fs/ocfs2/dlm/dlmdomain.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * dlmdomain.c
   6  *
   7  * defines domain join / leave apis
   8  *
   9  * Copyright (C) 2004 Oracle.  All rights reserved.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/slab.h>
  15 #include <linux/highmem.h>
  16 #include <linux/init.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/delay.h>
  19 #include <linux/err.h>
  20 #include <linux/debugfs.h>
  21 #include <linux/sched/signal.h>
  22
  23 #include "../cluster/heartbeat.h"
  24 #include "../cluster/nodemanager.h"
  25 #include "../cluster/tcp.h"
  26
  27 #include "dlmapi.h"
  28 #include "dlmcommon.h"
  29 #include "dlmdomain.h"
  30 #include "dlmdebug.h"
  31
  32 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
  33 #include "../cluster/masklog.h"
  34
  35 /*
  36  * ocfs2 node maps are array of long int, which limits to send them freely
  37  * across the wire due to endianness issues. To workaround this, we convert
  38  * long ints to byte arrays. Following 3 routines are helper functions to
  39  * set/test/copy bits within those array of bytes
  40  */
  41 static inline void byte_set_bit(u8 nr, u8 map[])
  42 {
  43         map[nr >> 3] |= (1UL << (nr & 7));
  44 }
  45
  46 static inline int byte_test_bit(u8 nr, u8 map[])
  47 {
  48         return ((1UL << (nr & 7)) & (map[nr >> 3])) != 0;
  49 }
  50
  51 static inline void byte_copymap(u8 dmap[], unsigned long smap[],
  52                         unsigned int sz)
  53 {
  54         unsigned int nn;
  55
  56         if (!sz)
  57                 return;
  58
  59         memset(dmap, 0, ((sz + 7) >> 3));
  60         for (nn = 0 ; nn < sz; nn++)
  61                 if (test_bit(nn, smap))
  62                         byte_set_bit(nn, dmap);
  63 }
  64
  65 static void dlm_free_pagevec(void **vec, int pages)
  66 {
  67         while (pages--)
  68                 free_page((unsigned long)vec[pages]);
  69         kfree(vec);
  70 }
  71
  72 static void **dlm_alloc_pagevec(int pages)
  73 {
  74         void **vec = kmalloc_array(pages, sizeof(void *), GFP_KERNEL);
  75         int i;
  76
  77         if (!vec)
  78                 return NULL;
  79
  80         for (i = 0; i < pages; i++)
  81                 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
  82                         goto out_free;
  83
  84         mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
  85              pages, (unsigned long)DLM_HASH_PAGES,
  86              (unsigned long)DLM_BUCKETS_PER_PAGE);
  87         return vec;
  88 out_free:
  89         dlm_free_pagevec(vec, i);
  90         return NULL;
  91 }
  92
  93 /*
  94  *
  95  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
  96  *    dlm_domain_lock
  97  *    struct dlm_ctxt->spinlock
  98  *    struct dlm_lock_resource->spinlock
  99  *    struct dlm_ctxt->master_lock
 100  *    struct dlm_ctxt->ast_lock
 101  *    dlm_master_list_entry->spinlock
 102  *    dlm_lock->spinlock
 103  *
 104  */
 105
 106 DEFINE_SPINLOCK(dlm_domain_lock);
 107 LIST_HEAD(dlm_domains);
 108 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
 109
 110 /*
 111  * The supported protocol version for DLM communication.  Running domains
 112  * will have a negotiated version with the same major number and a minor
 113  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
 114  * be used to determine what a running domain is actually using.
 115  *
 116  * New in version 1.1:
 117  *      - Message DLM_QUERY_REGION added to support global heartbeat
 118  *      - Message DLM_QUERY_NODEINFO added to allow online node removes
 119  * New in version 1.2:
 120  *      - Message DLM_BEGIN_EXIT_DOMAIN_MSG added to mark start of exit domain
 121  * New in version 1.3:
 122  *      - Message DLM_DEREF_LOCKRES_DONE added to inform non-master that the
 123  *        refmap is cleared
 124  */
 125 static const struct dlm_protocol_version dlm_protocol = {
 126         .pv_major = 1,
 127         .pv_minor = 3,
 128 };
 129
 130 #define DLM_DOMAIN_BACKOFF_MS 200
 131
 132 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 133                                   void **ret_data);
 134 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 135                                      void **ret_data);
 136 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
 137                                    void **ret_data);
 138 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
 139                                     void *data, void **ret_data);
 140 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 141                                    void **ret_data);
 142 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
 143                                 struct dlm_protocol_version *request);
 144
 145 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 146
 147 void __dlm_unhash_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 148 {
 149         if (hlist_unhashed(&res->hash_node))
 150                 return;
 151
 152         mlog(0, "%s: Unhash res %.*s\n", dlm->name, res->lockname.len,
 153              res->lockname.name);
 154         hlist_del_init(&res->hash_node);
 155         dlm_lockres_put(res);
 156 }
 157
 158 void __dlm_insert_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
 159 {
 160         struct hlist_head *bucket;
 161
 162         assert_spin_locked(&dlm->spinlock);
 163
 164         bucket = dlm_lockres_hash(dlm, res->lockname.hash);
 165
 166         /* get a reference for our hashtable */
 167         dlm_lockres_get(res);
 168
 169         hlist_add_head(&res->hash_node, bucket);
 170
 171         mlog(0, "%s: Hash res %.*s\n", dlm->name, res->lockname.len,
 172              res->lockname.name);
 173 }
 174
 175 struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
 176                                                      const char *name,
 177                                                      unsigned int len,
 178                                                      unsigned int hash)
 179 {
 180         struct hlist_head *bucket;
 181         struct dlm_lock_resource *res;
 182
 183         mlog(0, "%.*s\n", len, name);
 184
 185         assert_spin_locked(&dlm->spinlock);
 186
 187         bucket = dlm_lockres_hash(dlm, hash);
 188
 189         hlist_for_each_entry(res, bucket, hash_node) {
 190                 if (res->lockname.name[0] != name[0])
 191                         continue;
 192                 if (unlikely(res->lockname.len != len))
 193                         continue;
 194                 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
 195                         continue;
 196                 dlm_lockres_get(res);
 197                 return res;
 198         }
 199         return NULL;
 200 }
 201
 202 /* intended to be called by functions which do not care about lock
 203  * resources which are being purged (most net _handler functions).
 204  * this will return NULL for any lock resource which is found but
 205  * currently in the process of dropping its mastery reference.
 206  * use __dlm_lookup_lockres_full when you need the lock resource
 207  * regardless (e.g. dlm_get_lock_resource) */
 208 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 209                                                 const char *name,
 210                                                 unsigned int len,
 211                                                 unsigned int hash)
 212 {
 213         struct dlm_lock_resource *res = NULL;
 214
 215         mlog(0, "%.*s\n", len, name);
 216
 217         assert_spin_locked(&dlm->spinlock);
 218
 219         res = __dlm_lookup_lockres_full(dlm, name, len, hash);
 220         if (res) {
 221                 spin_lock(&res->spinlock);
 222                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
 223                         spin_unlock(&res->spinlock);
 224                         dlm_lockres_put(res);
 225                         return NULL;
 226                 }
 227                 spin_unlock(&res->spinlock);
 228         }
 229
 230         return res;
 231 }
 232
 233 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 234                                     const char *name,
 235                                     unsigned int len)
 236 {
 237         struct dlm_lock_resource *res;
 238         unsigned int hash = dlm_lockid_hash(name, len);
 239
 240         spin_lock(&dlm->spinlock);
 241         res = __dlm_lookup_lockres(dlm, name, len, hash);
 242         spin_unlock(&dlm->spinlock);
 243         return res;
 244 }
 245
 246 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 247 {
 248         struct dlm_ctxt *tmp;
 249
 250         assert_spin_locked(&dlm_domain_lock);
 251
 252         /* tmp->name here is always NULL terminated,
 253          * but domain may not be! */
 254         list_for_each_entry(tmp, &dlm_domains, list) {
 255                 if (strlen(tmp->name) == len &&
 256                     memcmp(tmp->name, domain, len)==0)
 257                         return tmp;
 258         }
 259
 260         return NULL;
 261 }
 262
 263 /* For null terminated domain strings ONLY */
 264 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
 265 {
 266         assert_spin_locked(&dlm_domain_lock);
 267
 268         return __dlm_lookup_domain_full(domain, strlen(domain));
 269 }
 270
 271
 272 /* returns true on one of two conditions:
 273  * 1) the domain does not exist
 274  * 2) the domain exists and it's state is "joined" */
 275 static int dlm_wait_on_domain_helper(const char *domain)
 276 {
 277         int ret = 0;
 278         struct dlm_ctxt *tmp = NULL;
 279
 280         spin_lock(&dlm_domain_lock);
 281
 282         tmp = __dlm_lookup_domain(domain);
 283         if (!tmp)
 284                 ret = 1;
 285         else if (tmp->dlm_state == DLM_CTXT_JOINED)
 286                 ret = 1;
 287
 288         spin_unlock(&dlm_domain_lock);
 289         return ret;
 290 }
 291
 292 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 293 {
 294         dlm_destroy_debugfs_subroot(dlm);
 295
 296         if (dlm->lockres_hash)
 297                 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 298
 299         if (dlm->master_hash)
 300                 dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
 301
 302         kfree(dlm->name);
 303         kfree(dlm);
 304 }
 305
 306 /* A little strange - this function will be called while holding
 307  * dlm_domain_lock and is expected to be holding it on the way out. We
 308  * will however drop and reacquire it multiple times */
 309 static void dlm_ctxt_release(struct kref *kref)
 310 {
 311         struct dlm_ctxt *dlm;
 312
 313         dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
 314
 315         BUG_ON(dlm->num_joins);
 316         BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
 317
 318         /* we may still be in the list if we hit an error during join. */
 319         list_del_init(&dlm->list);
 320
 321         spin_unlock(&dlm_domain_lock);
 322
 323         mlog(0, "freeing memory from domain %s\n", dlm->name);
 324
 325         wake_up(&dlm_domain_events);
 326
 327         dlm_free_ctxt_mem(dlm);
 328
 329         spin_lock(&dlm_domain_lock);
