reactos/drivers/filesystems/fastfat/direntry.c

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/*
* FILE: DirEntry.c
* PURPOSE: Routines to manipulate directory entries.
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* PROGRAMMER: Jason Filby (jasonfilby@yahoo.com)
* Rex Jolliff (rex@lvcablemodem.com)
* Herve Poussineau (reactos@poussine.freesurf.fr)
*/
/* ------------------------------------------------------- INCLUDES */
#include "vfat.h"
#define NDEBUG
#include <debug.h>
ULONG
vfatDirEntryGetFirstCluster(
PDEVICE_EXTENSION pDeviceExt,
PDIR_ENTRY pFatDirEntry)
{
ULONG cluster;
if (pDeviceExt->FatInfo.FatType == FAT32)
{
cluster = pFatDirEntry->Fat.FirstCluster |
(pFatDirEntry->Fat.FirstClusterHigh << 16);
}
else if (vfatVolumeIsFatX(pDeviceExt))
{
cluster = pFatDirEntry->FatX.FirstCluster;
}
else
{
cluster = pFatDirEntry->Fat.FirstCluster;
}
return cluster;
}
BOOLEAN
FATIsDirectoryEmpty(
PDEVICE_EXTENSION DeviceExt,
PVFATFCB Fcb)
{
LARGE_INTEGER FileOffset;
PVOID Context = NULL;
PFAT_DIR_ENTRY FatDirEntry;
ULONG Index, MaxIndex;
NTSTATUS Status;
if (vfatFCBIsRoot(Fcb))
{
Index = 0;
}
else
{
Index = 2;
}
FileOffset.QuadPart = 0;
MaxIndex = Fcb->RFCB.FileSize.u.LowPart / sizeof(FAT_DIR_ENTRY);
Status = vfatFCBInitializeCacheFromVolume(DeviceExt, Fcb);
if (!NT_SUCCESS(Status))
{
return FALSE;
}
while (Index < MaxIndex)
{
if (Context == NULL || (Index % FAT_ENTRIES_PER_PAGE) == 0)
{
if (Context != NULL)
{
CcUnpinData(Context);
}
_SEH2_TRY
{
CcMapData(Fcb->FileObject, &FileOffset, sizeof(FAT_DIR_ENTRY), MAP_WAIT, &Context, (PVOID*)&FatDirEntry);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
_SEH2_YIELD(return TRUE);
}
_SEH2_END;
FatDirEntry += Index % FAT_ENTRIES_PER_PAGE;
FileOffset.QuadPart += PAGE_SIZE;
}
if (FAT_ENTRY_END(FatDirEntry))
{
CcUnpinData(Context);
return TRUE;
}
if (!FAT_ENTRY_DELETED(FatDirEntry))
{
CcUnpinData(Context);
return FALSE;
}
Index++;
FatDirEntry++;
}
if (Context)
{
CcUnpinData(Context);
}
return TRUE;
}
BOOLEAN
FATXIsDirectoryEmpty(
PDEVICE_EXTENSION DeviceExt,
PVFATFCB Fcb)
{
LARGE_INTEGER FileOffset;
PVOID Context = NULL;
PFATX_DIR_ENTRY FatXDirEntry;
ULONG Index = 0, MaxIndex;
NTSTATUS Status;
FileOffset.QuadPart = 0;
MaxIndex = Fcb->RFCB.FileSize.u.LowPart / sizeof(FATX_DIR_ENTRY);
Status = vfatFCBInitializeCacheFromVolume(DeviceExt, Fcb);
if (!NT_SUCCESS(Status))
{
return FALSE;
}
while (Index < MaxIndex)
{
if (Context == NULL || (Index % FATX_ENTRIES_PER_PAGE) == 0)
{
if (Context != NULL)
{
CcUnpinData(Context);
}
_SEH2_TRY
{
CcMapData(Fcb->FileObject, &FileOffset, sizeof(FATX_DIR_ENTRY), MAP_WAIT, &Context, (PVOID*)&FatXDirEntry);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
_SEH2_YIELD(return TRUE);
}
_SEH2_END;
FatXDirEntry += Index % FATX_ENTRIES_PER_PAGE;
FileOffset.QuadPart += PAGE_SIZE;
}
if (FATX_ENTRY_END(FatXDirEntry))
{
CcUnpinData(Context);
