Linux preempt-rt

Check our new training course

Real-Time Linux with PREEMPT_RT

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

   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
/*
 * QEMU disk image utility
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qapi-visit.h"
#include "qapi/qmp-output-visitor.h"
#include "qapi/qmp/qjson.h"
#include "qemu-common.h"
#include "qemu/option.h"
#include "qemu/error-report.h"
#include "qemu/osdep.h"
#include "sysemu/sysemu.h"
#include "sysemu/block-backend.h"
#include "block/block_int.h"
#include "block/blockjob.h"
#include "block/qapi.h"
#include <getopt.h>

#define QEMU_IMG_VERSION "qemu-img version " QEMU_VERSION \
                          ", Copyright (c) 2004-2008 Fabrice Bellard\n"

typedef struct img_cmd_t {
    const char *name;
    int (*handler)(int argc, char **argv);
} img_cmd_t;

enum {
    OPTION_OUTPUT = 256,
    OPTION_BACKING_CHAIN = 257,
};

typedef enum OutputFormat {
    OFORMAT_JSON,
    OFORMAT_HUMAN,
} OutputFormat;

/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
#define BDRV_O_FLAGS BDRV_O_CACHE_WB
#define BDRV_DEFAULT_CACHE "writeback"

static void format_print(void *opaque, const char *name)
{
    printf(" %s", name);
}

static void QEMU_NORETURN GCC_FMT_ATTR(1, 2) error_exit(const char *fmt, ...)
{
    va_list ap;

    error_printf("qemu-img: ");

    va_start(ap, fmt);
    error_vprintf(fmt, ap);
    va_end(ap);

    error_printf("\nTry 'qemu-img --help' for more information\n");
    exit(EXIT_FAILURE);
}

/* Please keep in synch with qemu-img.texi */
static void QEMU_NORETURN help(void)
{
    const char *help_msg =
           QEMU_IMG_VERSION
           "usage: qemu-img command [command options]\n"
           "QEMU disk image utility\n"
           "\n"
           "Command syntax:\n"
#define DEF(option, callback, arg_string)        \
           "  " arg_string "\n"
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
           "\n"
           "Command parameters:\n"
           "  'filename' is a disk image filename\n"
           "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
           "  'cache' is the cache mode used to write the output disk image, the valid\n"
           "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
           "    'directsync' and 'unsafe' (default for convert)\n"
           "  'src_cache' is the cache mode used to read input disk images, the valid\n"
           "    options are the same as for the 'cache' option\n"
           "  'size' is the disk image size in bytes. Optional suffixes\n"
           "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
           "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"
           "    supported. 'b' is ignored.\n"
           "  'output_filename' is the destination disk image filename\n"
           "  'output_fmt' is the destination format\n"
           "  'options' is a comma separated list of format specific options in a\n"
           "    name=value format. Use -o ? for an overview of the options supported by the\n"
           "    used format\n"
           "  'snapshot_param' is param used for internal snapshot, format\n"
           "    is 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
           "    '[ID_OR_NAME]'\n"
           "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
           "    instead\n"
           "  '-c' indicates that target image must be compressed (qcow format only)\n"
           "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
           "       match exactly. The image doesn't need a working backing file before\n"
           "       rebasing in this case (useful for renaming the backing file)\n"
           "  '-h' with or without a command shows this help and lists the supported formats\n"
           "  '-p' show progress of command (only certain commands)\n"
           "  '-q' use Quiet mode - do not print any output (except errors)\n"
           "  '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
           "       contain only zeros for qemu-img to create a sparse image during\n"
           "       conversion. If the number of bytes is 0, the source will not be scanned for\n"
           "       unallocated or zero sectors, and the destination image will always be\n"
           "       fully allocated\n"
           "  '--output' takes the format in which the output must be done (human or json)\n"
           "  '-n' skips the target volume creation (useful if the volume is created\n"
           "       prior to running qemu-img)\n"
           "\n"
           "Parameters to check subcommand:\n"
           "  '-r' tries to repair any inconsistencies that are found during the check.\n"
           "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
           "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
           "       hiding corruption that has already occurred.\n"
           "\n"
           "Parameters to snapshot subcommand:\n"
           "  'snapshot' is the name of the snapshot to create, apply or delete\n"
           "  '-a' applies a snapshot (revert disk to saved state)\n"
           "  '-c' creates a snapshot\n"
           "  '-d' deletes a snapshot\n"
           "  '-l' lists all snapshots in the given image\n"
           "\n"
           "Parameters to compare subcommand:\n"
           "  '-f' first image format\n"
           "  '-F' second image format\n"
           "  '-s' run in Strict mode - fail on different image size or sector allocation\n";

    printf("%s\nSupported formats:", help_msg);
    bdrv_iterate_format(format_print, NULL);
    printf("\n");
    exit(EXIT_SUCCESS);
}

static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
{
    int ret = 0;
    if (!quiet) {
        va_list args;
        va_start(args, fmt);
        ret = vprintf(fmt, args);
        va_end(args);
    }
    return ret;
}

#if defined(WIN32)
/* XXX: put correct support for win32 */
static int read_password(char *buf, int buf_size)
{
    int c, i;

    printf("Password: ");
    fflush(stdout);
    i = 0;
    for(;;) {
        c = getchar();
        if (c < 0) {
            buf[i] = '\0';
            return -1;
        } else if (c == '\n') {
            break;
        } else if (i < (buf_size - 1)) {
            buf[i++] = c;
        }
    }
    buf[i] = '\0';
    return 0;
}

#else

#include <termios.h>

static struct termios oldtty;

static void term_exit(void)
{
    tcsetattr (0, TCSANOW, &oldtty);
}

static void term_init(void)
{
    struct termios tty;

    tcgetattr (0, &tty);
    oldtty = tty;

    tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
                          |INLCR|IGNCR|ICRNL|IXON);
    tty.c_oflag |= OPOST;
    tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
    tty.c_cflag &= ~(CSIZE|PARENB);
    tty.c_cflag |= CS8;
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;

    tcsetattr (0, TCSANOW, &tty);

    atexit(term_exit);
}

static int read_password(char *buf, int buf_size)
{
    uint8_t ch;
    int i, ret;

    printf("password: ");
    fflush(stdout);
    term_init();
    i = 0;
    for(;;) {
        ret = read(0, &ch, 1);
        if (ret == -1) {
            if (errno == EAGAIN || errno == EINTR) {
                continue;
            } else {
                break;
            }
        } else if (ret == 0) {
            ret = -1;
            break;
        } else {
            if (ch == '\r') {
                ret = 0;
                break;
            }
            if (i < (buf_size - 1))
                buf[i++] = ch;
        }
    }
    term_exit();
    buf[i] = '\0';
    printf("\n");
    return ret;
}
#endif

static int print_block_option_help(const char *filename, const char *fmt)
{
    BlockDriver *drv, *proto_drv;
    QemuOptsList *create_opts = NULL;

    /* Find driver and parse its options */
    drv = bdrv_find_format(fmt);
    if (!drv) {
        error_report("Unknown file format '%s'", fmt);
        return 1;
    }

    create_opts = qemu_opts_append(create_opts, drv->create_opts);
    if (filename) {
        proto_drv = bdrv_find_protocol(filename, true);
        if (!proto_drv) {
            error_report("Unknown protocol '%s'", filename);
            qemu_opts_free(create_opts);
            return 1;
        }
        create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
    }

    qemu_opts_print_help(create_opts);
    qemu_opts_free(create_opts);
    return 0;
}

static BlockBackend *img_open(const char *id, const char *filename,
                              const char *fmt, int flags,
                              bool require_io, bool quiet)
{
    BlockBackend *blk;
    BlockDriverState *bs;
    BlockDriver *drv;
    char password[256];
    Error *local_err = NULL;
    int ret;

    blk = blk_new_with_bs(id, &error_abort);
    bs = blk_bs(blk);

    if (fmt) {
        drv = bdrv_find_format(fmt);
        if (!drv) {
            error_report("Unknown file format '%s'", fmt);
            goto fail;
        }
    } else {
        drv = NULL;
    }

    ret = bdrv_open(&bs, filename, NULL, NULL, flags, drv, &local_err);
    if (ret < 0) {
        error_report("Could not open '%s': %s", filename,
                     error_get_pretty(local_err));
        error_free(local_err);
        goto fail;
    }

    if (bdrv_is_encrypted(bs) && require_io) {
        qprintf(quiet, "Disk image '%s' is encrypted.\n", filename);
        if (read_password(password, sizeof(password)) < 0) {
            error_report("No password given");
            goto fail;
        }
        if (bdrv_set_key(bs, password) < 0) {
            error_report("invalid password");
            goto fail;
        }
    }
    return blk;
fail:
    blk_unref(blk);
    return NULL;
}

static int add_old_style_options(const char *fmt, QemuOpts *opts,
                                 const char *base_filename,
                                 const char *base_fmt)
{
    if (base_filename) {
        if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename)) {
            error_report("Backing file not supported for file format '%s'",
                         fmt);
            return -1;
        }
    }
    if (base_fmt) {
        if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt)) {
            error_report("Backing file format not supported for file "
                         "format '%s'", fmt);
            return -1;
        }
    }
    return 0;
}

static int img_create(int argc, char **argv)
{
    int c;
    uint64_t img_size = -1;
    const char *fmt = "raw";
    const char *base_fmt = NULL;
    const char *filename;
    const char *base_filename = NULL;
    char *options = NULL;
    Error *local_err = NULL;
    bool quiet = false;

    for(;;) {
        c = getopt(argc, argv, "F:b:f:he6o:q");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'F':
            base_fmt = optarg;
            break;
        case 'b':
            base_filename = optarg;
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'e':
            error_report("option -e is deprecated, please use \'-o "
                  "encryption\' instead!");
            goto fail;
        case '6':
            error_report("option -6 is deprecated, please use \'-o "
                  "compat6\' instead!");
            goto fail;
        case 'o':
            if (!is_valid_option_list(optarg)) {
                error_report("Invalid option list: %s", optarg);
                goto fail;
            }
            if (!options) {
                options = g_strdup(optarg);
            } else {
                char *old_options = options;
                options = g_strdup_printf("%s,%s", options, optarg);
                g_free(old_options);
            }
            break;
        case 'q':
            quiet = true;
            break;
        }
    }

