1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmdomain.c
5  *
6  * defines domain join / leave apis
7  *
8  * Copyright (C) 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  *
25  */
26 
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/highmem.h>
31 #include <linux/init.h>
32 #include <linux/spinlock.h>
33 #include <linux/delay.h>
34 #include <linux/err.h>
35 #include <linux/debugfs.h>
36 #include <linux/sched/signal.h>
37 
38 #include "cluster/heartbeat.h"
39 #include "cluster/nodemanager.h"
40 #include "cluster/tcp.h"
41 
42 #include "dlmapi.h"
43 #include "dlmcommon.h"
44 #include "dlmdomain.h"
45 #include "dlmdebug.h"
46 
47 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
48 #include "cluster/masklog.h"
49 
50 /*
51  * ocfs2 node maps are array of long int, which limits to send them freely
52  * across the wire due to endianness issues. To workaround this, we convert
53  * long ints to byte arrays. Following 3 routines are helper functions to
54  * set/test/copy bits within those array of bytes
55  */
byte_set_bit(u8 nr,u8 map[])56 static inline void byte_set_bit(u8 nr, u8 map[])
57 {
58 	map[nr >> 3] |= (1UL << (nr & 7));
59 }
60 
byte_test_bit(u8 nr,u8 map[])61 static inline int byte_test_bit(u8 nr, u8 map[])
62 {
63 	return ((1UL << (nr & 7)) & (map[nr >> 3])) != 0;
64 }
65 
byte_copymap(u8 dmap[],unsigned long smap[],unsigned int sz)66 static inline void byte_copymap(u8 dmap[], unsigned long smap[],
67 			unsigned int sz)
68 {
69 	unsigned int nn;
70 
71 	if (!sz)
72 		return;
73 
74 	memset(dmap, 0, ((sz + 7) >> 3));
75 	for (nn = 0 ; nn < sz; nn++)
76 		if (test_bit(nn, smap))
77 			byte_set_bit(nn, dmap);
78 }
79 
dlm_free_pagevec(void ** vec,int pages)80 static void dlm_free_pagevec(void **vec, int pages)
81 {
82 	while (pages--)
83 		free_page((unsigned long)vec[pages]);
84 	kfree(vec);
85 }
86 
dlm_alloc_pagevec(int pages)87 static void **dlm_alloc_pagevec(int pages)
88 {
89 	void **vec = kmalloc_array(pages, sizeof(void *), GFP_KERNEL);
90 	int i;
91 
92 	if (!vec)
93 		return NULL;
94 
95 	for (i = 0; i < pages; i++)
96 		if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
97 			goto out_free;
98 
99 	mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
100 	     pages, (unsigned long)DLM_HASH_PAGES,
101 	     (unsigned long)DLM_BUCKETS_PER_PAGE);
102 	return vec;
103 out_free:
104 	dlm_free_pagevec(vec, i);
105 	return NULL;
106 }
107 
108 /*
109  *
110  * spinlock lock ordering: if multiple locks are needed, obey this ordering:
111  *    dlm_domain_lock
112  *    struct dlm_ctxt->spinlock
113  *    struct dlm_lock_resource->spinlock
114  *    struct dlm_ctxt->master_lock
115  *    struct dlm_ctxt->ast_lock
116  *    dlm_master_list_entry->spinlock
117  *    dlm_lock->spinlock
118  *
119  */
120 
121 DEFINE_SPINLOCK(dlm_domain_lock);
122 LIST_HEAD(dlm_domains);
123 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
124 
125 /*
126  * The supported protocol version for DLM communication.  Running domains
127  * will have a negotiated version with the same major number and a minor
128  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
129  * be used to determine what a running domain is actually using.
130  *
131  * New in version 1.1:
132  *	- Message DLM_QUERY_REGION added to support global heartbeat
133  *	- Message DLM_QUERY_NODEINFO added to allow online node removes
134  * New in version 1.2:
135  * 	- Message DLM_BEGIN_EXIT_DOMAIN_MSG added to mark start of exit domain
136  * New in version 1.3:
137  *	- Message DLM_DEREF_LOCKRES_DONE added to inform non-master that the
138  *	  refmap is cleared
139  */
140 static const struct dlm_protocol_version dlm_protocol = {
141 	.pv_major = 1,
142 	.pv_minor = 3,
143 };
144 
145 #define DLM_DOMAIN_BACKOFF_MS 200
146 
147 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
148 				  void **ret_data);
149 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
150 				     void **ret_data);
151 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
152 				   void **ret_data);
153 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
154 				    void *data, void **ret_data);
155 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
156 				   void **ret_data);
157 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
158 				struct dlm_protocol_version *request);
159 
160 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
161 
__dlm_unhash_lockres(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)162 void __dlm_unhash_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
163 {
164 	if (hlist_unhashed(&res->hash_node))
165 		return;
166 
167 	mlog(0, "%s: Unhash res %.*s\n", dlm->name, res->lockname.len,
168 	     res->lockname.name);
169 	hlist_del_init(&res->hash_node);
170 	dlm_lockres_put(res);
171 }
172 
__dlm_insert_lockres(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)173 void __dlm_insert_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
174 {
175 	struct hlist_head *bucket;
176 
177 	assert_spin_locked(&dlm->spinlock);
178 
179 	bucket = dlm_lockres_hash(dlm, res->lockname.hash);
180 
181 	/* get a reference for our hashtable */
182 	dlm_lockres_get(res);
183 
184 	hlist_add_head(&res->hash_node, bucket);
185 
186 	mlog(0, "%s: Hash res %.*s\n", dlm->name, res->lockname.len,
187 	     res->lockname.name);
188 }
189 
__dlm_lookup_lockres_full(struct dlm_ctxt * dlm,const char * name,unsigned int len,unsigned int hash)190 struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
191 						     const char *name,
192 						     unsigned int len,
193 						     unsigned int hash)
194 {
195 	struct hlist_head *bucket;
196 	struct dlm_lock_resource *res;
197 
198 	mlog(0, "%.*s\n", len, name);
199 
200 	assert_spin_locked(&dlm->spinlock);
201 
202 	bucket = dlm_lockres_hash(dlm, hash);
203 
204 	hlist_for_each_entry(res, bucket, hash_node) {
205 		if (res->lockname.name[0] != name[0])
206 			continue;
207 		if (unlikely(res->lockname.len != len))
208 			continue;
209 		if (memcmp(res->lockname.name + 1, name + 1, len - 1))
210 			continue;
211 		dlm_lockres_get(res);
212 		return res;
213 	}
214 	return NULL;
215 }
216 
217 /* intended to be called by functions which do not care about lock
218  * resources which are being purged (most net _handler functions).
219  * this will return NULL for any lock resource which is found but
220  * currently in the process of dropping its mastery reference.
221  * use __dlm_lookup_lockres_full when you need the lock resource
222  * regardless (e.g. dlm_get_lock_resource) */
__dlm_lookup_lockres(struct dlm_ctxt * dlm,const char * name,unsigned int len,unsigned int hash)223 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
224 						const char *name,
225 						unsigned int len,
226 						unsigned int hash)
227 {
228 	struct dlm_lock_resource *res = NULL;
229 
230 	mlog(0, "%.*s\n", len, name);
231 
232 	assert_spin_locked(&dlm->spinlock);
233 
234 	res = __dlm_lookup_lockres_full(dlm, name, len, hash);
235 	if (res) {
236 		spin_lock(&res->spinlock);
237 		if (res->state & DLM_LOCK_RES_DROPPING_REF) {
238 			spin_unlock(&res->spinlock);
239 			dlm_lockres_put(res);
240 			return NULL;
241 		}
242 		spin_unlock(&res->spinlock);
243 	}
244 
245 	return res;
246 }
247 
dlm_lookup_lockres(struct dlm_ctxt * dlm,const char * name,unsigned int len)248 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
249 				    const char *name,
250 				    unsigned int len)
251 {
252 	struct dlm_lock_resource *res;
253 	unsigned int hash = dlm_lockid_hash(name, len);
254 
255 	spin_lock(&dlm->spinlock);
256 	res = __dlm_lookup_lockres(dlm, name, len, hash);
257 	spin_unlock(&dlm->spinlock);
258 	return res;
259 }
260 
__dlm_lookup_domain_full(const char * domain,int len)261 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
262 {
263 	struct dlm_ctxt *tmp;
264 
265 	assert_spin_locked(&dlm_domain_lock);
266 
267 	/* tmp->name here is always NULL terminated,
268 	 * but domain may not be! */
269 	list_for_each_entry(tmp, &dlm_domains, list) {
270 		if (strlen(tmp->name) == len &&
271 		    memcmp(tmp->name, domain, len)==0)
272 			return tmp;
273 	}
274 
275 	return NULL;
276 }
277 
278 /* For null terminated domain strings ONLY */
__dlm_lookup_domain(const char * domain)279 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
280 {
281 	assert_spin_locked(&dlm_domain_lock);
282 
283 	return __dlm_lookup_domain_full(domain, strlen(domain));
284 }
285 
286 
287 /* returns true on one of two conditions:
288  * 1) the domain does not exist
289  * 2) the domain exists and it's state is "joined" */
dlm_wait_on_domain_helper(const char * domain)290 static int dlm_wait_on_domain_helper(const char *domain)
291 {
292 	int ret = 0;
293 	struct dlm_ctxt *tmp = NULL;
294 
295 	spin_lock(&dlm_domain_lock);
296 
297 	tmp = __dlm_lookup_domain(domain);
298 	if (!tmp)
299 		ret = 1;
300 	else if (tmp->dlm_state == DLM_CTXT_JOINED)
301 		ret = 1;
302 
303 	spin_unlock(&dlm_domain_lock);
304 	return ret;
305 }
306 
dlm_free_ctxt_mem(struct dlm_ctxt * dlm)307 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
308 {
309 	dlm_destroy_debugfs_subroot(dlm);
310 
311 	if (dlm->lockres_hash)
312 		dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
313 
314 	if (dlm->master_hash)
315 		dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
316 
317 	kfree(dlm->name);
318 	kfree(dlm);
319 }
320 
321 /* A little strange - this function will be called while holding
322  * dlm_domain_lock and is expected to be holding it on the way out. We
323  * will however drop and reacquire it multiple times */
dlm_ctxt_release(struct kref * kref)324 static void dlm_ctxt_release(struct kref *kref)
325 {
326 	struct dlm_ctxt *dlm;
327 
328 	dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
329 
330 	BUG_ON(dlm->num_joins);
331 	BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
