aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ocfs2/dlm/dlmdebug.c
blob: b32f60a5acfb9e4353ce3ad61d009bb6858d158f (plain) (blame)
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
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmdebug.c
 *
 * debug functionality for the dlm
 *
 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 *
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/utsname.h>
#include <linux/sysctl.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>

#include "cluster/heartbeat.h"
#include "cluster/nodemanager.h"
#include "cluster/tcp.h"

#include "dlmapi.h"
#include "dlmcommon.h"
#include "dlmdomain.h"
#include "dlmdebug.h"

#define MLOG_MASK_PREFIX ML_DLM
#include "cluster/masklog.h"

static int stringify_lockname(const char *lockname, int locklen, char *buf,
			      int len);

void dlm_print_one_lock_resource(struct dlm_lock_resource *res)
{
	spin_lock(&res->spinlock);
	__dlm_print_one_lock_resource(res);
	spin_unlock(&res->spinlock);
}

static void dlm_print_lockres_refmap(struct dlm_lock_resource *res)
{
	int bit;
	assert_spin_locked(&res->spinlock);

	printk("  refmap nodes: [ ");
	bit = 0;
	while (1) {
		bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
		if (bit >= O2NM_MAX_NODES)
			break;
		printk("%u ", bit);
		bit++;
	}
	printk("], inflight=%u\n", res->inflight_locks);
}

static void __dlm_print_lock(struct dlm_lock *lock)
{
	spin_lock(&lock->spinlock);

	printk("    type=%d, conv=%d, node=%u, cookie=%u:%llu, "
	       "ref=%u, ast=(empty=%c,pend=%c), bast=(empty=%c,pend=%c), "
	       "pending=(conv=%c,lock=%c,cancel=%c,unlock=%c)\n",
	       lock->ml.type, lock->ml.convert_type, lock->ml.node,
	       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
	       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
	       atomic_read(&lock->lock_refs.refcount),
	       (list_empty(&lock->ast_list) ? 'y' : 'n'),
	       (lock->ast_pending ? 'y' : 'n'),
	       (list_empty(&lock->bast_list) ? 'y' : 'n'),
	       (lock->bast_pending ? 'y' : 'n'),
	       (lock->convert_pending ? 'y' : 'n'),
	       (lock->lock_pending ? 'y' : 'n'),
	       (lock->cancel_pending ? 'y' : 'n'),
	       (lock->unlock_pending ? 'y' : 'n'));

	spin_unlock(&lock->spinlock);
}

void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
{
	struct list_head *iter2;
	struct dlm_lock *lock;
	char buf[DLM_LOCKID_NAME_MAX];

	assert_spin_locked(&res->spinlock);

	stringify_lockname(res->lockname.name, res->lockname.len,
			   buf, sizeof(buf) - 1);
	printk("lockres: %s, owner=%u, state=%u\n",
	       buf, res->owner, res->state);
	printk("  last used: %lu, refcnt: %u, on purge list: %s\n",
	       res->last_used, atomic_read(&res->refs.refcount),
	       list_empty(&res->purge) ? "no" : "yes");
	printk("  on dirty list: %s, on reco list: %s, "
	       "migrating pending: %s\n",
	       list_empty(&res->dirty) ? "no" : "yes",
	       list_empty(&res->recovering) ? "no" : "yes",
	       res->migration_pending ? "yes" : "no");
	printk("  inflight locks: %d, asts reserved: %d\n",
	       res->inflight_locks, atomic_read(&res->asts_reserved));
	dlm_print_lockres_refmap(res);
	printk("  granted queue:\n");
	list_for_each(iter2, &res->granted) {
		lock = list_entry(iter2, struct dlm_lock, list);
		__dlm_print_lock(lock);
	}
	printk("  converting queue:\n");
	list_for_each(iter2, &res->converting) {
		lock = list_entry(iter2, struct dlm_lock, list);
		__dlm_print_lock(lock);
	}
	printk("  blocked queue:\n");
	list_for_each(iter2, &res->blocked) {
		lock = list_entry(iter2, struct dlm_lock, list);
		__dlm_print_lock(lock);
	}
}

void dlm_print_one_lock(struct dlm_lock *lockid)
{
	dlm_print_one_lock_resource(lockid->lockres);
}
EXPORT_SYMBOL_GPL(dlm_print_one_lock);

