summaryrefslogtreecommitdiff
path: root/drivers/scsi/libiscsi.c
blob: 1eca82420aab06bbb96696fb916e8afddcd3890b (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
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
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
/*
 * iSCSI lib functions
 *
 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2004 - 2006 Mike Christie
 * Copyright (C) 2004 - 2005 Dmitry Yusupov
 * Copyright (C) 2004 - 2005 Alex Aizman
 * maintained by open-iscsi@googlegroups.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <linux/types.h>
#include <linux/kfifo.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <asm/unaligned.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/iscsi_proto.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/libiscsi.h>

/* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
#define SNA32_CHECK 2147483648UL

static int iscsi_sna_lt(u32 n1, u32 n2)
{
	return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
			    (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
}

/* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
static int iscsi_sna_lte(u32 n1, u32 n2)
{
	return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
			    (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
}

void
iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
	uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
	uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);

	/*
	 * standard specifies this check for when to update expected and
	 * max sequence numbers
	 */
	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
		return;

	if (exp_cmdsn != session->exp_cmdsn &&
	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
		session->exp_cmdsn = exp_cmdsn;

	if (max_cmdsn != session->max_cmdsn &&
	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
		session->max_cmdsn = max_cmdsn;
		/*
		 * if the window closed with IO queued, then kick the
		 * xmit thread
		 */
		if (!list_empty(&session->leadconn->xmitqueue) ||
		    !list_empty(&session->leadconn->mgmtqueue)) {
			if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
				scsi_queue_work(session->host,
						&session->leadconn->xmitwork);
		}
	}
}
EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);

void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *task,
				   struct iscsi_data *hdr)
{
	struct iscsi_conn *conn = task->conn;

	memset(hdr, 0, sizeof(struct iscsi_data));
	hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
	hdr->datasn = cpu_to_be32(task->unsol_datasn);
	task->unsol_datasn++;
	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
	memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));

	hdr->itt = task->hdr->itt;
	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
	hdr->offset = cpu_to_be32(task->unsol_offset);

	if (task->unsol_count > conn->max_xmit_dlength) {
		hton24(hdr->dlength, conn->max_xmit_dlength);
		task->data_count = conn->max_xmit_dlength;
		task->unsol_offset += task->data_count;
		hdr->flags = 0;
	} else {
		hton24(hdr->dlength, task->unsol_count);
		task->data_count = task->unsol_count;
		hdr->flags = ISCSI_FLAG_CMD_FINAL;
	}
}
EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);

static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
{
	unsigned exp_len = task->hdr_len + len;

	if (exp_len > task->hdr_max) {
		WARN_ON(1);
		return -EINVAL;
	}

	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
	task->hdr_len = exp_len;
	return 0;
}

/*
 * make an extended cdb AHS
 */
static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
{
	struct scsi_cmnd *cmd = task->sc;
	unsigned rlen, pad_len;
	unsigned short ahslength;
	struct iscsi_ecdb_ahdr *ecdb_ahdr;
	int rc;

	ecdb_ahdr = iscsi_next_hdr(task);
	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;

	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
	ahslength = rlen + sizeof(ecdb_ahdr->reserved);

	pad_len = iscsi_padding(rlen);

	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
	if (rc)
		return rc;

	if (pad_len)
		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);

	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
	ecdb_ahdr->reserved = 0;
	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);

	debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
		   "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
		   cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);

	return 0;
}

static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
{
	struct scsi_cmnd *sc = task->sc;
	struct iscsi_rlength_ahdr *rlen_ahdr;
	int rc;

	rlen_ahdr = iscsi_next_hdr(task);
	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
	if (rc)
		return rc;

	rlen_ahdr->ahslength =
		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
						  sizeof(rlen_ahdr->reserved));
	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
	rlen_ahdr->reserved = 0;
	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);

	debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
		   "rlen_ahdr->ahslength(%d)\n",
		   be32_to_cpu(rlen_ahdr->read_length),
		   be16_to_cpu(rlen_ahdr->ahslength));
	return 0;
}

/**
 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 * @task: iscsi task
 *
 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 * fields like dlength or final based on how much data it sends
 */
static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_session *session = conn->session;
	struct iscsi_cmd *hdr = task->hdr;
	struct scsi_cmnd *sc = task->sc;
	unsigned hdrlength, cmd_len;
	int rc;

	task->hdr_len = 0;
	rc = iscsi_add_hdr(task, sizeof(*hdr));
	if (rc)
		return rc;
	hdr->opcode = ISCSI_OP_SCSI_CMD;
	hdr->flags = ISCSI_ATTR_SIMPLE;
	int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
	hdr->itt = build_itt(task->itt, session->age);
	hdr->cmdsn = cpu_to_be32(session->cmdsn);
	session->cmdsn++;
	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
	cmd_len = sc->cmd_len;
	if (cmd_len < ISCSI_CDB_SIZE)
		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
	else if (cmd_len > ISCSI_CDB_SIZE) {
		rc = iscsi_prep_ecdb_ahs(task);
		if (rc)
			return rc;
		cmd_len = ISCSI_CDB_SIZE;
	}
	memcpy(hdr->cdb, sc->cmnd, cmd_len);

	task->imm_count = 0;
	if (scsi_bidi_cmnd(sc)) {
		hdr->flags |= ISCSI_FLAG_CMD_READ;
		rc = iscsi_prep_bidi_ahs(task);
		if (rc)
			return rc;
	}
	if (sc->sc_data_direction == DMA_TO_DEVICE) {
		unsigned out_len = scsi_out(sc)->length;
		hdr->data_length = cpu_to_be32(out_len);
		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
		/*
		 * Write counters:
		 *
		 *	imm_count	bytes to be sent right after
		 *			SCSI PDU Header
		 *
		 *	unsol_count	bytes(as Data-Out) to be sent
		 *			without	R2T ack right after
		 *			immediate data
		 *
		 *	r2t_data_count	bytes to be sent via R2T ack's
		 *
		 *      pad_count       bytes to be sent as zero-padding
		 */
		task->unsol_count = 0;
		task->unsol_offset = 0;
		task->unsol_datasn = 0;

		if (session->imm_data_en) {
			if (out_len >= session->first_burst)
				task->imm_count = min(session->first_burst,
							conn->max_xmit_dlength);
			else
				task->imm_count = min(out_len,
							conn->max_xmit_dlength);
			hton24(hdr->dlength, task->imm_count);
		} else
			zero_data(hdr->dlength);

		if (!session->initial_r2t_en) {
			task->unsol_count = min(session->first_burst, out_len)
							     - task->imm_count;
			task->unsol_offset = task->imm_count;
		}

		if (!task->unsol_count)
			/* No unsolicit Data-Out's */
			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
	} else {
		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
		zero_data(hdr->dlength);
		hdr->data_length = cpu_to_be32(scsi_in(sc)->length);

		if (sc->sc_data_direction == DMA_FROM_DEVICE)
			hdr->flags |= ISCSI_FLAG_CMD_READ;
	}

	/* calculate size of additional header segments (AHSs) */
	hdrlength = task->hdr_len - sizeof(*hdr);

	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
	hdrlength /= ISCSI_PAD_LEN;

	WARN_ON(hdrlength >= 256);
	hdr->hlength = hdrlength & 0xFF;

	if (conn->session->tt->init_task &&
	    conn->session->tt->init_task(task))
		return -EIO;

	task->state = ISCSI_TASK_RUNNING;
	list_move_tail(&task->running, &conn->run_list);

	conn->scsicmd_pdus_cnt++;
	debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
		   "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
		   "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
		   "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
		   scsi_bufflen(sc),
		   scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
		   session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
	return 0;
}

/**
 * iscsi_complete_command - finish a task
 * @task: iscsi cmd task
 *
 * Must be called with session lock.
 * This function returns the scsi command to scsi-ml or cleans
 * up mgmt tasks then returns the task to the pool.
 */
static void iscsi_complete_command(struct iscsi_task *task)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_session *session = conn->session;
	struct scsi_cmnd *sc = task->sc;

	list_del_init(&task->running);
	task->state = ISCSI_TASK_COMPLETED;
	task->sc = NULL;

	if (conn->task == task)
		conn->task = NULL;
	/*
	 * login task is preallocated so do not free
	 */
	if (conn->login_task == task)
		return;

	__kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));

	if (conn->ping_task == task)
		conn->ping_task = NULL;

	if (sc) {
		task->sc = NULL;
		/* SCSI eh reuses commands to verify us */
		sc->SCp.ptr = NULL;
		/*
		 * queue command may call this to free the task, but
		 * not have setup the sc callback
		 */
		if (sc->scsi_done)
			sc->scsi_done(sc);
	}
}

void __iscsi_get_task(struct iscsi_task *task)
{
	atomic_inc(&task->refcount);
}
EXPORT_SYMBOL_GPL(__iscsi_get_task);

static void __iscsi_put_task(struct iscsi_task *task)
{
	if (atomic_dec_and_test(&task->refcount))
		iscsi_complete_command(task);
}

void iscsi_put_task(struct iscsi_task *task)
{
	struct iscsi_session *session = task->conn->session;

	spin_lock_bh(&session->lock);
	__iscsi_put_task(task);
	spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_put_task);

