aboutsummaryrefslogtreecommitdiffstats
blob: 29e1be6c68cc115dbaa23d85d262e804fd2382bc (plain) (blame)
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
/*
 *  linux/fs/ext4/super.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/parser.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/vfs.h>
#include <linux/random.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/ctype.h>
#include <linux/log2.h>
#include <linux/crc16.h>
#include <linux/cleancache.h>
#include <asm/uaccess.h>

#include <linux/kthread.h>
#include <linux/freezer.h>

#include "ext4.h"
#include "ext4_extents.h"	/* Needed for trace points definition */
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
#include "mballoc.h"

#define CREATE_TRACE_POINTS
#include <trace/events/ext4.h>

static struct proc_dir_entry *ext4_proc_root;
static struct kset *ext4_kset;
static struct ext4_lazy_init *ext4_li_info;
static struct mutex ext4_li_mtx;
static struct ext4_features *ext4_feat;
static int ext4_mballoc_ready;

static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
			     unsigned long journal_devnum);
static int ext4_show_options(struct seq_file *seq, struct dentry *root);
static int ext4_commit_super(struct super_block *sb, int sync);
static void ext4_mark_recovery_complete(struct super_block *sb,
					struct ext4_super_block *es);
static void ext4_clear_journal_err(struct super_block *sb,
				   struct ext4_super_block *es);
static int ext4_sync_fs(struct super_block *sb, int wait);
static int ext4_remount(struct super_block *sb, int *flags, char *data);
static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
static int ext4_unfreeze(struct super_block *sb);
static int ext4_freeze(struct super_block *sb);
static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
		       const char *dev_name, void *data);
static inline int ext2_feature_set_ok(struct super_block *sb);
static inline int ext3_feature_set_ok(struct super_block *sb);
static int ext4_feature_set_ok(struct super_block *sb, int readonly);
static void ext4_destroy_lazyinit_thread(void);
static void ext4_unregister_li_request(struct super_block *sb);
static void ext4_clear_request_list(void);
static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);

#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
static struct file_system_type ext2_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "ext2",
	.mount		= ext4_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("ext2");
MODULE_ALIAS("ext2");
#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
#else
#define IS_EXT2_SB(sb) (0)
#endif


#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
static struct file_system_type ext3_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "ext3",
	.mount		= ext4_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("ext3");
MODULE_ALIAS("ext3");
#define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
#else
#define IS_EXT3_SB(sb) (0)
#endif

static int ext4_verify_csum_type(struct super_block *sb,
				 struct ext4_super_block *es)
{
	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return 1;

	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
}

static __le32 ext4_superblock_csum(struct super_block *sb,
				   struct ext4_super_block *es)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	int offset = offsetof(struct ext4_super_block, s_checksum);
	__u32 csum;

	csum = ext4_chksum(sbi, ~0, (char *)es, offset);

	return cpu_to_le32(csum);
}

static int ext4_superblock_csum_verify(struct super_block *sb,
				       struct ext4_super_block *es)
{
	if (!ext4_has_metadata_csum(sb))
		return 1;

	return es->s_checksum == ext4_superblock_csum(sb, es);
}

void ext4_superblock_csum_set(struct super_block *sb)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	if (!ext4_has_metadata_csum(sb))
		return;

	es->s_checksum = ext4_superblock_csum(sb, es);
}

void *ext4_kvmalloc(size_t size, gfp_t flags)
{
	void *ret;

	ret = kmalloc(size, flags | __GFP_NOWARN);
	if (!ret)
		ret = __vmalloc(size, flags, PAGE_KERNEL);
	return ret;
}

void *ext4_kvzalloc(size_t size, gfp_t flags)
{
	void *ret;

	ret = kzalloc(size, flags | __GFP_NOWARN);
	if (!ret)
		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
	return ret;
}

ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_block_bitmap_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
}

ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
}

ext4_fsblk_t ext4_inode_table(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_inode_table_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
}

__u32 ext4_free_group_clusters(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
}

__u32 ext4_free_inodes_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
}

__u32 ext4_used_dirs_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
}

__u32 ext4_itable_unused_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_itable_unused_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
}

void ext4_block_bitmap_set(struct super_block *sb,
			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
}

void ext4_inode_bitmap_set(struct super_block *sb,
			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
}

void ext4_inode_table_set(struct super_block *sb,
			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
}

void ext4_free_group_clusters_set(struct super_block *sb,
				  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
}

void ext4_free_inodes_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
}

void ext4_used_dirs_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
}

void ext4_itable_unused_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
}


static void __save_error_info(struct super_block *sb, const char *func,
			    unsigned int line)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
	if (bdev_read_only(sb->s_bdev))
		return;
	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
	es->s_last_error_time = cpu_to_le32(get_seconds());
	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
	es->s_last_error_line = cpu_to_le32(line);
	if (!es->s_first_error_time) {
		es->s_first_error_time = es->s_last_error_time;
		strncpy(es->s_first_error_func, func,
			sizeof(es->s_first_error_func));
		es->s_first_error_line = cpu_to_le32(line);
		es->s_first_error_ino = es->s_last_error_ino;
		es->s_first_error_block = es->s_last_error_block;
	}
	/*
	 * Start the daily error reporting function if it hasn't been
	 * started already
	 */
	if (!es->s_error_count)
		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
	le32_add_cpu(&es->s_error_count, 1);
}

static void save_error_info(struct super_block *sb, const char *func,
			    unsigned int line)
{
	__save_error_info(sb, func, line);
	ext4_commit_super(sb, 1);
}

/*
 * The del_gendisk() function uninitializes the disk-specific data
 * structures, including the bdi structure, without telling anyone
 * else.  Once this happens, any attempt to call mark_buffer_dirty()
 * (for example, by ext4_commit_super), will cause a kernel OOPS.
 * This is a kludge to prevent these oops until we can put in a proper
 * hook in del_gendisk() to inform the VFS and file system layers.
 */
static int block_device_ejected(struct super_block *sb)
{
	struct inode *bd_inode = sb->s_bdev->bd_inode;
	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);

	return bdi->dev == NULL;
}

static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
{
	struct super_block		*sb = journal->j_private;
	struct ext4_sb_info		*sbi = EXT4_SB(sb);
	int				error = is_journal_aborted(journal);
	struct ext4_journal_cb_entry	*jce;

	BUG_ON(txn->t_state == T_FINISHED);
	spin_lock(&sbi->s_md_lock);
	while (!list_empty(&txn->t_private_list)) {
		jce = list_entry(txn->t_private_list.next,
				 struct ext4_journal_cb_entry, jce_list);
		list_del_init(&jce->jce_list);
		spin_unlock(&sbi->s_md_lock);
		jce->jce_func(sb, jce, error);
		spin_lock(&sbi->s_md_lock);
	}
	spin_unlock(&sbi->s_md_lock);
}

/* Deal with the reporting of failure conditions on a filesystem such as
 * inconsistencies detected or read IO failures.
 *
 * On ext2, we can store the error state of the filesystem in the
 * superblock.  That is not possible on ext4, because we may have other
 * write ordering constraints on the superblock which prevent us from
 * writing it out straight away; and given that the journal is about to
 * be aborted, we can't rely on the current, or future, transactions to
 * write out the superblock safely.
 *
 * We'll just use the jbd2_journal_abort() error code to record an error in
 * the journal instead.  On recovery, the journal will complain about
 * that error until we've noted it down and cleared it.
 */

static void ext4_handle_error(struct super_block *sb)
{
	if (sb->s_flags & MS_RDONLY)
		return;

	if (!test_opt(sb, ERRORS_CONT)) {
		journal_t *journal = EXT4_SB(sb)->s_journal;

		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
		if (journal)
			jbd2_journal_abort(journal, -EIO);
	}
	if (test_opt(sb, ERRORS_RO)) {
		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
		/*
		 * Make sure updated value of ->s_mount_flags will be visible
		 * before ->s_flags update
		 */
		smp_wmb();
		sb->s_flags |= MS_RDONLY;
	}
	if (test_opt(sb, ERRORS_PANIC)) {
		if (EXT4_SB(sb)->s_journal &&
		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
			return;
		panic("EXT4-fs (device %s): panic forced after error\n",
			sb->s_id);
	}
}

#define ext4_error_ratelimit(sb)					\
		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
			     "EXT4-fs error")

void __ext4_error(struct super_block *sb, const char *function,
		  unsigned int line, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (ext4_error_ratelimit(sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		printk(KERN_CRIT
		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
		       sb->s_id, function, line, current->comm, &vaf);
		va_end(args);
	}
	save_error_info(sb, function, line);
	ext4_handle_error(sb);
}

void __ext4_error_inode(struct inode *inode, const char *function,
			unsigned int line, ext4_fsblk_t block,
			const char *fmt, ...)
{
	va_list args;
	struct va_format vaf;
	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;

	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
	es->s_last_error_block = cpu_to_le64(block);
	if (ext4_error_ratelimit(inode->i_sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		if (block)
			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
			       "inode #%lu: block %llu: comm %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       block, current->comm, &vaf);
		else
			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
			       "inode #%lu: comm %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       current->comm, &vaf);
		va_end(args);
	}
	save_error_info(inode->i_sb, function, line);
	ext4_handle_error(inode->i_sb);
}

void __ext4_error_file(struct file *file, const char *function,
		       unsigned int line, ext4_fsblk_t block,
		       const char *fmt, ...)
{
	va_list args;
	struct va_format vaf;
	struct ext4_super_block *es;
	struct inode *inode = file_inode(file);
	char pathname[80], *path;

	es = EXT4_SB(inode->i_sb)->s_es;
	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
	if (ext4_error_ratelimit(inode->i_sb)) {
		path = d_path(&(file->f_path), pathname, sizeof(pathname));
		if (IS_ERR(path))
			path = "(unknown)";
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		if (block)
			printk(KERN_CRIT
			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
			       "block %llu: comm %s: path %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       block, current->comm, path, &vaf);
		else
			printk(KERN_CRIT
			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
			       "comm %s: path %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       current->comm, path, &vaf);
		va_end(args);
	}
	save_error_info(inode->i_sb, function, line);
	ext4_handle_error(inode->i_sb);
}

const char *ext4_decode_error(struct super_block *sb, int errno,
			      char nbuf[16])
{
	char *errstr = NULL;

	switch (errno) {
	case -EIO:
		errstr = "IO failure";
		break;
	case -ENOMEM:
		errstr = "Out of memory";
		break;
	case -EROFS:
		if (!sb || (EXT4_SB(sb)->s_journal &&
			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
			errstr = "Journal has aborted";
		else
			errstr = "Readonly filesystem";
		break;
	default:
		/* If the caller passed in an extra buffer for unknown
		 * errors, textualise them now.  Else we just return
		 * NULL. */
		if (nbuf) {
			/* Check for truncated error codes... */
			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
				errstr = nbuf;
		}
		break;
	}

	return errstr;
}

/* __ext4_std_error decodes expected errors from journaling functions
 * automatically and invokes the appropriate error response.  */

void __ext4_std_error(struct super_block *sb, const char *function,
		      unsigned int line, int errno)
{
	char nbuf[16];
	const char *errstr;

	/* Special case: if the error is EROFS, and we're not already
	 * inside a transaction, then there's really no point in logging
	 * an error. */
	if (errno == -EROFS && journal_current_handle() == NULL &&
	    (sb->s_flags & MS_RDONLY))
		return;

	if (ext4_error_ratelimit(sb)) {
		errstr = ext4_decode_error(sb, errno, nbuf);
		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
		       sb->s_id, function, line, errstr);
	}

	save_error_info(sb, function, line);
	ext4_handle_error(sb);
}

/*
 * ext4_abort is a much stronger failure handler than ext4_error.  The
 * abort function may be used to deal with unrecoverable failures such
 * as journal IO errors or ENOMEM at a critical moment in log management.
 *
 * We unconditionally force the filesystem into an ABORT|READONLY state,
 * unless the error response on the fs has been set to panic in which
 * case we take the easy way out and panic immediately.
 */

void __ext4_abort(struct super_block *sb, const char *function,
		unsigned int line, const char *fmt, ...)
{
	va_list args;

	save_error_info(sb, function, line);
	va_start(args, fmt);
	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
	       function, line);
	vprintk(fmt, args);
	printk("\n");
	va_end(args);

	if ((sb->s_flags & MS_RDONLY) == 0) {
		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
		/*
		 * Make sure updated value of ->s_mount_flags will be visible
		 * before ->s_flags update
		 */
		smp_wmb();
		sb->s_flags |= MS_RDONLY;
		if (EXT4_SB(sb)->s_journal)
			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
		save_error_info(sb, function, line);
	}
	if (test_opt(sb, ERRORS_PANIC)) {
		if (EXT4_SB(sb)->s_journal &&
		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
			return;
		panic("EXT4-fs panic from previous error\n");
	}
}

void __ext4_msg(struct super_block *sb,
		const char *prefix, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
		return;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
	va_end(args);
}

void __ext4_warning(struct super_block *sb, const char *function,
		    unsigned int line, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
			  "EXT4-fs warning"))
		return;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
	       sb->s_id, function, line, &vaf);
	va_end(args);
}

void __ext4_grp_locked_error(const char *function, unsigned int line,
			     struct super_block *sb, ext4_group_t grp,
			     unsigned long ino, ext4_fsblk_t block,
			     const char *fmt, ...)
__releases(bitlock)
__acquires(bitlock)
{
	struct va_format vaf;
	va_list args;
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	es->s_last_error_ino = cpu_to_le32(ino);
	es->s_last_error_block = cpu_to_le64(block);
	__save_error_info(sb, function, line);

	if (ext4_error_ratelimit(sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
		       sb->s_id, function, line, grp);
		if (ino)
			printk(KERN_CONT "inode %lu: ", ino);
		if (block)
			printk(KERN_CONT "block %llu:",
			       (unsigned long long) block);
		printk(KERN_CONT "%pV\n", &vaf);
		va_end(args);
	}

	if (test_opt(sb, ERRORS_CONT)) {
		ext4_commit_super(sb, 0);
		return;
	}

	ext4_unlock_group(sb, grp);
	ext4_handle_error(sb);
	/*
	 * We only get here in the ERRORS_RO case; relocking the group
	 * may be dangerous, but nothing bad will happen since the
	 * filesystem will have already been marked read/only and the
	 * journal has been aborted.  We return 1 as a hint to callers
	 * who might what to use the return value from
	 * ext4_grp_locked_error() to distinguish between the
	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
	 * aggressively from the ext4 function in question, with a
	 * more appropriate error code.
	 */
	ext4_lock_group(sb, grp);
	return;
}

void ext4_update_dynamic_rev(struct super_block *sb)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
		return;

	ext4_warning(sb,
		     "updating to rev %d because of new feature flag, "
		     "running e2fsck is recommended",
		     EXT4_DYNAMIC_REV);

	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
	/* leave es->s_feature_*compat flags alone */
	/* es->s_uuid will be set by e2fsck if empty */

	/*
	 * The rest of the superblock fields should be zero, and if not it
	 * means they are likely already in use, so leave them alone.  We
	 * can leave it up to e2fsck to clean up any inconsistencies there.
	 */
}

/*
 * Open the external journal device
 */
static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
{
	struct block_device *bdev;
	char b[BDEVNAME_SIZE];

	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
	if (IS_ERR(bdev))
		goto fail;
	return bdev;

fail:
	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
			__bdevname(dev, b), PTR_ERR(bdev));
	return NULL;
}

/*
 * Release the journal device
 */
static void ext4_blkdev_put(struct block_device *bdev)
{
	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
}

static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
{
	struct block_device *bdev;
	bdev = sbi->journal_bdev;
	if (bdev) {
		ext4_blkdev_put(bdev);
		sbi->journal_bdev = NULL;
	}
}

static inline struct inode *orphan_list_entry(struct list_head *l)
{
	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
}

static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
{
	struct list_head *l;

	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
		 le32_to_cpu(sbi->s_es->s_last_orphan));

	printk(KERN_ERR "sb_info orphan list:\n");
	list_for_each(l, &sbi->s_orphan) {
		struct inode *inode = orphan_list_entry(l);
		printk(KERN_ERR "  "
		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
		       inode->i_sb->s_id, inode->i_ino, inode,
		       inode->i_mode, inode->i_nlink,
		       NEXT_ORPHAN(inode));
	}
}

static void ext4_put_super(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int i, err;

	ext4_unregister_li_request(sb);
	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);

	flush_workqueue(sbi->rsv_conversion_wq);
	destroy_workqueue(sbi->rsv_conversion_wq);

	if (sbi->s_journal) {
		err = jbd2_journal_destroy(sbi->s_journal);
		sbi->s_journal = NULL;
		if (err < 0)
			ext4_abort(sb, "Couldn't clean up the journal");
	}

	ext4_es_unregister_shrinker(sbi);
	del_timer_sync(&sbi->s_err_report);
	ext4_release_system_zone(sb);
	ext4_mb_release(sb);
	ext4_ext_release(sb);
	ext4_xattr_put_super(sb);

	if (!(sb->s_flags & MS_RDONLY)) {
		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
		es->s_state = cpu_to_le16(sbi->s_mount_state);
	}
	if (!(sb->s_flags & MS_RDONLY))
		ext4_commit_super(sb, 1);

	if (sbi->s_proc) {
		remove_proc_entry("options", sbi->s_proc);
		remove_proc_entry(sb->s_id, ext4_proc_root);
	}
	kobject_del(&sbi->s_kobj);

	for (i = 0; i < sbi->s_gdb_count; i++)
		brelse(sbi->s_group_desc[i]);
	kvfree(sbi->s_group_desc);
	kvfree(sbi->s_flex_groups);
	percpu_counter_destroy(&sbi->s_freeclusters_counter);
	percpu_counter_destroy(&sbi->s_freeinodes_counter);
	percpu_counter_destroy(&sbi->s_dirs_counter);
	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
	brelse(sbi->s_sbh);
#ifdef CONFIG_QUOTA
	for (i = 0; i < EXT4_MAXQUOTAS; i++)
		kfree(sbi->s_qf_names[i]);
#endif

