summaryrefslogtreecommitdiff
path: root/drivers/target/target_core_pr.c
blob: 10db5656fd5dcb8e95769a922223b8e88cf23983 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
/*******************************************************************************
 * Filename:  target_core_pr.c
 *
 * This file contains SPC-3 compliant persistent reservations and
 * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
 *
 * (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/list.h>
#include <linux/vmalloc.h>
#include <linux/file.h>
#include <linux/fcntl.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_pr.h"
#include "target_core_ua.h"

/*
 * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
 */
struct pr_transport_id_holder {
	struct t10_pr_registration *dest_pr_reg;
	struct se_portal_group *dest_tpg;
	struct se_node_acl *dest_node_acl;
	struct se_dev_entry *dest_se_deve;
	struct list_head dest_list;
};

void core_pr_dump_initiator_port(
	struct t10_pr_registration *pr_reg,
	char *buf,
	u32 size)
{
	if (!pr_reg->isid_present_at_reg) {
		buf[0] = '\0';
		return;
	}

	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
}

enum register_type {
	REGISTER,
	REGISTER_AND_IGNORE_EXISTING_KEY,
	REGISTER_AND_MOVE,
};

enum preempt_type {
	PREEMPT,
	PREEMPT_AND_ABORT,
};

static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
					      struct t10_pr_registration *, int, int);

static int is_reservation_holder(
	struct t10_pr_registration *pr_res_holder,
	struct t10_pr_registration *pr_reg)
{
	int pr_res_type;

	if (pr_res_holder) {
		pr_res_type = pr_res_holder->pr_res_type;

		return pr_res_holder == pr_reg ||
		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
	}
	return 0;
}

static sense_reason_t
target_scsi2_reservation_check(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *sess = cmd->se_sess;

	switch (cmd->t_task_cdb[0]) {
	case INQUIRY:
	case RELEASE:
	case RELEASE_10:
		return 0;
	default:
		break;
	}

	if (!dev->dev_reserved_node_acl || !sess)
		return 0;

	if (dev->dev_reserved_node_acl != sess->se_node_acl)
		return TCM_RESERVATION_CONFLICT;

	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
			return TCM_RESERVATION_CONFLICT;
	}

	return 0;
}

static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
					struct se_node_acl *, struct se_session *);
static void core_scsi3_put_pr_reg(struct t10_pr_registration *);

static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
{
	struct se_session *se_sess = cmd->se_sess;
	struct se_device *dev = cmd->se_dev;
	struct t10_pr_registration *pr_reg;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	int conflict = 0;

	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
			se_sess);
	if (pr_reg) {
		/*
		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
		 * behavior
		 *
		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
		 * status, but no reservation shall be established and the
		 * persistent reservation shall not be changed, if the command
		 * is received from a) and b) below.
		 *
		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
		 * status, but the persistent reservation shall not be released,
		 * if the command is received from a) and b)
		 *
		 * a) An I_T nexus that is a persistent reservation holder; or
		 * b) An I_T nexus that is registered if a registrants only or
		 *    all registrants type persistent reservation is present.
		 *
		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
		 * RELEASE(6) command, or RELEASE(10) command shall be processed
		 * as defined in SPC-2.
		 */
		if (pr_reg->pr_res_holder) {
			core_scsi3_put_pr_reg(pr_reg);
			return 1;
		}
		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
			core_scsi3_put_pr_reg(pr_reg);
			return 1;
		}
		core_scsi3_put_pr_reg(pr_reg);
		conflict = 1;
	} else {
		/*
		 * Following spc2r20 5.5.1 Reservations overview:
		 *
		 * If a logical unit has executed a PERSISTENT RESERVE OUT
		 * command with the REGISTER or the REGISTER AND IGNORE
		 * EXISTING KEY service action and is still registered by any
		 * initiator, all RESERVE commands and all RELEASE commands
		 * regardless of initiator shall conflict and shall terminate
		 * with a RESERVATION CONFLICT status.
		 */
		spin_lock(&pr_tmpl->registration_lock);
		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
		spin_unlock(&pr_tmpl->registration_lock);
	}

	if (conflict) {
		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
			" while active SPC-3 registrations exist,"
			" returning RESERVATION_CONFLICT\n");
		return -EBUSY;
	}

	return 0;
}

sense_reason_t
target_scsi2_reservation_release(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *sess = cmd->se_sess;
	struct se_portal_group *tpg;
	int rc;

	if (!sess || !sess->se_tpg)
		goto out;
	rc = target_check_scsi2_reservation_conflict(cmd);
	if (rc == 1)
		goto out;
	if (rc < 0)
		return TCM_RESERVATION_CONFLICT;

	spin_lock(&dev->dev_reservation_lock);
	if (!dev->dev_reserved_node_acl || !sess)
		goto out_unlock;

	if (dev->dev_reserved_node_acl != sess->se_node_acl)
		goto out_unlock;

	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
		goto out_unlock;

	dev->dev_reserved_node_acl = NULL;
	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
		dev->dev_res_bin_isid = 0;
		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
	}
	tpg = sess->se_tpg;
	pr_debug("SCSI-2 Released reservation for %s LUN: %llu ->"
		" MAPPED LUN: %llu for %s\n",
		tpg->se_tpg_tfo->get_fabric_name(),
		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
		sess->se_node_acl->initiatorname);

out_unlock:
	spin_unlock(&dev->dev_reservation_lock);
out:
	target_complete_cmd(cmd, GOOD);
	return 0;
}

sense_reason_t
target_scsi2_reservation_reserve(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *sess = cmd->se_sess;
	struct se_portal_group *tpg;
	sense_reason_t ret = 0;
	int rc;

	if ((cmd->t_task_cdb[1] & 0x01) &&
	    (cmd->t_task_cdb[1] & 0x02)) {
		pr_err("LongIO and Obsolete Bits set, returning ILLEGAL_REQUEST\n");
		return TCM_UNSUPPORTED_SCSI_OPCODE;
	}
	/*
	 * This is currently the case for target_core_mod passthrough struct se_cmd
	 * ops
	 */
	if (!sess || !sess->se_tpg)
		goto out;
	rc = target_check_scsi2_reservation_conflict(cmd);
	if (rc == 1)
		goto out;

	if (rc < 0)
		return TCM_RESERVATION_CONFLICT;

	tpg = sess->se_tpg;
	spin_lock(&dev->dev_reservation_lock);
	if (dev->dev_reserved_node_acl &&
	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
			tpg->se_tpg_tfo->get_fabric_name());
		pr_err("Original reserver LUN: %llu %s\n",
			cmd->se_lun->unpacked_lun,
			dev->dev_reserved_node_acl->initiatorname);
		pr_err("Current attempt - LUN: %llu -> MAPPED LUN: %llu"
			" from %s \n", cmd->se_lun->unpacked_lun,
			cmd->orig_fe_lun,
			sess->se_node_acl->initiatorname);
		ret = TCM_RESERVATION_CONFLICT;
		goto out_unlock;
	}

	dev->dev_reserved_node_acl = sess->se_node_acl;
	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
	if (sess->sess_bin_isid != 0) {
		dev->dev_res_bin_isid = sess->sess_bin_isid;
		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
	}
	pr_debug("SCSI-2 Reserved %s LUN: %llu -> MAPPED LUN: %llu"
		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
		sess->se_node_acl->initiatorname);

out_unlock:
	spin_unlock(&dev->dev_reservation_lock);
out:
	if (!ret)
		target_complete_cmd(cmd, GOOD);
	return ret;
}


/*
 * Begin SPC-3/SPC-4 Persistent Reservations emulation support
 *
 * This function is called by those initiator ports who are *NOT*
 * the active PR reservation holder when a reservation is present.
 */
static int core_scsi3_pr_seq_non_holder(struct se_cmd *cmd, u32 pr_reg_type,
					bool isid_mismatch)
{
	unsigned char *cdb = cmd->t_task_cdb;
	struct se_session *se_sess = cmd->se_sess;
	struct se_node_acl *nacl = se_sess->se_node_acl;
	int other_cdb = 0;
	int registered_nexus = 0, ret = 1; /* Conflict by default */
	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
	int we = 0; /* Write Exclusive */
	int legacy = 0; /* Act like a legacy device and return
			 * RESERVATION CONFLICT on some CDBs */

	if (isid_mismatch) {
		registered_nexus = 0;
	} else {
		struct se_dev_entry *se_deve;

		rcu_read_lock();
		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
		if (se_deve)
			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
						    &se_deve->deve_flags);
		rcu_read_unlock();
	}

	switch (pr_reg_type) {
	case PR_TYPE_WRITE_EXCLUSIVE:
		we = 1;
	case PR_TYPE_EXCLUSIVE_ACCESS:
		/*
		 * Some commands are only allowed for the persistent reservation
		 * holder.
		 */
		break;
	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
		we = 1;
		/* fall through */
	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
		/*
		 * Some commands are only allowed for registered I_T Nexuses.
		 */
		reg_only = 1;
		break;
	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
		we = 1;
		/* fall through */
	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
		/*
		 * Each registered I_T Nexus is a reservation holder.
		 */
		all_reg = 1;
		break;
	default:
		return -EINVAL;
	}
	/*
	 * Referenced from spc4r17 table 45 for *NON* PR holder access
	 */
	switch (cdb[0]) {
	case SECURITY_PROTOCOL_IN:
		if (registered_nexus)
			return 0;
		ret = (we) ? 0 : 1;
		break;
	case MODE_SENSE:
	case MODE_SENSE_10:
	case READ_ATTRIBUTE:
	case READ_BUFFER:
	case RECEIVE_DIAGNOSTIC:
		if (legacy) {
			ret = 1;
			break;
		}
		if (registered_nexus) {
			ret = 0;
			break;
		}
		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
		break;
	case PERSISTENT_RESERVE_OUT:
		/*
		 * This follows PERSISTENT_RESERVE_OUT service actions that
		 * are allowed in the presence of various reservations.
		 * See spc4r17, table 46
		 */
		switch (cdb[1] & 0x1f) {
		case PRO_CLEAR:
		case PRO_PREEMPT:
		case PRO_PREEMPT_AND_ABORT:
			ret = (registered_nexus) ? 0 : 1;
			break;
		case PRO_REGISTER:
		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
			ret = 0;
			break;
		case PRO_REGISTER_AND_MOVE:
		case PRO_RESERVE:
			ret = 1;
			break;
		case PRO_RELEASE:
			ret = (registered_nexus) ? 0 : 1;
			break;
		default:
			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
				" action: 0x%02x\n", cdb[1] & 0x1f);
			return -EINVAL;
		}
		break;
	case RELEASE:
	case RELEASE_10:
		/* Handled by CRH=1 in target_scsi2_reservation_release() */
		ret = 0;
		break;
	case RESERVE:
	case RESERVE_10:
		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
		ret = 0;
		break;
	case TEST_UNIT_READY:
		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
		break;
	case MAINTENANCE_IN:
		switch (cdb[1] & 0x1f) {
		case MI_MANAGEMENT_PROTOCOL_IN:
			if (registered_nexus) {
				ret = 0;
				break;
			}
			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
			break;
		case MI_REPORT_SUPPORTED_OPERATION_CODES:
		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
			if (legacy) {
				ret = 1;
				break;
			}
			if (registered_nexus) {
				ret = 0;
				break;
			}
			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
			break;
		case MI_REPORT_ALIASES:
		case MI_REPORT_IDENTIFYING_INFORMATION:
		case MI_REPORT_PRIORITY:
		case MI_REPORT_TARGET_PGS:
		case MI_REPORT_TIMESTAMP:
			ret = 0; /* Allowed */
			break;
		default:
			pr_err("Unknown MI Service Action: 0x%02x\n",
				(cdb[1] & 0x1f));
			return -EINVAL;
		}
		break;
	case ACCESS_CONTROL_IN:
	case ACCESS_CONTROL_OUT:
	case INQUIRY:
	case LOG_SENSE:
	case SERVICE_ACTION_IN_12:
	case REPORT_LUNS:
	case REQUEST_SENSE:
	case PERSISTENT_RESERVE_IN:
		ret = 0; /*/ Allowed CDBs */
		break;
	default:
		other_cdb = 1;
		break;
	}
	/*
	 * Case where the CDB is explicitly allowed in the above switch
	 * statement.
	 */
	if (!ret && !other_cdb) {
		pr_debug("Allowing explicit CDB: 0x%02x for %s"
			" reservation holder\n", cdb[0],
			core_scsi3_pr_dump_type(pr_reg_type));

		return ret;
	}
	/*
	 * Check if write exclusive initiator ports *NOT* holding the
	 * WRITE_EXCLUSIVE_* reservation.
	 */
	if (we && !registered_nexus) {
		if (cmd->data_direction == DMA_TO_DEVICE) {
			/*
			 * Conflict for write exclusive
			 */
			pr_debug("%s Conflict for unregistered nexus"
				" %s CDB: 0x%02x to %s reservation\n",
				transport_dump_cmd_direction(cmd),
				se_sess->se_node_acl->initiatorname, cdb[0],
				core_scsi3_pr_dump_type(pr_reg_type));
			return 1;
		} else {
			/*
			 * Allow non WRITE CDBs for all Write Exclusive
			 * PR TYPEs to pass for registered and
			 * non-registered_nexuxes NOT holding the reservation.
			 *
			 * We only make noise for the unregisterd nexuses,
			 * as we expect registered non-reservation holding
			 * nexuses to issue CDBs.
			 */

			if (!registered_nexus) {
				pr_debug("Allowing implicit CDB: 0x%02x"
					" for %s reservation on unregistered"
					" nexus\n", cdb[0],
					core_scsi3_pr_dump_type(pr_reg_type));
			}

			return 0;
		}
	} else if ((reg_only) || (all_reg)) {
		if (registered_nexus) {
			/*
			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
			 * allow commands from registered nexuses.
			 */

			pr_debug("Allowing implicit CDB: 0x%02x for %s"
				" reservation\n", cdb[0],
				core_scsi3_pr_dump_type(pr_reg_type));

			return 0;
		}
       } else if (we && registered_nexus) {
               /*
                * Reads are allowed for Write Exclusive locks
                * from all registrants.
                */
               if (cmd->data_direction == DMA_FROM_DEVICE) {
                       pr_debug("Allowing READ CDB: 0x%02x for %s"
                               " reservation\n", cdb[0],
                               core_scsi3_pr_dump_type(pr_reg_type));

                       return 0;
               }
	}
	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
		" for %s reservation\n", transport_dump_cmd_direction(cmd),
		(registered_nexus) ? "" : "un",
		se_sess->se_node_acl->initiatorname, cdb[0],
		core_scsi3_pr_dump_type(pr_reg_type));

	return 1; /* Conflict by default */
}

static sense_reason_t
target_scsi3_pr_reservation_check(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *sess = cmd->se_sess;
	u32 pr_reg_type;
	bool isid_mismatch = false;

	if (!dev->dev_pr_res_holder)
		return 0;

