summaryrefslogtreecommitdiffstats
path: root/lib/maple_tree.c
blob: 0e00a84e8e8faa95e572b23778ef5b6bf9179630 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
// SPDX-License-Identifier: GPL-2.0+
/*
 * Maple Tree implementation
 * Copyright (c) 2018-2022 Oracle Corporation
 * Authors: Liam R. Howlett <Liam.Howlett@oracle.com>
 *	    Matthew Wilcox <willy@infradead.org>
 */

/*
 * DOC: Interesting implementation details of the Maple Tree
 *
 * Each node type has a number of slots for entries and a number of slots for
 * pivots.  In the case of dense nodes, the pivots are implied by the position
 * and are simply the slot index + the minimum of the node.
 *
 * In regular B-Tree terms, pivots are called keys.  The term pivot is used to
 * indicate that the tree is specifying ranges,  Pivots may appear in the
 * subtree with an entry attached to the value where as keys are unique to a
 * specific position of a B-tree.  Pivot values are inclusive of the slot with
 * the same index.
 *
 *
 * The following illustrates the layout of a range64 nodes slots and pivots.
 *
 *
 *  Slots -> | 0 | 1 | 2 | ... | 12 | 13 | 14 | 15 |
 *           ┬   ┬   ┬   ┬     ┬    ┬    ┬    ┬    ┬
 *           │   │   │   │     │    │    │    │    └─ Implied maximum
 *           │   │   │   │     │    │    │    └─ Pivot 14
 *           │   │   │   │     │    │    └─ Pivot 13
 *           │   │   │   │     │    └─ Pivot 12
 *           │   │   │   │     └─ Pivot 11
 *           │   │   │   └─ Pivot 2
 *           │   │   └─ Pivot 1
 *           │   └─ Pivot 0
 *           └─  Implied minimum
 *
 * Slot contents:
 *  Internal (non-leaf) nodes contain pointers to other nodes.
 *  Leaf nodes contain entries.
 *
 * The location of interest is often referred to as an offset.  All offsets have
 * a slot, but the last offset has an implied pivot from the node above (or
 * UINT_MAX for the root node.
 *
 * Ranges complicate certain write activities.  When modifying any of
 * the B-tree variants, it is known that one entry will either be added or
 * deleted.  When modifying the Maple Tree, one store operation may overwrite
 * the entire data set, or one half of the tree, or the middle half of the tree.
 *
 */


#include <linux/maple_tree.h>
#include <linux/xarray.h>
#include <linux/types.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/limits.h>
#include <asm/barrier.h>

#define CREATE_TRACE_POINTS
#include <trace/events/maple_tree.h>

#define MA_ROOT_PARENT 1

/*
 * Maple state flags
 * * MA_STATE_BULK		- Bulk insert mode
 * * MA_STATE_REBALANCE		- Indicate a rebalance during bulk insert
 * * MA_STATE_PREALLOC		- Preallocated nodes, WARN_ON allocation
 */
#define MA_STATE_BULK		1
#define MA_STATE_REBALANCE	2
#define MA_STATE_PREALLOC	4

#define ma_parent_ptr(x) ((struct maple_pnode *)(x))
#define mas_tree_parent(x) ((unsigned long)(x->tree) | MA_ROOT_PARENT)
#define ma_mnode_ptr(x) ((struct maple_node *)(x))
#define ma_enode_ptr(x) ((struct maple_enode *)(x))
static struct kmem_cache *maple_node_cache;

#ifdef CONFIG_DEBUG_MAPLE_TREE
static const unsigned long mt_max[] = {
	[maple_dense]		= MAPLE_NODE_SLOTS,
	[maple_leaf_64]		= ULONG_MAX,
	[maple_range_64]	= ULONG_MAX,
	[maple_arange_64]	= ULONG_MAX,
};
#define mt_node_max(x) mt_max[mte_node_type(x)]
#endif

static const unsigned char mt_slots[] = {
	[maple_dense]		= MAPLE_NODE_SLOTS,
	[maple_leaf_64]		= MAPLE_RANGE64_SLOTS,
	[maple_range_64]	= MAPLE_RANGE64_SLOTS,
	[maple_arange_64]	= MAPLE_ARANGE64_SLOTS,
};
#define mt_slot_count(x) mt_slots[mte_node_type(x)]

static const unsigned char mt_pivots[] = {
	[maple_dense]		= 0,
	[maple_leaf_64]		= MAPLE_RANGE64_SLOTS - 1,
	[maple_range_64]	= MAPLE_RANGE64_SLOTS - 1,
	[maple_arange_64]	= MAPLE_ARANGE64_SLOTS - 1,
};
#define mt_pivot_count(x) mt_pivots[mte_node_type(x)]

static const unsigned char mt_min_slots[] = {
	[maple_dense]		= MAPLE_NODE_SLOTS / 2,
	[maple_leaf_64]		= (MAPLE_RANGE64_SLOTS / 2) - 2,
	[maple_range_64]	= (MAPLE_RANGE64_SLOTS / 2) - 2,
	[maple_arange_64]	= (MAPLE_ARANGE64_SLOTS / 2) - 1,
};
#define mt_min_slot_count(x) mt_min_slots[mte_node_type(x)]

#define MAPLE_BIG_NODE_SLOTS	(MAPLE_RANGE64_SLOTS * 2 + 2)
#define MAPLE_BIG_NODE_GAPS	(MAPLE_ARANGE64_SLOTS * 2 + 1)

struct maple_big_node {
	struct maple_pnode *parent;
	unsigned long pivot[MAPLE_BIG_NODE_SLOTS - 1];
	union {
		struct maple_enode *slot[MAPLE_BIG_NODE_SLOTS];
		struct {
			unsigned long padding[MAPLE_BIG_NODE_GAPS];
			unsigned long gap[MAPLE_BIG_NODE_GAPS];
		};
	};
	unsigned char b_end;
	enum maple_type type;
};

/*
 * The maple_subtree_state is used to build a tree to replace a segment of an
 * existing tree in a more atomic way.  Any walkers of the older tree will hit a
 * dead node and restart on updates.
 */
struct maple_subtree_state {
	struct ma_state *orig_l;	/* Original left side of subtree */
	struct ma_state *orig_r;	/* Original right side of subtree */
	struct ma_state *l;		/* New left side of subtree */
	struct ma_state *m;		/* New middle of subtree (rare) */
	struct ma_state *r;		/* New right side of subtree */
	struct ma_topiary *free;	/* nodes to be freed */
	struct ma_topiary *destroy;	/* Nodes to be destroyed (walked and freed) */
	struct maple_big_node *bn;
};

#ifdef CONFIG_KASAN_STACK
/* Prevent mas_wr_bnode() from exceeding the stack frame limit */
#define noinline_for_kasan noinline_for_stack
#else
#define noinline_for_kasan inline
#endif

/* Functions */
static inline struct maple_node *mt_alloc_one(gfp_t gfp)
{
	return kmem_cache_alloc(maple_node_cache, gfp);
}

static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes)
{
	return kmem_cache_alloc_bulk(maple_node_cache, gfp, size, nodes);
}

static inline void mt_free_bulk(size_t size, void __rcu **nodes)
{
	kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes);
}

static void mt_free_rcu(struct rcu_head *head)
{
	struct maple_node *node = container_of(head, struct maple_node, rcu);

	kmem_cache_free(maple_node_cache, node);
}

/*
 * ma_free_rcu() - Use rcu callback to free a maple node
 * @node: The node to free
 *
 * The maple tree uses the parent pointer to indicate this node is no longer in
 * use and will be freed.
 */
static void ma_free_rcu(struct maple_node *node)
{
	WARN_ON(node->parent != ma_parent_ptr(node));
	call_rcu(&node->rcu, mt_free_rcu);
}

static void mas_set_height(struct ma_state *mas)
{
	unsigned int new_flags = mas->tree->ma_flags;

	new_flags &= ~MT_FLAGS_HEIGHT_MASK;
	MAS_BUG_ON(mas, mas->depth > MAPLE_HEIGHT_MAX);
	new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET;
	mas->tree->ma_flags = new_flags;
}

static unsigned int mas_mt_height(struct ma_state *mas)
{
	return mt_height(mas->tree);
}

static inline enum maple_type mte_node_type(const struct maple_enode *entry)
{
	return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) &
		MAPLE_NODE_TYPE_MASK;
}

static inline bool ma_is_dense(const enum maple_type type)
{
	return type < maple_leaf_64;
}

static inline bool ma_is_leaf(const enum maple_type type)
{
	return type < maple_range_64;
}

static inline bool mte_is_leaf(const struct maple_enode *entry)
{
	return ma_is_leaf(mte_node_type(entry));
}

/*
 * We also reserve values with the bottom two bits set to '10' which are
 * below 4096
 */
static inline bool mt_is_reserved(const void *entry)
{
	return ((unsigned long)entry < MAPLE_RESERVED_RANGE) &&
		xa_is_internal(entry);
}

static inline void mas_set_err(struct ma_state *mas, long err)
{
	mas->node = MA_ERROR(err);
}

static inline bool mas_is_ptr(const struct ma_state *mas)
{
	return mas->node == MAS_ROOT;
}

static inline bool mas_is_start(const struct ma_state *mas)
{
	return mas->node == MAS_START;
}

bool mas_is_err(struct ma_state *mas)
{
	return xa_is_err(mas->node);
}

static __always_inline bool mas_is_overflow(struct ma_state *mas)
{
	if (unlikely(mas->node == MAS_OVERFLOW))
		return true;

	return false;
}

static __always_inline bool mas_is_underflow(struct ma_state *mas)
{
	if (unlikely(mas->node == MAS_UNDERFLOW))
		return true;

	return false;
}

static inline bool mas_searchable(struct ma_state *mas)
{
	if (mas_is_none(mas))
		return false;

	if (mas_is_ptr(mas))
		return false;

	return true;
}

static inline struct maple_node *mte_to_node(const struct maple_enode *entry)
{
	return (struct maple_node *)((unsigned long)entry & ~MAPLE_NODE_MASK);
}

/*
 * mte_to_mat() - Convert a maple encoded node to a maple topiary node.
 * @entry: The maple encoded node
 *
 * Return: a maple topiary pointer
 */
static inline struct maple_topiary *mte_to_mat(const struct maple_enode *entry)
{
	return (struct maple_topiary *)
		((unsigned long)entry & ~MAPLE_NODE_MASK);
}

/*
 * mas_mn() - Get the maple state node.
 * @mas: The maple state
 *
 * Return: the maple node (not encoded - bare pointer).
 */
static inline struct maple_node *mas_mn(const struct ma_state *mas)
{
	return mte_to_node(mas->node);
}

/*
 * mte_set_node_dead() - Set a maple encoded node as dead.
 * @mn: The maple encoded node.
 */
static inline void mte_set_node_dead(struct maple_enode *mn)
{
	mte_to_node(mn)->parent = ma_parent_ptr(mte_to_node(mn));
	smp_wmb(); /* Needed for RCU */
}

/* Bit 1 indicates the root is a node */
#define MAPLE_ROOT_NODE			0x02
/* maple_type stored bit 3-6 */
#define MAPLE_ENODE_TYPE_SHIFT		0x03
/* Bit 2 means a NULL somewhere below */
#define MAPLE_ENODE_NULL		0x04

static inline struct maple_enode *mt_mk_node(const struct maple_node *node,
					     enum maple_type type)
{
	return (void *)((unsigned long)node |
			(type << MAPLE_ENODE_TYPE_SHIFT) | MAPLE_ENODE_NULL);
}

static inline void *mte_mk_root(const struct maple_enode *node)
{
	return (void *)((unsigned long)node | MAPLE_ROOT_NODE);
}

static inline void *mte_safe_root(const struct maple_enode *node)
{
	return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
}

static inline void *mte_set_full(const struct maple_enode *node)
{
	return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
}

static inline void *mte_clear_full(const struct maple_enode *node)
{
	return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
}

static inline bool mte_has_null(const struct maple_enode *node)
{
	return (unsigned long)node & MAPLE_ENODE_NULL;
}

static inline bool ma_is_root(struct maple_node *node)
{
	return ((unsigned long)node->parent & MA_ROOT_PARENT);
}

static inline bool mte_is_root(const struct maple_enode *node)
{
	return ma_is_root(mte_to_node(node));
}

static inline bool mas_is_root_limits(const struct ma_state *mas)
{
	return !mas->min && mas->max == ULONG_MAX;
}

static inline bool mt_is_alloc(struct maple_tree *mt)
{
	return (mt->ma_flags & MT_FLAGS_ALLOC_RANGE);
}

/*
 * The Parent Pointer
 * Excluding root, the parent pointer is 256B aligned like all other tree nodes.
 * When storing a 32 or 64 bit values, the offset can fit into 5 bits.  The 16
 * bit values need an extra bit to store the offset.  This extra bit comes from
 * a reuse of the last bit in the node type.  This is possible by using bit 1 to
 * indicate if bit 2 is part of the type or the slot.
 *
 * Note types:
 *  0x??1 = Root
 *  0x?00 = 16 bit nodes
 *  0x010 = 32 bit nodes
 *  0x110 = 64 bit nodes
 *
 * Slot size and alignment
 *  0b??1 : Root
 *  0b?00 : 16 bit values, type in 0-1, slot in 2-7
 *  0b010 : 32 bit values, type in 0-2, slot in 3-7
 *  0b110 : 64 bit values, type in 0-2, slot in 3-7
 */

#define MAPLE_PARENT_ROOT		0x01

#define MAPLE_PARENT_SLOT_SHIFT		0x03
#define MAPLE_PARENT_SLOT_MASK		0xF8

#define MAPLE_PARENT_16B_SLOT_SHIFT	0x02
#define MAPLE_PARENT_16B_SLOT_MASK	0xFC

#define MAPLE_PARENT_RANGE64		0x06
#define MAPLE_PARENT_RANGE32		0x04
#define MAPLE_PARENT_NOT_RANGE16	0x02

/*
 * mte_parent_shift() - Get the parent shift for the slot storage.
 * @parent: The parent pointer cast as an unsigned long
 * Return: The shift into that pointer to the star to of the slot
 */
static inline unsigned long mte_parent_shift(unsigned long parent)
{
	/* Note bit 1 == 0 means 16B */
	if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
		return MAPLE_PARENT_SLOT_SHIFT;

	return MAPLE_PARENT_16B_SLOT_SHIFT;
}

/*
 * mte_parent_slot_mask() - Get the slot mask for the parent.
 * @parent: The parent pointer cast as an unsigned long.
 * Return: The slot mask for that parent.
 */
static inline unsigned long mte_parent_slot_mask(unsigned long parent)
{
	/* Note bit 1 == 0 means 16B */
	if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
		return MAPLE_PARENT_SLOT_MASK;

	return MAPLE_PARENT_16B_SLOT_MASK;
}

/*
 * mas_parent_type() - Return the maple_type of the parent from the stored
 * parent type.
 * @mas: The maple state
 * @enode: The maple_enode to extract the parent's enum
 * Return: The node->parent maple_type
 */
static inline
enum maple_type mas_parent_type(struct ma_state *mas, struct maple_enode *enode)
{
	unsigned long p_type;

	p_type = (unsigned long)mte_to_node(enode)->parent;
	if (WARN_ON(p_type & MAPLE_PARENT_ROOT))
		return 0;

	p_type &= MAPLE_NODE_MASK;
	p_type &= ~mte_parent_slot_mask(p_type);
	switch (p_type) {
	case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
		if (mt_is_alloc(mas->tree))
			return maple_arange_64;
		return maple_range_64;
	}

	return 0;
}

/*
 * mas_set_parent() - Set the parent node and encode the slot
 * @enode: The encoded maple node.
 * @parent: The encoded maple node that is the parent of @enode.
 * @slot: The slot that @enode resides in @parent.
 *
 * Slot number is encoded in the enode->parent bit 3-6 or 2-6, depending on the
 * parent type.
 */
static inline
void mas_set_parent(struct ma_state *mas, struct maple_enode *enode,
		    const struct maple_enode *parent, unsigned char slot)
{
	unsigned long val = (unsigned long)parent;
	unsigned long shift;
	unsigned long type;
	enum maple_type p_type = mte_node_type(parent);

	MAS_BUG_ON(mas, p_type == maple_dense);
	MAS_BUG_ON(mas, p_type == maple_leaf_64);

	switch (p_type) {
	case maple_range_64:
	case maple_arange_64:
		shift = MAPLE_PARENT_SLOT_SHIFT;
		type = MAPLE_PARENT_RANGE64;
		break;
	default:
	case maple_dense:
	case maple_leaf_64:
		shift = type = 0;
		break;
	}

	val &= ~MAPLE_NODE_MASK; /* Clear all node metadata in parent */
	val |= (slot << shift) | type;
	mte_to_node(enode)->parent = ma_parent_ptr(val);
}

/*
 * mte_parent_slot() - get the parent slot of @enode.
 * @enode: The encoded maple node.
 *
 * Return: The slot in the parent node where @enode resides.
 */
static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
{
	unsigned long val = (unsigned long)mte_to_node(enode)->parent;

	if (val & MA_ROOT_PARENT)
		return 0;

	/*
	 * Okay to use MAPLE_PARENT_16B_SLOT_MASK as the last bit will be lost
	 * by shift if the parent shift is MAPLE_PARENT_SLOT_SHIFT
	 */
	return (val & MAPLE_PARENT_16B_SLOT_MASK) >> mte_parent_shift(val);
}

/*
 * mte_parent() - Get the parent of @node.
 * @node: The encoded maple node.
 *
 * Return: The parent maple node.
 */
static inline struct maple_node *mte_parent(const struct maple_enode *enode)
{
	return (void *)((unsigned long)
			(mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK);
}

/*
 * ma_dead_node() - check if the @enode is dead.
 * @enode: The encoded maple node
 *
 * Return: true if dead, false otherwise.
 */
static inline bool ma_dead_node(const struct maple_node *node)
{
	struct maple_node *parent;

	/* Do not reorder reads from the node prior to the parent check */
	smp_rmb();
	parent = (void *)((unsigned long) node->parent & ~MAPLE_NODE_MASK);
	return (parent == node);
}

/*
 * mte_dead_node() - check if the @enode is dead.
 * @enode: The encoded maple node
 *
 * Return: true if dead, false otherwise.
 */
static inline bool mte_dead_node(const struct maple_enode *enode)
{
	struct maple_node *parent, *node;

	node = mte_to_node(enode);
	/* Do not reorder reads from the node prior to the parent check */
	smp_rmb();
	parent = mte_parent(enode);
	return (parent == node);
}

/*
 * mas_allocated() - Get the number of nodes allocated in a maple state.
 * @mas: The maple state
 *
 * The ma_state alloc member is overloaded to hold a pointer to the first
 * allocated node or to the number of requested nodes to allocate.  If bit 0 is
 * set, then the alloc contains the number of requested nodes.  If there is an
 * allocated node, then the total allocated nodes is in that node.
 *
 * Return: The total number of nodes allocated
 */
static inline unsigned long mas_allocated(const struct ma_state *mas)
{
	if (!mas->alloc || ((unsigned long)mas->alloc & 0x1))
		return 0;

	return mas->alloc->total;
}

/*
 * mas_set_alloc_req() - Set the requested number of allocations.
 * @mas: the maple state
 * @count: the number of allocations.
 *
 * The requested number of allocations is either in the first allocated node,
 * located in @mas->alloc->request_count, or directly in @mas->alloc if there is
 * no allocated node.  Set the request either in the node or do the necessary
 * encoding to store in @mas->alloc directly.
 */
static inline void mas_set_alloc_req(struct ma_state *mas, unsigned long count)
{
	if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) {
		if (!count)
			mas->alloc = NULL;
		else
			mas->alloc = (struct maple_alloc *)(((count) << 1U) | 1U);
		return;
	}

	mas->alloc->request_count = count;
}

/*
 * mas_alloc_req() - get the requested number of allocations.
 * @mas: The maple state
 *
 * The alloc count is either stored directly in @mas, or in
 * @mas->alloc->request_count if there is at least one node allocated.  Decode
 * the request count if it's stored directly in @mas->alloc.
 *
 * Return: The allocation request count.
 */
static inline unsigned int mas_alloc_req(const struct ma_state *mas)
{
	if ((unsigned long)mas->alloc & 0x1)
		return (unsigned long)(mas->alloc) >> 1;
	else if (mas->alloc)
		return mas->alloc->request_count;
	return 0;
}

/*
 * ma_pivots() - Get a pointer to the maple node pivots.
 * @node - the maple node
 * @type - the node type
 *
 * In the event of a dead node, this array may be %NULL
 *
 * Return: A pointer to the maple node pivots
 */
static inline unsigned long *ma_pivots(struct maple_node *node,
					   enum maple_type type)
{
	switch (type) {
	case maple_arange_64:
		return node->ma64.pivot;
	case maple_range_64:
	case maple_leaf_64:
		return node->mr64.pivot;
	case maple_dense:
		return NULL;
	}
	return NULL;
}

/*
 * ma_gaps() - Get a pointer to the maple node gaps.
 * @node - the maple node
 * @type - the node type
 *
 * Return: A pointer to the maple node gaps
 */
static inline unsigned long *ma_gaps(struct maple_node *node,
				     enum maple_type type)
{
	switch (type) {
	case maple_arange_64:
		return node->ma64.gap;
	case maple_range_64:
	case maple_leaf_64:
	case maple_dense:
		return NULL;
	}
	return NULL;
}

/*
 * mas_pivot() - Get the pivot at @piv of the maple encoded node.
 * @mas: The maple state.
 * @piv: The pivot.
 *
 * Return: the pivot at @piv of @mn.
 */
static inline unsigned long mas_pivot(struct ma_state *mas, unsigned char piv)
{
	struct maple_node *node = mas_mn(mas);
	enum maple_type type = mte_node_type(mas->node);

	if (MAS_WARN_ON(mas, piv >= mt_pivots[type])) {
		mas_set_err(mas, -EIO);
		return 0;
	}

	switch (type) {
	case maple_arange_64:
		return node->ma64.pivot[piv];
	case maple_range_64:
	case maple_leaf_64:
		return node->mr64.pivot[piv];
	case maple_dense:
		return 0;
	}
	return 0;
}

/*
 * mas_safe_pivot() - get the pivot at @piv or mas->max.
 * @mas: The maple state
 * @pivots: The pointer to the maple node pivots
 * @piv: The pivot to fetch
 * @type: The maple node type
 *
 * Return: The pivot at @piv within the limit of the @pivots array, @mas->max
 * otherwise.
 */
static inline unsigned long
mas_safe_pivot(const struct ma_state *mas, unsigned long *pivots,
	       unsigned char piv, enum maple_type type)
{
	if (piv >= mt_pivots[type])
		return mas->max;

	return pivots[piv];
}

/*
 * mas_safe_min() - Return the minimum for a given offset.
 * @mas: The maple state
 * @pivots: The pointer to the maple node pivots
 * @offset: The offset into the pivot array
 *
 * Return: The minimum range value that is contained in @offset.
 */
static inline unsigned long
mas_safe_min(struct ma_state *mas, unsigned long *pivots, unsigned char offset)
{
	if (likely(offset))
		return pivots[offset - 1] + 1;

	return mas->min;
}

/*
 * mte_set_pivot() - Set a pivot to a value in an encoded maple node.
 * @mn: The encoded maple node
 * @piv: The pivot offset
 * @val: The value of the pivot
 */
static inline void mte_set_pivot(struct maple_enode *mn, unsigned char piv,
				unsigned long val)
{
	struct maple_node *node = mte_to_node(mn);
	enum maple_type type = mte_node_type(mn);

	BUG_ON(piv >= mt_pivots[type]);
	switch (type) {
	default:
	case maple_range_64:
	case maple_leaf_64:
		node->mr64.pivot[piv] = val;
		break;
	case maple_arange_64:
		node->ma64.pivot[piv] = val;
		break;
	case maple_dense:
		break;
	}

}

/*
 * ma_slots() - Get a pointer to the maple node slots.
 * @mn: The maple node
 * @mt: The maple node type
 *
 * Return: A pointer to the maple node slots
 */
static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt)
{
	switch (mt) {
	default:
	case maple_arange_64:
		return mn->ma64.slot;
	case maple_range_64:
	case maple_leaf_64:
		return mn->mr64.slot;
	case maple_dense:
		return mn->slot;
	}
}

static inline bool mt_write_locked(const struct maple_tree *mt)
{
	return mt_external_lock(mt) ? mt_write_lock_is_held(mt) :
		lockdep_is_held(&mt->ma_lock);
}

static inline bool mt_locked(const struct maple_tree *mt)
{
	return mt_external_lock(mt) ? mt_lock_is_held(mt) :
		lockdep_is_held(&mt->ma_lock);
}

static inline void *mt_slot(const struct maple_tree *mt,
		void __rcu **slots, unsigned char offset)
{
	return rcu_dereference_check(slots[offset], mt_locked(mt));
}

static inline void *mt_slot_locked(struct maple_tree *mt, void __rcu **slots,
				   unsigned char offset)
{
	return rcu_dereference_protected(slots[offset], mt_write_locked(mt));
}
/*
 * mas_slot_locked() - Get the slot value when holding the maple tree lock.
 * @mas: The maple state
 * @slots: The pointer to the slots
 * @offset: The offset into the slots array to fetch
 *
 * Return: The entry stored in @slots at the @offset.
 */
static inline void *mas_slot_locked(struct ma_state *mas, void __rcu **slots,
				       unsigned char offset)
{
	return mt_slot_locked(mas->tree, slots, offset);
}

/*
 * mas_slot() - Get the slot value when not holding the maple tree lock.
 * @mas: The maple state
 * @slots: The pointer to the slots
 * @offset: The offset into the slots array to fetch
 *
 * Return: The entry stored in @slots at the @offset
 */
static inline void *mas_slot(struct ma_state *mas, void __rcu **slots,
			     unsigned char offset)
{
	return mt_slot(mas->tree, slots, offset);
}

/*
 * mas_root() - Get the maple tree root.
 * @mas: The maple state.
 *
 * Return: The pointer to the root of the tree
 */
static inline void *mas_root(struct ma_state *mas)
{
	return rcu_dereference_check(mas->tree->ma_root, mt_locked(mas->tree));
}

static inline void *mt_root_locked(struct maple_tree *mt)
{
	return rcu_dereference_protected(mt->ma_root, mt_write_locked(mt));
}

