xref: /linux/fs/dlm/member.c (revision 7f662eb1807ed732ac7d5e119753c8185f241bb8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /******************************************************************************
3 *******************************************************************************
4 **
5 **  Copyright (C) 2005-2011 Red Hat, Inc.  All rights reserved.
6 **
7 **
8 *******************************************************************************
9 ******************************************************************************/
10 
11 #include "dlm_internal.h"
12 #include "lockspace.h"
13 #include "member.h"
14 #include "recoverd.h"
15 #include "recover.h"
16 #include "rcom.h"
17 #include "config.h"
18 #include "midcomms.h"
19 #include "lowcomms.h"
20 
21 int dlm_slots_version(const struct dlm_header *h)
22 {
23 	if ((le32_to_cpu(h->h_version) & 0x0000FFFF) < DLM_HEADER_SLOTS)
24 		return 0;
25 	return 1;
26 }
27 
28 void dlm_slot_save(struct dlm_ls *ls, struct dlm_rcom *rc,
29 		   struct dlm_member *memb)
30 {
31 	struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
32 
33 	if (!dlm_slots_version(&rc->rc_header))
34 		return;
35 
36 	memb->slot = le16_to_cpu(rf->rf_our_slot);
37 	memb->generation = le32_to_cpu(rf->rf_generation);
38 }
39 
40 void dlm_slots_copy_out(struct dlm_ls *ls, struct dlm_rcom *rc)
41 {
42 	struct dlm_slot *slot;
43 	struct rcom_slot *ro;
44 	int i;
45 
46 	ro = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
47 
48 	/* ls_slots array is sparse, but not rcom_slots */
49 
50 	for (i = 0; i < ls->ls_slots_size; i++) {
51 		slot = &ls->ls_slots[i];
52 		if (!slot->nodeid)
53 			continue;
54 		ro->ro_nodeid = cpu_to_le32(slot->nodeid);
55 		ro->ro_slot = cpu_to_le16(slot->slot);
56 		ro++;
57 	}
58 }
59 
60 #define SLOT_DEBUG_LINE 128
61 
62 static void log_slots(struct dlm_ls *ls, uint32_t gen, int num_slots,
63 		      struct rcom_slot *ro0, struct dlm_slot *array,
64 		      int array_size)
65 {
66 	char line[SLOT_DEBUG_LINE];
67 	int len = SLOT_DEBUG_LINE - 1;
68 	int pos = 0;
69 	int ret, i;
70 
71 	memset(line, 0, sizeof(line));
72 
73 	if (array) {
74 		for (i = 0; i < array_size; i++) {
75 			if (!array[i].nodeid)
76 				continue;
77 
78 			ret = snprintf(line + pos, len - pos, " %d:%d",
79 				       array[i].slot, array[i].nodeid);
80 			if (ret >= len - pos)
81 				break;
82 			pos += ret;
83 		}
84 	} else if (ro0) {
85 		for (i = 0; i < num_slots; i++) {
86 			ret = snprintf(line + pos, len - pos, " %d:%d",
87 				       ro0[i].ro_slot, ro0[i].ro_nodeid);
88 			if (ret >= len - pos)
89 				break;
90 			pos += ret;
91 		}
92 	}
93 
94 	log_rinfo(ls, "generation %u slots %d%s", gen, num_slots, line);
95 }
96 
97 int dlm_slots_copy_in(struct dlm_ls *ls)
98 {
99 	struct dlm_member *memb;
100 	struct dlm_rcom *rc = ls->ls_recover_buf;
101 	struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
102 	struct rcom_slot *ro0, *ro;
103 	int our_nodeid = dlm_our_nodeid();
104 	int i, num_slots;
105 	uint32_t gen;
106 
107 	if (!dlm_slots_version(&rc->rc_header))
108 		return -1;
109 
110 	gen = le32_to_cpu(rf->rf_generation);
111 	if (gen <= ls->ls_generation) {
112 		log_error(ls, "dlm_slots_copy_in gen %u old %u",
113 			  gen, ls->ls_generation);
114 	}
115 	ls->ls_generation = gen;
116 
117 	num_slots = le16_to_cpu(rf->rf_num_slots);
118 	if (!num_slots)
119 		return -1;
120 
121 	ro0 = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
122 
123 	log_slots(ls, gen, num_slots, ro0, NULL, 0);
124 
125 	list_for_each_entry(memb, &ls->ls_nodes, list) {
126 		for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
