aboutsummaryrefslogtreecommitdiff
path: root/fs/ocfs2/dlm/dlmcommon.h
blob: d602abb51b610d525cc437daa05c25d2105fe0c3 (plain)
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
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmcommon.h
 *
 * Copyright (C) 2004 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.
 *
 */

#ifndef DLMCOMMON_H
#define DLMCOMMON_H

#include <linux/kref.h>

#define DLM_HB_NODE_DOWN_PRI     (0xf000000)
#define DLM_HB_NODE_UP_PRI       (0x8000000)

#define DLM_LOCKID_NAME_MAX    32

#define DLM_DOMAIN_NAME_MAX_LEN    255
#define DLM_LOCK_RES_OWNER_UNKNOWN     O2NM_MAX_NODES
#define DLM_THREAD_SHUFFLE_INTERVAL    5     // flush everything every 5 passes
#define DLM_THREAD_MS                  200   // flush at least every 200 ms

#define DLM_HASH_SIZE_DEFAULT	(1 << 17)
#if DLM_HASH_SIZE_DEFAULT < PAGE_SIZE
# define DLM_HASH_PAGES		1
#else
# define DLM_HASH_PAGES		(DLM_HASH_SIZE_DEFAULT / PAGE_SIZE)
#endif
#define DLM_BUCKETS_PER_PAGE	(PAGE_SIZE / sizeof(struct hlist_head))
#define DLM_HASH_BUCKETS	(DLM_HASH_PAGES * DLM_BUCKETS_PER_PAGE)

/* Intended to make it easier for us to switch out hash functions */
#define dlm_lockid_hash(_n, _l) full_name_hash(_n, _l)

enum dlm_mle_type {
	DLM_MLE_BLOCK = 0,
	DLM_MLE_MASTER = 1,
	DLM_MLE_MIGRATION = 2,
	DLM_MLE_NUM_TYPES = 3,
};

struct dlm_master_list_entry {
	struct hlist_node master_hash_node;
	struct list_head hb_events;
	struct dlm_ctxt *dlm;
	spinlock_t spinlock;
	wait_queue_head_t wq;
	atomic_t woken;
	struct kref mle_refs;
	int inuse;
	unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	u8 master;
	u8 new_master;
	enum dlm_mle_type type;
	struct o2hb_callback_func mle_hb_up;
	struct o2hb_callback_func mle_hb_down;
	struct dlm_lock_resource *mleres;
	unsigned char mname[DLM_LOCKID_NAME_MAX];
	unsigned int mnamelen;
	unsigned int mnamehash;
};

enum dlm_ast_type {
	DLM_AST = 0,
	DLM_BAST = 1,
	DLM_ASTUNLOCK = 2,
};


#define LKM_VALID_FLAGS (LKM_VALBLK | LKM_CONVERT | LKM_UNLOCK | \
			 LKM_CANCEL | LKM_INVVALBLK | LKM_FORCE | \
			 LKM_RECOVERY | LKM_LOCAL | LKM_NOQUEUE)

#define DLM_RECOVERY_LOCK_NAME       "$RECOVERY"
#define DLM_RECOVERY_LOCK_NAME_LEN   9

static inline int dlm_is_recovery_lock(const char *lock_name, int name_len)
{
	if (name_len == DLM_RECOVERY_LOCK_NAME_LEN &&
	    memcmp(lock_name, DLM_RECOVERY_LOCK_NAME, name_len)==0)
		return 1;
	return 0;
}

#define DLM_RECO_STATE_ACTIVE    0x0001
#define DLM_RECO_STATE_FINALIZE  0x0002

struct dlm_recovery_ctxt
{
	struct list_head resources;
	struct list_head received;
	struct list_head node_data;
	u8  new_master;
	u8  dead_node;
	u16 state;
	unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	wait_queue_head_t event;
};

enum dlm_ctxt_state {
	DLM_CTXT_NEW = 0,
	DLM_CTXT_JOINED = 1,
	DLM_CTXT_IN_SHUTDOWN = 2,
	DLM_CTXT_LEAVING = 3,
};

struct dlm_ctxt
{
	struct list_head list;
	struct hlist_head **lockres_hash;
	struct list_head dirty_list;
	struct list_head purge_list;
	struct list_head pending_asts;
	struct list_head pending_basts;
	struct list_head tracking_list;
	unsigned int purge_count;
	spinlock_t spinlock;
	spinlock_t ast_lock;
	spinlock_t track_lock;
	char *name;
	u8 node_num;
	u32 key;
	u8  joining_node;
	wait_queue_head_t dlm_join_events;
	unsigned long live_nodes_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long domain_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long exit_domain_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	struct dlm_recovery_ctxt reco;
	spinlock_t master_lock;
	struct hlist_head **master_hash;
	struct list_head mle_hb_events;

