summaryrefslogtreecommitdiff
path: root/drivers/target/iscsi/iscsi_target_erl1.c
blob: 0b52a2371305ee0a6d9b7814fc5837adff69e7e7 (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
/*******************************************************************************
 * This file contains error recovery level one used by the iSCSI Target driver.
 *
 * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
 *
 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
 *
 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 ******************************************************************************/

#include <linux/list.h>
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>

#include "iscsi_target_core.h"
#include "iscsi_target_seq_pdu_list.h"
#include "iscsi_target_datain_values.h"
#include "iscsi_target_device.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target.h"

#define OFFLOAD_BUF_SIZE	32768

/*
 *	Used to dump excess datain payload for certain error recovery
 *	situations.  Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().
 *
 *	dump_padding_digest denotes if padding and data digests need
 *	to be dumped.
 */
int iscsit_dump_data_payload(
	struct iscsi_conn *conn,
	u32 buf_len,
	int dump_padding_digest)
{
	char *buf, pad_bytes[4];
	int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
	u32 length, padding, offset = 0, size;
	struct kvec iov;

	length = (buf_len > OFFLOAD_BUF_SIZE) ? OFFLOAD_BUF_SIZE : buf_len;

	buf = kzalloc(length, GFP_ATOMIC);
	if (!buf) {
		pr_err("Unable to allocate %u bytes for offload"
				" buffer.\n", length);
		return -1;
	}
	memset(&iov, 0, sizeof(struct kvec));

	while (offset < buf_len) {
		size = ((offset + length) > buf_len) ?
			(buf_len - offset) : length;

		iov.iov_len = size;
		iov.iov_base = buf;

		rx_got = rx_data(conn, &iov, 1, size);
		if (rx_got != size) {
			ret = DATAOUT_CANNOT_RECOVER;
			goto out;
		}

		offset += size;
	}

	if (!dump_padding_digest)
		goto out;

	padding = ((-buf_len) & 3);
	if (padding != 0) {
		iov.iov_len = padding;
		iov.iov_base = pad_bytes;

		rx_got = rx_data(conn, &iov, 1, padding);
		if (rx_got != padding) {
			ret = DATAOUT_CANNOT_RECOVER;
			goto out;
		}
	}

	if (conn->conn_ops->DataDigest) {
		u32 data_crc;

		iov.iov_len = ISCSI_CRC_LEN;
		iov.iov_base = &data_crc;

		rx_got = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
		if (rx_got != ISCSI_CRC_LEN) {
			ret = DATAOUT_CANNOT_RECOVER;
			goto out;
		}
	}

out:
	kfree(buf);
	return ret;
}

/*
 *	Used for retransmitting R2Ts from a R2T SNACK request.
 */
static int iscsit_send_recovery_r2t_for_snack(
	struct iscsi_cmd *cmd,
	struct iscsi_r2t *r2t)
{
	/*
	 * If the struct iscsi_r2t has not been sent yet, we can safely
	 * ignore retransmission
	 * of the R2TSN in question.
	 */
	spin_lock_bh(&cmd->r2t_lock);
	if (!r2t->sent_r2t) {
		spin_unlock_bh(&cmd->r2t_lock);
		return 0;
	}
	r2t->sent_r2t = 0;
	spin_unlock_bh(&cmd->r2t_lock);

	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);

	return 0;
}

static int iscsit_handle_r2t_snack(
	struct iscsi_cmd *cmd,
	unsigned char *buf,
	u32 begrun,
	u32 runlength)
{
	u32 last_r2tsn;
	struct iscsi_r2t *r2t;

	/*
	 * Make sure the initiator is not requesting retransmission
	 * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
	 */
	if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
	    (begrun <= cmd->acked_data_sn)) {
		pr_err("ITT: 0x%08x, R2T SNACK requesting"
			" retransmission of R2TSN: 0x%08x to 0x%08x but already"
			" acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"
			" protocol error.\n", cmd->init_task_tag, begrun,
			(begrun + runlength), cmd->acked_data_sn);

			return iscsit_add_reject_from_cmd(
					ISCSI_REASON_PROTOCOL_ERROR,
					1, 0, buf, cmd);
	}

	if (runlength) {
		if ((begrun + runlength) > cmd->r2t_sn) {
			pr_err("Command ITT: 0x%08x received R2T SNACK"
			" with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
			" current R2TSN: 0x%08x, protocol error.\n",
			cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
			return iscsit_add_reject_from_cmd(
				ISCSI_REASON_BOOKMARK_INVALID, 1, 0, buf, cmd);
		}
		last_r2tsn = (begrun + runlength);
	} else
		last_r2tsn = cmd->r2t_sn;

