      node + 1)) < O2NM_MAX_NODES) {
1625                 if (node == dlm->node_num)
1626                         continue;
1627
1628                 status = dlm_request_join(dlm, node, &response);
1629                 if (status < 0) {
1630                         mlog_errno(status);
1631                         goto bail;
1632                 }
1633
1634                 /* Ok, either we got a response or the node doesn't have a
1635                  * dlm up. */
1636                 if (response == JOIN_OK)
1637                         set_bit(node, ctxt->yes_resp_map);
1638
1639                 if (dlm_should_restart_join(dlm, ctxt, response)) {
1640                         status = -EAGAIN;
1641                         goto bail;
1642                 }
1643         }
1644
1645         mlog(0, "Yay, done querying nodes!\n");
1646
1647         /* Yay, everyone agree's we can join the domain. My domain is
1648          * comprised of all nodes who were put in the
1649          * yes_resp_map. Copy that into our domain map and send a join
1650          * assert message to clean up everyone elses state. */
1651         spin_lock(&dlm->spinlock);
1652         memcpy(dlm->domain_map, ctxt->yes_resp_map,
1653                sizeof(ctxt->yes_resp_map));
1654         set_bit(dlm->node_num, dlm->domain_map);
1655         spin_unlock(&dlm->spinlock);
1656
1657         /* Support for global heartbeat and node info was added in 1.1 */
1658         if (dlm->dlm_locking_proto.pv_major > 1 ||
1659             dlm->dlm_locking_proto.pv_minor > 0) {
1660                 status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
1661                 if (status) {
1662                         mlog_errno(status);
1663                         goto bail;
1664                 }
1665                 status = dlm_send_regions(dlm, ctxt->yes_resp_map);
1666                 if (status) {
1667                         mlog_errno(status);
1668                         goto bail;
1669                 }
1670         }
1671
1672         dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
1673
1674         /* Joined state *must* be set before the joining node
1675          * information, otherwise the query_join handler may read no
1676          * current joiner but a state of NEW and tell joining nodes
1677          * we're not in the domain. */
1678         spin_lock(&dlm_domain_lock);
1679         dlm->dlm_state = DLM_CTXT_JOINED;
1680         dlm->num_joins++;
1681         spin_unlock(&dlm_domain_lock);
1682
1683 bail:
1684         spin_lock(&dlm->spinlock);
1685         __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1686         if (!status) {
1687                 printk(KERN_NOTICE "o2dlm: Joining domain %s ", dlm->name);
1688                 __dlm_print_nodes(dlm);
1689         }
1690         spin_unlock(&dlm->spinlock);
1691
1692         if (ctxt) {
1693                 /* Do we need to send a cancel message to any nodes? */
1694                 if (status < 0) {
1695                         tmpstat = dlm_send_join_cancels(dlm,
1696                                                         ctxt->yes_resp_map,
1697                                                         sizeof(ctxt->yes_resp_map));
1698                         if (tmpstat < 0)
1699                                 mlog_errno(tmpstat);
1700                 }
1701                 kfree(ctxt);
1702         }
1703
1704         mlog(0, "returning %d\n", status);
1705         return status;
1706 }
1707
1708 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1709 {
1710         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_up);
1711         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_down);
1712         o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1713 }
1714
1715 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1716 {
1717         int status;
1718
1719         mlog(0, "registering handlers.\n");
1720
1721         o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1722                             dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1723         o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1724                             dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1725
1726         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
1727         if (status)
1728                 goto bail;
1729
1730         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
1731         if (status)
1732                 goto bail;
1733
1734         status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1735                                         sizeof(struct dlm_master_request),
1736                                         dlm_master_request_handler,
1737                                         dlm, NULL, &dlm->dlm_domain_handlers);
1738         if (status)
1739                 goto bail;
1740
1741         status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1742                                         sizeof(struct dlm_assert_master),
1743                                         dlm_assert_master_handler,
