Free Electrons

Embedded Linux Experts

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
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
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmrecovery.c
 *
 * recovery stuff
 *
 * Copyright (C) 2004 Oracle.  All rights reserved.
 *
 * 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 021110-1307, USA.
 *
 */


#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/random.h>
#include <linux/blkdev.h>
#include <linux/socket.h>
#include <linux/inet.h>
#include <linux/timer.h>
#include <linux/kthread.h>
#include <linux/delay.h>


#include "cluster/heartbeat.h"
#include "cluster/nodemanager.h"
#include "cluster/tcp.h"

#include "dlmapi.h"
#include "dlmcommon.h"
#include "dlmdomain.h"

#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
#include "cluster/masklog.h"

static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);

static int dlm_recovery_thread(void *data);
void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
static int dlm_do_recovery(struct dlm_ctxt *dlm);

static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
static int dlm_request_all_locks(struct dlm_ctxt *dlm,
				 u8 request_from, u8 dead_node);
static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);

static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
					const char *lockname, int namelen,
					int total_locks, u64 cookie,
					u8 flags, u8 master);
static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
				    struct dlm_migratable_lockres *mres,
				    u8 send_to,
				    struct dlm_lock_resource *res,
				    int total_locks);
static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
				     struct dlm_lock_resource *res,
				     struct dlm_migratable_lockres *mres);
static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
				 u8 dead_node, u8 send_to);
static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
					struct list_head *list, u8 dead_node);
static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
					      u8 dead_node, u8 new_master);
static void dlm_reco_ast(void *astdata);
static void dlm_reco_bast(void *astdata, int blocked_type);
static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
static void dlm_request_all_locks_worker(struct dlm_work_item *item,
					 void *data);
static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
				      struct dlm_lock_resource *res,
				      u8 *real_master);

static u64 dlm_get_next_mig_cookie(void);

static DEFINE_SPINLOCK(dlm_reco_state_lock);
static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
static u64 dlm_mig_cookie = 1;

static u64 dlm_get_next_mig_cookie(void)
{
	u64 c;
	spin_lock(&dlm_mig_cookie_lock);
	c = dlm_mig_cookie;
	if (dlm_mig_cookie == (~0ULL))
		dlm_mig_cookie = 1;
	else
		dlm_mig_cookie++;
	spin_unlock(&dlm_mig_cookie_lock);
	return c;
}

static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
					  u8 dead_node)
{
	assert_spin_locked(&dlm->spinlock);
	if (dlm->reco.dead_node != dead_node)
		mlog(0, "%s: changing dead_node from %u to %u\n",
		     dlm->name, dlm->reco.dead_node, dead_node);
	dlm->reco.dead_node = dead_node;
}

static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
				       u8 master)
{
	assert_spin_locked(&dlm->spinlock);
	mlog(0, "%s: changing new_master from %u to %u\n",
	     dlm->name, dlm->reco.new_master, master);
	dlm->reco.new_master = master;
}

static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
{
	assert_spin_locked(&dlm->spinlock);
	clear_bit(dlm->reco.dead_node, dlm->recovery_map);
	dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
	dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
}

static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
{
	spin_lock(&dlm->spinlock);
	__dlm_reset_recovery(dlm);
	spin_unlock(&dlm->spinlock);
}

/* Worker function used during recovery. */
void dlm_dispatch_work(struct work_struct *work)
{
	struct dlm_ctxt *dlm =
		container_of(work, struct dlm_ctxt, dispatched_work);
	LIST_HEAD(tmp_list);
	struct dlm_work_item *item, *next;
	dlm_workfunc_t *workfunc;
	int tot=0;

	spin_lock(&dlm->work_lock);
	list_splice_init(&dlm->work_list, &tmp_list);
	spin_unlock(&dlm->work_lock);

	list_for_each_entry(item, &tmp_list, list) {
		tot++;
	}
	mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);

	list_for_each_entry_safe(item, next, &tmp_list, list) {
		workfunc = item->func;
		list_del_init(&item->list);

		/* already have ref on dlm to avoid having
		 * it disappear.  just double-check. */
		BUG_ON(item->dlm != dlm);

		/* this is allowed to sleep and
		 * call network stuff */
		workfunc(item, item->data);

		dlm_put(dlm);
		kfree(item);
	}
}

/*
 * RECOVERY THREAD
 */

void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
{
	/* wake the recovery thread
	 * this will wake the reco thread in one of three places
	 * 1) sleeping with no recovery happening
	 * 2) sleeping with recovery mastered elsewhere
	 * 3) recovery mastered here, waiting on reco data */

	wake_up(&dlm->dlm_reco_thread_wq);
}

/* Launch the recovery thread */
int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
{
	mlog(0, "starting dlm recovery thread...\n");

	dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
						"dlm_reco_thread");
	if (IS_ERR(dlm->dlm_reco_thread_task)) {
		mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
		dlm->dlm_reco_thread_task = NULL;
		return -EINVAL;
	}

	return 0;
}

void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
{
	if (dlm->dlm_reco_thread_task) {
		mlog(0, "waiting for dlm recovery thread to exit\n");
		kthread_stop(dlm->dlm_reco_thread_task);
		dlm->dlm_reco_thread_task = NULL;
	}
}



/*
 * this is lame, but here's how recovery works...
 * 1) all recovery threads cluster wide will work on recovering
 *    ONE node at a time
 * 2) negotiate who will take over all the locks for the dead node.
 *    thats right... ALL the locks.
 * 3) once a new master is chosen, everyone scans all locks
 *    and moves aside those mastered by the dead guy
 * 4) each of these locks should be locked until recovery is done
 * 5) the new master collects up all of secondary lock queue info
 *    one lock at a time, forcing each node to communicate back
 *    before continuing
 * 6) each secondary lock queue responds with the full known lock info
 * 7) once the new master has run all its locks, it sends a ALLDONE!
 *    message to everyone
 * 8) upon receiving this message, the secondary queue node unlocks
 *    and responds to the ALLDONE
 * 9) once the new master gets responses from everyone, he unlocks
 *    everything and recovery for this dead node is done
 *10) go back to 2) while there are still dead nodes
 *
 */

static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
{
	struct dlm_reco_node_data *ndata;
	struct dlm_lock_resource *res;

	mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
	     dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
	     dlm->reco.dead_node, dlm->reco.new_master);

	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
		char *st = "unknown";
		switch (ndata->state) {
			case DLM_RECO_NODE_DATA_INIT:
				st = "init";
				break;
			case DLM_RECO_NODE_DATA_REQUESTING:
				st = "requesting";
				break;
			case DLM_RECO_NODE_DATA_DEAD:
				st = "dead";
				break;
			case DLM_RECO_NODE_DATA_RECEIVING:
				st = "receiving";
				break;
			case DLM_RECO_NODE_DATA_REQUESTED:
				st = "requested";
				break;
			case DLM_RECO_NODE_DATA_DONE:
				st = "done";
				break;
			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
				st = "finalize-sent";
				break;
			default:
				st = "bad";
				break;
		}
		mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
		     dlm->name, ndata->node_num, st);
	}
	list_for_each_entry(res, &dlm->reco.resources, recovering) {
		mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
		     dlm->name, res->lockname.len, res->lockname.name);
	}
}

#define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)

static int dlm_recovery_thread(void *data)
{
	int status;
	struct dlm_ctxt *dlm = data;
	unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);

	mlog(0, "dlm thread running for %s...\n", dlm->name);

	while (!kthread_should_stop()) {
		if (dlm_domain_fully_joined(dlm)) {
			status = dlm_do_recovery(dlm);
			if (status == -EAGAIN) {
				/* do not sleep, recheck immediately. */
				continue;
			}
			if (status < 0)
				mlog_errno(status);
		}

		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
						 kthread_should_stop(),
						 timeout);
	}

	mlog(0, "quitting DLM recovery thread\n");
	return 0;
}

/* returns true when the recovery master has contacted us */
static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
{
	int ready;
	spin_lock(&dlm->spinlock);
	ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
	spin_unlock(&dlm->spinlock);
	return ready;
}

/* returns true if node is no longer in the domain
 * could be dead or just not joined */
int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
{
	int dead;
	spin_lock(&dlm->spinlock);
	dead = !test_bit(node, dlm->domain_map);
	spin_unlock(&dlm->spinlock);
	return dead;
}

/* returns true if node is no longer in the domain
 * could be dead or just not joined */
static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
{
	int recovered;
	spin_lock(&dlm->spinlock);
	recovered = !test_bit(node, dlm->recovery_map);
	spin_unlock(&dlm->spinlock);
	return recovered;
}


void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
{
	if (dlm_is_node_dead(dlm, node))
		return;

	printk(KERN_NOTICE "o2dlm: Waiting on the death of node %u in "
	       "domain %s\n", node, dlm->name);

	if (timeout)
		wait_event_timeout(dlm->dlm_reco_thread_wq,
				   dlm_is_node_dead(dlm, node),
				   msecs_to_jiffies(timeout));
	else
		wait_event(dlm->dlm_reco_thread_wq,
			   dlm_is_node_dead(dlm, node));
}

void dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
{
	if (dlm_is_node_recovered(dlm, node))
		return;

	printk(KERN_NOTICE "o2dlm: Waiting on the recovery of node %u in "
	       "domain %s\n", node, dlm->name);

	if (timeout)
		wait_event_timeout(dlm->dlm_reco_thread_wq,
				   dlm_is_node_recovered(dlm, node),
				   msecs_to_jiffies(timeout));
	else
		wait_event(dlm->dlm_reco_thread_wq,
			   dlm_is_node_recovered(dlm, node));
}