	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
		goto check_nonholder;

	if (dev->dev_pr_res_holder->isid_present_at_reg) {
		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
		    sess->sess_bin_isid) {
			isid_mismatch = true;
			goto check_nonholder;
		}
	}

	return 0;

check_nonholder:
	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
		return TCM_RESERVATION_CONFLICT;
	return 0;
}

static u32 core_scsi3_pr_generation(struct se_device *dev)
{
	u32 prg;

	/*
	 * PRGeneration field shall contain the value of a 32-bit wrapping
	 * counter mainted by the device server.
	 *
	 * Note that this is done regardless of Active Persist across
	 * Target PowerLoss (APTPL)
	 *
	 * See spc4r17 section 6.3.12 READ_KEYS service action
	 */
	spin_lock(&dev->dev_reservation_lock);
	prg = dev->t10_pr.pr_generation++;
	spin_unlock(&dev->dev_reservation_lock);

	return prg;
}

static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct se_lun *lun,
	struct se_dev_entry *dest_deve,
	u64 mapped_lun,
	unsigned char *isid,
	u64 sa_res_key,
	int all_tg_pt,
	int aptpl)
{
	struct t10_pr_registration *pr_reg;

	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
	if (!pr_reg) {
		pr_err("Unable to allocate struct t10_pr_registration\n");
		return NULL;
	}

	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
	atomic_set(&pr_reg->pr_res_holders, 0);
	pr_reg->pr_reg_nacl = nacl;
	/*
	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
	 * the se_dev_entry->pr_ref will have been already obtained by
	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
	 *
	 * Otherwise, locate se_dev_entry now and obtain a reference until
	 * registration completes in __core_scsi3_add_registration().
	 */
	if (dest_deve) {
		pr_reg->pr_reg_deve = dest_deve;
	} else {
		rcu_read_lock();
		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
		if (!pr_reg->pr_reg_deve) {
			rcu_read_unlock();
			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
				nacl->initiatorname, mapped_lun);
			kmem_cache_free(t10_pr_reg_cache, pr_reg);
			return NULL;
		}
		kref_get(&pr_reg->pr_reg_deve->pr_kref);
		rcu_read_unlock();
	}
	pr_reg->pr_res_mapped_lun = mapped_lun;
	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
	pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
	pr_reg->pr_res_key = sa_res_key;
	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
	pr_reg->pr_reg_aptpl = aptpl;
	/*
	 * If an ISID value for this SCSI Initiator Port exists,
	 * save it to the registration now.
	 */
	if (isid != NULL) {
		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
		pr_reg->isid_present_at_reg = 1;
	}

	return pr_reg;
}

static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);

/*
 * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
 * modes.
 */
static struct t10_pr_registration *__core_scsi3_alloc_registration(
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct se_lun *lun,
	struct se_dev_entry *deve,
	u64 mapped_lun,
	unsigned char *isid,
	u64 sa_res_key,
	int all_tg_pt,
	int aptpl)
{
	struct se_dev_entry *deve_tmp;
	struct se_node_acl *nacl_tmp;
	struct se_lun_acl *lacl_tmp;
	struct se_lun *lun_tmp, *next, *dest_lun;
	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
	int ret;
	/*
	 * Create a registration for the I_T Nexus upon which the
	 * PROUT REGISTER was received.
	 */
	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
						    isid, sa_res_key, all_tg_pt,
						    aptpl);
	if (!pr_reg)
		return NULL;
	/*
	 * Return pointer to pr_reg for ALL_TG_PT=0
	 */
	if (!all_tg_pt)
		return pr_reg;
	/*
	 * Create list of matching SCSI Initiator Port registrations
	 * for ALL_TG_PT=1
	 */
	spin_lock(&dev->se_port_lock);
	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
			continue;
		spin_unlock(&dev->se_port_lock);

		spin_lock(&lun_tmp->lun_deve_lock);
		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
			/*
			 * This pointer will be NULL for demo mode MappedLUNs
			 * that have not been make explicit via a ConfigFS
			 * MappedLUN group for the SCSI Initiator Node ACL.
			 */
			if (!deve_tmp->se_lun_acl)
				continue;

			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
						lockdep_is_held(&lun_tmp->lun_deve_lock));
			nacl_tmp = lacl_tmp->se_lun_nacl;
			/*
			 * Skip the matching struct se_node_acl that is allocated
			 * above..
			 */
			if (nacl == nacl_tmp)
				continue;
			/*
			 * Only perform PR registrations for target ports on
			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
			 * arrived.
			 */
			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
				continue;
			/*
			 * Look for a matching Initiator Node ACL in ASCII format
			 */
			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
				continue;

			kref_get(&deve_tmp->pr_kref);
			spin_unlock(&lun_tmp->lun_deve_lock);
			/*
			 * Grab a configfs group dependency that is released
			 * for the exception path at label out: below, or upon
			 * completion of adding ALL_TG_PT=1 registrations in
			 * __core_scsi3_add_registration()
			 */
			ret = core_scsi3_lunacl_depend_item(deve_tmp);
			if (ret < 0) {
				pr_err("core_scsi3_lunacl_depend"
						"_item() failed\n");
				percpu_ref_put(&lun_tmp->lun_ref);
				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
				goto out;
			}
			/*
			 * Located a matching SCSI Initiator Port on a different
			 * port, allocate the pr_reg_atp and attach it to the
			 * pr_reg->pr_reg_atp_list that will be processed once
			 * the original *pr_reg is processed in
			 * __core_scsi3_add_registration()
			 */
			dest_lun = rcu_dereference_check(deve_tmp->se_lun,
				kref_read(&deve_tmp->pr_kref) != 0);

			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
						nacl_tmp, dest_lun, deve_tmp,
						deve_tmp->mapped_lun, NULL,
						sa_res_key, all_tg_pt, aptpl);
			if (!pr_reg_atp) {
				percpu_ref_put(&lun_tmp->lun_ref);
				core_scsi3_lunacl_undepend_item(deve_tmp);
				goto out;
			}

			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
				      &pr_reg->pr_reg_atp_list);
			spin_lock(&lun_tmp->lun_deve_lock);
		}
		spin_unlock(&lun_tmp->lun_deve_lock);

		spin_lock(&dev->se_port_lock);
		percpu_ref_put(&lun_tmp->lun_ref);
	}
	spin_unlock(&dev->se_port_lock);

	return pr_reg;
out:
	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
	}
	kmem_cache_free(t10_pr_reg_cache, pr_reg);
	return NULL;
}

int core_scsi3_alloc_aptpl_registration(
	struct t10_reservation *pr_tmpl,
	u64 sa_res_key,
	unsigned char *i_port,
	unsigned char *isid,
	u64 mapped_lun,
	unsigned char *t_port,
	u16 tpgt,
	u64 target_lun,
	int res_holder,
	int all_tg_pt,
	u8 type)
{
	struct t10_pr_registration *pr_reg;

	if (!i_port || !t_port || !sa_res_key) {
		pr_err("Illegal parameters for APTPL registration\n");
		return -EINVAL;
	}

	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
	if (!pr_reg) {
		pr_err("Unable to allocate struct t10_pr_registration\n");
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
	atomic_set(&pr_reg->pr_res_holders, 0);
	pr_reg->pr_reg_nacl = NULL;
	pr_reg->pr_reg_deve = NULL;
	pr_reg->pr_res_mapped_lun = mapped_lun;
	pr_reg->pr_aptpl_target_lun = target_lun;
	pr_reg->pr_res_key = sa_res_key;
	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
	pr_reg->pr_reg_aptpl = 1;
	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
	pr_reg->pr_res_type = type;
	/*
	 * If an ISID value had been saved in APTPL metadata for this
	 * SCSI Initiator Port, restore it now.
	 */
	if (isid != NULL) {
		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
		pr_reg->isid_present_at_reg = 1;
	}
	/*
	 * Copy the i_port and t_port information from caller.
	 */
	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
	pr_reg->pr_reg_tpgt = tpgt;
	/*
	 * Set pr_res_holder from caller, the pr_reg who is the reservation
	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
	 * the Initiator Node LUN ACL from the fabric module is created for
	 * this registration.
	 */
	pr_reg->pr_res_holder = res_holder;

	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
			" metadata\n", (res_holder) ? "+reservation" : "");
	return 0;
}

static void core_scsi3_aptpl_reserve(
	struct se_device *dev,
	struct se_portal_group *tpg,
	struct se_node_acl *node_acl,
	struct t10_pr_registration *pr_reg)
{
	char i_buf[PR_REG_ISID_ID_LEN];

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);

	spin_lock(&dev->dev_reservation_lock);
	dev->dev_pr_res_holder = pr_reg;
	spin_unlock(&dev->dev_reservation_lock);

	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
		tpg->se_tpg_tfo->get_fabric_name(),
		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
		i_buf);
}

static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
				struct t10_pr_registration *, enum register_type, int);

static int __core_scsi3_check_aptpl_registration(
	struct se_device *dev,
	struct se_portal_group *tpg,
	struct se_lun *lun,
	u64 target_lun,
	struct se_node_acl *nacl,
	u64 mapped_lun)
{
	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
	u16 tpgt;

	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
	/*
	 * Copy Initiator Port information from struct se_node_acl
	 */
	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
	/*
	 * Look for the matching registrations+reservation from those
	 * created from APTPL metadata.  Note that multiple registrations
	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
	 * TransportIDs.
	 */
	spin_lock(&pr_tmpl->aptpl_reg_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
				pr_reg_aptpl_list) {

		if (!strcmp(pr_reg->pr_iport, i_port) &&
		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
		    !(strcmp(pr_reg->pr_tport, t_port)) &&
		     (pr_reg->pr_reg_tpgt == tpgt) &&
		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
			/*
			 * Obtain the ->pr_reg_deve pointer + reference, that
			 * is released by __core_scsi3_add_registration() below.
			 */
			rcu_read_lock();
			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
			if (!pr_reg->pr_reg_deve) {
				pr_err("Unable to locate PR APTPL %s mapped_lun:"
					" %llu\n", nacl->initiatorname, mapped_lun);
				rcu_read_unlock();
				continue;
			}
			kref_get(&pr_reg->pr_reg_deve->pr_kref);
			rcu_read_unlock();

			pr_reg->pr_reg_nacl = nacl;
			pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
			list_del(&pr_reg->pr_reg_aptpl_list);
			spin_unlock(&pr_tmpl->aptpl_reg_lock);
			/*
			 * At this point all of the pointers in *pr_reg will
			 * be setup, so go ahead and add the registration.
			 */
			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
			/*
			 * If this registration is the reservation holder,
			 * make that happen now..
			 */
			if (pr_reg->pr_res_holder)
				core_scsi3_aptpl_reserve(dev, tpg,
						nacl, pr_reg);
			/*
			 * Reenable pr_aptpl_active to accept new metadata
			 * updates once the SCSI device is active again..
			 */
			spin_lock(&pr_tmpl->aptpl_reg_lock);
			pr_tmpl->pr_aptpl_active = 1;
		}
	}
	spin_unlock(&pr_tmpl->aptpl_reg_lock);

	return 0;
}

int core_scsi3_check_aptpl_registration(
	struct se_device *dev,
	struct se_portal_group *tpg,
	struct se_lun *lun,
	struct se_node_acl *nacl,
	u64 mapped_lun)
{
	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
		return 0;

	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
						     lun->unpacked_lun, nacl,
						     mapped_lun);
}

static void __core_scsi3_dump_registration(
	const struct target_core_fabric_ops *tfo,
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct t10_pr_registration *pr_reg,
	enum register_type register_type)
{
	struct se_portal_group *se_tpg = nacl->se_tpg;
	char i_buf[PR_REG_ISID_ID_LEN];

	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);

	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
		i_buf);
	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
		tfo->tpg_get_tag(se_tpg));
	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
		" Port(s)\n",  tfo->get_fabric_name(),
		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
		dev->transport->name);
	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
		pr_reg->pr_res_key, pr_reg->pr_res_generation,
		pr_reg->pr_reg_aptpl);
}

static void __core_scsi3_add_registration(
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct t10_pr_registration *pr_reg,
	enum register_type register_type,
	int register_move)
{
	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct se_dev_entry *deve;