/*
 * session lock must be held
 */
static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
			 int err)
{
	struct scsi_cmnd *sc;

	sc = task->sc;
	if (!sc)
		return;

	if (task->state == ISCSI_TASK_PENDING)
		/*
		 * cmd never made it to the xmit thread, so we should not count
		 * the cmd in the sequencing
		 */
		conn->session->queued_cmdsn--;
	else
		conn->session->tt->cleanup_task(conn, task);
	/*
	 * Check if cleanup_task dropped the lock and the command completed,
	 */
	if (!task->sc)
		return;

	sc->result = err;
	if (!scsi_bidi_cmnd(sc))
		scsi_set_resid(sc, scsi_bufflen(sc));
	else {
		scsi_out(sc)->resid = scsi_out(sc)->length;
		scsi_in(sc)->resid = scsi_in(sc)->length;
	}

	if (conn->task == task)
		conn->task = NULL;
	/* release ref from queuecommand */
	__iscsi_put_task(task);
}

static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
				struct iscsi_task *task)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;

	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
		return -ENOTCONN;

	if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
	    hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
	/*
	 * pre-format CmdSN for outgoing PDU.
	 */
	nop->cmdsn = cpu_to_be32(session->cmdsn);
	if (hdr->itt != RESERVED_ITT) {
		hdr->itt = build_itt(task->itt, session->age);
		/*
		 * TODO: We always use immediate, so we never hit this.
		 * If we start to send tmfs or nops as non-immediate then
		 * we should start checking the cmdsn numbers for mgmt tasks.
		 */
		if (conn->c_stage == ISCSI_CONN_STARTED &&
		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
			session->queued_cmdsn++;
			session->cmdsn++;
		}
	}

	if (session->tt->init_task)
		session->tt->init_task(task);

	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
		session->state = ISCSI_STATE_LOGGING_OUT;

	list_move_tail(&task->running, &conn->mgmt_run_list);
	debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
		   hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
		   task->data_count);
	return 0;
}

static struct iscsi_task *
__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
		      char *data, uint32_t data_size)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_task *task;

	if (session->state == ISCSI_STATE_TERMINATE)
		return NULL;

	if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
	    hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
		/*
		 * Login and Text are sent serially, in
		 * request-followed-by-response sequence.
		 * Same task can be used. Same ITT must be used.
		 * Note that login_task is preallocated at conn_create().
		 */
		task = conn->login_task;
	else {
		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);

		if (!__kfifo_get(session->cmdpool.queue,
				 (void*)&task, sizeof(void*)))
			return NULL;

		if ((hdr->opcode == (ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE)) &&
		     hdr->ttt == RESERVED_ITT) {
			conn->ping_task = task;
			conn->last_ping = jiffies;
		}
	}
	/*
	 * released in complete pdu for task we expect a response for, and
	 * released by the lld when it has transmitted the task for
	 * pdus we do not expect a response for.
	 */
	atomic_set(&task->refcount, 1);
	task->conn = conn;
	task->sc = NULL;

	if (data_size) {
		memcpy(task->data, data, data_size);
		task->data_count = data_size;
	} else
		task->data_count = 0;

	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
	INIT_LIST_HEAD(&task->running);
	list_add_tail(&task->running, &conn->mgmtqueue);

	if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
		if (iscsi_prep_mgmt_task(conn, task)) {
			__iscsi_put_task(task);
			return NULL;
		}

		if (session->tt->xmit_task(task))
			task = NULL;

	} else
		scsi_queue_work(conn->session->host, &conn->xmitwork);

	return task;
}

int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
			char *data, uint32_t data_size)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;
	int err = 0;

	spin_lock_bh(&session->lock);
	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
		err = -EPERM;
	spin_unlock_bh(&session->lock);
	return err;
}
EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);

/**
 * iscsi_cmd_rsp - SCSI Command Response processing
 * @conn: iscsi connection
 * @hdr: iscsi header
 * @task: scsi command task
 * @data: cmd data buffer
 * @datalen: len of buffer
 *
 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 * then completes the command and task.
 **/
static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			       struct iscsi_task *task, char *data,
			       int datalen)
{
	struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
	struct iscsi_session *session = conn->session;
	struct scsi_cmnd *sc = task->sc;

	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;

	sc->result = (DID_OK << 16) | rhdr->cmd_status;

	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
		sc->result = DID_ERROR << 16;
		goto out;
	}

	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
		uint16_t senselen;

		if (datalen < 2) {
invalid_datalen:
			iscsi_conn_printk(KERN_ERR,  conn,
					 "Got CHECK_CONDITION but invalid data "
					 "buffer size of %d\n", datalen);
			sc->result = DID_BAD_TARGET << 16;
			goto out;
		}

		senselen = get_unaligned_be16(data);
		if (datalen < senselen)
			goto invalid_datalen;

		memcpy(sc->sense_buffer, data + 2,
		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
		debug_scsi("copied %d bytes of sense\n",
			   min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
	}

	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
		int res_count = be32_to_cpu(rhdr->bi_residual_count);

		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
				 res_count <= scsi_in(sc)->length))
			scsi_in(sc)->resid = res_count;
		else
			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
	}

	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
	                   ISCSI_FLAG_CMD_OVERFLOW)) {
		int res_count = be32_to_cpu(rhdr->residual_count);

		if (res_count > 0 &&
		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
		     res_count <= scsi_bufflen(sc)))
			/* write side for bidi or uni-io set_resid */
			scsi_set_resid(sc, res_count);
		else
			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
	}
out:
	debug_scsi("done [sc %lx res %d itt 0x%x]\n",
		   (long)sc, sc->result, task->itt);
	conn->scsirsp_pdus_cnt++;

	__iscsi_put_task(task);
}

static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
{
	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;

	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
	conn->tmfrsp_pdus_cnt++;

	if (conn->tmf_state != TMF_QUEUED)
		return;

	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
		conn->tmf_state = TMF_SUCCESS;
	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
		conn->tmf_state = TMF_NOT_FOUND;
	else
		conn->tmf_state = TMF_FAILED;
	wake_up(&conn->ehwait);
}

static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
{
        struct iscsi_nopout hdr;
	struct iscsi_task *task;

	if (!rhdr && conn->ping_task)
		return;

	memset(&hdr, 0, sizeof(struct iscsi_nopout));
	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
	hdr.flags = ISCSI_FLAG_CMD_FINAL;

	if (rhdr) {
		memcpy(hdr.lun, rhdr->lun, 8);
		hdr.ttt = rhdr->ttt;
		hdr.itt = RESERVED_ITT;
	} else
		hdr.ttt = RESERVED_ITT;

	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
	if (!task)
		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
}

static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			       char *data, int datalen)
{
	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
	struct iscsi_hdr rejected_pdu;
	uint32_t itt;

	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;

	if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
		if (ntoh24(reject->dlength) > datalen)
			return ISCSI_ERR_PROTO;

		if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
			memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
			itt = get_itt(rejected_pdu.itt);
			iscsi_conn_printk(KERN_ERR, conn,
					  "itt 0x%x had pdu (op 0x%x) rejected "
					  "due to DataDigest error.\n", itt,
					  rejected_pdu.opcode);
		}
	}
	return 0;
}

/**
 * iscsi_itt_to_task - look up task by itt
 * @conn: iscsi connection
 * @itt: itt
 *
 * This should be used for mgmt tasks like login and nops, or if
 * the LDD's itt space does not include the session age.
 *
 * The session lock must be held.
 */
static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
{
	struct iscsi_session *session = conn->session;
	uint32_t i;

	if (itt == RESERVED_ITT)
		return NULL;

	i = get_itt(itt);
	if (i >= session->cmds_max)
		return NULL;

	return session->cmds[i];
}

/**
 * __iscsi_complete_pdu - complete pdu
 * @conn: iscsi conn
 * @hdr: iscsi header
 * @data: data buffer
 * @datalen: len of data buffer
 *
 * Completes pdu processing by freeing any resources allocated at
 * queuecommand or send generic. session lock must be held and verify
 * itt must have been called.
 */
int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
			 char *data, int datalen)
{
	struct iscsi_session *session = conn->session;
	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
	struct iscsi_task *task;
	uint32_t itt;

	conn->last_recv = jiffies;
	rc = iscsi_verify_itt(conn, hdr->itt);
	if (rc)
		return rc;

	if (hdr->itt != RESERVED_ITT)
		itt = get_itt(hdr->itt);
	else
		itt = ~0U;

	debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
		   opcode, conn->id, itt, datalen);

	if (itt == ~0U) {
		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);

		switch(opcode) {
		case ISCSI_OP_NOOP_IN:
			if (datalen) {
				rc = ISCSI_ERR_PROTO;
				break;
			}