	while (begrun < last_r2tsn) {
		r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
		if (!r2t)
			return -1;
		if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
			return -1;

		begrun++;
	}

	return 0;
}

/*
 *	Generates Offsets and NextBurstLength based on Begrun and Runlength
 *	carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 *
 *	For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 *
 *	FIXME: How is this handled for a RData SNACK?
 */
int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
	struct iscsi_cmd *cmd,
	struct iscsi_datain_req *dr)
{
	u32 data_sn = 0, data_sn_count = 0;
	u32 pdu_start = 0, seq_no = 0;
	u32 begrun = dr->begrun;
	struct iscsi_conn *conn = cmd->conn;

	while (begrun > data_sn++) {
		data_sn_count++;
		if ((dr->next_burst_len +
		     conn->conn_ops->MaxRecvDataSegmentLength) <
		     conn->sess->sess_ops->MaxBurstLength) {
			dr->read_data_done +=
				conn->conn_ops->MaxRecvDataSegmentLength;
			dr->next_burst_len +=
				conn->conn_ops->MaxRecvDataSegmentLength;
		} else {
			dr->read_data_done +=
				(conn->sess->sess_ops->MaxBurstLength -
				 dr->next_burst_len);
			dr->next_burst_len = 0;
			pdu_start += data_sn_count;
			data_sn_count = 0;
			seq_no++;
		}
	}

	if (!conn->sess->sess_ops->DataPDUInOrder) {
		cmd->seq_no = seq_no;
		cmd->pdu_start = pdu_start;
		cmd->pdu_send_order = data_sn_count;
	}

	return 0;
}

/*
 *	Generates Offsets and NextBurstLength based on Begrun and Runlength
 *	carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 *
 *	For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 *
 *	FIXME: How is this handled for a RData SNACK?
 */
int iscsit_create_recovery_datain_values_datasequenceinorder_no(
	struct iscsi_cmd *cmd,
	struct iscsi_datain_req *dr)
{
	int found_seq = 0, i;
	u32 data_sn, read_data_done = 0, seq_send_order = 0;
	u32 begrun = dr->begrun;
	u32 runlength = dr->runlength;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_seq *first_seq = NULL, *seq = NULL;

	if (!cmd->seq_list) {
		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
		return -1;
	}

	/*
	 * Calculate read_data_done for all sequences containing a
	 * first_datasn and last_datasn less than the BegRun.
	 *
	 * Locate the struct iscsi_seq the BegRun lies within and calculate
	 * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
	 *
	 * Also use struct iscsi_seq->seq_send_order to determine where to start.
	 */
	for (i = 0; i < cmd->seq_count; i++) {
		seq = &cmd->seq_list[i];

		if (!seq->seq_send_order)
			first_seq = seq;

		/*
		 * No data has been transferred for this DataIN sequence, so the
		 * seq->first_datasn and seq->last_datasn have not been set.
		 */
		if (!seq->sent) {
			pr_err("Ignoring non-sent sequence 0x%08x ->"
				" 0x%08x\n\n", seq->first_datasn,
				seq->last_datasn);
			continue;
		}

		/*
		 * This DataIN sequence is precedes the received BegRun, add the
		 * total xfer_len of the sequence to read_data_done and reset
		 * seq->pdu_send_order.
		 */
		if ((seq->first_datasn < begrun) &&
				(seq->last_datasn < begrun)) {
			pr_err("Pre BegRun sequence 0x%08x ->"
				" 0x%08x\n", seq->first_datasn,
				seq->last_datasn);

			read_data_done += cmd->seq_list[i].xfer_len;
			seq->next_burst_len = seq->pdu_send_order = 0;
			continue;
		}

		/*
		 * The BegRun lies within this DataIN sequence.
		 */
		if ((seq->first_datasn <= begrun) &&
				(seq->last_datasn >= begrun)) {
			pr_err("Found sequence begrun: 0x%08x in"
				" 0x%08x -> 0x%08x\n", begrun,
				seq->first_datasn, seq->last_datasn);

			seq_send_order = seq->seq_send_order;
			data_sn = seq->first_datasn;
			seq->next_burst_len = seq->pdu_send_order = 0;
			found_seq = 1;

