summaryrefslogtreecommitdiff
path: root/drivers/target/target_core_alua.c
blob: a91b7c25ffd411abba6932d0c5e6ce9556cce657 (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
/*******************************************************************************
 * Filename:  target_core_alua.c
 *
 * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
 *
 * (c) Copyright 2009-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.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.
 *
 * 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/slab.h>
#include <linux/spinlock.h>
#include <linux/configfs.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/fcntl.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <scsi/scsi_proto.h>
#include <asm/unaligned.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>

#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_ua.h"

static sense_reason_t core_alua_check_transition(int state, int valid,
						 int *primary, int explicit);
static int core_alua_set_tg_pt_secondary_state(
		struct se_lun *lun, int explicit, int offline);

static char *core_alua_dump_state(int state);

static void __target_attach_tg_pt_gp(struct se_lun *lun,
		struct t10_alua_tg_pt_gp *tg_pt_gp);

static u16 alua_lu_gps_counter;
static u32 alua_lu_gps_count;

static DEFINE_SPINLOCK(lu_gps_lock);
static LIST_HEAD(lu_gps_list);

struct t10_alua_lu_gp *default_lu_gp;

/*
 * REPORT REFERRALS
 *
 * See sbc3r35 section 5.23
 */
sense_reason_t
target_emulate_report_referrals(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct t10_alua_lba_map *map;
	struct t10_alua_lba_map_member *map_mem;
	unsigned char *buf;
	u32 rd_len = 0, off;

	if (cmd->data_length < 4) {
		pr_warn("REPORT REFERRALS allocation length %u too"
			" small\n", cmd->data_length);
		return TCM_INVALID_CDB_FIELD;
	}

	buf = transport_kmap_data_sg(cmd);
	if (!buf)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	off = 4;
	spin_lock(&dev->t10_alua.lba_map_lock);
	if (list_empty(&dev->t10_alua.lba_map_list)) {
		spin_unlock(&dev->t10_alua.lba_map_lock);
		transport_kunmap_data_sg(cmd);

		return TCM_UNSUPPORTED_SCSI_OPCODE;
	}

	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
			    lba_map_list) {
		int desc_num = off + 3;
		int pg_num;

		off += 4;
		if (cmd->data_length > off)
			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
		off += 8;
		if (cmd->data_length > off)
			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
		off += 8;
		rd_len += 20;
		pg_num = 0;
		list_for_each_entry(map_mem, &map->lba_map_mem_list,
				    lba_map_mem_list) {
			int alua_state = map_mem->lba_map_mem_alua_state;
			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;

			if (cmd->data_length > off)
				buf[off] = alua_state & 0x0f;
			off += 2;
			if (cmd->data_length > off)
				buf[off] = (alua_pg_id >> 8) & 0xff;
			off++;
			if (cmd->data_length > off)
				buf[off] = (alua_pg_id & 0xff);
			off++;
			rd_len += 4;
			pg_num++;
		}
		if (cmd->data_length > desc_num)
			buf[desc_num] = pg_num;
	}
	spin_unlock(&dev->t10_alua.lba_map_lock);

	/*
	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
	 */
	put_unaligned_be16(rd_len, &buf[2]);

	transport_kunmap_data_sg(cmd);

	target_complete_cmd(cmd, GOOD);
	return 0;
}

/*
 * REPORT_TARGET_PORT_GROUPS
 *
 * See spc4r17 section 6.27
 */
sense_reason_t
target_emulate_report_target_port_groups(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct se_lun *lun;
	unsigned char *buf;
	u32 rd_len = 0, off;
	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);

	/*
	 * Skip over RESERVED area to first Target port group descriptor
	 * depending on the PARAMETER DATA FORMAT type..
	 */
	if (ext_hdr != 0)
		off = 8;
	else
		off = 4;

	if (cmd->data_length < off) {
		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
			" small for %s header\n", cmd->data_length,
			(ext_hdr) ? "extended" : "normal");
		return TCM_INVALID_CDB_FIELD;
	}
	buf = transport_kmap_data_sg(cmd);
	if (!buf)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
			tg_pt_gp_list) {
		/*
		 * Check if the Target port group and Target port descriptor list
		 * based on tg_pt_gp_members count will fit into the response payload.
		 * Otherwise, bump rd_len to let the initiator know we have exceeded
		 * the allocation length and the response is truncated.
		 */
		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
		     cmd->data_length) {
			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
			continue;
		}
		/*
		 * PREF: Preferred target port bit, determine if this
		 * bit should be set for port group.
		 */
		if (tg_pt_gp->tg_pt_gp_pref)
			buf[off] = 0x80;
		/*
		 * Set the ASYMMETRIC ACCESS State
		 */
		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
		/*
		 * Set supported ASYMMETRIC ACCESS State bits
		 */
		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
		/*
		 * TARGET PORT GROUP
		 */
		put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
		off += 2;

		off++; /* Skip over Reserved */
		/*
		 * STATUS CODE
		 */
		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
		/*
		 * Vendor Specific field
		 */
		buf[off++] = 0x00;
		/*
		 * TARGET PORT COUNT
		 */
		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
		rd_len += 8;

		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
				lun_tg_pt_gp_link) {
			/*
			 * Start Target Port descriptor format
			 *
			 * See spc4r17 section 6.2.7 Table 247
			 */
			off += 2; /* Skip over Obsolete */
			/*
			 * Set RELATIVE TARGET PORT IDENTIFIER
			 */
			put_unaligned_be16(lun->lun_rtpi, &buf[off]);
			off += 2;
			rd_len += 4;
		}
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
	}
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
	/*
	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
	 */
	put_unaligned_be32(rd_len, &buf[0]);

	/*
	 * Fill in the Extended header parameter data format if requested
	 */
	if (ext_hdr != 0) {
		buf[4] = 0x10;
		/*
		 * Set the implicit transition time (in seconds) for the application
		 * client to use as a base for it's transition timeout value.
		 *
		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
		 * this CDB was received upon to determine this value individually
		 * for ALUA target port group.
		 */
		spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
		tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
		if (tg_pt_gp)
			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
		spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
	}
	transport_kunmap_data_sg(cmd);

	target_complete_cmd(cmd, GOOD);
	return 0;
}

/*
 * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
 *
 * See spc4r17 section 6.35
 */
sense_reason_t
target_emulate_set_target_port_groups(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_lun *l_lun = cmd->se_lun;
	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
	unsigned char *buf;
	unsigned char *ptr;
	sense_reason_t rc = TCM_NO_SENSE;
	u32 len = 4; /* Skip over RESERVED area in header */
	int alua_access_state, primary = 0, valid_states;
	u16 tg_pt_id, rtpi;

	if (cmd->data_length < 4) {
		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
			" small\n", cmd->data_length);
		return TCM_INVALID_PARAMETER_LIST;
	}

	buf = transport_kmap_data_sg(cmd);
	if (!buf)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	/*
	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
	 * for the local tg_pt_gp.
	 */
	spin_lock(&l_lun->lun_tg_pt_gp_lock);
	l_tg_pt_gp = l_lun->lun_tg_pt_gp;
	if (!l_tg_pt_gp) {
		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
		pr_err("Unable to access l_lun->tg_pt_gp\n");
		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
		goto out;
	}

