xref: /openbmc/linux/fs/dlm/member.c (revision 9659281c)
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(struct dlm_header *h)
22 {
23 	if ((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 	for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
124 		ro->ro_nodeid = le32_to_cpu(ro->ro_nodeid);
125 		ro->ro_slot = le16_to_cpu(ro->ro_slot);
126 	}
127 
128 	log_slots(ls, gen, num_slots, ro0, NULL, 0);
129 
130 	list_for_each_entry(memb, &ls->ls_nodes, list) {
131 		for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
132 			if (ro->ro_nodeid != memb->nodeid)
133 				continue;
134 			memb->slot = ro->ro_slot;
135 			memb->slot_prev = memb->slot;
136 			break;
137 		}
138 
139 		if (memb->nodeid == our_nodeid) {
140 			if (ls->ls_slot && ls->ls_slot != memb->slot) {
141 				log_error(ls, "dlm_slots_copy_in our slot "
142 					  "changed %d %d", ls->ls_slot,
143 					  memb->slot);
144 				return -1;
145 			}
146 
147 			if (!ls->ls_slot)
148 				ls->ls_slot = memb->slot;
149 		}
150 
151 		if (!memb->slot) {
152 			log_error(ls, "dlm_slots_copy_in nodeid %d no slot",
153 				   memb->nodeid);
154 			return -1;
155 		}
156 	}
157 
158 	return 0;
159 }
160 
161 /* for any nodes that do not support slots, we will not have set memb->slot
162    in wait_status_all(), so memb->slot will remain -1, and we will not
163    assign slots or set ls_num_slots here */
164 
165 int dlm_slots_assign(struct dlm_ls *ls, int *num_slots, int *slots_size,
166 		     struct dlm_slot **slots_out, uint32_t *gen_out)
167 {
168 	struct dlm_member *memb;
169 	struct dlm_slot *array;
170 	int our_nodeid = dlm_our_nodeid();
171 	int array_size, max_slots, i;
172 	int need = 0;
173 	int max = 0;
174 	int num = 0;
175 	uint32_t gen = 0;
176 
177 	/* our own memb struct will have slot -1 gen 0 */
178 
179 	list_for_each_entry(memb, &ls->ls_nodes, list) {
180 		if (memb->nodeid == our_nodeid) {
181 			memb->slot = ls->ls_slot;
182 			memb->generation = ls->ls_generation;
183 			break;
184 		}
185 	}
186 
187 	list_for_each_entry(memb, &ls->ls_nodes, list) {
188 		if (memb->generation > gen)
189 			gen = memb->generation;
190 
191 		/* node doesn't support slots */
192 
193 		if (memb->slot == -1)
194 			return -1;
195 
196 		/* node needs a slot assigned */
197 
198 		if (!memb->slot)
199 			need++;
200 
201 		/* node has a slot assigned */
202 
203 		num++;
204 
205 		if (!max || max < memb->slot)
206 			max = memb->slot;
207 
208 		/* sanity check, once slot is assigned it shouldn't change */
209 
210 		if (memb->slot_prev && memb->slot && memb->slot_prev != memb->slot) {
211 			log_error(ls, "nodeid %d slot changed %d %d",
212 				  memb->nodeid, memb->slot_prev, memb->slot);
213 			return -1;
214 		}
215 		memb->slot_prev = memb->slot;
216 	}
217 
218 	array_size = max + need;
219 	array = kcalloc(array_size, sizeof(*array), GFP_NOFS);
220 	if (!array)
221 		return -ENOMEM;
222 
223 	num = 0;
224 
225 	/* fill in slots (offsets) that are used */
226 
227 	list_for_each_entry(memb, &ls->ls_nodes, list) {
228 		if (!memb->slot)
229 			continue;
230 
231 		if (memb->slot > array_size) {
232 			log_error(ls, "invalid slot number %d", memb->slot);
233 			kfree(array);
234 			return -1;
235 		}
236 
237 		array[memb->slot - 1].nodeid = memb->nodeid;
238 		array[memb->slot - 1].slot = memb->slot;
239 		num++;
240 	}
241 
