summaryrefslogtreecommitdiffstats
path: root/xlators/mgmt/glusterd/src/glusterd-sm.c
blob: db34ef1ddf87be6329406b7dcbe05f8179642d0e (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
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
/*
   Copyright (c) 2006-2012 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/

#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <sys/uio.h>
#include <sys/resource.h>

#include <libgen.h>
#include "uuid.h"

#include "fnmatch.h"
#include "xlator.h"
#include "protocol-common.h"
#include "glusterd.h"
#include "call-stub.h"
#include "defaults.h"
#include "list.h"
#include "glusterd-messages.h"
#include "dict.h"
#include "compat.h"
#include "compat-errno.h"
#include "statedump.h"
#include "glusterd-sm.h"
#include "glusterd-op-sm.h"
#include "glusterd-utils.h"
#include "glusterd-store.h"
#include "glusterd-snapshot-utils.h"

static struct cds_list_head gd_friend_sm_queue;

static  char *glusterd_friend_sm_state_names[] = {
        "Establishing Connection",
        "Probe Sent to Peer",
        "Probe Received from Peer",
        "Peer in Cluster",
        "Accepted peer request",
        "Sent and Received peer request",
        "Peer Rejected",
        "Peer detach in progress",
        "Probe Received from peer",
        "Connected to Peer",
        "Peer is connected and Accepted",
        "Invalid State"
};

static char *glusterd_friend_sm_event_names[] = {
        "GD_FRIEND_EVENT_NONE",
        "GD_FRIEND_EVENT_PROBE",
        "GD_FRIEND_EVENT_INIT_FRIEND_REQ",
        "GD_FRIEND_EVENT_RCVD_ACC",
        "GD_FRIEND_EVENT_LOCAL_ACC",
        "GD_FRIEND_EVENT_RCVD_RJT",
        "GD_FRIEND_EVENT_LOCAL_RJT",
        "GD_FRIEND_EVENT_RCVD_FRIEND_REQ",
        "GD_FRIEND_EVENT_INIT_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_RCVD_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_CONNECTED",
        "GD_FRIEND_EVENT_MAX"
};

char*
glusterd_friend_sm_state_name_get (int state)
{
        if (state < 0 || state >= GD_FRIEND_STATE_MAX)
                return glusterd_friend_sm_state_names[GD_FRIEND_STATE_MAX];
        return glusterd_friend_sm_state_names[state];
}

char*
glusterd_friend_sm_event_name_get (int event)
{
        if (event < 0 || event >= GD_FRIEND_EVENT_MAX)
                return glusterd_friend_sm_event_names[GD_FRIEND_EVENT_MAX];
        return glusterd_friend_sm_event_names[event];
}

void
glusterd_destroy_probe_ctx (glusterd_probe_ctx_t *ctx)
{
        if (!ctx)
                return;

        GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

void
glusterd_destroy_friend_req_ctx (glusterd_friend_req_ctx_t *ctx)
{
        if (!ctx)
                return;

        if (ctx->vols)
                dict_unref (ctx->vols);
        GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

void
glusterd_destroy_friend_update_ctx (glusterd_friend_update_ctx_t *ctx)
{
        if (!ctx)
                return;
        GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

int
glusterd_broadcast_friend_delete (char *hostname, uuid_t uuid)
{
        int                             ret = 0;
        rpc_clnt_procedure_t            *proc = NULL;
        xlator_t                        *this = NULL;
        glusterd_friend_update_ctx_t    ctx = {{0},};
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_conf_t                 *priv = NULL;
        dict_t                          *friends = NULL;
        char                            key[100] = {0,};
        int32_t                         count = 0;

        this = THIS;
        priv = this->private;

