Free Electrons

Embedded Linux Experts

   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
/*******************************************************************************
 * Filename:  target_core_alua.c
 *
 * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
 *
 * Copyright (c) 2009-2010 Rising Tide Systems
 * Copyright (c) 2009-2010 Linux-iSCSI.org
 *
 * 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/export.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.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/target_core_configfs.h>

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

static int core_alua_check_transition(int state, int *primary);
static int core_alua_set_tg_pt_secondary_state(
		struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
		struct se_port *port, int explict, int offline);

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_TARGET_PORT_GROUPS
 *
 * See spc4r17 section 6.27
 */
int target_emulate_report_target_port_groups(struct se_task *task)
{
	struct se_cmd *cmd = task->task_se_cmd;
	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
	struct se_port *port;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
	unsigned char *buf;
	u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
				    Target port group descriptor */
	/*
	 * Need at least 4 bytes of response data or else we can't
	 * even fit the return data length.
	 */
	if (cmd->data_length < 4) {
		pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
			" too small\n", cmd->data_length);
		return -EINVAL;
	}

	buf = transport_kmap_data_sg(cmd);

	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
	list_for_each_entry(tg_pt_gp, &su_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++] |= (atomic_read(
			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
		/*
		 * Set supported ASYMMETRIC ACCESS State bits
		 */
		buf[off] = 0x80; /* T_SUP */
		buf[off] |= 0x40; /* O_SUP */
		buf[off] |= 0x8; /* U_SUP */
		buf[off] |= 0x4; /* S_SUP */
		buf[off] |= 0x2; /* AN_SUP */
		buf[off++] |= 0x1; /* AO_SUP */
		/*
		 * TARGET PORT GROUP
		 */
		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);

		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(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
				tg_pt_gp_mem_list) {
			port = tg_pt_gp_mem->tg_pt;
			/*
			 * Start Target Port descriptor format
			 *
			 * See spc4r17 section 6.2.7 Table 247
			 */
			off += 2; /* Skip over Obsolete */
			/*
			 * Set RELATIVE TARGET PORT IDENTIFIER
			 */
			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
			buf[off++] = (port->sep_rtpi & 0xff);
			rd_len += 4;
		}
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
	}
	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
	/*
	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
	 */
	buf[0] = ((rd_len >> 24) & 0xff);
	buf[1] = ((rd_len >> 16) & 0xff);
	buf[2] = ((rd_len >> 8) & 0xff);
	buf[3] = (rd_len & 0xff);

	transport_kunmap_data_sg(cmd);

	task->task_scsi_status = GOOD;
	transport_complete_task(task, 1);
	return 0;
}

/*
 * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 *
 * See spc4r17 section 6.35
 */
int target_emulate_set_target_port_groups(struct se_task *task)
{
	struct se_cmd *cmd = task->task_se_cmd;
	struct se_device *dev = cmd->se_dev;
	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
	struct se_port *port, *l_port = cmd->se_lun->lun_sep;
	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;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
	unsigned char *buf;
	unsigned char *ptr;
	u32 len = 4; /* Skip over RESERVED area in header */
	int alua_access_state, primary = 0, rc;
	u16 tg_pt_id, rtpi;

	if (!l_port) {
		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		return -EINVAL;
	}
	buf = transport_kmap_data_sg(cmd);

	/*
	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
	 * for the local tg_pt_gp.
	 */
	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
	if (!l_tg_pt_gp_mem) {
		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
		rc = -EINVAL;
		goto out;
	}
	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
	if (!l_tg_pt_gp) {
		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
		rc = -EINVAL;
		goto out;
	}
	rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);

	if (!rc) {
		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
				" while TPGS_EXPLICT_ALUA is disabled\n");
		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
		rc = -EINVAL;
		goto out;
	}