242 	/* assign new slots from unused offsets */
243 
244 	list_for_each_entry(memb, &ls->ls_nodes, list) {
245 		if (memb->slot)
246 			continue;
247 
248 		for (i = 0; i < array_size; i++) {
249 			if (array[i].nodeid)
250 				continue;
251 
252 			memb->slot = i + 1;
253 			memb->slot_prev = memb->slot;
254 			array[i].nodeid = memb->nodeid;
255 			array[i].slot = memb->slot;
256 			num++;
257 
258 			if (!ls->ls_slot && memb->nodeid == our_nodeid)
259 				ls->ls_slot = memb->slot;
260 			break;
261 		}
262 
263 		if (!memb->slot) {
264 			log_error(ls, "no free slot found");
265 			kfree(array);
266 			return -1;
267 		}
268 	}
269 
270 	gen++;
271 
272 	log_slots(ls, gen, num, NULL, array, array_size);
273 
274 	max_slots = (DLM_MAX_APP_BUFSIZE - sizeof(struct dlm_rcom) -
275 		     sizeof(struct rcom_config)) / sizeof(struct rcom_slot);
276 
277 	if (num > max_slots) {
278 		log_error(ls, "num_slots %d exceeds max_slots %d",
279 			  num, max_slots);
280 		kfree(array);
281 		return -1;
282 	}
283 
284 	*gen_out = gen;
285 	*slots_out = array;
286 	*slots_size = array_size;
287 	*num_slots = num;
288 	return 0;
289 }
290 
291 static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
292 {
293 	struct dlm_member *memb = NULL;
294 	struct list_head *tmp;
295 	struct list_head *newlist = &new->list;
296 	struct list_head *head = &ls->ls_nodes;
297 
298 	list_for_each(tmp, head) {
299 		memb = list_entry(tmp, struct dlm_member, list);
300 		if (new->nodeid < memb->nodeid)
301 			break;
302 	}
303 
304 	if (!memb)
305 		list_add_tail(newlist, head);
306 	else {
307 		/* FIXME: can use list macro here */
308 		newlist->prev = tmp->prev;
309 		newlist->next = tmp;
310 		tmp->prev->next = newlist;
311 		tmp->prev = newlist;
312 	}
313 }
314 
315 static int dlm_add_member(struct dlm_ls *ls, struct dlm_config_node *node)
316 {
317 	struct dlm_member *memb;
318 	int error;
319 
320 	memb = kzalloc(sizeof(*memb), GFP_NOFS);
321 	if (!memb)
322 		return -ENOMEM;
323 
324 	error = dlm_lowcomms_connect_node(node->nodeid);
325 	if (error < 0) {
326 		kfree(memb);
327 		return error;
328 	}
329 
330 	memb->nodeid = node->nodeid;
331 	memb->weight = node->weight;
332 	memb->comm_seq = node->comm_seq;
333 	dlm_midcomms_add_member(node->nodeid);
334 	add_ordered_member(ls, memb);
335 	ls->ls_num_nodes++;
336 	return 0;
337 }
338 
339 static struct dlm_member *find_memb(struct list_head *head, int nodeid)
340 {
341 	struct dlm_member *memb;
342 
343 	list_for_each_entry(memb, head, list) {
344 		if (memb->nodeid == nodeid)
345 			return memb;
346 	}
347 	return NULL;
348 }
349 
350 int dlm_is_member(struct dlm_ls *ls, int nodeid)
351 {
352 	if (find_memb(&ls->ls_nodes, nodeid))
353 		return 1;
354 	return 0;
355 }
356 
357 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
358 {
359 	if (find_memb(&ls->ls_nodes_gone, nodeid))
360 		return 1;
361 	return 0;
362 }
363 
364 static void clear_memb_list(struct list_head *head,
365 			    void (*after_del)(int nodeid))
366 {
367 	struct dlm_member *memb;
368 
369 	while (!list_empty(head)) {
370 		memb = list_entry(head->next, struct dlm_member, list);
371 		list_del(&memb->list);
372 		if (after_del)
373 			after_del(memb->nodeid);
374 		kfree(memb);
375 	}
376 }
377 
378 static void clear_members_cb(int nodeid)
379 {
380 	dlm_midcomms_remove_member(nodeid);
381 }