    /* Get the filename */
    filename = (optind < argc) ? argv[optind] : NULL;
    if (options && has_help_option(options)) {
        g_free(options);
        return print_block_option_help(filename, fmt);
    }

    if (optind >= argc) {
        error_exit("Expecting image file name");
    }
    optind++;

    /* Get image size, if specified */
    if (optind < argc) {
        int64_t sval;
        char *end;
        sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
        if (sval < 0 || *end) {
            if (sval == -ERANGE) {
                error_report("Image size must be less than 8 EiB!");
            } else {
                error_report("Invalid image size specified! You may use k, M, "
                      "G, T, P or E suffixes for ");
                error_report("kilobytes, megabytes, gigabytes, terabytes, "
                             "petabytes and exabytes.");
            }
            goto fail;
        }
        img_size = (uint64_t)sval;
    }
    if (optind != argc) {
        error_exit("Unexpected argument: %s", argv[optind]);
    }

    bdrv_img_create(filename, fmt, base_filename, base_fmt,
                    options, img_size, BDRV_O_FLAGS, &local_err, quiet);
    if (local_err) {
        error_report("%s: %s", filename, error_get_pretty(local_err));
        error_free(local_err);
        goto fail;
    }

    g_free(options);
    return 0;

fail:
    g_free(options);
    return 1;
}

static void dump_json_image_check(ImageCheck *check, bool quiet)
{
    Error *local_err = NULL;
    QString *str;
    QmpOutputVisitor *ov = qmp_output_visitor_new();
    QObject *obj;
    visit_type_ImageCheck(qmp_output_get_visitor(ov),
                          &check, NULL, &local_err);
    obj = qmp_output_get_qobject(ov);
    str = qobject_to_json_pretty(obj);
    assert(str != NULL);
    qprintf(quiet, "%s\n", qstring_get_str(str));
    qobject_decref(obj);
    qmp_output_visitor_cleanup(ov);
    QDECREF(str);
}

static void dump_human_image_check(ImageCheck *check, bool quiet)
{
    if (!(check->corruptions || check->leaks || check->check_errors)) {
        qprintf(quiet, "No errors were found on the image.\n");
    } else {
        if (check->corruptions) {
            qprintf(quiet, "\n%" PRId64 " errors were found on the image.\n"
                    "Data may be corrupted, or further writes to the image "
                    "may corrupt it.\n",
                    check->corruptions);
        }

        if (check->leaks) {
            qprintf(quiet,
                    "\n%" PRId64 " leaked clusters were found on the image.\n"
                    "This means waste of disk space, but no harm to data.\n",
                    check->leaks);
        }

        if (check->check_errors) {
            qprintf(quiet,
                    "\n%" PRId64
                    " internal errors have occurred during the check.\n",
                    check->check_errors);
        }
    }

    if (check->total_clusters != 0 && check->allocated_clusters != 0) {
        qprintf(quiet, "%" PRId64 "/%" PRId64 " = %0.2f%% allocated, "
                "%0.2f%% fragmented, %0.2f%% compressed clusters\n",
                check->allocated_clusters, check->total_clusters,
                check->allocated_clusters * 100.0 / check->total_clusters,
                check->fragmented_clusters * 100.0 / check->allocated_clusters,
                check->compressed_clusters * 100.0 /
                check->allocated_clusters);
    }

    if (check->image_end_offset) {
        qprintf(quiet,
                "Image end offset: %" PRId64 "\n", check->image_end_offset);
    }
}

static int collect_image_check(BlockDriverState *bs,
                   ImageCheck *check,
                   const char *filename,
                   const char *fmt,
                   int fix)
{
    int ret;
    BdrvCheckResult result;

    ret = bdrv_check(bs, &result, fix);
    if (ret < 0) {
        return ret;
    }

    check->filename                 = g_strdup(filename);
    check->format                   = g_strdup(bdrv_get_format_name(bs));
    check->check_errors             = result.check_errors;
    check->corruptions              = result.corruptions;
    check->has_corruptions          = result.corruptions != 0;
    check->leaks                    = result.leaks;
    check->has_leaks                = result.leaks != 0;
    check->corruptions_fixed        = result.corruptions_fixed;
    check->has_corruptions_fixed    = result.corruptions != 0;
    check->leaks_fixed              = result.leaks_fixed;
    check->has_leaks_fixed          = result.leaks != 0;
    check->image_end_offset         = result.image_end_offset;
    check->has_image_end_offset     = result.image_end_offset != 0;
    check->total_clusters           = result.bfi.total_clusters;
    check->has_total_clusters       = result.bfi.total_clusters != 0;
    check->allocated_clusters       = result.bfi.allocated_clusters;
    check->has_allocated_clusters   = result.bfi.allocated_clusters != 0;
    check->fragmented_clusters      = result.bfi.fragmented_clusters;
    check->has_fragmented_clusters  = result.bfi.fragmented_clusters != 0;
    check->compressed_clusters      = result.bfi.compressed_clusters;
    check->has_compressed_clusters  = result.bfi.compressed_clusters != 0;

    return 0;
}

/*
 * Checks an image for consistency. Exit codes:
 *
 *  0 - Check completed, image is good
 *  1 - Check not completed because of internal errors
 *  2 - Check completed, image is corrupted
 *  3 - Check completed, image has leaked clusters, but is good otherwise
 * 63 - Checks are not supported by the image format
 */
static int img_check(int argc, char **argv)
{
    int c, ret;
    OutputFormat output_format = OFORMAT_HUMAN;
    const char *filename, *fmt, *output, *cache;
    BlockBackend *blk;
    BlockDriverState *bs;
    int fix = 0;
    int flags = BDRV_O_FLAGS | BDRV_O_CHECK;
    ImageCheck *check;
    bool quiet = false;

    fmt = NULL;
    output = NULL;
    cache = BDRV_DEFAULT_CACHE;
    for(;;) {
        int option_index = 0;
        static const struct option long_options[] = {
            {"help", no_argument, 0, 'h'},
            {"format", required_argument, 0, 'f'},
            {"repair", required_argument, 0, 'r'},
            {"output", required_argument, 0, OPTION_OUTPUT},
            {0, 0, 0, 0}
        };
        c = getopt_long(argc, argv, "hf:r:T:q",
                        long_options, &option_index);
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'r':
            flags |= BDRV_O_RDWR;

            if (!strcmp(optarg, "leaks")) {
                fix = BDRV_FIX_LEAKS;
            } else if (!strcmp(optarg, "all")) {
                fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
            } else {
                error_exit("Unknown option value for -r "
                           "(expecting 'leaks' or 'all'): %s", optarg);
            }
            break;
        case OPTION_OUTPUT:
            output = optarg;
            break;
        case 'T':
            cache = optarg;
            break;
        case 'q':
            quiet = true;
            break;
        }
    }
    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind++];

    if (output && !strcmp(output, "json")) {
        output_format = OFORMAT_JSON;
    } else if (output && !strcmp(output, "human")) {
        output_format = OFORMAT_HUMAN;
    } else if (output) {
        error_report("--output must be used with human or json as argument.");
        return 1;
    }

    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid source cache option: %s", cache);
        return 1;
    }

    blk = img_open("image", filename, fmt, flags, true, quiet);
    if (!blk) {
        return 1;
    }
    bs = blk_bs(blk);

    check = g_new0(ImageCheck, 1);
    ret = collect_image_check(bs, check, filename, fmt, fix);

    if (ret == -ENOTSUP) {
        error_report("This image format does not support checks");
        ret = 63;
        goto fail;
    }

    if (check->corruptions_fixed || check->leaks_fixed) {
        int corruptions_fixed, leaks_fixed;

        leaks_fixed         = check->leaks_fixed;
        corruptions_fixed   = check->corruptions_fixed;

        if (output_format == OFORMAT_HUMAN) {
            qprintf(quiet,
                    "The following inconsistencies were found and repaired:\n\n"
                    "    %" PRId64 " leaked clusters\n"
                    "    %" PRId64 " corruptions\n\n"
                    "Double checking the fixed image now...\n",
                    check->leaks_fixed,
                    check->corruptions_fixed);
        }

        ret = collect_image_check(bs, check, filename, fmt, 0);

        check->leaks_fixed          = leaks_fixed;
        check->corruptions_fixed    = corruptions_fixed;
    }

    if (!ret) {
        switch (output_format) {
        case OFORMAT_HUMAN:
            dump_human_image_check(check, quiet);
            break;
        case OFORMAT_JSON:
            dump_json_image_check(check, quiet);
            break;
        }
    }

    if (ret || check->check_errors) {
        if (ret) {
            error_report("Check failed: %s", strerror(-ret));
        } else {
            error_report("Check failed");
        }
        ret = 1;
        goto fail;
    }

    if (check->corruptions) {
        ret = 2;
    } else if (check->leaks) {
        ret = 3;
    } else {
        ret = 0;
    }

fail:
    qapi_free_ImageCheck(check);
    blk_unref(blk);
    return ret;
}

typedef struct CommonBlockJobCBInfo {
    BlockDriverState *bs;
    Error **errp;
} CommonBlockJobCBInfo;

static void common_block_job_cb(void *opaque, int ret)
{
    CommonBlockJobCBInfo *cbi = opaque;

    if (ret < 0) {
        error_setg_errno(cbi->errp, -ret, "Block job failed");
    }

    /* Drop this block job's reference */
    bdrv_unref(cbi->bs);
}

static void run_block_job(BlockJob *job, Error **errp)
{
    AioContext *aio_context = bdrv_get_aio_context(job->bs);

    do {
        aio_poll(aio_context, true);
        qemu_progress_print((float)job->offset / job->len * 100.f, 0);
    } while (!job->ready);

    block_job_complete_sync(job, errp);