			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
				break;

			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
			break;
		case ISCSI_OP_REJECT:
			rc = iscsi_handle_reject(conn, hdr, data, datalen);
			break;
		case ISCSI_OP_ASYNC_EVENT:
			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
				rc = ISCSI_ERR_CONN_FAILED;
			break;
		default:
			rc = ISCSI_ERR_BAD_OPCODE;
			break;
		}
		goto out;
	}

	switch(opcode) {
	case ISCSI_OP_SCSI_CMD_RSP:
	case ISCSI_OP_SCSI_DATA_IN:
		task = iscsi_itt_to_ctask(conn, hdr->itt);
		if (!task)
			return ISCSI_ERR_BAD_ITT;
		break;
	case ISCSI_OP_R2T:
		/*
		 * LLD handles R2Ts if they need to.
		 */
		return 0;
	case ISCSI_OP_LOGOUT_RSP:
	case ISCSI_OP_LOGIN_RSP:
	case ISCSI_OP_TEXT_RSP:
	case ISCSI_OP_SCSI_TMFUNC_RSP:
	case ISCSI_OP_NOOP_IN:
		task = iscsi_itt_to_task(conn, hdr->itt);
		if (!task)
			return ISCSI_ERR_BAD_ITT;
		break;
	default:
		return ISCSI_ERR_BAD_OPCODE;
	}

	switch(opcode) {
	case ISCSI_OP_SCSI_CMD_RSP:
		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
		break;
	case ISCSI_OP_SCSI_DATA_IN:
		if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
			conn->scsirsp_pdus_cnt++;
			iscsi_update_cmdsn(session,
					   (struct iscsi_nopin*) hdr);
			__iscsi_put_task(task);
		}
		break;
	case ISCSI_OP_LOGOUT_RSP:
		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
		if (datalen) {
			rc = ISCSI_ERR_PROTO;
			break;
		}
		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
		goto recv_pdu;
	case ISCSI_OP_LOGIN_RSP:
	case ISCSI_OP_TEXT_RSP:
		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
		/*
		 * login related PDU's exp_statsn is handled in
		 * userspace
		 */
		goto recv_pdu;
	case ISCSI_OP_SCSI_TMFUNC_RSP:
		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
		if (datalen) {
			rc = ISCSI_ERR_PROTO;
			break;
		}

		iscsi_tmf_rsp(conn, hdr);
		__iscsi_put_task(task);
		break;
	case ISCSI_OP_NOOP_IN:
		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
			rc = ISCSI_ERR_PROTO;
			break;
		}
		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;

		if (conn->ping_task != task)
			/*
			 * If this is not in response to one of our
			 * nops then it must be from userspace.
			 */
			goto recv_pdu;

		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
		__iscsi_put_task(task);
		break;
	default:
		rc = ISCSI_ERR_BAD_OPCODE;
		break;
	}

out:
	return rc;
recv_pdu:
	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
		rc = ISCSI_ERR_CONN_FAILED;
	__iscsi_put_task(task);
	return rc;
}
EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);

int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
		       char *data, int datalen)
{
	int rc;

	spin_lock(&conn->session->lock);
	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
	spin_unlock(&conn->session->lock);
	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_complete_pdu);

int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
{
	struct iscsi_session *session = conn->session;
	uint32_t i;

	if (itt == RESERVED_ITT)
		return 0;

	if (((__force u32)itt & ISCSI_AGE_MASK) !=
	    (session->age << ISCSI_AGE_SHIFT)) {
		iscsi_conn_printk(KERN_ERR, conn,
				  "received itt %x expected session age (%x)\n",
				  (__force u32)itt, session->age);
		return ISCSI_ERR_BAD_ITT;
	}

	i = get_itt(itt);
	if (i >= session->cmds_max) {
		iscsi_conn_printk(KERN_ERR, conn,
				  "received invalid itt index %u (max cmds "
				   "%u.\n", i, session->cmds_max);
		return ISCSI_ERR_BAD_ITT;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);

/**
 * iscsi_itt_to_ctask - look up ctask by itt
 * @conn: iscsi connection
 * @itt: itt
 *
 * This should be used for cmd tasks.
 *
 * The session lock must be held.
 */
struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
{
	struct iscsi_task *task;

	if (iscsi_verify_itt(conn, itt))
		return NULL;

	task = iscsi_itt_to_task(conn, itt);
	if (!task || !task->sc)
		return NULL;

	if (task->sc->SCp.phase != conn->session->age) {
		iscsi_session_printk(KERN_ERR, conn->session,
				  "task's session age %d, expected %d\n",
				  task->sc->SCp.phase, conn->session->age);
		return NULL;
	}

	return task;
}
EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);

void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
{
	struct iscsi_session *session = conn->session;
	unsigned long flags;

	spin_lock_irqsave(&session->lock, flags);
	if (session->state == ISCSI_STATE_FAILED) {
		spin_unlock_irqrestore(&session->lock, flags);
		return;
	}

	if (conn->stop_stage == 0)
		session->state = ISCSI_STATE_FAILED;
	spin_unlock_irqrestore(&session->lock, flags);
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
	iscsi_conn_error(conn->cls_conn, err);
}
EXPORT_SYMBOL_GPL(iscsi_conn_failure);

static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
{
	struct iscsi_session *session = conn->session;

	/*
	 * Check for iSCSI window and take care of CmdSN wrap-around
	 */
	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
		debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
			   "CmdSN %u/%u\n", session->exp_cmdsn,
			   session->max_cmdsn, session->cmdsn,
			   session->queued_cmdsn);
		return -ENOSPC;
	}
	return 0;
}

static int iscsi_xmit_task(struct iscsi_conn *conn)
{
	struct iscsi_task *task = conn->task;
	int rc;

	__iscsi_get_task(task);
	spin_unlock_bh(&conn->session->lock);
	rc = conn->session->tt->xmit_task(task);
	spin_lock_bh(&conn->session->lock);
	__iscsi_put_task(task);
	if (!rc)
		/* done with this task */
		conn->task = NULL;
	return rc;
}

/**
 * iscsi_requeue_task - requeue task to run from session workqueue
 * @task: task to requeue
 *
 * LLDs that need to run a task from the session workqueue should call
 * this. The session lock must be held. This should only be called
 * by software drivers.
 */
void iscsi_requeue_task(struct iscsi_task *task)
{
	struct iscsi_conn *conn = task->conn;

	list_move_tail(&task->running, &conn->requeue);
	scsi_queue_work(conn->session->host, &conn->xmitwork);
}
EXPORT_SYMBOL_GPL(iscsi_requeue_task);

/**
 * iscsi_data_xmit - xmit any command into the scheduled connection
 * @conn: iscsi connection
 *
 * Notes:
 *	The function can return -EAGAIN in which case the caller must
 *	re-schedule it again later or recover. '0' return code means
 *	successful xmit.
 **/
static int iscsi_data_xmit(struct iscsi_conn *conn)
{
	int rc = 0;

	spin_lock_bh(&conn->session->lock);
	if (unlikely(conn->suspend_tx)) {
		debug_scsi("conn %d Tx suspended!\n", conn->id);
		spin_unlock_bh(&conn->session->lock);
		return -ENODATA;
	}

	if (conn->task) {
		rc = iscsi_xmit_task(conn);
	        if (rc)
		        goto again;
	}

	/*
	 * process mgmt pdus like nops before commands since we should
	 * only have one nop-out as a ping from us and targets should not
	 * overflow us with nop-ins
	 */
check_mgmt:
	while (!list_empty(&conn->mgmtqueue)) {
		conn->task = list_entry(conn->mgmtqueue.next,
					 struct iscsi_task, running);
		if (iscsi_prep_mgmt_task(conn, conn->task)) {
			__iscsi_put_task(conn->task);
			conn->task = NULL;
			continue;
		}
		rc = iscsi_xmit_task(conn);
		if (rc)
			goto again;
	}

	/* process pending command queue */
	while (!list_empty(&conn->xmitqueue)) {
		if (conn->tmf_state == TMF_QUEUED)
			break;

		conn->task = list_entry(conn->xmitqueue.next,
					 struct iscsi_task, running);
		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
			fail_command(conn, conn->task, DID_IMM_RETRY << 16);
			continue;
		}
		if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
			fail_command(conn, conn->task, DID_ABORT << 16);
			continue;
		}
		rc = iscsi_xmit_task(conn);
		if (rc)
			goto again;
		/*
		 * we could continuously get new task requests so
		 * we need to check the mgmt queue for nops that need to
		 * be sent to aviod starvation
		 */
		if (!list_empty(&conn->mgmtqueue))
			goto check_mgmt;
	}

	while (!list_empty(&conn->requeue)) {
		if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
			break;