        GF_ASSERT (priv);

        ctx.hostname = hostname;
        ctx.op = GD_FRIEND_UPDATE_DEL;

        friends = dict_new ();
        if (!friends)
                goto out;

        snprintf (key, sizeof (key), "op");
        ret = dict_set_int32 (friends, key, ctx.op);
        if (ret)
                goto out;

        snprintf (key, sizeof (key), "hostname");
        ret = dict_set_str (friends, key, hostname);
        if (ret)
                goto out;

        ret = dict_set_int32 (friends, "count", count);
        if (ret)
                goto out;

        rcu_read_lock ();
        cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
                if (!peerinfo->connected || !peerinfo->peer)
                        continue;

                /* Setting a direct reference to peerinfo in the dict is okay as
                 * it is only going to be used within this read critical section
                 * (in glusterd_rpc_friend_update)
                 */
                ret = dict_set_static_ptr (friends, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto unlock;
                }

                proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_UPDATE];
                if (proc->fn) {
                        ret = proc->fn (NULL, this, friends);
                }
        }
unlock:
        rcu_read_unlock ();

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

out:
        if (friends)
                dict_unref (friends);

        return ret;
}


static int
glusterd_ac_none (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_error (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_ERROR, "Received event %d ", event->event);

        return ret;
}

static int
glusterd_ac_reverse_probe_begin (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_probe_ctx_t            *new_ev_ctx = NULL;

        GF_ASSERT (event);
        GF_ASSERT (ctx);

        rcu_read_lock ();

        peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!peerinfo) {
                gf_log (THIS->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                ret = -1;
                goto out;
        }

        ret = glusterd_friend_sm_new_event
                (GD_FRIEND_EVENT_PROBE, &new_event);

        if (ret) {
                gf_log ("glusterd", GF_LOG_ERROR, "Unable to get new new_event");
                ret = -1;
                goto out;
        }

        new_ev_ctx = GF_CALLOC (1, sizeof(*new_ev_ctx), gf_gld_mt_probe_ctx_t);

        if (!new_ev_ctx) {
                ret = -1;
                goto out;
        }

        new_ev_ctx->hostname = gf_strdup (peerinfo->hostname);
        new_ev_ctx->port = peerinfo->port;
        new_ev_ctx->req = NULL;

        new_event->peername = gf_strdup (peerinfo->hostname);
        uuid_copy (new_event->peerid, peerinfo->uuid);
        new_event->ctx = new_ev_ctx;

        ret = glusterd_friend_sm_inject_event (new_event);

        if (ret) {
                gf_log ("glusterd", GF_LOG_ERROR, "Unable to inject new_event %d, "
                                "ret = %d", new_event->event, ret);
        }

out:
        rcu_read_unlock ();

        if (ret) {
                if (new_event)
                        GF_FREE (new_event->peername);
                GF_FREE (new_event);
                if (new_ev_ctx)
                        GF_FREE (new_ev_ctx->hostname);
                GF_FREE (new_ev_ctx);
        }
        gf_log ("", GF_LOG_DEBUG, "returning with %d", ret);
        return ret;
}

static int
glusterd_ac_friend_add (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                     ret = 0;
        glusterd_peerinfo_t     *peerinfo = NULL;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;

        GF_ASSERT (event);

        this = THIS;
        conf = this->private;

        GF_ASSERT (conf);

        rcu_read_lock ();

        peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!peerinfo) {
                gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                goto out;
        }

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_ADD];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = ctx;
                ret = proc->fn (frame, this, event);
        }

out:
        rcu_read_unlock ();

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
        return ret;
}

static int
glusterd_ac_friend_probe (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                     ret = -1;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;
        glusterd_probe_ctx_t    *probe_ctx = NULL;
        glusterd_peerinfo_t     *peerinfo = NULL;
        dict_t                  *dict = NULL;

        GF_ASSERT (ctx);

        probe_ctx = ctx;

        this = THIS;

        GF_ASSERT (this);

        conf = this->private;

        GF_ASSERT (conf);

        rcu_read_lock ();
        peerinfo = glusterd_peerinfo_find (NULL, probe_ctx->hostname);
        if (peerinfo == NULL) {
                //We should not reach this state ideally
                ret = -1;
                goto out;
        }