	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
				" while TPGS_EXPLICIT_ALUA is disabled\n");
		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
		goto out;
	}
	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
	spin_unlock(&l_lun->lun_tg_pt_gp_lock);

	ptr = &buf[4]; /* Skip over RESERVED area in header */

	while (len < cmd->data_length) {
		bool found = false;
		alua_access_state = (ptr[0] & 0x0f);
		/*
		 * Check the received ALUA access state, and determine if
		 * the state is a primary or secondary target port asymmetric
		 * access state.
		 */
		rc = core_alua_check_transition(alua_access_state, valid_states,
						&primary, 1);
		if (rc) {
			/*
			 * If the SET TARGET PORT GROUPS attempts to establish
			 * an invalid combination of target port asymmetric
			 * access states or attempts to establish an
			 * unsupported target port asymmetric access state,
			 * then the command shall be terminated with CHECK
			 * CONDITION status, with the sense key set to ILLEGAL
			 * REQUEST, and the additional sense code set to INVALID
			 * FIELD IN PARAMETER LIST.
			 */
			goto out;
		}

		/*
		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
		 * specifies a primary target port asymmetric access state,
		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
		 * a primary target port group for which the primary target
		 * port asymmetric access state shall be changed. If the
		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
		 * port asymmetric access state, then the TARGET PORT GROUP OR
		 * TARGET PORT field specifies the relative target port
		 * identifier (see 3.1.120) of the target port for which the
		 * secondary target port asymmetric access state shall be
		 * changed.
		 */
		if (primary) {
			tg_pt_id = get_unaligned_be16(ptr + 2);
			/*
			 * Locate the matching target port group ID from
			 * the global tg_pt_gp list
			 */
			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
			list_for_each_entry(tg_pt_gp,
					&dev->t10_alua.tg_pt_gps_list,
					tg_pt_gp_list) {
				if (!tg_pt_gp->tg_pt_gp_valid_id)
					continue;

				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
					continue;

				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);

				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);

				if (!core_alua_do_port_transition(tg_pt_gp,
						dev, l_lun, nacl,
						alua_access_state, 1))
					found = true;

				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
				break;
			}
			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
		} else {
			struct se_lun *lun;

			/*
			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
			 * the Target Port in question for the the incoming
			 * SET_TARGET_PORT_GROUPS op.
			 */
			rtpi = get_unaligned_be16(ptr + 2);
			/*
			 * Locate the matching relative target port identifier
			 * for the struct se_device storage object.
			 */
			spin_lock(&dev->se_port_lock);
			list_for_each_entry(lun, &dev->dev_sep_list,
							lun_dev_link) {
				if (lun->lun_rtpi != rtpi)
					continue;

				// XXX: racy unlock
				spin_unlock(&dev->se_port_lock);

				if (!core_alua_set_tg_pt_secondary_state(
						lun, 1, 1))
					found = true;

				spin_lock(&dev->se_port_lock);
				break;
			}
			spin_unlock(&dev->se_port_lock);
		}

		if (!found) {
			rc = TCM_INVALID_PARAMETER_LIST;
			goto out;
		}

		ptr += 4;
		len += 4;
	}

out:
	transport_kunmap_data_sg(cmd);
	if (!rc)
		target_complete_cmd(cmd, GOOD);
	return rc;
}

static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
{
	/*
	 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
	 * The ALUA additional sense code qualifier (ASCQ) is determined
	 * by the ALUA primary or secondary access state..
	 */
	pr_debug("[%s]: ALUA TG Port not available, "
		"SenseKey: NOT_READY, ASC/ASCQ: "
		"0x04/0x%02x\n",
		cmd->se_tfo->get_fabric_name(), alua_ascq);

	cmd->scsi_asc = 0x04;
	cmd->scsi_ascq = alua_ascq;
}

static inline void core_alua_state_nonoptimized(
	struct se_cmd *cmd,
	unsigned char *cdb,
	int nonop_delay_msecs)
{
	/*
	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
	 * later to determine if processing of this cmd needs to be
	 * temporarily delayed for the Active/NonOptimized primary access state.
	 */
	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
	cmd->alua_nonop_delay = nonop_delay_msecs;
}

static inline int core_alua_state_lba_dependent(
	struct se_cmd *cmd,
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_device *dev = cmd->se_dev;
	u64 segment_size, segment_mult, sectors, lba;

	/* Only need to check for cdb actually containing LBAs */
	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
		return 0;

	spin_lock(&dev->t10_alua.lba_map_lock);
	segment_size = dev->t10_alua.lba_map_segment_size;
	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
	sectors = cmd->data_length / dev->dev_attrib.block_size;

	lba = cmd->t_task_lba;
	while (lba < cmd->t_task_lba + sectors) {
		struct t10_alua_lba_map *cur_map = NULL, *map;
		struct t10_alua_lba_map_member *map_mem;

		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
				    lba_map_list) {
			u64 start_lba, last_lba;
			u64 first_lba = map->lba_map_first_lba;

			if (segment_mult) {
				u64 tmp = lba;
				start_lba = do_div(tmp, segment_size * segment_mult);

				last_lba = first_lba + segment_size - 1;
				if (start_lba >= first_lba &&
				    start_lba <= last_lba) {
					lba += segment_size;
					cur_map = map;
					break;
				}
			} else {
				last_lba = map->lba_map_last_lba;
				if (lba >= first_lba && lba <= last_lba) {
					lba = last_lba + 1;
					cur_map = map;
					break;
				}
			}
		}
		if (!cur_map) {
			spin_unlock(&dev->t10_alua.lba_map_lock);
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
			return 1;
		}
		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
				    lba_map_mem_list) {
			if (map_mem->lba_map_mem_alua_pg_id !=
			    tg_pt_gp->tg_pt_gp_id)
				continue;
			switch(map_mem->lba_map_mem_alua_state) {
			case ALUA_ACCESS_STATE_STANDBY:
				spin_unlock(&dev->t10_alua.lba_map_lock);
				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
				return 1;
			case ALUA_ACCESS_STATE_UNAVAILABLE:
				spin_unlock(&dev->t10_alua.lba_map_lock);
				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
				return 1;
			default:
				break;
			}
		}
	}
	spin_unlock(&dev->t10_alua.lba_map_lock);
	return 0;
}