		/*
		 * we always do fastlogout - conn stop code will clean up.
		 */
		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
			break;

		conn->task = list_entry(conn->requeue.next,
					 struct iscsi_task, running);
		conn->task->state = ISCSI_TASK_RUNNING;
		list_move_tail(conn->requeue.next, &conn->run_list);
		rc = iscsi_xmit_task(conn);
		if (rc)
			goto again;
		if (!list_empty(&conn->mgmtqueue))
			goto check_mgmt;
	}
	spin_unlock_bh(&conn->session->lock);
	return -ENODATA;

again:
	if (unlikely(conn->suspend_tx))
		rc = -ENODATA;
	spin_unlock_bh(&conn->session->lock);
	return rc;
}

static void iscsi_xmitworker(struct work_struct *work)
{
	struct iscsi_conn *conn =
		container_of(work, struct iscsi_conn, xmitwork);
	int rc;
	/*
	 * serialize Xmit worker on a per-connection basis.
	 */
	do {
		rc = iscsi_data_xmit(conn);
	} while (rc >= 0 || rc == -EAGAIN);
}

enum {
	FAILURE_BAD_HOST = 1,
	FAILURE_SESSION_FAILED,
	FAILURE_SESSION_FREED,
	FAILURE_WINDOW_CLOSED,
	FAILURE_OOM,
	FAILURE_SESSION_TERMINATE,
	FAILURE_SESSION_IN_RECOVERY,
	FAILURE_SESSION_RECOVERY_TIMEOUT,
	FAILURE_SESSION_LOGGING_OUT,
	FAILURE_SESSION_NOT_READY,
};

int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
{
	struct iscsi_cls_session *cls_session;
	struct Scsi_Host *host;
	int reason = 0;
	struct iscsi_session *session;
	struct iscsi_conn *conn;
	struct iscsi_task *task = NULL;

	sc->scsi_done = done;
	sc->result = 0;
	sc->SCp.ptr = NULL;

	host = sc->device->host;
	spin_unlock(host->host_lock);

	cls_session = starget_to_session(scsi_target(sc->device));
	session = cls_session->dd_data;
	spin_lock(&session->lock);

	reason = iscsi_session_chkready(cls_session);
	if (reason) {
		sc->result = reason;
		goto fault;
	}

	/*
	 * ISCSI_STATE_FAILED is a temp. state. The recovery
	 * code will decide what is best to do with command queued
	 * during this time
	 */
	if (session->state != ISCSI_STATE_LOGGED_IN &&
	    session->state != ISCSI_STATE_FAILED) {
		/*
		 * to handle the race between when we set the recovery state
		 * and block the session we requeue here (commands could
		 * be entering our queuecommand while a block is starting
		 * up because the block code is not locked)
		 */
		switch (session->state) {
		case ISCSI_STATE_IN_RECOVERY:
			reason = FAILURE_SESSION_IN_RECOVERY;
			sc->result = DID_IMM_RETRY << 16;
			break;
		case ISCSI_STATE_LOGGING_OUT:
			reason = FAILURE_SESSION_LOGGING_OUT;
			sc->result = DID_IMM_RETRY << 16;
			break;
		case ISCSI_STATE_RECOVERY_FAILED:
			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
			sc->result = DID_NO_CONNECT << 16;
			break;
		case ISCSI_STATE_TERMINATE:
			reason = FAILURE_SESSION_TERMINATE;
			sc->result = DID_NO_CONNECT << 16;
			break;
		default:
			reason = FAILURE_SESSION_FREED;
			sc->result = DID_NO_CONNECT << 16;
		}
		goto fault;
	}

	conn = session->leadconn;
	if (!conn) {
		reason = FAILURE_SESSION_FREED;
		sc->result = DID_NO_CONNECT << 16;
		goto fault;
	}

	if (iscsi_check_cmdsn_window_closed(conn)) {
		reason = FAILURE_WINDOW_CLOSED;
		goto reject;
	}

	if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
			 sizeof(void*))) {
		reason = FAILURE_OOM;
		goto reject;
	}
	sc->SCp.phase = session->age;
	sc->SCp.ptr = (char *)task;

	atomic_set(&task->refcount, 1);
	task->state = ISCSI_TASK_PENDING;
	task->conn = conn;
	task->sc = sc;
	INIT_LIST_HEAD(&task->running);
	list_add_tail(&task->running, &conn->xmitqueue);

	if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
		if (iscsi_prep_scsi_cmd_pdu(task)) {
			sc->result = DID_ABORT << 16;
			sc->scsi_done = NULL;
			iscsi_complete_command(task);
			goto fault;
		}
		if (session->tt->xmit_task(task)) {
			sc->scsi_done = NULL;
			iscsi_complete_command(task);
			reason = FAILURE_SESSION_NOT_READY;
			goto reject;
		}
	} else
		scsi_queue_work(session->host, &conn->xmitwork);

	session->queued_cmdsn++;
	spin_unlock(&session->lock);
	spin_lock(host->host_lock);
	return 0;

reject:
	spin_unlock(&session->lock);
	debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
	spin_lock(host->host_lock);
	return SCSI_MLQUEUE_HOST_BUSY;

fault:
	spin_unlock(&session->lock);
	debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
	if (!scsi_bidi_cmnd(sc))
		scsi_set_resid(sc, scsi_bufflen(sc));
	else {
		scsi_out(sc)->resid = scsi_out(sc)->length;
		scsi_in(sc)->resid = scsi_in(sc)->length;
	}
	done(sc);
	spin_lock(host->host_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_queuecommand);

int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
	if (depth > ISCSI_MAX_CMD_PER_LUN)
		depth = ISCSI_MAX_CMD_PER_LUN;
	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
	return sdev->queue_depth;
}
EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);

void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
{
	struct iscsi_session *session = cls_session->dd_data;

	spin_lock_bh(&session->lock);
	if (session->state != ISCSI_STATE_LOGGED_IN) {
		session->state = ISCSI_STATE_RECOVERY_FAILED;
		if (session->leadconn)
			wake_up(&session->leadconn->ehwait);
	}
	spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);

int iscsi_eh_host_reset(struct scsi_cmnd *sc)
{
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	struct iscsi_conn *conn;

	cls_session = starget_to_session(scsi_target(sc->device));
	session = cls_session->dd_data;
	conn = session->leadconn;

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	if (session->state == ISCSI_STATE_TERMINATE) {
failed:
		debug_scsi("failing host reset: session terminated "
			   "[CID %d age %d]\n", conn->id, session->age);
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return FAILED;
	}

	spin_unlock_bh(&session->lock);
	mutex_unlock(&session->eh_mutex);
	/*
	 * we drop the lock here but the leadconn cannot be destoyed while
	 * we are in the scsi eh
	 */
	iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);

	debug_scsi("iscsi_eh_host_reset wait for relogin\n");
	wait_event_interruptible(conn->ehwait,
				 session->state == ISCSI_STATE_TERMINATE ||
				 session->state == ISCSI_STATE_LOGGED_IN ||
				 session->state == ISCSI_STATE_RECOVERY_FAILED);
	if (signal_pending(current))
		flush_signals(current);

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	if (session->state == ISCSI_STATE_LOGGED_IN)
		iscsi_session_printk(KERN_INFO, session,
				     "host reset succeeded\n");
	else
		goto failed;
	spin_unlock_bh(&session->lock);
	mutex_unlock(&session->eh_mutex);
	return SUCCESS;
}
EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);

static void iscsi_tmf_timedout(unsigned long data)
{
	struct iscsi_conn *conn = (struct iscsi_conn *)data;
	struct iscsi_session *session = conn->session;

	spin_lock(&session->lock);
	if (conn->tmf_state == TMF_QUEUED) {
		conn->tmf_state = TMF_TIMEDOUT;
		debug_scsi("tmf timedout\n");
		/* unblock eh_abort() */
		wake_up(&conn->ehwait);
	}
	spin_unlock(&session->lock);
}

static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
				   struct iscsi_tm *hdr, int age,
				   int timeout)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_task *task;

	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
				      NULL, 0);
	if (!task) {
		spin_unlock_bh(&session->lock);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
		spin_lock_bh(&session->lock);
		debug_scsi("tmf exec failure\n");
		return -EPERM;
	}
	conn->tmfcmd_pdus_cnt++;
	conn->tmf_timer.expires = timeout * HZ + jiffies;
	conn->tmf_timer.function = iscsi_tmf_timedout;
	conn->tmf_timer.data = (unsigned long)conn;
	add_timer(&conn->tmf_timer);
	debug_scsi("tmf set timeout\n");

	spin_unlock_bh(&session->lock);
	mutex_unlock(&session->eh_mutex);

