fs/ocfs2/dlm/dlmdomain.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * dlmdomain.c
   5  *
   6  * defines domain join / leave apis
   7  *
   8  * Copyright (C) 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  *
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31 #include <linux/init.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/delay.h>
  34 #include <linux/err.h>
  35 #include <linux/debugfs.h>
  36
  37 #include "cluster/heartbeat.h"
  38 #include "cluster/nodemanager.h"
  39 #include "cluster/tcp.h"
  40
  41 #include "dlmapi.h"
  42 #include "dlmcommon.h"
  43 #include "dlmdomain.h"
  44 #include "dlmdebug.h"
  45
  46 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
  47 #include "cluster/masklog.h"
  48
  49 /*
  50  * ocfs2 node maps are array of long int, which limits to send them freely
  51  * across the wire due to endianness issues. To workaround this, we convert
  52  * long ints to byte arrays. Following 3 routines are helper functions to
  53  * set/test/copy bits within those array of bytes
  54  */
  55 static inline void byte_set_bit(u8 nr, u8 map[])
  56 {
  57         map[nr >> 3] |= (1UL << (nr & 7));
  58 }
  59
  60 static inline int byte_test_bit(u8 nr, u8 map[])
  61 {
  62         return ((1UL << (nr & 7)) & (map[nr >> 3])) != 0;
  63 }
  64
  65 static inline void byte_copymap(u8 dmap[], unsigned long smap[],
  66                         unsigned int sz)
  67 {
  68         unsigned int nn;
  69
  70         if (!sz)
  71                 return;
  72
  73         memset(dmap, 0, ((sz + 7) >> 3));
  74         for (nn = 0 ; nn < sz; nn++)
  75                 if (test_bit(nn, smap))
  76                         byte_set_bit(nn, dmap);
  77 }
  78
  79 static void dlm_free_pagevec(void **vec, int pages)
  80 {
  81         while (pages--)
  82                 free_page((unsigned long)vec[pages]);
  83         kfree(vec);
  84 }
  85
  86 static void **dlm_alloc_pagevec(int pages)
  87 {
  88         void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
  89         int i;
  90
  91         if (!vec)
  92                 return NULL;
  93
  94         for (i = 0; i < pages; i++)
  95                 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
  96                         goto out_free;
  97
  98         mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
  99              pages, (unsigned long)DLM_HASH_PAGES,
 100              (unsigned long)DLM_BUCKETS_PER_PAGE);
 101         return vec;
 102 out_free:
 103         dlm_free_pagevec(vec, i);
 104         return NULL;
 105 }
 106
 107 /*
 108  *
 109  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
 110  *    dlm_domain_lock
 111  *    struct dlm_ctxt->spinlock
 112  *    struct dlm_lock_resource->spinlock
 113  *    struct dlm_ctxt->master_lock
 114  *    struct dlm_ctxt->ast_lock
 115  *    dlm_master_list_entry->spinlock
 116  *    dlm_lock->spinlock
 117  *
 118  */
 119
 120 DEFINE_SPINLOCK(dlm_domain_lock);
 121 LIST_HEAD(dlm_domains);
 122 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
 123
 124 /*
 125  * The supported protocol version for DLM communication.  Running domains
 126  * will have a negotiated version with the same major number and a minor
 127  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
 128  * be used to determine what a running domain is actually using.
 129  *
 130  * New in version 1.1:
 131  *      - Message DLM_QUERY_REGION added to support global heartbeat
 132  *      - Message DLM_QUERY_NODEINFO added to allow online node removes
 133  * New in version 1.2:
 134  *      - Message DLM_BEGIN_EXIT_DOMAIN_MSG added to mark start of exit domain
 135  */
 136 static const struct dlm_protocol_version dlm_protocol = {
 137         .pv_major = 1,
 138         .pv_minor = 2,
 139 };
 140
 141 #define DLM_DOMAIN_BACKOFF_MS 200
 142
 143 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 144                                   void **ret_data);
 145 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 146                                      void **ret_data);
 147 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
 148                                    void **ret_data);
 149 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
 150                                     void *data, void **ret_data);
 151 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 152                                    void **ret_data);
 153 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
 154                                 struct dlm_protocol_version *request);
 155
 156 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 157
 158 void __dlm_unhash_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 159 {
 160         if (hlist_unhashed(&res->hash_node))
 161                 return;
 162
 163         mlog(0, "%s: Unhash res %.*s\n", dlm->name, res->lockname.len,
 164              res->lockname.name);
 165         hlist_del_init(&res->hash_node);
 166         dlm_lockres_put(res);
 167 }
 168
 169 void __dlm_insert_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 170 {
 171         struct hlist_head *bucket;
 172         struct qstr *q;
 173
 174         assert_spin_locked(&dlm->spinlock);
 175
 176         q = &res->lockname;
 177         bucket = dlm_lockres_hash(dlm, q->hash);
 178
 179         /* get a reference for our hashtable */
 180         dlm_lockres_get(res);
 181
 182         hlist_add_head(&res->hash_node, bucket);
 183
 184         mlog(0, "%s: Hash res %.*s\n", dlm->name, res->lockname.len,
 185              res->lockname.name);
 186 }
 187
 188 struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
 189                                                      const char *name,
 190                                                      unsigned int len,
 191                                                      unsigned int hash)
 192 {
 193         struct hlist_head *bucket;
 194         struct dlm_lock_resource *res;
 195
 196         mlog(0, "%.*s\n", len, name);
 197
 198         assert_spin_locked(&dlm->spinlock);
 199
 200         bucket = dlm_lockres_hash(dlm, hash);
 201
 202         hlist_for_each_entry(res, bucket, hash_node) {
 203                 if (res->lockname.name[0] != name[0])
 204                         continue;
 205                 if (unlikely(res->lockname.len != len))
 206                         continue;
 207                 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
 208                         continue;
 209                 dlm_lockres_get(res);
 210                 return res;
 211         }
 212         return NULL;
 213 }
 214
 215 /* intended to be called by functions which do not care about lock
 216  * resources which are being purged (most net _handler functions).
 217  * this will return NULL for any lock resource which is found but
 218  * currently in the process of dropping its mastery reference.
 219  * use __dlm_lookup_lockres_full when you need the lock resource
 220  * regardless (e.g. dlm_get_lock_resource) */
 221 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 222                                                 const char *name,
 223                                                 unsigned int len,
 224                                                 unsigned int hash)
 225 {
 226         struct dlm_lock_resource *res = NULL;
 227
 228         mlog(0, "%.*s\n", len, name);
 229
 230         assert_spin_locked(&dlm->spinlock);
 231
 232         res = __dlm_lookup_lockres_full(dlm, name, len, hash);
 233         if (res) {
 234                 spin_lock(&res->spinlock);
 235                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
 236                         spin_unlock(&res->spinlock);
 237                         dlm_lockres_put(res);
 238                         return NULL;
 239                 }
 240                 spin_unlock(&res->spinlock);
 241         }
 242
 243         return res;
 244 }
 245
 246 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 247                                     const char *name,
 248                                     unsigned int len)
 249 {
 250         struct dlm_lock_resource *res;
 251         unsigned int hash = dlm_lockid_hash(name, len);
 252
 253         spin_lock(&dlm->spinlock);
 254         res = __dlm_lookup_lockres(dlm, name, len, hash);
 255         spin_unlock(&dlm->spinlock);
 256         return res;
 257 }
 258
 259 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 260 {
 261         struct dlm_ctxt *tmp;
 262
 263         assert_spin_locked(&dlm_domain_lock);
 264
 265         /* tmp->name here is always NULL terminated,
 266          * but domain may not be! */
 267         list_for_each_entry(tmp, &dlm_domains, list) {
 268                 if (strlen(tmp->name) == len &&
 269                     memcmp(tmp->name, domain, len)==0)
 270                         return tmp;
 271         }
 272
 273         return NULL;
 274 }
 275
 276 /* For null terminated domain strings ONLY */
 277 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
 278 {
 279         assert_spin_locked(&dlm_domain_lock);
 280
 281         return __dlm_lookup_domain_full(domain, strlen(domain));
 282 }
 283
 284
 285 /* returns true on one of two conditions:
 286  * 1) the domain does not exist
 287  * 2) the domain exists and it's state is "joined" */
 288 static int dlm_wait_on_domain_helper(const char *domain)
 289 {
 290         int ret = 0;
 291         struct dlm_ctxt *tmp = NULL;
 292
 293         spin_lock(&dlm_domain_lock);
 294
 295         tmp = __dlm_lookup_domain(domain);
 296         if (!tmp)
 297                 ret = 1;
 298         else if (tmp->dlm_state == DLM_CTXT_JOINED)
 299                 ret = 1;
 300
 301         spin_unlock(&dlm_domain_lock);
 302         return ret;
 303 }
 304
 305 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 306 {
 307         dlm_destroy_debugfs_subroot(dlm);
 308
 309         if (dlm->lockres_hash)
 310                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 311
 312         if (dlm->master_hash)
 313                 dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
 314
 315         kfree(dlm->name);
 316         kfree(dlm);
 317 }
 318
 319 /* A little strange - this function will be called while holding
 320  * dlm_domain_lock and is expected to be holding it on the way out. We
 321  * will however drop and reacquire it multiple times */
 322 static void dlm_ctxt_release(struct kref *kref)
 323 {
 324         struct dlm_ctxt *dlm;
 325
 326         dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
 327
 328         BUG_ON(dlm->num_joins);
 329         BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
 330
 331         /* we may still be in the list if we hit an error during join. */
 332         list_del_init(&dlm->list);
 333
 334         spin_unlock(&dlm_domain_lock);
 335