static inline int core_alua_state_standby(
	struct se_cmd *cmd,
	unsigned char *cdb)
{
	/*
	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
	 * spc4r17 section 5.9.2.4.4
	 */
	switch (cdb[0]) {
	case INQUIRY:
	case LOG_SELECT:
	case LOG_SENSE:
	case MODE_SELECT:
	case MODE_SENSE:
	case REPORT_LUNS:
	case RECEIVE_DIAGNOSTIC:
	case SEND_DIAGNOSTIC:
	case READ_CAPACITY:
		return 0;
	case SERVICE_ACTION_IN_16:
		switch (cdb[1] & 0x1f) {
		case SAI_READ_CAPACITY_16:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
			return 1;
		}
	case MAINTENANCE_IN:
		switch (cdb[1] & 0x1f) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
			return 1;
		}
	case MAINTENANCE_OUT:
		switch (cdb[1]) {
		case MO_SET_TARGET_PGS:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
			return 1;
		}
	case REQUEST_SENSE:
	case PERSISTENT_RESERVE_IN:
	case PERSISTENT_RESERVE_OUT:
	case READ_BUFFER:
	case WRITE_BUFFER:
		return 0;
	default:
		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
		return 1;
	}

	return 0;
}

static inline int core_alua_state_unavailable(
	struct se_cmd *cmd,
	unsigned char *cdb)
{
	/*
	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
	 * spc4r17 section 5.9.2.4.5
	 */
	switch (cdb[0]) {
	case INQUIRY:
	case REPORT_LUNS:
		return 0;
	case MAINTENANCE_IN:
		switch (cdb[1] & 0x1f) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
			return 1;
		}
	case MAINTENANCE_OUT:
		switch (cdb[1]) {
		case MO_SET_TARGET_PGS:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
			return 1;
		}
	case REQUEST_SENSE:
	case READ_BUFFER:
	case WRITE_BUFFER:
		return 0;
	default:
		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
		return 1;
	}

	return 0;
}

static inline int core_alua_state_transition(
	struct se_cmd *cmd,
	unsigned char *cdb)
{
	/*
	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
	 * spc4r17 section 5.9.2.5
	 */
	switch (cdb[0]) {
	case INQUIRY:
	case REPORT_LUNS:
		return 0;
	case MAINTENANCE_IN:
		switch (cdb[1] & 0x1f) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
			return 1;
		}
	case REQUEST_SENSE:
	case READ_BUFFER:
	case WRITE_BUFFER:
		return 0;
	default:
		set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
		return 1;
	}

	return 0;
}

/*
 * return 1: Is used to signal LUN not accessible, and check condition/not ready
 * return 0: Used to signal success
 * return -1: Used to signal failure, and invalid cdb field
 */
sense_reason_t
target_alua_state_check(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned char *cdb = cmd->t_task_cdb;
	struct se_lun *lun = cmd->se_lun;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	int out_alua_state, nonop_delay_msecs;

	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
		return 0;
	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
		return 0;

	/*
	 * First, check for a struct se_port specific secondary ALUA target port
	 * access state: OFFLINE
	 */
	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
		pr_debug("ALUA: Got secondary offline status for local"
				" target port\n");
		set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
		return TCM_CHECK_CONDITION_NOT_READY;
	}

	if (!lun->lun_tg_pt_gp)
		return 0;

	spin_lock(&lun->lun_tg_pt_gp_lock);
	tg_pt_gp = lun->lun_tg_pt_gp;
	out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;

	// XXX: keeps using tg_pt_gp witout reference after unlock
	spin_unlock(&lun->lun_tg_pt_gp_lock);
	/*
	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
	 * statement so the compiler knows explicitly to check this case first.
	 * For the Optimized ALUA access state case, we want to process the
	 * incoming fabric cmd ASAP..
	 */
	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
		return 0;

	switch (out_alua_state) {
	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
		break;
	case ALUA_ACCESS_STATE_STANDBY:
		if (core_alua_state_standby(cmd, cdb))
			return TCM_CHECK_CONDITION_NOT_READY;
		break;
	case ALUA_ACCESS_STATE_UNAVAILABLE:
		if (core_alua_state_unavailable(cmd, cdb))
			return TCM_CHECK_CONDITION_NOT_READY;
		break;
	case ALUA_ACCESS_STATE_TRANSITION:
		if (core_alua_state_transition(cmd, cdb))
			return TCM_CHECK_CONDITION_NOT_READY;
		break;
	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
		if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
			return TCM_CHECK_CONDITION_NOT_READY;
		break;
	/*
	 * OFFLINE is a secondary ALUA target port group access state, that is
	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
	 */
	case ALUA_ACCESS_STATE_OFFLINE:
	default:
		pr_err("Unknown ALUA access state: 0x%02x\n",
				out_alua_state);
		return TCM_INVALID_CDB_FIELD;
	}

	return 0;
}

/*
 * Check implicit and explicit ALUA state change request.
 */
static sense_reason_t
core_alua_check_transition(int state, int valid, int *primary, int explicit)
{
	/*
	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
	 * defined as primary target port asymmetric access states.
	 */
	switch (state) {
	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
		if (!(valid & ALUA_AO_SUP))
			goto not_supported;
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
		if (!(valid & ALUA_AN_SUP))
			goto not_supported;
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_STANDBY:
		if (!(valid & ALUA_S_SUP))
			goto not_supported;
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_UNAVAILABLE:
		if (!(valid & ALUA_U_SUP))
			goto not_supported;
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
		if (!(valid & ALUA_LBD_SUP))
			goto not_supported;
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_OFFLINE:
		/*
		 * OFFLINE state is defined as a secondary target port
		 * asymmetric access state.
		 */
		if (!(valid & ALUA_O_SUP))
			goto not_supported;
		*primary = 0;
		break;
	case ALUA_ACCESS_STATE_TRANSITION:
		if (!(valid & ALUA_T_SUP) || explicit)
			/*
			 * Transitioning is set internally and by tcmu daemon,
			 * and cannot be selected through a STPG.
			 */
			goto not_supported;
		*primary = 0;
		break;
	default:
		pr_err("Unknown ALUA access state: 0x%02x\n", state);
		return TCM_INVALID_PARAMETER_LIST;
	}

	return 0;

not_supported:
	pr_err("ALUA access state %s not supported",
	       core_alua_dump_state(state));
	return TCM_INVALID_PARAMETER_LIST;
}

static char *core_alua_dump_state(int state)
{
	switch (state) {
	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
		return "Active/Optimized";
	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
		return "Active/NonOptimized";
	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
		return "LBA Dependent";
	case ALUA_ACCESS_STATE_STANDBY:
		return "Standby";
	case ALUA_ACCESS_STATE_UNAVAILABLE:
		return "Unavailable";
	case ALUA_ACCESS_STATE_OFFLINE:
		return "Offline";
	case ALUA_ACCESS_STATE_TRANSITION:
		return "Transitioning";
	default:
		return "Unknown";
	}