			/*
			 * For DataPDUInOrder=Yes, while the first DataSN of
			 * the sequence is less than the received BegRun, add
			 * the MaxRecvDataSegmentLength to read_data_done and
			 * to the sequence's next_burst_len;
			 *
			 * For DataPDUInOrder=No, while the first DataSN of the
			 * sequence is less than the received BegRun, find the
			 * struct iscsi_pdu of the DataSN in question and add the
			 * MaxRecvDataSegmentLength to read_data_done and to the
			 * sequence's next_burst_len;
			 */
			if (conn->sess->sess_ops->DataPDUInOrder) {
				while (data_sn < begrun) {
					seq->pdu_send_order++;
					read_data_done +=
						conn->conn_ops->MaxRecvDataSegmentLength;
					seq->next_burst_len +=
						conn->conn_ops->MaxRecvDataSegmentLength;
					data_sn++;
				}
			} else {
				int j;
				struct iscsi_pdu *pdu;

				while (data_sn < begrun) {
					seq->pdu_send_order++;

					for (j = 0; j < seq->pdu_count; j++) {
						pdu = &cmd->pdu_list[
							seq->pdu_start + j];
						if (pdu->data_sn == data_sn) {
							read_data_done +=
								pdu->length;
							seq->next_burst_len +=
								pdu->length;
						}
					}
					data_sn++;
				}
			}
			continue;
		}

		/*
		 * This DataIN sequence is larger than the received BegRun,
		 * reset seq->pdu_send_order and continue.
		 */
		if ((seq->first_datasn > begrun) ||
				(seq->last_datasn > begrun)) {
			pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
					seq->first_datasn, seq->last_datasn);

			seq->next_burst_len = seq->pdu_send_order = 0;
			continue;
		}
	}

	if (!found_seq) {
		if (!begrun) {
			if (!first_seq) {
				pr_err("ITT: 0x%08x, Begrun: 0x%08x"
					" but first_seq is NULL\n",
					cmd->init_task_tag, begrun);
				return -1;
			}
			seq_send_order = first_seq->seq_send_order;
			seq->next_burst_len = seq->pdu_send_order = 0;
			goto done;
		}

		pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
			" BegRun: 0x%08x, RunLength: 0x%08x while"
			" DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
				cmd->init_task_tag, begrun, runlength,
			(conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
		return -1;
	}

done:
	dr->read_data_done = read_data_done;
	dr->seq_send_order = seq_send_order;

	return 0;
}

static int iscsit_handle_recovery_datain(
	struct iscsi_cmd *cmd,
	unsigned char *buf,
	u32 begrun,
	u32 runlength)
{
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_datain_req *dr;
	struct se_cmd *se_cmd = &cmd->se_cmd;

	if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
		pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
				cmd->init_task_tag);
		return 0;
	}

	/*
	 * Make sure the initiator is not requesting retransmission
	 * of DataSNs already acknowledged by a Data ACK SNACK.
	 */
	if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
	    (begrun <= cmd->acked_data_sn)) {
		pr_err("ITT: 0x%08x, Data SNACK requesting"
			" retransmission of DataSN: 0x%08x to 0x%08x but"
			" already acked to DataSN: 0x%08x by Data ACK SNACK,"
			" protocol error.\n", cmd->init_task_tag, begrun,
			(begrun + runlength), cmd->acked_data_sn);

		return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
				1, 0, buf, cmd);
	}

	/*
	 * Make sure BegRun and RunLength in the Data SNACK are sane.
	 * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
	 */
	if ((begrun + runlength) > (cmd->data_sn - 1)) {
		pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
			": 0x%08x greater than maximum DataSN: 0x%08x.\n",
				begrun, runlength, (cmd->data_sn - 1));
		return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_INVALID,
				1, 0, buf, cmd);
	}

	dr = iscsit_allocate_datain_req();
	if (!dr)
		return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
				1, 0, buf, cmd);

	dr->data_sn = dr->begrun = begrun;
	dr->runlength = runlength;
	dr->generate_recovery_values = 1;
	dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;

	iscsit_attach_datain_req(cmd, dr);

	cmd->i_state = ISTATE_SEND_DATAIN;
	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);

	return 0;
}

int iscsit_handle_recovery_datain_or_r2t(
	struct iscsi_conn *conn,
	unsigned char *buf,
	itt_t init_task_tag,
	u32 targ_xfer_tag,
	u32 begrun,
	u32 runlength)
{
	struct iscsi_cmd *cmd;

	cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
	if (!cmd)
		return 0;