	/*
	 * block eh thread until:
	 *
	 * 1) tmf response
	 * 2) tmf timeout
	 * 3) session is terminated or restarted or userspace has
	 * given up on recovery
	 */
	wait_event_interruptible(conn->ehwait, age != session->age ||
				 session->state != ISCSI_STATE_LOGGED_IN ||
				 conn->tmf_state != TMF_QUEUED);
	if (signal_pending(current))
		flush_signals(current);
	del_timer_sync(&conn->tmf_timer);

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	/* if the session drops it will clean up the task */
	if (age != session->age ||
	    session->state != ISCSI_STATE_LOGGED_IN)
		return -ENOTCONN;
	return 0;
}

/*
 * Fail commands. session lock held and recv side suspended and xmit
 * thread flushed
 */
static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
			      int error)
{
	struct iscsi_task *task, *tmp;

	if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
		conn->task = NULL;

	/* flush pending */
	list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
		if (lun == task->sc->device->lun || lun == -1) {
			debug_scsi("failing pending sc %p itt 0x%x\n",
				   task->sc, task->itt);
			fail_command(conn, task, error << 16);
		}
	}

	list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
		if (lun == task->sc->device->lun || lun == -1) {
			debug_scsi("failing requeued sc %p itt 0x%x\n",
				   task->sc, task->itt);
			fail_command(conn, task, error << 16);
		}
	}

	/* fail all other running */
	list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
		if (lun == task->sc->device->lun || lun == -1) {
			debug_scsi("failing in progress sc %p itt 0x%x\n",
				   task->sc, task->itt);
			fail_command(conn, task, DID_BUS_BUSY << 16);
		}
	}
}

void iscsi_suspend_tx(struct iscsi_conn *conn)
{
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
		scsi_flush_work(conn->session->host);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_tx);

static void iscsi_start_tx(struct iscsi_conn *conn)
{
	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
		scsi_queue_work(conn->session->host, &conn->xmitwork);
}

static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
{
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	struct iscsi_conn *conn;
	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;

	cls_session = starget_to_session(scsi_target(scmd->device));
	session = cls_session->dd_data;

	debug_scsi("scsi cmd %p timedout\n", scmd);

	spin_lock(&session->lock);
	if (session->state != ISCSI_STATE_LOGGED_IN) {
		/*
		 * We are probably in the middle of iscsi recovery so let
		 * that complete and handle the error.
		 */
		rc = BLK_EH_RESET_TIMER;
		goto done;
	}

	conn = session->leadconn;
	if (!conn) {
		/* In the middle of shuting down */
		rc = BLK_EH_RESET_TIMER;
		goto done;
	}

	if (!conn->recv_timeout && !conn->ping_timeout)
		goto done;
	/*
	 * if the ping timedout then we are in the middle of cleaning up
	 * and can let the iscsi eh handle it
	 */
	if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
			    (conn->ping_timeout * HZ), jiffies))
		rc = BLK_EH_RESET_TIMER;
	/*
	 * if we are about to check the transport then give the command
	 * more time
	 */
	if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
			   jiffies))
		rc = BLK_EH_RESET_TIMER;
	/* if in the middle of checking the transport then give us more time */
	if (conn->ping_task)
		rc = BLK_EH_RESET_TIMER;
done:
	spin_unlock(&session->lock);
	debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
					"timer reset" : "nh");
	return rc;
}

static void iscsi_check_transport_timeouts(unsigned long data)
{
	struct iscsi_conn *conn = (struct iscsi_conn *)data;
	struct iscsi_session *session = conn->session;
	unsigned long recv_timeout, next_timeout = 0, last_recv;

	spin_lock(&session->lock);
	if (session->state != ISCSI_STATE_LOGGED_IN)
		goto done;

	recv_timeout = conn->recv_timeout;
	if (!recv_timeout)
		goto done;

	recv_timeout *= HZ;
	last_recv = conn->last_recv;
	if (conn->ping_task &&
	    time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
			   jiffies)) {
		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
				  "expired, last rx %lu, last ping %lu, "
				  "now %lu\n", conn->ping_timeout, last_recv,
				  conn->last_ping, jiffies);
		spin_unlock(&session->lock);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
		return;
	}

	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
		/* send a ping to try to provoke some traffic */
		debug_scsi("Sending nopout as ping on conn %p\n", conn);
		iscsi_send_nopout(conn, NULL);
		next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
	} else
		next_timeout = last_recv + recv_timeout;

	debug_scsi("Setting next tmo %lu\n", next_timeout);
	mod_timer(&conn->transport_timer, next_timeout);
done:
	spin_unlock(&session->lock);
}

static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
				      struct iscsi_tm *hdr)
{
	memset(hdr, 0, sizeof(*hdr));
	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
	memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
	hdr->rtt = task->hdr->itt;
	hdr->refcmdsn = task->hdr->cmdsn;
}

int iscsi_eh_abort(struct scsi_cmnd *sc)
{
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	struct iscsi_conn *conn;
	struct iscsi_task *task;
	struct iscsi_tm *hdr;
	int rc, age;

	cls_session = starget_to_session(scsi_target(sc->device));
	session = cls_session->dd_data;

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	/*
	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
	 * got the command.
	 */
	if (!sc->SCp.ptr) {
		debug_scsi("sc never reached iscsi layer or it completed.\n");
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return SUCCESS;
	}

	/*
	 * If we are not logged in or we have started a new session
	 * then let the host reset code handle this
	 */
	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
	    sc->SCp.phase != session->age) {
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return FAILED;
	}

	conn = session->leadconn;
	conn->eh_abort_cnt++;
	age = session->age;

	task = (struct iscsi_task *)sc->SCp.ptr;
	debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);

	/* task completed before time out */
	if (!task->sc) {
		debug_scsi("sc completed while abort in progress\n");
		goto success;
	}

	if (task->state == ISCSI_TASK_PENDING) {
		fail_command(conn, task, DID_ABORT << 16);
		goto success;
	}

	/* only have one tmf outstanding at a time */
	if (conn->tmf_state != TMF_INITIAL)
		goto failed;
	conn->tmf_state = TMF_QUEUED;

	hdr = &conn->tmhdr;
	iscsi_prep_abort_task_pdu(task, hdr);

	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
		rc = FAILED;
		goto failed;
	}

	switch (conn->tmf_state) {
	case TMF_SUCCESS:
		spin_unlock_bh(&session->lock);
		/*
		 * stop tx side incase the target had sent a abort rsp but
		 * the initiator was still writing out data.
		 */
		iscsi_suspend_tx(conn);
		/*
		 * we do not stop the recv side because targets have been
		 * good and have never sent us a successful tmf response
		 * then sent more data for the cmd.
		 */
		spin_lock(&session->lock);
		fail_command(conn, task, DID_ABORT << 16);
		conn->tmf_state = TMF_INITIAL;
		spin_unlock(&session->lock);
		iscsi_start_tx(conn);
		goto success_unlocked;
	case TMF_TIMEDOUT:
		spin_unlock_bh(&session->lock);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
		goto failed_unlocked;
	case TMF_NOT_FOUND:
		if (!sc->SCp.ptr) {
			conn->tmf_state = TMF_INITIAL;
			/* task completed before tmf abort response */
			debug_scsi("sc completed while abort in progress\n");
			goto success;
		}
		/* fall through */
	default:
		conn->tmf_state = TMF_INITIAL;
		goto failed;
	}

success:
	spin_unlock_bh(&session->lock);
success_unlocked:
	debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
	mutex_unlock(&session->eh_mutex);
	return SUCCESS;

failed:
	spin_unlock_bh(&session->lock);
failed_unlocked:
	debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
		    task ? task->itt : 0);
	mutex_unlock(&session->eh_mutex);
	return FAILED;
}
EXPORT_SYMBOL_GPL(iscsi_eh_abort);

static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
{
	memset(hdr, 0, sizeof(*hdr));
	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
	int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
	hdr->rtt = RESERVED_ITT;
}

int iscsi_eh_device_reset(struct scsi_cmnd *sc)
{
	struct iscsi_cls_session *cls_session;
	struct iscsi_session *session;
	struct iscsi_conn *conn;
	struct iscsi_tm *hdr;
	int rc = FAILED;

	cls_session = starget_to_session(scsi_target(sc->device));
	session = cls_session->dd_data;

	debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	/*
	 * Just check if we are not logged in. We cannot check for
	 * the phase because the reset could come from a ioctl.
	 */
	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
		goto unlock;
	conn = session->leadconn;

	/* only have one tmf outstanding at a time */
	if (conn->tmf_state != TMF_INITIAL)
		goto unlock;
	conn->tmf_state = TMF_QUEUED;

	hdr = &conn->tmhdr;
	iscsi_prep_lun_reset_pdu(sc, hdr);

