sdk/lib/fslib/vfatlib/common.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS VFAT filesystem library
   4  * FILE:        lib\fslib\vfatlib\common.c
   5  * PURPOSE:     Common code for Fat support
   6  * PROGRAMMERS: Casper S. Hornstrup (chorns@users.sourceforge.net)
   7  *              Eric Kohl
   8  *              Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   9  */
  10
  11 /* INCLUDES *******************************************************************/
  12
  13 #include "vfatlib.h"
  14
  15 #define NDEBUG
  16 #include <debug.h>
  17
  18 /* FUNCTIONS ******************************************************************/
  19
  20 ULONG
  21 GetShiftCount(IN ULONG Value)
  22 {
  23     ULONG i = 1;
  24
  25     while (Value > 0)
  26     {
  27         i++;
  28         Value /= 2;
  29     }
  30
  31     return i - 2;
  32 }
  33
  34 ULONG
  35 CalcVolumeSerialNumber(VOID)
  36 {
  37     LARGE_INTEGER SystemTime;
  38     TIME_FIELDS TimeFields;
  39     ULONG Serial;
  40     PUCHAR Buffer;
  41
  42     NtQuerySystemTime(&SystemTime);
  43     RtlTimeToTimeFields(&SystemTime, &TimeFields);
  44
  45     Buffer = (PUCHAR)&Serial;
  46     Buffer[0] = (UCHAR)(TimeFields.Year & 0xFF) + (UCHAR)(TimeFields.Hour & 0xFF);
  47     Buffer[1] = (UCHAR)(TimeFields.Year >> 8) + (UCHAR)(TimeFields.Minute & 0xFF);
  48     Buffer[2] = (UCHAR)(TimeFields.Month & 0xFF) + (UCHAR)(TimeFields.Second & 0xFF);
  49     Buffer[3] = (UCHAR)(TimeFields.Day & 0xFF) + (UCHAR)(TimeFields.Milliseconds & 0xFF);
  50
  51     return Serial;
  52 }
  53
  54 /***** Wipe function for FAT12, FAT16 and FAT32 formats *****/
  55 NTSTATUS
  56 FatWipeSectors(
  57     IN HANDLE FileHandle,
  58     IN ULONG TotalSectors,
  59     IN ULONG SectorsPerCluster,
  60     IN ULONG BytesPerSector,
  61     IN OUT PFORMAT_CONTEXT Context)
  62 {
  63     IO_STATUS_BLOCK IoStatusBlock;
  64     PUCHAR Buffer;
  65     LARGE_INTEGER FileOffset;
  66     ULONGLONG Sector;
  67     ULONG Length;
  68     NTSTATUS Status;
  69
  70     Length = SectorsPerCluster * BytesPerSector;
  71
  72     /* Allocate buffer for the cluster */
  73     Buffer = (PUCHAR)RtlAllocateHeap(RtlGetProcessHeap(),
  74                                      HEAP_ZERO_MEMORY,
  75                                      Length);
  76     if (Buffer == NULL)
  77         return STATUS_INSUFFICIENT_RESOURCES;
  78
  79     /* Wipe all clusters */
  80     Sector = 0;
  81     while (Sector + SectorsPerCluster < TotalSectors)
  82     {
  83         FileOffset.QuadPart = Sector * BytesPerSector;
  84
  85         Status = NtWriteFile(FileHandle,
  86                              NULL,
  87                              NULL,
  88                              NULL,
  89                              &IoStatusBlock,
  90                              Buffer,
  91                              Length,
  92                              &FileOffset,
  93                              NULL);
  94         if (!NT_SUCCESS(Status))
  95         {
  96             DPRINT("NtWriteFile() failed (Status %lx)\n", Status);
  97             goto done;
  98         }
  99
 100         UpdateProgress(Context, SectorsPerCluster);
 101
 102         Sector += SectorsPerCluster;
 103     }
 104
 105     /* Wipe the trailing space behind the last cluster */
 106     if (Sector < TotalSectors)
 107     {
 108         DPRINT("Remaining sectors %lu\n", TotalSectors - Sector);
 109
 110         FileOffset.QuadPart = Sector * BytesPerSector;
 111         Length = (TotalSectors - Sector) * BytesPerSector;
 112
 113         Status = NtWriteFile(FileHandle,
 114                              NULL,
 115                              NULL,
 116                              NULL,
 117                              &IoStatusBlock,
 118                              Buffer,
 119                              Length,
 120                              &FileOffset,
 121                              NULL);
 122         if (!NT_SUCCESS(Status))
 123         {
 124             DPRINT("NtWriteFile() failed (Status %lx)\n", Status);
 125             goto done;
 126         }
 127
 128         UpdateProgress(Context, TotalSectors - Sector);
 129     }
 130
 131 done:
 132     /* Free the buffer */
 133     RtlFreeHeap(RtlGetProcessHeap(), 0, Buffer);
 134     return Status;
 135 }
 136
 137 /* EOF */