	/*
	 * Increment PRgeneration counter for struct se_device upon a successful
	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
	 *
	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
	 * action, the struct se_device->dev_reservation_lock will already be held,
	 * so we do not call core_scsi3_pr_generation() which grabs the lock
	 * for the REGISTER.
	 */
	pr_reg->pr_res_generation = (register_move) ?
			dev->t10_pr.pr_generation++ :
			core_scsi3_pr_generation(dev);

	spin_lock(&pr_tmpl->registration_lock);
	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);

	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
	spin_unlock(&pr_tmpl->registration_lock);
	/*
	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
	 */
	if (!pr_reg->pr_reg_all_tg_pt || register_move)
		goto out;
	/*
	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
	 * allocated in __core_scsi3_alloc_registration()
	 */
	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;

		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);

		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);

		spin_lock(&pr_tmpl->registration_lock);
		list_add_tail(&pr_reg_tmp->pr_reg_list,
			      &pr_tmpl->registration_list);

		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
					       register_type);
		spin_unlock(&pr_tmpl->registration_lock);
		/*
		 * Drop configfs group dependency reference and deve->pr_kref
		 * obtained from  __core_scsi3_alloc_registration() code.
		 */
		rcu_read_lock();
		deve = pr_reg_tmp->pr_reg_deve;
		if (deve) {
			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
			core_scsi3_lunacl_undepend_item(deve);
			pr_reg_tmp->pr_reg_deve = NULL;
		}
		rcu_read_unlock();
	}
out:
	/*
	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
	 */
	rcu_read_lock();
	deve = pr_reg->pr_reg_deve;
	if (deve) {
		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
		kref_put(&deve->pr_kref, target_pr_kref_release);
		pr_reg->pr_reg_deve = NULL;
	}
	rcu_read_unlock();
}

static int core_scsi3_alloc_registration(
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct se_lun *lun,
	struct se_dev_entry *deve,
	u64 mapped_lun,
	unsigned char *isid,
	u64 sa_res_key,
	int all_tg_pt,
	int aptpl,
	enum register_type register_type,
	int register_move)
{
	struct t10_pr_registration *pr_reg;

	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
						 isid, sa_res_key, all_tg_pt,
						 aptpl);
	if (!pr_reg)
		return -EPERM;

	__core_scsi3_add_registration(dev, nacl, pr_reg,
			register_type, register_move);
	return 0;
}

static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
	struct se_device *dev,
	struct se_node_acl *nacl,
	unsigned char *isid)
{
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
	struct se_portal_group *tpg;

	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {
		/*
		 * First look for a matching struct se_node_acl
		 */
		if (pr_reg->pr_reg_nacl != nacl)
			continue;

		tpg = pr_reg->pr_reg_nacl->se_tpg;
		/*
		 * If this registration does NOT contain a fabric provided
		 * ISID, then we have found a match.
		 */
		if (!pr_reg->isid_present_at_reg) {
			/*
			 * Determine if this SCSI device server requires that
			 * SCSI Intiatior TransportID w/ ISIDs is enforced
			 * for fabric modules (iSCSI) requiring them.
			 */
			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
				if (dev->dev_attrib.enforce_pr_isids)
					continue;
			}
			atomic_inc_mb(&pr_reg->pr_res_holders);
			spin_unlock(&pr_tmpl->registration_lock);
			return pr_reg;
		}
		/*
		 * If the *pr_reg contains a fabric defined ISID for multi-value
		 * SCSI Initiator Port TransportIDs, then we expect a valid
		 * matching ISID to be provided by the local SCSI Initiator Port.
		 */
		if (!isid)
			continue;
		if (strcmp(isid, pr_reg->pr_reg_isid))
			continue;

		atomic_inc_mb(&pr_reg->pr_res_holders);
		spin_unlock(&pr_tmpl->registration_lock);
		return pr_reg;
	}
	spin_unlock(&pr_tmpl->registration_lock);

	return NULL;
}

static struct t10_pr_registration *core_scsi3_locate_pr_reg(
	struct se_device *dev,
	struct se_node_acl *nacl,
	struct se_session *sess)
{
	struct se_portal_group *tpg = nacl->se_tpg;
	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;

	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
		memset(&buf[0], 0, PR_REG_ISID_LEN);
		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
					PR_REG_ISID_LEN);
		isid_ptr = &buf[0];
	}

	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
}

static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
{
	atomic_dec_mb(&pr_reg->pr_res_holders);
}

static int core_scsi3_check_implicit_release(
	struct se_device *dev,
	struct t10_pr_registration *pr_reg)
{
	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
	struct t10_pr_registration *pr_res_holder;
	int ret = 0;

	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (!pr_res_holder) {
		spin_unlock(&dev->dev_reservation_lock);
		return ret;
	}
	if (pr_res_holder == pr_reg) {
		/*
		 * Perform an implicit RELEASE if the registration that
		 * is being released is holding the reservation.
		 *
		 * From spc4r17, section 5.7.11.1:
		 *
		 * e) If the I_T nexus is the persistent reservation holder
		 *    and the persistent reservation is not an all registrants
		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
		 *    service action or REGISTER AND  IGNORE EXISTING KEY
		 *    service action with the SERVICE ACTION RESERVATION KEY
		 *    field set to zero (see 5.7.11.3).
		 */
		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
		ret = 1;
		/*
		 * For 'All Registrants' reservation types, all existing
		 * registrations are still processed as reservation holders
		 * in core_scsi3_pr_seq_non_holder() after the initial
		 * reservation holder is implicitly released here.
		 */
	} else if (pr_reg->pr_reg_all_tg_pt &&
		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
			  pr_reg->pr_reg_nacl->initiatorname)) &&
		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
			" UNREGISTER while existing reservation with matching"
			" key 0x%016Lx is present from another SCSI Initiator"
			" Port\n", pr_reg->pr_res_key);
		ret = -EPERM;
	}
	spin_unlock(&dev->dev_reservation_lock);

	return ret;
}

/*
 * Called with struct t10_reservation->registration_lock held.
 */
static void __core_scsi3_free_registration(
	struct se_device *dev,
	struct t10_pr_registration *pr_reg,
	struct list_head *preempt_and_abort_list,
	int dec_holders)
	__releases(&pr_tmpl->registration_lock)
	__acquires(&pr_tmpl->registration_lock)
{
	const struct target_core_fabric_ops *tfo =
			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
	struct se_dev_entry *deve;
	char i_buf[PR_REG_ISID_ID_LEN];

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);

	if (!list_empty(&pr_reg->pr_reg_list))
		list_del(&pr_reg->pr_reg_list);
	/*
	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
	 * so call core_scsi3_put_pr_reg() to decrement our reference.
	 */
	if (dec_holders)
		core_scsi3_put_pr_reg(pr_reg);

	spin_unlock(&pr_tmpl->registration_lock);
	/*
	 * Wait until all reference from any other I_T nexuses for this
	 * *pr_reg have been released.  Because list_del() is called above,
	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
	 * count back to zero, and we release *pr_reg.
	 */
	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
				tfo->get_fabric_name());
		cpu_relax();
	}

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
	if (deve)
		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
	rcu_read_unlock();

	spin_lock(&pr_tmpl->registration_lock);
	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
		" Node: %s%s\n", tfo->get_fabric_name(),
		pr_reg->pr_reg_nacl->initiatorname,
		i_buf);
	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
		" Port(s)\n", tfo->get_fabric_name(),
		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
		dev->transport->name);
	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
		pr_reg->pr_res_generation);

	if (!preempt_and_abort_list) {
		pr_reg->pr_reg_deve = NULL;
		pr_reg->pr_reg_nacl = NULL;
		kmem_cache_free(t10_pr_reg_cache, pr_reg);
		return;
	}
	/*
	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
	 * are released once the ABORT_TASK_SET has completed..
	 */
	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
}

void core_scsi3_free_pr_reg_from_nacl(
	struct se_device *dev,
	struct se_node_acl *nacl)
{
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
	bool free_reg = false;
	/*
	 * If the passed se_node_acl matches the reservation holder,
	 * release the reservation.
	 */
	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if ((pr_res_holder != NULL) &&
	    (pr_res_holder->pr_reg_nacl == nacl)) {
		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
		free_reg = true;
	}
	spin_unlock(&dev->dev_reservation_lock);
	/*
	 * Release any registration associated with the struct se_node_acl.
	 */
	spin_lock(&pr_tmpl->registration_lock);
	if (pr_res_holder && free_reg)
		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);

	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {

		if (pr_reg->pr_reg_nacl != nacl)
			continue;

		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
	}
	spin_unlock(&pr_tmpl->registration_lock);
}

void core_scsi3_free_all_registrations(
	struct se_device *dev)
{
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;

	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (pr_res_holder != NULL) {
		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
						  pr_res_holder, 0, 0);
	}
	spin_unlock(&dev->dev_reservation_lock);

	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {

		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
	}
	spin_unlock(&pr_tmpl->registration_lock);

	spin_lock(&pr_tmpl->aptpl_reg_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
				pr_reg_aptpl_list) {
		list_del(&pr_reg->pr_reg_aptpl_list);
		kmem_cache_free(t10_pr_reg_cache, pr_reg);
	}
	spin_unlock(&pr_tmpl->aptpl_reg_lock);
}

static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
{
	return target_depend_item(&tpg->tpg_group.cg_item);
}

static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
{
	target_undepend_item(&tpg->tpg_group.cg_item);
	atomic_dec_mb(&tpg->tpg_pr_ref_count);
}

static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
{
	if (nacl->dynamic_node_acl)
		return 0;
	return target_depend_item(&nacl->acl_group.cg_item);
}

static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
{
	if (!nacl->dynamic_node_acl)
		target_undepend_item(&nacl->acl_group.cg_item);
	atomic_dec_mb(&nacl->acl_pr_ref_count);
}

static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
{
	struct se_lun_acl *lun_acl;

	/*
	 * For nacl->dynamic_node_acl=1
	 */
	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
				kref_read(&se_deve->pr_kref) != 0);
	if (!lun_acl)
		return 0;

	return target_depend_item(&lun_acl->se_lun_group.cg_item);
}

static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
{
	struct se_lun_acl *lun_acl;

	/*
	 * For nacl->dynamic_node_acl=1
	 */
	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
				kref_read(&se_deve->pr_kref) != 0);
	if (!lun_acl) {
		kref_put(&se_deve->pr_kref, target_pr_kref_release);
		return;
	}

	target_undepend_item(&lun_acl->se_lun_group.cg_item);
	kref_put(&se_deve->pr_kref, target_pr_kref_release);
}

static sense_reason_t
core_scsi3_decode_spec_i_port(
	struct se_cmd *cmd,
	struct se_portal_group *tpg,
	unsigned char *l_isid,
	u64 sa_res_key,
	int all_tg_pt,
	int aptpl)
{
	struct se_device *dev = cmd->se_dev;
	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
	struct se_session *se_sess = cmd->se_sess;
	struct se_node_acl *dest_node_acl = NULL;
	struct se_dev_entry *dest_se_deve = NULL;
	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
	LIST_HEAD(tid_dest_list);
	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
	unsigned char *buf, *ptr, proto_ident;
	const unsigned char *i_str = NULL;
	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
	sense_reason_t ret;
	u32 tpdl, tid_len = 0;
	u32 dest_rtpi = 0;

	/*
	 * Allocate a struct pr_transport_id_holder and setup the
	 * local_node_acl pointer and add to struct list_head tid_dest_list
	 * for add registration processing in the loop of tid_dest_list below.
	 */
	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
	if (!tidh_new) {
		pr_err("Unable to allocate tidh_new\n");
		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
	}
	INIT_LIST_HEAD(&tidh_new->dest_list);
	tidh_new->dest_tpg = tpg;
	tidh_new->dest_node_acl = se_sess->se_node_acl;

	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
				se_sess->se_node_acl, cmd->se_lun,
				NULL, cmd->orig_fe_lun, l_isid,
				sa_res_key, all_tg_pt, aptpl);
	if (!local_pr_reg) {
		kfree(tidh_new);
		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
	}
	tidh_new->dest_pr_reg = local_pr_reg;
	/*
	 * The local I_T nexus does not hold any configfs dependances,
	 * so we set tidh_new->dest_se_deve to NULL to prevent the
	 * configfs_undepend_item() calls in the tid_dest_list loops below.
	 */
	tidh_new->dest_se_deve = NULL;
	list_add_tail(&tidh_new->dest_list, &tid_dest_list);

	if (cmd->data_length < 28) {
		pr_warn("SPC-PR: Received PR OUT parameter list"
			" length too small: %u\n", cmd->data_length);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	buf = transport_kmap_data_sg(cmd);
	if (!buf) {
		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
		goto out;
	}

	/*
	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
	 * first extract TransportID Parameter Data Length, and make sure
	 * the value matches up to the SCSI expected data transfer length.
	 */
	tpdl = get_unaligned_be32(&buf[24]);

	if ((tpdl + 28) != cmd->data_length) {
		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
			" does not equal CDB data_length: %u\n", tpdl,
			cmd->data_length);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out_unmap;
	}
	/*
	 * Start processing the received transport IDs using the
	 * receiving I_T Nexus portal's fabric dependent methods to
	 * obtain the SCSI Initiator Port/Device Identifiers.
	 */
	ptr = &buf[28];

	while (tpdl > 0) {
		struct se_lun *dest_lun, *tmp_lun;

		proto_ident = (ptr[0] & 0x0f);
		dest_tpg = NULL;

		spin_lock(&dev->se_port_lock);
		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
			tmp_tpg = tmp_lun->lun_tpg;