 330 }
 331
 332 void dlm_put(struct dlm_ctxt *dlm)
 333 {
 334         spin_lock(&dlm_domain_lock);
 335         kref_put(&dlm->dlm_refs, dlm_ctxt_release);
 336         spin_unlock(&dlm_domain_lock);
 337 }
 338
 339 static void __dlm_get(struct dlm_ctxt *dlm)
 340 {
 341         kref_get(&dlm->dlm_refs);
 342 }
 343
 344 /* given a questionable reference to a dlm object, gets a reference if
 345  * it can find it in the list, otherwise returns NULL in which case
 346  * you shouldn't trust your pointer. */
 347 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 348 {
 349         struct dlm_ctxt *target;
 350         struct dlm_ctxt *ret = NULL;
 351
 352         spin_lock(&dlm_domain_lock);
 353
 354         list_for_each_entry(target, &dlm_domains, list) {
 355                 if (target == dlm) {
 356                         __dlm_get(target);
 357                         ret = target;
 358                         break;
 359                 }
 360         }
 361
 362         spin_unlock(&dlm_domain_lock);
 363
 364         return ret;
 365 }
 366
 367 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
 368 {
 369         int ret;
 370
 371         spin_lock(&dlm_domain_lock);
 372         ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
 373                 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
 374         spin_unlock(&dlm_domain_lock);
 375
 376         return ret;
 377 }
 378
 379 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 380 {
 381         if (dlm->dlm_worker) {
 382                 destroy_workqueue(dlm->dlm_worker);
 383                 dlm->dlm_worker = NULL;
 384         }
 385 }
 386
 387 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 388 {
 389         dlm_unregister_domain_handlers(dlm);
 390         dlm_complete_thread(dlm);
 391         dlm_complete_recovery_thread(dlm);
 392         dlm_destroy_dlm_worker(dlm);
 393
 394         /* We've left the domain. Now we can take ourselves out of the
 395          * list and allow the kref stuff to help us free the
 396          * memory. */
 397         spin_lock(&dlm_domain_lock);
 398         list_del_init(&dlm->list);
 399         spin_unlock(&dlm_domain_lock);
 400
 401         /* Wake up anyone waiting for us to remove this domain */
 402         wake_up(&dlm_domain_events);
 403 }
 404
 405 static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
 406 {
 407         int i, num, n, ret = 0;
 408         struct dlm_lock_resource *res;
 409         struct hlist_node *iter;
 410         struct hlist_head *bucket;
 411         int dropped;
 412
 413         mlog(0, "Migrating locks from domain %s\n", dlm->name);
 414
 415         num = 0;
 416         spin_lock(&dlm->spinlock);
 417         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
 418 redo_bucket:
 419                 n = 0;
 420                 bucket = dlm_lockres_hash(dlm, i);
 421                 iter = bucket->first;
 422                 while (iter) {
 423                         n++;
 424                         res = hlist_entry(iter, struct dlm_lock_resource,
 425                                           hash_node);
 426                         dlm_lockres_get(res);
 427                         /* migrate, if necessary.  this will drop the dlm
 428                          * spinlock and retake it if it does migration. */
 429                         dropped = dlm_empty_lockres(dlm, res);
 430
 431                         spin_lock(&res->spinlock);
 432                         if (dropped)
 433                                 __dlm_lockres_calc_usage(dlm, res);
 434                         else
 435                                 iter = res->hash_node.next;
 436                         spin_unlock(&res->spinlock);
 437
 438                         dlm_lockres_put(res);
 439
 440                         if (dropped) {
 441                                 cond_resched_lock(&dlm->spinlock);
 442                                 goto redo_bucket;
 443                         }
 444                 }
 445                 cond_resched_lock(&dlm->spinlock);
 446                 num += n;
 447         }
 448
 449         if (!num) {
 450                 if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 451                         mlog(0, "%s: perhaps there are more lock resources "
 452                              "need to be migrated after dlm recovery\n", dlm->name);
 453                         ret = -EAGAIN;
 454                 } else {
 455                         mlog(0, "%s: we won't do dlm recovery after migrating "
 456                              "all lock resources\n", dlm->name);
 457                         dlm->migrate_done = 1;
 458                 }
 459         }
 460
 461         spin_unlock(&dlm->spinlock);
 462         wake_up(&dlm->dlm_thread_wq);
 463
 464         /* let the dlm thread take care of purging, keep scanning until
 465          * nothing remains in the hash */
 466         if (num) {
 467                 mlog(0, "%s: %d lock resources in hash last pass\n",
 468                      dlm->name, num);
 469                 ret = -EAGAIN;
 470         }
 471         mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
 472         return ret;
 473 }
 474
 475 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
 476 {
 477         int ret;
 478
 479         spin_lock(&dlm->spinlock);
 480         ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
 481         spin_unlock(&dlm->spinlock);
 482
 483         return ret;
 484 }
 485
 486 static int dlm_begin_exit_domain_handler(struct o2net_msg *msg, u32 len,
 487                                          void *data, void **ret_data)
 488 {
 489         struct dlm_ctxt *dlm = data;
 490         unsigned int node;
 491         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 492
 493         if (!dlm_grab(dlm))
 494                 return 0;
 495
 496         node = exit_msg->node_idx;
 497         mlog(0, "%s: Node %u sent a begin exit domain message\n", dlm->name, node);
 498
 499         spin_lock(&dlm->spinlock);
 500         set_bit(node, dlm->exit_domain_map);
 501         spin_unlock(&dlm->spinlock);
 502
 503         dlm_put(dlm);
 504
 505         return 0;
 506 }
 507
 508 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
 509 {
 510         /* Yikes, a double spinlock! I need domain_lock for the dlm
 511          * state and the dlm spinlock for join state... Sorry! */
 512 again:
 513         spin_lock(&dlm_domain_lock);
 514         spin_lock(&dlm->spinlock);
 515
 516         if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 517                 mlog(0, "Node %d is joining, we wait on it.\n",
 518                           dlm->joining_node);
 519                 spin_unlock(&dlm->spinlock);
 520                 spin_unlock(&dlm_domain_lock);
 521
 522                 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
 523                 goto again;
 524         }
 525
 526         dlm->dlm_state = DLM_CTXT_LEAVING;
 527         spin_unlock(&dlm->spinlock);
 528         spin_unlock(&dlm_domain_lock);
 529 }
 530
 531 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
 532 {
 533         int node = -1, num = 0;
 534
 535         assert_spin_locked(&dlm->spinlock);
 536
 537         printk("( ");
 538         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 539                                      node + 1)) < O2NM_MAX_NODES) {
 540                 printk("%d ", node);
 541                 ++num;
 542         }
 543         printk(") %u nodes\n", num);
 544 }
 545
 546 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
 547                                    void **ret_data)
 548 {
 549         struct dlm_ctxt *dlm = data;
 550         unsigned int node;
 551         struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
 552
 553         mlog(0, "%p %u %p", msg, len, data);
 554
 555         if (!dlm_grab(dlm))
 556                 return 0;
 557
 558         node = exit_msg->node_idx;
 559
 560         spin_lock(&dlm->spinlock);
 561         clear_bit(node, dlm->domain_map);
 562         clear_bit(node, dlm->exit_domain_map);
 563         printk(KERN_NOTICE "o2dlm: Node %u leaves domain %s ", node, dlm->name);
 564         __dlm_print_nodes(dlm);
 565
 566         /* notify anything attached to the heartbeat events */
 567         dlm_hb_event_notify_attached(dlm, node, 0);
 568
 569         spin_unlock(&dlm->spinlock);
 570
 571         dlm_put(dlm);
 572
 573         return 0;
 574 }
 575
 576 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, u32 msg_type,
 577                                     unsigned int node)
 578 {
 579         int status;
 580         struct dlm_exit_domain leave_msg;
 581
 582         mlog(0, "%s: Sending domain exit message %u to node %u\n", dlm->name,
 583              msg_type, node);
 584
 585         memset(&leave_msg, 0, sizeof(leave_msg));
 586         leave_msg.node_idx = dlm->node_num;
 587
 588         status = o2net_send_message(msg_type, dlm->key, &leave_msg,
 589                                     sizeof(leave_msg), node, NULL);
 590         if (status < 0)
 591                 mlog(ML_ERROR, "Error %d sending domain exit message %u "
 592                      "to node %u on domain %s\n", status, msg_type, node,
 593                      dlm->name);
 594
 595         return status;
 596 }
 597
 598 static void dlm_begin_exit_domain(struct dlm_ctxt *dlm)
 599 {
 600         int node = -1;
 601
 602         /* Support for begin exit domain was added in 1.2 */
 603         if (dlm->dlm_locking_proto.pv_major == 1 &&
 604             dlm->dlm_locking_proto.pv_minor < 2)
 605                 return;
 606
 607         /*
 608          * Unlike DLM_EXIT_DOMAIN_MSG, DLM_BEGIN_EXIT_DOMAIN_MSG is purely
 609          * informational. Meaning if a node does not receive the message,
 610          * so be it.
 611          */
 612         spin_lock(&dlm->spinlock);
 613         while (1) {
 614                 node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, node + 1);
 615                 if (node >= O2NM_MAX_NODES)
 616                         break;
 617                 if (node == dlm->node_num)
 618                         continue;
 619
 620                 spin_unlock(&dlm->spinlock);
 621                 dlm_send_one_domain_exit(dlm, DLM_BEGIN_EXIT_DOMAIN_MSG, node);
 622                 spin_lock(&dlm->spinlock);
 623         }
 624         spin_unlock(&dlm->spinlock);
 625 }
 626
 627 static void dlm_leave_domain(struct dlm_ctxt *dlm)
 628 {
 629         int node, clear_node, status;
 630
 631         /* At this point we've migrated away all our locks and won't
 632          * accept mastership of new ones. The dlm is responsible for
 633          * almost nothing now. We make sure not to confuse any joining
 634          * nodes and then commence shutdown procedure. */
 635
 636         spin_lock(&dlm->spinlock);
 637         /* Clear ourselves from the domain map */
 638         clear_bit(dlm->node_num, dlm->domain_map);
 639         while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
 640                                      0)) < O2NM_MAX_NODES) {
 641                 /* Drop the dlm spinlock. This is safe wrt the domain_map.