	/* these give a really vague idea of the system load */
	atomic_t mle_tot_count[DLM_MLE_NUM_TYPES];
	atomic_t mle_cur_count[DLM_MLE_NUM_TYPES];
	atomic_t res_tot_count;
	atomic_t res_cur_count;

	struct dlm_debug_ctxt *dlm_debug_ctxt;
	struct dentry *dlm_debugfs_subroot;

	/* NOTE: Next three are protected by dlm_domain_lock */
	struct kref dlm_refs;
	enum dlm_ctxt_state dlm_state;
	unsigned int num_joins;

	struct o2hb_callback_func dlm_hb_up;
	struct o2hb_callback_func dlm_hb_down;
	struct task_struct *dlm_thread_task;
	struct task_struct *dlm_reco_thread_task;
	struct workqueue_struct *dlm_worker;
	wait_queue_head_t dlm_thread_wq;
	wait_queue_head_t dlm_reco_thread_wq;
	wait_queue_head_t ast_wq;
	wait_queue_head_t migration_wq;

	struct work_struct dispatched_work;
	struct list_head work_list;
	spinlock_t work_lock;
	struct list_head dlm_domain_handlers;
	struct list_head	dlm_eviction_callbacks;

	/* The filesystem specifies this at domain registration.  We
	 * cache it here to know what to tell other nodes. */
	struct dlm_protocol_version fs_locking_proto;
	/* This is the inter-dlm communication version */
	struct dlm_protocol_version dlm_locking_proto;
};

static inline struct hlist_head *dlm_lockres_hash(struct dlm_ctxt *dlm, unsigned i)
{
	return dlm->lockres_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] + (i % DLM_BUCKETS_PER_PAGE);
}

static inline struct hlist_head *dlm_master_hash(struct dlm_ctxt *dlm,
						 unsigned i)
{
	return dlm->master_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] +
			(i % DLM_BUCKETS_PER_PAGE);
}

/* these keventd work queue items are for less-frequently
 * called functions that cannot be directly called from the
 * net message handlers for some reason, usually because
 * they need to send net messages of their own. */
void dlm_dispatch_work(struct work_struct *work);

struct dlm_lock_resource;
struct dlm_work_item;

typedef void (dlm_workfunc_t)(struct dlm_work_item *, void *);

struct dlm_request_all_locks_priv
{
	u8 reco_master;
	u8 dead_node;
};

struct dlm_mig_lockres_priv
{
	struct dlm_lock_resource *lockres;
	u8 real_master;
	u8 extra_ref;
};

struct dlm_assert_master_priv
{
	struct dlm_lock_resource *lockres;
	u8 request_from;
	u32 flags;
	unsigned ignore_higher:1;
};

struct dlm_deref_lockres_priv
{
	struct dlm_lock_resource *deref_res;
	u8 deref_node;
};

struct dlm_work_item
{
	struct list_head list;
	dlm_workfunc_t *func;
	struct dlm_ctxt *dlm;
	void *data;
	union {
		struct dlm_request_all_locks_priv ral;
		struct dlm_mig_lockres_priv ml;
		struct dlm_assert_master_priv am;
		struct dlm_deref_lockres_priv dl;
	} u;
};

static inline void dlm_init_work_item(struct dlm_ctxt *dlm,
				      struct dlm_work_item *i,
				      dlm_workfunc_t *f, void *data)
{
	memset(i, 0, sizeof(*i));
	i->func = f;
	INIT_LIST_HEAD(&i->list);
	i->data = data;
	i->dlm = dlm;  /* must have already done a dlm_grab on this! */
}



static inline void __dlm_set_joining_node(struct dlm_ctxt *dlm,
					  u8 node)
{
	assert_spin_locked(&dlm->spinlock);

	dlm->joining_node = node;
	wake_up(&dlm->dlm_join_events);
}

#define DLM_LOCK_RES_UNINITED             0x00000001
#define DLM_LOCK_RES_RECOVERING           0x00000002
#define DLM_LOCK_RES_READY                0x00000004
#define DLM_LOCK_RES_DIRTY                0x00000008
#define DLM_LOCK_RES_IN_PROGRESS          0x00000010
#define DLM_LOCK_RES_MIGRATING            0x00000020
#define DLM_LOCK_RES_DROPPING_REF         0x00000040
#define DLM_LOCK_RES_BLOCK_DIRTY          0x00001000
#define DLM_LOCK_RES_SETREF_INPROG        0x00002000