/* callers of the top-level api calls (dlmlock/dlmunlock) should
 * block on the dlm->reco.event when recovery is in progress.
 * the dlm recovery thread will set this state when it begins
 * recovering a dead node (as the new master or not) and clear
 * the state and wake as soon as all affected lock resources have
 * been marked with the RECOVERY flag */
static int dlm_in_recovery(struct dlm_ctxt *dlm)
{
	int in_recovery;
	spin_lock(&dlm->spinlock);
	in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
	spin_unlock(&dlm->spinlock);
	return in_recovery;
}


void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
{
	if (dlm_in_recovery(dlm)) {
		mlog(0, "%s: reco thread %d in recovery: "
		     "state=%d, master=%u, dead=%u\n",
		     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
		     dlm->reco.state, dlm->reco.new_master,
		     dlm->reco.dead_node);
	}
	wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
}

static void dlm_begin_recovery(struct dlm_ctxt *dlm)
{
	spin_lock(&dlm->spinlock);
	BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
	printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n",
	       dlm->name, dlm->reco.dead_node);
	dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
	spin_unlock(&dlm->spinlock);
}

static void dlm_end_recovery(struct dlm_ctxt *dlm)
{
	spin_lock(&dlm->spinlock);
	BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
	dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
	spin_unlock(&dlm->spinlock);
	printk(KERN_NOTICE "o2dlm: End recovery on domain %s\n", dlm->name);
	wake_up(&dlm->reco.event);
}

static void dlm_print_recovery_master(struct dlm_ctxt *dlm)
{
	printk(KERN_NOTICE "o2dlm: Node %u (%s) is the Recovery Master for the "
	       "dead node %u in domain %s\n", dlm->reco.new_master,
	       (dlm->node_num == dlm->reco.new_master ? "me" : "he"),
	       dlm->reco.dead_node, dlm->name);
}

static int dlm_do_recovery(struct dlm_ctxt *dlm)
{
	int status = 0;
	int ret;

	spin_lock(&dlm->spinlock);

	/* check to see if the new master has died */
	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
	    test_bit(dlm->reco.new_master, dlm->recovery_map)) {
		mlog(0, "new master %u died while recovering %u!\n",
		     dlm->reco.new_master, dlm->reco.dead_node);
		/* unset the new_master, leave dead_node */
		dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
	}

	/* select a target to recover */
	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
		int bit;

		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
		if (bit >= O2NM_MAX_NODES || bit < 0)
			dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
		else
			dlm_set_reco_dead_node(dlm, bit);
	} else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
		/* BUG? */
		mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
		     dlm->reco.dead_node);
		dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
	}

	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
		// mlog(0, "nothing to recover!  sleeping now!\n");
		spin_unlock(&dlm->spinlock);
		/* return to main thread loop and sleep. */
		return 0;
	}
	mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
	     dlm->reco.dead_node);
	spin_unlock(&dlm->spinlock);

	/* take write barrier */
	/* (stops the list reshuffling thread, proxy ast handling) */
	dlm_begin_recovery(dlm);

	if (dlm->reco.new_master == dlm->node_num)
		goto master_here;

	if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
		/* choose a new master, returns 0 if this node
		 * is the master, -EEXIST if it's another node.
		 * this does not return until a new master is chosen
		 * or recovery completes entirely. */
		ret = dlm_pick_recovery_master(dlm);
		if (!ret) {
			/* already notified everyone.  go. */
			goto master_here;
		}
		mlog(0, "another node will master this recovery session.\n");
	}

	dlm_print_recovery_master(dlm);

	/* it is safe to start everything back up here
	 * because all of the dead node's lock resources
	 * have been marked as in-recovery */
	dlm_end_recovery(dlm);

	/* sleep out in main dlm_recovery_thread loop. */
	return 0;

master_here:
	dlm_print_recovery_master(dlm);

	status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
	if (status < 0) {
		/* we should never hit this anymore */
		mlog(ML_ERROR, "%s: Error %d remastering locks for node %u, "
		     "retrying.\n", dlm->name, status, dlm->reco.dead_node);
		/* yield a bit to allow any final network messages
		 * to get handled on remaining nodes */
		msleep(100);
	} else {
		/* success!  see if any other nodes need recovery */
		mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
		     dlm->name, dlm->reco.dead_node, dlm->node_num);
		dlm_reset_recovery(dlm);
	}
	dlm_end_recovery(dlm);

	/* continue and look for another dead node */
	return -EAGAIN;
}

static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
{
	int status = 0;
	struct dlm_reco_node_data *ndata;
	int all_nodes_done;
	int destroy = 0;
	int pass = 0;

	do {
		/* we have become recovery master.  there is no escaping
		 * this, so just keep trying until we get it. */
		status = dlm_init_recovery_area(dlm, dead_node);
		if (status < 0) {
			mlog(ML_ERROR, "%s: failed to alloc recovery area, "
			     "retrying\n", dlm->name);
			msleep(1000);
		}
	} while (status != 0);

	/* safe to access the node data list without a lock, since this
	 * process is the only one to change the list */
	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
		BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
		ndata->state = DLM_RECO_NODE_DATA_REQUESTING;

		mlog(0, "%s: Requesting lock info from node %u\n", dlm->name,
		     ndata->node_num);

		if (ndata->node_num == dlm->node_num) {
			ndata->state = DLM_RECO_NODE_DATA_DONE;
			continue;
		}

		do {
			status = dlm_request_all_locks(dlm, ndata->node_num,
						       dead_node);
			if (status < 0) {
				mlog_errno(status);
				if (dlm_is_host_down(status)) {
					/* node died, ignore it for recovery */
					status = 0;
					ndata->state = DLM_RECO_NODE_DATA_DEAD;
					/* wait for the domain map to catch up
					 * with the network state. */
					wait_event_timeout(dlm->dlm_reco_thread_wq,
							   dlm_is_node_dead(dlm,
								ndata->node_num),
							   msecs_to_jiffies(1000));
					mlog(0, "waited 1 sec for %u, "
					     "dead? %s\n", ndata->node_num,
					     dlm_is_node_dead(dlm, ndata->node_num) ?
					     "yes" : "no");
				} else {
					/* -ENOMEM on the other node */
					mlog(0, "%s: node %u returned "
					     "%d during recovery, retrying "
					     "after a short wait\n",
					     dlm->name, ndata->node_num,
					     status);
					msleep(100);
				}
			}
		} while (status != 0);

		spin_lock(&dlm_reco_state_lock);
		switch (ndata->state) {
			case DLM_RECO_NODE_DATA_INIT:
			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
			case DLM_RECO_NODE_DATA_REQUESTED:
				BUG();
				break;
			case DLM_RECO_NODE_DATA_DEAD:
				mlog(0, "node %u died after requesting "
				     "recovery info for node %u\n",
				     ndata->node_num, dead_node);
				/* fine.  don't need this node's info.
				 * continue without it. */
				break;
			case DLM_RECO_NODE_DATA_REQUESTING:
				ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
				mlog(0, "now receiving recovery data from "
				     "node %u for dead node %u\n",
				     ndata->node_num, dead_node);
				break;
			case DLM_RECO_NODE_DATA_RECEIVING:
				mlog(0, "already receiving recovery data from "
				     "node %u for dead node %u\n",
				     ndata->node_num, dead_node);
				break;
			case DLM_RECO_NODE_DATA_DONE:
				mlog(0, "already DONE receiving recovery data "
				     "from node %u for dead node %u\n",
				     ndata->node_num, dead_node);
				break;
		}
		spin_unlock(&dlm_reco_state_lock);
	}

	mlog(0, "%s: Done requesting all lock info\n", dlm->name);

	/* nodes should be sending reco data now
	 * just need to wait */

	while (1) {
		/* check all the nodes now to see if we are
		 * done, or if anyone died */
		all_nodes_done = 1;
		spin_lock(&dlm_reco_state_lock);
		list_for_each_entry(ndata, &dlm->reco.node_data, list) {
			mlog(0, "checking recovery state of node %u\n",
			     ndata->node_num);
			switch (ndata->state) {
				case DLM_RECO_NODE_DATA_INIT:
				case DLM_RECO_NODE_DATA_REQUESTING:
					mlog(ML_ERROR, "bad ndata state for "
					     "node %u: state=%d\n",
					     ndata->node_num, ndata->state);
					BUG();
					break;
				case DLM_RECO_NODE_DATA_DEAD:
					mlog(0, "node %u died after "
					     "requesting recovery info for "
					     "node %u\n", ndata->node_num,
					     dead_node);
					break;
				case DLM_RECO_NODE_DATA_RECEIVING:
				case DLM_RECO_NODE_DATA_REQUESTED:
					mlog(0, "%s: node %u still in state %s\n",
					     dlm->name, ndata->node_num,
					     ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
					     "receiving" : "requested");
					all_nodes_done = 0;
					break;
				case DLM_RECO_NODE_DATA_DONE:
					mlog(0, "%s: node %u state is done\n",
					     dlm->name, ndata->node_num);
					break;
				case DLM_RECO_NODE_DATA_FINALIZE_SENT:
					mlog(0, "%s: node %u state is finalize\n",
					     dlm->name, ndata->node_num);
					break;
			}
		}
		spin_unlock(&dlm_reco_state_lock);

		mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
		     all_nodes_done?"yes":"no");
		if (all_nodes_done) {
			int ret;

			/* all nodes are now in DLM_RECO_NODE_DATA_DONE state
	 		 * just send a finalize message to everyone and
	 		 * clean up */
			mlog(0, "all nodes are done! send finalize\n");
			ret = dlm_send_finalize_reco_message(dlm);
			if (ret < 0)
				mlog_errno(ret);

			spin_lock(&dlm->spinlock);
			dlm_finish_local_lockres_recovery(dlm, dead_node,
							  dlm->node_num);
			spin_unlock(&dlm->spinlock);
			mlog(0, "should be done with recovery!\n");

			mlog(0, "finishing recovery of %s at %lu, "
			     "dead=%u, this=%u, new=%u\n", dlm->name,
			     jiffies, dlm->reco.dead_node,
			     dlm->node_num, dlm->reco.new_master);
			destroy = 1;
			status = 0;
			/* rescan everything marked dirty along the way */
			dlm_kick_thread(dlm, NULL);
			break;
		}
		/* wait to be signalled, with periodic timeout
		 * to check for node death */
		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
					 kthread_should_stop(),
					 msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));

	}

	if (destroy)
		dlm_destroy_recovery_area(dlm, dead_node);

	return status;
}

static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
{
	int num=0;
	struct dlm_reco_node_data *ndata;

	spin_lock(&dlm->spinlock);
	memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
	/* nodes can only be removed (by dying) after dropping
	 * this lock, and death will be trapped later, so this should do */
	spin_unlock(&dlm->spinlock);

	while (1) {
		num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
		if (num >= O2NM_MAX_NODES) {
			break;
		}
		BUG_ON(num == dead_node);

		ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
		if (!ndata) {
			dlm_destroy_recovery_area(dlm, dead_node);
			return -ENOMEM;
		}
		ndata->node_num = num;
		ndata->state = DLM_RECO_NODE_DATA_INIT;
		spin_lock(&dlm_reco_state_lock);
		list_add_tail(&ndata->list, &dlm->reco.node_data);
		spin_unlock(&dlm_reco_state_lock);
		num++;
	}

	return 0;
}

static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
{
	struct dlm_reco_node_data *ndata, *next;
	LIST_HEAD(tmplist);

	spin_lock(&dlm_reco_state_lock);
	list_splice_init(&dlm->reco.node_data, &tmplist);
	spin_unlock(&dlm_reco_state_lock);

	list_for_each_entry_safe(ndata, next, &tmplist, list) {
		list_del_init(&ndata->list);
		kfree(ndata);
	}
}

static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
				 u8 dead_node)
{
	struct dlm_lock_request lr;
	enum dlm_status ret;

	mlog(0, "\n");


	mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
		  "to %u\n", dead_node, request_from);

	memset(&lr, 0, sizeof(lr));
	lr.node_idx = dlm->node_num;
	lr.dead_node = dead_node;

	// send message
	ret = DLM_NOLOCKMGR;
	ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
				 &lr, sizeof(lr), request_from, NULL);

	/* negative status is handled by caller */
	if (ret < 0)
		mlog(ML_ERROR, "%s: Error %d send LOCK_REQUEST to node %u "
		     "to recover dead node %u\n", dlm->name, ret,
		     request_from, dead_node);
	// return from here, then
	// sleep until all received or error
	return ret;

}

int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
				  void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
	char *buf = NULL;
	struct dlm_work_item *item = NULL;

	if (!dlm_grab(dlm))
		return -EINVAL;

	if (lr->dead_node != dlm->reco.dead_node) {
		mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
		     "dead_node is %u\n", dlm->name, lr->node_idx,
		     lr->dead_node, dlm->reco.dead_node);
		dlm_print_reco_node_status(dlm);
		/* this is a hack */
		dlm_put(dlm);
		return -ENOMEM;
	}
	BUG_ON(lr->dead_node != dlm->reco.dead_node);

	item = kzalloc(sizeof(*item), GFP_NOFS);
	if (!item) {
		dlm_put(dlm);
		return -ENOMEM;
	}

	/* this will get freed by dlm_request_all_locks_worker */
	buf = (char *) __get_free_page(GFP_NOFS);
	if (!buf) {
		kfree(item);
		dlm_put(dlm);
		return -ENOMEM;
	}

	/* queue up work for dlm_request_all_locks_worker */
	dlm_grab(dlm);  /* get an extra ref for the work item */
	dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
	item->u.ral.reco_master = lr->node_idx;
	item->u.ral.dead_node = lr->dead_node;
	spin_lock(&dlm->work_lock);
	list_add_tail(&item->list, &dlm->work_list);
	spin_unlock(&dlm->work_lock);
	queue_work(dlm->dlm_worker, &dlm->dispatched_work);

	dlm_put(dlm);
	return 0;
}

static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
{
	struct dlm_migratable_lockres *mres;
	struct dlm_lock_resource *res;
	struct dlm_ctxt *dlm;
	LIST_HEAD(resources);
	int ret;
	u8 dead_node, reco_master;
	int skip_all_done = 0;

	dlm = item->dlm;
	dead_node = item->u.ral.dead_node;
	reco_master = item->u.ral.reco_master;
	mres = (struct dlm_migratable_lockres *)data;

	mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
	     dlm->name, dead_node, reco_master);

	if (dead_node != dlm->reco.dead_node ||
	    reco_master != dlm->reco.new_master) {
		/* worker could have been created before the recovery master
		 * died.  if so, do not continue, but do not error. */
		if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
			mlog(ML_NOTICE, "%s: will not send recovery state, "
			     "recovery master %u died, thread=(dead=%u,mas=%u)"
			     " current=(dead=%u,mas=%u)\n", dlm->name,
			     reco_master, dead_node, reco_master,
			     dlm->reco.dead_node, dlm->reco.new_master);
		} else {
			mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
			     "master=%u), request(dead=%u, master=%u)\n",
			     dlm->name, dlm->reco.dead_node,
			     dlm->reco.new_master, dead_node, reco_master);
		}
		goto leave;
	}

	/* lock resources should have already been moved to the
 	 * dlm->reco.resources list.  now move items from that list
 	 * to a temp list if the dead owner matches.  note that the
	 * whole cluster recovers only one node at a time, so we
	 * can safely move UNKNOWN lock resources for each recovery
	 * session. */
	dlm_move_reco_locks_to_list(dlm, &resources, dead_node);

	/* now we can begin blasting lockreses without the dlm lock */

	/* any errors returned will be due to the new_master dying,
	 * the dlm_reco_thread should detect this */
	list_for_each_entry(res, &resources, recovering) {
		ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
				   	DLM_MRES_RECOVERY);
		if (ret < 0) {
			mlog(ML_ERROR, "%s: node %u went down while sending "
			     "recovery state for dead node %u, ret=%d\n", dlm->name,
			     reco_master, dead_node, ret);
			skip_all_done = 1;
			break;
		}
	}

	/* move the resources back to the list */
	spin_lock(&dlm->spinlock);
	list_splice_init(&resources, &dlm->reco.resources);
	spin_unlock(&dlm->spinlock);

	if (!skip_all_done) {
		ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
		if (ret < 0) {
			mlog(ML_ERROR, "%s: node %u went down while sending "
			     "recovery all-done for dead node %u, ret=%d\n",
			     dlm->name, reco_master, dead_node, ret);
		}
	}
leave:
	free_page((unsigned long)data);
}


static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
{
	int ret, tmpret;
	struct dlm_reco_data_done done_msg;

	memset(&done_msg, 0, sizeof(done_msg));
	done_msg.node_idx = dlm->node_num;
	done_msg.dead_node = dead_node;
	mlog(0, "sending DATA DONE message to %u, "
	     "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
	     done_msg.dead_node);

	ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
				 sizeof(done_msg), send_to, &tmpret);
	if (ret < 0) {
		mlog(ML_ERROR, "%s: Error %d send RECO_DATA_DONE to node %u "
		     "to recover dead node %u\n", dlm->name, ret, send_to,
		     dead_node);
		if (!dlm_is_host_down(ret)) {
			BUG();
		}
	} else
		ret = tmpret;
	return ret;
}


int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
			       void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
	struct dlm_reco_node_data *ndata = NULL;
	int ret = -EINVAL;

	if (!dlm_grab(dlm))
		return -EINVAL;

	mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
	     "node_idx=%u, this node=%u\n", done->dead_node,
	     dlm->reco.dead_node, done->node_idx, dlm->node_num);

	mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
			"Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
			"node_idx=%u, this node=%u\n", done->dead_node,
			dlm->reco.dead_node, done->node_idx, dlm->node_num);

	spin_lock(&dlm_reco_state_lock);
	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
		if (ndata->node_num != done->node_idx)
			continue;

		switch (ndata->state) {
			/* should have moved beyond INIT but not to FINALIZE yet */
			case DLM_RECO_NODE_DATA_INIT:
			case DLM_RECO_NODE_DATA_DEAD:
			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
				mlog(ML_ERROR, "bad ndata state for node %u:"
				     " state=%d\n", ndata->node_num,
				     ndata->state);
				BUG();
				break;
			/* these states are possible at this point, anywhere along
			 * the line of recovery */
			case DLM_RECO_NODE_DATA_DONE:
			case DLM_RECO_NODE_DATA_RECEIVING:
			case DLM_RECO_NODE_DATA_REQUESTED:
			case DLM_RECO_NODE_DATA_REQUESTING:
				mlog(0, "node %u is DONE sending "
					  "recovery data!\n",
					  ndata->node_num);

				ndata->state = DLM_RECO_NODE_DATA_DONE;
				ret = 0;
				break;
		}
	}
	spin_unlock(&dlm_reco_state_lock);

	/* wake the recovery thread, some node is done */
	if (!ret)
		dlm_kick_recovery_thread(dlm);

	if (ret < 0)
		mlog(ML_ERROR, "failed to find recovery node data for node "
		     "%u\n", done->node_idx);
	dlm_put(dlm);

	mlog(0, "leaving reco data done handler, ret=%d\n", ret);
	return ret;
}

static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
					struct list_head *list,
				       	u8 dead_node)
{
	struct dlm_lock_resource *res, *next;
	struct dlm_lock *lock;

	spin_lock(&dlm->spinlock);
	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
		/* always prune any $RECOVERY entries for dead nodes,
		 * otherwise hangs can occur during later recovery */
		if (dlm_is_recovery_lock(res->lockname.name,
					 res->lockname.len)) {
			spin_lock(&res->spinlock);
			list_for_each_entry(lock, &res->granted, list) {
				if (lock->ml.node == dead_node) {
					mlog(0, "AHA! there was "
					     "a $RECOVERY lock for dead "
					     "node %u (%s)!\n",
					     dead_node, dlm->name);
					list_del_init(&lock->list);
					dlm_lock_put(lock);
					break;
				}
			}
			spin_unlock(&res->spinlock);
			continue;
		}

		if (res->owner == dead_node) {
			mlog(0, "found lockres owned by dead node while "
				  "doing recovery for node %u. sending it.\n",
				  dead_node);
			list_move_tail(&res->recovering, list);
		} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
			mlog(0, "found UNKNOWN owner while doing recovery "
				  "for node %u. sending it.\n", dead_node);
			list_move_tail(&res->recovering, list);
		}
	}
	spin_unlock(&dlm->spinlock);
}

static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
{
	int total_locks = 0;
	struct list_head *iter, *queue = &res->granted;
	int i;

	for (i=0; i<3; i++) {
		list_for_each(iter, queue)
			total_locks++;
		queue++;
	}
	return total_locks;
}


static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
				      struct dlm_migratable_lockres *mres,
				      u8 send_to,
				      struct dlm_lock_resource *res,
				      int total_locks)
{
	u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
	int mres_total_locks = be32_to_cpu(mres->total_locks);
	int sz, ret = 0, status = 0;
	u8 orig_flags = mres->flags,
	   orig_master = mres->master;

	BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
	if (!mres->num_locks)
		return 0;

	sz = sizeof(struct dlm_migratable_lockres) +
		(mres->num_locks * sizeof(struct dlm_migratable_lock));

	/* add an all-done flag if we reached the last lock */
	orig_flags = mres->flags;
	BUG_ON(total_locks > mres_total_locks);
	if (total_locks == mres_total_locks)
		mres->flags |= DLM_MRES_ALL_DONE;

	mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
	     dlm->name, res->lockname.len, res->lockname.name,
	     orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
	     send_to);