    /* A block job may finish instantaneously without publishing any progress,
     * so just signal completion here */
    qemu_progress_print(100.f, 0);
}

static int img_commit(int argc, char **argv)
{
    int c, ret, flags;
    const char *filename, *fmt, *cache, *base;
    BlockBackend *blk;
    BlockDriverState *bs, *base_bs;
    bool progress = false, quiet = false, drop = false;
    Error *local_err = NULL;
    CommonBlockJobCBInfo cbi;

    fmt = NULL;
    cache = BDRV_DEFAULT_CACHE;
    base = NULL;
    for(;;) {
        c = getopt(argc, argv, "f:ht:b:dpq");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case 't':
            cache = optarg;
            break;
        case 'b':
            base = optarg;
            /* -b implies -d */
            drop = true;
            break;
        case 'd':
            drop = true;
            break;
        case 'p':
            progress = true;
            break;
        case 'q':
            quiet = true;
            break;
        }
    }

    /* Progress is not shown in Quiet mode */
    if (quiet) {
        progress = false;
    }

    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind++];

    flags = BDRV_O_RDWR | BDRV_O_UNMAP;
    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid cache option: %s", cache);
        return 1;
    }

    blk = img_open("image", filename, fmt, flags, true, quiet);
    if (!blk) {
        return 1;
    }
    bs = blk_bs(blk);

    qemu_progress_init(progress, 1.f);
    qemu_progress_print(0.f, 100);

    if (base) {
        base_bs = bdrv_find_backing_image(bs, base);
        if (!base_bs) {
            error_set(&local_err, QERR_BASE_NOT_FOUND, base);
            goto done;
        }
    } else {
        /* This is different from QMP, which by default uses the deepest file in
         * the backing chain (i.e., the very base); however, the traditional
         * behavior of qemu-img commit is using the immediate backing file. */
        base_bs = bs->backing_hd;
        if (!base_bs) {
            error_setg(&local_err, "Image does not have a backing file");
            goto done;
        }
    }

    cbi = (CommonBlockJobCBInfo){
        .errp = &local_err,
        .bs   = bs,
    };

    commit_active_start(bs, base_bs, 0, BLOCKDEV_ON_ERROR_REPORT,
                        common_block_job_cb, &cbi, &local_err);
    if (local_err) {
        goto done;
    }

    /* The block job will swap base_bs and bs (which is not what we really want
     * here, but okay) and unref base_bs (after the swap, i.e., the old top
     * image). In order to still be able to empty that top image afterwards,
     * increment the reference counter here preemptively. */
    if (!drop) {
        bdrv_ref(base_bs);
    }

    run_block_job(bs->job, &local_err);
    if (local_err) {
        goto unref_backing;
    }

    if (!drop && base_bs->drv->bdrv_make_empty) {
        ret = base_bs->drv->bdrv_make_empty(base_bs);
        if (ret) {
            error_setg_errno(&local_err, -ret, "Could not empty %s",
                             filename);
            goto unref_backing;
        }
    }

unref_backing:
    if (!drop) {
        bdrv_unref(base_bs);
    }

done:
    qemu_progress_end();

    blk_unref(blk);

    if (local_err) {
        qerror_report_err(local_err);
        error_free(local_err);
        return 1;
    }

    qprintf(quiet, "Image committed.\n");
    return 0;
}

/*
 * Returns true iff the first sector pointed to by 'buf' contains at least
 * a non-NUL byte.
 *
 * 'pnum' is set to the number of sectors (including and immediately following
 * the first one) that are known to be in the same allocated/unallocated state.
 */
static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
{
    bool is_zero;
    int i;

    if (n <= 0) {
        *pnum = 0;
        return 0;
    }
    is_zero = buffer_is_zero(buf, 512);
    for(i = 1; i < n; i++) {
        buf += 512;
        if (is_zero != buffer_is_zero(buf, 512)) {
            break;
        }
    }
    *pnum = i;
    return !is_zero;
}

/*
 * Like is_allocated_sectors, but if the buffer starts with a used sector,
 * up to 'min' consecutive sectors containing zeros are ignored. This avoids
 * breaking up write requests for only small sparse areas.
 */
static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
    int min)
{
    int ret;
    int num_checked, num_used;

    if (n < min) {
        min = n;
    }

    ret = is_allocated_sectors(buf, n, pnum);
    if (!ret) {
        return ret;
    }

    num_used = *pnum;
    buf += BDRV_SECTOR_SIZE * *pnum;
    n -= *pnum;
    num_checked = num_used;

    while (n > 0) {
        ret = is_allocated_sectors(buf, n, pnum);

        buf += BDRV_SECTOR_SIZE * *pnum;
        n -= *pnum;
        num_checked += *pnum;
        if (ret) {
            num_used = num_checked;
        } else if (*pnum >= min) {
            break;
        }
    }

    *pnum = num_used;
    return 1;
}

/*
 * Compares two buffers sector by sector. Returns 0 if the first sector of both
 * buffers matches, non-zero otherwise.
 *
 * pnum is set to the number of sectors (including and immediately following
 * the first one) that are known to have the same comparison result
 */
static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
    int *pnum)
{
    int res, i;

    if (n <= 0) {
        *pnum = 0;
        return 0;
    }

    res = !!memcmp(buf1, buf2, 512);
    for(i = 1; i < n; i++) {
        buf1 += 512;
        buf2 += 512;

        if (!!memcmp(buf1, buf2, 512) != res) {
            break;
        }
    }

    *pnum = i;
    return res;
}

#define IO_BUF_SIZE (2 * 1024 * 1024)

static int64_t sectors_to_bytes(int64_t sectors)
{
    return sectors << BDRV_SECTOR_BITS;
}

static int64_t sectors_to_process(int64_t total, int64_t from)
{
    return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
}

/*
 * Check if passed sectors are empty (not allocated or contain only 0 bytes)
 *
 * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero
 * data and negative value on error.
 *
 * @param bs:  Driver used for accessing file
 * @param sect_num: Number of first sector to check
 * @param sect_count: Number of sectors to check
 * @param filename: Name of disk file we are checking (logging purpose)
 * @param buffer: Allocated buffer for storing read data
 * @param quiet: Flag for quiet mode
 */
static int check_empty_sectors(BlockDriverState *bs, int64_t sect_num,
                               int sect_count, const char *filename,
                               uint8_t *buffer, bool quiet)
{
    int pnum, ret = 0;
    ret = bdrv_read(bs, sect_num, buffer, sect_count);
    if (ret < 0) {
        error_report("Error while reading offset %" PRId64 " of %s: %s",
                     sectors_to_bytes(sect_num), filename, strerror(-ret));
        return ret;
    }
    ret = is_allocated_sectors(buffer, sect_count, &pnum);
    if (ret || pnum != sect_count) {
        qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
                sectors_to_bytes(ret ? sect_num : sect_num + pnum));
        return 1;
    }

    return 0;
}

/*
 * Compares two images. Exit codes:
 *
 * 0 - Images are identical
 * 1 - Images differ
 * >1 - Error occurred
 */
static int img_compare(int argc, char **argv)
{
    const char *fmt1 = NULL, *fmt2 = NULL, *cache, *filename1, *filename2;
    BlockBackend *blk1, *blk2;
    BlockDriverState *bs1, *bs2;
    int64_t total_sectors1, total_sectors2;
    uint8_t *buf1 = NULL, *buf2 = NULL;
    int pnum1, pnum2;
    int allocated1, allocated2;
    int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */
    bool progress = false, quiet = false, strict = false;
    int flags;
    int64_t total_sectors;
    int64_t sector_num = 0;
    int64_t nb_sectors;
    int c, pnum;
    uint64_t progress_base;

    cache = BDRV_DEFAULT_CACHE;
    for (;;) {
        c = getopt(argc, argv, "hf:F:T:pqs");
        if (c == -1) {
            break;
        }
        switch (c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt1 = optarg;
            break;
        case 'F':
            fmt2 = optarg;
            break;
        case 'T':
            cache = optarg;
            break;
        case 'p':
            progress = true;
            break;
        case 'q':
            quiet = true;
            break;
        case 's':
            strict = true;
            break;
        }
    }

    /* Progress is not shown in Quiet mode */
    if (quiet) {
        progress = false;
    }


    if (optind != argc - 2) {
        error_exit("Expecting two image file names");
    }
    filename1 = argv[optind++];
    filename2 = argv[optind++];

    /* Initialize before goto out */
    qemu_progress_init(progress, 2.0);

    flags = BDRV_O_FLAGS;
    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid source cache option: %s", cache);
        ret = 2;
        goto out3;
    }

    blk1 = img_open("image_1", filename1, fmt1, flags, true, quiet);
    if (!blk1) {
        ret = 2;
        goto out3;
    }
    bs1 = blk_bs(blk1);

    blk2 = img_open("image_2", filename2, fmt2, flags, true, quiet);
    if (!blk2) {
        ret = 2;
        goto out2;
    }
    bs2 = blk_bs(blk2);

    buf1 = qemu_blockalign(bs1, IO_BUF_SIZE);
    buf2 = qemu_blockalign(bs2, IO_BUF_SIZE);
    total_sectors1 = bdrv_nb_sectors(bs1);
    if (total_sectors1 < 0) {
        error_report("Can't get size of %s: %s",
                     filename1, strerror(-total_sectors1));
        ret = 4;
        goto out;
    }
    total_sectors2 = bdrv_nb_sectors(bs2);
    if (total_sectors2 < 0) {
        error_report("Can't get size of %s: %s",
                     filename2, strerror(-total_sectors2));
        ret = 4;
        goto out;
    }
    total_sectors = MIN(total_sectors1, total_sectors2);
    progress_base = MAX(total_sectors1, total_sectors2);

    qemu_progress_print(0, 100);

    if (strict && total_sectors1 != total_sectors2) {
        ret = 1;
        qprintf(quiet, "Strict mode: Image size mismatch!\n");
        goto out;
    }