			/*
			 * Look for the matching proto_ident provided by
			 * the received TransportID
			 */
			if (tmp_tpg->proto_id != proto_ident)
				continue;
			dest_rtpi = tmp_lun->lun_rtpi;

			i_str = target_parse_pr_out_transport_id(tmp_tpg,
					ptr, &tid_len, &iport_ptr);
			if (!i_str)
				continue;

			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
			spin_unlock(&dev->se_port_lock);

			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
				pr_err(" core_scsi3_tpg_depend_item()"
					" for tmp_tpg\n");
				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
				goto out_unmap;
			}
			/*
			 * Locate the destination initiator ACL to be registered
			 * from the decoded fabric module specific TransportID
			 * at *i_str.
			 */
			mutex_lock(&tmp_tpg->acl_node_mutex);
			dest_node_acl = __core_tpg_get_initiator_node_acl(
						tmp_tpg, i_str);
			if (dest_node_acl)
				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
			mutex_unlock(&tmp_tpg->acl_node_mutex);

			if (!dest_node_acl) {
				core_scsi3_tpg_undepend_item(tmp_tpg);
				spin_lock(&dev->se_port_lock);
				continue;
			}

			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
				pr_err("configfs_depend_item() failed"
					" for dest_node_acl->acl_group\n");
				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
				core_scsi3_tpg_undepend_item(tmp_tpg);
				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
				goto out_unmap;
			}

			dest_tpg = tmp_tpg;
			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
				" %s Port RTPI: %hu\n",
				dest_tpg->se_tpg_tfo->get_fabric_name(),
				dest_node_acl->initiatorname, dest_rtpi);

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

		if (!dest_tpg) {
			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
					" dest_tpg\n");
			ret = TCM_INVALID_PARAMETER_LIST;
			goto out_unmap;
		}

		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
			" tid_len: %d for %s + %s\n",
			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
			tpdl, tid_len, i_str, iport_ptr);

		if (tid_len > tpdl) {
			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
				" %u for Transport ID: %s\n", tid_len, ptr);
			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			ret = TCM_INVALID_PARAMETER_LIST;
			goto out_unmap;
		}
		/*
		 * Locate the desintation struct se_dev_entry pointer for matching
		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
		 * Target Port.
		 */
		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
					dest_rtpi);
		if (!dest_se_deve) {
			pr_err("Unable to locate %s dest_se_deve"
				" from destination RTPI: %hu\n",
				dest_tpg->se_tpg_tfo->get_fabric_name(),
				dest_rtpi);

			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			ret = TCM_INVALID_PARAMETER_LIST;
			goto out_unmap;
		}

		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
			pr_err("core_scsi3_lunacl_depend_item()"
					" failed\n");
			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
			goto out_unmap;
		}

		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
			" dest_se_deve mapped_lun: %llu\n",
			dest_tpg->se_tpg_tfo->get_fabric_name(),
			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);

		/*
		 * Skip any TransportIDs that already have a registration for
		 * this target port.
		 */
		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
					iport_ptr);
		if (pr_reg_e) {
			core_scsi3_put_pr_reg(pr_reg_e);
			core_scsi3_lunacl_undepend_item(dest_se_deve);
			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			ptr += tid_len;
			tpdl -= tid_len;
			tid_len = 0;
			continue;
		}
		/*
		 * Allocate a struct pr_transport_id_holder and setup
		 * the dest_node_acl and dest_se_deve pointers for the
		 * loop below.
		 */
		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
				GFP_KERNEL);
		if (!tidh_new) {
			pr_err("Unable to allocate tidh_new\n");
			core_scsi3_lunacl_undepend_item(dest_se_deve);
			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
			goto out_unmap;
		}
		INIT_LIST_HEAD(&tidh_new->dest_list);
		tidh_new->dest_tpg = dest_tpg;
		tidh_new->dest_node_acl = dest_node_acl;
		tidh_new->dest_se_deve = dest_se_deve;

		/*
		 * Allocate, but do NOT add the registration for the
		 * TransportID referenced SCSI Initiator port.  This
		 * done because of the following from spc4r17 in section
		 * 6.14.3 wrt SPEC_I_PT:
		 *
		 * "If a registration fails for any initiator port (e.g., if th
		 * logical unit does not have enough resources available to
		 * hold the registration information), no registrations shall be
		 * made, and the command shall be terminated with
		 * CHECK CONDITION status."
		 *
		 * That means we call __core_scsi3_alloc_registration() here,
		 * and then call __core_scsi3_add_registration() in the
		 * 2nd loop which will never fail.
		 */
		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
				kref_read(&dest_se_deve->pr_kref) != 0);

		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
					dest_node_acl, dest_lun, dest_se_deve,
					dest_se_deve->mapped_lun, iport_ptr,
					sa_res_key, all_tg_pt, aptpl);
		if (!dest_pr_reg) {
			core_scsi3_lunacl_undepend_item(dest_se_deve);
			core_scsi3_nodeacl_undepend_item(dest_node_acl);
			core_scsi3_tpg_undepend_item(dest_tpg);
			kfree(tidh_new);
			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
			goto out_unmap;
		}
		tidh_new->dest_pr_reg = dest_pr_reg;
		list_add_tail(&tidh_new->dest_list, &tid_dest_list);

		ptr += tid_len;
		tpdl -= tid_len;
		tid_len = 0;

	}

	transport_kunmap_data_sg(cmd);

	/*
	 * Go ahead and create a registrations from tid_dest_list for the
	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
	 * and dest_se_deve.
	 *
	 * The SA Reservation Key from the PROUT is set for the
	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
	 * means that the TransportID Initiator port will be
	 * registered on all of the target ports in the SCSI target device
	 * ALL_TG_PT=0 means the registration will only be for the
	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
	 * was received.
	 */
	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
		dest_tpg = tidh->dest_tpg;
		dest_node_acl = tidh->dest_node_acl;
		dest_se_deve = tidh->dest_se_deve;
		dest_pr_reg = tidh->dest_pr_reg;

		list_del(&tidh->dest_list);
		kfree(tidh);

		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);

		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
					dest_pr_reg, 0, 0);

		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
			" registered Transport ID for Node: %s%s Mapped LUN:"
			" %llu\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
			dest_se_deve->mapped_lun : 0);

		if (!dest_se_deve) {
			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
				 target_pr_kref_release);
			continue;
		}
		core_scsi3_lunacl_undepend_item(dest_se_deve);
		core_scsi3_nodeacl_undepend_item(dest_node_acl);
		core_scsi3_tpg_undepend_item(dest_tpg);
	}

	return 0;
out_unmap:
	transport_kunmap_data_sg(cmd);
out:
	/*
	 * For the failure case, release everything from tid_dest_list
	 * including *dest_pr_reg and the configfs dependances..
	 */
	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
		dest_tpg = tidh->dest_tpg;
		dest_node_acl = tidh->dest_node_acl;
		dest_se_deve = tidh->dest_se_deve;
		dest_pr_reg = tidh->dest_pr_reg;

		list_del(&tidh->dest_list);
		kfree(tidh);
		/*
		 * Release any extra ALL_TG_PT=1 registrations for
		 * the SPEC_I_PT=1 case.
		 */
		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
				&dest_pr_reg->pr_reg_atp_list,
				pr_reg_atp_mem_list) {
			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
		}

		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);

		if (!dest_se_deve) {
			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
				 target_pr_kref_release);
			continue;
		}
		core_scsi3_lunacl_undepend_item(dest_se_deve);
		core_scsi3_nodeacl_undepend_item(dest_node_acl);
		core_scsi3_tpg_undepend_item(dest_tpg);
	}
	return ret;
}

static int core_scsi3_update_aptpl_buf(
	struct se_device *dev,
	unsigned char *buf,
	u32 pr_aptpl_buf_len)
{
	struct se_portal_group *tpg;
	struct t10_pr_registration *pr_reg;
	unsigned char tmp[512], isid_buf[32];
	ssize_t len = 0;
	int reg_count = 0;
	int ret = 0;

	spin_lock(&dev->dev_reservation_lock);
	spin_lock(&dev->t10_pr.registration_lock);
	/*
	 * Walk the registration list..
	 */
	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
			pr_reg_list) {

		tmp[0] = '\0';
		isid_buf[0] = '\0';
		tpg = pr_reg->pr_reg_nacl->se_tpg;
		/*
		 * Write out any ISID value to APTPL metadata that was included
		 * in the original registration.
		 */
		if (pr_reg->isid_present_at_reg)
			snprintf(isid_buf, 32, "initiator_sid=%s\n",
					pr_reg->pr_reg_isid);
		/*
		 * Include special metadata if the pr_reg matches the
		 * reservation holder.
		 */
		if (dev->dev_pr_res_holder == pr_reg) {
			snprintf(tmp, 512, "PR_REG_START: %d"
				"\ninitiator_fabric=%s\n"
				"initiator_node=%s\n%s"
				"sa_res_key=%llu\n"
				"res_holder=1\nres_type=%02x\n"
				"res_scope=%02x\nres_all_tg_pt=%d\n"
				"mapped_lun=%llu\n", reg_count,
				tpg->se_tpg_tfo->get_fabric_name(),
				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
				pr_reg->pr_res_key, pr_reg->pr_res_type,
				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
				pr_reg->pr_res_mapped_lun);
		} else {
			snprintf(tmp, 512, "PR_REG_START: %d\n"
				"initiator_fabric=%s\ninitiator_node=%s\n%s"
				"sa_res_key=%llu\nres_holder=0\n"
				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
				pr_reg->pr_res_mapped_lun);
		}

		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
			pr_err("Unable to update renaming APTPL metadata,"
			       " reallocating larger buffer\n");
			ret = -EMSGSIZE;
			goto out;
		}
		len += sprintf(buf+len, "%s", tmp);

		/*
		 * Include information about the associated SCSI target port.
		 */
		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
			tpg->se_tpg_tfo->tpg_get_tag(tpg),
			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
			reg_count);

		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
			pr_err("Unable to update renaming APTPL metadata,"
			       " reallocating larger buffer\n");
			ret = -EMSGSIZE;
			goto out;
		}
		len += sprintf(buf+len, "%s", tmp);
		reg_count++;
	}

	if (!reg_count)
		len += sprintf(buf+len, "No Registrations or Reservations");

out:
	spin_unlock(&dev->t10_pr.registration_lock);
	spin_unlock(&dev->dev_reservation_lock);

	return ret;
}

static int __core_scsi3_write_aptpl_to_file(
	struct se_device *dev,
	unsigned char *buf)
{
	struct t10_wwn *wwn = &dev->t10_wwn;
	struct file *file;
	int flags = O_RDWR | O_CREAT | O_TRUNC;
	char *path;
	u32 pr_aptpl_buf_len;
	int ret;
	loff_t pos = 0;

	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
			&wwn->unit_serial[0]);
	if (!path)
		return -ENOMEM;

	file = filp_open(path, flags, 0600);
	if (IS_ERR(file)) {
		pr_err("filp_open(%s) for APTPL metadata"
			" failed\n", path);
		kfree(path);
		return PTR_ERR(file);
	}

	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */

	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);

	if (ret < 0)
		pr_debug("Error writing APTPL metadata file: %s\n", path);
	fput(file);
	kfree(path);

	return (ret < 0) ? -EIO : 0;
}

/*
 * Clear the APTPL metadata if APTPL has been disabled, otherwise
 * write out the updated metadata to struct file for this SCSI device.
 */
static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
{
	unsigned char *buf;
	int rc, len = PR_APTPL_BUF_LEN;

	if (!aptpl) {
		char *null_buf = "No Registrations or Reservations\n";

		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
		dev->t10_pr.pr_aptpl_active = 0;
		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");

		if (rc)
			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

		return 0;
	}
retry:
	buf = vzalloc(len);
	if (!buf)
		return TCM_OUT_OF_RESOURCES;

	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
	if (rc < 0) {
		vfree(buf);
		len *= 2;
		goto retry;
	}

	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
	if (rc != 0) {
		pr_err("SPC-3 PR: Could not update APTPL\n");
		vfree(buf);
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	dev->t10_pr.pr_aptpl_active = 1;
	vfree(buf);
	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
	return 0;
}

static sense_reason_t
core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
{
	struct se_session *se_sess = cmd->se_sess;
	struct se_device *dev = cmd->se_dev;
	struct se_lun *se_lun = cmd->se_lun;
	struct se_portal_group *se_tpg;
	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
	sense_reason_t ret = TCM_NO_SENSE;
	int pr_holder = 0, type;

	if (!se_sess || !se_lun) {
		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	se_tpg = se_sess->se_tpg;

	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
				PR_REG_ISID_LEN);
		isid_ptr = &isid_buf[0];
	}
	/*
	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
	 */
	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
	if (!pr_reg) {
		if (res_key) {
			pr_warn("SPC-3 PR: Reservation Key non-zero"
				" for SA REGISTER, returning CONFLICT\n");
			return TCM_RESERVATION_CONFLICT;
		}
		/*
		 * Do nothing but return GOOD status.
		 */
		if (!sa_res_key)
			return 0;

		if (!spec_i_pt) {
			/*
			 * Perform the Service Action REGISTER on the Initiator
			 * Port Endpoint that the PRO was received from on the
			 * Logical Unit of the SCSI device server.
			 */
			if (core_scsi3_alloc_registration(cmd->se_dev,
					se_sess->se_node_acl, cmd->se_lun,
					NULL, cmd->orig_fe_lun, isid_ptr,
					sa_res_key, all_tg_pt, aptpl,
					register_type, 0)) {
				pr_err("Unable to allocate"
					" struct t10_pr_registration\n");
				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
			}
		} else {
			/*
			 * Register both the Initiator port that received
			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
			 * TransportID from Parameter list and loop through
			 * fabric dependent parameter list while calling
			 * logic from of core_scsi3_alloc_registration() for
			 * each TransportID provided SCSI Initiator Port/Device
			 */
			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
					isid_ptr, sa_res_key, all_tg_pt, aptpl);
			if (ret != 0)
				return ret;
		}
		return core_scsi3_update_and_write_aptpl(dev, aptpl);
	}

