xref: /openbmc/linux/fs/ocfs2/dlm/dlmrecovery.c (revision cd34edd8cf80b507bb84b3f0c2988fe05099ffb5)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmrecovery.c
5  *
6  * recovery stuff
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 
28 #include <linux/module.h>
29 #include <linux/fs.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/init.h>
34 #include <linux/sysctl.h>
35 #include <linux/random.h>
36 #include <linux/blkdev.h>
37 #include <linux/socket.h>
38 #include <linux/inet.h>
39 #include <linux/timer.h>
40 #include <linux/kthread.h>
41 #include <linux/delay.h>
42 
43 
44 #include "cluster/heartbeat.h"
45 #include "cluster/nodemanager.h"
46 #include "cluster/tcp.h"
47 
48 #include "dlmapi.h"
49 #include "dlmcommon.h"
50 #include "dlmdomain.h"
51 
52 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
53 #include "cluster/masklog.h"
54 
55 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
56 
57 static int dlm_recovery_thread(void *data);
58 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
59 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
60 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
61 static int dlm_do_recovery(struct dlm_ctxt *dlm);
62 
63 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
64 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
65 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
66 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
67 				 u8 request_from, u8 dead_node);
68 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
69 
70 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
71 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
72 					const char *lockname, int namelen,
73 					int total_locks, u64 cookie,
74 					u8 flags, u8 master);
75 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
76 				    struct dlm_migratable_lockres *mres,
77 				    u8 send_to,
78 				    struct dlm_lock_resource *res,
79 				    int total_locks);
80 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
81 				     struct dlm_lock_resource *res,
82 				     struct dlm_migratable_lockres *mres);
83 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
84 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
85 				 u8 dead_node, u8 send_to);
86 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
87 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
88 					struct list_head *list, u8 dead_node);
89 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
90 					      u8 dead_node, u8 new_master);
91 static void dlm_reco_ast(void *astdata);
92 static void dlm_reco_bast(void *astdata, int blocked_type);
93 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
94 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
95 					 void *data);
96 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
97 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
98 				      struct dlm_lock_resource *res,
99 				      u8 *real_master);
100 
101 static u64 dlm_get_next_mig_cookie(void);
102 
103 static DEFINE_SPINLOCK(dlm_reco_state_lock);
104 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
105 static u64 dlm_mig_cookie = 1;
106 
107 static u64 dlm_get_next_mig_cookie(void)
108 {
109 	u64 c;
110 	spin_lock(&dlm_mig_cookie_lock);
111 	c = dlm_mig_cookie;
112 	if (dlm_mig_cookie == (~0ULL))
113 		dlm_mig_cookie = 1;
114 	else
115 		dlm_mig_cookie++;
116 	spin_unlock(&dlm_mig_cookie_lock);
117 	return c;
118 }
119 
120 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
121 					  u8 dead_node)
122 {
123 	assert_spin_locked(&dlm->spinlock);
124 	if (dlm->reco.dead_node != dead_node)
125 		mlog(0, "%s: changing dead_node from %u to %u\n",
126 		     dlm->name, dlm->reco.dead_node, dead_node);
127 	dlm->reco.dead_node = dead_node;
128 }
129 
130 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
131 				       u8 master)
132 {
133 	assert_spin_locked(&dlm->spinlock);
134 	mlog(0, "%s: changing new_master from %u to %u\n",
135 	     dlm->name, dlm->reco.new_master, master);
136 	dlm->reco.new_master = master;
137 }
138 
139 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
140 {
141 	assert_spin_locked(&dlm->spinlock);
142 	clear_bit(dlm->reco.dead_node, dlm->recovery_map);
143 	dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
144 	dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
145 }
146 
147 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
148 {
149 	spin_lock(&dlm->spinlock);
150 	__dlm_reset_recovery(dlm);
151 	spin_unlock(&dlm->spinlock);
152 }
153 
154 /* Worker function used during recovery. */
155 void dlm_dispatch_work(struct work_struct *work)
156 {
157 	struct dlm_ctxt *dlm =
158 		container_of(work, struct dlm_ctxt, dispatched_work);
159 	LIST_HEAD(tmp_list);
160 	struct dlm_work_item *item, *next;
161 	dlm_workfunc_t *workfunc;
162 	int tot=0;
163 
164 	spin_lock(&dlm->work_lock);
165 	list_splice_init(&dlm->work_list, &tmp_list);
166 	spin_unlock(&dlm->work_lock);
167 
168 	list_for_each_entry(item, &tmp_list, list) {
169 		tot++;
170 	}
171 	mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
172 
173 	list_for_each_entry_safe(item, next, &tmp_list, list) {
174 		workfunc = item->func;
175 		list_del_init(&item->list);
176 
177 		/* already have ref on dlm to avoid having
178 		 * it disappear.  just double-check. */
179 		BUG_ON(item->dlm != dlm);
180 
181 		/* this is allowed to sleep and
182 		 * call network stuff */
183 		workfunc(item, item->data);
184 
185 		dlm_put(dlm);
186 		kfree(item);
187 	}
188 }
189 
190 /*
191  * RECOVERY THREAD
192  */
193 
194 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
195 {
196 	/* wake the recovery thread
197 	 * this will wake the reco thread in one of three places
198 	 * 1) sleeping with no recovery happening
199 	 * 2) sleeping with recovery mastered elsewhere
200 	 * 3) recovery mastered here, waiting on reco data */
201 
202 	wake_up(&dlm->dlm_reco_thread_wq);
203 }
204 
205 /* Launch the recovery thread */
206 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
207 {
208 	mlog(0, "starting dlm recovery thread...\n");
209 
210 	dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
211 						"dlm_reco_thread");
212 	if (IS_ERR(dlm->dlm_reco_thread_task)) {
213 		mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
214 		dlm->dlm_reco_thread_task = NULL;
215 		return -EINVAL;
216 	}
217 
218 	return 0;
219 }
220 
221 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
222 {
223 	if (dlm->dlm_reco_thread_task) {
224 		mlog(0, "waiting for dlm recovery thread to exit\n");
225 		kthread_stop(dlm->dlm_reco_thread_task);
226 		dlm->dlm_reco_thread_task = NULL;
227 	}
228 }
229 
230 
231 
232 /*
233  * this is lame, but here's how recovery works...
234  * 1) all recovery threads cluster wide will work on recovering
235  *    ONE node at a time
236  * 2) negotiate who will take over all the locks for the dead node.
237  *    thats right... ALL the locks.
238  * 3) once a new master is chosen, everyone scans all locks
239  *    and moves aside those mastered by the dead guy
240  * 4) each of these locks should be locked until recovery is done
241  * 5) the new master collects up all of secondary lock queue info
242  *    one lock at a time, forcing each node to communicate back
243  *    before continuing
244  * 6) each secondary lock queue responds with the full known lock info
245  * 7) once the new master has run all its locks, it sends a ALLDONE!
246  *    message to everyone
247  * 8) upon receiving this message, the secondary queue node unlocks
248  *    and responds to the ALLDONE
249  * 9) once the new master gets responses from everyone, he unlocks
250  *    everything and recovery for this dead node is done
251  *10) go back to 2) while there are still dead nodes
252  *
253  */
254 
255 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
256 {
257 	struct dlm_reco_node_data *ndata;
258 	struct dlm_lock_resource *res;
259 
260 	mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
261 	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
262 	     dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
263 	     dlm->reco.dead_node, dlm->reco.new_master);
264 
265 	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
266 		char *st = "unknown";
267 		switch (ndata->state) {
268 			case DLM_RECO_NODE_DATA_INIT:
269 				st = "init";
270 				break;
271 			case DLM_RECO_NODE_DATA_REQUESTING:
272 				st = "requesting";
273 				break;
274 			case DLM_RECO_NODE_DATA_DEAD:
275 				st = "dead";
276 				break;
277 			case DLM_RECO_NODE_DATA_RECEIVING:
278 				st = "receiving";
279 				break;
280 			case DLM_RECO_NODE_DATA_REQUESTED:
281 				st = "requested";
282 				break;
283 			case DLM_RECO_NODE_DATA_DONE:
284 				st = "done";
285 				break;
286 			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
287 				st = "finalize-sent";
288 				break;
289 			default:
290 				st = "bad";
291 				break;
292 		}
293 		mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
294 		     dlm->name, ndata->node_num, st);
295 	}
296 	list_for_each_entry(res, &dlm->reco.resources, recovering) {
297 		mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
298 		     dlm->name, res->lockname.len, res->lockname.name);
299 	}
300 }
301 
302 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
303 
304 static int dlm_recovery_thread(void *data)
305 {
306 	int status;
307 	struct dlm_ctxt *dlm = data;
308 	unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
309 
310 	mlog(0, "dlm thread running for %s...\n", dlm->name);
311 
312 	while (!kthread_should_stop()) {
313 		if (dlm_joined(dlm)) {
314 			status = dlm_do_recovery(dlm);
315 			if (status == -EAGAIN) {
316 				/* do not sleep, recheck immediately. */
317 				continue;
318 			}
319 			if (status < 0)
320 				mlog_errno(status);
321 		}
322 
323 		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
324 						 kthread_should_stop(),
325 						 timeout);
326 	}
327 
328 	mlog(0, "quitting DLM recovery thread\n");
329 	return 0;
330 }
331 
332 /* returns true when the recovery master has contacted us */
333 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
334 {
335 	int ready;
336 	spin_lock(&dlm->spinlock);
337 	ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
338 	spin_unlock(&dlm->spinlock);
339 	return ready;
340 }
341 
342 /* returns true if node is no longer in the domain
343  * could be dead or just not joined */
344 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
345 {
346 	int dead;
347 	spin_lock(&dlm->spinlock);
348 	dead = !test_bit(node, dlm->domain_map);
349 	spin_unlock(&dlm->spinlock);
350 	return dead;
351 }
352 
353 /* returns true if node is no longer in the domain
354  * could be dead or just not joined */
355 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
356 {
357 	int recovered;
358 	spin_lock(&dlm->spinlock);
359 	recovered = !test_bit(node, dlm->recovery_map);
360 	spin_unlock(&dlm->spinlock);
361 	return recovered;
362 }
363 
364 
365 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
366 {
367 	if (timeout) {
368 		mlog(ML_NOTICE, "%s: waiting %dms for notification of "
369 		     "death of node %u\n", dlm->name, timeout, node);
370 		wait_event_timeout(dlm->dlm_reco_thread_wq,
371 			   dlm_is_node_dead(dlm, node),
372 			   msecs_to_jiffies(timeout));
373 	} else {
374 		mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
375 		     "of death of node %u\n", dlm->name, node);
376 		wait_event(dlm->dlm_reco_thread_wq,
377 			   dlm_is_node_dead(dlm, node));
378 	}
379 	/* for now, return 0 */
380 	return 0;
381 }
382 
383 int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
384 {
385 	if (timeout) {
386 		mlog(0, "%s: waiting %dms for notification of "
387 		     "recovery of node %u\n", dlm->name, timeout, node);
388 		wait_event_timeout(dlm->dlm_reco_thread_wq,
389 			   dlm_is_node_recovered(dlm, node),
390 			   msecs_to_jiffies(timeout));
391 	} else {
392 		mlog(0, "%s: waiting indefinitely for notification "
393 		     "of recovery of node %u\n", dlm->name, node);
394 		wait_event(dlm->dlm_reco_thread_wq,
395 			   dlm_is_node_recovered(dlm, node));
396 	}
397 	/* for now, return 0 */
398 	return 0;
399 }
400 
401 /* callers of the top-level api calls (dlmlock/dlmunlock) should
402  * block on the dlm->reco.event when recovery is in progress.
