aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ceph/osd_client.c
blob: 92b7251a53f1415275ba8fd0a2d09f3b0cac6010 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
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
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
#include "ceph_debug.h"

#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include "super.h"
#include "osd_client.h"
#include "messenger.h"
#include "decode.h"
#include "auth.h"

#define OSD_OP_FRONT_LEN	4096
#define OSD_OPREPLY_FRONT_LEN	512

static const struct ceph_connection_operations osd_con_ops;
static int __kick_requests(struct ceph_osd_client *osdc,
			  struct ceph_osd *kickosd);

static void kick_requests(struct ceph_osd_client *osdc, struct ceph_osd *osd);

/*
 * Implement client access to distributed object storage cluster.
 *
 * All data objects are stored within a cluster/cloud of OSDs, or
 * "object storage devices."  (Note that Ceph OSDs have _nothing_ to
 * do with the T10 OSD extensions to SCSI.)  Ceph OSDs are simply
 * remote daemons serving up and coordinating consistent and safe
 * access to storage.
 *
 * Cluster membership and the mapping of data objects onto storage devices
 * are described by the osd map.
 *
 * We keep track of pending OSD requests (read, write), resubmit
 * requests to different OSDs when the cluster topology/data layout
 * change, or retry the affected requests when the communications
 * channel with an OSD is reset.
 */

/*
 * calculate the mapping of a file extent onto an object, and fill out the
 * request accordingly.  shorten extent as necessary if it crosses an
 * object boundary.
 *
 * fill osd op in request message.
 */
static void calc_layout(struct ceph_osd_client *osdc,
			struct ceph_vino vino, struct ceph_file_layout *layout,
			u64 off, u64 *plen,
			struct ceph_osd_request *req)
{
	struct ceph_osd_request_head *reqhead = req->r_request->front.iov_base;
	struct ceph_osd_op *op = (void *)(reqhead + 1);
	u64 orig_len = *plen;
	u64 objoff, objlen;    /* extent in object */
	u64 bno;

	reqhead->snapid = cpu_to_le64(vino.snap);

	/* object extent? */
	ceph_calc_file_object_mapping(layout, off, plen, &bno,
				      &objoff, &objlen);
	if (*plen < orig_len)
		dout(" skipping last %llu, final file extent %llu~%llu\n",
		     orig_len - *plen, off, *plen);

	sprintf(req->r_oid, "%llx.%08llx", vino.ino, bno);
	req->r_oid_len = strlen(req->r_oid);

	op->extent.offset = cpu_to_le64(objoff);
	op->extent.length = cpu_to_le64(objlen);
	req->r_num_pages = calc_pages_for(off, *plen);

	dout("calc_layout %s (%d) %llu~%llu (%d pages)\n",
	     req->r_oid, req->r_oid_len, objoff, objlen, req->r_num_pages);
}

/*
 * requests
 */
void ceph_osdc_release_request(struct kref *kref)
{
	struct ceph_osd_request *req = container_of(kref,
						    struct ceph_osd_request,
						    r_kref);

	if (req->r_request)
		ceph_msg_put(req->r_request);
	if (req->r_reply)
		ceph_msg_put(req->r_reply);
	if (req->r_con_filling_msg) {
		dout("release_request revoking pages %p from con %p\n",
		     req->r_pages, req->r_con_filling_msg);
		ceph_con_revoke_message(req->r_con_filling_msg,
				      req->r_reply);
		ceph_con_put(req->r_con_filling_msg);
	}
	if (req->r_own_pages)
		ceph_release_page_vector(req->r_pages,
					 req->r_num_pages);
	ceph_put_snap_context(req->r_snapc);
	if (req->r_mempool)
		mempool_free(req, req->r_osdc->req_mempool);
	else
		kfree(req);
}

/*
 * build new request AND message, calculate layout, and adjust file
 * extent as needed.
 *
 * if the file was recently truncated, we include information about its
 * old and new size so that the object can be updated appropriately.  (we
 * avoid synchronously deleting truncated objects because it's slow.)
 *
 * if @do_sync, include a 'startsync' command so that the osd will flush
 * data quickly.
 */
struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
					       struct ceph_file_layout *layout,
					       struct ceph_vino vino,
					       u64 off, u64 *plen,
					       int opcode, int flags,
					       struct ceph_snap_context *snapc,
					       int do_sync,
					       u32 truncate_seq,
					       u64 truncate_size,
					       struct timespec *mtime,
					       bool use_mempool, int num_reply)
{
	struct ceph_osd_request *req;
	struct ceph_msg *msg;
	struct ceph_osd_request_head *head;
	struct ceph_osd_op *op;
	void *p;
	int num_op = 1 + do_sync;
	size_t msg_size = sizeof(*head) + num_op*sizeof(*op);
	int i;

	if (use_mempool) {
		req = mempool_alloc(osdc->req_mempool, GFP_NOFS);
		memset(req, 0, sizeof(*req));
	} else {
		req = kzalloc(sizeof(*req), GFP_NOFS);
	}
	if (req == NULL)
		return NULL;

	req->r_osdc = osdc;
	req->r_mempool = use_mempool;
	kref_init(&req->r_kref);
	init_completion(&req->r_completion);
	init_completion(&req->r_safe_completion);
	INIT_LIST_HEAD(&req->r_unsafe_item);
	req->r_flags = flags;

	WARN_ON((flags & (CEPH_OSD_FLAG_READ|CEPH_OSD_FLAG_WRITE)) == 0);

	/* create reply message */
	if (use_mempool)
		msg = ceph_msgpool_get(&osdc->msgpool_op_reply, 0);
	else
		msg = ceph_msg_new(CEPH_MSG_OSD_OPREPLY,
				   OSD_OPREPLY_FRONT_LEN, GFP_NOFS);
	if (!msg) {
		ceph_osdc_put_request(req);
		return NULL;
	}
	req->r_reply = msg;