 336         mlog(0, "freeing memory from domain %s\n", dlm->name);
 337
 338         wake_up(&dlm_domain_events);
 339
 340         dlm_free_ctxt_mem(dlm);
 341
 342         spin_lock(&dlm_domain_lock);
 343 }
 344
 345 void dlm_put(struct dlm_ctxt *dlm)
 346 {
 347         spin_lock(&dlm_domain_lock);
 348         kref_put(&dlm->dlm_refs, dlm_ctxt_release);
 349         spin_unlock(&dlm_domain_lock);
 350 }
 351
 352 static void __dlm_get(struct dlm_ctxt *dlm)
 353 {
 354         kref_get(&dlm->dlm_refs);
 355 }
 356
 357 /* given a questionable reference to a dlm object, gets a reference if
 358  * it can find it in the list, otherwise returns NULL in which case
 359  * you shouldn't trust your pointer. */
 360 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 361 {
 362         struct dlm_ctxt *target;
 363         struct dlm_ctxt *ret = NULL;
 364
 365         spin_lock(&dlm_domain_lock);
 366
 367         list_for_each_entry(target, &dlm_domains, list) {
 368                 if (target == dlm) {
 369                         __dlm_get(target);
 370                         ret = target;
 371                         break;
 372                 }
 373         }
 374
 375         spin_unlock(&dlm_domain_lock);
 376
 377         return ret;
 378 }
 379
 380 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 381 {
 382         int ret;
 383
 384         spin_lock(&dlm_domain_lock);
 385         ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
 386                 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
 387         spin_unlock(&dlm_domain_lock);
 388
 389         return ret;
 390 }
 391
 392 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 393 {
 394         if (dlm->dlm_worker) {
 395                 flush_workqueue(dlm->dlm_worker);
 396                 destroy_workqueue(dlm->dlm_worker);
 397                 dlm->dlm_worker = NULL;
 398         }
 399 }
 400
 401 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 402 {
 403         dlm_unregister_domain_handlers(dlm);
 404         dlm_debug_shutdown(dlm);
 405         dlm_complete_thread(dlm);
 406         dlm_complete_recovery_thread(dlm);
 407         dlm_destroy_dlm_worker(dlm);
 408
 409         /* We've left the domain. Now we can take ourselves out of the
 410          * list and allow the kref stuff to help us free the
 411          * memory. */
 412         spin_lock(&dlm_domain_lock);
 413         list_del_init(&dlm->list);
 414         spin_unlock(&dlm_domain_lock);
 415
 416         /* Wake up anyone waiting for us to remove this domain */
 417         wake_up(&dlm_domain_events);
 418 }
 419
 420 static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 421 {
 422         int i, num, n, ret = 0;
 423         struct dlm_lock_resource *res;
 424         struct hlist_node *iter;
 425         struct hlist_head *bucket;
 426         int dropped;
 427
 428         mlog(0, "Migrating locks from domain %s\n", dlm->name);
 429
 430         num = 0;
 431         spin_lock(&dlm->spinlock);
 432         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
 433 redo_bucket:
 434                 n = 0;
 435                 bucket = dlm_lockres_hash(dlm, i);
 436                 iter = bucket->first;
 437                 while (iter) {
 438                         n++;
 439                         res = hlist_entry(iter, struct dlm_lock_resource,
 440                                           hash_node);
 441                         dlm_lockres_get(res);
 442                         /* migrate, if necessary.  this will drop the dlm
 443                          * spinlock and retake it if it does migration. */
 444                         dropped = dlm_empty_lockres(dlm, res);
 445
 446                         spin_lock(&res->spinlock);
 447                         if (dropped)
 448                                 __dlm_lockres_calc_usage(dlm, res);
 449                         else
 450                                 iter = res->hash_node.next;
 451                         spin_unlock(&res->spinlock);
 452
 453                         dlm_lockres_put(res);
 454
 455                         if (dropped) {
 456                                 cond_resched_lock(&dlm->spinlock);
 457                                 goto redo_bucket;
 458                         }
 459                 }
 460                 cond_resched_lock(&dlm->spinlock);
 461                 num += n;
 462         }
 463         spin_unlock(&dlm->spinlock);
 464         wake_up(&dlm->dlm_thread_wq);
 465
 466         /* let the dlm thread take care of purging, keep scanning until
 467          * nothing remains in the hash */
 468         if (num) {
 469                 mlog(0, "%s: %d lock resources in hash last pass\n",
 470                      dlm->name, num);
 471                 ret = -EAGAIN;
 472         }
 473         mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
 474         return ret;
 475 }
 476
 477 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
 478 {
 479         int ret;
 480
 481         spin_lock(&dlm->spinlock);
 482         ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
 483         spin_unlock(&dlm->spinlock);
 484
 485         return ret;
 486 }
 487
 488 static int dlm_begin_exit_domain_handler(struct o2net_msg *msg, u32 len,
 489                                          void *data, void **ret_data)
 490 {
 491         struct dlm_ctxt *dlm = data;
 492         unsigned int node;
 493         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 494
 495         if (!dlm_grab(dlm))
 496                 return 0;
 497
 498         node = exit_msg->node_idx;
 499         mlog(0, "%s: Node %u sent a begin exit domain message\n", dlm->name, node);
 500
 501         spin_lock(&dlm->spinlock);
 502         set_bit(node, dlm->exit_domain_map);
 503         spin_unlock(&dlm->spinlock);
 504
 505         dlm_put(dlm);
 506
 507         return 0;
 508 }
 509
 510 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
 511 {
 512         /* Yikes, a double spinlock! I need domain_lock for the dlm
 513          * state and the dlm spinlock for join state... Sorry! */
 514 again:
 515         spin_lock(&dlm_domain_lock);
 516         spin_lock(&dlm->spinlock);
 517
 518         if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 519                 mlog(0, "Node %d is joining, we wait on it.\n",
 520                           dlm->joining_node);
 521                 spin_unlock(&dlm->spinlock);
 522                 spin_unlock(&dlm_domain_lock);
 523
 524                 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
 525                 goto again;
 526         }
 527
 528         dlm->dlm_state = DLM_CTXT_LEAVING;
 529         spin_unlock(&dlm->spinlock);
 530         spin_unlock(&dlm_domain_lock);
 531 }
 532
 533 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
 534 {
 535         int node = -1, num = 0;
 536
 537         assert_spin_locked(&dlm->spinlock);
 538
 539         printk("( ");
 540         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 541                                      node + 1)) < O2NM_MAX_NODES) {
 542                 printk("%d ", node);
 543                 ++num;
 544         }
 545         printk(") %u nodes\n", num);
 546 }
 547
 548 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 549                                    void **ret_data)
 550 {
 551         struct dlm_ctxt *dlm = data;
 552         unsigned int node;
 553         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 554
 555         mlog(0, "%p %u %p", msg, len, data);
 556
 557         if (!dlm_grab(dlm))
 558                 return 0;
 559
 560         node = exit_msg->node_idx;
 561
 562         spin_lock(&dlm->spinlock);
 563         clear_bit(node, dlm->domain_map);
 564         clear_bit(node, dlm->exit_domain_map);
 565         printk(KERN_NOTICE "o2dlm: Node %u leaves domain %s ", node, dlm->name);
 566         __dlm_print_nodes(dlm);
 567
 568         /* notify anything attached to the heartbeat events */
 569         dlm_hb_event_notify_attached(dlm, node, 0);
 570
 571         spin_unlock(&dlm->spinlock);
 572
 573         dlm_put(dlm);
 574
 575         return 0;
 576 }
 577
 578 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, u32 msg_type,
 579                                     unsigned int node)
 580 {
 581         int status;
 582         struct dlm_exit_domain leave_msg;
 583
 584         mlog(0, "%s: Sending domain exit message %u to node %u\n", dlm->name,
 585              msg_type, node);
 586
 587         memset(&leave_msg, 0, sizeof(leave_msg));
 588         leave_msg.node_idx = dlm->node_num;
 589
 590         status = o2net_send_message(msg_type, dlm->key, &leave_msg,
 591                                     sizeof(leave_msg), node, NULL);
 592         if (status < 0)
 593                 mlog(ML_ERROR, "Error %d sending domain exit message %u "
 594                      "to node %u on domain %s\n", status, msg_type, node,
 595                      dlm->name);
 596
 597         return status;
 598 }
 599
 600 static void dlm_begin_exit_domain(struct dlm_ctxt *dlm)
 601 {
 602         int node = -1;
 603
 604         /* Support for begin exit domain was added in 1.2 */
 605         if (dlm->dlm_locking_proto.pv_major == 1 &&
 606             dlm->dlm_locking_proto.pv_minor < 2)
 607                 return;
 608
 609         /*
 610          * Unlike DLM_EXIT_DOMAIN_MSG, DLM_BEGIN_EXIT_DOMAIN_MSG is purely
 611          * informational. Meaning if a node does not receive the message,
 612          * so be it.
 613          */
 614         spin_lock(&dlm->spinlock);
 615         while (1) {
 616                 node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, node + 1);
 617                 if (node >= O2NM_MAX_NODES)
 618                         break;
 619                 if (node == dlm->node_num)
 620                         continue;
 621
 622                 spin_unlock(&dlm->spinlock);
 623                 dlm_send_one_domain_exit(dlm, DLM_BEGIN_EXIT_DOMAIN_MSG, node);
 624                 spin_lock(&dlm->spinlock);
 625         }
 626         spin_unlock(&dlm->spinlock);
 627 }
 628
 629 static void dlm_leave_domain(struct dlm_ctxt *dlm)
 630 {
 631         int node, clear_node, status;
 632
 633         /* At this point we've migrated away all our locks and won't
 634          * accept mastership of new ones. The dlm is responsible for
 635          * almost nothing now. We make sure not to confuse any joining
 636          * nodes and then commence shutdown procedure. */
 637
 638         spin_lock(&dlm->spinlock);
 639         /* Clear ourselves from the domain map */
 640         clear_bit(dlm->node_num, dlm->domain_map);
 641         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 642                                      0)) < O2NM_MAX_NODES) {
 643                 /* Drop the dlm spinlock. This is safe wrt the domain_map.