/*
 * mas_root_locked() - Get the maple tree root when holding the maple tree lock.
 * @mas: The maple state.
 *
 * Return: The pointer to the root of the tree
 */
static inline void *mas_root_locked(struct ma_state *mas)
{
	return mt_root_locked(mas->tree);
}

static inline struct maple_metadata *ma_meta(struct maple_node *mn,
					     enum maple_type mt)
{
	switch (mt) {
	case maple_arange_64:
		return &mn->ma64.meta;
	default:
		return &mn->mr64.meta;
	}
}

/*
 * ma_set_meta() - Set the metadata information of a node.
 * @mn: The maple node
 * @mt: The maple node type
 * @offset: The offset of the highest sub-gap in this node.
 * @end: The end of the data in this node.
 */
static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt,
			       unsigned char offset, unsigned char end)
{
	struct maple_metadata *meta = ma_meta(mn, mt);

	meta->gap = offset;
	meta->end = end;
}

/*
 * mt_clear_meta() - clear the metadata information of a node, if it exists
 * @mt: The maple tree
 * @mn: The maple node
 * @type: The maple node type
 * @offset: The offset of the highest sub-gap in this node.
 * @end: The end of the data in this node.
 */
static inline void mt_clear_meta(struct maple_tree *mt, struct maple_node *mn,
				  enum maple_type type)
{
	struct maple_metadata *meta;
	unsigned long *pivots;
	void __rcu **slots;
	void *next;

	switch (type) {
	case maple_range_64:
		pivots = mn->mr64.pivot;
		if (unlikely(pivots[MAPLE_RANGE64_SLOTS - 2])) {
			slots = mn->mr64.slot;
			next = mt_slot_locked(mt, slots,
					      MAPLE_RANGE64_SLOTS - 1);
			if (unlikely((mte_to_node(next) &&
				      mte_node_type(next))))
				return; /* no metadata, could be node */
		}
		fallthrough;
	case maple_arange_64:
		meta = ma_meta(mn, type);
		break;
	default:
		return;
	}

	meta->gap = 0;
	meta->end = 0;
}

/*
 * ma_meta_end() - Get the data end of a node from the metadata
 * @mn: The maple node
 * @mt: The maple node type
 */
static inline unsigned char ma_meta_end(struct maple_node *mn,
					enum maple_type mt)
{
	struct maple_metadata *meta = ma_meta(mn, mt);

	return meta->end;
}

/*
 * ma_meta_gap() - Get the largest gap location of a node from the metadata
 * @mn: The maple node
 * @mt: The maple node type
 */
static inline unsigned char ma_meta_gap(struct maple_node *mn,
					enum maple_type mt)
{
	return mn->ma64.meta.gap;
}

/*
 * ma_set_meta_gap() - Set the largest gap location in a nodes metadata
 * @mn: The maple node
 * @mn: The maple node type
 * @offset: The location of the largest gap.
 */
static inline void ma_set_meta_gap(struct maple_node *mn, enum maple_type mt,
				   unsigned char offset)
{

	struct maple_metadata *meta = ma_meta(mn, mt);

	meta->gap = offset;
}

/*
 * mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes.
 * @mat - the ma_topiary, a linked list of dead nodes.
 * @dead_enode - the node to be marked as dead and added to the tail of the list
 *
 * Add the @dead_enode to the linked list in @mat.
 */
static inline void mat_add(struct ma_topiary *mat,
			   struct maple_enode *dead_enode)
{
	mte_set_node_dead(dead_enode);
	mte_to_mat(dead_enode)->next = NULL;
	if (!mat->tail) {
		mat->tail = mat->head = dead_enode;
		return;
	}

	mte_to_mat(mat->tail)->next = dead_enode;
	mat->tail = dead_enode;
}

static void mt_free_walk(struct rcu_head *head);
static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt,
			    bool free);
/*
 * mas_mat_destroy() - Free all nodes and subtrees in a dead list.
 * @mas - the maple state
 * @mat - the ma_topiary linked list of dead nodes to free.
 *
 * Destroy walk a dead list.
 */
static void mas_mat_destroy(struct ma_state *mas, struct ma_topiary *mat)
{
	struct maple_enode *next;
	struct maple_node *node;
	bool in_rcu = mt_in_rcu(mas->tree);

	while (mat->head) {
		next = mte_to_mat(mat->head)->next;
		node = mte_to_node(mat->head);
		mt_destroy_walk(mat->head, mas->tree, !in_rcu);
		if (in_rcu)
			call_rcu(&node->rcu, mt_free_walk);
		mat->head = next;
	}
}
/*
 * mas_descend() - Descend into the slot stored in the ma_state.
 * @mas - the maple state.
 *
 * Note: Not RCU safe, only use in write side or debug code.
 */
static inline void mas_descend(struct ma_state *mas)
{
	enum maple_type type;
	unsigned long *pivots;
	struct maple_node *node;
	void __rcu **slots;

	node = mas_mn(mas);
	type = mte_node_type(mas->node);
	pivots = ma_pivots(node, type);
	slots = ma_slots(node, type);

	if (mas->offset)
		mas->min = pivots[mas->offset - 1] + 1;
	mas->max = mas_safe_pivot(mas, pivots, mas->offset, type);
	mas->node = mas_slot(mas, slots, mas->offset);
}

/*
 * mte_set_gap() - Set a maple node gap.
 * @mn: The encoded maple node
 * @gap: The offset of the gap to set
 * @val: The gap value
 */
static inline void mte_set_gap(const struct maple_enode *mn,
				 unsigned char gap, unsigned long val)
{
	switch (mte_node_type(mn)) {
	default:
		break;
	case maple_arange_64:
		mte_to_node(mn)->ma64.gap[gap] = val;
		break;
	}
}

/*
 * mas_ascend() - Walk up a level of the tree.
 * @mas: The maple state
 *
 * Sets the @mas->max and @mas->min to the correct values when walking up.  This
 * may cause several levels of walking up to find the correct min and max.
 * May find a dead node which will cause a premature return.
 * Return: 1 on dead node, 0 otherwise
 */
static int mas_ascend(struct ma_state *mas)
{
	struct maple_enode *p_enode; /* parent enode. */
	struct maple_enode *a_enode; /* ancestor enode. */
	struct maple_node *a_node; /* ancestor node. */
	struct maple_node *p_node; /* parent node. */
	unsigned char a_slot;
	enum maple_type a_type;
	unsigned long min, max;
	unsigned long *pivots;
	bool set_max = false, set_min = false;

	a_node = mas_mn(mas);
	if (ma_is_root(a_node)) {
		mas->offset = 0;
		return 0;
	}

	p_node = mte_parent(mas->node);
	if (unlikely(a_node == p_node))
		return 1;

	a_type = mas_parent_type(mas, mas->node);
	mas->offset = mte_parent_slot(mas->node);
	a_enode = mt_mk_node(p_node, a_type);

	/* Check to make sure all parent information is still accurate */
	if (p_node != mte_parent(mas->node))
		return 1;

	mas->node = a_enode;

	if (mte_is_root(a_enode)) {
		mas->max = ULONG_MAX;
		mas->min = 0;
		return 0;
	}

	if (!mas->min)
		set_min = true;

	if (mas->max == ULONG_MAX)
		set_max = true;

	min = 0;
	max = ULONG_MAX;
	do {
		p_enode = a_enode;
		a_type = mas_parent_type(mas, p_enode);
		a_node = mte_parent(p_enode);
		a_slot = mte_parent_slot(p_enode);
		a_enode = mt_mk_node(a_node, a_type);
		pivots = ma_pivots(a_node, a_type);

		if (unlikely(ma_dead_node(a_node)))
			return 1;

		if (!set_min && a_slot) {
			set_min = true;
			min = pivots[a_slot - 1] + 1;
		}

		if (!set_max && a_slot < mt_pivots[a_type]) {
			set_max = true;
			max = pivots[a_slot];
		}

		if (unlikely(ma_dead_node(a_node)))
			return 1;

		if (unlikely(ma_is_root(a_node)))
			break;

	} while (!set_min || !set_max);

	mas->max = max;
	mas->min = min;
	return 0;
}

/*
 * mas_pop_node() - Get a previously allocated maple node from the maple state.
 * @mas: The maple state
 *
 * Return: A pointer to a maple node.
 */
static inline struct maple_node *mas_pop_node(struct ma_state *mas)
{
	struct maple_alloc *ret, *node = mas->alloc;
	unsigned long total = mas_allocated(mas);
	unsigned int req = mas_alloc_req(mas);

	/* nothing or a request pending. */
	if (WARN_ON(!total))
		return NULL;

	if (total == 1) {
		/* single allocation in this ma_state */
		mas->alloc = NULL;
		ret = node;
		goto single_node;
	}

	if (node->node_count == 1) {
		/* Single allocation in this node. */
		mas->alloc = node->slot[0];
		mas->alloc->total = node->total - 1;
		ret = node;
		goto new_head;
	}
	node->total--;
	ret = node->slot[--node->node_count];
	node->slot[node->node_count] = NULL;

single_node:
new_head:
	if (req) {
		req++;
		mas_set_alloc_req(mas, req);
	}

	memset(ret, 0, sizeof(*ret));
	return (struct maple_node *)ret;
}

/*
 * mas_push_node() - Push a node back on the maple state allocation.
 * @mas: The maple state
 * @used: The used maple node
 *
 * Stores the maple node back into @mas->alloc for reuse.  Updates allocated and
 * requested node count as necessary.
 */
static inline void mas_push_node(struct ma_state *mas, struct maple_node *used)
{
	struct maple_alloc *reuse = (struct maple_alloc *)used;
	struct maple_alloc *head = mas->alloc;
	unsigned long count;
	unsigned int requested = mas_alloc_req(mas);

	count = mas_allocated(mas);

	reuse->request_count = 0;
	reuse->node_count = 0;
	if (count && (head->node_count < MAPLE_ALLOC_SLOTS)) {
		head->slot[head->node_count++] = reuse;
		head->total++;
		goto done;
	}

	reuse->total = 1;
	if ((head) && !((unsigned long)head & 0x1)) {
		reuse->slot[0] = head;
		reuse->node_count = 1;
		reuse->total += head->total;
	}

	mas->alloc = reuse;
done:
	if (requested > 1)
		mas_set_alloc_req(mas, requested - 1);
}

/*
 * mas_alloc_nodes() - Allocate nodes into a maple state
 * @mas: The maple state
 * @gfp: The GFP Flags
 */
static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
{
	struct maple_alloc *node;
	unsigned long allocated = mas_allocated(mas);
	unsigned int requested = mas_alloc_req(mas);
	unsigned int count;
	void **slots = NULL;
	unsigned int max_req = 0;

	if (!requested)
		return;

	mas_set_alloc_req(mas, 0);
	if (mas->mas_flags & MA_STATE_PREALLOC) {
		if (allocated)
			return;
		WARN_ON(!allocated);
	}

	if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS) {
		node = (struct maple_alloc *)mt_alloc_one(gfp);
		if (!node)
			goto nomem_one;

		if (allocated) {
			node->slot[0] = mas->alloc;
			node->node_count = 1;
		} else {
			node->node_count = 0;
		}

		mas->alloc = node;
		node->total = ++allocated;
		requested--;
	}

	node = mas->alloc;
	node->request_count = 0;
	while (requested) {
		max_req = MAPLE_ALLOC_SLOTS - node->node_count;
		slots = (void **)&node->slot[node->node_count];
		max_req = min(requested, max_req);
		count = mt_alloc_bulk(gfp, max_req, slots);
		if (!count)
			goto nomem_bulk;

		if (node->node_count == 0) {
			node->slot[0]->node_count = 0;
			node->slot[0]->request_count = 0;
		}

		node->node_count += count;
		allocated += count;
		node = node->slot[0];
		requested -= count;
	}
	mas->alloc->total = allocated;
	return;

nomem_bulk:
	/* Clean up potential freed allocations on bulk failure */
	memset(slots, 0, max_req * sizeof(unsigned long));
nomem_one:
	mas_set_alloc_req(mas, requested);
	if (mas->alloc && !(((unsigned long)mas->alloc & 0x1)))
		mas->alloc->total = allocated;
	mas_set_err(mas, -ENOMEM);
}

/*
 * mas_free() - Free an encoded maple node
 * @mas: The maple state
 * @used: The encoded maple node to free.
 *
 * Uses rcu free if necessary, pushes @used back on the maple state allocations
 * otherwise.
 */
static inline void mas_free(struct ma_state *mas, struct maple_enode *used)
{
	struct maple_node *tmp = mte_to_node(used);

	if (mt_in_rcu(mas->tree))
		ma_free_rcu(tmp);
	else
		mas_push_node(mas, tmp);
}

/*
 * mas_node_count() - Check if enough nodes are allocated and request more if
 * there is not enough nodes.
 * @mas: The maple state
 * @count: The number of nodes needed
 * @gfp: the gfp flags
 */
static void mas_node_count_gfp(struct ma_state *mas, int count, gfp_t gfp)
{
	unsigned long allocated = mas_allocated(mas);

	if (allocated < count) {
		mas_set_alloc_req(mas, count - allocated);
		mas_alloc_nodes(mas, gfp);
	}
}

/*
 * mas_node_count() - Check if enough nodes are allocated and request more if
 * there is not enough nodes.
 * @mas: The maple state
 * @count: The number of nodes needed
 *
 * Note: Uses GFP_NOWAIT | __GFP_NOWARN for gfp flags.
 */
static void mas_node_count(struct ma_state *mas, int count)
{
	return mas_node_count_gfp(mas, count, GFP_NOWAIT | __GFP_NOWARN);
}

/*
 * mas_start() - Sets up maple state for operations.
 * @mas: The maple state.
 *
 * If mas->node == MAS_START, then set the min, max and depth to
 * defaults.
 *
 * Return:
 * - If mas->node is an error or not MAS_START, return NULL.
 * - If it's an empty tree:     NULL & mas->node == MAS_NONE
 * - If it's a single entry:    The entry & mas->node == MAS_ROOT
 * - If it's a tree:            NULL & mas->node == safe root node.
 */
static inline struct maple_enode *mas_start(struct ma_state *mas)
{
	if (likely(mas_is_start(mas))) {
		struct maple_enode *root;

		mas->min = 0;
		mas->max = ULONG_MAX;

retry:
		mas->depth = 0;
		root = mas_root(mas);
		/* Tree with nodes */
		if (likely(xa_is_node(root))) {
			mas->depth = 1;
			mas->node = mte_safe_root(root);
			mas->offset = 0;
			if (mte_dead_node(mas->node))
				goto retry;

			return NULL;
		}

		/* empty tree */
		if (unlikely(!root)) {
			mas->node = MAS_NONE;
			mas->offset = MAPLE_NODE_SLOTS;
			return NULL;
		}

		/* Single entry tree */
		mas->node = MAS_ROOT;
		mas->offset = MAPLE_NODE_SLOTS;

		/* Single entry tree. */
		if (mas->index > 0)
			return NULL;

		return root;
	}

	return NULL;
}

/*
 * ma_data_end() - Find the end of the data in a node.
 * @node: The maple node
 * @type: The maple node type
 * @pivots: The array of pivots in the node
 * @max: The maximum value in the node
 *
 * Uses metadata to find the end of the data when possible.
 * Return: The zero indexed last slot with data (may be null).
 */
static inline unsigned char ma_data_end(struct maple_node *node,
					enum maple_type type,
					unsigned long *pivots,
					unsigned long max)
{
	unsigned char offset;

	if (!pivots)
		return 0;

	if (type == maple_arange_64)
		return ma_meta_end(node, type);

	offset = mt_pivots[type] - 1;
	if (likely(!pivots[offset]))
		return ma_meta_end(node, type);

	if (likely(pivots[offset] == max))
		return offset;

	return mt_pivots[type];
}

/*
 * mas_data_end() - Find the end of the data (slot).
 * @mas: the maple state
 *
 * This method is optimized to check the metadata of a node if the node type
 * supports data end metadata.
 *
 * Return: The zero indexed last slot with data (may be null).
 */
static inline unsigned char mas_data_end(struct ma_state *mas)
{
	enum maple_type type;
	struct maple_node *node;
	unsigned char offset;
	unsigned long *pivots;

	type = mte_node_type(mas->node);
	node = mas_mn(mas);
	if (type == maple_arange_64)
		return ma_meta_end(node, type);

	pivots = ma_pivots(node, type);
	if (unlikely(ma_dead_node(node)))
		return 0;

	offset = mt_pivots[type] - 1;
	if (likely(!pivots[offset]))
		return ma_meta_end(node, type);

	if (likely(pivots[offset] == mas->max))
		return offset;

	return mt_pivots[type];
}

/*
 * mas_leaf_max_gap() - Returns the largest gap in a leaf node
 * @mas - the maple state
 *
 * Return: The maximum gap in the leaf.
 */
static unsigned long mas_leaf_max_gap(struct ma_state *mas)
{
	enum maple_type mt;
	unsigned long pstart, gap, max_gap;
	struct maple_node *mn;
	unsigned long *pivots;
	void __rcu **slots;
	unsigned char i;
	unsigned char max_piv;

	mt = mte_node_type(mas->node);
	mn = mas_mn(mas);
	slots = ma_slots(mn, mt);
	max_gap = 0;
	if (unlikely(ma_is_dense(mt))) {
		gap = 0;
		for (i = 0; i < mt_slots[mt]; i++) {
			if (slots[i]) {
				if (gap > max_gap)
					max_gap = gap;
				gap = 0;
			} else {
				gap++;
			}
		}
		if (gap > max_gap)
			max_gap = gap;
		return max_gap;
	}

	/*
	 * Check the first implied pivot optimizes the loop below and slot 1 may
	 * be skipped if there is a gap in slot 0.
	 */
	pivots = ma_pivots(mn, mt);
	if (likely(!slots[0])) {
		max_gap = pivots[0] - mas->min + 1;
		i = 2;
	} else {
		i = 1;
	}

	/* reduce max_piv as the special case is checked before the loop */
	max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1;
	/*
	 * Check end implied pivot which can only be a gap on the right most
	 * node.
	 */
	if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) {
		gap = ULONG_MAX - pivots[max_piv];
		if (gap > max_gap)
			max_gap = gap;
	}

	for (; i <= max_piv; i++) {
		/* data == no gap. */
		if (likely(slots[i]))
			continue;

		pstart = pivots[i - 1];
		gap = pivots[i] - pstart;
		if (gap > max_gap)
			max_gap = gap;

		/* There cannot be two gaps in a row. */
		i++;
	}
	return max_gap;
}

/*
 * ma_max_gap() - Get the maximum gap in a maple node (non-leaf)
 * @node: The maple node
 * @gaps: The pointer to the gaps
 * @mt: The maple node type
 * @*off: Pointer to store the offset location of the gap.
 *
 * Uses the metadata data end to scan backwards across set gaps.
 *
 * Return: The maximum gap value
 */
static inline unsigned long
ma_max_gap(struct maple_node *node, unsigned long *gaps, enum maple_type mt,
	    unsigned char *off)
{
	unsigned char offset, i;
	unsigned long max_gap = 0;

	i = offset = ma_meta_end(node, mt);
	do {
		if (gaps[i] > max_gap) {
			max_gap = gaps[i];
			offset = i;
		}
	} while (i--);

	*off = offset;
	return max_gap;
}

/*
 * mas_max_gap() - find the largest gap in a non-leaf node and set the slot.
 * @mas: The maple state.
 *
 * Return: The gap value.
 */
static inline unsigned long mas_max_gap(struct ma_state *mas)
{
	unsigned long *gaps;
	unsigned char offset;
	enum maple_type mt;
	struct maple_node *node;

	mt = mte_node_type(mas->node);
	if (ma_is_leaf(mt))
		return mas_leaf_max_gap(mas);

	node = mas_mn(mas);
	MAS_BUG_ON(mas, mt != maple_arange_64);
	offset = ma_meta_gap(node, mt);
	gaps = ma_gaps(node, mt);
	return gaps[offset];
}

/*
 * mas_parent_gap() - Set the parent gap and any gaps above, as needed
 * @mas: The maple state
 * @offset: The gap offset in the parent to set
 * @new: The new gap value.
 *
 * Set the parent gap then continue to set the gap upwards, using the metadata
 * of the parent to see if it is necessary to check the node above.
 */
static inline void mas_parent_gap(struct ma_state *mas, unsigned char offset,
		unsigned long new)
{
	unsigned long meta_gap = 0;
	struct maple_node *pnode;
	struct maple_enode *penode;
	unsigned long *pgaps;
	unsigned char meta_offset;
	enum maple_type pmt;

	pnode = mte_parent(mas->node);
	pmt = mas_parent_type(mas, mas->node);
	penode = mt_mk_node(pnode, pmt);
	pgaps = ma_gaps(pnode, pmt);

ascend:
	MAS_BUG_ON(mas, pmt != maple_arange_64);
	meta_offset = ma_meta_gap(pnode, pmt);
	meta_gap = pgaps[meta_offset];

	pgaps[offset] = new;

	if (meta_gap == new)
		return;

	if (offset != meta_offset) {
		if (meta_gap > new)
			return;

		ma_set_meta_gap(pnode, pmt, offset);
	} else if (new < meta_gap) {
		new = ma_max_gap(pnode, pgaps, pmt, &meta_offset);
		ma_set_meta_gap(pnode, pmt, meta_offset);
	}

	if (ma_is_root(pnode))
		return;

	/* Go to the parent node. */
	pnode = mte_parent(penode);
	pmt = mas_parent_type(mas, penode);
	pgaps = ma_gaps(pnode, pmt);
	offset = mte_parent_slot(penode);
	penode = mt_mk_node(pnode, pmt);
	goto ascend;
}

/*
 * mas_update_gap() - Update a nodes gaps and propagate up if necessary.
 * @mas - the maple state.
 */
static inline void mas_update_gap(struct ma_state *mas)
{
	unsigned char pslot;
	unsigned long p_gap;
	unsigned long max_gap;

	if (!mt_is_alloc(mas->tree))
		return;

	if (mte_is_root(mas->node))
		return;

	max_gap = mas_max_gap(mas);

	pslot = mte_parent_slot(mas->node);
	p_gap = ma_gaps(mte_parent(mas->node),
			mas_parent_type(mas, mas->node))[pslot];

	if (p_gap != max_gap)
		mas_parent_gap(mas, pslot, max_gap);
}

/*
 * mas_adopt_children() - Set the parent pointer of all nodes in @parent to
 * @parent with the slot encoded.
 * @mas - the maple state (for the tree)
 * @parent - the maple encoded node containing the children.
 */
static inline void mas_adopt_children(struct ma_state *mas,
		struct maple_enode *parent)
{
	enum maple_type type = mte_node_type(parent);
	struct maple_node *node = mte_to_node(parent);
	void __rcu **slots = ma_slots(node, type);
	unsigned long *pivots = ma_pivots(node, type);
	struct maple_enode *child;
	unsigned char offset;

	offset = ma_data_end(node, type, pivots, mas->max);
	do {
		child = mas_slot_locked(mas, slots, offset);
		mas_set_parent(mas, child, parent, offset);
	} while (offset--);
}

/*
 * mas_put_in_tree() - Put a new node in the tree, smp_wmb(), and mark the old
 * node as dead.
 * @mas - the maple state with the new node
 * @old_enode - The old maple encoded node to replace.
 */
static inline void mas_put_in_tree(struct ma_state *mas,
		struct maple_enode *old_enode)
	__must_hold(mas->tree->ma_lock)
{
	unsigned char offset;
	void __rcu **slots;

	if (mte_is_root(mas->node)) {
		mas_mn(mas)->parent = ma_parent_ptr(mas_tree_parent(mas));
		rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
		mas_set_height(mas);
	} else {

		offset = mte_parent_slot(mas->node);
		slots = ma_slots(mte_parent(mas->node),
				 mas_parent_type(mas, mas->node));
		rcu_assign_pointer(slots[offset], mas->node);
	}

	mte_set_node_dead(old_enode);
}

/*
 * mas_replace_node() - Replace a node by putting it in the tree, marking it
 * dead, and freeing it.
 * the parent encoding to locate the maple node in the tree.
 * @mas - the ma_state with @mas->node pointing to the new node.
 * @old_enode - The old maple encoded node.
 */
static inline void mas_replace_node(struct ma_state *mas,
		struct maple_enode *old_enode)
	__must_hold(mas->tree->ma_lock)
{
	mas_put_in_tree(mas, old_enode);
	mas_free(mas, old_enode);
}

/*
 * mas_find_child() - Find a child who has the parent @mas->node.
 * @mas: the maple state with the parent.
 * @child: the maple state to store the child.
 */
static inline bool mas_find_child(struct ma_state *mas, struct ma_state *child)
	__must_hold(mas->tree->ma_lock)
{
	enum maple_type mt;
	unsigned char offset;
	unsigned char end;
	unsigned long *pivots;
	struct maple_enode *entry;
	struct maple_node *node;
	void __rcu **slots;

	mt = mte_node_type(mas->node);
	node = mas_mn(mas);
	slots = ma_slots(node, mt);
	pivots = ma_pivots(node, mt);
	end = ma_data_end(node, mt, pivots, mas->max);
	for (offset = mas->offset; offset <= end; offset++) {
		entry = mas_slot_locked(mas, slots, offset);
		if (mte_parent(entry) == node) {
			*child = *mas;
			mas->offset = offset + 1;
			child->offset = offset;
			mas_descend(child);
			child->offset = 0;
			return true;
		}
	}
	return false;
}

/*
 * mab_shift_right() - Shift the data in mab right. Note, does not clean out the
 * old data or set b_node->b_end.
 * @b_node: the maple_big_node
 * @shift: the shift count
 */
static inline void mab_shift_right(struct maple_big_node *b_node,
				 unsigned char shift)
{
	unsigned long size = b_node->b_end * sizeof(unsigned long);

	memmove(b_node->pivot + shift, b_node->pivot, size);
	memmove(b_node->slot + shift, b_node->slot, size);
	if (b_node->type == maple_arange_64)
		memmove(b_node->gap + shift, b_node->gap, size);
}