	/* create request message; allow space for oid */
	msg_size += 40;
	if (snapc)
		msg_size += sizeof(u64) * snapc->num_snaps;
	if (use_mempool)
		msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
	else
		msg = ceph_msg_new(CEPH_MSG_OSD_OP, msg_size, GFP_NOFS);
	if (!msg) {
		ceph_osdc_put_request(req);
		return NULL;
	}
	msg->hdr.type = cpu_to_le16(CEPH_MSG_OSD_OP);
	memset(msg->front.iov_base, 0, msg->front.iov_len);
	head = msg->front.iov_base;
	op = (void *)(head + 1);
	p = (void *)(op + num_op);

	req->r_request = msg;
	req->r_snapc = ceph_get_snap_context(snapc);

	head->client_inc = cpu_to_le32(1); /* always, for now. */
	head->flags = cpu_to_le32(flags);
	if (flags & CEPH_OSD_FLAG_WRITE)
		ceph_encode_timespec(&head->mtime, mtime);
	head->num_ops = cpu_to_le16(num_op);
	op->op = cpu_to_le16(opcode);

	/* calculate max write size */
	calc_layout(osdc, vino, layout, off, plen, req);
	req->r_file_layout = *layout;  /* keep a copy */

	if (flags & CEPH_OSD_FLAG_WRITE) {
		req->r_request->hdr.data_off = cpu_to_le16(off);
		req->r_request->hdr.data_len = cpu_to_le32(*plen);
		op->payload_len = cpu_to_le32(*plen);
	}
	op->extent.truncate_size = cpu_to_le64(truncate_size);
	op->extent.truncate_seq = cpu_to_le32(truncate_seq);

	/* fill in oid */
	head->object_len = cpu_to_le32(req->r_oid_len);
	memcpy(p, req->r_oid, req->r_oid_len);
	p += req->r_oid_len;

	if (do_sync) {
		op++;
		op->op = cpu_to_le16(CEPH_OSD_OP_STARTSYNC);
	}
	if (snapc) {
		head->snap_seq = cpu_to_le64(snapc->seq);
		head->num_snaps = cpu_to_le32(snapc->num_snaps);
		for (i = 0; i < snapc->num_snaps; i++) {
			put_unaligned_le64(snapc->snaps[i], p);
			p += sizeof(u64);
		}
	}

	BUG_ON(p > msg->front.iov_base + msg->front.iov_len);
	msg_size = p - msg->front.iov_base;
	msg->front.iov_len = msg_size;
	msg->hdr.front_len = cpu_to_le32(msg_size);
	return req;
}

/*
 * We keep osd requests in an rbtree, sorted by ->r_tid.
 */
static void __insert_request(struct ceph_osd_client *osdc,
			     struct ceph_osd_request *new)
{
	struct rb_node **p = &osdc->requests.rb_node;
	struct rb_node *parent = NULL;
	struct ceph_osd_request *req = NULL;

	while (*p) {
		parent = *p;
		req = rb_entry(parent, struct ceph_osd_request, r_node);
		if (new->r_tid < req->r_tid)
			p = &(*p)->rb_left;
		else if (new->r_tid > req->r_tid)
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&new->r_node, parent, p);
	rb_insert_color(&new->r_node, &osdc->requests);
}

static struct ceph_osd_request *__lookup_request(struct ceph_osd_client *osdc,
						 u64 tid)
{
	struct ceph_osd_request *req;
	struct rb_node *n = osdc->requests.rb_node;

	while (n) {
		req = rb_entry(n, struct ceph_osd_request, r_node);
		if (tid < req->r_tid)
			n = n->rb_left;
		else if (tid > req->r_tid)
			n = n->rb_right;
		else
			return req;
	}
	return NULL;
}

static struct ceph_osd_request *
__lookup_request_ge(struct ceph_osd_client *osdc,
		    u64 tid)
{
	struct ceph_osd_request *req;
	struct rb_node *n = osdc->requests.rb_node;

	while (n) {
		req = rb_entry(n, struct ceph_osd_request, r_node);
		if (tid < req->r_tid) {
			if (!n->rb_left)
				return req;
			n = n->rb_left;
		} else if (tid > req->r_tid) {
			n = n->rb_right;
		} else {
			return req;
		}
	}
	return NULL;
}


/*
 * If the osd connection drops, we need to resubmit all requests.
 */
static void osd_reset(struct ceph_connection *con)
{
	struct ceph_osd *osd = con->private;
	struct ceph_osd_client *osdc;

	if (!osd)
		return;
	dout("osd_reset osd%d\n", osd->o_osd);
	osdc = osd->o_osdc;
	down_read(&osdc->map_sem);
	kick_requests(osdc, osd);
	up_read(&osdc->map_sem);
}

/*
 * Track open sessions with osds.
 */
static struct ceph_osd *create_osd(struct ceph_osd_client *osdc)
{
	struct ceph_osd *osd;

	osd = kzalloc(sizeof(*osd), GFP_NOFS);
	if (!osd)
		return NULL;

	atomic_set(&osd->o_ref, 1);
	osd->o_osdc = osdc;
	INIT_LIST_HEAD(&osd->o_requests);
	INIT_LIST_HEAD(&osd->o_osd_lru);
	osd->o_incarnation = 1;

	ceph_con_init(osdc->client->msgr, &osd->o_con);
	osd->o_con.private = osd;
	osd->o_con.ops = &osd_con_ops;
	osd->o_con.peer_name.type = CEPH_ENTITY_TYPE_OSD;

	INIT_LIST_HEAD(&osd->o_keepalive_item);
	return osd;
}

static struct ceph_osd *get_osd(struct ceph_osd *osd)
{
	if (atomic_inc_not_zero(&osd->o_ref)) {
		dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1,
		     atomic_read(&osd->o_ref));
		return osd;
	} else {
		dout("get_osd %p FAIL\n", osd);
		return NULL;
	}
}

static void put_osd(struct ceph_osd *osd)
{
	dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),
	     atomic_read(&osd->o_ref) - 1);
	if (atomic_dec_and_test(&osd->o_ref)) {
		struct ceph_auth_client *ac = osd->o_osdc->client->monc.auth;

		if (osd->o_authorizer)
			ac->ops->destroy_authorizer(ac, osd->o_authorizer);
		kfree(osd);
	}
}