 642                  * -nodes cannot be added now as the
 643                  *   query_join_handlers knows to respond with OK_NO_MAP
 644                  * -we catch the right network errors if a node is
 645                  *   removed from the map while we're sending him the
 646                  *   exit message. */
 647                 spin_unlock(&dlm->spinlock);
 648
 649                 clear_node = 1;
 650
 651                 status = dlm_send_one_domain_exit(dlm, DLM_EXIT_DOMAIN_MSG,
 652                                                   node);
 653                 if (status < 0 &&
 654                     status != -ENOPROTOOPT &&
 655                     status != -ENOTCONN) {
 656                         mlog(ML_NOTICE, "Error %d sending domain exit message "
 657                              "to node %d\n", status, node);
 658
 659                         /* Not sure what to do here but lets sleep for
 660                          * a bit in case this was a transient
 661                          * error... */
 662                         msleep(DLM_DOMAIN_BACKOFF_MS);
 663                         clear_node = 0;
 664                 }
 665
 666                 spin_lock(&dlm->spinlock);
 667                 /* If we're not clearing the node bit then we intend
 668                  * to loop back around to try again. */
 669                 if (clear_node)
 670                         clear_bit(node, dlm->domain_map);
 671         }
 672         spin_unlock(&dlm->spinlock);
 673 }
 674
 675 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 676 {
 677         int leave = 0;
 678         struct dlm_lock_resource *res;
 679
 680         spin_lock(&dlm_domain_lock);
 681         BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
 682         BUG_ON(!dlm->num_joins);
 683
 684         dlm->num_joins--;
 685         if (!dlm->num_joins) {
 686                 /* We mark it "in shutdown" now so new register
 687                  * requests wait until we've completely left the
 688                  * domain. Don't use DLM_CTXT_LEAVING yet as we still
 689                  * want new domain joins to communicate with us at
 690                  * least until we've completed migration of our
 691                  * resources. */
 692                 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
 693                 leave = 1;
 694         }
 695         spin_unlock(&dlm_domain_lock);
 696
 697         if (leave) {
 698                 mlog(0, "shutting down domain %s\n", dlm->name);
 699                 dlm_begin_exit_domain(dlm);
 700
 701                 /* We changed dlm state, notify the thread */
 702                 dlm_kick_thread(dlm, NULL);
 703
 704                 while (dlm_migrate_all_locks(dlm)) {
 705                         /* Give dlm_thread time to purge the lockres' */
 706                         msleep(500);
 707                         mlog(0, "%s: more migration to do\n", dlm->name);
 708                 }
 709
 710                 /* This list should be empty. If not, print remaining lockres */
 711                 if (!list_empty(&dlm->tracking_list)) {
 712                         mlog(ML_ERROR, "Following lockres' are still on the "
 713                              "tracking list:\n");
 714                         list_for_each_entry(res, &dlm->tracking_list, tracking)
 715                                 dlm_print_one_lock_resource(res);
 716                 }
 717
 718                 dlm_mark_domain_leaving(dlm);
 719                 dlm_leave_domain(dlm);
 720                 printk(KERN_NOTICE "o2dlm: Leaving domain %s\n", dlm->name);
 721                 dlm_force_free_mles(dlm);
 722                 dlm_complete_dlm_shutdown(dlm);
 723         }
 724         dlm_put(dlm);
 725 }
 726 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 727
 728 static int dlm_query_join_proto_check(char *proto_type, int node,
 729                                       struct dlm_protocol_version *ours,
 730                                       struct dlm_protocol_version *request)
 731 {
 732         int rc;
 733         struct dlm_protocol_version proto = *request;
 734
 735         if (!dlm_protocol_compare(ours, &proto)) {
 736                 mlog(0,
 737                      "node %u wanted to join with %s locking protocol "
 738                      "%u.%u, we respond with %u.%u\n",
 739                      node, proto_type,
 740                      request->pv_major,
 741                      request->pv_minor,
 742                      proto.pv_major, proto.pv_minor);
 743                 request->pv_minor = proto.pv_minor;
 744                 rc = 0;
 745         } else {
 746                 mlog(ML_NOTICE,
 747                      "Node %u wanted to join with %s locking "
 748                      "protocol %u.%u, but we have %u.%u, disallowing\n",
 749                      node, proto_type,
 750                      request->pv_major,
 751                      request->pv_minor,
 752                      ours->pv_major,
 753                      ours->pv_minor);
 754                 rc = 1;
 755         }
 756
 757         return rc;
 758 }
 759
 760 /*
 761  * struct dlm_query_join_packet is made up of four one-byte fields.  They
 762  * are effectively in big-endian order already.  However, little-endian
 763  * machines swap them before putting the packet on the wire (because
 764  * query_join's response is a status, and that status is treated as a u32
 765  * on the wire).  Thus, a big-endian and little-endian machines will treat
 766  * this structure differently.
 767  *
 768  * The solution is to have little-endian machines swap the structure when
 769  * converting from the structure to the u32 representation.  This will
 770  * result in the structure having the correct format on the wire no matter
 771  * the host endian format.
 772  */
 773 static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
 774                                           u32 *wire)
 775 {
 776         union dlm_query_join_response response;
 777
 778         response.packet = *packet;
 779         *wire = be32_to_cpu(response.intval);
 780 }
 781
 782 static void dlm_query_join_wire_to_packet(u32 wire,
 783                                           struct dlm_query_join_packet *packet)
 784 {
 785         union dlm_query_join_response response;
 786
 787         response.intval = cpu_to_be32(wire);
 788         *packet = response.packet;
 789 }
 790
 791 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
 792                                   void **ret_data)
 793 {
 794         struct dlm_query_join_request *query;
 795         struct dlm_query_join_packet packet = {
 796                 .code = JOIN_DISALLOW,
 797         };
 798         struct dlm_ctxt *dlm = NULL;
 799         u32 response;
 800         u8 nodenum;
 801
 802         query = (struct dlm_query_join_request *) msg->buf;
 803
 804         mlog(0, "node %u wants to join domain %s\n", query->node_idx,
 805                   query->domain);
 806
 807         /*
 808          * If heartbeat doesn't consider the node live, tell it
 809          * to back off and try again.  This gives heartbeat a chance
 810          * to catch up.
 811          */
 812         if (!o2hb_check_node_heartbeating_no_sem(query->node_idx)) {
 813                 mlog(0, "node %u is not in our live map yet\n",
 814                      query->node_idx);
 815
 816                 packet.code = JOIN_DISALLOW;
 817                 goto respond;
 818         }
 819
 820         packet.code = JOIN_OK_NO_MAP;
 821
 822         spin_lock(&dlm_domain_lock);
 823         dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 824         if (!dlm)
 825                 goto unlock_respond;
 826
 827         /*
 828          * There is a small window where the joining node may not see the
 829          * node(s) that just left but still part of the cluster. DISALLOW
 830          * join request if joining node has different node map.
 831          */
 832         nodenum=0;
 833         while (nodenum < O2NM_MAX_NODES) {
 834                 if (test_bit(nodenum, dlm->domain_map)) {
 835                         if (!byte_test_bit(nodenum, query->node_map)) {
 836                                 mlog(0, "disallow join as node %u does not "
 837                                      "have node %u in its nodemap\n",
 838                                      query->node_idx, nodenum);
 839                                 packet.code = JOIN_DISALLOW;
 840                                 goto unlock_respond;
 841                         }
 842                 }
 843                 nodenum++;
 844         }
 845
 846         /* Once the dlm ctxt is marked as leaving then we don't want
 847          * to be put in someone's domain map.