	return NULL;
}

char *core_alua_dump_status(int status)
{
	switch (status) {
	case ALUA_STATUS_NONE:
		return "None";
	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
		return "Altered by Explicit STPG";
	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
		return "Altered by Implicit ALUA";
	default:
		return "Unknown";
	}

	return NULL;
}

/*
 * Used by fabric modules to determine when we need to delay processing
 * for the Active/NonOptimized paths..
 */
int core_alua_check_nonop_delay(
	struct se_cmd *cmd)
{
	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
		return 0;
	if (in_interrupt())
		return 0;
	/*
	 * The ALUA Active/NonOptimized access state delay can be disabled
	 * in via configfs with a value of zero
	 */
	if (!cmd->alua_nonop_delay)
		return 0;
	/*
	 * struct se_cmd->alua_nonop_delay gets set by a target port group
	 * defined interval in core_alua_state_nonoptimized()
	 */
	msleep_interruptible(cmd->alua_nonop_delay);
	return 0;
}
EXPORT_SYMBOL(core_alua_check_nonop_delay);

static int core_alua_write_tpg_metadata(
	const char *path,
	unsigned char *md_buf,
	u32 md_buf_len)
{
	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
	int ret;

	if (IS_ERR(file)) {
		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
		return -ENODEV;
	}
	ret = kernel_write(file, md_buf, md_buf_len, 0);
	if (ret < 0)
		pr_err("Error writing ALUA metadata file: %s\n", path);
	fput(file);
	return (ret < 0) ? -EIO : 0;
}

/*
 * Called with tg_pt_gp->tg_pt_gp_transition_mutex held
 */
static int core_alua_update_tpg_primary_metadata(
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	unsigned char *md_buf;
	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
	char path[ALUA_METADATA_PATH_LEN];
	int len, rc;

	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
	if (!md_buf) {
		pr_err("Unable to allocate buf for ALUA metadata\n");
		return -ENOMEM;
	}

	memset(path, 0, ALUA_METADATA_PATH_LEN);

	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
			"tg_pt_gp_id=%hu\n"
			"alua_access_state=0x%02x\n"
			"alua_access_status=0x%02x\n",
			tg_pt_gp->tg_pt_gp_id,
			tg_pt_gp->tg_pt_gp_alua_access_state,
			tg_pt_gp->tg_pt_gp_alua_access_status);

	snprintf(path, ALUA_METADATA_PATH_LEN,
		"%s/alua/tpgs_%s/%s", db_root, &wwn->unit_serial[0],
		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));

	rc = core_alua_write_tpg_metadata(path, md_buf, len);
	kfree(md_buf);
	return rc;
}

static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_dev_entry *se_deve;
	struct se_lun *lun;
	struct se_lun_acl *lacl;

	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
				lun_tg_pt_gp_link) {
		/*
		 * After an implicit target port asymmetric access state
		 * change, a device server shall establish a unit attention
		 * condition for the initiator port associated with every I_T
		 * nexus with the additional sense code set to ASYMMETRIC
		 * ACCESS STATE CHANGED.
		 *
		 * After an explicit target port asymmetric access state
		 * change, a device server shall establish a unit attention
		 * condition with the additional sense code set to ASYMMETRIC
		 * ACCESS STATE CHANGED for the initiator port associated with
		 * every I_T nexus other than the I_T nexus on which the SET
		 * TARGET PORT GROUPS command
		 */
		if (!percpu_ref_tryget_live(&lun->lun_ref))
			continue;
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);

		spin_lock(&lun->lun_deve_lock);
		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
			lacl = rcu_dereference_check(se_deve->se_lun_acl,
					lockdep_is_held(&lun->lun_deve_lock));

			/*
			 * spc4r37 p.242:
			 * After an explicit target port asymmetric access
			 * state change, a device server shall establish a
			 * unit attention condition with the additional sense
			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
			 * the initiator port associated with every I_T nexus
			 * other than the I_T nexus on which the SET TARGET
			 * PORT GROUPS command was received.
			 */
			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
				continue;

			/*
			 * se_deve->se_lun_acl pointer may be NULL for a
			 * entry created without explicit Node+MappedLUN ACLs
			 */
			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
				continue;

			core_scsi3_ua_allocate(se_deve, 0x2A,
				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
		}
		spin_unlock(&lun->lun_deve_lock);

		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
		percpu_ref_put(&lun->lun_ref);
	}
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
}

static int core_alua_do_transition_tg_pt(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	int new_state,
	int explicit)
{
	int prev_state;

	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
	/* Nothing to be done here */
	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
		return 0;
	}

	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
		return -EAGAIN;
	}

	/*
	 * Save the old primary ALUA access state, and set the current state
	 * to ALUA_ACCESS_STATE_TRANSITION.
	 */
	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;

	core_alua_queue_state_change_ua(tg_pt_gp);

	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
		return 0;
	}

	/*
	 * Check for the optional ALUA primary state transition delay
	 */
	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);

	/*
	 * Set the current primary ALUA access state to the requested new state
	 */
	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;

	/*
	 * Update the ALUA metadata buf that has been allocated in
	 * core_alua_do_port_transition(), this metadata will be written
	 * to struct file.
	 *
	 * Note that there is the case where we do not want to update the
	 * metadata when the saved metadata is being parsed in userspace
	 * when setting the existing port access state and access status.
	 *
	 * Also note that the failure to write out the ALUA metadata to
	 * struct file does NOT affect the actual ALUA transition.
	 */
	if (tg_pt_gp->tg_pt_gp_write_metadata) {
		core_alua_update_tpg_primary_metadata(tg_pt_gp);
	}

	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
		" from primary access state %s to %s\n", (explicit) ? "explicit" :
		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
		tg_pt_gp->tg_pt_gp_id,
		core_alua_dump_state(prev_state),
		core_alua_dump_state(new_state));

	core_alua_queue_state_change_ua(tg_pt_gp);

	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
	return 0;
}

int core_alua_do_port_transition(
	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
	struct se_device *l_dev,
	struct se_lun *l_lun,
	struct se_node_acl *l_nacl,
	int new_state,
	int explicit)
{
	struct se_device *dev;
	struct t10_alua_lu_gp *lu_gp;
	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	int primary, valid_states, rc = 0;

	if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
		return -ENODEV;

	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
	if (core_alua_check_transition(new_state, valid_states, &primary,
				       explicit) != 0)
		return -EINVAL;