/*
 * remove an osd from our map
 */
static void __remove_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
{
	dout("__remove_osd %p\n", osd);
	BUG_ON(!list_empty(&osd->o_requests));
	rb_erase(&osd->o_node, &osdc->osds);
	list_del_init(&osd->o_osd_lru);
	ceph_con_close(&osd->o_con);
	put_osd(osd);
}

static void __move_osd_to_lru(struct ceph_osd_client *osdc,
			      struct ceph_osd *osd)
{
	dout("__move_osd_to_lru %p\n", osd);
	BUG_ON(!list_empty(&osd->o_osd_lru));
	list_add_tail(&osd->o_osd_lru, &osdc->osd_lru);
	osd->lru_ttl = jiffies + osdc->client->mount_args->osd_idle_ttl * HZ;
}

static void __remove_osd_from_lru(struct ceph_osd *osd)
{
	dout("__remove_osd_from_lru %p\n", osd);
	if (!list_empty(&osd->o_osd_lru))
		list_del_init(&osd->o_osd_lru);
}

static void remove_old_osds(struct ceph_osd_client *osdc, int remove_all)
{
	struct ceph_osd *osd, *nosd;

	dout("__remove_old_osds %p\n", osdc);
	mutex_lock(&osdc->request_mutex);
	list_for_each_entry_safe(osd, nosd, &osdc->osd_lru, o_osd_lru) {
		if (!remove_all && time_before(jiffies, osd->lru_ttl))
			break;
		__remove_osd(osdc, osd);
	}
	mutex_unlock(&osdc->request_mutex);
}

/*
 * reset osd connect
 */
static int __reset_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
{
	struct ceph_osd_request *req;
	int ret = 0;

	dout("__reset_osd %p osd%d\n", osd, osd->o_osd);
	if (list_empty(&osd->o_requests)) {
		__remove_osd(osdc, osd);
	} else if (memcmp(&osdc->osdmap->osd_addr[osd->o_osd],
			  &osd->o_con.peer_addr,
			  sizeof(osd->o_con.peer_addr)) == 0 &&
		   !ceph_con_opened(&osd->o_con)) {
		dout(" osd addr hasn't changed and connection never opened,"
		     " letting msgr retry");
		/* touch each r_stamp for handle_timeout()'s benfit */
		list_for_each_entry(req, &osd->o_requests, r_osd_item)
			req->r_stamp = jiffies;
		ret = -EAGAIN;
	} else {
		ceph_con_close(&osd->o_con);
		ceph_con_open(&osd->o_con, &osdc->osdmap->osd_addr[osd->o_osd]);
		osd->o_incarnation++;
	}
	return ret;
}

static void __insert_osd(struct ceph_osd_client *osdc, struct ceph_osd *new)
{
	struct rb_node **p = &osdc->osds.rb_node;
	struct rb_node *parent = NULL;
	struct ceph_osd *osd = NULL;

	while (*p) {
		parent = *p;
		osd = rb_entry(parent, struct ceph_osd, o_node);
		if (new->o_osd < osd->o_osd)
			p = &(*p)->rb_left;
		else if (new->o_osd > osd->o_osd)
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&new->o_node, parent, p);
	rb_insert_color(&new->o_node, &osdc->osds);
}

static struct ceph_osd *__lookup_osd(struct ceph_osd_client *osdc, int o)
{
	struct ceph_osd *osd;
	struct rb_node *n = osdc->osds.rb_node;

	while (n) {
		osd = rb_entry(n, struct ceph_osd, o_node);
		if (o < osd->o_osd)
			n = n->rb_left;
		else if (o > osd->o_osd)
			n = n->rb_right;
		else
			return osd;
	}
	return NULL;
}

static void __schedule_osd_timeout(struct ceph_osd_client *osdc)
{
	schedule_delayed_work(&osdc->timeout_work,
			osdc->client->mount_args->osd_keepalive_timeout * HZ);
}

static void __cancel_osd_timeout(struct ceph_osd_client *osdc)
{
	cancel_delayed_work(&osdc->timeout_work);
}

/*
 * Register request, assign tid.  If this is the first request, set up
 * the timeout event.
 */
static void register_request(struct ceph_osd_client *osdc,
			     struct ceph_osd_request *req)
{
	mutex_lock(&osdc->request_mutex);
	req->r_tid = ++osdc->last_tid;
	req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
	INIT_LIST_HEAD(&req->r_req_lru_item);

	dout("register_request %p tid %lld\n", req, req->r_tid);
	__insert_request(osdc, req);
	ceph_osdc_get_request(req);
	osdc->num_requests++;

	if (osdc->num_requests == 1) {
		dout(" first request, scheduling timeout\n");
		__schedule_osd_timeout(osdc);
	}
	mutex_unlock(&osdc->request_mutex);
}

/*
 * called under osdc->request_mutex
 */
static void __unregister_request(struct ceph_osd_client *osdc,
				 struct ceph_osd_request *req)
{
	dout("__unregister_request %p tid %lld\n", req, req->r_tid);
	rb_erase(&req->r_node, &osdc->requests);
	osdc->num_requests--;

	if (req->r_osd) {
		/* make sure the original request isn't in flight. */
		ceph_con_revoke(&req->r_osd->o_con, req->r_request);

		list_del_init(&req->r_osd_item);
		if (list_empty(&req->r_osd->o_requests))
			__move_osd_to_lru(osdc, req->r_osd);
		req->r_osd = NULL;
	}

	ceph_osdc_put_request(req);

	list_del_init(&req->r_req_lru_item);
	if (osdc->num_requests == 0) {
		dout(" no requests, canceling timeout\n");
		__cancel_osd_timeout(osdc);
	}
}

/*
 * Cancel a previously queued request message
 */
static void __cancel_request(struct ceph_osd_request *req)
{
	if (req->r_sent) {
		ceph_con_revoke(&req->r_osd->o_con, req->r_request);
		req->r_sent = 0;
	}
	list_del_init(&req->r_req_lru_item);
}

/*
 * Pick an osd (the first 'up' osd in the pg), allocate the osd struct
 * (as needed), and set the request r_osd appropriately.  If there is
 * no up osd, set r_osd to NULL.
 *
 * Return 0 if unchanged, 1 if changed, or negative on error.
 *
 * Caller should hold map_sem for read and request_mutex.
 */
static int __map_osds(struct ceph_osd_client *osdc,
		      struct ceph_osd_request *req)
{
	struct ceph_osd_request_head *reqhead = req->r_request->front.iov_base;
	struct ceph_pg pgid;
	int acting[CEPH_PG_MAX_SIZE];
	int o = -1, num = 0;
	int err;

	dout("map_osds %p tid %lld\n", req, req->r_tid);
	err = ceph_calc_object_layout(&reqhead->layout, req->r_oid,
				      &req->r_file_layout, osdc->osdmap);
	if (err)
		return err;
	pgid = reqhead->layout.ol_pgid;
	req->r_pgid = pgid;

	err = ceph_calc_pg_acting(osdc->osdmap, pgid, acting);
	if (err > 0) {
		o = acting[0];
		num = err;
	}

	if ((req->r_osd && req->r_osd->o_osd == o &&
	     req->r_sent >= req->r_osd->o_incarnation &&
	     req->r_num_pg_osds == num &&
	     memcmp(req->r_pg_osds, acting, sizeof(acting[0])*num) == 0) ||
	    (req->r_osd == NULL && o == -1))
		return 0;  /* no change */

	dout("map_osds tid %llu pgid %d.%x osd%d (was osd%d)\n",
	     req->r_tid, le32_to_cpu(pgid.pool), le16_to_cpu(pgid.ps), o,
	     req->r_osd ? req->r_osd->o_osd : -1);