127 			if (le32_to_cpu(ro->ro_nodeid) != memb->nodeid)
128 				continue;
129 			memb->slot = le16_to_cpu(ro->ro_slot);
130 			memb->slot_prev = memb->slot;
131 			break;
132 		}
133 
134 		if (memb->nodeid == our_nodeid) {
135 			if (ls->ls_slot && ls->ls_slot != memb->slot) {
136 				log_error(ls, "dlm_slots_copy_in our slot "
137 					  "changed %d %d", ls->ls_slot,
138 					  memb->slot);
139 				return -1;
140 			}
141 
142 			if (!ls->ls_slot)
143 				ls->ls_slot = memb->slot;
144 		}
145 
146 		if (!memb->slot) {
147 			log_error(ls, "dlm_slots_copy_in nodeid %d no slot",
148 				   memb->nodeid);
149 			return -1;
150 		}
151 	}
152 
153 	return 0;
154 }
155 
156 /* for any nodes that do not support slots, we will not have set memb->slot
157    in wait_status_all(), so memb->slot will remain -1, and we will not
158    assign slots or set ls_num_slots here */
159 
160 int dlm_slots_assign(struct dlm_ls *ls, int *num_slots, int *slots_size,
161 		     struct dlm_slot **slots_out, uint32_t *gen_out)
162 {
163 	struct dlm_member *memb;
164 	struct dlm_slot *array;
165 	int our_nodeid = dlm_our_nodeid();
166 	int array_size, max_slots, i;
167 	int need = 0;
168 	int max = 0;
169 	int num = 0;
170 	uint32_t gen = 0;
171 
172 	/* our own memb struct will have slot -1 gen 0 */
173 
174 	list_for_each_entry(memb, &ls->ls_nodes, list) {
175 		if (memb->nodeid == our_nodeid) {
176 			memb->slot = ls->ls_slot;
177 			memb->generation = ls->ls_generation;
178 			break;
179 		}
180 	}
181 
182 	list_for_each_entry(memb, &ls->ls_nodes, list) {
183 		if (memb->generation > gen)
184 			gen = memb->generation;
185 
186 		/* node doesn't support slots */
187 
188 		if (memb->slot == -1)
189 			return -1;
190 
191 		/* node needs a slot assigned */
192 
193 		if (!memb->slot)
194 			need++;
195 
196 		/* node has a slot assigned */
197 
198 		num++;
199 
200 		if (!max || max < memb->slot)
201 			max = memb->slot;
202 
203 		/* sanity check, once slot is assigned it shouldn't change */
204 
205 		if (memb->slot_prev && memb->slot && memb->slot_prev != memb->slot) {
206 			log_error(ls, "nodeid %d slot changed %d %d",
207 				  memb->nodeid, memb->slot_prev, memb->slot);
208 			return -1;
209 		}
210 		memb->slot_prev = memb->slot;
211 	}
212 
213 	array_size = max + need;
214 	array = kzalloc_objs(*array, array_size, GFP_NOFS);
215 	if (!array)
216 		return -ENOMEM;
217 
218 	num = 0;
219 
220 	/* fill in slots (offsets) that are used */
221 
222 	list_for_each_entry(memb, &ls->ls_nodes, list) {
223 		if (!memb->slot)
224 			continue;
225 
226 		if (memb->slot > array_size) {
227 			log_error(ls, "invalid slot number %d", memb->slot);
228 			kfree(array);
229 			return -1;
230 		}
231 
232 		array[memb->slot - 1].nodeid = memb->nodeid;
233 		array[memb->slot - 1].slot = memb->slot;
234 		num++;
235 	}
236 
237 	/* assign new slots from unused offsets */
238 
239 	list_for_each_entry(memb, &ls->ls_nodes, list) {
240 		if (memb->slot)
241 			continue;
242 
243 		for (i = 0; i < array_size; i++) {
244 			if (array[i].nodeid)
245 				continue;
246 
247 			memb->slot = i + 1;
248 			memb->slot_prev = memb->slot;
249 			array[i].nodeid = memb->nodeid;
250 			array[i].slot = memb->slot;
251 			num++;
252 
253 			if (!ls->ls_slot && memb->nodeid == our_nodeid)
254 				ls->ls_slot = memb->slot;
255 			break;
256 		}
257 
258 		if (!memb->slot) {
259 			log_error(ls, "no free slot found");
260 			kfree(array);
261 			return -1;
262 		}
263 	}
264 
265 	gen++;
266 
267 	log_slots(ls, gen, num, NULL, array, array_size);
268 