/*
 * mab_middle_node() - Check if a middle node is needed (unlikely)
 * @b_node: the maple_big_node that contains the data.
 * @size: the amount of data in the b_node
 * @split: the potential split location
 * @slot_count: the size that can be stored in a single node being considered.
 *
 * Return: true if a middle node is required.
 */
static inline bool mab_middle_node(struct maple_big_node *b_node, int split,
				   unsigned char slot_count)
{
	unsigned char size = b_node->b_end;

	if (size >= 2 * slot_count)
		return true;

	if (!b_node->slot[split] && (size >= 2 * slot_count - 1))
		return true;

	return false;
}

/*
 * mab_no_null_split() - ensure the split doesn't fall on a NULL
 * @b_node: the maple_big_node with the data
 * @split: the suggested split location
 * @slot_count: the number of slots in the node being considered.
 *
 * Return: the split location.
 */
static inline int mab_no_null_split(struct maple_big_node *b_node,
				    unsigned char split, unsigned char slot_count)
{
	if (!b_node->slot[split]) {
		/*
		 * If the split is less than the max slot && the right side will
		 * still be sufficient, then increment the split on NULL.
		 */
		if ((split < slot_count - 1) &&
		    (b_node->b_end - split) > (mt_min_slots[b_node->type]))
			split++;
		else
			split--;
	}
	return split;
}

/*
 * mab_calc_split() - Calculate the split location and if there needs to be two
 * splits.
 * @bn: The maple_big_node with the data
 * @mid_split: The second split, if required.  0 otherwise.
 *
 * Return: The first split location.  The middle split is set in @mid_split.
 */
static inline int mab_calc_split(struct ma_state *mas,
	 struct maple_big_node *bn, unsigned char *mid_split, unsigned long min)
{
	unsigned char b_end = bn->b_end;
	int split = b_end / 2; /* Assume equal split. */
	unsigned char slot_min, slot_count = mt_slots[bn->type];

	/*
	 * To support gap tracking, all NULL entries are kept together and a node cannot
	 * end on a NULL entry, with the exception of the left-most leaf.  The
	 * limitation means that the split of a node must be checked for this condition
	 * and be able to put more data in one direction or the other.
	 */
	if (unlikely((mas->mas_flags & MA_STATE_BULK))) {
		*mid_split = 0;
		split = b_end - mt_min_slots[bn->type];

		if (!ma_is_leaf(bn->type))
			return split;

		mas->mas_flags |= MA_STATE_REBALANCE;
		if (!bn->slot[split])
			split--;
		return split;
	}

	/*
	 * Although extremely rare, it is possible to enter what is known as the 3-way
	 * split scenario.  The 3-way split comes about by means of a store of a range
	 * that overwrites the end and beginning of two full nodes.  The result is a set
	 * of entries that cannot be stored in 2 nodes.  Sometimes, these two nodes can
	 * also be located in different parent nodes which are also full.  This can
	 * carry upwards all the way to the root in the worst case.
	 */
	if (unlikely(mab_middle_node(bn, split, slot_count))) {
		split = b_end / 3;
		*mid_split = split * 2;
	} else {
		slot_min = mt_min_slots[bn->type];

		*mid_split = 0;
		/*
		 * Avoid having a range less than the slot count unless it
		 * causes one node to be deficient.
		 * NOTE: mt_min_slots is 1 based, b_end and split are zero.
		 */
		while ((split < slot_count - 1) &&
		       ((bn->pivot[split] - min) < slot_count - 1) &&
		       (b_end - split > slot_min))
			split++;
	}

	/* Avoid ending a node on a NULL entry */
	split = mab_no_null_split(bn, split, slot_count);

	if (unlikely(*mid_split))
		*mid_split = mab_no_null_split(bn, *mid_split, slot_count);

	return split;
}

/*
 * mas_mab_cp() - Copy data from a maple state inclusively to a maple_big_node
 * and set @b_node->b_end to the next free slot.
 * @mas: The maple state
 * @mas_start: The starting slot to copy
 * @mas_end: The end slot to copy (inclusively)
 * @b_node: The maple_big_node to place the data
 * @mab_start: The starting location in maple_big_node to store the data.
 */
static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
			unsigned char mas_end, struct maple_big_node *b_node,
			unsigned char mab_start)
{
	enum maple_type mt;
	struct maple_node *node;
	void __rcu **slots;
	unsigned long *pivots, *gaps;
	int i = mas_start, j = mab_start;
	unsigned char piv_end;

	node = mas_mn(mas);
	mt = mte_node_type(mas->node);
	pivots = ma_pivots(node, mt);
	if (!i) {
		b_node->pivot[j] = pivots[i++];
		if (unlikely(i > mas_end))
			goto complete;
		j++;
	}

	piv_end = min(mas_end, mt_pivots[mt]);
	for (; i < piv_end; i++, j++) {
		b_node->pivot[j] = pivots[i];
		if (unlikely(!b_node->pivot[j]))
			break;

		if (unlikely(mas->max == b_node->pivot[j]))
			goto complete;
	}

	if (likely(i <= mas_end))
		b_node->pivot[j] = mas_safe_pivot(mas, pivots, i, mt);

complete:
	b_node->b_end = ++j;
	j -= mab_start;
	slots = ma_slots(node, mt);
	memcpy(b_node->slot + mab_start, slots + mas_start, sizeof(void *) * j);
	if (!ma_is_leaf(mt) && mt_is_alloc(mas->tree)) {
		gaps = ma_gaps(node, mt);
		memcpy(b_node->gap + mab_start, gaps + mas_start,
		       sizeof(unsigned long) * j);
	}
}

/*
 * mas_leaf_set_meta() - Set the metadata of a leaf if possible.
 * @mas: The maple state
 * @node: The maple node
 * @pivots: pointer to the maple node pivots
 * @mt: The maple type
 * @end: The assumed end
 *
 * Note, end may be incremented within this function but not modified at the
 * source.  This is fine since the metadata is the last thing to be stored in a
 * node during a write.
 */
static inline void mas_leaf_set_meta(struct ma_state *mas,
		struct maple_node *node, unsigned long *pivots,
		enum maple_type mt, unsigned char end)
{
	/* There is no room for metadata already */
	if (mt_pivots[mt] <= end)
		return;

	if (pivots[end] && pivots[end] < mas->max)
		end++;

	if (end < mt_slots[mt] - 1)
		ma_set_meta(node, mt, 0, end);
}

/*
 * mab_mas_cp() - Copy data from maple_big_node to a maple encoded node.
 * @b_node: the maple_big_node that has the data
 * @mab_start: the start location in @b_node.
 * @mab_end: The end location in @b_node (inclusively)
 * @mas: The maple state with the maple encoded node.
 */
static inline void mab_mas_cp(struct maple_big_node *b_node,
			      unsigned char mab_start, unsigned char mab_end,
			      struct ma_state *mas, bool new_max)
{
	int i, j = 0;
	enum maple_type mt = mte_node_type(mas->node);
	struct maple_node *node = mte_to_node(mas->node);
	void __rcu **slots = ma_slots(node, mt);
	unsigned long *pivots = ma_pivots(node, mt);
	unsigned long *gaps = NULL;
	unsigned char end;

	if (mab_end - mab_start > mt_pivots[mt])
		mab_end--;

	if (!pivots[mt_pivots[mt] - 1])
		slots[mt_pivots[mt]] = NULL;

	i = mab_start;
	do {
		pivots[j++] = b_node->pivot[i++];
	} while (i <= mab_end && likely(b_node->pivot[i]));

	memcpy(slots, b_node->slot + mab_start,
	       sizeof(void *) * (i - mab_start));

	if (new_max)
		mas->max = b_node->pivot[i - 1];

	end = j - 1;
	if (likely(!ma_is_leaf(mt) && mt_is_alloc(mas->tree))) {
		unsigned long max_gap = 0;
		unsigned char offset = 0;

		gaps = ma_gaps(node, mt);
		do {
			gaps[--j] = b_node->gap[--i];
			if (gaps[j] > max_gap) {
				offset = j;
				max_gap = gaps[j];
			}
		} while (j);

		ma_set_meta(node, mt, offset, end);
	} else {
		mas_leaf_set_meta(mas, node, pivots, mt, end);
	}
}

/*
 * mas_bulk_rebalance() - Rebalance the end of a tree after a bulk insert.
 * @mas: The maple state
 * @end: The maple node end
 * @mt: The maple node type
 */
static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end,
				      enum maple_type mt)
{
	if (!(mas->mas_flags & MA_STATE_BULK))
		return;

	if (mte_is_root(mas->node))
		return;

	if (end > mt_min_slots[mt]) {
		mas->mas_flags &= ~MA_STATE_REBALANCE;
		return;
	}
}

/*
 * mas_store_b_node() - Store an @entry into the b_node while also copying the
 * data from a maple encoded node.
 * @wr_mas: the maple write state
 * @b_node: the maple_big_node to fill with data
 * @offset_end: the offset to end copying
 *
 * Return: The actual end of the data stored in @b_node
 */
static noinline_for_kasan void mas_store_b_node(struct ma_wr_state *wr_mas,
		struct maple_big_node *b_node, unsigned char offset_end)
{
	unsigned char slot;
	unsigned char b_end;
	/* Possible underflow of piv will wrap back to 0 before use. */
	unsigned long piv;
	struct ma_state *mas = wr_mas->mas;

	b_node->type = wr_mas->type;
	b_end = 0;
	slot = mas->offset;
	if (slot) {
		/* Copy start data up to insert. */
		mas_mab_cp(mas, 0, slot - 1, b_node, 0);
		b_end = b_node->b_end;
		piv = b_node->pivot[b_end - 1];
	} else
		piv = mas->min - 1;

	if (piv + 1 < mas->index) {
		/* Handle range starting after old range */
		b_node->slot[b_end] = wr_mas->content;
		if (!wr_mas->content)
			b_node->gap[b_end] = mas->index - 1 - piv;
		b_node->pivot[b_end++] = mas->index - 1;
	}

	/* Store the new entry. */
	mas->offset = b_end;
	b_node->slot[b_end] = wr_mas->entry;
	b_node->pivot[b_end] = mas->last;

	/* Appended. */
	if (mas->last >= mas->max)
		goto b_end;

	/* Handle new range ending before old range ends */
	piv = mas_safe_pivot(mas, wr_mas->pivots, offset_end, wr_mas->type);
	if (piv > mas->last) {
		if (piv == ULONG_MAX)
			mas_bulk_rebalance(mas, b_node->b_end, wr_mas->type);

		if (offset_end != slot)
			wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
							  offset_end);

		b_node->slot[++b_end] = wr_mas->content;
		if (!wr_mas->content)
			b_node->gap[b_end] = piv - mas->last + 1;
		b_node->pivot[b_end] = piv;
	}

	slot = offset_end + 1;
	if (slot > wr_mas->node_end)
		goto b_end;

	/* Copy end data to the end of the node. */
	mas_mab_cp(mas, slot, wr_mas->node_end + 1, b_node, ++b_end);
	b_node->b_end--;
	return;

b_end:
	b_node->b_end = b_end;
}

/*
 * mas_prev_sibling() - Find the previous node with the same parent.
 * @mas: the maple state
 *
 * Return: True if there is a previous sibling, false otherwise.
 */
static inline bool mas_prev_sibling(struct ma_state *mas)
{
	unsigned int p_slot = mte_parent_slot(mas->node);

	if (mte_is_root(mas->node))
		return false;

	if (!p_slot)
		return false;

	mas_ascend(mas);
	mas->offset = p_slot - 1;
	mas_descend(mas);
	return true;
}

/*
 * mas_next_sibling() - Find the next node with the same parent.
 * @mas: the maple state
 *
 * Return: true if there is a next sibling, false otherwise.
 */
static inline bool mas_next_sibling(struct ma_state *mas)
{
	MA_STATE(parent, mas->tree, mas->index, mas->last);

	if (mte_is_root(mas->node))
		return false;

	parent = *mas;
	mas_ascend(&parent);
	parent.offset = mte_parent_slot(mas->node) + 1;
	if (parent.offset > mas_data_end(&parent))
		return false;

	*mas = parent;
	mas_descend(mas);
	return true;
}

/*
 * mte_node_or_node() - Return the encoded node or MAS_NONE.
 * @enode: The encoded maple node.
 *
 * Shorthand to avoid setting %NULLs in the tree or maple_subtree_state.
 *
 * Return: @enode or MAS_NONE
 */
static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode)
{
	if (enode)
		return enode;

	return ma_enode_ptr(MAS_NONE);
}

/*
 * mas_wr_node_walk() - Find the correct offset for the index in the @mas.
 * @wr_mas: The maple write state
 *
 * Uses mas_slot_locked() and does not need to worry about dead nodes.
 */
static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;
	unsigned char count, offset;

	if (unlikely(ma_is_dense(wr_mas->type))) {
		wr_mas->r_max = wr_mas->r_min = mas->index;
		mas->offset = mas->index = mas->min;
		return;
	}

	wr_mas->node = mas_mn(wr_mas->mas);
	wr_mas->pivots = ma_pivots(wr_mas->node, wr_mas->type);
	count = wr_mas->node_end = ma_data_end(wr_mas->node, wr_mas->type,
					       wr_mas->pivots, mas->max);
	offset = mas->offset;

	while (offset < count && mas->index > wr_mas->pivots[offset])
		offset++;

	wr_mas->r_max = offset < count ? wr_mas->pivots[offset] : mas->max;
	wr_mas->r_min = mas_safe_min(mas, wr_mas->pivots, offset);
	wr_mas->offset_end = mas->offset = offset;
}

/*
 * mast_rebalance_next() - Rebalance against the next node
 * @mast: The maple subtree state
 * @old_r: The encoded maple node to the right (next node).
 */
static inline void mast_rebalance_next(struct maple_subtree_state *mast)
{
	unsigned char b_end = mast->bn->b_end;

	mas_mab_cp(mast->orig_r, 0, mt_slot_count(mast->orig_r->node),
		   mast->bn, b_end);
	mast->orig_r->last = mast->orig_r->max;
}

/*
 * mast_rebalance_prev() - Rebalance against the previous node
 * @mast: The maple subtree state
 * @old_l: The encoded maple node to the left (previous node)
 */
static inline void mast_rebalance_prev(struct maple_subtree_state *mast)
{
	unsigned char end = mas_data_end(mast->orig_l) + 1;
	unsigned char b_end = mast->bn->b_end;

	mab_shift_right(mast->bn, end);
	mas_mab_cp(mast->orig_l, 0, end - 1, mast->bn, 0);
	mast->l->min = mast->orig_l->min;
	mast->orig_l->index = mast->orig_l->min;
	mast->bn->b_end = end + b_end;
	mast->l->offset += end;
}

/*
 * mast_spanning_rebalance() - Rebalance nodes with nearest neighbour favouring
 * the node to the right.  Checking the nodes to the right then the left at each
 * level upwards until root is reached.
 * Data is copied into the @mast->bn.
 * @mast: The maple_subtree_state.
 */
static inline
bool mast_spanning_rebalance(struct maple_subtree_state *mast)
{
	struct ma_state r_tmp = *mast->orig_r;
	struct ma_state l_tmp = *mast->orig_l;
	unsigned char depth = 0;

	r_tmp = *mast->orig_r;
	l_tmp = *mast->orig_l;
	do {
		mas_ascend(mast->orig_r);
		mas_ascend(mast->orig_l);
		depth++;
		if (mast->orig_r->offset < mas_data_end(mast->orig_r)) {
			mast->orig_r->offset++;
			do {
				mas_descend(mast->orig_r);
				mast->orig_r->offset = 0;
			} while (--depth);

			mast_rebalance_next(mast);
			*mast->orig_l = l_tmp;
			return true;
		} else if (mast->orig_l->offset != 0) {
			mast->orig_l->offset--;
			do {
				mas_descend(mast->orig_l);
				mast->orig_l->offset =
					mas_data_end(mast->orig_l);
			} while (--depth);

			mast_rebalance_prev(mast);
			*mast->orig_r = r_tmp;
			return true;
		}
	} while (!mte_is_root(mast->orig_r->node));

	*mast->orig_r = r_tmp;
	*mast->orig_l = l_tmp;
	return false;
}

/*
 * mast_ascend() - Ascend the original left and right maple states.
 * @mast: the maple subtree state.
 *
 * Ascend the original left and right sides.  Set the offsets to point to the
 * data already in the new tree (@mast->l and @mast->r).
 */
static inline void mast_ascend(struct maple_subtree_state *mast)
{
	MA_WR_STATE(wr_mas, mast->orig_r,  NULL);
	mas_ascend(mast->orig_l);
	mas_ascend(mast->orig_r);

	mast->orig_r->offset = 0;
	mast->orig_r->index = mast->r->max;
	/* last should be larger than or equal to index */
	if (mast->orig_r->last < mast->orig_r->index)
		mast->orig_r->last = mast->orig_r->index;

	wr_mas.type = mte_node_type(mast->orig_r->node);
	mas_wr_node_walk(&wr_mas);
	/* Set up the left side of things */
	mast->orig_l->offset = 0;
	mast->orig_l->index = mast->l->min;
	wr_mas.mas = mast->orig_l;
	wr_mas.type = mte_node_type(mast->orig_l->node);
	mas_wr_node_walk(&wr_mas);

	mast->bn->type = wr_mas.type;
}

/*
 * mas_new_ma_node() - Create and return a new maple node.  Helper function.
 * @mas: the maple state with the allocations.
 * @b_node: the maple_big_node with the type encoding.
 *
 * Use the node type from the maple_big_node to allocate a new node from the
 * ma_state.  This function exists mainly for code readability.
 *
 * Return: A new maple encoded node
 */
static inline struct maple_enode
*mas_new_ma_node(struct ma_state *mas, struct maple_big_node *b_node)
{
	return mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), b_node->type);
}

/*
 * mas_mab_to_node() - Set up right and middle nodes
 *
 * @mas: the maple state that contains the allocations.
 * @b_node: the node which contains the data.
 * @left: The pointer which will have the left node
 * @right: The pointer which may have the right node
 * @middle: the pointer which may have the middle node (rare)
 * @mid_split: the split location for the middle node
 *
 * Return: the split of left.
 */
static inline unsigned char mas_mab_to_node(struct ma_state *mas,
	struct maple_big_node *b_node, struct maple_enode **left,
	struct maple_enode **right, struct maple_enode **middle,
	unsigned char *mid_split, unsigned long min)
{
	unsigned char split = 0;
	unsigned char slot_count = mt_slots[b_node->type];

	*left = mas_new_ma_node(mas, b_node);
	*right = NULL;
	*middle = NULL;
	*mid_split = 0;

	if (b_node->b_end < slot_count) {
		split = b_node->b_end;
	} else {
		split = mab_calc_split(mas, b_node, mid_split, min);
		*right = mas_new_ma_node(mas, b_node);
	}

	if (*mid_split)
		*middle = mas_new_ma_node(mas, b_node);

	return split;

}

/*
 * mab_set_b_end() - Add entry to b_node at b_node->b_end and increment the end
 * pointer.
 * @b_node - the big node to add the entry
 * @mas - the maple state to get the pivot (mas->max)
 * @entry - the entry to add, if NULL nothing happens.
 */
static inline void mab_set_b_end(struct maple_big_node *b_node,
				 struct ma_state *mas,
				 void *entry)
{
	if (!entry)
		return;

	b_node->slot[b_node->b_end] = entry;
	if (mt_is_alloc(mas->tree))
		b_node->gap[b_node->b_end] = mas_max_gap(mas);
	b_node->pivot[b_node->b_end++] = mas->max;
}

/*
 * mas_set_split_parent() - combine_then_separate helper function.  Sets the parent
 * of @mas->node to either @left or @right, depending on @slot and @split
 *
 * @mas - the maple state with the node that needs a parent
 * @left - possible parent 1
 * @right - possible parent 2
 * @slot - the slot the mas->node was placed
 * @split - the split location between @left and @right
 */
static inline void mas_set_split_parent(struct ma_state *mas,
					struct maple_enode *left,
					struct maple_enode *right,
					unsigned char *slot, unsigned char split)
{
	if (mas_is_none(mas))
		return;

	if ((*slot) <= split)
		mas_set_parent(mas, mas->node, left, *slot);
	else if (right)
		mas_set_parent(mas, mas->node, right, (*slot) - split - 1);

	(*slot)++;
}

/*
 * mte_mid_split_check() - Check if the next node passes the mid-split
 * @**l: Pointer to left encoded maple node.
 * @**m: Pointer to middle encoded maple node.
 * @**r: Pointer to right encoded maple node.
 * @slot: The offset
 * @*split: The split location.
 * @mid_split: The middle split.
 */
static inline void mte_mid_split_check(struct maple_enode **l,
				       struct maple_enode **r,
				       struct maple_enode *right,
				       unsigned char slot,
				       unsigned char *split,
				       unsigned char mid_split)
{
	if (*r == right)
		return;

	if (slot < mid_split)
		return;

	*l = *r;
	*r = right;
	*split = mid_split;
}

/*
 * mast_set_split_parents() - Helper function to set three nodes parents.  Slot
 * is taken from @mast->l.
 * @mast - the maple subtree state
 * @left - the left node
 * @right - the right node
 * @split - the split location.
 */
static inline void mast_set_split_parents(struct maple_subtree_state *mast,
					  struct maple_enode *left,
					  struct maple_enode *middle,
					  struct maple_enode *right,
					  unsigned char split,
					  unsigned char mid_split)
{
	unsigned char slot;
	struct maple_enode *l = left;
	struct maple_enode *r = right;

	if (mas_is_none(mast->l))
		return;

	if (middle)
		r = middle;

	slot = mast->l->offset;

	mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
	mas_set_split_parent(mast->l, l, r, &slot, split);

	mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
	mas_set_split_parent(mast->m, l, r, &slot, split);

	mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
	mas_set_split_parent(mast->r, l, r, &slot, split);
}

/*
 * mas_topiary_node() - Dispose of a singe node
 * @mas: The maple state for pushing nodes
 * @enode: The encoded maple node
 * @in_rcu: If the tree is in rcu mode
 *
 * The node will either be RCU freed or pushed back on the maple state.
 */
static inline void mas_topiary_node(struct ma_state *mas,
		struct maple_enode *enode, bool in_rcu)
{
	struct maple_node *tmp;

	if (enode == MAS_NONE)
		return;

	tmp = mte_to_node(enode);
	mte_set_node_dead(enode);
	if (in_rcu)
		ma_free_rcu(tmp);
	else
		mas_push_node(mas, tmp);
}

/*
 * mas_topiary_replace() - Replace the data with new data, then repair the
 * parent links within the new tree.  Iterate over the dead sub-tree and collect
 * the dead subtrees and topiary the nodes that are no longer of use.
 *
 * The new tree will have up to three children with the correct parent.  Keep
 * track of the new entries as they need to be followed to find the next level
 * of new entries.
 *
 * The old tree will have up to three children with the old parent.  Keep track
 * of the old entries as they may have more nodes below replaced.  Nodes within
 * [index, last] are dead subtrees, others need to be freed and followed.
 *
 * @mas: The maple state pointing at the new data
 * @old_enode: The maple encoded node being replaced
 *
 */
static inline void mas_topiary_replace(struct ma_state *mas,
		struct maple_enode *old_enode)
{
	struct ma_state tmp[3], tmp_next[3];
	MA_TOPIARY(subtrees, mas->tree);
	bool in_rcu;
	int i, n;

	/* Place data in tree & then mark node as old */
	mas_put_in_tree(mas, old_enode);

	/* Update the parent pointers in the tree */
	tmp[0] = *mas;
	tmp[0].offset = 0;
	tmp[1].node = MAS_NONE;
	tmp[2].node = MAS_NONE;
	while (!mte_is_leaf(tmp[0].node)) {
		n = 0;
		for (i = 0; i < 3; i++) {
			if (mas_is_none(&tmp[i]))
				continue;

			while (n < 3) {
				if (!mas_find_child(&tmp[i], &tmp_next[n]))
					break;
				n++;
			}

			mas_adopt_children(&tmp[i], tmp[i].node);
		}

		if (MAS_WARN_ON(mas, n == 0))
			break;

		while (n < 3)
			tmp_next[n++].node = MAS_NONE;

		for (i = 0; i < 3; i++)
			tmp[i] = tmp_next[i];
	}

	/* Collect the old nodes that need to be discarded */
	if (mte_is_leaf(old_enode))
		return mas_free(mas, old_enode);

	tmp[0] = *mas;
	tmp[0].offset = 0;
	tmp[0].node = old_enode;
	tmp[1].node = MAS_NONE;
	tmp[2].node = MAS_NONE;
	in_rcu = mt_in_rcu(mas->tree);
	do {
		n = 0;
		for (i = 0; i < 3; i++) {
			if (mas_is_none(&tmp[i]))
				continue;

			while (n < 3) {
				if (!mas_find_child(&tmp[i], &tmp_next[n]))
					break;

				if ((tmp_next[n].min >= tmp_next->index) &&
				    (tmp_next[n].max <= tmp_next->last)) {
					mat_add(&subtrees, tmp_next[n].node);
					tmp_next[n].node = MAS_NONE;
				} else {
					n++;
				}
			}
		}

		if (MAS_WARN_ON(mas, n == 0))
			break;

		while (n < 3)
			tmp_next[n++].node = MAS_NONE;

		for (i = 0; i < 3; i++) {
			mas_topiary_node(mas, tmp[i].node, in_rcu);
			tmp[i] = tmp_next[i];
		}
	} while (!mte_is_leaf(tmp[0].node));

	for (i = 0; i < 3; i++)
		mas_topiary_node(mas, tmp[i].node, in_rcu);

	mas_mat_destroy(mas, &subtrees);
}

/*
 * mas_wmb_replace() - Write memory barrier and replace
 * @mas: The maple state
 * @old: The old maple encoded node that is being replaced.
 *
 * Updates gap as necessary.
 */
static inline void mas_wmb_replace(struct ma_state *mas,
		struct maple_enode *old_enode)
{
	/* Insert the new data in the tree */
	mas_topiary_replace(mas, old_enode);

	if (mte_is_leaf(mas->node))
		return;

	mas_update_gap(mas);
}

/*
 * mast_cp_to_nodes() - Copy data out to nodes.
 * @mast: The maple subtree state
 * @left: The left encoded maple node
 * @middle: The middle encoded maple node
 * @right: The right encoded maple node
 * @split: The location to split between left and (middle ? middle : right)
 * @mid_split: The location to split between middle and right.
 */
static inline void mast_cp_to_nodes(struct maple_subtree_state *mast,
	struct maple_enode *left, struct maple_enode *middle,
	struct maple_enode *right, unsigned char split, unsigned char mid_split)
{
	bool new_lmax = true;

	mast->l->node = mte_node_or_none(left);
	mast->m->node = mte_node_or_none(middle);
	mast->r->node = mte_node_or_none(right);

	mast->l->min = mast->orig_l->min;
	if (split == mast->bn->b_end) {
		mast->l->max = mast->orig_r->max;
		new_lmax = false;
	}

	mab_mas_cp(mast->bn, 0, split, mast->l, new_lmax);

	if (middle) {
		mab_mas_cp(mast->bn, 1 + split, mid_split, mast->m, true);
		mast->m->min = mast->bn->pivot[split] + 1;
		split = mid_split;
	}

	mast->r->max = mast->orig_r->max;
	if (right) {
		mab_mas_cp(mast->bn, 1 + split, mast->bn->b_end, mast->r, false);
		mast->r->min = mast->bn->pivot[split] + 1;
	}
}