	/* record full pg acting set */
	memcpy(req->r_pg_osds, acting, sizeof(acting[0]) * num);
	req->r_num_pg_osds = num;

	if (req->r_osd) {
		__cancel_request(req);
		list_del_init(&req->r_osd_item);
		req->r_osd = NULL;
	}

	req->r_osd = __lookup_osd(osdc, o);
	if (!req->r_osd && o >= 0) {
		err = -ENOMEM;
		req->r_osd = create_osd(osdc);
		if (!req->r_osd)
			goto out;

		dout("map_osds osd %p is osd%d\n", req->r_osd, o);
		req->r_osd->o_osd = o;
		req->r_osd->o_con.peer_name.num = cpu_to_le64(o);
		__insert_osd(osdc, req->r_osd);

		ceph_con_open(&req->r_osd->o_con, &osdc->osdmap->osd_addr[o]);
	}

	if (req->r_osd) {
		__remove_osd_from_lru(req->r_osd);
		list_add(&req->r_osd_item, &req->r_osd->o_requests);
	}
	err = 1;   /* osd or pg changed */

out:
	return err;
}

/*
 * caller should hold map_sem (for read) and request_mutex
 */
static int __send_request(struct ceph_osd_client *osdc,
			  struct ceph_osd_request *req)
{
	struct ceph_osd_request_head *reqhead;
	int err;

	err = __map_osds(osdc, req);
	if (err < 0)
		return err;
	if (req->r_osd == NULL) {
		dout("send_request %p no up osds in pg\n", req);
		ceph_monc_request_next_osdmap(&osdc->client->monc);
		return 0;
	}

	dout("send_request %p tid %llu to osd%d flags %d\n",
	     req, req->r_tid, req->r_osd->o_osd, req->r_flags);

	reqhead = req->r_request->front.iov_base;
	reqhead->osdmap_epoch = cpu_to_le32(osdc->osdmap->epoch);
	reqhead->flags |= cpu_to_le32(req->r_flags);  /* e.g., RETRY */
	reqhead->reassert_version = req->r_reassert_version;

	req->r_stamp = jiffies;
	list_move_tail(&osdc->req_lru, &req->r_req_lru_item);

	ceph_msg_get(req->r_request); /* send consumes a ref */
	ceph_con_send(&req->r_osd->o_con, req->r_request);
	req->r_sent = req->r_osd->o_incarnation;
	return 0;
}

/*
 * Timeout callback, called every N seconds when 1 or more osd
 * requests has been active for more than N seconds.  When this
 * happens, we ping all OSDs with requests who have timed out to
 * ensure any communications channel reset is detected.  Reset the
 * request timeouts another N seconds in the future as we go.
 * Reschedule the timeout event another N seconds in future (unless
 * there are no open requests).
 */
static void handle_timeout(struct work_struct *work)
{
	struct ceph_osd_client *osdc =
		container_of(work, struct ceph_osd_client, timeout_work.work);
	struct ceph_osd_request *req, *last_req = NULL;
	struct ceph_osd *osd;
	unsigned long timeout = osdc->client->mount_args->osd_timeout * HZ;
	unsigned long keepalive =
		osdc->client->mount_args->osd_keepalive_timeout * HZ;
	unsigned long last_stamp = 0;
	struct rb_node *p;
	struct list_head slow_osds;

	dout("timeout\n");
	down_read(&osdc->map_sem);

	ceph_monc_request_next_osdmap(&osdc->client->monc);

	mutex_lock(&osdc->request_mutex);
	for (p = rb_first(&osdc->requests); p; p = rb_next(p)) {
		req = rb_entry(p, struct ceph_osd_request, r_node);

		if (req->r_resend) {
			int err;

			dout("osdc resending prev failed %lld\n", req->r_tid);
			err = __send_request(osdc, req);
			if (err)
				dout("osdc failed again on %lld\n", req->r_tid);
			else
				req->r_resend = false;
			continue;
		}
	}

	/*
	 * reset osds that appear to be _really_ unresponsive.  this
	 * is a failsafe measure.. we really shouldn't be getting to
	 * this point if the system is working properly.  the monitors
	 * should mark the osd as failed and we should find out about
	 * it from an updated osd map.
	 */
	while (timeout && !list_empty(&osdc->req_lru)) {
		req = list_entry(osdc->req_lru.next, struct ceph_osd_request,
				 r_req_lru_item);

		if (time_before(jiffies, req->r_stamp + timeout))
			break;

		BUG_ON(req == last_req && req->r_stamp == last_stamp);
		last_req = req;
		last_stamp = req->r_stamp;

		osd = req->r_osd;
		BUG_ON(!osd);
		pr_warning(" tid %llu timed out on osd%d, will reset osd\n",
			   req->r_tid, osd->o_osd);
		__kick_requests(osdc, osd);
	}

	/*
	 * ping osds that are a bit slow.  this ensures that if there
	 * is a break in the TCP connection we will notice, and reopen
	 * a connection with that osd (from the fault callback).
	 */
	INIT_LIST_HEAD(&slow_osds);
	list_for_each_entry(req, &osdc->req_lru, r_req_lru_item) {
		if (time_before(jiffies, req->r_stamp + keepalive))
			break;

		osd = req->r_osd;
		BUG_ON(!osd);
		dout(" tid %llu is slow, will send keepalive on osd%d\n",
		     req->r_tid, osd->o_osd);
		list_move_tail(&osd->o_keepalive_item, &slow_osds);
	}
	while (!list_empty(&slow_osds)) {
		osd = list_entry(slow_osds.next, struct ceph_osd,
				 o_keepalive_item);
		list_del_init(&osd->o_keepalive_item);
		ceph_con_keepalive(&osd->o_con);
	}