	/* send it */
	ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
				 sz, send_to, &status);
	if (ret < 0) {
		/* XXX: negative status is not handled.
		 * this will end up killing this node. */
		mlog(ML_ERROR, "%s: res %.*s, Error %d send MIG_LOCKRES to "
		     "node %u (%s)\n", dlm->name, mres->lockname_len,
		     mres->lockname, ret, send_to,
		     (orig_flags & DLM_MRES_MIGRATION ?
		      "migration" : "recovery"));
	} else {
		/* might get an -ENOMEM back here */
		ret = status;
		if (ret < 0) {
			mlog_errno(ret);

			if (ret == -EFAULT) {
				mlog(ML_ERROR, "node %u told me to kill "
				     "myself!\n", send_to);
				BUG();
			}
		}
	}

	/* zero and reinit the message buffer */
	dlm_init_migratable_lockres(mres, res->lockname.name,
				    res->lockname.len, mres_total_locks,
				    mig_cookie, orig_flags, orig_master);
	return ret;
}

static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
					const char *lockname, int namelen,
					int total_locks, u64 cookie,
					u8 flags, u8 master)
{
	/* mres here is one full page */
	clear_page(mres);
	mres->lockname_len = namelen;
	memcpy(mres->lockname, lockname, namelen);
	mres->num_locks = 0;
	mres->total_locks = cpu_to_be32(total_locks);
	mres->mig_cookie = cpu_to_be64(cookie);
	mres->flags = flags;
	mres->master = master;
}

static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
					  struct dlm_migratable_lockres *mres,
					  int queue)
{
	if (!lock->lksb)
	       return;

	/* Ignore lvb in all locks in the blocked list */
	if (queue == DLM_BLOCKED_LIST)
		return;

	/* Only consider lvbs in locks with granted EX or PR lock levels */
	if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
		return;

	if (dlm_lvb_is_empty(mres->lvb)) {
		memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
		return;
	}

	/* Ensure the lvb copied for migration matches in other valid locks */
	if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
		return;

	mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
	     "node=%u\n",
	     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
	     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
	     lock->lockres->lockname.len, lock->lockres->lockname.name,
	     lock->ml.node);
	dlm_print_one_lock_resource(lock->lockres);
	BUG();
}

/* returns 1 if this lock fills the network structure,
 * 0 otherwise */
static int dlm_add_lock_to_array(struct dlm_lock *lock,
				 struct dlm_migratable_lockres *mres, int queue)
{
	struct dlm_migratable_lock *ml;
	int lock_num = mres->num_locks;

	ml = &(mres->ml[lock_num]);
	ml->cookie = lock->ml.cookie;
	ml->type = lock->ml.type;
	ml->convert_type = lock->ml.convert_type;
	ml->highest_blocked = lock->ml.highest_blocked;
	ml->list = queue;
	if (lock->lksb) {
		ml->flags = lock->lksb->flags;
		dlm_prepare_lvb_for_migration(lock, mres, queue);
	}
	ml->node = lock->ml.node;
	mres->num_locks++;
	/* we reached the max, send this network message */
	if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
		return 1;
	return 0;
}

static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
			       struct dlm_migratable_lockres *mres)
{
	struct dlm_lock dummy;
	memset(&dummy, 0, sizeof(dummy));
	dummy.ml.cookie = 0;
	dummy.ml.type = LKM_IVMODE;
	dummy.ml.convert_type = LKM_IVMODE;
	dummy.ml.highest_blocked = LKM_IVMODE;
	dummy.lksb = NULL;
	dummy.ml.node = dlm->node_num;
	dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
}

static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
				    struct dlm_migratable_lock *ml,
				    u8 *nodenum)
{
	if (unlikely(ml->cookie == 0 &&
	    ml->type == LKM_IVMODE &&
	    ml->convert_type == LKM_IVMODE &&
	    ml->highest_blocked == LKM_IVMODE &&
	    ml->list == DLM_BLOCKED_LIST)) {
		*nodenum = ml->node;
		return 1;
	}
	return 0;
}

int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
			 struct dlm_migratable_lockres *mres,
			 u8 send_to, u8 flags)
{
	struct list_head *queue;
	int total_locks, i;
	u64 mig_cookie = 0;
	struct dlm_lock *lock;
	int ret = 0;

	BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));

	mlog(0, "sending to %u\n", send_to);

	total_locks = dlm_num_locks_in_lockres(res);
	if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
		/* rare, but possible */
		mlog(0, "argh.  lockres has %d locks.  this will "
			  "require more than one network packet to "
			  "migrate\n", total_locks);
		mig_cookie = dlm_get_next_mig_cookie();
	}

	dlm_init_migratable_lockres(mres, res->lockname.name,
				    res->lockname.len, total_locks,
				    mig_cookie, flags, res->owner);

	total_locks = 0;
	for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
		queue = dlm_list_idx_to_ptr(res, i);
		list_for_each_entry(lock, queue, list) {
			/* add another lock. */
			total_locks++;
			if (!dlm_add_lock_to_array(lock, mres, i))
				continue;

			/* this filled the lock message,
			 * we must send it immediately. */
			ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
						       res, total_locks);
			if (ret < 0)
				goto error;
		}
	}
	if (total_locks == 0) {
		/* send a dummy lock to indicate a mastery reference only */
		mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
		     dlm->name, res->lockname.len, res->lockname.name,
		     send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
		     "migration");
		dlm_add_dummy_lock(dlm, mres);
	}
	/* flush any remaining locks */
	ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
	if (ret < 0)
		goto error;
	return ret;

error:
	mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
	     dlm->name, ret);
	if (!dlm_is_host_down(ret))
		BUG();
	mlog(0, "%s: node %u went down while sending %s "
	     "lockres %.*s\n", dlm->name, send_to,
	     flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
	     res->lockname.len, res->lockname.name);
	return ret;
}



/*
 * this message will contain no more than one page worth of
 * recovery data, and it will work on only one lockres.
 * there may be many locks in this page, and we may need to wait
 * for additional packets to complete all the locks (rare, but
 * possible).
 */
/*
 * NOTE: the allocation error cases here are scary
 * we really cannot afford to fail an alloc in recovery
 * do we spin?  returning an error only delays the problem really
 */

int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
			    void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_migratable_lockres *mres =
		(struct dlm_migratable_lockres *)msg->buf;
	int ret = 0;
	u8 real_master;
	u8 extra_refs = 0;
	char *buf = NULL;
	struct dlm_work_item *item = NULL;
	struct dlm_lock_resource *res = NULL;

	if (!dlm_grab(dlm))
		return -EINVAL;

	BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));

	real_master = mres->master;
	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
		/* cannot migrate a lockres with no master */
		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
	}

	mlog(0, "%s message received from node %u\n",
		  (mres->flags & DLM_MRES_RECOVERY) ?
		  "recovery" : "migration", mres->master);
	if (mres->flags & DLM_MRES_ALL_DONE)
		mlog(0, "all done flag.  all lockres data received!\n");

	ret = -ENOMEM;
	buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
	item = kzalloc(sizeof(*item), GFP_NOFS);
	if (!buf || !item)
		goto leave;

	/* lookup the lock to see if we have a secondary queue for this
	 * already...  just add the locks in and this will have its owner
	 * and RECOVERY flag changed when it completes. */
	res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
	if (res) {
	 	/* this will get a ref on res */
		/* mark it as recovering/migrating and hash it */
		spin_lock(&res->spinlock);
		if (mres->flags & DLM_MRES_RECOVERY) {
			res->state |= DLM_LOCK_RES_RECOVERING;
		} else {
			if (res->state & DLM_LOCK_RES_MIGRATING) {
				/* this is at least the second
				 * lockres message */
				mlog(0, "lock %.*s is already migrating\n",
					  mres->lockname_len,
					  mres->lockname);
			} else if (res->state & DLM_LOCK_RES_RECOVERING) {
				/* caller should BUG */
				mlog(ML_ERROR, "node is attempting to migrate "
				     "lock %.*s, but marked as recovering!\n",
				     mres->lockname_len, mres->lockname);
				ret = -EFAULT;
				spin_unlock(&res->spinlock);
				goto leave;
			}
			res->state |= DLM_LOCK_RES_MIGRATING;
		}
		spin_unlock(&res->spinlock);
	} else {
		/* need to allocate, just like if it was
		 * mastered here normally  */
		res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
		if (!res)
			goto leave;

		/* to match the ref that we would have gotten if
		 * dlm_lookup_lockres had succeeded */
		dlm_lockres_get(res);

		/* mark it as recovering/migrating and hash it */
		if (mres->flags & DLM_MRES_RECOVERY)
			res->state |= DLM_LOCK_RES_RECOVERING;
		else
			res->state |= DLM_LOCK_RES_MIGRATING;

		spin_lock(&dlm->spinlock);
		__dlm_insert_lockres(dlm, res);
		spin_unlock(&dlm->spinlock);

		/* Add an extra ref for this lock-less lockres lest the
		 * dlm_thread purges it before we get the chance to add
		 * locks to it */
		dlm_lockres_get(res);

		/* There are three refs that need to be put.
		 * 1. Taken above.
		 * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
		 * 3. dlm_lookup_lockres()
		 * The first one is handled at the end of this function. The
		 * other two are handled in the worker thread after locks have
		 * been attached. Yes, we don't wait for purge time to match
		 * kref_init. The lockres will still have atleast one ref
		 * added because it is in the hash __dlm_insert_lockres() */
		extra_refs++;

		/* now that the new lockres is inserted,
		 * make it usable by other processes */
		spin_lock(&res->spinlock);
		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
		spin_unlock(&res->spinlock);
		wake_up(&res->wq);
	}

	/* at this point we have allocated everything we need,
	 * and we have a hashed lockres with an extra ref and
	 * the proper res->state flags. */
	ret = 0;
	spin_lock(&res->spinlock);
	/* drop this either when master requery finds a different master
	 * or when a lock is added by the recovery worker */
	dlm_lockres_grab_inflight_ref(dlm, res);
	if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
		/* migration cannot have an unknown master */
		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
		mlog(0, "recovery has passed me a lockres with an "
			  "unknown owner.. will need to requery: "
			  "%.*s\n", mres->lockname_len, mres->lockname);
	} else {
		/* take a reference now to pin the lockres, drop it
		 * when locks are added in the worker */
		dlm_change_lockres_owner(dlm, res, dlm->node_num);
	}
	spin_unlock(&res->spinlock);