332 
333 	/* we may still be in the list if we hit an error during join. */
334 	list_del_init(&dlm->list);
335 
336 	spin_unlock(&dlm_domain_lock);
337 
338 	mlog(0, "freeing memory from domain %s\n", dlm->name);
339 
340 	wake_up(&dlm_domain_events);
341 
342 	dlm_free_ctxt_mem(dlm);
343 
344 	spin_lock(&dlm_domain_lock);
345 }
346 
dlm_put(struct dlm_ctxt * dlm)347 void dlm_put(struct dlm_ctxt *dlm)
348 {
349 	spin_lock(&dlm_domain_lock);
350 	kref_put(&dlm->dlm_refs, dlm_ctxt_release);
351 	spin_unlock(&dlm_domain_lock);
352 }
353 
__dlm_get(struct dlm_ctxt * dlm)354 static void __dlm_get(struct dlm_ctxt *dlm)
355 {
356 	kref_get(&dlm->dlm_refs);
357 }
358 
359 /* given a questionable reference to a dlm object, gets a reference if
360  * it can find it in the list, otherwise returns NULL in which case
361  * you shouldn't trust your pointer. */
dlm_grab(struct dlm_ctxt * dlm)362 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
363 {
364 	struct dlm_ctxt *target;
365 	struct dlm_ctxt *ret = NULL;
366 
367 	spin_lock(&dlm_domain_lock);
368 
369 	list_for_each_entry(target, &dlm_domains, list) {
370 		if (target == dlm) {
371 			__dlm_get(target);
372 			ret = target;
373 			break;
374 		}
375 	}
376 
377 	spin_unlock(&dlm_domain_lock);
378 
379 	return ret;
380 }
381 
dlm_domain_fully_joined(struct dlm_ctxt * dlm)382 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
383 {
384 	int ret;
385 
386 	spin_lock(&dlm_domain_lock);
387 	ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
388 		(dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
389 	spin_unlock(&dlm_domain_lock);
390 
391 	return ret;
392 }
393 
dlm_destroy_dlm_worker(struct dlm_ctxt * dlm)394 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
395 {
396 	if (dlm->dlm_worker) {
397 		destroy_workqueue(dlm->dlm_worker);
398 		dlm->dlm_worker = NULL;
399 	}
400 }
401 
dlm_complete_dlm_shutdown(struct dlm_ctxt * dlm)402 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
403 {
404 	dlm_unregister_domain_handlers(dlm);
405 	dlm_debug_shutdown(dlm);
406 	dlm_complete_thread(dlm);
407 	dlm_complete_recovery_thread(dlm);
408 	dlm_destroy_dlm_worker(dlm);
409 
410 	/* We've left the domain. Now we can take ourselves out of the
411 	 * list and allow the kref stuff to help us free the
412 	 * memory. */
413 	spin_lock(&dlm_domain_lock);
414 	list_del_init(&dlm->list);
415 	spin_unlock(&dlm_domain_lock);
416 
417 	/* Wake up anyone waiting for us to remove this domain */
418 	wake_up(&dlm_domain_events);
419 }
420 
dlm_migrate_all_locks(struct dlm_ctxt * dlm)421 static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
422 {
423 	int i, num, n, ret = 0;
424 	struct dlm_lock_resource *res;
425 	struct hlist_node *iter;
426 	struct hlist_head *bucket;
427 	int dropped;
428 
429 	mlog(0, "Migrating locks from domain %s\n", dlm->name);
430 
431 	num = 0;
432 	spin_lock(&dlm->spinlock);
433 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
434 redo_bucket:
435 		n = 0;
436 		bucket = dlm_lockres_hash(dlm, i);
437 		iter = bucket->first;
438 		while (iter) {
439 			n++;
440 			res = hlist_entry(iter, struct dlm_lock_resource,
441 					  hash_node);
442 			dlm_lockres_get(res);
443 			/* migrate, if necessary.  this will drop the dlm
444 			 * spinlock and retake it if it does migration. */
445 			dropped = dlm_empty_lockres(dlm, res);
446 
447 			spin_lock(&res->spinlock);
448 			if (dropped)
449 				__dlm_lockres_calc_usage(dlm, res);
450 			else
451 				iter = res->hash_node.next;
452 			spin_unlock(&res->spinlock);
453 
454 			dlm_lockres_put(res);
455 
456 			if (dropped) {
457 				cond_resched_lock(&dlm->spinlock);
458 				goto redo_bucket;
459 			}
460 		}
461 		cond_resched_lock(&dlm->spinlock);
462 		num += n;
463 	}
464 
465 	if (!num) {
466 		if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
467 			mlog(0, "%s: perhaps there are more lock resources "
468 			     "need to be migrated after dlm recovery\n", dlm->name);
469 			ret = -EAGAIN;
470 		} else {
471 			mlog(0, "%s: we won't do dlm recovery after migrating "
472 			     "all lock resources\n", dlm->name);
473 			dlm->migrate_done = 1;
474 		}
475 	}
476 
477 	spin_unlock(&dlm->spinlock);
478 	wake_up(&dlm->dlm_thread_wq);
479 
480 	/* let the dlm thread take care of purging, keep scanning until
481 	 * nothing remains in the hash */
482 	if (num) {
483 		mlog(0, "%s: %d lock resources in hash last pass\n",
484 		     dlm->name, num);
485 		ret = -EAGAIN;
486 	}
487 	mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
488 	return ret;
489 }
490 
dlm_no_joining_node(struct dlm_ctxt * dlm)491 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
492 {
493 	int ret;
494 
495 	spin_lock(&dlm->spinlock);
496 	ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
497 	spin_unlock(&dlm->spinlock);
498 
499 	return ret;
500 }
501 
dlm_begin_exit_domain_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)502 static int dlm_begin_exit_domain_handler(struct o2net_msg *msg, u32 len,
503 					 void *data, void **ret_data)
504 {
505 	struct dlm_ctxt *dlm = data;
506 	unsigned int node;
507 	struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
508 
509 	if (!dlm_grab(dlm))
510 		return 0;
511 
512 	node = exit_msg->node_idx;
513 	mlog(0, "%s: Node %u sent a begin exit domain message\n", dlm->name, node);
514 
515 	spin_lock(&dlm->spinlock);
516 	set_bit(node, dlm->exit_domain_map);
517 	spin_unlock(&dlm->spinlock);
518 
519 	dlm_put(dlm);
520 
521 	return 0;
522 }
523 
dlm_mark_domain_leaving(struct dlm_ctxt * dlm)524 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
525 {
526 	/* Yikes, a double spinlock! I need domain_lock for the dlm
527 	 * state and the dlm spinlock for join state... Sorry! */
528 again:
529 	spin_lock(&dlm_domain_lock);
530 	spin_lock(&dlm->spinlock);
531 
532 	if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
533 		mlog(0, "Node %d is joining, we wait on it.\n",
534 			  dlm->joining_node);
535 		spin_unlock(&dlm->spinlock);
536 		spin_unlock(&dlm_domain_lock);
537 
538 		wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
539 		goto again;
540 	}
541 
542 	dlm->dlm_state = DLM_CTXT_LEAVING;
543 	spin_unlock(&dlm->spinlock);
544 	spin_unlock(&dlm_domain_lock);
545 }
546 
__dlm_print_nodes(struct dlm_ctxt * dlm)547 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
548 {
549 	int node = -1, num = 0;
550 
551 	assert_spin_locked(&dlm->spinlock);
552 
553 	printk("( ");
554 	while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
555 				     node + 1)) < O2NM_MAX_NODES) {
556 		printk("%d ", node);
557 		++num;
558 	}
559 	printk(") %u nodes\n", num);
560 }
561 
dlm_exit_domain_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)562 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
563 				   void **ret_data)
564 {
565 	struct dlm_ctxt *dlm = data;
566 	unsigned int node;
567 	struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
568 
569 	mlog(0, "%p %u %p", msg, len, data);
570 
571 	if (!dlm_grab(dlm))
572 		return 0;
573 
574 	node = exit_msg->node_idx;
575 
576 	spin_lock(&dlm->spinlock);
577 	clear_bit(node, dlm->domain_map);
578 	clear_bit(node, dlm->exit_domain_map);
579 	printk(KERN_NOTICE "o2dlm: Node %u leaves domain %s ", node, dlm->name);
580 	__dlm_print_nodes(dlm);
581 
582 	/* notify anything attached to the heartbeat events */
583 	dlm_hb_event_notify_attached(dlm, node, 0);
584 
585 	spin_unlock(&dlm->spinlock);
586 
587 	dlm_put(dlm);
588 
589 	return 0;
590 }
591 
dlm_send_one_domain_exit(struct dlm_ctxt * dlm,u32 msg_type,unsigned int node)592 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, u32 msg_type,
593 				    unsigned int node)
594 {
595 	int status;
596 	struct dlm_exit_domain leave_msg;
597 
598 	mlog(0, "%s: Sending domain exit message %u to node %u\n", dlm->name,
599 	     msg_type, node);
600 
601 	memset(&leave_msg, 0, sizeof(leave_msg));
602 	leave_msg.node_idx = dlm->node_num;
603 
604 	status = o2net_send_message(msg_type, dlm->key, &leave_msg,
605 				    sizeof(leave_msg), node, NULL);
606 	if (status < 0)
607 		mlog(ML_ERROR, "Error %d sending domain exit message %u "
608 		     "to node %u on domain %s\n", status, msg_type, node,
609 		     dlm->name);
610 
611 	return status;
612 }
613 
dlm_begin_exit_domain(struct dlm_ctxt * dlm)614 static void dlm_begin_exit_domain(struct dlm_ctxt *dlm)
615 {
616 	int node = -1;
617 
618 	/* Support for begin exit domain was added in 1.2 */
619 	if (dlm->dlm_locking_proto.pv_major == 1 &&
620 	    dlm->dlm_locking_proto.pv_minor < 2)
621 		return;
622 
623 	/*
624 	 * Unlike DLM_EXIT_DOMAIN_MSG, DLM_BEGIN_EXIT_DOMAIN_MSG is purely
625 	 * informational. Meaning if a node does not receive the message,
626 	 * so be it.
627 	 */
628 	spin_lock(&dlm->spinlock);
629 	while (1) {
630 		node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, node + 1);
631 		if (node >= O2NM_MAX_NODES)
632 			break;
633 		if (node == dlm->node_num)
634 			continue;
635 
636 		spin_unlock(&dlm->spinlock);
637 		dlm_send_one_domain_exit(dlm, DLM_BEGIN_EXIT_DOMAIN_MSG, node);
638 		spin_lock(&dlm->spinlock);
639 	}
640 	spin_unlock(&dlm->spinlock);
641 }
642 
dlm_leave_domain(struct dlm_ctxt * dlm)643 static void dlm_leave_domain(struct dlm_ctxt *dlm)
644 {
645 	int node, clear_node, status;
646 
647 	/* At this point we've migrated away all our locks and won't
648 	 * accept mastership of new ones. The dlm is responsible for
649 	 * almost nothing now. We make sure not to confuse any joining
650 	 * nodes and then commence shutdown procedure. */
651 
652 	spin_lock(&dlm->spinlock);
653 	/* Clear ourselves from the domain map */
654 	clear_bit(dlm->node_num, dlm->domain_map);
655 	while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
656 				     0)) < O2NM_MAX_NODES) {
657 		/* Drop the dlm spinlock. This is safe wrt the domain_map.