	__schedule_osd_timeout(osdc);
	mutex_unlock(&osdc->request_mutex);

	up_read(&osdc->map_sem);
}

static void handle_osds_timeout(struct work_struct *work)
{
	struct ceph_osd_client *osdc =
		container_of(work, struct ceph_osd_client,
			     osds_timeout_work.work);
	unsigned long delay =
		osdc->client->mount_args->osd_idle_ttl * HZ >> 2;

	dout("osds timeout\n");
	down_read(&osdc->map_sem);
	remove_old_osds(osdc, 0);
	up_read(&osdc->map_sem);

	schedule_delayed_work(&osdc->osds_timeout_work,
			      round_jiffies_relative(delay));
}

/*
 * handle osd op reply.  either call the callback if it is specified,
 * or do the completion to wake up the waiting thread.
 */
static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
			 struct ceph_connection *con)
{
	struct ceph_osd_reply_head *rhead = msg->front.iov_base;
	struct ceph_osd_request *req;
	u64 tid;
	int numops, object_len, flags;
	s32 result;

	tid = le64_to_cpu(msg->hdr.tid);
	if (msg->front.iov_len < sizeof(*rhead))
		goto bad;
	numops = le32_to_cpu(rhead->num_ops);
	object_len = le32_to_cpu(rhead->object_len);
	result = le32_to_cpu(rhead->result);
	if (msg->front.iov_len != sizeof(*rhead) + object_len +
	    numops * sizeof(struct ceph_osd_op))
		goto bad;
	dout("handle_reply %p tid %llu result %d\n", msg, tid, (int)result);

	/* lookup */
	mutex_lock(&osdc->request_mutex);
	req = __lookup_request(osdc, tid);
	if (req == NULL) {
		dout("handle_reply tid %llu dne\n", tid);
		mutex_unlock(&osdc->request_mutex);
		return;
	}
	ceph_osdc_get_request(req);
	flags = le32_to_cpu(rhead->flags);

	/*
	 * if this connection filled our message, drop our reference now, to
	 * avoid a (safe but slower) revoke later.
	 */
	if (req->r_con_filling_msg == con && req->r_reply == msg) {
		dout(" dropping con_filling_msg ref %p\n", con);
		req->r_con_filling_msg = NULL;
		ceph_con_put(con);
	}

	if (!req->r_got_reply) {
		unsigned bytes;

		req->r_result = le32_to_cpu(rhead->result);
		bytes = le32_to_cpu(msg->hdr.data_len);
		dout("handle_reply result %d bytes %d\n", req->r_result,
		     bytes);
		if (req->r_result == 0)
			req->r_result = bytes;

		/* in case this is a write and we need to replay, */
		req->r_reassert_version = rhead->reassert_version;

		req->r_got_reply = 1;
	} else if ((flags & CEPH_OSD_FLAG_ONDISK) == 0) {
		dout("handle_reply tid %llu dup ack\n", tid);
		mutex_unlock(&osdc->request_mutex);
		goto done;
	}

	dout("handle_reply tid %llu flags %d\n", tid, flags);

	/* either this is a read, or we got the safe response */
	if (result < 0 ||
	    (flags & CEPH_OSD_FLAG_ONDISK) ||
	    ((flags & CEPH_OSD_FLAG_WRITE) == 0))
		__unregister_request(osdc, req);

	mutex_unlock(&osdc->request_mutex);

	if (req->r_callback)
		req->r_callback(req, msg);
	else
		complete(&req->r_completion);

	if (flags & CEPH_OSD_FLAG_ONDISK) {
		if (req->r_safe_callback)
			req->r_safe_callback(req, msg);
		complete(&req->r_safe_completion);  /* fsync waiter */
	}

done:
	ceph_osdc_put_request(req);
	return;

bad:
	pr_err("corrupt osd_op_reply got %d %d expected %d\n",
	       (int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len),
	       (int)sizeof(*rhead));
	ceph_msg_dump(msg);
}


static int __kick_requests(struct ceph_osd_client *osdc,
			  struct ceph_osd *kickosd)
{
	struct ceph_osd_request *req;
	struct rb_node *p, *n;
	int needmap = 0;
	int err;

	dout("kick_requests osd%d\n", kickosd ? kickosd->o_osd : -1);
	if (kickosd) {
		err = __reset_osd(osdc, kickosd);
		if (err == -EAGAIN)
			return 1;
	} else {
		for (p = rb_first(&osdc->osds); p; p = n) {
			struct ceph_osd *osd =
				rb_entry(p, struct ceph_osd, o_node);

			n = rb_next(p);
			if (!ceph_osd_is_up(osdc->osdmap, osd->o_osd) ||
			    memcmp(&osd->o_con.peer_addr,
				   ceph_osd_addr(osdc->osdmap,
						 osd->o_osd),
				   sizeof(struct ceph_entity_addr)) != 0)
				__reset_osd(osdc, osd);
		}
	}

	for (p = rb_first(&osdc->requests); p; p = rb_next(p)) {
		req = rb_entry(p, struct ceph_osd_request, r_node);

		if (req->r_resend) {
			dout(" r_resend set on tid %llu\n", req->r_tid);
			__cancel_request(req);
			goto kick;
		}
		if (req->r_osd && kickosd == req->r_osd) {
			__cancel_request(req);
			goto kick;
		}

		err = __map_osds(osdc, req);
		if (err == 0)
			continue;  /* no change */
		if (err < 0) {
			/*
			 * FIXME: really, we should set the request
			 * error and fail if this isn't a 'nofail'
			 * request, but that's a fair bit more
			 * complicated to do.  So retry!
			 */
			dout(" setting r_resend on %llu\n", req->r_tid);
			req->r_resend = true;
			continue;
		}
		if (req->r_osd == NULL) {
			dout("tid %llu maps to no valid osd\n", req->r_tid);
			needmap++;  /* request a newer map */
			continue;
		}

kick:
		dout("kicking %p tid %llu osd%d\n", req, req->r_tid,
		     req->r_osd ? req->r_osd->o_osd : -1);
		req->r_flags |= CEPH_OSD_FLAG_RETRY;
		err = __send_request(osdc, req);
		if (err) {
			dout(" setting r_resend on %llu\n", req->r_tid);
			req->r_resend = true;
		}
	}

	return needmap;
}

/*
 * Resubmit osd requests whose osd or osd address has changed.  Request
 * a new osd map if osds are down, or we are otherwise unable to determine
 * how to direct a request.
 *
 * Close connections to down osds.
 *
 * If @who is specified, resubmit requests for that specific osd.
 *
 * Caller should hold map_sem for read and request_mutex.
 */
static void kick_requests(struct ceph_osd_client *osdc,
			  struct ceph_osd *kickosd)
{
	int needmap;

	mutex_lock(&osdc->request_mutex);
	needmap = __kick_requests(osdc, kickosd);
	mutex_unlock(&osdc->request_mutex);

	if (needmap) {
		dout("%d requests for down osds, need new map\n", needmap);
		ceph_monc_request_next_osdmap(&osdc->client->monc);
	}