	/* Debugging code just in case the in-memory inode orphan list
	 * isn't empty.  The on-disk one can be non-empty if we've
	 * detected an error and taken the fs readonly, but the
	 * in-memory list had better be clean by this point. */
	if (!list_empty(&sbi->s_orphan))
		dump_orphan_list(sb, sbi);
	J_ASSERT(list_empty(&sbi->s_orphan));

	sync_blockdev(sb->s_bdev);
	invalidate_bdev(sb->s_bdev);
	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
		/*
		 * Invalidate the journal device's buffers.  We don't want them
		 * floating about in memory - the physical journal device may
		 * hotswapped, and it breaks the `ro-after' testing code.
		 */
		sync_blockdev(sbi->journal_bdev);
		invalidate_bdev(sbi->journal_bdev);
		ext4_blkdev_remove(sbi);
	}
	if (sbi->s_mb_cache) {
		ext4_xattr_destroy_cache(sbi->s_mb_cache);
		sbi->s_mb_cache = NULL;
	}
	if (sbi->s_mmp_tsk)
		kthread_stop(sbi->s_mmp_tsk);
	sb->s_fs_info = NULL;
	/*
	 * Now that we are completely done shutting down the
	 * superblock, we need to actually destroy the kobject.
	 */
	kobject_put(&sbi->s_kobj);
	wait_for_completion(&sbi->s_kobj_unregister);
	if (sbi->s_chksum_driver)
		crypto_free_shash(sbi->s_chksum_driver);
	kfree(sbi->s_blockgroup_lock);
	kfree(sbi);
}

static struct kmem_cache *ext4_inode_cachep;

/*
 * Called inside transaction, so use GFP_NOFS
 */
static struct inode *ext4_alloc_inode(struct super_block *sb)
{
	struct ext4_inode_info *ei;

	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;

	ei->vfs_inode.i_version = 1;
	spin_lock_init(&ei->i_raw_lock);
	INIT_LIST_HEAD(&ei->i_prealloc_list);
	spin_lock_init(&ei->i_prealloc_lock);
	ext4_es_init_tree(&ei->i_es_tree);
	rwlock_init(&ei->i_es_lock);
	INIT_LIST_HEAD(&ei->i_es_list);
	ei->i_es_all_nr = 0;
	ei->i_es_shk_nr = 0;
	ei->i_es_shrink_lblk = 0;
	ei->i_reserved_data_blocks = 0;
	ei->i_reserved_meta_blocks = 0;
	ei->i_allocated_meta_blocks = 0;
	ei->i_da_metadata_calc_len = 0;
	ei->i_da_metadata_calc_last_lblock = 0;
	spin_lock_init(&(ei->i_block_reservation_lock));
#ifdef CONFIG_QUOTA
	ei->i_reserved_quota = 0;
	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
#endif
	ei->jinode = NULL;
	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
	spin_lock_init(&ei->i_completed_io_lock);
	ei->i_sync_tid = 0;
	ei->i_datasync_tid = 0;
	atomic_set(&ei->i_ioend_count, 0);
	atomic_set(&ei->i_unwritten, 0);
	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	ei->i_encryption_key.mode = EXT4_ENCRYPTION_MODE_INVALID;
#endif

	return &ei->vfs_inode;
}

static int ext4_drop_inode(struct inode *inode)
{
	int drop = generic_drop_inode(inode);

	trace_ext4_drop_inode(inode, drop);
	return drop;
}

static void ext4_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
}

static void ext4_destroy_inode(struct inode *inode)
{
	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
		ext4_msg(inode->i_sb, KERN_ERR,
			 "Inode %lu (%p): orphan list check failed!",
			 inode->i_ino, EXT4_I(inode));
		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
				EXT4_I(inode), sizeof(struct ext4_inode_info),
				true);
		dump_stack();
	}
	call_rcu(&inode->i_rcu, ext4_i_callback);
}

static void init_once(void *foo)
{
	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;

	INIT_LIST_HEAD(&ei->i_orphan);
	init_rwsem(&ei->xattr_sem);
	init_rwsem(&ei->i_data_sem);
	init_rwsem(&ei->i_mmap_sem);
	inode_init_once(&ei->vfs_inode);
}

static int __init init_inodecache(void)
{
	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
					     sizeof(struct ext4_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once);
	if (ext4_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(ext4_inode_cachep);
}

void ext4_clear_inode(struct inode *inode)
{
	invalidate_inode_buffers(inode);
	clear_inode(inode);
	dquot_drop(inode);
	ext4_discard_preallocations(inode);
	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
	if (EXT4_I(inode)->jinode) {
		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
					       EXT4_I(inode)->jinode);
		jbd2_free_inode(EXT4_I(inode)->jinode);
		EXT4_I(inode)->jinode = NULL;
	}
}

static struct inode *ext4_nfs_get_inode(struct super_block *sb,
					u64 ino, u32 generation)
{
	struct inode *inode;

	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
		return ERR_PTR(-ESTALE);
	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
		return ERR_PTR(-ESTALE);

	/* iget isn't really right if the inode is currently unallocated!!
	 *
	 * ext4_read_inode will return a bad_inode if the inode had been
	 * deleted, so we should be safe.
	 *
	 * Currently we don't know the generation for parent directory, so
	 * a generation of 0 means "accept any"
	 */
	inode = ext4_iget_normal(sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);
	if (generation && inode->i_generation != generation) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return inode;
}

static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    ext4_nfs_get_inode);
}

static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    ext4_nfs_get_inode);
}

/*
 * Try to release metadata pages (indirect blocks, directories) which are
 * mapped via the block device.  Since these pages could have journal heads
 * which would prevent try_to_free_buffers() from freeing them, we must use
 * jbd2 layer's try_to_free_buffers() function to release them.
 */
static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
				 gfp_t wait)
{
	journal_t *journal = EXT4_SB(sb)->s_journal;

	WARN_ON(PageChecked(page));
	if (!page_has_buffers(page))
		return 0;
	if (journal)
		return jbd2_journal_try_to_free_buffers(journal, page,
							wait & ~__GFP_WAIT);
	return try_to_free_buffers(page);
}

#ifdef CONFIG_QUOTA
#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))

static int ext4_write_dquot(struct dquot *dquot);
static int ext4_acquire_dquot(struct dquot *dquot);
static int ext4_release_dquot(struct dquot *dquot);
static int ext4_mark_dquot_dirty(struct dquot *dquot);
static int ext4_write_info(struct super_block *sb, int type);
static int ext4_quota_on(struct super_block *sb, int type, int format_id,
			 struct path *path);
static int ext4_quota_off(struct super_block *sb, int type);
static int ext4_quota_on_mount(struct super_block *sb, int type);
static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
			       size_t len, loff_t off);
static ssize_t ext4_quota_write(struct super_block *sb, int type,
				const char *data, size_t len, loff_t off);
static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
			     unsigned int flags);
static int ext4_enable_quotas(struct super_block *sb);

static struct dquot **ext4_get_dquots(struct inode *inode)
{
	return EXT4_I(inode)->i_dquot;
}

static const struct dquot_operations ext4_quota_operations = {
	.get_reserved_space = ext4_get_reserved_space,
	.write_dquot	= ext4_write_dquot,
	.acquire_dquot	= ext4_acquire_dquot,
	.release_dquot	= ext4_release_dquot,
	.mark_dirty	= ext4_mark_dquot_dirty,
	.write_info	= ext4_write_info,
	.alloc_dquot	= dquot_alloc,
	.destroy_dquot	= dquot_destroy,
};

static const struct quotactl_ops ext4_qctl_operations = {
	.quota_on	= ext4_quota_on,
	.quota_off	= ext4_quota_off,
	.quota_sync	= dquot_quota_sync,
	.get_state	= dquot_get_state,
	.set_info	= dquot_set_dqinfo,
	.get_dqblk	= dquot_get_dqblk,
	.set_dqblk	= dquot_set_dqblk
};
#endif

static const struct super_operations ext4_sops = {
	.alloc_inode	= ext4_alloc_inode,
	.destroy_inode	= ext4_destroy_inode,
	.write_inode	= ext4_write_inode,
	.dirty_inode	= ext4_dirty_inode,
	.drop_inode	= ext4_drop_inode,
	.evict_inode	= ext4_evict_inode,
	.put_super	= ext4_put_super,
	.sync_fs	= ext4_sync_fs,
	.freeze_fs	= ext4_freeze,
	.unfreeze_fs	= ext4_unfreeze,
	.statfs		= ext4_statfs,
	.remount_fs	= ext4_remount,
	.show_options	= ext4_show_options,
#ifdef CONFIG_QUOTA
	.quota_read	= ext4_quota_read,
	.quota_write	= ext4_quota_write,
	.get_dquots	= ext4_get_dquots,
#endif
	.bdev_try_to_free_page = bdev_try_to_free_page,
};

static const struct export_operations ext4_export_ops = {
	.fh_to_dentry = ext4_fh_to_dentry,
	.fh_to_parent = ext4_fh_to_parent,
	.get_parent = ext4_get_parent,
};

enum {
	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
	Opt_nouid32, Opt_debug, Opt_removed,
	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
	Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
	Opt_lazytime, Opt_nolazytime,
	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
	Opt_inode_readahead_blks, Opt_journal_ioprio,
	Opt_dioread_nolock, Opt_dioread_lock,
	Opt_no_mbcache,
	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
	Opt_max_dir_size_kb, Opt_nojournal_checksum,
};

static const match_table_t tokens = {
	{Opt_bsd_df, "bsddf"},
	{Opt_minix_df, "minixdf"},
	{Opt_grpid, "grpid"},
	{Opt_grpid, "bsdgroups"},
	{Opt_nogrpid, "nogrpid"},
	{Opt_nogrpid, "sysvgroups"},
	{Opt_resgid, "resgid=%u"},
	{Opt_resuid, "resuid=%u"},
	{Opt_sb, "sb=%u"},
	{Opt_err_cont, "errors=continue"},
	{Opt_err_panic, "errors=panic"},
	{Opt_err_ro, "errors=remount-ro"},
	{Opt_nouid32, "nouid32"},
	{Opt_debug, "debug"},
	{Opt_removed, "oldalloc"},
	{Opt_removed, "orlov"},
	{Opt_user_xattr, "user_xattr"},
	{Opt_nouser_xattr, "nouser_xattr"},
	{Opt_acl, "acl"},
	{Opt_noacl, "noacl"},
	{Opt_noload, "norecovery"},
	{Opt_noload, "noload"},
	{Opt_removed, "nobh"},
	{Opt_removed, "bh"},
	{Opt_commit, "commit=%u"},
	{Opt_min_batch_time, "min_batch_time=%u"},
	{Opt_max_batch_time, "max_batch_time=%u"},
	{Opt_journal_dev, "journal_dev=%u"},
	{Opt_journal_path, "journal_path=%s"},
	{Opt_journal_checksum, "journal_checksum"},
	{Opt_nojournal_checksum, "nojournal_checksum"},
	{Opt_journal_async_commit, "journal_async_commit"},
	{Opt_abort, "abort"},
	{Opt_data_journal, "data=journal"},
	{Opt_data_ordered, "data=ordered"},
	{Opt_data_writeback, "data=writeback"},
	{Opt_data_err_abort, "data_err=abort"},
	{Opt_data_err_ignore, "data_err=ignore"},
	{Opt_offusrjquota, "usrjquota="},
	{Opt_usrjquota, "usrjquota=%s"},
	{Opt_offgrpjquota, "grpjquota="},
	{Opt_grpjquota, "grpjquota=%s"},
	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
	{Opt_grpquota, "grpquota"},
	{Opt_noquota, "noquota"},
	{Opt_quota, "quota"},
	{Opt_usrquota, "usrquota"},
	{Opt_barrier, "barrier=%u"},
	{Opt_barrier, "barrier"},
	{Opt_nobarrier, "nobarrier"},
	{Opt_i_version, "i_version"},
	{Opt_dax, "dax"},
	{Opt_stripe, "stripe=%u"},
	{Opt_delalloc, "delalloc"},
	{Opt_lazytime, "lazytime"},
	{Opt_nolazytime, "nolazytime"},
	{Opt_nodelalloc, "nodelalloc"},
	{Opt_removed, "mblk_io_submit"},
	{Opt_removed, "nomblk_io_submit"},
	{Opt_block_validity, "block_validity"},
	{Opt_noblock_validity, "noblock_validity"},
	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
	{Opt_journal_ioprio, "journal_ioprio=%u"},
	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
	{Opt_auto_da_alloc, "auto_da_alloc"},
	{Opt_noauto_da_alloc, "noauto_da_alloc"},
	{Opt_dioread_nolock, "dioread_nolock"},
	{Opt_dioread_lock, "dioread_lock"},
	{Opt_discard, "discard"},
	{Opt_nodiscard, "nodiscard"},
	{Opt_init_itable, "init_itable=%u"},
	{Opt_no_mbcache, "no_mbcache"},
	{Opt_init_itable, "init_itable"},
	{Opt_noinit_itable, "noinit_itable"},
	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
	{Opt_test_dummy_encryption, "test_dummy_encryption"},
	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
	{Opt_err, NULL},
};

static ext4_fsblk_t get_sb_block(void **data)
{
	ext4_fsblk_t	sb_block;
	char		*options = (char *) *data;

	if (!options || strncmp(options, "sb=", 3) != 0)
		return 1;	/* Default location */

	options += 3;
	/* TODO: use simple_strtoll with >32bit ext4 */
	sb_block = simple_strtoul(options, &options, 0);
	if (*options && *options != ',') {
		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
		       (char *) *data);
		return 1;
	}
	if (*options == ',')
		options++;
	*data = (void *) options;

	return sb_block;
}

#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";

#ifdef CONFIG_QUOTA
static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	char *qname;
	int ret = -1;

	if (sb_any_quota_loaded(sb) &&
		!sbi->s_qf_names[qtype]) {
		ext4_msg(sb, KERN_ERR,
			"Cannot change journaled "
			"quota options when quota turned on");
		return -1;
	}
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
		ext4_msg(sb, KERN_INFO, "Journaled quota options "
			 "ignored when QUOTA feature is enabled");
		return 1;
	}
	qname = match_strdup(args);
	if (!qname) {
		ext4_msg(sb, KERN_ERR,
			"Not enough memory for storing quotafile name");
		return -1;
	}
	if (sbi->s_qf_names[qtype]) {
		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
			ret = 1;
		else
			ext4_msg(sb, KERN_ERR,
				 "%s quota file already specified",
				 QTYPE2NAME(qtype));
		goto errout;
	}
	if (strchr(qname, '/')) {
		ext4_msg(sb, KERN_ERR,
			"quotafile must be on filesystem root");
		goto errout;
	}
	sbi->s_qf_names[qtype] = qname;
	set_opt(sb, QUOTA);
	return 1;
errout:
	kfree(qname);
	return ret;
}

static int clear_qf_name(struct super_block *sb, int qtype)
{

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (sb_any_quota_loaded(sb) &&
		sbi->s_qf_names[qtype]) {
		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
			" when quota turned on");
		return -1;
	}
	kfree(sbi->s_qf_names[qtype]);
	sbi->s_qf_names[qtype] = NULL;
	return 1;
}
#endif

#define MOPT_SET	0x0001
#define MOPT_CLEAR	0x0002
#define MOPT_NOSUPPORT	0x0004
#define MOPT_EXPLICIT	0x0008
#define MOPT_CLEAR_ERR	0x0010
#define MOPT_GTE0	0x0020
#ifdef CONFIG_QUOTA
#define MOPT_Q		0
#define MOPT_QFMT	0x0040
#else
#define MOPT_Q		MOPT_NOSUPPORT
#define MOPT_QFMT	MOPT_NOSUPPORT
#endif
#define MOPT_DATAJ	0x0080
#define MOPT_NO_EXT2	0x0100
#define MOPT_NO_EXT3	0x0200
#define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
#define MOPT_STRING	0x0400

static const struct mount_opts {
	int	token;
	int	mount_opt;
	int	flags;
} ext4_mount_opts[] = {
	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
	 MOPT_EXT4_ONLY | MOPT_SET},
	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
	 MOPT_EXT4_ONLY | MOPT_SET},
	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
				    EXT4_MOUNT_JOURNAL_CHECKSUM),
	 MOPT_EXT4_ONLY | MOPT_SET},
	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
	 MOPT_NO_EXT2 | MOPT_SET},
	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
	 MOPT_NO_EXT2 | MOPT_CLEAR},
	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
	{Opt_no_mbcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
	{Opt_commit, 0, MOPT_GTE0},
	{Opt_max_batch_time, 0, MOPT_GTE0},
	{Opt_min_batch_time, 0, MOPT_GTE0},
	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
	{Opt_init_itable, 0, MOPT_GTE0},
	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
	{Opt_stripe, 0, MOPT_GTE0},
	{Opt_resuid, 0, MOPT_GTE0},
	{Opt_resgid, 0, MOPT_GTE0},
	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
	 MOPT_NO_EXT2 | MOPT_DATAJ},
	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
#ifdef CONFIG_EXT4_FS_POSIX_ACL
	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
#else
	{Opt_acl, 0, MOPT_NOSUPPORT},
	{Opt_noacl, 0, MOPT_NOSUPPORT},
#endif
	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
							MOPT_SET | MOPT_Q},
	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
							MOPT_SET | MOPT_Q},
	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
	{Opt_usrjquota, 0, MOPT_Q},
	{Opt_grpjquota, 0, MOPT_Q},
	{Opt_offusrjquota, 0, MOPT_Q},
	{Opt_offgrpjquota, 0, MOPT_Q},
	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
	{Opt_err, 0, 0}
};

static int handle_mount_opt(struct super_block *sb, char *opt, int token,
			    substring_t *args, unsigned long *journal_devnum,
			    unsigned int *journal_ioprio, int is_remount)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	const struct mount_opts *m;
	kuid_t uid;
	kgid_t gid;
	int arg = 0;