403  * the dlm recovery thread will set this state when it begins
404  * recovering a dead node (as the new master or not) and clear
405  * the state and wake as soon as all affected lock resources have
406  * been marked with the RECOVERY flag */
407 static int dlm_in_recovery(struct dlm_ctxt *dlm)
408 {
409 	int in_recovery;
410 	spin_lock(&dlm->spinlock);
411 	in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
412 	spin_unlock(&dlm->spinlock);
413 	return in_recovery;
414 }
415 
416 
417 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
418 {
419 	if (dlm_in_recovery(dlm)) {
420 		mlog(0, "%s: reco thread %d in recovery: "
421 		     "state=%d, master=%u, dead=%u\n",
422 		     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
423 		     dlm->reco.state, dlm->reco.new_master,
424 		     dlm->reco.dead_node);
425 	}
426 	wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
427 }
428 
429 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
430 {
431 	spin_lock(&dlm->spinlock);
432 	BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
433 	dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
434 	spin_unlock(&dlm->spinlock);
435 }
436 
437 static void dlm_end_recovery(struct dlm_ctxt *dlm)
438 {
439 	spin_lock(&dlm->spinlock);
440 	BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
441 	dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
442 	spin_unlock(&dlm->spinlock);
443 	wake_up(&dlm->reco.event);
444 }
445 
446 static int dlm_do_recovery(struct dlm_ctxt *dlm)
447 {
448 	int status = 0;
449 	int ret;
450 
451 	spin_lock(&dlm->spinlock);
452 
453 	/* check to see if the new master has died */
454 	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
455 	    test_bit(dlm->reco.new_master, dlm->recovery_map)) {
456 		mlog(0, "new master %u died while recovering %u!\n",
457 		     dlm->reco.new_master, dlm->reco.dead_node);
458 		/* unset the new_master, leave dead_node */
459 		dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
460 	}
461 
462 	/* select a target to recover */
463 	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
464 		int bit;
465 
466 		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
467 		if (bit >= O2NM_MAX_NODES || bit < 0)
468 			dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
469 		else
470 			dlm_set_reco_dead_node(dlm, bit);
471 	} else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
472 		/* BUG? */
473 		mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
474 		     dlm->reco.dead_node);
475 		dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
476 	}
477 
478 	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
479 		// mlog(0, "nothing to recover!  sleeping now!\n");
480 		spin_unlock(&dlm->spinlock);
481 		/* return to main thread loop and sleep. */
482 		return 0;
483 	}
484 	mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
485 	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
486 	     dlm->reco.dead_node);
487 	spin_unlock(&dlm->spinlock);
488 
489 	/* take write barrier */
490 	/* (stops the list reshuffling thread, proxy ast handling) */
491 	dlm_begin_recovery(dlm);
492 
493 	if (dlm->reco.new_master == dlm->node_num)
494 		goto master_here;
495 
496 	if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
497 		/* choose a new master, returns 0 if this node
498 		 * is the master, -EEXIST if it's another node.
499 		 * this does not return until a new master is chosen
500 		 * or recovery completes entirely. */
501 		ret = dlm_pick_recovery_master(dlm);
502 		if (!ret) {
503 			/* already notified everyone.  go. */
504 			goto master_here;
505 		}
506 		mlog(0, "another node will master this recovery session.\n");
507 	}
508 	mlog(0, "dlm=%s (%d), new_master=%u, this node=%u, dead_node=%u\n",
509 	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task), dlm->reco.new_master,
510 	     dlm->node_num, dlm->reco.dead_node);
511 
512 	/* it is safe to start everything back up here
513 	 * because all of the dead node's lock resources
514 	 * have been marked as in-recovery */
515 	dlm_end_recovery(dlm);
516 
517 	/* sleep out in main dlm_recovery_thread loop. */
518 	return 0;
519 
520 master_here:
521 	mlog(ML_NOTICE, "(%d) Node %u is the Recovery Master for the Dead Node "
522 	     "%u for Domain %s\n", task_pid_nr(dlm->dlm_reco_thread_task),
523 	     dlm->node_num, dlm->reco.dead_node, dlm->name);
524 
525 	status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
526 	if (status < 0) {
527 		/* we should never hit this anymore */
528 		mlog(ML_ERROR, "error %d remastering locks for node %u, "
529 		     "retrying.\n", status, dlm->reco.dead_node);
530 		/* yield a bit to allow any final network messages
531 		 * to get handled on remaining nodes */
532 		msleep(100);
533 	} else {
534 		/* success!  see if any other nodes need recovery */
535 		mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
536 		     dlm->name, dlm->reco.dead_node, dlm->node_num);
537 		dlm_reset_recovery(dlm);
538 	}
539 	dlm_end_recovery(dlm);
540 
541 	/* continue and look for another dead node */
542 	return -EAGAIN;
543 }
544 
545 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
546 {
547 	int status = 0;
548 	struct dlm_reco_node_data *ndata;
549 	int all_nodes_done;
550 	int destroy = 0;
551 	int pass = 0;
552 
553 	do {
554 		/* we have become recovery master.  there is no escaping
555 		 * this, so just keep trying until we get it. */
556 		status = dlm_init_recovery_area(dlm, dead_node);
557 		if (status < 0) {
558 			mlog(ML_ERROR, "%s: failed to alloc recovery area, "
559 			     "retrying\n", dlm->name);
560 			msleep(1000);
561 		}
562 	} while (status != 0);
563 
564 	/* safe to access the node data list without a lock, since this
565 	 * process is the only one to change the list */
566 	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
567 		BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
568 		ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
569 
570 		mlog(0, "requesting lock info from node %u\n",
571 		     ndata->node_num);
572 
573 		if (ndata->node_num == dlm->node_num) {
574 			ndata->state = DLM_RECO_NODE_DATA_DONE;
575 			continue;
576 		}
577 
578 		do {
579 			status = dlm_request_all_locks(dlm, ndata->node_num,
580 						       dead_node);
581 			if (status < 0) {
582 				mlog_errno(status);
583 				if (dlm_is_host_down(status)) {
584 					/* node died, ignore it for recovery */
585 					status = 0;
586 					ndata->state = DLM_RECO_NODE_DATA_DEAD;
587 					/* wait for the domain map to catch up
588 					 * with the network state. */
589 					wait_event_timeout(dlm->dlm_reco_thread_wq,
590 							   dlm_is_node_dead(dlm,
591 								ndata->node_num),
592 							   msecs_to_jiffies(1000));
593 					mlog(0, "waited 1 sec for %u, "
594 					     "dead? %s\n", ndata->node_num,
595 					     dlm_is_node_dead(dlm, ndata->node_num) ?
596 					     "yes" : "no");
597 				} else {
598 					/* -ENOMEM on the other node */
599 					mlog(0, "%s: node %u returned "
600 					     "%d during recovery, retrying "
601 					     "after a short wait\n",
602 					     dlm->name, ndata->node_num,
603 					     status);
604 					msleep(100);
605 				}
606 			}
607 		} while (status != 0);
608 
609 		spin_lock(&dlm_reco_state_lock);
610 		switch (ndata->state) {
611 			case DLM_RECO_NODE_DATA_INIT:
612 			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
613 			case DLM_RECO_NODE_DATA_REQUESTED:
614 				BUG();
615 				break;
616 			case DLM_RECO_NODE_DATA_DEAD:
617 				mlog(0, "node %u died after requesting "
618 				     "recovery info for node %u\n",
619 				     ndata->node_num, dead_node);
620 				/* fine.  don't need this node's info.
621 				 * continue without it. */
622 				break;
623 			case DLM_RECO_NODE_DATA_REQUESTING:
624 				ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
625 				mlog(0, "now receiving recovery data from "
626 				     "node %u for dead node %u\n",
627 				     ndata->node_num, dead_node);
628 				break;
629 			case DLM_RECO_NODE_DATA_RECEIVING:
630 				mlog(0, "already receiving recovery data from "
631 				     "node %u for dead node %u\n",
632 				     ndata->node_num, dead_node);
633 				break;
634 			case DLM_RECO_NODE_DATA_DONE:
635 				mlog(0, "already DONE receiving recovery data "
636 				     "from node %u for dead node %u\n",
637 				     ndata->node_num, dead_node);
638 				break;
639 		}
640 		spin_unlock(&dlm_reco_state_lock);
641 	}
642 
643 	mlog(0, "done requesting all lock info\n");
644 
645 	/* nodes should be sending reco data now
646 	 * just need to wait */
647 
648 	while (1) {
649 		/* check all the nodes now to see if we are
650 		 * done, or if anyone died */
651 		all_nodes_done = 1;
652 		spin_lock(&dlm_reco_state_lock);
653 		list_for_each_entry(ndata, &dlm->reco.node_data, list) {
654 			mlog(0, "checking recovery state of node %u\n",
655 			     ndata->node_num);
656 			switch (ndata->state) {
657 				case DLM_RECO_NODE_DATA_INIT:
658 				case DLM_RECO_NODE_DATA_REQUESTING:
659 					mlog(ML_ERROR, "bad ndata state for "
660 					     "node %u: state=%d\n",
661 					     ndata->node_num, ndata->state);
662 					BUG();
663 					break;
664 				case DLM_RECO_NODE_DATA_DEAD:
665 					mlog(0, "node %u died after "
666 					     "requesting recovery info for "
667 					     "node %u\n", ndata->node_num,
668 					     dead_node);
669 					break;
670 				case DLM_RECO_NODE_DATA_RECEIVING:
671 				case DLM_RECO_NODE_DATA_REQUESTED:
672 					mlog(0, "%s: node %u still in state %s\n",
673 					     dlm->name, ndata->node_num,
674 					     ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
675 					     "receiving" : "requested");
676 					all_nodes_done = 0;
677 					break;
678 				case DLM_RECO_NODE_DATA_DONE:
679 					mlog(0, "%s: node %u state is done\n",
680 					     dlm->name, ndata->node_num);
681 					break;
682 				case DLM_RECO_NODE_DATA_FINALIZE_SENT:
683 					mlog(0, "%s: node %u state is finalize\n",
684 					     dlm->name, ndata->node_num);
685 					break;
686 			}
687 		}
688 		spin_unlock(&dlm_reco_state_lock);
689 
690 		mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
691 		     all_nodes_done?"yes":"no");
692 		if (all_nodes_done) {
693 			int ret;
694 
695 			/* all nodes are now in DLM_RECO_NODE_DATA_DONE state
696 	 		 * just send a finalize message to everyone and
697 	 		 * clean up */
698 			mlog(0, "all nodes are done! send finalize\n");
699 			ret = dlm_send_finalize_reco_message(dlm);
700 			if (ret < 0)
701 				mlog_errno(ret);
702 
703 			spin_lock(&dlm->spinlock);
704 			dlm_finish_local_lockres_recovery(dlm, dead_node,
705 							  dlm->node_num);
706 			spin_unlock(&dlm->spinlock);
707 			mlog(0, "should be done with recovery!\n");
708 
709 			mlog(0, "finishing recovery of %s at %lu, "
710 			     "dead=%u, this=%u, new=%u\n", dlm->name,
711 			     jiffies, dlm->reco.dead_node,
712 			     dlm->node_num, dlm->reco.new_master);
713 			destroy = 1;
714 			status = 0;
715 			/* rescan everything marked dirty along the way */
716 			dlm_kick_thread(dlm, NULL);
717 			break;
718 		}
719 		/* wait to be signalled, with periodic timeout
720 		 * to check for node death */
721 		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
722 					 kthread_should_stop(),
723 					 msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
724 
725 	}
726 
727 	if (destroy)
728 		dlm_destroy_recovery_area(dlm, dead_node);
729 
730 	mlog_exit(status);
731 	return status;
732 }
733 
734 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
735 {
736 	int num=0;
737 	struct dlm_reco_node_data *ndata;
738 
739 	spin_lock(&dlm->spinlock);
740 	memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
741 	/* nodes can only be removed (by dying) after dropping
742 	 * this lock, and death will be trapped later, so this should do */
743 	spin_unlock(&dlm->spinlock);
744 
745 	while (1) {
746 		num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
747 		if (num >= O2NM_MAX_NODES) {
748 			break;
749 		}
750 		BUG_ON(num == dead_node);
751 