658 		 * -nodes cannot be added now as the
659 		 *   query_join_handlers knows to respond with OK_NO_MAP
660 		 * -we catch the right network errors if a node is
661 		 *   removed from the map while we're sending him the
662 		 *   exit message. */
663 		spin_unlock(&dlm->spinlock);
664 
665 		clear_node = 1;
666 
667 		status = dlm_send_one_domain_exit(dlm, DLM_EXIT_DOMAIN_MSG,
668 						  node);
669 		if (status < 0 &&
670 		    status != -ENOPROTOOPT &&
671 		    status != -ENOTCONN) {
672 			mlog(ML_NOTICE, "Error %d sending domain exit message "
673 			     "to node %d\n", status, node);
674 
675 			/* Not sure what to do here but lets sleep for
676 			 * a bit in case this was a transient
677 			 * error... */
678 			msleep(DLM_DOMAIN_BACKOFF_MS);
679 			clear_node = 0;
680 		}
681 
682 		spin_lock(&dlm->spinlock);
683 		/* If we're not clearing the node bit then we intend
684 		 * to loop back around to try again. */
685 		if (clear_node)
686 			clear_bit(node, dlm->domain_map);
687 	}
688 	spin_unlock(&dlm->spinlock);
689 }
690 
dlm_unregister_domain(struct dlm_ctxt * dlm)691 void dlm_unregister_domain(struct dlm_ctxt *dlm)
692 {
693 	int leave = 0;
694 	struct dlm_lock_resource *res;
695 
696 	spin_lock(&dlm_domain_lock);
697 	BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
698 	BUG_ON(!dlm->num_joins);
699 
700 	dlm->num_joins--;
701 	if (!dlm->num_joins) {
702 		/* We mark it "in shutdown" now so new register
703 		 * requests wait until we've completely left the
704 		 * domain. Don't use DLM_CTXT_LEAVING yet as we still
705 		 * want new domain joins to communicate with us at
706 		 * least until we've completed migration of our
707 		 * resources. */
708 		dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
709 		leave = 1;
710 	}
711 	spin_unlock(&dlm_domain_lock);
712 
713 	if (leave) {
714 		mlog(0, "shutting down domain %s\n", dlm->name);
715 		dlm_begin_exit_domain(dlm);
716 
717 		/* We changed dlm state, notify the thread */
718 		dlm_kick_thread(dlm, NULL);
719 
720 		while (dlm_migrate_all_locks(dlm)) {
721 			/* Give dlm_thread time to purge the lockres' */
722 			msleep(500);
723 			mlog(0, "%s: more migration to do\n", dlm->name);
724 		}
725 
726 		/* This list should be empty. If not, print remaining lockres */
727 		if (!list_empty(&dlm->tracking_list)) {
728 			mlog(ML_ERROR, "Following lockres' are still on the "
729 			     "tracking list:\n");
730 			list_for_each_entry(res, &dlm->tracking_list, tracking)
731 				dlm_print_one_lock_resource(res);
732 		}
733 
734 		dlm_mark_domain_leaving(dlm);
735 		dlm_leave_domain(dlm);
736 		printk(KERN_NOTICE "o2dlm: Leaving domain %s\n", dlm->name);
737 		dlm_force_free_mles(dlm);
738 		dlm_complete_dlm_shutdown(dlm);
739 	}
740 	dlm_put(dlm);
741 }
742 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
743 
dlm_query_join_proto_check(char * proto_type,int node,struct dlm_protocol_version * ours,struct dlm_protocol_version * request)744 static int dlm_query_join_proto_check(char *proto_type, int node,
745 				      struct dlm_protocol_version *ours,
746 				      struct dlm_protocol_version *request)
747 {
748 	int rc;
749 	struct dlm_protocol_version proto = *request;
750 
751 	if (!dlm_protocol_compare(ours, &proto)) {
752 		mlog(0,
753 		     "node %u wanted to join with %s locking protocol "
754 		     "%u.%u, we respond with %u.%u\n",
755 		     node, proto_type,
756 		     request->pv_major,
757 		     request->pv_minor,
758 		     proto.pv_major, proto.pv_minor);
759 		request->pv_minor = proto.pv_minor;
760 		rc = 0;
761 	} else {
762 		mlog(ML_NOTICE,
763 		     "Node %u wanted to join with %s locking "
764 		     "protocol %u.%u, but we have %u.%u, disallowing\n",
765 		     node, proto_type,
766 		     request->pv_major,
767 		     request->pv_minor,
768 		     ours->pv_major,
769 		     ours->pv_minor);
770 		rc = 1;
771 	}
772 
773 	return rc;
774 }
775 
776 /*
777  * struct dlm_query_join_packet is made up of four one-byte fields.  They
778  * are effectively in big-endian order already.  However, little-endian
779  * machines swap them before putting the packet on the wire (because
780  * query_join's response is a status, and that status is treated as a u32
781  * on the wire).  Thus, a big-endian and little-endian machines will treat
782  * this structure differently.
783  *
784  * The solution is to have little-endian machines swap the structure when
785  * converting from the structure to the u32 representation.  This will
786  * result in the structure having the correct format on the wire no matter
787  * the host endian format.
788  */
dlm_query_join_packet_to_wire(struct dlm_query_join_packet * packet,u32 * wire)789 static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
790 					  u32 *wire)
791 {
792 	union dlm_query_join_response response;
793 
794 	response.packet = *packet;
795 	*wire = be32_to_cpu(response.intval);
796 }
797 
dlm_query_join_wire_to_packet(u32 wire,struct dlm_query_join_packet * packet)798 static void dlm_query_join_wire_to_packet(u32 wire,
799 					  struct dlm_query_join_packet *packet)
800 {
801 	union dlm_query_join_response response;
802 
803 	response.intval = cpu_to_be32(wire);
804 	*packet = response.packet;
805 }
806 
dlm_query_join_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)807 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
808 				  void **ret_data)
809 {
810 	struct dlm_query_join_request *query;
811 	struct dlm_query_join_packet packet = {
812 		.code = JOIN_DISALLOW,
813 	};
814 	struct dlm_ctxt *dlm = NULL;
815 	u32 response;
816 	u8 nodenum;
817 
818 	query = (struct dlm_query_join_request *) msg->buf;
819 
820 	mlog(0, "node %u wants to join domain %s\n", query->node_idx,
821 		  query->domain);
822 
823 	/*
824 	 * If heartbeat doesn't consider the node live, tell it
825 	 * to back off and try again.  This gives heartbeat a chance
826 	 * to catch up.
827 	 */
828 	if (!o2hb_check_node_heartbeating_no_sem(query->node_idx)) {
829 		mlog(0, "node %u is not in our live map yet\n",
830 		     query->node_idx);
831 
832 		packet.code = JOIN_DISALLOW;
833 		goto respond;
834 	}
835 
836 	packet.code = JOIN_OK_NO_MAP;
837 
838 	spin_lock(&dlm_domain_lock);
839 	dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
840 	if (!dlm)
841 		goto unlock_respond;
842 
843 	/*
844 	 * There is a small window where the joining node may not see the
845 	 * node(s) that just left but still part of the cluster. DISALLOW
846 	 * join request if joining node has different node map.
847 	 */
848 	nodenum=0;
849 	while (nodenum < O2NM_MAX_NODES) {
850 		if (test_bit(nodenum, dlm->domain_map)) {
851 			if (!byte_test_bit(nodenum, query->node_map)) {
852 				mlog(0, "disallow join as node %u does not "
853 				     "have node %u in its nodemap\n",
854 				     query->node_idx, nodenum);
855 				packet.code = JOIN_DISALLOW;
856 				goto unlock_respond;
857 			}
858 		}
859 		nodenum++;
860 	}
861 
862 	/* Once the dlm ctxt is marked as leaving then we don't want
863 	 * to be put in someone's domain map.