    for (;;) {
        nb_sectors = sectors_to_process(total_sectors, sector_num);
        if (nb_sectors <= 0) {
            break;
        }
        allocated1 = bdrv_is_allocated_above(bs1, NULL, sector_num, nb_sectors,
                                             &pnum1);
        if (allocated1 < 0) {
            ret = 3;
            error_report("Sector allocation test failed for %s", filename1);
            goto out;
        }

        allocated2 = bdrv_is_allocated_above(bs2, NULL, sector_num, nb_sectors,
                                             &pnum2);
        if (allocated2 < 0) {
            ret = 3;
            error_report("Sector allocation test failed for %s", filename2);
            goto out;
        }
        nb_sectors = MIN(pnum1, pnum2);

        if (allocated1 == allocated2) {
            if (allocated1) {
                ret = bdrv_read(bs1, sector_num, buf1, nb_sectors);
                if (ret < 0) {
                    error_report("Error while reading offset %" PRId64 " of %s:"
                                 " %s", sectors_to_bytes(sector_num), filename1,
                                 strerror(-ret));
                    ret = 4;
                    goto out;
                }
                ret = bdrv_read(bs2, sector_num, buf2, nb_sectors);
                if (ret < 0) {
                    error_report("Error while reading offset %" PRId64
                                 " of %s: %s", sectors_to_bytes(sector_num),
                                 filename2, strerror(-ret));
                    ret = 4;
                    goto out;
                }
                ret = compare_sectors(buf1, buf2, nb_sectors, &pnum);
                if (ret || pnum != nb_sectors) {
                    qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
                            sectors_to_bytes(
                                ret ? sector_num : sector_num + pnum));
                    ret = 1;
                    goto out;
                }
            }
        } else {
            if (strict) {
                ret = 1;
                qprintf(quiet, "Strict mode: Offset %" PRId64
                        " allocation mismatch!\n",
                        sectors_to_bytes(sector_num));
                goto out;
            }

            if (allocated1) {
                ret = check_empty_sectors(bs1, sector_num, nb_sectors,
                                          filename1, buf1, quiet);
            } else {
                ret = check_empty_sectors(bs2, sector_num, nb_sectors,
                                          filename2, buf1, quiet);
            }
            if (ret) {
                if (ret < 0) {
                    error_report("Error while reading offset %" PRId64 ": %s",
                                 sectors_to_bytes(sector_num), strerror(-ret));
                    ret = 4;
                }
                goto out;
            }
        }
        sector_num += nb_sectors;
        qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
    }

    if (total_sectors1 != total_sectors2) {
        BlockDriverState *bs_over;
        int64_t total_sectors_over;
        const char *filename_over;

        qprintf(quiet, "Warning: Image size mismatch!\n");
        if (total_sectors1 > total_sectors2) {
            total_sectors_over = total_sectors1;
            bs_over = bs1;
            filename_over = filename1;
        } else {
            total_sectors_over = total_sectors2;
            bs_over = bs2;
            filename_over = filename2;
        }

        for (;;) {
            nb_sectors = sectors_to_process(total_sectors_over, sector_num);
            if (nb_sectors <= 0) {
                break;
            }
            ret = bdrv_is_allocated_above(bs_over, NULL, sector_num,
                                          nb_sectors, &pnum);
            if (ret < 0) {
                ret = 3;
                error_report("Sector allocation test failed for %s",
                             filename_over);
                goto out;

            }
            nb_sectors = pnum;
            if (ret) {
                ret = check_empty_sectors(bs_over, sector_num, nb_sectors,
                                          filename_over, buf1, quiet);
                if (ret) {
                    if (ret < 0) {
                        error_report("Error while reading offset %" PRId64
                                     " of %s: %s", sectors_to_bytes(sector_num),
                                     filename_over, strerror(-ret));
                        ret = 4;
                    }
                    goto out;
                }
            }
            sector_num += nb_sectors;
            qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
        }
    }

    qprintf(quiet, "Images are identical.\n");
    ret = 0;

out:
    qemu_vfree(buf1);
    qemu_vfree(buf2);
    blk_unref(blk2);
out2:
    blk_unref(blk1);
out3:
    qemu_progress_end();
    return ret;
}

static int img_convert(int argc, char **argv)
{
    int c, n, n1, bs_n, bs_i, compress, cluster_sectors, skip_create;
    int64_t ret = 0;
    int progress = 0, flags, src_flags;
    const char *fmt, *out_fmt, *cache, *src_cache, *out_baseimg, *out_filename;
    BlockDriver *drv, *proto_drv;
    BlockBackend **blk = NULL, *out_blk = NULL;
    BlockDriverState **bs = NULL, *out_bs = NULL;
    int64_t total_sectors, nb_sectors, sector_num, bs_offset;
    int64_t *bs_sectors = NULL;
    uint8_t * buf = NULL;
    size_t bufsectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE;
    const uint8_t *buf1;
    BlockDriverInfo bdi;
    QemuOpts *opts = NULL;
    QemuOptsList *create_opts = NULL;
    const char *out_baseimg_param;
    char *options = NULL;
    const char *snapshot_name = NULL;
    int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
    bool quiet = false;
    Error *local_err = NULL;
    QemuOpts *sn_opts = NULL;

    fmt = NULL;
    out_fmt = "raw";
    cache = "unsafe";
    src_cache = BDRV_DEFAULT_CACHE;
    out_baseimg = NULL;
    compress = 0;
    skip_create = 0;
    for(;;) {
        c = getopt(argc, argv, "hf:O:B:ce6o:s:l:S:pt:T:qn");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'O':
            out_fmt = optarg;
            break;
        case 'B':
            out_baseimg = optarg;
            break;
        case 'c':
            compress = 1;
            break;
        case 'e':
            error_report("option -e is deprecated, please use \'-o "
                  "encryption\' instead!");
            ret = -1;
            goto fail_getopt;
        case '6':
            error_report("option -6 is deprecated, please use \'-o "
                  "compat6\' instead!");
            ret = -1;
            goto fail_getopt;
        case 'o':
            if (!is_valid_option_list(optarg)) {
                error_report("Invalid option list: %s", optarg);
                ret = -1;
                goto fail_getopt;
            }
            if (!options) {
                options = g_strdup(optarg);
            } else {
                char *old_options = options;
                options = g_strdup_printf("%s,%s", options, optarg);
                g_free(old_options);
            }
            break;
        case 's':
            snapshot_name = optarg;
            break;
        case 'l':
            if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
                sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
                if (!sn_opts) {
                    error_report("Failed in parsing snapshot param '%s'",
                                 optarg);
                    ret = -1;
                    goto fail_getopt;
                }
            } else {
                snapshot_name = optarg;
            }
            break;
        case 'S':
        {
            int64_t sval;
            char *end;
            sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
            if (sval < 0 || *end) {
                error_report("Invalid minimum zero buffer size for sparse output specified");
                ret = -1;
                goto fail_getopt;
            }

            min_sparse = sval / BDRV_SECTOR_SIZE;
            break;
        }
        case 'p':
            progress = 1;
            break;
        case 't':
            cache = optarg;
            break;
        case 'T':
            src_cache = optarg;
            break;
        case 'q':
            quiet = true;
            break;
        case 'n':
            skip_create = 1;
            break;
        }
    }

    /* Initialize before goto out */
    if (quiet) {
        progress = 0;
    }
    qemu_progress_init(progress, 1.0);


    bs_n = argc - optind - 1;
    out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;

    if (options && has_help_option(options)) {
        ret = print_block_option_help(out_filename, out_fmt);
        goto out;
    }

    if (bs_n < 1) {
        error_exit("Must specify image file name");
    }


    if (bs_n > 1 && out_baseimg) {
        error_report("-B makes no sense when concatenating multiple input "
                     "images");
        ret = -1;
        goto out;
    }

    src_flags = BDRV_O_FLAGS;
    ret = bdrv_parse_cache_flags(src_cache, &src_flags);
    if (ret < 0) {
        error_report("Invalid source cache option: %s", src_cache);
        goto out;
    }

    qemu_progress_print(0, 100);

    blk = g_new0(BlockBackend *, bs_n);
    bs = g_new0(BlockDriverState *, bs_n);
    bs_sectors = g_new(int64_t, bs_n);

    total_sectors = 0;
    for (bs_i = 0; bs_i < bs_n; bs_i++) {
        char *id = bs_n > 1 ? g_strdup_printf("source_%d", bs_i)
                            : g_strdup("source");
        blk[bs_i] = img_open(id, argv[optind + bs_i], fmt, src_flags,
                             true, quiet);
        g_free(id);
        if (!blk[bs_i]) {
            ret = -1;
            goto out;
        }
        bs[bs_i] = blk_bs(blk[bs_i]);
        bs_sectors[bs_i] = bdrv_nb_sectors(bs[bs_i]);
        if (bs_sectors[bs_i] < 0) {
            error_report("Could not get size of %s: %s",
                         argv[optind + bs_i], strerror(-bs_sectors[bs_i]));
            ret = -1;
            goto out;
        }
        total_sectors += bs_sectors[bs_i];
    }

    if (sn_opts) {
        ret = bdrv_snapshot_load_tmp(bs[0],
                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
                                     &local_err);
    } else if (snapshot_name != NULL) {
        if (bs_n > 1) {
            error_report("No support for concatenating multiple snapshot");
            ret = -1;
            goto out;
        }

        bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
    }
    if (local_err) {
        error_report("Failed to load snapshot: %s",
                     error_get_pretty(local_err));
        error_free(local_err);
        ret = -1;
        goto out;
    }

    /* Find driver and parse its options */
    drv = bdrv_find_format(out_fmt);
    if (!drv) {
        error_report("Unknown file format '%s'", out_fmt);
        ret = -1;
        goto out;
    }

    proto_drv = bdrv_find_protocol(out_filename, true);
    if (!proto_drv) {
        error_report("Unknown protocol '%s'", out_filename);
        ret = -1;
        goto out;
    }

    create_opts = qemu_opts_append(create_opts, drv->create_opts);
    create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);

    opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
    if (options && qemu_opts_do_parse(opts, options, NULL)) {
        error_report("Invalid options for file format '%s'", out_fmt);
        ret = -1;
        goto out;
    }

    qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_sectors * 512);
    ret = add_old_style_options(out_fmt, opts, out_baseimg, NULL);
    if (ret < 0) {
        goto out;
    }