static const char *dlm_errnames[] = {
	[DLM_NORMAL] =			"DLM_NORMAL",
	[DLM_GRANTED] =			"DLM_GRANTED",
	[DLM_DENIED] =			"DLM_DENIED",
	[DLM_DENIED_NOLOCKS] =		"DLM_DENIED_NOLOCKS",
	[DLM_WORKING] =			"DLM_WORKING",
	[DLM_BLOCKED] =			"DLM_BLOCKED",
	[DLM_BLOCKED_ORPHAN] =		"DLM_BLOCKED_ORPHAN",
	[DLM_DENIED_GRACE_PERIOD] =	"DLM_DENIED_GRACE_PERIOD",
	[DLM_SYSERR] =			"DLM_SYSERR",
	[DLM_NOSUPPORT] =		"DLM_NOSUPPORT",
	[DLM_CANCELGRANT] =		"DLM_CANCELGRANT",
	[DLM_IVLOCKID] =		"DLM_IVLOCKID",
	[DLM_SYNC] =			"DLM_SYNC",
	[DLM_BADTYPE] =			"DLM_BADTYPE",
	[DLM_BADRESOURCE] =		"DLM_BADRESOURCE",
	[DLM_MAXHANDLES] =		"DLM_MAXHANDLES",
	[DLM_NOCLINFO] =		"DLM_NOCLINFO",
	[DLM_NOLOCKMGR] =		"DLM_NOLOCKMGR",
	[DLM_NOPURGED] =		"DLM_NOPURGED",
	[DLM_BADARGS] =			"DLM_BADARGS",
	[DLM_VOID] =			"DLM_VOID",
	[DLM_NOTQUEUED] =		"DLM_NOTQUEUED",
	[DLM_IVBUFLEN] =		"DLM_IVBUFLEN",
	[DLM_CVTUNGRANT] =		"DLM_CVTUNGRANT",
	[DLM_BADPARAM] =		"DLM_BADPARAM",
	[DLM_VALNOTVALID] =		"DLM_VALNOTVALID",
	[DLM_REJECTED] =		"DLM_REJECTED",
	[DLM_ABORT] =			"DLM_ABORT",
	[DLM_CANCEL] =			"DLM_CANCEL",
	[DLM_IVRESHANDLE] =		"DLM_IVRESHANDLE",
	[DLM_DEADLOCK] =		"DLM_DEADLOCK",
	[DLM_DENIED_NOASTS] =		"DLM_DENIED_NOASTS",
	[DLM_FORWARD] =			"DLM_FORWARD",
	[DLM_TIMEOUT] =			"DLM_TIMEOUT",
	[DLM_IVGROUPID] =		"DLM_IVGROUPID",
	[DLM_VERS_CONFLICT] =		"DLM_VERS_CONFLICT",
	[DLM_BAD_DEVICE_PATH] =		"DLM_BAD_DEVICE_PATH",
	[DLM_NO_DEVICE_PERMISSION] =	"DLM_NO_DEVICE_PERMISSION",
	[DLM_NO_CONTROL_DEVICE ] =	"DLM_NO_CONTROL_DEVICE ",
	[DLM_RECOVERING] =		"DLM_RECOVERING",
	[DLM_MIGRATING] =		"DLM_MIGRATING",
	[DLM_MAXSTATS] =		"DLM_MAXSTATS",
};