	/*
	 * FIXME: This will not work for bidi commands.
	 */
	switch (cmd->data_direction) {
	case DMA_TO_DEVICE:
		return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
	case DMA_FROM_DEVICE:
		return iscsit_handle_recovery_datain(cmd, buf, begrun,
				runlength);
	default:
		pr_err("Unknown cmd->data_direction: 0x%02x\n",
				cmd->data_direction);
		return -1;
	}

	return 0;
}

/* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
int iscsit_handle_status_snack(
	struct iscsi_conn *conn,
	itt_t init_task_tag,
	u32 targ_xfer_tag,
	u32 begrun,
	u32 runlength)
{
	struct iscsi_cmd *cmd = NULL;
	u32 last_statsn;
	int found_cmd;

	if (conn->exp_statsn > begrun) {
		pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
			" 0x%08x but already got ExpStatSN: 0x%08x on CID:"
			" %hu.\n", begrun, runlength, conn->exp_statsn,
			conn->cid);
		return 0;
	}

	last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);

	while (begrun < last_statsn) {
		found_cmd = 0;

		spin_lock_bh(&conn->cmd_lock);
		list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
			if (cmd->stat_sn == begrun) {
				found_cmd = 1;
				break;
			}
		}
		spin_unlock_bh(&conn->cmd_lock);

		if (!found_cmd) {
			pr_err("Unable to find StatSN: 0x%08x for"
				" a Status SNACK, assuming this was a"
				" protactic SNACK for an untransmitted"
				" StatSN, ignoring.\n", begrun);
			begrun++;
			continue;
		}

		spin_lock_bh(&cmd->istate_lock);
		if (cmd->i_state == ISTATE_SEND_DATAIN) {
			spin_unlock_bh(&cmd->istate_lock);
			pr_err("Ignoring Status SNACK for BegRun:"
				" 0x%08x, RunLength: 0x%08x, assuming this was"
				" a protactic SNACK for an untransmitted"
				" StatSN\n", begrun, runlength);
			begrun++;
			continue;
		}
		spin_unlock_bh(&cmd->istate_lock);

		cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
		begrun++;
	}

	return 0;
}

int iscsit_handle_data_ack(
	struct iscsi_conn *conn,
	u32 targ_xfer_tag,
	u32 begrun,
	u32 runlength)
{
	struct iscsi_cmd *cmd = NULL;

	cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
	if (!cmd) {
		pr_err("Data ACK SNACK for TTT: 0x%08x is"
			" invalid.\n", targ_xfer_tag);
		return -1;
	}

	if (begrun <= cmd->acked_data_sn) {
		pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
			" less than the already acked DataSN: 0x%08x.\n",
			cmd->init_task_tag, begrun, cmd->acked_data_sn);
		return -1;
	}

	/*
	 * For Data ACK SNACK, BegRun is the next expected DataSN.
	 * (see iSCSI v19: 10.16.6)
	 */
	cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
	cmd->acked_data_sn = (begrun - 1);

	pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
		" updated acked DataSN to 0x%08x.\n",
			cmd->init_task_tag, cmd->acked_data_sn);

	return 0;
}

static int iscsit_send_recovery_r2t(
	struct iscsi_cmd *cmd,
	u32 offset,
	u32 xfer_len)
{
	int ret;

	spin_lock_bh(&cmd->r2t_lock);
	ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
	spin_unlock_bh(&cmd->r2t_lock);

	return ret;
}

int iscsit_dataout_datapduinorder_no_fbit(
	struct iscsi_cmd *cmd,
	struct iscsi_pdu *pdu)
{
	int i, send_recovery_r2t = 0, recovery = 0;
	u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_pdu *first_pdu = NULL;

	/*
	 * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
	 * of the DataOUT sequence.
	 */
	if (conn->sess->sess_ops->DataSequenceInOrder) {
		for (i = 0; i < cmd->pdu_count; i++) {
			if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
				if (!first_pdu)
					first_pdu = &cmd->pdu_list[i];
				 xfer_len += cmd->pdu_list[i].length;
				 pdu_count++;
			} else if (pdu_count)
				break;
		}
	} else {
		struct iscsi_seq *seq = cmd->seq_ptr;

		first_pdu = &cmd->pdu_list[seq->pdu_start];
		pdu_count = seq->pdu_count;
	}

	if (!first_pdu || !pdu_count)
		return DATAOUT_CANNOT_RECOVER;