	/* ok, existing registration */

	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
		pr_err("SPC-3 PR REGISTER: Received"
		       " res_key: 0x%016Lx does not match"
		       " existing SA REGISTER res_key:"
		       " 0x%016Lx\n", res_key,
		       pr_reg->pr_res_key);
		ret = TCM_RESERVATION_CONFLICT;
		goto out;
	}

	if (spec_i_pt) {
		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
			" set on a registered nexus\n");
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	/*
	 * An existing ALL_TG_PT=1 registration being released
	 * must also set ALL_TG_PT=1 in the incoming PROUT.
	 */
	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
			" registration exists, but ALL_TG_PT=1 bit not"
			" present in received PROUT\n");
		ret = TCM_INVALID_CDB_FIELD;
		goto out;
	}

	/*
	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
	 */
	if (sa_res_key) {
		/*
		 * Increment PRgeneration counter for struct se_device"
		 * upon a successful REGISTER, see spc4r17 section 6.3.2
		 * READ_KEYS service action.
		 */
		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
		pr_reg->pr_res_key = sa_res_key;
		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
			 " Key for %s to: 0x%016Lx PRgeneration:"
			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
			 pr_reg->pr_reg_nacl->initiatorname,
			 pr_reg->pr_res_key, pr_reg->pr_res_generation);

	} else {
		/*
		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
		 */
		type = pr_reg->pr_res_type;
		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
							      pr_reg);
		if (pr_holder < 0) {
			ret = TCM_RESERVATION_CONFLICT;
			goto out;
		}

		spin_lock(&pr_tmpl->registration_lock);
		/*
		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
		 * and matching pr_res_key.
		 */
		if (pr_reg->pr_reg_all_tg_pt) {
			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
					&pr_tmpl->registration_list,
					pr_reg_list) {

				if (!pr_reg_p->pr_reg_all_tg_pt)
					continue;
				if (pr_reg_p->pr_res_key != res_key)
					continue;
				if (pr_reg == pr_reg_p)
					continue;
				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
					   pr_reg_p->pr_reg_nacl->initiatorname))
					continue;

				__core_scsi3_free_registration(dev,
						pr_reg_p, NULL, 0);
			}
		}

		/*
		 * Release the calling I_T Nexus registration now..
		 */
		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
		pr_reg = NULL;

		/*
		 * From spc4r17, section 5.7.11.3 Unregistering
		 *
		 * If the persistent reservation is a registrants only
		 * type, the device server shall establish a unit
		 * attention condition for the initiator port associated
		 * with every registered I_T nexus except for the I_T
		 * nexus on which the PERSISTENT RESERVE OUT command was
		 * received, with the additional sense code set to
		 * RESERVATIONS RELEASED.
		 */
		if (pr_holder &&
		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
			list_for_each_entry(pr_reg_p,
					&pr_tmpl->registration_list,
					pr_reg_list) {

				target_ua_allocate_lun(
					pr_reg_p->pr_reg_nacl,
					pr_reg_p->pr_res_mapped_lun,
					0x2A,
					ASCQ_2AH_RESERVATIONS_RELEASED);
			}
		}

		spin_unlock(&pr_tmpl->registration_lock);
	}

	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);

out:
	if (pr_reg)
		core_scsi3_put_pr_reg(pr_reg);
	return ret;
}

unsigned char *core_scsi3_pr_dump_type(int type)
{
	switch (type) {
	case PR_TYPE_WRITE_EXCLUSIVE:
		return "Write Exclusive Access";
	case PR_TYPE_EXCLUSIVE_ACCESS:
		return "Exclusive Access";
	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
		return "Write Exclusive Access, Registrants Only";
	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
		return "Exclusive Access, Registrants Only";
	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
		return "Write Exclusive Access, All Registrants";
	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
		return "Exclusive Access, All Registrants";
	default:
		break;
	}

	return "Unknown SPC-3 PR Type";
}

static sense_reason_t
core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *se_sess = cmd->se_sess;
	struct se_lun *se_lun = cmd->se_lun;
	struct t10_pr_registration *pr_reg, *pr_res_holder;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	char i_buf[PR_REG_ISID_ID_LEN];
	sense_reason_t ret;

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);

	if (!se_sess || !se_lun) {
		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * Locate the existing *pr_reg via struct se_node_acl pointers
	 */
	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
				se_sess);
	if (!pr_reg) {
		pr_err("SPC-3 PR: Unable to locate"
			" PR_REGISTERED *pr_reg for RESERVE\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * From spc4r17 Section 5.7.9: Reserving:
	 *
	 * An application client creates a persistent reservation by issuing
	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
	 * a registered I_T nexus with the following parameters:
	 *    a) RESERVATION KEY set to the value of the reservation key that is
	 * 	 registered with the logical unit for the I_T nexus; and
	 */
	if (res_key != pr_reg->pr_res_key) {
		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
			" does not match existing SA REGISTER res_key:"
			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
		ret = TCM_RESERVATION_CONFLICT;
		goto out_put_pr_reg;
	}
	/*
	 * From spc4r17 Section 5.7.9: Reserving:
	 *
	 * From above:
	 *  b) TYPE field and SCOPE field set to the persistent reservation
	 *     being created.
	 *
	 * Only one persistent reservation is allowed at a time per logical unit
	 * and that persistent reservation has a scope of LU_SCOPE.
	 */
	if (scope != PR_SCOPE_LU_SCOPE) {
		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out_put_pr_reg;
	}
	/*
	 * See if we have an existing PR reservation holder pointer at
	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
	 * *pr_res_holder.
	 */
	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (pr_res_holder) {
		/*
		 * From spc4r17 Section 5.7.9: Reserving:
		 *
		 * If the device server receives a PERSISTENT RESERVE OUT
		 * command from an I_T nexus other than a persistent reservation
		 * holder (see 5.7.10) that attempts to create a persistent
		 * reservation when a persistent reservation already exists for
		 * the logical unit, then the command shall be completed with
		 * RESERVATION CONFLICT status.
		 */
		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
			pr_err("SPC-3 PR: Attempted RESERVE from"
				" [%s]: %s while reservation already held by"
				" [%s]: %s, returning RESERVATION_CONFLICT\n",
				cmd->se_tfo->get_fabric_name(),
				se_sess->se_node_acl->initiatorname,
				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
				pr_res_holder->pr_reg_nacl->initiatorname);

			spin_unlock(&dev->dev_reservation_lock);
			ret = TCM_RESERVATION_CONFLICT;
			goto out_put_pr_reg;
		}
		/*
		 * From spc4r17 Section 5.7.9: Reserving:
		 *
		 * If a persistent reservation holder attempts to modify the
		 * type or scope of an existing persistent reservation, the
		 * command shall be completed with RESERVATION CONFLICT status.
		 */
		if ((pr_res_holder->pr_res_type != type) ||
		    (pr_res_holder->pr_res_scope != scope)) {
			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
			pr_err("SPC-3 PR: Attempted RESERVE from"
				" [%s]: %s trying to change TYPE and/or SCOPE,"
				" while reservation already held by [%s]: %s,"
				" returning RESERVATION_CONFLICT\n",
				cmd->se_tfo->get_fabric_name(),
				se_sess->se_node_acl->initiatorname,
				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
				pr_res_holder->pr_reg_nacl->initiatorname);

			spin_unlock(&dev->dev_reservation_lock);
			ret = TCM_RESERVATION_CONFLICT;
			goto out_put_pr_reg;
		}
		/*
		 * From spc4r17 Section 5.7.9: Reserving:
		 *
		 * If the device server receives a PERSISTENT RESERVE OUT
		 * command with RESERVE service action where the TYPE field and
		 * the SCOPE field contain the same values as the existing type
		 * and scope from a persistent reservation holder, it shall not
		 * make any change to the existing persistent reservation and
		 * shall completethe command with GOOD status.
		 */
		spin_unlock(&dev->dev_reservation_lock);
		ret = 0;
		goto out_put_pr_reg;
	}
	/*
	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
	 */
	pr_reg->pr_res_scope = scope;
	pr_reg->pr_res_type = type;
	pr_reg->pr_res_holder = 1;
	dev->dev_pr_res_holder = pr_reg;
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);

	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
			cmd->se_tfo->get_fabric_name(),
			se_sess->se_node_acl->initiatorname,
			i_buf);
	spin_unlock(&dev->dev_reservation_lock);

	if (pr_tmpl->pr_aptpl_active)
		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);

	ret = 0;
out_put_pr_reg:
	core_scsi3_put_pr_reg(pr_reg);
	return ret;
}

static sense_reason_t
core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
		u64 res_key)
{
	switch (type) {
	case PR_TYPE_WRITE_EXCLUSIVE:
	case PR_TYPE_EXCLUSIVE_ACCESS:
	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
	default:
		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
			" 0x%02x\n", type);
		return TCM_INVALID_CDB_FIELD;
	}
}

/*
 * Called with struct se_device->dev_reservation_lock held.
 */
static void __core_scsi3_complete_pro_release(
	struct se_device *dev,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int explicit,
	int unreg)
{
	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
	char i_buf[PR_REG_ISID_ID_LEN];
	int pr_res_type = 0, pr_res_scope = 0;

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
	/*
	 * Go ahead and release the current PR reservation holder.
	 * If an All Registrants reservation is currently active and
	 * a unregister operation is requested, replace the current
	 * dev_pr_res_holder with another active registration.
	 */
	if (dev->dev_pr_res_holder) {
		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
		dev->dev_pr_res_holder->pr_res_type = 0;
		dev->dev_pr_res_holder->pr_res_scope = 0;
		dev->dev_pr_res_holder->pr_res_holder = 0;
		dev->dev_pr_res_holder = NULL;
	}
	if (!unreg)
		goto out;

	spin_lock(&dev->t10_pr.registration_lock);
	list_del_init(&pr_reg->pr_reg_list);
	/*
	 * If the I_T nexus is a reservation holder, the persistent reservation
	 * is of an all registrants type, and the I_T nexus is the last remaining
	 * registered I_T nexus, then the device server shall also release the
	 * persistent reservation.
	 */
	if (!list_empty(&dev->t10_pr.registration_list) &&
	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
		dev->dev_pr_res_holder =
			list_entry(dev->t10_pr.registration_list.next,
				   struct t10_pr_registration, pr_reg_list);
		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
		dev->dev_pr_res_holder->pr_res_holder = 1;
	}
	spin_unlock(&dev->t10_pr.registration_lock);
out:
	if (!dev->dev_pr_res_holder) {
		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
			tfo->get_fabric_name(), (explicit) ? "explicit" :
			"implicit", core_scsi3_pr_dump_type(pr_res_type),
			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
	}
	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
		tfo->get_fabric_name(), se_nacl->initiatorname,
		i_buf);
	/*
	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
	 */
	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
}

static sense_reason_t
core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
		u64 res_key)
{
	struct se_device *dev = cmd->se_dev;
	struct se_session *se_sess = cmd->se_sess;
	struct se_lun *se_lun = cmd->se_lun;
	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	sense_reason_t ret = 0;

	if (!se_sess || !se_lun) {
		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * Locate the existing *pr_reg via struct se_node_acl pointers
	 */
	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
	if (!pr_reg) {
		pr_err("SPC-3 PR: Unable to locate"
			" PR_REGISTERED *pr_reg for RELEASE\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * From spc4r17 Section 5.7.11.2 Releasing:
	 *
	 * If there is no persistent reservation or in response to a persistent
	 * reservation release request from a registered I_T nexus that is not a
	 * persistent reservation holder (see 5.7.10), the device server shall
	 * do the following:
	 *
	 *     a) Not release the persistent reservation, if any;
	 *     b) Not remove any registrations; and
	 *     c) Complete the command with GOOD status.
	 */
	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (!pr_res_holder) {
		/*
		 * No persistent reservation, return GOOD status.
		 */
		spin_unlock(&dev->dev_reservation_lock);
		goto out_put_pr_reg;
	}

	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
		/*
		 * Release request from a registered I_T nexus that is not a
		 * persistent reservation holder. return GOOD status.
		 */
		spin_unlock(&dev->dev_reservation_lock);
		goto out_put_pr_reg;
	}