static const char *dlm_errmsgs[] = {
	[DLM_NORMAL] = 			"request in progress",
	[DLM_GRANTED] = 		"request granted",
	[DLM_DENIED] = 			"request denied",
	[DLM_DENIED_NOLOCKS] = 		"request denied, out of system resources",
	[DLM_WORKING] = 		"async request in progress",
	[DLM_BLOCKED] = 		"lock request blocked",
	[DLM_BLOCKED_ORPHAN] = 		"lock request blocked by a orphan lock",
	[DLM_DENIED_GRACE_PERIOD] = 	"topological change in progress",
	[DLM_SYSERR] = 			"system error",
	[DLM_NOSUPPORT] = 		"unsupported",
	[DLM_CANCELGRANT] = 		"can't cancel convert: already granted",
	[DLM_IVLOCKID] = 		"bad lockid",
	[DLM_SYNC] = 			"synchronous request granted",
	[DLM_BADTYPE] = 		"bad resource type",
	[DLM_BADRESOURCE] = 		"bad resource handle",
	[DLM_MAXHANDLES] = 		"no more resource handles",
	[DLM_NOCLINFO] = 		"can't contact cluster manager",
	[DLM_NOLOCKMGR] = 		"can't contact lock manager",
	[DLM_NOPURGED] = 		"can't contact purge daemon",
	[DLM_BADARGS] = 		"bad api args",
	[DLM_VOID] = 			"no status",
	[DLM_NOTQUEUED] = 		"NOQUEUE was specified and request failed",
	[DLM_IVBUFLEN] = 		"invalid resource name length",
	[DLM_CVTUNGRANT] = 		"attempted to convert ungranted lock",
	[DLM_BADPARAM] = 		"invalid lock mode specified",
	[DLM_VALNOTVALID] = 		"value block has been invalidated",
	[DLM_REJECTED] = 		"request rejected, unrecognized client",
	[DLM_ABORT] = 			"blocked lock request cancelled",
	[DLM_CANCEL] = 			"conversion request cancelled",
	[DLM_IVRESHANDLE] = 		"invalid resource handle",
	[DLM_DEADLOCK] = 		"deadlock recovery refused this request",
	[DLM_DENIED_NOASTS] = 		"failed to allocate AST",
	[DLM_FORWARD] = 		"request must wait for primary's response",
	[DLM_TIMEOUT] = 		"timeout value for lock has expired",
	[DLM_IVGROUPID] = 		"invalid group specification",
	[DLM_VERS_CONFLICT] = 		"version conflicts prevent request handling",
	[DLM_BAD_DEVICE_PATH] = 	"Locks device does not exist or path wrong",
	[DLM_NO_DEVICE_PERMISSION] = 	"Client has insufficient perms for device",
	[DLM_NO_CONTROL_DEVICE] = 	"Cannot set options on opened device ",
	[DLM_RECOVERING] = 		"lock resource being recovered",
	[DLM_MIGRATING] = 		"lock resource being migrated",
	[DLM_MAXSTATS] = 		"invalid error number",
};

const char *dlm_errmsg(enum dlm_status err)
{
	if (err >= DLM_MAXSTATS || err < 0)
		return dlm_errmsgs[DLM_MAXSTATS];
	return dlm_errmsgs[err];
}
EXPORT_SYMBOL_GPL(dlm_errmsg);

const char *dlm_errname(enum dlm_status err)
{
	if (err >= DLM_MAXSTATS || err < 0)
		return dlm_errnames[DLM_MAXSTATS];
	return dlm_errnames[err];
}
EXPORT_SYMBOL_GPL(dlm_errname);

/* NOTE: This function converts a lockname into a string. It uses knowledge
 * of the format of the lockname that should be outside the purview of the dlm.
 * We are adding only to make dlm debugging slightly easier.
 *
 * For more on lockname formats, please refer to dlmglue.c and ocfs2_lockid.h.
 */
static int stringify_lockname(const char *lockname, int locklen, char *buf,
			      int len)
{
	int out = 0;
	__be64 inode_blkno_be;

#define OCFS2_DENTRY_LOCK_INO_START	18
	if (*lockname == 'N') {
		memcpy((__be64 *)&inode_blkno_be,
		       (char *)&lockname[OCFS2_DENTRY_LOCK_INO_START],
		       sizeof(__be64));
		out += snprintf(buf + out, len - out, "%.*s%08x",
				OCFS2_DENTRY_LOCK_INO_START - 1, lockname,
				(unsigned int)be64_to_cpu(inode_blkno_be));
	} else
		out += snprintf(buf + out, len - out, "%.*s",
				locklen, lockname);
	return out;
}

static int stringify_nodemap(unsigned long *nodemap, int maxnodes,
			     char *buf, int len)
{
	int out = 0;
	int i = -1;

	while ((i = find_next_bit(nodemap, maxnodes, i + 1)) < maxnodes)
		out += snprintf(buf + out, len - out, "%d ", i);

	return out;
}

static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
{
	int out = 0;
	unsigned int namelen;
	const char *name;
	char *mle_type;

	if (mle->type != DLM_MLE_MASTER) {
		namelen = mle->u.name.len;
		name = mle->u.name.name;
	} else {
		namelen = mle->u.res->lockname.len;
		name = mle->u.res->lockname.name;
	}

	if (mle->type == DLM_MLE_BLOCK)
		mle_type = "BLK";
	else if (mle->type == DLM_MLE_MASTER)
		mle_type = "MAS";
	else
		mle_type = "MIG";