	/* queue up work for dlm_mig_lockres_worker */
	dlm_grab(dlm);  /* get an extra ref for the work item */
	memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
	dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
	item->u.ml.lockres = res; /* already have a ref */
	item->u.ml.real_master = real_master;
	item->u.ml.extra_ref = extra_refs;
	spin_lock(&dlm->work_lock);
	list_add_tail(&item->list, &dlm->work_list);
	spin_unlock(&dlm->work_lock);
	queue_work(dlm->dlm_worker, &dlm->dispatched_work);

leave:
	/* One extra ref taken needs to be put here */
	if (extra_refs)
		dlm_lockres_put(res);

	dlm_put(dlm);
	if (ret < 0) {
		if (buf)
			kfree(buf);
		if (item)
			kfree(item);
		mlog_errno(ret);
	}

	return ret;
}


static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
{
	struct dlm_ctxt *dlm;
	struct dlm_migratable_lockres *mres;
	int ret = 0;
	struct dlm_lock_resource *res;
	u8 real_master;
	u8 extra_ref;

	dlm = item->dlm;
	mres = (struct dlm_migratable_lockres *)data;

	res = item->u.ml.lockres;
	real_master = item->u.ml.real_master;
	extra_ref = item->u.ml.extra_ref;

	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
		/* this case is super-rare. only occurs if
		 * node death happens during migration. */
again:
		ret = dlm_lockres_master_requery(dlm, res, &real_master);
		if (ret < 0) {
			mlog(0, "dlm_lockres_master_requery ret=%d\n",
				  ret);
			goto again;
		}
		if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
			mlog(0, "lockres %.*s not claimed.  "
				   "this node will take it.\n",
				   res->lockname.len, res->lockname.name);
		} else {
			spin_lock(&res->spinlock);
			dlm_lockres_drop_inflight_ref(dlm, res);
			spin_unlock(&res->spinlock);
			mlog(0, "master needs to respond to sender "
				  "that node %u still owns %.*s\n",
				  real_master, res->lockname.len,
				  res->lockname.name);
			/* cannot touch this lockres */
			goto leave;
		}
	}

	ret = dlm_process_recovery_data(dlm, res, mres);
	if (ret < 0)
		mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
	else
		mlog(0, "dlm_process_recovery_data succeeded\n");

	if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
	                   (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
		ret = dlm_finish_migration(dlm, res, mres->master);
		if (ret < 0)
			mlog_errno(ret);
	}

leave:
	/* See comment in dlm_mig_lockres_handler() */
	if (res) {
		if (extra_ref)
			dlm_lockres_put(res);
		dlm_lockres_put(res);
	}
	kfree(data);
}



static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
				      struct dlm_lock_resource *res,
				      u8 *real_master)
{
	struct dlm_node_iter iter;
	int nodenum;
	int ret = 0;

	*real_master = DLM_LOCK_RES_OWNER_UNKNOWN;

	/* we only reach here if one of the two nodes in a
	 * migration died while the migration was in progress.
	 * at this point we need to requery the master.  we
	 * know that the new_master got as far as creating
	 * an mle on at least one node, but we do not know
	 * if any nodes had actually cleared the mle and set
	 * the master to the new_master.  the old master
	 * is supposed to set the owner to UNKNOWN in the
	 * event of a new_master death, so the only possible
	 * responses that we can get from nodes here are
	 * that the master is new_master, or that the master
	 * is UNKNOWN.
	 * if all nodes come back with UNKNOWN then we know
	 * the lock needs remastering here.
	 * if any node comes back with a valid master, check
	 * to see if that master is the one that we are
	 * recovering.  if so, then the new_master died and
	 * we need to remaster this lock.  if not, then the
	 * new_master survived and that node will respond to
	 * other nodes about the owner.
	 * if there is an owner, this node needs to dump this
	 * lockres and alert the sender that this lockres
	 * was rejected. */
	spin_lock(&dlm->spinlock);
	dlm_node_iter_init(dlm->domain_map, &iter);
	spin_unlock(&dlm->spinlock);

	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
		/* do not send to self */
		if (nodenum == dlm->node_num)
			continue;
		ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
		if (ret < 0) {
			mlog_errno(ret);
			if (!dlm_is_host_down(ret))
				BUG();
			/* host is down, so answer for that node would be
			 * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
		}
		if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
			mlog(0, "lock master is %u\n", *real_master);
			break;
		}
	}
	return ret;
}


int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
			  u8 nodenum, u8 *real_master)
{
	int ret = -EINVAL;
	struct dlm_master_requery req;
	int status = DLM_LOCK_RES_OWNER_UNKNOWN;

	memset(&req, 0, sizeof(req));
	req.node_idx = dlm->node_num;
	req.namelen = res->lockname.len;
	memcpy(req.name, res->lockname.name, res->lockname.len);

	ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
				 &req, sizeof(req), nodenum, &status);
	/* XXX: negative status not handled properly here. */
	if (ret < 0)
		mlog(ML_ERROR, "Error %d when sending message %u (key "
		     "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
		     dlm->key, nodenum);
	else {
		BUG_ON(status < 0);
		BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
		*real_master = (u8) (status & 0xff);
		mlog(0, "node %u responded to master requery with %u\n",
			  nodenum, *real_master);
		ret = 0;
	}
	return ret;
}


/* this function cannot error, so unless the sending
 * or receiving of the message failed, the owner can
 * be trusted */
int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
			       void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
	struct dlm_lock_resource *res = NULL;
	unsigned int hash;
	int master = DLM_LOCK_RES_OWNER_UNKNOWN;
	u32 flags = DLM_ASSERT_MASTER_REQUERY;

	if (!dlm_grab(dlm)) {
		/* since the domain has gone away on this
		 * node, the proper response is UNKNOWN */
		return master;
	}

	hash = dlm_lockid_hash(req->name, req->namelen);

	spin_lock(&dlm->spinlock);
	res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
	if (res) {
		spin_lock(&res->spinlock);
		master = res->owner;
		if (master == dlm->node_num) {
			int ret = dlm_dispatch_assert_master(dlm, res,
							     0, 0, flags);
			if (ret < 0) {
				mlog_errno(-ENOMEM);
				/* retry!? */
				BUG();
			}
		} else /* put.. incase we are not the master */
			dlm_lockres_put(res);
		spin_unlock(&res->spinlock);
	}
	spin_unlock(&dlm->spinlock);

	dlm_put(dlm);
	return master;
}

static inline struct list_head *
dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
{
	struct list_head *ret;
	BUG_ON(list_num < 0);
	BUG_ON(list_num > 2);
	ret = &(res->granted);
	ret += list_num;
	return ret;
}
/* TODO: do ast flush business
 * TODO: do MIGRATING and RECOVERING spinning
 */

/*
* NOTE about in-flight requests during migration:
*
* Before attempting the migrate, the master has marked the lockres as
* MIGRATING and then flushed all of its pending ASTS.  So any in-flight
* requests either got queued before the MIGRATING flag got set, in which
* case the lock data will reflect the change and a return message is on
* the way, or the request failed to get in before MIGRATING got set.  In
* this case, the caller will be told to spin and wait for the MIGRATING
* flag to be dropped, then recheck the master.
* This holds true for the convert, cancel and unlock cases, and since lvb
* updates are tied to these same messages, it applies to lvb updates as
* well.  For the lock case, there is no way a lock can be on the master
* queue and not be on the secondary queue since the lock is always added
* locally first.  This means that the new target node will never be sent
* a lock that he doesn't already have on the list.
* In total, this means that the local lock is correct and should not be
* updated to match the one sent by the master.  Any messages sent back
* from the master before the MIGRATING flag will bring the lock properly
* up-to-date, and the change will be ordered properly for the waiter.
* We will *not* attempt to modify the lock underneath the waiter.
*/

static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
				     struct dlm_lock_resource *res,
				     struct dlm_migratable_lockres *mres)
{
	struct dlm_migratable_lock *ml;
	struct list_head *queue;
	struct list_head *tmpq = NULL;
	struct dlm_lock *newlock = NULL;
	struct dlm_lockstatus *lksb = NULL;
	int ret = 0;
	int i, j, bad;
	struct dlm_lock *lock = NULL;
	u8 from = O2NM_MAX_NODES;
	unsigned int added = 0;
	__be64 c;

	mlog(0, "running %d locks for this lockres\n", mres->num_locks);
	for (i=0; i<mres->num_locks; i++) {
		ml = &(mres->ml[i]);

		if (dlm_is_dummy_lock(dlm, ml, &from)) {
			/* placeholder, just need to set the refmap bit */
			BUG_ON(mres->num_locks != 1);
			mlog(0, "%s:%.*s: dummy lock for %u\n",
			     dlm->name, mres->lockname_len, mres->lockname,
			     from);
			spin_lock(&res->spinlock);
			dlm_lockres_set_refmap_bit(dlm, res, from);
			spin_unlock(&res->spinlock);
			added++;
			break;
		}
		BUG_ON(ml->highest_blocked != LKM_IVMODE);
		newlock = NULL;
		lksb = NULL;

		queue = dlm_list_num_to_pointer(res, ml->list);
		tmpq = NULL;

		/* if the lock is for the local node it needs to
		 * be moved to the proper location within the queue.
		 * do not allocate a new lock structure. */
		if (ml->node == dlm->node_num) {
			/* MIGRATION ONLY! */
			BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));

			spin_lock(&res->spinlock);
			for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
				tmpq = dlm_list_idx_to_ptr(res, j);
				list_for_each_entry(lock, tmpq, list) {
					if (lock->ml.cookie != ml->cookie)
						lock = NULL;
					else
						break;
				}
				if (lock)
					break;
			}

			/* lock is always created locally first, and
			 * destroyed locally last.  it must be on the list */
			if (!lock) {
				c = ml->cookie;
				mlog(ML_ERROR, "Could not find local lock "
					       "with cookie %u:%llu, node %u, "
					       "list %u, flags 0x%x, type %d, "
					       "conv %d, highest blocked %d\n",
				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
				     ml->node, ml->list, ml->flags, ml->type,
				     ml->convert_type, ml->highest_blocked);
				__dlm_print_one_lock_resource(res);
				BUG();
			}

			if (lock->ml.node != ml->node) {
				c = lock->ml.cookie;
				mlog(ML_ERROR, "Mismatched node# in lock "
				     "cookie %u:%llu, name %.*s, node %u\n",
				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
				     res->lockname.len, res->lockname.name,
				     lock->ml.node);
				c = ml->cookie;
				mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
				     "node %u, list %u, flags 0x%x, type %d, "
				     "conv %d, highest blocked %d\n",
				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
				     ml->node, ml->list, ml->flags, ml->type,
				     ml->convert_type, ml->highest_blocked);
				__dlm_print_one_lock_resource(res);
				BUG();
			}

			if (tmpq != queue) {
				c = ml->cookie;
				mlog(0, "Lock cookie %u:%llu was on list %u "
				     "instead of list %u for %.*s\n",
				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
				     j, ml->list, res->lockname.len,
				     res->lockname.name);
				__dlm_print_one_lock_resource(res);
				spin_unlock(&res->spinlock);
				continue;
			}