 848          * Also, explicitly disallow joining at certain troublesome
 849          * times (ie. during recovery). */
 850         if (dlm->dlm_state != DLM_CTXT_LEAVING) {
 851                 int bit = query->node_idx;
 852                 spin_lock(&dlm->spinlock);
 853
 854                 if (dlm->dlm_state == DLM_CTXT_NEW &&
 855                     dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
 856                         /*If this is a brand new context and we
 857                          * haven't started our join process yet, then
 858                          * the other node won the race. */
 859                         packet.code = JOIN_OK_NO_MAP;
 860                 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 861                         /* Disallow parallel joins. */
 862                         packet.code = JOIN_DISALLOW;
 863                 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 864                         mlog(0, "node %u trying to join, but recovery "
 865                              "is ongoing.\n", bit);
 866                         packet.code = JOIN_DISALLOW;
 867                 } else if (test_bit(bit, dlm->recovery_map)) {
 868                         mlog(0, "node %u trying to join, but it "
 869                              "still needs recovery.\n", bit);
 870                         packet.code = JOIN_DISALLOW;
 871                 } else if (test_bit(bit, dlm->domain_map)) {
 872                         mlog(0, "node %u trying to join, but it "
 873                              "is still in the domain! needs recovery?\n",
 874                              bit);
 875                         packet.code = JOIN_DISALLOW;
 876                 } else {
 877                         /* Alright we're fully a part of this domain
 878                          * so we keep some state as to who's joining
 879                          * and indicate to him that needs to be fixed
 880                          * up. */
 881
 882                         /* Make sure we speak compatible locking protocols.  */
 883                         if (dlm_query_join_proto_check("DLM", bit,
 884                                                        &dlm->dlm_locking_proto,
 885                                                        &query->dlm_proto)) {
 886                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 887                         } else if (dlm_query_join_proto_check("fs", bit,
 888                                                               &dlm->fs_locking_proto,
 889                                                               &query->fs_proto)) {
 890                                 packet.code = JOIN_PROTOCOL_MISMATCH;
 891                         } else {
 892                                 packet.dlm_minor = query->dlm_proto.pv_minor;
 893                                 packet.fs_minor = query->fs_proto.pv_minor;
 894                                 packet.code = JOIN_OK;
 895                                 __dlm_set_joining_node(dlm, query->node_idx);
 896                         }
 897                 }
 898
 899                 spin_unlock(&dlm->spinlock);
 900         }
 901 unlock_respond:
 902         spin_unlock(&dlm_domain_lock);
 903
 904 respond:
 905         mlog(0, "We respond with %u\n", packet.code);
 906
 907         dlm_query_join_packet_to_wire(&packet, &response);
 908         return response;
 909 }
 910
 911 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
 912                                      void **ret_data)
 913 {
 914         struct dlm_assert_joined *assert;
 915         struct dlm_ctxt *dlm = NULL;
 916
 917         assert = (struct dlm_assert_joined *) msg->buf;
 918
 919         mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
 920                   assert->domain);
 921
 922         spin_lock(&dlm_domain_lock);
 923         dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
 924         /* XXX should we consider no dlm ctxt an error? */
 925         if (dlm) {
 926                 spin_lock(&dlm->spinlock);
 927
 928                 /* Alright, this node has officially joined our
 929                  * domain. Set him in the map and clean up our
 930                  * leftover join state. */
 931                 BUG_ON(dlm->joining_node != assert->node_idx);
 932
 933                 if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
 934                         mlog(0, "dlm recovery is ongoing, disallow join\n");
 935                         spin_unlock(&dlm->spinlock);
 936                         spin_unlock(&dlm_domain_lock);
 937                         return -EAGAIN;
 938                 }
 939
 940                 set_bit(assert->node_idx, dlm->domain_map);
 941                 clear_bit(assert->node_idx, dlm->exit_domain_map);
 942                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
 943
 944                 printk(KERN_NOTICE "o2dlm: Node %u joins domain %s ",
 945                        assert->node_idx, dlm->name);
 946                 __dlm_print_nodes(dlm);
 947
 948                 /* notify anything attached to the heartbeat events */
 949                 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
 950
 951                 spin_unlock(&dlm->spinlock);
 952         }
 953         spin_unlock(&dlm_domain_lock);
 954
 955         return 0;
 956 }
 957
 958 static int dlm_match_regions(struct dlm_ctxt *dlm,
 959                              struct dlm_query_region *qr,
 960                              char *local, int locallen)
 961 {
 962         char *remote = qr->qr_regions;
 963         char *l, *r;
 964         int localnr, i, j, foundit;
 965         int status = 0;
 966
 967         if (!o2hb_global_heartbeat_active()) {
 968                 if (qr->qr_numregions) {
 969                         mlog(ML_ERROR, "Domain %s: Joining node %d has global "
 970                              "heartbeat enabled but local node %d does not\n",
 971                              qr->qr_domain, qr->qr_node, dlm->node_num);
 972                         status = -EINVAL;
 973                 }
 974                 goto bail;
 975         }
 976
 977         if (o2hb_global_heartbeat_active() && !qr->qr_numregions) {
 978                 mlog(ML_ERROR, "Domain %s: Local node %d has global "
 979                      "heartbeat enabled but joining node %d does not\n",
 980                      qr->qr_domain, dlm->node_num, qr->qr_node);
 981                 status = -EINVAL;
 982                 goto bail;
 983         }
 984
 985         r = remote;
 986         for (i = 0; i < qr->qr_numregions; ++i) {
 987                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, r);
 988                 r += O2HB_MAX_REGION_NAME_LEN;
 989         }
 990
 991         localnr = min(O2NM_MAX_REGIONS, locallen/O2HB_MAX_REGION_NAME_LEN);
 992         localnr = o2hb_get_all_regions(local, (u8)localnr);
 993
 994         /* compare local regions with remote */
 995         l = local;
 996         for (i = 0; i < localnr; ++i) {
 997                 foundit = 0;
 998                 r = remote;
 999                 for (j = 0; j <= qr->qr_numregions; ++j) {
1000                         if (!memcmp(l, r, O2HB_MAX_REGION_NAME_LEN)) {
1001                                 foundit = 1;
1002                                 break;
1003                         }
1004                         r += O2HB_MAX_REGION_NAME_LEN;
1005                 }
1006                 if (!foundit) {
1007                         status = -EINVAL;
1008                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1009                              "in local node %d but not in joining node %d\n",
1010                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, l,
1011                              dlm->node_num, qr->qr_node);
1012                         goto bail;
1013                 }
1014                 l += O2HB_MAX_REGION_NAME_LEN;
1015         }
1016
1017         /* compare remote with local regions */
1018         r = remote;
1019         for (i = 0; i < qr->qr_numregions; ++i) {
1020                 foundit = 0;
1021                 l = local;
1022                 for (j = 0; j < localnr; ++j) {
1023                         if (!memcmp(r, l, O2HB_MAX_REGION_NAME_LEN)) {
1024                                 foundit = 1;
1025                                 break;
1026                         }
1027                         l += O2HB_MAX_REGION_NAME_LEN;
1028                 }
1029                 if (!foundit) {
1030                         status = -EINVAL;
1031                         mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1032                              "in joining node %d but not in local node %d\n",
1033                              qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, r,
1034                              qr->qr_node, dlm->node_num);
1035                         goto bail;
1036                 }
1037                 r += O2HB_MAX_REGION_NAME_LEN;
1038         }
1039
1040 bail:
1041         return status;
1042 }
1043
1044 static int dlm_send_regions(struct dlm_ctxt *dlm, unsigned long *node_map)
1045 {
1046         struct dlm_query_region *qr = NULL;
1047         int status, ret = 0, i;
1048         char *p;
1049
1050         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1051                 goto bail;
1052
1053         qr = kzalloc(sizeof(struct dlm_query_region), GFP_KERNEL);
1054         if (!qr) {
1055                 ret = -ENOMEM;
1056                 mlog_errno(ret);
1057                 goto bail;
1058         }
1059
1060         qr->qr_node = dlm->node_num;
1061         qr->qr_namelen = strlen(dlm->name);
1062         memcpy(qr->qr_domain, dlm->name, qr->qr_namelen);
1063         /* if local hb, the numregions will be zero */
1064         if (o2hb_global_heartbeat_active())
1065                 qr->qr_numregions = o2hb_get_all_regions(qr->qr_regions,
1066                                                          O2NM_MAX_REGIONS);
1067
1068         p = qr->qr_regions;
1069         for (i = 0; i < qr->qr_numregions; ++i, p += O2HB_MAX_REGION_NAME_LEN)
1070                 mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, p);
1071
1072         i = -1;
1073         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1074                                   i + 1)) < O2NM_MAX_NODES) {
1075                 if (i == dlm->node_num)
1076                         continue;
1077
1078                 mlog(0, "Sending regions to node %d\n", i);
1079
1080                 ret = o2net_send_message(DLM_QUERY_REGION, DLM_MOD_KEY, qr,
1081                                          sizeof(struct dlm_query_region),
1082                                          i, &status);
1083                 if (ret >= 0)
1084                         ret = status;
1085                 if (ret) {
1086                         mlog(ML_ERROR, "Region mismatch %d, node %d\n",
1087                              ret, i);
1088                         break;
1089                 }
1090         }
1091
1092 bail:
1093         kfree(qr);
1094         return ret;
1095 }
1096
1097 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
1098                                     void *data, void **ret_data)
1099 {
1100         struct dlm_query_region *qr;
1101         struct dlm_ctxt *dlm = NULL;
1102         char *local = NULL;
1103         int status = 0;
1104
1105         qr = (struct dlm_query_region *) msg->buf;
1106
1107         mlog(0, "Node %u queries hb regions on domain %s\n", qr->qr_node,
1108              qr->qr_domain);
1109
1110         /* buffer used in dlm_mast_regions() */
1111         local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
1112         if (!local)
1113                 return -ENOMEM;
1114
1115         status = -EINVAL;
1116
1117         spin_lock(&dlm_domain_lock);
1118         dlm = __dlm_lookup_domain_full(qr->qr_domain, qr->qr_namelen);
1119         if (!dlm) {
1120                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1121                      "before join domain\n", qr->qr_node, qr->qr_domain);
1122                 goto out_domain_lock;
1123         }
1124
1125         spin_lock(&dlm->spinlock);
1126         if (dlm->joining_node != qr->qr_node) {
1127                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1128                      "but joining node is %d\n", qr->qr_node, qr->qr_domain,
1129                      dlm->joining_node);
1130                 goto out_dlm_lock;
1131         }
1132
1133         /* Support for global heartbeat was added in 1.1 */
1134         if (dlm->dlm_locking_proto.pv_major == 1 &&
1135             dlm->dlm_locking_proto.pv_minor == 0) {
1136                 mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1137                      "but active dlm protocol is %d.%d\n", qr->qr_node,