	out += stringify_lockname(name, namelen, buf + out, len - out);
	out += snprintf(buf + out, len - out,
			"\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
			mle_type, mle->master, mle->new_master,
			!list_empty(&mle->hb_events),
			!!mle->inuse,
			atomic_read(&mle->mle_refs.refcount));

	out += snprintf(buf + out, len - out, "Maybe=");
	out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
				 buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

	out += snprintf(buf + out, len - out, "Vote=");
	out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
				 buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

	out += snprintf(buf + out, len - out, "Response=");
	out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
				 buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

	out += snprintf(buf + out, len - out, "Node=");
	out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
				 buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

	out += snprintf(buf + out, len - out, "\n");

	return out;
}

void dlm_print_one_mle(struct dlm_master_list_entry *mle)
{
	char *buf;

	buf = (char *) get_zeroed_page(GFP_NOFS);
	if (buf) {
		dump_mle(mle, buf, PAGE_SIZE - 1);
		free_page((unsigned long)buf);
	}
}

#ifdef CONFIG_DEBUG_FS

static struct dentry *dlm_debugfs_root = NULL;

#define DLM_DEBUGFS_DIR				"o2dlm"
#define DLM_DEBUGFS_DLM_STATE			"dlm_state"
#define DLM_DEBUGFS_LOCKING_STATE		"locking_state"
#define DLM_DEBUGFS_MLE_STATE			"mle_state"
#define DLM_DEBUGFS_PURGE_LIST			"purge_list"

/* begin - utils funcs */
static void dlm_debug_free(struct kref *kref)
{
	struct dlm_debug_ctxt *dc;

	dc = container_of(kref, struct dlm_debug_ctxt, debug_refcnt);

	kfree(dc);
}

static void dlm_debug_put(struct dlm_debug_ctxt *dc)
{
	if (dc)
		kref_put(&dc->debug_refcnt, dlm_debug_free);
}

static void dlm_debug_get(struct dlm_debug_ctxt *dc)
{
	kref_get(&dc->debug_refcnt);
}

static struct debug_buffer *debug_buffer_allocate(void)
{
	struct debug_buffer *db = NULL;

	db = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);
	if (!db)
		goto bail;

	db->len = PAGE_SIZE;
	db->buf = kmalloc(db->len, GFP_KERNEL);
	if (!db->buf)
		goto bail;

	return db;
bail:
	kfree(db);
	return NULL;
}

static ssize_t debug_buffer_read(struct file *file, char __user *buf,
				 size_t nbytes, loff_t *ppos)
{
	struct debug_buffer *db = file->private_data;

	return simple_read_from_buffer(buf, nbytes, ppos, db->buf, db->len);
}

static loff_t debug_buffer_llseek(struct file *file, loff_t off, int whence)
{
	struct debug_buffer *db = file->private_data;
	loff_t new = -1;

	switch (whence) {
	case 0:
		new = off;
		break;
	case 1:
		new = file->f_pos + off;
		break;
	}

	if (new < 0 || new > db->len)
		return -EINVAL;

	return (file->f_pos = new);
}

static int debug_buffer_release(struct inode *inode, struct file *file)
{
	struct debug_buffer *db = (struct debug_buffer *)file->private_data;

	if (db)
		kfree(db->buf);
	kfree(db);

	return 0;
}
/* end - util funcs */

/* begin - purge list funcs */
static int debug_purgelist_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
{
	struct dlm_lock_resource *res;
	int out = 0;
	unsigned long total = 0;

	out += snprintf(db->buf + out, db->len - out,
			"Dumping Purgelist for Domain: %s\n", dlm->name);

	spin_lock(&dlm->spinlock);
	list_for_each_entry(res, &dlm->purge_list, purge) {
		++total;
		if (db->len - out < 100)
			continue;
		spin_lock(&res->spinlock);
		out += stringify_lockname(res->lockname.name,
					  res->lockname.len,
					  db->buf + out, db->len - out);
		out += snprintf(db->buf + out, db->len - out, "\t%ld\n",
				(jiffies - res->last_used)/HZ);
		spin_unlock(&res->spinlock);
	}
	spin_unlock(&dlm->spinlock);

	out += snprintf(db->buf + out, db->len - out,
			"Total on list: %ld\n", total);

	return out;
}

static int debug_purgelist_open(struct inode *inode, struct file *file)
{
	struct dlm_ctxt *dlm = inode->i_private;
	struct debug_buffer *db;

	db = debug_buffer_allocate();
	if (!db)
		goto bail;

	db->len = debug_purgelist_print(dlm, db);

	file->private_data = db;

	return 0;
bail:
	return -ENOMEM;
}

static struct file_operations debug_purgelist_fops = {
	.open =		debug_purgelist_open,
	.release =	debug_buffer_release,
	.read =		debug_buffer_read,
	.llseek =	debug_buffer_llseek,
};
/* end - purge list funcs */