#ifdef CONFIG_QUOTA
	if (token == Opt_usrjquota)
		return set_qf_name(sb, USRQUOTA, &args[0]);
	else if (token == Opt_grpjquota)
		return set_qf_name(sb, GRPQUOTA, &args[0]);
	else if (token == Opt_offusrjquota)
		return clear_qf_name(sb, USRQUOTA);
	else if (token == Opt_offgrpjquota)
		return clear_qf_name(sb, GRPQUOTA);
#endif
	switch (token) {
	case Opt_noacl:
	case Opt_nouser_xattr:
		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
		break;
	case Opt_sb:
		return 1;	/* handled by get_sb_block() */
	case Opt_removed:
		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
		return 1;
	case Opt_abort:
		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
		return 1;
	case Opt_i_version:
		sb->s_flags |= MS_I_VERSION;
		return 1;
	case Opt_lazytime:
		sb->s_flags |= MS_LAZYTIME;
		return 1;
	case Opt_nolazytime:
		sb->s_flags &= ~MS_LAZYTIME;
		return 1;
	}

	for (m = ext4_mount_opts; m->token != Opt_err; m++)
		if (token == m->token)
			break;

	if (m->token == Opt_err) {
		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
			 "or missing value", opt);
		return -1;
	}

	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
		ext4_msg(sb, KERN_ERR,
			 "Mount option \"%s\" incompatible with ext2", opt);
		return -1;
	}
	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
		ext4_msg(sb, KERN_ERR,
			 "Mount option \"%s\" incompatible with ext3", opt);
		return -1;
	}

	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
		return -1;
	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
		return -1;
	if (m->flags & MOPT_EXPLICIT)
		set_opt2(sb, EXPLICIT_DELALLOC);
	if (m->flags & MOPT_CLEAR_ERR)
		clear_opt(sb, ERRORS_MASK);
	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
		ext4_msg(sb, KERN_ERR, "Cannot change quota "
			 "options when quota turned on");
		return -1;
	}

	if (m->flags & MOPT_NOSUPPORT) {
		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
	} else if (token == Opt_commit) {
		if (arg == 0)
			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
		sbi->s_commit_interval = HZ * arg;
	} else if (token == Opt_max_batch_time) {
		sbi->s_max_batch_time = arg;
	} else if (token == Opt_min_batch_time) {
		sbi->s_min_batch_time = arg;
	} else if (token == Opt_inode_readahead_blks) {
		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
			ext4_msg(sb, KERN_ERR,
				 "EXT4-fs: inode_readahead_blks must be "
				 "0 or a power of 2 smaller than 2^31");
			return -1;
		}
		sbi->s_inode_readahead_blks = arg;
	} else if (token == Opt_init_itable) {
		set_opt(sb, INIT_INODE_TABLE);
		if (!args->from)
			arg = EXT4_DEF_LI_WAIT_MULT;
		sbi->s_li_wait_mult = arg;
	} else if (token == Opt_max_dir_size_kb) {
		sbi->s_max_dir_size_kb = arg;
	} else if (token == Opt_stripe) {
		sbi->s_stripe = arg;
	} else if (token == Opt_resuid) {
		uid = make_kuid(current_user_ns(), arg);
		if (!uid_valid(uid)) {
			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
			return -1;
		}
		sbi->s_resuid = uid;
	} else if (token == Opt_resgid) {
		gid = make_kgid(current_user_ns(), arg);
		if (!gid_valid(gid)) {
			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
			return -1;
		}
		sbi->s_resgid = gid;
	} else if (token == Opt_journal_dev) {
		if (is_remount) {
			ext4_msg(sb, KERN_ERR,
				 "Cannot specify journal on remount");
			return -1;
		}
		*journal_devnum = arg;
	} else if (token == Opt_journal_path) {
		char *journal_path;
		struct inode *journal_inode;
		struct path path;
		int error;

		if (is_remount) {
			ext4_msg(sb, KERN_ERR,
				 "Cannot specify journal on remount");
			return -1;
		}
		journal_path = match_strdup(&args[0]);
		if (!journal_path) {
			ext4_msg(sb, KERN_ERR, "error: could not dup "
				"journal device string");
			return -1;
		}

		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
		if (error) {
			ext4_msg(sb, KERN_ERR, "error: could not find "
				"journal device path: error %d", error);
			kfree(journal_path);
			return -1;
		}

		journal_inode = d_inode(path.dentry);
		if (!S_ISBLK(journal_inode->i_mode)) {
			ext4_msg(sb, KERN_ERR, "error: journal path %s "
				"is not a block device", journal_path);
			path_put(&path);
			kfree(journal_path);
			return -1;
		}

		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
		path_put(&path);
		kfree(journal_path);
	} else if (token == Opt_journal_ioprio) {
		if (arg > 7) {
			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
				 " (must be 0-7)");
			return -1;
		}
		*journal_ioprio =
			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
	} else if (token == Opt_test_dummy_encryption) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
		ext4_msg(sb, KERN_WARNING,
			 "Test dummy encryption mode enabled");
#else
		ext4_msg(sb, KERN_WARNING,
			 "Test dummy encryption mount option ignored");
#endif
	} else if (m->flags & MOPT_DATAJ) {
		if (is_remount) {
			if (!sbi->s_journal)
				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
				ext4_msg(sb, KERN_ERR,
					 "Cannot change data mode on remount");
				return -1;
			}
		} else {
			clear_opt(sb, DATA_FLAGS);
			sbi->s_mount_opt |= m->mount_opt;
		}
#ifdef CONFIG_QUOTA
	} else if (m->flags & MOPT_QFMT) {
		if (sb_any_quota_loaded(sb) &&
		    sbi->s_jquota_fmt != m->mount_opt) {
			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
				 "quota options when quota turned on");
			return -1;
		}
		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
			ext4_msg(sb, KERN_INFO,
				 "Quota format mount options ignored "
				 "when QUOTA feature is enabled");
			return 1;
		}
		sbi->s_jquota_fmt = m->mount_opt;
#endif
#ifndef CONFIG_FS_DAX
	} else if (token == Opt_dax) {
		ext4_msg(sb, KERN_INFO, "dax option not supported");
		return -1;
#endif
	} else {
		if (!args->from)
			arg = 1;
		if (m->flags & MOPT_CLEAR)
			arg = !arg;
		else if (unlikely(!(m->flags & MOPT_SET))) {
			ext4_msg(sb, KERN_WARNING,
				 "buggy handling of option %s", opt);
			WARN_ON(1);
			return -1;
		}
		if (arg != 0)
			sbi->s_mount_opt |= m->mount_opt;
		else
			sbi->s_mount_opt &= ~m->mount_opt;
	}
	return 1;
}

static int parse_options(char *options, struct super_block *sb,
			 unsigned long *journal_devnum,
			 unsigned int *journal_ioprio,
			 int is_remount)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int token;

	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		if (!*p)
			continue;
		/*
		 * Initialize args struct so we know whether arg was
		 * found; some options take optional arguments.
		 */
		args[0].to = args[0].from = NULL;
		token = match_token(p, tokens, args);
		if (handle_mount_opt(sb, p, token, args, journal_devnum,
				     journal_ioprio, is_remount) < 0)
			return 0;
	}
#ifdef CONFIG_QUOTA
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
		ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
			 "mount options ignored.");
		clear_opt(sb, USRQUOTA);
		clear_opt(sb, GRPQUOTA);
	} else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
			clear_opt(sb, USRQUOTA);

		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
			clear_opt(sb, GRPQUOTA);

		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
			ext4_msg(sb, KERN_ERR, "old and new quota "
					"format mixing");
			return 0;
		}

		if (!sbi->s_jquota_fmt) {
			ext4_msg(sb, KERN_ERR, "journaled quota format "
					"not specified");
			return 0;
		}
	}
#endif
	if (test_opt(sb, DIOREAD_NOLOCK)) {
		int blocksize =
			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);

		if (blocksize < PAGE_CACHE_SIZE) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "dioread_nolock if block size != PAGE_SIZE");
			return 0;
		}
	}
	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
			 "in data=ordered mode");
		return 0;
	}
	return 1;
}

static inline void ext4_show_quota_options(struct seq_file *seq,
					   struct super_block *sb)
{
#if defined(CONFIG_QUOTA)
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (sbi->s_jquota_fmt) {
		char *fmtname = "";

		switch (sbi->s_jquota_fmt) {
		case QFMT_VFS_OLD:
			fmtname = "vfsold";
			break;
		case QFMT_VFS_V0:
			fmtname = "vfsv0";
			break;
		case QFMT_VFS_V1:
			fmtname = "vfsv1";
			break;
		}
		seq_printf(seq, ",jqfmt=%s", fmtname);
	}

	if (sbi->s_qf_names[USRQUOTA])
		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);

	if (sbi->s_qf_names[GRPQUOTA])
		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
#endif
}

static const char *token2str(int token)
{
	const struct match_token *t;

	for (t = tokens; t->token != Opt_err; t++)
		if (t->token == token && !strchr(t->pattern, '='))
			break;
	return t->pattern;
}

/*
 * Show an option if
 *  - it's set to a non-default value OR
 *  - if the per-sb default is different from the global default
 */
static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
			      int nodefs)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
	const struct mount_opts *m;
	char sep = nodefs ? '\n' : ',';

#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)

	if (sbi->s_sb_block != 1)
		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);

	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
		int want_set = m->flags & MOPT_SET;
		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
		    (m->flags & MOPT_CLEAR_ERR))
			continue;
		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
			continue; /* skip if same as the default */
		if ((want_set &&
		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
			continue; /* select Opt_noFoo vs Opt_Foo */
		SEQ_OPTS_PRINT("%s", token2str(m->token));
	}

	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
		SEQ_OPTS_PRINT("resuid=%u",
				from_kuid_munged(&init_user_ns, sbi->s_resuid));
	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
		SEQ_OPTS_PRINT("resgid=%u",
				from_kgid_munged(&init_user_ns, sbi->s_resgid));
	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
		SEQ_OPTS_PUTS("errors=remount-ro");
	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
		SEQ_OPTS_PUTS("errors=continue");
	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
		SEQ_OPTS_PUTS("errors=panic");
	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
	if (sb->s_flags & MS_I_VERSION)
		SEQ_OPTS_PUTS("i_version");
	if (nodefs || sbi->s_stripe)
		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
			SEQ_OPTS_PUTS("data=journal");
		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
			SEQ_OPTS_PUTS("data=ordered");
		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
			SEQ_OPTS_PUTS("data=writeback");
	}
	if (nodefs ||
	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
			       sbi->s_inode_readahead_blks);

	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
	if (nodefs || sbi->s_max_dir_size_kb)
		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);

	ext4_show_quota_options(seq, sb);
	return 0;
}

static int ext4_show_options(struct seq_file *seq, struct dentry *root)
{
	return _ext4_show_options(seq, root->d_sb, 0);
}

static int options_seq_show(struct seq_file *seq, void *offset)
{
	struct super_block *sb = seq->private;
	int rc;

	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
	rc = _ext4_show_options(seq, sb, 1);
	seq_puts(seq, "\n");
	return rc;
}

static int options_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, options_seq_show, PDE_DATA(inode));
}

static const struct file_operations ext4_seq_options_fops = {
	.owner = THIS_MODULE,
	.open = options_open_fs,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
			    int read_only)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	int res = 0;

	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
		ext4_msg(sb, KERN_ERR, "revision level too high, "
			 "forcing read-only mode");
		res = MS_RDONLY;
	}
	if (read_only)
		goto done;
	if (!(sbi->s_mount_state & EXT4_VALID_FS))
		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
			 "running e2fsck is recommended");
	else if (sbi->s_mount_state & EXT4_ERROR_FS)
		ext4_msg(sb, KERN_WARNING,
			 "warning: mounting fs with errors, "
			 "running e2fsck is recommended");
	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
		 le16_to_cpu(es->s_mnt_count) >=
		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
		ext4_msg(sb, KERN_WARNING,
			 "warning: maximal mount count reached, "
			 "running e2fsck is recommended");
	else if (le32_to_cpu(es->s_checkinterval) &&
		(le32_to_cpu(es->s_lastcheck) +
			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
		ext4_msg(sb, KERN_WARNING,
			 "warning: checktime reached, "
			 "running e2fsck is recommended");
	if (!sbi->s_journal)
		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
	le16_add_cpu(&es->s_mnt_count, 1);
	es->s_mtime = cpu_to_le32(get_seconds());
	ext4_update_dynamic_rev(sb);
	if (sbi->s_journal)
		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);

	ext4_commit_super(sb, 1);
done:
	if (test_opt(sb, DEBUG))
		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
			sb->s_blocksize,
			sbi->s_groups_count,
			EXT4_BLOCKS_PER_GROUP(sb),
			EXT4_INODES_PER_GROUP(sb),
			sbi->s_mount_opt, sbi->s_mount_opt2);

	cleancache_init_fs(sb);
	return res;
}

int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct flex_groups *new_groups;
	int size;

	if (!sbi->s_log_groups_per_flex)
		return 0;

	size = ext4_flex_group(sbi, ngroup - 1) + 1;
	if (size <= sbi->s_flex_groups_allocated)
		return 0;

	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
	if (!new_groups) {
		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
			 size / (int) sizeof(struct flex_groups));
		return -ENOMEM;
	}

	if (sbi->s_flex_groups) {
		memcpy(new_groups, sbi->s_flex_groups,
		       (sbi->s_flex_groups_allocated *
			sizeof(struct flex_groups)));
		kvfree(sbi->s_flex_groups);
	}
	sbi->s_flex_groups = new_groups;
	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
	return 0;
}

static int ext4_fill_flex_info(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_group_desc *gdp = NULL;
	ext4_group_t flex_group;
	int i, err;

	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
		sbi->s_log_groups_per_flex = 0;
		return 1;
	}

	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
	if (err)
		goto failed;

	for (i = 0; i < sbi->s_groups_count; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);

		flex_group = ext4_flex_group(sbi, i);
		atomic_add(ext4_free_inodes_count(sb, gdp),
			   &sbi->s_flex_groups[flex_group].free_inodes);
		atomic64_add(ext4_free_group_clusters(sb, gdp),
			     &sbi->s_flex_groups[flex_group].free_clusters);
		atomic_add(ext4_used_dirs_count(sb, gdp),
			   &sbi->s_flex_groups[flex_group].used_dirs);
	}

	return 1;
failed:
	return 0;
}

static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
				   struct ext4_group_desc *gdp)
{
	int offset;
	__u16 crc = 0;
	__le32 le_group = cpu_to_le32(block_group);

	if (ext4_has_metadata_csum(sbi->s_sb)) {
		/* Use new metadata_csum algorithm */
		__le16 save_csum;
		__u32 csum32;

		save_csum = gdp->bg_checksum;
		gdp->bg_checksum = 0;
		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
				     sizeof(le_group));
		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
				     sbi->s_desc_size);
		gdp->bg_checksum = save_csum;

		crc = csum32 & 0xFFFF;
		goto out;
	}

	/* old crc16 code */
	if (!(sbi->s_es->s_feature_ro_compat &
	      cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
		return 0;

	offset = offsetof(struct ext4_group_desc, bg_checksum);

	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
	crc = crc16(crc, (__u8 *)gdp, offset);
	offset += sizeof(gdp->bg_checksum); /* skip checksum */
	/* for checksum of struct ext4_group_desc do the rest...*/
	if ((sbi->s_es->s_feature_incompat &
	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
		crc = crc16(crc, (__u8 *)gdp + offset,
			    le16_to_cpu(sbi->s_es->s_desc_size) -
				offset);

out:
	return cpu_to_le16(crc);
}

int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
				struct ext4_group_desc *gdp)
{
	if (ext4_has_group_desc_csum(sb) &&
	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
						      block_group, gdp)))
		return 0;

	return 1;
}

void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
			      struct ext4_group_desc *gdp)
{
	if (!ext4_has_group_desc_csum(sb))
		return;
	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
}

/* Called at mount-time, super-block is locked */
static int ext4_check_descriptors(struct super_block *sb,
				  ext4_fsblk_t sb_block,
				  ext4_group_t *first_not_zeroed)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
	ext4_fsblk_t last_block;
	ext4_fsblk_t block_bitmap;
	ext4_fsblk_t inode_bitmap;
	ext4_fsblk_t inode_table;
	int flexbg_flag = 0;
	ext4_group_t i, grp = sbi->s_groups_count;

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
		flexbg_flag = 1;

	ext4_debug("Checking group descriptors");

	for (i = 0; i < sbi->s_groups_count; i++) {
		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);

		if (i == sbi->s_groups_count - 1 || flexbg_flag)
			last_block = ext4_blocks_count(sbi->s_es) - 1;
		else
			last_block = first_block +
				(EXT4_BLOCKS_PER_GROUP(sb) - 1);

		if ((grp == sbi->s_groups_count) &&
		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
			grp = i;

		block_bitmap = ext4_block_bitmap(sb, gdp);
		if (block_bitmap == sb_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
				 "Block bitmap for group %u overlaps "
				 "superblock", i);
		}
		if (block_bitmap < first_block || block_bitmap > last_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
			       "Block bitmap for group %u not in group "
			       "(block %llu)!", i, block_bitmap);
			return 0;
		}
		inode_bitmap = ext4_inode_bitmap(sb, gdp);
		if (inode_bitmap == sb_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
				 "Inode bitmap for group %u overlaps "
				 "superblock", i);
		}
		if (inode_bitmap < first_block || inode_bitmap > last_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
			       "Inode bitmap for group %u not in group "
			       "(block %llu)!", i, inode_bitmap);
			return 0;
		}
		inode_table = ext4_inode_table(sb, gdp);
		if (inode_table == sb_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
				 "Inode table for group %u overlaps "
				 "superblock", i);
		}
		if (inode_table < first_block ||
		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
			       "Inode table for group %u not in group "
			       "(block %llu)!", i, inode_table);
			return 0;
		}
		ext4_lock_group(sb, i);
		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
				 "Checksum for group %u failed (%u!=%u)",
				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
				     gdp)), le16_to_cpu(gdp->bg_checksum));
			if (!(sb->s_flags & MS_RDONLY)) {
				ext4_unlock_group(sb, i);
				return 0;
			}
		}
		ext4_unlock_group(sb, i);
		if (!flexbg_flag)
			first_block += EXT4_BLOCKS_PER_GROUP(sb);
	}
	if (NULL != first_not_zeroed)
		*first_not_zeroed = grp;
	return 1;
}