1138                      qr->qr_domain, dlm->dlm_locking_proto.pv_major,
1139                      dlm->dlm_locking_proto.pv_minor);
1140                 goto out_dlm_lock;
1141         }
1142
1143         status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
1144
1145 out_dlm_lock:
1146         spin_unlock(&dlm->spinlock);
1147
1148 out_domain_lock:
1149         spin_unlock(&dlm_domain_lock);
1150
1151         kfree(local);
1152
1153         return status;
1154 }
1155
1156 static int dlm_match_nodes(struct dlm_ctxt *dlm, struct dlm_query_nodeinfo *qn)
1157 {
1158         struct o2nm_node *local;
1159         struct dlm_node_info *remote;
1160         int i, j;
1161         int status = 0;
1162
1163         for (j = 0; j < qn->qn_numnodes; ++j)
1164                 mlog(0, "Node %3d, %pI4:%u\n", qn->qn_nodes[j].ni_nodenum,
1165                      &(qn->qn_nodes[j].ni_ipv4_address),
1166                      ntohs(qn->qn_nodes[j].ni_ipv4_port));
1167
1168         for (i = 0; i < O2NM_MAX_NODES && !status; ++i) {
1169                 local = o2nm_get_node_by_num(i);
1170                 remote = NULL;
1171                 for (j = 0; j < qn->qn_numnodes; ++j) {
1172                         if (qn->qn_nodes[j].ni_nodenum == i) {
1173                                 remote = &(qn->qn_nodes[j]);
1174                                 break;
1175                         }
1176                 }
1177
1178                 if (!local && !remote)
1179                         continue;
1180
1181                 if ((local && !remote) || (!local && remote))
1182                         status = -EINVAL;
1183
1184                 if (!status &&
1185                     ((remote->ni_nodenum != local->nd_num) ||
1186                      (remote->ni_ipv4_port != local->nd_ipv4_port) ||
1187                      (remote->ni_ipv4_address != local->nd_ipv4_address)))
1188                         status = -EINVAL;
1189
1190                 if (status) {
1191                         if (remote && !local)
1192                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1193                                      "registered in joining node %d but not in "
1194                                      "local node %d\n", qn->qn_domain,
1195                                      remote->ni_nodenum,
1196                                      &(remote->ni_ipv4_address),
1197                                      ntohs(remote->ni_ipv4_port),
1198                                      qn->qn_nodenum, dlm->node_num);
1199                         if (local && !remote)
1200                                 mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1201                                      "registered in local node %d but not in "
1202                                      "joining node %d\n", qn->qn_domain,
1203                                      local->nd_num, &(local->nd_ipv4_address),
1204                                      ntohs(local->nd_ipv4_port),
1205                                      dlm->node_num, qn->qn_nodenum);
1206                         BUG_ON((!local && !remote));
1207                 }
1208
1209                 if (local)
1210                         o2nm_node_put(local);
1211         }
1212
1213         return status;
1214 }
1215
1216 static int dlm_send_nodeinfo(struct dlm_ctxt *dlm, unsigned long *node_map)
1217 {
1218         struct dlm_query_nodeinfo *qn = NULL;
1219         struct o2nm_node *node;
1220         int ret = 0, status, count, i;
1221
1222         if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1223                 goto bail;
1224
1225         qn = kzalloc(sizeof(struct dlm_query_nodeinfo), GFP_KERNEL);
1226         if (!qn) {
1227                 ret = -ENOMEM;
1228                 mlog_errno(ret);
1229                 goto bail;
1230         }
1231
1232         for (i = 0, count = 0; i < O2NM_MAX_NODES; ++i) {
1233                 node = o2nm_get_node_by_num(i);
1234                 if (!node)
1235                         continue;
1236                 qn->qn_nodes[count].ni_nodenum = node->nd_num;
1237                 qn->qn_nodes[count].ni_ipv4_port = node->nd_ipv4_port;
1238                 qn->qn_nodes[count].ni_ipv4_address = node->nd_ipv4_address;
1239                 mlog(0, "Node %3d, %pI4:%u\n", node->nd_num,
1240                      &(node->nd_ipv4_address), ntohs(node->nd_ipv4_port));
1241                 ++count;
1242                 o2nm_node_put(node);
1243         }
1244
1245         qn->qn_nodenum = dlm->node_num;
1246         qn->qn_numnodes = count;
1247         qn->qn_namelen = strlen(dlm->name);
1248         memcpy(qn->qn_domain, dlm->name, qn->qn_namelen);
1249
1250         i = -1;
1251         while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1252                                   i + 1)) < O2NM_MAX_NODES) {
1253                 if (i == dlm->node_num)
1254                         continue;
1255
1256                 mlog(0, "Sending nodeinfo to node %d\n", i);
1257
1258                 ret = o2net_send_message(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
1259                                          qn, sizeof(struct dlm_query_nodeinfo),
1260                                          i, &status);
1261                 if (ret >= 0)
1262                         ret = status;
1263                 if (ret) {
1264                         mlog(ML_ERROR, "node mismatch %d, node %d\n", ret, i);
1265                         break;
1266                 }
1267         }
1268
1269 bail:
1270         kfree(qn);
1271         return ret;
1272 }
1273
1274 static int dlm_query_nodeinfo_handler(struct o2net_msg *msg, u32 len,
1275                                       void *data, void **ret_data)
1276 {
1277         struct dlm_query_nodeinfo *qn;
1278         struct dlm_ctxt *dlm = NULL;
1279         int locked = 0, status = -EINVAL;
1280
1281         qn = (struct dlm_query_nodeinfo *) msg->buf;
1282
1283         mlog(0, "Node %u queries nodes on domain %s\n", qn->qn_nodenum,
1284              qn->qn_domain);
1285
1286         spin_lock(&dlm_domain_lock);
1287         dlm = __dlm_lookup_domain_full(qn->qn_domain, qn->qn_namelen);
1288         if (!dlm) {
1289                 mlog(ML_ERROR, "Node %d queried nodes on domain %s before "
1290                      "join domain\n", qn->qn_nodenum, qn->qn_domain);
1291                 goto bail;
1292         }
1293
1294         spin_lock(&dlm->spinlock);
1295         locked = 1;
1296         if (dlm->joining_node != qn->qn_nodenum) {
1297                 mlog(ML_ERROR, "Node %d queried nodes on domain %s but "
1298                      "joining node is %d\n", qn->qn_nodenum, qn->qn_domain,
1299                      dlm->joining_node);
1300                 goto bail;
1301         }
1302
1303         /* Support for node query was added in 1.1 */
1304         if (dlm->dlm_locking_proto.pv_major == 1 &&
1305             dlm->dlm_locking_proto.pv_minor == 0) {
1306                 mlog(ML_ERROR, "Node %d queried nodes on domain %s "
1307                      "but active dlm protocol is %d.%d\n", qn->qn_nodenum,
1308                      qn->qn_domain, dlm->dlm_locking_proto.pv_major,
1309                      dlm->dlm_locking_proto.pv_minor);
1310                 goto bail;
1311         }
1312
1313         status = dlm_match_nodes(dlm, qn);
1314
1315 bail:
1316         if (locked)
1317                 spin_unlock(&dlm->spinlock);
1318         spin_unlock(&dlm_domain_lock);
1319
1320         return status;
1321 }
1322
1323 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
1324                                    void **ret_data)
1325 {
1326         struct dlm_cancel_join *cancel;
1327         struct dlm_ctxt *dlm = NULL;
1328
1329         cancel = (struct dlm_cancel_join *) msg->buf;
1330
1331         mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
1332                   cancel->domain);
1333
1334         spin_lock(&dlm_domain_lock);
1335         dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
1336
1337         if (dlm) {
1338                 spin_lock(&dlm->spinlock);
1339
1340                 /* Yikes, this guy wants to cancel his join. No
1341                  * problem, we simply cleanup our join state. */
1342                 BUG_ON(dlm->joining_node != cancel->node_idx);
1343                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1344
1345                 spin_unlock(&dlm->spinlock);
1346         }
1347         spin_unlock(&dlm_domain_lock);
1348
1349         return 0;
1350 }
1351
1352 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
1353                                     unsigned int node)
1354 {
1355         int status;
1356         struct dlm_cancel_join cancel_msg;
1357
1358         memset(&cancel_msg, 0, sizeof(cancel_msg));
1359         cancel_msg.node_idx = dlm->node_num;
1360         cancel_msg.name_len = strlen(dlm->name);
1361         memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
1362
1363         status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1364                                     &cancel_msg, sizeof(cancel_msg), node,
1365                                     NULL);
1366         if (status < 0) {
1367                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1368                      "node %u\n", status, DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1369                      node);
1370                 goto bail;
1371         }
1372
1373 bail:
1374         return status;
1375 }
1376
1377 /* map_size should be in bytes. */
1378 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
1379                                  unsigned long *node_map,
1380                                  unsigned int map_size)
1381 {
1382         int status, tmpstat;
1383         int node;
1384
1385         if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
1386                          sizeof(unsigned long))) {
1387                 mlog(ML_ERROR,
1388                      "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
1389                      map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
1390                 return -EINVAL;
1391         }
1392
1393         status = 0;
1394         node = -1;
1395         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1396                                      node + 1)) < O2NM_MAX_NODES) {
1397                 if (node == dlm->node_num)
1398                         continue;
1399
1400                 tmpstat = dlm_send_one_join_cancel(dlm, node);
1401                 if (tmpstat) {
1402                         mlog(ML_ERROR, "Error return %d cancelling join on "
1403                              "node %d\n", tmpstat, node);
1404                         if (!status)
1405                                 status = tmpstat;
1406                 }
1407         }
1408
1409         if (status)
1410                 mlog_errno(status);
1411         return status;
1412 }
1413
1414 static int dlm_request_join(struct dlm_ctxt *dlm,
1415                             int node,
1416                             enum dlm_query_join_response_code *response)
1417 {
1418         int status;
1419         struct dlm_query_join_request join_msg;
1420         struct dlm_query_join_packet packet;
1421         u32 join_resp;
1422
1423         mlog(0, "querying node %d\n", node);
1424
1425         memset(&join_msg, 0, sizeof(join_msg));
1426         join_msg.node_idx = dlm->node_num;
1427         join_msg.name_len = strlen(dlm->name);
1428         memcpy(join_msg.domain, dlm->name, join_msg.name_len);
1429         join_msg.dlm_proto = dlm->dlm_locking_proto;
1430         join_msg.fs_proto = dlm->fs_locking_proto;
1431
1432         /* copy live node map to join message */
1433         byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
1434
1435         status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
1436                                     sizeof(join_msg), node, &join_resp);
1437         if (status < 0 && status != -ENOPROTOOPT) {
1438                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1439                      "node %u\n", status, DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1440                      node);
1441                 goto bail;
1442         }
1443         dlm_query_join_wire_to_packet(join_resp, &packet);
1444
1445         /* -ENOPROTOOPT from the net code means the other side isn't
1446             listening for our message type -- that's fine, it means
1447             his dlm isn't up, so we can consider him a 'yes' but not
1448             joined into the domain.  */
1449         if (status == -ENOPROTOOPT) {
1450                 status = 0;
1451                 *response = JOIN_OK_NO_MAP;
1452         } else {
1453                 *response = packet.code;
1454                 switch (packet.code) {
1455                 case JOIN_DISALLOW:
1456                 case JOIN_OK_NO_MAP:
1457                         break;