/*
 * mast_combine_cp_left - Copy in the original left side of the tree into the
 * combined data set in the maple subtree state big node.
 * @mast: The maple subtree state
 */
static inline void mast_combine_cp_left(struct maple_subtree_state *mast)
{
	unsigned char l_slot = mast->orig_l->offset;

	if (!l_slot)
		return;

	mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
}

/*
 * mast_combine_cp_right: Copy in the original right side of the tree into the
 * combined data set in the maple subtree state big node.
 * @mast: The maple subtree state
 */
static inline void mast_combine_cp_right(struct maple_subtree_state *mast)
{
	if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max)
		return;

	mas_mab_cp(mast->orig_r, mast->orig_r->offset + 1,
		   mt_slot_count(mast->orig_r->node), mast->bn,
		   mast->bn->b_end);
	mast->orig_r->last = mast->orig_r->max;
}

/*
 * mast_sufficient: Check if the maple subtree state has enough data in the big
 * node to create at least one sufficient node
 * @mast: the maple subtree state
 */
static inline bool mast_sufficient(struct maple_subtree_state *mast)
{
	if (mast->bn->b_end > mt_min_slot_count(mast->orig_l->node))
		return true;

	return false;
}

/*
 * mast_overflow: Check if there is too much data in the subtree state for a
 * single node.
 * @mast: The maple subtree state
 */
static inline bool mast_overflow(struct maple_subtree_state *mast)
{
	if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node))
		return true;

	return false;
}

static inline void *mtree_range_walk(struct ma_state *mas)
{
	unsigned long *pivots;
	unsigned char offset;
	struct maple_node *node;
	struct maple_enode *next, *last;
	enum maple_type type;
	void __rcu **slots;
	unsigned char end;
	unsigned long max, min;
	unsigned long prev_max, prev_min;

	next = mas->node;
	min = mas->min;
	max = mas->max;
	do {
		offset = 0;
		last = next;
		node = mte_to_node(next);
		type = mte_node_type(next);
		pivots = ma_pivots(node, type);
		end = ma_data_end(node, type, pivots, max);
		if (unlikely(ma_dead_node(node)))
			goto dead_node;

		if (pivots[offset] >= mas->index) {
			prev_max = max;
			prev_min = min;
			max = pivots[offset];
			goto next;
		}

		do {
			offset++;
		} while ((offset < end) && (pivots[offset] < mas->index));

		prev_min = min;
		min = pivots[offset - 1] + 1;
		prev_max = max;
		if (likely(offset < end && pivots[offset]))
			max = pivots[offset];

next:
		slots = ma_slots(node, type);
		next = mt_slot(mas->tree, slots, offset);
		if (unlikely(ma_dead_node(node)))
			goto dead_node;
	} while (!ma_is_leaf(type));

	mas->offset = offset;
	mas->index = min;
	mas->last = max;
	mas->min = prev_min;
	mas->max = prev_max;
	mas->node = last;
	return (void *)next;

dead_node:
	mas_reset(mas);
	return NULL;
}

/*
 * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
 * @mas: The starting maple state
 * @mast: The maple_subtree_state, keeps track of 4 maple states.
 * @count: The estimated count of iterations needed.
 *
 * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
 * is hit.  First @b_node is split into two entries which are inserted into the
 * next iteration of the loop.  @b_node is returned populated with the final
 * iteration. @mas is used to obtain allocations.  orig_l_mas keeps track of the
 * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
 * to account of what has been copied into the new sub-tree.  The update of
 * orig_l_mas->last is used in mas_consume to find the slots that will need to
 * be either freed or destroyed.  orig_l_mas->depth keeps track of the height of
 * the new sub-tree in case the sub-tree becomes the full tree.
 *
 * Return: the number of elements in b_node during the last loop.
 */
static int mas_spanning_rebalance(struct ma_state *mas,
		struct maple_subtree_state *mast, unsigned char count)
{
	unsigned char split, mid_split;
	unsigned char slot = 0;
	struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
	struct maple_enode *old_enode;

	MA_STATE(l_mas, mas->tree, mas->index, mas->index);
	MA_STATE(r_mas, mas->tree, mas->index, mas->last);
	MA_STATE(m_mas, mas->tree, mas->index, mas->index);

	/*
	 * The tree needs to be rebalanced and leaves need to be kept at the same level.
	 * Rebalancing is done by use of the ``struct maple_topiary``.
	 */
	mast->l = &l_mas;
	mast->m = &m_mas;
	mast->r = &r_mas;
	l_mas.node = r_mas.node = m_mas.node = MAS_NONE;

	/* Check if this is not root and has sufficient data.  */
	if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) &&
	    unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
		mast_spanning_rebalance(mast);

	l_mas.depth = 0;

	/*
	 * Each level of the tree is examined and balanced, pushing data to the left or
	 * right, or rebalancing against left or right nodes is employed to avoid
	 * rippling up the tree to limit the amount of churn.  Once a new sub-section of
	 * the tree is created, there may be a mix of new and old nodes.  The old nodes
	 * will have the incorrect parent pointers and currently be in two trees: the
	 * original tree and the partially new tree.  To remedy the parent pointers in
	 * the old tree, the new data is swapped into the active tree and a walk down
	 * the tree is performed and the parent pointers are updated.
	 * See mas_topiary_replace() for more information.
	 */
	while (count--) {
		mast->bn->b_end--;
		mast->bn->type = mte_node_type(mast->orig_l->node);
		split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
					&mid_split, mast->orig_l->min);
		mast_set_split_parents(mast, left, middle, right, split,
				       mid_split);
		mast_cp_to_nodes(mast, left, middle, right, split, mid_split);

		/*
		 * Copy data from next level in the tree to mast->bn from next
		 * iteration
		 */
		memset(mast->bn, 0, sizeof(struct maple_big_node));
		mast->bn->type = mte_node_type(left);
		l_mas.depth++;

		/* Root already stored in l->node. */
		if (mas_is_root_limits(mast->l))
			goto new_root;

		mast_ascend(mast);
		mast_combine_cp_left(mast);
		l_mas.offset = mast->bn->b_end;
		mab_set_b_end(mast->bn, &l_mas, left);
		mab_set_b_end(mast->bn, &m_mas, middle);
		mab_set_b_end(mast->bn, &r_mas, right);

		/* Copy anything necessary out of the right node. */
		mast_combine_cp_right(mast);
		mast->orig_l->last = mast->orig_l->max;

		if (mast_sufficient(mast))
			continue;

		if (mast_overflow(mast))
			continue;

		/* May be a new root stored in mast->bn */
		if (mas_is_root_limits(mast->orig_l))
			break;

		mast_spanning_rebalance(mast);

		/* rebalancing from other nodes may require another loop. */
		if (!count)
			count++;
	}

	l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
				mte_node_type(mast->orig_l->node));
	l_mas.depth++;
	mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
	mas_set_parent(mas, left, l_mas.node, slot);
	if (middle)
		mas_set_parent(mas, middle, l_mas.node, ++slot);

	if (right)
		mas_set_parent(mas, right, l_mas.node, ++slot);

	if (mas_is_root_limits(mast->l)) {
new_root:
		mas_mn(mast->l)->parent = ma_parent_ptr(mas_tree_parent(mas));
		while (!mte_is_root(mast->orig_l->node))
			mast_ascend(mast);
	} else {
		mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent;
	}

	old_enode = mast->orig_l->node;
	mas->depth = l_mas.depth;
	mas->node = l_mas.node;
	mas->min = l_mas.min;
	mas->max = l_mas.max;
	mas->offset = l_mas.offset;
	mas_wmb_replace(mas, old_enode);
	mtree_range_walk(mas);
	return mast->bn->b_end;
}

/*
 * mas_rebalance() - Rebalance a given node.
 * @mas: The maple state
 * @b_node: The big maple node.
 *
 * Rebalance two nodes into a single node or two new nodes that are sufficient.
 * Continue upwards until tree is sufficient.
 *
 * Return: the number of elements in b_node during the last loop.
 */
static inline int mas_rebalance(struct ma_state *mas,
				struct maple_big_node *b_node)
{
	char empty_count = mas_mt_height(mas);
	struct maple_subtree_state mast;
	unsigned char shift, b_end = ++b_node->b_end;

	MA_STATE(l_mas, mas->tree, mas->index, mas->last);
	MA_STATE(r_mas, mas->tree, mas->index, mas->last);

	trace_ma_op(__func__, mas);

	/*
	 * Rebalancing occurs if a node is insufficient.  Data is rebalanced
	 * against the node to the right if it exists, otherwise the node to the
	 * left of this node is rebalanced against this node.  If rebalancing
	 * causes just one node to be produced instead of two, then the parent
	 * is also examined and rebalanced if it is insufficient.  Every level
	 * tries to combine the data in the same way.  If one node contains the
	 * entire range of the tree, then that node is used as a new root node.
	 */
	mas_node_count(mas, empty_count * 2 - 1);
	if (mas_is_err(mas))
		return 0;

	mast.orig_l = &l_mas;
	mast.orig_r = &r_mas;
	mast.bn = b_node;
	mast.bn->type = mte_node_type(mas->node);

	l_mas = r_mas = *mas;

	if (mas_next_sibling(&r_mas)) {
		mas_mab_cp(&r_mas, 0, mt_slot_count(r_mas.node), b_node, b_end);
		r_mas.last = r_mas.index = r_mas.max;
	} else {
		mas_prev_sibling(&l_mas);
		shift = mas_data_end(&l_mas) + 1;
		mab_shift_right(b_node, shift);
		mas->offset += shift;
		mas_mab_cp(&l_mas, 0, shift - 1, b_node, 0);
		b_node->b_end = shift + b_end;
		l_mas.index = l_mas.last = l_mas.min;
	}

	return mas_spanning_rebalance(mas, &mast, empty_count);
}

/*
 * mas_destroy_rebalance() - Rebalance left-most node while destroying the maple
 * state.
 * @mas: The maple state
 * @end: The end of the left-most node.
 *
 * During a mass-insert event (such as forking), it may be necessary to
 * rebalance the left-most node when it is not sufficient.
 */
static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end)
{
	enum maple_type mt = mte_node_type(mas->node);
	struct maple_node reuse, *newnode, *parent, *new_left, *left, *node;
	struct maple_enode *eparent, *old_eparent;
	unsigned char offset, tmp, split = mt_slots[mt] / 2;
	void __rcu **l_slots, **slots;
	unsigned long *l_pivs, *pivs, gap;
	bool in_rcu = mt_in_rcu(mas->tree);

	MA_STATE(l_mas, mas->tree, mas->index, mas->last);

	l_mas = *mas;
	mas_prev_sibling(&l_mas);

	/* set up node. */
	if (in_rcu) {
		/* Allocate for both left and right as well as parent. */
		mas_node_count(mas, 3);
		if (mas_is_err(mas))
			return;

		newnode = mas_pop_node(mas);
	} else {
		newnode = &reuse;
	}

	node = mas_mn(mas);
	newnode->parent = node->parent;
	slots = ma_slots(newnode, mt);
	pivs = ma_pivots(newnode, mt);
	left = mas_mn(&l_mas);
	l_slots = ma_slots(left, mt);
	l_pivs = ma_pivots(left, mt);
	if (!l_slots[split])
		split++;
	tmp = mas_data_end(&l_mas) - split;

	memcpy(slots, l_slots + split + 1, sizeof(void *) * tmp);
	memcpy(pivs, l_pivs + split + 1, sizeof(unsigned long) * tmp);
	pivs[tmp] = l_mas.max;
	memcpy(slots + tmp, ma_slots(node, mt), sizeof(void *) * end);
	memcpy(pivs + tmp, ma_pivots(node, mt), sizeof(unsigned long) * end);

	l_mas.max = l_pivs[split];
	mas->min = l_mas.max + 1;
	old_eparent = mt_mk_node(mte_parent(l_mas.node),
			     mas_parent_type(&l_mas, l_mas.node));
	tmp += end;
	if (!in_rcu) {
		unsigned char max_p = mt_pivots[mt];
		unsigned char max_s = mt_slots[mt];

		if (tmp < max_p)
			memset(pivs + tmp, 0,
			       sizeof(unsigned long) * (max_p - tmp));

		if (tmp < mt_slots[mt])
			memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp));

		memcpy(node, newnode, sizeof(struct maple_node));
		ma_set_meta(node, mt, 0, tmp - 1);
		mte_set_pivot(old_eparent, mte_parent_slot(l_mas.node),
			      l_pivs[split]);

		/* Remove data from l_pivs. */
		tmp = split + 1;
		memset(l_pivs + tmp, 0, sizeof(unsigned long) * (max_p - tmp));
		memset(l_slots + tmp, 0, sizeof(void *) * (max_s - tmp));
		ma_set_meta(left, mt, 0, split);
		eparent = old_eparent;

		goto done;
	}

	/* RCU requires replacing both l_mas, mas, and parent. */
	mas->node = mt_mk_node(newnode, mt);
	ma_set_meta(newnode, mt, 0, tmp);

	new_left = mas_pop_node(mas);
	new_left->parent = left->parent;
	mt = mte_node_type(l_mas.node);
	slots = ma_slots(new_left, mt);
	pivs = ma_pivots(new_left, mt);
	memcpy(slots, l_slots, sizeof(void *) * split);
	memcpy(pivs, l_pivs, sizeof(unsigned long) * split);
	ma_set_meta(new_left, mt, 0, split);
	l_mas.node = mt_mk_node(new_left, mt);

	/* replace parent. */
	offset = mte_parent_slot(mas->node);
	mt = mas_parent_type(&l_mas, l_mas.node);
	parent = mas_pop_node(mas);
	slots = ma_slots(parent, mt);
	pivs = ma_pivots(parent, mt);
	memcpy(parent, mte_to_node(old_eparent), sizeof(struct maple_node));
	rcu_assign_pointer(slots[offset], mas->node);
	rcu_assign_pointer(slots[offset - 1], l_mas.node);
	pivs[offset - 1] = l_mas.max;
	eparent = mt_mk_node(parent, mt);
done:
	gap = mas_leaf_max_gap(mas);
	mte_set_gap(eparent, mte_parent_slot(mas->node), gap);
	gap = mas_leaf_max_gap(&l_mas);
	mte_set_gap(eparent, mte_parent_slot(l_mas.node), gap);
	mas_ascend(mas);

	if (in_rcu) {
		mas_replace_node(mas, old_eparent);
		mas_adopt_children(mas, mas->node);
	}

	mas_update_gap(mas);
}

/*
 * mas_split_final_node() - Split the final node in a subtree operation.
 * @mast: the maple subtree state
 * @mas: The maple state
 * @height: The height of the tree in case it's a new root.
 */
static inline bool mas_split_final_node(struct maple_subtree_state *mast,
					struct ma_state *mas, int height)
{
	struct maple_enode *ancestor;

	if (mte_is_root(mas->node)) {
		if (mt_is_alloc(mas->tree))
			mast->bn->type = maple_arange_64;
		else
			mast->bn->type = maple_range_64;
		mas->depth = height;
	}
	/*
	 * Only a single node is used here, could be root.
	 * The Big_node data should just fit in a single node.
	 */
	ancestor = mas_new_ma_node(mas, mast->bn);
	mas_set_parent(mas, mast->l->node, ancestor, mast->l->offset);
	mas_set_parent(mas, mast->r->node, ancestor, mast->r->offset);
	mte_to_node(ancestor)->parent = mas_mn(mas)->parent;

	mast->l->node = ancestor;
	mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true);
	mas->offset = mast->bn->b_end - 1;
	return true;
}

/*
 * mast_fill_bnode() - Copy data into the big node in the subtree state
 * @mast: The maple subtree state
 * @mas: the maple state
 * @skip: The number of entries to skip for new nodes insertion.
 */
static inline void mast_fill_bnode(struct maple_subtree_state *mast,
					 struct ma_state *mas,
					 unsigned char skip)
{
	bool cp = true;
	unsigned char split;

	memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap));
	memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot));
	memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot));
	mast->bn->b_end = 0;

	if (mte_is_root(mas->node)) {
		cp = false;
	} else {
		mas_ascend(mas);
		mas->offset = mte_parent_slot(mas->node);
	}

	if (cp && mast->l->offset)
		mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0);

	split = mast->bn->b_end;
	mab_set_b_end(mast->bn, mast->l, mast->l->node);
	mast->r->offset = mast->bn->b_end;
	mab_set_b_end(mast->bn, mast->r, mast->r->node);
	if (mast->bn->pivot[mast->bn->b_end - 1] == mas->max)
		cp = false;

	if (cp)
		mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1,
			   mast->bn, mast->bn->b_end);

	mast->bn->b_end--;
	mast->bn->type = mte_node_type(mas->node);
}

/*
 * mast_split_data() - Split the data in the subtree state big node into regular
 * nodes.
 * @mast: The maple subtree state
 * @mas: The maple state
 * @split: The location to split the big node
 */
static inline void mast_split_data(struct maple_subtree_state *mast,
	   struct ma_state *mas, unsigned char split)
{
	unsigned char p_slot;

	mab_mas_cp(mast->bn, 0, split, mast->l, true);
	mte_set_pivot(mast->r->node, 0, mast->r->max);
	mab_mas_cp(mast->bn, split + 1, mast->bn->b_end, mast->r, false);
	mast->l->offset = mte_parent_slot(mas->node);
	mast->l->max = mast->bn->pivot[split];
	mast->r->min = mast->l->max + 1;
	if (mte_is_leaf(mas->node))
		return;

	p_slot = mast->orig_l->offset;
	mas_set_split_parent(mast->orig_l, mast->l->node, mast->r->node,
			     &p_slot, split);
	mas_set_split_parent(mast->orig_r, mast->l->node, mast->r->node,
			     &p_slot, split);
}

/*
 * mas_push_data() - Instead of splitting a node, it is beneficial to push the
 * data to the right or left node if there is room.
 * @mas: The maple state
 * @height: The current height of the maple state
 * @mast: The maple subtree state
 * @left: Push left or not.
 *
 * Keeping the height of the tree low means faster lookups.
 *
 * Return: True if pushed, false otherwise.
 */
static inline bool mas_push_data(struct ma_state *mas, int height,
				 struct maple_subtree_state *mast, bool left)
{
	unsigned char slot_total = mast->bn->b_end;
	unsigned char end, space, split;

	MA_STATE(tmp_mas, mas->tree, mas->index, mas->last);
	tmp_mas = *mas;
	tmp_mas.depth = mast->l->depth;

	if (left && !mas_prev_sibling(&tmp_mas))
		return false;
	else if (!left && !mas_next_sibling(&tmp_mas))
		return false;

	end = mas_data_end(&tmp_mas);
	slot_total += end;
	space = 2 * mt_slot_count(mas->node) - 2;
	/* -2 instead of -1 to ensure there isn't a triple split */
	if (ma_is_leaf(mast->bn->type))
		space--;

	if (mas->max == ULONG_MAX)
		space--;

	if (slot_total >= space)
		return false;

	/* Get the data; Fill mast->bn */
	mast->bn->b_end++;
	if (left) {
		mab_shift_right(mast->bn, end + 1);
		mas_mab_cp(&tmp_mas, 0, end, mast->bn, 0);
		mast->bn->b_end = slot_total + 1;
	} else {
		mas_mab_cp(&tmp_mas, 0, end, mast->bn, mast->bn->b_end);
	}

	/* Configure mast for splitting of mast->bn */
	split = mt_slots[mast->bn->type] - 2;
	if (left) {
		/*  Switch mas to prev node  */
		*mas = tmp_mas;
		/* Start using mast->l for the left side. */
		tmp_mas.node = mast->l->node;
		*mast->l = tmp_mas;
	} else {
		tmp_mas.node = mast->r->node;
		*mast->r = tmp_mas;
		split = slot_total - split;
	}
	split = mab_no_null_split(mast->bn, split, mt_slots[mast->bn->type]);
	/* Update parent slot for split calculation. */
	if (left)
		mast->orig_l->offset += end + 1;

	mast_split_data(mast, mas, split);
	mast_fill_bnode(mast, mas, 2);
	mas_split_final_node(mast, mas, height + 1);
	return true;
}

/*
 * mas_split() - Split data that is too big for one node into two.
 * @mas: The maple state
 * @b_node: The maple big node
 * Return: 1 on success, 0 on failure.
 */
static int mas_split(struct ma_state *mas, struct maple_big_node *b_node)
{
	struct maple_subtree_state mast;
	int height = 0;
	unsigned char mid_split, split = 0;
	struct maple_enode *old;

	/*
	 * Splitting is handled differently from any other B-tree; the Maple
	 * Tree splits upwards.  Splitting up means that the split operation
	 * occurs when the walk of the tree hits the leaves and not on the way
	 * down.  The reason for splitting up is that it is impossible to know
	 * how much space will be needed until the leaf is (or leaves are)
	 * reached.  Since overwriting data is allowed and a range could
	 * overwrite more than one range or result in changing one entry into 3
	 * entries, it is impossible to know if a split is required until the
	 * data is examined.
	 *
	 * Splitting is a balancing act between keeping allocations to a minimum
	 * and avoiding a 'jitter' event where a tree is expanded to make room
	 * for an entry followed by a contraction when the entry is removed.  To
	 * accomplish the balance, there are empty slots remaining in both left
	 * and right nodes after a split.
	 */
	MA_STATE(l_mas, mas->tree, mas->index, mas->last);
	MA_STATE(r_mas, mas->tree, mas->index, mas->last);
	MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last);
	MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);

	trace_ma_op(__func__, mas);
	mas->depth = mas_mt_height(mas);
	/* Allocation failures will happen early. */
	mas_node_count(mas, 1 + mas->depth * 2);
	if (mas_is_err(mas))
		return 0;

	mast.l = &l_mas;
	mast.r = &r_mas;
	mast.orig_l = &prev_l_mas;
	mast.orig_r = &prev_r_mas;
	mast.bn = b_node;

	while (height++ <= mas->depth) {
		if (mt_slots[b_node->type] > b_node->b_end) {
			mas_split_final_node(&mast, mas, height);
			break;
		}

		l_mas = r_mas = *mas;
		l_mas.node = mas_new_ma_node(mas, b_node);
		r_mas.node = mas_new_ma_node(mas, b_node);
		/*
		 * Another way that 'jitter' is avoided is to terminate a split up early if the
		 * left or right node has space to spare.  This is referred to as "pushing left"
		 * or "pushing right" and is similar to the B* tree, except the nodes left or
		 * right can rarely be reused due to RCU, but the ripple upwards is halted which
		 * is a significant savings.
		 */
		/* Try to push left. */
		if (mas_push_data(mas, height, &mast, true))
			break;

		/* Try to push right. */
		if (mas_push_data(mas, height, &mast, false))
			break;

		split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min);
		mast_split_data(&mast, mas, split);
		/*
		 * Usually correct, mab_mas_cp in the above call overwrites
		 * r->max.
		 */
		mast.r->max = mas->max;
		mast_fill_bnode(&mast, mas, 1);
		prev_l_mas = *mast.l;
		prev_r_mas = *mast.r;
	}

	/* Set the original node as dead */
	old = mas->node;
	mas->node = l_mas.node;
	mas_wmb_replace(mas, old);
	mtree_range_walk(mas);
	return 1;
}

/*
 * mas_reuse_node() - Reuse the node to store the data.
 * @wr_mas: The maple write state
 * @bn: The maple big node
 * @end: The end of the data.
 *
 * Will always return false in RCU mode.
 *
 * Return: True if node was reused, false otherwise.
 */
static inline bool mas_reuse_node(struct ma_wr_state *wr_mas,
			  struct maple_big_node *bn, unsigned char end)
{
	/* Need to be rcu safe. */
	if (mt_in_rcu(wr_mas->mas->tree))
		return false;

	if (end > bn->b_end) {
		int clear = mt_slots[wr_mas->type] - bn->b_end;

		memset(wr_mas->slots + bn->b_end, 0, sizeof(void *) * clear--);
		memset(wr_mas->pivots + bn->b_end, 0, sizeof(void *) * clear);
	}
	mab_mas_cp(bn, 0, bn->b_end, wr_mas->mas, false);
	return true;
}

/*
 * mas_commit_b_node() - Commit the big node into the tree.
 * @wr_mas: The maple write state
 * @b_node: The maple big node
 * @end: The end of the data.
 */
static noinline_for_kasan int mas_commit_b_node(struct ma_wr_state *wr_mas,
			    struct maple_big_node *b_node, unsigned char end)
{
	struct maple_node *node;
	struct maple_enode *old_enode;
	unsigned char b_end = b_node->b_end;
	enum maple_type b_type = b_node->type;

	old_enode = wr_mas->mas->node;
	if ((b_end < mt_min_slots[b_type]) &&
	    (!mte_is_root(old_enode)) &&
	    (mas_mt_height(wr_mas->mas) > 1))
		return mas_rebalance(wr_mas->mas, b_node);

	if (b_end >= mt_slots[b_type])
		return mas_split(wr_mas->mas, b_node);

	if (mas_reuse_node(wr_mas, b_node, end))
		goto reuse_node;

	mas_node_count(wr_mas->mas, 1);
	if (mas_is_err(wr_mas->mas))
		return 0;

	node = mas_pop_node(wr_mas->mas);
	node->parent = mas_mn(wr_mas->mas)->parent;
	wr_mas->mas->node = mt_mk_node(node, b_type);
	mab_mas_cp(b_node, 0, b_end, wr_mas->mas, false);
	mas_replace_node(wr_mas->mas, old_enode);
reuse_node:
	mas_update_gap(wr_mas->mas);
	return 1;
}