/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
 * the superblock) which were deleted from all directories, but held open by
 * a process at the time of a crash.  We walk the list and try to delete these
 * inodes at recovery time (only with a read-write filesystem).
 *
 * In order to keep the orphan inode chain consistent during traversal (in
 * case of crash during recovery), we link each inode into the superblock
 * orphan list_head and handle it the same way as an inode deletion during
 * normal operation (which journals the operations for us).
 *
 * We only do an iget() and an iput() on each inode, which is very safe if we
 * accidentally point at an in-use or already deleted inode.  The worst that
 * can happen in this case is that we get a "bit already cleared" message from
 * ext4_free_inode().  The only reason we would point at a wrong inode is if
 * e2fsck was run on this filesystem, and it must have already done the orphan
 * inode cleanup for us, so we can safely abort without any further action.
 */
static void ext4_orphan_cleanup(struct super_block *sb,
				struct ext4_super_block *es)
{
	unsigned int s_flags = sb->s_flags;
	int nr_orphans = 0, nr_truncates = 0;
#ifdef CONFIG_QUOTA
	int i;
#endif
	if (!es->s_last_orphan) {
		jbd_debug(4, "no orphan inodes to clean up\n");
		return;
	}

	if (bdev_read_only(sb->s_bdev)) {
		ext4_msg(sb, KERN_ERR, "write access "
			"unavailable, skipping orphan cleanup");
		return;
	}

	/* Check if feature set would not allow a r/w mount */
	if (!ext4_feature_set_ok(sb, 0)) {
		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
			 "unknown ROCOMPAT features");
		return;
	}

	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
		/* don't clear list on RO mount w/ errors */
		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
				  "clearing orphan list.\n");
			es->s_last_orphan = 0;
		}
		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
		return;
	}

	if (s_flags & MS_RDONLY) {
		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
		sb->s_flags &= ~MS_RDONLY;
	}
#ifdef CONFIG_QUOTA
	/* Needed for iput() to work correctly and not trash data */
	sb->s_flags |= MS_ACTIVE;
	/* Turn on quotas so that they are updated correctly */
	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
		if (EXT4_SB(sb)->s_qf_names[i]) {
			int ret = ext4_quota_on_mount(sb, i);
			if (ret < 0)
				ext4_msg(sb, KERN_ERR,
					"Cannot turn on journaled "
					"quota: error %d", ret);
		}
	}
#endif

	while (es->s_last_orphan) {
		struct inode *inode;

		/*
		 * We may have encountered an error during cleanup; if
		 * so, skip the rest.
		 */
		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
			es->s_last_orphan = 0;
			break;
		}

		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
		if (IS_ERR(inode)) {
			es->s_last_orphan = 0;
			break;
		}

		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
		dquot_initialize(inode);
		if (inode->i_nlink) {
			if (test_opt(sb, DEBUG))
				ext4_msg(sb, KERN_DEBUG,
					"%s: truncating inode %lu to %lld bytes",
					__func__, inode->i_ino, inode->i_size);
			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
				  inode->i_ino, inode->i_size);
			mutex_lock(&inode->i_mutex);
			truncate_inode_pages(inode->i_mapping, inode->i_size);
			ext4_truncate(inode);
			mutex_unlock(&inode->i_mutex);
			nr_truncates++;
		} else {
			if (test_opt(sb, DEBUG))
				ext4_msg(sb, KERN_DEBUG,
					"%s: deleting unreferenced inode %lu",
					__func__, inode->i_ino);
			jbd_debug(2, "deleting unreferenced inode %lu\n",
				  inode->i_ino);
			nr_orphans++;
		}
		iput(inode);  /* The delete magic happens here! */
	}

#define PLURAL(x) (x), ((x) == 1) ? "" : "s"

	if (nr_orphans)
		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
		       PLURAL(nr_orphans));
	if (nr_truncates)
		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
		       PLURAL(nr_truncates));
#ifdef CONFIG_QUOTA
	/* Turn quotas off */
	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
		if (sb_dqopt(sb)->files[i])
			dquot_quota_off(sb, i);
	}
#endif
	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
}

/*
 * Maximal extent format file size.
 * Resulting logical blkno at s_maxbytes must fit in our on-disk
 * extent format containers, within a sector_t, and within i_blocks
 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
 * so that won't be a limiting factor.
 *
 * However there is other limiting factor. We do store extents in the form
 * of starting block and length, hence the resulting length of the extent
 * covering maximum file size must fit into on-disk format containers as
 * well. Given that length is always by 1 unit bigger than max unit (because
 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
 *
 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
 */
static loff_t ext4_max_size(int blkbits, int has_huge_files)
{
	loff_t res;
	loff_t upper_limit = MAX_LFS_FILESIZE;

	/* small i_blocks in vfs inode? */
	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
		/*
		 * CONFIG_LBDAF is not enabled implies the inode
		 * i_block represent total blocks in 512 bytes
		 * 32 == size of vfs inode i_blocks * 8
		 */
		upper_limit = (1LL << 32) - 1;

		/* total blocks in file system block size */
		upper_limit >>= (blkbits - 9);
		upper_limit <<= blkbits;
	}

	/*
	 * 32-bit extent-start container, ee_block. We lower the maxbytes
	 * by one fs block, so ee_len can cover the extent of maximum file
	 * size
	 */
	res = (1LL << 32) - 1;
	res <<= blkbits;

	/* Sanity check against vm- & vfs- imposed limits */
	if (res > upper_limit)
		res = upper_limit;

	return res;
}

/*
 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
 * We need to be 1 filesystem block less than the 2^48 sector limit.
 */
static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
{
	loff_t res = EXT4_NDIR_BLOCKS;
	int meta_blocks;
	loff_t upper_limit;
	/* This is calculated to be the largest file size for a dense, block
	 * mapped file such that the file's total number of 512-byte sectors,
	 * including data and all indirect blocks, does not exceed (2^48 - 1).
	 *
	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
	 * number of 512-byte sectors of the file.
	 */

	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
		/*
		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
		 * the inode i_block field represents total file blocks in
		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
		 */
		upper_limit = (1LL << 32) - 1;

		/* total blocks in file system block size */
		upper_limit >>= (bits - 9);

	} else {
		/*
		 * We use 48 bit ext4_inode i_blocks
		 * With EXT4_HUGE_FILE_FL set the i_blocks
		 * represent total number of blocks in
		 * file system block size
		 */
		upper_limit = (1LL << 48) - 1;

	}

	/* indirect blocks */
	meta_blocks = 1;
	/* double indirect blocks */
	meta_blocks += 1 + (1LL << (bits-2));
	/* tripple indirect blocks */
	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));

	upper_limit -= meta_blocks;
	upper_limit <<= bits;

	res += 1LL << (bits-2);
	res += 1LL << (2*(bits-2));
	res += 1LL << (3*(bits-2));
	res <<= bits;
	if (res > upper_limit)
		res = upper_limit;

	if (res > MAX_LFS_FILESIZE)
		res = MAX_LFS_FILESIZE;

	return res;
}

static ext4_fsblk_t descriptor_loc(struct super_block *sb,
				   ext4_fsblk_t logical_sb_block, int nr)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	ext4_group_t bg, first_meta_bg;
	int has_super = 0;

	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);

	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
	    nr < first_meta_bg)
		return logical_sb_block + nr + 1;
	bg = sbi->s_desc_per_block * nr;
	if (ext4_bg_has_super(sb, bg))
		has_super = 1;

	/*
	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
	 * compensate.
	 */
	if (sb->s_blocksize == 1024 && nr == 0 &&
	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
		has_super++;

	return (has_super + ext4_group_first_block_no(sb, bg));
}

/**
 * ext4_get_stripe_size: Get the stripe size.
 * @sbi: In memory super block info
 *
 * If we have specified it via mount option, then
 * use the mount option value. If the value specified at mount time is
 * greater than the blocks per group use the super block value.
 * If the super block value is greater than blocks per group return 0.
 * Allocator needs it be less than blocks per group.
 *
 */
static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
{
	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
	unsigned long stripe_width =
			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
	int ret;

	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
		ret = sbi->s_stripe;
	else if (stripe_width <= sbi->s_blocks_per_group)
		ret = stripe_width;
	else if (stride <= sbi->s_blocks_per_group)
		ret = stride;
	else
		ret = 0;

	/*
	 * If the stripe width is 1, this makes no sense and
	 * we set it to 0 to turn off stripe handling code.
	 */
	if (ret <= 1)
		ret = 0;

	return ret;
}

/* sysfs supprt */

struct ext4_attr {
	struct attribute attr;
	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
			 const char *, size_t);
	union {
		int offset;
		int deprecated_val;
	} u;
};

static int parse_strtoull(const char *buf,
		unsigned long long max, unsigned long long *value)
{
	int ret;

	ret = kstrtoull(skip_spaces(buf), 0, value);
	if (!ret && *value > max)
		ret = -EINVAL;
	return ret;
}

static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
					      struct ext4_sb_info *sbi,
					      char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(s64) EXT4_C2B(sbi,
			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
}

static ssize_t session_write_kbytes_show(struct ext4_attr *a,
					 struct ext4_sb_info *sbi, char *buf)
{
	struct super_block *sb = sbi->s_buddy_cache->i_sb;

	if (!sb->s_bdev->bd_part)
		return snprintf(buf, PAGE_SIZE, "0\n");
	return snprintf(buf, PAGE_SIZE, "%lu\n",
			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
			 sbi->s_sectors_written_start) >> 1);
}

static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
					  struct ext4_sb_info *sbi, char *buf)
{
	struct super_block *sb = sbi->s_buddy_cache->i_sb;

	if (!sb->s_bdev->bd_part)
		return snprintf(buf, PAGE_SIZE, "0\n");
	return snprintf(buf, PAGE_SIZE, "%llu\n",
			(unsigned long long)(sbi->s_kbytes_written +
			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
}

static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
					  struct ext4_sb_info *sbi,
					  const char *buf, size_t count)
{
	unsigned long t;
	int ret;

	ret = kstrtoul(skip_spaces(buf), 0, &t);
	if (ret)
		return ret;

	if (t && (!is_power_of_2(t) || t > 0x40000000))
		return -EINVAL;

	sbi->s_inode_readahead_blks = t;
	return count;
}

static ssize_t sbi_ui_show(struct ext4_attr *a,
			   struct ext4_sb_info *sbi, char *buf)
{
	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);

	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
}

static ssize_t sbi_ui_store(struct ext4_attr *a,
			    struct ext4_sb_info *sbi,
			    const char *buf, size_t count)
{
	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
	unsigned long t;
	int ret;

	ret = kstrtoul(skip_spaces(buf), 0, &t);
	if (ret)
		return ret;
	*ui = t;
	return count;
}

static ssize_t es_ui_show(struct ext4_attr *a,
			   struct ext4_sb_info *sbi, char *buf)
{

	unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
			   a->u.offset);

	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
}

static ssize_t reserved_clusters_show(struct ext4_attr *a,
				  struct ext4_sb_info *sbi, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
}

static ssize_t reserved_clusters_store(struct ext4_attr *a,
				   struct ext4_sb_info *sbi,
				   const char *buf, size_t count)
{
	unsigned long long val;
	int ret;

	if (parse_strtoull(buf, -1ULL, &val))
		return -EINVAL;
	ret = ext4_reserve_clusters(sbi, val);

	return ret ? ret : count;
}

static ssize_t trigger_test_error(struct ext4_attr *a,
				  struct ext4_sb_info *sbi,
				  const char *buf, size_t count)
{
	int len = count;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (len && buf[len-1] == '\n')
		len--;

	if (len)
		ext4_error(sbi->s_sb, "%.*s", len, buf);
	return count;
}

static ssize_t sbi_deprecated_show(struct ext4_attr *a,
				   struct ext4_sb_info *sbi, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
}

#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
static struct ext4_attr ext4_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = _mode },	\
	.show	= _show,					\
	.store	= _store,					\
	.u = {							\
		.offset = offsetof(struct ext4_sb_info, _elname),\
	},							\
}

#define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)		\
static struct ext4_attr ext4_attr_##_name = {				\
	.attr = {.name = __stringify(_name), .mode = _mode },		\
	.show	= _show,						\
	.store	= _store,						\
	.u = {								\
		.offset = offsetof(struct ext4_super_block, _elname),	\
	},								\
}

#define EXT4_ATTR(name, mode, show, store) \
static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)

#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)

#define EXT4_RO_ATTR_ES_UI(name, elname)	\
	EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
#define EXT4_RW_ATTR_SBI_UI(name, elname)	\
	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)

#define ATTR_LIST(name) &ext4_attr_##name.attr
#define EXT4_DEPRECATED_ATTR(_name, _val)	\
static struct ext4_attr ext4_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = 0444 },	\
	.show	= sbi_deprecated_show,				\
	.u = {							\
		.deprecated_val = _val,				\
	},							\
}

EXT4_RO_ATTR(delayed_allocation_blocks);
EXT4_RO_ATTR(session_write_kbytes);
EXT4_RO_ATTR(lifetime_write_kbytes);
EXT4_RW_ATTR(reserved_clusters);
EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
		 inode_readahead_blks_store, s_inode_readahead_blks);
EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);

static struct attribute *ext4_attrs[] = {
	ATTR_LIST(delayed_allocation_blocks),
	ATTR_LIST(session_write_kbytes),
	ATTR_LIST(lifetime_write_kbytes),
	ATTR_LIST(reserved_clusters),
	ATTR_LIST(inode_readahead_blks),
	ATTR_LIST(inode_goal),
	ATTR_LIST(mb_stats),
	ATTR_LIST(mb_max_to_scan),
	ATTR_LIST(mb_min_to_scan),
	ATTR_LIST(mb_order2_req),
	ATTR_LIST(mb_stream_req),
	ATTR_LIST(mb_group_prealloc),
	ATTR_LIST(max_writeback_mb_bump),
	ATTR_LIST(extent_max_zeroout_kb),
	ATTR_LIST(trigger_fs_error),
	ATTR_LIST(err_ratelimit_interval_ms),
	ATTR_LIST(err_ratelimit_burst),
	ATTR_LIST(warning_ratelimit_interval_ms),
	ATTR_LIST(warning_ratelimit_burst),
	ATTR_LIST(msg_ratelimit_interval_ms),
	ATTR_LIST(msg_ratelimit_burst),
	ATTR_LIST(errors_count),
	ATTR_LIST(first_error_time),
	ATTR_LIST(last_error_time),
	NULL,
};

/* Features this copy of ext4 supports */
EXT4_INFO_ATTR(lazy_itable_init);
EXT4_INFO_ATTR(batched_discard);
EXT4_INFO_ATTR(meta_bg_resize);
EXT4_INFO_ATTR(encryption);

static struct attribute *ext4_feat_attrs[] = {
	ATTR_LIST(lazy_itable_init),
	ATTR_LIST(batched_discard),
	ATTR_LIST(meta_bg_resize),
	ATTR_LIST(encryption),
	NULL,
};

static ssize_t ext4_attr_show(struct kobject *kobj,
			      struct attribute *attr, char *buf)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);

	return a->show ? a->show(a, sbi, buf) : 0;
}

static ssize_t ext4_attr_store(struct kobject *kobj,
			       struct attribute *attr,
			       const char *buf, size_t len)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);

	return a->store ? a->store(a, sbi, buf, len) : 0;
}

static void ext4_sb_release(struct kobject *kobj)
{
	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
						s_kobj);
	complete(&sbi->s_kobj_unregister);
}

static const struct sysfs_ops ext4_attr_ops = {
	.show	= ext4_attr_show,
	.store	= ext4_attr_store,
};

static struct kobj_type ext4_ktype = {
	.default_attrs	= ext4_attrs,
	.sysfs_ops	= &ext4_attr_ops,
	.release	= ext4_sb_release,
};

static void ext4_feat_release(struct kobject *kobj)
{
	complete(&ext4_feat->f_kobj_unregister);
}

static ssize_t ext4_feat_show(struct kobject *kobj,
			      struct attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "supported\n");
}

/*
 * We can not use ext4_attr_show/store because it relies on the kobject
 * being embedded in the ext4_sb_info structure which is definitely not
 * true in this case.
 */
static const struct sysfs_ops ext4_feat_ops = {
	.show	= ext4_feat_show,
	.store	= NULL,
};

static struct kobj_type ext4_feat_ktype = {
	.default_attrs	= ext4_feat_attrs,
	.sysfs_ops	= &ext4_feat_ops,
	.release	= ext4_feat_release,
};

/*
 * Check whether this filesystem can be mounted based on
 * the features present and the RDONLY/RDWR mount requested.
 * Returns 1 if this filesystem can be mounted as requested,
 * 0 if it cannot be.
 */
static int ext4_feature_set_ok(struct super_block *sb, int readonly)
{
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
		ext4_msg(sb, KERN_ERR,
			"Couldn't mount because of "
			"unsupported optional features (%x)",
			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
			~EXT4_FEATURE_INCOMPAT_SUPP));
		return 0;
	}

	if (readonly)
		return 1;

	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
		sb->s_flags |= MS_RDONLY;
		return 1;
	}

	/* Check that feature set is OK for a read-write mount */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
			 "unsupported optional features (%x)",
			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
				~EXT4_FEATURE_RO_COMPAT_SUPP));
		return 0;
	}
	/*
	 * Large file size enabled file system can only be mounted
	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
	 */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
		if (sizeof(blkcnt_t) < sizeof(u64)) {
			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
				 "cannot be mounted RDWR without "
				 "CONFIG_LBDAF");
			return 0;
		}
	}
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
		ext4_msg(sb, KERN_ERR,
			 "Can't support bigalloc feature without "
			 "extents feature\n");
		return 0;
	}

#ifndef CONFIG_QUOTA
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
	    !readonly) {
		ext4_msg(sb, KERN_ERR,
			 "Filesystem with quota feature cannot be mounted RDWR "
			 "without CONFIG_QUOTA");
		return 0;
	}
#endif  /* CONFIG_QUOTA */
	return 1;
}