/* begin - debug mle funcs */
static int debug_mle_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
{
	struct dlm_master_list_entry *mle;
	int out = 0;
	unsigned long total = 0;

	out += snprintf(db->buf + out, db->len - out,
			"Dumping MLEs for Domain: %s\n", dlm->name);

	spin_lock(&dlm->master_lock);
	list_for_each_entry(mle, &dlm->master_list, list) {
		++total;
		if (db->len - out < 200)
			continue;
		out += dump_mle(mle, db->buf + out, db->len - out);
	}
	spin_unlock(&dlm->master_lock);

	out += snprintf(db->buf + out, db->len - out,
			"Total on list: %ld\n", total);
	return out;
}

static int debug_mle_open(struct inode *inode, struct file *file)
{
	struct dlm_ctxt *dlm = inode->i_private;
	struct debug_buffer *db;

	db = debug_buffer_allocate();
	if (!db)
		goto bail;

	db->len = debug_mle_print(dlm, db);

	file->private_data = db;

	return 0;
bail:
	return -ENOMEM;
}

static struct file_operations debug_mle_fops = {
	.open =		debug_mle_open,
	.release =	debug_buffer_release,
	.read =		debug_buffer_read,
	.llseek =	debug_buffer_llseek,
};

/* end - debug mle funcs */

/* begin - debug lockres funcs */
static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
{
	int out;

#define DEBUG_LOCK_VERSION	1
	spin_lock(&lock->spinlock);
	out = snprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,%d,"
		       "%d,%d,%d,%d\n",
		       DEBUG_LOCK_VERSION,
		       list_type, lock->ml.type, lock->ml.convert_type,
		       lock->ml.node,
		       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
		       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
		       !list_empty(&lock->ast_list),
		       !list_empty(&lock->bast_list),
		       lock->ast_pending, lock->bast_pending,
		       lock->convert_pending, lock->lock_pending,
		       lock->cancel_pending, lock->unlock_pending,
		       atomic_read(&lock->lock_refs.refcount));
	spin_unlock(&lock->spinlock);

	return out;
}

static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
{
	struct dlm_lock *lock;
	int i;
	int out = 0;

	out += snprintf(buf + out, len - out, "NAME:");
	out += stringify_lockname(res->lockname.name, res->lockname.len,
				  buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

#define DEBUG_LRES_VERSION	1
	out += snprintf(buf + out, len - out,
			"LRES:%d,%d,%d,%ld,%d,%d,%d,%d,%d,%d,%d\n",
			DEBUG_LRES_VERSION,
			res->owner, res->state, res->last_used,
			!list_empty(&res->purge),
			!list_empty(&res->dirty),
			!list_empty(&res->recovering),
			res->inflight_locks, res->migration_pending,
			atomic_read(&res->asts_reserved),
			atomic_read(&res->refs.refcount));

	/* refmap */
	out += snprintf(buf + out, len - out, "RMAP:");
	out += stringify_nodemap(res->refmap, O2NM_MAX_NODES,
				 buf + out, len - out);
	out += snprintf(buf + out, len - out, "\n");

	/* lvb */
	out += snprintf(buf + out, len - out, "LVBX:");
	for (i = 0; i < DLM_LVB_LEN; i++)
		out += snprintf(buf + out, len - out,
					"%02x", (unsigned char)res->lvb[i]);
	out += snprintf(buf + out, len - out, "\n");

	/* granted */
	list_for_each_entry(lock, &res->granted, list)
		out += dump_lock(lock, 0, buf + out, len - out);

	/* converting */
	list_for_each_entry(lock, &res->converting, list)
		out += dump_lock(lock, 1, buf + out, len - out);