 644                  * -nodes cannot be added now as the
 645                  *   query_join_handlers knows to respond with OK_NO_MAP
 646                  * -we catch the right network errors if a node is
 647                  *   removed from the map while we're sending him the
 648                  *   exit message. */
 649                 spin_unlock(&dlm->spinlock);
 650
 651                 clear_node = 1;
 652
 653                 status = dlm_send_one_domain_exit(dlm, DLM_EXIT_DOMAIN_MSG,
 654                                                   node);
 655                 if (status < 0 &&
 656                     status != -ENOPROTOOPT &&
 657                     status != -ENOTCONN) {
 658                         mlog(ML_NOTICE, "Error %d sending domain exit message "
 659                              "to node %d\n", status, node);
 660
 661                         /* Not sure what to do here but lets sleep for
 662                          * a bit in case this was a transient
 663                          * error... */
 664                         msleep(DLM_DOMAIN_BACKOFF_MS);
 665                         clear_node = 0;
 666                 }
 667
 668                 spin_lock(&dlm->spinlock);
 669                 /* If we're not clearing the node bit then we intend
 670                  * to loop back around to try again. */
 671                 if (clear_node)
 672                         clear_bit(node, dlm->domain_map);
 673         }
 674         spin_unlock(&dlm->spinlock);
 675 }
 676
 677 int dlm_joined(struct dlm_ctxt *dlm)
 678 {
 679         int ret = 0;
 680
 681         spin_lock(&dlm_domain_lock);
 682
 683         if (dlm->dlm_state == DLM_CTXT_JOINED)
 684                 ret = 1;
 685
 686         spin_unlock(&dlm_domain_lock);
 687
 688         return ret;
 689 }
 690
 691 int dlm_shutting_down(struct dlm_ctxt *dlm)
 692 {
 693         int ret = 0;
 694
 695         spin_lock(&dlm_domain_lock);
 696
 697         if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
 698                 ret = 1;
 699
 700         spin_unlock(&dlm_domain_lock);
 701
 702         return ret;
 703 }
 704
 705 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 706 {
 707         int leave = 0;
 708         struct dlm_lock_resource *res;
 709
 710         spin_lock(&dlm_domain_lock);
 711         BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
 712         BUG_ON(!dlm->num_joins);
 713
 714         dlm->num_joins--;
 715         if (!dlm->num_joins) {
 716                 /* We mark it "in shutdown" now so new register
 717                  * requests wait until we've completely left the
 718                  * domain. Don't use DLM_CTXT_LEAVING yet as we still
 719                  * want new domain joins to communicate with us at
 720                  * least until we've completed migration of our
 721                  * resources. */
 722                 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
 723                 leave = 1;
 724         }
 725         spin_unlock(&dlm_domain_lock);
 726
 727         if (leave) {
 728                 mlog(0, "shutting down domain %s\n", dlm->name);
 729                 dlm_begin_exit_domain(dlm);
 730
 731                 /* We changed dlm state, notify the thread */
 732                 dlm_kick_thread(dlm, NULL);
 733
 734                 while (dlm_migrate_all_locks(dlm)) {
 735                         /* Give dlm_thread time to purge the lockres' */
 736                         msleep(500);
 737                         mlog(0, "%s: more migration to do\n", dlm->name);
 738                 }
 739
 740                 /* This list should be empty. If not, print remaining lockres */
 741                 if (!list_empty(&dlm->tracking_list)) {
 742                         mlog(ML_ERROR, "Following lockres' are still on the "
 743                              "tracking list:\n");
 744                         list_for_each_entry(res, &dlm->tracking_list, tracking)
 745                                 dlm_print_one_lock_resource(res);
 746                 }
 747
 748                 dlm_mark_domain_leaving(dlm);
 749                 dlm_leave_domain(dlm);
 750                 printk(KERN_NOTICE "o2dlm: Leaving domain %s\n", dlm->name);
 751                 dlm_force_free_mles(dlm);
 752                 dlm_complete_dlm_shutdown(dlm);
 753         }
 754         dlm_put(dlm);
 755 }
 756 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 757
 758 static int dlm_query_join_proto_check(char *proto_type, int node,
 759                                       struct dlm_protocol_version *ours,
 760                                       struct dlm_protocol_version *request)
 761 {
 762         int rc;
 763         struct dlm_protocol_version proto = *request;
 764
 765         if (!dlm_protocol_compare(ours, &proto)) {
 766                 mlog(0,
 767                      "node %u wanted to join with %s locking protocol "
 768                      "%u.%u, we respond with %u.%u\n",
 769                      node, proto_type,
 770                      request->pv_major,
 771                      request->pv_minor,
 772                      proto.pv_major, proto.pv_minor);
 773                 request->pv_minor = proto.pv_minor;
 774                 rc = 0;
 775         } else {
 776                 mlog(ML_NOTICE,
 777                      "Node %u wanted to join with %s locking "
 778                      "protocol %u.%u, but we have %u.%u, disallowing\n",
 779                      node, proto_type,
 780                      request->pv_major,
 781                      request->pv_minor,
 782                      ours->pv_major,
 783                      ours->pv_minor);
 784                 rc = 1;
 785         }
 786
 787         return rc;
 788 }
 789
 790 /*
 791  * struct dlm_query_join_packet is made up of four one-byte fields.  They
 792  * are effectively in big-endian order already.  However, little-endian
 793  * machines swap them before putting the packet on the wire (because
 794  * query_join's response is a status, and that status is treated as a u32
 795  * on the wire).  Thus, a big-endian and little-endian machines will treat
 796  * this structure differently.
 797  *
 798  * The solution is to have little-endian machines swap the structure when
 799  * converting from the structure to the u32 representation.  This will
 800  * result in the structure having the correct format on the wire no matter
 801  * the host endian format.
 802  */
 803 static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
 804                                           u32 *wire)
 805 {
 806         union dlm_query_join_response response;
 807
 808         response.packet = *packet;
 809         *wire = be32_to_cpu(response.intval);
 810 }
 811
 812 static void dlm_query_join_wire_to_packet(u32 wire,
 813                                           struct dlm_query_join_packet *packet)
 814 {
 815         union dlm_query_join_response response;
 816
 817         response.intval = cpu_to_be32(wire);
 818         *packet = response.packet;
 819 }
 820
 821 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 822                                   void **ret_data)
 823 {
 824         struct dlm_query_join_request *query;
 825         struct dlm_query_join_packet packet = {
 826                 .code = JOIN_DISALLOW,
 827         };
 828         struct dlm_ctxt *dlm = NULL;
 829         u32 response;
 830         u8 nodenum;
 831
 832         query = (struct dlm_query_join_request *) msg->buf;
 833
 834         mlog(0, "node %u wants to join domain %s\n", query->node_idx,
 835                   query->domain);
 836
 837         /*
 838          * If heartbeat doesn't consider the node live, tell it
 839          * to back off and try again.  This gives heartbeat a chance
 840          * to catch up.
 841          */
 842         if (!o2hb_check_node_heartbeating(query->node_idx)) {
 843                 mlog(0, "node %u is not in our live map yet\n",
 844                      query->node_idx);
 845
 846                 packet.code = JOIN_DISALLOW;
 847                 goto respond;
 848         }
 849
 850         packet.code = JOIN_OK_NO_MAP;
 851
 852         spin_lock(&dlm_domain_lock);
 853         dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 854         if (!dlm)
 855                 goto unlock_respond;
 856
 857         /*
 858          * There is a small window where the joining node may not see the
 859          * node(s) that just left but still part of the cluster. DISALLOW
 860          * join request if joining node has different node map.
 861          */
 862         nodenum=0;
 863         while (nodenum < O2NM_MAX_NODES) {
 864                 if (test_bit(nodenum, dlm->domain_map)) {
 865                         if (!byte_test_bit(nodenum, query->node_map)) {
 866                                 mlog(0, "disallow join as node %u does not "
 867                                      "have node %u in its nodemap\n",
 868                                      query->node_idx, nodenum);
 869                                 packet.code = JOIN_DISALLOW;
 870                                 goto unlock_respond;
 871                         }
 872                 }
 873                 nodenum++;
 874         }
 875
 876         /* Once the dlm ctxt is marked as leaving then we don't want
 877          * to be put in someone's domain map.
