File: config.c

package info (click to toggle)
linux 4.19.37-3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 962,264 kB
  • sloc: ansic: 16,757,120; asm: 271,404; makefile: 38,285; sh: 33,529; perl: 27,681; python: 21,031; cpp: 5,063; yacc: 4,648; lex: 2,585; awk: 1,385; ruby: 25; sed: 5
file content (882 lines) | stat: -rw-r--r-- 22,164 bytes parent folder | download | duplicates (7)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
**
**  This copyrighted material is made available to anyone wishing to use,
**  modify, copy, or redistribute it subject to the terms and conditions
**  of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/configfs.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/dlmconstants.h>
#include <net/ipv6.h>
#include <net/sock.h>

#include "config.h"
#include "lowcomms.h"

/*
 * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/nodeid
 * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
 * /config/dlm/<cluster>/comms/<comm>/nodeid
 * /config/dlm/<cluster>/comms/<comm>/local
 * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
 * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)
 * The <cluster> level is useless, but I haven't figured out how to avoid it.
 */

static struct config_group *space_list;
static struct config_group *comm_list;
static struct dlm_comm *local_comm;
static uint32_t dlm_comm_count;

struct dlm_clusters;
struct dlm_cluster;
struct dlm_spaces;
struct dlm_space;
struct dlm_comms;
struct dlm_comm;
struct dlm_nodes;
struct dlm_node;

static struct config_group *make_cluster(struct config_group *, const char *);
static void drop_cluster(struct config_group *, struct config_item *);
static void release_cluster(struct config_item *);
static struct config_group *make_space(struct config_group *, const char *);
static void drop_space(struct config_group *, struct config_item *);
static void release_space(struct config_item *);
static struct config_item *make_comm(struct config_group *, const char *);
static void drop_comm(struct config_group *, struct config_item *);
static void release_comm(struct config_item *);
static struct config_item *make_node(struct config_group *, const char *);
static void drop_node(struct config_group *, struct config_item *);
static void release_node(struct config_item *);

static struct configfs_attribute *comm_attrs[];
static struct configfs_attribute *node_attrs[];

struct dlm_cluster {
	struct config_group group;
	unsigned int cl_tcp_port;
	unsigned int cl_buffer_size;
	unsigned int cl_rsbtbl_size;
	unsigned int cl_recover_timer;
	unsigned int cl_toss_secs;
	unsigned int cl_scan_secs;
	unsigned int cl_log_debug;
	unsigned int cl_log_info;
	unsigned int cl_protocol;
	unsigned int cl_timewarn_cs;
	unsigned int cl_waitwarn_us;
	unsigned int cl_new_rsb_count;
	unsigned int cl_recover_callbacks;
	char cl_cluster_name[DLM_LOCKSPACE_LEN];
};

static struct dlm_cluster *config_item_to_cluster(struct config_item *i)
{
	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
		   NULL;
}

enum {
	CLUSTER_ATTR_TCP_PORT = 0,
	CLUSTER_ATTR_BUFFER_SIZE,
	CLUSTER_ATTR_RSBTBL_SIZE,
	CLUSTER_ATTR_RECOVER_TIMER,
	CLUSTER_ATTR_TOSS_SECS,
	CLUSTER_ATTR_SCAN_SECS,
	CLUSTER_ATTR_LOG_DEBUG,
	CLUSTER_ATTR_LOG_INFO,
	CLUSTER_ATTR_PROTOCOL,
	CLUSTER_ATTR_TIMEWARN_CS,
	CLUSTER_ATTR_WAITWARN_US,
	CLUSTER_ATTR_NEW_RSB_COUNT,
	CLUSTER_ATTR_RECOVER_CALLBACKS,
	CLUSTER_ATTR_CLUSTER_NAME,
};

static ssize_t cluster_cluster_name_show(struct config_item *item, char *buf)
{
	struct dlm_cluster *cl = config_item_to_cluster(item);
	return sprintf(buf, "%s\n", cl->cl_cluster_name);
}

static ssize_t cluster_cluster_name_store(struct config_item *item,
					  const char *buf, size_t len)
{
	struct dlm_cluster *cl = config_item_to_cluster(item);

	strlcpy(dlm_config.ci_cluster_name, buf,
				sizeof(dlm_config.ci_cluster_name));
	strlcpy(cl->cl_cluster_name, buf, sizeof(cl->cl_cluster_name));
	return len;
}