	/*
	 * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
	 * The following ugly logic does batching of not received PDUs.
	 */
	for (i = 0; i < pdu_count; i++) {
		if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
			if (!send_recovery_r2t)
				continue;

			if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
				return DATAOUT_CANNOT_RECOVER;

			send_recovery_r2t = length = offset = 0;
			continue;
		}
		/*
		 * Set recovery = 1 for any missing, CRC failed, or timed
		 * out PDUs to let the DataOUT logic know that this sequence
		 * has not been completed yet.
		 *
		 * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
		 * We assume if the PDU either failed CRC or timed out
		 * that a Recovery R2T has already been sent.
		 */
		recovery = 1;

		if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
			continue;

		if (!offset)
			offset = first_pdu[i].offset;
		length += first_pdu[i].length;

		send_recovery_r2t = 1;
	}

	if (send_recovery_r2t)
		if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
			return DATAOUT_CANNOT_RECOVER;

	return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
}

static int iscsit_recalculate_dataout_values(
	struct iscsi_cmd *cmd,
	u32 pdu_offset,
	u32 pdu_length,
	u32 *r2t_offset,
	u32 *r2t_length)
{
	int i;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_pdu *pdu = NULL;

	if (conn->sess->sess_ops->DataSequenceInOrder) {
		cmd->data_sn = 0;

		if (conn->sess->sess_ops->DataPDUInOrder) {
			*r2t_offset = cmd->write_data_done;
			*r2t_length = (cmd->seq_end_offset -
					cmd->write_data_done);
			return 0;
		}

		*r2t_offset = cmd->seq_start_offset;
		*r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);

		for (i = 0; i < cmd->pdu_count; i++) {
			pdu = &cmd->pdu_list[i];

			if (pdu->status != ISCSI_PDU_RECEIVED_OK)
				continue;

			if ((pdu->offset >= cmd->seq_start_offset) &&
			   ((pdu->offset + pdu->length) <=
			     cmd->seq_end_offset)) {
				if (!cmd->unsolicited_data)
					cmd->next_burst_len -= pdu->length;
				else
					cmd->first_burst_len -= pdu->length;

				cmd->write_data_done -= pdu->length;
				pdu->status = ISCSI_PDU_NOT_RECEIVED;
			}
		}
	} else {
		struct iscsi_seq *seq = NULL;

		seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
		if (!seq)
			return -1;

		*r2t_offset = seq->orig_offset;
		*r2t_length = seq->xfer_len;

		cmd->write_data_done -= (seq->offset - seq->orig_offset);
		if (cmd->immediate_data)
			cmd->first_burst_len = cmd->write_data_done;

		seq->data_sn = 0;
		seq->offset = seq->orig_offset;
		seq->next_burst_len = 0;
		seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;

		if (conn->sess->sess_ops->DataPDUInOrder)
			return 0;

		for (i = 0; i < seq->pdu_count; i++) {
			pdu = &cmd->pdu_list[i+seq->pdu_start];

			if (pdu->status != ISCSI_PDU_RECEIVED_OK)
				continue;

			pdu->status = ISCSI_PDU_NOT_RECEIVED;
		}
	}

	return 0;
}

int iscsit_recover_dataout_sequence(
	struct iscsi_cmd *cmd,
	u32 pdu_offset,
	u32 pdu_length)
{
	u32 r2t_length = 0, r2t_offset = 0;

	spin_lock_bh(&cmd->istate_lock);
	cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
	spin_unlock_bh(&cmd->istate_lock);

	if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
			&r2t_offset, &r2t_length) < 0)
		return DATAOUT_CANNOT_RECOVER;

	iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);

	return DATAOUT_WITHIN_COMMAND_RECOVERY;
}

static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
{
	struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;

	ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
	if (!ooo_cmdsn) {
		pr_err("Unable to allocate memory for"
			" struct iscsi_ooo_cmdsn.\n");
		return NULL;
	}
	INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);

	return ooo_cmdsn;
}

/*
 *	Called with sess->cmdsn_mutex held.
 */
static int iscsit_attach_ooo_cmdsn(
	struct iscsi_session *sess,
	struct iscsi_ooo_cmdsn *ooo_cmdsn)
{
	struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
	/*
	 * We attach the struct iscsi_ooo_cmdsn entry to the out of order
	 * list in increasing CmdSN order.
	 * This allows iscsi_execute_ooo_cmdsns() to detect any
	 * additional CmdSN holes while performing delayed execution.
	 */
	if (list_empty(&sess->sess_ooo_cmdsn_list))
		list_add_tail(&ooo_cmdsn->ooo_list,
				&sess->sess_ooo_cmdsn_list);
	else {
		ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
				typeof(*ooo_tail), ooo_list);
		/*
		 * CmdSN is greater than the tail of the list.
		 */
		if (ooo_tail->cmdsn < ooo_cmdsn->cmdsn)
			list_add_tail(&ooo_cmdsn->ooo_list,
					&sess->sess_ooo_cmdsn_list);
		else {
			/*
			 * CmdSN is either lower than the head,  or somewhere
			 * in the middle.
			 */
			list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
						ooo_list) {
				if (ooo_tmp->cmdsn < ooo_cmdsn->cmdsn)
					continue;