 878          * Also, explicitly disallow joining at certain troublesome
 879          * times (ie. during recovery). */
 880         if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
 881                 int bit = query->node_idx;
 882                 spin_lock(&dlm->spinlock);
 883
 884                 if (dlm->dlm_state == DLM_CTXT_NEW &&
 885                     dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
 886                         /*If this is a brand new context and we
 887                          * haven't started our join process yet, then
 888                          * the other node won the race. */
 889                         packet.code = JOIN_OK_NO_MAP;
 890                 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 891                         /* Disallow parallel joins. */
 892                         packet.code = JOIN_DISALLOW;
 893                 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 894                         mlog(0, "node %u trying to join, but recovery "
 895                              "is ongoing.\n", bit);
 896                         packet.code = JOIN_DISALLOW;
 897                 } else if (test_bit(bit, dlm->recovery_map)) {
 898                         mlog(0, "node %u trying to join, but it "
 899                              "still needs recovery.\n", bit);
 900                         packet.code = JOIN_DISALLOW;
 901                 } else if (test_bit(bit, dlm->domain_map)) {
 902                         mlog(0, "node %u trying to join, but it "
 903                              "is still in the domain! needs recovery?\n",
 904                              bit);
 905                         packet.code = JOIN_DISALLOW;
 906                 } else {
 907                         /* Alright we're fully a part of this domain
 908                          * so we keep some state as to who's joining
 909                          * and indicate to him that needs to be fixed
 910                          * up. */
 911
 912                         /* Make sure we speak compatible locking protocols.  */
 913                         if (dlm_query_join_proto_check("DLM", bit,
 914                                                        &dlm->dlm_locking_proto,
 915                                                        &query->dlm_proto)) {
 916                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 917                         } else if (dlm_query_join_proto_check("fs", bit,
 918                                                               &dlm->fs_locking_proto,
 919                                                               &query->fs_proto)) {
 920                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 921                         } else {
 922                                 packet.dlm_minor = query->dlm_proto.pv_minor;
 923                                 packet.fs_minor = query->fs_proto.pv_minor;
 924                                 packet.code = JOIN_OK;
 925                                 __dlm_set_joining_node(dlm, query->node_idx);
 926                         }
 927                 }
 928
 929                 spin_unlock(&dlm->spinlock);
 930         }
 931 unlock_respond:
 932         spin_unlock(&dlm_domain_lock);
 933
 934 respond:
 935         mlog(0, "We respond with %u\n", packet.code);
 936
 937         dlm_query_join_packet_to_wire(&packet, &response);
 938         return response;
 939 }
 940
 941 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 942                                      void **ret_data)
 943 {
 944         struct dlm_assert_joined *assert;
 945         struct dlm_ctxt *dlm = NULL;
 946
 947         assert = (struct dlm_assert_joined *) msg->buf;
 948
 949         mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
 950                   assert->domain);
 951
 952         spin_lock(&dlm_domain_lock);
 953         dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
 954         /* XXX should we consider no dlm ctxt an error? */
 955         if (dlm) {
 956                 spin_lock(&dlm->spinlock);
 957
 958                 /* Alright, this node has officially joined our
 959                  * domain. Set him in the map and clean up our
 960                  * leftover join state. */
 961                 BUG_ON(dlm->joining_node != assert->node_idx);
 962                 set_bit(assert->node_idx, dlm->domain_map);
 963                 clear_bit(assert->node_idx, dlm->exit_domain_map);
 964                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 965
 966                 printk(KERN_NOTICE "o2dlm: Node %u joins domain %s ",
 967                        assert->node_idx, dlm->name);
 968                 __dlm_print_nodes(dlm);
 969
 970                 /* notify anything attached to the heartbeat events */
 971                 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
 972
 973                 spin_unlock(&dlm->spinlock);
 974         }
 975         spin_unlock(&dlm_domain_lock);
 976
 977         return 0;
 978 }
 979
 980 static int dlm_match_regions(struct dlm_ctxt *dlm,
 981                              struct dlm_query_region *qr,
 982                              char *local, int locallen)
 983 {
 984         char *remote = qr->qr_regions;
 985         char *l, *r;
 986         int localnr, i, j, foundit;
 987         int status = 0;
 988
 989         if (!o2hb_global_heartbeat_active()) {
 990                 if (qr->qr_numregions) {
 991                         mlog(ML_ERROR, "Domain %s: Joining node %d has global "
 992                              "heartbeat enabled but local node %d does not\n",
 993                              qr->qr_domain, qr->qr_node, dlm->node_num);
 994                         status = -EINVAL;
 995                 }
 996                 goto bail;
 997         }
 998
 999         if (o2hb_global_heartbeat_active() && !qr->qr_numregions) {
1000                 mlog(ML_ERROR, "Domain %s: Local node %d has global "
1001                      "heartbeat enabled but joining node %d does not\n",
1002                      qr->qr_domain, dlm->node_num, qr->qr_node);
1003                 status = -EINVAL;
1004                 goto bail;
1005         }
1006
1007         r = remote;
1008         for (i = 0; i < qr->qr_numregions; ++i) {
1009                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, r);
1010                 r += O2HB_MAX_REGION_NAME_LEN;
1011         }
1012
1013         localnr = min(O2NM_MAX_REGIONS, locallen/O2HB_MAX_REGION_NAME_LEN);
1014         localnr = o2hb_get_all_regions(local, (u8)localnr);
1015
1016         /* compare local regions with remote */
1017         l = local;
1018         for (i = 0; i < localnr; ++i) {
1019                 foundit = 0;
1020                 r = remote;
1021                 for (j = 0; j <= qr->qr_numregions; ++j) {
1022                         if (!memcmp(l, r, O2HB_MAX_REGION_NAME_LEN)) {
1023                                 foundit = 1;
1024                                 break;
1025                         }
1026                         r += O2HB_MAX_REGION_NAME_LEN;
1027                 }
1028                 if (!foundit) {
1029                         status = -EINVAL;
1030                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1031                              "in local node %d but not in joining node %d\n",
1032                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, l,
1033                              dlm->node_num, qr->qr_node);
1034                         goto bail;
1035                 }
1036                 l += O2HB_MAX_REGION_NAME_LEN;
1037         }
1038
1039         /* compare remote with local regions */
1040         r = remote;
1041         for (i = 0; i < qr->qr_numregions; ++i) {
1042                 foundit = 0;
1043                 l = local;
1044                 for (j = 0; j < localnr; ++j) {
1045                         if (!memcmp(r, l, O2HB_MAX_REGION_NAME_LEN)) {
1046                                 foundit = 1;
1047                                 break;
1048                         }
1049                         l += O2HB_MAX_REGION_NAME_LEN;
1050                 }
1051                 if (!foundit) {
1052                         status = -EINVAL;
1053                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1054                              "in joining node %d but not in local node %d\n",
1055                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, r,
1056                              qr->qr_node, dlm->node_num);
1057                         goto bail;
1058                 }
1059                 r += O2HB_MAX_REGION_NAME_LEN;
1060         }
1061
1062 bail:
1063         return status;
1064 }
1065
1066 static int dlm_send_regions(struct dlm_ctxt *dlm, unsigned long *node_map)
1067 {
1068         struct dlm_query_region *qr = NULL;
1069         int status, ret = 0, i;
1070         char *p;
1071
1072         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1073                 goto bail;
1074
1075         qr = kzalloc(sizeof(struct dlm_query_region), GFP_KERNEL);
1076         if (!qr) {
1077                 ret = -ENOMEM;
1078                 mlog_errno(ret);
1079                 goto bail;
1080         }
1081
1082         qr->qr_node = dlm->node_num;
1083         qr->qr_namelen = strlen(dlm->name);
1084         memcpy(qr->qr_domain, dlm->name, qr->qr_namelen);
1085         /* if local hb, the numregions will be zero */
1086         if (o2hb_global_heartbeat_active())
1087                 qr->qr_numregions = o2hb_get_all_regions(qr->qr_regions,
1088                                                          O2NM_MAX_REGIONS);
1089
1090         p = qr->qr_regions;
1091         for (i = 0; i < qr->qr_numregions; ++i, p += O2HB_MAX_REGION_NAME_LEN)
1092                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, p);
1093
1094         i = -1;
1095         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1096                                   i + 1)) < O2NM_MAX_NODES) {
1097                 if (i == dlm->node_num)
1098                         continue;
1099
1100                 mlog(0, "Sending regions to node %d\n", i);
1101
1102                 ret = o2net_send_message(DLM_QUERY_REGION, DLM_MOD_KEY, qr,
1103                                          sizeof(struct dlm_query_region),
1104                                          i, &status);
1105                 if (ret >= 0)
1106                         ret = status;
1107                 if (ret) {
1108                         mlog(ML_ERROR, "Region mismatch %d, node %d\n",
1109                              ret, i);
1110                         break;
1111                 }
1112         }
1113
1114 bail:
1115         kfree(qr);
1116         return ret;
1117 }
1118
1119 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
1120                                     void *data, void **ret_data)
1121 {
1122         struct dlm_query_region *qr;
1123         struct dlm_ctxt *dlm = NULL;
1124         char *local = NULL;
1125         int status = 0;
1126
1127         qr = (struct dlm_query_region *) msg->buf;
1128
1129         mlog(0, "Node %u queries hb regions on domain %s\n", qr->qr_node,
1130              qr->qr_domain);
1131
1132         /* buffer used in dlm_mast_regions() */
1133         local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
1134         if (!local)
1135                 return -ENOMEM;
1136
1137         status = -EINVAL;
1138
1139         spin_lock(&dlm_domain_lock);
1140         dlm = __dlm_lookup_domain_full(qr->qr_domain, qr->qr_namelen);
1141         if (!dlm) {
1142                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1143                      "before join domain\n", qr->qr_node, qr->qr_domain);
1144                 goto out_domain_lock;
1145         }
1146
1147         spin_lock(&dlm->spinlock);
1148         if (dlm->joining_node != qr->qr_node) {
1149                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1150                      "but joining node is %d\n", qr->qr_node, qr->qr_domain,
1151                      dlm->joining_node);
1152                 goto out_dlm_lock;
1153         }
1154
1155         /* Support for global heartbeat was added in 1.1 */
1156         if (dlm->dlm_locking_proto.pv_major == 1 &&
1157             dlm->dlm_locking_proto.pv_minor == 0) {
1158                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1159                      "but active dlm protocol is %d.%d\n", qr->qr_node,
1160                      qr->qr_domain, dlm->dlm_locking_proto.pv_major,