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_PROBE_QUERY];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = ctx;
                dict = dict_new ();
                if (!dict)
                        goto out;
                ret = dict_set_str (dict, "hostname", probe_ctx->hostname);
                if (ret)
                        goto out;

                ret = dict_set_int32 (dict, "port", probe_ctx->port);
                if (ret)
                        goto out;

                /* The peerinfo reference being set here is going to be used
                 * only within this critical section, in glusterd_rpc_probe
                 * (ie. proc->fn).
                 */
                ret = dict_set_static_ptr (dict, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto out;
                }

                ret = proc->fn (frame, this, dict);
                if (ret)
                        goto out;

        }

out:
        rcu_read_unlock ();

        if (dict)
                dict_unref (dict);
        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_send_friend_remove_req (glusterd_friend_sm_event_t *event,
                                    void *data)
{
        int                     ret = 0;
        glusterd_peerinfo_t     *peerinfo = NULL;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;
        glusterd_friend_sm_event_type_t event_type = GD_FRIEND_EVENT_NONE;
        glusterd_probe_ctx_t            *ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;

        GF_ASSERT (event);

        this = THIS;
        conf = this->private;

        GF_ASSERT (conf);

        rcu_read_lock ();

        peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!peerinfo) {
                gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                goto out;
        }
        ctx = event->ctx;

        if (!peerinfo->connected) {
                event_type = GD_FRIEND_EVENT_REMOVE_FRIEND;

                ret = glusterd_friend_sm_new_event (event_type, &new_event);

                if (!ret) {
                        new_event->peername = peerinfo->hostname;
                        uuid_copy (new_event->peerid, peerinfo->uuid);
                        ret = glusterd_friend_sm_inject_event (new_event);
                } else {
                        gf_log ("glusterd", GF_LOG_ERROR,
                                 "Unable to get event");
                }

                if (ctx) {
                        ret = glusterd_xfer_cli_deprobe_resp (ctx->req, ret, 0,
                                                              NULL,
                                                              ctx->hostname,
                                                              ctx->dict);
                        glusterd_broadcast_friend_delete (ctx->hostname, NULL);
                        glusterd_destroy_probe_ctx (ctx);
                }
                goto out;
        }

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_REMOVE];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = data;
                ret = proc->fn (frame, this, event);
        }

out:
        rcu_read_unlock ();

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static gf_boolean_t
glusterd_should_update_peer (glusterd_peerinfo_t *peerinfo,
                             glusterd_peerinfo_t *cur_peerinfo)
{
        gf_boolean_t is_valid = _gf_false;

        if ((peerinfo == cur_peerinfo) ||
            (peerinfo->state.state == GD_FRIEND_STATE_BEFRIENDED))
                is_valid = _gf_true;

        return is_valid;
}

static int
glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                           ret               = 0;
        glusterd_peerinfo_t          *cur_peerinfo      = NULL;
        glusterd_peerinfo_t          *peerinfo          = NULL;
        rpc_clnt_procedure_t         *proc              = NULL;
        xlator_t                     *this              = NULL;
        glusterd_friend_update_ctx_t  ev_ctx            = {{0}};
        glusterd_conf_t              *priv              = NULL;
        dict_t                       *friends           = NULL;
        char                          key[100]          = {0,};
        int32_t                       count             = 0;

        GF_ASSERT (event);

        this = THIS;
        priv = this->private;

        GF_ASSERT (priv);

        rcu_read_lock ();

        cur_peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!cur_peerinfo) {
                gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                ret = -1;
                goto out;
        }

        ev_ctx.op = GD_FRIEND_UPDATE_ADD;

        friends = dict_new ();
        if (!friends)
                goto out;

        snprintf (key, sizeof (key), "op");
        ret = dict_set_int32 (friends, key, ev_ctx.op);
        if (ret)
                goto out;

        cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
                if (!glusterd_should_update_peer (peerinfo, cur_peerinfo))
                        continue;

                count++;