1744                                         dlm, dlm_assert_master_post_handler,
1745                                         &dlm->dlm_domain_handlers);
1746         if (status)
1747                 goto bail;
1748
1749         status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1750                                         sizeof(struct dlm_create_lock),
1751                                         dlm_create_lock_handler,
1752                                         dlm, NULL, &dlm->dlm_domain_handlers);
1753         if (status)
1754                 goto bail;
1755
1756         status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1757                                         DLM_CONVERT_LOCK_MAX_LEN,
1758                                         dlm_convert_lock_handler,
1759                                         dlm, NULL, &dlm->dlm_domain_handlers);
1760         if (status)
1761                 goto bail;
1762
1763         status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1764                                         DLM_UNLOCK_LOCK_MAX_LEN,
1765                                         dlm_unlock_lock_handler,
1766                                         dlm, NULL, &dlm->dlm_domain_handlers);
1767         if (status)
1768                 goto bail;
1769
1770         status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1771                                         DLM_PROXY_AST_MAX_LEN,
1772                                         dlm_proxy_ast_handler,
1773                                         dlm, NULL, &dlm->dlm_domain_handlers);
1774         if (status)
1775                 goto bail;
1776
1777         status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1778                                         sizeof(struct dlm_exit_domain),
1779                                         dlm_exit_domain_handler,
1780                                         dlm, NULL, &dlm->dlm_domain_handlers);
1781         if (status)
1782                 goto bail;
1783
1784         status = o2net_register_handler(DLM_DEREF_LOCKRES_MSG, dlm->key,
1785                                         sizeof(struct dlm_deref_lockres),
1786                                         dlm_deref_lockres_handler,
1787                                         dlm, NULL, &dlm->dlm_domain_handlers);
1788         if (status)
1789                 goto bail;
1790
1791         status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1792                                         sizeof(struct dlm_migrate_request),
1793                                         dlm_migrate_request_handler,
1794                                         dlm, NULL, &dlm->dlm_domain_handlers);
1795         if (status)
1796                 goto bail;
1797
1798         status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1799                                         DLM_MIG_LOCKRES_MAX_LEN,
1800                                         dlm_mig_lockres_handler,
1801                                         dlm, NULL, &dlm->dlm_domain_handlers);
1802         if (status)
1803                 goto bail;
1804
1805         status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1806                                         sizeof(struct dlm_master_requery),
1807                                         dlm_master_requery_handler,
1808                                         dlm, NULL, &dlm->dlm_domain_handlers);
1809         if (status)
1810                 goto bail;
1811
1812         status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1813                                         sizeof(struct dlm_lock_request),
1814                                         dlm_request_all_locks_handler,
1815                                         dlm, NULL, &dlm->dlm_domain_handlers);
1816         if (status)
1817                 goto bail;
1818
1819         status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1820                                         sizeof(struct dlm_reco_data_done),
1821                                         dlm_reco_data_done_handler,
1822                                         dlm, NULL, &dlm->dlm_domain_handlers);
1823         if (status)
1824                 goto bail;
1825
1826         status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1827                                         sizeof(struct dlm_begin_reco),
1828                                         dlm_begin_reco_handler,
1829                                         dlm, NULL, &dlm->dlm_domain_handlers);
1830         if (status)
1831                 goto bail;
1832
1833         status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1834                                         sizeof(struct dlm_finalize_reco),
1835                                         dlm_finalize_reco_handler,
1836                                         dlm, NULL, &dlm->dlm_domain_handlers);
1837         if (status)
1838                 goto bail;
1839
1840         status = o2net_register_handler(DLM_BEGIN_EXIT_DOMAIN_MSG, dlm->key,