864 	 * Also, explicitly disallow joining at certain troublesome
865 	 * times (ie. during recovery). */
866 	if (dlm->dlm_state != DLM_CTXT_LEAVING) {
867 		int bit = query->node_idx;
868 		spin_lock(&dlm->spinlock);
869 
870 		if (dlm->dlm_state == DLM_CTXT_NEW &&
871 		    dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
872 			/*If this is a brand new context and we
873 			 * haven't started our join process yet, then
874 			 * the other node won the race. */
875 			packet.code = JOIN_OK_NO_MAP;
876 		} else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
877 			/* Disallow parallel joins. */
878 			packet.code = JOIN_DISALLOW;
879 		} else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
880 			mlog(0, "node %u trying to join, but recovery "
881 			     "is ongoing.\n", bit);
882 			packet.code = JOIN_DISALLOW;
883 		} else if (test_bit(bit, dlm->recovery_map)) {
884 			mlog(0, "node %u trying to join, but it "
885 			     "still needs recovery.\n", bit);
886 			packet.code = JOIN_DISALLOW;
887 		} else if (test_bit(bit, dlm->domain_map)) {
888 			mlog(0, "node %u trying to join, but it "
889 			     "is still in the domain! needs recovery?\n",
890 			     bit);
891 			packet.code = JOIN_DISALLOW;
892 		} else {
893 			/* Alright we're fully a part of this domain
894 			 * so we keep some state as to who's joining
895 			 * and indicate to him that needs to be fixed
896 			 * up. */
897 
898 			/* Make sure we speak compatible locking protocols.  */
899 			if (dlm_query_join_proto_check("DLM", bit,
900 						       &dlm->dlm_locking_proto,
901 						       &query->dlm_proto)) {
902 				packet.code = JOIN_PROTOCOL_MISMATCH;
903 			} else if (dlm_query_join_proto_check("fs", bit,
904 							      &dlm->fs_locking_proto,
905 							      &query->fs_proto)) {
906 				packet.code = JOIN_PROTOCOL_MISMATCH;
907 			} else {
908 				packet.dlm_minor = query->dlm_proto.pv_minor;
909 				packet.fs_minor = query->fs_proto.pv_minor;
910 				packet.code = JOIN_OK;
911 				__dlm_set_joining_node(dlm, query->node_idx);
912 			}
913 		}
914 
915 		spin_unlock(&dlm->spinlock);
916 	}
917 unlock_respond:
918 	spin_unlock(&dlm_domain_lock);
919 
920 respond:
921 	mlog(0, "We respond with %u\n", packet.code);
922 
923 	dlm_query_join_packet_to_wire(&packet, &response);
924 	return response;
925 }
926 
dlm_assert_joined_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)927 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data,
928 				     void **ret_data)
929 {
930 	struct dlm_assert_joined *assert;
931 	struct dlm_ctxt *dlm = NULL;
932 
933 	assert = (struct dlm_assert_joined *) msg->buf;
934 
935 	mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
936 		  assert->domain);
937 
938 	spin_lock(&dlm_domain_lock);
939 	dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
940 	/* XXX should we consider no dlm ctxt an error? */
941 	if (dlm) {
942 		spin_lock(&dlm->spinlock);
943 
944 		/* Alright, this node has officially joined our
945 		 * domain. Set him in the map and clean up our
946 		 * leftover join state. */
947 		BUG_ON(dlm->joining_node != assert->node_idx);
948 
949 		if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
950 			mlog(0, "dlm recovery is ongoing, disallow join\n");
951 			spin_unlock(&dlm->spinlock);
952 			spin_unlock(&dlm_domain_lock);
953 			return -EAGAIN;
954 		}
955 
956 		set_bit(assert->node_idx, dlm->domain_map);
957 		clear_bit(assert->node_idx, dlm->exit_domain_map);
958 		__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
959 
960 		printk(KERN_NOTICE "o2dlm: Node %u joins domain %s ",
961 		       assert->node_idx, dlm->name);
962 		__dlm_print_nodes(dlm);
963 
964 		/* notify anything attached to the heartbeat events */
965 		dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
966 
967 		spin_unlock(&dlm->spinlock);
968 	}
969 	spin_unlock(&dlm_domain_lock);
970 
971 	return 0;
972 }
973 
dlm_match_regions(struct dlm_ctxt * dlm,struct dlm_query_region * qr,char * local,int locallen)974 static int dlm_match_regions(struct dlm_ctxt *dlm,
975 			     struct dlm_query_region *qr,
976 			     char *local, int locallen)
977 {
978 	char *remote = qr->qr_regions;
979 	char *l, *r;
980 	int localnr, i, j, foundit;
981 	int status = 0;
982 
983 	if (!o2hb_global_heartbeat_active()) {
984 		if (qr->qr_numregions) {
985 			mlog(ML_ERROR, "Domain %s: Joining node %d has global "
986 			     "heartbeat enabled but local node %d does not\n",
987 			     qr->qr_domain, qr->qr_node, dlm->node_num);
988 			status = -EINVAL;
989 		}
990 		goto bail;
991 	}
992 
993 	if (o2hb_global_heartbeat_active() && !qr->qr_numregions) {
994 		mlog(ML_ERROR, "Domain %s: Local node %d has global "
995 		     "heartbeat enabled but joining node %d does not\n",
996 		     qr->qr_domain, dlm->node_num, qr->qr_node);
997 		status = -EINVAL;
998 		goto bail;
999 	}
1000 
1001 	r = remote;
1002 	for (i = 0; i < qr->qr_numregions; ++i) {
1003 		mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, r);
1004 		r += O2HB_MAX_REGION_NAME_LEN;
1005 	}
1006 
1007 	localnr = min(O2NM_MAX_REGIONS, locallen/O2HB_MAX_REGION_NAME_LEN);
1008 	localnr = o2hb_get_all_regions(local, (u8)localnr);
1009 
1010 	/* compare local regions with remote */
1011 	l = local;
1012 	for (i = 0; i < localnr; ++i) {
1013 		foundit = 0;
1014 		r = remote;
1015 		for (j = 0; j <= qr->qr_numregions; ++j) {
1016 			if (!memcmp(l, r, O2HB_MAX_REGION_NAME_LEN)) {
1017 				foundit = 1;
1018 				break;
1019 			}
1020 			r += O2HB_MAX_REGION_NAME_LEN;
1021 		}
1022 		if (!foundit) {
1023 			status = -EINVAL;
1024 			mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1025 			     "in local node %d but not in joining node %d\n",
1026 			     qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, l,
1027 			     dlm->node_num, qr->qr_node);
1028 			goto bail;
1029 		}
1030 		l += O2HB_MAX_REGION_NAME_LEN;
1031 	}
1032 
1033 	/* compare remote with local regions */
1034 	r = remote;
1035 	for (i = 0; i < qr->qr_numregions; ++i) {
1036 		foundit = 0;
1037 		l = local;
1038 		for (j = 0; j < localnr; ++j) {
1039 			if (!memcmp(r, l, O2HB_MAX_REGION_NAME_LEN)) {
1040 				foundit = 1;
1041 				break;
1042 			}
1043 			l += O2HB_MAX_REGION_NAME_LEN;
1044 		}
1045 		if (!foundit) {
1046 			status = -EINVAL;
1047 			mlog(ML_ERROR, "Domain %s: Region '%.*s' registered "
1048 			     "in joining node %d but not in local node %d\n",
1049 			     qr->qr_domain, O2HB_MAX_REGION_NAME_LEN, r,
1050 			     qr->qr_node, dlm->node_num);
1051 			goto bail;
1052 		}
1053 		r += O2HB_MAX_REGION_NAME_LEN;
1054 	}
1055 
1056 bail:
1057 	return status;
1058 }
1059 
dlm_send_regions(struct dlm_ctxt * dlm,unsigned long * node_map)1060 static int dlm_send_regions(struct dlm_ctxt *dlm, unsigned long *node_map)
1061 {
1062 	struct dlm_query_region *qr = NULL;
1063 	int status, ret = 0, i;
1064 	char *p;
1065 
1066 	if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1067 		goto bail;
1068 
1069 	qr = kzalloc(sizeof(struct dlm_query_region), GFP_KERNEL);
1070 	if (!qr) {
1071 		ret = -ENOMEM;
1072 		mlog_errno(ret);
1073 		goto bail;
1074 	}
1075 
1076 	qr->qr_node = dlm->node_num;
1077 	qr->qr_namelen = strlen(dlm->name);
1078 	memcpy(qr->qr_domain, dlm->name, qr->qr_namelen);
1079 	/* if local hb, the numregions will be zero */
1080 	if (o2hb_global_heartbeat_active())
1081 		qr->qr_numregions = o2hb_get_all_regions(qr->qr_regions,
1082 							 O2NM_MAX_REGIONS);
1083 
1084 	p = qr->qr_regions;
1085 	for (i = 0; i < qr->qr_numregions; ++i, p += O2HB_MAX_REGION_NAME_LEN)
1086 		mlog(0, "Region %.*s\n", O2HB_MAX_REGION_NAME_LEN, p);
1087 
1088 	i = -1;
1089 	while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1090 				  i + 1)) < O2NM_MAX_NODES) {
1091 		if (i == dlm->node_num)
1092 			continue;
1093 
1094 		mlog(0, "Sending regions to node %d\n", i);
1095 
1096 		ret = o2net_send_message(DLM_QUERY_REGION, DLM_MOD_KEY, qr,
1097 					 sizeof(struct dlm_query_region),
1098 					 i, &status);
1099 		if (ret >= 0)
1100 			ret = status;
1101 		if (ret) {
1102 			mlog(ML_ERROR, "Region mismatch %d, node %d\n",
1103 			     ret, i);
1104 			break;
1105 		}
1106 	}
1107 
1108 bail:
1109 	kfree(qr);
1110 	return ret;
1111 }
1112 
dlm_query_region_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)1113 static int dlm_query_region_handler(struct o2net_msg *msg, u32 len,
1114 				    void *data, void **ret_data)
1115 {
1116 	struct dlm_query_region *qr;
1117 	struct dlm_ctxt *dlm = NULL;
1118 	char *local = NULL;
1119 	int status = 0;
1120 
1121 	qr = (struct dlm_query_region *) msg->buf;
1122 
1123 	mlog(0, "Node %u queries hb regions on domain %s\n", qr->qr_node,
1124 	     qr->qr_domain);
1125 
1126 	/* buffer used in dlm_mast_regions() */
1127 	local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);
1128 	if (!local)
1129 		return -ENOMEM;
1130 
1131 	status = -EINVAL;
1132 
1133 	spin_lock(&dlm_domain_lock);
1134 	dlm = __dlm_lookup_domain_full(qr->qr_domain, qr->qr_namelen);
1135 	if (!dlm) {
1136 		mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1137 		     "before join domain\n", qr->qr_node, qr->qr_domain);
1138 		goto out_domain_lock;
1139 	}
1140 
1141 	spin_lock(&dlm->spinlock);
1142 	if (dlm->joining_node != qr->qr_node) {
1143 		mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1144 		     "but joining node is %d\n", qr->qr_node, qr->qr_domain,
1145 		     dlm->joining_node);
1146 		goto out_dlm_lock;
1147 	}
1148 
1149 	/* Support for global heartbeat was added in 1.1 */
1150 	if (dlm->dlm_locking_proto.pv_major == 1 &&
1151 	    dlm->dlm_locking_proto.pv_minor == 0) {
1152 		mlog(ML_ERROR, "Node %d queried hb regions on domain %s "
1153 		     "but active dlm protocol is %d.%d\n", qr->qr_node,
1154 		     qr->qr_domain, dlm->dlm_locking_proto.pv_major,
1155 		     dlm->dlm_locking_proto.pv_minor);
1156 		goto out_dlm_lock;
1157 	}
1158 
1159 	status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));