/*
 * mas_root_expand() - Expand a root to a node
 * @mas: The maple state
 * @entry: The entry to store into the tree
 */
static inline int mas_root_expand(struct ma_state *mas, void *entry)
{
	void *contents = mas_root_locked(mas);
	enum maple_type type = maple_leaf_64;
	struct maple_node *node;
	void __rcu **slots;
	unsigned long *pivots;
	int slot = 0;

	mas_node_count(mas, 1);
	if (unlikely(mas_is_err(mas)))
		return 0;

	node = mas_pop_node(mas);
	pivots = ma_pivots(node, type);
	slots = ma_slots(node, type);
	node->parent = ma_parent_ptr(mas_tree_parent(mas));
	mas->node = mt_mk_node(node, type);

	if (mas->index) {
		if (contents) {
			rcu_assign_pointer(slots[slot], contents);
			if (likely(mas->index > 1))
				slot++;
		}
		pivots[slot++] = mas->index - 1;
	}

	rcu_assign_pointer(slots[slot], entry);
	mas->offset = slot;
	pivots[slot] = mas->last;
	if (mas->last != ULONG_MAX)
		pivots[++slot] = ULONG_MAX;

	mas->depth = 1;
	mas_set_height(mas);
	ma_set_meta(node, maple_leaf_64, 0, slot);
	/* swap the new root into the tree */
	rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
	return slot;
}

static inline void mas_store_root(struct ma_state *mas, void *entry)
{
	if (likely((mas->last != 0) || (mas->index != 0)))
		mas_root_expand(mas, entry);
	else if (((unsigned long) (entry) & 3) == 2)
		mas_root_expand(mas, entry);
	else {
		rcu_assign_pointer(mas->tree->ma_root, entry);
		mas->node = MAS_START;
	}
}

/*
 * mas_is_span_wr() - Check if the write needs to be treated as a write that
 * spans the node.
 * @mas: The maple state
 * @piv: The pivot value being written
 * @type: The maple node type
 * @entry: The data to write
 *
 * Spanning writes are writes that start in one node and end in another OR if
 * the write of a %NULL will cause the node to end with a %NULL.
 *
 * Return: True if this is a spanning write, false otherwise.
 */
static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
{
	unsigned long max = wr_mas->r_max;
	unsigned long last = wr_mas->mas->last;
	enum maple_type type = wr_mas->type;
	void *entry = wr_mas->entry;

	/* Contained in this pivot, fast path */
	if (last < max)
		return false;

	if (ma_is_leaf(type)) {
		max = wr_mas->mas->max;
		if (last < max)
			return false;
	}

	if (last == max) {
		/*
		 * The last entry of leaf node cannot be NULL unless it is the
		 * rightmost node (writing ULONG_MAX), otherwise it spans slots.
		 */
		if (entry || last == ULONG_MAX)
			return false;
	}

	trace_ma_write(__func__, wr_mas->mas, wr_mas->r_max, entry);
	return true;
}

static inline void mas_wr_walk_descend(struct ma_wr_state *wr_mas)
{
	wr_mas->type = mte_node_type(wr_mas->mas->node);
	mas_wr_node_walk(wr_mas);
	wr_mas->slots = ma_slots(wr_mas->node, wr_mas->type);
}

static inline void mas_wr_walk_traverse(struct ma_wr_state *wr_mas)
{
	wr_mas->mas->max = wr_mas->r_max;
	wr_mas->mas->min = wr_mas->r_min;
	wr_mas->mas->node = wr_mas->content;
	wr_mas->mas->offset = 0;
	wr_mas->mas->depth++;
}
/*
 * mas_wr_walk() - Walk the tree for a write.
 * @wr_mas: The maple write state
 *
 * Uses mas_slot_locked() and does not need to worry about dead nodes.
 *
 * Return: True if it's contained in a node, false on spanning write.
 */
static bool mas_wr_walk(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;

	while (true) {
		mas_wr_walk_descend(wr_mas);
		if (unlikely(mas_is_span_wr(wr_mas)))
			return false;

		wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
						  mas->offset);
		if (ma_is_leaf(wr_mas->type))
			return true;

		mas_wr_walk_traverse(wr_mas);
	}

	return true;
}

static bool mas_wr_walk_index(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;

	while (true) {
		mas_wr_walk_descend(wr_mas);
		wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
						  mas->offset);
		if (ma_is_leaf(wr_mas->type))
			return true;
		mas_wr_walk_traverse(wr_mas);

	}
	return true;
}
/*
 * mas_extend_spanning_null() - Extend a store of a %NULL to include surrounding %NULLs.
 * @l_wr_mas: The left maple write state
 * @r_wr_mas: The right maple write state
 */
static inline void mas_extend_spanning_null(struct ma_wr_state *l_wr_mas,
					    struct ma_wr_state *r_wr_mas)
{
	struct ma_state *r_mas = r_wr_mas->mas;
	struct ma_state *l_mas = l_wr_mas->mas;
	unsigned char l_slot;

	l_slot = l_mas->offset;
	if (!l_wr_mas->content)
		l_mas->index = l_wr_mas->r_min;

	if ((l_mas->index == l_wr_mas->r_min) &&
		 (l_slot &&
		  !mas_slot_locked(l_mas, l_wr_mas->slots, l_slot - 1))) {
		if (l_slot > 1)
			l_mas->index = l_wr_mas->pivots[l_slot - 2] + 1;
		else
			l_mas->index = l_mas->min;

		l_mas->offset = l_slot - 1;
	}

	if (!r_wr_mas->content) {
		if (r_mas->last < r_wr_mas->r_max)
			r_mas->last = r_wr_mas->r_max;
		r_mas->offset++;
	} else if ((r_mas->last == r_wr_mas->r_max) &&
	    (r_mas->last < r_mas->max) &&
	    !mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) {
		r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots,
					     r_wr_mas->type, r_mas->offset + 1);
		r_mas->offset++;
	}
}

static inline void *mas_state_walk(struct ma_state *mas)
{
	void *entry;

	entry = mas_start(mas);
	if (mas_is_none(mas))
		return NULL;

	if (mas_is_ptr(mas))
		return entry;

	return mtree_range_walk(mas);
}

/*
 * mtree_lookup_walk() - Internal quick lookup that does not keep maple state up
 * to date.
 *
 * @mas: The maple state.
 *
 * Note: Leaves mas in undesirable state.
 * Return: The entry for @mas->index or %NULL on dead node.
 */
static inline void *mtree_lookup_walk(struct ma_state *mas)
{
	unsigned long *pivots;
	unsigned char offset;
	struct maple_node *node;
	struct maple_enode *next;
	enum maple_type type;
	void __rcu **slots;
	unsigned char end;
	unsigned long max;

	next = mas->node;
	max = ULONG_MAX;
	do {
		offset = 0;
		node = mte_to_node(next);
		type = mte_node_type(next);
		pivots = ma_pivots(node, type);
		end = ma_data_end(node, type, pivots, max);
		if (unlikely(ma_dead_node(node)))
			goto dead_node;
		do {
			if (pivots[offset] >= mas->index) {
				max = pivots[offset];
				break;
			}
		} while (++offset < end);

		slots = ma_slots(node, type);
		next = mt_slot(mas->tree, slots, offset);
		if (unlikely(ma_dead_node(node)))
			goto dead_node;
	} while (!ma_is_leaf(type));

	return (void *)next;

dead_node:
	mas_reset(mas);
	return NULL;
}

static void mte_destroy_walk(struct maple_enode *, struct maple_tree *);
/*
 * mas_new_root() - Create a new root node that only contains the entry passed
 * in.
 * @mas: The maple state
 * @entry: The entry to store.
 *
 * Only valid when the index == 0 and the last == ULONG_MAX
 *
 * Return 0 on error, 1 on success.
 */
static inline int mas_new_root(struct ma_state *mas, void *entry)
{
	struct maple_enode *root = mas_root_locked(mas);
	enum maple_type type = maple_leaf_64;
	struct maple_node *node;
	void __rcu **slots;
	unsigned long *pivots;

	if (!entry && !mas->index && mas->last == ULONG_MAX) {
		mas->depth = 0;
		mas_set_height(mas);
		rcu_assign_pointer(mas->tree->ma_root, entry);
		mas->node = MAS_START;
		goto done;
	}

	mas_node_count(mas, 1);
	if (mas_is_err(mas))
		return 0;

	node = mas_pop_node(mas);
	pivots = ma_pivots(node, type);
	slots = ma_slots(node, type);
	node->parent = ma_parent_ptr(mas_tree_parent(mas));
	mas->node = mt_mk_node(node, type);
	rcu_assign_pointer(slots[0], entry);
	pivots[0] = mas->last;
	mas->depth = 1;
	mas_set_height(mas);
	rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));

done:
	if (xa_is_node(root))
		mte_destroy_walk(root, mas->tree);

	return 1;
}
/*
 * mas_wr_spanning_store() - Create a subtree with the store operation completed
 * and new nodes where necessary, then place the sub-tree in the actual tree.
 * Note that mas is expected to point to the node which caused the store to
 * span.
 * @wr_mas: The maple write state
 *
 * Return: 0 on error, positive on success.
 */
static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
{
	struct maple_subtree_state mast;
	struct maple_big_node b_node;
	struct ma_state *mas;
	unsigned char height;

	/* Left and Right side of spanning store */
	MA_STATE(l_mas, NULL, 0, 0);
	MA_STATE(r_mas, NULL, 0, 0);
	MA_WR_STATE(r_wr_mas, &r_mas, wr_mas->entry);
	MA_WR_STATE(l_wr_mas, &l_mas, wr_mas->entry);

	/*
	 * A store operation that spans multiple nodes is called a spanning
	 * store and is handled early in the store call stack by the function
	 * mas_is_span_wr().  When a spanning store is identified, the maple
	 * state is duplicated.  The first maple state walks the left tree path
	 * to ``index``, the duplicate walks the right tree path to ``last``.
	 * The data in the two nodes are combined into a single node, two nodes,
	 * or possibly three nodes (see the 3-way split above).  A ``NULL``
	 * written to the last entry of a node is considered a spanning store as
	 * a rebalance is required for the operation to complete and an overflow
	 * of data may happen.
	 */
	mas = wr_mas->mas;
	trace_ma_op(__func__, mas);

	if (unlikely(!mas->index && mas->last == ULONG_MAX))
		return mas_new_root(mas, wr_mas->entry);
	/*
	 * Node rebalancing may occur due to this store, so there may be three new
	 * entries per level plus a new root.
	 */
	height = mas_mt_height(mas);
	mas_node_count(mas, 1 + height * 3);
	if (mas_is_err(mas))
		return 0;

	/*
	 * Set up right side.  Need to get to the next offset after the spanning
	 * store to ensure it's not NULL and to combine both the next node and
	 * the node with the start together.
	 */
	r_mas = *mas;
	/* Avoid overflow, walk to next slot in the tree. */
	if (r_mas.last + 1)
		r_mas.last++;

	r_mas.index = r_mas.last;
	mas_wr_walk_index(&r_wr_mas);
	r_mas.last = r_mas.index = mas->last;

	/* Set up left side. */
	l_mas = *mas;
	mas_wr_walk_index(&l_wr_mas);

	if (!wr_mas->entry) {
		mas_extend_spanning_null(&l_wr_mas, &r_wr_mas);
		mas->offset = l_mas.offset;
		mas->index = l_mas.index;
		mas->last = l_mas.last = r_mas.last;
	}

	/* expanding NULLs may make this cover the entire range */
	if (!l_mas.index && r_mas.last == ULONG_MAX) {
		mas_set_range(mas, 0, ULONG_MAX);
		return mas_new_root(mas, wr_mas->entry);
	}

	memset(&b_node, 0, sizeof(struct maple_big_node));
	/* Copy l_mas and store the value in b_node. */
	mas_store_b_node(&l_wr_mas, &b_node, l_wr_mas.node_end);
	/* Copy r_mas into b_node. */
	if (r_mas.offset <= r_wr_mas.node_end)
		mas_mab_cp(&r_mas, r_mas.offset, r_wr_mas.node_end,
			   &b_node, b_node.b_end + 1);
	else
		b_node.b_end++;

	/* Stop spanning searches by searching for just index. */
	l_mas.index = l_mas.last = mas->index;

	mast.bn = &b_node;
	mast.orig_l = &l_mas;
	mast.orig_r = &r_mas;
	/* Combine l_mas and r_mas and split them up evenly again. */
	return mas_spanning_rebalance(mas, &mast, height + 1);
}

/*
 * mas_wr_node_store() - Attempt to store the value in a node
 * @wr_mas: The maple write state
 *
 * Attempts to reuse the node, but may allocate.
 *
 * Return: True if stored, false otherwise
 */
static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas,
				     unsigned char new_end)
{
	struct ma_state *mas = wr_mas->mas;
	void __rcu **dst_slots;
	unsigned long *dst_pivots;
	unsigned char dst_offset, offset_end = wr_mas->offset_end;
	struct maple_node reuse, *newnode;
	unsigned char copy_size, node_pivots = mt_pivots[wr_mas->type];
	bool in_rcu = mt_in_rcu(mas->tree);

	/* Check if there is enough data. The room is enough. */
	if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) &&
	    !(mas->mas_flags & MA_STATE_BULK))
		return false;

	if (mas->last == wr_mas->end_piv)
		offset_end++; /* don't copy this offset */
	else if (unlikely(wr_mas->r_max == ULONG_MAX))
		mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);

	/* set up node. */
	if (in_rcu) {
		mas_node_count(mas, 1);
		if (mas_is_err(mas))
			return false;

		newnode = mas_pop_node(mas);
	} else {
		memset(&reuse, 0, sizeof(struct maple_node));
		newnode = &reuse;
	}

	newnode->parent = mas_mn(mas)->parent;
	dst_pivots = ma_pivots(newnode, wr_mas->type);
	dst_slots = ma_slots(newnode, wr_mas->type);
	/* Copy from start to insert point */
	memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * mas->offset);
	memcpy(dst_slots, wr_mas->slots, sizeof(void *) * mas->offset);

	/* Handle insert of new range starting after old range */
	if (wr_mas->r_min < mas->index) {
		rcu_assign_pointer(dst_slots[mas->offset], wr_mas->content);
		dst_pivots[mas->offset++] = mas->index - 1;
	}

	/* Store the new entry and range end. */
	if (mas->offset < node_pivots)
		dst_pivots[mas->offset] = mas->last;
	rcu_assign_pointer(dst_slots[mas->offset], wr_mas->entry);

	/*
	 * this range wrote to the end of the node or it overwrote the rest of
	 * the data
	 */
	if (offset_end > wr_mas->node_end)
		goto done;

	dst_offset = mas->offset + 1;
	/* Copy to the end of node if necessary. */
	copy_size = wr_mas->node_end - offset_end + 1;
	memcpy(dst_slots + dst_offset, wr_mas->slots + offset_end,
	       sizeof(void *) * copy_size);
	memcpy(dst_pivots + dst_offset, wr_mas->pivots + offset_end,
	       sizeof(unsigned long) * (copy_size - 1));

	if (new_end < node_pivots)
		dst_pivots[new_end] = mas->max;

done:
	mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end);
	if (in_rcu) {
		struct maple_enode *old_enode = mas->node;

		mas->node = mt_mk_node(newnode, wr_mas->type);
		mas_replace_node(mas, old_enode);
	} else {
		memcpy(wr_mas->node, newnode, sizeof(struct maple_node));
	}
	trace_ma_write(__func__, mas, 0, wr_mas->entry);
	mas_update_gap(mas);
	return true;
}

/*
 * mas_wr_slot_store: Attempt to store a value in a slot.
 * @wr_mas: the maple write state
 *
 * Return: True if stored, false otherwise
 */
static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;
	unsigned char offset = mas->offset;
	void __rcu **slots = wr_mas->slots;
	bool gap = false;

	gap |= !mt_slot_locked(mas->tree, slots, offset);
	gap |= !mt_slot_locked(mas->tree, slots, offset + 1);

	if (wr_mas->offset_end - offset == 1) {
		if (mas->index == wr_mas->r_min) {
			/* Overwriting the range and a part of the next one */
			rcu_assign_pointer(slots[offset], wr_mas->entry);
			wr_mas->pivots[offset] = mas->last;
		} else {
			/* Overwriting a part of the range and the next one */
			rcu_assign_pointer(slots[offset + 1], wr_mas->entry);
			wr_mas->pivots[offset] = mas->index - 1;
			mas->offset++; /* Keep mas accurate. */
		}
	} else if (!mt_in_rcu(mas->tree)) {
		/*
		 * Expand the range, only partially overwriting the previous and
		 * next ranges
		 */
		gap |= !mt_slot_locked(mas->tree, slots, offset + 2);
		rcu_assign_pointer(slots[offset + 1], wr_mas->entry);
		wr_mas->pivots[offset] = mas->index - 1;
		wr_mas->pivots[offset + 1] = mas->last;
		mas->offset++; /* Keep mas accurate. */
	} else {
		return false;
	}

	trace_ma_write(__func__, mas, 0, wr_mas->entry);
	/*
	 * Only update gap when the new entry is empty or there is an empty
	 * entry in the original two ranges.
	 */
	if (!wr_mas->entry || gap)
		mas_update_gap(mas);

	return true;
}

static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;

	if (!wr_mas->slots[wr_mas->offset_end]) {
		/* If this one is null, the next and prev are not */
		mas->last = wr_mas->end_piv;
	} else {
		/* Check next slot(s) if we are overwriting the end */
		if ((mas->last == wr_mas->end_piv) &&
		    (wr_mas->node_end != wr_mas->offset_end) &&
		    !wr_mas->slots[wr_mas->offset_end + 1]) {
			wr_mas->offset_end++;
			if (wr_mas->offset_end == wr_mas->node_end)
				mas->last = mas->max;
			else
				mas->last = wr_mas->pivots[wr_mas->offset_end];
			wr_mas->end_piv = mas->last;
		}
	}

	if (!wr_mas->content) {
		/* If this one is null, the next and prev are not */
		mas->index = wr_mas->r_min;
	} else {
		/* Check prev slot if we are overwriting the start */
		if (mas->index == wr_mas->r_min && mas->offset &&
		    !wr_mas->slots[mas->offset - 1]) {
			mas->offset--;
			wr_mas->r_min = mas->index =
				mas_safe_min(mas, wr_mas->pivots, mas->offset);
			wr_mas->r_max = wr_mas->pivots[mas->offset];
		}
	}
}

static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
{
	while ((wr_mas->offset_end < wr_mas->node_end) &&
	       (wr_mas->mas->last > wr_mas->pivots[wr_mas->offset_end]))
		wr_mas->offset_end++;

	if (wr_mas->offset_end < wr_mas->node_end)
		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
	else
		wr_mas->end_piv = wr_mas->mas->max;

	if (!wr_mas->entry)
		mas_wr_extend_null(wr_mas);
}

static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;
	unsigned char new_end = wr_mas->node_end + 2;

	new_end -= wr_mas->offset_end - mas->offset;
	if (wr_mas->r_min == mas->index)
		new_end--;

	if (wr_mas->end_piv == mas->last)
		new_end--;

	return new_end;
}

/*
 * mas_wr_append: Attempt to append
 * @wr_mas: the maple write state
 * @new_end: The end of the node after the modification
 *
 * This is currently unsafe in rcu mode since the end of the node may be cached
 * by readers while the node contents may be updated which could result in
 * inaccurate information.
 *
 * Return: True if appended, false otherwise
 */
static inline bool mas_wr_append(struct ma_wr_state *wr_mas,
		unsigned char new_end)
{
	struct ma_state *mas;
	void __rcu **slots;
	unsigned char end;

	mas = wr_mas->mas;
	if (mt_in_rcu(mas->tree))
		return false;

	if (mas->offset != wr_mas->node_end)
		return false;

	end = wr_mas->node_end;
	if (mas->offset != end)
		return false;

	if (new_end < mt_pivots[wr_mas->type]) {
		wr_mas->pivots[new_end] = wr_mas->pivots[end];
		ma_set_meta(wr_mas->node, wr_mas->type, 0, new_end);
	}

	slots = wr_mas->slots;
	if (new_end == end + 1) {
		if (mas->last == wr_mas->r_max) {
			/* Append to end of range */
			rcu_assign_pointer(slots[new_end], wr_mas->entry);
			wr_mas->pivots[end] = mas->index - 1;
			mas->offset = new_end;
		} else {
			/* Append to start of range */
			rcu_assign_pointer(slots[new_end], wr_mas->content);
			wr_mas->pivots[end] = mas->last;
			rcu_assign_pointer(slots[end], wr_mas->entry);
		}
	} else {
		/* Append to the range without touching any boundaries. */
		rcu_assign_pointer(slots[new_end], wr_mas->content);
		wr_mas->pivots[end + 1] = mas->last;
		rcu_assign_pointer(slots[end + 1], wr_mas->entry);
		wr_mas->pivots[end] = mas->index - 1;
		mas->offset = end + 1;
	}

	if (!wr_mas->content || !wr_mas->entry)
		mas_update_gap(mas);

	trace_ma_write(__func__, mas, new_end, wr_mas->entry);
	return  true;
}

/*
 * mas_wr_bnode() - Slow path for a modification.
 * @wr_mas: The write maple state
 *
 * This is where split, rebalance end up.
 */
static void mas_wr_bnode(struct ma_wr_state *wr_mas)
{
	struct maple_big_node b_node;

	trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
	memset(&b_node, 0, sizeof(struct maple_big_node));
	mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
	mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
}

static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;
	unsigned char new_end;

	/* Direct replacement */
	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
		rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
		if (!!wr_mas->entry ^ !!wr_mas->content)
			mas_update_gap(mas);
		return;
	}

	/*
	 * new_end exceeds the size of the maple node and cannot enter the fast
	 * path.
	 */
	new_end = mas_wr_new_end(wr_mas);
	if (new_end >= mt_slots[wr_mas->type])
		goto slow_path;

	/* Attempt to append */
	if (mas_wr_append(wr_mas, new_end))
		return;

	if (new_end == wr_mas->node_end && mas_wr_slot_store(wr_mas))
		return;

	if (mas_wr_node_store(wr_mas, new_end))
		return;

	if (mas_is_err(mas))
		return;

slow_path:
	mas_wr_bnode(wr_mas);
}

/*
 * mas_wr_store_entry() - Internal call to store a value
 * @mas: The maple state
 * @entry: The entry to store.
 *
 * Return: The contents that was stored at the index.
 */
static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas)
{
	struct ma_state *mas = wr_mas->mas;

	wr_mas->content = mas_start(mas);
	if (mas_is_none(mas) || mas_is_ptr(mas)) {
		mas_store_root(mas, wr_mas->entry);
		return wr_mas->content;
	}

	if (unlikely(!mas_wr_walk(wr_mas))) {
		mas_wr_spanning_store(wr_mas);
		return wr_mas->content;
	}

	/* At this point, we are at the leaf node that needs to be altered. */
	mas_wr_end_piv(wr_mas);
	/* New root for a single pointer */
	if (unlikely(!mas->index && mas->last == ULONG_MAX)) {
		mas_new_root(mas, wr_mas->entry);
		return wr_mas->content;
	}

	mas_wr_modify(wr_mas);
	return wr_mas->content;
}

/**
 * mas_insert() - Internal call to insert a value
 * @mas: The maple state
 * @entry: The entry to store
 *
 * Return: %NULL or the contents that already exists at the requested index
 * otherwise.  The maple state needs to be checked for error conditions.
 */
static inline void *mas_insert(struct ma_state *mas, void *entry)
{
	MA_WR_STATE(wr_mas, mas, entry);

	/*
	 * Inserting a new range inserts either 0, 1, or 2 pivots within the
	 * tree.  If the insert fits exactly into an existing gap with a value
	 * of NULL, then the slot only needs to be written with the new value.
	 * If the range being inserted is adjacent to another range, then only a
	 * single pivot needs to be inserted (as well as writing the entry).  If
	 * the new range is within a gap but does not touch any other ranges,
	 * then two pivots need to be inserted: the start - 1, and the end.  As
	 * usual, the entry must be written.  Most operations require a new node
	 * to be allocated and replace an existing node to ensure RCU safety,
	 * when in RCU mode.  The exception to requiring a newly allocated node
	 * is when inserting at the end of a node (appending).  When done
	 * carefully, appending can reuse the node in place.
	 */
	wr_mas.content = mas_start(mas);
	if (wr_mas.content)
		goto exists;

	if (mas_is_none(mas) || mas_is_ptr(mas)) {
		mas_store_root(mas, entry);
		return NULL;
	}

	/* spanning writes always overwrite something */
	if (!mas_wr_walk(&wr_mas))
		goto exists;

	/* At this point, we are at the leaf node that needs to be altered. */
	wr_mas.offset_end = mas->offset;
	wr_mas.end_piv = wr_mas.r_max;

	if (wr_mas.content || (mas->last > wr_mas.r_max))
		goto exists;

	if (!entry)
		return NULL;

	mas_wr_modify(&wr_mas);
	return wr_mas.content;

exists:
	mas_set_err(mas, -EEXIST);
	return wr_mas.content;

}

static inline void mas_rewalk(struct ma_state *mas, unsigned long index)
{
retry:
	mas_set(mas, index);
	mas_state_walk(mas);
	if (mas_is_start(mas))
		goto retry;
}

static inline bool mas_rewalk_if_dead(struct ma_state *mas,
		struct maple_node *node, const unsigned long index)
{
	if (unlikely(ma_dead_node(node))) {
		mas_rewalk(mas, index);
		return true;
	}
	return false;
}

/*
 * mas_prev_node() - Find the prev non-null entry at the same level in the
 * tree.  The prev value will be mas->node[mas->offset] or MAS_NONE.
 * @mas: The maple state
 * @min: The lower limit to search
 *
 * The prev node value will be mas->node[mas->offset] or MAS_NONE.
 * Return: 1 if the node is dead, 0 otherwise.
 */
static inline int mas_prev_node(struct ma_state *mas, unsigned long min)
{
	enum maple_type mt;
	int offset, level;
	void __rcu **slots;
	struct maple_node *node;
	unsigned long *pivots;
	unsigned long max;

	node = mas_mn(mas);
	if (!mas->min)
		goto no_entry;

	max = mas->min - 1;
	if (max < min)
		goto no_entry;

	level = 0;
	do {
		if (ma_is_root(node))
			goto no_entry;