/*
 * This function is called once a day if we have errors logged
 * on the file system
 */
static void print_daily_error_info(unsigned long arg)
{
	struct super_block *sb = (struct super_block *) arg;
	struct ext4_sb_info *sbi;
	struct ext4_super_block *es;

	sbi = EXT4_SB(sb);
	es = sbi->s_es;

	if (es->s_error_count)
		/* fsck newer than v1.41.13 is needed to clean this condition. */
		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
			 le32_to_cpu(es->s_error_count));
	if (es->s_first_error_time) {
		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
		       sb->s_id, le32_to_cpu(es->s_first_error_time),
		       (int) sizeof(es->s_first_error_func),
		       es->s_first_error_func,
		       le32_to_cpu(es->s_first_error_line));
		if (es->s_first_error_ino)
			printk(": inode %u",
			       le32_to_cpu(es->s_first_error_ino));
		if (es->s_first_error_block)
			printk(": block %llu", (unsigned long long)
			       le64_to_cpu(es->s_first_error_block));
		printk("\n");
	}
	if (es->s_last_error_time) {
		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
		       sb->s_id, le32_to_cpu(es->s_last_error_time),
		       (int) sizeof(es->s_last_error_func),
		       es->s_last_error_func,
		       le32_to_cpu(es->s_last_error_line));
		if (es->s_last_error_ino)
			printk(": inode %u",
			       le32_to_cpu(es->s_last_error_ino));
		if (es->s_last_error_block)
			printk(": block %llu", (unsigned long long)
			       le64_to_cpu(es->s_last_error_block));
		printk("\n");
	}
	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
}

/* Find next suitable group and run ext4_init_inode_table */
static int ext4_run_li_request(struct ext4_li_request *elr)
{
	struct ext4_group_desc *gdp = NULL;
	ext4_group_t group, ngroups;
	struct super_block *sb;
	unsigned long timeout = 0;
	int ret = 0;

	sb = elr->lr_super;
	ngroups = EXT4_SB(sb)->s_groups_count;

	sb_start_write(sb);
	for (group = elr->lr_next_group; group < ngroups; group++) {
		gdp = ext4_get_group_desc(sb, group, NULL);
		if (!gdp) {
			ret = 1;
			break;
		}

		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
			break;
	}

	if (group >= ngroups)
		ret = 1;

	if (!ret) {
		timeout = jiffies;
		ret = ext4_init_inode_table(sb, group,
					    elr->lr_timeout ? 0 : 1);
		if (elr->lr_timeout == 0) {
			timeout = (jiffies - timeout) *
				  elr->lr_sbi->s_li_wait_mult;
			elr->lr_timeout = timeout;
		}
		elr->lr_next_sched = jiffies + elr->lr_timeout;
		elr->lr_next_group = group + 1;
	}
	sb_end_write(sb);

	return ret;
}

/*
 * Remove lr_request from the list_request and free the
 * request structure. Should be called with li_list_mtx held
 */
static void ext4_remove_li_request(struct ext4_li_request *elr)
{
	struct ext4_sb_info *sbi;

	if (!elr)
		return;

	sbi = elr->lr_sbi;

	list_del(&elr->lr_request);
	sbi->s_li_request = NULL;
	kfree(elr);
}

static void ext4_unregister_li_request(struct super_block *sb)
{
	mutex_lock(&ext4_li_mtx);
	if (!ext4_li_info) {
		mutex_unlock(&ext4_li_mtx);
		return;
	}

	mutex_lock(&ext4_li_info->li_list_mtx);
	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
	mutex_unlock(&ext4_li_info->li_list_mtx);
	mutex_unlock(&ext4_li_mtx);
}

static struct task_struct *ext4_lazyinit_task;

/*
 * This is the function where ext4lazyinit thread lives. It walks
 * through the request list searching for next scheduled filesystem.
 * When such a fs is found, run the lazy initialization request
 * (ext4_rn_li_request) and keep track of the time spend in this
 * function. Based on that time we compute next schedule time of
 * the request. When walking through the list is complete, compute
 * next waking time and put itself into sleep.
 */
static int ext4_lazyinit_thread(void *arg)
{
	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
	struct list_head *pos, *n;
	struct ext4_li_request *elr;
	unsigned long next_wakeup, cur;

	BUG_ON(NULL == eli);

cont_thread:
	while (true) {
		next_wakeup = MAX_JIFFY_OFFSET;

		mutex_lock(&eli->li_list_mtx);
		if (list_empty(&eli->li_request_list)) {
			mutex_unlock(&eli->li_list_mtx);
			goto exit_thread;
		}

		list_for_each_safe(pos, n, &eli->li_request_list) {
			elr = list_entry(pos, struct ext4_li_request,
					 lr_request);

			if (time_after_eq(jiffies, elr->lr_next_sched)) {
				if (ext4_run_li_request(elr) != 0) {
					/* error, remove the lazy_init job */
					ext4_remove_li_request(elr);
					continue;
				}
			}

			if (time_before(elr->lr_next_sched, next_wakeup))
				next_wakeup = elr->lr_next_sched;
		}
		mutex_unlock(&eli->li_list_mtx);

		try_to_freeze();

		cur = jiffies;
		if ((time_after_eq(cur, next_wakeup)) ||
		    (MAX_JIFFY_OFFSET == next_wakeup)) {
			cond_resched();
			continue;
		}

		schedule_timeout_interruptible(next_wakeup - cur);

		if (kthread_should_stop()) {
			ext4_clear_request_list();
			goto exit_thread;
		}
	}

exit_thread:
	/*
	 * It looks like the request list is empty, but we need
	 * to check it under the li_list_mtx lock, to prevent any
	 * additions into it, and of course we should lock ext4_li_mtx
	 * to atomically free the list and ext4_li_info, because at
	 * this point another ext4 filesystem could be registering
	 * new one.
	 */
	mutex_lock(&ext4_li_mtx);
	mutex_lock(&eli->li_list_mtx);
	if (!list_empty(&eli->li_request_list)) {
		mutex_unlock(&eli->li_list_mtx);
		mutex_unlock(&ext4_li_mtx);
		goto cont_thread;
	}
	mutex_unlock(&eli->li_list_mtx);
	kfree(ext4_li_info);
	ext4_li_info = NULL;
	mutex_unlock(&ext4_li_mtx);

	return 0;
}

static void ext4_clear_request_list(void)
{
	struct list_head *pos, *n;
	struct ext4_li_request *elr;

	mutex_lock(&ext4_li_info->li_list_mtx);
	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
		elr = list_entry(pos, struct ext4_li_request,
				 lr_request);
		ext4_remove_li_request(elr);
	}
	mutex_unlock(&ext4_li_info->li_list_mtx);
}

static int ext4_run_lazyinit_thread(void)
{
	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
					 ext4_li_info, "ext4lazyinit");
	if (IS_ERR(ext4_lazyinit_task)) {
		int err = PTR_ERR(ext4_lazyinit_task);
		ext4_clear_request_list();
		kfree(ext4_li_info);
		ext4_li_info = NULL;
		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
				 "initialization thread\n",
				 err);
		return err;
	}
	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
	return 0;
}

/*
 * Check whether it make sense to run itable init. thread or not.
 * If there is at least one uninitialized inode table, return
 * corresponding group number, else the loop goes through all
 * groups and return total number of groups.
 */
static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
{
	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
	struct ext4_group_desc *gdp = NULL;

	for (group = 0; group < ngroups; group++) {
		gdp = ext4_get_group_desc(sb, group, NULL);
		if (!gdp)
			continue;

		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
			break;
	}

	return group;
}

static int ext4_li_info_new(void)
{
	struct ext4_lazy_init *eli = NULL;

	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
	if (!eli)
		return -ENOMEM;

	INIT_LIST_HEAD(&eli->li_request_list);
	mutex_init(&eli->li_list_mtx);

	eli->li_state |= EXT4_LAZYINIT_QUIT;

	ext4_li_info = eli;

	return 0;
}

static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
					    ext4_group_t start)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_li_request *elr;

	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
	if (!elr)
		return NULL;

	elr->lr_super = sb;
	elr->lr_sbi = sbi;
	elr->lr_next_group = start;

	/*
	 * Randomize first schedule time of the request to
	 * spread the inode table initialization requests
	 * better.
	 */
	elr->lr_next_sched = jiffies + (prandom_u32() %
				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
	return elr;
}

int ext4_register_li_request(struct super_block *sb,
			     ext4_group_t first_not_zeroed)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_li_request *elr = NULL;
	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
	int ret = 0;

	mutex_lock(&ext4_li_mtx);
	if (sbi->s_li_request != NULL) {
		/*
		 * Reset timeout so it can be computed again, because
		 * s_li_wait_mult might have changed.
		 */
		sbi->s_li_request->lr_timeout = 0;
		goto out;
	}

	if (first_not_zeroed == ngroups ||
	    (sb->s_flags & MS_RDONLY) ||
	    !test_opt(sb, INIT_INODE_TABLE))
		goto out;

	elr = ext4_li_request_new(sb, first_not_zeroed);
	if (!elr) {
		ret = -ENOMEM;
		goto out;
	}

	if (NULL == ext4_li_info) {
		ret = ext4_li_info_new();
		if (ret)
			goto out;
	}

	mutex_lock(&ext4_li_info->li_list_mtx);
	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
	mutex_unlock(&ext4_li_info->li_list_mtx);

	sbi->s_li_request = elr;
	/*
	 * set elr to NULL here since it has been inserted to
	 * the request_list and the removal and free of it is
	 * handled by ext4_clear_request_list from now on.
	 */
	elr = NULL;

	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
		ret = ext4_run_lazyinit_thread();
		if (ret)
			goto out;
	}
out:
	mutex_unlock(&ext4_li_mtx);
	if (ret)
		kfree(elr);
	return ret;
}

/*
 * We do not need to lock anything since this is called on
 * module unload.
 */
static void ext4_destroy_lazyinit_thread(void)
{
	/*
	 * If thread exited earlier
	 * there's nothing to be done.
	 */
	if (!ext4_li_info || !ext4_lazyinit_task)
		return;

	kthread_stop(ext4_lazyinit_task);
}

static int set_journal_csum_feature_set(struct super_block *sb)
{
	int ret = 1;
	int compat, incompat;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (ext4_has_metadata_csum(sb)) {
		/* journal checksum v3 */
		compat = 0;
		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
	} else {
		/* journal checksum v1 */
		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
		incompat = 0;
	}

	jbd2_journal_clear_features(sbi->s_journal,
			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
			JBD2_FEATURE_INCOMPAT_CSUM_V2);
	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
		ret = jbd2_journal_set_features(sbi->s_journal,
				compat, 0,
				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
				incompat);
	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
		ret = jbd2_journal_set_features(sbi->s_journal,
				compat, 0,
				incompat);
		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
	} else {
		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
	}

	return ret;
}

/*
 * Note: calculating the overhead so we can be compatible with
 * historical BSD practice is quite difficult in the face of
 * clusters/bigalloc.  This is because multiple metadata blocks from
 * different block group can end up in the same allocation cluster.
 * Calculating the exact overhead in the face of clustered allocation
 * requires either O(all block bitmaps) in memory or O(number of block
 * groups**2) in time.  We will still calculate the superblock for
 * older file systems --- and if we come across with a bigalloc file
 * system with zero in s_overhead_clusters the estimate will be close to
 * correct especially for very large cluster sizes --- but for newer
 * file systems, it's better to calculate this figure once at mkfs
 * time, and store it in the superblock.  If the superblock value is
 * present (even for non-bigalloc file systems), we will use it.
 */
static int count_overhead(struct super_block *sb, ext4_group_t grp,
			  char *buf)
{
	struct ext4_sb_info	*sbi = EXT4_SB(sb);
	struct ext4_group_desc	*gdp;
	ext4_fsblk_t		first_block, last_block, b;
	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
	int			s, j, count = 0;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
			sbi->s_itb_per_group + 2);

	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
		(grp * EXT4_BLOCKS_PER_GROUP(sb));
	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		b = ext4_block_bitmap(sb, gdp);
		if (b >= first_block && b <= last_block) {
			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
			count++;
		}
		b = ext4_inode_bitmap(sb, gdp);
		if (b >= first_block && b <= last_block) {
			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
			count++;
		}
		b = ext4_inode_table(sb, gdp);
		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
				int c = EXT4_B2C(sbi, b - first_block);
				ext4_set_bit(c, buf);
				count++;
			}
		if (i != grp)
			continue;
		s = 0;
		if (ext4_bg_has_super(sb, grp)) {
			ext4_set_bit(s++, buf);
			count++;
		}
		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
			count++;
		}
	}
	if (!count)
		return 0;
	return EXT4_CLUSTERS_PER_GROUP(sb) -
		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
}

/*
 * Compute the overhead and stash it in sbi->s_overhead
 */
int ext4_calculate_overhead(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
	ext4_fsblk_t overhead = 0;
	char *buf = (char *) get_zeroed_page(GFP_NOFS);

	if (!buf)
		return -ENOMEM;

	/*
	 * Compute the overhead (FS structures).  This is constant
	 * for a given filesystem unless the number of block groups
	 * changes so we cache the previous value until it does.
	 */

	/*
	 * All of the blocks before first_data_block are overhead
	 */
	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));

	/*
	 * Add the overhead found in each block group
	 */
	for (i = 0; i < ngroups; i++) {
		int blks;

		blks = count_overhead(sb, i, buf);
		overhead += blks;
		if (blks)
			memset(buf, 0, PAGE_SIZE);
		cond_resched();
	}
	/* Add the internal journal blocks as well */
	if (sbi->s_journal && !sbi->journal_bdev)
		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);

	sbi->s_overhead = overhead;
	smp_wmb();
	free_page((unsigned long) buf);
	return 0;
}


static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
{
	ext4_fsblk_t resv_clusters;

	/*
	 * There's no need to reserve anything when we aren't using extents.
	 * The space estimates are exact, there are no unwritten extents,
	 * hole punching doesn't need new metadata... This is needed especially
	 * to keep ext2/3 backward compatibility.
	 */
	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
		return 0;
	/*
	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
	 * This should cover the situations where we can not afford to run
	 * out of space like for example punch hole, or converting
	 * unwritten extents in delalloc path. In most cases such
	 * allocation would require 1, or 2 blocks, higher numbers are
	 * very rare.
	 */
	resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
			EXT4_SB(sb)->s_cluster_bits;

	do_div(resv_clusters, 50);
	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);

	return resv_clusters;
}


static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
{
	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
				sbi->s_cluster_bits;

	if (count >= clusters)
		return -EINVAL;

	atomic64_set(&sbi->s_resv_clusters, count);
	return 0;
}

static int ext4_fill_super(struct super_block *sb, void *data, int silent)
{
	char *orig_data = kstrdup(data, GFP_KERNEL);
	struct buffer_head *bh;
	struct ext4_super_block *es = NULL;
	struct ext4_sb_info *sbi;
	ext4_fsblk_t block;
	ext4_fsblk_t sb_block = get_sb_block(&data);
	ext4_fsblk_t logical_sb_block;
	unsigned long offset = 0;
	unsigned long journal_devnum = 0;
	unsigned long def_mount_opts;
	struct inode *root;
	char *cp;
	const char *descr;
	int ret = -ENOMEM;
	int blocksize, clustersize;
	unsigned int db_count;
	unsigned int i;
	int needs_recovery, has_huge_files, has_bigalloc;
	__u64 blocks_count;
	int err = 0;
	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
	ext4_group_t first_not_zeroed;

	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	if (!sbi)
		goto out_free_orig;

	sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
	if (!sbi->s_blockgroup_lock) {
		kfree(sbi);
		goto out_free_orig;
	}
	sb->s_fs_info = sbi;
	sbi->s_sb = sb;
	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
	sbi->s_sb_block = sb_block;
	if (sb->s_bdev->bd_part)
		sbi->s_sectors_written_start =
			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	/* Modes of operations for file and directory encryption. */
	sbi->s_file_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
	sbi->s_dir_encryption_mode = EXT4_ENCRYPTION_MODE_INVALID;
#endif

	/* Cleanup superblock name */
	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
		*cp = '!';

	/* -EINVAL is default */
	ret = -EINVAL;
	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
	if (!blocksize) {
		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
		goto out_fail;
	}

	/*
	 * The ext4 superblock will not be buffer aligned for other than 1kB
	 * block sizes.  We need to calculate the offset from buffer start.
	 */
	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
		offset = do_div(logical_sb_block, blocksize);
	} else {
		logical_sb_block = sb_block;
	}

	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
		ext4_msg(sb, KERN_ERR, "unable to read superblock");
		goto out_fail;
	}
	/*
	 * Note: s_es must be initialized as soon as possible because
	 *       some ext4 macro-instructions depend on its value
	 */
	es = (struct ext4_super_block *) (bh->b_data + offset);
	sbi->s_es = es;
	sb->s_magic = le16_to_cpu(es->s_magic);
	if (sb->s_magic != EXT4_SUPER_MAGIC)
		goto cantfind_ext4;
	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);

	/* Warn if metadata_csum and gdt_csum are both set. */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
		ext4_warning(sb, "metadata_csum and uninit_bg are "
			     "redundant flags; please run fsck.");

	/* Check for a known checksum algorithm */
	if (!ext4_verify_csum_type(sb, es)) {
		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
			 "unknown checksum algorithm.");
		silent = 1;
		goto cantfind_ext4;
	}

	/* Load the checksum driver */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
		if (IS_ERR(sbi->s_chksum_driver)) {
			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
			ret = PTR_ERR(sbi->s_chksum_driver);
			sbi->s_chksum_driver = NULL;
			goto failed_mount;
		}
	}

	/* Check superblock checksum */
	if (!ext4_superblock_csum_verify(sb, es)) {
		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
			 "invalid superblock checksum.  Run e2fsck?");
		silent = 1;
		goto cantfind_ext4;
	}

	/* Precompute checksum seed for all metadata */
	if (ext4_has_metadata_csum(sb))
		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
					       sizeof(es->s_uuid));

	/* Set defaults before we parse the mount options */
	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
	set_opt(sb, INIT_INODE_TABLE);
	if (def_mount_opts & EXT4_DEFM_DEBUG)
		set_opt(sb, DEBUG);
	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
		set_opt(sb, GRPID);
	if (def_mount_opts & EXT4_DEFM_UID16)
		set_opt(sb, NO_UID32);
	/* xattr user namespace & acls are now defaulted on */
	set_opt(sb, XATTR_USER);
#ifdef CONFIG_EXT4_FS_POSIX_ACL
	set_opt(sb, POSIX_ACL);
#endif
	/* don't forget to enable journal_csum when metadata_csum is enabled. */
	if (ext4_has_metadata_csum(sb))
		set_opt(sb, JOURNAL_CHECKSUM);