	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
				    session->lu_reset_timeout)) {
		rc = FAILED;
		goto unlock;
	}

	switch (conn->tmf_state) {
	case TMF_SUCCESS:
		break;
	case TMF_TIMEDOUT:
		spin_unlock_bh(&session->lock);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
		goto done;
	default:
		conn->tmf_state = TMF_INITIAL;
		goto unlock;
	}

	rc = SUCCESS;
	spin_unlock_bh(&session->lock);

	iscsi_suspend_tx(conn);

	spin_lock(&session->lock);
	fail_all_commands(conn, sc->device->lun, DID_ERROR);
	conn->tmf_state = TMF_INITIAL;
	spin_unlock(&session->lock);

	iscsi_start_tx(conn);
	goto done;

unlock:
	spin_unlock_bh(&session->lock);
done:
	debug_scsi("iscsi_eh_device_reset %s\n",
		  rc == SUCCESS ? "SUCCESS" : "FAILED");
	mutex_unlock(&session->eh_mutex);
	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);

/*
 * Pre-allocate a pool of @max items of @item_size. By default, the pool
 * should be accessed via kfifo_{get,put} on q->queue.
 * Optionally, the caller can obtain the array of object pointers
 * by passing in a non-NULL @items pointer
 */
int
iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
{
	int i, num_arrays = 1;

	memset(q, 0, sizeof(*q));

	q->max = max;

	/* If the user passed an items pointer, he wants a copy of
	 * the array. */
	if (items)
		num_arrays++;
	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
	if (q->pool == NULL)
		goto enomem;

	q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
			      GFP_KERNEL, NULL);
	if (q->queue == ERR_PTR(-ENOMEM))
		goto enomem;

	for (i = 0; i < max; i++) {
		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
		if (q->pool[i] == NULL) {
			q->max = i;
			goto enomem;
		}
		__kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
	}

	if (items) {
		*items = q->pool + max;
		memcpy(*items, q->pool, max * sizeof(void *));
	}

	return 0;

enomem:
	iscsi_pool_free(q);
	return -ENOMEM;
}
EXPORT_SYMBOL_GPL(iscsi_pool_init);

void iscsi_pool_free(struct iscsi_pool *q)
{
	int i;

	for (i = 0; i < q->max; i++)
		kfree(q->pool[i]);
	if (q->pool)
		kfree(q->pool);
}
EXPORT_SYMBOL_GPL(iscsi_pool_free);

/**
 * iscsi_host_add - add host to system
 * @shost: scsi host
 * @pdev: parent device
 *
 * This should be called by partial offload and software iscsi drivers
 * to add a host to the system.
 */
int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
{
	if (!shost->can_queue)
		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;

	return scsi_add_host(shost, pdev);
}
EXPORT_SYMBOL_GPL(iscsi_host_add);

/**
 * iscsi_host_alloc - allocate a host and driver data
 * @sht: scsi host template
 * @dd_data_size: driver host data size
 * @qdepth: default device queue depth
 *
 * This should be called by partial offload and software iscsi drivers.
 * To access the driver specific memory use the iscsi_host_priv() macro.
 */
struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
				   int dd_data_size, uint16_t qdepth)
{
	struct Scsi_Host *shost;

	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
	if (!shost)
		return NULL;
	shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;

	if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
		if (qdepth != 0)
			printk(KERN_ERR "iscsi: invalid queue depth of %d. "
			       "Queue depth must be between 1 and %d.\n",
			       qdepth, ISCSI_MAX_CMD_PER_LUN);
		qdepth = ISCSI_DEF_CMD_PER_LUN;
	}
	shost->cmd_per_lun = qdepth;
	return shost;
}
EXPORT_SYMBOL_GPL(iscsi_host_alloc);

/**
 * iscsi_host_remove - remove host and sessions
 * @shost: scsi host
 *
 * This will also remove any sessions attached to the host, but if userspace
 * is managing the session at the same time this will break. TODO: add
 * refcounting to the netlink iscsi interface so a rmmod or host hot unplug
 * does not remove the memory from under us.
 */
void iscsi_host_remove(struct Scsi_Host *shost)
{
	iscsi_host_for_each_session(shost, iscsi_session_teardown);
	scsi_remove_host(shost);
}
EXPORT_SYMBOL_GPL(iscsi_host_remove);

void iscsi_host_free(struct Scsi_Host *shost)
{
	struct iscsi_host *ihost = shost_priv(shost);

	kfree(ihost->netdev);
	kfree(ihost->hwaddress);
	kfree(ihost->initiatorname);
	scsi_host_put(shost);
}
EXPORT_SYMBOL_GPL(iscsi_host_free);

/**
 * iscsi_session_setup - create iscsi cls session and host and session
 * @iscsit: iscsi transport template
 * @shost: scsi host
 * @cmds_max: session can queue
 * @cmd_task_size: LLD task private data size
 * @initial_cmdsn: initial CmdSN
 *
 * This can be used by software iscsi_transports that allocate
 * a session per scsi host.
 *
 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
 * for nop handling and login/logout requests.
 */
struct iscsi_cls_session *
iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
		    uint16_t cmds_max, int cmd_task_size,
		    uint32_t initial_cmdsn, unsigned int id)
{
	struct iscsi_session *session;
	struct iscsi_cls_session *cls_session;
	int cmd_i, scsi_cmds, total_cmds = cmds_max;

	if (!total_cmds)
		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
	/*
	 * The iscsi layer needs some tasks for nop handling and tmfs,
	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
	 * + 1 command for scsi IO.
	 */
	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
		       "must be a power of two that is at least %d.\n",
		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
		return NULL;
	}

	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
		       "must be a power of 2 less than or equal to %d.\n",
		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
		total_cmds = ISCSI_TOTAL_CMDS_MAX;
	}

	if (!is_power_of_2(total_cmds)) {
		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
		       "must be a power of 2.\n", total_cmds);
		total_cmds = rounddown_pow_of_two(total_cmds);
		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
			return NULL;
		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
		       total_cmds);
	}
	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;

	cls_session = iscsi_alloc_session(shost, iscsit,
					  sizeof(struct iscsi_session));
	if (!cls_session)
		return NULL;
	session = cls_session->dd_data;
	session->cls_session = cls_session;
	session->host = shost;
	session->state = ISCSI_STATE_FREE;
	session->fast_abort = 1;
	session->lu_reset_timeout = 15;
	session->abort_timeout = 10;
	session->scsi_cmds_max = scsi_cmds;
	session->cmds_max = total_cmds;
	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
	session->exp_cmdsn = initial_cmdsn + 1;
	session->max_cmdsn = initial_cmdsn + 1;
	session->max_r2t = 1;
	session->tt = iscsit;
	mutex_init(&session->eh_mutex);
	spin_lock_init(&session->lock);

	/* initialize SCSI PDU commands pool */
	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
			    (void***)&session->cmds,
			    cmd_task_size + sizeof(struct iscsi_task)))
		goto cmdpool_alloc_fail;

	/* pre-format cmds pool with ITT */
	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
		struct iscsi_task *task = session->cmds[cmd_i];

		if (cmd_task_size)
			task->dd_data = &task[1];
		task->itt = cmd_i;
		INIT_LIST_HEAD(&task->running);
	}

	if (!try_module_get(iscsit->owner))
		goto module_get_fail;

	if (iscsi_add_session(cls_session, id))
		goto cls_session_fail;
	return cls_session;

cls_session_fail:
	module_put(iscsit->owner);
module_get_fail:
	iscsi_pool_free(&session->cmdpool);
cmdpool_alloc_fail:
	iscsi_free_session(cls_session);
	return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_session_setup);

/**
 * iscsi_session_teardown - destroy session, host, and cls_session
 * @cls_session: iscsi session
 *
 * The driver must have called iscsi_remove_session before
 * calling this.
 */
void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
{
	struct iscsi_session *session = cls_session->dd_data;
	struct module *owner = cls_session->transport->owner;

	iscsi_pool_free(&session->cmdpool);

	kfree(session->password);
	kfree(session->password_in);
	kfree(session->username);
	kfree(session->username_in);
	kfree(session->targetname);
	kfree(session->initiatorname);
	kfree(session->ifacename);

	iscsi_destroy_session(cls_session);
	module_put(owner);
}
EXPORT_SYMBOL_GPL(iscsi_session_teardown);

/**
 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
 * @cls_session: iscsi_cls_session
 * @dd_size: private driver data size
 * @conn_idx: cid
 */
struct iscsi_cls_conn *
iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
		 uint32_t conn_idx)
{
	struct iscsi_session *session = cls_session->dd_data;
	struct iscsi_conn *conn;
	struct iscsi_cls_conn *cls_conn;
	char *data;

	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
				     conn_idx);
	if (!cls_conn)
		return NULL;
	conn = cls_conn->dd_data;
	memset(conn, 0, sizeof(*conn) + dd_size);

	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
	conn->session = session;
	conn->cls_conn = cls_conn;
	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
	conn->id = conn_idx;
	conn->exp_statsn = 0;
	conn->tmf_state = TMF_INITIAL;

	init_timer(&conn->transport_timer);
	conn->transport_timer.data = (unsigned long)conn;
	conn->transport_timer.function = iscsi_check_transport_timeouts;