}
/*
 * Process updated osd map.
 *
 * The message contains any number of incremental and full maps, normally
 * indicating some sort of topology change in the cluster.  Kick requests
 * off to different OSDs as needed.
 */
void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
{
	void *p, *end, *next;
	u32 nr_maps, maplen;
	u32 epoch;
	struct ceph_osdmap *newmap = NULL, *oldmap;
	int err;
	struct ceph_fsid fsid;

	dout("handle_map have %u\n", osdc->osdmap ? osdc->osdmap->epoch : 0);
	p = msg->front.iov_base;
	end = p + msg->front.iov_len;

	/* verify fsid */
	ceph_decode_need(&p, end, sizeof(fsid), bad);
	ceph_decode_copy(&p, &fsid, sizeof(fsid));
	if (ceph_check_fsid(osdc->client, &fsid) < 0)
		return;

	down_write(&osdc->map_sem);

	/* incremental maps */
	ceph_decode_32_safe(&p, end, nr_maps, bad);
	dout(" %d inc maps\n", nr_maps);
	while (nr_maps > 0) {
		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
		epoch = ceph_decode_32(&p);
		maplen = ceph_decode_32(&p);
		ceph_decode_need(&p, end, maplen, bad);
		next = p + maplen;
		if (osdc->osdmap && osdc->osdmap->epoch+1 == epoch) {
			dout("applying incremental map %u len %d\n",
			     epoch, maplen);
			newmap = osdmap_apply_incremental(&p, next,
							  osdc->osdmap,
							  osdc->client->msgr);
			if (IS_ERR(newmap)) {
				err = PTR_ERR(newmap);
				goto bad;
			}
			BUG_ON(!newmap);
			if (newmap != osdc->osdmap) {
				ceph_osdmap_destroy(osdc->osdmap);
				osdc->osdmap = newmap;
			}
		} else {
			dout("ignoring incremental map %u len %d\n",
			     epoch, maplen);
		}
		p = next;
		nr_maps--;
	}
	if (newmap)
		goto done;

	/* full maps */
	ceph_decode_32_safe(&p, end, nr_maps, bad);
	dout(" %d full maps\n", nr_maps);
	while (nr_maps) {
		ceph_decode_need(&p, end, 2*sizeof(u32), bad);
		epoch = ceph_decode_32(&p);
		maplen = ceph_decode_32(&p);
		ceph_decode_need(&p, end, maplen, bad);
		if (nr_maps > 1) {
			dout("skipping non-latest full map %u len %d\n",
			     epoch, maplen);
		} else if (osdc->osdmap && osdc->osdmap->epoch >= epoch) {
			dout("skipping full map %u len %d, "
			     "older than our %u\n", epoch, maplen,
			     osdc->osdmap->epoch);
		} else {
			dout("taking full map %u len %d\n", epoch, maplen);
			newmap = osdmap_decode(&p, p+maplen);
			if (IS_ERR(newmap)) {
				err = PTR_ERR(newmap);
				goto bad;
			}
			BUG_ON(!newmap);
			oldmap = osdc->osdmap;
			osdc->osdmap = newmap;
			if (oldmap)
				ceph_osdmap_destroy(oldmap);
		}
		p += maplen;
		nr_maps--;
	}

done:
	downgrade_write(&osdc->map_sem);
	ceph_monc_got_osdmap(&osdc->client->monc, osdc->osdmap->epoch);
	if (newmap)
		kick_requests(osdc, NULL);
	up_read(&osdc->map_sem);
	wake_up(&osdc->client->auth_wq);
	return;

bad:
	pr_err("osdc handle_map corrupt msg\n");
	ceph_msg_dump(msg);
	up_write(&osdc->map_sem);
	return;
}

/*
 * Register request, send initial attempt.
 */
int ceph_osdc_start_request(struct ceph_osd_client *osdc,
			    struct ceph_osd_request *req,
			    bool nofail)
{
	int rc = 0;

	req->r_request->pages = req->r_pages;
	req->r_request->nr_pages = req->r_num_pages;

	register_request(osdc, req);

	down_read(&osdc->map_sem);
	mutex_lock(&osdc->request_mutex);
	/*
	 * a racing kick_requests() may have sent the message for us
	 * while we dropped request_mutex above, so only send now if
	 * the request still han't been touched yet.
	 */
	if (req->r_sent == 0) {
		rc = __send_request(osdc, req);
		if (rc) {
			if (nofail) {
				dout("osdc_start_request failed send, "
				     " marking %lld\n", req->r_tid);
				req->r_resend = true;
				rc = 0;
			} else {
				__unregister_request(osdc, req);
			}
		}
	}
	mutex_unlock(&osdc->request_mutex);
	up_read(&osdc->map_sem);
	return rc;
}

/*
 * wait for a request to complete
 */
int ceph_osdc_wait_request(struct ceph_osd_client *osdc,
			   struct ceph_osd_request *req)
{
	int rc;

	rc = wait_for_completion_interruptible(&req->r_completion);
	if (rc < 0) {
		mutex_lock(&osdc->request_mutex);
		__cancel_request(req);
		__unregister_request(osdc, req);
		mutex_unlock(&osdc->request_mutex);
		dout("wait_request tid %llu canceled/timed out\n", req->r_tid);
		return rc;
	}

	dout("wait_request tid %llu result %d\n", req->r_tid, req->r_result);
	return req->r_result;
}