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

	while (len < cmd->data_length) {
		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, &primary);
		if (rc != 0) {
			/*
			 * 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.
			 */
			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
			rc = -EINVAL;
			goto out;
		}
		rc = -1;
		/*
		 * 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(&su_dev->t10_alua.tg_pt_gps_lock);
			list_for_each_entry(tg_pt_gp,
					&su_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(&tg_pt_gp->tg_pt_gp_ref_cnt);
				smp_mb__after_atomic_inc();
				spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);

				rc = core_alua_do_port_transition(tg_pt_gp,
						dev, l_port, nacl,
						alua_access_state, 1);

				spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
				smp_mb__after_atomic_dec();
				break;
			}
			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
			/*
			 * If not matching target port group ID can be located
			 * throw an exception with ASCQ: INVALID_PARAMETER_LIST
			 */
			if (rc != 0) {
				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
				rc = -EINVAL;
				goto out;
			}
		} else {
			/*
			 * Extact 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 identifer
			 * for the struct se_device storage object.
			 */
			spin_lock(&dev->se_port_lock);
			list_for_each_entry(port, &dev->dev_sep_list,
							sep_list) {
				if (port->sep_rtpi != rtpi)
					continue;

				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
				spin_unlock(&dev->se_port_lock);

				rc = core_alua_set_tg_pt_secondary_state(
						tg_pt_gp_mem, port, 1, 1);

				spin_lock(&dev->se_port_lock);
				break;
			}
			spin_unlock(&dev->se_port_lock);
			/*
			 * If not matching relative target port identifier can
			 * be located, throw an exception with ASCQ:
			 * INVALID_PARAMETER_LIST
			 */
			if (rc != 0) {
				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
				rc = -EINVAL;
				goto out;
			}
		}

		ptr += 4;
		len += 4;
	}

out:
	transport_kunmap_data_sg(cmd);
	task->task_scsi_status = GOOD;
	transport_complete_task(task, 1);
	return 0;
}

static inline int core_alua_state_nonoptimized(
	struct se_cmd *cmd,
	unsigned char *cdb,
	int nonop_delay_msecs,
	u8 *alua_ascq)
{
	/*
	 * 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;
	return 0;
}

static inline int core_alua_state_standby(
	struct se_cmd *cmd,
	unsigned char *cdb,
	u8 *alua_ascq)
{
	/*
	 * 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 MAINTENANCE_IN:
		switch (cdb[1]) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
			return 1;
		}
	case MAINTENANCE_OUT:
		switch (cdb[1]) {
		case MO_SET_TARGET_PGS:
			return 0;
		default:
			*alua_ascq = 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:
		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
		return 1;
	}

	return 0;
}

static inline int core_alua_state_unavailable(
	struct se_cmd *cmd,
	unsigned char *cdb,
	u8 *alua_ascq)
{
	/*
	 * 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:
	case MAINTENANCE_IN:
		switch (cdb[1]) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
			return 1;
		}
	case MAINTENANCE_OUT:
		switch (cdb[1]) {
		case MO_SET_TARGET_PGS:
			return 0;
		default:
			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
			return 1;
		}
	case REQUEST_SENSE:
	case READ_BUFFER:
	case WRITE_BUFFER:
		return 0;
	default:
		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
		return 1;
	}

	return 0;
}

static inline int core_alua_state_transition(
	struct se_cmd *cmd,
	unsigned char *cdb,
	u8 *alua_ascq)
{
	/*
	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
	 * spc4r17 section 5.9.2.5
	 */
	switch (cdb[0]) {
	case INQUIRY:
	case REPORT_LUNS:
	case MAINTENANCE_IN:
		switch (cdb[1]) {
		case MI_REPORT_TARGET_PGS:
			return 0;
		default:
			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
			return 1;
		}
	case REQUEST_SENSE:
	case READ_BUFFER:
	case WRITE_BUFFER:
		return 0;
	default:
		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
		return 1;
	}

	return 0;
}

/*
 * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 * in transport_cmd_sequencer().  This function is assigned to
 * struct t10_alua *->state_check() in core_setup_alua()
 */
static int core_alua_state_check_nop(
	struct se_cmd *cmd,
	unsigned char *cdb,
	u8 *alua_ascq)
{
	return 0;
}

/*
 * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 * This function is assigned to struct t10_alua *->state_check() in
 * core_setup_alua()
 *
 * Also, this function can return three different return codes to
 * signal transport_generic_cmd_sequencer()
 *
 * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 * return 0: Used to signal success
 * reutrn -1: Used to signal failure, and invalid cdb field
 */
static int core_alua_state_check(
	struct se_cmd *cmd,
	unsigned char *cdb,
	u8 *alua_ascq)
{
	struct se_lun *lun = cmd->se_lun;
	struct se_port *port = lun->lun_sep;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
	int out_alua_state, nonop_delay_msecs;

	if (!port)
		return 0;
	/*
	 * First, check for a struct se_port specific secondary ALUA target port
	 * access state: OFFLINE
	 */
	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
		pr_debug("ALUA: Got secondary offline status for local"
				" target port\n");
		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
		return 1;
	}
	 /*
	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
	 * ALUA target port group, to obtain current ALUA access state.
	 * Otherwise look for the underlying struct se_device association with
	 * a ALUA logical unit group.
	 */
	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	/*
	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED 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_OPTMIZED)
		return 0;