	/*
	 * From spc4r17 Section 5.7.11.2 Releasing:
	 *
	 * Only the persistent reservation holder (see 5.7.10) is allowed to
	 * release a persistent reservation.
	 *
	 * An application client releases the persistent reservation by issuing
	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
	 * an I_T nexus that is a persistent reservation holder with the
	 * following parameters:
	 *
	 *     a) RESERVATION KEY field set to the value of the reservation key
	 *	  that is registered with the logical unit for the I_T nexus;
	 */
	if (res_key != pr_reg->pr_res_key) {
		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
			" does not match existing SA REGISTER res_key:"
			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
		spin_unlock(&dev->dev_reservation_lock);
		ret = TCM_RESERVATION_CONFLICT;
		goto out_put_pr_reg;
	}
	/*
	 * From spc4r17 Section 5.7.11.2 Releasing and above:
	 *
	 * b) TYPE field and SCOPE field set to match the persistent
	 *    reservation being released.
	 */
	if ((pr_res_holder->pr_res_type != type) ||
	    (pr_res_holder->pr_res_scope != scope)) {
		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
		pr_err("SPC-3 PR RELEASE: Attempted to release"
			" reservation from [%s]: %s with different TYPE "
			"and/or SCOPE  while reservation already held by"
			" [%s]: %s, returning RESERVATION_CONFLICT\n",
			cmd->se_tfo->get_fabric_name(),
			se_sess->se_node_acl->initiatorname,
			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
			pr_res_holder->pr_reg_nacl->initiatorname);

		spin_unlock(&dev->dev_reservation_lock);
		ret = TCM_RESERVATION_CONFLICT;
		goto out_put_pr_reg;
	}
	/*
	 * In response to a persistent reservation release request from the
	 * persistent reservation holder the device server shall perform a
	 * release by doing the following as an uninterrupted series of actions:
	 * a) Release the persistent reservation;
	 * b) Not remove any registration(s);
	 * c) If the released persistent reservation is a registrants only type
	 * or all registrants type persistent reservation,
	 *    the device server shall establish a unit attention condition for
	 *    the initiator port associated with every regis-
	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
	 *    RESERVE OUT command with RELEASE service action was received,
	 *    with the additional sense code set to RESERVATIONS RELEASED; and
	 * d) If the persistent reservation is of any other type, the device
	 *    server shall not establish a unit attention condition.
	 */
	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
					  pr_reg, 1, 0);

	spin_unlock(&dev->dev_reservation_lock);

	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
		/*
		 * If no UNIT ATTENTION conditions will be established for
		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
		 * go ahead and check for APTPL=1 update+write below
		 */
		goto write_aptpl;
	}

	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
			pr_reg_list) {
		/*
		 * Do not establish a UNIT ATTENTION condition
		 * for the calling I_T Nexus
		 */
		if (pr_reg_p == pr_reg)
			continue;

		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
				pr_reg_p->pr_res_mapped_lun,
				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
	}
	spin_unlock(&pr_tmpl->registration_lock);

write_aptpl:
	if (pr_tmpl->pr_aptpl_active)
		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);

out_put_pr_reg:
	core_scsi3_put_pr_reg(pr_reg);
	return ret;
}

static sense_reason_t
core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
{
	struct se_device *dev = cmd->se_dev;
	struct se_node_acl *pr_reg_nacl;
	struct se_session *se_sess = cmd->se_sess;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
	u64 pr_res_mapped_lun = 0;
	int calling_it_nexus = 0;
	/*
	 * Locate the existing *pr_reg via struct se_node_acl pointers
	 */
	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
			se_sess->se_node_acl, se_sess);
	if (!pr_reg_n) {
		pr_err("SPC-3 PR: Unable to locate"
			" PR_REGISTERED *pr_reg for CLEAR\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * From spc4r17 section 5.7.11.6, Clearing:
	 *
	 * Any application client may release the persistent reservation and
	 * remove all registrations from a device server by issuing a
	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
	 * registered I_T nexus with the following parameter:
	 *
	 *	a) RESERVATION KEY field set to the value of the reservation key
	 * 	   that is registered with the logical unit for the I_T nexus.
	 */
	if (res_key != pr_reg_n->pr_res_key) {
		pr_err("SPC-3 PR REGISTER: Received"
			" res_key: 0x%016Lx does not match"
			" existing SA REGISTER res_key:"
			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
		core_scsi3_put_pr_reg(pr_reg_n);
		return TCM_RESERVATION_CONFLICT;
	}
	/*
	 * a) Release the persistent reservation, if any;
	 */
	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (pr_res_holder) {
		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
						  pr_res_holder, 0, 0);
	}
	spin_unlock(&dev->dev_reservation_lock);
	/*
	 * b) Remove all registration(s) (see spc4r17 5.7.7);
	 */
	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {

		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
		pr_reg_nacl = pr_reg->pr_reg_nacl;
		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
		__core_scsi3_free_registration(dev, pr_reg, NULL,
					calling_it_nexus);
		/*
		 * e) Establish a unit attention condition for the initiator
		 *    port associated with every registered I_T nexus other
		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
		 *    command with CLEAR service action was received, with the
		 *    additional sense code set to RESERVATIONS PREEMPTED.
		 */
		if (!calling_it_nexus)
			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
	}
	spin_unlock(&pr_tmpl->registration_lock);

	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
		cmd->se_tfo->get_fabric_name());

	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);

	core_scsi3_pr_generation(dev);
	return 0;
}

/*
 * Called with struct se_device->dev_reservation_lock held.
 */
static void __core_scsi3_complete_pro_preempt(
	struct se_device *dev,
	struct t10_pr_registration *pr_reg,
	struct list_head *preempt_and_abort_list,
	int type,
	int scope,
	enum preempt_type preempt_type)
{
	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
	char i_buf[PR_REG_ISID_ID_LEN];

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
	/*
	 * Do an implicit RELEASE of the existing reservation.
	 */
	if (dev->dev_pr_res_holder)
		__core_scsi3_complete_pro_release(dev, nacl,
						  dev->dev_pr_res_holder, 0, 0);

	dev->dev_pr_res_holder = pr_reg;
	pr_reg->pr_res_holder = 1;
	pr_reg->pr_res_type = type;
	pr_reg->pr_res_scope = scope;

	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
		core_scsi3_pr_dump_type(type),
		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
		nacl->initiatorname, i_buf);
	/*
	 * For PREEMPT_AND_ABORT, add the preempting reservation's
	 * struct t10_pr_registration to the list that will be compared
	 * against received CDBs..
	 */
	if (preempt_and_abort_list)
		list_add_tail(&pr_reg->pr_reg_abort_list,
				preempt_and_abort_list);
}

static void core_scsi3_release_preempt_and_abort(
	struct list_head *preempt_and_abort_list,
	struct t10_pr_registration *pr_reg_holder)
{
	struct t10_pr_registration *pr_reg, *pr_reg_tmp;

	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
				pr_reg_abort_list) {

		list_del(&pr_reg->pr_reg_abort_list);
		if (pr_reg_holder == pr_reg)
			continue;
		if (pr_reg->pr_res_holder) {
			pr_warn("pr_reg->pr_res_holder still set\n");
			continue;
		}

		pr_reg->pr_reg_deve = NULL;
		pr_reg->pr_reg_nacl = NULL;
		kmem_cache_free(t10_pr_reg_cache, pr_reg);
	}
}

static sense_reason_t
core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
		u64 sa_res_key, enum preempt_type preempt_type)
{
	struct se_device *dev = cmd->se_dev;
	struct se_node_acl *pr_reg_nacl;
	struct se_session *se_sess = cmd->se_sess;
	LIST_HEAD(preempt_and_abort_list);
	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	u64 pr_res_mapped_lun = 0;
	int all_reg = 0, calling_it_nexus = 0;
	bool sa_res_key_unmatched = sa_res_key != 0;
	int prh_type = 0, prh_scope = 0;

	if (!se_sess)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
				se_sess);
	if (!pr_reg_n) {
		pr_err("SPC-3 PR: Unable to locate"
			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
		return TCM_RESERVATION_CONFLICT;
	}
	if (pr_reg_n->pr_res_key != res_key) {
		core_scsi3_put_pr_reg(pr_reg_n);
		return TCM_RESERVATION_CONFLICT;
	}
	if (scope != PR_SCOPE_LU_SCOPE) {
		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
		core_scsi3_put_pr_reg(pr_reg_n);
		return TCM_INVALID_PARAMETER_LIST;
	}

	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (pr_res_holder &&
	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
		all_reg = 1;

	if (!all_reg && !sa_res_key) {
		spin_unlock(&dev->dev_reservation_lock);
		core_scsi3_put_pr_reg(pr_reg_n);
		return TCM_INVALID_PARAMETER_LIST;
	}
	/*
	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
	 *
	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
	 * persistent reservation holder or there is no persistent reservation
	 * holder (i.e., there is no persistent reservation), then the device
	 * server shall perform a preempt by doing the following in an
	 * uninterrupted series of actions. (See below..)
	 */
	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
		/*
		 * No existing or SA Reservation Key matching reservations..
		 *
		 * PROUT SA PREEMPT with All Registrant type reservations are
		 * allowed to be processed without a matching SA Reservation Key
		 */
		spin_lock(&pr_tmpl->registration_lock);
		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
				&pr_tmpl->registration_list, pr_reg_list) {
			/*
			 * Removing of registrations in non all registrants
			 * type reservations without a matching SA reservation
			 * key.
			 *
			 * a) Remove the registrations for all I_T nexuses
			 *    specified by the SERVICE ACTION RESERVATION KEY
			 *    field;
			 * b) Ignore the contents of the SCOPE and TYPE fields;
			 * c) Process tasks as defined in 5.7.1; and
			 * d) Establish a unit attention condition for the
			 *    initiator port associated with every I_T nexus
			 *    that lost its registration other than the I_T
			 *    nexus on which the PERSISTENT RESERVE OUT command
			 *    was received, with the additional sense code set
			 *    to REGISTRATIONS PREEMPTED.
			 */
			if (!all_reg) {
				if (pr_reg->pr_res_key != sa_res_key)
					continue;
				sa_res_key_unmatched = false;

				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
				pr_reg_nacl = pr_reg->pr_reg_nacl;
				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
				__core_scsi3_free_registration(dev, pr_reg,
					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
						NULL, calling_it_nexus);
			} else {
				/*
				 * Case for any existing all registrants type
				 * reservation, follow logic in spc4r17 section
				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
				 *
				 * For a ZERO SA Reservation key, release
				 * all other registrations and do an implicit
				 * release of active persistent reservation.
				 *
				 * For a non-ZERO SA Reservation key, only
				 * release the matching reservation key from
				 * registrations.
				 */
				if ((sa_res_key) &&
				     (pr_reg->pr_res_key != sa_res_key))
					continue;
				sa_res_key_unmatched = false;

				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
				if (calling_it_nexus)
					continue;

				pr_reg_nacl = pr_reg->pr_reg_nacl;
				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
				__core_scsi3_free_registration(dev, pr_reg,
					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
						NULL, 0);
			}
			if (!calling_it_nexus)
				target_ua_allocate_lun(pr_reg_nacl,
					pr_res_mapped_lun, 0x2A,
					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
		}
		spin_unlock(&pr_tmpl->registration_lock);
		/*
		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
		 * RESERVATION KEY field to a value that does not match any
		 * registered reservation key, then the device server shall
		 * complete the command with RESERVATION CONFLICT status.
		 */
		if (sa_res_key_unmatched) {
			spin_unlock(&dev->dev_reservation_lock);
			core_scsi3_put_pr_reg(pr_reg_n);
			return TCM_RESERVATION_CONFLICT;
		}
		/*
		 * For an existing all registrants type reservation
		 * with a zero SA rservation key, preempt the existing
		 * reservation with the new PR type and scope.
		 */
		if (pr_res_holder && all_reg && !(sa_res_key)) {
			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
				type, scope, preempt_type);

			if (preempt_type == PREEMPT_AND_ABORT)
				core_scsi3_release_preempt_and_abort(
					&preempt_and_abort_list, pr_reg_n);
		}
		spin_unlock(&dev->dev_reservation_lock);

		if (pr_tmpl->pr_aptpl_active)
			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);

		core_scsi3_put_pr_reg(pr_reg_n);
		core_scsi3_pr_generation(cmd->se_dev);
		return 0;
	}
	/*
	 * The PREEMPTing SA reservation key matches that of the
	 * existing persistent reservation, first, we check if
	 * we are preempting our own reservation.
	 * From spc4r17, section 5.7.11.4.3 Preempting
	 * persistent reservations and registration handling
	 *
	 * If an all registrants persistent reservation is not
	 * present, it is not an error for the persistent
	 * reservation holder to preempt itself (i.e., a
	 * PERSISTENT RESERVE OUT with a PREEMPT service action
	 * or a PREEMPT AND ABORT service action with the
	 * SERVICE ACTION RESERVATION KEY value equal to the
	 * persistent reservation holder's reservation key that
	 * is received from the persistent reservation holder).
	 * In that case, the device server shall establish the
	 * new persistent reservation and maintain the
	 * registration.
	 */
	prh_type = pr_res_holder->pr_res_type;
	prh_scope = pr_res_holder->pr_res_scope;
	/*
	 * If the SERVICE ACTION RESERVATION KEY field identifies a
	 * persistent reservation holder (see 5.7.10), the device
	 * server shall perform a preempt by doing the following as
	 * an uninterrupted series of actions:
	 *
	 * a) Release the persistent reservation for the holder
	 *    identified by the SERVICE ACTION RESERVATION KEY field;
	 */
	if (pr_reg_n != pr_res_holder)
		__core_scsi3_complete_pro_release(dev,
						  pr_res_holder->pr_reg_nacl,
						  dev->dev_pr_res_holder, 0, 0);
	/*
	 * b) Remove the registrations for all I_T nexuses identified
	 *    by the SERVICE ACTION RESERVATION KEY field, except the
	 *    I_T nexus that is being used for the PERSISTENT RESERVE
	 *    OUT command. If an all registrants persistent reservation
	 *    is present and the SERVICE ACTION RESERVATION KEY field
	 *    is set to zero, then all registrations shall be removed
	 *    except for that of the I_T nexus that is being used for
	 *    the PERSISTENT RESERVE OUT command;
	 */
	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {

		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
		if (calling_it_nexus)
			continue;

		if (pr_reg->pr_res_key != sa_res_key)
			continue;

		pr_reg_nacl = pr_reg->pr_reg_nacl;
		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
		__core_scsi3_free_registration(dev, pr_reg,
				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
				calling_it_nexus);
		/*
		 * e) Establish a unit attention condition for the initiator
		 *    port associated with every I_T nexus that lost its
		 *    persistent reservation and/or registration, with the
		 *    additional sense code set to REGISTRATIONS PREEMPTED;
		 */
		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
	}
	spin_unlock(&pr_tmpl->registration_lock);
	/*
	 * c) Establish a persistent reservation for the preempting
	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
	 */
	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
			type, scope, preempt_type);
	/*
	 * d) Process tasks as defined in 5.7.1;
	 * e) See above..
	 * f) If the type or scope has changed, then for every I_T nexus
	 *    whose reservation key was not removed, except for the I_T
	 *    nexus on which the PERSISTENT RESERVE OUT command was
	 *    received, the device server shall establish a unit
	 *    attention condition for the initiator port associated with
	 *    that I_T nexus, with the additional sense code set to
	 *    RESERVATIONS RELEASED. If the type or scope have not
	 *    changed, then no unit attention condition(s) shall be
	 *    established for this reason.
	 */
	if ((prh_type != type) || (prh_scope != scope)) {
		spin_lock(&pr_tmpl->registration_lock);
		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
				&pr_tmpl->registration_list, pr_reg_list) {

			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
			if (calling_it_nexus)
				continue;

			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
					pr_reg->pr_res_mapped_lun, 0x2A,
					ASCQ_2AH_RESERVATIONS_RELEASED);
		}
		spin_unlock(&pr_tmpl->registration_lock);
	}
	spin_unlock(&dev->dev_reservation_lock);
	/*
	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
	 * All received CDBs for the matching existing reservation and
	 * registrations undergo ABORT_TASK logic.
	 *
	 * From there, core_scsi3_release_preempt_and_abort() will
	 * release every registration in the list (which have already
	 * been removed from the primary pr_reg list), except the
	 * new persistent reservation holder, the calling Initiator Port.
	 */
	if (preempt_type == PREEMPT_AND_ABORT) {
		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
						pr_reg_n);
	}

	if (pr_tmpl->pr_aptpl_active)
		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);

	core_scsi3_put_pr_reg(pr_reg_n);
	core_scsi3_pr_generation(cmd->se_dev);
	return 0;
}

static sense_reason_t
core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
{
	switch (type) {
	case PR_TYPE_WRITE_EXCLUSIVE:
	case PR_TYPE_EXCLUSIVE_ACCESS:
	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
					      sa_res_key, preempt_type);
	default:
		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
		return TCM_INVALID_CDB_FIELD;
	}
}


static sense_reason_t
core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
		u64 sa_res_key, int aptpl, int unreg)
{
	struct se_session *se_sess = cmd->se_sess;
	struct se_device *dev = cmd->se_dev;
	struct se_dev_entry *dest_se_deve = NULL;
	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	unsigned char *buf;
	const unsigned char *initiator_str;
	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
	u32 tid_len, tmp_tid_len;
	int new_reg = 0, type, scope, matching_iname;
	sense_reason_t ret;
	unsigned short rtpi;
	unsigned char proto_ident;

	if (!se_sess || !se_lun) {
		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}

	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
	se_tpg = se_sess->se_tpg;
	tf_ops = se_tpg->se_tpg_tfo;
	/*
	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
	 *	Register behaviors for a REGISTER AND MOVE service action
	 *
	 * Locate the existing *pr_reg via struct se_node_acl pointers
	 */
	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
				se_sess);
	if (!pr_reg) {
		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
			" *pr_reg for REGISTER_AND_MOVE\n");
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
	/*
	 * The provided reservation key much match the existing reservation key
	 * provided during this initiator's I_T nexus registration.
	 */
	if (res_key != pr_reg->pr_res_key) {
		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
			" res_key: 0x%016Lx does not match existing SA REGISTER"
			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
		ret = TCM_RESERVATION_CONFLICT;
		goto out_put_pr_reg;
	}
	/*
	 * The service active reservation key needs to be non zero
	 */
	if (!sa_res_key) {
		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
			" sa_res_key\n");
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out_put_pr_reg;
	}

	/*
	 * Determine the Relative Target Port Identifier where the reservation
	 * will be moved to for the TransportID containing SCSI initiator WWN
	 * information.
	 */
	buf = transport_kmap_data_sg(cmd);
	if (!buf) {
		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
		goto out_put_pr_reg;
	}

	rtpi = get_unaligned_be16(&buf[18]);
	tid_len = get_unaligned_be32(&buf[20]);
	transport_kunmap_data_sg(cmd);
	buf = NULL;

	if ((tid_len + 24) != cmd->data_length) {
		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
			" does not equal CDB data_length: %u\n", tid_len,
			cmd->data_length);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out_put_pr_reg;
	}

	spin_lock(&dev->se_port_lock);
	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
		if (tmp_lun->lun_rtpi != rtpi)
			continue;
		dest_se_tpg = tmp_lun->lun_tpg;
		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
		if (!dest_tf_ops)
			continue;

		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
		spin_unlock(&dev->se_port_lock);

		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
			pr_err("core_scsi3_tpg_depend_item() failed"
				" for dest_se_tpg\n");
			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
			goto out_put_pr_reg;
		}

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

	if (!dest_se_tpg || !dest_tf_ops) {
		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
			" fabric ops from Relative Target Port Identifier:"
			" %hu\n", rtpi);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out_put_pr_reg;
	}

	buf = transport_kmap_data_sg(cmd);
	if (!buf) {
		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
		goto out_put_pr_reg;
	}
	proto_ident = (buf[24] & 0x0f);

	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
			" 0x%02x\n", proto_ident);

	if (proto_ident != dest_se_tpg->proto_id) {
		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
			" proto_ident: 0x%02x does not match ident: 0x%02x"
			" from fabric: %s\n", proto_ident,
			dest_se_tpg->proto_id,
			dest_tf_ops->get_fabric_name());
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}
	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
			&buf[24], &tmp_tid_len, &iport_ptr);
	if (!initiator_str) {
		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
			" initiator_str from Transport ID\n");
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	transport_kunmap_data_sg(cmd);
	buf = NULL;

	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
		"port" : "device", initiator_str, (iport_ptr != NULL) ?
		iport_ptr : "");
	/*
	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
	 * action specifies a TransportID that is the same as the initiator port
	 * of the I_T nexus for the command received, 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.
	 */
	pr_reg_nacl = pr_reg->pr_reg_nacl;
	matching_iname = (!strcmp(initiator_str,
				  pr_reg_nacl->initiatorname)) ? 1 : 0;
	if (!matching_iname)
		goto after_iport_check;

	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
			" matches: %s on received I_T Nexus\n", initiator_str,
			pr_reg_nacl->initiatorname);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}
	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
			" matches: %s %s on received I_T Nexus\n",
			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
			pr_reg->pr_reg_isid);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}
after_iport_check:
	/*
	 * Locate the destination struct se_node_acl from the received Transport ID
	 */
	mutex_lock(&dest_se_tpg->acl_node_mutex);
	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
				initiator_str);
	if (dest_node_acl)
		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
	mutex_unlock(&dest_se_tpg->acl_node_mutex);

	if (!dest_node_acl) {
		pr_err("Unable to locate %s dest_node_acl for"
			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
			initiator_str);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
		pr_err("core_scsi3_nodeacl_depend_item() for"
			" dest_node_acl\n");
		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
		dest_node_acl = NULL;
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
		dest_node_acl->initiatorname);

	/*
	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
	 * PORT IDENTIFIER.
	 */
	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
	if (!dest_se_deve) {
		pr_err("Unable to locate %s dest_se_deve from RTPI:"
			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
		ret = TCM_INVALID_PARAMETER_LIST;
		goto out;
	}

	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
		pr_err("core_scsi3_lunacl_depend_item() failed\n");
		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
		dest_se_deve = NULL;
		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		goto out;
	}

	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
		" ACL for dest_se_deve->mapped_lun: %llu\n",
		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
		dest_se_deve->mapped_lun);

	/*
	 * A persistent reservation needs to already existing in order to
	 * successfully complete the REGISTER_AND_MOVE service action..
	 */
	spin_lock(&dev->dev_reservation_lock);
	pr_res_holder = dev->dev_pr_res_holder;
	if (!pr_res_holder) {
		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
			" currently held\n");
		spin_unlock(&dev->dev_reservation_lock);
		ret = TCM_INVALID_CDB_FIELD;
		goto out;
	}
	/*
	 * The received on I_T Nexus must be the reservation holder.
	 *
	 * From spc4r17 section 5.7.8  Table 50 --
	 * 	Register behaviors for a REGISTER AND MOVE service action
	 */
	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
			" Nexus is not reservation holder\n");
		spin_unlock(&dev->dev_reservation_lock);
		ret = TCM_RESERVATION_CONFLICT;
		goto out;
	}
	/*
	 * From spc4r17 section 5.7.8: registering and moving reservation
	 *
	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
	 * action is received and the established persistent reservation is a
	 * Write Exclusive - All Registrants type or Exclusive Access -
	 * All Registrants type reservation, then the command shall be completed
	 * with RESERVATION CONFLICT status.
	 */
	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
			" reservation for type: %s\n",
			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
		spin_unlock(&dev->dev_reservation_lock);
		ret = TCM_RESERVATION_CONFLICT;
		goto out;
	}
	pr_res_nacl = pr_res_holder->pr_reg_nacl;
	/*
	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
	 */
	type = pr_res_holder->pr_res_type;
	scope = pr_res_holder->pr_res_type;
	/*
	 * c) Associate the reservation key specified in the SERVICE ACTION
	 *    RESERVATION KEY field with the I_T nexus specified as the
	 *    destination of the register and move, where:
	 *    A) The I_T nexus is specified by the TransportID and the
	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
	 *    B) Regardless of the TransportID format used, the association for
	 *       the initiator port is based on either the initiator port name
	 *       (see 3.1.71) on SCSI transport protocols where port names are
	 *       required or the initiator port identifier (see 3.1.70) on SCSI
	 *       transport protocols where port names are not required;
	 * d) Register the reservation key specified in the SERVICE ACTION
	 *    RESERVATION KEY field;
	 * e) Retain the reservation key specified in the SERVICE ACTION
	 *    RESERVATION KEY field and associated information;
	 *
	 * Also, It is not an error for a REGISTER AND MOVE service action to
	 * register an I_T nexus that is already registered with the same
	 * reservation key or a different reservation key.
	 */
	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
					iport_ptr);
	if (!dest_pr_reg) {
		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
				kref_read(&dest_se_deve->pr_kref) != 0);

		spin_unlock(&dev->dev_reservation_lock);
		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
			goto out;
		}
		spin_lock(&dev->dev_reservation_lock);
		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
						iport_ptr);
		new_reg = 1;
	}
	/*
	 * f) Release the persistent reservation for the persistent reservation
	 *    holder (i.e., the I_T nexus on which the
	 */
	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
					  dev->dev_pr_res_holder, 0, 0);
	/*
	 * g) Move the persistent reservation to the specified I_T nexus using
	 *    the same scope and type as the persistent reservation released in
	 *    item f); and
	 */
	dev->dev_pr_res_holder = dest_pr_reg;
	dest_pr_reg->pr_res_holder = 1;
	dest_pr_reg->pr_res_type = type;
	pr_reg->pr_res_scope = scope;
	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
	/*
	 * Increment PRGeneration for existing registrations..
	 */
	if (!new_reg)
		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
	spin_unlock(&dev->dev_reservation_lock);

	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
		" created new reservation holder TYPE: %s on object RTPI:"
		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
		core_scsi3_pr_dump_type(type), rtpi,
		dest_pr_reg->pr_res_generation);
	pr_debug("SPC-3 PR Successfully moved reservation from"
		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
		i_buf, dest_tf_ops->get_fabric_name(),
		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
		iport_ptr : "");
	/*
	 * It is now safe to release configfs group dependencies for destination
	 * of Transport ID Initiator Device/Port Identifier
	 */
	core_scsi3_lunacl_undepend_item(dest_se_deve);
	core_scsi3_nodeacl_undepend_item(dest_node_acl);
	core_scsi3_tpg_undepend_item(dest_se_tpg);
	/*
	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
	 * nexus on which PERSISTENT RESERVE OUT command was received.
	 */
	if (unreg) {
		spin_lock(&pr_tmpl->registration_lock);
		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
		spin_unlock(&pr_tmpl->registration_lock);
	} else
		core_scsi3_put_pr_reg(pr_reg);

	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);

	core_scsi3_put_pr_reg(dest_pr_reg);
	return 0;
out:
	if (buf)
		transport_kunmap_data_sg(cmd);
	if (dest_se_deve)
		core_scsi3_lunacl_undepend_item(dest_se_deve);
	if (dest_node_acl)
		core_scsi3_nodeacl_undepend_item(dest_node_acl);
	core_scsi3_tpg_undepend_item(dest_se_tpg);

out_put_pr_reg:
	core_scsi3_put_pr_reg(pr_reg);
	return ret;
}

/*
 * See spc4r17 section 6.14 Table 170
 */
sense_reason_t
target_scsi3_emulate_pr_out(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned char *cdb = &cmd->t_task_cdb[0];
	unsigned char *buf;
	u64 res_key, sa_res_key;
	int sa, scope, type, aptpl;
	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
	sense_reason_t ret;