	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
	lu_gp = local_lu_gp_mem->lu_gp;
	atomic_inc(&lu_gp->lu_gp_ref_cnt);
	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
	/*
	 * For storage objects that are members of the 'default_lu_gp',
	 * we only do transition on the passed *l_tp_pt_gp, and not
	 * on all of the matching target port groups IDs in default_lu_gp.
	 */
	if (!lu_gp->lu_gp_id) {
		/*
		 * core_alua_do_transition_tg_pt() will always return
		 * success.
		 */
		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
						   new_state, explicit);
		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
		return rc;
	}
	/*
	 * For all other LU groups aside from 'default_lu_gp', walk all of
	 * the associated storage objects looking for a matching target port
	 * group ID from the local target port group.
	 */
	spin_lock(&lu_gp->lu_gp_lock);
	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
				lu_gp_mem_list) {

		dev = lu_gp_mem->lu_gp_mem_dev;
		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
		spin_unlock(&lu_gp->lu_gp_lock);

		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
		list_for_each_entry(tg_pt_gp,
				&dev->t10_alua.tg_pt_gps_list,
				tg_pt_gp_list) {

			if (!tg_pt_gp->tg_pt_gp_valid_id)
				continue;
			/*
			 * If the target behavior port asymmetric access state
			 * is changed for any target port group accessible via
			 * a logical unit within a LU group, the target port
			 * behavior group asymmetric access states for the same
			 * target port group accessible via other logical units
			 * in that LU group will also change.
			 */
			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
				continue;

			if (l_tg_pt_gp == tg_pt_gp) {
				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
			} else {
				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
			}
			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
			/*
			 * core_alua_do_transition_tg_pt() will always return
			 * success.
			 */
			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
					new_state, explicit);

			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
			if (rc)
				break;
		}
		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);

		spin_lock(&lu_gp->lu_gp_lock);
		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
	}
	spin_unlock(&lu_gp->lu_gp_lock);

	if (!rc) {
		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
			 " Group IDs: %hu %s transition to primary state: %s\n",
			 config_item_name(&lu_gp->lu_gp_group.cg_item),
			 l_tg_pt_gp->tg_pt_gp_id,
			 (explicit) ? "explicit" : "implicit",
			 core_alua_dump_state(new_state));
	}

	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
	return rc;
}

static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
{
	struct se_portal_group *se_tpg = lun->lun_tpg;
	unsigned char *md_buf;
	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
	int len, rc;

	mutex_lock(&lun->lun_tg_pt_md_mutex);

	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
	if (!md_buf) {
		pr_err("Unable to allocate buf for ALUA metadata\n");
		rc = -ENOMEM;
		goto out_unlock;
	}

	memset(path, 0, ALUA_METADATA_PATH_LEN);
	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);

	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));

	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));

	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
			"alua_tg_pt_status=0x%02x\n",
			atomic_read(&lun->lun_tg_pt_secondary_offline),
			lun->lun_tg_pt_secondary_stat);

	snprintf(path, ALUA_METADATA_PATH_LEN, "%s/alua/%s/%s/lun_%llu",
			db_root, se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
			lun->unpacked_lun);

	rc = core_alua_write_tpg_metadata(path, md_buf, len);
	kfree(md_buf);

out_unlock:
	mutex_unlock(&lun->lun_tg_pt_md_mutex);
	return rc;
}

static int core_alua_set_tg_pt_secondary_state(
	struct se_lun *lun,
	int explicit,
	int offline)
{
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	int trans_delay_msecs;

	spin_lock(&lun->lun_tg_pt_gp_lock);
	tg_pt_gp = lun->lun_tg_pt_gp;
	if (!tg_pt_gp) {
		spin_unlock(&lun->lun_tg_pt_gp_lock);
		pr_err("Unable to complete secondary state"
				" transition\n");
		return -EINVAL;
	}
	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
	/*
	 * Set the secondary ALUA target port access state to OFFLINE
	 * or release the previously secondary state for struct se_lun
	 */
	if (offline)
		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
	else
		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);

	lun->lun_tg_pt_secondary_stat = (explicit) ?
			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;

	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
		" to secondary access state: %s\n", (explicit) ? "explicit" :
		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");

	spin_unlock(&lun->lun_tg_pt_gp_lock);
	/*
	 * Do the optional transition delay after we set the secondary
	 * ALUA access state.
	 */
	if (trans_delay_msecs != 0)
		msleep_interruptible(trans_delay_msecs);
	/*
	 * See if we need to update the ALUA fabric port metadata for
	 * secondary state and status
	 */
	if (lun->lun_tg_pt_secondary_write_md)
		core_alua_update_tpg_secondary_metadata(lun);

	return 0;
}

struct t10_alua_lba_map *
core_alua_allocate_lba_map(struct list_head *list,
			   u64 first_lba, u64 last_lba)
{
	struct t10_alua_lba_map *lba_map;

	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
	if (!lba_map) {
		pr_err("Unable to allocate struct t10_alua_lba_map\n");
		return ERR_PTR(-ENOMEM);
	}
	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
	lba_map->lba_map_first_lba = first_lba;
	lba_map->lba_map_last_lba = last_lba;

	list_add_tail(&lba_map->lba_map_list, list);
	return lba_map;
}

int
core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
			       int pg_id, int state)
{
	struct t10_alua_lba_map_member *lba_map_mem;

	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
			    lba_map_mem_list) {
		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
			return -EINVAL;
		}
	}

	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
	if (!lba_map_mem) {
		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
		return -ENOMEM;
	}
	lba_map_mem->lba_map_mem_alua_state = state;
	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;

	list_add_tail(&lba_map_mem->lba_map_mem_list,
		      &lba_map->lba_map_mem_list);
	return 0;
}

void
core_alua_free_lba_map(struct list_head *lba_list)
{
	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;

	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
				 lba_map_list) {
		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
					 &lba_map->lba_map_mem_list,
					 lba_map_mem_list) {
			list_del(&lba_map_mem->lba_map_mem_list);
			kmem_cache_free(t10_alua_lba_map_mem_cache,
					lba_map_mem);
		}
		list_del(&lba_map->lba_map_list);
		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
	}
}

void
core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
		      int segment_size, int segment_mult)
{
	struct list_head old_lba_map_list;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	int activate = 0, supported;

	INIT_LIST_HEAD(&old_lba_map_list);
	spin_lock(&dev->t10_alua.lba_map_lock);
	dev->t10_alua.lba_map_segment_size = segment_size;
	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
	if (lba_map_list) {
		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
		activate = 1;
	}
	spin_unlock(&dev->t10_alua.lba_map_lock);
	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
			    tg_pt_gp_list) {

		if (!tg_pt_gp->tg_pt_gp_valid_id)
			continue;
		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
		if (activate)
			supported |= ALUA_LBD_SUP;
		else
			supported &= ~ALUA_LBD_SUP;
		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
	}
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
	core_alua_free_lba_map(&old_lba_map_list);
}

struct t10_alua_lu_gp *
core_alua_allocate_lu_gp(const char *name, int def_group)
{
	struct t10_alua_lu_gp *lu_gp;