752 		ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
753 		if (!ndata) {
754 			dlm_destroy_recovery_area(dlm, dead_node);
755 			return -ENOMEM;
756 		}
757 		ndata->node_num = num;
758 		ndata->state = DLM_RECO_NODE_DATA_INIT;
759 		spin_lock(&dlm_reco_state_lock);
760 		list_add_tail(&ndata->list, &dlm->reco.node_data);
761 		spin_unlock(&dlm_reco_state_lock);
762 		num++;
763 	}
764 
765 	return 0;
766 }
767 
768 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
769 {
770 	struct dlm_reco_node_data *ndata, *next;
771 	LIST_HEAD(tmplist);
772 
773 	spin_lock(&dlm_reco_state_lock);
774 	list_splice_init(&dlm->reco.node_data, &tmplist);
775 	spin_unlock(&dlm_reco_state_lock);
776 
777 	list_for_each_entry_safe(ndata, next, &tmplist, list) {
778 		list_del_init(&ndata->list);
779 		kfree(ndata);
780 	}
781 }
782 
783 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
784 				 u8 dead_node)
785 {
786 	struct dlm_lock_request lr;
787 	enum dlm_status ret;
788 
789 	mlog(0, "\n");
790 
791 
792 	mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
793 		  "to %u\n", dead_node, request_from);
794 
795 	memset(&lr, 0, sizeof(lr));
796 	lr.node_idx = dlm->node_num;
797 	lr.dead_node = dead_node;
798 
799 	// send message
800 	ret = DLM_NOLOCKMGR;
801 	ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
802 				 &lr, sizeof(lr), request_from, NULL);
803 
804 	/* negative status is handled by caller */
805 	if (ret < 0)
806 		mlog_errno(ret);
807 
808 	// return from here, then
809 	// sleep until all received or error
810 	return ret;
811 
812 }
813 
814 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
815 				  void **ret_data)
816 {
817 	struct dlm_ctxt *dlm = data;
818 	struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
819 	char *buf = NULL;
820 	struct dlm_work_item *item = NULL;
821 
822 	if (!dlm_grab(dlm))
823 		return -EINVAL;
824 
825 	if (lr->dead_node != dlm->reco.dead_node) {
826 		mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
827 		     "dead_node is %u\n", dlm->name, lr->node_idx,
828 		     lr->dead_node, dlm->reco.dead_node);
829 		dlm_print_reco_node_status(dlm);
830 		/* this is a hack */
831 		dlm_put(dlm);
832 		return -ENOMEM;
833 	}
834 	BUG_ON(lr->dead_node != dlm->reco.dead_node);
835 
836 	item = kzalloc(sizeof(*item), GFP_NOFS);
837 	if (!item) {
838 		dlm_put(dlm);
839 		return -ENOMEM;
840 	}
841 
842 	/* this will get freed by dlm_request_all_locks_worker */
843 	buf = (char *) __get_free_page(GFP_NOFS);
844 	if (!buf) {
845 		kfree(item);
846 		dlm_put(dlm);
847 		return -ENOMEM;
848 	}
849 
850 	/* queue up work for dlm_request_all_locks_worker */
851 	dlm_grab(dlm);  /* get an extra ref for the work item */
852 	dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
853 	item->u.ral.reco_master = lr->node_idx;
854 	item->u.ral.dead_node = lr->dead_node;
855 	spin_lock(&dlm->work_lock);
856 	list_add_tail(&item->list, &dlm->work_list);
857 	spin_unlock(&dlm->work_lock);
858 	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
859 
860 	dlm_put(dlm);
861 	return 0;
862 }
863 
864 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
865 {
866 	struct dlm_migratable_lockres *mres;
867 	struct dlm_lock_resource *res;
868 	struct dlm_ctxt *dlm;
869 	LIST_HEAD(resources);
870 	int ret;
871 	u8 dead_node, reco_master;
872 	int skip_all_done = 0;
873 
874 	dlm = item->dlm;
875 	dead_node = item->u.ral.dead_node;
876 	reco_master = item->u.ral.reco_master;
877 	mres = (struct dlm_migratable_lockres *)data;
878 
879 	mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
880 	     dlm->name, dead_node, reco_master);
881 
882 	if (dead_node != dlm->reco.dead_node ||
883 	    reco_master != dlm->reco.new_master) {
884 		/* worker could have been created before the recovery master
885 		 * died.  if so, do not continue, but do not error. */
886 		if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
887 			mlog(ML_NOTICE, "%s: will not send recovery state, "
888 			     "recovery master %u died, thread=(dead=%u,mas=%u)"
889 			     " current=(dead=%u,mas=%u)\n", dlm->name,
890 			     reco_master, dead_node, reco_master,
891 			     dlm->reco.dead_node, dlm->reco.new_master);
892 		} else {
893 			mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
894 			     "master=%u), request(dead=%u, master=%u)\n",
895 			     dlm->name, dlm->reco.dead_node,
896 			     dlm->reco.new_master, dead_node, reco_master);
897 		}
898 		goto leave;
899 	}
900 
901 	/* lock resources should have already been moved to the
902  	 * dlm->reco.resources list.  now move items from that list
903  	 * to a temp list if the dead owner matches.  note that the
904 	 * whole cluster recovers only one node at a time, so we
905 	 * can safely move UNKNOWN lock resources for each recovery
906 	 * session. */
907 	dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
908 
909 	/* now we can begin blasting lockreses without the dlm lock */
910 
911 	/* any errors returned will be due to the new_master dying,
912 	 * the dlm_reco_thread should detect this */
913 	list_for_each_entry(res, &resources, recovering) {
914 		ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
915 				   	DLM_MRES_RECOVERY);
916 		if (ret < 0) {
917 			mlog(ML_ERROR, "%s: node %u went down while sending "
918 			     "recovery state for dead node %u, ret=%d\n", dlm->name,
919 			     reco_master, dead_node, ret);
920 			skip_all_done = 1;
921 			break;
922 		}
923 	}
924 
925 	/* move the resources back to the list */
926 	spin_lock(&dlm->spinlock);
927 	list_splice_init(&resources, &dlm->reco.resources);
928 	spin_unlock(&dlm->spinlock);
929 
930 	if (!skip_all_done) {
931 		ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
932 		if (ret < 0) {
933 			mlog(ML_ERROR, "%s: node %u went down while sending "
934 			     "recovery all-done for dead node %u, ret=%d\n",
935 			     dlm->name, reco_master, dead_node, ret);
936 		}
937 	}
938 leave:
939 	free_page((unsigned long)data);
940 }
941 
942 
943 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
944 {
945 	int ret, tmpret;
946 	struct dlm_reco_data_done done_msg;
947 
948 	memset(&done_msg, 0, sizeof(done_msg));
949 	done_msg.node_idx = dlm->node_num;
950 	done_msg.dead_node = dead_node;
951 	mlog(0, "sending DATA DONE message to %u, "
952 	     "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
953 	     done_msg.dead_node);
954 
955 	ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
956 				 sizeof(done_msg), send_to, &tmpret);
957 	if (ret < 0) {
958 		if (!dlm_is_host_down(ret)) {
959 			mlog_errno(ret);
960 			mlog(ML_ERROR, "%s: unknown error sending data-done "
961 			     "to %u\n", dlm->name, send_to);
962 			BUG();
963 		}
964 	} else
965 		ret = tmpret;
966 	return ret;
967 }
968 
969 
970 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
971 			       void **ret_data)
972 {
973 	struct dlm_ctxt *dlm = data;
974 	struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
975 	struct dlm_reco_node_data *ndata = NULL;
976 	int ret = -EINVAL;
977 
978 	if (!dlm_grab(dlm))
979 		return -EINVAL;
980 
981 	mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
982 	     "node_idx=%u, this node=%u\n", done->dead_node,
983 	     dlm->reco.dead_node, done->node_idx, dlm->node_num);
984 
985 	mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
986 			"Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
987 			"node_idx=%u, this node=%u\n", done->dead_node,
988 			dlm->reco.dead_node, done->node_idx, dlm->node_num);
989 
990 	spin_lock(&dlm_reco_state_lock);
991 	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
992 		if (ndata->node_num != done->node_idx)
993 			continue;
994 
995 		switch (ndata->state) {
996 			/* should have moved beyond INIT but not to FINALIZE yet */
997 			case DLM_RECO_NODE_DATA_INIT:
998 			case DLM_RECO_NODE_DATA_DEAD:
999 			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1000 				mlog(ML_ERROR, "bad ndata state for node %u:"
1001 				     " state=%d\n", ndata->node_num,
1002 				     ndata->state);
1003 				BUG();
1004 				break;
1005 			/* these states are possible at this point, anywhere along
1006 			 * the line of recovery */
1007 			case DLM_RECO_NODE_DATA_DONE:
1008 			case DLM_RECO_NODE_DATA_RECEIVING:
1009 			case DLM_RECO_NODE_DATA_REQUESTED:
1010 			case DLM_RECO_NODE_DATA_REQUESTING:
1011 				mlog(0, "node %u is DONE sending "
1012 					  "recovery data!\n",
1013 					  ndata->node_num);
1014 
1015 				ndata->state = DLM_RECO_NODE_DATA_DONE;
1016 				ret = 0;
1017 				break;
1018 		}
1019 	}
1020 	spin_unlock(&dlm_reco_state_lock);
1021 
1022 	/* wake the recovery thread, some node is done */
1023 	if (!ret)
1024 		dlm_kick_recovery_thread(dlm);
1025 
1026 	if (ret < 0)
1027 		mlog(ML_ERROR, "failed to find recovery node data for node "
1028 		     "%u\n", done->node_idx);
1029 	dlm_put(dlm);
1030 
1031 	mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1032 	return ret;
1033 }
1034 
1035 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1036 					struct list_head *list,
1037 				       	u8 dead_node)
1038 {
1039 	struct dlm_lock_resource *res, *next;
1040 	struct dlm_lock *lock;
1041 
1042 	spin_lock(&dlm->spinlock);
1043 	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
1044 		/* always prune any $RECOVERY entries for dead nodes,
1045 		 * otherwise hangs can occur during later recovery */
1046 		if (dlm_is_recovery_lock(res->lockname.name,
1047 					 res->lockname.len)) {
1048 			spin_lock(&res->spinlock);
1049 			list_for_each_entry(lock, &res->granted, list) {
1050 				if (lock->ml.node == dead_node) {
1051 					mlog(0, "AHA! there was "
1052 					     "a $RECOVERY lock for dead "
1053 					     "node %u (%s)!\n",
1054 					     dead_node, dlm->name);
1055 					list_del_init(&lock->list);
1056 					dlm_lock_put(lock);
1057 					break;
1058 				}
1059 			}
1060 			spin_unlock(&res->spinlock);
1061 			continue;
1062 		}
1063 
1064 		if (res->owner == dead_node) {
1065 			mlog(0, "found lockres owned by dead node while "
1066 				  "doing recovery for node %u. sending it.\n",
1067 				  dead_node);
1068 			list_move_tail(&res->recovering, list);
1069 		} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1070 			mlog(0, "found UNKNOWN owner while doing recovery "
1071 				  "for node %u. sending it.\n", dead_node);
1072 			list_move_tail(&res->recovering, list);
1073 		}
1074 	}
1075 	spin_unlock(&dlm->spinlock);
1076 }
1077 
1078 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1079 {
1080 	int total_locks = 0;
1081 	struct list_head *iter, *queue = &res->granted;
1082 	int i;
1083 
1084 	for (i=0; i<3; i++) {
1085 		list_for_each(iter, queue)
1086 			total_locks++;
1087 		queue++;
1088 	}
1089 	return total_locks;
1090 }
1091 
1092 
1093 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1094 				      struct dlm_migratable_lockres *mres,
1095 				      u8 send_to,
1096 				      struct dlm_lock_resource *res,
1097 				      int total_locks)
1098 {
1099 	u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1100 	int mres_total_locks = be32_to_cpu(mres->total_locks);
1101 	int sz, ret = 0, status = 0;
1102 	u8 orig_flags = mres->flags,
1103 	   orig_master = mres->master;
1104 
1105 	BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1106 	if (!mres->num_locks)
1107 		return 0;
1108 
1109 	sz = sizeof(struct dlm_migratable_lockres) +
1110 		(mres->num_locks * sizeof(struct dlm_migratable_lock));
1111 
1112 	/* add an all-done flag if we reached the last lock */
1113 	orig_flags = mres->flags;
1114 	BUG_ON(total_locks > mres_total_locks);
1115 	if (total_locks == mres_total_locks)
1116 		mres->flags |= DLM_MRES_ALL_DONE;
1117 
1118 	mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
1119 	     dlm->name, res->lockname.len, res->lockname.name,
1120 	     orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
1121 	     send_to);
1122 
1123 	/* send it */
1124 	ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1125 				 sz, send_to, &status);
1126 	if (ret < 0) {
1127 		/* XXX: negative status is not handled.