	INIT_LIST_HEAD(&conn->run_list);
	INIT_LIST_HEAD(&conn->mgmt_run_list);
	INIT_LIST_HEAD(&conn->mgmtqueue);
	INIT_LIST_HEAD(&conn->xmitqueue);
	INIT_LIST_HEAD(&conn->requeue);
	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);

	/* allocate login_task used for the login/text sequences */
	spin_lock_bh(&session->lock);
	if (!__kfifo_get(session->cmdpool.queue,
                         (void*)&conn->login_task,
			 sizeof(void*))) {
		spin_unlock_bh(&session->lock);
		goto login_task_alloc_fail;
	}
	spin_unlock_bh(&session->lock);

	data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
	if (!data)
		goto login_task_data_alloc_fail;
	conn->login_task->data = conn->data = data;

	init_timer(&conn->tmf_timer);
	init_waitqueue_head(&conn->ehwait);

	return cls_conn;

login_task_data_alloc_fail:
	__kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
		    sizeof(void*));
login_task_alloc_fail:
	iscsi_destroy_conn(cls_conn);
	return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_conn_setup);

/**
 * iscsi_conn_teardown - teardown iscsi connection
 * cls_conn: iscsi class connection
 *
 * TODO: we may need to make this into a two step process
 * like scsi-mls remove + put host
 */
void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;
	unsigned long flags;

	del_timer_sync(&conn->transport_timer);

	spin_lock_bh(&session->lock);
	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
	if (session->leadconn == conn) {
		/*
		 * leading connection? then give up on recovery.
		 */
		session->state = ISCSI_STATE_TERMINATE;
		wake_up(&conn->ehwait);
	}
	spin_unlock_bh(&session->lock);

	/*
	 * Block until all in-progress commands for this connection
	 * time out or fail.
	 */
	for (;;) {
		spin_lock_irqsave(session->host->host_lock, flags);
		if (!session->host->host_busy) { /* OK for ERL == 0 */
			spin_unlock_irqrestore(session->host->host_lock, flags);
			break;
		}
		spin_unlock_irqrestore(session->host->host_lock, flags);
		msleep_interruptible(500);
		iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
				  "host_busy %d host_failed %d\n",
				  session->host->host_busy,
				  session->host->host_failed);
		/*
		 * force eh_abort() to unblock
		 */
		wake_up(&conn->ehwait);
	}

	/* flush queued up work because we free the connection below */
	iscsi_suspend_tx(conn);

	spin_lock_bh(&session->lock);
	kfree(conn->data);
	kfree(conn->persistent_address);
	__kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
		    sizeof(void*));
	if (session->leadconn == conn)
		session->leadconn = NULL;
	spin_unlock_bh(&session->lock);

	iscsi_destroy_conn(cls_conn);
}
EXPORT_SYMBOL_GPL(iscsi_conn_teardown);

int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;

	if (!session) {
		iscsi_conn_printk(KERN_ERR, conn,
				  "can't start unbound connection\n");
		return -EPERM;
	}

	if ((session->imm_data_en || !session->initial_r2t_en) &&
	     session->first_burst > session->max_burst) {
		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
				  "first_burst %d max_burst %d\n",
				  session->first_burst, session->max_burst);
		return -EINVAL;
	}

	if (conn->ping_timeout && !conn->recv_timeout) {
		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
				  "zero. Using 5 seconds\n.");
		conn->recv_timeout = 5;
	}

	if (conn->recv_timeout && !conn->ping_timeout) {
		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
				  "zero. Using 5 seconds.\n");
		conn->ping_timeout = 5;
	}

	spin_lock_bh(&session->lock);
	conn->c_stage = ISCSI_CONN_STARTED;
	session->state = ISCSI_STATE_LOGGED_IN;
	session->queued_cmdsn = session->cmdsn;

	conn->last_recv = jiffies;
	conn->last_ping = jiffies;
	if (conn->recv_timeout && conn->ping_timeout)
		mod_timer(&conn->transport_timer,
			  jiffies + (conn->recv_timeout * HZ));

	switch(conn->stop_stage) {
	case STOP_CONN_RECOVER:
		/*
		 * unblock eh_abort() if it is blocked. re-try all
		 * commands after successful recovery
		 */
		conn->stop_stage = 0;
		conn->tmf_state = TMF_INITIAL;
		session->age++;
		if (session->age == 16)
			session->age = 0;
		break;
	case STOP_CONN_TERM:
		conn->stop_stage = 0;
		break;
	default:
		break;
	}
	spin_unlock_bh(&session->lock);

	iscsi_unblock_session(session->cls_session);
	wake_up(&conn->ehwait);
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_start);

static void
flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
{
	struct iscsi_task *task, *tmp;

	/* handle pending */
	list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
		debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
		/* release ref from prep task */
		__iscsi_put_task(task);
	}

	/* handle running */
	list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
		debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
		/* release ref from prep task */
		__iscsi_put_task(task);
	}

	conn->task = NULL;
}

static void iscsi_start_session_recovery(struct iscsi_session *session,
					 struct iscsi_conn *conn, int flag)
{
	int old_stop_stage;

	del_timer_sync(&conn->transport_timer);

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	if (conn->stop_stage == STOP_CONN_TERM) {
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return;
	}

	/*
	 * When this is called for the in_login state, we only want to clean
	 * up the login task and connection. We do not need to block and set
	 * the recovery state again
	 */
	if (flag == STOP_CONN_TERM)
		session->state = ISCSI_STATE_TERMINATE;
	else if (conn->stop_stage != STOP_CONN_RECOVER)
		session->state = ISCSI_STATE_IN_RECOVERY;

	old_stop_stage = conn->stop_stage;
	conn->stop_stage = flag;
	conn->c_stage = ISCSI_CONN_STOPPED;
	spin_unlock_bh(&session->lock);

	iscsi_suspend_tx(conn);
	/*
	 * for connection level recovery we should not calculate
	 * header digest. conn->hdr_size used for optimization
	 * in hdr_extract() and will be re-negotiated at
	 * set_param() time.
	 */
	if (flag == STOP_CONN_RECOVER) {
		conn->hdrdgst_en = 0;
		conn->datadgst_en = 0;
		if (session->state == ISCSI_STATE_IN_RECOVERY &&
		    old_stop_stage != STOP_CONN_RECOVER) {
			debug_scsi("blocking session\n");
			iscsi_block_session(session->cls_session);
		}
	}

	/*
	 * flush queues.
	 */
	spin_lock_bh(&session->lock);
	fail_all_commands(conn, -1,
			STOP_CONN_RECOVER ? DID_BUS_BUSY : DID_ERROR);
	flush_control_queues(session, conn);
	spin_unlock_bh(&session->lock);
	mutex_unlock(&session->eh_mutex);
}

void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;

	switch (flag) {
	case STOP_CONN_RECOVER:
	case STOP_CONN_TERM:
		iscsi_start_session_recovery(session, conn, flag);
		break;
	default:
		iscsi_conn_printk(KERN_ERR, conn,
				  "invalid stop flag %d\n", flag);
	}
}
EXPORT_SYMBOL_GPL(iscsi_conn_stop);

int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
		    struct iscsi_cls_conn *cls_conn, int is_leading)
{
	struct iscsi_session *session = cls_session->dd_data;
	struct iscsi_conn *conn = cls_conn->dd_data;

	spin_lock_bh(&session->lock);
	if (is_leading)
		session->leadconn = conn;
	spin_unlock_bh(&session->lock);

	/*
	 * Unblock xmitworker(), Login Phase will pass through.
	 */
	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_bind);


int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
		    enum iscsi_param param, char *buf, int buflen)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;
	uint32_t value;