1841                                         sizeof(struct dlm_exit_domain),
1842                                         dlm_begin_exit_domain_handler,
1843                                         dlm, NULL, &dlm->dlm_domain_handlers);
1844         if (status)
1845                 goto bail;
1846
1847         status = o2net_register_handler(DLM_DEREF_LOCKRES_DONE, dlm->key,
1848                                         sizeof(struct dlm_deref_lockres_done),
1849                                         dlm_deref_lockres_done_handler,
1850                                         dlm, NULL, &dlm->dlm_domain_handlers);
1851 bail:
1852         if (status)
1853                 dlm_unregister_domain_handlers(dlm);
1854
1855         return status;
1856 }
1857
1858 static int dlm_join_domain(struct dlm_ctxt *dlm)
1859 {
1860         int status;
1861         unsigned int backoff;
1862         unsigned int total_backoff = 0;
1863         char wq_name[O2NM_MAX_NAME_LEN];
1864
1865         BUG_ON(!dlm);
1866
1867         mlog(0, "Join domain %s\n", dlm->name);
1868
1869         status = dlm_register_domain_handlers(dlm);
1870         if (status) {
1871                 mlog_errno(status);
1872                 goto bail;
1873         }
1874
1875         status = dlm_launch_thread(dlm);
1876         if (status < 0) {
1877                 mlog_errno(status);
1878                 goto bail;
1879         }
1880
1881         status = dlm_launch_recovery_thread(dlm);
1882         if (status < 0) {
1883                 mlog_errno(status);
1884                 goto bail;
1885         }
1886
1887         status = dlm_debug_init(dlm);
1888         if (status < 0) {
1889                 mlog_errno(status);
1890                 goto bail;
1891         }
1892
1893         snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
1894         dlm->dlm_worker = alloc_workqueue(wq_name, WQ_MEM_RECLAIM, 0);
1895         if (!dlm->dlm_worker) {
1896                 status = -ENOMEM;
1897                 mlog_errno(status);
1898                 goto bail;
1899         }
1900
1901         do {
1902                 status = dlm_try_to_join_domain(dlm);
1903
1904                 /* If we're racing another node to the join, then we
1905                  * need to back off temporarily and let them
1906                  * complete. */
1907 #define DLM_JOIN_TIMEOUT_MSECS  90000
1908                 if (status == -EAGAIN) {
1909                         if (signal_pending(current)) {
1910                                 status = -ERESTARTSYS;
1911                                 goto bail;
1912                         }
1913
1914                         if (total_backoff > DLM_JOIN_TIMEOUT_MSECS) {
1915                                 status = -ERESTARTSYS;
1916                                 mlog(ML_NOTICE, "Timed out joining dlm domain "
1917                                      "%s after %u msecs\n", dlm->name,
1918                                      total_backoff);
1919                                 goto bail;
1920                         }
1921
1922                         /*
1923                          * <chip> After you!
1924                          * <dale> No, after you!
1925                          * <chip> I insist!
1926                          * <dale> But you first!
1927                          * ...
1928                          */
1929                         backoff = (unsigned int)(jiffies & 0x3);
1930                         backoff *= DLM_DOMAIN_BACKOFF_MS;
1931                         total_backoff += backoff;
1932                         mlog(0, "backoff %d\n", backoff);
1933                         msleep(backoff);
1934                 }
1935         } while (status == -EAGAIN);
1936
1937         if (status < 0) {
1938                 mlog_errno(status);
1939                 goto bail;
1940         }
1941
1942         status = 0;
1943 bail:
1944         wake_up(&dlm_domain_events);
1945
1946         if (status) {
1947                 dlm_unregister_domain_handlers(dlm);
1948                 dlm_debug_shutdown(dlm);
1949                 dlm_complete_thread(dlm);
1950                 dlm_complete_recovery_thread(dlm);
1951                 dlm_destroy_dlm_worker(dlm);
1952         }
1953
1954         return status;
1955 }
1956
1957 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1958                                 u32 key)
1959 {
1960         int i;
1961         int ret;
1962         struct dlm_ctxt *dlm = NULL;
1963
1964         dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1965         if (!dlm) {
1966                 ret = -ENOMEM;
1967                 mlog_errno(ret);
1968                 goto leave;
1969         }
1970
1971         dlm->name = kstrdup(domain, GFP_KERNEL);
1972         if (dlm->name == NULL) {
1973                 ret = -ENOMEM;
1974                 mlog_errno(ret);
1975                 goto leave;
1976         }
1977
1978         dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1979         if (!dlm->lockres_hash) {
1980                 ret = -ENOMEM;