return TRUE;
}
if (!FATX_ENTRY_DELETED(FatXDirEntry))
{
CcUnpinData(Context);
return FALSE;
}
Index++;
FatXDirEntry++;
}
if (Context)
{
CcUnpinData(Context);
}
return TRUE;
}
NTSTATUS
FATGetNextDirEntry(
PVOID *pContext,
PVOID *pPage,
IN PVFATFCB pDirFcb,
PVFAT_DIRENTRY_CONTEXT DirContext,
BOOLEAN First)
{
ULONG dirMap;
PWCHAR pName;
LARGE_INTEGER FileOffset;
PFAT_DIR_ENTRY fatDirEntry;
slot * longNameEntry;
ULONG index;
UCHAR CheckSum, shortCheckSum;
USHORT i;
BOOLEAN Valid = TRUE;
BOOLEAN Back = FALSE;
NTSTATUS Status;
DirContext->LongNameU.Length = 0;
DirContext->LongNameU.Buffer[0] = UNICODE_NULL;
FileOffset.u.HighPart = 0;
FileOffset.u.LowPart = ROUND_DOWN(DirContext->DirIndex * sizeof(FAT_DIR_ENTRY), PAGE_SIZE);
Status = vfatFCBInitializeCacheFromVolume(DirContext->DeviceExt, pDirFcb);
if (!NT_SUCCESS(Status))
{
return Status;
}
if (*pContext == NULL || (DirContext->DirIndex % FAT_ENTRIES_PER_PAGE) == 0)
{
if (*pContext != NULL)
{
CcUnpinData(*pContext);
}
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
}
fatDirEntry = (PFAT_DIR_ENTRY)(*pPage) + DirContext->DirIndex % FAT_ENTRIES_PER_PAGE;
longNameEntry = (slot*) fatDirEntry;
dirMap = 0;
if (First)
{
/* This is the first call to vfatGetNextDirEntry. Possible the start index points
* into a long name or points to a short name with an assigned long name.
* We must go back to the real start of the entry */
while (DirContext->DirIndex > 0 &&
!FAT_ENTRY_END(fatDirEntry) &&
!FAT_ENTRY_DELETED(fatDirEntry) &&
((!FAT_ENTRY_LONG(fatDirEntry) && !Back) ||
(FAT_ENTRY_LONG(fatDirEntry) && !(longNameEntry->id & 0x40))))
{
DirContext->DirIndex--;
Back = TRUE;
if ((DirContext->DirIndex % FAT_ENTRIES_PER_PAGE) == FAT_ENTRIES_PER_PAGE - 1)
{
CcUnpinData(*pContext);
FileOffset.u.LowPart -= PAGE_SIZE;
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
fatDirEntry = (PFAT_DIR_ENTRY)(*pPage) + DirContext->DirIndex % FAT_ENTRIES_PER_PAGE;
longNameEntry = (slot*) fatDirEntry;
}
else
{
fatDirEntry--;
longNameEntry--;
}
}
if (Back && !FAT_ENTRY_END(fatDirEntry) &&
(FAT_ENTRY_DELETED(fatDirEntry) || !FAT_ENTRY_LONG(fatDirEntry)))
{
DirContext->DirIndex++;
if ((DirContext->DirIndex % FAT_ENTRIES_PER_PAGE) == 0)
{
CcUnpinData(*pContext);
FileOffset.u.LowPart += PAGE_SIZE;
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
fatDirEntry = (PFAT_DIR_ENTRY)*pPage;
longNameEntry = (slot*) *pPage;
}
else
{
fatDirEntry++;
longNameEntry++;
}
}
}
DirContext->StartIndex = DirContext->DirIndex;
CheckSum = 0;
while (TRUE)
{
if (FAT_ENTRY_END(fatDirEntry))
{
CcUnpinData(*pContext);
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
if (FAT_ENTRY_DELETED(fatDirEntry))
{
dirMap = 0;
DirContext->LongNameU.Buffer[0] = 0;
DirContext->StartIndex = DirContext->DirIndex + 1;
}
else
{
if (FAT_ENTRY_LONG(fatDirEntry))
{
if (dirMap == 0)
{
DPRINT (" long name entry found at %u\n", DirContext->DirIndex);