				list_add(&ooo_cmdsn->ooo_list,
					&ooo_tmp->ooo_list);
				break;
			}
		}
	}

	return 0;
}

/*
 *	Removes an struct iscsi_ooo_cmdsn from a session's list,
 *	called with struct iscsi_session->cmdsn_mutex held.
 */
void iscsit_remove_ooo_cmdsn(
	struct iscsi_session *sess,
	struct iscsi_ooo_cmdsn *ooo_cmdsn)
{
	list_del(&ooo_cmdsn->ooo_list);
	kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
}

void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
{
	struct iscsi_ooo_cmdsn *ooo_cmdsn;
	struct iscsi_session *sess = conn->sess;

	mutex_lock(&sess->cmdsn_mutex);
	list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
		if (ooo_cmdsn->cid != conn->cid)
			continue;

		ooo_cmdsn->cmd = NULL;
	}
	mutex_unlock(&sess->cmdsn_mutex);
}

/*
 *	Called with sess->cmdsn_mutex held.
 */
int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
{
	int ooo_count = 0;
	struct iscsi_cmd *cmd = NULL;
	struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;

	list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
				&sess->sess_ooo_cmdsn_list, ooo_list) {
		if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
			continue;

		if (!ooo_cmdsn->cmd) {
			sess->exp_cmd_sn++;
			iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
			continue;
		}

		cmd = ooo_cmdsn->cmd;
		cmd->i_state = cmd->deferred_i_state;
		ooo_count++;
		sess->exp_cmd_sn++;
		pr_debug("Executing out of order CmdSN: 0x%08x,"
			" incremented ExpCmdSN to 0x%08x.\n",
			cmd->cmd_sn, sess->exp_cmd_sn);

		iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);

		if (iscsit_execute_cmd(cmd, 1) < 0)
			return -1;

		continue;
	}

	return ooo_count;
}

/*
 *	Called either:
 *
 *	1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 *	or iscsi_check_received_cmdsn().
 *	2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 *	for immediate commands.
 */
int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	int lr = 0;

	spin_lock_bh(&cmd->istate_lock);
	if (ooo)
		cmd->cmd_flags &= ~ICF_OOO_CMDSN;

	switch (cmd->iscsi_opcode) {
	case ISCSI_OP_SCSI_CMD:
		/*
		 * Go ahead and send the CHECK_CONDITION status for
		 * any SCSI CDB exceptions that may have occurred.
		 */
		if (cmd->sense_reason) {
			if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
				cmd->i_state = ISTATE_SEND_STATUS;
				spin_unlock_bh(&cmd->istate_lock);
				iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
						cmd->i_state);
				return 0;
			}
			spin_unlock_bh(&cmd->istate_lock);
			/*
			 * Determine if delayed TASK_ABORTED status for WRITEs
			 * should be sent now if no unsolicited data out
			 * payloads are expected, or if the delayed status
			 * should be sent after unsolicited data out with
			 * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
			 */
			if (transport_check_aborted_status(se_cmd,
					(cmd->unsolicited_data == 0)) != 0)
				return 0;
			/*
			 * Otherwise send CHECK_CONDITION and sense for
			 * exception
			 */
			return transport_send_check_condition_and_sense(se_cmd,
					cmd->sense_reason, 0);
		}
		/*
		 * Special case for delayed CmdSN with Immediate
		 * Data and/or Unsolicited Data Out attached.
		 */
		if (cmd->immediate_data) {
			if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
				spin_unlock_bh(&cmd->istate_lock);
				target_execute_cmd(&cmd->se_cmd);
				return 0;
			}
			spin_unlock_bh(&cmd->istate_lock);

			if (!(cmd->cmd_flags &
					ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
				/*
				 * Send the delayed TASK_ABORTED status for
				 * WRITEs if no more unsolicitied data is
				 * expected.
				 */
				if (transport_check_aborted_status(se_cmd, 1)
						!= 0)
					return 0;

				iscsit_set_dataout_sequence_values(cmd);
				iscsit_build_r2ts_for_cmd(cmd, cmd->conn, false);
			}
			return 0;
		}
		/*
		 * The default handler.
		 */
		spin_unlock_bh(&cmd->istate_lock);