    /* Get backing file name if -o backing_file was used */
    out_baseimg_param = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
    if (out_baseimg_param) {
        out_baseimg = out_baseimg_param;
    }

    /* Check if compression is supported */
    if (compress) {
        bool encryption =
            qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, false);
        const char *preallocation =
            qemu_opt_get(opts, BLOCK_OPT_PREALLOC);

        if (!drv->bdrv_write_compressed) {
            error_report("Compression not supported for this file format");
            ret = -1;
            goto out;
        }

        if (encryption) {
            error_report("Compression and encryption not supported at "
                         "the same time");
            ret = -1;
            goto out;
        }

        if (preallocation
            && strcmp(preallocation, "off"))
        {
            error_report("Compression and preallocation not supported at "
                         "the same time");
            ret = -1;
            goto out;
        }
    }

    if (!skip_create) {
        /* Create the new image */
        ret = bdrv_create(drv, out_filename, opts, &local_err);
        if (ret < 0) {
            error_report("%s: error while converting %s: %s",
                         out_filename, out_fmt, error_get_pretty(local_err));
            error_free(local_err);
            goto out;
        }
    }

    flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid cache option: %s", cache);
        goto out;
    }

    out_blk = img_open("target", out_filename, out_fmt, flags, true, quiet);
    if (!out_blk) {
        ret = -1;
        goto out;
    }
    out_bs = blk_bs(out_blk);

    bs_i = 0;
    bs_offset = 0;

    /* increase bufsectors from the default 4096 (2M) if opt_transfer_length
     * or discard_alignment of the out_bs is greater. Limit to 32768 (16MB)
     * as maximum. */
    bufsectors = MIN(32768,
                     MAX(bufsectors, MAX(out_bs->bl.opt_transfer_length,
                                         out_bs->bl.discard_alignment))
                    );

    buf = qemu_blockalign(out_bs, bufsectors * BDRV_SECTOR_SIZE);

    if (skip_create) {
        int64_t output_sectors = bdrv_nb_sectors(out_bs);
        if (output_sectors < 0) {
            error_report("unable to get output image length: %s\n",
                         strerror(-output_sectors));
            ret = -1;
            goto out;
        } else if (output_sectors < total_sectors) {
            error_report("output file is smaller than input file");
            ret = -1;
            goto out;
        }
    }

    cluster_sectors = 0;
    ret = bdrv_get_info(out_bs, &bdi);
    if (ret < 0) {
        if (compress) {
            error_report("could not get block driver info");
            goto out;
        }
    } else {
        compress = compress || bdi.needs_compressed_writes;
        cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
    }

    if (compress) {
        if (cluster_sectors <= 0 || cluster_sectors > bufsectors) {
            error_report("invalid cluster size");
            ret = -1;
            goto out;
        }
        sector_num = 0;

        nb_sectors = total_sectors;

        for(;;) {
            int64_t bs_num;
            int remainder;
            uint8_t *buf2;

            nb_sectors = total_sectors - sector_num;
            if (nb_sectors <= 0)
                break;
            if (nb_sectors >= cluster_sectors)
                n = cluster_sectors;
            else
                n = nb_sectors;

            bs_num = sector_num - bs_offset;
            assert (bs_num >= 0);
            remainder = n;
            buf2 = buf;
            while (remainder > 0) {
                int nlow;
                while (bs_num == bs_sectors[bs_i]) {
                    bs_offset += bs_sectors[bs_i];
                    bs_i++;
                    assert (bs_i < bs_n);
                    bs_num = 0;
                    /* printf("changing part: sector_num=%" PRId64 ", "
                       "bs_i=%d, bs_offset=%" PRId64 ", bs_sectors=%" PRId64
                       "\n", sector_num, bs_i, bs_offset, bs_sectors[bs_i]); */
                }
                assert (bs_num < bs_sectors[bs_i]);

                nlow = remainder > bs_sectors[bs_i] - bs_num
                    ? bs_sectors[bs_i] - bs_num : remainder;

                ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
                if (ret < 0) {
                    error_report("error while reading sector %" PRId64 ": %s",
                                 bs_num, strerror(-ret));
                    goto out;
                }

                buf2 += nlow * 512;
                bs_num += nlow;

                remainder -= nlow;
            }
            assert (remainder == 0);

            if (!buffer_is_zero(buf, n * BDRV_SECTOR_SIZE)) {
                ret = bdrv_write_compressed(out_bs, sector_num, buf, n);
                if (ret != 0) {
                    error_report("error while compressing sector %" PRId64
                                 ": %s", sector_num, strerror(-ret));
                    goto out;
                }
            }
            sector_num += n;
            qemu_progress_print(100.0 * sector_num / total_sectors, 0);
        }
        /* signal EOF to align */
        bdrv_write_compressed(out_bs, 0, NULL, 0);
    } else {
        int64_t sectors_to_read, sectors_read, sector_num_next_status;
        bool count_allocated_sectors;
        int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0;

        if (!has_zero_init && bdrv_can_write_zeroes_with_unmap(out_bs)) {
            ret = bdrv_make_zero(out_bs, BDRV_REQ_MAY_UNMAP);
            if (ret < 0) {
                goto out;
            }
            has_zero_init = 1;
        }

        sectors_to_read = total_sectors;
        count_allocated_sectors = progress && (out_baseimg || has_zero_init);
restart:
        sector_num = 0; // total number of sectors converted so far
        sectors_read = 0;
        sector_num_next_status = 0;

        for(;;) {
            nb_sectors = total_sectors - sector_num;
            if (nb_sectors <= 0) {
                if (count_allocated_sectors) {
                    sectors_to_read = sectors_read;
                    count_allocated_sectors = false;
                    goto restart;
                }
                ret = 0;
                break;
            }

            while (sector_num - bs_offset >= bs_sectors[bs_i]) {
                bs_offset += bs_sectors[bs_i];
                bs_i ++;
                assert (bs_i < bs_n);
                /* printf("changing part: sector_num=%" PRId64 ", bs_i=%d, "
                  "bs_offset=%" PRId64 ", bs_sectors=%" PRId64 "\n",
                   sector_num, bs_i, bs_offset, bs_sectors[bs_i]); */
            }

            if ((out_baseimg || has_zero_init) &&
                sector_num >= sector_num_next_status) {
                n = nb_sectors > INT_MAX ? INT_MAX : nb_sectors;
                ret = bdrv_get_block_status(bs[bs_i], sector_num - bs_offset,
                                            n, &n1);
                if (ret < 0) {
                    error_report("error while reading block status of sector %"
                                 PRId64 ": %s", sector_num - bs_offset,
                                 strerror(-ret));
                    goto out;
                }
                /* If the output image is zero initialized, we are not working
                 * on a shared base and the input is zero we can skip the next
                 * n1 sectors */
                if (has_zero_init && !out_baseimg && (ret & BDRV_BLOCK_ZERO)) {
                    sector_num += n1;
                    continue;
                }
                /* If the output image is being created as a copy on write
                 * image, assume that sectors which are unallocated in the
                 * input image are present in both the output's and input's
                 * base images (no need to copy them). */
                if (out_baseimg) {
                    if (!(ret & BDRV_BLOCK_DATA)) {
                        sector_num += n1;
                        continue;
                    }
                    /* The next 'n1' sectors are allocated in the input image.
                     * Copy only those as they may be followed by unallocated
                     * sectors. */
                    nb_sectors = n1;
                }
                /* avoid redundant callouts to get_block_status */
                sector_num_next_status = sector_num + n1;
            }

            n = MIN(nb_sectors, bufsectors);

            /* round down request length to an aligned sector, but
             * do not bother doing this on short requests. They happen
             * when we found an all-zero area, and the next sector to
             * write will not be sector_num + n. */
            if (cluster_sectors > 0 && n >= cluster_sectors) {
                int64_t next_aligned_sector = (sector_num + n);
                next_aligned_sector -= next_aligned_sector % cluster_sectors;
                if (sector_num + n > next_aligned_sector) {
                    n = next_aligned_sector - sector_num;
                }
            }

            n = MIN(n, bs_sectors[bs_i] - (sector_num - bs_offset));

            sectors_read += n;
            if (count_allocated_sectors) {
                sector_num += n;
                continue;
            }

            n1 = n;
            ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
            if (ret < 0) {
                error_report("error while reading sector %" PRId64 ": %s",
                             sector_num - bs_offset, strerror(-ret));
                goto out;
            }
            /* NOTE: at the same time we convert, we do not write zero
               sectors to have a chance to compress the image. Ideally, we
               should add a specific call to have the info to go faster */
            buf1 = buf;
            while (n > 0) {
                if (!has_zero_init ||
                    is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
                    ret = bdrv_write(out_bs, sector_num, buf1, n1);
                    if (ret < 0) {
                        error_report("error while writing sector %" PRId64
                                     ": %s", sector_num, strerror(-ret));
                        goto out;
                    }
                }
                sector_num += n1;
                n -= n1;
                buf1 += n1 * 512;
            }
            qemu_progress_print(100.0 * sectors_read / sectors_to_read, 0);
        }
    }
out:
    if (!ret) {
        qemu_progress_print(100, 0);
    }
    qemu_progress_end();
    qemu_opts_del(opts);
    qemu_opts_free(create_opts);
    qemu_vfree(buf);
    qemu_opts_del(sn_opts);
    blk_unref(out_blk);
    g_free(bs);
    if (blk) {
        for (bs_i = 0; bs_i < bs_n; bs_i++) {
            blk_unref(blk[bs_i]);
        }
        g_free(blk);
    }
    g_free(bs_sectors);
fail_getopt:
    g_free(options);

    if (ret) {
        return 1;
    }
    return 0;
}


static void dump_snapshots(BlockDriverState *bs)
{
    QEMUSnapshotInfo *sn_tab, *sn;
    int nb_sns, i;