1981                 mlog_errno(ret);
1982                 goto leave;
1983         }
1984
1985         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1986                 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1987
1988         dlm->master_hash = (struct hlist_head **)
1989                                 dlm_alloc_pagevec(DLM_HASH_PAGES);
1990         if (!dlm->master_hash) {
1991                 ret = -ENOMEM;
1992                 mlog_errno(ret);
1993                 goto leave;
1994         }
1995
1996         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1997                 INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
1998
1999         dlm->key = key;
2000         dlm->node_num = o2nm_this_node();
2001
2002         ret = dlm_create_debugfs_subroot(dlm);
2003         if (ret < 0)
2004                 goto leave;
2005
2006         spin_lock_init(&dlm->spinlock);
2007         spin_lock_init(&dlm->master_lock);
2008         spin_lock_init(&dlm->ast_lock);
2009         spin_lock_init(&dlm->track_lock);
2010         INIT_LIST_HEAD(&dlm->list);
2011         INIT_LIST_HEAD(&dlm->dirty_list);
2012         INIT_LIST_HEAD(&dlm->reco.resources);
2013         INIT_LIST_HEAD(&dlm->reco.node_data);
2014         INIT_LIST_HEAD(&dlm->purge_list);
2015         INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
2016         INIT_LIST_HEAD(&dlm->tracking_list);
2017         dlm->reco.state = 0;
2018
2019         INIT_LIST_HEAD(&dlm->pending_asts);
2020         INIT_LIST_HEAD(&dlm->pending_basts);
2021
2022         mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
2023                   dlm->recovery_map, &(dlm->recovery_map[0]));
2024
2025         memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
2026         memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
2027         memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
2028
2029         dlm->dlm_thread_task = NULL;
2030         dlm->dlm_reco_thread_task = NULL;
2031         dlm->dlm_worker = NULL;
2032         init_waitqueue_head(&dlm->dlm_thread_wq);
2033         init_waitqueue_head(&dlm->dlm_reco_thread_wq);
2034         init_waitqueue_head(&dlm->reco.event);
2035         init_waitqueue_head(&dlm->ast_wq);
2036         init_waitqueue_head(&dlm->migration_wq);
2037         INIT_LIST_HEAD(&dlm->mle_hb_events);
2038
2039         dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
2040         init_waitqueue_head(&dlm->dlm_join_events);
2041
2042         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
2043         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
2044
2045         atomic_set(&dlm->res_tot_count, 0);
2046         atomic_set(&dlm->res_cur_count, 0);
2047         for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
2048                 atomic_set(&dlm->mle_tot_count[i], 0);
2049                 atomic_set(&dlm->mle_cur_count[i], 0);
2050         }
2051
2052         spin_lock_init(&dlm->work_lock);
2053         INIT_LIST_HEAD(&dlm->work_list);
2054         INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
2055
2056         kref_init(&dlm->dlm_refs);
2057         dlm->dlm_state = DLM_CTXT_NEW;
2058
2059         INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
2060
2061         mlog(0, "context init: refcount %u\n",
2062                   kref_read(&dlm->dlm_refs));
2063
2064 leave:
2065         if (ret < 0 && dlm) {
2066                 if (dlm->master_hash)
2067                         dlm_free_pagevec((void **)dlm->master_hash,
2068                                         DLM_HASH_PAGES);
2069
2070                 if (dlm->lockres_hash)
2071                         dlm_free_pagevec((void **)dlm->lockres_hash,
2072                                         DLM_HASH_PAGES);
2073
2074                 kfree(dlm->name);
2075                 kfree(dlm);
2076                 dlm = NULL;
2077         }
2078         return dlm;
2079 }
2080
2081 /*
2082  * Compare a requested locking protocol version against the current one.
2083  *
2084  * If the major numbers are different, they are incompatible.
2085  * If the current minor is greater than the request, they are incompatible.
2086  * If the current minor is less than or equal to the request, they are
2087  * compatible, and the requester should run at the current minor version.
2088  */
2089 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
2090                                 struct dlm_protocol_version *request)
2091 {
2092         if (existing->pv_major != request->pv_major)
2093                 return 1;
2094
2095         if (existing->pv_minor > request->pv_minor)
2096                 return 1;
2097
2098         if (existing->pv_minor < request->pv_minor)
2099                 request->pv_minor = existing->pv_minor;
2100
2101         return 0;
2102 }
2103
2104 /*
2105  * dlm_register_domain: one-time setup per "domain".
2106  *
2107  * The filesystem passes in the requested locking version via proto.
2108  * If registration was successful, proto will contain the negotiated
2109  * locking protocol.