		if ((cmd->data_direction == DMA_TO_DEVICE) &&
		    !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
			/*
			 * Send the delayed TASK_ABORTED status for WRITEs if
			 * no more nsolicitied data is expected.
			 */
			if (transport_check_aborted_status(se_cmd, 1) != 0)
				return 0;

			iscsit_set_dataout_sequence_values(cmd);
			spin_lock_bh(&cmd->dataout_timeout_lock);
			iscsit_start_dataout_timer(cmd, cmd->conn);
			spin_unlock_bh(&cmd->dataout_timeout_lock);
		}
		return transport_handle_cdb_direct(&cmd->se_cmd);

	case ISCSI_OP_NOOP_OUT:
	case ISCSI_OP_TEXT:
		spin_unlock_bh(&cmd->istate_lock);
		iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
		break;
	case ISCSI_OP_SCSI_TMFUNC:
		if (cmd->se_cmd.se_tmr_req->response) {
			spin_unlock_bh(&cmd->istate_lock);
			iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
					cmd->i_state);
			return 0;
		}
		spin_unlock_bh(&cmd->istate_lock);

		return transport_generic_handle_tmr(&cmd->se_cmd);
	case ISCSI_OP_LOGOUT:
		spin_unlock_bh(&cmd->istate_lock);
		switch (cmd->logout_reason) {
		case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
			lr = iscsit_logout_closesession(cmd, cmd->conn);
			break;
		case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
			lr = iscsit_logout_closeconnection(cmd, cmd->conn);
			break;
		case ISCSI_LOGOUT_REASON_RECOVERY:
			lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
			break;
		default:
			pr_err("Unknown iSCSI Logout Request Code:"
				" 0x%02x\n", cmd->logout_reason);
			return -1;
		}

		return lr;
	default:
		spin_unlock_bh(&cmd->istate_lock);
		pr_err("Cannot perform out of order execution for"
		" unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
		return -1;
	}

	return 0;
}

void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
{
	struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;

	mutex_lock(&sess->cmdsn_mutex);
	list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
			&sess->sess_ooo_cmdsn_list, ooo_list) {

		list_del(&ooo_cmdsn->ooo_list);
		kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
	}
	mutex_unlock(&sess->cmdsn_mutex);
}

int iscsit_handle_ooo_cmdsn(
	struct iscsi_session *sess,
	struct iscsi_cmd *cmd,
	u32 cmdsn)
{
	int batch = 0;
	struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;

	cmd->deferred_i_state		= cmd->i_state;
	cmd->i_state			= ISTATE_DEFERRED_CMD;
	cmd->cmd_flags			|= ICF_OOO_CMDSN;

	if (list_empty(&sess->sess_ooo_cmdsn_list))
		batch = 1;
	else {
		ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
				typeof(*ooo_tail), ooo_list);
		if (ooo_tail->cmdsn != (cmdsn - 1))
			batch = 1;
	}

	ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
	if (!ooo_cmdsn)
		return CMDSN_ERROR_CANNOT_RECOVER;

	ooo_cmdsn->cmd			= cmd;
	ooo_cmdsn->batch_count		= (batch) ?
					  (cmdsn - sess->exp_cmd_sn) : 1;
	ooo_cmdsn->cid			= cmd->conn->cid;
	ooo_cmdsn->exp_cmdsn		= sess->exp_cmd_sn;
	ooo_cmdsn->cmdsn		= cmdsn;

	if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
		kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
		return CMDSN_ERROR_CANNOT_RECOVER;
	}

	return CMDSN_HIGHER_THAN_EXP;
}

static int iscsit_set_dataout_timeout_values(
	struct iscsi_cmd *cmd,
	u32 *offset,
	u32 *length)
{
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_r2t *r2t;

	if (cmd->unsolicited_data) {
		*offset = 0;
		*length = (conn->sess->sess_ops->FirstBurstLength >
			   cmd->se_cmd.data_length) ?
			   cmd->se_cmd.data_length :
			   conn->sess->sess_ops->FirstBurstLength;
		return 0;
	}

	spin_lock_bh(&cmd->r2t_lock);
	if (list_empty(&cmd->cmd_r2t_list)) {
		pr_err("cmd->cmd_r2t_list is empty!\n");
		spin_unlock_bh(&cmd->r2t_lock);
		return -1;
	}