1161                      dlm->dlm_locking_proto.pv_minor);
1162                 goto out_dlm_lock;
1163         }
1164
1165         status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
1166
1167 out_dlm_lock:
1168         spin_unlock(&dlm->spinlock);
1169
1170 out_domain_lock:
1171         spin_unlock(&dlm_domain_lock);
1172
1173         kfree(local);
1174
1175         return status;
1176 }
1177
1178 static int dlm_match_nodes(struct dlm_ctxt *dlm, struct dlm_query_nodeinfo *qn)
1179 {
1180         struct o2nm_node *local;
1181         struct dlm_node_info *remote;
1182         int i, j;
1183         int status = 0;
1184
1185         for (j = 0; j < qn->qn_numnodes; ++j)
1186                 mlog(0, "Node %3d, %pI4:%u\n", qn->qn_nodes[j].ni_nodenum,
1187                      &(qn->qn_nodes[j].ni_ipv4_address),
1188                      ntohs(qn->qn_nodes[j].ni_ipv4_port));
1189
1190         for (i = 0; i < O2NM_MAX_NODES && !status; ++i) {
1191                 local = o2nm_get_node_by_num(i);
1192                 remote = NULL;
1193                 for (j = 0; j < qn->qn_numnodes; ++j) {
1194                         if (qn->qn_nodes[j].ni_nodenum == i) {
1195                                 remote = &(qn->qn_nodes[j]);
1196                                 break;
1197                         }
1198                 }
1199
1200                 if (!local && !remote)
1201                         continue;
1202
1203                 if ((local && !remote) || (!local && remote))
1204                         status = -EINVAL;
1205
1206                 if (!status &&
1207                     ((remote->ni_nodenum != local->nd_num) ||
1208                      (remote->ni_ipv4_port != local->nd_ipv4_port) ||
1209                      (remote->ni_ipv4_address != local->nd_ipv4_address)))
1210                         status = -EINVAL;
1211
1212                 if (status) {
1213                         if (remote && !local)
1214                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1215                                      "registered in joining node %d but not in "
1216                                      "local node %d\n", qn->qn_domain,
1217                                      remote->ni_nodenum,
1218                                      &(remote->ni_ipv4_address),
1219                                      ntohs(remote->ni_ipv4_port),
1220                                      qn->qn_nodenum, dlm->node_num);
1221                         if (local && !remote)
1222                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1223                                      "registered in local node %d but not in "
1224                                      "joining node %d\n", qn->qn_domain,
1225                                      local->nd_num, &(local->nd_ipv4_address),
1226                                      ntohs(local->nd_ipv4_port),
1227                                      dlm->node_num, qn->qn_nodenum);
1228                         BUG_ON((!local && !remote));
1229                 }
1230
1231                 if (local)
1232                         o2nm_node_put(local);
1233         }
1234
1235         return status;
1236 }
1237
1238 static int dlm_send_nodeinfo(struct dlm_ctxt *dlm, unsigned long *node_map)
1239 {
1240         struct dlm_query_nodeinfo *qn = NULL;
1241         struct o2nm_node *node;
1242         int ret = 0, status, count, i;
1243
1244         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1245                 goto bail;
1246
1247         qn = kzalloc(sizeof(struct dlm_query_nodeinfo), GFP_KERNEL);
1248         if (!qn) {
1249                 ret = -ENOMEM;
1250                 mlog_errno(ret);
1251                 goto bail;
1252         }
1253
1254         for (i = 0, count = 0; i < O2NM_MAX_NODES; ++i) {
1255                 node = o2nm_get_node_by_num(i);
1256                 if (!node)
1257                         continue;
1258                 qn->qn_nodes[count].ni_nodenum = node->nd_num;
1259                 qn->qn_nodes[count].ni_ipv4_port = node->nd_ipv4_port;
1260                 qn->qn_nodes[count].ni_ipv4_address = node->nd_ipv4_address;
1261                 mlog(0, "Node %3d, %pI4:%u\n", node->nd_num,
1262                      &(node->nd_ipv4_address), ntohs(node->nd_ipv4_port));
1263                 ++count;
1264                 o2nm_node_put(node);
1265         }
1266
1267         qn->qn_nodenum = dlm->node_num;
1268         qn->qn_numnodes = count;
1269         qn->qn_namelen = strlen(dlm->name);
1270         memcpy(qn->qn_domain, dlm->name, qn->qn_namelen);
1271
1272         i = -1;
1273         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1274                                   i + 1)) < O2NM_MAX_NODES) {
1275                 if (i == dlm->node_num)
1276                         continue;
1277
1278                 mlog(0, "Sending nodeinfo to node %d\n", i);
1279
1280                 ret = o2net_send_message(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
1281                                          qn, sizeof(struct dlm_query_nodeinfo),
1282                                          i, &status);
1283                 if (ret >= 0)
1284                         ret = status;
1285                 if (ret) {
1286                         mlog(ML_ERROR, "node mismatch %d, node %d\n", ret, i);
1287                         break;
1288                 }
1289         }
1290
1291 bail:
1292         kfree(qn);
1293         return ret;
1294 }
1295
1296 static int dlm_query_nodeinfo_handler(struct o2net_msg *msg, u32 len,
1297                                       void *data, void **ret_data)
1298 {
1299         struct dlm_query_nodeinfo *qn;
1300         struct dlm_ctxt *dlm = NULL;
1301         int locked = 0, status = -EINVAL;
1302
1303         qn = (struct dlm_query_nodeinfo *) msg->buf;
1304
1305         mlog(0, "Node %u queries nodes on domain %s\n", qn->qn_nodenum,
1306              qn->qn_domain);
1307
1308         spin_lock(&dlm_domain_lock);
1309         dlm = __dlm_lookup_domain_full(qn->qn_domain, qn->qn_namelen);
1310         if (!dlm) {
1311                 mlog(ML_ERROR, "Node %d queried nodes on domain %s before "
1312                      "join domain\n", qn->qn_nodenum, qn->qn_domain);
1313                 goto bail;
1314         }
1315
1316         spin_lock(&dlm->spinlock);
1317         locked = 1;
1318         if (dlm->joining_node != qn->qn_nodenum) {
1319                 mlog(ML_ERROR, "Node %d queried nodes on domain %s but "
1320                      "joining node is %d\n", qn->qn_nodenum, qn->qn_domain,
1321                      dlm->joining_node);
1322                 goto bail;
1323         }
1324
1325         /* Support for node query was added in 1.1 */
1326         if (dlm->dlm_locking_proto.pv_major == 1 &&
1327             dlm->dlm_locking_proto.pv_minor == 0) {
1328                 mlog(ML_ERROR, "Node %d queried nodes on domain %s "
1329                      "but active dlm protocol is %d.%d\n", qn->qn_nodenum,
1330                      qn->qn_domain, dlm->dlm_locking_proto.pv_major,
1331                      dlm->dlm_locking_proto.pv_minor);
1332                 goto bail;
1333         }
1334
1335         status = dlm_match_nodes(dlm, qn);
1336
1337 bail:
1338         if (locked)
1339                 spin_unlock(&dlm->spinlock);
1340         spin_unlock(&dlm_domain_lock);
1341
1342         return status;
1343 }
1344
1345 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
1346                                    void **ret_data)
1347 {
1348         struct dlm_cancel_join *cancel;
1349         struct dlm_ctxt *dlm = NULL;
1350
1351         cancel = (struct dlm_cancel_join *) msg->buf;
1352
1353         mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
1354                   cancel->domain);
1355
1356         spin_lock(&dlm_domain_lock);
1357         dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
1358
1359         if (dlm) {
1360                 spin_lock(&dlm->spinlock);
1361
1362                 /* Yikes, this guy wants to cancel his join. No
1363                  * problem, we simply cleanup our join state. */
1364                 BUG_ON(dlm->joining_node != cancel->node_idx);
1365                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1366
1367                 spin_unlock(&dlm->spinlock);
1368         }
1369         spin_unlock(&dlm_domain_lock);
1370
1371         return 0;
1372 }
1373
1374 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
1375                                     unsigned int node)
1376 {
1377         int status;
1378         struct dlm_cancel_join cancel_msg;
1379
1380         memset(&cancel_msg, 0, sizeof(cancel_msg));
1381         cancel_msg.node_idx = dlm->node_num;
1382         cancel_msg.name_len = strlen(dlm->name);
1383         memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
1384
1385         status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1386                                     &cancel_msg, sizeof(cancel_msg), node,
1387                                     NULL);
1388         if (status < 0) {
1389                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1390                      "node %u\n", status, DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1391                      node);
1392                 goto bail;
1393         }
1394
1395 bail:
1396         return status;
1397 }
1398
1399 /* map_size should be in bytes. */
1400 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
1401                                  unsigned long *node_map,
1402                                  unsigned int map_size)
1403 {
1404         int status, tmpstat;
1405         unsigned int node;
1406
1407         if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
1408                          sizeof(unsigned long))) {
1409                 mlog(ML_ERROR,
1410                      "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
1411                      map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
1412                 return -EINVAL;
1413         }
1414
1415         status = 0;
1416         node = -1;
1417         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1418                                      node + 1)) < O2NM_MAX_NODES) {
1419                 if (node == dlm->node_num)
1420                         continue;
1421
1422                 tmpstat = dlm_send_one_join_cancel(dlm, node);
1423                 if (tmpstat) {
1424                         mlog(ML_ERROR, "Error return %d cancelling join on "
1425                              "node %d\n", tmpstat, node);
1426                         if (!status)
1427                                 status = tmpstat;
1428                 }
1429         }
1430
1431         if (status)
1432                 mlog_errno(status);
1433         return status;
1434 }
1435
1436 static int dlm_request_join(struct dlm_ctxt *dlm,
1437                             int node,
1438                             enum dlm_query_join_response_code *response)
1439 {
1440         int status;
1441         struct dlm_query_join_request join_msg;
1442         struct dlm_query_join_packet packet;
1443         u32 join_resp;
1444
1445         mlog(0, "querying node %d\n", node);
1446
1447         memset(&join_msg, 0, sizeof(join_msg));
1448         join_msg.node_idx = dlm->node_num;
1449         join_msg.name_len = strlen(dlm->name);
1450         memcpy(join_msg.domain, dlm->name, join_msg.name_len);
1451         join_msg.dlm_proto = dlm->dlm_locking_proto;
1452         join_msg.fs_proto = dlm->fs_locking_proto;
1453
1454         /* copy live node map to join message */
1455         byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
1456
1457         status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
1458                                     sizeof(join_msg), node, &join_resp);
1459         if (status < 0 && status != -ENOPROTOOPT) {
1460                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1461                      "node %u\n", status, DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1462                      node);
1463                 goto bail;
1464         }
1465         dlm_query_join_wire_to_packet(join_resp, &packet);
1466
1467         /* -ENOPROTOOPT from the net code means the other side isn't
1468             listening for our message type -- that's fine, it means
1469             his dlm isn't up, so we can consider him a 'yes' but not
1470             joined into the domain.  */
1471         if (status == -ENOPROTOOPT) {
1472                 status = 0;
1473                 *response = JOIN_OK_NO_MAP;