/*
 * sync - wait for all in-flight requests to flush.  avoid starvation.
 */
void ceph_osdc_sync(struct ceph_osd_client *osdc)
{
	struct ceph_osd_request *req;
	u64 last_tid, next_tid = 0;

	mutex_lock(&osdc->request_mutex);
	last_tid = osdc->last_tid;
	while (1) {
		req = __lookup_request_ge(osdc, next_tid);
		if (!req)
			break;
		if (req->r_tid > last_tid)
			break;

		next_tid = req->r_tid + 1;
		if ((req->r_flags & CEPH_OSD_FLAG_WRITE) == 0)
			continue;

		ceph_osdc_get_request(req);
		mutex_unlock(&osdc->request_mutex);
		dout("sync waiting on tid %llu (last is %llu)\n",
		     req->r_tid, last_tid);
		wait_for_completion(&req->r_safe_completion);
		mutex_lock(&osdc->request_mutex);
		ceph_osdc_put_request(req);
	}
	mutex_unlock(&osdc->request_mutex);
	dout("sync done (thru tid %llu)\n", last_tid);
}

/*
 * init, shutdown
 */
int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
{
	int err;

	dout("init\n");
	osdc->client = client;
	osdc->osdmap = NULL;
	init_rwsem(&osdc->map_sem);
	init_completion(&osdc->map_waiters);
	osdc->last_requested_map = 0;
	mutex_init(&osdc->request_mutex);
	osdc->last_tid = 0;
	osdc->osds = RB_ROOT;
	INIT_LIST_HEAD(&osdc->osd_lru);
	osdc->requests = RB_ROOT;
	INIT_LIST_HEAD(&osdc->req_lru);
	osdc->num_requests = 0;
	INIT_DELAYED_WORK(&osdc->timeout_work, handle_timeout);
	INIT_DELAYED_WORK(&osdc->osds_timeout_work, handle_osds_timeout);

	schedule_delayed_work(&osdc->osds_timeout_work,
	   round_jiffies_relative(osdc->client->mount_args->osd_idle_ttl * HZ));

	err = -ENOMEM;
	osdc->req_mempool = mempool_create_kmalloc_pool(10,
					sizeof(struct ceph_osd_request));
	if (!osdc->req_mempool)
		goto out;

	err = ceph_msgpool_init(&osdc->msgpool_op, OSD_OP_FRONT_LEN, 10, true,
				"osd_op");
	if (err < 0)
		goto out_mempool;
	err = ceph_msgpool_init(&osdc->msgpool_op_reply,
				OSD_OPREPLY_FRONT_LEN, 10, true,
				"osd_op_reply");
	if (err < 0)
		goto out_msgpool;
	return 0;

out_msgpool:
	ceph_msgpool_destroy(&osdc->msgpool_op);
out_mempool:
	mempool_destroy(osdc->req_mempool);
out:
	return err;
}

void ceph_osdc_stop(struct ceph_osd_client *osdc)
{
	cancel_delayed_work_sync(&osdc->timeout_work);
	cancel_delayed_work_sync(&osdc->osds_timeout_work);
	if (osdc->osdmap) {
		ceph_osdmap_destroy(osdc->osdmap);
		osdc->osdmap = NULL;
	}
	remove_old_osds(osdc, 1);
	mempool_destroy(osdc->req_mempool);
	ceph_msgpool_destroy(&osdc->msgpool_op);
	ceph_msgpool_destroy(&osdc->msgpool_op_reply);
}

/*
 * Read some contiguous pages.  If we cross a stripe boundary, shorten
 * *plen.  Return number of bytes read, or error.
 */
int ceph_osdc_readpages(struct ceph_osd_client *osdc,
			struct ceph_vino vino, struct ceph_file_layout *layout,
			u64 off, u64 *plen,
			u32 truncate_seq, u64 truncate_size,
			struct page **pages, int num_pages)
{
	struct ceph_osd_request *req;
	int rc = 0;

	dout("readpages on ino %llx.%llx on %llu~%llu\n", vino.ino,
	     vino.snap, off, *plen);
	req = ceph_osdc_new_request(osdc, layout, vino, off, plen,
				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
				    NULL, 0, truncate_seq, truncate_size, NULL,
				    false, 1);
	if (!req)
		return -ENOMEM;

	/* it may be a short read due to an object boundary */
	req->r_pages = pages;
	num_pages = calc_pages_for(off, *plen);
	req->r_num_pages = num_pages;

	dout("readpages  final extent is %llu~%llu (%d pages)\n",
	     off, *plen, req->r_num_pages);

	rc = ceph_osdc_start_request(osdc, req, false);
	if (!rc)
		rc = ceph_osdc_wait_request(osdc, req);

	ceph_osdc_put_request(req);
	dout("readpages result %d\n", rc);
	return rc;
}

/*
 * do a synchronous write on N pages
 */
int ceph_osdc_writepages(struct ceph_osd_client *osdc, struct ceph_vino vino,
			 struct ceph_file_layout *layout,
			 struct ceph_snap_context *snapc,
			 u64 off, u64 len,
			 u32 truncate_seq, u64 truncate_size,
			 struct timespec *mtime,
			 struct page **pages, int num_pages,
			 int flags, int do_sync, bool nofail)
{
	struct ceph_osd_request *req;
	int rc = 0;

	BUG_ON(vino.snap != CEPH_NOSNAP);
	req = ceph_osdc_new_request(osdc, layout, vino, off, &len,
				    CEPH_OSD_OP_WRITE,
				    flags | CEPH_OSD_FLAG_ONDISK |
					    CEPH_OSD_FLAG_WRITE,
				    snapc, do_sync,
				    truncate_seq, truncate_size, mtime,
				    nofail, 1);
	if (!req)
		return -ENOMEM;

	/* it may be a short write due to an object boundary */
	req->r_pages = pages;
	req->r_num_pages = calc_pages_for(off, len);
	dout("writepages %llu~%llu (%d pages)\n", off, len,
	     req->r_num_pages);

	rc = ceph_osdc_start_request(osdc, req, nofail);
	if (!rc)
		rc = ceph_osdc_wait_request(osdc, req);

	ceph_osdc_put_request(req);
	if (rc == 0)
		rc = len;
	dout("writepages result %d\n", rc);
	return rc;
}