1160 
1161 out_dlm_lock:
1162 	spin_unlock(&dlm->spinlock);
1163 
1164 out_domain_lock:
1165 	spin_unlock(&dlm_domain_lock);
1166 
1167 	kfree(local);
1168 
1169 	return status;
1170 }
1171 
dlm_match_nodes(struct dlm_ctxt * dlm,struct dlm_query_nodeinfo * qn)1172 static int dlm_match_nodes(struct dlm_ctxt *dlm, struct dlm_query_nodeinfo *qn)
1173 {
1174 	struct o2nm_node *local;
1175 	struct dlm_node_info *remote;
1176 	int i, j;
1177 	int status = 0;
1178 
1179 	for (j = 0; j < qn->qn_numnodes; ++j)
1180 		mlog(0, "Node %3d, %pI4:%u\n", qn->qn_nodes[j].ni_nodenum,
1181 		     &(qn->qn_nodes[j].ni_ipv4_address),
1182 		     ntohs(qn->qn_nodes[j].ni_ipv4_port));
1183 
1184 	for (i = 0; i < O2NM_MAX_NODES && !status; ++i) {
1185 		local = o2nm_get_node_by_num(i);
1186 		remote = NULL;
1187 		for (j = 0; j < qn->qn_numnodes; ++j) {
1188 			if (qn->qn_nodes[j].ni_nodenum == i) {
1189 				remote = &(qn->qn_nodes[j]);
1190 				break;
1191 			}
1192 		}
1193 
1194 		if (!local && !remote)
1195 			continue;
1196 
1197 		if ((local && !remote) || (!local && remote))
1198 			status = -EINVAL;
1199 
1200 		if (!status &&
1201 		    ((remote->ni_nodenum != local->nd_num) ||
1202 		     (remote->ni_ipv4_port != local->nd_ipv4_port) ||
1203 		     (remote->ni_ipv4_address != local->nd_ipv4_address)))
1204 			status = -EINVAL;
1205 
1206 		if (status) {
1207 			if (remote && !local)
1208 				mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1209 				     "registered in joining node %d but not in "
1210 				     "local node %d\n", qn->qn_domain,
1211 				     remote->ni_nodenum,
1212 				     &(remote->ni_ipv4_address),
1213 				     ntohs(remote->ni_ipv4_port),
1214 				     qn->qn_nodenum, dlm->node_num);
1215 			if (local && !remote)
1216 				mlog(ML_ERROR, "Domain %s: Node %d (%pI4:%u) "
1217 				     "registered in local node %d but not in "
1218 				     "joining node %d\n", qn->qn_domain,
1219 				     local->nd_num, &(local->nd_ipv4_address),
1220 				     ntohs(local->nd_ipv4_port),
1221 				     dlm->node_num, qn->qn_nodenum);
1222 			BUG_ON((!local && !remote));
1223 		}
1224 
1225 		if (local)
1226 			o2nm_node_put(local);
1227 	}
1228 
1229 	return status;
1230 }
1231 
dlm_send_nodeinfo(struct dlm_ctxt * dlm,unsigned long * node_map)1232 static int dlm_send_nodeinfo(struct dlm_ctxt *dlm, unsigned long *node_map)
1233 {
1234 	struct dlm_query_nodeinfo *qn = NULL;
1235 	struct o2nm_node *node;
1236 	int ret = 0, status, count, i;
1237 
1238 	if (find_next_bit(node_map, O2NM_MAX_NODES, 0) >= O2NM_MAX_NODES)
1239 		goto bail;
1240 
1241 	qn = kzalloc(sizeof(struct dlm_query_nodeinfo), GFP_KERNEL);
1242 	if (!qn) {
1243 		ret = -ENOMEM;
1244 		mlog_errno(ret);
1245 		goto bail;
1246 	}
1247 
1248 	for (i = 0, count = 0; i < O2NM_MAX_NODES; ++i) {
1249 		node = o2nm_get_node_by_num(i);
1250 		if (!node)
1251 			continue;
1252 		qn->qn_nodes[count].ni_nodenum = node->nd_num;
1253 		qn->qn_nodes[count].ni_ipv4_port = node->nd_ipv4_port;
1254 		qn->qn_nodes[count].ni_ipv4_address = node->nd_ipv4_address;
1255 		mlog(0, "Node %3d, %pI4:%u\n", node->nd_num,
1256 		     &(node->nd_ipv4_address), ntohs(node->nd_ipv4_port));
1257 		++count;
1258 		o2nm_node_put(node);
1259 	}
1260 
1261 	qn->qn_nodenum = dlm->node_num;
1262 	qn->qn_numnodes = count;
1263 	qn->qn_namelen = strlen(dlm->name);
1264 	memcpy(qn->qn_domain, dlm->name, qn->qn_namelen);
1265 
1266 	i = -1;
1267 	while ((i = find_next_bit(node_map, O2NM_MAX_NODES,
1268 				  i + 1)) < O2NM_MAX_NODES) {
1269 		if (i == dlm->node_num)
1270 			continue;
1271 
1272 		mlog(0, "Sending nodeinfo to node %d\n", i);
1273 
1274 		ret = o2net_send_message(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
1275 					 qn, sizeof(struct dlm_query_nodeinfo),
1276 					 i, &status);
1277 		if (ret >= 0)
1278 			ret = status;
1279 		if (ret) {
1280 			mlog(ML_ERROR, "node mismatch %d, node %d\n", ret, i);
1281 			break;
1282 		}
1283 	}
1284 
1285 bail:
1286 	kfree(qn);
1287 	return ret;
1288 }
1289 
dlm_query_nodeinfo_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)1290 static int dlm_query_nodeinfo_handler(struct o2net_msg *msg, u32 len,
1291 				      void *data, void **ret_data)
1292 {
1293 	struct dlm_query_nodeinfo *qn;
1294 	struct dlm_ctxt *dlm = NULL;
1295 	int locked = 0, status = -EINVAL;
1296 
1297 	qn = (struct dlm_query_nodeinfo *) msg->buf;
1298 
1299 	mlog(0, "Node %u queries nodes on domain %s\n", qn->qn_nodenum,
1300 	     qn->qn_domain);
1301 
1302 	spin_lock(&dlm_domain_lock);
1303 	dlm = __dlm_lookup_domain_full(qn->qn_domain, qn->qn_namelen);
1304 	if (!dlm) {
1305 		mlog(ML_ERROR, "Node %d queried nodes on domain %s before "
1306 		     "join domain\n", qn->qn_nodenum, qn->qn_domain);
1307 		goto bail;
1308 	}
1309 
1310 	spin_lock(&dlm->spinlock);
1311 	locked = 1;
1312 	if (dlm->joining_node != qn->qn_nodenum) {
1313 		mlog(ML_ERROR, "Node %d queried nodes on domain %s but "
1314 		     "joining node is %d\n", qn->qn_nodenum, qn->qn_domain,
1315 		     dlm->joining_node);
1316 		goto bail;
1317 	}
1318 
1319 	/* Support for node query was added in 1.1 */
1320 	if (dlm->dlm_locking_proto.pv_major == 1 &&
1321 	    dlm->dlm_locking_proto.pv_minor == 0) {
1322 		mlog(ML_ERROR, "Node %d queried nodes on domain %s "
1323 		     "but active dlm protocol is %d.%d\n", qn->qn_nodenum,
1324 		     qn->qn_domain, dlm->dlm_locking_proto.pv_major,
1325 		     dlm->dlm_locking_proto.pv_minor);
1326 		goto bail;
1327 	}
1328 
1329 	status = dlm_match_nodes(dlm, qn);
1330 
1331 bail:
1332 	if (locked)
1333 		spin_unlock(&dlm->spinlock);
1334 	spin_unlock(&dlm_domain_lock);
1335 
1336 	return status;
1337 }
1338 
dlm_cancel_join_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)1339 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
1340 				   void **ret_data)
1341 {
1342 	struct dlm_cancel_join *cancel;
1343 	struct dlm_ctxt *dlm = NULL;
1344 
1345 	cancel = (struct dlm_cancel_join *) msg->buf;
1346 
1347 	mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
1348 		  cancel->domain);
1349 
1350 	spin_lock(&dlm_domain_lock);
1351 	dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
1352 
1353 	if (dlm) {
1354 		spin_lock(&dlm->spinlock);
1355 
1356 		/* Yikes, this guy wants to cancel his join. No
1357 		 * problem, we simply cleanup our join state. */
1358 		BUG_ON(dlm->joining_node != cancel->node_idx);
1359 		__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1360 
1361 		spin_unlock(&dlm->spinlock);
1362 	}
1363 	spin_unlock(&dlm_domain_lock);
1364 
1365 	return 0;
1366 }
1367 
dlm_send_one_join_cancel(struct dlm_ctxt * dlm,unsigned int node)1368 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
1369 				    unsigned int node)
1370 {
1371 	int status;
1372 	struct dlm_cancel_join cancel_msg;
1373 
1374 	memset(&cancel_msg, 0, sizeof(cancel_msg));
1375 	cancel_msg.node_idx = dlm->node_num;
1376 	cancel_msg.name_len = strlen(dlm->name);
1377 	memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
1378 
1379 	status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1380 				    &cancel_msg, sizeof(cancel_msg), node,
1381 				    NULL);
1382 	if (status < 0) {
1383 		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1384 		     "node %u\n", status, DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1385 		     node);
1386 		goto bail;
1387 	}
1388 
1389 bail:
1390 	return status;
1391 }
1392 
1393 /* map_size should be in bytes. */
dlm_send_join_cancels(struct dlm_ctxt * dlm,unsigned long * node_map,unsigned int map_size)1394 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
1395 				 unsigned long *node_map,
1396 				 unsigned int map_size)
1397 {
1398 	int status, tmpstat;
1399 	int node;
1400 
1401 	if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
1402 			 sizeof(unsigned long))) {
1403 		mlog(ML_ERROR,
1404 		     "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
1405 		     map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
1406 		return -EINVAL;
1407 	}
1408 
1409 	status = 0;
1410 	node = -1;
1411 	while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1412 				     node + 1)) < O2NM_MAX_NODES) {
1413 		if (node == dlm->node_num)
1414 			continue;
1415 
1416 		tmpstat = dlm_send_one_join_cancel(dlm, node);
1417 		if (tmpstat) {
1418 			mlog(ML_ERROR, "Error return %d cancelling join on "
1419 			     "node %d\n", tmpstat, node);
1420 			if (!status)
1421 				status = tmpstat;
1422 		}
1423 	}
1424 
1425 	if (status)
1426 		mlog_errno(status);
1427 	return status;
1428 }
1429 
dlm_request_join(struct dlm_ctxt * dlm,int node,enum dlm_query_join_response_code * response)1430 static int dlm_request_join(struct dlm_ctxt *dlm,
1431 			    int node,
1432 			    enum dlm_query_join_response_code *response)
1433 {
1434 	int status;
1435 	struct dlm_query_join_request join_msg;
1436 	struct dlm_query_join_packet packet;
1437 	u32 join_resp;
1438 
1439 	mlog(0, "querying node %d\n", node);
1440 
1441 	memset(&join_msg, 0, sizeof(join_msg));
1442 	join_msg.node_idx = dlm->node_num;
1443 	join_msg.name_len = strlen(dlm->name);
1444 	memcpy(join_msg.domain, dlm->name, join_msg.name_len);
1445 	join_msg.dlm_proto = dlm->dlm_locking_proto;
1446 	join_msg.fs_proto = dlm->fs_locking_proto;
1447 
1448 	/* copy live node map to join message */
1449 	byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
1450 
1451 	status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
1452 				    sizeof(join_msg), node, &join_resp);
1453 	if (status < 0 && status != -ENOPROTOOPT) {
1454 		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1455 		     "node %u\n", status, DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1456 		     node);
1457 		goto bail;
1458 	}
1459 	dlm_query_join_wire_to_packet(join_resp, &packet);
1460 
1461 	/* -ENOPROTOOPT from the net code means the other side isn't
1462 	    listening for our message type -- that's fine, it means