269 	max_slots = (DLM_MAX_APP_BUFSIZE - sizeof(struct dlm_rcom) -
270 		     sizeof(struct rcom_config)) / sizeof(struct rcom_slot);
271 
272 	if (num > max_slots) {
273 		log_error(ls, "num_slots %d exceeds max_slots %d",
274 			  num, max_slots);
275 		kfree(array);
276 		return -1;
277 	}
278 
279 	*gen_out = gen;
280 	*slots_out = array;
281 	*slots_size = array_size;
282 	*num_slots = num;
283 	return 0;
284 }
285 
286 static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
287 {
288 	struct dlm_member *memb = NULL;
289 	struct list_head *tmp;
290 	struct list_head *newlist = &new->list;
291 	struct list_head *head = &ls->ls_nodes;
292 
293 	list_for_each(tmp, head) {
294 		memb = list_entry(tmp, struct dlm_member, list);
295 		if (new->nodeid < memb->nodeid)
296 			break;
297 	}
298 
299 	if (!memb)
300 		list_add_tail(newlist, head);
301 	else {
302 		list_add_tail(newlist, tmp);
303 	}
304 }
305 
306 static int add_remote_member(int nodeid)
307 {
308 	int error;
309 
310 	if (nodeid == dlm_our_nodeid())
311 		return 0;
312 
313 	error = dlm_lowcomms_connect_node(nodeid);
314 	if (error < 0)
315 		return error;
316 
317 	dlm_midcomms_add_member(nodeid);
318 	return 0;
319 }
320 
321 static int dlm_add_member(struct dlm_ls *ls, struct dlm_config_node *node)
322 {
323 	struct dlm_member *memb;
324 	int error;
325 
326 	memb = kzalloc_obj(*memb, GFP_NOFS);
327 	if (!memb)
328 		return -ENOMEM;
329 
330 	memb->nodeid = node->nodeid;
331 	memb->weight = node->weight;
332 	memb->comm_seq = node->comm_seq;
333 
334 	error = add_remote_member(node->nodeid);
335 	if (error < 0) {
336 		kfree(memb);
337 		return error;
338 	}
339 
340 	add_ordered_member(ls, memb);
341 	ls->ls_num_nodes++;
342 	return 0;
343 }
344 
345 static struct dlm_member *find_memb(struct list_head *head, int nodeid)
346 {
347 	struct dlm_member *memb;
348 
349 	list_for_each_entry(memb, head, list) {
350 		if (memb->nodeid == nodeid)
351 			return memb;
352 	}
353 	return NULL;
354 }
355 
356 int dlm_is_member(struct dlm_ls *ls, int nodeid)
357 {
358 	if (find_memb(&ls->ls_nodes, nodeid))
359 		return 1;
360 	return 0;
361 }
362 
363 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
364 {
365 	WARN_ON_ONCE(!nodeid || nodeid == -1);
366 
367 	if (find_memb(&ls->ls_nodes_gone, nodeid))
368 		return 1;
369 	return 0;
370 }
371 
372 static void clear_memb_list(struct list_head *head,
373 			    void (*after_del)(int nodeid))
374 {
375 	struct dlm_member *memb;
376 
377 	while (!list_empty(head)) {
378 		memb = list_entry(head->next, struct dlm_member, list);
379 		list_del(&memb->list);
380 		if (after_del)
381 			after_del(memb->nodeid);
382 		kfree(memb);
383 	}
384 }
385 
386 static void remove_remote_member(int nodeid)
387 {
388 	if (nodeid == dlm_our_nodeid())
389 		return;
390 
391 	dlm_midcomms_remove_member(nodeid);
392 }
393 
394 void dlm_clear_members(struct dlm_ls *ls)
395 {
396 	clear_memb_list(&ls->ls_nodes, remove_remote_member);
397 	ls->ls_num_nodes = 0;
398 }
399 
400 void dlm_clear_members_gone(struct dlm_ls *ls)
401 {
402 	clear_memb_list(&ls->ls_nodes_gone, NULL);
403 }
404 
405 static int make_member_array(struct dlm_ls *ls)
406 {
407 	struct dlm_member *memb;
408 	int i, w, x = 0, total = 0, all_zero = 0, *array;
409 
410 	kfree(ls->ls_node_array);
411 	ls->ls_node_array = NULL;
412 
413 	list_for_each_entry(memb, &ls->ls_nodes, list) {
414 		if (check_add_overflow(total, memb->weight, &total))
415 			return -EOVERFLOW;
416 	}
417 
418 	/* all nodes revert to weight of 1 if all have weight 0 */
419 
420 	if (!total) {
421 		total = ls->ls_num_nodes;
422 		all_zero = 1;