                memset (key, 0, sizeof (key));
                snprintf (key, sizeof (key), "friend%d", count);
                ret = gd_add_friend_to_dict (peerinfo, friends, key);
                if (ret)
                        goto out;
        }

        ret = dict_set_int32 (friends, "count", count);
        if (ret)
                goto out;

        cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {
                if (!peerinfo->connected || !peerinfo->peer)
                        continue;

                if (!glusterd_should_update_peer (peerinfo, cur_peerinfo))
                        continue;

                ret = dict_set_static_ptr (friends, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto out;
                }

                proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_UPDATE];
                if (proc->fn) {
                        ret = proc->fn (NULL, this, friends);
                }
        }

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

out:
        rcu_read_unlock ();

        if (friends)
                dict_unref (friends);

        return ret;
}

/* Clean up stale volumes on the peer being detached. The volumes which have
 * bricks on other peers are stale with respect to the detached peer.
 */
static int
glusterd_peer_detach_cleanup (glusterd_conf_t *priv)
{
        int                     ret = -1;
        glusterd_volinfo_t      *volinfo = NULL;
        glusterd_volinfo_t      *tmp_volinfo = NULL;

        GF_ASSERT (priv);

        cds_list_for_each_entry_safe (volinfo, tmp_volinfo, &priv->volumes,
                                      vol_list) {
                /* The peer detach checks make sure that, at this point in the
                 * detach process, there are only volumes contained completely
                 * within or completely outside the detached peer.
                 * The only stale volumes at this point are the ones
                 * completely outside the peer and can be safely deleted.
                 */
                if (!glusterd_friend_contains_vol_bricks (volinfo,
                                                          MY_UUID)) {
                        gf_log (THIS->name, GF_LOG_INFO,
                                "Deleting stale volume %s", volinfo->volname);
                        ret = glusterd_delete_volume (volinfo);
                        if (ret) {
                                gf_log (THIS->name, GF_LOG_ERROR,
                                        "Error deleting stale volume");
                                goto out;
                        }
                }
        }
        ret = 0;
out:
        gf_log (THIS->name, GF_LOG_DEBUG, "Returning %d", ret);
        return ret;
}

static int
glusterd_ac_handle_friend_remove_req (glusterd_friend_sm_event_t *event,
                                      void *ctx)
{
        int                             ret = 0;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_req_ctx_t       *ev_ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_conf_t                 *priv = NULL;

        GF_ASSERT (ctx);
        ev_ctx = ctx;

        priv = THIS->private;
        GF_ASSERT (priv);

        ret = glusterd_xfer_friend_remove_resp (ev_ctx->req, ev_ctx->hostname,
                                                ev_ctx->port);

        rcu_read_lock ();
        cds_list_for_each_entry_rcu (peerinfo, &priv->peers, uuid_list) {

                ret = glusterd_friend_sm_new_event (GD_FRIEND_EVENT_REMOVE_FRIEND,
                                                    &new_event);
                if (ret) {
                        rcu_read_unlock ();
                        goto out;
                }

                new_event->peername = gf_strdup (peerinfo->hostname);
                uuid_copy (new_event->peerid, peerinfo->uuid);

                ret = glusterd_friend_sm_inject_event (new_event);
                if (ret) {
                        rcu_read_unlock ();
                        goto out;
                }

                new_event = NULL;
        }
        rcu_read_unlock ();

        ret = glusterd_peer_detach_cleanup (priv);
        if (ret) {
                gf_log (THIS->name, GF_LOG_WARNING,
                        "Peer detach cleanup was not successful");
                ret = 0;
        }
out:
        if (new_event)
                GF_FREE (new_event->peername);
        GF_FREE (new_event);

        gf_log (THIS->name, GF_LOG_DEBUG, "Returning with %d", ret);
        return ret;
}

static int
glusterd_ac_friend_remove (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                  ret = -1;
        glusterd_peerinfo_t *peerinfo = NULL;