	/* blocked */
	list_for_each_entry(lock, &res->blocked, list)
		out += dump_lock(lock, 2, buf + out, len - out);

	out += snprintf(buf + out, len - out, "\n");

	return out;
}

static void *lockres_seq_start(struct seq_file *m, loff_t *pos)
{
	struct debug_lockres *dl = m->private;
	struct dlm_ctxt *dlm = dl->dl_ctxt;
	struct dlm_lock_resource *oldres = dl->dl_res;
	struct dlm_lock_resource *res = NULL;
	struct list_head *track_list;

	spin_lock(&dlm->track_lock);
	if (oldres)
		track_list = &oldres->tracking;
	else
		track_list = &dlm->tracking_list;

	list_for_each_entry(res, track_list, tracking) {
		if (&res->tracking == &dlm->tracking_list)
			res = NULL;
		else
			dlm_lockres_get(res);
		break;
	}
	spin_unlock(&dlm->track_lock);

	if (oldres)
		dlm_lockres_put(oldres);

	dl->dl_res = res;

	if (res) {
		spin_lock(&res->spinlock);
		dump_lockres(res, dl->dl_buf, dl->dl_len - 1);
		spin_unlock(&res->spinlock);
	} else
		dl = NULL;

	/* passed to seq_show */
	return dl;
}

static void lockres_seq_stop(struct seq_file *m, void *v)
{
}

static void *lockres_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
	return NULL;
}

static int lockres_seq_show(struct seq_file *s, void *v)
{
	struct debug_lockres *dl = (struct debug_lockres *)v;

	seq_printf(s, "%s", dl->dl_buf);

	return 0;
}

static struct seq_operations debug_lockres_ops = {
	.start =	lockres_seq_start,
	.stop =		lockres_seq_stop,
	.next =		lockres_seq_next,
	.show =		lockres_seq_show,
};

static int debug_lockres_open(struct inode *inode, struct file *file)
{
	struct dlm_ctxt *dlm = inode->i_private;
	int ret = -ENOMEM;
	struct seq_file *seq;
	struct debug_lockres *dl = NULL;

	dl = kzalloc(sizeof(struct debug_lockres), GFP_KERNEL);
	if (!dl) {
		mlog_errno(ret);
		goto bail;
	}

	dl->dl_len = PAGE_SIZE;
	dl->dl_buf = kmalloc(dl->dl_len, GFP_KERNEL);
	if (!dl->dl_buf) {
		mlog_errno(ret);
		goto bail;
	}

	ret = seq_open(file, &debug_lockres_ops);
	if (ret) {
		mlog_errno(ret);
		goto bail;
	}

	seq = (struct seq_file *) file->private_data;
	seq->private = dl;

	dlm_grab(dlm);
	dl->dl_ctxt = dlm;

	return 0;
bail:
	if (dl)
		kfree(dl->dl_buf);
	kfree(dl);
	return ret;
}

static int debug_lockres_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = (struct seq_file *)file->private_data;
	struct debug_lockres *dl = (struct debug_lockres *)seq->private;

	if (dl->dl_res)
		dlm_lockres_put(dl->dl_res);
	dlm_put(dl->dl_ctxt);
	kfree(dl->dl_buf);
	return seq_release_private(inode, file);
}

static struct file_operations debug_lockres_fops = {
	.open =		debug_lockres_open,
	.release =	debug_lockres_release,
	.read =		seq_read,
	.llseek =	seq_lseek,
};
/* end - debug lockres funcs */

/* begin - debug state funcs */
static int debug_state_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
{
	int out = 0;
	struct dlm_reco_node_data *node;
	char *state;
	int lres, rres, ures, tres;

	lres = atomic_read(&dlm->local_resources);
	rres = atomic_read(&dlm->remote_resources);
	ures = atomic_read(&dlm->unknown_resources);
	tres = lres + rres + ures;

	spin_lock(&dlm->spinlock);

	switch (dlm->dlm_state) {
	case DLM_CTXT_NEW:
		state = "NEW"; break;
	case DLM_CTXT_JOINED:
		state = "JOINED"; break;
	case DLM_CTXT_IN_SHUTDOWN:
		state = "SHUTDOWN"; break;
	case DLM_CTXT_LEAVING:
		state = "LEAVING"; break;
	default:
		state = "UNKNOWN"; break;
	}

	/* Domain: xxxxxxxxxx  Key: 0xdfbac769 */
	out += snprintf(db->buf + out, db->len - out,
			"Domain: %s  Key: 0x%08x\n", dlm->name, dlm->key);