1128 		 * this will end up killing this node. */
1129 		mlog_errno(ret);
1130 	} else {
1131 		/* might get an -ENOMEM back here */
1132 		ret = status;
1133 		if (ret < 0) {
1134 			mlog_errno(ret);
1135 
1136 			if (ret == -EFAULT) {
1137 				mlog(ML_ERROR, "node %u told me to kill "
1138 				     "myself!\n", send_to);
1139 				BUG();
1140 			}
1141 		}
1142 	}
1143 
1144 	/* zero and reinit the message buffer */
1145 	dlm_init_migratable_lockres(mres, res->lockname.name,
1146 				    res->lockname.len, mres_total_locks,
1147 				    mig_cookie, orig_flags, orig_master);
1148 	return ret;
1149 }
1150 
1151 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1152 					const char *lockname, int namelen,
1153 					int total_locks, u64 cookie,
1154 					u8 flags, u8 master)
1155 {
1156 	/* mres here is one full page */
1157 	clear_page(mres);
1158 	mres->lockname_len = namelen;
1159 	memcpy(mres->lockname, lockname, namelen);
1160 	mres->num_locks = 0;
1161 	mres->total_locks = cpu_to_be32(total_locks);
1162 	mres->mig_cookie = cpu_to_be64(cookie);
1163 	mres->flags = flags;
1164 	mres->master = master;
1165 }
1166 
1167 static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
1168 					  struct dlm_migratable_lockres *mres,
1169 					  int queue)
1170 {
1171 	if (!lock->lksb)
1172 	       return;
1173 
1174 	/* Ignore lvb in all locks in the blocked list */
1175 	if (queue == DLM_BLOCKED_LIST)
1176 		return;
1177 
1178 	/* Only consider lvbs in locks with granted EX or PR lock levels */
1179 	if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
1180 		return;
1181 
1182 	if (dlm_lvb_is_empty(mres->lvb)) {
1183 		memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1184 		return;
1185 	}
1186 
1187 	/* Ensure the lvb copied for migration matches in other valid locks */
1188 	if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
1189 		return;
1190 
1191 	mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
1192 	     "node=%u\n",
1193 	     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
1194 	     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
1195 	     lock->lockres->lockname.len, lock->lockres->lockname.name,
1196 	     lock->ml.node);
1197 	dlm_print_one_lock_resource(lock->lockres);
1198 	BUG();
1199 }
1200 
1201 /* returns 1 if this lock fills the network structure,
1202  * 0 otherwise */
1203 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1204 				 struct dlm_migratable_lockres *mres, int queue)
1205 {
1206 	struct dlm_migratable_lock *ml;
1207 	int lock_num = mres->num_locks;
1208 
1209 	ml = &(mres->ml[lock_num]);
1210 	ml->cookie = lock->ml.cookie;
1211 	ml->type = lock->ml.type;
1212 	ml->convert_type = lock->ml.convert_type;
1213 	ml->highest_blocked = lock->ml.highest_blocked;
1214 	ml->list = queue;
1215 	if (lock->lksb) {
1216 		ml->flags = lock->lksb->flags;
1217 		dlm_prepare_lvb_for_migration(lock, mres, queue);
1218 	}
1219 	ml->node = lock->ml.node;
1220 	mres->num_locks++;
1221 	/* we reached the max, send this network message */
1222 	if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1223 		return 1;
1224 	return 0;
1225 }
1226 
1227 static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1228 			       struct dlm_migratable_lockres *mres)
1229 {
1230 	struct dlm_lock dummy;
1231 	memset(&dummy, 0, sizeof(dummy));
1232 	dummy.ml.cookie = 0;
1233 	dummy.ml.type = LKM_IVMODE;
1234 	dummy.ml.convert_type = LKM_IVMODE;
1235 	dummy.ml.highest_blocked = LKM_IVMODE;
1236 	dummy.lksb = NULL;
1237 	dummy.ml.node = dlm->node_num;
1238 	dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1239 }
1240 
1241 static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1242 				    struct dlm_migratable_lock *ml,
1243 				    u8 *nodenum)
1244 {
1245 	if (unlikely(ml->cookie == 0 &&
1246 	    ml->type == LKM_IVMODE &&
1247 	    ml->convert_type == LKM_IVMODE &&
1248 	    ml->highest_blocked == LKM_IVMODE &&
1249 	    ml->list == DLM_BLOCKED_LIST)) {
1250 		*nodenum = ml->node;
1251 		return 1;
1252 	}
1253 	return 0;
1254 }
1255 
1256 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1257 			 struct dlm_migratable_lockres *mres,
1258 			 u8 send_to, u8 flags)
1259 {
1260 	struct list_head *queue;
1261 	int total_locks, i;
1262 	u64 mig_cookie = 0;
1263 	struct dlm_lock *lock;
1264 	int ret = 0;
1265 
1266 	BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1267 
1268 	mlog(0, "sending to %u\n", send_to);
1269 
1270 	total_locks = dlm_num_locks_in_lockres(res);
1271 	if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1272 		/* rare, but possible */
1273 		mlog(0, "argh.  lockres has %d locks.  this will "
1274 			  "require more than one network packet to "
1275 			  "migrate\n", total_locks);
1276 		mig_cookie = dlm_get_next_mig_cookie();
1277 	}
1278 
1279 	dlm_init_migratable_lockres(mres, res->lockname.name,
1280 				    res->lockname.len, total_locks,
1281 				    mig_cookie, flags, res->owner);
1282 
1283 	total_locks = 0;
1284 	for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1285 		queue = dlm_list_idx_to_ptr(res, i);
1286 		list_for_each_entry(lock, queue, list) {
1287 			/* add another lock. */
1288 			total_locks++;
1289 			if (!dlm_add_lock_to_array(lock, mres, i))
1290 				continue;
1291 
1292 			/* this filled the lock message,
1293 			 * we must send it immediately. */
1294 			ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1295 						       res, total_locks);
1296 			if (ret < 0)
1297 				goto error;
1298 		}
1299 	}
1300 	if (total_locks == 0) {
1301 		/* send a dummy lock to indicate a mastery reference only */
1302 		mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1303 		     dlm->name, res->lockname.len, res->lockname.name,
1304 		     send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1305 		     "migration");
1306 		dlm_add_dummy_lock(dlm, mres);
1307 	}
1308 	/* flush any remaining locks */
1309 	ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1310 	if (ret < 0)
1311 		goto error;
1312 	return ret;
1313 
1314 error:
1315 	mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1316 	     dlm->name, ret);
1317 	if (!dlm_is_host_down(ret))
1318 		BUG();
1319 	mlog(0, "%s: node %u went down while sending %s "
1320 	     "lockres %.*s\n", dlm->name, send_to,
1321 	     flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1322 	     res->lockname.len, res->lockname.name);
1323 	return ret;
1324 }
1325 
1326 
1327 
1328 /*
1329  * this message will contain no more than one page worth of
1330  * recovery data, and it will work on only one lockres.
1331  * there may be many locks in this page, and we may need to wait
1332  * for additional packets to complete all the locks (rare, but
1333  * possible).
1334  */
1335 /*
1336  * NOTE: the allocation error cases here are scary
1337  * we really cannot afford to fail an alloc in recovery
1338  * do we spin?  returning an error only delays the problem really
1339  */
1340 
1341 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1342 			    void **ret_data)
1343 {
1344 	struct dlm_ctxt *dlm = data;
1345 	struct dlm_migratable_lockres *mres =
1346 		(struct dlm_migratable_lockres *)msg->buf;
1347 	int ret = 0;
1348 	u8 real_master;
1349 	u8 extra_refs = 0;
1350 	char *buf = NULL;
1351 	struct dlm_work_item *item = NULL;
1352 	struct dlm_lock_resource *res = NULL;
1353 
1354 	if (!dlm_grab(dlm))
1355 		return -EINVAL;
1356 
1357 	BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1358 
1359 	real_master = mres->master;
1360 	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1361 		/* cannot migrate a lockres with no master */
1362 		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1363 	}
1364 
1365 	mlog(0, "%s message received from node %u\n",
1366 		  (mres->flags & DLM_MRES_RECOVERY) ?
1367 		  "recovery" : "migration", mres->master);
1368 	if (mres->flags & DLM_MRES_ALL_DONE)
1369 		mlog(0, "all done flag.  all lockres data received!\n");
1370 
1371 	ret = -ENOMEM;
1372 	buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1373 	item = kzalloc(sizeof(*item), GFP_NOFS);
1374 	if (!buf || !item)
1375 		goto leave;
1376 
1377 	/* lookup the lock to see if we have a secondary queue for this
1378 	 * already...  just add the locks in and this will have its owner
1379 	 * and RECOVERY flag changed when it completes. */
1380 	res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1381 	if (res) {
1382 	 	/* this will get a ref on res */
1383 		/* mark it as recovering/migrating and hash it */
1384 		spin_lock(&res->spinlock);
1385 		if (mres->flags & DLM_MRES_RECOVERY) {
1386 			res->state |= DLM_LOCK_RES_RECOVERING;
1387 		} else {
1388 			if (res->state & DLM_LOCK_RES_MIGRATING) {
1389 				/* this is at least the second
1390 				 * lockres message */
1391 				mlog(0, "lock %.*s is already migrating\n",
1392 					  mres->lockname_len,
1393 					  mres->lockname);
1394 			} else if (res->state & DLM_LOCK_RES_RECOVERING) {
1395 				/* caller should BUG */
1396 				mlog(ML_ERROR, "node is attempting to migrate "
1397 				     "lock %.*s, but marked as recovering!\n",
1398 				     mres->lockname_len, mres->lockname);
1399 				ret = -EFAULT;
1400 				spin_unlock(&res->spinlock);
1401 				goto leave;
1402 			}
1403 			res->state |= DLM_LOCK_RES_MIGRATING;
1404 		}
1405 		spin_unlock(&res->spinlock);
1406 	} else {
1407 		/* need to allocate, just like if it was
1408 		 * mastered here normally  */
1409 		res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1410 		if (!res)
1411 			goto leave;
1412 
1413 		/* to match the ref that we would have gotten if
1414 		 * dlm_lookup_lockres had succeeded */
1415 		dlm_lockres_get(res);
1416 
1417 		/* mark it as recovering/migrating and hash it */
1418 		if (mres->flags & DLM_MRES_RECOVERY)
1419 			res->state |= DLM_LOCK_RES_RECOVERING;
1420 		else
1421 			res->state |= DLM_LOCK_RES_MIGRATING;
1422 
1423 		spin_lock(&dlm->spinlock);
1424 		__dlm_insert_lockres(dlm, res);
1425 		spin_unlock(&dlm->spinlock);
1426 
1427 		/* Add an extra ref for this lock-less lockres lest the
1428 		 * dlm_thread purges it before we get the chance to add
1429 		 * locks to it */
1430 		dlm_lockres_get(res);
1431 
1432 		/* There are three refs that need to be put.
1433 		 * 1. Taken above.
1434 		 * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
1435 		 * 3. dlm_lookup_lockres()
1436 		 * The first one is handled at the end of this function. The
1437 		 * other two are handled in the worker thread after locks have
1438 		 * been attached. Yes, we don't wait for purge time to match
1439 		 * kref_init. The lockres will still have atleast one ref
1440 		 * added because it is in the hash __dlm_insert_lockres() */
1441 		extra_refs++;
1442 
1443 		/* now that the new lockres is inserted,
1444 		 * make it usable by other processes */
1445 		spin_lock(&res->spinlock);
1446 		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1447 		spin_unlock(&res->spinlock);
1448 		wake_up(&res->wq);
1449 	}
1450 
1451 	/* at this point we have allocated everything we need,
1452 	 * and we have a hashed lockres with an extra ref and
1453 	 * the proper res->state flags. */
1454 	ret = 0;
1455 	spin_lock(&res->spinlock);
1456 	/* drop this either when master requery finds a different master
1457 	 * or when a lock is added by the recovery worker */
1458 	dlm_lockres_grab_inflight_ref(dlm, res);
1459 	if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1460 		/* migration cannot have an unknown master */
1461 		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1462 		mlog(0, "recovery has passed me a lockres with an "
1463 			  "unknown owner.. will need to requery: "
1464 			  "%.*s\n", mres->lockname_len, mres->lockname);
1465 	} else {
1466 		/* take a reference now to pin the lockres, drop it
1467 		 * when locks are added in the worker */
1468 		dlm_change_lockres_owner(dlm, res, dlm->node_num);
1469 	}
1470 	spin_unlock(&res->spinlock);
1471 
1472 	/* queue up work for dlm_mig_lockres_worker */
1473 	dlm_grab(dlm);  /* get an extra ref for the work item */
1474 	memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1475 	dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1476 	item->u.ml.lockres = res; /* already have a ref */
1477 	item->u.ml.real_master = real_master;
1478 	item->u.ml.extra_ref = extra_refs;
1479 	spin_lock(&dlm->work_lock);
1480 	list_add_tail(&item->list, &dlm->work_list);
1481 	spin_unlock(&dlm->work_lock);
1482 	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1483 
1484 leave:
1485 	/* One extra ref taken needs to be put here */
1486 	if (extra_refs)
1487 		dlm_lockres_put(res);
1488 
1489 	dlm_put(dlm);
1490 	if (ret < 0) {
1491 		if (buf)
1492 			kfree(buf);
1493 		if (item)
1494 			kfree(item);
1495 	}
1496 
1497 	mlog_exit(ret);
1498 	return ret;
1499 }
1500 
1501 
1502 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1503 {
1504 	struct dlm_ctxt *dlm;
1505 	struct dlm_migratable_lockres *mres;
1506 	int ret = 0;
1507 	struct dlm_lock_resource *res;
1508 	u8 real_master;
1509 	u8 extra_ref;
1510 
1511 	dlm = item->dlm;
1512 	mres = (struct dlm_migratable_lockres *)data;
1513 
1514 	res = item->u.ml.lockres;
1515 	real_master = item->u.ml.real_master;
1516 	extra_ref = item->u.ml.extra_ref;
1517 
1518 	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1519 		/* this case is super-rare. only occurs if
1520 		 * node death happens during migration. */
1521 again:
1522 		ret = dlm_lockres_master_requery(dlm, res, &real_master);
1523 		if (ret < 0) {
1524 			mlog(0, "dlm_lockres_master_requery ret=%d\n",
1525 				  ret);
1526 			goto again;
1527 		}
1528 		if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1529 			mlog(0, "lockres %.*s not claimed.  "
1530 				   "this node will take it.\n",
1531 				   res->lockname.len, res->lockname.name);
1532 		} else {
1533 			spin_lock(&res->spinlock);
1534 			dlm_lockres_drop_inflight_ref(dlm, res);
1535 			spin_unlock(&res->spinlock);
1536 			mlog(0, "master needs to respond to sender "
1537 				  "that node %u still owns %.*s\n",
1538 				  real_master, res->lockname.len,
1539 				  res->lockname.name);
1540 			/* cannot touch this lockres */
1541 			goto leave;
1542 		}
1543 	}
1544 
1545 	ret = dlm_process_recovery_data(dlm, res, mres);
1546 	if (ret < 0)
1547 		mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1548 	else
1549 		mlog(0, "dlm_process_recovery_data succeeded\n");
1550 
1551 	if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1552 	                   (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1553 		ret = dlm_finish_migration(dlm, res, mres->master);
1554 		if (ret < 0)
1555 			mlog_errno(ret);
1556 	}
1557 
1558 leave:
1559 	/* See comment in dlm_mig_lockres_handler() */
1560 	if (res) {
1561 		if (extra_ref)
1562 			dlm_lockres_put(res);
1563 		dlm_lockres_put(res);
1564 	}
1565 	kfree(data);
1566 	mlog_exit(ret);
1567 }
1568 
1569 
1570 
1571 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1572 				      struct dlm_lock_resource *res,
1573 				      u8 *real_master)
1574 {
1575 	struct dlm_node_iter iter;
1576 	int nodenum;
1577 	int ret = 0;
1578 
1579 	*real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1580 
1581 	/* we only reach here if one of the two nodes in a
1582 	 * migration died while the migration was in progress.