        GF_ASSERT (event);

        rcu_read_lock ();

        peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!peerinfo) {
                gf_log (THIS->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                rcu_read_unlock ();
                goto out;
        }
        ret = glusterd_friend_remove_cleanup_vols (peerinfo->uuid);
        if (ret)
                gf_msg (THIS->name, GF_LOG_WARNING, 0, GD_MSG_VOL_CLEANUP_FAIL,
                        "Volumes cleanup failed");

        rcu_read_unlock ();
        /* Exiting read critical section as glusterd_peerinfo_cleanup calls
         * synchronize_rcu before freeing the peerinfo
         */

        ret = glusterd_peerinfo_cleanup (peerinfo);
        if (ret) {
                gf_log (THIS->name, GF_LOG_ERROR, "Cleanup returned: %d", ret);
        }
out:
        return 0;
}

/*static int
glusterd_ac_none (void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}*/

static int
glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                             ret = 0;
        uuid_t                          uuid;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_req_ctx_t       *ev_ctx = NULL;
        glusterd_friend_update_ctx_t    *new_ev_ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_friend_sm_event_type_t event_type = GD_FRIEND_EVENT_NONE;
        glusterd_conf_t                *conf       = NULL;
        int                             status = 0;
        int32_t                         op_ret = -1;
        int32_t                         op_errno = 0;
        xlator_t                       *this       = NULL;

        this = THIS;
        GF_ASSERT (this);

        GF_ASSERT (ctx);
        ev_ctx = ctx;
        uuid_copy (uuid, ev_ctx->uuid);

        rcu_read_lock ();
        peerinfo = glusterd_peerinfo_find (event->peerid, event->peername);
        if (!peerinfo) {
                gf_log (this->name, GF_LOG_ERROR, "Could not find peer %s(%s)",
                        event->peername, uuid_utoa (event->peerid));
                ret = -1;
                rcu_read_unlock ();
                goto out;
        }

        /* TODO: How do you do an atomic copy of uuid_t */
        /* TODO: Updating within a read-critical section is also invalid
         *       Update properly with updater synchronization
         */
        uuid_copy (peerinfo->uuid, ev_ctx->uuid);

        rcu_read_unlock ();

        conf = this->private;
        GF_ASSERT (conf);

        /* Passing the peername from the event. glusterd_compare_friend_data
         * updates volumes and will use synchronize_rcu. If we were to pass
         * peerinfo->hostname, we would have to do it under a read critical
         * section which would lead to a deadlock
         */

        //Build comparison logic here.
        ret = glusterd_compare_friend_data (ev_ctx->vols, &status,
                                            event->peername);
        if (ret)
                goto out;

        if (GLUSTERD_VOL_COMP_RJT != status) {
                event_type = GD_FRIEND_EVENT_LOCAL_ACC;
                op_ret = 0;
        } else {
                event_type = GD_FRIEND_EVENT_LOCAL_RJT;
                op_errno = GF_PROBE_VOLUME_CONFLICT;
                op_ret = -1;
        }

        /* Compare missed_snapshot list with the peer *
         * if volume comparison is successful */
        if ((op_ret == 0) &&
            (conf->op_version >= GD_OP_VERSION_3_6_0)) {
                ret = glusterd_import_friend_missed_snap_list (ev_ctx->vols);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Failed to import peer's "
                                "missed_snaps_list.");
                        event_type = GD_FRIEND_EVENT_LOCAL_RJT;
                        op_errno = GF_PROBE_MISSED_SNAP_CONFLICT;
                        op_ret = -1;
                }