			/* see NOTE above about why we do not update
			 * to match the master here */

			/* move the lock to its proper place */
			/* do not alter lock refcount.  switching lists. */
			list_move_tail(&lock->list, queue);
			spin_unlock(&res->spinlock);
			added++;

			mlog(0, "just reordered a local lock!\n");
			continue;
		}

		/* lock is for another node. */
		newlock = dlm_new_lock(ml->type, ml->node,
				       be64_to_cpu(ml->cookie), NULL);
		if (!newlock) {
			ret = -ENOMEM;
			goto leave;
		}
		lksb = newlock->lksb;
		dlm_lock_attach_lockres(newlock, res);

		if (ml->convert_type != LKM_IVMODE) {
			BUG_ON(queue != &res->converting);
			newlock->ml.convert_type = ml->convert_type;
		}
		lksb->flags |= (ml->flags &
				(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));

		if (ml->type == LKM_NLMODE)
			goto skip_lvb;

		if (!dlm_lvb_is_empty(mres->lvb)) {
			if (lksb->flags & DLM_LKSB_PUT_LVB) {
				/* other node was trying to update
				 * lvb when node died.  recreate the
				 * lksb with the updated lvb. */
				memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
				/* the lock resource lvb update must happen
				 * NOW, before the spinlock is dropped.
				 * we no longer wait for the AST to update
				 * the lvb. */
				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
			} else {
				/* otherwise, the node is sending its
				 * most recent valid lvb info */
				BUG_ON(ml->type != LKM_EXMODE &&
				       ml->type != LKM_PRMODE);
				if (!dlm_lvb_is_empty(res->lvb) &&
 				    (ml->type == LKM_EXMODE ||
 				     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
 					int i;
 					mlog(ML_ERROR, "%s:%.*s: received bad "
 					     "lvb! type=%d\n", dlm->name,
 					     res->lockname.len,
 					     res->lockname.name, ml->type);
 					printk("lockres lvb=[");
 					for (i=0; i<DLM_LVB_LEN; i++)
 						printk("%02x", res->lvb[i]);
 					printk("]\nmigrated lvb=[");
 					for (i=0; i<DLM_LVB_LEN; i++)
 						printk("%02x", mres->lvb[i]);
 					printk("]\n");
 					dlm_print_one_lock_resource(res);
 					BUG();
				}
				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
			}
		}
skip_lvb:

		/* NOTE:
		 * wrt lock queue ordering and recovery:
		 *    1. order of locks on granted queue is
		 *       meaningless.
		 *    2. order of locks on converting queue is
		 *       LOST with the node death.  sorry charlie.
		 *    3. order of locks on the blocked queue is
		 *       also LOST.
		 * order of locks does not affect integrity, it
		 * just means that a lock request may get pushed
		 * back in line as a result of the node death.
		 * also note that for a given node the lock order
		 * for its secondary queue locks is preserved
		 * relative to each other, but clearly *not*
		 * preserved relative to locks from other nodes.
		 */
		bad = 0;
		spin_lock(&res->spinlock);
		list_for_each_entry(lock, queue, list) {
			if (lock->ml.cookie == ml->cookie) {
				c = lock->ml.cookie;
				mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
				     "exists on this lockres!\n", dlm->name,
				     res->lockname.len, res->lockname.name,
				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(c)));

				mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
				     "node=%u, cookie=%u:%llu, queue=%d\n",
	      			     ml->type, ml->convert_type, ml->node,
				     dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
				     dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
				     ml->list);

				__dlm_print_one_lock_resource(res);
				bad = 1;
				break;
			}
		}
		if (!bad) {
			dlm_lock_get(newlock);
			list_add_tail(&newlock->list, queue);
			mlog(0, "%s:%.*s: added lock for node %u, "
			     "setting refmap bit\n", dlm->name,
			     res->lockname.len, res->lockname.name, ml->node);
			dlm_lockres_set_refmap_bit(dlm, res, ml->node);
			added++;
		}
		spin_unlock(&res->spinlock);
	}
	mlog(0, "done running all the locks\n");

leave:
	/* balance the ref taken when the work was queued */
	spin_lock(&res->spinlock);
	dlm_lockres_drop_inflight_ref(dlm, res);
	spin_unlock(&res->spinlock);

	if (ret < 0) {
		mlog_errno(ret);
		if (newlock)
			dlm_lock_put(newlock);
	}

	return ret;
}

void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
				       struct dlm_lock_resource *res)
{
	int i;
	struct list_head *queue;
	struct dlm_lock *lock, *next;

	assert_spin_locked(&dlm->spinlock);
	assert_spin_locked(&res->spinlock);
	res->state |= DLM_LOCK_RES_RECOVERING;
	if (!list_empty(&res->recovering)) {
		mlog(0,
		     "Recovering res %s:%.*s, is already on recovery list!\n",
		     dlm->name, res->lockname.len, res->lockname.name);
		list_del_init(&res->recovering);
		dlm_lockres_put(res);
	}
	/* We need to hold a reference while on the recovery list */
	dlm_lockres_get(res);
	list_add_tail(&res->recovering, &dlm->reco.resources);

	/* find any pending locks and put them back on proper list */
	for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
		queue = dlm_list_idx_to_ptr(res, i);
		list_for_each_entry_safe(lock, next, queue, list) {
			dlm_lock_get(lock);
			if (lock->convert_pending) {
				/* move converting lock back to granted */
				BUG_ON(i != DLM_CONVERTING_LIST);
				mlog(0, "node died with convert pending "
				     "on %.*s. move back to granted list.\n",
				     res->lockname.len, res->lockname.name);
				dlm_revert_pending_convert(res, lock);
				lock->convert_pending = 0;
			} else if (lock->lock_pending) {
				/* remove pending lock requests completely */
				BUG_ON(i != DLM_BLOCKED_LIST);
				mlog(0, "node died with lock pending "
				     "on %.*s. remove from blocked list and skip.\n",
				     res->lockname.len, res->lockname.name);
				/* lock will be floating until ref in
				 * dlmlock_remote is freed after the network
				 * call returns.  ok for it to not be on any
				 * list since no ast can be called
				 * (the master is dead). */
				dlm_revert_pending_lock(res, lock);
				lock->lock_pending = 0;
			} else if (lock->unlock_pending) {
				/* if an unlock was in progress, treat as
				 * if this had completed successfully
				 * before sending this lock state to the
				 * new master.  note that the dlm_unlock
				 * call is still responsible for calling
				 * the unlockast.  that will happen after
				 * the network call times out.  for now,
				 * just move lists to prepare the new
				 * recovery master.  */
				BUG_ON(i != DLM_GRANTED_LIST);
				mlog(0, "node died with unlock pending "
				     "on %.*s. remove from blocked list and skip.\n",
				     res->lockname.len, res->lockname.name);
				dlm_commit_pending_unlock(res, lock);
				lock->unlock_pending = 0;
			} else if (lock->cancel_pending) {
				/* if a cancel was in progress, treat as
				 * if this had completed successfully
				 * before sending this lock state to the
				 * new master */
				BUG_ON(i != DLM_CONVERTING_LIST);
				mlog(0, "node died with cancel pending "
				     "on %.*s. move back to granted list.\n",
				     res->lockname.len, res->lockname.name);
				dlm_commit_pending_cancel(res, lock);
				lock->cancel_pending = 0;
			}
			dlm_lock_put(lock);
		}
	}
}



/* removes all recovered locks from the recovery list.
 * sets the res->owner to the new master.
 * unsets the RECOVERY flag and wakes waiters. */
static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
					      u8 dead_node, u8 new_master)
{
	int i;
	struct hlist_node *hash_iter;
	struct hlist_head *bucket;
	struct dlm_lock_resource *res, *next;

	assert_spin_locked(&dlm->spinlock);

	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
		if (res->owner == dead_node) {
			mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
			     dlm->name, res->lockname.len, res->lockname.name,
			     res->owner, new_master);
			list_del_init(&res->recovering);
			spin_lock(&res->spinlock);
			/* new_master has our reference from
			 * the lock state sent during recovery */
			dlm_change_lockres_owner(dlm, res, new_master);
			res->state &= ~DLM_LOCK_RES_RECOVERING;
			if (__dlm_lockres_has_locks(res))
				__dlm_dirty_lockres(dlm, res);
			spin_unlock(&res->spinlock);
			wake_up(&res->wq);
			dlm_lockres_put(res);
		}
	}

	/* this will become unnecessary eventually, but
	 * for now we need to run the whole hash, clear
	 * the RECOVERING state and set the owner
	 * if necessary */
	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
		bucket = dlm_lockres_hash(dlm, i);
		hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
			if (!(res->state & DLM_LOCK_RES_RECOVERING))
				continue;

			if (res->owner != dead_node &&
			    res->owner != dlm->node_num)
				continue;

			if (!list_empty(&res->recovering)) {
				list_del_init(&res->recovering);
				dlm_lockres_put(res);
			}

			/* new_master has our reference from
			 * the lock state sent during recovery */
			mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
			     dlm->name, res->lockname.len, res->lockname.name,
			     res->owner, new_master);
			spin_lock(&res->spinlock);
			dlm_change_lockres_owner(dlm, res, new_master);
			res->state &= ~DLM_LOCK_RES_RECOVERING;
			if (__dlm_lockres_has_locks(res))
				__dlm_dirty_lockres(dlm, res);
			spin_unlock(&res->spinlock);
			wake_up(&res->wq);
		}
	}
}

static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
{
	if (local) {
		if (lock->ml.type != LKM_EXMODE &&
		    lock->ml.type != LKM_PRMODE)
			return 1;
	} else if (lock->ml.type == LKM_EXMODE)
		return 1;
	return 0;
}

static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
			       struct dlm_lock_resource *res, u8 dead_node)
{
	struct list_head *queue;
	struct dlm_lock *lock;
	int blank_lvb = 0, local = 0;
	int i;
	u8 search_node;

	assert_spin_locked(&dlm->spinlock);
	assert_spin_locked(&res->spinlock);

	if (res->owner == dlm->node_num)
		/* if this node owned the lockres, and if the dead node
		 * had an EX when he died, blank out the lvb */
		search_node = dead_node;
	else {
		/* if this is a secondary lockres, and we had no EX or PR
		 * locks granted, we can no longer trust the lvb */
		search_node = dlm->node_num;
		local = 1;  /* check local state for valid lvb */
	}

	for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
		queue = dlm_list_idx_to_ptr(res, i);
		list_for_each_entry(lock, queue, list) {
			if (lock->ml.node == search_node) {
				if (dlm_lvb_needs_invalidation(lock, local)) {
					/* zero the lksb lvb and lockres lvb */
					blank_lvb = 1;
					memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
				}
			}
		}
	}

	if (blank_lvb) {
		mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
		     res->lockname.len, res->lockname.name, dead_node);
		memset(res->lvb, 0, DLM_LVB_LEN);
	}
}

static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
				struct dlm_lock_resource *res, u8 dead_node)
{
	struct dlm_lock *lock, *next;
	unsigned int freed = 0;