	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
	if (!lu_gp) {
		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
		return ERR_PTR(-ENOMEM);
	}
	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
	spin_lock_init(&lu_gp->lu_gp_lock);
	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);

	if (def_group) {
		lu_gp->lu_gp_id = alua_lu_gps_counter++;
		lu_gp->lu_gp_valid_id = 1;
		alua_lu_gps_count++;
	}

	return lu_gp;
}

int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
{
	struct t10_alua_lu_gp *lu_gp_tmp;
	u16 lu_gp_id_tmp;
	/*
	 * The lu_gp->lu_gp_id may only be set once..
	 */
	if (lu_gp->lu_gp_valid_id) {
		pr_warn("ALUA LU Group already has a valid ID,"
			" ignoring request\n");
		return -EINVAL;
	}

	spin_lock(&lu_gps_lock);
	if (alua_lu_gps_count == 0x0000ffff) {
		pr_err("Maximum ALUA alua_lu_gps_count:"
				" 0x0000ffff reached\n");
		spin_unlock(&lu_gps_lock);
		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
		return -ENOSPC;
	}
again:
	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
				alua_lu_gps_counter++;

	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
			if (!lu_gp_id)
				goto again;

			pr_warn("ALUA Logical Unit Group ID: %hu"
				" already exists, ignoring request\n",
				lu_gp_id);
			spin_unlock(&lu_gps_lock);
			return -EINVAL;
		}
	}

	lu_gp->lu_gp_id = lu_gp_id_tmp;
	lu_gp->lu_gp_valid_id = 1;
	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
	alua_lu_gps_count++;
	spin_unlock(&lu_gps_lock);

	return 0;
}

static struct t10_alua_lu_gp_member *
core_alua_allocate_lu_gp_mem(struct se_device *dev)
{
	struct t10_alua_lu_gp_member *lu_gp_mem;

	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
	if (!lu_gp_mem) {
		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
		return ERR_PTR(-ENOMEM);
	}
	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);

	lu_gp_mem->lu_gp_mem_dev = dev;
	dev->dev_alua_lu_gp_mem = lu_gp_mem;

	return lu_gp_mem;
}

void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
{
	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
	/*
	 * Once we have reached this point, config_item_put() has
	 * already been called from target_core_alua_drop_lu_gp().
	 *
	 * Here, we remove the *lu_gp from the global list so that
	 * no associations can be made while we are releasing
	 * struct t10_alua_lu_gp.
	 */
	spin_lock(&lu_gps_lock);
	list_del(&lu_gp->lu_gp_node);
	alua_lu_gps_count--;
	spin_unlock(&lu_gps_lock);
	/*
	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
	 * released with core_alua_put_lu_gp_from_name()
	 */
	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
		cpu_relax();
	/*
	 * Release reference to struct t10_alua_lu_gp * from all associated
	 * struct se_device.
	 */
	spin_lock(&lu_gp->lu_gp_lock);
	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
		if (lu_gp_mem->lu_gp_assoc) {
			list_del(&lu_gp_mem->lu_gp_mem_list);
			lu_gp->lu_gp_members--;
			lu_gp_mem->lu_gp_assoc = 0;
		}
		spin_unlock(&lu_gp->lu_gp_lock);
		/*
		 *
		 * lu_gp_mem is associated with a single
		 * struct se_device->dev_alua_lu_gp_mem, and is released when
		 * struct se_device is released via core_alua_free_lu_gp_mem().
		 *
		 * If the passed lu_gp does NOT match the default_lu_gp, assume
		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
		 */
		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
		if (lu_gp != default_lu_gp)
			__core_alua_attach_lu_gp_mem(lu_gp_mem,
					default_lu_gp);
		else
			lu_gp_mem->lu_gp = NULL;
		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);

		spin_lock(&lu_gp->lu_gp_lock);
	}
	spin_unlock(&lu_gp->lu_gp_lock);

	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
}

void core_alua_free_lu_gp_mem(struct se_device *dev)
{
	struct t10_alua_lu_gp *lu_gp;
	struct t10_alua_lu_gp_member *lu_gp_mem;

	lu_gp_mem = dev->dev_alua_lu_gp_mem;
	if (!lu_gp_mem)
		return;

	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
		cpu_relax();

	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
	lu_gp = lu_gp_mem->lu_gp;
	if (lu_gp) {
		spin_lock(&lu_gp->lu_gp_lock);
		if (lu_gp_mem->lu_gp_assoc) {
			list_del(&lu_gp_mem->lu_gp_mem_list);
			lu_gp->lu_gp_members--;
			lu_gp_mem->lu_gp_assoc = 0;
		}
		spin_unlock(&lu_gp->lu_gp_lock);
		lu_gp_mem->lu_gp = NULL;
	}
	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);

	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
}

struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
{
	struct t10_alua_lu_gp *lu_gp;
	struct config_item *ci;

	spin_lock(&lu_gps_lock);
	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
		if (!lu_gp->lu_gp_valid_id)
			continue;
		ci = &lu_gp->lu_gp_group.cg_item;
		if (!strcmp(config_item_name(ci), name)) {
			atomic_inc(&lu_gp->lu_gp_ref_cnt);
			spin_unlock(&lu_gps_lock);
			return lu_gp;
		}
	}
	spin_unlock(&lu_gps_lock);

	return NULL;
}

void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
{
	spin_lock(&lu_gps_lock);
	atomic_dec(&lu_gp->lu_gp_ref_cnt);
	spin_unlock(&lu_gps_lock);
}

/*
 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
 */
void __core_alua_attach_lu_gp_mem(
	struct t10_alua_lu_gp_member *lu_gp_mem,
	struct t10_alua_lu_gp *lu_gp)
{
	spin_lock(&lu_gp->lu_gp_lock);
	lu_gp_mem->lu_gp = lu_gp;
	lu_gp_mem->lu_gp_assoc = 1;
	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
	lu_gp->lu_gp_members++;
	spin_unlock(&lu_gp->lu_gp_lock);
}

/*
 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
 */
void __core_alua_drop_lu_gp_mem(
	struct t10_alua_lu_gp_member *lu_gp_mem,
	struct t10_alua_lu_gp *lu_gp)
{
	spin_lock(&lu_gp->lu_gp_lock);
	list_del(&lu_gp_mem->lu_gp_mem_list);
	lu_gp_mem->lu_gp = NULL;
	lu_gp_mem->lu_gp_assoc = 0;
	lu_gp->lu_gp_members--;
	spin_unlock(&lu_gp->lu_gp_lock);
}

struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
		const char *name, int def_group)
{
	struct t10_alua_tg_pt_gp *tg_pt_gp;