423 	}
424 
425 	array = kmalloc_objs(*array, total, GFP_NOFS);
426 	if (!array)
427 		return -ENOMEM;
428 
429 	list_for_each_entry(memb, &ls->ls_nodes, list) {
430 		if (!all_zero && !memb->weight)
431 			continue;
432 
433 		if (all_zero)
434 			w = 1;
435 		else
436 			w = memb->weight;
437 
438 		DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
439 
440 		for (i = 0; i < w; i++)
441 			array[x++] = memb->nodeid;
442 	}
443 
444 	ls->ls_total_weight = total;
445 	ls->ls_node_array = array;
446 
447 	return 0;
448 }
449 
450 /* send a status request to all members just to establish comms connections */
451 
452 static int ping_members(struct dlm_ls *ls, uint64_t seq)
453 {
454 	struct dlm_member *memb;
455 	int error = 0;
456 
457 	list_for_each_entry(memb, &ls->ls_nodes, list) {
458 		if (dlm_recovery_stopped(ls)) {
459 			error = -EINTR;
460 			break;
461 		}
462 		error = dlm_rcom_status(ls, memb->nodeid, 0, seq);
463 		if (error)
464 			break;
465 	}
466 	if (error)
467 		log_rinfo(ls, "ping_members aborted %d last nodeid %d",
468 			  error, ls->ls_recover_nodeid);
469 	return error;
470 }
471 
472 static void dlm_lsop_recover_prep(struct dlm_ls *ls)
473 {
474 	if (!ls->ls_ops || !ls->ls_ops->recover_prep)
475 		return;
476 	ls->ls_ops->recover_prep(ls->ls_ops_arg);
477 }
478 
479 static void dlm_lsop_recover_slot(struct dlm_ls *ls, struct dlm_member *memb,
480 				  unsigned int release_recover)
481 {
482 	struct dlm_slot slot;
483 	uint32_t seq;
484 	int error;
485 
486 	if (!ls->ls_ops || !ls->ls_ops->recover_slot)
487 		return;
488 
489 	/* if there is no comms connection with this node
490 	   or the present comms connection is newer
491 	   than the one when this member was added, then
492 	   we consider the node to have failed (versus
493 	   being removed due to dlm_release_lockspace) */
494 
495 	error = dlm_comm_seq(memb->nodeid, &seq, false);
496 
497 	if (!release_recover && !error && seq == memb->comm_seq)
498 		return;
499 
500 	slot.nodeid = memb->nodeid;
501 	slot.slot = memb->slot;
502 
503 	ls->ls_ops->recover_slot(ls->ls_ops_arg, &slot);
504 }
505 
506 void dlm_lsop_recover_done(struct dlm_ls *ls)
507 {
508 	struct dlm_member *memb;
509 	struct dlm_slot *slots;
510 	int i, num;
511 
512 	if (!ls->ls_ops || !ls->ls_ops->recover_done)
513 		return;
514 
515 	num = ls->ls_num_nodes;
516 	slots = kzalloc_objs(*slots, num);
517 	if (!slots)
518 		return;
519 
520 	i = 0;
521 	list_for_each_entry(memb, &ls->ls_nodes, list) {
522 		if (i == num) {
523 			log_error(ls, "dlm_lsop_recover_done bad num %d", num);
524 			goto out;
525 		}
526 		slots[i].nodeid = memb->nodeid;
527 		slots[i].slot = memb->slot;
528 		i++;
529 	}
530 
531 	ls->ls_ops->recover_done(ls->ls_ops_arg, slots, num,
532 				 ls->ls_slot, ls->ls_generation);
533  out:
534 	kfree(slots);
535 }
536 
537 static struct dlm_config_node *find_config_node(struct dlm_recover *rv,
538 						int nodeid)
539 {
540 	int i;
541 
542 	for (i = 0; i < rv->nodes_count; i++) {
543 		if (rv->nodes[i].nodeid == nodeid)
544 			return &rv->nodes[i];
545 	}
546 	return NULL;
547 }
548 
549 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
550 {
551 	struct dlm_member *memb, *safe;
552 	struct dlm_config_node *node;
553 	int i, error, neg = 0, low = -1;
554 	unsigned int release_recover;
555 
556 	/* previously removed members that we've not finished removing need to
557 	 * count as a negative change so the "neg" recovery steps will happen
558 	 *
559 	 * This functionality must report all member changes to lsops or
560 	 * midcomms layer and must never return before.