	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
		set_opt(sb, JOURNAL_DATA);
	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
		set_opt(sb, ORDERED_DATA);
	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
		set_opt(sb, WRITEBACK_DATA);

	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
		set_opt(sb, ERRORS_PANIC);
	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
		set_opt(sb, ERRORS_CONT);
	else
		set_opt(sb, ERRORS_RO);
	/* block_validity enabled by default; disable with noblock_validity */
	set_opt(sb, BLOCK_VALIDITY);
	if (def_mount_opts & EXT4_DEFM_DISCARD)
		set_opt(sb, DISCARD);

	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;

	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
		set_opt(sb, BARRIER);

	/*
	 * enable delayed allocation by default
	 * Use -o nodelalloc to turn it off
	 */
	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
		set_opt(sb, DELALLOC);

	/*
	 * set default s_li_wait_mult for lazyinit, for the case there is
	 * no mount option specified.
	 */
	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;

	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
			   &journal_devnum, &journal_ioprio, 0)) {
		ext4_msg(sb, KERN_WARNING,
			 "failed to parse options in superblock: %s",
			 sbi->s_es->s_mount_opts);
	}
	sbi->s_def_mount_opt = sbi->s_mount_opt;
	if (!parse_options((char *) data, sb, &journal_devnum,
			   &journal_ioprio, 0))
		goto failed_mount;

	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
			    "with data=journal disables delayed "
			    "allocation and O_DIRECT support!\n");
		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and delalloc");
			goto failed_mount;
		}
		if (test_opt(sb, DIOREAD_NOLOCK)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and dioread_nolock");
			goto failed_mount;
		}
		if (test_opt(sb, DAX)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and dax");
			goto failed_mount;
		}
		if (test_opt(sb, DELALLOC))
			clear_opt(sb, DELALLOC);
	} else {
		sb->s_iflags |= SB_I_CGROUPWB;
	}

	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);

	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
		ext4_msg(sb, KERN_WARNING,
		       "feature flags set on rev 0 fs, "
		       "running e2fsck is recommended");

	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
		set_opt2(sb, HURD_COMPAT);
		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
					      EXT4_FEATURE_INCOMPAT_64BIT)) {
			ext4_msg(sb, KERN_ERR,
				 "The Hurd can't support 64-bit file systems");
			goto failed_mount;
		}
	}

	if (IS_EXT2_SB(sb)) {
		if (ext2_feature_set_ok(sb))
			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
				 "using the ext4 subsystem");
		else {
			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
				 "to feature incompatibilities");
			goto failed_mount;
		}
	}

	if (IS_EXT3_SB(sb)) {
		if (ext3_feature_set_ok(sb))
			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
				 "using the ext4 subsystem");
		else {
			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
				 "to feature incompatibilities");
			goto failed_mount;
		}
	}

	/*
	 * Check feature flags regardless of the revision level, since we
	 * previously didn't change the revision level when setting the flags,
	 * so there is a chance incompat flags are set on a rev 0 filesystem.
	 */
	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
		goto failed_mount;

	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
	    blocksize > EXT4_MAX_BLOCK_SIZE) {
		ext4_msg(sb, KERN_ERR,
		       "Unsupported filesystem blocksize %d", blocksize);
		goto failed_mount;
	}

	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
		ext4_msg(sb, KERN_ERR,
			 "Number of reserved GDT blocks insanely large: %d",
			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
		goto failed_mount;
	}

	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
		if (blocksize != PAGE_SIZE) {
			ext4_msg(sb, KERN_ERR,
					"error: unsupported blocksize for dax");
			goto failed_mount;
		}
		if (!sb->s_bdev->bd_disk->fops->direct_access) {
			ext4_msg(sb, KERN_ERR,
					"error: device does not support dax");
			goto failed_mount;
		}
	}

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT) &&
	    es->s_encryption_level) {
		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
			 es->s_encryption_level);
		goto failed_mount;
	}

	if (sb->s_blocksize != blocksize) {
		/* Validate the filesystem blocksize */
		if (!sb_set_blocksize(sb, blocksize)) {
			ext4_msg(sb, KERN_ERR, "bad block size %d",
					blocksize);
			goto failed_mount;
		}

		brelse(bh);
		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
		offset = do_div(logical_sb_block, blocksize);
		bh = sb_bread_unmovable(sb, logical_sb_block);
		if (!bh) {
			ext4_msg(sb, KERN_ERR,
			       "Can't read superblock on 2nd try");
			goto failed_mount;
		}
		es = (struct ext4_super_block *)(bh->b_data + offset);
		sbi->s_es = es;
		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
			ext4_msg(sb, KERN_ERR,
			       "Magic mismatch, very weird!");
			goto failed_mount;
		}
	}

	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
						      has_huge_files);
	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);

	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
	} else {
		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
		    (!is_power_of_2(sbi->s_inode_size)) ||
		    (sbi->s_inode_size > blocksize)) {
			ext4_msg(sb, KERN_ERR,
			       "unsupported inode size: %d",
			       sbi->s_inode_size);
			goto failed_mount;
		}
		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
	}

	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
		    !is_power_of_2(sbi->s_desc_size)) {
			ext4_msg(sb, KERN_ERR,
			       "unsupported descriptor size %lu",
			       sbi->s_desc_size);
			goto failed_mount;
		}
	} else
		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;

	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
		goto cantfind_ext4;

	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
	if (sbi->s_inodes_per_block == 0)
		goto cantfind_ext4;
	sbi->s_itb_per_group = sbi->s_inodes_per_group /
					sbi->s_inodes_per_block;
	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
	sbi->s_sbh = bh;
	sbi->s_mount_state = le16_to_cpu(es->s_state);
	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));

	for (i = 0; i < 4; i++)
		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
	sbi->s_def_hash_version = es->s_def_hash_version;
	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
		i = le32_to_cpu(es->s_flags);
		if (i & EXT2_FLAGS_UNSIGNED_HASH)
			sbi->s_hash_unsigned = 3;
		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
#ifdef __CHAR_UNSIGNED__
			if (!(sb->s_flags & MS_RDONLY))
				es->s_flags |=
					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
			sbi->s_hash_unsigned = 3;
#else
			if (!(sb->s_flags & MS_RDONLY))
				es->s_flags |=
					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
#endif
		}
	}

	/* Handle clustersize */
	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
	if (has_bigalloc) {
		if (clustersize < blocksize) {
			ext4_msg(sb, KERN_ERR,
				 "cluster size (%d) smaller than "
				 "block size (%d)", clustersize, blocksize);
			goto failed_mount;
		}
		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
			le32_to_cpu(es->s_log_block_size);
		sbi->s_clusters_per_group =
			le32_to_cpu(es->s_clusters_per_group);
		if (sbi->s_clusters_per_group > blocksize * 8) {
			ext4_msg(sb, KERN_ERR,
				 "#clusters per group too big: %lu",
				 sbi->s_clusters_per_group);
			goto failed_mount;
		}
		if (sbi->s_blocks_per_group !=
		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
				 "clusters per group (%lu) inconsistent",
				 sbi->s_blocks_per_group,
				 sbi->s_clusters_per_group);
			goto failed_mount;
		}
	} else {
		if (clustersize != blocksize) {
			ext4_warning(sb, "fragment/cluster size (%d) != "
				     "block size (%d)", clustersize,
				     blocksize);
			clustersize = blocksize;
		}
		if (sbi->s_blocks_per_group > blocksize * 8) {
			ext4_msg(sb, KERN_ERR,
				 "#blocks per group too big: %lu",
				 sbi->s_blocks_per_group);
			goto failed_mount;
		}
		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
		sbi->s_cluster_bits = 0;
	}
	sbi->s_cluster_ratio = clustersize / blocksize;

	if (sbi->s_inodes_per_group > blocksize * 8) {
		ext4_msg(sb, KERN_ERR,
		       "#inodes per group too big: %lu",
		       sbi->s_inodes_per_group);
		goto failed_mount;
	}

	/* Do we have standard group size of clustersize * 8 blocks ? */
	if (sbi->s_blocks_per_group == clustersize << 3)
		set_opt2(sb, STD_GROUP_SIZE);

	/*
	 * Test whether we have more sectors than will fit in sector_t,
	 * and whether the max offset is addressable by the page cache.
	 */
	err = generic_check_addressable(sb->s_blocksize_bits,
					ext4_blocks_count(es));
	if (err) {
		ext4_msg(sb, KERN_ERR, "filesystem"
			 " too large to mount safely on this system");
		if (sizeof(sector_t) < 8)
			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
		goto failed_mount;
	}

	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
		goto cantfind_ext4;

	/* check blocks count against device size */
	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
		       "exceeds size of device (%llu blocks)",
		       ext4_blocks_count(es), blocks_count);
		goto failed_mount;
	}

	/*
	 * It makes no sense for the first data block to be beyond the end
	 * of the filesystem.
	 */
	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
			 "block %u is beyond end of filesystem (%llu)",
			 le32_to_cpu(es->s_first_data_block),
			 ext4_blocks_count(es));
		goto failed_mount;
	}
	blocks_count = (ext4_blocks_count(es) -
			le32_to_cpu(es->s_first_data_block) +
			EXT4_BLOCKS_PER_GROUP(sb) - 1);
	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
		       "(block count %llu, first data block %u, "
		       "blocks per group %lu)", sbi->s_groups_count,
		       ext4_blocks_count(es),
		       le32_to_cpu(es->s_first_data_block),
		       EXT4_BLOCKS_PER_GROUP(sb));
		goto failed_mount;
	}
	sbi->s_groups_count = blocks_count;
	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
		   EXT4_DESC_PER_BLOCK(sb);
	sbi->s_group_desc = ext4_kvmalloc(db_count *
					  sizeof(struct buffer_head *),
					  GFP_KERNEL);
	if (sbi->s_group_desc == NULL) {
		ext4_msg(sb, KERN_ERR, "not enough memory");
		ret = -ENOMEM;
		goto failed_mount;
	}

	if (ext4_proc_root)
		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);

	if (sbi->s_proc)
		proc_create_data("options", S_IRUGO, sbi->s_proc,
				 &ext4_seq_options_fops, sb);

	bgl_lock_init(sbi->s_blockgroup_lock);

	for (i = 0; i < db_count; i++) {
		block = descriptor_loc(sb, logical_sb_block, i);
		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
		if (!sbi->s_group_desc[i]) {
			ext4_msg(sb, KERN_ERR,
			       "can't read group descriptor %d", i);
			db_count = i;
			goto failed_mount2;
		}
	}
	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
		goto failed_mount2;
	}

	sbi->s_gdb_count = db_count;
	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
	spin_lock_init(&sbi->s_next_gen_lock);

	setup_timer(&sbi->s_err_report, print_daily_error_info,
		(unsigned long) sb);

	/* Register extent status tree shrinker */
	if (ext4_es_register_shrinker(sbi))
		goto failed_mount3;

	sbi->s_stripe = ext4_get_stripe_size(sbi);
	sbi->s_extent_max_zeroout_kb = 32;

	/*
	 * set up enough so that it can read an inode
	 */
	sb->s_op = &ext4_sops;
	sb->s_export_op = &ext4_export_ops;
	sb->s_xattr = ext4_xattr_handlers;
#ifdef CONFIG_QUOTA
	sb->dq_op = &ext4_quota_operations;
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
		sb->s_qcop = &dquot_quotactl_sysfile_ops;
	else
		sb->s_qcop = &ext4_qctl_operations;
	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
#endif
	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));

	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
	mutex_init(&sbi->s_orphan_lock);

	sb->s_root = NULL;

	needs_recovery = (es->s_last_orphan != 0 ||
			  EXT4_HAS_INCOMPAT_FEATURE(sb,
				    EXT4_FEATURE_INCOMPAT_RECOVER));

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
	    !(sb->s_flags & MS_RDONLY))
		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
			goto failed_mount3a;

	/*
	 * The first inode we look at is the journal inode.  Don't try
	 * root first: it may be modified in the journal!
	 */
	if (!test_opt(sb, NOLOAD) &&
	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
		if (ext4_load_journal(sb, es, journal_devnum))
			goto failed_mount3a;
	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
		ext4_msg(sb, KERN_ERR, "required journal recovery "
		       "suppressed and not mounted read-only");
		goto failed_mount_wq;
	} else {
		clear_opt(sb, DATA_FLAGS);
		sbi->s_journal = NULL;
		needs_recovery = 0;
		goto no_journal;
	}

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
				       JBD2_FEATURE_INCOMPAT_64BIT)) {
		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
		goto failed_mount_wq;
	}

	if (!set_journal_csum_feature_set(sb)) {
		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
			 "feature set");
		goto failed_mount_wq;
	}

	/* We have now updated the journal if required, so we can
	 * validate the data journaling mode. */
	switch (test_opt(sb, DATA_FLAGS)) {
	case 0:
		/* No mode set, assume a default based on the journal
		 * capabilities: ORDERED_DATA if the journal can
		 * cope, else JOURNAL_DATA
		 */
		if (jbd2_journal_check_available_features
		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
			set_opt(sb, ORDERED_DATA);
		else
			set_opt(sb, JOURNAL_DATA);
		break;

	case EXT4_MOUNT_ORDERED_DATA:
	case EXT4_MOUNT_WRITEBACK_DATA:
		if (!jbd2_journal_check_available_features
		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
			ext4_msg(sb, KERN_ERR, "Journal does not support "
			       "requested data journaling mode");
			goto failed_mount_wq;
		}
	default:
		break;
	}
	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);

	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;

no_journal:
	if (ext4_mballoc_ready) {
		sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
		if (!sbi->s_mb_cache) {
			ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
			goto failed_mount_wq;
		}
	}

	if (unlikely(sbi->s_mount_flags & EXT4_MF_TEST_DUMMY_ENCRYPTION) &&
	    !(sb->s_flags & MS_RDONLY) &&
	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT);
		ext4_commit_super(sb, 1);
	}

	/*
	 * Get the # of file system overhead blocks from the
	 * superblock if present.
	 */
	if (es->s_overhead_clusters)
		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
	else {
		err = ext4_calculate_overhead(sb);
		if (err)
			goto failed_mount_wq;
	}

	/*
	 * The maximum number of concurrent works can be high and
	 * concurrency isn't really necessary.  Limit it to 1.
	 */
	EXT4_SB(sb)->rsv_conversion_wq =
		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
	if (!EXT4_SB(sb)->rsv_conversion_wq) {
		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
		ret = -ENOMEM;
		goto failed_mount4;
	}

	/*
	 * The jbd2_journal_load will have done any necessary log recovery,
	 * so we can safely mount the rest of the filesystem now.
	 */

	root = ext4_iget(sb, EXT4_ROOT_INO);
	if (IS_ERR(root)) {
		ext4_msg(sb, KERN_ERR, "get root inode failed");
		ret = PTR_ERR(root);
		root = NULL;
		goto failed_mount4;
	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
		iput(root);
		goto failed_mount4;
	}
	sb->s_root = d_make_root(root);
	if (!sb->s_root) {
		ext4_msg(sb, KERN_ERR, "get root dentry failed");
		ret = -ENOMEM;
		goto failed_mount4;
	}

	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
		sb->s_flags |= MS_RDONLY;

	/* determine the minimum size of new large inodes, if present */
	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
						     EXT4_GOOD_OLD_INODE_SIZE;
		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
			if (sbi->s_want_extra_isize <
			    le16_to_cpu(es->s_want_extra_isize))
				sbi->s_want_extra_isize =
					le16_to_cpu(es->s_want_extra_isize);
			if (sbi->s_want_extra_isize <
			    le16_to_cpu(es->s_min_extra_isize))
				sbi->s_want_extra_isize =
					le16_to_cpu(es->s_min_extra_isize);
		}
	}
	/* Check if enough inode space is available */
	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
							sbi->s_inode_size) {
		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
						       EXT4_GOOD_OLD_INODE_SIZE;
		ext4_msg(sb, KERN_INFO, "required extra inode space not"
			 "available");
	}

	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
	if (err) {
		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
			 "reserved pool", ext4_calculate_resv_clusters(sb));
		goto failed_mount4a;
	}

	err = ext4_setup_system_zone(sb);
	if (err) {
		ext4_msg(sb, KERN_ERR, "failed to initialize system "
			 "zone (%d)", err);
		goto failed_mount4a;
	}

	ext4_ext_init(sb);
	err = ext4_mb_init(sb);
	if (err) {
		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
			 err);
		goto failed_mount5;
	}

	block = ext4_count_free_clusters(sb);
	ext4_free_blocks_count_set(sbi->s_es, 
				   EXT4_C2B(sbi, block));
	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
				  GFP_KERNEL);
	if (!err) {
		unsigned long freei = ext4_count_free_inodes(sb);
		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
					  GFP_KERNEL);
	}
	if (!err)
		err = percpu_counter_init(&sbi->s_dirs_counter,
					  ext4_count_dirs(sb), GFP_KERNEL);
	if (!err)
		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
					  GFP_KERNEL);
	if (err) {
		ext4_msg(sb, KERN_ERR, "insufficient memory");
		goto failed_mount6;
	}

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
		if (!ext4_fill_flex_info(sb)) {
			ext4_msg(sb, KERN_ERR,
			       "unable to initialize "
			       "flex_bg meta info!");
			goto failed_mount6;
		}

	err = ext4_register_li_request(sb, first_not_zeroed);
	if (err)
		goto failed_mount6;

	sbi->s_kobj.kset = ext4_kset;
	init_completion(&sbi->s_kobj_unregister);
	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
				   "%s", sb->s_id);
	if (err)
		goto failed_mount7;

#ifdef CONFIG_QUOTA
	/* Enable quota usage during mount. */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
	    !(sb->s_flags & MS_RDONLY)) {
		err = ext4_enable_quotas(sb);
		if (err)
			goto failed_mount8;
	}
#endif  /* CONFIG_QUOTA */