/* max milliseconds to wait to sync up a network failure with a node death */
#define DLM_NODE_DEATH_WAIT_MAX (5 * 1000)

#define DLM_PURGE_INTERVAL_MS   (8 * 1000)

struct dlm_lock_resource
{
	/* WARNING: Please see the comment in dlm_init_lockres before
	 * adding fields here. */
	struct hlist_node hash_node;
	struct qstr lockname;
	struct kref      refs;

	/*
	 * Please keep granted, converting, and blocked in this order,
	 * as some funcs want to iterate over all lists.
	 *
	 * All four lists are protected by the hash's reference.
	 */
	struct list_head granted;
	struct list_head converting;
	struct list_head blocked;
	struct list_head purge;

	/*
	 * These two lists require you to hold an additional reference
	 * while they are on the list.
	 */
	struct list_head dirty;
	struct list_head recovering; // dlm_recovery_ctxt.resources list

	/* Added during init and removed during release */
	struct list_head tracking;	/* dlm->tracking_list */

	/* unused lock resources have their last_used stamped and are
	 * put on a list for the dlm thread to run. */
	unsigned long    last_used;

	struct dlm_ctxt *dlm;

	unsigned migration_pending:1;
	atomic_t asts_reserved;
	spinlock_t spinlock;
	wait_queue_head_t wq;
	u8  owner;              //node which owns the lock resource, or unknown
	u16 state;
	char lvb[DLM_LVB_LEN];
	unsigned int inflight_locks;
	unsigned long refmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
};

struct dlm_migratable_lock
{
	__be64 cookie;

	/* these 3 are just padding for the in-memory structure, but
	 * list and flags are actually used when sent over the wire */
	__be16 pad1;
	u8 list;  // 0=granted, 1=converting, 2=blocked
	u8 flags;

	s8 type;
	s8 convert_type;
	s8 highest_blocked;
	u8 node;
};  // 16 bytes

struct dlm_lock
{
	struct dlm_migratable_lock ml;

	struct list_head list;
	struct list_head ast_list;
	struct list_head bast_list;
	struct dlm_lock_resource *lockres;
	spinlock_t spinlock;
	struct kref lock_refs;

	// ast and bast must be callable while holding a spinlock!
	dlm_astlockfunc_t *ast;
	dlm_bastlockfunc_t *bast;
	void *astdata;
	struct dlm_lockstatus *lksb;
	unsigned ast_pending:1,
		 bast_pending:1,
		 convert_pending:1,
		 lock_pending:1,
		 cancel_pending:1,
		 unlock_pending:1,
		 lksb_kernel_allocated:1;
};


#define DLM_LKSB_UNUSED1           0x01
#define DLM_LKSB_PUT_LVB           0x02
#define DLM_LKSB_GET_LVB           0x04
#define DLM_LKSB_UNUSED2           0x08
#define DLM_LKSB_UNUSED3           0x10
#define DLM_LKSB_UNUSED4           0x20
#define DLM_LKSB_UNUSED5           0x40
#define DLM_LKSB_UNUSED6           0x80


enum dlm_lockres_list {
	DLM_GRANTED_LIST = 0,
	DLM_CONVERTING_LIST = 1,
	DLM_BLOCKED_LIST = 2,
};

static inline int dlm_lvb_is_empty(char *lvb)
{
	int i;
	for (i=0; i<DLM_LVB_LEN; i++)
		if (lvb[i])
			return 0;
	return 1;
}

static inline char *dlm_list_in_text(enum dlm_lockres_list idx)
{
	if (idx == DLM_GRANTED_LIST)
		return "granted";
	else if (idx == DLM_CONVERTING_LIST)
		return "converting";
	else if (idx == DLM_BLOCKED_LIST)
		return "blocked";
	else
		return "unknown";
}

static inline struct list_head *
dlm_list_idx_to_ptr(struct dlm_lock_resource *res, enum dlm_lockres_list idx)
{
	struct list_head *ret = NULL;
	if (idx == DLM_GRANTED_LIST)
		ret = &res->granted;
	else if (idx == DLM_CONVERTING_LIST)
		ret = &res->converting;
	else if (idx == DLM_BLOCKED_LIST)
		ret = &res->blocked;
	else
		BUG();
	return ret;
}




struct dlm_node_iter
{
	unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
	int curnode;
};