1583 	 * at this point we need to requery the master.  we
1584 	 * know that the new_master got as far as creating
1585 	 * an mle on at least one node, but we do not know
1586 	 * if any nodes had actually cleared the mle and set
1587 	 * the master to the new_master.  the old master
1588 	 * is supposed to set the owner to UNKNOWN in the
1589 	 * event of a new_master death, so the only possible
1590 	 * responses that we can get from nodes here are
1591 	 * that the master is new_master, or that the master
1592 	 * is UNKNOWN.
1593 	 * if all nodes come back with UNKNOWN then we know
1594 	 * the lock needs remastering here.
1595 	 * if any node comes back with a valid master, check
1596 	 * to see if that master is the one that we are
1597 	 * recovering.  if so, then the new_master died and
1598 	 * we need to remaster this lock.  if not, then the
1599 	 * new_master survived and that node will respond to
1600 	 * other nodes about the owner.
1601 	 * if there is an owner, this node needs to dump this
1602 	 * lockres and alert the sender that this lockres
1603 	 * was rejected. */
1604 	spin_lock(&dlm->spinlock);
1605 	dlm_node_iter_init(dlm->domain_map, &iter);
1606 	spin_unlock(&dlm->spinlock);
1607 
1608 	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1609 		/* do not send to self */
1610 		if (nodenum == dlm->node_num)
1611 			continue;
1612 		ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1613 		if (ret < 0) {
1614 			mlog_errno(ret);
1615 			if (!dlm_is_host_down(ret))
1616 				BUG();
1617 			/* host is down, so answer for that node would be
1618 			 * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1619 		}
1620 		if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1621 			mlog(0, "lock master is %u\n", *real_master);
1622 			break;
1623 		}
1624 	}
1625 	return ret;
1626 }
1627 
1628 
1629 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1630 			  u8 nodenum, u8 *real_master)
1631 {
1632 	int ret = -EINVAL;
1633 	struct dlm_master_requery req;
1634 	int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1635 
1636 	memset(&req, 0, sizeof(req));
1637 	req.node_idx = dlm->node_num;
1638 	req.namelen = res->lockname.len;
1639 	memcpy(req.name, res->lockname.name, res->lockname.len);
1640 
1641 	ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1642 				 &req, sizeof(req), nodenum, &status);
1643 	/* XXX: negative status not handled properly here. */
1644 	if (ret < 0)
1645 		mlog_errno(ret);
1646 	else {
1647 		BUG_ON(status < 0);
1648 		BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1649 		*real_master = (u8) (status & 0xff);
1650 		mlog(0, "node %u responded to master requery with %u\n",
1651 			  nodenum, *real_master);
1652 		ret = 0;
1653 	}
1654 	return ret;
1655 }
1656 
1657 
1658 /* this function cannot error, so unless the sending
1659  * or receiving of the message failed, the owner can
1660  * be trusted */
1661 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1662 			       void **ret_data)
1663 {
1664 	struct dlm_ctxt *dlm = data;
1665 	struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1666 	struct dlm_lock_resource *res = NULL;
1667 	unsigned int hash;
1668 	int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1669 	u32 flags = DLM_ASSERT_MASTER_REQUERY;
1670 
1671 	if (!dlm_grab(dlm)) {
1672 		/* since the domain has gone away on this
1673 		 * node, the proper response is UNKNOWN */
1674 		return master;
1675 	}
1676 
1677 	hash = dlm_lockid_hash(req->name, req->namelen);
1678 
1679 	spin_lock(&dlm->spinlock);
1680 	res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1681 	if (res) {
1682 		spin_lock(&res->spinlock);
1683 		master = res->owner;
1684 		if (master == dlm->node_num) {
1685 			int ret = dlm_dispatch_assert_master(dlm, res,
1686 							     0, 0, flags);
1687 			if (ret < 0) {
1688 				mlog_errno(-ENOMEM);
1689 				/* retry!? */
1690 				BUG();
1691 			}
1692 		} else /* put.. incase we are not the master */
1693 			dlm_lockres_put(res);
1694 		spin_unlock(&res->spinlock);
1695 	}
1696 	spin_unlock(&dlm->spinlock);
1697 
1698 	dlm_put(dlm);
1699 	return master;
1700 }
1701 
1702 static inline struct list_head *
1703 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1704 {
1705 	struct list_head *ret;
1706 	BUG_ON(list_num < 0);
1707 	BUG_ON(list_num > 2);
1708 	ret = &(res->granted);
1709 	ret += list_num;
1710 	return ret;
1711 }
1712 /* TODO: do ast flush business
1713  * TODO: do MIGRATING and RECOVERING spinning
1714  */
1715 
1716 /*
1717 * NOTE about in-flight requests during migration:
1718 *
1719 * Before attempting the migrate, the master has marked the lockres as
1720 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1721 * requests either got queued before the MIGRATING flag got set, in which
1722 * case the lock data will reflect the change and a return message is on
1723 * the way, or the request failed to get in before MIGRATING got set.  In
1724 * this case, the caller will be told to spin and wait for the MIGRATING
1725 * flag to be dropped, then recheck the master.
1726 * This holds true for the convert, cancel and unlock cases, and since lvb
1727 * updates are tied to these same messages, it applies to lvb updates as
1728 * well.  For the lock case, there is no way a lock can be on the master
1729 * queue and not be on the secondary queue since the lock is always added
1730 * locally first.  This means that the new target node will never be sent
1731 * a lock that he doesn't already have on the list.
1732 * In total, this means that the local lock is correct and should not be
1733 * updated to match the one sent by the master.  Any messages sent back
1734 * from the master before the MIGRATING flag will bring the lock properly
1735 * up-to-date, and the change will be ordered properly for the waiter.
1736 * We will *not* attempt to modify the lock underneath the waiter.
1737 */
1738 
1739 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1740 				     struct dlm_lock_resource *res,
1741 				     struct dlm_migratable_lockres *mres)
1742 {
1743 	struct dlm_migratable_lock *ml;
1744 	struct list_head *queue;
1745 	struct list_head *tmpq = NULL;
1746 	struct dlm_lock *newlock = NULL;
1747 	struct dlm_lockstatus *lksb = NULL;
1748 	int ret = 0;
1749 	int i, j, bad;
1750 	struct dlm_lock *lock = NULL;
1751 	u8 from = O2NM_MAX_NODES;
1752 	unsigned int added = 0;
1753 	__be64 c;
1754 
1755 	mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1756 	for (i=0; i<mres->num_locks; i++) {
1757 		ml = &(mres->ml[i]);
1758 
1759 		if (dlm_is_dummy_lock(dlm, ml, &from)) {
1760 			/* placeholder, just need to set the refmap bit */
1761 			BUG_ON(mres->num_locks != 1);
1762 			mlog(0, "%s:%.*s: dummy lock for %u\n",
1763 			     dlm->name, mres->lockname_len, mres->lockname,
1764 			     from);
1765 			spin_lock(&res->spinlock);
1766 			dlm_lockres_set_refmap_bit(from, res);
1767 			spin_unlock(&res->spinlock);
1768 			added++;
1769 			break;
1770 		}
1771 		BUG_ON(ml->highest_blocked != LKM_IVMODE);
1772 		newlock = NULL;
1773 		lksb = NULL;
1774 
1775 		queue = dlm_list_num_to_pointer(res, ml->list);
1776 		tmpq = NULL;
1777 
1778 		/* if the lock is for the local node it needs to
1779 		 * be moved to the proper location within the queue.
1780 		 * do not allocate a new lock structure. */
1781 		if (ml->node == dlm->node_num) {
1782 			/* MIGRATION ONLY! */
1783 			BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1784 
1785 			spin_lock(&res->spinlock);
1786 			for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1787 				tmpq = dlm_list_idx_to_ptr(res, j);
1788 				list_for_each_entry(lock, tmpq, list) {
1789 					if (lock->ml.cookie != ml->cookie)
1790 						lock = NULL;
1791 					else
1792 						break;
1793 				}
1794 				if (lock)
1795 					break;
1796 			}
1797 
1798 			/* lock is always created locally first, and
1799 			 * destroyed locally last.  it must be on the list */
1800 			if (!lock) {
1801 				c = ml->cookie;
1802 				mlog(ML_ERROR, "Could not find local lock "
1803 					       "with cookie %u:%llu, node %u, "
1804 					       "list %u, flags 0x%x, type %d, "
1805 					       "conv %d, highest blocked %d\n",
1806 				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1807 				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1808 				     ml->node, ml->list, ml->flags, ml->type,
1809 				     ml->convert_type, ml->highest_blocked);
1810 				__dlm_print_one_lock_resource(res);
1811 				BUG();
1812 			}
1813 
1814 			if (lock->ml.node != ml->node) {
1815 				c = lock->ml.cookie;
1816 				mlog(ML_ERROR, "Mismatched node# in lock "
1817 				     "cookie %u:%llu, name %.*s, node %u\n",
1818 				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1819 				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1820 				     res->lockname.len, res->lockname.name,
1821 				     lock->ml.node);
1822 				c = ml->cookie;
1823 				mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
1824 				     "node %u, list %u, flags 0x%x, type %d, "
1825 				     "conv %d, highest blocked %d\n",
1826 				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1827 				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1828 				     ml->node, ml->list, ml->flags, ml->type,
1829 				     ml->convert_type, ml->highest_blocked);
1830 				__dlm_print_one_lock_resource(res);
1831 				BUG();
1832 			}
1833 
1834 			if (tmpq != queue) {
1835 				c = ml->cookie;
1836 				mlog(0, "Lock cookie %u:%llu was on list %u "
1837 				     "instead of list %u for %.*s\n",
1838 				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1839 				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1840 				     j, ml->list, res->lockname.len,
1841 				     res->lockname.name);
1842 				__dlm_print_one_lock_resource(res);
1843 				spin_unlock(&res->spinlock);
1844 				continue;
1845 			}
1846 
1847 			/* see NOTE above about why we do not update
1848 			 * to match the master here */
1849 
1850 			/* move the lock to its proper place */
1851 			/* do not alter lock refcount.  switching lists. */
1852 			list_move_tail(&lock->list, queue);
1853 			spin_unlock(&res->spinlock);
1854 			added++;
1855 
1856 			mlog(0, "just reordered a local lock!\n");
1857 			continue;
1858 		}
1859 
1860 		/* lock is for another node. */
1861 		newlock = dlm_new_lock(ml->type, ml->node,
1862 				       be64_to_cpu(ml->cookie), NULL);
1863 		if (!newlock) {
1864 			ret = -ENOMEM;
1865 			goto leave;
1866 		}
1867 		lksb = newlock->lksb;
1868 		dlm_lock_attach_lockres(newlock, res);
1869 
1870 		if (ml->convert_type != LKM_IVMODE) {
1871 			BUG_ON(queue != &res->converting);
1872 			newlock->ml.convert_type = ml->convert_type;
1873 		}
1874 		lksb->flags |= (ml->flags &
1875 				(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1876 
1877 		if (ml->type == LKM_NLMODE)
1878 			goto skip_lvb;
1879 
1880 		if (!dlm_lvb_is_empty(mres->lvb)) {
1881 			if (lksb->flags & DLM_LKSB_PUT_LVB) {
1882 				/* other node was trying to update
1883 				 * lvb when node died.  recreate the
1884 				 * lksb with the updated lvb. */
1885 				memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1886 				/* the lock resource lvb update must happen
1887 				 * NOW, before the spinlock is dropped.