CONFIGFS_ATTR(cluster_, cluster_name);

static ssize_t cluster_set(struct dlm_cluster *cl, unsigned int *cl_field,
			   int *info_field, int check_zero,
			   const char *buf, size_t len)
{
	unsigned int x;
	int rc;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	rc = kstrtouint(buf, 0, &x);
	if (rc)
		return rc;

	if (check_zero && !x)
		return -EINVAL;

	*cl_field = x;
	*info_field = x;

	return len;
}

#define CLUSTER_ATTR(name, check_zero)                                        \
static ssize_t cluster_##name##_store(struct config_item *item, \
		const char *buf, size_t len) \
{                                                                             \
	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
	return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name,         \
			   check_zero, buf, len);                             \
}                                                                             \
static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
{                                                                             \
	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
	return snprintf(buf, PAGE_SIZE, "%u\n", cl->cl_##name);               \
}                                                                             \
CONFIGFS_ATTR(cluster_, name);

CLUSTER_ATTR(tcp_port, 1);
CLUSTER_ATTR(buffer_size, 1);
CLUSTER_ATTR(rsbtbl_size, 1);
CLUSTER_ATTR(recover_timer, 1);
CLUSTER_ATTR(toss_secs, 1);
CLUSTER_ATTR(scan_secs, 1);
CLUSTER_ATTR(log_debug, 0);
CLUSTER_ATTR(log_info, 0);
CLUSTER_ATTR(protocol, 0);
CLUSTER_ATTR(timewarn_cs, 1);
CLUSTER_ATTR(waitwarn_us, 0);
CLUSTER_ATTR(new_rsb_count, 0);
CLUSTER_ATTR(recover_callbacks, 0);

static struct configfs_attribute *cluster_attrs[] = {
	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port,
	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size,
	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size,
	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer,
	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs,
	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs,
	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug,
	[CLUSTER_ATTR_LOG_INFO] = &cluster_attr_log_info,
	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol,
	[CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs,
	[CLUSTER_ATTR_WAITWARN_US] = &cluster_attr_waitwarn_us,
	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count,
	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks,
	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name,
	NULL,
};

enum {
	COMM_ATTR_NODEID = 0,
	COMM_ATTR_LOCAL,
	COMM_ATTR_ADDR,
	COMM_ATTR_ADDR_LIST,
};

enum {
	NODE_ATTR_NODEID = 0,
	NODE_ATTR_WEIGHT,
};

struct dlm_clusters {
	struct configfs_subsystem subsys;
};

struct dlm_spaces {
	struct config_group ss_group;
};

struct dlm_space {
	struct config_group group;
	struct list_head members;
	struct mutex members_lock;
	int members_count;
};

struct dlm_comms {
	struct config_group cs_group;
};

struct dlm_comm {
	struct config_item item;
	int seq;
	int nodeid;
	int local;
	int addr_count;
	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
};

struct dlm_nodes {
	struct config_group ns_group;
};

struct dlm_node {
	struct config_item item;
	struct list_head list; /* space->members */
	int nodeid;
	int weight;
	int new;
	int comm_seq; /* copy of cm->seq when nd->nodeid is set */
};

static struct configfs_group_operations clusters_ops = {
	.make_group = make_cluster,
	.drop_item = drop_cluster,
};

static struct configfs_item_operations cluster_ops = {
	.release = release_cluster,
};

static struct configfs_group_operations spaces_ops = {
	.make_group = make_space,
	.drop_item = drop_space,
};

static struct configfs_item_operations space_ops = {
	.release = release_space,
};

static struct configfs_group_operations comms_ops = {
	.make_item = make_comm,
	.drop_item = drop_comm,
};

static struct configfs_item_operations comm_ops = {
	.release = release_comm,
};

static struct configfs_group_operations nodes_ops = {
	.make_item = make_node,
	.drop_item = drop_node,
};

static struct configfs_item_operations node_ops = {
	.release = release_node,
};

