reactos/drivers/fs/vfat/direntry.c

   1 /* $Id: direntry.c,v 1.2 2001/07/13 10:31:14 ekohl Exp $
   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  CACHEPAGESIZE(pDeviceExt) ((pDeviceExt)->BytesPerCluster > PAGESIZE ? \
  24                    (pDeviceExt)->BytesPerCluster : PAGESIZE)
  25
  26 #define  ENTRIES_PER_CACHEPAGE(pDeviceExt)  (ENTRIES_PER_SECTOR * \
  27                    (CACHEPAGESIZE(pDeviceExt) / ((pDeviceExt)->BytesPerSector)))
  28
  29
  30 ULONG
  31 vfatDirEntryGetFirstCluster (PDEVICE_EXTENSION  pDeviceExt,
  32                              PFAT_DIR_ENTRY  pFatDirEntry)
  33 {
  34   ULONG  cluster;
  35
  36   if (pDeviceExt->FatType == FAT32)
  37   {
  38     cluster = pFatDirEntry->FirstCluster +
  39       pFatDirEntry->FirstClusterHigh * 65536;
  40   }
  41   else
  42   {
  43     cluster = pFatDirEntry->FirstCluster;
  44   }
  45
  46   return  cluster;
  47 }
  48
  49 BOOL
  50 vfatIsDirEntryDeleted (FATDirEntry * pFatDirEntry)
  51 {
  52   return  pFatDirEntry->Filename [0] == 0xe5;
  53 }
  54
  55 BOOL
  56 vfatIsDirEntryEndMarker (FATDirEntry * pFatDirEntry)
  57 {
  58   return  pFatDirEntry->Filename [0] == 0;
  59 }
  60
  61 BOOL
  62 vfatIsDirEntryLongName (FATDirEntry * pFatDirEntry)
  63 {
  64   return  pFatDirEntry->Attrib == 0x0f;
  65 }
  66
  67 void
  68 vfatGetDirEntryName (PFAT_DIR_ENTRY  dirEntry,  PWSTR  entryName)
  69 {
  70   vfat8Dot3ToString (dirEntry->Filename, dirEntry->Ext, entryName);
  71 }
  72
  73 NTSTATUS
  74 vfatGetNextDirEntry (PDEVICE_EXTENSION  pDeviceExt,
  75                      PVFATFCB  pDirectoryFCB,
  76                      ULONG * pDirectoryIndex,
  77                      PWSTR pLongFileName,
  78                      PFAT_DIR_ENTRY pDirEntry)
  79 {
  80   NTSTATUS  status;
  81   ULONG  indexInPage = *pDirectoryIndex % ENTRIES_PER_CACHEPAGE(pDeviceExt);
  82   ULONG  pageNumber = *pDirectoryIndex / ENTRIES_PER_CACHEPAGE(pDeviceExt);
  83   PVOID  currentPage = NULL;
  84   PCACHE_SEGMENT  cacheSegment = NULL;
  85   FATDirEntry * fatDirEntry;
  86   slot * longNameEntry;
  87   ULONG  cpos;
  88
  89   DPRINT ("vfatGetNextDirEntry (%x,%x,%d,%x,%x)\n",
  90           pDeviceExt,
  91           pDirectoryFCB,
  92           *pDirectoryIndex,
  93           pLongFileName,
  94           pDirEntry);
  95
  96   *pLongFileName = 0;
  97
  98   DPRINT ("Validating current directory page\n");
  99   status = vfatRequestAndValidateRegion (pDeviceExt,
 100                                          pDirectoryFCB,
 101                                          pageNumber * CACHEPAGESIZE(pDeviceExt),
 102                                          (PVOID *) &currentPage,
 103                                          &cacheSegment,
 104                                          FALSE);
 105   if (!NT_SUCCESS (status))
 106   {
 107     return  status;
 108   }
 109
 110   while (TRUE)
 111   {
 112     fatDirEntry = (FATDirEntry *) currentPage;
 113
 114     if (vfatIsDirEntryEndMarker (&fatDirEntry [indexInPage]))
 115     {
 116       DPRINT ("end of directory, returning no more entries\n");
 117       status = vfatReleaseRegion (pDeviceExt,
 118                                   pDirectoryFCB,
 119                                   cacheSegment);
 120       return  STATUS_NO_MORE_ENTRIES;
 121     }
 122     else if (vfatIsDirEntryLongName (&fatDirEntry [indexInPage]))
 123     {
 124       DPRINT ("  long name entry found at %d\n", *pDirectoryIndex);
 125       longNameEntry = (slot *) currentPage;
 126
 127       DPRINT ("  name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
 128               5, longNameEntry [indexInPage].name0_4,
 129               6, longNameEntry [indexInPage].name5_10,
 130               2, longNameEntry [indexInPage].name11_12);
 131
 132       vfat_initstr (pLongFileName, 256);