    nb_sns = bdrv_snapshot_list(bs, &sn_tab);
    if (nb_sns <= 0)
        return;
    printf("Snapshot list:\n");
    bdrv_snapshot_dump(fprintf, stdout, NULL);
    printf("\n");
    for(i = 0; i < nb_sns; i++) {
        sn = &sn_tab[i];
        bdrv_snapshot_dump(fprintf, stdout, sn);
        printf("\n");
    }
    g_free(sn_tab);
}

static void dump_json_image_info_list(ImageInfoList *list)
{
    Error *local_err = NULL;
    QString *str;
    QmpOutputVisitor *ov = qmp_output_visitor_new();
    QObject *obj;
    visit_type_ImageInfoList(qmp_output_get_visitor(ov),
                             &list, NULL, &local_err);
    obj = qmp_output_get_qobject(ov);
    str = qobject_to_json_pretty(obj);
    assert(str != NULL);
    printf("%s\n", qstring_get_str(str));
    qobject_decref(obj);
    qmp_output_visitor_cleanup(ov);
    QDECREF(str);
}

static void dump_json_image_info(ImageInfo *info)
{
    Error *local_err = NULL;
    QString *str;
    QmpOutputVisitor *ov = qmp_output_visitor_new();
    QObject *obj;
    visit_type_ImageInfo(qmp_output_get_visitor(ov),
                         &info, NULL, &local_err);
    obj = qmp_output_get_qobject(ov);
    str = qobject_to_json_pretty(obj);
    assert(str != NULL);
    printf("%s\n", qstring_get_str(str));
    qobject_decref(obj);
    qmp_output_visitor_cleanup(ov);
    QDECREF(str);
}

static void dump_human_image_info_list(ImageInfoList *list)
{
    ImageInfoList *elem;
    bool delim = false;

    for (elem = list; elem; elem = elem->next) {
        if (delim) {
            printf("\n");
        }
        delim = true;

        bdrv_image_info_dump(fprintf, stdout, elem->value);
    }
}

static gboolean str_equal_func(gconstpointer a, gconstpointer b)
{
    return strcmp(a, b) == 0;
}

/**
 * Open an image file chain and return an ImageInfoList
 *
 * @filename: topmost image filename
 * @fmt: topmost image format (may be NULL to autodetect)
 * @chain: true  - enumerate entire backing file chain
 *         false - only topmost image file
 *
 * Returns a list of ImageInfo objects or NULL if there was an error opening an
 * image file.  If there was an error a message will have been printed to
 * stderr.
 */
static ImageInfoList *collect_image_info_list(const char *filename,
                                              const char *fmt,
                                              bool chain)
{
    ImageInfoList *head = NULL;
    ImageInfoList **last = &head;
    GHashTable *filenames;
    Error *err = NULL;

    filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);

    while (filename) {
        BlockBackend *blk;
        BlockDriverState *bs;
        ImageInfo *info;
        ImageInfoList *elem;

        if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
            error_report("Backing file '%s' creates an infinite loop.",
                         filename);
            goto err;
        }
        g_hash_table_insert(filenames, (gpointer)filename, NULL);

        blk = img_open("image", filename, fmt,
                       BDRV_O_FLAGS | BDRV_O_NO_BACKING, false, false);
        if (!blk) {
            goto err;
        }
        bs = blk_bs(blk);

        bdrv_query_image_info(bs, &info, &err);
        if (err) {
            error_report("%s", error_get_pretty(err));
            error_free(err);
            blk_unref(blk);
            goto err;
        }

        elem = g_new0(ImageInfoList, 1);
        elem->value = info;
        *last = elem;
        last = &elem->next;

        blk_unref(blk);

        filename = fmt = NULL;
        if (chain) {
            if (info->has_full_backing_filename) {
                filename = info->full_backing_filename;
            } else if (info->has_backing_filename) {
                filename = info->backing_filename;
            }
            if (info->has_backing_filename_format) {
                fmt = info->backing_filename_format;
            }
        }
    }
    g_hash_table_destroy(filenames);
    return head;

err:
    qapi_free_ImageInfoList(head);
    g_hash_table_destroy(filenames);
    return NULL;
}

static int img_info(int argc, char **argv)
{
    int c;
    OutputFormat output_format = OFORMAT_HUMAN;
    bool chain = false;
    const char *filename, *fmt, *output;
    ImageInfoList *list;

    fmt = NULL;
    output = NULL;
    for(;;) {
        int option_index = 0;
        static const struct option long_options[] = {
            {"help", no_argument, 0, 'h'},
            {"format", required_argument, 0, 'f'},
            {"output", required_argument, 0, OPTION_OUTPUT},
            {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
            {0, 0, 0, 0}
        };
        c = getopt_long(argc, argv, "f:h",
                        long_options, &option_index);
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case OPTION_OUTPUT:
            output = optarg;
            break;
        case OPTION_BACKING_CHAIN:
            chain = true;
            break;
        }
    }
    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind++];

    if (output && !strcmp(output, "json")) {
        output_format = OFORMAT_JSON;
    } else if (output && !strcmp(output, "human")) {
        output_format = OFORMAT_HUMAN;
    } else if (output) {
        error_report("--output must be used with human or json as argument.");
        return 1;
    }

    list = collect_image_info_list(filename, fmt, chain);
    if (!list) {
        return 1;
    }

    switch (output_format) {
    case OFORMAT_HUMAN:
        dump_human_image_info_list(list);
        break;
    case OFORMAT_JSON:
        if (chain) {
            dump_json_image_info_list(list);
        } else {
            dump_json_image_info(list->value);
        }
        break;
    }

    qapi_free_ImageInfoList(list);
    return 0;
}


typedef struct MapEntry {
    int flags;
    int depth;
    int64_t start;
    int64_t length;
    int64_t offset;
    BlockDriverState *bs;
} MapEntry;

static void dump_map_entry(OutputFormat output_format, MapEntry *e,
                           MapEntry *next)
{
    switch (output_format) {
    case OFORMAT_HUMAN:
        if ((e->flags & BDRV_BLOCK_DATA) &&
            !(e->flags & BDRV_BLOCK_OFFSET_VALID)) {
            error_report("File contains external, encrypted or compressed clusters.");
            exit(1);
        }
        if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) == BDRV_BLOCK_DATA) {
            printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
                   e->start, e->length, e->offset, e->bs->filename);
        }
        /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
         * Modify the flags here to allow more coalescing.
         */
        if (next &&
            (next->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) != BDRV_BLOCK_DATA) {
            next->flags &= ~BDRV_BLOCK_DATA;
            next->flags |= BDRV_BLOCK_ZERO;
        }
        break;
    case OFORMAT_JSON:
        printf("%s{ \"start\": %"PRId64", \"length\": %"PRId64", \"depth\": %d,"
               " \"zero\": %s, \"data\": %s",
               (e->start == 0 ? "[" : ",\n"),
               e->start, e->length, e->depth,
               (e->flags & BDRV_BLOCK_ZERO) ? "true" : "false",
               (e->flags & BDRV_BLOCK_DATA) ? "true" : "false");
        if (e->flags & BDRV_BLOCK_OFFSET_VALID) {
            printf(", \"offset\": %"PRId64"", e->offset);
        }
        putchar('}');

        if (!next) {
            printf("]\n");
        }
        break;
    }
}

static int get_block_status(BlockDriverState *bs, int64_t sector_num,
                            int nb_sectors, MapEntry *e)
{
    int64_t ret;
    int depth;

    /* As an optimization, we could cache the current range of unallocated
     * clusters in each file of the chain, and avoid querying the same
     * range repeatedly.
     */

    depth = 0;
    for (;;) {
        ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors);
        if (ret < 0) {
            return ret;
        }
        assert(nb_sectors);
        if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) {
            break;
        }
        bs = bs->backing_hd;
        if (bs == NULL) {
            ret = 0;
            break;
        }

        depth++;
    }

    e->start = sector_num * BDRV_SECTOR_SIZE;
    e->length = nb_sectors * BDRV_SECTOR_SIZE;
    e->flags = ret & ~BDRV_BLOCK_OFFSET_MASK;
    e->offset = ret & BDRV_BLOCK_OFFSET_MASK;
    e->depth = depth;
    e->bs = bs;
    return 0;
}

static int img_map(int argc, char **argv)
{
    int c;
    OutputFormat output_format = OFORMAT_HUMAN;
    BlockBackend *blk;
    BlockDriverState *bs;
    const char *filename, *fmt, *output;
    int64_t length;
    MapEntry curr = { .length = 0 }, next;
    int ret = 0;

    fmt = NULL;
    output = NULL;
    for (;;) {
        int option_index = 0;
        static const struct option long_options[] = {
            {"help", no_argument, 0, 'h'},
            {"format", required_argument, 0, 'f'},
            {"output", required_argument, 0, OPTION_OUTPUT},
            {0, 0, 0, 0}
        };
        c = getopt_long(argc, argv, "f:h",
                        long_options, &option_index);
        if (c == -1) {
            break;
        }
        switch (c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case OPTION_OUTPUT:
            output = optarg;
            break;
        }
    }
    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind];

    if (output && !strcmp(output, "json")) {
        output_format = OFORMAT_JSON;
    } else if (output && !strcmp(output, "human")) {
        output_format = OFORMAT_HUMAN;
    } else if (output) {
        error_report("--output must be used with human or json as argument.");
        return 1;
    }

    blk = img_open("image", filename, fmt, BDRV_O_FLAGS, true, false);
    if (!blk) {
        return 1;
    }
    bs = blk_bs(blk);

    if (output_format == OFORMAT_HUMAN) {
        printf("%-16s%-16s%-16s%s\n", "Offset", "Length", "Mapped to", "File");
    }

    length = bdrv_getlength(bs);
    while (curr.start + curr.length < length) {
        int64_t nsectors_left;
        int64_t sector_num;
        int n;

        sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;