static const struct config_item_type clusters_type = {
	.ct_group_ops = &clusters_ops,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type cluster_type = {
	.ct_item_ops = &cluster_ops,
	.ct_attrs = cluster_attrs,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type spaces_type = {
	.ct_group_ops = &spaces_ops,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type space_type = {
	.ct_item_ops = &space_ops,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type comms_type = {
	.ct_group_ops = &comms_ops,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type comm_type = {
	.ct_item_ops = &comm_ops,
	.ct_attrs = comm_attrs,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type nodes_type = {
	.ct_group_ops = &nodes_ops,
	.ct_owner = THIS_MODULE,
};

static const struct config_item_type node_type = {
	.ct_item_ops = &node_ops,
	.ct_attrs = node_attrs,
	.ct_owner = THIS_MODULE,
};

static struct dlm_space *config_item_to_space(struct config_item *i)
{
	return i ? container_of(to_config_group(i), struct dlm_space, group) :
		   NULL;
}

static struct dlm_comm *config_item_to_comm(struct config_item *i)
{
	return i ? container_of(i, struct dlm_comm, item) : NULL;
}

static struct dlm_node *config_item_to_node(struct config_item *i)
{
	return i ? container_of(i, struct dlm_node, item) : NULL;
}

static struct config_group *make_cluster(struct config_group *g,
					 const char *name)
{
	struct dlm_cluster *cl = NULL;
	struct dlm_spaces *sps = NULL;
	struct dlm_comms *cms = NULL;

	cl = kzalloc(sizeof(struct dlm_cluster), GFP_NOFS);
	sps = kzalloc(sizeof(struct dlm_spaces), GFP_NOFS);
	cms = kzalloc(sizeof(struct dlm_comms), GFP_NOFS);

	if (!cl || !sps || !cms)
		goto fail;

	config_group_init_type_name(&cl->group, name, &cluster_type);
	config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
	config_group_init_type_name(&cms->cs_group, "comms", &comms_type);

	configfs_add_default_group(&sps->ss_group, &cl->group);
	configfs_add_default_group(&cms->cs_group, &cl->group);

	cl->cl_tcp_port = dlm_config.ci_tcp_port;
	cl->cl_buffer_size = dlm_config.ci_buffer_size;
	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;
	cl->cl_recover_timer = dlm_config.ci_recover_timer;
	cl->cl_toss_secs = dlm_config.ci_toss_secs;
	cl->cl_scan_secs = dlm_config.ci_scan_secs;
	cl->cl_log_debug = dlm_config.ci_log_debug;
	cl->cl_log_info = dlm_config.ci_log_info;
	cl->cl_protocol = dlm_config.ci_protocol;
	cl->cl_timewarn_cs = dlm_config.ci_timewarn_cs;
	cl->cl_waitwarn_us = dlm_config.ci_waitwarn_us;
	cl->cl_new_rsb_count = dlm_config.ci_new_rsb_count;
	cl->cl_recover_callbacks = dlm_config.ci_recover_callbacks;
	memcpy(cl->cl_cluster_name, dlm_config.ci_cluster_name,
	       DLM_LOCKSPACE_LEN);

	space_list = &sps->ss_group;
	comm_list = &cms->cs_group;
	return &cl->group;

 fail:
	kfree(cl);
	kfree(sps);
	kfree(cms);
	return ERR_PTR(-ENOMEM);
}

static void drop_cluster(struct config_group *g, struct config_item *i)
{
	struct dlm_cluster *cl = config_item_to_cluster(i);

	configfs_remove_default_groups(&cl->group);

	space_list = NULL;
	comm_list = NULL;

	config_item_put(i);
}

static void release_cluster(struct config_item *i)
{
	struct dlm_cluster *cl = config_item_to_cluster(i);
	kfree(cl);
}

static struct config_group *make_space(struct config_group *g, const char *name)
{
	struct dlm_space *sp = NULL;
	struct dlm_nodes *nds = NULL;

	sp = kzalloc(sizeof(struct dlm_space), GFP_NOFS);
	nds = kzalloc(sizeof(struct dlm_nodes), GFP_NOFS);

	if (!sp || !nds)
		goto fail;

	config_group_init_type_name(&sp->group, name, &space_type);

	config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
	configfs_add_default_group(&nds->ns_group, &sp->group);

	INIT_LIST_HEAD(&sp->members);
	mutex_init(&sp->members_lock);
	sp->members_count = 0;
	return &sp->group;

 fail:
	kfree(sp);
	kfree(nds);
	return ERR_PTR(-ENOMEM);
}

static void drop_space(struct config_group *g, struct config_item *i)
{
	struct dlm_space *sp = config_item_to_space(i);