enum {
	DLM_MASTER_REQUEST_MSG		= 500,
	DLM_UNUSED_MSG1			= 501,
	DLM_ASSERT_MASTER_MSG		= 502,
	DLM_CREATE_LOCK_MSG		= 503,
	DLM_CONVERT_LOCK_MSG		= 504,
	DLM_PROXY_AST_MSG		= 505,
	DLM_UNLOCK_LOCK_MSG		= 506,
	DLM_DEREF_LOCKRES_MSG		= 507,
	DLM_MIGRATE_REQUEST_MSG		= 508,
	DLM_MIG_LOCKRES_MSG		= 509,
	DLM_QUERY_JOIN_MSG		= 510,
	DLM_ASSERT_JOINED_MSG		= 511,
	DLM_CANCEL_JOIN_MSG		= 512,
	DLM_EXIT_DOMAIN_MSG		= 513,
	DLM_MASTER_REQUERY_MSG		= 514,
	DLM_LOCK_REQUEST_MSG		= 515,
	DLM_RECO_DATA_DONE_MSG		= 516,
	DLM_BEGIN_RECO_MSG		= 517,
	DLM_FINALIZE_RECO_MSG		= 518,
	DLM_QUERY_REGION		= 519,
	DLM_QUERY_NODEINFO		= 520,
	DLM_BEGIN_EXIT_DOMAIN_MSG	= 521,
};

struct dlm_reco_node_data
{
	int state;
	u8 node_num;
	struct list_head list;
};

enum {
	DLM_RECO_NODE_DATA_DEAD = -1,
	DLM_RECO_NODE_DATA_INIT = 0,
	DLM_RECO_NODE_DATA_REQUESTING = 1,
	DLM_RECO_NODE_DATA_REQUESTED = 2,
	DLM_RECO_NODE_DATA_RECEIVING = 3,
	DLM_RECO_NODE_DATA_DONE = 4,
	DLM_RECO_NODE_DATA_FINALIZE_SENT = 5,
};


enum {
	DLM_MASTER_RESP_NO = 0,
	DLM_MASTER_RESP_YES = 1,
	DLM_MASTER_RESP_MAYBE = 2,
	DLM_MASTER_RESP_ERROR = 3,
};


struct dlm_master_request
{
	u8 node_idx;
	u8 namelen;
	__be16 pad1;
	__be32 flags;

	u8 name[O2NM_MAX_NAME_LEN];
};

#define DLM_ASSERT_RESPONSE_REASSERT       0x00000001
#define DLM_ASSERT_RESPONSE_MASTERY_REF    0x00000002

#define DLM_ASSERT_MASTER_MLE_CLEANUP      0x00000001
#define DLM_ASSERT_MASTER_REQUERY          0x00000002
#define DLM_ASSERT_MASTER_FINISH_MIGRATION 0x00000004
struct dlm_assert_master
{
	u8 node_idx;
	u8 namelen;
	__be16 pad1;
	__be32 flags;

	u8 name[O2NM_MAX_NAME_LEN];
};

#define DLM_MIGRATE_RESPONSE_MASTERY_REF   0x00000001

struct dlm_migrate_request
{
	u8 master;
	u8 new_master;
	u8 namelen;
	u8 pad1;
	__be32 pad2;
	u8 name[O2NM_MAX_NAME_LEN];
};

struct dlm_master_requery
{
	u8 pad1;
	u8 pad2;
	u8 node_idx;
	u8 namelen;
	__be32 pad3;
	u8 name[O2NM_MAX_NAME_LEN];
};

#define DLM_MRES_RECOVERY   0x01
#define DLM_MRES_MIGRATION  0x02
#define DLM_MRES_ALL_DONE   0x04

/*
 * We would like to get one whole lockres into a single network
 * message whenever possible.  Generally speaking, there will be
 * at most one dlm_lock on a lockres for each node in the cluster,
 * plus (infrequently) any additional locks coming in from userdlm.
 *
 * struct _dlm_lockres_page
 * {
 * 	dlm_migratable_lockres mres;
 * 	dlm_migratable_lock ml[DLM_MAX_MIGRATABLE_LOCKS];
 * 	u8 pad[DLM_MIG_LOCKRES_RESERVED];
 * };
 *
 * from ../cluster/tcp.h
 *    NET_MAX_PAYLOAD_BYTES  (4096 - sizeof(net_msg))
 *    (roughly 4080 bytes)
 * and sizeof(dlm_migratable_lockres) = 112 bytes
 * and sizeof(dlm_migratable_lock) = 16 bytes
 *
 * Choosing DLM_MAX_MIGRATABLE_LOCKS=240 and
 * DLM_MIG_LOCKRES_RESERVED=128 means we have this:
 *
 *  (DLM_MAX_MIGRATABLE_LOCKS * sizeof(dlm_migratable_lock)) +
 *     sizeof(dlm_migratable_lockres) + DLM_MIG_LOCKRES_RESERVED =
 *        NET_MAX_PAYLOAD_BYTES
 *  (240 * 16) + 112 + 128 = 4080
 *
 * So a lockres would need more than 240 locks before it would
 * use more than one network packet to recover.  Not too bad.
 */
#define DLM_MAX_MIGRATABLE_LOCKS   240