2110  */
2111 struct dlm_ctxt * dlm_register_domain(const char *domain,
2112                                u32 key,
2113                                struct dlm_protocol_version *fs_proto)
2114 {
2115         int ret;
2116         struct dlm_ctxt *dlm = NULL;
2117         struct dlm_ctxt *new_ctxt = NULL;
2118
2119         if (strlen(domain) >= O2NM_MAX_NAME_LEN) {
2120                 ret = -ENAMETOOLONG;
2121                 mlog(ML_ERROR, "domain name length too long\n");
2122                 goto leave;
2123         }
2124
2125         mlog(0, "register called for domain \"%s\"\n", domain);
2126
2127 retry:
2128         dlm = NULL;
2129         if (signal_pending(current)) {
2130                 ret = -ERESTARTSYS;
2131                 mlog_errno(ret);
2132                 goto leave;
2133         }
2134
2135         spin_lock(&dlm_domain_lock);
2136
2137         dlm = __dlm_lookup_domain(domain);
2138         if (dlm) {
2139                 if (dlm->dlm_state != DLM_CTXT_JOINED) {
2140                         spin_unlock(&dlm_domain_lock);
2141
2142                         mlog(0, "This ctxt is not joined yet!\n");
2143                         wait_event_interruptible(dlm_domain_events,
2144                                                  dlm_wait_on_domain_helper(
2145                                                          domain));
2146                         goto retry;
2147                 }
2148
2149                 if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
2150                         spin_unlock(&dlm_domain_lock);
2151                         mlog(ML_ERROR,
2152                              "Requested locking protocol version is not "
2153                              "compatible with already registered domain "
2154                              "\"%s\"\n", domain);
2155                         ret = -EPROTO;
2156                         goto leave;
2157                 }
2158
2159                 __dlm_get(dlm);
2160                 dlm->num_joins++;
2161
2162                 spin_unlock(&dlm_domain_lock);
2163
2164                 ret = 0;
2165                 goto leave;
2166         }
2167
2168         /* doesn't exist */
2169         if (!new_ctxt) {
2170                 spin_unlock(&dlm_domain_lock);
2171
2172                 new_ctxt = dlm_alloc_ctxt(domain, key);
2173                 if (new_ctxt)
2174                         goto retry;
2175
2176                 ret = -ENOMEM;
2177                 mlog_errno(ret);
2178                 goto leave;
2179         }
2180
2181         /* a little variable switch-a-roo here... */
2182         dlm = new_ctxt;
2183         new_ctxt = NULL;
2184
2185         /* add the new domain */
2186         list_add_tail(&dlm->list, &dlm_domains);
2187         spin_unlock(&dlm_domain_lock);
2188
2189         /*
2190          * Pass the locking protocol version into the join.  If the join
2191          * succeeds, it will have the negotiated protocol set.
2192          */
2193         dlm->dlm_locking_proto = dlm_protocol;
2194         dlm->fs_locking_proto = *fs_proto;
2195
2196         ret = dlm_join_domain(dlm);
2197         if (ret) {
2198                 mlog_errno(ret);
2199                 dlm_put(dlm);
2200                 goto leave;
2201         }
2202
2203         /* Tell the caller what locking protocol we negotiated */
2204         *fs_proto = dlm->fs_locking_proto;
2205
2206         ret = 0;
2207 leave:
2208         if (new_ctxt)
2209                 dlm_free_ctxt_mem(new_ctxt);
2210
2211         if (ret < 0)
2212                 dlm = ERR_PTR(ret);
2213
2214         return dlm;
2215 }
2216 EXPORT_SYMBOL_GPL(dlm_register_domain);
2217
2218 static LIST_HEAD(dlm_join_handlers);
2219
2220 static void dlm_unregister_net_handlers(void)
2221 {
2222         o2net_unregister_handler_list(&dlm_join_handlers);
2223 }
2224
2225 static int dlm_register_net_handlers(void)
2226 {
2227         int status = 0;
2228
2229         status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
2230                                         sizeof(struct dlm_query_join_request),
2231                                         dlm_query_join_handler,
2232                                         NULL, NULL, &dlm_join_handlers);
2233         if (status)
2234                 goto bail;
2235
2236         status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
2237                                         sizeof(struct dlm_assert_joined),
2238                                         dlm_assert_joined_handler,
2239                                         NULL, NULL, &dlm_join_handlers);
2240         if (status)
2241                 goto bail;
2242
2243         status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
2244                                         sizeof(struct dlm_cancel_join),
2245                                         dlm_cancel_join_handler,
2246                                         NULL, NULL, &dlm_join_handlers);
2247         if (status)
2248                 goto bail;
2249
2250         status = o2net_register_handler(DLM_QUERY_REGION, DLM_MOD_KEY,
2251                                         sizeof(struct dlm_query_region),
2252                                         dlm_query_region_handler,
2253                                         NULL, NULL, &dlm_join_handlers);
2254
2255         if (status)
2256                 goto bail;
2257
2258         status = o2net_register_handler(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
2259                                         sizeof(struct dlm_query_nodeinfo),
2260                                         dlm_query_nodeinfo_handler,
2261                                         NULL, NULL, &dlm_join_handlers);
2262 bail:
2263         if (status < 0)
2264                 dlm_unregister_net_handlers();
2265
2266         return status;
2267 }
2268
2269 /* Domain eviction callback handling.