1458                 case JOIN_PROTOCOL_MISMATCH:
1459                         mlog(ML_NOTICE,
1460                              "This node requested DLM locking protocol %u.%u and "
1461                              "filesystem locking protocol %u.%u.  At least one of "
1462                              "the protocol versions on node %d is not compatible, "
1463                              "disconnecting\n",
1464                              dlm->dlm_locking_proto.pv_major,
1465                              dlm->dlm_locking_proto.pv_minor,
1466                              dlm->fs_locking_proto.pv_major,
1467                              dlm->fs_locking_proto.pv_minor,
1468                              node);
1469                         status = -EPROTO;
1470                         break;
1471                 case JOIN_OK:
1472                         /* Use the same locking protocol as the remote node */
1473                         dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
1474                         dlm->fs_locking_proto.pv_minor = packet.fs_minor;
1475                         mlog(0,
1476                              "Node %d responds JOIN_OK with DLM locking protocol "
1477                              "%u.%u and fs locking protocol %u.%u\n",
1478                              node,
1479                              dlm->dlm_locking_proto.pv_major,
1480                              dlm->dlm_locking_proto.pv_minor,
1481                              dlm->fs_locking_proto.pv_major,
1482                              dlm->fs_locking_proto.pv_minor);
1483                         break;
1484                 default:
1485                         status = -EINVAL;
1486                         mlog(ML_ERROR, "invalid response %d from node %u\n",
1487                              packet.code, node);
1488                         /* Reset response to JOIN_DISALLOW */
1489                         *response = JOIN_DISALLOW;
1490                         break;
1491                 }
1492         }
1493
1494         mlog(0, "status %d, node %d response is %d\n", status, node,
1495              *response);
1496
1497 bail:
1498         return status;
1499 }
1500
1501 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
1502                                     unsigned int node)
1503 {
1504         int status;
1505         int ret;
1506         struct dlm_assert_joined assert_msg;
1507
1508         mlog(0, "Sending join assert to node %u\n", node);
1509
1510         memset(&assert_msg, 0, sizeof(assert_msg));
1511         assert_msg.node_idx = dlm->node_num;
1512         assert_msg.name_len = strlen(dlm->name);
1513         memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
1514
1515         status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1516                                     &assert_msg, sizeof(assert_msg), node,
1517                                     &ret);
1518         if (status < 0)
1519                 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1520                      "node %u\n", status, DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1521                      node);
1522         else
1523                 status = ret;
1524
1525         return status;
1526 }
1527
1528 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
1529                                   unsigned long *node_map)
1530 {
1531         int status, node, live;
1532
1533         status = 0;
1534         node = -1;
1535         while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1536                                      node + 1)) < O2NM_MAX_NODES) {
1537                 if (node == dlm->node_num)
1538                         continue;
1539
1540                 do {
1541                         /* It is very important that this message be
1542                          * received so we spin until either the node
1543                          * has died or it gets the message. */
1544                         status = dlm_send_one_join_assert(dlm, node);
1545
1546                         spin_lock(&dlm->spinlock);
1547                         live = test_bit(node, dlm->live_nodes_map);
1548                         spin_unlock(&dlm->spinlock);
1549
1550                         if (status) {
1551                                 mlog(ML_ERROR, "Error return %d asserting "
1552                                      "join on node %d\n", status, node);
1553
1554                                 /* give us some time between errors... */
1555                                 if (live)
1556                                         msleep(DLM_DOMAIN_BACKOFF_MS);
1557                         }
1558                 } while (status && live);
1559         }
1560 }
1561
1562 struct domain_join_ctxt {
1563         unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1564         unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1565 };
1566
1567 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
1568                                    struct domain_join_ctxt *ctxt,
1569                                    enum dlm_query_join_response_code response)
1570 {
1571         int ret;
1572
1573         if (response == JOIN_DISALLOW) {
1574                 mlog(0, "Latest response of disallow -- should restart\n");
1575                 return 1;
1576         }
1577
1578         spin_lock(&dlm->spinlock);
1579         /* For now, we restart the process if the node maps have
1580          * changed at all */
1581         ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
1582                      sizeof(dlm->live_nodes_map));
1583         spin_unlock(&dlm->spinlock);
1584
1585         if (ret)
1586                 mlog(0, "Node maps changed -- should restart\n");
1587
1588         return ret;
1589 }
1590
1591 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
1592 {
1593         int status = 0, tmpstat, node;
1594         struct domain_join_ctxt *ctxt;
1595         enum dlm_query_join_response_code response = JOIN_DISALLOW;
1596
1597         mlog(0, "%p", dlm);
1598
1599         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
1600         if (!ctxt) {
1601                 status = -ENOMEM;
1602                 mlog_errno(status);
1603                 goto bail;
1604         }
1605
1606         /* group sem locking should work for us here -- we're already
1607          * registered for heartbeat events so filling this should be
1608          * atomic wrt getting those handlers called. */
1609         o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
1610
1611         spin_lock(&dlm->spinlock);
1612         memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
1613
1614         __dlm_set_joining_node(dlm, dlm->node_num);
1615
1616         spin_unlock(&dlm->spinlock);
1617
1618         node = -1;
1619         while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
1620                                      node + 1)) < O2NM_MAX_NODES) {
1621                 if (node == dlm->node_num)
1622                         continue;
1623
1624                 status = dlm_request_join(dlm, node, &response);
1625                 if (status < 0) {
1626                         mlog_errno(status);
1627                         goto bail;
1628                 }
1629
1630                 /* Ok, either we got a response or the node doesn't have a
1631                  * dlm up. */
1632                 if (response == JOIN_OK)
1633                         set_bit(node, ctxt->yes_resp_map);
1634
1635                 if (dlm_should_restart_join(dlm, ctxt, response)) {
1636                         status = -EAGAIN;
1637                         goto bail;
1638                 }
1639         }
1640
1641         mlog(0, "Yay, done querying nodes!\n");
1642
1643         /* Yay, everyone agree's we can join the domain. My domain is
1644          * comprised of all nodes who were put in the
1645          * yes_resp_map. Copy that into our domain map and send a join
1646          * assert message to clean up everyone elses state. */
1647         spin_lock(&dlm->spinlock);
1648         memcpy(dlm->domain_map, ctxt->yes_resp_map,
1649                sizeof(ctxt->yes_resp_map));
1650         set_bit(dlm->node_num, dlm->domain_map);
1651         spin_unlock(&dlm->spinlock);
1652
1653         /* Support for global heartbeat and node info was added in 1.1 */
1654         if (dlm->dlm_locking_proto.pv_major > 1 ||
1655             dlm->dlm_locking_proto.pv_minor > 0) {
1656                 status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
1657                 if (status) {
1658                         mlog_errno(status);
1659                         goto bail;
1660                 }
1661                 status = dlm_send_regions(dlm, ctxt->yes_resp_map);
1662                 if (status) {
1663                         mlog_errno(status);
1664                         goto bail;
1665                 }
1666         }
1667
1668         dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
1669
1670         /* Joined state *must* be set before the joining node
1671          * information, otherwise the query_join handler may read no
1672          * current joiner but a state of NEW and tell joining nodes
1673          * we're not in the domain. */
1674         spin_lock(&dlm_domain_lock);
1675         dlm->dlm_state = DLM_CTXT_JOINED;
1676         dlm->num_joins++;
1677         spin_unlock(&dlm_domain_lock);
1678
1679 bail:
1680         spin_lock(&dlm->spinlock);
1681         __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1682         if (!status) {
1683                 printk(KERN_NOTICE "o2dlm: Joining domain %s ", dlm->name);
1684                 __dlm_print_nodes(dlm);
1685         }
1686         spin_unlock(&dlm->spinlock);
1687
1688         if (ctxt) {
1689                 /* Do we need to send a cancel message to any nodes? */
1690                 if (status < 0) {
1691                         tmpstat = dlm_send_join_cancels(dlm,
1692                                                         ctxt->yes_resp_map,
1693                                                         sizeof(ctxt->yes_resp_map));
1694                         if (tmpstat < 0)
1695                                 mlog_errno(tmpstat);
1696                 }
1697                 kfree(ctxt);
1698         }
1699
1700         mlog(0, "returning %d\n", status);
1701         return status;
1702 }
1703
1704 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1705 {
1706         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_up);
1707         o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_down);
1708         o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1709 }
1710
1711 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1712 {
1713         int status;
1714
1715         mlog(0, "registering handlers.\n");
1716
1717         o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1718                             dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1719         o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1720                             dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1721
1722         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
1723         if (status)
1724                 goto bail;
1725
1726         status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
1727         if (status)
1728                 goto bail;
1729
1730         status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1731                                         sizeof(struct dlm_master_request),
1732                                         dlm_master_request_handler,
1733                                         dlm, NULL, &dlm->dlm_domain_handlers);
1734         if (status)
1735                 goto bail;
1736
1737         status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1738                                         sizeof(struct dlm_assert_master),
1739                                         dlm_assert_master_handler,
1740                                         dlm, dlm_assert_master_post_handler,
1741                                         &dlm->dlm_domain_handlers);
1742         if (status)
1743                 goto bail;
1744
1745         status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1746                                         sizeof(struct dlm_create_lock),
1747                                         dlm_create_lock_handler,
1748                                         dlm, NULL, &dlm->dlm_domain_handlers);
1749         if (status)
1750                 goto bail;
1751
1752         status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1753                                         DLM_CONVERT_LOCK_MAX_LEN,
1754                                         dlm_convert_lock_handler,
1755                                         dlm, NULL, &dlm->dlm_domain_handlers);
1756         if (status)
1757                 goto bail;
1758
