Free Electrons

Embedded Linux Experts

   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
/* -*- 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);
void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout);
void 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_ctxt *dlm, 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);

void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
				struct dlm_lock_resource *res, int bit);
void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
				  struct dlm_lock_resource *res, int bit);

void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
				   struct dlm_lock_resource *res);
void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
				   struct dlm_lock_resource *res);

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 */