2270  *
2271  * The file system requires notification of node death *before* the
2272  * dlm completes it's recovery work, otherwise it may be able to
2273  * acquire locks on resources requiring recovery. Since the dlm can
2274  * evict a node from it's domain *before* heartbeat fires, a similar
2275  * mechanism is required. */
2276
2277 /* Eviction is not expected to happen often, so a per-domain lock is
2278  * not necessary. Eviction callbacks are allowed to sleep for short
2279  * periods of time. */
2280 static DECLARE_RWSEM(dlm_callback_sem);
2281
2282 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
2283                                         int node_num)
2284 {
2285         struct dlm_eviction_cb *cb;
2286
2287         down_read(&dlm_callback_sem);
2288         list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
2289                 cb->ec_func(node_num, cb->ec_data);
2290         }
2291         up_read(&dlm_callback_sem);
2292 }
2293
2294 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
2295                            dlm_eviction_func *f,
2296                            void *data)
2297 {
2298         INIT_LIST_HEAD(&cb->ec_item);
2299         cb->ec_func = f;
2300         cb->ec_data = data;
2301 }
2302 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
2303
2304 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
2305                               struct dlm_eviction_cb *cb)
2306 {
2307         down_write(&dlm_callback_sem);
2308         list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
2309         up_write(&dlm_callback_sem);
2310 }
2311 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
2312
2313 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
2314 {
2315         down_write(&dlm_callback_sem);
2316         list_del_init(&cb->ec_item);
2317         up_write(&dlm_callback_sem);
2318 }
2319 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
2320
2321 static int __init dlm_init(void)
2322 {
2323         int status;
2324
2325         status = dlm_init_mle_cache();
2326         if (status) {
2327                 mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
2328                 goto error;
2329         }
2330
2331         status = dlm_init_master_caches();
2332         if (status) {
2333                 mlog(ML_ERROR, "Could not create o2dlm_lockres and "
2334                      "o2dlm_lockname slabcaches\n");
2335                 goto error;
2336         }
2337
2338         status = dlm_init_lock_cache();
2339         if (status) {
2340                 mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
2341                 goto error;
2342         }
2343
2344         status = dlm_register_net_handlers();
2345         if (status) {
2346                 mlog(ML_ERROR, "Unable to register network handlers\n");
2347                 goto error;
2348         }
2349
2350         status = dlm_create_debugfs_root();
2351         if (status)
2352                 goto error;
2353
2354         return 0;
2355 error:
2356         dlm_unregister_net_handlers();
2357         dlm_destroy_lock_cache();
2358         dlm_destroy_master_caches();
2359         dlm_destroy_mle_cache();
2360         return -1;
2361 }
2362
2363 static void __exit dlm_exit (void)
2364 {
2365         dlm_destroy_debugfs_root();
2366         dlm_unregister_net_handlers();
2367         dlm_destroy_lock_cache();
2368         dlm_destroy_master_caches();
2369         dlm_destroy_mle_cache();
2370 }
2371
2372 MODULE_AUTHOR("Oracle");
2373 MODULE_LICENSE("GPL");
2374 MODULE_DESCRIPTION("OCFS2 Distributed Lock Management");
2375
2376 module_init(dlm_init);
2377 module_exit(dlm_exit);