	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
	if (!tg_pt_gp) {
		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
		return NULL;
	}
	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
	tg_pt_gp->tg_pt_gp_dev = dev;
	tg_pt_gp->tg_pt_gp_alua_access_state =
			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
	/*
	 * Enable both explicit and implicit ALUA support by default
	 */
	tg_pt_gp->tg_pt_gp_alua_access_type =
			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
	/*
	 * Set the default Active/NonOptimized Delay in milliseconds
	 */
	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;

	/*
	 * Enable all supported states
	 */
	tg_pt_gp->tg_pt_gp_alua_supported_states =
	    ALUA_T_SUP | ALUA_O_SUP |
	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;

	if (def_group) {
		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
		tg_pt_gp->tg_pt_gp_id =
				dev->t10_alua.alua_tg_pt_gps_counter++;
		tg_pt_gp->tg_pt_gp_valid_id = 1;
		dev->t10_alua.alua_tg_pt_gps_count++;
		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
			      &dev->t10_alua.tg_pt_gps_list);
		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
	}

	return tg_pt_gp;
}

int core_alua_set_tg_pt_gp_id(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	u16 tg_pt_gp_id)
{
	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
	u16 tg_pt_gp_id_tmp;

	/*
	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
	 */
	if (tg_pt_gp->tg_pt_gp_valid_id) {
		pr_warn("ALUA TG PT Group already has a valid ID,"
			" ignoring request\n");
		return -EINVAL;
	}

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
			" 0x0000ffff reached\n");
		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
		return -ENOSPC;
	}
again:
	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
			dev->t10_alua.alua_tg_pt_gps_counter++;

	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
			tg_pt_gp_list) {
		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
			if (!tg_pt_gp_id)
				goto again;

			pr_err("ALUA Target Port Group ID: %hu already"
				" exists, ignoring request\n", tg_pt_gp_id);
			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
			return -EINVAL;
		}
	}

	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
	tg_pt_gp->tg_pt_gp_valid_id = 1;
	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
			&dev->t10_alua.tg_pt_gps_list);
	dev->t10_alua.alua_tg_pt_gps_count++;
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);

	return 0;
}

void core_alua_free_tg_pt_gp(
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
	struct se_lun *lun, *next;

	/*
	 * Once we have reached this point, config_item_put() has already
	 * been called from target_core_alua_drop_tg_pt_gp().
	 *
	 * Here we remove *tg_pt_gp from the global list so that
	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
	 */
	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	list_del(&tg_pt_gp->tg_pt_gp_list);
	dev->t10_alua.alua_tg_pt_gps_counter--;
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);

	/*
	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
	 * core_alua_get_tg_pt_gp_by_name() in
	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
	 * to be released with core_alua_put_tg_pt_gp_from_name().
	 */
	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
		cpu_relax();

	/*
	 * Release reference to struct t10_alua_tg_pt_gp from all associated
	 * struct se_port.
	 */
	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	list_for_each_entry_safe(lun, next,
			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
		list_del_init(&lun->lun_tg_pt_gp_link);
		tg_pt_gp->tg_pt_gp_members--;

		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
		/*
		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
		 * assume we want to re-associate a given tg_pt_gp_mem with
		 * default_tg_pt_gp.
		 */
		spin_lock(&lun->lun_tg_pt_gp_lock);
		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
			__target_attach_tg_pt_gp(lun,
					dev->t10_alua.default_tg_pt_gp);
		} else
			lun->lun_tg_pt_gp = NULL;
		spin_unlock(&lun->lun_tg_pt_gp_lock);

		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	}
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);

	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
}

static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
		struct se_device *dev, const char *name)
{
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct config_item *ci;

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
			tg_pt_gp_list) {
		if (!tg_pt_gp->tg_pt_gp_valid_id)
			continue;
		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
		if (!strcmp(config_item_name(ci), name)) {
			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
			return tg_pt_gp;
		}
	}
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);

	return NULL;
}

static void core_alua_put_tg_pt_gp_from_name(
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
}

static void __target_attach_tg_pt_gp(struct se_lun *lun,
		struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_dev_entry *se_deve;

	assert_spin_locked(&lun->lun_tg_pt_gp_lock);

	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	lun->lun_tg_pt_gp = tg_pt_gp;
	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
	tg_pt_gp->tg_pt_gp_members++;
	spin_lock(&lun->lun_deve_lock);
	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
		core_scsi3_ua_allocate(se_deve, 0x3f,
				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
	spin_unlock(&lun->lun_deve_lock);
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
}

void target_attach_tg_pt_gp(struct se_lun *lun,
		struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	spin_lock(&lun->lun_tg_pt_gp_lock);
	__target_attach_tg_pt_gp(lun, tg_pt_gp);
	spin_unlock(&lun->lun_tg_pt_gp_lock);
}

static void __target_detach_tg_pt_gp(struct se_lun *lun,
		struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	assert_spin_locked(&lun->lun_tg_pt_gp_lock);

	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	list_del_init(&lun->lun_tg_pt_gp_link);
	tg_pt_gp->tg_pt_gp_members--;
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);

	lun->lun_tg_pt_gp = NULL;
}

void target_detach_tg_pt_gp(struct se_lun *lun)
{
	struct t10_alua_tg_pt_gp *tg_pt_gp;

	spin_lock(&lun->lun_tg_pt_gp_lock);
	tg_pt_gp = lun->lun_tg_pt_gp;
	if (tg_pt_gp)
		__target_detach_tg_pt_gp(lun, tg_pt_gp);
	spin_unlock(&lun->lun_tg_pt_gp_lock);
}

ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
{
	struct config_item *tg_pt_ci;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	ssize_t len = 0;

	spin_lock(&lun->lun_tg_pt_gp_lock);
	tg_pt_gp = lun->lun_tg_pt_gp;
	if (tg_pt_gp) {
		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
			" %hu\nTG Port Primary Access State: %s\nTG Port "
			"Primary Access Status: %s\nTG Port Secondary Access"
			" State: %s\nTG Port Secondary Access Status: %s\n",
			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
			core_alua_dump_state(
				tg_pt_gp->tg_pt_gp_alua_access_state),
			core_alua_dump_status(
				tg_pt_gp->tg_pt_gp_alua_access_status),
			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
			"Offline" : "None",
			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
	}
	spin_unlock(&lun->lun_tg_pt_gp_lock);

	return len;
}

ssize_t core_alua_store_tg_pt_gp_info(
	struct se_lun *lun,
	const char *page,
	size_t count)
{
	struct se_portal_group *tpg = lun->lun_tpg;
	/*
	 * rcu_dereference_raw protected by se_lun->lun_group symlink
	 * reference to se_device->dev_group.
	 */
	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
	unsigned char buf[TG_PT_GROUP_NAME_BUF];
	int move = 0;