	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
	ext4_orphan_cleanup(sb, es);
	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
	if (needs_recovery) {
		ext4_msg(sb, KERN_INFO, "recovery complete");
		ext4_mark_recovery_complete(sb, es);
	}
	if (EXT4_SB(sb)->s_journal) {
		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
			descr = " journalled data mode";
		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
			descr = " ordered data mode";
		else
			descr = " writeback data mode";
	} else
		descr = "out journal";

	if (test_opt(sb, DISCARD)) {
		struct request_queue *q = bdev_get_queue(sb->s_bdev);
		if (!blk_queue_discard(q))
			ext4_msg(sb, KERN_WARNING,
				 "mounting with \"discard\" option, but "
				 "the device does not support discard");
	}

	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);

	if (es->s_error_count)
		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */

	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);

	kfree(orig_data);
	return 0;

cantfind_ext4:
	if (!silent)
		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
	goto failed_mount;

#ifdef CONFIG_QUOTA
failed_mount8:
	kobject_del(&sbi->s_kobj);
#endif
failed_mount7:
	ext4_unregister_li_request(sb);
failed_mount6:
	ext4_mb_release(sb);
	if (sbi->s_flex_groups)
		kvfree(sbi->s_flex_groups);
	percpu_counter_destroy(&sbi->s_freeclusters_counter);
	percpu_counter_destroy(&sbi->s_freeinodes_counter);
	percpu_counter_destroy(&sbi->s_dirs_counter);
	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
failed_mount5:
	ext4_ext_release(sb);
	ext4_release_system_zone(sb);
failed_mount4a:
	dput(sb->s_root);
	sb->s_root = NULL;
failed_mount4:
	ext4_msg(sb, KERN_ERR, "mount failed");
	if (EXT4_SB(sb)->rsv_conversion_wq)
		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
failed_mount_wq:
	if (sbi->s_journal) {
		jbd2_journal_destroy(sbi->s_journal);
		sbi->s_journal = NULL;
	}
failed_mount3a:
	ext4_es_unregister_shrinker(sbi);
failed_mount3:
	del_timer_sync(&sbi->s_err_report);
	if (sbi->s_mmp_tsk)
		kthread_stop(sbi->s_mmp_tsk);
failed_mount2:
	for (i = 0; i < db_count; i++)
		brelse(sbi->s_group_desc[i]);
	kvfree(sbi->s_group_desc);
failed_mount:
	if (sbi->s_chksum_driver)
		crypto_free_shash(sbi->s_chksum_driver);
	if (sbi->s_proc) {
		remove_proc_entry("options", sbi->s_proc);
		remove_proc_entry(sb->s_id, ext4_proc_root);
	}
#ifdef CONFIG_QUOTA
	for (i = 0; i < EXT4_MAXQUOTAS; i++)
		kfree(sbi->s_qf_names[i]);
#endif
	ext4_blkdev_remove(sbi);
	brelse(bh);
out_fail:
	sb->s_fs_info = NULL;
	kfree(sbi->s_blockgroup_lock);
	kfree(sbi);
out_free_orig:
	kfree(orig_data);
	return err ? err : ret;
}

/*
 * Setup any per-fs journal parameters now.  We'll do this both on
 * initial mount, once the journal has been initialised but before we've
 * done any recovery; and again on any subsequent remount.
 */
static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	journal->j_commit_interval = sbi->s_commit_interval;
	journal->j_min_batch_time = sbi->s_min_batch_time;
	journal->j_max_batch_time = sbi->s_max_batch_time;

	write_lock(&journal->j_state_lock);
	if (test_opt(sb, BARRIER))
		journal->j_flags |= JBD2_BARRIER;
	else
		journal->j_flags &= ~JBD2_BARRIER;
	if (test_opt(sb, DATA_ERR_ABORT))
		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
	else
		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
	write_unlock(&journal->j_state_lock);
}

static journal_t *ext4_get_journal(struct super_block *sb,
				   unsigned int journal_inum)
{
	struct inode *journal_inode;
	journal_t *journal;

	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));

	/* First, test for the existence of a valid inode on disk.  Bad
	 * things happen if we iget() an unused inode, as the subsequent
	 * iput() will try to delete it. */

	journal_inode = ext4_iget(sb, journal_inum);
	if (IS_ERR(journal_inode)) {
		ext4_msg(sb, KERN_ERR, "no journal found");
		return NULL;
	}
	if (!journal_inode->i_nlink) {
		make_bad_inode(journal_inode);
		iput(journal_inode);
		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
		return NULL;
	}

	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
		  journal_inode, journal_inode->i_size);
	if (!S_ISREG(journal_inode->i_mode)) {
		ext4_msg(sb, KERN_ERR, "invalid journal inode");
		iput(journal_inode);
		return NULL;
	}

	journal = jbd2_journal_init_inode(journal_inode);
	if (!journal) {
		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
		iput(journal_inode);
		return NULL;
	}
	journal->j_private = sb;
	ext4_init_journal_params(sb, journal);
	return journal;
}

static journal_t *ext4_get_dev_journal(struct super_block *sb,
				       dev_t j_dev)
{
	struct buffer_head *bh;
	journal_t *journal;
	ext4_fsblk_t start;
	ext4_fsblk_t len;
	int hblock, blocksize;
	ext4_fsblk_t sb_block;
	unsigned long offset;
	struct ext4_super_block *es;
	struct block_device *bdev;

	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));

	bdev = ext4_blkdev_get(j_dev, sb);
	if (bdev == NULL)
		return NULL;

	blocksize = sb->s_blocksize;
	hblock = bdev_logical_block_size(bdev);
	if (blocksize < hblock) {
		ext4_msg(sb, KERN_ERR,
			"blocksize too small for journal device");
		goto out_bdev;
	}

	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
	set_blocksize(bdev, blocksize);
	if (!(bh = __bread(bdev, sb_block, blocksize))) {
		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
		       "external journal");
		goto out_bdev;
	}

	es = (struct ext4_super_block *) (bh->b_data + offset);
	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
	    !(le32_to_cpu(es->s_feature_incompat) &
	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
		ext4_msg(sb, KERN_ERR, "external journal has "
					"bad superblock");
		brelse(bh);
		goto out_bdev;
	}

	if ((le32_to_cpu(es->s_feature_ro_compat) &
	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
	    es->s_checksum != ext4_superblock_csum(sb, es)) {
		ext4_msg(sb, KERN_ERR, "external journal has "
				       "corrupt superblock");
		brelse(bh);
		goto out_bdev;
	}

	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
		brelse(bh);
		goto out_bdev;
	}

	len = ext4_blocks_count(es);
	start = sb_block + 1;
	brelse(bh);	/* we're done with the superblock */

	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
					start, len, blocksize);
	if (!journal) {
		ext4_msg(sb, KERN_ERR, "failed to create device journal");
		goto out_bdev;
	}
	journal->j_private = sb;
	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
	wait_on_buffer(journal->j_sb_buffer);
	if (!buffer_uptodate(journal->j_sb_buffer)) {
		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
		goto out_journal;
	}
	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
		ext4_msg(sb, KERN_ERR, "External journal has more than one "
					"user (unsupported) - %d",
			be32_to_cpu(journal->j_superblock->s_nr_users));
		goto out_journal;
	}
	EXT4_SB(sb)->journal_bdev = bdev;
	ext4_init_journal_params(sb, journal);
	return journal;

out_journal:
	jbd2_journal_destroy(journal);
out_bdev:
	ext4_blkdev_put(bdev);
	return NULL;
}

static int ext4_load_journal(struct super_block *sb,
			     struct ext4_super_block *es,
			     unsigned long journal_devnum)
{
	journal_t *journal;
	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
	dev_t journal_dev;
	int err = 0;
	int really_read_only;

	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));

	if (journal_devnum &&
	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
			"numbers have changed");
		journal_dev = new_decode_dev(journal_devnum);
	} else
		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));

	really_read_only = bdev_read_only(sb->s_bdev);

	/*
	 * Are we loading a blank journal or performing recovery after a
	 * crash?  For recovery, we need to check in advance whether we
	 * can get read-write access to the device.
	 */
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
		if (sb->s_flags & MS_RDONLY) {
			ext4_msg(sb, KERN_INFO, "INFO: recovery "
					"required on readonly filesystem");
			if (really_read_only) {
				ext4_msg(sb, KERN_ERR, "write access "
					"unavailable, cannot proceed");
				return -EROFS;
			}
			ext4_msg(sb, KERN_INFO, "write access will "
			       "be enabled during recovery");
		}
	}

	if (journal_inum && journal_dev) {
		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
		       "and inode journals!");
		return -EINVAL;
	}

	if (journal_inum) {
		if (!(journal = ext4_get_journal(sb, journal_inum)))
			return -EINVAL;
	} else {
		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
			return -EINVAL;
	}

	if (!(journal->j_flags & JBD2_BARRIER))
		ext4_msg(sb, KERN_INFO, "barriers disabled");

	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
		err = jbd2_journal_wipe(journal, !really_read_only);
	if (!err) {
		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
		if (save)
			memcpy(save, ((char *) es) +
			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
		err = jbd2_journal_load(journal);
		if (save)
			memcpy(((char *) es) + EXT4_S_ERR_START,
			       save, EXT4_S_ERR_LEN);
		kfree(save);
	}

	if (err) {
		ext4_msg(sb, KERN_ERR, "error loading journal");
		jbd2_journal_destroy(journal);
		return err;
	}

	EXT4_SB(sb)->s_journal = journal;
	ext4_clear_journal_err(sb, es);

	if (!really_read_only && journal_devnum &&
	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
		es->s_journal_dev = cpu_to_le32(journal_devnum);

		/* Make sure we flush the recovery flag to disk. */
		ext4_commit_super(sb, 1);
	}

	return 0;
}

static int ext4_commit_super(struct super_block *sb, int sync)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
	int error = 0;

	if (!sbh || block_device_ejected(sb))
		return error;
	if (buffer_write_io_error(sbh)) {
		/*
		 * Oh, dear.  A previous attempt to write the
		 * superblock failed.  This could happen because the
		 * USB device was yanked out.  Or it could happen to
		 * be a transient write error and maybe the block will
		 * be remapped.  Nothing we can do but to retry the
		 * write and hope for the best.
		 */
		ext4_msg(sb, KERN_ERR, "previous I/O error to "
		       "superblock detected");
		clear_buffer_write_io_error(sbh);
		set_buffer_uptodate(sbh);
	}
	/*
	 * If the file system is mounted read-only, don't update the
	 * superblock write time.  This avoids updating the superblock
	 * write time when we are mounting the root file system
	 * read/only but we need to replay the journal; at that point,
	 * for people who are east of GMT and who make their clock
	 * tick in localtime for Windows bug-for-bug compatibility,
	 * the clock is set in the future, and this will cause e2fsck
	 * to complain and force a full file system check.
	 */
	if (!(sb->s_flags & MS_RDONLY))
		es->s_wtime = cpu_to_le32(get_seconds());
	if (sb->s_bdev->bd_part)
		es->s_kbytes_written =
			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
	else
		es->s_kbytes_written =
			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
		ext4_free_blocks_count_set(es,
			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
				&EXT4_SB(sb)->s_freeclusters_counter)));
	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
		es->s_free_inodes_count =
			cpu_to_le32(percpu_counter_sum_positive(
				&EXT4_SB(sb)->s_freeinodes_counter));
	BUFFER_TRACE(sbh, "marking dirty");
	ext4_superblock_csum_set(sb);
	mark_buffer_dirty(sbh);
	if (sync) {
		error = sync_dirty_buffer(sbh);
		if (error)
			return error;

		error = buffer_write_io_error(sbh);
		if (error) {
			ext4_msg(sb, KERN_ERR, "I/O error while writing "
			       "superblock");
			clear_buffer_write_io_error(sbh);
			set_buffer_uptodate(sbh);
		}
	}
	return error;
}

/*
 * Have we just finished recovery?  If so, and if we are mounting (or
 * remounting) the filesystem readonly, then we will end up with a
 * consistent fs on disk.  Record that fact.
 */
static void ext4_mark_recovery_complete(struct super_block *sb,
					struct ext4_super_block *es)
{
	journal_t *journal = EXT4_SB(sb)->s_journal;

	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
		BUG_ON(journal != NULL);
		return;
	}
	jbd2_journal_lock_updates(journal);
	if (jbd2_journal_flush(journal) < 0)
		goto out;

	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
	    sb->s_flags & MS_RDONLY) {
		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
		ext4_commit_super(sb, 1);
	}

out:
	jbd2_journal_unlock_updates(journal);
}

/*
 * If we are mounting (or read-write remounting) a filesystem whose journal
 * has recorded an error from a previous lifetime, move that error to the
 * main filesystem now.
 */
static void ext4_clear_journal_err(struct super_block *sb,
				   struct ext4_super_block *es)
{
	journal_t *journal;
	int j_errno;
	const char *errstr;

	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));

	journal = EXT4_SB(sb)->s_journal;

	/*
	 * Now check for any error status which may have been recorded in the
	 * journal by a prior ext4_error() or ext4_abort()
	 */

	j_errno = jbd2_journal_errno(journal);
	if (j_errno) {
		char nbuf[16];

		errstr = ext4_decode_error(sb, j_errno, nbuf);
		ext4_warning(sb, "Filesystem error recorded "
			     "from previous mount: %s", errstr);
		ext4_warning(sb, "Marking fs in need of filesystem check.");

		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
		ext4_commit_super(sb, 1);

		jbd2_journal_clear_err(journal);
		jbd2_journal_update_sb_errno(journal);
	}
}

/*
 * Force the running and committing transactions to commit,
 * and wait on the commit.
 */
int ext4_force_commit(struct super_block *sb)
{
	journal_t *journal;

	if (sb->s_flags & MS_RDONLY)
		return 0;

	journal = EXT4_SB(sb)->s_journal;
	return ext4_journal_force_commit(journal);
}

static int ext4_sync_fs(struct super_block *sb, int wait)
{
	int ret = 0;
	tid_t target;
	bool needs_barrier = false;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	trace_ext4_sync_fs(sb, wait);
	flush_workqueue(sbi->rsv_conversion_wq);
	/*
	 * Writeback quota in non-journalled quota case - journalled quota has
	 * no dirty dquots
	 */
	dquot_writeback_dquots(sb, -1);
	/*
	 * Data writeback is possible w/o journal transaction, so barrier must
	 * being sent at the end of the function. But we can skip it if
	 * transaction_commit will do it for us.
	 */
	if (sbi->s_journal) {
		target = jbd2_get_latest_transaction(sbi->s_journal);
		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
			needs_barrier = true;

		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
			if (wait)
				ret = jbd2_log_wait_commit(sbi->s_journal,
							   target);
		}
	} else if (wait && test_opt(sb, BARRIER))
		needs_barrier = true;
	if (needs_barrier) {
		int err;
		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
		if (!ret)
			ret = err;
	}

	return ret;
}

/*
 * LVM calls this function before a (read-only) snapshot is created.  This
 * gives us a chance to flush the journal completely and mark the fs clean.
 *
 * Note that only this function cannot bring a filesystem to be in a clean
 * state independently. It relies on upper layer to stop all data & metadata
 * modifications.
 */
static int ext4_freeze(struct super_block *sb)
{
	int error = 0;
	journal_t *journal;

	if (sb->s_flags & MS_RDONLY)
		return 0;

	journal = EXT4_SB(sb)->s_journal;

	if (journal) {
		/* Now we set up the journal barrier. */
		jbd2_journal_lock_updates(journal);

		/*
		 * Don't clear the needs_recovery flag if we failed to
		 * flush the journal.
		 */
		error = jbd2_journal_flush(journal);
		if (error < 0)
			goto out;

		/* Journal blocked and flushed, clear needs_recovery flag. */
		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
	}

	error = ext4_commit_super(sb, 1);
out:
	if (journal)
		/* we rely on upper layer to stop further updates */
		jbd2_journal_unlock_updates(journal);
	return error;
}

/*
 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
 * flag here, even though the filesystem is not technically dirty yet.
 */
static int ext4_unfreeze(struct super_block *sb)
{
	if (sb->s_flags & MS_RDONLY)
		return 0;

	if (EXT4_SB(sb)->s_journal) {
		/* Reset the needs_recovery flag before the fs is unlocked. */
		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
	}

	ext4_commit_super(sb, 1);
	return 0;
}

/*
 * Structure to save mount options for ext4_remount's benefit
 */
struct ext4_mount_options {
	unsigned long s_mount_opt;
	unsigned long s_mount_opt2;
	kuid_t s_resuid;
	kgid_t s_resgid;
	unsigned long s_commit_interval;
	u32 s_min_batch_time, s_max_batch_time;
#ifdef CONFIG_QUOTA
	int s_jquota_fmt;
	char *s_qf_names[EXT4_MAXQUOTAS];
#endif
};

static int ext4_remount(struct super_block *sb, int *flags, char *data)
{
	struct ext4_super_block *es;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	unsigned long old_sb_flags;
	struct ext4_mount_options old_opts;
	int enable_quota = 0;
	ext4_group_t g;
	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
	int err = 0;
#ifdef CONFIG_QUOTA
	int i, j;
#endif
	char *orig_data = kstrdup(data, GFP_KERNEL);

	/* Store the original options */
	old_sb_flags = sb->s_flags;
	old_opts.s_mount_opt = sbi->s_mount_opt;
	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
	old_opts.s_resuid = sbi->s_resuid;
	old_opts.s_resgid = sbi->s_resgid;
	old_opts.s_commit_interval = sbi->s_commit_interval;
	old_opts.s_min_batch_time = sbi->s_min_batch_time;
	old_opts.s_max_batch_time = sbi->s_max_batch_time;
#ifdef CONFIG_QUOTA
	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
	for (i = 0; i < EXT4_MAXQUOTAS; i++)
		if (sbi->s_qf_names[i]) {
			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
							 GFP_KERNEL);
			if (!old_opts.s_qf_names[i]) {
				for (j = 0; j < i; j++)
					kfree(old_opts.s_qf_names[j]);
				kfree(orig_data);
				return -ENOMEM;
			}
		} else
			old_opts.s_qf_names[i] = NULL;
#endif
	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;

	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
		err = -EINVAL;
		goto restore_opts;
	}

	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
	    test_opt(sb, JOURNAL_CHECKSUM)) {
		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
			 "during remount not supported; ignoring");
		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
	}

