drivers/fs/vfat/direntry.c

   1 /* $Id$
   2  *
   3  *
   4  * FILE:             DirEntry.c
   5  * PURPOSE:          Routines to manipulate directory entries.
   6  * COPYRIGHT:        See COPYING in the top level directory
   7  * PROJECT:          ReactOS kernel
   8  * PROGRAMMER:       Jason Filby (jasonfilby@yahoo.com)
   9  *                   Rex Jolliff (rex@lvcablemodem.com)
  10  */
  11
  12 /*  -------------------------------------------------------  INCLUDES  */
  13
  14 #include <ddk/ntddk.h>
  15 #include <wchar.h>
  16 #include <limits.h>
  17
  18 #define NDEBUG
  19 #include <debug.h>
  20
  21 #include "vfat.h"
  22
  23 #define ENTRIES_PER_PAGE   (PAGE_SIZE / sizeof (FATDirEntry))
  24
  25 ULONG
  26 vfatDirEntryGetFirstCluster (PDEVICE_EXTENSION  pDeviceExt,
  27                              PFAT_DIR_ENTRY  pFatDirEntry)
  28 {
  29   ULONG  cluster;
  30
  31   if (pDeviceExt->FatInfo.FatType == FAT32)
  32   {
  33     cluster = pFatDirEntry->FirstCluster +
  34       pFatDirEntry->FirstClusterHigh * 65536;
  35   }
  36   else
  37   {
  38     cluster = pFatDirEntry->FirstCluster;
  39   }
  40
  41   return  cluster;
  42 }
  43
  44 BOOL
  45 vfatIsDirEntryDeleted (FATDirEntry * pFatDirEntry)
  46 {
  47   return  pFatDirEntry->Filename [0] == 0xe5;
  48 }
  49
  50 BOOL
  51 vfatIsDirEntryEndMarker (FATDirEntry * pFatDirEntry)
  52 {
  53   return  pFatDirEntry->Filename [0] == 0;
  54 }
  55
  56 BOOL
  57 vfatIsDirEntryLongName (FATDirEntry * pFatDirEntry)
  58 {
  59   return  pFatDirEntry->Attrib == 0x0f;
  60 }
  61
  62 BOOL
  63 vfatIsDirEntryVolume (FATDirEntry * pFatDirEntry)
  64 {
  65   return 0x08 == (pFatDirEntry->Attrib & 0x1f);
  66 }
  67
  68 void
  69 vfatGetDirEntryName (PFAT_DIR_ENTRY  dirEntry,  PWSTR  entryName)
  70 {
  71   vfat8Dot3ToString (dirEntry, entryName);
  72 }
  73
  74
  75 NTSTATUS vfatGetNextDirEntry(PVOID * pContext,
  76                              PVOID * pPage,
  77                              IN PVFATFCB pDirFcb,
  78                              IN OUT PULONG pDirIndex,
  79                              OUT PWSTR pFileName,
  80                              OUT PFAT_DIR_ENTRY pDirEntry,
  81                              OUT PULONG pStartIndex)
  82 {
  83     ULONG dirMap;
  84     PWCHAR pName;
  85     LARGE_INTEGER FileOffset;
  86     FATDirEntry * fatDirEntry;
  87     slot * longNameEntry;
  88     ULONG index;
  89
  90     *pFileName = 0;
  91
  92     FileOffset.u.HighPart = 0;
  93     FileOffset.u.LowPart = ROUND_DOWN(*pDirIndex * sizeof(FATDirEntry), PAGE_SIZE);
  94
  95     if (*pContext == NULL || (*pDirIndex % ENTRIES_PER_PAGE) == 0)
  96     {
  97        if (*pContext != NULL)
  98        {
  99           CcUnpinData(*pContext);
 100        }
 101        if (!CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, TRUE, pContext, pPage))
 102        {
 103           *pContext = NULL;
 104           return STATUS_NO_MORE_ENTRIES;
 105        }
 106     }
 107
 108
 109     fatDirEntry = (FATDirEntry*)(*pPage) + *pDirIndex % ENTRIES_PER_PAGE;
 110     longNameEntry = (slot*) fatDirEntry;
 111     dirMap = 0;
 112
 113     if (pStartIndex)
 114     {
 115         *pStartIndex = *pDirIndex;
 116     }
 117
 118     while (TRUE)
 119     {
 120         if (vfatIsDirEntryEndMarker(fatDirEntry))
 121         {
 122             CcUnpinData(*pContext);
 123             *pContext = NULL;
 124             return STATUS_NO_MORE_ENTRIES;
 125         }
 126
 127         if (vfatIsDirEntryDeleted (fatDirEntry))
 128         {
 129             dirMap = 0;
 130             *pFileName = 0;
 131             if (pStartIndex)
 132             {
 133                 *pStartIndex = *pDirIndex + 1;
 134             }
 135         }
 136         else
 137         {
 138             if (vfatIsDirEntryLongName (fatDirEntry))
 139             {
 140                 if (dirMap == 0)
 141                 {
 142                     DPRINT ("  long name entry found at %d\n", *pDirIndex);
 143                     memset(pFileName, 0, 256 * sizeof(WCHAR));
 144                 }
 145
 146                 DPRINT ("  name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
 147                          5, longNameEntry->name0_4,
 148                          6, longNameEntry->name5_10,
 149                          2, longNameEntry->name11_12);
 150
 151                 index = (longNameEntry->id & 0x1f) - 1;
 152                 dirMap |= 1 << index;
 153                 pName = pFileName + 13 * index;
 154
 155                 memcpy(pName, longNameEntry->name0_4, 5 * sizeof(WCHAR));
 156                 memcpy(pName + 5, longNameEntry->name5_10, 6 * sizeof(WCHAR));
 157                 memcpy(pName + 11, longNameEntry->name11_12, 2 * sizeof(WCHAR));
 158
 159                 DPRINT ("  longName: [%S]\n", pFileName);
 160             }
 161             else
 162             {
 163                 memcpy (pDirEntry, fatDirEntry, sizeof (FAT_DIR_ENTRY));
 164                 break;
 165             }
 166         }
 167         (*pDirIndex)++;
 168         if ((*pDirIndex % ENTRIES_PER_PAGE) == 0)
 169         {
 170             CcUnpinData(*pContext);
 171             FileOffset.u.LowPart += PAGE_SIZE;
 172             if (!CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, TRUE, pContext, pPage))
 173             {
 174                 CHECKPOINT;
 175                 *pContext = NULL;
 176                 return STATUS_NO_MORE_ENTRIES;
 177             }
 178             fatDirEntry = (FATDirEntry*)*pPage;
 179             longNameEntry = (slot*) *pPage;
 180         }
 181         else
 182         {
 183             fatDirEntry++;
 184             longNameEntry++;
 185         }
 186     }
 187     return STATUS_SUCCESS;
 188 }
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