		/* Walk up. */
		if (unlikely(mas_ascend(mas)))
			return 1;
		offset = mas->offset;
		level++;
		node = mas_mn(mas);
	} while (!offset);

	offset--;
	mt = mte_node_type(mas->node);
	while (level > 1) {
		level--;
		slots = ma_slots(node, mt);
		mas->node = mas_slot(mas, slots, offset);
		if (unlikely(ma_dead_node(node)))
			return 1;

		mt = mte_node_type(mas->node);
		node = mas_mn(mas);
		pivots = ma_pivots(node, mt);
		offset = ma_data_end(node, mt, pivots, max);
		if (unlikely(ma_dead_node(node)))
			return 1;
	}

	slots = ma_slots(node, mt);
	mas->node = mas_slot(mas, slots, offset);
	pivots = ma_pivots(node, mt);
	if (unlikely(ma_dead_node(node)))
		return 1;

	if (likely(offset))
		mas->min = pivots[offset - 1] + 1;
	mas->max = max;
	mas->offset = mas_data_end(mas);
	if (unlikely(mte_dead_node(mas->node)))
		return 1;

	return 0;

no_entry:
	if (unlikely(ma_dead_node(node)))
		return 1;

	mas->node = MAS_NONE;
	return 0;
}

/*
 * mas_prev_slot() - Get the entry in the previous slot
 *
 * @mas: The maple state
 * @max: The minimum starting range
 * @empty: Can be empty
 * @set_underflow: Set the @mas->node to underflow state on limit.
 *
 * Return: The entry in the previous slot which is possibly NULL
 */
static void *mas_prev_slot(struct ma_state *mas, unsigned long min, bool empty,
			   bool set_underflow)
{
	void *entry;
	void __rcu **slots;
	unsigned long pivot;
	enum maple_type type;
	unsigned long *pivots;
	struct maple_node *node;
	unsigned long save_point = mas->index;

retry:
	node = mas_mn(mas);
	type = mte_node_type(mas->node);
	pivots = ma_pivots(node, type);
	if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
		goto retry;

	if (mas->min <= min) {
		pivot = mas_safe_min(mas, pivots, mas->offset);

		if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
			goto retry;

		if (pivot <= min)
			goto underflow;
	}

again:
	if (likely(mas->offset)) {
		mas->offset--;
		mas->last = mas->index - 1;
		mas->index = mas_safe_min(mas, pivots, mas->offset);
	} else  {
		if (mas_prev_node(mas, min)) {
			mas_rewalk(mas, save_point);
			goto retry;
		}

		if (mas_is_none(mas))
			goto underflow;

		mas->last = mas->max;
		node = mas_mn(mas);
		type = mte_node_type(mas->node);
		pivots = ma_pivots(node, type);
		mas->index = pivots[mas->offset - 1] + 1;
	}

	slots = ma_slots(node, type);
	entry = mas_slot(mas, slots, mas->offset);
	if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
		goto retry;

	if (likely(entry))
		return entry;

	if (!empty) {
		if (mas->index <= min)
			goto underflow;

		goto again;
	}

	return entry;

underflow:
	if (set_underflow)
		mas->node = MAS_UNDERFLOW;
	return NULL;
}

/*
 * mas_next_node() - Get the next node at the same level in the tree.
 * @mas: The maple state
 * @max: The maximum pivot value to check.
 *
 * The next value will be mas->node[mas->offset] or MAS_NONE.
 * Return: 1 on dead node, 0 otherwise.
 */
static inline int mas_next_node(struct ma_state *mas, struct maple_node *node,
				unsigned long max)
{
	unsigned long min;
	unsigned long *pivots;
	struct maple_enode *enode;
	int level = 0;
	unsigned char node_end;
	enum maple_type mt;
	void __rcu **slots;

	if (mas->max >= max)
		goto no_entry;

	min = mas->max + 1;
	level = 0;
	do {
		if (ma_is_root(node))
			goto no_entry;

		/* Walk up. */
		if (unlikely(mas_ascend(mas)))
			return 1;

		level++;
		node = mas_mn(mas);
		mt = mte_node_type(mas->node);
		pivots = ma_pivots(node, mt);
		node_end = ma_data_end(node, mt, pivots, mas->max);
		if (unlikely(ma_dead_node(node)))
			return 1;

	} while (unlikely(mas->offset == node_end));

	slots = ma_slots(node, mt);
	mas->offset++;
	enode = mas_slot(mas, slots, mas->offset);
	if (unlikely(ma_dead_node(node)))
		return 1;

	if (level > 1)
		mas->offset = 0;

	while (unlikely(level > 1)) {
		level--;
		mas->node = enode;
		node = mas_mn(mas);
		mt = mte_node_type(mas->node);
		slots = ma_slots(node, mt);
		enode = mas_slot(mas, slots, 0);
		if (unlikely(ma_dead_node(node)))
			return 1;
	}

	if (!mas->offset)
		pivots = ma_pivots(node, mt);

	mas->max = mas_safe_pivot(mas, pivots, mas->offset, mt);
	if (unlikely(ma_dead_node(node)))
		return 1;

	mas->node = enode;
	mas->min = min;
	return 0;

no_entry:
	if (unlikely(ma_dead_node(node)))
		return 1;

	mas->node = MAS_NONE;
	return 0;
}

/*
 * mas_next_slot() - Get the entry in the next slot
 *
 * @mas: The maple state
 * @max: The maximum starting range
 * @empty: Can be empty
 * @set_overflow: Should @mas->node be set to overflow when the limit is
 * reached.
 *
 * Return: The entry in the next slot which is possibly NULL
 */
static void *mas_next_slot(struct ma_state *mas, unsigned long max, bool empty,
			   bool set_overflow)
{
	void __rcu **slots;
	unsigned long *pivots;
	unsigned long pivot;
	enum maple_type type;
	struct maple_node *node;
	unsigned char data_end;
	unsigned long save_point = mas->last;
	void *entry;

retry:
	node = mas_mn(mas);
	type = mte_node_type(mas->node);
	pivots = ma_pivots(node, type);
	data_end = ma_data_end(node, type, pivots, mas->max);
	if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
		goto retry;

	if (mas->max >= max) {
		if (likely(mas->offset < data_end))
			pivot = pivots[mas->offset];
		else
			goto overflow;

		if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
			goto retry;

		if (pivot >= max)
			goto overflow;
	}

	if (likely(mas->offset < data_end)) {
		mas->index = pivots[mas->offset] + 1;
again:
		mas->offset++;
		if (likely(mas->offset < data_end))
			mas->last = pivots[mas->offset];
		else
			mas->last = mas->max;
	} else  {
		if (mas_next_node(mas, node, max)) {
			mas_rewalk(mas, save_point);
			goto retry;
		}

		if (WARN_ON_ONCE(mas_is_none(mas))) {
			mas->node = MAS_OVERFLOW;
			return NULL;
			goto overflow;
		}

		mas->offset = 0;
		mas->index = mas->min;
		node = mas_mn(mas);
		type = mte_node_type(mas->node);
		pivots = ma_pivots(node, type);
		mas->last = pivots[0];
	}

	slots = ma_slots(node, type);
	entry = mt_slot(mas->tree, slots, mas->offset);
	if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
		goto retry;

	if (entry)
		return entry;

	if (!empty) {
		if (mas->last >= max)
			goto overflow;

		mas->index = mas->last + 1;
		/* Node cannot end on NULL, so it's safe to short-cut here */
		goto again;
	}

	return entry;

overflow:
	if (set_overflow)
		mas->node = MAS_OVERFLOW;
	return NULL;
}

/*
 * mas_next_entry() - Internal function to get the next entry.
 * @mas: The maple state
 * @limit: The maximum range start.
 *
 * Set the @mas->node to the next entry and the range_start to
 * the beginning value for the entry.  Does not check beyond @limit.
 * Sets @mas->index and @mas->last to the range, Does not update @mas->index and
 * @mas->last on overflow.
 * Restarts on dead nodes.
 *
 * Return: the next entry or %NULL.
 */
static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit)
{
	if (mas->last >= limit) {
		mas->node = MAS_OVERFLOW;
		return NULL;
	}

	return mas_next_slot(mas, limit, false, true);
}

/*
 * mas_rev_awalk() - Internal function.  Reverse allocation walk.  Find the
 * highest gap address of a given size in a given node and descend.
 * @mas: The maple state
 * @size: The needed size.
 *
 * Return: True if found in a leaf, false otherwise.
 *
 */
static bool mas_rev_awalk(struct ma_state *mas, unsigned long size,
		unsigned long *gap_min, unsigned long *gap_max)
{
	enum maple_type type = mte_node_type(mas->node);
	struct maple_node *node = mas_mn(mas);
	unsigned long *pivots, *gaps;
	void __rcu **slots;
	unsigned long gap = 0;
	unsigned long max, min;
	unsigned char offset;

	if (unlikely(mas_is_err(mas)))
		return true;

	if (ma_is_dense(type)) {
		/* dense nodes. */
		mas->offset = (unsigned char)(mas->index - mas->min);
		return true;
	}

	pivots = ma_pivots(node, type);
	slots = ma_slots(node, type);
	gaps = ma_gaps(node, type);
	offset = mas->offset;
	min = mas_safe_min(mas, pivots, offset);
	/* Skip out of bounds. */
	while (mas->last < min)
		min = mas_safe_min(mas, pivots, --offset);

	max = mas_safe_pivot(mas, pivots, offset, type);
	while (mas->index <= max) {
		gap = 0;
		if (gaps)
			gap = gaps[offset];
		else if (!mas_slot(mas, slots, offset))
			gap = max - min + 1;

		if (gap) {
			if ((size <= gap) && (size <= mas->last - min + 1))
				break;

			if (!gaps) {
				/* Skip the next slot, it cannot be a gap. */
				if (offset < 2)
					goto ascend;

				offset -= 2;
				max = pivots[offset];
				min = mas_safe_min(mas, pivots, offset);
				continue;
			}
		}

		if (!offset)
			goto ascend;

		offset--;
		max = min - 1;
		min = mas_safe_min(mas, pivots, offset);
	}

	if (unlikely((mas->index > max) || (size - 1 > max - mas->index)))
		goto no_space;

	if (unlikely(ma_is_leaf(type))) {
		mas->offset = offset;
		*gap_min = min;
		*gap_max = min + gap - 1;
		return true;
	}

	/* descend, only happens under lock. */
	mas->node = mas_slot(mas, slots, offset);
	mas->min = min;
	mas->max = max;
	mas->offset = mas_data_end(mas);
	return false;

ascend:
	if (!mte_is_root(mas->node))
		return false;

no_space:
	mas_set_err(mas, -EBUSY);
	return false;
}

static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
{
	enum maple_type type = mte_node_type(mas->node);
	unsigned long pivot, min, gap = 0;
	unsigned char offset, data_end;
	unsigned long *gaps, *pivots;
	void __rcu **slots;
	struct maple_node *node;
	bool found = false;

	if (ma_is_dense(type)) {
		mas->offset = (unsigned char)(mas->index - mas->min);
		return true;
	}

	node = mas_mn(mas);
	pivots = ma_pivots(node, type);
	slots = ma_slots(node, type);
	gaps = ma_gaps(node, type);
	offset = mas->offset;
	min = mas_safe_min(mas, pivots, offset);
	data_end = ma_data_end(node, type, pivots, mas->max);
	for (; offset <= data_end; offset++) {
		pivot = mas_safe_pivot(mas, pivots, offset, type);

		/* Not within lower bounds */
		if (mas->index > pivot)
			goto next_slot;

		if (gaps)
			gap = gaps[offset];
		else if (!mas_slot(mas, slots, offset))
			gap = min(pivot, mas->last) - max(mas->index, min) + 1;
		else
			goto next_slot;

		if (gap >= size) {
			if (ma_is_leaf(type)) {
				found = true;
				goto done;
			}
			if (mas->index <= pivot) {
				mas->node = mas_slot(mas, slots, offset);
				mas->min = min;
				mas->max = pivot;
				offset = 0;
				break;
			}
		}
next_slot:
		min = pivot + 1;
		if (mas->last <= pivot) {
			mas_set_err(mas, -EBUSY);
			return true;
		}
	}

	if (mte_is_root(mas->node))
		found = true;
done:
	mas->offset = offset;
	return found;
}

/**
 * mas_walk() - Search for @mas->index in the tree.
 * @mas: The maple state.
 *
 * mas->index and mas->last will be set to the range if there is a value.  If
 * mas->node is MAS_NONE, reset to MAS_START.
 *
 * Return: the entry at the location or %NULL.
 */
void *mas_walk(struct ma_state *mas)
{
	void *entry;

	if (!mas_is_active(mas) || !mas_is_start(mas))
		mas->node = MAS_START;
retry:
	entry = mas_state_walk(mas);
	if (mas_is_start(mas)) {
		goto retry;
	} else if (mas_is_none(mas)) {
		mas->index = 0;
		mas->last = ULONG_MAX;
	} else if (mas_is_ptr(mas)) {
		if (!mas->index) {
			mas->last = 0;
			return entry;
		}

		mas->index = 1;
		mas->last = ULONG_MAX;
		mas->node = MAS_NONE;
		return NULL;
	}

	return entry;
}
EXPORT_SYMBOL_GPL(mas_walk);

static inline bool mas_rewind_node(struct ma_state *mas)
{
	unsigned char slot;

	do {
		if (mte_is_root(mas->node)) {
			slot = mas->offset;
			if (!slot)
				return false;
		} else {
			mas_ascend(mas);
			slot = mas->offset;
		}
	} while (!slot);

	mas->offset = --slot;
	return true;
}

/*
 * mas_skip_node() - Internal function.  Skip over a node.
 * @mas: The maple state.
 *
 * Return: true if there is another node, false otherwise.
 */
static inline bool mas_skip_node(struct ma_state *mas)
{
	if (mas_is_err(mas))
		return false;

	do {
		if (mte_is_root(mas->node)) {
			if (mas->offset >= mas_data_end(mas)) {
				mas_set_err(mas, -EBUSY);
				return false;
			}
		} else {
			mas_ascend(mas);
		}
	} while (mas->offset >= mas_data_end(mas));

	mas->offset++;
	return true;
}

/*
 * mas_awalk() - Allocation walk.  Search from low address to high, for a gap of
 * @size
 * @mas: The maple state
 * @size: The size of the gap required
 *
 * Search between @mas->index and @mas->last for a gap of @size.
 */
static inline void mas_awalk(struct ma_state *mas, unsigned long size)
{
	struct maple_enode *last = NULL;

	/*
	 * There are 4 options:
	 * go to child (descend)
	 * go back to parent (ascend)
	 * no gap found. (return, slot == MAPLE_NODE_SLOTS)
	 * found the gap. (return, slot != MAPLE_NODE_SLOTS)
	 */
	while (!mas_is_err(mas) && !mas_anode_descend(mas, size)) {
		if (last == mas->node)
			mas_skip_node(mas);
		else
			last = mas->node;
	}
}

/*
 * mas_sparse_area() - Internal function.  Return upper or lower limit when
 * searching for a gap in an empty tree.
 * @mas: The maple state
 * @min: the minimum range
 * @max: The maximum range
 * @size: The size of the gap
 * @fwd: Searching forward or back
 */
static inline int mas_sparse_area(struct ma_state *mas, unsigned long min,
				unsigned long max, unsigned long size, bool fwd)
{
	if (!unlikely(mas_is_none(mas)) && min == 0) {
		min++;
		/*
		 * At this time, min is increased, we need to recheck whether
		 * the size is satisfied.
		 */
		if (min > max || max - min + 1 < size)
			return -EBUSY;
	}
	/* mas_is_ptr */

	if (fwd) {
		mas->index = min;
		mas->last = min + size - 1;
	} else {
		mas->last = max;
		mas->index = max - size + 1;
	}
	return 0;
}

/*
 * mas_empty_area() - Get the lowest address within the range that is
 * sufficient for the size requested.
 * @mas: The maple state
 * @min: The lowest value of the range
 * @max: The highest value of the range
 * @size: The size needed
 */
int mas_empty_area(struct ma_state *mas, unsigned long min,
		unsigned long max, unsigned long size)
{
	unsigned char offset;
	unsigned long *pivots;
	enum maple_type mt;

	if (min > max)
		return -EINVAL;

	if (size == 0 || max - min < size - 1)
		return -EINVAL;

	if (mas_is_start(mas))
		mas_start(mas);
	else if (mas->offset >= 2)
		mas->offset -= 2;
	else if (!mas_skip_node(mas))
		return -EBUSY;

	/* Empty set */
	if (mas_is_none(mas) || mas_is_ptr(mas))
		return mas_sparse_area(mas, min, max, size, true);

	/* The start of the window can only be within these values */
	mas->index = min;
	mas->last = max;
	mas_awalk(mas, size);

	if (unlikely(mas_is_err(mas)))
		return xa_err(mas->node);

	offset = mas->offset;
	if (unlikely(offset == MAPLE_NODE_SLOTS))
		return -EBUSY;

	mt = mte_node_type(mas->node);
	pivots = ma_pivots(mas_mn(mas), mt);
	min = mas_safe_min(mas, pivots, offset);
	if (mas->index < min)
		mas->index = min;
	mas->last = mas->index + size - 1;
	return 0;
}
EXPORT_SYMBOL_GPL(mas_empty_area);

/*
 * mas_empty_area_rev() - Get the highest address within the range that is
 * sufficient for the size requested.
 * @mas: The maple state
 * @min: The lowest value of the range
 * @max: The highest value of the range
 * @size: The size needed
 */
int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
		unsigned long max, unsigned long size)
{
	struct maple_enode *last = mas->node;

	if (min > max)
		return -EINVAL;

	if (size == 0 || max - min < size - 1)
		return -EINVAL;

	if (mas_is_start(mas)) {
		mas_start(mas);
		mas->offset = mas_data_end(mas);
	} else if (mas->offset >= 2) {
		mas->offset -= 2;
	} else if (!mas_rewind_node(mas)) {
		return -EBUSY;
	}

	/* Empty set. */
	if (mas_is_none(mas) || mas_is_ptr(mas))
		return mas_sparse_area(mas, min, max, size, false);

	/* The start of the window can only be within these values. */
	mas->index = min;
	mas->last = max;

	while (!mas_rev_awalk(mas, size, &min, &max)) {
		if (last == mas->node) {
			if (!mas_rewind_node(mas))
				return -EBUSY;
		} else {
			last = mas->node;
		}
	}

	if (mas_is_err(mas))
		return xa_err(mas->node);

	if (unlikely(mas->offset == MAPLE_NODE_SLOTS))
		return -EBUSY;

	/* Trim the upper limit to the max. */
	if (max < mas->last)
		mas->last = max;

	mas->index = mas->last - size + 1;
	return 0;
}
EXPORT_SYMBOL_GPL(mas_empty_area_rev);

/*
 * mte_dead_leaves() - Mark all leaves of a node as dead.
 * @mas: The maple state
 * @slots: Pointer to the slot array
 * @type: The maple node type
 *
 * Must hold the write lock.
 *
 * Return: The number of leaves marked as dead.
 */
static inline
unsigned char mte_dead_leaves(struct maple_enode *enode, struct maple_tree *mt,
			      void __rcu **slots)
{
	struct maple_node *node;
	enum maple_type type;
	void *entry;
	int offset;

	for (offset = 0; offset < mt_slot_count(enode); offset++) {
		entry = mt_slot(mt, slots, offset);
		type = mte_node_type(entry);
		node = mte_to_node(entry);
		/* Use both node and type to catch LE & BE metadata */
		if (!node || !type)
			break;

		mte_set_node_dead(entry);
		node->type = type;
		rcu_assign_pointer(slots[offset], node);
	}

	return offset;
}

/**
 * mte_dead_walk() - Walk down a dead tree to just before the leaves
 * @enode: The maple encoded node
 * @offset: The starting offset
 *
 * Note: This can only be used from the RCU callback context.
 */
static void __rcu **mte_dead_walk(struct maple_enode **enode, unsigned char offset)
{
	struct maple_node *node, *next;
	void __rcu **slots = NULL;

	next = mte_to_node(*enode);
	do {
		*enode = ma_enode_ptr(next);
		node = mte_to_node(*enode);
		slots = ma_slots(node, node->type);
		next = rcu_dereference_protected(slots[offset],
					lock_is_held(&rcu_callback_map));
		offset = 0;
	} while (!ma_is_leaf(next->type));

	return slots;
}

/**
 * mt_free_walk() - Walk & free a tree in the RCU callback context
 * @head: The RCU head that's within the node.
 *
 * Note: This can only be used from the RCU callback context.
 */
static void mt_free_walk(struct rcu_head *head)
{
	void __rcu **slots;
	struct maple_node *node, *start;
	struct maple_enode *enode;
	unsigned char offset;
	enum maple_type type;

	node = container_of(head, struct maple_node, rcu);

	if (ma_is_leaf(node->type))
		goto free_leaf;

	start = node;
	enode = mt_mk_node(node, node->type);
	slots = mte_dead_walk(&enode, 0);
	node = mte_to_node(enode);
	do {
		mt_free_bulk(node->slot_len, slots);
		offset = node->parent_slot + 1;
		enode = node->piv_parent;
		if (mte_to_node(enode) == node)
			goto free_leaf;

		type = mte_node_type(enode);
		slots = ma_slots(mte_to_node(enode), type);
		if ((offset < mt_slots[type]) &&
		    rcu_dereference_protected(slots[offset],
					      lock_is_held(&rcu_callback_map)))
			slots = mte_dead_walk(&enode, offset);
		node = mte_to_node(enode);
	} while ((node != start) || (node->slot_len < offset));

	slots = ma_slots(node, node->type);
	mt_free_bulk(node->slot_len, slots);

free_leaf:
	mt_free_rcu(&node->rcu);
}

static inline void __rcu **mte_destroy_descend(struct maple_enode **enode,
	struct maple_tree *mt, struct maple_enode *prev, unsigned char offset)
{
	struct maple_node *node;
	struct maple_enode *next = *enode;
	void __rcu **slots = NULL;
	enum maple_type type;
	unsigned char next_offset = 0;

	do {
		*enode = next;
		node = mte_to_node(*enode);
		type = mte_node_type(*enode);
		slots = ma_slots(node, type);
		next = mt_slot_locked(mt, slots, next_offset);
		if ((mte_dead_node(next)))
			next = mt_slot_locked(mt, slots, ++next_offset);

		mte_set_node_dead(*enode);
		node->type = type;
		node->piv_parent = prev;
		node->parent_slot = offset;
		offset = next_offset;
		next_offset = 0;
		prev = *enode;
	} while (!mte_is_leaf(next));

	return slots;
}

static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt,
			    bool free)
{
	void __rcu **slots;
	struct maple_node *node = mte_to_node(enode);
	struct maple_enode *start;

	if (mte_is_leaf(enode)) {
		node->type = mte_node_type(enode);
		goto free_leaf;
	}

	start = enode;
	slots = mte_destroy_descend(&enode, mt, start, 0);
	node = mte_to_node(enode); // Updated in the above call.
	do {
		enum maple_type type;
		unsigned char offset;
		struct maple_enode *parent, *tmp;

		node->slot_len = mte_dead_leaves(enode, mt, slots);
		if (free)
			mt_free_bulk(node->slot_len, slots);
		offset = node->parent_slot + 1;
		enode = node->piv_parent;
		if (mte_to_node(enode) == node)
			goto free_leaf;

		type = mte_node_type(enode);
		slots = ma_slots(mte_to_node(enode), type);
		if (offset >= mt_slots[type])
			goto next;

		tmp = mt_slot_locked(mt, slots, offset);
		if (mte_node_type(tmp) && mte_to_node(tmp)) {
			parent = enode;
			enode = tmp;
			slots = mte_destroy_descend(&enode, mt, parent, offset);
		}
next:
		node = mte_to_node(enode);
	} while (start != enode);

	node = mte_to_node(enode);
	node->slot_len = mte_dead_leaves(enode, mt, slots);
	if (free)
		mt_free_bulk(node->slot_len, slots);

free_leaf:
	if (free)
		mt_free_rcu(&node->rcu);
	else
		mt_clear_meta(mt, node, node->type);
}

/*
 * mte_destroy_walk() - Free a tree or sub-tree.
 * @enode: the encoded maple node (maple_enode) to start
 * @mt: the tree to free - needed for node types.
 *
 * Must hold the write lock.
 */
static inline void mte_destroy_walk(struct maple_enode *enode,
				    struct maple_tree *mt)
{
	struct maple_node *node = mte_to_node(enode);

	if (mt_in_rcu(mt)) {
		mt_destroy_walk(enode, mt, false);
		call_rcu(&node->rcu, mt_free_walk);
	} else {
		mt_destroy_walk(enode, mt, true);
	}
}

static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
{
	if (!mas_is_active(wr_mas->mas)) {
		if (mas_is_start(wr_mas->mas))
			return;

		if (unlikely(mas_is_paused(wr_mas->mas)))
			goto reset;

		if (unlikely(mas_is_none(wr_mas->mas)))
			goto reset;

		if (unlikely(mas_is_overflow(wr_mas->mas)))
			goto reset;

		if (unlikely(mas_is_underflow(wr_mas->mas)))
			goto reset;
	}

	/*
	 * A less strict version of mas_is_span_wr() where we allow spanning
	 * writes within this node.  This is to stop partial walks in
	 * mas_prealloc() from being reset.
	 */
	if (wr_mas->mas->last > wr_mas->mas->max)
		goto reset;

	if (wr_mas->entry)
		return;

	if (mte_is_leaf(wr_mas->mas->node) &&
	    wr_mas->mas->last == wr_mas->mas->max)
		goto reset;

	return;

reset:
	mas_reset(wr_mas->mas);
}

/* Interface */

/**
 * mas_store() - Store an @entry.
 * @mas: The maple state.
 * @entry: The entry to store.
 *
 * The @mas->index and @mas->last is used to set the range for the @entry.
 * Note: The @mas should have pre-allocated entries to ensure there is memory to
 * store the entry.  Please see mas_expected_entries()/mas_destroy() for more details.
 *
 * Return: the first entry between mas->index and mas->last or %NULL.
 */
void *mas_store(struct ma_state *mas, void *entry)
{
	MA_WR_STATE(wr_mas, mas, entry);

	trace_ma_write(__func__, mas, 0, entry);
#ifdef CONFIG_DEBUG_MAPLE_TREE
	if (MAS_WARN_ON(mas, mas->index > mas->last))
		pr_err("Error %lX > %lX %p\n", mas->index, mas->last, entry);

	if (mas->index > mas->last) {
		mas_set_err(mas, -EINVAL);
		return NULL;
	}

#endif

	/*
	 * Storing is the same operation as insert with the added caveat that it
	 * can overwrite entries.  Although this seems simple enough, one may
	 * want to examine what happens if a single store operation was to
	 * overwrite multiple entries within a self-balancing B-Tree.
	 */
	mas_wr_store_setup(&wr_mas);
	mas_wr_store_entry(&wr_mas);
	return wr_mas.content;
}
EXPORT_SYMBOL_GPL(mas_store);