	/* Thread Pid: xxx  Node: xxx  State: xxxxx */
	out += snprintf(db->buf + out, db->len - out,
			"Thread Pid: %d  Node: %d  State: %s\n",
			dlm->dlm_thread_task->pid, dlm->node_num, state);

	/* Number of Joins: xxx  Joining Node: xxx */
	out += snprintf(db->buf + out, db->len - out,
			"Number of Joins: %d  Joining Node: %d\n",
			dlm->num_joins, dlm->joining_node);

	/* Domain Map: xx xx xx */
	out += snprintf(db->buf + out, db->len - out, "Domain Map: ");
	out += stringify_nodemap(dlm->domain_map, O2NM_MAX_NODES,
				 db->buf + out, db->len - out);
	out += snprintf(db->buf + out, db->len - out, "\n");

	/* Live Map: xx xx xx */
	out += snprintf(db->buf + out, db->len - out, "Live Map: ");
	out += stringify_nodemap(dlm->live_nodes_map, O2NM_MAX_NODES,
				 db->buf + out, db->len - out);
	out += snprintf(db->buf + out, db->len - out, "\n");

	/* Mastered Resources Total: xxx  Locally: xxx  Remotely: ... */
	out += snprintf(db->buf + out, db->len - out,
			"Mastered Resources Total: %d  Locally: %d  "
			"Remotely: %d  Unknown: %d\n",
			tres, lres, rres, ures);

	/* Lists: Dirty=Empty  Purge=InUse  PendingASTs=Empty  ... */
	out += snprintf(db->buf + out, db->len - out,
			"Lists: Dirty=%s  Purge=%s  PendingASTs=%s  "
			"PendingBASTs=%s  Master=%s\n",
			(list_empty(&dlm->dirty_list) ? "Empty" : "InUse"),
			(list_empty(&dlm->purge_list) ? "Empty" : "InUse"),
			(list_empty(&dlm->pending_asts) ? "Empty" : "InUse"),
			(list_empty(&dlm->pending_basts) ? "Empty" : "InUse"),
			(list_empty(&dlm->master_list) ? "Empty" : "InUse"));

	/* Purge Count: xxx  Refs: xxx */
	out += snprintf(db->buf + out, db->len - out,
			"Purge Count: %d  Refs: %d\n", dlm->purge_count,
			atomic_read(&dlm->dlm_refs.refcount));

	/* Dead Node: xxx */
	out += snprintf(db->buf + out, db->len - out,
			"Dead Node: %d\n", dlm->reco.dead_node);

	/* What about DLM_RECO_STATE_FINALIZE? */
	if (dlm->reco.state == DLM_RECO_STATE_ACTIVE)
		state = "ACTIVE";
	else
		state = "INACTIVE";

	/* Recovery Pid: xxxx  Master: xxx  State: xxxx */
	out += snprintf(db->buf + out, db->len - out,
			"Recovery Pid: %d  Master: %d  State: %s\n",
			dlm->dlm_reco_thread_task->pid,
			dlm->reco.new_master, state);

	/* Recovery Map: xx xx */
	out += snprintf(db->buf + out, db->len - out, "Recovery Map: ");
	out += stringify_nodemap(dlm->recovery_map, O2NM_MAX_NODES,
				 db->buf + out, db->len - out);
	out += snprintf(db->buf + out, db->len - out, "\n");

	/* Recovery Node State: */
	out += snprintf(db->buf + out, db->len - out, "Recovery Node State:\n");
	list_for_each_entry(node, &dlm->reco.node_data, list) {
		switch (node->state) {
		case DLM_RECO_NODE_DATA_INIT:
			state = "INIT";
			break;
		case DLM_RECO_NODE_DATA_REQUESTING:
			state = "REQUESTING";
			break;
		case DLM_RECO_NODE_DATA_DEAD:
			state = "DEAD";
			break;
		case DLM_RECO_NODE_DATA_RECEIVING:
			state = "RECEIVING";
			break;
		case DLM_RECO_NODE_DATA_REQUESTED:
			state = "REQUESTED";
			break;
		case DLM_RECO_NODE_DATA_DONE:
			state = "DONE";
			break;
		case DLM_RECO_NODE_DATA_FINALIZE_SENT:
			state = "FINALIZE-SENT";
			break;
		default:
			state = "BAD";
			break;
		}
		out += snprintf(db->buf + out, db->len - out, "\t%u - %s\n",
				node->node_num, state);
	}