                /* glusterd_compare_friend_snapshots and functions only require
                 * a peers hostname and uuid. It also does updates, which
                 * require use of synchronize_rcu. So we pass the hostname and
                 * id from the event instead of the peerinfo object to prevent
                 * deadlocks as above.
                 */
                ret = glusterd_compare_friend_snapshots (ev_ctx->vols,
                                                         event->peername,
                                                         event->peerid);
                if (ret) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Conflict in comparing peer's snapshots");
                        event_type = GD_FRIEND_EVENT_LOCAL_RJT;
                        op_errno = GF_PROBE_SNAP_CONFLICT;
                        op_ret = -1;
                }
        }

        ret = glusterd_friend_sm_new_event (event_type, &new_event);

        if (ret) {
                gf_log ("", GF_LOG_ERROR, "Out of Memory");
        }

        new_event->peername = gf_strdup (event->peername);
        uuid_copy (new_event->peerid, event->peerid);

        new_ev_ctx = GF_CALLOC (1, sizeof (*new_ev_ctx),
                                gf_gld_mt_friend_update_ctx_t);
        if (!new_ev_ctx) {
                ret = -1;
                goto out;
        }

        uuid_copy (new_ev_ctx->uuid, ev_ctx->uuid);
        new_ev_ctx->hostname = gf_strdup (ev_ctx->hostname);
        new_ev_ctx->op = GD_FRIEND_UPDATE_ADD;

        new_event->ctx = new_ev_ctx;

        glusterd_friend_sm_inject_event (new_event);
        new_event = NULL;

        ret = glusterd_xfer_friend_add_resp (ev_ctx->req, ev_ctx->hostname,
                                             event->peername, ev_ctx->port,
                                             op_ret, op_errno);

out:
        if (new_event)
                GF_FREE (new_event->peername);
        GF_FREE (new_event);

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
        return ret;
}

static int
glusterd_friend_sm_transition_state (uuid_t peerid, char *peername,
                                     glusterd_sm_t *state,
                                     glusterd_friend_sm_event_type_t event_type)
{
        int ret = -1;
        glusterd_peerinfo_t *peerinfo = NULL;

        GF_ASSERT (state);
        GF_ASSERT (peername);

        rcu_read_lock ();
        peerinfo = glusterd_peerinfo_find (peerid, peername);
        if (!peerinfo) {
                goto out;
        }

        (void) glusterd_sm_tr_log_transition_add (&peerinfo->sm_log,
                                           peerinfo->state.state,
                                           state[event_type].next_state,
                                           event_type);

        uatomic_set (&peerinfo->state.state, state[event_type].next_state);

        ret = 0;
out:
        rcu_read_unlock ();
        return ret;
}


glusterd_sm_t glusterd_state_default [] = {
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none},
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_probe},//EV_PROBE
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_friend_add}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_probe}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_probe_rcvd [] = {
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none},
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EV_PROBE
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_connected_rcvd [] = {
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none},
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EV_PROBE
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_reverse_probe_begin}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_connected_accepted [] = {
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none},
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_friend_probe}, //EV_PROBE
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_friend_add}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_sent [] = {
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_rcvd [] = {
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_befriended [] = {
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_friend_add},//EVENT_CONNECTED
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_sent_rcvd [] = {
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_rejected [] = {
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_friend_probe}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_friend_add}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_friend_add},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_accepted [] = {
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_reverse_probe_begin},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_unfriend_sent [] = {
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_PROBE,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t *glusterd_friend_state_table [] = {
        glusterd_state_default,
        glusterd_state_req_sent,
        glusterd_state_req_rcvd,
        glusterd_state_befriended,
        glusterd_state_req_accepted,
        glusterd_state_req_sent_rcvd,
        glusterd_state_rejected,
        glusterd_state_unfriend_sent,
        glusterd_state_probe_rcvd,
        glusterd_state_connected_rcvd,
        glusterd_state_connected_accepted
};

int
glusterd_friend_sm_new_event (glusterd_friend_sm_event_type_t event_type,
                              glusterd_friend_sm_event_t **new_event)
{
        glusterd_friend_sm_event_t      *event = NULL;

        GF_ASSERT (new_event);
        GF_ASSERT (GD_FRIEND_EVENT_NONE <= event_type &&
                        GD_FRIEND_EVENT_MAX > event_type);

        event = GF_CALLOC (1, sizeof (*event), gf_gld_mt_friend_sm_event_t);

        if (!event)
                return -1;