	/* assert list_empty(&sp->members) */

	configfs_remove_default_groups(&sp->group);
	config_item_put(i);
}

static void release_space(struct config_item *i)
{
	struct dlm_space *sp = config_item_to_space(i);
	kfree(sp);
}

static struct config_item *make_comm(struct config_group *g, const char *name)
{
	struct dlm_comm *cm;

	cm = kzalloc(sizeof(struct dlm_comm), GFP_NOFS);
	if (!cm)
		return ERR_PTR(-ENOMEM);

	config_item_init_type_name(&cm->item, name, &comm_type);

	cm->seq = dlm_comm_count++;
	if (!cm->seq)
		cm->seq = dlm_comm_count++;

	cm->nodeid = -1;
	cm->local = 0;
	cm->addr_count = 0;
	return &cm->item;
}

static void drop_comm(struct config_group *g, struct config_item *i)
{
	struct dlm_comm *cm = config_item_to_comm(i);
	if (local_comm == cm)
		local_comm = NULL;
	dlm_lowcomms_close(cm->nodeid);
	while (cm->addr_count--)
		kfree(cm->addr[cm->addr_count]);
	config_item_put(i);
}

static void release_comm(struct config_item *i)
{
	struct dlm_comm *cm = config_item_to_comm(i);
	kfree(cm);
}

static struct config_item *make_node(struct config_group *g, const char *name)
{
	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
	struct dlm_node *nd;

	nd = kzalloc(sizeof(struct dlm_node), GFP_NOFS);
	if (!nd)
		return ERR_PTR(-ENOMEM);

	config_item_init_type_name(&nd->item, name, &node_type);
	nd->nodeid = -1;
	nd->weight = 1;  /* default weight of 1 if none is set */
	nd->new = 1;     /* set to 0 once it's been read by dlm_nodeid_list() */

	mutex_lock(&sp->members_lock);
	list_add(&nd->list, &sp->members);
	sp->members_count++;
	mutex_unlock(&sp->members_lock);

	return &nd->item;
}

static void drop_node(struct config_group *g, struct config_item *i)
{
	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
	struct dlm_node *nd = config_item_to_node(i);

	mutex_lock(&sp->members_lock);
	list_del(&nd->list);
	sp->members_count--;
	mutex_unlock(&sp->members_lock);

	config_item_put(i);
}

static void release_node(struct config_item *i)
{
	struct dlm_node *nd = config_item_to_node(i);
	kfree(nd);
}

static struct dlm_clusters clusters_root = {
	.subsys = {
		.su_group = {
			.cg_item = {
				.ci_namebuf = "dlm",
				.ci_type = &clusters_type,
			},
		},
	},
};

int __init dlm_config_init(void)
{
	config_group_init(&clusters_root.subsys.su_group);
	mutex_init(&clusters_root.subsys.su_mutex);
	return configfs_register_subsystem(&clusters_root.subsys);
}

void dlm_config_exit(void)
{
	configfs_unregister_subsystem(&clusters_root.subsys);
}

/*
 * Functions for user space to read/write attributes
 */

static ssize_t comm_nodeid_show(struct config_item *item, char *buf)
{
	return sprintf(buf, "%d\n", config_item_to_comm(item)->nodeid);
}

static ssize_t comm_nodeid_store(struct config_item *item, const char *buf,
				 size_t len)
{
	int rc = kstrtoint(buf, 0, &config_item_to_comm(item)->nodeid);

	if (rc)
		return rc;
	return len;
}

static ssize_t comm_local_show(struct config_item *item, char *buf)
{
	return sprintf(buf, "%d\n", config_item_to_comm(item)->local);
}

static ssize_t comm_local_store(struct config_item *item, const char *buf,
				size_t len)
{
	struct dlm_comm *cm = config_item_to_comm(item);
	int rc = kstrtoint(buf, 0, &cm->local);

	if (rc)
		return rc;
	if (cm->local && !local_comm)
		local_comm = cm;
	return len;
}

static ssize_t comm_addr_store(struct config_item *item, const char *buf,
		size_t len)
{
	struct dlm_comm *cm = config_item_to_comm(item);
	struct sockaddr_storage *addr;
	int rv;