	/*
	 * Following spc2r20 5.5.1 Reservations overview:
	 *
	 * If a logical unit has been reserved by any RESERVE command and is
	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
	 * initiator or service action and shall terminate with a RESERVATION
	 * CONFLICT status.
	 */
	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
			" SPC-2 reservation is held, returning"
			" RESERVATION_CONFLICT\n");
		return TCM_RESERVATION_CONFLICT;
	}

	/*
	 * FIXME: A NULL struct se_session pointer means an this is not coming from
	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
	 */
	if (!cmd->se_sess)
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	if (cmd->data_length < 24) {
		pr_warn("SPC-PR: Received PR OUT parameter list"
			" length too small: %u\n", cmd->data_length);
		return TCM_PARAMETER_LIST_LENGTH_ERROR;
	}

	/*
	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
	 */
	sa = (cdb[1] & 0x1f);
	scope = (cdb[2] & 0xf0);
	type = (cdb[2] & 0x0f);

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

	/*
	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
	 */
	res_key = get_unaligned_be64(&buf[0]);
	sa_res_key = get_unaligned_be64(&buf[8]);
	/*
	 * REGISTER_AND_MOVE uses a different SA parameter list containing
	 * SCSI TransportIDs.
	 */
	if (sa != PRO_REGISTER_AND_MOVE) {
		spec_i_pt = (buf[20] & 0x08);
		all_tg_pt = (buf[20] & 0x04);
		aptpl = (buf[20] & 0x01);
	} else {
		aptpl = (buf[17] & 0x01);
		unreg = (buf[17] & 0x02);
	}
	/*
	 * If the backend device has been configured to force APTPL metadata
	 * write-out, go ahead and propigate aptpl=1 down now.
	 */
	if (dev->dev_attrib.force_pr_aptpl)
		aptpl = 1;

	transport_kunmap_data_sg(cmd);
	buf = NULL;

	/*
	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
	 */
	if (spec_i_pt && (sa != PRO_REGISTER))
		return TCM_INVALID_PARAMETER_LIST;

	/*
	 * From spc4r17 section 6.14:
	 *
	 * If the SPEC_I_PT bit is set to zero, the service action is not
	 * REGISTER AND MOVE, and the parameter list length is not 24, 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 PARAMETER LIST LENGTH ERROR.
	 */
	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
	    (cmd->data_length != 24)) {
		pr_warn("SPC-PR: Received PR OUT illegal parameter"
			" list length: %u\n", cmd->data_length);
		return TCM_PARAMETER_LIST_LENGTH_ERROR;
	}

	/*
	 * (core_scsi3_emulate_pro_* function parameters
	 * are defined by spc4r17 Table 174:
	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
	 */
	switch (sa) {
	case PRO_REGISTER:
		ret = core_scsi3_emulate_pro_register(cmd,
			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
		break;
	case PRO_RESERVE:
		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
		break;
	case PRO_RELEASE:
		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
		break;
	case PRO_CLEAR:
		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
		break;
	case PRO_PREEMPT:
		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
					res_key, sa_res_key, PREEMPT);
		break;
	case PRO_PREEMPT_AND_ABORT:
		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
					res_key, sa_res_key, PREEMPT_AND_ABORT);
		break;
	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
		ret = core_scsi3_emulate_pro_register(cmd,
			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
		break;
	case PRO_REGISTER_AND_MOVE:
		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
				sa_res_key, aptpl, unreg);
		break;
	default:
		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
			" action: 0x%02x\n", sa);
		return TCM_INVALID_CDB_FIELD;
	}

	if (!ret)
		target_complete_cmd(cmd, GOOD);
	return ret;
}

/*
 * PERSISTENT_RESERVE_IN Service Action READ_KEYS
 *
 * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
 */
static sense_reason_t
core_scsi3_pri_read_keys(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct t10_pr_registration *pr_reg;
	unsigned char *buf;
	u32 add_len = 0, off = 8;

	if (cmd->data_length < 8) {
		pr_err("PRIN SA READ_KEYS SCSI Data 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;

	put_unaligned_be32(dev->t10_pr.pr_generation, buf);

	spin_lock(&dev->t10_pr.registration_lock);
	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
			pr_reg_list) {
		/*
		 * Check for overflow of 8byte PRI READ_KEYS payload and
		 * next reservation key list descriptor.
		 */
		if (off + 8 <= cmd->data_length) {
			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
			off += 8;
		}
		/*
		 * SPC5r17: 6.16.2 READ KEYS service action
		 * The ADDITIONAL LENGTH field indicates the number of bytes in
		 * the Reservation key list. The contents of the ADDITIONAL
		 * LENGTH field are not altered based on the allocation length
		 */
		add_len += 8;
	}
	spin_unlock(&dev->t10_pr.registration_lock);

	put_unaligned_be32(add_len, &buf[4]);

	transport_kunmap_data_sg(cmd);

	return 0;
}

/*
 * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
 *
 * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
 */
static sense_reason_t
core_scsi3_pri_read_reservation(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct t10_pr_registration *pr_reg;
	unsigned char *buf;
	u64 pr_res_key;
	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */

	if (cmd->data_length < 8) {
		pr_err("PRIN SA READ_RESERVATIONS SCSI Data 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;

	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);

	spin_lock(&dev->dev_reservation_lock);
	pr_reg = dev->dev_pr_res_holder;
	if (pr_reg) {
		/*
		 * Set the hardcoded Additional Length
		 */
		put_unaligned_be32(add_len, &buf[4]);

		if (cmd->data_length < 22)
			goto err;

		/*
		 * Set the Reservation key.
		 *
		 * From spc4r17, section 5.7.10:
		 * A persistent reservation holder has its reservation key
		 * returned in the parameter data from a PERSISTENT
		 * RESERVE IN command with READ RESERVATION service action as
		 * follows:
		 * a) For a persistent reservation of the type Write Exclusive
		 *    - All Registrants or Exclusive Access ­ All Regitrants,
		 *      the reservation key shall be set to zero; or
		 * b) For all other persistent reservation types, the
		 *    reservation key shall be set to the registered
		 *    reservation key for the I_T nexus that holds the
		 *    persistent reservation.
		 */
		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
			pr_res_key = 0;
		else
			pr_res_key = pr_reg->pr_res_key;

		put_unaligned_be64(pr_res_key, &buf[8]);
		/*
		 * Set the SCOPE and TYPE
		 */
		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
			  (pr_reg->pr_res_type & 0x0f);
	}

err:
	spin_unlock(&dev->dev_reservation_lock);
	transport_kunmap_data_sg(cmd);

	return 0;
}

/*
 * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
 *
 * See spc4r17 section 6.13.4 Table 165
 */
static sense_reason_t
core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	unsigned char *buf;
	u16 add_len = 8; /* Hardcoded to 8. */

	if (cmd->data_length < 6) {
		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data 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;

	put_unaligned_be16(add_len, &buf[0]);
	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
	/*
	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
	 * set the TMV: Task Mask Valid bit.
	 */
	buf[3] |= 0x80;
	/*
	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
	 */
	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
	/*
	 * PTPL_A: Persistence across Target Power Loss Active bit
	 */
	if (pr_tmpl->pr_aptpl_active)
		buf[3] |= 0x01;
	/*
	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
	 */
	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */

	transport_kunmap_data_sg(cmd);

	return 0;
}

/*
 * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
 *
 * See spc4r17 section 6.13.5 Table 168 and 169
 */
static sense_reason_t
core_scsi3_pri_read_full_status(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_node_acl *se_nacl;
	struct se_portal_group *se_tpg;
	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
	struct t10_reservation *pr_tmpl = &dev->t10_pr;
	unsigned char *buf;
	u32 add_desc_len = 0, add_len = 0;
	u32 off = 8; /* off into first Full Status descriptor */
	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
	int exp_desc_len, desc_len;
	bool all_reg = false;

	if (cmd->data_length < 8) {
		pr_err("PRIN SA READ_FULL_STATUS SCSI Data 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;

	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);

	spin_lock(&dev->dev_reservation_lock);
	if (dev->dev_pr_res_holder) {
		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;

		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
			all_reg = true;
			pr_res_type = pr_holder->pr_res_type;
			pr_res_scope = pr_holder->pr_res_scope;
		}
	}
	spin_unlock(&dev->dev_reservation_lock);

	spin_lock(&pr_tmpl->registration_lock);
	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
			&pr_tmpl->registration_list, pr_reg_list) {

		se_nacl = pr_reg->pr_reg_nacl;
		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
		add_desc_len = 0;

		atomic_inc_mb(&pr_reg->pr_res_holders);
		spin_unlock(&pr_tmpl->registration_lock);
		/*
		 * Determine expected length of $FABRIC_MOD specific
		 * TransportID full status descriptor..
		 */
		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
					&format_code);
		if (exp_desc_len < 0 ||
		    exp_desc_len + add_len > cmd->data_length) {
			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
				" out of buffer: %d\n", cmd->data_length);
			spin_lock(&pr_tmpl->registration_lock);
			atomic_dec_mb(&pr_reg->pr_res_holders);
			break;
		}
		/*
		 * Set RESERVATION KEY
		 */
		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
		off += 8;
		off += 4; /* Skip Over Reserved area */

		/*
		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
		 */
		if (pr_reg->pr_reg_all_tg_pt)
			buf[off] = 0x02;
		/*
		 * The struct se_lun pointer will be present for the
		 * reservation holder for PR_HOLDER bit.
		 *
		 * Also, if this registration is the reservation
		 * holder or there is an All Registrants reservation
		 * active, fill in SCOPE and TYPE in the next byte.
		 */
		if (pr_reg->pr_res_holder) {
			buf[off++] |= 0x01;
			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
				     (pr_reg->pr_res_type & 0x0f);
		} else if (all_reg) {
			buf[off++] |= 0x01;
			buf[off++] = (pr_res_scope & 0xf0) |
				     (pr_res_type & 0x0f);
		} else {
			off += 2;
		}

		off += 4; /* Skip over reserved area */
		/*
		 * From spc4r17 6.3.15:
		 *
		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
		 * IDENTIFIER field contains the relative port identifier (see
		 * 3.1.120) of the target port that is part of the I_T nexus
		 * described by this full status descriptor. If the ALL_TG_PT
		 * bit is set to one, the contents of the RELATIVE TARGET PORT
		 * IDENTIFIER field are not defined by this standard.
		 */
		if (!pr_reg->pr_reg_all_tg_pt) {
			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;

			put_unaligned_be16(sep_rtpi, &buf[off]);
			off += 2;
		} else
			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */

		buf[off+4] = se_tpg->proto_id;

		/*
		 * Now, have the $FABRIC_MOD fill in the transport ID.
		 */
		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
				&format_code, &buf[off+4]);

		spin_lock(&pr_tmpl->registration_lock);
		atomic_dec_mb(&pr_reg->pr_res_holders);

		if (desc_len < 0)
			break;
		/*
		 * Set the ADDITIONAL DESCRIPTOR LENGTH
		 */
		put_unaligned_be32(desc_len, &buf[off]);
		off += 4;
		/*
		 * Size of full desctipor header minus TransportID
		 * containing $FABRIC_MOD specific) initiator device/port
		 * WWN information.
		 *
		 *  See spc4r17 Section 6.13.5 Table 169
		 */
		add_desc_len = (24 + desc_len);

		off += desc_len;
		add_len += add_desc_len;
	}
	spin_unlock(&pr_tmpl->registration_lock);
	/*
	 * Set ADDITIONAL_LENGTH
	 */
	put_unaligned_be32(add_len, &buf[4]);

	transport_kunmap_data_sg(cmd);

	return 0;
}

sense_reason_t
target_scsi3_emulate_pr_in(struct se_cmd *cmd)
{
	sense_reason_t ret;

	/*
	 * Following spc2r20 5.5.1 Reservations overview:
	 *
	 * If a logical unit has been reserved by any RESERVE command and is
	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
	 * initiator or service action and shall terminate with a RESERVATION
	 * CONFLICT status.
	 */
	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
			" SPC-2 reservation is held, returning"
			" RESERVATION_CONFLICT\n");
		return TCM_RESERVATION_CONFLICT;
	}

	switch (cmd->t_task_cdb[1] & 0x1f) {
	case PRI_READ_KEYS:
		ret = core_scsi3_pri_read_keys(cmd);
		break;
	case PRI_READ_RESERVATION:
		ret = core_scsi3_pri_read_reservation(cmd);
		break;
	case PRI_REPORT_CAPABILITIES:
		ret = core_scsi3_pri_report_capabilities(cmd);
		break;
	case PRI_READ_FULL_STATUS:
		ret = core_scsi3_pri_read_full_status(cmd);
		break;
	default:
		pr_err("Unknown PERSISTENT_RESERVE_IN service"
			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
		return TCM_INVALID_CDB_FIELD;
	}

	if (!ret)
		target_complete_cmd(cmd, GOOD);
	return ret;
}

sense_reason_t
target_check_reservation(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	sense_reason_t ret;

	if (!cmd->se_sess)
		return 0;
	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
		return 0;
	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
		return 0;

	spin_lock(&dev->dev_reservation_lock);
	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
		ret = target_scsi2_reservation_check(cmd);
	else
		ret = target_scsi3_pr_reservation_check(cmd);
	spin_unlock(&dev->dev_reservation_lock);

	return ret;
}