	/* this node is the lockres master:
	 * 1) remove any stale locks for the dead node
	 * 2) if the dead node had an EX when he died, blank out the lvb
	 */
	assert_spin_locked(&dlm->spinlock);
	assert_spin_locked(&res->spinlock);

	/* We do two dlm_lock_put(). One for removing from list and the other is
	 * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */

	/* TODO: check pending_asts, pending_basts here */
	list_for_each_entry_safe(lock, next, &res->granted, list) {
		if (lock->ml.node == dead_node) {
			list_del_init(&lock->list);
			dlm_lock_put(lock);
			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
			dlm_lock_put(lock);
			freed++;
		}
	}
	list_for_each_entry_safe(lock, next, &res->converting, list) {
		if (lock->ml.node == dead_node) {
			list_del_init(&lock->list);
			dlm_lock_put(lock);
			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
			dlm_lock_put(lock);
			freed++;
		}
	}
	list_for_each_entry_safe(lock, next, &res->blocked, list) {
		if (lock->ml.node == dead_node) {
			list_del_init(&lock->list);
			dlm_lock_put(lock);
			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
			dlm_lock_put(lock);
			freed++;
		}
	}

	if (freed) {
		mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
		     "dropping ref from lockres\n", dlm->name,
		     res->lockname.len, res->lockname.name, freed, dead_node);
		if(!test_bit(dead_node, res->refmap)) {
			mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
			     "but ref was not set\n", dlm->name,
			     res->lockname.len, res->lockname.name, freed, dead_node);
			__dlm_print_one_lock_resource(res);
		}
		dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
	} else if (test_bit(dead_node, res->refmap)) {
		mlog(0, "%s:%.*s: dead node %u had a ref, but had "
		     "no locks and had not purged before dying\n", dlm->name,
		     res->lockname.len, res->lockname.name, dead_node);
		dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
	}

	/* do not kick thread yet */
	__dlm_dirty_lockres(dlm, res);
}

/* if this node is the recovery master, and there are no
 * locks for a given lockres owned by this node that are in
 * either PR or EX mode, zero out the lvb before requesting.
 *
 */


static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
{
	struct hlist_node *iter;
	struct dlm_lock_resource *res;
	int i;
	struct hlist_head *bucket;
	struct dlm_lock *lock;


	/* purge any stale mles */
	dlm_clean_master_list(dlm, dead_node);

	/*
	 * now clean up all lock resources.  there are two rules:
	 *
	 * 1) if the dead node was the master, move the lockres
	 *    to the recovering list.  set the RECOVERING flag.
	 *    this lockres needs to be cleaned up before it can
	 *    be used further.
	 *
	 * 2) if this node was the master, remove all locks from
	 *    each of the lockres queues that were owned by the
	 *    dead node.  once recovery finishes, the dlm thread
	 *    can be kicked again to see if any ASTs or BASTs
	 *    need to be fired as a result.
	 */
	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
		bucket = dlm_lockres_hash(dlm, i);
		hlist_for_each_entry(res, iter, bucket, hash_node) {
 			/* always prune any $RECOVERY entries for dead nodes,
 			 * otherwise hangs can occur during later recovery */
			if (dlm_is_recovery_lock(res->lockname.name,
						 res->lockname.len)) {
				spin_lock(&res->spinlock);
				list_for_each_entry(lock, &res->granted, list) {
					if (lock->ml.node == dead_node) {
						mlog(0, "AHA! there was "
						     "a $RECOVERY lock for dead "
						     "node %u (%s)!\n",
						     dead_node, dlm->name);
						list_del_init(&lock->list);
						dlm_lock_put(lock);
						break;
					}
				}
				spin_unlock(&res->spinlock);
				continue;
			}
			spin_lock(&res->spinlock);
			/* zero the lvb if necessary */
			dlm_revalidate_lvb(dlm, res, dead_node);
			if (res->owner == dead_node) {
				if (res->state & DLM_LOCK_RES_DROPPING_REF) {
					mlog(ML_NOTICE, "%s: res %.*s, Skip "
					     "recovery as it is being freed\n",
					     dlm->name, res->lockname.len,
					     res->lockname.name);
				} else
					dlm_move_lockres_to_recovery_list(dlm,
									  res);

			} else if (res->owner == dlm->node_num) {
				dlm_free_dead_locks(dlm, res, dead_node);
				__dlm_lockres_calc_usage(dlm, res);
			}
			spin_unlock(&res->spinlock);
		}
	}

}

static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
{
	assert_spin_locked(&dlm->spinlock);

	if (dlm->reco.new_master == idx) {
		mlog(0, "%s: recovery master %d just died\n",
		     dlm->name, idx);
		if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
			/* finalize1 was reached, so it is safe to clear
			 * the new_master and dead_node.  that recovery
			 * is complete. */
			mlog(0, "%s: dead master %d had reached "
			     "finalize1 state, clearing\n", dlm->name, idx);
			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
			__dlm_reset_recovery(dlm);
		}
	}

	/* Clean up join state on node death. */
	if (dlm->joining_node == idx) {
		mlog(0, "Clearing join state for node %u\n", idx);
		__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
	}

	/* check to see if the node is already considered dead */
	if (!test_bit(idx, dlm->live_nodes_map)) {
		mlog(0, "for domain %s, node %d is already dead. "
		     "another node likely did recovery already.\n",
		     dlm->name, idx);
		return;
	}

	/* check to see if we do not care about this node */
	if (!test_bit(idx, dlm->domain_map)) {
		/* This also catches the case that we get a node down
		 * but haven't joined the domain yet. */
		mlog(0, "node %u already removed from domain!\n", idx);
		return;
	}

	clear_bit(idx, dlm->live_nodes_map);

	/* make sure local cleanup occurs before the heartbeat events */
	if (!test_bit(idx, dlm->recovery_map))
		dlm_do_local_recovery_cleanup(dlm, idx);

	/* notify anything attached to the heartbeat events */
	dlm_hb_event_notify_attached(dlm, idx, 0);

	mlog(0, "node %u being removed from domain map!\n", idx);
	clear_bit(idx, dlm->domain_map);
	clear_bit(idx, dlm->exit_domain_map);
	/* wake up migration waiters if a node goes down.
	 * perhaps later we can genericize this for other waiters. */
	wake_up(&dlm->migration_wq);

	if (test_bit(idx, dlm->recovery_map))
		mlog(0, "domain %s, node %u already added "
		     "to recovery map!\n", dlm->name, idx);
	else
		set_bit(idx, dlm->recovery_map);
}

void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
{
	struct dlm_ctxt *dlm = data;

	if (!dlm_grab(dlm))
		return;

	/*
	 * This will notify any dlm users that a node in our domain
	 * went away without notifying us first.
	 */
	if (test_bit(idx, dlm->domain_map))
		dlm_fire_domain_eviction_callbacks(dlm, idx);

	spin_lock(&dlm->spinlock);
	__dlm_hb_node_down(dlm, idx);
	spin_unlock(&dlm->spinlock);

	dlm_put(dlm);
}

void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
{
	struct dlm_ctxt *dlm = data;

	if (!dlm_grab(dlm))
		return;

	spin_lock(&dlm->spinlock);
	set_bit(idx, dlm->live_nodes_map);
	/* do NOT notify mle attached to the heartbeat events.
	 * new nodes are not interesting in mastery until joined. */
	spin_unlock(&dlm->spinlock);

	dlm_put(dlm);
}

static void dlm_reco_ast(void *astdata)
{
	struct dlm_ctxt *dlm = astdata;
	mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
	     dlm->node_num, dlm->name);
}
static void dlm_reco_bast(void *astdata, int blocked_type)
{
	struct dlm_ctxt *dlm = astdata;
	mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
	     dlm->node_num, dlm->name);
}
static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
{
	mlog(0, "unlockast for recovery lock fired!\n");
}

/*
 * dlm_pick_recovery_master will continually attempt to use
 * dlmlock() on the special "$RECOVERY" lockres with the
 * LKM_NOQUEUE flag to get an EX.  every thread that enters
 * this function on each node racing to become the recovery
 * master will not stop attempting this until either:
 * a) this node gets the EX (and becomes the recovery master),
 * or b) dlm->reco.new_master gets set to some nodenum
 * != O2NM_INVALID_NODE_NUM (another node will do the reco).
 * so each time a recovery master is needed, the entire cluster
 * will sync at this point.  if the new master dies, that will
 * be detected in dlm_do_recovery */
static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
{
	enum dlm_status ret;
	struct dlm_lockstatus lksb;
	int status = -EINVAL;

	mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
	     dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
again:
	memset(&lksb, 0, sizeof(lksb));

	ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
		      DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
		      dlm_reco_ast, dlm, dlm_reco_bast);

	mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
	     dlm->name, ret, lksb.status);

	if (ret == DLM_NORMAL) {
		mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
		     dlm->name, dlm->node_num);

		/* got the EX lock.  check to see if another node
		 * just became the reco master */
		if (dlm_reco_master_ready(dlm)) {
			mlog(0, "%s: got reco EX lock, but %u will "
			     "do the recovery\n", dlm->name,
			     dlm->reco.new_master);
			status = -EEXIST;
		} else {
			status = 0;

			/* see if recovery was already finished elsewhere */
			spin_lock(&dlm->spinlock);
			if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
				status = -EINVAL;
				mlog(0, "%s: got reco EX lock, but "
				     "node got recovered already\n", dlm->name);
				if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
					mlog(ML_ERROR, "%s: new master is %u "
					     "but no dead node!\n",
					     dlm->name, dlm->reco.new_master);
					BUG();
				}
			}
			spin_unlock(&dlm->spinlock);
		}

		/* if this node has actually become the recovery master,
		 * set the master and send the messages to begin recovery */
		if (!status) {
			mlog(0, "%s: dead=%u, this=%u, sending "
			     "begin_reco now\n", dlm->name,
			     dlm->reco.dead_node, dlm->node_num);
			status = dlm_send_begin_reco_message(dlm,
				      dlm->reco.dead_node);
			/* this always succeeds */
			BUG_ON(status);