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

	return 0;
}

/*
 * Check implict and explict ALUA state change request.
 */
static int core_alua_check_transition(int state, int *primary)
{
	switch (state) {
	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
	case ALUA_ACCESS_STATE_STANDBY:
	case ALUA_ACCESS_STATE_UNAVAILABLE:
		/*
		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
		 * defined as primary target port asymmetric access states.
		 */
		*primary = 1;
		break;
	case ALUA_ACCESS_STATE_OFFLINE:
		/*
		 * OFFLINE state is defined as a secondary target port
		 * asymmetric access state.
		 */
		*primary = 0;
		break;
	default:
		pr_err("Unknown ALUA access state: 0x%02x\n", state);
		return -EINVAL;
	}

	return 0;
}

static char *core_alua_dump_state(int state)
{
	switch (state) {
	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
		return "Active/Optimized";
	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
		return "Active/NonOptimized";
	case ALUA_ACCESS_STATE_STANDBY:
		return "Standby";
	case ALUA_ACCESS_STATE_UNAVAILABLE:
		return "Unavailable";
	case ALUA_ACCESS_STATE_OFFLINE:
		return "Offline";
	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_EXPLICT_STPG:
		return "Altered by Explict STPG";
	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
		return "Altered by Implict 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);

/*
 * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 *
 */
static int core_alua_write_tpg_metadata(
	const char *path,
	unsigned char *md_buf,
	u32 md_buf_len)
{
	mm_segment_t old_fs;
	struct file *file;
	struct iovec iov[1];
	int flags = O_RDWR | O_CREAT | O_TRUNC, ret;

	memset(iov, 0, sizeof(struct iovec));

	file = filp_open(path, flags, 0600);
	if (IS_ERR(file) || !file || !file->f_dentry) {
		pr_err("filp_open(%s) for ALUA metadata failed\n",
			path);
		return -ENODEV;
	}

	iov[0].iov_base = &md_buf[0];
	iov[0].iov_len = md_buf_len;

	old_fs = get_fs();
	set_fs(get_ds());
	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
	set_fs(old_fs);

	if (ret < 0) {
		pr_err("Error writing ALUA metadata file: %s\n", path);
		filp_close(file, NULL);
		return -EIO;
	}
	filp_close(file, NULL);

	return 0;
}

/*
 * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 */
static int core_alua_update_tpg_primary_metadata(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	int primary_state,
	unsigned char *md_buf)
{
	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
	struct t10_wwn *wwn = &su_dev->t10_wwn;
	char path[ALUA_METADATA_PATH_LEN];
	int len;

	memset(path, 0, ALUA_METADATA_PATH_LEN);

	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_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, primary_state,
			tg_pt_gp->tg_pt_gp_alua_access_status);

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

	return core_alua_write_tpg_metadata(path, md_buf, len);
}

static int core_alua_do_transition_tg_pt(
	struct t10_alua_tg_pt_gp *tg_pt_gp,
	struct se_port *l_port,
	struct se_node_acl *nacl,
	unsigned char *md_buf,
	int new_state,
	int explict)
{
	struct se_dev_entry *se_deve;
	struct se_lun_acl *lacl;
	struct se_port *port;
	struct t10_alua_tg_pt_gp_member *mem;
	int old_state = 0;
	/*
	 * Save the old primary ALUA access state, and set the current state
	 * to ALUA_ACCESS_STATE_TRANSITION.
	 */
	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
			ALUA_ACCESS_STATE_TRANSITION);
	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
	/*
	 * 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);