1474         } else if (packet.code == JOIN_DISALLOW ||
1475                    packet.code == JOIN_OK_NO_MAP) {
1476                 *response = packet.code;
1477         } else if (packet.code == JOIN_PROTOCOL_MISMATCH) {
1478                 mlog(ML_NOTICE,
1479                      "This node requested DLM locking protocol %u.%u and "
1480                      "filesystem locking protocol %u.%u.  At least one of "
1481                      "the protocol versions on node %d is not compatible, "
1482                      "disconnecting\n",
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                      node);
1488                 status = -EPROTO;
1489                 *response = packet.code;
1490         } else if (packet.code == JOIN_OK) {
1491                 *response = packet.code;
1492                 /* Use the same locking protocol as the remote node */
1493                 dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
1494                 dlm->fs_locking_proto.pv_minor = packet.fs_minor;
1495                 mlog(0,
1496                      "Node %d responds JOIN_OK with DLM locking protocol "
1497                      "%u.%u and fs locking protocol %u.%u\n",
1498                      node,
1499                      dlm->dlm_locking_proto.pv_major,
1500                      dlm->dlm_locking_proto.pv_minor,
1501                      dlm->fs_locking_proto.pv_major,
1502                      dlm->fs_locking_proto.pv_minor);
1503         } else {
1504                 status = -EINVAL;
1505                 mlog(ML_ERROR, "invalid response %d from node %u\n",
1506                      packet.code, node);
1507         }
1508
1509         mlog(0, "status %d, node %d response is %d\n", status, node,
1510              *response);
1511
1512 bail:
1513         return status;
1514 }
1515
1516 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
1517                                     unsigned int node)
1518 {
1519         int status;
1520         struct dlm_assert_joined assert_msg;
1521
1522         mlog(0, "Sending join assert to node %u\n", node);
1523
1524         memset(&assert_msg, 0, sizeof(assert_msg));
1525         assert_msg.node_idx = dlm->node_num;
1526         assert_msg.name_len = strlen(dlm->name);
1527         memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
1528
1529         status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1530                                     &assert_msg, sizeof(assert_msg), node,
1531                                     NULL);
1532         if (status < 0)
1533                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1534                      "node %u\n", status, DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1535                      node);
1536
1537         return status;
1538 }
1539
1540 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
1541                                   unsigned long *node_map)
1542 {
1543         int status, node, live;
1544
1545         status = 0;
1546         node = -1;
1547         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1548                                      node + 1)) < O2NM_MAX_NODES) {
1549                 if (node == dlm->node_num)
1550                         continue;
1551
1552                 do {
1553                         /* It is very important that this message be
1554                          * received so we spin until either the node
1555                          * has died or it gets the message. */
1556                         status = dlm_send_one_join_assert(dlm, node);
1557
1558                         spin_lock(&dlm->spinlock);
1559                         live = test_bit(node, dlm->live_nodes_map);
1560                         spin_unlock(&dlm->spinlock);
1561
1562                         if (status) {
1563                                 mlog(ML_ERROR, "Error return %d asserting "
1564                                      "join on node %d\n", status, node);
1565
1566                                 /* give us some time between errors... */
1567                                 if (live)
1568                                         msleep(DLM_DOMAIN_BACKOFF_MS);
1569                         }
1570                 } while (status && live);
1571         }
1572 }
1573
1574 struct domain_join_ctxt {
1575         unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1576         unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1577 };
1578
1579 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
1580                                    struct domain_join_ctxt *ctxt,
1581                                    enum dlm_query_join_response_code response)
1582 {
1583         int ret;
1584
1585         if (response == JOIN_DISALLOW) {
1586                 mlog(0, "Latest response of disallow -- should restart\n");
1587                 return 1;
1588         }
1589
1590         spin_lock(&dlm->spinlock);
1591         /* For now, we restart the process if the node maps have
1592          * changed at all */
1593         ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
1594                      sizeof(dlm->live_nodes_map));
1595         spin_unlock(&dlm->spinlock);
1596
1597         if (ret)
1598                 mlog(0, "Node maps changed -- should restart\n");
1599
1600         return ret;
1601 }
1602
1603 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
1604 {
1605         int status = 0, tmpstat, node;
1606         struct domain_join_ctxt *ctxt;
1607         enum dlm_query_join_response_code response = JOIN_DISALLOW;
1608
1609         mlog(0, "%p", dlm);
1610
1611         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
1612         if (!ctxt) {
1613                 status = -ENOMEM;
1614                 mlog_errno(status);
1615                 goto bail;
1616         }
1617
1618         /* group sem locking should work for us here -- we're already
1619          * registered for heartbeat events so filling this should be
1620          * atomic wrt getting those handlers called. */
1621         o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
1622
1623         spin_lock(&dlm->spinlock);
1624         memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
1625
1626         __dlm_set_joining_node(dlm, dlm->node_num);
1627
1628         spin_unlock(&dlm->spinlock);
1629
1630         node = -1;
1631         while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
1632                                      node + 1)) < O2NM_MAX_NODES) {
1633                 if (node == dlm->node_num)
1634                         continue;
1635
1636                 status = dlm_request_join(dlm, node, &response);
1637                 if (status < 0) {
1638                         mlog_errno(status);
1639                         goto bail;
1640                 }
1641
1642                 /* Ok, either we got a response or the node doesn't have a
1643                  * dlm up. */
1644                 if (response == JOIN_OK)
1645                         set_bit(node, ctxt->yes_resp_map);
1646
1647                 if (dlm_should_restart_join(dlm, ctxt, response)) {
1648                         status = -EAGAIN;
1649                         goto bail;
1650                 }
1651         }
1652
1653         mlog(0, "Yay, done querying nodes!\n");
1654
1655         /* Yay, everyone agree's we can join the domain. My domain is
1656          * comprised of all nodes who were put in the
1657          * yes_resp_map. Copy that into our domain map and send a join
1658          * assert message to clean up everyone elses state. */
1659         spin_lock(&dlm->spinlock);
1660         memcpy(dlm->domain_map, ctxt->yes_resp_map,
1661                sizeof(ctxt->yes_resp_map));
1662         set_bit(dlm->node_num, dlm->domain_map);
1663         spin_unlock(&dlm->spinlock);
1664
1665         /* Support for global heartbeat and node info was added in 1.1 */
1666         if (dlm->dlm_locking_proto.pv_major > 1 ||
1667             dlm->dlm_locking_proto.pv_minor > 0) {
1668                 status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
1669                 if (status) {
1670                         mlog_errno(status);
1671                         goto bail;
1672                 }
1673                 status = dlm_send_regions(dlm, ctxt->yes_resp_map);
1674                 if (status) {
1675                         mlog_errno(status);
1676                         goto bail;
1677                 }
1678         }
1679
1680         dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
1681
1682         /* Joined state *must* be set before the joining node
1683          * information, otherwise the query_join handler may read no
1684          * current joiner but a state of NEW and tell joining nodes
1685          * we're not in the domain. */
1686         spin_lock(&dlm_domain_lock);
1687         dlm->dlm_state = DLM_CTXT_JOINED;
1688         dlm->num_joins++;
1689         spin_unlock(&dlm_domain_lock);
1690
1691 bail:
1692         spin_lock(&dlm->spinlock);
1693         __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1694         if (!status) {
1695                 printk(KERN_NOTICE "o2dlm: Joining domain %s ", dlm->name);
1696                 __dlm_print_nodes(dlm);
1697         }
1698         spin_unlock(&dlm->spinlock);
1699
1700         if (ctxt) {
1701                 /* Do we need to send a cancel message to any nodes? */
1702                 if (status < 0) {
1703                         tmpstat = dlm_send_join_cancels(dlm,
1704                                                         ctxt->yes_resp_map,
1705                                                         sizeof(ctxt->yes_resp_map));
1706                         if (tmpstat < 0)
1707                                 mlog_errno(tmpstat);
1708                 }
1709                 kfree(ctxt);
1710         }
1711
1712         mlog(0, "returning %d\n", status);
1713         return status;
1714 }
1715
1716 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1717 {
1718         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_up);
1719         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_down);
1720         o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1721 }
1722
1723 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1724 {
1725         int status;
1726
1727         mlog(0, "registering handlers.\n");
1728
1729         o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1730                             dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1731         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
1732         if (status)
1733                 goto bail;
1734
1735         o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1736                             dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1737         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
1738         if (status)
1739                 goto bail;
1740
1741         status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1742                                         sizeof(struct dlm_master_request),
1743                                         dlm_master_request_handler,
1744                                         dlm, NULL, &dlm->dlm_domain_handlers);
1745         if (status)
1746                 goto bail;
1747
1748         status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1749                                         sizeof(struct dlm_assert_master),
1750                                         dlm_assert_master_handler,
1751                                         dlm, dlm_assert_master_post_handler,
1752                                         &dlm->dlm_domain_handlers);
1753         if (status)
1754                 goto bail;
1755
1756         status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1757                                         sizeof(struct dlm_create_lock),
1758                                         dlm_create_lock_handler,
1759                                         dlm, NULL, &dlm->dlm_domain_handlers);
1760         if (status)
1761                 goto bail;
1762
1763         status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1764                                         DLM_CONVERT_LOCK_MAX_LEN,
1765                                         dlm_convert_lock_handler,
1766                                         dlm, NULL, &dlm->dlm_domain_handlers);
1767         if (status)
1768                 goto bail;
1769
1770         status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1771                                         DLM_UNLOCK_LOCK_MAX_LEN,