1463 	    his dlm isn't up, so we can consider him a 'yes' but not
1464 	    joined into the domain.  */
1465 	if (status == -ENOPROTOOPT) {
1466 		status = 0;
1467 		*response = JOIN_OK_NO_MAP;
1468 	} else {
1469 		*response = packet.code;
1470 		switch (packet.code) {
1471 		case JOIN_DISALLOW:
1472 		case JOIN_OK_NO_MAP:
1473 			break;
1474 		case JOIN_PROTOCOL_MISMATCH:
1475 			mlog(ML_NOTICE,
1476 			     "This node requested DLM locking protocol %u.%u and "
1477 			     "filesystem locking protocol %u.%u.  At least one of "
1478 			     "the protocol versions on node %d is not compatible, "
1479 			     "disconnecting\n",
1480 			     dlm->dlm_locking_proto.pv_major,
1481 			     dlm->dlm_locking_proto.pv_minor,
1482 			     dlm->fs_locking_proto.pv_major,
1483 			     dlm->fs_locking_proto.pv_minor,
1484 			     node);
1485 			status = -EPROTO;
1486 			break;
1487 		case JOIN_OK:
1488 			/* Use the same locking protocol as the remote node */
1489 			dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
1490 			dlm->fs_locking_proto.pv_minor = packet.fs_minor;
1491 			mlog(0,
1492 			     "Node %d responds JOIN_OK with DLM locking protocol "
1493 			     "%u.%u and fs locking protocol %u.%u\n",
1494 			     node,
1495 			     dlm->dlm_locking_proto.pv_major,
1496 			     dlm->dlm_locking_proto.pv_minor,
1497 			     dlm->fs_locking_proto.pv_major,
1498 			     dlm->fs_locking_proto.pv_minor);
1499 			break;
1500 		default:
1501 			status = -EINVAL;
1502 			mlog(ML_ERROR, "invalid response %d from node %u\n",
1503 			     packet.code, node);
1504 			/* Reset response to JOIN_DISALLOW */
1505 			*response = JOIN_DISALLOW;
1506 			break;
1507 		}
1508 	}
1509 
1510 	mlog(0, "status %d, node %d response is %d\n", status, node,
1511 	     *response);
1512 
1513 bail:
1514 	return status;
1515 }
1516 
dlm_send_one_join_assert(struct dlm_ctxt * dlm,unsigned int node)1517 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
1518 				    unsigned int node)
1519 {
1520 	int status;
1521 	int ret;
1522 	struct dlm_assert_joined assert_msg;
1523 
1524 	mlog(0, "Sending join assert to node %u\n", node);
1525 
1526 	memset(&assert_msg, 0, sizeof(assert_msg));
1527 	assert_msg.node_idx = dlm->node_num;
1528 	assert_msg.name_len = strlen(dlm->name);
1529 	memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
1530 
1531 	status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1532 				    &assert_msg, sizeof(assert_msg), node,
1533 				    &ret);
1534 	if (status < 0)
1535 		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
1536 		     "node %u\n", status, DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1537 		     node);
1538 	else
1539 		status = ret;
1540 
1541 	return status;
1542 }
1543 
dlm_send_join_asserts(struct dlm_ctxt * dlm,unsigned long * node_map)1544 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
1545 				  unsigned long *node_map)
1546 {
1547 	int status, node, live;
1548 
1549 	status = 0;
1550 	node = -1;
1551 	while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
1552 				     node + 1)) < O2NM_MAX_NODES) {
1553 		if (node == dlm->node_num)
1554 			continue;
1555 
1556 		do {
1557 			/* It is very important that this message be
1558 			 * received so we spin until either the node
1559 			 * has died or it gets the message. */
1560 			status = dlm_send_one_join_assert(dlm, node);
1561 
1562 			spin_lock(&dlm->spinlock);
1563 			live = test_bit(node, dlm->live_nodes_map);
1564 			spin_unlock(&dlm->spinlock);
1565 
1566 			if (status) {
1567 				mlog(ML_ERROR, "Error return %d asserting "
1568 				     "join on node %d\n", status, node);
1569 
1570 				/* give us some time between errors... */
1571 				if (live)
1572 					msleep(DLM_DOMAIN_BACKOFF_MS);
1573 			}
1574 		} while (status && live);
1575 	}
1576 }
1577 
1578 struct domain_join_ctxt {
1579 	unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1580 	unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1581 };
1582 
dlm_should_restart_join(struct dlm_ctxt * dlm,struct domain_join_ctxt * ctxt,enum dlm_query_join_response_code response)1583 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
1584 				   struct domain_join_ctxt *ctxt,
1585 				   enum dlm_query_join_response_code response)
1586 {
1587 	int ret;
1588 
1589 	if (response == JOIN_DISALLOW) {
1590 		mlog(0, "Latest response of disallow -- should restart\n");
1591 		return 1;
1592 	}
1593 
1594 	spin_lock(&dlm->spinlock);
1595 	/* For now, we restart the process if the node maps have
1596 	 * changed at all */
1597 	ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
1598 		     sizeof(dlm->live_nodes_map));
1599 	spin_unlock(&dlm->spinlock);
1600 
1601 	if (ret)
1602 		mlog(0, "Node maps changed -- should restart\n");
1603 
1604 	return ret;
1605 }
1606 
dlm_try_to_join_domain(struct dlm_ctxt * dlm)1607 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
1608 {
1609 	int status = 0, tmpstat, node;
1610 	struct domain_join_ctxt *ctxt;
1611 	enum dlm_query_join_response_code response = JOIN_DISALLOW;
1612 
1613 	mlog(0, "%p", dlm);
1614 
1615 	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
1616 	if (!ctxt) {
1617 		status = -ENOMEM;
1618 		mlog_errno(status);
1619 		goto bail;
1620 	}
1621 
1622 	/* group sem locking should work for us here -- we're already
1623 	 * registered for heartbeat events so filling this should be
1624 	 * atomic wrt getting those handlers called. */
1625 	o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
1626 
1627 	spin_lock(&dlm->spinlock);
1628 	memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
1629 
1630 	__dlm_set_joining_node(dlm, dlm->node_num);
1631 
1632 	spin_unlock(&dlm->spinlock);
1633 
1634 	node = -1;
1635 	while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
1636 				     node + 1)) < O2NM_MAX_NODES) {
1637 		if (node == dlm->node_num)
1638 			continue;
1639 
1640 		status = dlm_request_join(dlm, node, &response);
1641 		if (status < 0) {
1642 			mlog_errno(status);
1643 			goto bail;
1644 		}
1645 
1646 		/* Ok, either we got a response or the node doesn't have a
1647 		 * dlm up. */
1648 		if (response == JOIN_OK)
1649 			set_bit(node, ctxt->yes_resp_map);
1650 
1651 		if (dlm_should_restart_join(dlm, ctxt, response)) {
1652 			status = -EAGAIN;
1653 			goto bail;
1654 		}
1655 	}
1656 
1657 	mlog(0, "Yay, done querying nodes!\n");
1658 
1659 	/* Yay, everyone agree's we can join the domain. My domain is
1660 	 * comprised of all nodes who were put in the
1661 	 * yes_resp_map. Copy that into our domain map and send a join
1662 	 * assert message to clean up everyone elses state. */
1663 	spin_lock(&dlm->spinlock);
1664 	memcpy(dlm->domain_map, ctxt->yes_resp_map,
1665 	       sizeof(ctxt->yes_resp_map));
1666 	set_bit(dlm->node_num, dlm->domain_map);
1667 	spin_unlock(&dlm->spinlock);
1668 
1669 	/* Support for global heartbeat and node info was added in 1.1 */
1670 	if (dlm->dlm_locking_proto.pv_major > 1 ||
1671 	    dlm->dlm_locking_proto.pv_minor > 0) {
1672 		status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
1673 		if (status) {
1674 			mlog_errno(status);
1675 			goto bail;
1676 		}
1677 		status = dlm_send_regions(dlm, ctxt->yes_resp_map);
1678 		if (status) {
1679 			mlog_errno(status);
1680 			goto bail;
1681 		}
1682 	}
1683 
1684 	dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
1685 
1686 	/* Joined state *must* be set before the joining node
1687 	 * information, otherwise the query_join handler may read no
1688 	 * current joiner but a state of NEW and tell joining nodes
1689 	 * we're not in the domain. */
1690 	spin_lock(&dlm_domain_lock);
1691 	dlm->dlm_state = DLM_CTXT_JOINED;
1692 	dlm->num_joins++;
1693 	spin_unlock(&dlm_domain_lock);
1694 
1695 bail:
1696 	spin_lock(&dlm->spinlock);
1697 	__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
1698 	if (!status) {
1699 		printk(KERN_NOTICE "o2dlm: Joining domain %s ", dlm->name);
1700 		__dlm_print_nodes(dlm);
1701 	}
1702 	spin_unlock(&dlm->spinlock);
1703 
1704 	if (ctxt) {
1705 		/* Do we need to send a cancel message to any nodes? */
1706 		if (status < 0) {
1707 			tmpstat = dlm_send_join_cancels(dlm,
1708 							ctxt->yes_resp_map,
1709 							sizeof(ctxt->yes_resp_map));
1710 			if (tmpstat < 0)
1711 				mlog_errno(tmpstat);
1712 		}
1713 		kfree(ctxt);
1714 	}
1715 
1716 	mlog(0, "returning %d\n", status);
1717 	return status;
1718 }
1719 
dlm_unregister_domain_handlers(struct dlm_ctxt * dlm)1720 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1721 {
1722 	o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_up);
1723 	o2hb_unregister_callback(dlm->name, &dlm->dlm_hb_down);
1724 	o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1725 }
1726 
dlm_register_domain_handlers(struct dlm_ctxt * dlm)1727 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1728 {
1729 	int status;
1730 
1731 	mlog(0, "registering handlers.\n");
1732 
1733 	o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1734 			    dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1735 	o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1736 			    dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1737 
1738 	status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
1739 	if (status)
1740 		goto bail;
1741 
1742 	status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
1743 	if (status)
1744 		goto bail;
1745 
1746 	status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1747 					sizeof(struct dlm_master_request),
1748 					dlm_master_request_handler,
1749 					dlm, NULL, &dlm->dlm_domain_handlers);
1750 	if (status)
1751 		goto bail;
1752 
1753 	status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1754 					sizeof(struct dlm_assert_master),
1755 					dlm_assert_master_handler,
1756 					dlm, dlm_assert_master_post_handler,
1757 					&dlm->dlm_domain_handlers);
1758 	if (status)
1759 		goto bail;
1760 
1761 	status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1762 					sizeof(struct dlm_create_lock),