/*
 * handle incoming message
 */
static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
{
	struct ceph_osd *osd = con->private;
	struct ceph_osd_client *osdc;
	int type = le16_to_cpu(msg->hdr.type);

	if (!osd)
		goto out;
	osdc = osd->o_osdc;

	switch (type) {
	case CEPH_MSG_OSD_MAP:
		ceph_osdc_handle_map(osdc, msg);
		break;
	case CEPH_MSG_OSD_OPREPLY:
		handle_reply(osdc, msg, con);
		break;

	default:
		pr_err("received unknown message type %d %s\n", type,
		       ceph_msg_type_name(type));
	}
out:
	ceph_msg_put(msg);
}

/*
 * lookup and return message for incoming reply.  set up reply message
 * pages.
 */
static struct ceph_msg *get_reply(struct ceph_connection *con,
				  struct ceph_msg_header *hdr,
				  int *skip)
{
	struct ceph_osd *osd = con->private;
	struct ceph_osd_client *osdc = osd->o_osdc;
	struct ceph_msg *m;
	struct ceph_osd_request *req;
	int front = le32_to_cpu(hdr->front_len);
	int data_len = le32_to_cpu(hdr->data_len);
	u64 tid;

	tid = le64_to_cpu(hdr->tid);
	mutex_lock(&osdc->request_mutex);
	req = __lookup_request(osdc, tid);
	if (!req) {
		*skip = 1;
		m = NULL;
		pr_info("get_reply unknown tid %llu from osd%d\n", tid,
			osd->o_osd);
		goto out;
	}

	if (req->r_con_filling_msg) {
		dout("get_reply revoking msg %p from old con %p\n",
		     req->r_reply, req->r_con_filling_msg);
		ceph_con_revoke_message(req->r_con_filling_msg, req->r_reply);
		ceph_con_put(req->r_con_filling_msg);
		req->r_con_filling_msg = NULL;
	}

	if (front > req->r_reply->front.iov_len) {
		pr_warning("get_reply front %d > preallocated %d\n",
			   front, (int)req->r_reply->front.iov_len);
		m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front, GFP_NOFS);
		if (!m)
			goto out;
		ceph_msg_put(req->r_reply);
		req->r_reply = m;
	}
	m = ceph_msg_get(req->r_reply);

	if (data_len > 0) {
		unsigned data_off = le16_to_cpu(hdr->data_off);
		int want = calc_pages_for(data_off & ~PAGE_MASK, data_len);

		if (unlikely(req->r_num_pages < want)) {
			pr_warning("tid %lld reply %d > expected %d pages\n",
				   tid, want, m->nr_pages);
			*skip = 1;
			ceph_msg_put(m);
			m = NULL;
			goto out;
		}
		m->pages = req->r_pages;
		m->nr_pages = req->r_num_pages;
	}
	*skip = 0;
	req->r_con_filling_msg = ceph_con_get(con);
	dout("get_reply tid %lld %p\n", tid, m);

out:
	mutex_unlock(&osdc->request_mutex);
	return m;

}

static struct ceph_msg *alloc_msg(struct ceph_connection *con,
				  struct ceph_msg_header *hdr,
				  int *skip)
{
	struct ceph_osd *osd = con->private;
	int type = le16_to_cpu(hdr->type);
	int front = le32_to_cpu(hdr->front_len);

	switch (type) {
	case CEPH_MSG_OSD_MAP:
		return ceph_msg_new(type, front, GFP_NOFS);
	case CEPH_MSG_OSD_OPREPLY:
		return get_reply(con, hdr, skip);
	default:
		pr_info("alloc_msg unexpected msg type %d from osd%d\n", type,
			osd->o_osd);
		*skip = 1;
		return NULL;
	}
}

/*
 * Wrappers to refcount containing ceph_osd struct
 */
static struct ceph_connection *get_osd_con(struct ceph_connection *con)
{
	struct ceph_osd *osd = con->private;
	if (get_osd(osd))
		return con;
	return NULL;
}

static void put_osd_con(struct ceph_connection *con)
{
	struct ceph_osd *osd = con->private;
	put_osd(osd);
}

/*
 * authentication
 */
static int get_authorizer(struct ceph_connection *con,
	                  void **buf, int *len, int *proto,
	                  void **reply_buf, int *reply_len, int force_new)
{
	struct ceph_osd *o = con->private;
	struct ceph_osd_client *osdc = o->o_osdc;
	struct ceph_auth_client *ac = osdc->client->monc.auth;
	int ret = 0;

	if (force_new && o->o_authorizer) {
		ac->ops->destroy_authorizer(ac, o->o_authorizer);
		o->o_authorizer = NULL;
	}
	if (o->o_authorizer == NULL) {
		ret = ac->ops->create_authorizer(
			ac, CEPH_ENTITY_TYPE_OSD,
			&o->o_authorizer,
			&o->o_authorizer_buf,
			&o->o_authorizer_buf_len,
			&o->o_authorizer_reply_buf,
			&o->o_authorizer_reply_buf_len);
		if (ret)
		return ret;
	}

	*proto = ac->protocol;
	*buf = o->o_authorizer_buf;
	*len = o->o_authorizer_buf_len;
	*reply_buf = o->o_authorizer_reply_buf;
	*reply_len = o->o_authorizer_reply_buf_len;
	return 0;
}


static int verify_authorizer_reply(struct ceph_connection *con, int len)
{
	struct ceph_osd *o = con->private;
	struct ceph_osd_client *osdc = o->o_osdc;
	struct ceph_auth_client *ac = osdc->client->monc.auth;

	return ac->ops->verify_authorizer_reply(ac, o->o_authorizer, len);
}

static int invalidate_authorizer(struct ceph_connection *con)
{
	struct ceph_osd *o = con->private;
	struct ceph_osd_client *osdc = o->o_osdc;
	struct ceph_auth_client *ac = osdc->client->monc.auth;

	if (ac->ops->invalidate_authorizer)
		ac->ops->invalidate_authorizer(ac, CEPH_ENTITY_TYPE_OSD);

	return ceph_monc_validate_auth(&osdc->client->monc);
}

static const struct ceph_connection_operations osd_con_ops = {
	.get = get_osd_con,
	.put = put_osd_con,
	.dispatch = dispatch,
	.get_authorizer = get_authorizer,
	.verify_authorizer_reply = verify_authorizer_reply,
	.invalidate_authorizer = invalidate_authorizer,
	.alloc_msg = alloc_msg,
	.fault = osd_reset,
};