	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and delalloc");
			err = -EINVAL;
			goto restore_opts;
		}
		if (test_opt(sb, DIOREAD_NOLOCK)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and dioread_nolock");
			err = -EINVAL;
			goto restore_opts;
		}
		if (test_opt(sb, DAX)) {
			ext4_msg(sb, KERN_ERR, "can't mount with "
				 "both data=journal and dax");
			err = -EINVAL;
			goto restore_opts;
		}
	}

	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
			"dax flag with busy inodes while remounting");
		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
	}

	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
		ext4_abort(sb, "Abort forced by user");

	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);

	es = sbi->s_es;

	if (sbi->s_journal) {
		ext4_init_journal_params(sb, sbi->s_journal);
		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
	}

	if (*flags & MS_LAZYTIME)
		sb->s_flags |= MS_LAZYTIME;

	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
			err = -EROFS;
			goto restore_opts;
		}

		if (*flags & MS_RDONLY) {
			err = sync_filesystem(sb);
			if (err < 0)
				goto restore_opts;
			err = dquot_suspend(sb, -1);
			if (err < 0)
				goto restore_opts;

			/*
			 * First of all, the unconditional stuff we have to do
			 * to disable replay of the journal when we next remount
			 */
			sb->s_flags |= MS_RDONLY;

			/*
			 * OK, test if we are remounting a valid rw partition
			 * readonly, and if so set the rdonly flag and then
			 * mark the partition as valid again.
			 */
			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
			    (sbi->s_mount_state & EXT4_VALID_FS))
				es->s_state = cpu_to_le16(sbi->s_mount_state);

			if (sbi->s_journal)
				ext4_mark_recovery_complete(sb, es);
		} else {
			/* Make sure we can mount this feature set readwrite */
			if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_READONLY) ||
			    !ext4_feature_set_ok(sb, 0)) {
				err = -EROFS;
				goto restore_opts;
			}
			/*
			 * Make sure the group descriptor checksums
			 * are sane.  If they aren't, refuse to remount r/w.
			 */
			for (g = 0; g < sbi->s_groups_count; g++) {
				struct ext4_group_desc *gdp =
					ext4_get_group_desc(sb, g, NULL);

				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
					ext4_msg(sb, KERN_ERR,
	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
					       le16_to_cpu(gdp->bg_checksum));
					err = -EINVAL;
					goto restore_opts;
				}
			}

			/*
			 * If we have an unprocessed orphan list hanging
			 * around from a previously readonly bdev mount,
			 * require a full umount/remount for now.
			 */
			if (es->s_last_orphan) {
				ext4_msg(sb, KERN_WARNING, "Couldn't "
				       "remount RDWR because of unprocessed "
				       "orphan inode list.  Please "
				       "umount/remount instead");
				err = -EINVAL;
				goto restore_opts;
			}

			/*
			 * Mounting a RDONLY partition read-write, so reread
			 * and store the current valid flag.  (It may have
			 * been changed by e2fsck since we originally mounted
			 * the partition.)
			 */
			if (sbi->s_journal)
				ext4_clear_journal_err(sb, es);
			sbi->s_mount_state = le16_to_cpu(es->s_state);
			if (!ext4_setup_super(sb, es, 0))
				sb->s_flags &= ~MS_RDONLY;
			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
						     EXT4_FEATURE_INCOMPAT_MMP))
				if (ext4_multi_mount_protect(sb,
						le64_to_cpu(es->s_mmp_block))) {
					err = -EROFS;
					goto restore_opts;
				}
			enable_quota = 1;
		}
	}

	/*
	 * Reinitialize lazy itable initialization thread based on
	 * current settings
	 */
	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
		ext4_unregister_li_request(sb);
	else {
		ext4_group_t first_not_zeroed;
		first_not_zeroed = ext4_has_uninit_itable(sb);
		ext4_register_li_request(sb, first_not_zeroed);
	}

	ext4_setup_system_zone(sb);
	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
		ext4_commit_super(sb, 1);

#ifdef CONFIG_QUOTA
	/* Release old quota file names */
	for (i = 0; i < EXT4_MAXQUOTAS; i++)
		kfree(old_opts.s_qf_names[i]);
	if (enable_quota) {
		if (sb_any_quota_suspended(sb))
			dquot_resume(sb, -1);
		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
			err = ext4_enable_quotas(sb);
			if (err)
				goto restore_opts;
		}
	}
#endif

	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
	kfree(orig_data);
	return 0;

restore_opts:
	sb->s_flags = old_sb_flags;
	sbi->s_mount_opt = old_opts.s_mount_opt;
	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
	sbi->s_resuid = old_opts.s_resuid;
	sbi->s_resgid = old_opts.s_resgid;
	sbi->s_commit_interval = old_opts.s_commit_interval;
	sbi->s_min_batch_time = old_opts.s_min_batch_time;
	sbi->s_max_batch_time = old_opts.s_max_batch_time;
#ifdef CONFIG_QUOTA
	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
		kfree(sbi->s_qf_names[i]);
		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
	}
#endif
	kfree(orig_data);
	return err;
}

static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	ext4_fsblk_t overhead = 0, resv_blocks;
	u64 fsid;
	s64 bfree;
	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));

	if (!test_opt(sb, MINIX_DF))
		overhead = sbi->s_overhead;

	buf->f_type = EXT4_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
	/* prevent underflow in case that few free space is available */
	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
	buf->f_bavail = buf->f_bfree -
			(ext4_r_blocks_count(es) + resv_blocks);
	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
		buf->f_bavail = 0;
	buf->f_files = le32_to_cpu(es->s_inodes_count);
	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
	buf->f_namelen = EXT4_NAME_LEN;
	fsid = le64_to_cpup((void *)es->s_uuid) ^
	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;

	return 0;
}

/* Helper function for writing quotas on sync - we need to start transaction
 * before quota file is locked for write. Otherwise the are possible deadlocks:
 * Process 1                         Process 2
 * ext4_create()                     quota_sync()
 *   jbd2_journal_start()                  write_dquot()
 *   dquot_initialize()                         down(dqio_mutex)
 *     down(dqio_mutex)                    jbd2_journal_start()
 *
 */

#ifdef CONFIG_QUOTA

static inline struct inode *dquot_to_inode(struct dquot *dquot)
{
	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
}

static int ext4_write_dquot(struct dquot *dquot)
{
	int ret, err;
	handle_t *handle;
	struct inode *inode;

	inode = dquot_to_inode(dquot);
	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);
	ret = dquot_commit(dquot);
	err = ext4_journal_stop(handle);
	if (!ret)
		ret = err;
	return ret;
}

static int ext4_acquire_dquot(struct dquot *dquot)
{
	int ret, err;
	handle_t *handle;

	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);
	ret = dquot_acquire(dquot);
	err = ext4_journal_stop(handle);
	if (!ret)
		ret = err;
	return ret;
}

static int ext4_release_dquot(struct dquot *dquot)
{
	int ret, err;
	handle_t *handle;

	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
	if (IS_ERR(handle)) {
		/* Release dquot anyway to avoid endless cycle in dqput() */
		dquot_release(dquot);
		return PTR_ERR(handle);
	}
	ret = dquot_release(dquot);
	err = ext4_journal_stop(handle);
	if (!ret)
		ret = err;
	return ret;
}

static int ext4_mark_dquot_dirty(struct dquot *dquot)
{
	struct super_block *sb = dquot->dq_sb;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	/* Are we journaling quotas? */
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
		dquot_mark_dquot_dirty(dquot);
		return ext4_write_dquot(dquot);
	} else {
		return dquot_mark_dquot_dirty(dquot);
	}
}

static int ext4_write_info(struct super_block *sb, int type)
{
	int ret, err;
	handle_t *handle;

	/* Data block + inode block */
	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
	if (IS_ERR(handle))
		return PTR_ERR(handle);
	ret = dquot_commit_info(sb, type);
	err = ext4_journal_stop(handle);
	if (!ret)
		ret = err;
	return ret;
}

/*
 * Turn on quotas during mount time - we need to find
 * the quota file and such...
 */
static int ext4_quota_on_mount(struct super_block *sb, int type)
{
	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
					EXT4_SB(sb)->s_jquota_fmt, type);
}

static void lockdep_set_quota_inode(struct inode *inode, int subclass)
{
	struct ext4_inode_info *ei = EXT4_I(inode);

	/* The first argument of lockdep_set_subclass has to be
	 * *exactly* the same as the argument to init_rwsem() --- in
	 * this case, in init_once() --- or lockdep gets unhappy
	 * because the name of the lock is set using the
	 * stringification of the argument to init_rwsem().
	 */
	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
	lockdep_set_subclass(&ei->i_data_sem, subclass);
}

/*
 * Standard function to be called on quota_on
 */
static int ext4_quota_on(struct super_block *sb, int type, int format_id,
			 struct path *path)
{
	int err;

	if (!test_opt(sb, QUOTA))
		return -EINVAL;

	/* Quotafile not on the same filesystem? */
	if (path->dentry->d_sb != sb)
		return -EXDEV;
	/* Journaling quota? */
	if (EXT4_SB(sb)->s_qf_names[type]) {
		/* Quotafile not in fs root? */
		if (path->dentry->d_parent != sb->s_root)
			ext4_msg(sb, KERN_WARNING,
				"Quota file not on filesystem root. "
				"Journaled quota will not work");
	}

	/*
	 * When we journal data on quota file, we have to flush journal to see
	 * all updates to the file when we bypass pagecache...
	 */
	if (EXT4_SB(sb)->s_journal &&
	    ext4_should_journal_data(d_inode(path->dentry))) {
		/*
		 * We don't need to lock updates but journal_flush() could
		 * otherwise be livelocked...
		 */
		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
		if (err)
			return err;
	}
	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
	err = dquot_quota_on(sb, type, format_id, path);
	if (err)
		lockdep_set_quota_inode(path->dentry->d_inode,
					     I_DATA_SEM_NORMAL);
	return err;
}

static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
			     unsigned int flags)
{
	int err;
	struct inode *qf_inode;
	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
	};

	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));

	if (!qf_inums[type])
		return -EPERM;

	qf_inode = ext4_iget(sb, qf_inums[type]);
	if (IS_ERR(qf_inode)) {
		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
		return PTR_ERR(qf_inode);
	}

	/* Don't account quota for quota files to avoid recursion */
	qf_inode->i_flags |= S_NOQUOTA;
	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
	err = dquot_enable(qf_inode, type, format_id, flags);
	iput(qf_inode);
	if (err)
		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);

	return err;
}

/* Enable usage tracking for all quota types. */
static int ext4_enable_quotas(struct super_block *sb)
{
	int type, err = 0;
	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
	};

	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
		if (qf_inums[type]) {
			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
						DQUOT_USAGE_ENABLED);
			if (err) {
				ext4_warning(sb,
					"Failed to enable quota tracking "
					"(type=%d, err=%d). Please run "
					"e2fsck to fix.", type, err);
				return err;
			}
		}
	}
	return 0;
}

static int ext4_quota_off(struct super_block *sb, int type)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	handle_t *handle;

	/* Force all delayed allocation blocks to be allocated.
	 * Caller already holds s_umount sem */
	if (test_opt(sb, DELALLOC))
		sync_filesystem(sb);

	if (!inode)
		goto out;

	/* Update modification times of quota files when userspace can
	 * start looking at them */
	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
	if (IS_ERR(handle))
		goto out;
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	ext4_mark_inode_dirty(handle, inode);
	ext4_journal_stop(handle);

out:
	return dquot_quota_off(sb, type);
}

/* Read data from quotafile - avoid pagecache and such because we cannot afford
 * acquiring the locks... As quota files are never truncated and quota code
 * itself serializes the operations (and no one else should touch the files)
 * we don't have to be afraid of races */
static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
			       size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
	int offset = off & (sb->s_blocksize - 1);
	int tocopy;
	size_t toread;
	struct buffer_head *bh;
	loff_t i_size = i_size_read(inode);

	if (off > i_size)
		return 0;
	if (off+len > i_size)
		len = i_size-off;
	toread = len;
	while (toread > 0) {
		tocopy = sb->s_blocksize - offset < toread ?
				sb->s_blocksize - offset : toread;
		bh = ext4_bread(NULL, inode, blk, 0);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
		if (!bh)	/* A hole? */
			memset(data, 0, tocopy);
		else
			memcpy(data, bh->b_data+offset, tocopy);
		brelse(bh);
		offset = 0;
		toread -= tocopy;
		data += tocopy;
		blk++;
	}
	return len;
}

/* Write to quotafile (we know the transaction is already started and has
 * enough credits) */
static ssize_t ext4_quota_write(struct super_block *sb, int type,
				const char *data, size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
	int err, offset = off & (sb->s_blocksize - 1);
	struct buffer_head *bh;
	handle_t *handle = journal_current_handle();

	if (EXT4_SB(sb)->s_journal && !handle) {
		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
			" cancelled because transaction is not started",
			(unsigned long long)off, (unsigned long long)len);
		return -EIO;
	}
	/*
	 * Since we account only one data block in transaction credits,
	 * then it is impossible to cross a block boundary.
	 */
	if (sb->s_blocksize - offset < len) {
		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
			" cancelled because not block aligned",
			(unsigned long long)off, (unsigned long long)len);
		return -EIO;
	}

	bh = ext4_bread(handle, inode, blk, 1);
	if (IS_ERR(bh))
		return PTR_ERR(bh);
	if (!bh)
		goto out;
	BUFFER_TRACE(bh, "get write access");
	err = ext4_journal_get_write_access(handle, bh);
	if (err) {
		brelse(bh);
		return err;
	}
	lock_buffer(bh);
	memcpy(bh->b_data+offset, data, len);
	flush_dcache_page(bh->b_page);
	unlock_buffer(bh);
	err = ext4_handle_dirty_metadata(handle, NULL, bh);
	brelse(bh);
out:
	if (inode->i_size < off + len) {
		i_size_write(inode, off + len);
		EXT4_I(inode)->i_disksize = inode->i_size;
		ext4_mark_inode_dirty(handle, inode);
	}
	return len;
}

#endif

static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
		       const char *dev_name, void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
}

#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
static inline void register_as_ext2(void)
{
	int err = register_filesystem(&ext2_fs_type);
	if (err)
		printk(KERN_WARNING
		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
}

static inline void unregister_as_ext2(void)
{
	unregister_filesystem(&ext2_fs_type);
}

static inline int ext2_feature_set_ok(struct super_block *sb)
{
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
		return 0;
	if (sb->s_flags & MS_RDONLY)
		return 1;
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
		return 0;
	return 1;
}
#else
static inline void register_as_ext2(void) { }
static inline void unregister_as_ext2(void) { }
static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
#endif

#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
static inline void register_as_ext3(void)
{
	int err = register_filesystem(&ext3_fs_type);
	if (err)
		printk(KERN_WARNING
		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
}

static inline void unregister_as_ext3(void)
{
	unregister_filesystem(&ext3_fs_type);
}

static inline int ext3_feature_set_ok(struct super_block *sb)
{
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
		return 0;
	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
		return 0;
	if (sb->s_flags & MS_RDONLY)
		return 1;
	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
		return 0;
	return 1;
}
#else
static inline void register_as_ext3(void) { }
static inline void unregister_as_ext3(void) { }
static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
#endif

static struct file_system_type ext4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "ext4",
	.mount		= ext4_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("ext4");

static int __init ext4_init_feat_adverts(void)
{
	struct ext4_features *ef;
	int ret = -ENOMEM;

	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
	if (!ef)
		goto out;

	ef->f_kobj.kset = ext4_kset;
	init_completion(&ef->f_kobj_unregister);
	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
				   "features");
	if (ret) {
		kfree(ef);
		goto out;
	}

	ext4_feat = ef;
	ret = 0;
out:
	return ret;
}

static void ext4_exit_feat_adverts(void)
{
	kobject_put(&ext4_feat->f_kobj);
	wait_for_completion(&ext4_feat->f_kobj_unregister);
	kfree(ext4_feat);
}

/* Shared across all ext4 file systems */
wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];

static int __init ext4_init_fs(void)
{
	int i, err;

	ext4_li_info = NULL;
	mutex_init(&ext4_li_mtx);

	/* Build-time check for flags consistency */
	ext4_check_flag_values();

	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
		mutex_init(&ext4__aio_mutex[i]);
		init_waitqueue_head(&ext4__ioend_wq[i]);
	}

	err = ext4_init_es();
	if (err)
		return err;

	err = ext4_init_pageio();
	if (err)
		goto out7;

	err = ext4_init_system_zone();
	if (err)
		goto out6;
	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
	if (!ext4_kset) {
		err = -ENOMEM;
		goto out5;
	}
	ext4_proc_root = proc_mkdir("fs/ext4", NULL);

	err = ext4_init_feat_adverts();
	if (err)
		goto out4;

	err = ext4_init_mballoc();
	if (err)
		goto out2;
	else
		ext4_mballoc_ready = 1;
	err = init_inodecache();
	if (err)
		goto out1;
	register_as_ext3();
	register_as_ext2();
	err = register_filesystem(&ext4_fs_type);
	if (err)
		goto out;

	return 0;
out:
	unregister_as_ext2();
	unregister_as_ext3();
	destroy_inodecache();
out1:
	ext4_mballoc_ready = 0;
	ext4_exit_mballoc();
out2:
	ext4_exit_feat_adverts();
out4:
	if (ext4_proc_root)
		remove_proc_entry("fs/ext4", NULL);
	kset_unregister(ext4_kset);
out5:
	ext4_exit_system_zone();
out6:
	ext4_exit_pageio();
out7:
	ext4_exit_es();

	return err;
}

static void __exit ext4_exit_fs(void)
{
	ext4_destroy_lazyinit_thread();
	unregister_as_ext2();
	unregister_as_ext3();
	unregister_filesystem(&ext4_fs_type);
	destroy_inodecache();
	ext4_exit_mballoc();
	ext4_exit_feat_adverts();
	remove_proc_entry("fs/ext4", NULL);
	kset_unregister(ext4_kset);
	ext4_exit_system_zone();
	ext4_exit_pageio();
	ext4_exit_es();
}

MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
MODULE_DESCRIPTION("Fourth Extended Filesystem");
MODULE_LICENSE("GPL");
module_init(ext4_init_fs)
module_exit(ext4_exit_fs)