        *new_event = event;
        event->event = event_type;
        CDS_INIT_LIST_HEAD (&event->list);

        return 0;
}

int
glusterd_friend_sm_inject_event (glusterd_friend_sm_event_t *event)
{
        GF_ASSERT (event);
        gf_log ("glusterd", GF_LOG_DEBUG, "Enqueue event: '%s'",
                glusterd_friend_sm_event_name_get (event->event));
        cds_list_add_tail (&event->list, &gd_friend_sm_queue);

        return 0;
}

void
glusterd_destroy_friend_event_context (glusterd_friend_sm_event_t *event)
{
        if (!event)
                return;

        switch (event->event) {
        case GD_FRIEND_EVENT_RCVD_FRIEND_REQ:
        case GD_FRIEND_EVENT_RCVD_REMOVE_FRIEND:
                glusterd_destroy_friend_req_ctx (event->ctx);
                break;
        case GD_FRIEND_EVENT_LOCAL_ACC:
        case GD_FRIEND_EVENT_LOCAL_RJT:
        case GD_FRIEND_EVENT_RCVD_ACC:
        case GD_FRIEND_EVENT_RCVD_RJT:
                glusterd_destroy_friend_update_ctx (event->ctx);
                break;
        default:
                break;
        }
}

gf_boolean_t
gd_does_peer_affect_quorum (glusterd_friend_sm_state_t old_state,
                            glusterd_friend_sm_event_type_t event_type,
                            glusterd_peerinfo_t *peerinfo)
{
        gf_boolean_t    affects = _gf_false;

        //When glusterd comes up with friends in BEFRIENDED state in store,
        //wait until compare-data happens.
        if ((old_state == GD_FRIEND_STATE_BEFRIENDED) &&
            (event_type != GD_FRIEND_EVENT_RCVD_ACC) &&
            (event_type != GD_FRIEND_EVENT_LOCAL_ACC))
                goto out;
        if ((peerinfo->state.state == GD_FRIEND_STATE_BEFRIENDED)
            && peerinfo->connected) {
                affects = _gf_true;
        }
out:
        return affects;
}

int
glusterd_friend_sm ()
{
        glusterd_friend_sm_event_t      *event      = NULL;
        glusterd_friend_sm_event_t      *tmp        = NULL;
        int                              ret        = -1;
        glusterd_friend_sm_ac_fn         handler    = NULL;
        glusterd_sm_t                   *state      = NULL;
        glusterd_peerinfo_t             *peerinfo   = NULL;
        glusterd_friend_sm_event_type_t  event_type = 0;
        gf_boolean_t                     is_await_conn = _gf_false;
        gf_boolean_t                     quorum_action = _gf_false;
        glusterd_friend_sm_state_t       old_state = GD_FRIEND_STATE_DEFAULT;
        xlator_t                        *this = NULL;
        glusterd_conf_t                 *priv = NULL;

        this = THIS;
        GF_ASSERT (this);
        priv = this->private;
        GF_ASSERT (priv);

        while (!cds_list_empty (&gd_friend_sm_queue)) {
                cds_list_for_each_entry_safe (event, tmp, &gd_friend_sm_queue,
                                              list) {

                        cds_list_del_init (&event->list);
                        event_type = event->event;

                        rcu_read_lock ();

                        peerinfo = glusterd_peerinfo_find (event->peerid,
                                                           event->peername);
                        if (!peerinfo) {
                                gf_log ("glusterd", GF_LOG_CRITICAL, "Received"
                                        " event %s with empty peer info",
                                glusterd_friend_sm_event_name_get (event_type));

                                GF_FREE (event);
                                rcu_read_unlock ();
                                continue;
                        }
                        gf_log ("", GF_LOG_DEBUG, "Dequeued event of type: '%s'",
                                glusterd_friend_sm_event_name_get (event_type));


                        old_state = peerinfo->state.state;

                        rcu_read_unlock ();
                        /* Giving up read-critical section here as we only need
                         * the current state to call the handler.
                         *
                         * We cannot continue into the handler in a read
                         * critical section as there are handlers who do
                         * updates, and could cause deadlocks.
                         */