 133       vfat_wcsncpy (pLongFileName, longNameEntry [indexInPage].name0_4, 5);
 134       vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name5_10, 5, 6);
 135       vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name11_12, 11, 2);
 136
 137       DPRINT ("  longName: [%S]\n", pLongFileName);
 138
 139       cpos = 0;
 140       while ((longNameEntry [indexInPage].id != 0x41) &&
 141              (longNameEntry [indexInPage].id != 0x01) &&
 142              (longNameEntry [indexInPage].attr > 0))
 143       {
 144         (*pDirectoryIndex)++;
 145         indexInPage++;
 146         if (indexInPage == ENTRIES_PER_CACHEPAGE(pDeviceExt))
 147         {
 148           indexInPage = 0;
 149           pageNumber++;
 150
 151           status = vfatReleaseRegion (pDeviceExt,
 152                                       pDirectoryFCB,
 153                                       cacheSegment);
 154           if (!NT_SUCCESS (status))
 155           {
 156             return  status;
 157           }
 158           status = vfatRequestAndValidateRegion (pDeviceExt,
 159                                                  pDirectoryFCB,
 160                                                  pageNumber * CACHEPAGESIZE(pDeviceExt),
 161                                                  (PVOID *) &currentPage,
 162                                                  &cacheSegment,
 163                                                  FALSE);
 164           if (!NT_SUCCESS (status))
 165           {
 166             return  status;
 167           }
 168           longNameEntry = (slot *) currentPage;
 169         }
 170         DPRINT ("  index %d\n", *pDirectoryIndex);
 171
 172         DPRINT ("  name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
 173                 5, longNameEntry [indexInPage].name0_4,
 174                 6, longNameEntry [indexInPage].name5_10,
 175                 2, longNameEntry [indexInPage].name11_12);
 176
 177         cpos++;
 178         vfat_movstr (pLongFileName, 13, 0, cpos * 13);
 179         vfat_wcsncpy (pLongFileName, longNameEntry [indexInPage].name0_4, 5);
 180         vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name5_10, 5, 6);
 181         vfat_wcsncat (pLongFileName, longNameEntry [indexInPage].name11_12, 11, 2);
 182
 183         DPRINT ("  longName: [%S]\n", pLongFileName);
 184
 185       }
 186       (*pDirectoryIndex)++;
 187       indexInPage++;
 188       if (indexInPage == ENTRIES_PER_CACHEPAGE(pDeviceExt))
 189       {
 190         indexInPage = 0;
 191         pageNumber++;
 192
 193         status = vfatReleaseRegion (pDeviceExt,
 194                                     pDirectoryFCB,
 195                                     cacheSegment);
 196         if (!NT_SUCCESS (status))
 197         {
 198           return  status;
 199         }
 200         status = vfatRequestAndValidateRegion (pDeviceExt,
 201                                                pDirectoryFCB,
 202                                                pageNumber * CACHEPAGESIZE(pDeviceExt),
 203                                                (PVOID *) &currentPage,
 204                                                &cacheSegment,
 205                                                FALSE);
 206         if (!NT_SUCCESS (status))
 207         {
 208           return  status;
 209         }
 210       }
 211     }
 212     else
 213     {
 214       memcpy (pDirEntry, &fatDirEntry [indexInPage], sizeof (FAT_DIR_ENTRY));
 215       (*pDirectoryIndex)++;
 216       break;
 217     }
 218   }
 219
 220   DPRINT ("Releasing current directory page\n");
 221   status = vfatReleaseRegion (pDeviceExt,
 222                               pDirectoryFCB,
 223                               cacheSegment);
 224
 225   return  status;
 226 }
 227
 228
 229
 230
 231