	spin_unlock(&dlm->spinlock);

	return out;
}

static int debug_state_open(struct inode *inode, struct file *file)
{
	struct dlm_ctxt *dlm = inode->i_private;
	struct debug_buffer *db = NULL;

	db = debug_buffer_allocate();
	if (!db)
		goto bail;

	db->len = debug_state_print(dlm, db);

	file->private_data = db;

	return 0;
bail:
	return -ENOMEM;
}

static struct file_operations debug_state_fops = {
	.open =		debug_state_open,
	.release =	debug_buffer_release,
	.read =		debug_buffer_read,
	.llseek =	debug_buffer_llseek,
};
/* end  - debug state funcs */

/* files in subroot */
int dlm_debug_init(struct dlm_ctxt *dlm)
{
	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;

	/* for dumping dlm_ctxt */
	dc->debug_state_dentry = debugfs_create_file(DLM_DEBUGFS_DLM_STATE,
						     S_IFREG|S_IRUSR,
						     dlm->dlm_debugfs_subroot,
						     dlm, &debug_state_fops);
	if (!dc->debug_state_dentry) {
		mlog_errno(-ENOMEM);
		goto bail;
	}

	/* for dumping lockres */
	dc->debug_lockres_dentry =
			debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE,
					    S_IFREG|S_IRUSR,
					    dlm->dlm_debugfs_subroot,
					    dlm, &debug_lockres_fops);
	if (!dc->debug_lockres_dentry) {
		mlog_errno(-ENOMEM);
		goto bail;
	}

	/* for dumping mles */
	dc->debug_mle_dentry = debugfs_create_file(DLM_DEBUGFS_MLE_STATE,
						   S_IFREG|S_IRUSR,
						   dlm->dlm_debugfs_subroot,
						   dlm, &debug_mle_fops);
	if (!dc->debug_mle_dentry) {
		mlog_errno(-ENOMEM);
		goto bail;
	}

	/* for dumping lockres on the purge list */
	dc->debug_purgelist_dentry =
			debugfs_create_file(DLM_DEBUGFS_PURGE_LIST,
					    S_IFREG|S_IRUSR,
					    dlm->dlm_debugfs_subroot,
					    dlm, &debug_purgelist_fops);
	if (!dc->debug_purgelist_dentry) {
		mlog_errno(-ENOMEM);
		goto bail;
	}

	dlm_debug_get(dc);
	return 0;

bail:
	dlm_debug_shutdown(dlm);
	return -ENOMEM;
}

void dlm_debug_shutdown(struct dlm_ctxt *dlm)
{
	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;

	if (dc) {
		if (dc->debug_purgelist_dentry)
			debugfs_remove(dc->debug_purgelist_dentry);
		if (dc->debug_mle_dentry)
			debugfs_remove(dc->debug_mle_dentry);
		if (dc->debug_lockres_dentry)
			debugfs_remove(dc->debug_lockres_dentry);
		if (dc->debug_state_dentry)
			debugfs_remove(dc->debug_state_dentry);
		dlm_debug_put(dc);
	}
}

/* subroot - domain dir */
int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
{
	dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
						      dlm_debugfs_root);
	if (!dlm->dlm_debugfs_subroot) {
		mlog_errno(-ENOMEM);
		goto bail;
	}

	dlm->dlm_debug_ctxt = kzalloc(sizeof(struct dlm_debug_ctxt),
				      GFP_KERNEL);
	if (!dlm->dlm_debug_ctxt) {
		mlog_errno(-ENOMEM);
		goto bail;
	}
	kref_init(&dlm->dlm_debug_ctxt->debug_refcnt);

	return 0;
bail:
	dlm_destroy_debugfs_subroot(dlm);
	return -ENOMEM;
}

void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
{
	if (dlm->dlm_debugfs_subroot)
		debugfs_remove(dlm->dlm_debugfs_subroot);
}

/* debugfs root */
int dlm_create_debugfs_root(void)
{
	dlm_debugfs_root = debugfs_create_dir(DLM_DEBUGFS_DIR, NULL);
	if (!dlm_debugfs_root) {
		mlog_errno(-ENOMEM);
		return -ENOMEM;
	}
	return 0;
}

void dlm_destroy_debugfs_root(void)
{
	if (dlm_debugfs_root)
		debugfs_remove(dlm_debugfs_root);
}
#endif	/* CONFIG_DEBUG_FS */