1888 				 * we no longer wait for the AST to update
1889 				 * the lvb. */
1890 				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1891 			} else {
1892 				/* otherwise, the node is sending its
1893 				 * most recent valid lvb info */
1894 				BUG_ON(ml->type != LKM_EXMODE &&
1895 				       ml->type != LKM_PRMODE);
1896 				if (!dlm_lvb_is_empty(res->lvb) &&
1897  				    (ml->type == LKM_EXMODE ||
1898  				     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1899  					int i;
1900  					mlog(ML_ERROR, "%s:%.*s: received bad "
1901  					     "lvb! type=%d\n", dlm->name,
1902  					     res->lockname.len,
1903  					     res->lockname.name, ml->type);
1904  					printk("lockres lvb=[");
1905  					for (i=0; i<DLM_LVB_LEN; i++)
1906  						printk("%02x", res->lvb[i]);
1907  					printk("]\nmigrated lvb=[");
1908  					for (i=0; i<DLM_LVB_LEN; i++)
1909  						printk("%02x", mres->lvb[i]);
1910  					printk("]\n");
1911  					dlm_print_one_lock_resource(res);
1912  					BUG();
1913 				}
1914 				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1915 			}
1916 		}
1917 skip_lvb:
1918 
1919 		/* NOTE:
1920 		 * wrt lock queue ordering and recovery:
1921 		 *    1. order of locks on granted queue is
1922 		 *       meaningless.
1923 		 *    2. order of locks on converting queue is
1924 		 *       LOST with the node death.  sorry charlie.
1925 		 *    3. order of locks on the blocked queue is
1926 		 *       also LOST.
1927 		 * order of locks does not affect integrity, it
1928 		 * just means that a lock request may get pushed
1929 		 * back in line as a result of the node death.
1930 		 * also note that for a given node the lock order
1931 		 * for its secondary queue locks is preserved
1932 		 * relative to each other, but clearly *not*
1933 		 * preserved relative to locks from other nodes.
1934 		 */
1935 		bad = 0;
1936 		spin_lock(&res->spinlock);
1937 		list_for_each_entry(lock, queue, list) {
1938 			if (lock->ml.cookie == ml->cookie) {
1939 				c = lock->ml.cookie;
1940 				mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1941 				     "exists on this lockres!\n", dlm->name,
1942 				     res->lockname.len, res->lockname.name,
1943 				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
1944 				     dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1945 
1946 				mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1947 				     "node=%u, cookie=%u:%llu, queue=%d\n",
1948 	      			     ml->type, ml->convert_type, ml->node,
1949 				     dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
1950 				     dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
1951 				     ml->list);
1952 
1953 				__dlm_print_one_lock_resource(res);
1954 				bad = 1;
1955 				break;
1956 			}
1957 		}
1958 		if (!bad) {
1959 			dlm_lock_get(newlock);
1960 			list_add_tail(&newlock->list, queue);
1961 			mlog(0, "%s:%.*s: added lock for node %u, "
1962 			     "setting refmap bit\n", dlm->name,
1963 			     res->lockname.len, res->lockname.name, ml->node);
1964 			dlm_lockres_set_refmap_bit(ml->node, res);
1965 			added++;
1966 		}
1967 		spin_unlock(&res->spinlock);
1968 	}
1969 	mlog(0, "done running all the locks\n");
1970 
1971 leave:
1972 	/* balance the ref taken when the work was queued */
1973 	spin_lock(&res->spinlock);
1974 	dlm_lockres_drop_inflight_ref(dlm, res);
1975 	spin_unlock(&res->spinlock);
1976 
1977 	if (ret < 0) {
1978 		mlog_errno(ret);
1979 		if (newlock)
1980 			dlm_lock_put(newlock);
1981 	}
1982 
1983 	mlog_exit(ret);
1984 	return ret;
1985 }
1986 
1987 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1988 				       struct dlm_lock_resource *res)
1989 {
1990 	int i;
1991 	struct list_head *queue;
1992 	struct dlm_lock *lock, *next;
1993 
1994 	res->state |= DLM_LOCK_RES_RECOVERING;
1995 	if (!list_empty(&res->recovering)) {
1996 		mlog(0,
1997 		     "Recovering res %s:%.*s, is already on recovery list!\n",
1998 		     dlm->name, res->lockname.len, res->lockname.name);
1999 		list_del_init(&res->recovering);
2000 		dlm_lockres_put(res);
2001 	}
2002 	/* We need to hold a reference while on the recovery list */
2003 	dlm_lockres_get(res);
2004 	list_add_tail(&res->recovering, &dlm->reco.resources);
2005 
2006 	/* find any pending locks and put them back on proper list */
2007 	for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
2008 		queue = dlm_list_idx_to_ptr(res, i);
2009 		list_for_each_entry_safe(lock, next, queue, list) {
2010 			dlm_lock_get(lock);
2011 			if (lock->convert_pending) {
2012 				/* move converting lock back to granted */
2013 				BUG_ON(i != DLM_CONVERTING_LIST);
2014 				mlog(0, "node died with convert pending "
2015 				     "on %.*s. move back to granted list.\n",
2016 				     res->lockname.len, res->lockname.name);
2017 				dlm_revert_pending_convert(res, lock);
2018 				lock->convert_pending = 0;
2019 			} else if (lock->lock_pending) {
2020 				/* remove pending lock requests completely */
2021 				BUG_ON(i != DLM_BLOCKED_LIST);
2022 				mlog(0, "node died with lock pending "
2023 				     "on %.*s. remove from blocked list and skip.\n",
2024 				     res->lockname.len, res->lockname.name);
2025 				/* lock will be floating until ref in
2026 				 * dlmlock_remote is freed after the network
2027 				 * call returns.  ok for it to not be on any
2028 				 * list since no ast can be called
2029 				 * (the master is dead). */
2030 				dlm_revert_pending_lock(res, lock);
2031 				lock->lock_pending = 0;
2032 			} else if (lock->unlock_pending) {
2033 				/* if an unlock was in progress, treat as
2034 				 * if this had completed successfully
2035 				 * before sending this lock state to the
2036 				 * new master.  note that the dlm_unlock
2037 				 * call is still responsible for calling
2038 				 * the unlockast.  that will happen after
2039 				 * the network call times out.  for now,
2040 				 * just move lists to prepare the new
2041 				 * recovery master.  */
2042 				BUG_ON(i != DLM_GRANTED_LIST);
2043 				mlog(0, "node died with unlock pending "
2044 				     "on %.*s. remove from blocked list and skip.\n",
2045 				     res->lockname.len, res->lockname.name);
2046 				dlm_commit_pending_unlock(res, lock);
2047 				lock->unlock_pending = 0;
2048 			} else if (lock->cancel_pending) {
2049 				/* if a cancel was in progress, treat as
2050 				 * if this had completed successfully
2051 				 * before sending this lock state to the
2052 				 * new master */
2053 				BUG_ON(i != DLM_CONVERTING_LIST);
2054 				mlog(0, "node died with cancel pending "
2055 				     "on %.*s. move back to granted list.\n",
2056 				     res->lockname.len, res->lockname.name);
2057 				dlm_commit_pending_cancel(res, lock);
2058 				lock->cancel_pending = 0;
2059 			}
2060 			dlm_lock_put(lock);
2061 		}
2062 	}
2063 }
2064 
2065 
2066 
2067 /* removes all recovered locks from the recovery list.
2068  * sets the res->owner to the new master.
2069  * unsets the RECOVERY flag and wakes waiters. */
2070 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
2071 					      u8 dead_node, u8 new_master)
2072 {
2073 	int i;
2074 	struct hlist_node *hash_iter;
2075 	struct hlist_head *bucket;
2076 	struct dlm_lock_resource *res, *next;
2077 
2078 	mlog_entry_void();
2079 
2080 	assert_spin_locked(&dlm->spinlock);
2081 
2082 	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
2083 		if (res->owner == dead_node) {
2084 			list_del_init(&res->recovering);
2085 			spin_lock(&res->spinlock);
2086 			/* new_master has our reference from
2087 			 * the lock state sent during recovery */
2088 			dlm_change_lockres_owner(dlm, res, new_master);
2089 			res->state &= ~DLM_LOCK_RES_RECOVERING;
2090 			if (__dlm_lockres_has_locks(res))
2091 				__dlm_dirty_lockres(dlm, res);
2092 			spin_unlock(&res->spinlock);
2093 			wake_up(&res->wq);
2094 			dlm_lockres_put(res);
2095 		}
2096 	}
2097 
2098 	/* this will become unnecessary eventually, but
2099 	 * for now we need to run the whole hash, clear
2100 	 * the RECOVERING state and set the owner
2101 	 * if necessary */
2102 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2103 		bucket = dlm_lockres_hash(dlm, i);
2104 		hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
2105 			if (res->state & DLM_LOCK_RES_RECOVERING) {
2106 				if (res->owner == dead_node) {
2107 					mlog(0, "(this=%u) res %.*s owner=%u "
2108 					     "was not on recovering list, but "
2109 					     "clearing state anyway\n",
2110 					     dlm->node_num, res->lockname.len,
2111 					     res->lockname.name, new_master);
2112 				} else if (res->owner == dlm->node_num) {
2113 					mlog(0, "(this=%u) res %.*s owner=%u "
2114 					     "was not on recovering list, "
2115 					     "owner is THIS node, clearing\n",
2116 					     dlm->node_num, res->lockname.len,
2117 					     res->lockname.name, new_master);
2118 				} else
2119 					continue;
2120 
2121 				if (!list_empty(&res->recovering)) {
2122 					mlog(0, "%s:%.*s: lockres was "
2123 					     "marked RECOVERING, owner=%u\n",
2124 					     dlm->name, res->lockname.len,
2125 					     res->lockname.name, res->owner);
2126 					list_del_init(&res->recovering);
2127 					dlm_lockres_put(res);
2128 				}
2129 				spin_lock(&res->spinlock);
2130 				/* new_master has our reference from
2131 				 * the lock state sent during recovery */
2132 				dlm_change_lockres_owner(dlm, res, new_master);
2133 				res->state &= ~DLM_LOCK_RES_RECOVERING;
2134 				if (__dlm_lockres_has_locks(res))
2135 					__dlm_dirty_lockres(dlm, res);
2136 				spin_unlock(&res->spinlock);
2137 				wake_up(&res->wq);
2138 			}
2139 		}
2140 	}
2141 }
2142 
2143 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2144 {
2145 	if (local) {
2146 		if (lock->ml.type != LKM_EXMODE &&
2147 		    lock->ml.type != LKM_PRMODE)
2148 			return 1;
2149 	} else if (lock->ml.type == LKM_EXMODE)
2150 		return 1;
2151 	return 0;
2152 }
2153 
2154 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2155 			       struct dlm_lock_resource *res, u8 dead_node)
2156 {
2157 	struct list_head *queue;
2158 	struct dlm_lock *lock;
2159 	int blank_lvb = 0, local = 0;
2160 	int i;
2161 	u8 search_node;
2162 
2163 	assert_spin_locked(&dlm->spinlock);
2164 	assert_spin_locked(&res->spinlock);
2165 
2166 	if (res->owner == dlm->node_num)
2167 		/* if this node owned the lockres, and if the dead node
2168 		 * had an EX when he died, blank out the lvb */
2169 		search_node = dead_node;
2170 	else {
2171 		/* if this is a secondary lockres, and we had no EX or PR
2172 		 * locks granted, we can no longer trust the lvb */
2173 		search_node = dlm->node_num;
2174 		local = 1;  /* check local state for valid lvb */
2175 	}
2176 
2177 	for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2178 		queue = dlm_list_idx_to_ptr(res, i);
2179 		list_for_each_entry(lock, queue, list) {
2180 			if (lock->ml.node == search_node) {
2181 				if (dlm_lvb_needs_invalidation(lock, local)) {
2182 					/* zero the lksb lvb and lockres lvb */
2183 					blank_lvb = 1;
2184 					memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2185 				}
2186 			}
2187 		}
2188 	}
2189 
2190 	if (blank_lvb) {
2191 		mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2192 		     res->lockname.len, res->lockname.name, dead_node);
2193 		memset(res->lvb, 0, DLM_LVB_LEN);
2194 	}
2195 }
2196 
2197 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2198 				struct dlm_lock_resource *res, u8 dead_node)
2199 {
2200 	struct dlm_lock *lock, *next;
2201 	unsigned int freed = 0;
2202 
2203 	/* this node is the lockres master:
2204 	 * 1) remove any stale locks for the dead node
2205 	 * 2) if the dead node had an EX when he died, blank out the lvb
2206 	 */
2207 	assert_spin_locked(&dlm->spinlock);
2208 	assert_spin_locked(&res->spinlock);
2209 
2210 	/* We do two dlm_lock_put(). One for removing from list and the other is
2211 	 * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
2212 
2213 	/* TODO: check pending_asts, pending_basts here */
2214 	list_for_each_entry_safe(lock, next, &res->granted, list) {
2215 		if (lock->ml.node == dead_node) {
2216 			list_del_init(&lock->list);
2217 			dlm_lock_put(lock);
2218 			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2219 			dlm_lock_put(lock);
2220 			freed++;
2221 		}
2222 	}
2223 	list_for_each_entry_safe(lock, next, &res->converting, list) {
2224 		if (lock->ml.node == dead_node) {
2225 			list_del_init(&lock->list);
2226 			dlm_lock_put(lock);
2227 			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2228 			dlm_lock_put(lock);
2229 			freed++;
2230 		}
2231 	}
2232 	list_for_each_entry_safe(lock, next, &res->blocked, list) {
2233 		if (lock->ml.node == dead_node) {
2234 			list_del_init(&lock->list);
2235 			dlm_lock_put(lock);
2236 			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2237 			dlm_lock_put(lock);
2238 			freed++;
2239 		}
2240 	}
2241 
2242 	if (freed) {
2243 		mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2244 		     "dropping ref from lockres\n", dlm->name,
2245 		     res->lockname.len, res->lockname.name, freed, dead_node);
2246 		BUG_ON(!test_bit(dead_node, res->refmap));
2247 		dlm_lockres_clear_refmap_bit(dead_node, res);
2248 	} else if (test_bit(dead_node, res->refmap)) {
2249 		mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2250 		     "no locks and had not purged before dying\n", dlm->name,
2251 		     res->lockname.len, res->lockname.name, dead_node);
2252 		dlm_lockres_clear_refmap_bit(dead_node, res);
2253 	}
2254 
2255 	/* do not kick thread yet */
2256 	__dlm_dirty_lockres(dlm, res);
2257 }
2258 
2259 /* if this node is the recovery master, and there are no
2260  * locks for a given lockres owned by this node that are in
2261  * either PR or EX mode, zero out the lvb before requesting.