	if (len != sizeof(struct sockaddr_storage))
		return -EINVAL;

	if (cm->addr_count >= DLM_MAX_ADDR_COUNT)
		return -ENOSPC;

	addr = kzalloc(sizeof(*addr), GFP_NOFS);
	if (!addr)
		return -ENOMEM;

	memcpy(addr, buf, len);

	rv = dlm_lowcomms_addr(cm->nodeid, addr, len);
	if (rv) {
		kfree(addr);
		return rv;
	}

	cm->addr[cm->addr_count++] = addr;
	return len;
}

static ssize_t comm_addr_list_show(struct config_item *item, char *buf)
{
	struct dlm_comm *cm = config_item_to_comm(item);
	ssize_t s;
	ssize_t allowance;
	int i;
	struct sockaddr_storage *addr;
	struct sockaddr_in *addr_in;
	struct sockaddr_in6 *addr_in6;
	
	/* Taken from ip6_addr_string() defined in lib/vsprintf.c */
	char buf0[sizeof("AF_INET6	xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255\n")];
	

	/* Derived from SIMPLE_ATTR_SIZE of fs/configfs/file.c */
	allowance = 4096;
	buf[0] = '\0';

	for (i = 0; i < cm->addr_count; i++) {
		addr = cm->addr[i];

		switch(addr->ss_family) {
		case AF_INET:
			addr_in = (struct sockaddr_in *)addr;
			s = sprintf(buf0, "AF_INET	%pI4\n", &addr_in->sin_addr.s_addr);
			break;
		case AF_INET6:
			addr_in6 = (struct sockaddr_in6 *)addr;
			s = sprintf(buf0, "AF_INET6	%pI6\n", &addr_in6->sin6_addr);
			break;
		default:
			s = sprintf(buf0, "%s\n", "<UNKNOWN>");
			break;
		}
		allowance -= s;
		if (allowance >= 0)
			strcat(buf, buf0);
		else {
			allowance += s;
			break;
		}
	}
	return 4096 - allowance;
}

CONFIGFS_ATTR(comm_, nodeid);
CONFIGFS_ATTR(comm_, local);
CONFIGFS_ATTR_WO(comm_, addr);
CONFIGFS_ATTR_RO(comm_, addr_list);

static struct configfs_attribute *comm_attrs[] = {
	[COMM_ATTR_NODEID] = &comm_attr_nodeid,
	[COMM_ATTR_LOCAL] = &comm_attr_local,
	[COMM_ATTR_ADDR] = &comm_attr_addr,
	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list,
	NULL,
};

static ssize_t node_nodeid_show(struct config_item *item, char *buf)
{
	return sprintf(buf, "%d\n", config_item_to_node(item)->nodeid);
}

static ssize_t node_nodeid_store(struct config_item *item, const char *buf,
				 size_t len)
{
	struct dlm_node *nd = config_item_to_node(item);
	uint32_t seq = 0;
	int rc = kstrtoint(buf, 0, &nd->nodeid);

	if (rc)
		return rc;
	dlm_comm_seq(nd->nodeid, &seq);
	nd->comm_seq = seq;
	return len;
}

static ssize_t node_weight_show(struct config_item *item, char *buf)
{
	return sprintf(buf, "%d\n", config_item_to_node(item)->weight);
}

static ssize_t node_weight_store(struct config_item *item, const char *buf,
				 size_t len)
{
	int rc = kstrtoint(buf, 0, &config_item_to_node(item)->weight);

	if (rc)
		return rc;
	return len;
}

CONFIGFS_ATTR(node_, nodeid);
CONFIGFS_ATTR(node_, weight);

static struct configfs_attribute *node_attrs[] = {
	[NODE_ATTR_NODEID] = &node_attr_nodeid,
	[NODE_ATTR_WEIGHT] = &node_attr_weight,
	NULL,
};