	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
		return -ENODEV;

	if (count > TG_PT_GROUP_NAME_BUF) {
		pr_err("ALUA Target Port Group alias too large!\n");
		return -EINVAL;
	}
	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
	memcpy(buf, page, count);
	/*
	 * Any ALUA target port group alias besides "NULL" means we will be
	 * making a new group association.
	 */
	if (strcmp(strstrip(buf), "NULL")) {
		/*
		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
		 * struct t10_alua_tg_pt_gp.  This reference is released with
		 * core_alua_put_tg_pt_gp_from_name() below.
		 */
		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
					strstrip(buf));
		if (!tg_pt_gp_new)
			return -ENODEV;
	}

	spin_lock(&lun->lun_tg_pt_gp_lock);
	tg_pt_gp = lun->lun_tg_pt_gp;
	if (tg_pt_gp) {
		/*
		 * Clearing an existing tg_pt_gp association, and replacing
		 * with the default_tg_pt_gp.
		 */
		if (!tg_pt_gp_new) {
			pr_debug("Target_Core_ConfigFS: Moving"
				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
				" alua/%s, ID: %hu back to"
				" default_tg_pt_gp\n",
				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
				tpg->se_tpg_tfo->tpg_get_tag(tpg),
				config_item_name(&lun->lun_group.cg_item),
				config_item_name(
					&tg_pt_gp->tg_pt_gp_group.cg_item),
				tg_pt_gp->tg_pt_gp_id);

			__target_detach_tg_pt_gp(lun, tg_pt_gp);
			__target_attach_tg_pt_gp(lun,
					dev->t10_alua.default_tg_pt_gp);
			spin_unlock(&lun->lun_tg_pt_gp_lock);

			return count;
		}
		__target_detach_tg_pt_gp(lun, tg_pt_gp);
		move = 1;
	}

	__target_attach_tg_pt_gp(lun, tg_pt_gp_new);
	spin_unlock(&lun->lun_tg_pt_gp_lock);
	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
		tpg->se_tpg_tfo->tpg_get_tag(tpg),
		config_item_name(&lun->lun_group.cg_item),
		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
		tg_pt_gp_new->tg_pt_gp_id);

	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
	return count;
}

ssize_t core_alua_show_access_type(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	char *page)
{
	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
		return sprintf(page, "Implicit and Explicit\n");
	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
		return sprintf(page, "Implicit\n");
	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
		return sprintf(page, "Explicit\n");
	else
		return sprintf(page, "None\n");
}

ssize_t core_alua_store_access_type(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_access_type\n");
		return ret;
	}
	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
		pr_err("Illegal value for alua_access_type:"
				" %lu\n", tmp);
		return -EINVAL;
	}
	if (tmp == 3)
		tg_pt_gp->tg_pt_gp_alua_access_type =
			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
	else if (tmp == 2)
		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
	else if (tmp == 1)
		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
	else
		tg_pt_gp->tg_pt_gp_alua_access_type = 0;

	return count;
}

ssize_t core_alua_show_nonop_delay_msecs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	char *page)
{
	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
}

ssize_t core_alua_store_nonop_delay_msecs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract nonop_delay_msecs\n");
		return ret;
	}
	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
			ALUA_MAX_NONOP_DELAY_MSECS);
		return -EINVAL;
	}
	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;

	return count;
}

ssize_t core_alua_show_trans_delay_msecs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	char *page)
{
	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
}

ssize_t core_alua_store_trans_delay_msecs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract trans_delay_msecs\n");
		return ret;
	}
	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
		pr_err("Passed trans_delay_msecs: %lu, exceeds"
			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
			ALUA_MAX_TRANS_DELAY_MSECS);
		return -EINVAL;
	}
	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;

	return count;
}

ssize_t core_alua_show_implicit_trans_secs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	char *page)
{
	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
}

ssize_t core_alua_store_implicit_trans_secs(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract implicit_trans_secs\n");
		return ret;
	}
	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
		pr_err("Passed implicit_trans_secs: %lu, exceeds"
			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
			ALUA_MAX_IMPLICIT_TRANS_SECS);
		return  -EINVAL;
	}
	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;

	return count;
}

ssize_t core_alua_show_preferred_bit(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	char *page)
{
	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
}

ssize_t core_alua_store_preferred_bit(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract preferred ALUA value\n");
		return ret;
	}
	if ((tmp != 0) && (tmp != 1)) {
		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
		return -EINVAL;
	}
	tg_pt_gp->tg_pt_gp_pref = (int)tmp;

	return count;
}

ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
{
	return sprintf(page, "%d\n",
		atomic_read(&lun->lun_tg_pt_secondary_offline));
}

ssize_t core_alua_store_offline_bit(
	struct se_lun *lun,
	const char *page,
	size_t count)
{
	/*
	 * rcu_dereference_raw protected by se_lun->lun_group symlink
	 * reference to se_device->dev_group.
	 */
	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
	unsigned long tmp;
	int ret;

	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
		return -ENODEV;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_offline value\n");
		return ret;
	}
	if ((tmp != 0) && (tmp != 1)) {
		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
				tmp);
		return -EINVAL;
	}

	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
	if (ret < 0)
		return -EINVAL;

	return count;
}

ssize_t core_alua_show_secondary_status(
	struct se_lun *lun,
	char *page)
{
	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
}

ssize_t core_alua_store_secondary_status(
	struct se_lun *lun,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_status\n");
		return ret;
	}
	if ((tmp != ALUA_STATUS_NONE) &&
	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
				tmp);
		return -EINVAL;
	}
	lun->lun_tg_pt_secondary_stat = (int)tmp;

	return count;
}

ssize_t core_alua_show_secondary_write_metadata(
	struct se_lun *lun,
	char *page)
{
	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
}

ssize_t core_alua_store_secondary_write_metadata(
	struct se_lun *lun,
	const char *page,
	size_t count)
{
	unsigned long tmp;
	int ret;

	ret = kstrtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_write_md\n");
		return ret;
	}
	if ((tmp != 0) && (tmp != 1)) {
		pr_err("Illegal value for alua_tg_pt_write_md:"
				" %lu\n", tmp);
		return -EINVAL;
	}
	lun->lun_tg_pt_secondary_write_md = (int)tmp;

	return count;
}

int core_setup_alua(struct se_device *dev)
{
	if (!(dev->transport->transport_flags &
	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
		struct t10_alua_lu_gp_member *lu_gp_mem;

		/*
		 * Associate this struct se_device with the default ALUA
		 * LUN Group.
		 */
		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
		if (IS_ERR(lu_gp_mem))
			return PTR_ERR(lu_gp_mem);

		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
		__core_alua_attach_lu_gp_mem(lu_gp_mem,
				default_lu_gp);
		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);

		pr_debug("%s: Adding to default ALUA LU Group:"
			" core/alua/lu_gps/default_lu_gp\n",
			dev->transport->name);
	}

	return 0;
}