	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
				tg_pt_gp_mem_list) {
		port = mem->tg_pt;
		/*
		 * 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 CHAGED.
		 *
		 * 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
		 */
		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
		smp_mb__after_atomic_inc();
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);

		spin_lock_bh(&port->sep_alua_lock);
		list_for_each_entry(se_deve, &port->sep_alua_list,
					alua_port_list) {
			lacl = se_deve->se_lun_acl;
			/*
			 * se_deve->se_lun_acl pointer may be NULL for a
			 * entry created without explict Node+MappedLUN ACLs
			 */
			if (!lacl)
				continue;

			if (explict &&
			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
			   (l_port != NULL) && (l_port == port))
				continue;

			core_scsi3_ua_allocate(lacl->se_lun_nacl,
				se_deve->mapped_lun, 0x2A,
				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
		}
		spin_unlock_bh(&port->sep_alua_lock);

		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
		smp_mb__after_atomic_dec();
	}
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
	/*
	 * 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) {
		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
		core_alua_update_tpg_primary_metadata(tg_pt_gp,
					new_state, md_buf);
		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
	}
	/*
	 * Set the current primary ALUA access state to the requested new state
	 */
	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);

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

	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_port *l_port,
	struct se_node_acl *l_nacl,
	int new_state,
	int explict)
{
	struct se_device *dev;
	struct se_port *port;
	struct se_subsystem_dev *su_dev;
	struct se_node_acl *nacl;
	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;
	unsigned char *md_buf;
	int primary;

	if (core_alua_check_transition(new_state, &primary) != 0)
		return -EINVAL;

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

	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);
	smp_mb__after_atomic_inc();
	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.
		 */
		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
					md_buf, new_state, explict);
		atomic_dec(&lu_gp->lu_gp_ref_cnt);
		smp_mb__after_atomic_dec();
		kfree(md_buf);
		return 0;
	}
	/*
	 * 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;
		su_dev = dev->se_sub_dev;
		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
		smp_mb__after_atomic_inc();
		spin_unlock(&lu_gp->lu_gp_lock);

		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
		list_for_each_entry(tg_pt_gp,
				&su_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 accessiable 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) {
				port = l_port;
				nacl = l_nacl;
			} else {
				port = NULL;
				nacl = NULL;
			}
			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
			smp_mb__after_atomic_inc();
			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
			/*
			 * core_alua_do_transition_tg_pt() will always return
			 * success.
			 */
			core_alua_do_transition_tg_pt(tg_pt_gp, port,
					nacl, md_buf, new_state, explict);

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

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

	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, (explict) ? "explict" : "implict",
		core_alua_dump_state(new_state));

	atomic_dec(&lu_gp->lu_gp_ref_cnt);
	smp_mb__after_atomic_dec();
	kfree(md_buf);
	return 0;
}

/*
 * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
 */
static int core_alua_update_tpg_secondary_metadata(
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
	struct se_port *port,
	unsigned char *md_buf,
	u32 md_buf_len)
{
	struct se_portal_group *se_tpg = port->sep_tpg;
	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
	int len;

	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, md_buf_len, "alua_tg_pt_offline=%d\n"
			"alua_tg_pt_status=0x%02x\n",
			atomic_read(&port->sep_tg_pt_secondary_offline),
			port->sep_tg_pt_secondary_stat);

	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
			port->sep_lun->unpacked_lun);

	return core_alua_write_tpg_metadata(path, md_buf, len);
}

static int core_alua_set_tg_pt_secondary_state(
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
	struct se_port *port,
	int explict,
	int offline)
{
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	unsigned char *md_buf;
	u32 md_buf_len;
	int trans_delay_msecs;

	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
	if (!tg_pt_gp) {
		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_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_port
	 */
	if (offline)
		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
	else
		atomic_set(&port->sep_tg_pt_secondary_offline, 0);

	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
	port->sep_tg_pt_secondary_stat = (explict) ?
			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;

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

	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_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 (port->sep_tg_pt_secondary_write_md) {
		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
		if (!md_buf) {
			pr_err("Unable to allocate md_buf for"
				" secondary ALUA access metadata\n");
			return -ENOMEM;
		}
		mutex_lock(&port->sep_tg_pt_md_mutex);
		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
				md_buf, md_buf_len);
		mutex_unlock(&port->sep_tg_pt_md_mutex);

		kfree(md_buf);
	}

	return 0;
}

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-assocate 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 se_subsystem_dev *su_dev = dev->se_sub_dev;
	struct t10_alua *alua = &su_dev->t10_alua;
	struct t10_alua_lu_gp *lu_gp;
	struct t10_alua_lu_gp_member *lu_gp_mem;

	if (alua->alua_type != SPC3_ALUA_EMULATED)
		return;