struct dlm_migratable_lockres
{
	u8 master;
	u8 lockname_len;
	u8 num_locks;    // locks sent in this structure
	u8 flags;
	__be32 total_locks; // locks to be sent for this migration cookie
	__be64 mig_cookie;  // cookie for this lockres migration
			 // or zero if not needed
	// 16 bytes
	u8 lockname[DLM_LOCKID_NAME_MAX];
	// 48 bytes
	u8 lvb[DLM_LVB_LEN];
	// 112 bytes
	struct dlm_migratable_lock ml[0];  // 16 bytes each, begins at byte 112
};
#define DLM_MIG_LOCKRES_MAX_LEN  \
	(sizeof(struct dlm_migratable_lockres) + \
	 (sizeof(struct dlm_migratable_lock) * \
	  DLM_MAX_MIGRATABLE_LOCKS) )

/* from above, 128 bytes
 * for some undetermined future use */
#define DLM_MIG_LOCKRES_RESERVED   (NET_MAX_PAYLOAD_BYTES - \
				    DLM_MIG_LOCKRES_MAX_LEN)

struct dlm_create_lock
{
	__be64 cookie;

	__be32 flags;
	u8 pad1;
	u8 node_idx;
	s8 requested_type;
	u8 namelen;

	u8 name[O2NM_MAX_NAME_LEN];
};

struct dlm_convert_lock
{
	__be64 cookie;

	__be32 flags;
	u8 pad1;
	u8 node_idx;
	s8 requested_type;
	u8 namelen;

	u8 name[O2NM_MAX_NAME_LEN];

	s8 lvb[0];
};
#define DLM_CONVERT_LOCK_MAX_LEN  (sizeof(struct dlm_convert_lock)+DLM_LVB_LEN)

struct dlm_unlock_lock
{
	__be64 cookie;

	__be32 flags;
	__be16 pad1;
	u8 node_idx;
	u8 namelen;

	u8 name[O2NM_MAX_NAME_LEN];

	s8 lvb[0];
};
#define DLM_UNLOCK_LOCK_MAX_LEN  (sizeof(struct dlm_unlock_lock)+DLM_LVB_LEN)

struct dlm_proxy_ast
{
	__be64 cookie;

	__be32 flags;
	u8 node_idx;
	u8 type;
	u8 blocked_type;
	u8 namelen;

	u8 name[O2NM_MAX_NAME_LEN];

	s8 lvb[0];
};
#define DLM_PROXY_AST_MAX_LEN  (sizeof(struct dlm_proxy_ast)+DLM_LVB_LEN)

#define DLM_MOD_KEY (0x666c6172)
enum dlm_query_join_response_code {
	JOIN_DISALLOW = 0,
	JOIN_OK = 1,
	JOIN_OK_NO_MAP = 2,
	JOIN_PROTOCOL_MISMATCH = 3,
};

struct dlm_query_join_packet {
	u8 code;	/* Response code.  dlm_minor and fs_minor
			   are only valid if this is JOIN_OK */
	u8 dlm_minor;	/* The minor version of the protocol the
			   dlm is speaking. */
	u8 fs_minor;	/* The minor version of the protocol the
			   filesystem is speaking. */
	u8 reserved;
};

union dlm_query_join_response {
	u32 intval;
	struct dlm_query_join_packet packet;
};

struct dlm_lock_request
{
	u8 node_idx;
	u8 dead_node;
	__be16 pad1;
	__be32 pad2;
};

struct dlm_reco_data_done
{
	u8 node_idx;
	u8 dead_node;
	__be16 pad1;
	__be32 pad2;

	/* unused for now */
	/* eventually we can use this to attempt
	 * lvb recovery based on each node's info */
	u8 reco_lvb[DLM_LVB_LEN];
};

struct dlm_begin_reco
{
	u8 node_idx;
	u8 dead_node;
	__be16 pad1;
	__be32 pad2;
};