			/* set the new_master to this node */
			spin_lock(&dlm->spinlock);
			dlm_set_reco_master(dlm, dlm->node_num);
			spin_unlock(&dlm->spinlock);
		}

		/* recovery lock is a special case.  ast will not get fired,
		 * so just go ahead and unlock it. */
		ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
		if (ret == DLM_DENIED) {
			mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
			ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
		}
		if (ret != DLM_NORMAL) {
			/* this would really suck. this could only happen
			 * if there was a network error during the unlock
			 * because of node death.  this means the unlock
			 * is actually "done" and the lock structure is
			 * even freed.  we can continue, but only
			 * because this specific lock name is special. */
			mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
		}
	} else if (ret == DLM_NOTQUEUED) {
		mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
		     dlm->name, dlm->node_num);
		/* another node is master. wait on
		 * reco.new_master != O2NM_INVALID_NODE_NUM
		 * for at most one second */
		wait_event_timeout(dlm->dlm_reco_thread_wq,
					 dlm_reco_master_ready(dlm),
					 msecs_to_jiffies(1000));
		if (!dlm_reco_master_ready(dlm)) {
			mlog(0, "%s: reco master taking awhile\n",
			     dlm->name);
			goto again;
		}
		/* another node has informed this one that it is reco master */
		mlog(0, "%s: reco master %u is ready to recover %u\n",
		     dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
		status = -EEXIST;
	} else if (ret == DLM_RECOVERING) {
		mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
		     dlm->name, dlm->node_num);
		goto again;
	} else {
		struct dlm_lock_resource *res;

		/* dlmlock returned something other than NOTQUEUED or NORMAL */
		mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
		     "lksb.status=%s\n", dlm->name, dlm_errname(ret),
		     dlm_errname(lksb.status));
		res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
					 DLM_RECOVERY_LOCK_NAME_LEN);
		if (res) {
			dlm_print_one_lock_resource(res);
			dlm_lockres_put(res);
		} else {
			mlog(ML_ERROR, "recovery lock not found\n");
		}
		BUG();
	}

	return status;
}

static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
{
	struct dlm_begin_reco br;
	int ret = 0;
	struct dlm_node_iter iter;
	int nodenum;
	int status;

	mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);

	spin_lock(&dlm->spinlock);
	dlm_node_iter_init(dlm->domain_map, &iter);
	spin_unlock(&dlm->spinlock);

	clear_bit(dead_node, iter.node_map);

	memset(&br, 0, sizeof(br));
	br.node_idx = dlm->node_num;
	br.dead_node = dead_node;

	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
		ret = 0;
		if (nodenum == dead_node) {
			mlog(0, "not sending begin reco to dead node "
				  "%u\n", dead_node);
			continue;
		}
		if (nodenum == dlm->node_num) {
			mlog(0, "not sending begin reco to self\n");
			continue;
		}
retry:
		ret = -EINVAL;
		mlog(0, "attempting to send begin reco msg to %d\n",
			  nodenum);
		ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
					 &br, sizeof(br), nodenum, &status);
		/* negative status is handled ok by caller here */
		if (ret >= 0)
			ret = status;
		if (dlm_is_host_down(ret)) {
			/* node is down.  not involved in recovery
			 * so just keep going */
			mlog(ML_NOTICE, "%s: node %u was down when sending "
			     "begin reco msg (%d)\n", dlm->name, nodenum, ret);
			ret = 0;
		}

		/*
		 * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
		 * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
		 * We are handling both for compatibility reasons.
		 */
		if (ret == -EAGAIN || ret == EAGAIN) {
			mlog(0, "%s: trying to start recovery of node "
			     "%u, but node %u is waiting for last recovery "
			     "to complete, backoff for a bit\n", dlm->name,
			     dead_node, nodenum);
			msleep(100);
			goto retry;
		}
		if (ret < 0) {
			struct dlm_lock_resource *res;

			/* this is now a serious problem, possibly ENOMEM
			 * in the network stack.  must retry */
			mlog_errno(ret);
			mlog(ML_ERROR, "begin reco of dlm %s to node %u "
			     "returned %d\n", dlm->name, nodenum, ret);
			res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
						 DLM_RECOVERY_LOCK_NAME_LEN);
			if (res) {
				dlm_print_one_lock_resource(res);
				dlm_lockres_put(res);
			} else {
				mlog(ML_ERROR, "recovery lock not found\n");
			}
			/* sleep for a bit in hopes that we can avoid
			 * another ENOMEM */
			msleep(100);
			goto retry;
		}
	}

	return ret;
}

int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
			   void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;

	/* ok to return 0, domain has gone away */
	if (!dlm_grab(dlm))
		return 0;

	spin_lock(&dlm->spinlock);
	if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
		mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
		     "but this node is in finalize state, waiting on finalize2\n",
		     dlm->name, br->node_idx, br->dead_node,
		     dlm->reco.dead_node, dlm->reco.new_master);
		spin_unlock(&dlm->spinlock);
		return -EAGAIN;
	}
	spin_unlock(&dlm->spinlock);

	mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
	     dlm->name, br->node_idx, br->dead_node,
	     dlm->reco.dead_node, dlm->reco.new_master);

	dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);

	spin_lock(&dlm->spinlock);
	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
		if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
			mlog(0, "%s: new_master %u died, changing "
			     "to %u\n", dlm->name, dlm->reco.new_master,
			     br->node_idx);
		} else {
			mlog(0, "%s: new_master %u NOT DEAD, changing "
			     "to %u\n", dlm->name, dlm->reco.new_master,
			     br->node_idx);
			/* may not have seen the new master as dead yet */
		}
	}
	if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
		mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
		     "node %u changing it to %u\n", dlm->name,
		     dlm->reco.dead_node, br->node_idx, br->dead_node);
	}
	dlm_set_reco_master(dlm, br->node_idx);
	dlm_set_reco_dead_node(dlm, br->dead_node);
	if (!test_bit(br->dead_node, dlm->recovery_map)) {
		mlog(0, "recovery master %u sees %u as dead, but this "
		     "node has not yet.  marking %u as dead\n",
		     br->node_idx, br->dead_node, br->dead_node);
		if (!test_bit(br->dead_node, dlm->domain_map) ||
		    !test_bit(br->dead_node, dlm->live_nodes_map))
			mlog(0, "%u not in domain/live_nodes map "
			     "so setting it in reco map manually\n",
			     br->dead_node);
		/* force the recovery cleanup in __dlm_hb_node_down
		 * both of these will be cleared in a moment */
		set_bit(br->dead_node, dlm->domain_map);
		set_bit(br->dead_node, dlm->live_nodes_map);
		__dlm_hb_node_down(dlm, br->dead_node);
	}
	spin_unlock(&dlm->spinlock);

	dlm_kick_recovery_thread(dlm);

	mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
	     dlm->name, br->node_idx, br->dead_node,
	     dlm->reco.dead_node, dlm->reco.new_master);

	dlm_put(dlm);
	return 0;
}

#define DLM_FINALIZE_STAGE2  0x01
static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
{
	int ret = 0;
	struct dlm_finalize_reco fr;
	struct dlm_node_iter iter;
	int nodenum;
	int status;
	int stage = 1;

	mlog(0, "finishing recovery for node %s:%u, "
	     "stage %d\n", dlm->name, dlm->reco.dead_node, stage);

	spin_lock(&dlm->spinlock);
	dlm_node_iter_init(dlm->domain_map, &iter);
	spin_unlock(&dlm->spinlock);

stage2:
	memset(&fr, 0, sizeof(fr));
	fr.node_idx = dlm->node_num;
	fr.dead_node = dlm->reco.dead_node;
	if (stage == 2)
		fr.flags |= DLM_FINALIZE_STAGE2;

	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
		if (nodenum == dlm->node_num)
			continue;
		ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
					 &fr, sizeof(fr), nodenum, &status);
		if (ret >= 0)
			ret = status;
		if (ret < 0) {
			mlog(ML_ERROR, "Error %d when sending message %u (key "
			     "0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
			     dlm->key, nodenum);
			if (dlm_is_host_down(ret)) {
				/* this has no effect on this recovery
				 * session, so set the status to zero to
				 * finish out the last recovery */
				mlog(ML_ERROR, "node %u went down after this "
				     "node finished recovery.\n", nodenum);
				ret = 0;
				continue;
			}
			break;
		}
	}
	if (stage == 1) {
		/* reset the node_iter back to the top and send finalize2 */
		iter.curnode = -1;
		stage = 2;
		goto stage2;
	}

	return ret;
}

int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
			      void **ret_data)
{
	struct dlm_ctxt *dlm = data;
	struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
	int stage = 1;

	/* ok to return 0, domain has gone away */
	if (!dlm_grab(dlm))
		return 0;

	if (fr->flags & DLM_FINALIZE_STAGE2)
		stage = 2;

	mlog(0, "%s: node %u finalizing recovery stage%d of "
	     "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
	     fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);

	spin_lock(&dlm->spinlock);

	if (dlm->reco.new_master != fr->node_idx) {
		mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
		     "%u is supposed to be the new master, dead=%u\n",
		     fr->node_idx, dlm->reco.new_master, fr->dead_node);
		BUG();
	}
	if (dlm->reco.dead_node != fr->dead_node) {
		mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
		     "node %u, but node %u is supposed to be dead\n",
		     fr->node_idx, fr->dead_node, dlm->reco.dead_node);
		BUG();
	}

	switch (stage) {
		case 1:
			dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
			if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
				mlog(ML_ERROR, "%s: received finalize1 from "
				     "new master %u for dead node %u, but "
				     "this node has already received it!\n",
				     dlm->name, fr->node_idx, fr->dead_node);
				dlm_print_reco_node_status(dlm);
				BUG();
			}
			dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
			spin_unlock(&dlm->spinlock);
			break;
		case 2:
			if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
				mlog(ML_ERROR, "%s: received finalize2 from "
				     "new master %u for dead node %u, but "
				     "this node did not have finalize1!\n",
				     dlm->name, fr->node_idx, fr->dead_node);
				dlm_print_reco_node_status(dlm);
				BUG();
			}
			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
			spin_unlock(&dlm->spinlock);
			dlm_reset_recovery(dlm);
			dlm_kick_recovery_thread(dlm);
			break;
		default:
			BUG();
	}

	mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
	     dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);

	dlm_put(dlm);
	return 0;
}