	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_subsystem_dev *su_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_mem_list);
	mutex_init(&tg_pt_gp->tg_pt_gp_md_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_su_dev = su_dev;
	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
	/*
	 * Enable both explict and implict ALUA support by default
	 */
	tg_pt_gp->tg_pt_gp_alua_access_type =
			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_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;

	if (def_group) {
		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
		tg_pt_gp->tg_pt_gp_id =
				su_dev->t10_alua.alua_tg_pt_gps_counter++;
		tg_pt_gp->tg_pt_gp_valid_id = 1;
		su_dev->t10_alua.alua_tg_pt_gps_count++;
		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
			      &su_dev->t10_alua.tg_pt_gps_list);
		spin_unlock(&su_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_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_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(&su_dev->t10_alua.tg_pt_gps_lock);
	if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
			" 0x0000ffff reached\n");
		spin_unlock(&su_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 :
			su_dev->t10_alua.alua_tg_pt_gps_counter++;

	list_for_each_entry(tg_pt_gp_tmp, &su_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(&su_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,
			&su_dev->t10_alua.tg_pt_gps_list);
	su_dev->t10_alua.alua_tg_pt_gps_count++;
	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);

	return 0;
}

struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
	struct se_port *port)
{
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;

	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
				GFP_KERNEL);
	if (!tg_pt_gp_mem) {
		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
		return ERR_PTR(-ENOMEM);
	}
	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);

	tg_pt_gp_mem->tg_pt = port;
	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;

	return tg_pt_gp_mem;
}

void core_alua_free_tg_pt_gp(
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
	/*
	 * 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 assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
	 */
	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
	list_del(&tg_pt_gp->tg_pt_gp_list);
	su_dev->t10_alua.alua_tg_pt_gps_counter--;
	spin_unlock(&su_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(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
			tg_pt_gp->tg_pt_gp_members--;
			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
		}
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
		/*
		 * tg_pt_gp_mem is associated with a single
		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
		 * core_alua_free_tg_pt_gp_mem().
		 *
		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
		 * assume we want to re-assocate a given tg_pt_gp_mem with
		 * default_tg_pt_gp.
		 */
		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
		if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
					su_dev->t10_alua.default_tg_pt_gp);
		} else
			tg_pt_gp_mem->tg_pt_gp = NULL;
		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_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);
}

void core_alua_free_tg_pt_gp_mem(struct se_port *port)
{
	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
	struct t10_alua *alua = &su_dev->t10_alua;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;

	if (alua->alua_type != SPC3_ALUA_EMULATED)
		return;

	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
	if (!tg_pt_gp_mem)
		return;

	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
		cpu_relax();

	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
	if (tg_pt_gp) {
		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
			tg_pt_gp->tg_pt_gp_members--;
			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
		}
		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
		tg_pt_gp_mem->tg_pt_gp = NULL;
	}
	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);

	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
}

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

	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
	list_for_each_entry(tg_pt_gp, &su_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(&su_dev->t10_alua.tg_pt_gps_lock);
			return tg_pt_gp;
		}
	}
	spin_unlock(&su_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_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;

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

/*
 * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
 */
void __core_alua_attach_tg_pt_gp_mem(
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
			&tg_pt_gp->tg_pt_gp_mem_list);
	tg_pt_gp->tg_pt_gp_members++;
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
}

/*
 * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
 */
static void __core_alua_drop_tg_pt_gp_mem(
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
	struct t10_alua_tg_pt_gp *tg_pt_gp)
{
	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
	tg_pt_gp_mem->tg_pt_gp = NULL;
	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
	tg_pt_gp->tg_pt_gp_members--;
	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
}

ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
{
	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
	struct config_item *tg_pt_ci;
	struct t10_alua *alua = &su_dev->t10_alua;
	struct t10_alua_tg_pt_gp *tg_pt_gp;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
	ssize_t len = 0;

	if (alua->alua_type != SPC3_ALUA_EMULATED)
		return len;

	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
	if (!tg_pt_gp_mem)
		return len;