1772                                         dlm_unlock_lock_handler,
1773                                         dlm, NULL, &dlm->dlm_domain_handlers);
1774         if (status)
1775                 goto bail;
1776
1777         status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1778                                         DLM_PROXY_AST_MAX_LEN,
1779                                         dlm_proxy_ast_handler,
1780                                         dlm, NULL, &dlm->dlm_domain_handlers);
1781         if (status)
1782                 goto bail;
1783
1784         status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1785                                         sizeof(struct dlm_exit_domain),
1786                                         dlm_exit_domain_handler,
1787                                         dlm, NULL, &dlm->dlm_domain_handlers);
1788         if (status)
1789                 goto bail;
1790
1791         status = o2net_register_handler(DLM_DEREF_LOCKRES_MSG, dlm->key,
1792                                         sizeof(struct dlm_deref_lockres),
1793                                         dlm_deref_lockres_handler,
1794                                         dlm, NULL, &dlm->dlm_domain_handlers);
1795         if (status)
1796                 goto bail;
1797
1798         status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1799                                         sizeof(struct dlm_migrate_request),
1800                                         dlm_migrate_request_handler,
1801                                         dlm, NULL, &dlm->dlm_domain_handlers);
1802         if (status)
1803                 goto bail;
1804
1805         status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1806                                         DLM_MIG_LOCKRES_MAX_LEN,
1807                                         dlm_mig_lockres_handler,
1808                                         dlm, NULL, &dlm->dlm_domain_handlers);
1809         if (status)
1810                 goto bail;
1811
1812         status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1813                                         sizeof(struct dlm_master_requery),
1814                                         dlm_master_requery_handler,
1815                                         dlm, NULL, &dlm->dlm_domain_handlers);
1816         if (status)
1817                 goto bail;
1818
1819         status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1820                                         sizeof(struct dlm_lock_request),
1821                                         dlm_request_all_locks_handler,
1822                                         dlm, NULL, &dlm->dlm_domain_handlers);
1823         if (status)
1824                 goto bail;
1825
1826         status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1827                                         sizeof(struct dlm_reco_data_done),
1828                                         dlm_reco_data_done_handler,
1829                                         dlm, NULL, &dlm->dlm_domain_handlers);
1830         if (status)
1831                 goto bail;
1832
1833         status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1834                                         sizeof(struct dlm_begin_reco),
1835                                         dlm_begin_reco_handler,
1836                                         dlm, NULL, &dlm->dlm_domain_handlers);
1837         if (status)
1838                 goto bail;
1839
1840         status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1841                                         sizeof(struct dlm_finalize_reco),
1842                                         dlm_finalize_reco_handler,
1843                                         dlm, NULL, &dlm->dlm_domain_handlers);
1844         if (status)
1845                 goto bail;
1846
1847         status = o2net_register_handler(DLM_BEGIN_EXIT_DOMAIN_MSG, dlm->key,
1848                                         sizeof(struct dlm_exit_domain),
1849                                         dlm_begin_exit_domain_handler,
1850                                         dlm, NULL, &dlm->dlm_domain_handlers);
1851         if (status)
1852                 goto bail;
1853
1854 bail:
1855         if (status)
1856                 dlm_unregister_domain_handlers(dlm);
1857
1858         return status;
1859 }
1860
1861 static int dlm_join_domain(struct dlm_ctxt *dlm)
1862 {
1863         int status;
1864         unsigned int backoff;
1865         unsigned int total_backoff = 0;
1866
1867         BUG_ON(!dlm);
1868
1869         mlog(0, "Join domain %s\n", dlm->name);
1870
1871         status = dlm_register_domain_handlers(dlm);
1872         if (status) {
1873                 mlog_errno(status);
1874                 goto bail;
1875         }
1876
1877         status = dlm_launch_thread(dlm);
1878         if (status < 0) {
1879                 mlog_errno(status);
1880                 goto bail;
1881         }
1882
1883         status = dlm_launch_recovery_thread(dlm);
1884         if (status < 0) {
1885                 mlog_errno(status);
1886                 goto bail;
1887         }
1888
1889         status = dlm_debug_init(dlm);
1890         if (status < 0) {
1891                 mlog_errno(status);
1892                 goto bail;
1893         }
1894
1895         dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1896         if (!dlm->dlm_worker) {
1897                 status = -ENOMEM;
1898                 mlog_errno(status);
1899                 goto bail;
1900         }
1901
1902         do {
1903                 status = dlm_try_to_join_domain(dlm);
1904
1905                 /* If we're racing another node to the join, then we
1906                  * need to back off temporarily and let them
1907                  * complete. */
1908 #define DLM_JOIN_TIMEOUT_MSECS  90000
1909                 if (status == -EAGAIN) {
1910                         if (signal_pending(current)) {
1911                                 status = -ERESTARTSYS;
1912                                 goto bail;
1913                         }
1914
1915                         if (total_backoff >
1916                             msecs_to_jiffies(DLM_JOIN_TIMEOUT_MSECS)) {
1917                                 status = -ERESTARTSYS;
1918                                 mlog(ML_NOTICE, "Timed out joining dlm domain "
1919                                      "%s after %u msecs\n", dlm->name,
1920                                      jiffies_to_msecs(total_backoff));
1921                                 goto bail;
1922                         }
1923
1924                         /*
1925                          * <chip> After you!
1926                          * <dale> No, after you!
1927                          * <chip> I insist!
1928                          * <dale> But you first!
1929                          * ...
1930                          */
1931                         backoff = (unsigned int)(jiffies & 0x3);
1932                         backoff *= DLM_DOMAIN_BACKOFF_MS;
1933                         total_backoff += backoff;
1934                         mlog(0, "backoff %d\n", backoff);
1935                         msleep(backoff);
1936                 }
1937         } while (status == -EAGAIN);
1938
1939         if (status < 0) {
1940                 mlog_errno(status);
1941                 goto bail;
1942         }
1943
1944         status = 0;
1945 bail:
1946         wake_up(&dlm_domain_events);
1947
1948         if (status) {
1949                 dlm_unregister_domain_handlers(dlm);
1950                 dlm_debug_shutdown(dlm);
1951                 dlm_complete_thread(dlm);
1952                 dlm_complete_recovery_thread(dlm);
1953                 dlm_destroy_dlm_worker(dlm);
1954         }
1955
1956         return status;
1957 }
1958
1959 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1960                                 u32 key)
1961 {
1962         int i;
1963         int ret;
1964         struct dlm_ctxt *dlm = NULL;
1965
1966         dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1967         if (!dlm) {
1968                 mlog_errno(-ENOMEM);
1969                 goto leave;
1970         }
1971
1972         dlm->name = kstrdup(domain, GFP_KERNEL);
1973         if (dlm->name == NULL) {
1974                 mlog_errno(-ENOMEM);
1975                 kfree(dlm);
1976                 dlm = NULL;
1977                 goto leave;
1978         }
1979
1980         dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1981         if (!dlm->lockres_hash) {
1982                 mlog_errno(-ENOMEM);
1983                 kfree(dlm->name);
1984                 kfree(dlm);
1985                 dlm = NULL;
1986                 goto leave;
1987         }
1988
1989         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1990                 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1991
1992         dlm->master_hash = (struct hlist_head **)
1993                                 dlm_alloc_pagevec(DLM_HASH_PAGES);
1994         if (!dlm->master_hash) {
1995                 mlog_errno(-ENOMEM);
1996                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
1997                 kfree(dlm->name);
1998                 kfree(dlm);
1999                 dlm = NULL;
2000                 goto leave;
2001         }
2002
2003         for (i = 0; i < DLM_HASH_BUCKETS; i++)
2004                 INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
2005
2006         dlm->key = key;
2007         dlm->node_num = o2nm_this_node();
2008
2009         ret = dlm_create_debugfs_subroot(dlm);
2010         if (ret < 0) {
2011                 dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
2012                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
2013                 kfree(dlm->name);
2014                 kfree(dlm);
2015                 dlm = NULL;
2016                 goto leave;
2017         }
2018
2019         spin_lock_init(&dlm->spinlock);
2020         spin_lock_init(&dlm->master_lock);
2021         spin_lock_init(&dlm->ast_lock);
2022         spin_lock_init(&dlm->track_lock);
2023         INIT_LIST_HEAD(&dlm->list);
2024         INIT_LIST_HEAD(&dlm->dirty_list);
2025         INIT_LIST_HEAD(&dlm->reco.resources);
2026         INIT_LIST_HEAD(&dlm->reco.received);
2027         INIT_LIST_HEAD(&dlm->reco.node_data);
2028         INIT_LIST_HEAD(&dlm->purge_list);
2029         INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
2030         INIT_LIST_HEAD(&dlm->tracking_list);
2031         dlm->reco.state = 0;
2032
2033         INIT_LIST_HEAD(&dlm->pending_asts);
2034         INIT_LIST_HEAD(&dlm->pending_basts);
2035
2036         mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
2037                   dlm->recovery_map, &(dlm->recovery_map[0]));
2038
2039         memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
2040         memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
2041         memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
2042
2043         dlm->dlm_thread_task = NULL;
2044         dlm->dlm_reco_thread_task = NULL;
2045         dlm->dlm_worker = NULL;
2046         init_waitqueue_head(&dlm->dlm_thread_wq);
2047         init_waitqueue_head(&dlm->dlm_reco_thread_wq);
2048         init_waitqueue_head(&dlm->reco.event);
2049         init_waitqueue_head(&dlm->ast_wq);
2050         init_waitqueue_head(&dlm->migration_wq);
2051         INIT_LIST_HEAD(&dlm->mle_hb_events);
2052
2053         dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
2054         init_waitqueue_head(&dlm->dlm_join_events);
2055
2056         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
2057         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
2058
2059         atomic_set(&dlm->res_tot_count, 0);
2060         atomic_set(&dlm->res_cur_count, 0);
2061         for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
2062                 atomic_set(&dlm->mle_tot_count[i], 0);
2063                 atomic_set(&dlm->mle_cur_count[i], 0);
2064         }
2065
2066         spin_lock_init(&dlm->work_lock);
2067         INIT_LIST_HEAD(&dlm->work_list);
2068         INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
2069
2070         kref_init(&dlm->dlm_refs);
2071         dlm->dlm_state = DLM_CTXT_NEW;
2072
2073         INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
2074
2075         mlog(0, "context init: refcount %u\n",
2076                   atomic_read(&dlm->dlm_refs.refcount));
2077
2078 leave:
2079         return dlm;
2080 }
2081
2082 /*
2083  * Compare a requested locking protocol version against the current one.
