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TOMOYO Linux Cross Reference
Linux/fs/ocfs2/dlm/dlmdomain.c

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

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