RtlZeroMemory(DirContext->LongNameU.Buffer, DirContext->LongNameU.MaximumLength);
CheckSum = longNameEntry->alias_checksum;
Valid = TRUE;
}
DPRINT(" name chunk1:[%.*S] chunk2:[%.*S] chunk3:[%.*S]\n",
5, longNameEntry->name0_4,
6, longNameEntry->name5_10,
2, longNameEntry->name11_12);
index = longNameEntry->id & 0x3f; // Note: it can be 0 for corrupted FS
/* Make sure index is valid and we have enough space in buffer
(we count one char for \0) */
if (index > 0 &&
index * 13 < DirContext->LongNameU.MaximumLength / sizeof(WCHAR))
{
index--; // make index 0 based
dirMap |= 1 << index;
pName = DirContext->LongNameU.Buffer + index * 13;
RtlCopyMemory(pName, longNameEntry->name0_4, 5 * sizeof(WCHAR));
RtlCopyMemory(pName + 5, longNameEntry->name5_10, 6 * sizeof(WCHAR));
RtlCopyMemory(pName + 11, longNameEntry->name11_12, 2 * sizeof(WCHAR));
if (longNameEntry->id & 0x40)
{
/* It's last LFN entry. Terminate filename with \0 */
pName[13] = UNICODE_NULL;
}
}
else
DPRINT1("Long name entry has invalid index: %x!\n", longNameEntry->id);
DPRINT (" longName: [%S]\n", DirContext->LongNameU.Buffer);
if (CheckSum != longNameEntry->alias_checksum)
{
DPRINT1("Found wrong alias checksum in long name entry (first %x, current %x, %S)\n",
CheckSum, longNameEntry->alias_checksum, DirContext->LongNameU.Buffer);
Valid = FALSE;
}
}
else
{
shortCheckSum = 0;
for (i = 0; i < 11; i++)
{
shortCheckSum = (((shortCheckSum & 1) << 7)
| ((shortCheckSum & 0xfe) >> 1))
+ fatDirEntry->ShortName[i];
}
if (shortCheckSum != CheckSum && DirContext->LongNameU.Buffer[0])
{
DPRINT1("Checksum from long and short name is not equal (short: %x, long: %x, %S)\n",
shortCheckSum, CheckSum, DirContext->LongNameU.Buffer);
DirContext->LongNameU.Buffer[0] = 0;
}
if (Valid == FALSE)
{
DirContext->LongNameU.Buffer[0] = 0;
}
RtlCopyMemory (&DirContext->DirEntry.Fat, fatDirEntry, sizeof (FAT_DIR_ENTRY));
break;
}
}
DirContext->DirIndex++;
if ((DirContext->DirIndex % FAT_ENTRIES_PER_PAGE) == 0)
{
CcUnpinData(*pContext);
FileOffset.u.LowPart += PAGE_SIZE;
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
fatDirEntry = (PFAT_DIR_ENTRY)*pPage;
longNameEntry = (slot*) *pPage;
}
else
{
fatDirEntry++;
longNameEntry++;
}
}
/* Make sure filename is NULL terminate and calculate length */
DirContext->LongNameU.Buffer[DirContext->LongNameU.MaximumLength / sizeof(WCHAR) - 1]
= UNICODE_NULL;
DirContext->LongNameU.Length = wcslen(DirContext->LongNameU.Buffer) * sizeof(WCHAR);
/* Init short name */
vfat8Dot3ToString(&DirContext->DirEntry.Fat, &DirContext->ShortNameU);
/* If we found no LFN, use short name as long */
if (DirContext->LongNameU.Length == 0)
RtlCopyUnicodeString(&DirContext->LongNameU, &DirContext->ShortNameU);
return STATUS_SUCCESS;
}
NTSTATUS
FATXGetNextDirEntry(
PVOID *pContext,
PVOID *pPage,
IN PVFATFCB pDirFcb,