1763 					dlm_create_lock_handler,
1764 					dlm, NULL, &dlm->dlm_domain_handlers);
1765 	if (status)
1766 		goto bail;
1767 
1768 	status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1769 					DLM_CONVERT_LOCK_MAX_LEN,
1770 					dlm_convert_lock_handler,
1771 					dlm, NULL, &dlm->dlm_domain_handlers);
1772 	if (status)
1773 		goto bail;
1774 
1775 	status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1776 					DLM_UNLOCK_LOCK_MAX_LEN,
1777 					dlm_unlock_lock_handler,
1778 					dlm, NULL, &dlm->dlm_domain_handlers);
1779 	if (status)
1780 		goto bail;
1781 
1782 	status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1783 					DLM_PROXY_AST_MAX_LEN,
1784 					dlm_proxy_ast_handler,
1785 					dlm, NULL, &dlm->dlm_domain_handlers);
1786 	if (status)
1787 		goto bail;
1788 
1789 	status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1790 					sizeof(struct dlm_exit_domain),
1791 					dlm_exit_domain_handler,
1792 					dlm, NULL, &dlm->dlm_domain_handlers);
1793 	if (status)
1794 		goto bail;
1795 
1796 	status = o2net_register_handler(DLM_DEREF_LOCKRES_MSG, dlm->key,
1797 					sizeof(struct dlm_deref_lockres),
1798 					dlm_deref_lockres_handler,
1799 					dlm, NULL, &dlm->dlm_domain_handlers);
1800 	if (status)
1801 		goto bail;
1802 
1803 	status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1804 					sizeof(struct dlm_migrate_request),
1805 					dlm_migrate_request_handler,
1806 					dlm, NULL, &dlm->dlm_domain_handlers);
1807 	if (status)
1808 		goto bail;
1809 
1810 	status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1811 					DLM_MIG_LOCKRES_MAX_LEN,
1812 					dlm_mig_lockres_handler,
1813 					dlm, NULL, &dlm->dlm_domain_handlers);
1814 	if (status)
1815 		goto bail;
1816 
1817 	status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1818 					sizeof(struct dlm_master_requery),
1819 					dlm_master_requery_handler,
1820 					dlm, NULL, &dlm->dlm_domain_handlers);
1821 	if (status)
1822 		goto bail;
1823 
1824 	status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1825 					sizeof(struct dlm_lock_request),
1826 					dlm_request_all_locks_handler,
1827 					dlm, NULL, &dlm->dlm_domain_handlers);
1828 	if (status)
1829 		goto bail;
1830 
1831 	status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1832 					sizeof(struct dlm_reco_data_done),
1833 					dlm_reco_data_done_handler,
1834 					dlm, NULL, &dlm->dlm_domain_handlers);
1835 	if (status)
1836 		goto bail;
1837 
1838 	status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1839 					sizeof(struct dlm_begin_reco),
1840 					dlm_begin_reco_handler,
1841 					dlm, NULL, &dlm->dlm_domain_handlers);
1842 	if (status)
1843 		goto bail;
1844 
1845 	status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1846 					sizeof(struct dlm_finalize_reco),
1847 					dlm_finalize_reco_handler,
1848 					dlm, NULL, &dlm->dlm_domain_handlers);
1849 	if (status)
1850 		goto bail;
1851 
1852 	status = o2net_register_handler(DLM_BEGIN_EXIT_DOMAIN_MSG, dlm->key,
1853 					sizeof(struct dlm_exit_domain),
1854 					dlm_begin_exit_domain_handler,
1855 					dlm, NULL, &dlm->dlm_domain_handlers);
1856 	if (status)
1857 		goto bail;
1858 
1859 	status = o2net_register_handler(DLM_DEREF_LOCKRES_DONE, dlm->key,
1860 					sizeof(struct dlm_deref_lockres_done),
1861 					dlm_deref_lockres_done_handler,
1862 					dlm, NULL, &dlm->dlm_domain_handlers);
1863 bail:
1864 	if (status)
1865 		dlm_unregister_domain_handlers(dlm);
1866 
1867 	return status;
1868 }
1869 
dlm_join_domain(struct dlm_ctxt * dlm)1870 static int dlm_join_domain(struct dlm_ctxt *dlm)
1871 {
1872 	int status;
1873 	unsigned int backoff;
1874 	unsigned int total_backoff = 0;
1875 	char wq_name[O2NM_MAX_NAME_LEN];
1876 
1877 	BUG_ON(!dlm);
1878 
1879 	mlog(0, "Join domain %s\n", dlm->name);
1880 
1881 	status = dlm_register_domain_handlers(dlm);
1882 	if (status) {
1883 		mlog_errno(status);
1884 		goto bail;
1885 	}
1886 
1887 	status = dlm_launch_thread(dlm);
1888 	if (status < 0) {
1889 		mlog_errno(status);
1890 		goto bail;
1891 	}
1892 
1893 	status = dlm_launch_recovery_thread(dlm);
1894 	if (status < 0) {
1895 		mlog_errno(status);
1896 		goto bail;
1897 	}
1898 
1899 	status = dlm_debug_init(dlm);
1900 	if (status < 0) {
1901 		mlog_errno(status);
1902 		goto bail;
1903 	}
1904 
1905 	snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
1906 	dlm->dlm_worker = alloc_workqueue(wq_name, WQ_MEM_RECLAIM, 0);
1907 	if (!dlm->dlm_worker) {
1908 		status = -ENOMEM;
1909 		mlog_errno(status);
1910 		goto bail;
1911 	}
1912 
1913 	do {
1914 		status = dlm_try_to_join_domain(dlm);
1915 
1916 		/* If we're racing another node to the join, then we
1917 		 * need to back off temporarily and let them
1918 		 * complete. */
1919 #define	DLM_JOIN_TIMEOUT_MSECS	90000
1920 		if (status == -EAGAIN) {
1921 			if (signal_pending(current)) {
1922 				status = -ERESTARTSYS;
1923 				goto bail;
1924 			}
1925 
1926 			if (total_backoff > DLM_JOIN_TIMEOUT_MSECS) {
1927 				status = -ERESTARTSYS;
1928 				mlog(ML_NOTICE, "Timed out joining dlm domain "
1929 				     "%s after %u msecs\n", dlm->name,
1930 				     total_backoff);
1931 				goto bail;
1932 			}
1933 
1934 			/*
1935 			 * <chip> After you!
1936 			 * <dale> No, after you!
1937 			 * <chip> I insist!
1938 			 * <dale> But you first!
1939 			 * ...
1940 			 */
1941 			backoff = (unsigned int)(jiffies & 0x3);
1942 			backoff *= DLM_DOMAIN_BACKOFF_MS;
1943 			total_backoff += backoff;
1944 			mlog(0, "backoff %d\n", backoff);
1945 			msleep(backoff);
1946 		}
1947 	} while (status == -EAGAIN);
1948 
1949 	if (status < 0) {
1950 		mlog_errno(status);
1951 		goto bail;
1952 	}
1953 
1954 	status = 0;
1955 bail:
1956 	wake_up(&dlm_domain_events);
1957 
1958 	if (status) {
1959 		dlm_unregister_domain_handlers(dlm);
1960 		dlm_debug_shutdown(dlm);
1961 		dlm_complete_thread(dlm);
1962 		dlm_complete_recovery_thread(dlm);
1963 		dlm_destroy_dlm_worker(dlm);
1964 	}
1965 
1966 	return status;
1967 }
1968 
dlm_alloc_ctxt(const char * domain,u32 key)1969 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1970 				u32 key)
1971 {
1972 	int i;
1973 	int ret;
1974 	struct dlm_ctxt *dlm = NULL;
1975 
1976 	dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1977 	if (!dlm) {
1978 		ret = -ENOMEM;
1979 		mlog_errno(ret);
1980 		goto leave;
1981 	}
1982 
1983 	dlm->name = kstrdup(domain, GFP_KERNEL);
1984 	if (dlm->name == NULL) {
1985 		ret = -ENOMEM;
1986 		mlog_errno(ret);
1987 		goto leave;
1988 	}
1989 
1990 	dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1991 	if (!dlm->lockres_hash) {
1992 		ret = -ENOMEM;
1993 		mlog_errno(ret);
1994 		goto leave;
1995 	}
1996 
1997 	for (i = 0; i < DLM_HASH_BUCKETS; i++)
1998 		INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1999 
2000 	dlm->master_hash = (struct hlist_head **)
2001 				dlm_alloc_pagevec(DLM_HASH_PAGES);
2002 	if (!dlm->master_hash) {
2003 		ret = -ENOMEM;
2004 		mlog_errno(ret);
2005 		goto leave;
2006 	}
2007 
2008 	for (i = 0; i < DLM_HASH_BUCKETS; i++)
2009 		INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
2010 
2011 	dlm->key = key;
2012 	dlm->node_num = o2nm_this_node();
2013 
2014 	ret = dlm_create_debugfs_subroot(dlm);
2015 	if (ret < 0)
2016 		goto leave;
2017 
2018 	spin_lock_init(&dlm->spinlock);
2019 	spin_lock_init(&dlm->master_lock);
2020 	spin_lock_init(&dlm->ast_lock);
2021 	spin_lock_init(&dlm->track_lock);
2022 	INIT_LIST_HEAD(&dlm->list);
2023 	INIT_LIST_HEAD(&dlm->dirty_list);
2024 	INIT_LIST_HEAD(&dlm->reco.resources);
2025 	INIT_LIST_HEAD(&dlm->reco.node_data);
2026 	INIT_LIST_HEAD(&dlm->purge_list);
2027 	INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
2028 	INIT_LIST_HEAD(&dlm->tracking_list);
2029 	dlm->reco.state = 0;
2030 
2031 	INIT_LIST_HEAD(&dlm->pending_asts);
2032 	INIT_LIST_HEAD(&dlm->pending_basts);
2033 
2034 	mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
2035 		  dlm->recovery_map, &(dlm->recovery_map[0]));
2036 
2037 	memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
2038 	memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
2039 	memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
2040 
2041 	dlm->dlm_thread_task = NULL;
2042 	dlm->dlm_reco_thread_task = NULL;
2043 	dlm->dlm_worker = NULL;
2044 	init_waitqueue_head(&dlm->dlm_thread_wq);
2045 	init_waitqueue_head(&dlm->dlm_reco_thread_wq);
2046 	init_waitqueue_head(&dlm->reco.event);
2047 	init_waitqueue_head(&dlm->ast_wq);
2048 	init_waitqueue_head(&dlm->migration_wq);
2049 	INIT_LIST_HEAD(&dlm->mle_hb_events);
2050 
2051 	dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
2052 	init_waitqueue_head(&dlm->dlm_join_events);
2053 
2054 	dlm->migrate_done = 0;
2055 
2056 	dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
2057 	dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
2058 
2059 	atomic_set(&dlm->res_tot_count, 0);
2060 	atomic_set(&dlm->res_cur_count, 0);
2061 	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
2062 		atomic_set(&dlm->mle_tot_count[i], 0);
2063 		atomic_set(&dlm->mle_cur_count[i], 0);
2064 	}
2065 
2066 	spin_lock_init(&dlm->work_lock);
2067 	INIT_LIST_HEAD(&dlm->work_list);
2068 	INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
2069 
2070 	kref_init(&dlm->dlm_refs);
2071 	dlm->dlm_state = DLM_CTXT_NEW;
2072 
2073 	INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
2074 
2075 	mlog(0, "context init: refcount %u\n",
2076 		  kref_read(&dlm->dlm_refs));
2077 
2078 leave:
2079 	if (ret < 0 && dlm) {
2080 		if (dlm->master_hash)
2081 			dlm_free_pagevec((void **)dlm->master_hash,
2082 					DLM_HASH_PAGES);
2083 
2084 		if (dlm->lockres_hash)
2085 			dlm_free_pagevec((void **)dlm->lockres_hash,
2086 					DLM_HASH_PAGES);
2087 
2088 		kfree(dlm->name);
2089 		kfree(dlm);
2090 		dlm = NULL;
2091 	}
2092 	return dlm;
2093 }
2094 
2095 /*
2096  * Compare a requested locking protocol version against the current one.