561 	 */
562 
563 	list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
564 		log_rinfo(ls, "prev removed member %d", memb->nodeid);
565 		neg++;
566 	}
567 
568 	/* move departed members from ls_nodes to ls_nodes_gone */
569 
570 	list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
571 		node = find_config_node(rv, memb->nodeid);
572 		if (!node) {
573 			log_error(ls, "remove member %d invalid",
574 				  memb->nodeid);
575 			return -EFAULT;
576 		}
577 
578 		if (!node->new && !node->gone)
579 			continue;
580 
581 		release_recover = 0;
582 
583 		if (node->gone) {
584 			release_recover = node->release_recover;
585 			log_rinfo(ls, "remove member %d%s", memb->nodeid,
586 				  release_recover ? " (release_recover)" : "");
587 		} else {
588 			/* removed and re-added */
589 			log_rinfo(ls, "remove member %d comm_seq %u %u",
590 				  memb->nodeid, memb->comm_seq, node->comm_seq);
591 		}
592 
593 		neg++;
594 		list_move(&memb->list, &ls->ls_nodes_gone);
595 		remove_remote_member(memb->nodeid);
596 		ls->ls_num_nodes--;
597 		dlm_lsop_recover_slot(ls, memb, release_recover);
598 	}
599 
600 	/* add new members to ls_nodes */
601 
602 	for (i = 0; i < rv->nodes_count; i++) {
603 		node = &rv->nodes[i];
604 		if (node->gone)
605 			continue;
606 
607 		if (dlm_is_member(ls, node->nodeid))
608 			continue;
609 		error = dlm_add_member(ls, node);
610 		if (error)
611 			return error;
612 
613 		log_rinfo(ls, "add member %d", node->nodeid);
614 	}
615 
616 	list_for_each_entry(memb, &ls->ls_nodes, list) {
617 		if (low == -1 || memb->nodeid < low)
618 			low = memb->nodeid;
619 	}
620 	ls->ls_low_nodeid = low;
621 
622 	error = make_member_array(ls);
623 	if (error)
624 		return error;
625 
626 	*neg_out = neg;
627 
628 	error = ping_members(ls, rv->seq);
629 	log_rinfo(ls, "dlm_recover_members %d nodes", ls->ls_num_nodes);
630 	return error;
631 }
632 
633 /* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
634    dlm_ls_start() is called on any of them to start the new recovery. */
635 
636 int dlm_ls_stop(struct dlm_ls *ls)
637 {
638 	int new;
639 
640 	/*
641 	 * Prevent dlm_recv from being in the middle of something when we do
642 	 * the stop.  This includes ensuring dlm_recv isn't processing a
643 	 * recovery message (rcom), while dlm_recoverd is aborting and
644 	 * resetting things from an in-progress recovery.  i.e. we want
645 	 * dlm_recoverd to abort its recovery without worrying about dlm_recv
646 	 * processing an rcom at the same time.  Stopping dlm_recv also makes
647 	 * it easy for dlm_receive_message() to check locking stopped and add a
648 	 * message to the requestqueue without races.