PVFAT_DIRENTRY_CONTEXT DirContext,
BOOLEAN First)
{
LARGE_INTEGER FileOffset;
PFATX_DIR_ENTRY fatxDirEntry;
OEM_STRING StringO;
ULONG DirIndex = DirContext->DirIndex;
NTSTATUS Status;
FileOffset.u.HighPart = 0;
UNREFERENCED_PARAMETER(First);
if (!vfatFCBIsRoot(pDirFcb))
{
/* need to add . and .. entries */
switch (DirContext->DirIndex)
{
case 0: /* entry . */
DirContext->ShortNameU.Buffer[0] = 0;
DirContext->ShortNameU.Length = 0;
wcscpy(DirContext->LongNameU.Buffer, L".");
DirContext->LongNameU.Length = sizeof(WCHAR);
RtlCopyMemory(&DirContext->DirEntry.FatX, &pDirFcb->entry.FatX, sizeof(FATX_DIR_ENTRY));
DirContext->DirEntry.FatX.Filename[0] = '.';
DirContext->DirEntry.FatX.FilenameLength = 1;
DirContext->StartIndex = 0;
return STATUS_SUCCESS;
case 1: /* entry .. */
DirContext->ShortNameU.Buffer[0] = 0;
DirContext->ShortNameU.Length = 0;
wcscpy(DirContext->LongNameU.Buffer, L"..");
DirContext->LongNameU.Length = 2 * sizeof(WCHAR);
RtlCopyMemory(&DirContext->DirEntry.FatX, &pDirFcb->entry.FatX, sizeof(FATX_DIR_ENTRY));
DirContext->DirEntry.FatX.Filename[0] = DirContext->DirEntry.FatX.Filename[1] = '.';
DirContext->DirEntry.FatX.FilenameLength = 2;
DirContext->StartIndex = 1;
return STATUS_SUCCESS;
default:
DirIndex -= 2;
}
}
Status = vfatFCBInitializeCacheFromVolume(DirContext->DeviceExt, pDirFcb);
if (!NT_SUCCESS(Status))
{
return Status;
}
if (*pContext == NULL || (DirIndex % FATX_ENTRIES_PER_PAGE) == 0)
{
if (*pContext != NULL)
{
CcUnpinData(*pContext);
}
FileOffset.u.LowPart = ROUND_DOWN(DirIndex * sizeof(FATX_DIR_ENTRY), PAGE_SIZE);
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
}
fatxDirEntry = (PFATX_DIR_ENTRY)(*pPage) + DirIndex % FATX_ENTRIES_PER_PAGE;
DirContext->StartIndex = DirContext->DirIndex;
while (TRUE)
{
if (FATX_ENTRY_END(fatxDirEntry))
{
CcUnpinData(*pContext);
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
if (!FATX_ENTRY_DELETED(fatxDirEntry))
{
RtlCopyMemory(&DirContext->DirEntry.FatX, fatxDirEntry, sizeof(FATX_DIR_ENTRY));
break;
}
DirContext->DirIndex++;
DirContext->StartIndex++;
DirIndex++;
if ((DirIndex % FATX_ENTRIES_PER_PAGE) == 0)
{
CcUnpinData(*pContext);
FileOffset.u.LowPart += PAGE_SIZE;
if (FileOffset.u.LowPart >= pDirFcb->RFCB.FileSize.u.LowPart)
{
*pContext = NULL;
return STATUS_NO_MORE_ENTRIES;
}
_SEH2_TRY
{
CcMapData(pDirFcb->FileObject, &FileOffset, PAGE_SIZE, MAP_WAIT, pContext, pPage);
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
*pContext = NULL;
_SEH2_YIELD(return STATUS_NO_MORE_ENTRIES);
}
_SEH2_END;
fatxDirEntry = (PFATX_DIR_ENTRY)*pPage;
}
else
{
fatxDirEntry++;
}
}
DirContext->ShortNameU.Buffer[0] = 0;
DirContext->ShortNameU.Length = 0;
StringO.Buffer = (PCHAR)fatxDirEntry->Filename;
StringO.Length = StringO.MaximumLength = fatxDirEntry->FilenameLength;
RtlOemStringToUnicodeString(&DirContext->LongNameU, &StringO, FALSE);
return STATUS_SUCCESS;
}