382 
383 void dlm_clear_members(struct dlm_ls *ls)
384 {
385 	clear_memb_list(&ls->ls_nodes, clear_members_cb);
386 	ls->ls_num_nodes = 0;
387 }
388 
389 void dlm_clear_members_gone(struct dlm_ls *ls)
390 {
391 	clear_memb_list(&ls->ls_nodes_gone, NULL);
392 }
393 
394 static void make_member_array(struct dlm_ls *ls)
395 {
396 	struct dlm_member *memb;
397 	int i, w, x = 0, total = 0, all_zero = 0, *array;
398 
399 	kfree(ls->ls_node_array);
400 	ls->ls_node_array = NULL;
401 
402 	list_for_each_entry(memb, &ls->ls_nodes, list) {
403 		if (memb->weight)
404 			total += memb->weight;
405 	}
406 
407 	/* all nodes revert to weight of 1 if all have weight 0 */
408 
409 	if (!total) {
410 		total = ls->ls_num_nodes;
411 		all_zero = 1;
412 	}
413 
414 	ls->ls_total_weight = total;
415 	array = kmalloc_array(total, sizeof(*array), GFP_NOFS);
416 	if (!array)
417 		return;
418 
419 	list_for_each_entry(memb, &ls->ls_nodes, list) {
420 		if (!all_zero && !memb->weight)
421 			continue;
422 
423 		if (all_zero)
424 			w = 1;
425 		else
426 			w = memb->weight;
427 
428 		DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
429 
430 		for (i = 0; i < w; i++)
431 			array[x++] = memb->nodeid;
432 	}
433 
434 	ls->ls_node_array = array;
435 }
436 
437 /* send a status request to all members just to establish comms connections */
438 
439 static int ping_members(struct dlm_ls *ls)
440 {
441 	struct dlm_member *memb;
442 	int error = 0;
443 
444 	list_for_each_entry(memb, &ls->ls_nodes, list) {
445 		error = dlm_recovery_stopped(ls);
446 		if (error)
447 			break;
448 		error = dlm_rcom_status(ls, memb->nodeid, 0);
449 		if (error)
450 			break;
451 	}
452 	if (error)
453 		log_rinfo(ls, "ping_members aborted %d last nodeid %d",
454 			  error, ls->ls_recover_nodeid);
455 	return error;
456 }
457 
458 static void dlm_lsop_recover_prep(struct dlm_ls *ls)
459 {
460 	if (!ls->ls_ops || !ls->ls_ops->recover_prep)
461 		return;
462 	ls->ls_ops->recover_prep(ls->ls_ops_arg);
463 }
464 
465 static void dlm_lsop_recover_slot(struct dlm_ls *ls, struct dlm_member *memb)
466 {
467 	struct dlm_slot slot;
468 	uint32_t seq;
469 	int error;
470 
471 	if (!ls->ls_ops || !ls->ls_ops->recover_slot)
472 		return;
473 
474 	/* if there is no comms connection with this node
475 	   or the present comms connection is newer
476 	   than the one when this member was added, then
477 	   we consider the node to have failed (versus
478 	   being removed due to dlm_release_lockspace) */
479 
480 	error = dlm_comm_seq(memb->nodeid, &seq);
481 
482 	if (!error && seq == memb->comm_seq)
483 		return;
484 
485 	slot.nodeid = memb->nodeid;
486 	slot.slot = memb->slot;
487 
488 	ls->ls_ops->recover_slot(ls->ls_ops_arg, &slot);
489 }
490 
491 void dlm_lsop_recover_done(struct dlm_ls *ls)
492 {
493 	struct dlm_member *memb;
494 	struct dlm_slot *slots;
495 	int i, num;
496 
497 	if (!ls->ls_ops || !ls->ls_ops->recover_done)
498 		return;
499 
500 	num = ls->ls_num_nodes;
501 	slots = kcalloc(num, sizeof(*slots), GFP_KERNEL);
502 	if (!slots)
503 		return;
504 
505 	i = 0;
506 	list_for_each_entry(memb, &ls->ls_nodes, list) {
507 		if (i == num) {
508 			log_error(ls, "dlm_lsop_recover_done bad num %d", num);
509 			goto out;
510 		}
511 		slots[i].nodeid = memb->nodeid;
512 		slots[i].slot = memb->slot;
513 		i++;
514 	}
515 