	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	tg_pt_gp = tg_pt_gp_mem->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(atomic_read(
					&tg_pt_gp->tg_pt_gp_alua_access_state)),
			core_alua_dump_status(
				tg_pt_gp->tg_pt_gp_alua_access_status),
			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
			"Offline" : "None",
			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
	}
	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);

	return len;
}

ssize_t core_alua_store_tg_pt_gp_info(
	struct se_port *port,
	const char *page,
	size_t count)
{
	struct se_portal_group *tpg;
	struct se_lun *lun;
	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
	unsigned char buf[TG_PT_GROUP_NAME_BUF];
	int move = 0;

	tpg = port->sep_tpg;
	lun = port->sep_lun;

	if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
		pr_warn("SPC3_ALUA_EMULATED not enabled for"
			" %s/tpgt_%hu/%s\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));
		return -EINVAL;
	}

	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(su_dev,
					strstrip(buf));
		if (!tg_pt_gp_new)
			return -ENODEV;
	}
	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
	if (!tg_pt_gp_mem) {
		if (tg_pt_gp_new)
			core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
		pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
		return -EINVAL;
	}

	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
	tg_pt_gp = tg_pt_gp_mem->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);

			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
					su_dev->t10_alua.default_tg_pt_gp);
			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);

			return count;
		}
		/*
		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
		 */
		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
		move = 1;
	}
	/*
	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
	 */
	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_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_EXPLICT_ALUA) &&
	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
		return sprintf(page, "Implict and Explict\n");
	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
		return sprintf(page, "Implict\n");
	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
		return sprintf(page, "Explict\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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_access_type\n");
		return -EINVAL;
	}
	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_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
	else if (tmp == 2)
		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
	else if (tmp == 1)
		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract nonop_delay_msecs\n");
		return -EINVAL;
	}
	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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract trans_delay_msecs\n");
		return -EINVAL;
	}
	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_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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract preferred ALUA value\n");
		return -EINVAL;
	}
	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)
{
	if (!lun->lun_sep)
		return -ENODEV;

	return sprintf(page, "%d\n",
		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
}

ssize_t core_alua_store_offline_bit(
	struct se_lun *lun,
	const char *page,
	size_t count)
{
	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
	unsigned long tmp;
	int ret;

	if (!lun->lun_sep)
		return -ENODEV;

	ret = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_offline value\n");
		return -EINVAL;
	}
	if ((tmp != 0) && (tmp != 1)) {
		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
				tmp);
		return -EINVAL;
	}
	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
	if (!tg_pt_gp_mem) {
		pr_err("Unable to locate *tg_pt_gp_mem\n");
		return -EINVAL;
	}

	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
			lun->lun_sep, 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_sep->sep_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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_status\n");
		return -EINVAL;
	}
	if ((tmp != ALUA_STATUS_NONE) &&
	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
				tmp);
		return -EINVAL;
	}
	lun->lun_sep->sep_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_sep->sep_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 = strict_strtoul(page, 0, &tmp);
	if (ret < 0) {
		pr_err("Unable to extract alua_tg_pt_write_md\n");
		return -EINVAL;
	}
	if ((tmp != 0) && (tmp != 1)) {
		pr_err("Illegal value for alua_tg_pt_write_md:"
				" %lu\n", tmp);
		return -EINVAL;
	}
	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;

	return count;
}

int core_setup_alua(struct se_device *dev, int force_pt)
{
	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
	struct t10_alua *alua = &su_dev->t10_alua;
	struct t10_alua_lu_gp_member *lu_gp_mem;
	/*
	 * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
	 * cause a problem because libata and some SATA RAID HBAs appear
	 * under Linux/SCSI, but emulate SCSI logic themselves.
	 */
	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
	    !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
		alua->alua_type = SPC_ALUA_PASSTHROUGH;
		alua->alua_state_check = &core_alua_state_check_nop;
		pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
			" emulation\n", dev->transport->name);
		return 0;
	}
	/*
	 * If SPC-3 or above is reported by real or emulated struct se_device,
	 * use emulated ALUA.
	 */
	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
		pr_debug("%s: Enabling ALUA Emulation for SPC-3"
			" device\n", dev->transport->name);
		/*
		 * 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);

		alua->alua_type = SPC3_ALUA_EMULATED;
		alua->alua_state_check = &core_alua_state_check;
		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);
	} else {
		alua->alua_type = SPC2_ALUA_DISABLED;
		alua->alua_state_check = &core_alua_state_check_nop;
		pr_debug("%s: Disabling ALUA Emulation for SPC-2"
			" device\n", dev->transport->name);
	}

	return 0;
}