/*
 * Functions for the dlm to get the info that's been configured
 */

static struct dlm_space *get_space(char *name)
{
	struct config_item *i;

	if (!space_list)
		return NULL;

	mutex_lock(&space_list->cg_subsys->su_mutex);
	i = config_group_find_item(space_list, name);
	mutex_unlock(&space_list->cg_subsys->su_mutex);

	return config_item_to_space(i);
}

static void put_space(struct dlm_space *sp)
{
	config_item_put(&sp->group.cg_item);
}

static struct dlm_comm *get_comm(int nodeid)
{
	struct config_item *i;
	struct dlm_comm *cm = NULL;
	int found = 0;

	if (!comm_list)
		return NULL;

	mutex_lock(&clusters_root.subsys.su_mutex);

	list_for_each_entry(i, &comm_list->cg_children, ci_entry) {
		cm = config_item_to_comm(i);

		if (cm->nodeid != nodeid)
			continue;
		found = 1;
		config_item_get(i);
		break;
	}
	mutex_unlock(&clusters_root.subsys.su_mutex);

	if (!found)
		cm = NULL;
	return cm;
}

static void put_comm(struct dlm_comm *cm)
{
	config_item_put(&cm->item);
}

/* caller must free mem */
int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out,
		     int *count_out)
{
	struct dlm_space *sp;
	struct dlm_node *nd;
	struct dlm_config_node *nodes, *node;
	int rv, count;

	sp = get_space(lsname);
	if (!sp)
		return -EEXIST;

	mutex_lock(&sp->members_lock);
	if (!sp->members_count) {
		rv = -EINVAL;
		printk(KERN_ERR "dlm: zero members_count\n");
		goto out;
	}

	count = sp->members_count;

	nodes = kcalloc(count, sizeof(struct dlm_config_node), GFP_NOFS);
	if (!nodes) {
		rv = -ENOMEM;
		goto out;
	}

	node = nodes;
	list_for_each_entry(nd, &sp->members, list) {
		node->nodeid = nd->nodeid;
		node->weight = nd->weight;
		node->new = nd->new;
		node->comm_seq = nd->comm_seq;
		node++;

		nd->new = 0;
	}

	*count_out = count;
	*nodes_out = nodes;
	rv = 0;
 out:
	mutex_unlock(&sp->members_lock);
	put_space(sp);
	return rv;
}

int dlm_comm_seq(int nodeid, uint32_t *seq)
{
	struct dlm_comm *cm = get_comm(nodeid);
	if (!cm)
		return -EEXIST;
	*seq = cm->seq;
	put_comm(cm);
	return 0;
}

int dlm_our_nodeid(void)
{
	return local_comm ? local_comm->nodeid : 0;
}

/* num 0 is first addr, num 1 is second addr */
int dlm_our_addr(struct sockaddr_storage *addr, int num)
{
	if (!local_comm)
		return -1;
	if (num + 1 > local_comm->addr_count)
		return -1;
	memcpy(addr, local_comm->addr[num], sizeof(*addr));
	return 0;
}

/* Config file defaults */
#define DEFAULT_TCP_PORT       21064
#define DEFAULT_BUFFER_SIZE     4096
#define DEFAULT_RSBTBL_SIZE     1024
#define DEFAULT_RECOVER_TIMER      5
#define DEFAULT_TOSS_SECS         10
#define DEFAULT_SCAN_SECS          5
#define DEFAULT_LOG_DEBUG          0
#define DEFAULT_LOG_INFO           1
#define DEFAULT_PROTOCOL           0
#define DEFAULT_TIMEWARN_CS      500 /* 5 sec = 500 centiseconds */
#define DEFAULT_WAITWARN_US	   0
#define DEFAULT_NEW_RSB_COUNT    128
#define DEFAULT_RECOVER_CALLBACKS  0
#define DEFAULT_CLUSTER_NAME      ""

struct dlm_config_info dlm_config = {
	.ci_tcp_port = DEFAULT_TCP_PORT,
	.ci_buffer_size = DEFAULT_BUFFER_SIZE,
	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,
	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
	.ci_toss_secs = DEFAULT_TOSS_SECS,
	.ci_scan_secs = DEFAULT_SCAN_SECS,
	.ci_log_debug = DEFAULT_LOG_DEBUG,
	.ci_log_info = DEFAULT_LOG_INFO,
	.ci_protocol = DEFAULT_PROTOCOL,
	.ci_timewarn_cs = DEFAULT_TIMEWARN_CS,
	.ci_waitwarn_us = DEFAULT_WAITWARN_US,
	.ci_new_rsb_count = DEFAULT_NEW_RSB_COUNT,
	.ci_recover_callbacks = DEFAULT_RECOVER_CALLBACKS,
	.ci_cluster_name = DEFAULT_CLUSTER_NAME
};