516 	ls->ls_ops->recover_done(ls->ls_ops_arg, slots, num,
517 				 ls->ls_slot, ls->ls_generation);
518  out:
519 	kfree(slots);
520 }
521 
522 static struct dlm_config_node *find_config_node(struct dlm_recover *rv,
523 						int nodeid)
524 {
525 	int i;
526 
527 	for (i = 0; i < rv->nodes_count; i++) {
528 		if (rv->nodes[i].nodeid == nodeid)
529 			return &rv->nodes[i];
530 	}
531 	return NULL;
532 }
533 
534 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
535 {
536 	struct dlm_member *memb, *safe;
537 	struct dlm_config_node *node;
538 	int i, error, neg = 0, low = -1;
539 
540 	/* previously removed members that we've not finished removing need to
541 	   count as a negative change so the "neg" recovery steps will happen */
542 
543 	list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
544 		log_rinfo(ls, "prev removed member %d", memb->nodeid);
545 		neg++;
546 	}
547 
548 	/* move departed members from ls_nodes to ls_nodes_gone */
549 
550 	list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
551 		node = find_config_node(rv, memb->nodeid);
552 		if (node && !node->new)
553 			continue;
554 
555 		if (!node) {
556 			log_rinfo(ls, "remove member %d", memb->nodeid);
557 		} else {
558 			/* removed and re-added */
559 			log_rinfo(ls, "remove member %d comm_seq %u %u",
560 				  memb->nodeid, memb->comm_seq, node->comm_seq);
561 		}
562 
563 		neg++;
564 		list_move(&memb->list, &ls->ls_nodes_gone);
565 		dlm_midcomms_remove_member(memb->nodeid);
566 		ls->ls_num_nodes--;
567 		dlm_lsop_recover_slot(ls, memb);
568 	}
569 
570 	/* add new members to ls_nodes */
571 
572 	for (i = 0; i < rv->nodes_count; i++) {
573 		node = &rv->nodes[i];
574 		if (dlm_is_member(ls, node->nodeid))
575 			continue;
576 		dlm_add_member(ls, node);
577 		log_rinfo(ls, "add member %d", node->nodeid);
578 	}
579 
580 	list_for_each_entry(memb, &ls->ls_nodes, list) {
581 		if (low == -1 || memb->nodeid < low)
582 			low = memb->nodeid;
583 	}
584 	ls->ls_low_nodeid = low;
585 
586 	make_member_array(ls);
587 	*neg_out = neg;
588 
589 	error = ping_members(ls);
590 	/* error -EINTR means that a new recovery action is triggered.
591 	 * We ignore this recovery action and let run the new one which might
592 	 * have new member configuration.
593 	 */
594 	if (error == -EINTR)
595 		error = 0;
596 
597 	/* new_lockspace() may be waiting to know if the config
598 	 * is good or bad
599 	 */
600 	ls->ls_members_result = error;
601 	complete(&ls->ls_members_done);
602 
603 	log_rinfo(ls, "dlm_recover_members %d nodes", ls->ls_num_nodes);
604 	return error;
605 }
606 
607 /* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
608    dlm_ls_start() is called on any of them to start the new recovery. */
609 
610 int dlm_ls_stop(struct dlm_ls *ls)
611 {
612 	int new;
613 
614 	/*
615 	 * Prevent dlm_recv from being in the middle of something when we do
616 	 * the stop.  This includes ensuring dlm_recv isn't processing a
617 	 * recovery message (rcom), while dlm_recoverd is aborting and
618 	 * resetting things from an in-progress recovery.  i.e. we want
619 	 * dlm_recoverd to abort its recovery without worrying about dlm_recv
620 	 * processing an rcom at the same time.  Stopping dlm_recv also makes
621 	 * it easy for dlm_receive_message() to check locking stopped and add a
622 	 * message to the requestqueue without races.