2262  *
2263  */
2264 
2265 
2266 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2267 {
2268 	struct hlist_node *iter;
2269 	struct dlm_lock_resource *res;
2270 	int i;
2271 	struct hlist_head *bucket;
2272 	struct dlm_lock *lock;
2273 
2274 
2275 	/* purge any stale mles */
2276 	dlm_clean_master_list(dlm, dead_node);
2277 
2278 	/*
2279 	 * now clean up all lock resources.  there are two rules:
2280 	 *
2281 	 * 1) if the dead node was the master, move the lockres
2282 	 *    to the recovering list.  set the RECOVERING flag.
2283 	 *    this lockres needs to be cleaned up before it can
2284 	 *    be used further.
2285 	 *
2286 	 * 2) if this node was the master, remove all locks from
2287 	 *    each of the lockres queues that were owned by the
2288 	 *    dead node.  once recovery finishes, the dlm thread
2289 	 *    can be kicked again to see if any ASTs or BASTs
2290 	 *    need to be fired as a result.
2291 	 */
2292 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2293 		bucket = dlm_lockres_hash(dlm, i);
2294 		hlist_for_each_entry(res, iter, bucket, hash_node) {
2295  			/* always prune any $RECOVERY entries for dead nodes,
2296  			 * otherwise hangs can occur during later recovery */
2297 			if (dlm_is_recovery_lock(res->lockname.name,
2298 						 res->lockname.len)) {
2299 				spin_lock(&res->spinlock);
2300 				list_for_each_entry(lock, &res->granted, list) {
2301 					if (lock->ml.node == dead_node) {
2302 						mlog(0, "AHA! there was "
2303 						     "a $RECOVERY lock for dead "
2304 						     "node %u (%s)!\n",
2305 						     dead_node, dlm->name);
2306 						list_del_init(&lock->list);
2307 						dlm_lock_put(lock);
2308 						break;
2309 					}
2310 				}
2311 				spin_unlock(&res->spinlock);
2312 				continue;
2313 			}
2314 			spin_lock(&res->spinlock);
2315 			/* zero the lvb if necessary */
2316 			dlm_revalidate_lvb(dlm, res, dead_node);
2317 			if (res->owner == dead_node) {
2318 				if (res->state & DLM_LOCK_RES_DROPPING_REF)
2319 					mlog(0, "%s:%.*s: owned by "
2320 					     "dead node %u, this node was "
2321 					     "dropping its ref when it died. "
2322 					     "continue, dropping the flag.\n",
2323 					     dlm->name, res->lockname.len,
2324 					     res->lockname.name, dead_node);
2325 
2326 				/* the wake_up for this will happen when the
2327 				 * RECOVERING flag is dropped later */
2328 				res->state &= ~DLM_LOCK_RES_DROPPING_REF;
2329 
2330 				dlm_move_lockres_to_recovery_list(dlm, res);
2331 			} else if (res->owner == dlm->node_num) {
2332 				dlm_free_dead_locks(dlm, res, dead_node);
2333 				__dlm_lockres_calc_usage(dlm, res);
2334 			}
2335 			spin_unlock(&res->spinlock);
2336 		}
2337 	}
2338 
2339 }
2340 
2341 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2342 {
2343 	assert_spin_locked(&dlm->spinlock);
2344 
2345 	if (dlm->reco.new_master == idx) {
2346 		mlog(0, "%s: recovery master %d just died\n",
2347 		     dlm->name, idx);
2348 		if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2349 			/* finalize1 was reached, so it is safe to clear
2350 			 * the new_master and dead_node.  that recovery
2351 			 * is complete. */
2352 			mlog(0, "%s: dead master %d had reached "
2353 			     "finalize1 state, clearing\n", dlm->name, idx);
2354 			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2355 			__dlm_reset_recovery(dlm);
2356 		}
2357 	}
2358 
2359 	/* Clean up join state on node death. */
2360 	if (dlm->joining_node == idx) {
2361 		mlog(0, "Clearing join state for node %u\n", idx);
2362 		__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2363 	}
2364 
2365 	/* check to see if the node is already considered dead */
2366 	if (!test_bit(idx, dlm->live_nodes_map)) {
2367 		mlog(0, "for domain %s, node %d is already dead. "
2368 		     "another node likely did recovery already.\n",
2369 		     dlm->name, idx);
2370 		return;
2371 	}
2372 
2373 	/* check to see if we do not care about this node */
2374 	if (!test_bit(idx, dlm->domain_map)) {
2375 		/* This also catches the case that we get a node down
2376 		 * but haven't joined the domain yet. */
2377 		mlog(0, "node %u already removed from domain!\n", idx);
2378 		return;
2379 	}
2380 
2381 	clear_bit(idx, dlm->live_nodes_map);
2382 
2383 	/* make sure local cleanup occurs before the heartbeat events */
2384 	if (!test_bit(idx, dlm->recovery_map))
2385 		dlm_do_local_recovery_cleanup(dlm, idx);
2386 
2387 	/* notify anything attached to the heartbeat events */
2388 	dlm_hb_event_notify_attached(dlm, idx, 0);
2389 
2390 	mlog(0, "node %u being removed from domain map!\n", idx);
2391 	clear_bit(idx, dlm->domain_map);
2392 	/* wake up migration waiters if a node goes down.
2393 	 * perhaps later we can genericize this for other waiters. */
2394 	wake_up(&dlm->migration_wq);
2395 
2396 	if (test_bit(idx, dlm->recovery_map))
2397 		mlog(0, "domain %s, node %u already added "
2398 		     "to recovery map!\n", dlm->name, idx);
2399 	else
2400 		set_bit(idx, dlm->recovery_map);
2401 }
2402 
2403 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2404 {
2405 	struct dlm_ctxt *dlm = data;
2406 
2407 	if (!dlm_grab(dlm))
2408 		return;
2409 
2410 	/*
2411 	 * This will notify any dlm users that a node in our domain
2412 	 * went away without notifying us first.
2413 	 */
2414 	if (test_bit(idx, dlm->domain_map))
2415 		dlm_fire_domain_eviction_callbacks(dlm, idx);
2416 
2417 	spin_lock(&dlm->spinlock);
2418 	__dlm_hb_node_down(dlm, idx);
2419 	spin_unlock(&dlm->spinlock);
2420 
2421 	dlm_put(dlm);
2422 }
2423 
2424 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2425 {
2426 	struct dlm_ctxt *dlm = data;
2427 
2428 	if (!dlm_grab(dlm))
2429 		return;
2430 
2431 	spin_lock(&dlm->spinlock);
2432 	set_bit(idx, dlm->live_nodes_map);
2433 	/* do NOT notify mle attached to the heartbeat events.