1759         status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1760                                         DLM_UNLOCK_LOCK_MAX_LEN,
1761                                         dlm_unlock_lock_handler,
1762                                         dlm, NULL, &dlm->dlm_domain_handlers);
1763         if (status)
1764                 goto bail;
1765
1766         status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1767                                         DLM_PROXY_AST_MAX_LEN,
1768                                         dlm_proxy_ast_handler,
1769                                         dlm, NULL, &dlm->dlm_domain_handlers);
1770         if (status)
1771                 goto bail;
1772
1773         status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1774                                         sizeof(struct dlm_exit_domain),
1775                                         dlm_exit_domain_handler,
1776                                         dlm, NULL, &dlm->dlm_domain_handlers);
1777         if (status)
1778                 goto bail;
1779
1780         status = o2net_register_handler(DLM_DEREF_LOCKRES_MSG, dlm->key,
1781                                         sizeof(struct dlm_deref_lockres),
1782                                         dlm_deref_lockres_handler,
1783                                         dlm, NULL, &dlm->dlm_domain_handlers);
1784         if (status)
1785                 goto bail;
1786
1787         status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1788                                         sizeof(struct dlm_migrate_request),
1789                                         dlm_migrate_request_handler,
1790                                         dlm, NULL, &dlm->dlm_domain_handlers);
1791         if (status)
1792                 goto bail;
1793
1794         status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1795                                         DLM_MIG_LOCKRES_MAX_LEN,
1796                                         dlm_mig_lockres_handler,
1797                                         dlm, NULL, &dlm->dlm_domain_handlers);
1798         if (status)
1799                 goto bail;
1800
1801         status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1802                                         sizeof(struct dlm_master_requery),
1803                                         dlm_master_requery_handler,
1804                                         dlm, NULL, &dlm->dlm_domain_handlers);
1805         if (status)
1806                 goto bail;
1807
1808         status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1809                                         sizeof(struct dlm_lock_request),
1810                                         dlm_request_all_locks_handler,
1811                                         dlm, NULL, &dlm->dlm_domain_handlers);
1812         if (status)
1813                 goto bail;
1814
1815         status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1816                                         sizeof(struct dlm_reco_data_done),
1817                                         dlm_reco_data_done_handler,
1818                                         dlm, NULL, &dlm->dlm_domain_handlers);
1819         if (status)
1820                 goto bail;
1821
1822         status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1823                                         sizeof(struct dlm_begin_reco),
1824                                         dlm_begin_reco_handler,
1825                                         dlm, NULL, &dlm->dlm_domain_handlers);
1826         if (status)
1827                 goto bail;
1828
1829         status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1830                                         sizeof(struct dlm_finalize_reco),
1831                                         dlm_finalize_reco_handler,
1832                                         dlm, NULL, &dlm->dlm_domain_handlers);
1833         if (status)
1834                 goto bail;
1835
1836         status = o2net_register_handler(DLM_BEGIN_EXIT_DOMAIN_MSG, dlm->key,
1837                                         sizeof(struct dlm_exit_domain),
1838                                         dlm_begin_exit_domain_handler,
1839                                         dlm, NULL, &dlm->dlm_domain_handlers);
1840         if (status)
1841                 goto bail;
1842
1843         status = o2net_register_handler(DLM_DEREF_LOCKRES_DONE, dlm->key,
1844                                         sizeof(struct dlm_deref_lockres_done),
1845                                         dlm_deref_lockres_done_handler,
1846                                         dlm, NULL, &dlm->dlm_domain_handlers);
1847 bail:
1848         if (status)
1849                 dlm_unregister_domain_handlers(dlm);
1850
1851         return status;
1852 }
1853
1854 static int dlm_join_domain(struct dlm_ctxt *dlm)
1855 {
1856         int status;
1857         unsigned int backoff;
1858         unsigned int total_backoff = 0;
1859         char wq_name[O2NM_MAX_NAME_LEN];
1860
1861         BUG_ON(!dlm);
1862
1863         mlog(0, "Join domain %s\n", dlm->name);
1864
1865         status = dlm_register_domain_handlers(dlm);
1866         if (status) {
1867                 mlog_errno(status);
1868                 goto bail;
1869         }
1870
1871         status = dlm_launch_thread(dlm);
1872         if (status < 0) {
1873                 mlog_errno(status);
1874                 goto bail;
1875         }
1876
1877         status = dlm_launch_recovery_thread(dlm);
1878         if (status < 0) {
1879                 mlog_errno(status);
1880                 goto bail;
1881         }
1882
1883         dlm_debug_init(dlm);
1884
1885         snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
1886         dlm->dlm_worker = alloc_workqueue(wq_name, WQ_MEM_RECLAIM, 0);
1887         if (!dlm->dlm_worker) {
1888                 status = -ENOMEM;
1889                 mlog_errno(status);
1890                 goto bail;
1891         }
1892
1893         do {
1894                 status = dlm_try_to_join_domain(dlm);
1895
1896                 /* If we're racing another node to the join, then we
1897                  * need to back off temporarily and let them
1898                  * complete. */
1899 #define DLM_JOIN_TIMEOUT_MSECS  90000
1900                 if (status == -EAGAIN) {
1901                         if (signal_pending(current)) {
1902                                 status = -ERESTARTSYS;
1903                                 goto bail;
1904                         }
1905
1906                         if (total_backoff > DLM_JOIN_TIMEOUT_MSECS) {
1907                                 status = -ERESTARTSYS;
1908                                 mlog(ML_NOTICE, "Timed out joining dlm domain "
1909                                      "%s after %u msecs\n", dlm->name,
1910                                      total_backoff);
1911                                 goto bail;
1912                         }
1913
1914                         /*
1915                          * <chip> After you!
1916                          * <dale> No, after you!
1917                          * <chip> I insist!
1918                          * <dale> But you first!
1919                          * ...
1920                          */
1921                         backoff = (unsigned int)(jiffies & 0x3);
1922                         backoff *= DLM_DOMAIN_BACKOFF_MS;
1923                         total_backoff += backoff;
1924                         mlog(0, "backoff %d\n", backoff);
1925                         msleep(backoff);
1926                 }
1927         } while (status == -EAGAIN);
1928
1929         if (status < 0) {
1930                 mlog_errno(status);
1931                 goto bail;
1932         }
1933
1934         status = 0;
1935 bail:
1936         wake_up(&dlm_domain_events);
1937
1938         if (status) {
1939                 dlm_unregister_domain_handlers(dlm);
1940                 dlm_complete_thread(dlm);
1941                 dlm_complete_recovery_thread(dlm);
1942                 dlm_destroy_dlm_worker(dlm);
1943         }
1944
1945         return status;
1946 }
1947
1948 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1949                                 u32 key)
1950 {
1951         int i;
1952         int ret;
1953         struct dlm_ctxt *dlm = NULL;
1954
1955         dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1956         if (!dlm) {
1957                 ret = -ENOMEM;
1958                 mlog_errno(ret);
1959                 goto leave;
1960         }
1961
1962         dlm->name = kstrdup(domain, GFP_KERNEL);
1963         if (dlm->name == NULL) {
1964                 ret = -ENOMEM;
1965                 mlog_errno(ret);
1966                 goto leave;
1967         }
1968
1969         dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1970         if (!dlm->lockres_hash) {
1971                 ret = -ENOMEM;
1972                 mlog_errno(ret);
1973                 goto leave;
1974         }
1975
1976         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1977                 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1978
1979         dlm->master_hash = (struct hlist_head **)
1980                                 dlm_alloc_pagevec(DLM_HASH_PAGES);
1981         if (!dlm->master_hash) {
1982                 ret = -ENOMEM;
1983                 mlog_errno(ret);
1984                 goto leave;
1985         }
1986
1987         for (i = 0; i < DLM_HASH_BUCKETS; i++)
1988                 INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
1989
1990         dlm->key = key;
1991         dlm->node_num = o2nm_this_node();
1992
1993         dlm_create_debugfs_subroot(dlm);
1994
1995         spin_lock_init(&dlm->spinlock);
1996         spin_lock_init(&dlm->master_lock);
1997         spin_lock_init(&dlm->ast_lock);
1998         spin_lock_init(&dlm->track_lock);
1999         INIT_LIST_HEAD(&dlm->list);
2000         INIT_LIST_HEAD(&dlm->dirty_list);
2001         INIT_LIST_HEAD(&dlm->reco.resources);
2002         INIT_LIST_HEAD(&dlm->reco.node_data);
2003         INIT_LIST_HEAD(&dlm->purge_list);
2004         INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
2005         INIT_LIST_HEAD(&dlm->tracking_list);
2006         dlm->reco.state = 0;
2007
2008         INIT_LIST_HEAD(&dlm->pending_asts);
2009         INIT_LIST_HEAD(&dlm->pending_basts);
2010
2011         mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
2012                   dlm->recovery_map, &(dlm->recovery_map[0]));
2013
2014         memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
2015         memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
2016         memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
2017
2018         dlm->dlm_thread_task = NULL;
2019         dlm->dlm_reco_thread_task = NULL;
2020         dlm->dlm_worker = NULL;
2021         init_waitqueue_head(&dlm->dlm_thread_wq);
2022         init_waitqueue_head(&dlm->dlm_reco_thread_wq);
2023         init_waitqueue_head(&dlm->reco.event);
2024         init_waitqueue_head(&dlm->ast_wq);
2025         init_waitqueue_head(&dlm->migration_wq);
2026         INIT_LIST_HEAD(&dlm->mle_hb_events);
2027
2028         dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
2029         init_waitqueue_head(&dlm->dlm_join_events);
2030
2031         dlm->migrate_done = 0;
2032
2033         dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
2034         dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
2035
2036         atomic_set(&dlm->res_tot_count, 0);
2037         atomic_set(&dlm->res_cur_count, 0);
2038         for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
2039                 atomic_set(&dlm->mle_tot_count[i], 0);
2040                 atomic_set(&dlm->mle_cur_count[i], 0);
2041         }
2042
2043         spin_lock_init(&dlm->work_lock);
2044         INIT_LIST_HEAD(&dlm->work_list);
2045         INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
2046
2047         kref_init(&dlm->dlm_refs);
2048         dlm->dlm_state = DLM_CTXT_NEW;
2049
2050         INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
2051
2052         mlog(0, "context init: refcount %u\n",
2053                   kref_read(&dlm->dlm_refs));
2054
2055         ret = 0;
2056 leave:
2057         if (ret < 0 && dlm) {
2058                 if (dlm->master_hash)
2059                         dlm_free_pagevec((void **)dlm->master_hash,
2060                                         DLM_HASH_PAGES);
2061
2062                 if (dlm->lockres_hash)
2063                         dlm_free_pagevec((void **)dlm->lockres_hash,
2064                                         DLM_HASH_PAGES);
2065
2066                 kfree(dlm->name);
2067                 kfree(dlm);
2068                 dlm = NULL;
2069         }
2070         return dlm;
2071 }
2072
2073 /*
2074  * Compare a requested locking protocol version against the current one.