#define BITS_PER_BYTE 8
#define BITS_TO_BYTES(bits) (((bits)+BITS_PER_BYTE-1)/BITS_PER_BYTE)

struct dlm_query_join_request
{
	u8 node_idx;
	u8 pad1[2];
	u8 name_len;
	struct dlm_protocol_version dlm_proto;
	struct dlm_protocol_version fs_proto;
	u8 domain[O2NM_MAX_NAME_LEN];
	u8 node_map[BITS_TO_BYTES(O2NM_MAX_NODES)];
};

struct dlm_assert_joined
{
	u8 node_idx;
	u8 pad1[2];
	u8 name_len;
	u8 domain[O2NM_MAX_NAME_LEN];
};

struct dlm_cancel_join
{
	u8 node_idx;
	u8 pad1[2];
	u8 name_len;
	u8 domain[O2NM_MAX_NAME_LEN];
};

struct dlm_query_region {
	u8 qr_node;
	u8 qr_numregions;
	u8 qr_namelen;
	u8 pad1;
	u8 qr_domain[O2NM_MAX_NAME_LEN];
	u8 qr_regions[O2HB_MAX_REGION_NAME_LEN * O2NM_MAX_REGIONS];
};

struct dlm_node_info {
	u8 ni_nodenum;
	u8 pad1;
	u16 ni_ipv4_port;
	u32 ni_ipv4_address;
};

struct dlm_query_nodeinfo {
	u8 qn_nodenum;
	u8 qn_numnodes;
	u8 qn_namelen;
	u8 pad1;
	u8 qn_domain[O2NM_MAX_NAME_LEN];
	struct dlm_node_info qn_nodes[O2NM_MAX_NODES];
};

struct dlm_exit_domain
{
	u8 node_idx;
	u8 pad1[3];
};

struct dlm_finalize_reco
{
	u8 node_idx;
	u8 dead_node;
	u8 flags;
	u8 pad1;
	__be32 pad2;
};

struct dlm_deref_lockres
{
	u32 pad1;
	u16 pad2;
	u8 node_idx;
	u8 namelen;

	u8 name[O2NM_MAX_NAME_LEN];
};

static inline enum dlm_status
__dlm_lockres_state_to_status(struct dlm_lock_resource *res)
{
	enum dlm_status status = DLM_NORMAL;

	assert_spin_locked(&res->spinlock);

	if (res->state & DLM_LOCK_RES_RECOVERING)
		status = DLM_RECOVERING;
	else if (res->state & DLM_LOCK_RES_MIGRATING)
		status = DLM_MIGRATING;
	else if (res->state & DLM_LOCK_RES_IN_PROGRESS)
		status = DLM_FORWARD;

	return status;
}

static inline u8 dlm_get_lock_cookie_node(u64 cookie)
{
	u8 ret;
	cookie >>= 56;
	ret = (u8)(cookie & 0xffULL);
	return ret;
}

static inline unsigned long long dlm_get_lock_cookie_seq(u64 cookie)
{
	unsigned long long ret;
	ret = ((unsigned long long)cookie) & 0x00ffffffffffffffULL;
	return ret;
}

struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
			       struct dlm_lockstatus *lksb);
void dlm_lock_get(struct dlm_lock *lock);
void dlm_lock_put(struct dlm_lock *lock);

void dlm_lock_attach_lockres(struct dlm_lock *lock,
			     struct dlm_lock_resource *res);

int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
			    void **ret_data);
int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
			     void **ret_data);
int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
			  void **ret_data);

void dlm_revert_pending_convert(struct dlm_lock_resource *res,
				struct dlm_lock *lock);
void dlm_revert_pending_lock(struct dlm_lock_resource *res,
			     struct dlm_lock *lock);

int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data,
			    void **ret_data);
void dlm_commit_pending_cancel(struct dlm_lock_resource *res,
			       struct dlm_lock *lock);
void dlm_commit_pending_unlock(struct dlm_lock_resource *res,
			       struct dlm_lock *lock);

int dlm_launch_thread(struct dlm_ctxt *dlm);
void dlm_complete_thread(struct dlm_ctxt *dlm);
int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
void dlm_wait_for_recovery(struct dlm_ctxt *dlm);
void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node);
int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout);
int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout);

void dlm_put(struct dlm_ctxt *dlm);
struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm);
int dlm_domain_fully_joined(struct dlm_ctxt *dlm);