	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
		if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
			*offset = r2t->offset;
			*length = r2t->xfer_len;
			spin_unlock_bh(&cmd->r2t_lock);
			return 0;
		}
	}
	spin_unlock_bh(&cmd->r2t_lock);

	pr_err("Unable to locate any incomplete DataOUT"
		" sequences for ITT: 0x%08x.\n", cmd->init_task_tag);

	return -1;
}

/*
 *	NOTE: Called from interrupt (timer) context.
 */
static void iscsit_handle_dataout_timeout(unsigned long data)
{
	u32 pdu_length = 0, pdu_offset = 0;
	u32 r2t_length = 0, r2t_offset = 0;
	struct iscsi_cmd *cmd = (struct iscsi_cmd *) data;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_session *sess = NULL;
	struct iscsi_node_attrib *na;

	iscsit_inc_conn_usage_count(conn);

	spin_lock_bh(&cmd->dataout_timeout_lock);
	if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
		spin_unlock_bh(&cmd->dataout_timeout_lock);
		iscsit_dec_conn_usage_count(conn);
		return;
	}
	cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
	sess = conn->sess;
	na = iscsit_tpg_get_node_attrib(sess);

	if (!sess->sess_ops->ErrorRecoveryLevel) {
		pr_debug("Unable to recover from DataOut timeout while"
			" in ERL=0.\n");
		goto failure;
	}

	if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
		pr_debug("Command ITT: 0x%08x exceeded max retries"
			" for DataOUT timeout %u, closing iSCSI connection.\n",
			cmd->init_task_tag, na->dataout_timeout_retries);
		goto failure;
	}

	cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;

	if (conn->sess->sess_ops->DataSequenceInOrder) {
		if (conn->sess->sess_ops->DataPDUInOrder) {
			pdu_offset = cmd->write_data_done;
			if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
			     cmd->next_burst_len)) > cmd->se_cmd.data_length)
				pdu_length = (cmd->se_cmd.data_length -
					cmd->write_data_done);
			else
				pdu_length = (conn->sess->sess_ops->MaxBurstLength -
						cmd->next_burst_len);
		} else {
			pdu_offset = cmd->seq_start_offset;
			pdu_length = (cmd->seq_end_offset -
				cmd->seq_start_offset);
		}
	} else {
		if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
				&pdu_length) < 0)
			goto failure;
	}

	if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
			&r2t_offset, &r2t_length) < 0)
		goto failure;

	pr_debug("Command ITT: 0x%08x timed out waiting for"
		" completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
		cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
		"", r2t_offset, r2t_length);

	if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
		goto failure;

	iscsit_start_dataout_timer(cmd, conn);
	spin_unlock_bh(&cmd->dataout_timeout_lock);
	iscsit_dec_conn_usage_count(conn);

	return;

failure:
	spin_unlock_bh(&cmd->dataout_timeout_lock);
	iscsit_cause_connection_reinstatement(conn, 0);
	iscsit_dec_conn_usage_count(conn);
}

void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
{
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_session *sess = conn->sess;
	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);

	spin_lock_bh(&cmd->dataout_timeout_lock);
	if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
		spin_unlock_bh(&cmd->dataout_timeout_lock);
		return;
	}

	mod_timer(&cmd->dataout_timer,
		(get_jiffies_64() + na->dataout_timeout * HZ));
	pr_debug("Updated DataOUT timer for ITT: 0x%08x",
			cmd->init_task_tag);
	spin_unlock_bh(&cmd->dataout_timeout_lock);
}

/*
 *	Called with cmd->dataout_timeout_lock held.
 */
void iscsit_start_dataout_timer(
	struct iscsi_cmd *cmd,
	struct iscsi_conn *conn)
{
	struct iscsi_session *sess = conn->sess;
	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);

	if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
		return;

	pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
		" CID: %hu.\n", cmd->init_task_tag, conn->cid);

	init_timer(&cmd->dataout_timer);
	cmd->dataout_timer.expires = (get_jiffies_64() + na->dataout_timeout * HZ);
	cmd->dataout_timer.data = (unsigned long)cmd;
	cmd->dataout_timer.function = iscsit_handle_dataout_timeout;
	cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
	cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
	add_timer(&cmd->dataout_timer);
}

void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
{
	spin_lock_bh(&cmd->dataout_timeout_lock);
	if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
		spin_unlock_bh(&cmd->dataout_timeout_lock);
		return;
	}
	cmd->dataout_timer_flags |= ISCSI_TF_STOP;
	spin_unlock_bh(&cmd->dataout_timeout_lock);

	del_timer_sync(&cmd->dataout_timer);

	spin_lock_bh(&cmd->dataout_timeout_lock);
	cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
	pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
			cmd->init_task_tag);
	spin_unlock_bh(&cmd->dataout_timeout_lock);
}