/**
 * mas_store_gfp() - Store a value into the tree.
 * @mas: The maple state
 * @entry: The entry to store
 * @gfp: The GFP_FLAGS to use for allocations if necessary.
 *
 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
 * be allocated.
 */
int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp)
{
	MA_WR_STATE(wr_mas, mas, entry);

	mas_wr_store_setup(&wr_mas);
	trace_ma_write(__func__, mas, 0, entry);
retry:
	mas_wr_store_entry(&wr_mas);
	if (unlikely(mas_nomem(mas, gfp)))
		goto retry;

	if (unlikely(mas_is_err(mas)))
		return xa_err(mas->node);

	return 0;
}
EXPORT_SYMBOL_GPL(mas_store_gfp);

/**
 * mas_store_prealloc() - Store a value into the tree using memory
 * preallocated in the maple state.
 * @mas: The maple state
 * @entry: The entry to store.
 */
void mas_store_prealloc(struct ma_state *mas, void *entry)
{
	MA_WR_STATE(wr_mas, mas, entry);

	mas_wr_store_setup(&wr_mas);
	trace_ma_write(__func__, mas, 0, entry);
	mas_wr_store_entry(&wr_mas);
	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
	mas_destroy(mas);
}
EXPORT_SYMBOL_GPL(mas_store_prealloc);

/**
 * mas_preallocate() - Preallocate enough nodes for a store operation
 * @mas: The maple state
 * @entry: The entry that will be stored
 * @gfp: The GFP_FLAGS to use for allocations.
 *
 * Return: 0 on success, -ENOMEM if memory could not be allocated.
 */
int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
{
	MA_WR_STATE(wr_mas, mas, entry);
	unsigned char node_size;
	int request = 1;
	int ret;


	if (unlikely(!mas->index && mas->last == ULONG_MAX))
		goto ask_now;

	mas_wr_store_setup(&wr_mas);
	wr_mas.content = mas_start(mas);
	/* Root expand */
	if (unlikely(mas_is_none(mas) || mas_is_ptr(mas)))
		goto ask_now;

	if (unlikely(!mas_wr_walk(&wr_mas))) {
		/* Spanning store, use worst case for now */
		request = 1 + mas_mt_height(mas) * 3;
		goto ask_now;
	}

	/* At this point, we are at the leaf node that needs to be altered. */
	/* Exact fit, no nodes needed. */
	if (wr_mas.r_min == mas->index && wr_mas.r_max == mas->last)
		return 0;

	mas_wr_end_piv(&wr_mas);
	node_size = mas_wr_new_end(&wr_mas);
	if (node_size >= mt_slots[wr_mas.type]) {
		/* Split, worst case for now. */
		request = 1 + mas_mt_height(mas) * 2;
		goto ask_now;
	}

	/* New root needs a singe node */
	if (unlikely(mte_is_root(mas->node)))
		goto ask_now;

	/* Potential spanning rebalance collapsing a node, use worst-case */
	if (node_size  - 1 <= mt_min_slots[wr_mas.type])
		request = mas_mt_height(mas) * 2 - 1;

	/* node store, slot store needs one node */
ask_now:
	mas_node_count_gfp(mas, request, gfp);
	mas->mas_flags |= MA_STATE_PREALLOC;
	if (likely(!mas_is_err(mas)))
		return 0;

	mas_set_alloc_req(mas, 0);
	ret = xa_err(mas->node);
	mas_reset(mas);
	mas_destroy(mas);
	mas_reset(mas);
	return ret;
}
EXPORT_SYMBOL_GPL(mas_preallocate);

/*
 * mas_destroy() - destroy a maple state.
 * @mas: The maple state
 *
 * Upon completion, check the left-most node and rebalance against the node to
 * the right if necessary.  Frees any allocated nodes associated with this maple
 * state.
 */
void mas_destroy(struct ma_state *mas)
{
	struct maple_alloc *node;
	unsigned long total;

	/*
	 * When using mas_for_each() to insert an expected number of elements,
	 * it is possible that the number inserted is less than the expected
	 * number.  To fix an invalid final node, a check is performed here to
	 * rebalance the previous node with the final node.
	 */
	if (mas->mas_flags & MA_STATE_REBALANCE) {
		unsigned char end;

		mas_start(mas);
		mtree_range_walk(mas);
		end = mas_data_end(mas) + 1;
		if (end < mt_min_slot_count(mas->node) - 1)
			mas_destroy_rebalance(mas, end);

		mas->mas_flags &= ~MA_STATE_REBALANCE;
	}
	mas->mas_flags &= ~(MA_STATE_BULK|MA_STATE_PREALLOC);

	total = mas_allocated(mas);
	while (total) {
		node = mas->alloc;
		mas->alloc = node->slot[0];
		if (node->node_count > 1) {
			size_t count = node->node_count - 1;

			mt_free_bulk(count, (void __rcu **)&node->slot[1]);
			total -= count;
		}
		kmem_cache_free(maple_node_cache, node);
		total--;
	}

	mas->alloc = NULL;
}
EXPORT_SYMBOL_GPL(mas_destroy);

/*
 * mas_expected_entries() - Set the expected number of entries that will be inserted.
 * @mas: The maple state
 * @nr_entries: The number of expected entries.
 *
 * This will attempt to pre-allocate enough nodes to store the expected number
 * of entries.  The allocations will occur using the bulk allocator interface
 * for speed.  Please call mas_destroy() on the @mas after inserting the entries
 * to ensure any unused nodes are freed.
 *
 * Return: 0 on success, -ENOMEM if memory could not be allocated.
 */
int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
{
	int nonleaf_cap = MAPLE_ARANGE64_SLOTS - 2;
	struct maple_enode *enode = mas->node;
	int nr_nodes;
	int ret;

	/*
	 * Sometimes it is necessary to duplicate a tree to a new tree, such as
	 * forking a process and duplicating the VMAs from one tree to a new
	 * tree.  When such a situation arises, it is known that the new tree is
	 * not going to be used until the entire tree is populated.  For
	 * performance reasons, it is best to use a bulk load with RCU disabled.
	 * This allows for optimistic splitting that favours the left and reuse
	 * of nodes during the operation.
	 */

	/* Optimize splitting for bulk insert in-order */
	mas->mas_flags |= MA_STATE_BULK;

	/*
	 * Avoid overflow, assume a gap between each entry and a trailing null.
	 * If this is wrong, it just means allocation can happen during
	 * insertion of entries.
	 */
	nr_nodes = max(nr_entries, nr_entries * 2 + 1);
	if (!mt_is_alloc(mas->tree))
		nonleaf_cap = MAPLE_RANGE64_SLOTS - 2;

	/* Leaves; reduce slots to keep space for expansion */
	nr_nodes = DIV_ROUND_UP(nr_nodes, MAPLE_RANGE64_SLOTS - 2);
	/* Internal nodes */
	nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
	/* Add working room for split (2 nodes) + new parents */
	mas_node_count(mas, nr_nodes + 3);

	/* Detect if allocations run out */
	mas->mas_flags |= MA_STATE_PREALLOC;

	if (!mas_is_err(mas))
		return 0;

	ret = xa_err(mas->node);
	mas->node = enode;
	mas_destroy(mas);
	return ret;

}
EXPORT_SYMBOL_GPL(mas_expected_entries);

static inline bool mas_next_setup(struct ma_state *mas, unsigned long max,
		void **entry)
{
	bool was_none = mas_is_none(mas);

	if (unlikely(mas->last >= max)) {
		mas->node = MAS_OVERFLOW;
		return true;
	}

	if (mas_is_active(mas))
		return false;

	if (mas_is_none(mas) || mas_is_paused(mas)) {
		mas->node = MAS_START;
	} else if (mas_is_overflow(mas)) {
		/* Overflowed before, but the max changed */
		mas->node = MAS_START;
	} else if (mas_is_underflow(mas)) {
		mas->node = MAS_START;
		*entry = mas_walk(mas);
		if (*entry)
			return true;
	}

	if (mas_is_start(mas))
		*entry = mas_walk(mas); /* Retries on dead nodes handled by mas_walk */

	if (mas_is_ptr(mas)) {
		*entry = NULL;
		if (was_none && mas->index == 0) {
			mas->index = mas->last = 0;
			return true;
		}
		mas->index = 1;
		mas->last = ULONG_MAX;
		mas->node = MAS_NONE;
		return true;
	}

	if (mas_is_none(mas))
		return true;

	return false;
}

/**
 * mas_next() - Get the next entry.
 * @mas: The maple state
 * @max: The maximum index to check.
 *
 * Returns the next entry after @mas->index.
 * Must hold rcu_read_lock or the write lock.
 * Can return the zero entry.
 *
 * Return: The next entry or %NULL
 */
void *mas_next(struct ma_state *mas, unsigned long max)
{
	void *entry = NULL;

	if (mas_next_setup(mas, max, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_next_slot */
	return mas_next_slot(mas, max, false, true);
}
EXPORT_SYMBOL_GPL(mas_next);

/**
 * mas_next_range() - Advance the maple state to the next range
 * @mas: The maple state
 * @max: The maximum index to check.
 *
 * Sets @mas->index and @mas->last to the range.
 * Must hold rcu_read_lock or the write lock.
 * Can return the zero entry.
 *
 * Return: The next entry or %NULL
 */
void *mas_next_range(struct ma_state *mas, unsigned long max)
{
	void *entry = NULL;

	if (mas_next_setup(mas, max, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_next_slot */
	return mas_next_slot(mas, max, true, true);
}
EXPORT_SYMBOL_GPL(mas_next_range);

/**
 * mt_next() - get the next value in the maple tree
 * @mt: The maple tree
 * @index: The start index
 * @max: The maximum index to check
 *
 * Takes RCU read lock internally to protect the search, which does not
 * protect the returned pointer after dropping RCU read lock.
 * See also: Documentation/core-api/maple_tree.rst
 *
 * Return: The entry higher than @index or %NULL if nothing is found.
 */
void *mt_next(struct maple_tree *mt, unsigned long index, unsigned long max)
{
	void *entry = NULL;
	MA_STATE(mas, mt, index, index);

	rcu_read_lock();
	entry = mas_next(&mas, max);
	rcu_read_unlock();
	return entry;
}
EXPORT_SYMBOL_GPL(mt_next);

static inline bool mas_prev_setup(struct ma_state *mas, unsigned long min,
		void **entry)
{
	if (unlikely(mas->index <= min)) {
		mas->node = MAS_UNDERFLOW;
		return true;
	}

	if (mas_is_active(mas))
		return false;

	if (mas_is_overflow(mas)) {
		mas->node = MAS_START;
		*entry = mas_walk(mas);
		if (*entry)
			return true;
	}

	if (mas_is_none(mas) || mas_is_paused(mas)) {
		mas->node = MAS_START;
	} else if (mas_is_underflow(mas)) {
		/* underflowed before but the min changed */
		mas->node = MAS_START;
	}

	if (mas_is_start(mas))
		mas_walk(mas);

	if (unlikely(mas_is_ptr(mas))) {
		if (!mas->index)
			goto none;
		mas->index = mas->last = 0;
		*entry = mas_root(mas);
		return true;
	}

	if (mas_is_none(mas)) {
		if (mas->index) {
			/* Walked to out-of-range pointer? */
			mas->index = mas->last = 0;
			mas->node = MAS_ROOT;
			*entry = mas_root(mas);
			return true;
		}
		return true;
	}

	return false;

none:
	mas->node = MAS_NONE;
	return true;
}

/**
 * mas_prev() - Get the previous entry
 * @mas: The maple state
 * @min: The minimum value to check.
 *
 * Must hold rcu_read_lock or the write lock.
 * Will reset mas to MAS_START if the node is MAS_NONE.  Will stop on not
 * searchable nodes.
 *
 * Return: the previous value or %NULL.
 */
void *mas_prev(struct ma_state *mas, unsigned long min)
{
	void *entry = NULL;

	if (mas_prev_setup(mas, min, &entry))
		return entry;

	return mas_prev_slot(mas, min, false, true);
}
EXPORT_SYMBOL_GPL(mas_prev);

/**
 * mas_prev_range() - Advance to the previous range
 * @mas: The maple state
 * @min: The minimum value to check.
 *
 * Sets @mas->index and @mas->last to the range.
 * Must hold rcu_read_lock or the write lock.
 * Will reset mas to MAS_START if the node is MAS_NONE.  Will stop on not
 * searchable nodes.
 *
 * Return: the previous value or %NULL.
 */
void *mas_prev_range(struct ma_state *mas, unsigned long min)
{
	void *entry = NULL;

	if (mas_prev_setup(mas, min, &entry))
		return entry;

	return mas_prev_slot(mas, min, true, true);
}
EXPORT_SYMBOL_GPL(mas_prev_range);

/**
 * mt_prev() - get the previous value in the maple tree
 * @mt: The maple tree
 * @index: The start index
 * @min: The minimum index to check
 *
 * Takes RCU read lock internally to protect the search, which does not
 * protect the returned pointer after dropping RCU read lock.
 * See also: Documentation/core-api/maple_tree.rst
 *
 * Return: The entry before @index or %NULL if nothing is found.
 */
void *mt_prev(struct maple_tree *mt, unsigned long index, unsigned long min)
{
	void *entry = NULL;
	MA_STATE(mas, mt, index, index);

	rcu_read_lock();
	entry = mas_prev(&mas, min);
	rcu_read_unlock();
	return entry;
}
EXPORT_SYMBOL_GPL(mt_prev);

/**
 * mas_pause() - Pause a mas_find/mas_for_each to drop the lock.
 * @mas: The maple state to pause
 *
 * Some users need to pause a walk and drop the lock they're holding in
 * order to yield to a higher priority thread or carry out an operation
 * on an entry.  Those users should call this function before they drop
 * the lock.  It resets the @mas to be suitable for the next iteration
 * of the loop after the user has reacquired the lock.  If most entries
 * found during a walk require you to call mas_pause(), the mt_for_each()
 * iterator may be more appropriate.
 *
 */
void mas_pause(struct ma_state *mas)
{
	mas->node = MAS_PAUSE;
}
EXPORT_SYMBOL_GPL(mas_pause);

/**
 * mas_find_setup() - Internal function to set up mas_find*().
 * @mas: The maple state
 * @max: The maximum index
 * @entry: Pointer to the entry
 *
 * Returns: True if entry is the answer, false otherwise.
 */
static inline bool mas_find_setup(struct ma_state *mas, unsigned long max,
		void **entry)
{
	if (mas_is_active(mas)) {
		if (mas->last < max)
			return false;

		return true;
	}

	if (mas_is_paused(mas)) {
		if (unlikely(mas->last >= max))
			return true;

		mas->index = ++mas->last;
		mas->node = MAS_START;
	} else if (mas_is_none(mas)) {
		if (unlikely(mas->last >= max))
			return true;

		mas->index = mas->last;
		mas->node = MAS_START;
	} else if (mas_is_overflow(mas) || mas_is_underflow(mas)) {
		if (mas->index > max) {
			mas->node = MAS_OVERFLOW;
			return true;
		}

		mas->node = MAS_START;
	}

	if (mas_is_start(mas)) {
		/* First run or continue */
		if (mas->index > max)
			return true;

		*entry = mas_walk(mas);
		if (*entry)
			return true;

	}

	if (unlikely(!mas_searchable(mas))) {
		if (unlikely(mas_is_ptr(mas)))
			goto ptr_out_of_range;

		return true;
	}

	if (mas->index == max)
		return true;

	return false;

ptr_out_of_range:
	mas->node = MAS_NONE;
	mas->index = 1;
	mas->last = ULONG_MAX;
	return true;
}

/**
 * mas_find() - On the first call, find the entry at or after mas->index up to
 * %max.  Otherwise, find the entry after mas->index.
 * @mas: The maple state
 * @max: The maximum value to check.
 *
 * Must hold rcu_read_lock or the write lock.
 * If an entry exists, last and index are updated accordingly.
 * May set @mas->node to MAS_NONE.
 *
 * Return: The entry or %NULL.
 */
void *mas_find(struct ma_state *mas, unsigned long max)
{
	void *entry = NULL;

	if (mas_find_setup(mas, max, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_next_slot */
	return mas_next_slot(mas, max, false, false);
}
EXPORT_SYMBOL_GPL(mas_find);

/**
 * mas_find_range() - On the first call, find the entry at or after
 * mas->index up to %max.  Otherwise, advance to the next slot mas->index.
 * @mas: The maple state
 * @max: The maximum value to check.
 *
 * Must hold rcu_read_lock or the write lock.
 * If an entry exists, last and index are updated accordingly.
 * May set @mas->node to MAS_NONE.
 *
 * Return: The entry or %NULL.
 */
void *mas_find_range(struct ma_state *mas, unsigned long max)
{
	void *entry = NULL;

	if (mas_find_setup(mas, max, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_next_slot */
	return mas_next_slot(mas, max, true, false);
}
EXPORT_SYMBOL_GPL(mas_find_range);

/**
 * mas_find_rev_setup() - Internal function to set up mas_find_*_rev()
 * @mas: The maple state
 * @min: The minimum index
 * @entry: Pointer to the entry
 *
 * Returns: True if entry is the answer, false otherwise.
 */
static inline bool mas_find_rev_setup(struct ma_state *mas, unsigned long min,
		void **entry)
{
	if (mas_is_active(mas)) {
		if (mas->index > min)
			return false;

		return true;
	}

	if (mas_is_paused(mas)) {
		if (unlikely(mas->index <= min)) {
			mas->node = MAS_NONE;
			return true;
		}
		mas->node = MAS_START;
		mas->last = --mas->index;
	} else if (mas_is_none(mas)) {
		if (mas->index <= min)
			goto none;

		mas->last = mas->index;
		mas->node = MAS_START;
	} else if (mas_is_underflow(mas) || mas_is_overflow(mas)) {
		if (mas->last <= min) {
			mas->node = MAS_UNDERFLOW;
			return true;
		}

		mas->node = MAS_START;
	}

	if (mas_is_start(mas)) {
		/* First run or continue */
		if (mas->index < min)
			return true;

		*entry = mas_walk(mas);
		if (*entry)
			return true;
	}

	if (unlikely(!mas_searchable(mas))) {
		if (mas_is_ptr(mas))
			goto none;

		if (mas_is_none(mas)) {
			/*
			 * Walked to the location, and there was nothing so the
			 * previous location is 0.
			 */
			mas->last = mas->index = 0;
			mas->node = MAS_ROOT;
			*entry = mas_root(mas);
			return true;
		}
	}

	if (mas->index < min)
		return true;

	return false;

none:
	mas->node = MAS_NONE;
	return true;
}

/**
 * mas_find_rev: On the first call, find the first non-null entry at or below
 * mas->index down to %min.  Otherwise find the first non-null entry below
 * mas->index down to %min.
 * @mas: The maple state
 * @min: The minimum value to check.
 *
 * Must hold rcu_read_lock or the write lock.
 * If an entry exists, last and index are updated accordingly.
 * May set @mas->node to MAS_NONE.
 *
 * Return: The entry or %NULL.
 */
void *mas_find_rev(struct ma_state *mas, unsigned long min)
{
	void *entry = NULL;

	if (mas_find_rev_setup(mas, min, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_prev_slot */
	return mas_prev_slot(mas, min, false, false);

}
EXPORT_SYMBOL_GPL(mas_find_rev);

/**
 * mas_find_range_rev: On the first call, find the first non-null entry at or
 * below mas->index down to %min.  Otherwise advance to the previous slot after
 * mas->index down to %min.
 * @mas: The maple state
 * @min: The minimum value to check.
 *
 * Must hold rcu_read_lock or the write lock.
 * If an entry exists, last and index are updated accordingly.
 * May set @mas->node to MAS_NONE.
 *
 * Return: The entry or %NULL.
 */
void *mas_find_range_rev(struct ma_state *mas, unsigned long min)
{
	void *entry = NULL;

	if (mas_find_rev_setup(mas, min, &entry))
		return entry;

	/* Retries on dead nodes handled by mas_prev_slot */
	return mas_prev_slot(mas, min, true, false);
}
EXPORT_SYMBOL_GPL(mas_find_range_rev);

/**
 * mas_erase() - Find the range in which index resides and erase the entire
 * range.
 * @mas: The maple state
 *
 * Must hold the write lock.
 * Searches for @mas->index, sets @mas->index and @mas->last to the range and
 * erases that range.
 *
 * Return: the entry that was erased or %NULL, @mas->index and @mas->last are updated.
 */
void *mas_erase(struct ma_state *mas)
{
	void *entry;
	MA_WR_STATE(wr_mas, mas, NULL);

	if (mas_is_none(mas) || mas_is_paused(mas))
		mas->node = MAS_START;

	/* Retry unnecessary when holding the write lock. */
	entry = mas_state_walk(mas);
	if (!entry)
		return NULL;

write_retry:
	/* Must reset to ensure spanning writes of last slot are detected */
	mas_reset(mas);
	mas_wr_store_setup(&wr_mas);
	mas_wr_store_entry(&wr_mas);
	if (mas_nomem(mas, GFP_KERNEL))
		goto write_retry;

	return entry;
}
EXPORT_SYMBOL_GPL(mas_erase);

/**
 * mas_nomem() - Check if there was an error allocating and do the allocation
 * if necessary If there are allocations, then free them.
 * @mas: The maple state
 * @gfp: The GFP_FLAGS to use for allocations
 * Return: true on allocation, false otherwise.
 */
bool mas_nomem(struct ma_state *mas, gfp_t gfp)
	__must_hold(mas->tree->ma_lock)
{
	if (likely(mas->node != MA_ERROR(-ENOMEM))) {
		mas_destroy(mas);
		return false;
	}

	if (gfpflags_allow_blocking(gfp) && !mt_external_lock(mas->tree)) {
		mtree_unlock(mas->tree);
		mas_alloc_nodes(mas, gfp);
		mtree_lock(mas->tree);
	} else {
		mas_alloc_nodes(mas, gfp);
	}

	if (!mas_allocated(mas))
		return false;

	mas->node = MAS_START;
	return true;
}

void __init maple_tree_init(void)
{
	maple_node_cache = kmem_cache_create("maple_node",
			sizeof(struct maple_node), sizeof(struct maple_node),
			SLAB_PANIC, NULL);
}

/**
 * mtree_load() - Load a value stored in a maple tree
 * @mt: The maple tree
 * @index: The index to load
 *
 * Return: the entry or %NULL
 */
void *mtree_load(struct maple_tree *mt, unsigned long index)
{
	MA_STATE(mas, mt, index, index);
	void *entry;

	trace_ma_read(__func__, &mas);
	rcu_read_lock();
retry:
	entry = mas_start(&mas);
	if (unlikely(mas_is_none(&mas)))
		goto unlock;

	if (unlikely(mas_is_ptr(&mas))) {
		if (index)
			entry = NULL;

		goto unlock;
	}

	entry = mtree_lookup_walk(&mas);
	if (!entry && unlikely(mas_is_start(&mas)))
		goto retry;
unlock:
	rcu_read_unlock();
	if (xa_is_zero(entry))
		return NULL;

	return entry;
}
EXPORT_SYMBOL(mtree_load);

/**
 * mtree_store_range() - Store an entry at a given range.
 * @mt: The maple tree
 * @index: The start of the range
 * @last: The end of the range
 * @entry: The entry to store
 * @gfp: The GFP_FLAGS to use for allocations
 *
 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
 * be allocated.
 */
int mtree_store_range(struct maple_tree *mt, unsigned long index,
		unsigned long last, void *entry, gfp_t gfp)
{
	MA_STATE(mas, mt, index, last);
	MA_WR_STATE(wr_mas, &mas, entry);

	trace_ma_write(__func__, &mas, 0, entry);
	if (WARN_ON_ONCE(xa_is_advanced(entry)))
		return -EINVAL;

	if (index > last)
		return -EINVAL;

	mtree_lock(mt);
retry:
	mas_wr_store_entry(&wr_mas);
	if (mas_nomem(&mas, gfp))
		goto retry;

	mtree_unlock(mt);
	if (mas_is_err(&mas))
		return xa_err(mas.node);

	return 0;
}
EXPORT_SYMBOL(mtree_store_range);

/**
 * mtree_store() - Store an entry at a given index.
 * @mt: The maple tree
 * @index: The index to store the value
 * @entry: The entry to store
 * @gfp: The GFP_FLAGS to use for allocations
 *
 * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
 * be allocated.
 */
int mtree_store(struct maple_tree *mt, unsigned long index, void *entry,
		 gfp_t gfp)
{
	return mtree_store_range(mt, index, index, entry, gfp);
}
EXPORT_SYMBOL(mtree_store);

/**
 * mtree_insert_range() - Insert an entry at a given range if there is no value.
 * @mt: The maple tree
 * @first: The start of the range
 * @last: The end of the range
 * @entry: The entry to store
 * @gfp: The GFP_FLAGS to use for allocations.
 *
 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
 * request, -ENOMEM if memory could not be allocated.
 */
int mtree_insert_range(struct maple_tree *mt, unsigned long first,
		unsigned long last, void *entry, gfp_t gfp)
{
	MA_STATE(ms, mt, first, last);

	if (WARN_ON_ONCE(xa_is_advanced(entry)))
		return -EINVAL;

	if (first > last)
		return -EINVAL;

	mtree_lock(mt);
retry:
	mas_insert(&ms, entry);
	if (mas_nomem(&ms, gfp))
		goto retry;

	mtree_unlock(mt);
	if (mas_is_err(&ms))
		return xa_err(ms.node);

	return 0;
}
EXPORT_SYMBOL(mtree_insert_range);

/**
 * mtree_insert() - Insert an entry at a given index if there is no value.
 * @mt: The maple tree
 * @index : The index to store the value
 * @entry: The entry to store
 * @gfp: The GFP_FLAGS to use for allocations.
 *
 * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
 * request, -ENOMEM if memory could not be allocated.
 */
int mtree_insert(struct maple_tree *mt, unsigned long index, void *entry,
		 gfp_t gfp)
{
	return mtree_insert_range(mt, index, index, entry, gfp);
}
EXPORT_SYMBOL(mtree_insert);

int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
		void *entry, unsigned long size, unsigned long min,
		unsigned long max, gfp_t gfp)
{
	int ret = 0;

	MA_STATE(mas, mt, 0, 0);
	if (!mt_is_alloc(mt))
		return -EINVAL;

	if (WARN_ON_ONCE(mt_is_reserved(entry)))
		return -EINVAL;

	mtree_lock(mt);
retry:
	ret = mas_empty_area(&mas, min, max, size);
	if (ret)
		goto unlock;

	mas_insert(&mas, entry);
	/*
	 * mas_nomem() may release the lock, causing the allocated area
	 * to be unavailable, so try to allocate a free area again.
	 */
	if (mas_nomem(&mas, gfp))
		goto retry;

	if (mas_is_err(&mas))
		ret = xa_err(mas.node);
	else
		*startp = mas.index;

unlock:
	mtree_unlock(mt);
	return ret;
}
EXPORT_SYMBOL(mtree_alloc_range);

int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
		void *entry, unsigned long size, unsigned long min,
		unsigned long max, gfp_t gfp)
{
	int ret = 0;