                        state = glusterd_friend_state_table[old_state];

                        GF_ASSERT (state);

                        handler = state[event_type].handler;
                        GF_ASSERT (handler);

                        ret = handler (event, event->ctx);
                        if (ret == GLUSTERD_CONNECTION_AWAITED) {
                                is_await_conn = _gf_true;
                                ret = 0;
                        }

                        if (ret) {
                                gf_log ("glusterd", GF_LOG_ERROR, "handler returned: "
                                                "%d", ret);
                                glusterd_destroy_friend_event_context (event);
                                GF_FREE (event);
                                continue;
                        }

                        if ((GD_FRIEND_EVENT_REMOVE_FRIEND == event_type) ||
                           (GD_FRIEND_EVENT_INIT_REMOVE_FRIEND == event_type)){
                                glusterd_destroy_friend_event_context (event);
                                GF_FREE (event);
                                continue;
                        }

                        ret = glusterd_friend_sm_transition_state
                                (event->peerid, event->peername, state,
                                 event_type);

                        if (ret) {
                                gf_log ("glusterd", GF_LOG_ERROR, "Unable to transition"
                                        " state from '%s' to '%s' for event '%s'",
                        glusterd_friend_sm_state_name_get(old_state),
                        glusterd_friend_sm_state_name_get(state[event_type].next_state),
                                glusterd_friend_sm_event_name_get(event_type));
                                goto out;
                        }

                        peerinfo = NULL;
                        /* We need to obtain peerinfo reference once again as we
                         * had exited the read critical section above.
                         */
                        rcu_read_lock ();
                        peerinfo = glusterd_peerinfo_find (event->peerid,
                                        event->peername);
                        if (!peerinfo) {
                                rcu_read_unlock ();
                                /* A peer can only be deleted as a effect of
                                 * this state machine, and two such state
                                 * machines can never run at the same time.
                                 * So if we cannot find the peerinfo here,
                                 * something has gone terribly wrong.
                                 */
                                ret = -1;
                                gf_log ("glusterd", GF_LOG_ERROR,
                                        "Cannot find peer %s(%s)",
                                        event->peername, uuid_utoa (event->peerid));
                                goto out;
                        }
                        if (gd_does_peer_affect_quorum (old_state, event_type,
                                                        peerinfo)) {
                                peerinfo->quorum_contrib = QUORUM_UP;
                                if (peerinfo->quorum_action) {
                                        peerinfo->quorum_action = _gf_false;
                                        quorum_action = _gf_true;
                                }
                        }

                        ret = glusterd_store_peerinfo (peerinfo);
                        rcu_read_unlock ();

                        glusterd_destroy_friend_event_context (event);
                        GF_FREE (event);
                        if (is_await_conn)
                                break;
                }
                if (is_await_conn)
                        break;
        }

        ret = 0;
out:
        if (quorum_action) {
            /* When glusterd is restarted, it needs to wait until the 'friends' view
             * of the volumes settle, before it starts any of the internal daemons.
             *
             * Every friend that was part of the cluster, would send its
             * cluster-view, 'our' way. For every friend, who belongs to
             * a partition which has a different cluster-view from our
             * partition, we may update our cluster-view. For subsequent
             * friends from that partition would agree with us, if the first
             * friend wasn't rejected. For every first friend, whom we agreed with,
             * we would need to start internal daemons/bricks belonging to the
             * new volumes.
             * glusterd_spawn_daemons calls functions that are idempotent. ie,
             * the functions spawn process(es) only if they are not started yet.
             *
             * */
                synclock_unlock (&priv->big_lock);
                glusterd_launch_synctask (glusterd_spawn_daemons, NULL);
                synclock_lock (&priv->big_lock);
                glusterd_do_quorum_action ();
        }
        return ret;
}


int
glusterd_friend_sm_init ()
{
        CDS_INIT_LIST_HEAD (&gd_friend_sm_queue);
        return 0;
}