2075  *
2076  * If the major numbers are different, they are incompatible.
2077  * If the current minor is greater than the request, they are incompatible.
2078  * If the current minor is less than or equal to the request, they are
2079  * compatible, and the requester should run at the current minor version.
2080  */
2081 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
2082                                 struct dlm_protocol_version *request)
2083 {
2084         if (existing->pv_major != request->pv_major)
2085                 return 1;
2086
2087         if (existing->pv_minor > request->pv_minor)
2088                 return 1;
2089
2090         if (existing->pv_minor < request->pv_minor)
2091                 request->pv_minor = existing->pv_minor;
2092
2093         return 0;
2094 }
2095
2096 /*
2097  * dlm_register_domain: one-time setup per "domain".
2098  *
2099  * The filesystem passes in the requested locking version via proto.
2100  * If registration was successful, proto will contain the negotiated
2101  * locking protocol.
2102  */
2103 struct dlm_ctxt * dlm_register_domain(const char *domain,
2104                                u32 key,
2105                                struct dlm_protocol_version *fs_proto)
2106 {
2107         int ret;
2108         struct dlm_ctxt *dlm = NULL;
2109         struct dlm_ctxt *new_ctxt = NULL;
2110
2111         if (strlen(domain) >= O2NM_MAX_NAME_LEN) {
2112                 ret = -ENAMETOOLONG;
2113                 mlog(ML_ERROR, "domain name length too long\n");
2114                 goto leave;
2115         }
2116
2117         mlog(0, "register called for domain \"%s\"\n", domain);
2118
2119 retry:
2120         dlm = NULL;
2121         if (signal_pending(current)) {
2122                 ret = -ERESTARTSYS;
2123                 mlog_errno(ret);
2124                 goto leave;
2125         }
2126
2127         spin_lock(&dlm_domain_lock);
2128
2129         dlm = __dlm_lookup_domain(domain);
2130         if (dlm) {
2131                 if (dlm->dlm_state != DLM_CTXT_JOINED) {
2132                         spin_unlock(&dlm_domain_lock);
2133
2134                         mlog(0, "This ctxt is not joined yet!\n");
2135                         wait_event_interruptible(dlm_domain_events,
2136                                                  dlm_wait_on_domain_helper(
2137                                                          domain));
2138                         goto retry;
2139                 }
2140
2141                 if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
2142                         spin_unlock(&dlm_domain_lock);
2143                         mlog(ML_ERROR,
2144                              "Requested locking protocol version is not "
2145                              "compatible with already registered domain "
2146                              "\"%s\"\n", domain);
2147                         ret = -EPROTO;
2148                         goto leave;
2149                 }
2150
2151                 __dlm_get(dlm);
2152                 dlm->num_joins++;
2153
2154                 spin_unlock(&dlm_domain_lock);
2155
2156                 ret = 0;
2157                 goto leave;
2158         }
2159
2160         /* doesn't exist */
2161         if (!new_ctxt) {
2162                 spin_unlock(&dlm_domain_lock);
2163
2164                 new_ctxt = dlm_alloc_ctxt(domain, key);
2165                 if (new_ctxt)
2166                         goto retry;
2167
2168                 ret = -ENOMEM;
2169                 mlog_errno(ret);
2170                 goto leave;
2171         }
2172
2173         /* a little variable switch-a-roo here... */
2174         dlm = new_ctxt;
2175         new_ctxt = NULL;
2176
2177         /* add the new domain */
2178         list_add_tail(&dlm->list, &dlm_domains);
2179         spin_unlock(&dlm_domain_lock);
2180
2181         /*
2182          * Pass the locking protocol version into the join.  If the join
2183          * succeeds, it will have the negotiated protocol set.
2184          */
2185         dlm->dlm_locking_proto = dlm_protocol;
2186         dlm->fs_locking_proto = *fs_proto;
2187
2188         ret = dlm_join_domain(dlm);
2189         if (ret) {
2190                 mlog_errno(ret);
2191                 dlm_put(dlm);
2192                 goto leave;
2193         }
2194
2195         /* Tell the caller what locking protocol we negotiated */
2196         *fs_proto = dlm->fs_locking_proto;
2197
2198         ret = 0;
2199 leave:
2200         if (new_ctxt)
2201                 dlm_free_ctxt_mem(new_ctxt);
2202
2203         if (ret < 0)
2204                 dlm = ERR_PTR(ret);
2205
2206         return dlm;
2207 }
2208 EXPORT_SYMBOL_GPL(dlm_register_domain);
2209
2210 static LIST_HEAD(dlm_join_handlers);
2211
2212 static void dlm_unregister_net_handlers(void)
2213 {
2214         o2net_unregister_handler_list(&dlm_join_handlers);
2215 }
2216
2217 static int dlm_register_net_handlers(void)
2218 {
2219         int status = 0;
2220
2221         status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
2222                                         sizeof(struct dlm_query_join_request),
2223                                         dlm_query_join_handler,
2224                                         NULL, NULL, &dlm_join_handlers);
2225         if (status)
2226                 goto bail;
2227
2228         status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
2229                                         sizeof(struct dlm_assert_joined),
2230                                         dlm_assert_joined_handler,
2231                                         NULL, NULL, &dlm_join_handlers);
2232         if (status)
2233                 goto bail;
2234
2235         status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
2236                                         sizeof(struct dlm_cancel_join),
2237                                         dlm_cancel_join_handler,
2238                                         NULL, NULL, &dlm_join_handlers);
2239         if (status)
2240                 goto bail;
2241
2242         status = o2net_register_handler(DLM_QUERY_REGION, DLM_MOD_KEY,
2243                                         sizeof(struct dlm_query_region),
2244                                         dlm_query_region_handler,
2245                                         NULL, NULL, &dlm_join_handlers);
2246
2247         if (status)
2248                 goto bail;
2249
2250         status = o2net_register_handler(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
2251                                         sizeof(struct dlm_query_nodeinfo),
2252                                         dlm_query_nodeinfo_handler,
2253                                         NULL, NULL, &dlm_join_handlers);
2254 bail:
2255         if (status < 0)
2256                 dlm_unregister_net_handlers();
2257
2258         return status;
2259 }
2260
2261 /* Domain eviction callback handling.
2262  *
2263  * The file system requires notification of node death *before* the
2264  * dlm completes it's recovery work, otherwise it may be able to
2265  * acquire locks on resources requiring recovery. Since the dlm can
2266  * evict a node from it's domain *before* heartbeat fires, a similar
2267  * mechanism is required. */
2268
2269 /* Eviction is not expected to happen often, so a per-domain lock is
2270  * not necessary. Eviction callbacks are allowed to sleep for short
2271  * periods of time. */
2272 static DECLARE_RWSEM(dlm_callback_sem);
2273
2274 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
2275                                         int node_num)
2276 {
2277         struct dlm_eviction_cb *cb;
2278
2279         down_read(&dlm_callback_sem);
2280         list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
2281                 cb->ec_func(node_num, cb->ec_data);
2282         }
2283         up_read(&dlm_callback_sem);
2284 }
2285
2286 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
2287                            dlm_eviction_func *f,
2288                            void *data)
2289 {
2290         INIT_LIST_HEAD(&cb->ec_item);
2291         cb->ec_func = f;
2292         cb->ec_data = data;
2293 }
2294 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
2295
2296 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
2297                               struct dlm_eviction_cb *cb)
2298 {
2299         down_write(&dlm_callback_sem);
2300         list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
2301         up_write(&dlm_callback_sem);
2302 }
2303 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
2304
2305 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
2306 {
2307         down_write(&dlm_callback_sem);
2308         list_del_init(&cb->ec_item);
2309         up_write(&dlm_callback_sem);
2310 }
2311 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
2312
2313 static int __init dlm_init(void)
2314 {
2315         int status;
2316
2317         status = dlm_init_mle_cache();
2318         if (status) {
2319                 mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
2320                 goto error;
2321         }
2322
2323         status = dlm_init_master_caches();
2324         if (status) {
2325                 mlog(ML_ERROR, "Could not create o2dlm_lockres and "
2326                      "o2dlm_lockname slabcaches\n");
2327                 goto error;
2328         }
2329
2330         status = dlm_init_lock_cache();
2331         if (status) {
2332                 mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
2333                 goto error;
2334         }
2335
2336         status = dlm_register_net_handlers();
2337         if (status) {
2338                 mlog(ML_ERROR, "Unable to register network handlers\n");
2339                 goto error;
2340         }
2341
2342         dlm_create_debugfs_root();
2343
2344         return 0;
2345 error:
2346         dlm_unregister_net_handlers();
2347         dlm_destroy_lock_cache();
2348         dlm_destroy_master_caches();
2349         dlm_destroy_mle_cache();
2350         return -1;
2351 }
2352
2353 static void __exit dlm_exit (void)
2354 {
2355         dlm_destroy_debugfs_root();
2356         dlm_unregister_net_handlers();
2357         dlm_destroy_lock_cache();
2358         dlm_destroy_master_caches();
2359         dlm_destroy_mle_cache();
2360 }
2361
2362 MODULE_AUTHOR("Oracle");
2363 MODULE_LICENSE("GPL");
2364 MODULE_DESCRIPTION("OCFS2 Distributed Lock Management");
2365
2366 module_init(dlm_init);
2367 module_exit(dlm_exit);