649 	 */
650 
651 	write_lock_bh(&ls->ls_recv_active);
652 
653 	/*
654 	 * Abort any recovery that's in progress (see RECOVER_STOP,
655 	 * dlm_recovery_stopped()) and tell any other threads running in the
656 	 * dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
657 	 */
658 
659 	spin_lock_bh(&ls->ls_recover_lock);
660 	set_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
661 	new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
662 	if (new)
663 		timer_delete_sync(&ls->ls_scan_timer);
664 	ls->ls_recover_seq++;
665 
666 	/* activate requestqueue and stop processing */
667 	write_lock_bh(&ls->ls_requestqueue_lock);
668 	set_bit(LSFL_RECV_MSG_BLOCKED, &ls->ls_flags);
669 	write_unlock_bh(&ls->ls_requestqueue_lock);
670 	spin_unlock_bh(&ls->ls_recover_lock);
671 
672 	/*
673 	 * Let dlm_recv run again, now any normal messages will be saved on the
674 	 * requestqueue for later.
675 	 */
676 
677 	write_unlock_bh(&ls->ls_recv_active);
678 
679 	/*
680 	 * This in_recovery lock does two things:
681 	 * 1) Keeps this function from returning until all threads are out
682 	 *    of locking routines and locking is truly stopped.
683 	 * 2) Keeps any new requests from being processed until it's unlocked
684 	 *    when recovery is complete.
685 	 */
686 
687 	if (new) {
688 		set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags);
689 		wake_up_process(ls->ls_recoverd_task);
690 		wait_event(ls->ls_recover_lock_wait,
691 			   test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
692 	}
693 
694 	/*
695 	 * The recoverd suspend/resume makes sure that dlm_recoverd (if
696 	 * running) has noticed RECOVER_STOP above and quit processing the
697 	 * previous recovery.
698 	 */
699 
700 	dlm_recoverd_suspend(ls);
701 
702 	spin_lock_bh(&ls->ls_recover_lock);
703 	kfree(ls->ls_slots);
704 	ls->ls_slots = NULL;
705 	ls->ls_num_slots = 0;
706 	ls->ls_slots_size = 0;
707 	ls->ls_recover_status = 0;
708 	spin_unlock_bh(&ls->ls_recover_lock);
709 
710 	dlm_recoverd_resume(ls);
711 
712 	if (!ls->ls_recover_begin)
713 		ls->ls_recover_begin = jiffies;
714 
715 	/* call recover_prep ops only once and not multiple times
716 	 * for each possible dlm_ls_stop() when recovery is already
717 	 * stopped.
718 	 *
719 	 * If we successful was able to clear LSFL_RUNNING bit and
720 	 * it was set we know it is the first dlm_ls_stop() call.
721 	 */
722 	if (new)
723 		dlm_lsop_recover_prep(ls);
724 
725 	return 0;
726 }
727 
728 int dlm_ls_start(struct dlm_ls *ls)
729 {
730 	struct dlm_recover *rv, *rv_old;
731 	struct dlm_config_node *nodes = NULL;
732 	int error, count;
733 
734 	rv = kzalloc_obj(*rv, GFP_NOFS);
735 	if (!rv)
736 		return -ENOMEM;
737 
738 	error = dlm_config_nodes(ls->ls_name, &nodes, &count);
739 	if (error < 0)
740 		goto fail_rv;
741 
742 	spin_lock_bh(&ls->ls_recover_lock);
743 
744 	/* the lockspace needs to be stopped before it can be started */
745 
746 	if (!dlm_locking_stopped(ls)) {
747 		spin_unlock_bh(&ls->ls_recover_lock);
748 		log_error(ls, "start ignored: lockspace running");
749 		error = -EINVAL;
750 		goto fail;
751 	}
752 
753 	rv->nodes = nodes;
754 	rv->nodes_count = count;
755 	rv->seq = ++ls->ls_recover_seq;
756 	rv_old = ls->ls_recover_args;
757 	ls->ls_recover_args = rv;
758 	spin_unlock_bh(&ls->ls_recover_lock);
759 
760 	if (rv_old) {
761 		log_error(ls, "unused recovery %llx %d",
762 			  (unsigned long long)rv_old->seq, rv_old->nodes_count);
763 		kfree(rv_old->nodes);
764 		kfree(rv_old);
765 	}
766 
767 	set_bit(LSFL_RECOVER_WORK, &ls->ls_flags);
768 	wake_up_process(ls->ls_recoverd_task);
769 	return 0;
770 
771  fail:
772 	kfree(nodes);
773  fail_rv:
774 	kfree(rv);
775 	return error;
776 }
777 
778