        /* Probe up to 1 GiB at a time.  */
        nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
        n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
        ret = get_block_status(bs, sector_num, n, &next);

        if (ret < 0) {
            error_report("Could not read file metadata: %s", strerror(-ret));
            goto out;
        }

        if (curr.length != 0 && curr.flags == next.flags &&
            curr.depth == next.depth &&
            ((curr.flags & BDRV_BLOCK_OFFSET_VALID) == 0 ||
             curr.offset + curr.length == next.offset)) {
            curr.length += next.length;
            continue;
        }

        if (curr.length > 0) {
            dump_map_entry(output_format, &curr, &next);
        }
        curr = next;
    }

    dump_map_entry(output_format, &curr, NULL);

out:
    blk_unref(blk);
    return ret < 0;
}

#define SNAPSHOT_LIST   1
#define SNAPSHOT_CREATE 2
#define SNAPSHOT_APPLY  3
#define SNAPSHOT_DELETE 4

static int img_snapshot(int argc, char **argv)
{
    BlockBackend *blk;
    BlockDriverState *bs;
    QEMUSnapshotInfo sn;
    char *filename, *snapshot_name = NULL;
    int c, ret = 0, bdrv_oflags;
    int action = 0;
    qemu_timeval tv;
    bool quiet = false;
    Error *err = NULL;

    bdrv_oflags = BDRV_O_FLAGS | BDRV_O_RDWR;
    /* Parse commandline parameters */
    for(;;) {
        c = getopt(argc, argv, "la:c:d:hq");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            return 0;
        case 'l':
            if (action) {
                error_exit("Cannot mix '-l', '-a', '-c', '-d'");
                return 0;
            }
            action = SNAPSHOT_LIST;
            bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
            break;
        case 'a':
            if (action) {
                error_exit("Cannot mix '-l', '-a', '-c', '-d'");
                return 0;
            }
            action = SNAPSHOT_APPLY;
            snapshot_name = optarg;
            break;
        case 'c':
            if (action) {
                error_exit("Cannot mix '-l', '-a', '-c', '-d'");
                return 0;
            }
            action = SNAPSHOT_CREATE;
            snapshot_name = optarg;
            break;
        case 'd':
            if (action) {
                error_exit("Cannot mix '-l', '-a', '-c', '-d'");
                return 0;
            }
            action = SNAPSHOT_DELETE;
            snapshot_name = optarg;
            break;
        case 'q':
            quiet = true;
            break;
        }
    }

    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind++];

    /* Open the image */
    blk = img_open("image", filename, NULL, bdrv_oflags, true, quiet);
    if (!blk) {
        return 1;
    }
    bs = blk_bs(blk);

    /* Perform the requested action */
    switch(action) {
    case SNAPSHOT_LIST:
        dump_snapshots(bs);
        break;

    case SNAPSHOT_CREATE:
        memset(&sn, 0, sizeof(sn));
        pstrcpy(sn.name, sizeof(sn.name), snapshot_name);

        qemu_gettimeofday(&tv);
        sn.date_sec = tv.tv_sec;
        sn.date_nsec = tv.tv_usec * 1000;

        ret = bdrv_snapshot_create(bs, &sn);
        if (ret) {
            error_report("Could not create snapshot '%s': %d (%s)",
                snapshot_name, ret, strerror(-ret));
        }
        break;

    case SNAPSHOT_APPLY:
        ret = bdrv_snapshot_goto(bs, snapshot_name);
        if (ret) {
            error_report("Could not apply snapshot '%s': %d (%s)",
                snapshot_name, ret, strerror(-ret));
        }
        break;

    case SNAPSHOT_DELETE:
        bdrv_snapshot_delete_by_id_or_name(bs, snapshot_name, &err);
        if (err) {
            error_report("Could not delete snapshot '%s': (%s)",
                         snapshot_name, error_get_pretty(err));
            error_free(err);
            ret = 1;
        }
        break;
    }

    /* Cleanup */
    blk_unref(blk);
    if (ret) {
        return 1;
    }
    return 0;
}

static int img_rebase(int argc, char **argv)
{
    BlockBackend *blk = NULL, *blk_old_backing = NULL, *blk_new_backing = NULL;
    BlockDriverState *bs = NULL, *bs_old_backing = NULL, *bs_new_backing = NULL;
    BlockDriver *old_backing_drv, *new_backing_drv;
    char *filename;
    const char *fmt, *cache, *src_cache, *out_basefmt, *out_baseimg;
    int c, flags, src_flags, ret;
    int unsafe = 0;
    int progress = 0;
    bool quiet = false;
    Error *local_err = NULL;

    /* Parse commandline parameters */
    fmt = NULL;
    cache = BDRV_DEFAULT_CACHE;
    src_cache = BDRV_DEFAULT_CACHE;
    out_baseimg = NULL;
    out_basefmt = NULL;
    for(;;) {
        c = getopt(argc, argv, "hf:F:b:upt:T:q");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            return 0;
        case 'f':
            fmt = optarg;
            break;
        case 'F':
            out_basefmt = optarg;
            break;
        case 'b':
            out_baseimg = optarg;
            break;
        case 'u':
            unsafe = 1;
            break;
        case 'p':
            progress = 1;
            break;
        case 't':
            cache = optarg;
            break;
        case 'T':
            src_cache = optarg;
            break;
        case 'q':
            quiet = true;
            break;
        }
    }

    if (quiet) {
        progress = 0;
    }

    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    if (!unsafe && !out_baseimg) {
        error_exit("Must specify backing file (-b) or use unsafe mode (-u)");
    }
    filename = argv[optind++];

    qemu_progress_init(progress, 2.0);
    qemu_progress_print(0, 100);

    flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid cache option: %s", cache);
        goto out;
    }

    src_flags = BDRV_O_FLAGS;
    ret = bdrv_parse_cache_flags(src_cache, &src_flags);
    if (ret < 0) {
        error_report("Invalid source cache option: %s", src_cache);
        goto out;
    }

    /*
     * Open the images.
     *
     * Ignore the old backing file for unsafe rebase in case we want to correct
     * the reference to a renamed or moved backing file.
     */
    blk = img_open("image", filename, fmt, flags, true, quiet);
    if (!blk) {
        ret = -1;
        goto out;
    }
    bs = blk_bs(blk);

    /* Find the right drivers for the backing files */
    old_backing_drv = NULL;
    new_backing_drv = NULL;

    if (!unsafe && bs->backing_format[0] != '\0') {
        old_backing_drv = bdrv_find_format(bs->backing_format);
        if (old_backing_drv == NULL) {
            error_report("Invalid format name: '%s'", bs->backing_format);
            ret = -1;
            goto out;
        }
    }

    if (out_basefmt != NULL) {
        new_backing_drv = bdrv_find_format(out_basefmt);
        if (new_backing_drv == NULL) {
            error_report("Invalid format name: '%s'", out_basefmt);
            ret = -1;
            goto out;
        }
    }

    /* For safe rebasing we need to compare old and new backing file */
    if (!unsafe) {
        char backing_name[1024];

        blk_old_backing = blk_new_with_bs("old_backing", &error_abort);
        bs_old_backing = blk_bs(blk_old_backing);
        bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
        ret = bdrv_open(&bs_old_backing, backing_name, NULL, NULL, src_flags,
                        old_backing_drv, &local_err);
        if (ret) {
            error_report("Could not open old backing file '%s': %s",
                         backing_name, error_get_pretty(local_err));
            error_free(local_err);
            goto out;
        }
        if (out_baseimg[0]) {
            blk_new_backing = blk_new_with_bs("new_backing", &error_abort);
            bs_new_backing = blk_bs(blk_new_backing);
            ret = bdrv_open(&bs_new_backing, out_baseimg, NULL, NULL, src_flags,
                            new_backing_drv, &local_err);
            if (ret) {
                error_report("Could not open new backing file '%s': %s",
                             out_baseimg, error_get_pretty(local_err));
                error_free(local_err);
                goto out;
            }
        }
    }

    /*
     * Check each unallocated cluster in the COW file. If it is unallocated,
     * accesses go to the backing file. We must therefore compare this cluster
     * in the old and new backing file, and if they differ we need to copy it
     * from the old backing file into the COW file.
     *
     * If qemu-img crashes during this step, no harm is done. The content of
     * the image is the same as the original one at any time.
     */
    if (!unsafe) {
        int64_t num_sectors;
        int64_t old_backing_num_sectors;
        int64_t new_backing_num_sectors = 0;
        uint64_t sector;
        int n;
        uint8_t * buf_old;
        uint8_t * buf_new;
        float local_progress = 0;

        buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
        buf_new = qemu_blockalign(bs, IO_BUF_SIZE);

        num_sectors = bdrv_nb_sectors(bs);
        if (num_sectors < 0) {
            error_report("Could not get size of '%s': %s",
                         filename, strerror(-num_sectors));
            ret = -1;
            goto out;
        }
        old_backing_num_sectors = bdrv_nb_sectors(bs_old_backing);
        if (old_backing_num_sectors < 0) {
            char backing_name[1024];

            bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
            error_report("Could not get size of '%s': %s",
                         backing_name, strerror(-old_backing_num_sectors));
            ret = -1;
            goto out;
        }
        if (bs_new_backing) {
            new_backing_num_sectors = bdrv_nb_sectors(bs_new_backing);
            if (new_backing_num_sectors < 0) {
                error_report("Could not get size of '%s': %s",
                             out_baseimg, strerror(-new_backing_num_sectors));
                ret = -1;
                goto out;
            }
        }

        if (num_sectors != 0) {
            local_progress = (float)100 /
                (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
        }

        for (sector = 0; sector < num_sectors; sector += n) {

            /* How many sectors can we handle with the next read? */
            if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
                n = (IO_BUF_SIZE / 512);
            } else {
                n = num_sectors - sector;
            }

            /* If the cluster is allocated, we don't need to take action */
            ret = bdrv_is_allocated(bs, sector, n, &n);
            if (ret < 0) {
                error_report("error while reading image metadata: %s",
                             strerror(-ret));
                goto out;
            }
            if (ret) {
                continue;
            }