void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
			      struct dlm_lock_resource *res);
void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
			    struct dlm_lock_resource *res);
static inline void dlm_lockres_get(struct dlm_lock_resource *res)
{
	/* This is called on every lookup, so it might be worth
	 * inlining. */
	kref_get(&res->refs);
}
void dlm_lockres_put(struct dlm_lock_resource *res);
void __dlm_unhash_lockres(struct dlm_lock_resource *res);
void __dlm_insert_lockres(struct dlm_ctxt *dlm,
			  struct dlm_lock_resource *res);
struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
						     const char *name,
						     unsigned int len,
						     unsigned int hash);
struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
						const char *name,
						unsigned int len,
						unsigned int hash);
struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
					      const char *name,
					      unsigned int len);

int dlm_is_host_down(int errno);

struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
						 const char *lockid,
						 int namelen,
						 int flags);
struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
					  const char *name,
					  unsigned int namelen);

#define dlm_lockres_set_refmap_bit(bit,res)  \
	__dlm_lockres_set_refmap_bit(bit,res,__FILE__,__LINE__)
#define dlm_lockres_clear_refmap_bit(bit,res)  \
	__dlm_lockres_clear_refmap_bit(bit,res,__FILE__,__LINE__)

static inline void __dlm_lockres_set_refmap_bit(int bit,
						struct dlm_lock_resource *res,
						const char *file,
						int line)
{
	//printk("%s:%d:%.*s: setting bit %d\n", file, line,
	//     res->lockname.len, res->lockname.name, bit);
	set_bit(bit, res->refmap);
}

static inline void __dlm_lockres_clear_refmap_bit(int bit,
						  struct dlm_lock_resource *res,
						  const char *file,
						  int line)
{
	//printk("%s:%d:%.*s: clearing bit %d\n", file, line,
	//     res->lockname.len, res->lockname.name, bit);
	clear_bit(bit, res->refmap);
}

void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
				   struct dlm_lock_resource *res,
				   const char *file,
				   int line);
void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
				   struct dlm_lock_resource *res,
				   int new_lockres,
				   const char *file,
				   int line);
#define dlm_lockres_drop_inflight_ref(d,r)  \
	__dlm_lockres_drop_inflight_ref(d,r,__FILE__,__LINE__)
#define dlm_lockres_grab_inflight_ref(d,r)  \
	__dlm_lockres_grab_inflight_ref(d,r,0,__FILE__,__LINE__)
#define dlm_lockres_grab_inflight_ref_new(d,r)  \
	__dlm_lockres_grab_inflight_ref(d,r,1,__FILE__,__LINE__)

void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void dlm_do_local_ast(struct dlm_ctxt *dlm,
		      struct dlm_lock_resource *res,
		      struct dlm_lock *lock);
int dlm_do_remote_ast(struct dlm_ctxt *dlm,
		      struct dlm_lock_resource *res,
		      struct dlm_lock *lock);
void dlm_do_local_bast(struct dlm_ctxt *dlm,
		       struct dlm_lock_resource *res,
		       struct dlm_lock *lock,
		       int blocked_type);
int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm,
			   struct dlm_lock_resource *res,
			   struct dlm_lock *lock,
			   int msg_type,
			   int blocked_type, int flags);
static inline int dlm_send_proxy_bast(struct dlm_ctxt *dlm,
				      struct dlm_lock_resource *res,
				      struct dlm_lock *lock,
				      int blocked_type)
{
	return dlm_send_proxy_ast_msg(dlm, res, lock, DLM_BAST,
				      blocked_type, 0);
}

static inline int dlm_send_proxy_ast(struct dlm_ctxt *dlm,
				     struct dlm_lock_resource *res,
				     struct dlm_lock *lock,
				     int flags)
{
	return dlm_send_proxy_ast_msg(dlm, res, lock, DLM_AST,
				      0, flags);
}

void dlm_print_one_lock_resource(struct dlm_lock_resource *res);
void __dlm_print_one_lock_resource(struct dlm_lock_resource *res);

u8 dlm_nm_this_node(struct dlm_ctxt *dlm);
void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);


int dlm_nm_init(struct dlm_ctxt *dlm);
int dlm_heartbeat_init(struct dlm_ctxt *dlm);
void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data);
void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data);

int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res);
int dlm_finish_migration(struct dlm_ctxt *dlm,
			 struct dlm_lock_resource *res,
			 u8 old_master);
void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
			     struct dlm_lock_resource *res);
void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res);

int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
			       void **ret_data);
int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
			      void **ret_data);
void dlm_assert_master_post_handler(int status, void *data, void *ret_data);
int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
			      void **ret_data);
int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
				void **ret_data);
int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
			    void **ret_data);
int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
			       void **ret_data);
int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
				  void **ret_data);
int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
			       void **ret_data);
int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
			   void **ret_data);
int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
			      void **ret_data);
int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
			  u8 nodenum, u8 *real_master);


int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
			       struct dlm_lock_resource *res,
			       int ignore_higher,
			       u8 request_from,
			       u32 flags);


int dlm_send_one_lockres(struct dlm_ctxt *dlm,
			 struct dlm_lock_resource *res,
			 struct dlm_migratable_lockres *mres,
			 u8 send_to,
			 u8 flags);
void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
				       struct dlm_lock_resource *res);