	MA_STATE(mas, mt, 0, 0);
	if (!mt_is_alloc(mt))
		return -EINVAL;

	if (WARN_ON_ONCE(mt_is_reserved(entry)))
		return -EINVAL;

	mtree_lock(mt);
retry:
	ret = mas_empty_area_rev(&mas, min, max, size);
	if (ret)
		goto unlock;

	mas_insert(&mas, entry);
	/*
	 * mas_nomem() may release the lock, causing the allocated area
	 * to be unavailable, so try to allocate a free area again.
	 */
	if (mas_nomem(&mas, gfp))
		goto retry;

	if (mas_is_err(&mas))
		ret = xa_err(mas.node);
	else
		*startp = mas.index;

unlock:
	mtree_unlock(mt);
	return ret;
}
EXPORT_SYMBOL(mtree_alloc_rrange);

/**
 * mtree_erase() - Find an index and erase the entire range.
 * @mt: The maple tree
 * @index: The index to erase
 *
 * Erasing is the same as a walk to an entry then a store of a NULL to that
 * ENTIRE range.  In fact, it is implemented as such using the advanced API.
 *
 * Return: The entry stored at the @index or %NULL
 */
void *mtree_erase(struct maple_tree *mt, unsigned long index)
{
	void *entry = NULL;

	MA_STATE(mas, mt, index, index);
	trace_ma_op(__func__, &mas);

	mtree_lock(mt);
	entry = mas_erase(&mas);
	mtree_unlock(mt);

	return entry;
}
EXPORT_SYMBOL(mtree_erase);

/**
 * __mt_destroy() - Walk and free all nodes of a locked maple tree.
 * @mt: The maple tree
 *
 * Note: Does not handle locking.
 */
void __mt_destroy(struct maple_tree *mt)
{
	void *root = mt_root_locked(mt);

	rcu_assign_pointer(mt->ma_root, NULL);
	if (xa_is_node(root))
		mte_destroy_walk(root, mt);

	mt->ma_flags = 0;
}
EXPORT_SYMBOL_GPL(__mt_destroy);

/**
 * mtree_destroy() - Destroy a maple tree
 * @mt: The maple tree
 *
 * Frees all resources used by the tree.  Handles locking.
 */
void mtree_destroy(struct maple_tree *mt)
{
	mtree_lock(mt);
	__mt_destroy(mt);
	mtree_unlock(mt);
}
EXPORT_SYMBOL(mtree_destroy);

/**
 * mt_find() - Search from the start up until an entry is found.
 * @mt: The maple tree
 * @index: Pointer which contains the start location of the search
 * @max: The maximum value of the search range
 *
 * Takes RCU read lock internally to protect the search, which does not
 * protect the returned pointer after dropping RCU read lock.
 * See also: Documentation/core-api/maple_tree.rst
 *
 * In case that an entry is found @index is updated to point to the next
 * possible entry independent whether the found entry is occupying a
 * single index or a range if indices.
 *
 * Return: The entry at or after the @index or %NULL
 */
void *mt_find(struct maple_tree *mt, unsigned long *index, unsigned long max)
{
	MA_STATE(mas, mt, *index, *index);
	void *entry;
#ifdef CONFIG_DEBUG_MAPLE_TREE
	unsigned long copy = *index;
#endif

	trace_ma_read(__func__, &mas);

	if ((*index) > max)
		return NULL;

	rcu_read_lock();
retry:
	entry = mas_state_walk(&mas);
	if (mas_is_start(&mas))
		goto retry;

	if (unlikely(xa_is_zero(entry)))
		entry = NULL;

	if (entry)
		goto unlock;

	while (mas_searchable(&mas) && (mas.last < max)) {
		entry = mas_next_entry(&mas, max);
		if (likely(entry && !xa_is_zero(entry)))
			break;
	}

	if (unlikely(xa_is_zero(entry)))
		entry = NULL;
unlock:
	rcu_read_unlock();
	if (likely(entry)) {
		*index = mas.last + 1;
#ifdef CONFIG_DEBUG_MAPLE_TREE
		if (MT_WARN_ON(mt, (*index) && ((*index) <= copy)))
			pr_err("index not increased! %lx <= %lx\n",
			       *index, copy);
#endif
	}

	return entry;
}
EXPORT_SYMBOL(mt_find);

/**
 * mt_find_after() - Search from the start up until an entry is found.
 * @mt: The maple tree
 * @index: Pointer which contains the start location of the search
 * @max: The maximum value to check
 *
 * Same as mt_find() except that it checks @index for 0 before
 * searching. If @index == 0, the search is aborted. This covers a wrap
 * around of @index to 0 in an iterator loop.
 *
 * Return: The entry at or after the @index or %NULL
 */
void *mt_find_after(struct maple_tree *mt, unsigned long *index,
		    unsigned long max)
{
	if (!(*index))
		return NULL;

	return mt_find(mt, index, max);
}
EXPORT_SYMBOL(mt_find_after);

#ifdef CONFIG_DEBUG_MAPLE_TREE
atomic_t maple_tree_tests_run;
EXPORT_SYMBOL_GPL(maple_tree_tests_run);
atomic_t maple_tree_tests_passed;
EXPORT_SYMBOL_GPL(maple_tree_tests_passed);

#ifndef __KERNEL__
extern void kmem_cache_set_non_kernel(struct kmem_cache *, unsigned int);
void mt_set_non_kernel(unsigned int val)
{
	kmem_cache_set_non_kernel(maple_node_cache, val);
}

extern unsigned long kmem_cache_get_alloc(struct kmem_cache *);
unsigned long mt_get_alloc_size(void)
{
	return kmem_cache_get_alloc(maple_node_cache);
}

extern void kmem_cache_zero_nr_tallocated(struct kmem_cache *);
void mt_zero_nr_tallocated(void)
{
	kmem_cache_zero_nr_tallocated(maple_node_cache);
}

extern unsigned int kmem_cache_nr_tallocated(struct kmem_cache *);
unsigned int mt_nr_tallocated(void)
{
	return kmem_cache_nr_tallocated(maple_node_cache);
}

extern unsigned int kmem_cache_nr_allocated(struct kmem_cache *);
unsigned int mt_nr_allocated(void)
{
	return kmem_cache_nr_allocated(maple_node_cache);
}

/*
 * mas_dead_node() - Check if the maple state is pointing to a dead node.
 * @mas: The maple state
 * @index: The index to restore in @mas.
 *
 * Used in test code.
 * Return: 1 if @mas has been reset to MAS_START, 0 otherwise.
 */
static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
{
	if (unlikely(!mas_searchable(mas) || mas_is_start(mas)))
		return 0;

	if (likely(!mte_dead_node(mas->node)))
		return 0;

	mas_rewalk(mas, index);
	return 1;
}

void mt_cache_shrink(void)
{
}
#else
/*
 * mt_cache_shrink() - For testing, don't use this.
 *
 * Certain testcases can trigger an OOM when combined with other memory
 * debugging configuration options.  This function is used to reduce the
 * possibility of an out of memory even due to kmem_cache objects remaining
 * around for longer than usual.
 */
void mt_cache_shrink(void)
{
	kmem_cache_shrink(maple_node_cache);

}
EXPORT_SYMBOL_GPL(mt_cache_shrink);

#endif /* not defined __KERNEL__ */
/*
 * mas_get_slot() - Get the entry in the maple state node stored at @offset.
 * @mas: The maple state
 * @offset: The offset into the slot array to fetch.
 *
 * Return: The entry stored at @offset.
 */
static inline struct maple_enode *mas_get_slot(struct ma_state *mas,
		unsigned char offset)
{
	return mas_slot(mas, ma_slots(mas_mn(mas), mte_node_type(mas->node)),
			offset);
}

/* Depth first search, post-order */
static void mas_dfs_postorder(struct ma_state *mas, unsigned long max)
{

	struct maple_enode *p = MAS_NONE, *mn = mas->node;
	unsigned long p_min, p_max;

	mas_next_node(mas, mas_mn(mas), max);
	if (!mas_is_none(mas))
		return;

	if (mte_is_root(mn))
		return;

	mas->node = mn;
	mas_ascend(mas);
	do {
		p = mas->node;
		p_min = mas->min;
		p_max = mas->max;
		mas_prev_node(mas, 0);
	} while (!mas_is_none(mas));

	mas->node = p;
	mas->max = p_max;
	mas->min = p_min;
}

/* Tree validations */
static void mt_dump_node(const struct maple_tree *mt, void *entry,
		unsigned long min, unsigned long max, unsigned int depth,
		enum mt_dump_format format);
static void mt_dump_range(unsigned long min, unsigned long max,
			  unsigned int depth, enum mt_dump_format format)
{
	static const char spaces[] = "                                ";

	switch(format) {
	case mt_dump_hex:
		if (min == max)
			pr_info("%.*s%lx: ", depth * 2, spaces, min);
		else
			pr_info("%.*s%lx-%lx: ", depth * 2, spaces, min, max);
		break;
	default:
	case mt_dump_dec:
		if (min == max)
			pr_info("%.*s%lu: ", depth * 2, spaces, min);
		else
			pr_info("%.*s%lu-%lu: ", depth * 2, spaces, min, max);
	}
}

static void mt_dump_entry(void *entry, unsigned long min, unsigned long max,
			  unsigned int depth, enum mt_dump_format format)
{
	mt_dump_range(min, max, depth, format);

	if (xa_is_value(entry))
		pr_cont("value %ld (0x%lx) [%p]\n", xa_to_value(entry),
				xa_to_value(entry), entry);
	else if (xa_is_zero(entry))
		pr_cont("zero (%ld)\n", xa_to_internal(entry));
	else if (mt_is_reserved(entry))
		pr_cont("UNKNOWN ENTRY (%p)\n", entry);
	else
		pr_cont("%p\n", entry);
}

static void mt_dump_range64(const struct maple_tree *mt, void *entry,
		unsigned long min, unsigned long max, unsigned int depth,
		enum mt_dump_format format)
{
	struct maple_range_64 *node = &mte_to_node(entry)->mr64;
	bool leaf = mte_is_leaf(entry);
	unsigned long first = min;
	int i;

	pr_cont(" contents: ");
	for (i = 0; i < MAPLE_RANGE64_SLOTS - 1; i++) {
		switch(format) {
		case mt_dump_hex:
			pr_cont("%p %lX ", node->slot[i], node->pivot[i]);
			break;
		default:
		case mt_dump_dec:
			pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
		}
	}
	pr_cont("%p\n", node->slot[i]);
	for (i = 0; i < MAPLE_RANGE64_SLOTS; i++) {
		unsigned long last = max;

		if (i < (MAPLE_RANGE64_SLOTS - 1))
			last = node->pivot[i];
		else if (!node->slot[i] && max != mt_node_max(entry))
			break;
		if (last == 0 && i > 0)
			break;
		if (leaf)
			mt_dump_entry(mt_slot(mt, node->slot, i),
					first, last, depth + 1, format);
		else if (node->slot[i])
			mt_dump_node(mt, mt_slot(mt, node->slot, i),
					first, last, depth + 1, format);

		if (last == max)
			break;
		if (last > max) {
			switch(format) {
			case mt_dump_hex:
				pr_err("node %p last (%lx) > max (%lx) at pivot %d!\n",
					node, last, max, i);
				break;
			default:
			case mt_dump_dec:
				pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
					node, last, max, i);
			}
		}
		first = last + 1;
	}
}

static void mt_dump_arange64(const struct maple_tree *mt, void *entry,
	unsigned long min, unsigned long max, unsigned int depth,
	enum mt_dump_format format)
{
	struct maple_arange_64 *node = &mte_to_node(entry)->ma64;
	bool leaf = mte_is_leaf(entry);
	unsigned long first = min;
	int i;

	pr_cont(" contents: ");
	for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) {
		switch (format) {
		case mt_dump_hex:
			pr_cont("%lx ", node->gap[i]);
			break;
		default:
		case mt_dump_dec:
			pr_cont("%lu ", node->gap[i]);
		}
	}
	pr_cont("| %02X %02X| ", node->meta.end, node->meta.gap);
	for (i = 0; i < MAPLE_ARANGE64_SLOTS - 1; i++) {
		switch (format) {
		case mt_dump_hex:
			pr_cont("%p %lX ", node->slot[i], node->pivot[i]);
			break;
		default:
		case mt_dump_dec:
			pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
		}
	}
	pr_cont("%p\n", node->slot[i]);
	for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) {
		unsigned long last = max;

		if (i < (MAPLE_ARANGE64_SLOTS - 1))
			last = node->pivot[i];
		else if (!node->slot[i])
			break;
		if (last == 0 && i > 0)
			break;
		if (leaf)
			mt_dump_entry(mt_slot(mt, node->slot, i),
					first, last, depth + 1, format);
		else if (node->slot[i])
			mt_dump_node(mt, mt_slot(mt, node->slot, i),
					first, last, depth + 1, format);

		if (last == max)
			break;
		if (last > max) {
			pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
					node, last, max, i);
			break;
		}
		first = last + 1;
	}
}

static void mt_dump_node(const struct maple_tree *mt, void *entry,
		unsigned long min, unsigned long max, unsigned int depth,
		enum mt_dump_format format)
{
	struct maple_node *node = mte_to_node(entry);
	unsigned int type = mte_node_type(entry);
	unsigned int i;

	mt_dump_range(min, max, depth, format);

	pr_cont("node %p depth %d type %d parent %p", node, depth, type,
			node ? node->parent : NULL);
	switch (type) {
	case maple_dense:
		pr_cont("\n");
		for (i = 0; i < MAPLE_NODE_SLOTS; i++) {
			if (min + i > max)
				pr_cont("OUT OF RANGE: ");
			mt_dump_entry(mt_slot(mt, node->slot, i),
					min + i, min + i, depth, format);
		}
		break;
	case maple_leaf_64:
	case maple_range_64:
		mt_dump_range64(mt, entry, min, max, depth, format);
		break;
	case maple_arange_64:
		mt_dump_arange64(mt, entry, min, max, depth, format);
		break;

	default:
		pr_cont(" UNKNOWN TYPE\n");
	}
}

void mt_dump(const struct maple_tree *mt, enum mt_dump_format format)
{
	void *entry = rcu_dereference_check(mt->ma_root, mt_locked(mt));

	pr_info("maple_tree(%p) flags %X, height %u root %p\n",
		 mt, mt->ma_flags, mt_height(mt), entry);
	if (!xa_is_node(entry))
		mt_dump_entry(entry, 0, 0, 0, format);
	else if (entry)
		mt_dump_node(mt, entry, 0, mt_node_max(entry), 0, format);
}
EXPORT_SYMBOL_GPL(mt_dump);

/*
 * Calculate the maximum gap in a node and check if that's what is reported in
 * the parent (unless root).
 */
static void mas_validate_gaps(struct ma_state *mas)
{
	struct maple_enode *mte = mas->node;
	struct maple_node *p_mn, *node = mte_to_node(mte);
	enum maple_type mt = mte_node_type(mas->node);
	unsigned long gap = 0, max_gap = 0;
	unsigned long p_end, p_start = mas->min;
	unsigned char p_slot, offset;
	unsigned long *gaps = NULL;
	unsigned long *pivots = ma_pivots(node, mt);
	unsigned int i;

	if (ma_is_dense(mt)) {
		for (i = 0; i < mt_slot_count(mte); i++) {
			if (mas_get_slot(mas, i)) {
				if (gap > max_gap)
					max_gap = gap;
				gap = 0;
				continue;
			}
			gap++;
		}
		goto counted;
	}

	gaps = ma_gaps(node, mt);
	for (i = 0; i < mt_slot_count(mte); i++) {
		p_end = mas_safe_pivot(mas, pivots, i, mt);

		if (!gaps) {
			if (!mas_get_slot(mas, i))
				gap = p_end - p_start + 1;
		} else {
			void *entry = mas_get_slot(mas, i);

			gap = gaps[i];
			MT_BUG_ON(mas->tree, !entry);

			if (gap > p_end - p_start + 1) {
				pr_err("%p[%u] %lu >= %lu - %lu + 1 (%lu)\n",
				       mas_mn(mas), i, gap, p_end, p_start,
				       p_end - p_start + 1);
				MT_BUG_ON(mas->tree, gap > p_end - p_start + 1);
			}
		}

		if (gap > max_gap)
			max_gap = gap;

		p_start = p_end + 1;
		if (p_end >= mas->max)
			break;
	}

counted:
	if (mt == maple_arange_64) {
		offset = ma_meta_gap(node, mt);
		if (offset > i) {
			pr_err("gap offset %p[%u] is invalid\n", node, offset);
			MT_BUG_ON(mas->tree, 1);
		}

		if (gaps[offset] != max_gap) {
			pr_err("gap %p[%u] is not the largest gap %lu\n",
			       node, offset, max_gap);
			MT_BUG_ON(mas->tree, 1);
		}

		MT_BUG_ON(mas->tree, !gaps);
		for (i++ ; i < mt_slot_count(mte); i++) {
			if (gaps[i] != 0) {
				pr_err("gap %p[%u] beyond node limit != 0\n",
				       node, i);
				MT_BUG_ON(mas->tree, 1);
			}
		}
	}

	if (mte_is_root(mte))
		return;

	p_slot = mte_parent_slot(mas->node);
	p_mn = mte_parent(mte);
	MT_BUG_ON(mas->tree, max_gap > mas->max);
	if (ma_gaps(p_mn, mas_parent_type(mas, mte))[p_slot] != max_gap) {
		pr_err("gap %p[%u] != %lu\n", p_mn, p_slot, max_gap);
		mt_dump(mas->tree, mt_dump_hex);
		MT_BUG_ON(mas->tree, 1);
	}
}

static void mas_validate_parent_slot(struct ma_state *mas)
{
	struct maple_node *parent;
	struct maple_enode *node;
	enum maple_type p_type;
	unsigned char p_slot;
	void __rcu **slots;
	int i;

	if (mte_is_root(mas->node))
		return;

	p_slot = mte_parent_slot(mas->node);
	p_type = mas_parent_type(mas, mas->node);
	parent = mte_parent(mas->node);
	slots = ma_slots(parent, p_type);
	MT_BUG_ON(mas->tree, mas_mn(mas) == parent);

	/* Check prev/next parent slot for duplicate node entry */

	for (i = 0; i < mt_slots[p_type]; i++) {
		node = mas_slot(mas, slots, i);
		if (i == p_slot) {
			if (node != mas->node)
				pr_err("parent %p[%u] does not have %p\n",
					parent, i, mas_mn(mas));
			MT_BUG_ON(mas->tree, node != mas->node);
		} else if (node == mas->node) {
			pr_err("Invalid child %p at parent %p[%u] p_slot %u\n",
			       mas_mn(mas), parent, i, p_slot);
			MT_BUG_ON(mas->tree, node == mas->node);
		}
	}
}

static void mas_validate_child_slot(struct ma_state *mas)
{
	enum maple_type type = mte_node_type(mas->node);
	void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
	unsigned long *pivots = ma_pivots(mte_to_node(mas->node), type);
	struct maple_enode *child;
	unsigned char i;

	if (mte_is_leaf(mas->node))
		return;

	for (i = 0; i < mt_slots[type]; i++) {
		child = mas_slot(mas, slots, i);

		if (!child) {
			pr_err("Non-leaf node lacks child at %p[%u]\n",
			       mas_mn(mas), i);
			MT_BUG_ON(mas->tree, 1);
		}

		if (mte_parent_slot(child) != i) {
			pr_err("Slot error at %p[%u]: child %p has pslot %u\n",
			       mas_mn(mas), i, mte_to_node(child),
			       mte_parent_slot(child));
			MT_BUG_ON(mas->tree, 1);
		}

		if (mte_parent(child) != mte_to_node(mas->node)) {
			pr_err("child %p has parent %p not %p\n",
			       mte_to_node(child), mte_parent(child),
			       mte_to_node(mas->node));
			MT_BUG_ON(mas->tree, 1);
		}

		if (i < mt_pivots[type] && pivots[i] == mas->max)
			break;
	}
}

/*
 * Validate all pivots are within mas->min and mas->max, check metadata ends
 * where the maximum ends and ensure there is no slots or pivots set outside of
 * the end of the data.
 */
static void mas_validate_limits(struct ma_state *mas)
{
	int i;
	unsigned long prev_piv = 0;
	enum maple_type type = mte_node_type(mas->node);
	void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
	unsigned long *pivots = ma_pivots(mas_mn(mas), type);

	for (i = 0; i < mt_slots[type]; i++) {
		unsigned long piv;

		piv = mas_safe_pivot(mas, pivots, i, type);

		if (!piv && (i != 0)) {
			pr_err("Missing node limit pivot at %p[%u]",
			       mas_mn(mas), i);
			MAS_WARN_ON(mas, 1);
		}

		if (prev_piv > piv) {
			pr_err("%p[%u] piv %lu < prev_piv %lu\n",
				mas_mn(mas), i, piv, prev_piv);
			MAS_WARN_ON(mas, piv < prev_piv);
		}

		if (piv < mas->min) {
			pr_err("%p[%u] %lu < %lu\n", mas_mn(mas), i,
				piv, mas->min);
			MAS_WARN_ON(mas, piv < mas->min);
		}
		if (piv > mas->max) {
			pr_err("%p[%u] %lu > %lu\n", mas_mn(mas), i,
				piv, mas->max);
			MAS_WARN_ON(mas, piv > mas->max);
		}
		prev_piv = piv;
		if (piv == mas->max)
			break;
	}

	if (mas_data_end(mas) != i) {
		pr_err("node%p: data_end %u != the last slot offset %u\n",
		       mas_mn(mas), mas_data_end(mas), i);
		MT_BUG_ON(mas->tree, 1);
	}

	for (i += 1; i < mt_slots[type]; i++) {
		void *entry = mas_slot(mas, slots, i);

		if (entry && (i != mt_slots[type] - 1)) {
			pr_err("%p[%u] should not have entry %p\n", mas_mn(mas),
			       i, entry);
			MT_BUG_ON(mas->tree, entry != NULL);
		}

		if (i < mt_pivots[type]) {
			unsigned long piv = pivots[i];

			if (!piv)
				continue;

			pr_err("%p[%u] should not have piv %lu\n",
			       mas_mn(mas), i, piv);
			MAS_WARN_ON(mas, i < mt_pivots[type] - 1);
		}
	}
}

static void mt_validate_nulls(struct maple_tree *mt)
{
	void *entry, *last = (void *)1;
	unsigned char offset = 0;
	void __rcu **slots;
	MA_STATE(mas, mt, 0, 0);

	mas_start(&mas);
	if (mas_is_none(&mas) || (mas.node == MAS_ROOT))
		return;

	while (!mte_is_leaf(mas.node))
		mas_descend(&mas);

	slots = ma_slots(mte_to_node(mas.node), mte_node_type(mas.node));
	do {
		entry = mas_slot(&mas, slots, offset);
		if (!last && !entry) {
			pr_err("Sequential nulls end at %p[%u]\n",
				mas_mn(&mas), offset);
		}
		MT_BUG_ON(mt, !last && !entry);
		last = entry;
		if (offset == mas_data_end(&mas)) {
			mas_next_node(&mas, mas_mn(&mas), ULONG_MAX);
			if (mas_is_none(&mas))
				return;
			offset = 0;
			slots = ma_slots(mte_to_node(mas.node),
					 mte_node_type(mas.node));
		} else {
			offset++;
		}

	} while (!mas_is_none(&mas));
}

/*
 * validate a maple tree by checking:
 * 1. The limits (pivots are within mas->min to mas->max)
 * 2. The gap is correctly set in the parents
 */
void mt_validate(struct maple_tree *mt)
{
	unsigned char end;

	MA_STATE(mas, mt, 0, 0);
	rcu_read_lock();
	mas_start(&mas);
	if (!mas_searchable(&mas))
		goto done;

	while (!mte_is_leaf(mas.node))
		mas_descend(&mas);

	while (!mas_is_none(&mas)) {
		MAS_WARN_ON(&mas, mte_dead_node(mas.node));
		end = mas_data_end(&mas);
		if (MAS_WARN_ON(&mas, (end < mt_min_slot_count(mas.node)) &&
				(mas.max != ULONG_MAX))) {
			pr_err("Invalid size %u of %p\n", end, mas_mn(&mas));
		}

		mas_validate_parent_slot(&mas);
		mas_validate_limits(&mas);
		mas_validate_child_slot(&mas);
		if (mt_is_alloc(mt))
			mas_validate_gaps(&mas);
		mas_dfs_postorder(&mas, ULONG_MAX);
	}
	mt_validate_nulls(mt);
done:
	rcu_read_unlock();

}
EXPORT_SYMBOL_GPL(mt_validate);

void mas_dump(const struct ma_state *mas)
{
	pr_err("MAS: tree=%p enode=%p ", mas->tree, mas->node);
	if (mas_is_none(mas))
		pr_err("(MAS_NONE) ");
	else if (mas_is_ptr(mas))
		pr_err("(MAS_ROOT) ");
	else if (mas_is_start(mas))
		 pr_err("(MAS_START) ");
	else if (mas_is_paused(mas))
		pr_err("(MAS_PAUSED) ");

	pr_err("[%u] index=%lx last=%lx\n", mas->offset, mas->index, mas->last);
	pr_err("     min=%lx max=%lx alloc=%p, depth=%u, flags=%x\n",
	       mas->min, mas->max, mas->alloc, mas->depth, mas->mas_flags);
	if (mas->index > mas->last)
		pr_err("Check index & last\n");
}
EXPORT_SYMBOL_GPL(mas_dump);

void mas_wr_dump(const struct ma_wr_state *wr_mas)
{
	pr_err("WR_MAS: node=%p r_min=%lx r_max=%lx\n",
	       wr_mas->node, wr_mas->r_min, wr_mas->r_max);
	pr_err("        type=%u off_end=%u, node_end=%u, end_piv=%lx\n",
	       wr_mas->type, wr_mas->offset_end, wr_mas->node_end,
	       wr_mas->end_piv);
}
EXPORT_SYMBOL_GPL(mas_wr_dump);

#endif /* CONFIG_DEBUG_MAPLE_TREE */