623 	 */
624 
625 	down_write(&ls->ls_recv_active);
626 
627 	/*
628 	 * Abort any recovery that's in progress (see RECOVER_STOP,
629 	 * dlm_recovery_stopped()) and tell any other threads running in the
630 	 * dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
631 	 */
632 
633 	spin_lock(&ls->ls_recover_lock);
634 	set_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
635 	new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
636 	ls->ls_recover_seq++;
637 	spin_unlock(&ls->ls_recover_lock);
638 
639 	/*
640 	 * Let dlm_recv run again, now any normal messages will be saved on the
641 	 * requestqueue for later.
642 	 */
643 
644 	up_write(&ls->ls_recv_active);
645 
646 	/*
647 	 * This in_recovery lock does two things:
648 	 * 1) Keeps this function from returning until all threads are out
649 	 *    of locking routines and locking is truly stopped.
650 	 * 2) Keeps any new requests from being processed until it's unlocked
651 	 *    when recovery is complete.
652 	 */
653 
654 	if (new) {
655 		set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags);
656 		wake_up_process(ls->ls_recoverd_task);
657 		wait_event(ls->ls_recover_lock_wait,
658 			   test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
659 	}
660 
661 	/*
662 	 * The recoverd suspend/resume makes sure that dlm_recoverd (if
663 	 * running) has noticed RECOVER_STOP above and quit processing the
664 	 * previous recovery.
665 	 */
666 
667 	dlm_recoverd_suspend(ls);
668 
669 	spin_lock(&ls->ls_recover_lock);
670 	kfree(ls->ls_slots);
671 	ls->ls_slots = NULL;
672 	ls->ls_num_slots = 0;
673 	ls->ls_slots_size = 0;
674 	ls->ls_recover_status = 0;
675 	spin_unlock(&ls->ls_recover_lock);
676 
677 	dlm_recoverd_resume(ls);
678 
679 	if (!ls->ls_recover_begin)
680 		ls->ls_recover_begin = jiffies;
681 
682 	dlm_lsop_recover_prep(ls);
683 	return 0;
684 }
685 
686 int dlm_ls_start(struct dlm_ls *ls)
687 {
688 	struct dlm_recover *rv, *rv_old;
689 	struct dlm_config_node *nodes = NULL;
690 	int error, count;
691 
692 	rv = kzalloc(sizeof(*rv), GFP_NOFS);
693 	if (!rv)
694 		return -ENOMEM;
695 
696 	error = dlm_config_nodes(ls->ls_name, &nodes, &count);
697 	if (error < 0)
698 		goto fail_rv;
699 
700 	spin_lock(&ls->ls_recover_lock);
701 
702 	/* the lockspace needs to be stopped before it can be started */
703 
704 	if (!dlm_locking_stopped(ls)) {
705 		spin_unlock(&ls->ls_recover_lock);
706 		log_error(ls, "start ignored: lockspace running");
707 		error = -EINVAL;
708 		goto fail;
709 	}
710 
711 	rv->nodes = nodes;
712 	rv->nodes_count = count;
713 	rv->seq = ++ls->ls_recover_seq;
714 	rv_old = ls->ls_recover_args;
715 	ls->ls_recover_args = rv;
716 	spin_unlock(&ls->ls_recover_lock);
717 
718 	if (rv_old) {
719 		log_error(ls, "unused recovery %llx %d",
720 			  (unsigned long long)rv_old->seq, rv_old->nodes_count);
721 		kfree(rv_old->nodes);
722 		kfree(rv_old);
723 	}
724 
725 	set_bit(LSFL_RECOVER_WORK, &ls->ls_flags);
726 	wake_up_process(ls->ls_recoverd_task);
727 	return 0;
728 
729  fail:
730 	kfree(nodes);
731  fail_rv:
732 	kfree(rv);
733 	return error;
734 }
735 
736