2084  *
2085  * If the major numbers are different, they are incompatible.
2086  * If the current minor is greater than the request, they are incompatible.
2087  * If the current minor is less than or equal to the request, they are
2088  * compatible, and the requester should run at the current minor version.
2089  */
2090 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
2091                                 struct dlm_protocol_version *request)
2092 {
2093         if (existing->pv_major != request->pv_major)
2094                 return 1;
2095
2096         if (existing->pv_minor > request->pv_minor)
2097                 return 1;
2098
2099         if (existing->pv_minor < request->pv_minor)
2100                 request->pv_minor = existing->pv_minor;
2101
2102         return 0;
2103 }
2104
2105 /*
2106  * dlm_register_domain: one-time setup per "domain".
2107  *
2108  * The filesystem passes in the requested locking version via proto.
2109  * If registration was successful, proto will contain the negotiated
2110  * locking protocol.
2111  */
2112 struct dlm_ctxt * dlm_register_domain(const char *domain,
2113                                u32 key,
2114                                struct dlm_protocol_version *fs_proto)
2115 {
2116         int ret;
2117         struct dlm_ctxt *dlm = NULL;
2118         struct dlm_ctxt *new_ctxt = NULL;
2119
2120         if (strlen(domain) >= O2NM_MAX_NAME_LEN) {
2121                 ret = -ENAMETOOLONG;
2122                 mlog(ML_ERROR, "domain name length too long\n");
2123                 goto leave;
2124         }
2125
2126         mlog(0, "register called for domain \"%s\"\n", domain);
2127
2128 retry:
2129         dlm = NULL;
2130         if (signal_pending(current)) {
2131                 ret = -ERESTARTSYS;
2132                 mlog_errno(ret);
2133                 goto leave;
2134         }
2135
2136         spin_lock(&dlm_domain_lock);
2137
2138         dlm = __dlm_lookup_domain(domain);
2139         if (dlm) {
2140                 if (dlm->dlm_state != DLM_CTXT_JOINED) {
2141                         spin_unlock(&dlm_domain_lock);
2142
2143                         mlog(0, "This ctxt is not joined yet!\n");
2144                         wait_event_interruptible(dlm_domain_events,
2145                                                  dlm_wait_on_domain_helper(
2146                                                          domain));
2147                         goto retry;
2148                 }
2149
2150                 if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
2151                         spin_unlock(&dlm_domain_lock);
2152                         mlog(ML_ERROR,
2153                              "Requested locking protocol version is not "
2154                              "compatible with already registered domain "
2155                              "\"%s\"\n", domain);
2156                         ret = -EPROTO;
2157                         goto leave;
2158                 }
2159
2160                 __dlm_get(dlm);
2161                 dlm->num_joins++;
2162
2163                 spin_unlock(&dlm_domain_lock);
2164
2165                 ret = 0;
2166                 goto leave;
2167         }
2168
2169         /* doesn't exist */
2170         if (!new_ctxt) {
2171                 spin_unlock(&dlm_domain_lock);
2172
2173                 new_ctxt = dlm_alloc_ctxt(domain, key);
2174                 if (new_ctxt)
2175                         goto retry;
2176
2177                 ret = -ENOMEM;
2178                 mlog_errno(ret);
2179                 goto leave;
2180         }
2181
2182         /* a little variable switch-a-roo here... */
2183         dlm = new_ctxt;
2184         new_ctxt = NULL;
2185
2186         /* add the new domain */
2187         list_add_tail(&dlm->list, &dlm_domains);
2188         spin_unlock(&dlm_domain_lock);
2189
2190         /*
2191          * Pass the locking protocol version into the join.  If the join
2192          * succeeds, it will have the negotiated protocol set.
2193          */
2194         dlm->dlm_locking_proto = dlm_protocol;
2195         dlm->fs_locking_proto = *fs_proto;
2196
2197         ret = dlm_join_domain(dlm);
2198         if (ret) {
2199                 mlog_errno(ret);
2200                 dlm_put(dlm);
2201                 goto leave;
2202         }
2203
2204         /* Tell the caller what locking protocol we negotiated */
2205         *fs_proto = dlm->fs_locking_proto;
2206
2207         ret = 0;
2208 leave:
2209         if (new_ctxt)
2210                 dlm_free_ctxt_mem(new_ctxt);
2211
2212         if (ret < 0)
2213                 dlm = ERR_PTR(ret);
2214
2215         return dlm;
2216 }
2217 EXPORT_SYMBOL_GPL(dlm_register_domain);
2218
2219 static LIST_HEAD(dlm_join_handlers);
2220
2221 static void dlm_unregister_net_handlers(void)
2222 {
2223         o2net_unregister_handler_list(&dlm_join_handlers);
2224 }
2225
2226 static int dlm_register_net_handlers(void)
2227 {
2228         int status = 0;
2229
2230         status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
2231                                         sizeof(struct dlm_query_join_request),
2232                                         dlm_query_join_handler,
2233                                         NULL, NULL, &dlm_join_handlers);
2234         if (status)
2235                 goto bail;
2236
2237         status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
2238                                         sizeof(struct dlm_assert_joined),
2239                                         dlm_assert_joined_handler,
2240                                         NULL, NULL, &dlm_join_handlers);
2241         if (status)
2242                 goto bail;
2243
2244         status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
2245                                         sizeof(struct dlm_cancel_join),
2246                                         dlm_cancel_join_handler,
2247                                         NULL, NULL, &dlm_join_handlers);
2248         if (status)
2249                 goto bail;
2250
2251         status = o2net_register_handler(DLM_QUERY_REGION, DLM_MOD_KEY,
2252                                         sizeof(struct dlm_query_region),
2253                                         dlm_query_region_handler,
2254                                         NULL, NULL, &dlm_join_handlers);
2255
2256         if (status)
2257                 goto bail;
2258
2259         status = o2net_register_handler(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
2260                                         sizeof(struct dlm_query_nodeinfo),
2261                                         dlm_query_nodeinfo_handler,
2262                                         NULL, NULL, &dlm_join_handlers);
2263 bail:
2264         if (status < 0)
2265                 dlm_unregister_net_handlers();
2266
2267         return status;
2268 }
2269
2270 /* Domain eviction callback handling.
2271  *
2272  * The file system requires notification of node death *before* the
2273  * dlm completes it's recovery work, otherwise it may be able to
2274  * acquire locks on resources requiring recovery. Since the dlm can
2275  * evict a node from it's domain *before* heartbeat fires, a similar
2276  * mechanism is required. */
2277
2278 /* Eviction is not expected to happen often, so a per-domain lock is
2279  * not necessary. Eviction callbacks are allowed to sleep for short
2280  * periods of time. */
2281 static DECLARE_RWSEM(dlm_callback_sem);
2282
2283 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
2284                                         int node_num)
2285 {
2286         struct dlm_eviction_cb *cb;
2287
2288         down_read(&dlm_callback_sem);
2289         list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
2290                 cb->ec_func(node_num, cb->ec_data);
2291         }
2292         up_read(&dlm_callback_sem);
2293 }
2294
2295 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
2296                            dlm_eviction_func *f,
2297                            void *data)
2298 {
2299         INIT_LIST_HEAD(&cb->ec_item);
2300         cb->ec_func = f;
2301         cb->ec_data = data;
2302 }
2303 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
2304
2305 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
2306                               struct dlm_eviction_cb *cb)
2307 {
2308         down_write(&dlm_callback_sem);
2309         list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
2310         up_write(&dlm_callback_sem);
2311 }
2312 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
2313
2314 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
2315 {
2316         down_write(&dlm_callback_sem);
2317         list_del_init(&cb->ec_item);
2318         up_write(&dlm_callback_sem);
2319 }
2320 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
2321
2322 static int __init dlm_init(void)
2323 {
2324         int status;
2325
2326         status = dlm_init_mle_cache();
2327         if (status) {
2328                 mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
2329                 goto error;
2330         }
2331
2332         status = dlm_init_master_caches();
2333         if (status) {
2334                 mlog(ML_ERROR, "Could not create o2dlm_lockres and "
2335                      "o2dlm_lockname slabcaches\n");
2336                 goto error;
2337         }
2338
2339         status = dlm_init_lock_cache();
2340         if (status) {
2341                 mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
2342                 goto error;
2343         }
2344
2345         status = dlm_register_net_handlers();
2346         if (status) {
2347                 mlog(ML_ERROR, "Unable to register network handlers\n");
2348                 goto error;
2349         }
2350
2351         status = dlm_create_debugfs_root();
2352         if (status)
2353                 goto error;
2354
2355         return 0;
2356 error:
2357         dlm_unregister_net_handlers();
2358         dlm_destroy_lock_cache();
2359         dlm_destroy_master_caches();
2360         dlm_destroy_mle_cache();
2361         return -1;
2362 }
2363
2364 static void __exit dlm_exit (void)
2365 {
2366         dlm_destroy_debugfs_root();
2367         dlm_unregister_net_handlers();
2368         dlm_destroy_lock_cache();
2369         dlm_destroy_master_caches();
2370         dlm_destroy_mle_cache();
2371 }
2372
2373 MODULE_AUTHOR("Oracle");
2374 MODULE_LICENSE("GPL");
2375 MODULE_DESCRIPTION("OCFS2 Distributed Lock Management");
2376
2377 module_init(dlm_init);
2378 module_exit(dlm_exit);