2097  *
2098  * If the major numbers are different, they are incompatible.
2099  * If the current minor is greater than the request, they are incompatible.
2100  * If the current minor is less than or equal to the request, they are
2101  * compatible, and the requester should run at the current minor version.
2102  */
dlm_protocol_compare(struct dlm_protocol_version * existing,struct dlm_protocol_version * request)2103 static int dlm_protocol_compare(struct dlm_protocol_version *existing,
2104 				struct dlm_protocol_version *request)
2105 {
2106 	if (existing->pv_major != request->pv_major)
2107 		return 1;
2108 
2109 	if (existing->pv_minor > request->pv_minor)
2110 		return 1;
2111 
2112 	if (existing->pv_minor < request->pv_minor)
2113 		request->pv_minor = existing->pv_minor;
2114 
2115 	return 0;
2116 }
2117 
2118 /*
2119  * dlm_register_domain: one-time setup per "domain".
2120  *
2121  * The filesystem passes in the requested locking version via proto.
2122  * If registration was successful, proto will contain the negotiated
2123  * locking protocol.
2124  */
dlm_register_domain(const char * domain,u32 key,struct dlm_protocol_version * fs_proto)2125 struct dlm_ctxt * dlm_register_domain(const char *domain,
2126 			       u32 key,
2127 			       struct dlm_protocol_version *fs_proto)
2128 {
2129 	int ret;
2130 	struct dlm_ctxt *dlm = NULL;
2131 	struct dlm_ctxt *new_ctxt = NULL;
2132 
2133 	if (strlen(domain) >= O2NM_MAX_NAME_LEN) {
2134 		ret = -ENAMETOOLONG;
2135 		mlog(ML_ERROR, "domain name length too long\n");
2136 		goto leave;
2137 	}
2138 
2139 	mlog(0, "register called for domain \"%s\"\n", domain);
2140 
2141 retry:
2142 	dlm = NULL;
2143 	if (signal_pending(current)) {
2144 		ret = -ERESTARTSYS;
2145 		mlog_errno(ret);
2146 		goto leave;
2147 	}
2148 
2149 	spin_lock(&dlm_domain_lock);
2150 
2151 	dlm = __dlm_lookup_domain(domain);
2152 	if (dlm) {
2153 		if (dlm->dlm_state != DLM_CTXT_JOINED) {
2154 			spin_unlock(&dlm_domain_lock);
2155 
2156 			mlog(0, "This ctxt is not joined yet!\n");
2157 			wait_event_interruptible(dlm_domain_events,
2158 						 dlm_wait_on_domain_helper(
2159 							 domain));
2160 			goto retry;
2161 		}
2162 
2163 		if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
2164 			spin_unlock(&dlm_domain_lock);
2165 			mlog(ML_ERROR,
2166 			     "Requested locking protocol version is not "
2167 			     "compatible with already registered domain "
2168 			     "\"%s\"\n", domain);
2169 			ret = -EPROTO;
2170 			goto leave;
2171 		}
2172 
2173 		__dlm_get(dlm);
2174 		dlm->num_joins++;
2175 
2176 		spin_unlock(&dlm_domain_lock);
2177 
2178 		ret = 0;
2179 		goto leave;
2180 	}
2181 
2182 	/* doesn't exist */
2183 	if (!new_ctxt) {
2184 		spin_unlock(&dlm_domain_lock);
2185 
2186 		new_ctxt = dlm_alloc_ctxt(domain, key);
2187 		if (new_ctxt)
2188 			goto retry;
2189 
2190 		ret = -ENOMEM;
2191 		mlog_errno(ret);
2192 		goto leave;
2193 	}
2194 
2195 	/* a little variable switch-a-roo here... */
2196 	dlm = new_ctxt;
2197 	new_ctxt = NULL;
2198 
2199 	/* add the new domain */
2200 	list_add_tail(&dlm->list, &dlm_domains);
2201 	spin_unlock(&dlm_domain_lock);
2202 
2203 	/*
2204 	 * Pass the locking protocol version into the join.  If the join
2205 	 * succeeds, it will have the negotiated protocol set.
2206 	 */
2207 	dlm->dlm_locking_proto = dlm_protocol;
2208 	dlm->fs_locking_proto = *fs_proto;
2209 
2210 	ret = dlm_join_domain(dlm);
2211 	if (ret) {
2212 		mlog_errno(ret);
2213 		dlm_put(dlm);
2214 		goto leave;
2215 	}
2216 
2217 	/* Tell the caller what locking protocol we negotiated */
2218 	*fs_proto = dlm->fs_locking_proto;
2219 
2220 	ret = 0;
2221 leave:
2222 	if (new_ctxt)
2223 		dlm_free_ctxt_mem(new_ctxt);
2224 
2225 	if (ret < 0)
2226 		dlm = ERR_PTR(ret);
2227 
2228 	return dlm;
2229 }
2230 EXPORT_SYMBOL_GPL(dlm_register_domain);
2231 
2232 static LIST_HEAD(dlm_join_handlers);
2233 
dlm_unregister_net_handlers(void)2234 static void dlm_unregister_net_handlers(void)
2235 {
2236 	o2net_unregister_handler_list(&dlm_join_handlers);
2237 }
2238 
dlm_register_net_handlers(void)2239 static int dlm_register_net_handlers(void)
2240 {
2241 	int status = 0;
2242 
2243 	status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
2244 					sizeof(struct dlm_query_join_request),
2245 					dlm_query_join_handler,
2246 					NULL, NULL, &dlm_join_handlers);
2247 	if (status)
2248 		goto bail;
2249 
2250 	status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
2251 					sizeof(struct dlm_assert_joined),
2252 					dlm_assert_joined_handler,
2253 					NULL, NULL, &dlm_join_handlers);
2254 	if (status)
2255 		goto bail;
2256 
2257 	status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
2258 					sizeof(struct dlm_cancel_join),
2259 					dlm_cancel_join_handler,
2260 					NULL, NULL, &dlm_join_handlers);
2261 	if (status)
2262 		goto bail;
2263 
2264 	status = o2net_register_handler(DLM_QUERY_REGION, DLM_MOD_KEY,
2265 					sizeof(struct dlm_query_region),
2266 					dlm_query_region_handler,
2267 					NULL, NULL, &dlm_join_handlers);
2268 
2269 	if (status)
2270 		goto bail;
2271 
2272 	status = o2net_register_handler(DLM_QUERY_NODEINFO, DLM_MOD_KEY,
2273 					sizeof(struct dlm_query_nodeinfo),
2274 					dlm_query_nodeinfo_handler,
2275 					NULL, NULL, &dlm_join_handlers);
2276 bail:
2277 	if (status < 0)
2278 		dlm_unregister_net_handlers();
2279 
2280 	return status;
2281 }
2282 
2283 /* Domain eviction callback handling.
2284  *
2285  * The file system requires notification of node death *before* the
2286  * dlm completes it's recovery work, otherwise it may be able to
2287  * acquire locks on resources requiring recovery. Since the dlm can
2288  * evict a node from it's domain *before* heartbeat fires, a similar
2289  * mechanism is required. */
2290 
2291 /* Eviction is not expected to happen often, so a per-domain lock is
2292  * not necessary. Eviction callbacks are allowed to sleep for short
2293  * periods of time. */
2294 static DECLARE_RWSEM(dlm_callback_sem);
2295 
dlm_fire_domain_eviction_callbacks(struct dlm_ctxt * dlm,int node_num)2296 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
2297 					int node_num)
2298 {
2299 	struct dlm_eviction_cb *cb;
2300 
2301 	down_read(&dlm_callback_sem);
2302 	list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
2303 		cb->ec_func(node_num, cb->ec_data);
2304 	}
2305 	up_read(&dlm_callback_sem);
2306 }
2307 
dlm_setup_eviction_cb(struct dlm_eviction_cb * cb,dlm_eviction_func * f,void * data)2308 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
2309 			   dlm_eviction_func *f,
2310 			   void *data)
2311 {
2312 	INIT_LIST_HEAD(&cb->ec_item);
2313 	cb->ec_func = f;
2314 	cb->ec_data = data;
2315 }
2316 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
2317 
dlm_register_eviction_cb(struct dlm_ctxt * dlm,struct dlm_eviction_cb * cb)2318 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
2319 			      struct dlm_eviction_cb *cb)
2320 {
2321 	down_write(&dlm_callback_sem);
2322 	list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
2323 	up_write(&dlm_callback_sem);
2324 }
2325 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
2326 
dlm_unregister_eviction_cb(struct dlm_eviction_cb * cb)2327 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
2328 {
2329 	down_write(&dlm_callback_sem);
2330 	list_del_init(&cb->ec_item);
2331 	up_write(&dlm_callback_sem);
2332 }
2333 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
2334 
dlm_init(void)2335 static int __init dlm_init(void)
2336 {
2337 	int status;
2338 
2339 	status = dlm_init_mle_cache();
2340 	if (status) {
2341 		mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
2342 		goto error;
2343 	}
2344 
2345 	status = dlm_init_master_caches();
2346 	if (status) {
2347 		mlog(ML_ERROR, "Could not create o2dlm_lockres and "
2348 		     "o2dlm_lockname slabcaches\n");
2349 		goto error;
2350 	}
2351 
2352 	status = dlm_init_lock_cache();
2353 	if (status) {
2354 		mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
2355 		goto error;
2356 	}
2357 
2358 	status = dlm_register_net_handlers();
2359 	if (status) {
2360 		mlog(ML_ERROR, "Unable to register network handlers\n");
2361 		goto error;
2362 	}
2363 
2364 	status = dlm_create_debugfs_root();
2365 	if (status)
2366 		goto error;
2367 
2368 	return 0;
2369 error:
2370 	dlm_unregister_net_handlers();
2371 	dlm_destroy_lock_cache();
2372 	dlm_destroy_master_caches();
2373 	dlm_destroy_mle_cache();
2374 	return -1;
2375 }
2376 
dlm_exit(void)2377 static void __exit dlm_exit (void)
2378 {
2379 	dlm_destroy_debugfs_root();
2380 	dlm_unregister_net_handlers();
2381 	dlm_destroy_lock_cache();
2382 	dlm_destroy_master_caches();
2383 	dlm_destroy_mle_cache();
2384 }
2385 
2386 MODULE_AUTHOR("Oracle");
2387 MODULE_LICENSE("GPL");
2388 MODULE_DESCRIPTION("OCFS2 Distributed Lock Management");
2389 
2390 module_init(dlm_init);
2391 module_exit(dlm_exit);
2392