/* will exit holding res->spinlock, but may drop in function */
void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags);
void __dlm_wait_on_lockres_flags_set(struct dlm_lock_resource *res, int flags);

/* will exit holding res->spinlock, but may drop in function */
static inline void __dlm_wait_on_lockres(struct dlm_lock_resource *res)
{
	__dlm_wait_on_lockres_flags(res, (DLM_LOCK_RES_IN_PROGRESS|
				    	  DLM_LOCK_RES_RECOVERING|
					  DLM_LOCK_RES_MIGRATING));
}

void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle);
void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle);

/* create/destroy slab caches */
int dlm_init_master_caches(void);
void dlm_destroy_master_caches(void);

int dlm_init_lock_cache(void);
void dlm_destroy_lock_cache(void);

int dlm_init_mle_cache(void);
void dlm_destroy_mle_cache(void);

void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up);
int dlm_drop_lockres_ref(struct dlm_ctxt *dlm,
			 struct dlm_lock_resource *res);
void dlm_clean_master_list(struct dlm_ctxt *dlm,
			   u8 dead_node);
void dlm_force_free_mles(struct dlm_ctxt *dlm);
int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
int __dlm_lockres_has_locks(struct dlm_lock_resource *res);
int __dlm_lockres_unused(struct dlm_lock_resource *res);

static inline const char * dlm_lock_mode_name(int mode)
{
	switch (mode) {
		case LKM_EXMODE:
			return "EX";
		case LKM_PRMODE:
			return "PR";
		case LKM_NLMODE:
			return "NL";
	}
	return "UNKNOWN";
}


static inline int dlm_lock_compatible(int existing, int request)
{
	/* NO_LOCK compatible with all */
	if (request == LKM_NLMODE ||
	    existing == LKM_NLMODE)
		return 1;

	/* EX incompatible with all non-NO_LOCK */
	if (request == LKM_EXMODE)
		return 0;

	/* request must be PR, which is compatible with PR */
	if (existing == LKM_PRMODE)
		return 1;

	return 0;
}

static inline int dlm_lock_on_list(struct list_head *head,
				   struct dlm_lock *lock)
{
	struct list_head *iter;
	struct dlm_lock *tmplock;

	list_for_each(iter, head) {
		tmplock = list_entry(iter, struct dlm_lock, list);
		if (tmplock == lock)
			return 1;
	}
	return 0;
}


static inline enum dlm_status dlm_err_to_dlm_status(int err)
{
	enum dlm_status ret;
	if (err == -ENOMEM)
		ret = DLM_SYSERR;
	else if (err == -ETIMEDOUT || o2net_link_down(err, NULL))
		ret = DLM_NOLOCKMGR;
	else if (err == -EINVAL)
		ret = DLM_BADPARAM;
	else if (err == -ENAMETOOLONG)
		ret = DLM_IVBUFLEN;
	else
		ret = DLM_BADARGS;
	return ret;
}


static inline void dlm_node_iter_init(unsigned long *map,
				      struct dlm_node_iter *iter)
{
	memcpy(iter->node_map, map, sizeof(iter->node_map));
	iter->curnode = -1;
}

static inline int dlm_node_iter_next(struct dlm_node_iter *iter)
{
	int bit;
	bit = find_next_bit(iter->node_map, O2NM_MAX_NODES, iter->curnode+1);
	if (bit >= O2NM_MAX_NODES) {
		iter->curnode = O2NM_MAX_NODES;
		return -ENOENT;
	}
	iter->curnode = bit;
	return bit;
}

static inline void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
					 struct dlm_lock_resource *res,
					 u8 owner)
{
	assert_spin_locked(&res->spinlock);

	res->owner = owner;
}

static inline void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
					    struct dlm_lock_resource *res,
					    u8 owner)
{
	assert_spin_locked(&res->spinlock);

	if (owner != res->owner)
		dlm_set_lockres_owner(dlm, res, owner);
}

#endif /* DLMCOMMON_H */