	switch(param) {
	case ISCSI_PARAM_FAST_ABORT:
		sscanf(buf, "%d", &session->fast_abort);
		break;
	case ISCSI_PARAM_ABORT_TMO:
		sscanf(buf, "%d", &session->abort_timeout);
		break;
	case ISCSI_PARAM_LU_RESET_TMO:
		sscanf(buf, "%d", &session->lu_reset_timeout);
		break;
	case ISCSI_PARAM_PING_TMO:
		sscanf(buf, "%d", &conn->ping_timeout);
		break;
	case ISCSI_PARAM_RECV_TMO:
		sscanf(buf, "%d", &conn->recv_timeout);
		break;
	case ISCSI_PARAM_MAX_RECV_DLENGTH:
		sscanf(buf, "%d", &conn->max_recv_dlength);
		break;
	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
		sscanf(buf, "%d", &conn->max_xmit_dlength);
		break;
	case ISCSI_PARAM_HDRDGST_EN:
		sscanf(buf, "%d", &conn->hdrdgst_en);
		break;
	case ISCSI_PARAM_DATADGST_EN:
		sscanf(buf, "%d", &conn->datadgst_en);
		break;
	case ISCSI_PARAM_INITIAL_R2T_EN:
		sscanf(buf, "%d", &session->initial_r2t_en);
		break;
	case ISCSI_PARAM_MAX_R2T:
		sscanf(buf, "%d", &session->max_r2t);
		break;
	case ISCSI_PARAM_IMM_DATA_EN:
		sscanf(buf, "%d", &session->imm_data_en);
		break;
	case ISCSI_PARAM_FIRST_BURST:
		sscanf(buf, "%d", &session->first_burst);
		break;
	case ISCSI_PARAM_MAX_BURST:
		sscanf(buf, "%d", &session->max_burst);
		break;
	case ISCSI_PARAM_PDU_INORDER_EN:
		sscanf(buf, "%d", &session->pdu_inorder_en);
		break;
	case ISCSI_PARAM_DATASEQ_INORDER_EN:
		sscanf(buf, "%d", &session->dataseq_inorder_en);
		break;
	case ISCSI_PARAM_ERL:
		sscanf(buf, "%d", &session->erl);
		break;
	case ISCSI_PARAM_IFMARKER_EN:
		sscanf(buf, "%d", &value);
		BUG_ON(value);
		break;
	case ISCSI_PARAM_OFMARKER_EN:
		sscanf(buf, "%d", &value);
		BUG_ON(value);
		break;
	case ISCSI_PARAM_EXP_STATSN:
		sscanf(buf, "%u", &conn->exp_statsn);
		break;
	case ISCSI_PARAM_USERNAME:
		kfree(session->username);
		session->username = kstrdup(buf, GFP_KERNEL);
		if (!session->username)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_USERNAME_IN:
		kfree(session->username_in);
		session->username_in = kstrdup(buf, GFP_KERNEL);
		if (!session->username_in)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_PASSWORD:
		kfree(session->password);
		session->password = kstrdup(buf, GFP_KERNEL);
		if (!session->password)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_PASSWORD_IN:
		kfree(session->password_in);
		session->password_in = kstrdup(buf, GFP_KERNEL);
		if (!session->password_in)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_TARGET_NAME:
		/* this should not change between logins */
		if (session->targetname)
			break;

		session->targetname = kstrdup(buf, GFP_KERNEL);
		if (!session->targetname)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_TPGT:
		sscanf(buf, "%d", &session->tpgt);
		break;
	case ISCSI_PARAM_PERSISTENT_PORT:
		sscanf(buf, "%d", &conn->persistent_port);
		break;
	case ISCSI_PARAM_PERSISTENT_ADDRESS:
		/*
		 * this is the address returned in discovery so it should
		 * not change between logins.
		 */
		if (conn->persistent_address)
			break;

		conn->persistent_address = kstrdup(buf, GFP_KERNEL);
		if (!conn->persistent_address)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_IFACE_NAME:
		if (!session->ifacename)
			session->ifacename = kstrdup(buf, GFP_KERNEL);
		break;
	case ISCSI_PARAM_INITIATOR_NAME:
		if (!session->initiatorname)
			session->initiatorname = kstrdup(buf, GFP_KERNEL);
		break;
	default:
		return -ENOSYS;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_set_param);

int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
			    enum iscsi_param param, char *buf)
{
	struct iscsi_session *session = cls_session->dd_data;
	int len;

	switch(param) {
	case ISCSI_PARAM_FAST_ABORT:
		len = sprintf(buf, "%d\n", session->fast_abort);
		break;
	case ISCSI_PARAM_ABORT_TMO:
		len = sprintf(buf, "%d\n", session->abort_timeout);
		break;
	case ISCSI_PARAM_LU_RESET_TMO:
		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
		break;
	case ISCSI_PARAM_INITIAL_R2T_EN:
		len = sprintf(buf, "%d\n", session->initial_r2t_en);
		break;
	case ISCSI_PARAM_MAX_R2T:
		len = sprintf(buf, "%hu\n", session->max_r2t);
		break;
	case ISCSI_PARAM_IMM_DATA_EN:
		len = sprintf(buf, "%d\n", session->imm_data_en);
		break;
	case ISCSI_PARAM_FIRST_BURST:
		len = sprintf(buf, "%u\n", session->first_burst);
		break;
	case ISCSI_PARAM_MAX_BURST:
		len = sprintf(buf, "%u\n", session->max_burst);
		break;
	case ISCSI_PARAM_PDU_INORDER_EN:
		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
		break;
	case ISCSI_PARAM_DATASEQ_INORDER_EN:
		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
		break;
	case ISCSI_PARAM_ERL:
		len = sprintf(buf, "%d\n", session->erl);
		break;
	case ISCSI_PARAM_TARGET_NAME:
		len = sprintf(buf, "%s\n", session->targetname);
		break;
	case ISCSI_PARAM_TPGT:
		len = sprintf(buf, "%d\n", session->tpgt);
		break;
	case ISCSI_PARAM_USERNAME:
		len = sprintf(buf, "%s\n", session->username);
		break;
	case ISCSI_PARAM_USERNAME_IN:
		len = sprintf(buf, "%s\n", session->username_in);
		break;
	case ISCSI_PARAM_PASSWORD:
		len = sprintf(buf, "%s\n", session->password);
		break;
	case ISCSI_PARAM_PASSWORD_IN:
		len = sprintf(buf, "%s\n", session->password_in);
		break;
	case ISCSI_PARAM_IFACE_NAME:
		len = sprintf(buf, "%s\n", session->ifacename);
		break;
	case ISCSI_PARAM_INITIATOR_NAME:
		if (!session->initiatorname)
			len = sprintf(buf, "%s\n", "unknown");
		else
			len = sprintf(buf, "%s\n", session->initiatorname);
		break;
	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_session_get_param);

int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
			 enum iscsi_param param, char *buf)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	int len;

	switch(param) {
	case ISCSI_PARAM_PING_TMO:
		len = sprintf(buf, "%u\n", conn->ping_timeout);
		break;
	case ISCSI_PARAM_RECV_TMO:
		len = sprintf(buf, "%u\n", conn->recv_timeout);
		break;
	case ISCSI_PARAM_MAX_RECV_DLENGTH:
		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
		break;
	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
		break;
	case ISCSI_PARAM_HDRDGST_EN:
		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
		break;
	case ISCSI_PARAM_DATADGST_EN:
		len = sprintf(buf, "%d\n", conn->datadgst_en);
		break;
	case ISCSI_PARAM_IFMARKER_EN:
		len = sprintf(buf, "%d\n", conn->ifmarker_en);
		break;
	case ISCSI_PARAM_OFMARKER_EN:
		len = sprintf(buf, "%d\n", conn->ofmarker_en);
		break;
	case ISCSI_PARAM_EXP_STATSN:
		len = sprintf(buf, "%u\n", conn->exp_statsn);
		break;
	case ISCSI_PARAM_PERSISTENT_PORT:
		len = sprintf(buf, "%d\n", conn->persistent_port);
		break;
	case ISCSI_PARAM_PERSISTENT_ADDRESS:
		len = sprintf(buf, "%s\n", conn->persistent_address);
		break;
	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_conn_get_param);

int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
			 char *buf)
{
	struct iscsi_host *ihost = shost_priv(shost);
	int len;

	switch (param) {
	case ISCSI_HOST_PARAM_NETDEV_NAME:
		if (!ihost->netdev)
			len = sprintf(buf, "%s\n", "default");
		else
			len = sprintf(buf, "%s\n", ihost->netdev);
		break;
	case ISCSI_HOST_PARAM_HWADDRESS:
		if (!ihost->hwaddress)
			len = sprintf(buf, "%s\n", "default");
		else
			len = sprintf(buf, "%s\n", ihost->hwaddress);
		break;
	case ISCSI_HOST_PARAM_INITIATOR_NAME:
		if (!ihost->initiatorname)
			len = sprintf(buf, "%s\n", "unknown");
		else
			len = sprintf(buf, "%s\n", ihost->initiatorname);
		break;
	case ISCSI_HOST_PARAM_IPADDRESS:
		if (!strlen(ihost->local_address))
			len = sprintf(buf, "%s\n", "unknown");
		else
			len = sprintf(buf, "%s\n",
				      ihost->local_address);
		break;
	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_host_get_param);

int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
			 char *buf, int buflen)
{
	struct iscsi_host *ihost = shost_priv(shost);

	switch (param) {
	case ISCSI_HOST_PARAM_NETDEV_NAME:
		if (!ihost->netdev)
			ihost->netdev = kstrdup(buf, GFP_KERNEL);
		break;
	case ISCSI_HOST_PARAM_HWADDRESS:
		if (!ihost->hwaddress)
			ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
		break;
	case ISCSI_HOST_PARAM_INITIATOR_NAME:
		if (!ihost->initiatorname)
			ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
		break;
	default:
		return -ENOSYS;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_host_set_param);

MODULE_AUTHOR("Mike Christie");
MODULE_DESCRIPTION("iSCSI library functions");
MODULE_LICENSE("GPL");