            /*
             * Read old and new backing file and take into consideration that
             * backing files may be smaller than the COW image.
             */
            if (sector >= old_backing_num_sectors) {
                memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
            } else {
                if (sector + n > old_backing_num_sectors) {
                    n = old_backing_num_sectors - sector;
                }

                ret = bdrv_read(bs_old_backing, sector, buf_old, n);
                if (ret < 0) {
                    error_report("error while reading from old backing file");
                    goto out;
                }
            }

            if (sector >= new_backing_num_sectors || !bs_new_backing) {
                memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
            } else {
                if (sector + n > new_backing_num_sectors) {
                    n = new_backing_num_sectors - sector;
                }

                ret = bdrv_read(bs_new_backing, sector, buf_new, n);
                if (ret < 0) {
                    error_report("error while reading from new backing file");
                    goto out;
                }
            }

            /* If they differ, we need to write to the COW file */
            uint64_t written = 0;

            while (written < n) {
                int pnum;

                if (compare_sectors(buf_old + written * 512,
                    buf_new + written * 512, n - written, &pnum))
                {
                    ret = bdrv_write(bs, sector + written,
                        buf_old + written * 512, pnum);
                    if (ret < 0) {
                        error_report("Error while writing to COW image: %s",
                            strerror(-ret));
                        goto out;
                    }
                }

                written += pnum;
            }
            qemu_progress_print(local_progress, 100);
        }

        qemu_vfree(buf_old);
        qemu_vfree(buf_new);
    }

    /*
     * Change the backing file. All clusters that are different from the old
     * backing file are overwritten in the COW file now, so the visible content
     * doesn't change when we switch the backing file.
     */
    if (out_baseimg && *out_baseimg) {
        ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
    } else {
        ret = bdrv_change_backing_file(bs, NULL, NULL);
    }

    if (ret == -ENOSPC) {
        error_report("Could not change the backing file to '%s': No "
                     "space left in the file header", out_baseimg);
    } else if (ret < 0) {
        error_report("Could not change the backing file to '%s': %s",
            out_baseimg, strerror(-ret));
    }

    qemu_progress_print(100, 0);
    /*
     * TODO At this point it is possible to check if any clusters that are
     * allocated in the COW file are the same in the backing file. If so, they
     * could be dropped from the COW file. Don't do this before switching the
     * backing file, in case of a crash this would lead to corruption.
     */
out:
    qemu_progress_end();
    /* Cleanup */
    if (!unsafe) {
        blk_unref(blk_old_backing);
        blk_unref(blk_new_backing);
    }

    blk_unref(blk);
    if (ret) {
        return 1;
    }
    return 0;
}

static int img_resize(int argc, char **argv)
{
    int c, ret, relative;
    const char *filename, *fmt, *size;
    int64_t n, total_size;
    bool quiet = false;
    BlockBackend *blk = NULL;
    BlockDriverState *bs = NULL;
    QemuOpts *param;
    static QemuOptsList resize_options = {
        .name = "resize_options",
        .head = QTAILQ_HEAD_INITIALIZER(resize_options.head),
        .desc = {
            {
                .name = BLOCK_OPT_SIZE,
                .type = QEMU_OPT_SIZE,
                .help = "Virtual disk size"
            }, {
                /* end of list */
            }
        },
    };

    /* Remove size from argv manually so that negative numbers are not treated
     * as options by getopt. */
    if (argc < 3) {
        error_exit("Not enough arguments");
        return 1;
    }

    size = argv[--argc];

    /* Parse getopt arguments */
    fmt = NULL;
    for(;;) {
        c = getopt(argc, argv, "f:hq");
        if (c == -1) {
            break;
        }
        switch(c) {
        case '?':
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'q':
            quiet = true;
            break;
        }
    }
    if (optind != argc - 1) {
        error_exit("Expecting one image file name");
    }
    filename = argv[optind++];

    /* Choose grow, shrink, or absolute resize mode */
    switch (size[0]) {
    case '+':
        relative = 1;
        size++;
        break;
    case '-':
        relative = -1;
        size++;
        break;
    default:
        relative = 0;
        break;
    }

    /* Parse size */
    param = qemu_opts_create(&resize_options, NULL, 0, &error_abort);
    if (qemu_opt_set(param, BLOCK_OPT_SIZE, size)) {
        /* Error message already printed when size parsing fails */
        ret = -1;
        qemu_opts_del(param);
        goto out;
    }
    n = qemu_opt_get_size(param, BLOCK_OPT_SIZE, 0);
    qemu_opts_del(param);

    blk = img_open("image", filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR,
                   true, quiet);
    if (!blk) {
        ret = -1;
        goto out;
    }
    bs = blk_bs(blk);

    if (relative) {
        total_size = bdrv_getlength(bs) + n * relative;
    } else {
        total_size = n;
    }
    if (total_size <= 0) {
        error_report("New image size must be positive");
        ret = -1;
        goto out;
    }

    ret = bdrv_truncate(bs, total_size);
    switch (ret) {
    case 0:
        qprintf(quiet, "Image resized.\n");
        break;
    case -ENOTSUP:
        error_report("This image does not support resize");
        break;
    case -EACCES:
        error_report("Image is read-only");
        break;
    default:
        error_report("Error resizing image (%d)", -ret);
        break;
    }
out:
    blk_unref(blk);
    if (ret) {
        return 1;
    }
    return 0;
}

static void amend_status_cb(BlockDriverState *bs,
                            int64_t offset, int64_t total_work_size)
{
    qemu_progress_print(100.f * offset / total_work_size, 0);
}

static int img_amend(int argc, char **argv)
{
    int c, ret = 0;
    char *options = NULL;
    QemuOptsList *create_opts = NULL;
    QemuOpts *opts = NULL;
    const char *fmt = NULL, *filename, *cache;
    int flags;
    bool quiet = false, progress = false;
    BlockBackend *blk = NULL;
    BlockDriverState *bs = NULL;

    cache = BDRV_DEFAULT_CACHE;
    for (;;) {
        c = getopt(argc, argv, "ho:f:t:pq");
        if (c == -1) {
            break;
        }

        switch (c) {
            case 'h':
            case '?':
                help();
                break;
            case 'o':
                if (!is_valid_option_list(optarg)) {
                    error_report("Invalid option list: %s", optarg);
                    ret = -1;
                    goto out;
                }
                if (!options) {
                    options = g_strdup(optarg);
                } else {
                    char *old_options = options;
                    options = g_strdup_printf("%s,%s", options, optarg);
                    g_free(old_options);
                }
                break;
            case 'f':
                fmt = optarg;
                break;
            case 't':
                cache = optarg;
                break;
            case 'p':
                progress = true;
                break;
            case 'q':
                quiet = true;
                break;
        }
    }

    if (!options) {
        error_exit("Must specify options (-o)");
    }

    if (quiet) {
        progress = false;
    }
    qemu_progress_init(progress, 1.0);

    filename = (optind == argc - 1) ? argv[argc - 1] : NULL;
    if (fmt && has_help_option(options)) {
        /* If a format is explicitly specified (and possibly no filename is
         * given), print option help here */
        ret = print_block_option_help(filename, fmt);
        goto out;
    }

    if (optind != argc - 1) {
        error_report("Expecting one image file name");
        ret = -1;
        goto out;
    }

    flags = BDRV_O_FLAGS | BDRV_O_RDWR;
    ret = bdrv_parse_cache_flags(cache, &flags);
    if (ret < 0) {
        error_report("Invalid cache option: %s", cache);
        goto out;
    }

    blk = img_open("image", filename, fmt, flags, true, quiet);
    if (!blk) {
        ret = -1;
        goto out;
    }
    bs = blk_bs(blk);

    fmt = bs->drv->format_name;

    if (has_help_option(options)) {
        /* If the format was auto-detected, print option help here */
        ret = print_block_option_help(filename, fmt);
        goto out;
    }

    create_opts = qemu_opts_append(create_opts, bs->drv->create_opts);
    opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
    if (options && qemu_opts_do_parse(opts, options, NULL)) {
        error_report("Invalid options for file format '%s'", fmt);
        ret = -1;
        goto out;
    }

    /* In case the driver does not call amend_status_cb() */
    qemu_progress_print(0.f, 0);
    ret = bdrv_amend_options(bs, opts, &amend_status_cb);
    qemu_progress_print(100.f, 0);
    if (ret < 0) {
        error_report("Error while amending options: %s", strerror(-ret));
        goto out;
    }

out:
    qemu_progress_end();

    blk_unref(blk);
    qemu_opts_del(opts);
    qemu_opts_free(create_opts);
    g_free(options);

    if (ret) {
        return 1;
    }
    return 0;
}

static const img_cmd_t img_cmds[] = {
#define DEF(option, callback, arg_string)        \
    { option, callback },
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
    { NULL, NULL, },
};

int main(int argc, char **argv)
{
    const img_cmd_t *cmd;
    const char *cmdname;
    Error *local_error = NULL;
    int c;
    static const struct option long_options[] = {
        {"help", no_argument, 0, 'h'},
        {"version", no_argument, 0, 'v'},
        {0, 0, 0, 0}
    };

#ifdef CONFIG_POSIX
    signal(SIGPIPE, SIG_IGN);
#endif

    error_set_progname(argv[0]);
    qemu_init_exec_dir(argv[0]);

    if (qemu_init_main_loop(&local_error)) {
        error_report("%s", error_get_pretty(local_error));
        error_free(local_error);
        exit(EXIT_FAILURE);
    }

    bdrv_init();
    if (argc < 2) {
        error_exit("Not enough arguments");
    }
    cmdname = argv[1];

    /* find the command */
    for (cmd = img_cmds; cmd->name != NULL; cmd++) {
        if (!strcmp(cmdname, cmd->name)) {
            return cmd->handler(argc - 1, argv + 1);
        }
    }

    c = getopt_long(argc, argv, "h", long_options, NULL);

    if (c == 'h') {
        help();
    }
    if (c == 'v') {
        printf(QEMU_IMG_VERSION);
        return 0;
    }

    /* not found */
    error_exit("Command not found: %s", cmdname);
}