2434 	 * new nodes are not interesting in mastery until joined. */
2435 	spin_unlock(&dlm->spinlock);
2436 
2437 	dlm_put(dlm);
2438 }
2439 
2440 static void dlm_reco_ast(void *astdata)
2441 {
2442 	struct dlm_ctxt *dlm = astdata;
2443 	mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2444 	     dlm->node_num, dlm->name);
2445 }
2446 static void dlm_reco_bast(void *astdata, int blocked_type)
2447 {
2448 	struct dlm_ctxt *dlm = astdata;
2449 	mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2450 	     dlm->node_num, dlm->name);
2451 }
2452 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2453 {
2454 	mlog(0, "unlockast for recovery lock fired!\n");
2455 }
2456 
2457 /*
2458  * dlm_pick_recovery_master will continually attempt to use
2459  * dlmlock() on the special "$RECOVERY" lockres with the
2460  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2461  * this function on each node racing to become the recovery
2462  * master will not stop attempting this until either:
2463  * a) this node gets the EX (and becomes the recovery master),
2464  * or b) dlm->reco.new_master gets set to some nodenum
2465  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2466  * so each time a recovery master is needed, the entire cluster
2467  * will sync at this point.  if the new master dies, that will
2468  * be detected in dlm_do_recovery */
2469 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2470 {
2471 	enum dlm_status ret;
2472 	struct dlm_lockstatus lksb;
2473 	int status = -EINVAL;
2474 
2475 	mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2476 	     dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2477 again:
2478 	memset(&lksb, 0, sizeof(lksb));
2479 
2480 	ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2481 		      DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2482 		      dlm_reco_ast, dlm, dlm_reco_bast);
2483 
2484 	mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2485 	     dlm->name, ret, lksb.status);
2486 
2487 	if (ret == DLM_NORMAL) {
2488 		mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2489 		     dlm->name, dlm->node_num);
2490 
2491 		/* got the EX lock.  check to see if another node
2492 		 * just became the reco master */
2493 		if (dlm_reco_master_ready(dlm)) {
2494 			mlog(0, "%s: got reco EX lock, but %u will "
2495 			     "do the recovery\n", dlm->name,
2496 			     dlm->reco.new_master);
2497 			status = -EEXIST;
2498 		} else {
2499 			status = 0;
2500 
2501 			/* see if recovery was already finished elsewhere */
2502 			spin_lock(&dlm->spinlock);
2503 			if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2504 				status = -EINVAL;
2505 				mlog(0, "%s: got reco EX lock, but "
2506 				     "node got recovered already\n", dlm->name);
2507 				if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2508 					mlog(ML_ERROR, "%s: new master is %u "
2509 					     "but no dead node!\n",
2510 					     dlm->name, dlm->reco.new_master);
2511 					BUG();
2512 				}
2513 			}
2514 			spin_unlock(&dlm->spinlock);
2515 		}
2516 
2517 		/* if this node has actually become the recovery master,
2518 		 * set the master and send the messages to begin recovery */
2519 		if (!status) {
2520 			mlog(0, "%s: dead=%u, this=%u, sending "
2521 			     "begin_reco now\n", dlm->name,
2522 			     dlm->reco.dead_node, dlm->node_num);
2523 			status = dlm_send_begin_reco_message(dlm,
2524 				      dlm->reco.dead_node);
2525 			/* this always succeeds */
2526 			BUG_ON(status);
2527 
2528 			/* set the new_master to this node */
2529 			spin_lock(&dlm->spinlock);
2530 			dlm_set_reco_master(dlm, dlm->node_num);
2531 			spin_unlock(&dlm->spinlock);
2532 		}
2533 
2534 		/* recovery lock is a special case.  ast will not get fired,
2535 		 * so just go ahead and unlock it. */
2536 		ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2537 		if (ret == DLM_DENIED) {
2538 			mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2539 			ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2540 		}
2541 		if (ret != DLM_NORMAL) {
2542 			/* this would really suck. this could only happen
2543 			 * if there was a network error during the unlock
2544 			 * because of node death.  this means the unlock
2545 			 * is actually "done" and the lock structure is
2546 			 * even freed.  we can continue, but only
2547 			 * because this specific lock name is special. */
2548 			mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2549 		}
2550 	} else if (ret == DLM_NOTQUEUED) {
2551 		mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2552 		     dlm->name, dlm->node_num);
2553 		/* another node is master. wait on
2554 		 * reco.new_master != O2NM_INVALID_NODE_NUM
2555 		 * for at most one second */
2556 		wait_event_timeout(dlm->dlm_reco_thread_wq,
2557 					 dlm_reco_master_ready(dlm),
2558 					 msecs_to_jiffies(1000));
2559 		if (!dlm_reco_master_ready(dlm)) {
2560 			mlog(0, "%s: reco master taking awhile\n",
2561 			     dlm->name);
2562 			goto again;
2563 		}
2564 		/* another node has informed this one that it is reco master */
2565 		mlog(0, "%s: reco master %u is ready to recover %u\n",
2566 		     dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2567 		status = -EEXIST;
2568 	} else if (ret == DLM_RECOVERING) {
2569 		mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2570 		     dlm->name, dlm->node_num);
2571 		goto again;
2572 	} else {
2573 		struct dlm_lock_resource *res;
2574 
2575 		/* dlmlock returned something other than NOTQUEUED or NORMAL */
2576 		mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2577 		     "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2578 		     dlm_errname(lksb.status));
2579 		res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2580 					 DLM_RECOVERY_LOCK_NAME_LEN);
2581 		if (res) {
2582 			dlm_print_one_lock_resource(res);
2583 			dlm_lockres_put(res);
2584 		} else {
2585 			mlog(ML_ERROR, "recovery lock not found\n");
2586 		}
2587 		BUG();
2588 	}
2589 
2590 	return status;
2591 }
2592 
2593 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2594 {
2595 	struct dlm_begin_reco br;
2596 	int ret = 0;
2597 	struct dlm_node_iter iter;
2598 	int nodenum;
2599 	int status;
2600 
2601 	mlog_entry("%u\n", dead_node);
2602 
2603 	mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2604 
2605 	spin_lock(&dlm->spinlock);
2606 	dlm_node_iter_init(dlm->domain_map, &iter);
2607 	spin_unlock(&dlm->spinlock);
2608 
2609 	clear_bit(dead_node, iter.node_map);
2610 
2611 	memset(&br, 0, sizeof(br));
2612 	br.node_idx = dlm->node_num;
2613 	br.dead_node = dead_node;
2614 
2615 	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2616 		ret = 0;
2617 		if (nodenum == dead_node) {
2618 			mlog(0, "not sending begin reco to dead node "
2619 				  "%u\n", dead_node);
2620 			continue;
2621 		}
2622 		if (nodenum == dlm->node_num) {
2623 			mlog(0, "not sending begin reco to self\n");
2624 			continue;
2625 		}
2626 retry:
2627 		ret = -EINVAL;
2628 		mlog(0, "attempting to send begin reco msg to %d\n",
2629 			  nodenum);
2630 		ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2631 					 &br, sizeof(br), nodenum, &status);
2632 		/* negative status is handled ok by caller here */
2633 		if (ret >= 0)
2634 			ret = status;
2635 		if (dlm_is_host_down(ret)) {
2636 			/* node is down.  not involved in recovery
2637 			 * so just keep going */
2638 			mlog(0, "%s: node %u was down when sending "
2639 			     "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2640 			ret = 0;
2641 		}
2642 
2643 		/*
2644 		 * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
2645 		 * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
2646 		 * We are handling both for compatibility reasons.
2647 		 */
2648 		if (ret == -EAGAIN || ret == EAGAIN) {
2649 			mlog(0, "%s: trying to start recovery of node "
2650 			     "%u, but node %u is waiting for last recovery "
2651 			     "to complete, backoff for a bit\n", dlm->name,
2652 			     dead_node, nodenum);
2653 			msleep(100);
2654 			goto retry;
2655 		}
2656 		if (ret < 0) {
2657 			struct dlm_lock_resource *res;
2658 			/* this is now a serious problem, possibly ENOMEM
2659 			 * in the network stack.  must retry */
2660 			mlog_errno(ret);
2661 			mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2662 			    " returned %d\n", dlm->name, nodenum, ret);
2663 			res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2664 						 DLM_RECOVERY_LOCK_NAME_LEN);
2665 			if (res) {
2666 				dlm_print_one_lock_resource(res);
2667 				dlm_lockres_put(res);
2668 			} else {
2669 				mlog(ML_ERROR, "recovery lock not found\n");
2670 			}
2671 			/* sleep for a bit in hopes that we can avoid
2672 			 * another ENOMEM */
2673 			msleep(100);
2674 			goto retry;
2675 		}
2676 	}
2677 
2678 	return ret;
2679 }
2680 
2681 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2682 			   void **ret_data)
2683 {
2684 	struct dlm_ctxt *dlm = data;
2685 	struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2686 
2687 	/* ok to return 0, domain has gone away */
2688 	if (!dlm_grab(dlm))
2689 		return 0;
2690 
2691 	spin_lock(&dlm->spinlock);
2692 	if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2693 		mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2694 		     "but this node is in finalize state, waiting on finalize2\n",
2695 		     dlm->name, br->node_idx, br->dead_node,
2696 		     dlm->reco.dead_node, dlm->reco.new_master);
2697 		spin_unlock(&dlm->spinlock);
2698 		return -EAGAIN;
2699 	}
2700 	spin_unlock(&dlm->spinlock);
2701 
2702 	mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2703 	     dlm->name, br->node_idx, br->dead_node,
2704 	     dlm->reco.dead_node, dlm->reco.new_master);
2705 
2706 	dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2707 
2708 	spin_lock(&dlm->spinlock);
2709 	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2710 		if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2711 			mlog(0, "%s: new_master %u died, changing "
2712 			     "to %u\n", dlm->name, dlm->reco.new_master,
2713 			     br->node_idx);
2714 		} else {
2715 			mlog(0, "%s: new_master %u NOT DEAD, changing "
2716 			     "to %u\n", dlm->name, dlm->reco.new_master,
2717 			     br->node_idx);
2718 			/* may not have seen the new master as dead yet */
2719 		}
2720 	}
2721 	if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2722 		mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2723 		     "node %u changing it to %u\n", dlm->name,
2724 		     dlm->reco.dead_node, br->node_idx, br->dead_node);
2725 	}
2726 	dlm_set_reco_master(dlm, br->node_idx);
2727 	dlm_set_reco_dead_node(dlm, br->dead_node);
2728 	if (!test_bit(br->dead_node, dlm->recovery_map)) {
2729 		mlog(0, "recovery master %u sees %u as dead, but this "
2730 		     "node has not yet.  marking %u as dead\n",
2731 		     br->node_idx, br->dead_node, br->dead_node);
2732 		if (!test_bit(br->dead_node, dlm->domain_map) ||
2733 		    !test_bit(br->dead_node, dlm->live_nodes_map))
2734 			mlog(0, "%u not in domain/live_nodes map "
2735 			     "so setting it in reco map manually\n",
2736 			     br->dead_node);
2737 		/* force the recovery cleanup in __dlm_hb_node_down
2738 		 * both of these will be cleared in a moment */
2739 		set_bit(br->dead_node, dlm->domain_map);
2740 		set_bit(br->dead_node, dlm->live_nodes_map);
2741 		__dlm_hb_node_down(dlm, br->dead_node);
2742 	}
2743 	spin_unlock(&dlm->spinlock);
2744 
2745 	dlm_kick_recovery_thread(dlm);
2746 
2747 	mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2748 	     dlm->name, br->node_idx, br->dead_node,
2749 	     dlm->reco.dead_node, dlm->reco.new_master);
2750 
2751 	dlm_put(dlm);
2752 	return 0;
2753 }
2754 
2755 #define DLM_FINALIZE_STAGE2  0x01
2756 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2757 {
2758 	int ret = 0;
2759 	struct dlm_finalize_reco fr;
2760 	struct dlm_node_iter iter;
2761 	int nodenum;
2762 	int status;
2763 	int stage = 1;
2764 
2765 	mlog(0, "finishing recovery for node %s:%u, "
2766 	     "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2767 
2768 	spin_lock(&dlm->spinlock);
2769 	dlm_node_iter_init(dlm->domain_map, &iter);
2770 	spin_unlock(&dlm->spinlock);
2771 
2772 stage2:
2773 	memset(&fr, 0, sizeof(fr));
2774 	fr.node_idx = dlm->node_num;
2775 	fr.dead_node = dlm->reco.dead_node;
2776 	if (stage == 2)
2777 		fr.flags |= DLM_FINALIZE_STAGE2;
2778 
2779 	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2780 		if (nodenum == dlm->node_num)
2781 			continue;
2782 		ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2783 					 &fr, sizeof(fr), nodenum, &status);
2784 		if (ret >= 0)
2785 			ret = status;
2786 		if (ret < 0) {
2787 			mlog_errno(ret);
2788 			if (dlm_is_host_down(ret)) {
2789 				/* this has no effect on this recovery
2790 				 * session, so set the status to zero to
2791 				 * finish out the last recovery */
2792 				mlog(ML_ERROR, "node %u went down after this "
2793 				     "node finished recovery.\n", nodenum);
2794 				ret = 0;
2795 				continue;
2796 			}
2797 			break;
2798 		}
2799 	}
2800 	if (stage == 1) {
2801 		/* reset the node_iter back to the top and send finalize2 */
2802 		iter.curnode = -1;
2803 		stage = 2;
2804 		goto stage2;
2805 	}
2806 
2807 	return ret;
2808 }
2809 
2810 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2811 			      void **ret_data)
2812 {
2813 	struct dlm_ctxt *dlm = data;
2814 	struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2815 	int stage = 1;
2816 
2817 	/* ok to return 0, domain has gone away */
2818 	if (!dlm_grab(dlm))
2819 		return 0;
2820 
2821 	if (fr->flags & DLM_FINALIZE_STAGE2)
2822 		stage = 2;
2823 
2824 	mlog(0, "%s: node %u finalizing recovery stage%d of "
2825 	     "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2826 	     fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2827 
2828 	spin_lock(&dlm->spinlock);
2829 
2830 	if (dlm->reco.new_master != fr->node_idx) {
2831 		mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2832 		     "%u is supposed to be the new master, dead=%u\n",
2833 		     fr->node_idx, dlm->reco.new_master, fr->dead_node);
2834 		BUG();
2835 	}
2836 	if (dlm->reco.dead_node != fr->dead_node) {
2837 		mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2838 		     "node %u, but node %u is supposed to be dead\n",
2839 		     fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2840 		BUG();
2841 	}
2842 
2843 	switch (stage) {
2844 		case 1:
2845 			dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2846 			if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2847 				mlog(ML_ERROR, "%s: received finalize1 from "
2848 				     "new master %u for dead node %u, but "
2849 				     "this node has already received it!\n",
2850 				     dlm->name, fr->node_idx, fr->dead_node);
2851 				dlm_print_reco_node_status(dlm);
2852 				BUG();
2853 			}
2854 			dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2855 			spin_unlock(&dlm->spinlock);
2856 			break;
2857 		case 2:
2858 			if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2859 				mlog(ML_ERROR, "%s: received finalize2 from "
2860 				     "new master %u for dead node %u, but "
2861 				     "this node did not have finalize1!\n",
2862 				     dlm->name, fr->node_idx, fr->dead_node);
2863 				dlm_print_reco_node_status(dlm);
2864 				BUG();
2865 			}
2866 			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2867 			spin_unlock(&dlm->spinlock);
2868 			dlm_reset_recovery(dlm);
2869 			dlm_kick_recovery_thread(dlm);
2870 			break;
2871 		default:
2872 			BUG();
2873 	}
2874 
2875 	mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2876 	     dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2877 
2878 	dlm_put(dlm);
2879 	return 0;
2880 }
2881