Fix for buffer conflict between fat code and cache code - by Mike Lerwill

[reactos.git] / freeldr / freeldr / fs / fat.c

diff --git a/freeldr/freeldr/fs/fat.c b/freeldr/freeldr/fs/fat.c
index b9bdecc..8cb6836 100644 (file)
--- a/freeldr/freeldr/fs/fat.c
+++ b/freeldr/freeldr/fs/fat.c
@@ -40,7 +40,6 @@ ULONG                         RootDirSectors;                 // Number of sectors of the root directory (fat32)
 ULONG                          FatType = 0;                    // FAT12, FAT16, or FAT32
 ULONG                          FatDriveNumber = 0;
 
-
 BOOL FatOpenVolume(ULONG DriveNumber, ULONG VolumeStartSector)
 {
 
@@ -77,6 +76,7 @@ BOOL FatOpenVolume(ULONG DriveNumber, ULONG VolumeStartSector)
 
        // Now try to read the boot sector
        // If this fails then abort
+
        if (!DiskReadLogicalSectors(DriveNumber, VolumeStartSector, 1, FatVolumeBootSector))
        {
                return FALSE;
@@ -247,7 +247,12 @@ ULONG FatDetermineFatType(PFAT_BOOTSECTOR FatBootSector)
        SectorsPerFat = FatBootSector->SectorsPerFat ? FatBootSector->SectorsPerFat : Fat32BootSector->SectorsPerFatBig;
        TotalSectors = FatBootSector->TotalSectors ? FatBootSector->TotalSectors : FatBootSector->TotalSectorsBig;
        DataSectorCount = TotalSectors - (FatBootSector->ReservedSectors + (FatBootSector->NumberOfFats * SectorsPerFat) + RootDirSectors);
-       CountOfClusters = DataSectorCount / FatBootSector->SectorsPerCluster;
+       
+//mjl 
+       if (FatBootSector->SectorsPerCluster == 0)
+               CountOfClusters = 0;
+       else
+               CountOfClusters = DataSectorCount / FatBootSector->SectorsPerCluster;
 
        if (CountOfClusters < 4085)
        {
@@ -771,20 +776,20 @@ BOOL FatGetFatEntry(UINT32 Cluster, PUINT32 ClusterPointer)
 
                if (ThisFatEntOffset == (FatVolumeBootSector->BytesPerSector - 1))
                {
-                       if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 2, (PVOID)DISKREADBUFFER))
+                       if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 2, (PVOID)FILESYSBUFFER))
                        {
                                return FALSE;
                        }
                }
                else
                {
-                       if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)DISKREADBUFFER))
+                       if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)FILESYSBUFFER))
                        {
                                return FALSE;
                        }
                }
 
-               fat = *((WORD *) (DISKREADBUFFER + ThisFatEntOffset));
+               fat = *((WORD *) ((PVOID)FILESYSBUFFER + ThisFatEntOffset));
                if (Cluster & 0x0001) 
                        fat = fat >> 4; /* Cluster number is ODD */
                else
@@ -798,12 +803,12 @@ BOOL FatGetFatEntry(UINT32 Cluster, PUINT32 ClusterPointer)
                ThisFatSecNum = FatVolumeBootSector->ReservedSectors + (FatOffset / FatVolumeBootSector->BytesPerSector);
                ThisFatEntOffset = (FatOffset % FatVolumeBootSector->BytesPerSector);
 
-               if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)DISKREADBUFFER))
+               if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)FILESYSBUFFER))
                {
                        return FALSE;
                }
 
-               fat = *((WORD *) (DISKREADBUFFER + ThisFatEntOffset));
+               fat = *((WORD *) ((PVOID)FILESYSBUFFER + ThisFatEntOffset));
 
                break;
 
@@ -814,13 +819,13 @@ BOOL FatGetFatEntry(UINT32 Cluster, PUINT32 ClusterPointer)
                ThisFatSecNum += FatVolumeBootSector->ReservedSectors + (FatOffset / FatVolumeBootSector->BytesPerSector);
                ThisFatEntOffset = (FatOffset % FatVolumeBootSector->BytesPerSector);
 
-               if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)DISKREADBUFFER))
+               if (!FatReadVolumeSectors(FatDriveNumber, ThisFatSecNum, 1, (PVOID)FILESYSBUFFER))
                {
                        return FALSE;
                }
 
                // Get the fat entry
-               fat = (*((DWORD *) (DISKREADBUFFER + ThisFatEntOffset))) & 0x0FFFFFFF;
+               fat = (*((DWORD *) ((PVOID)FILESYSBUFFER + ThisFatEntOffset))) & 0x0FFFFFFF;
 
                break;
 
@@ -968,12 +973,12 @@ BOOL FatReadCluster(ULONG ClusterNumber, PVOID Buffer)
 
        DbgPrint((DPRINT_FILESYSTEM, "FatReadCluster() ClusterNumber = %d Buffer = 0x%x ClusterStartSector = %d\n", ClusterNumber, Buffer, ClusterStartSector));
 
-       if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)DISKREADBUFFER))
+       if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)FILESYSBUFFER))
        {
                return FALSE;
        }
 
-       memcpy(Buffer, (PVOID)DISKREADBUFFER, FatVolumeBootSector->SectorsPerCluster * FatVolumeBootSector->BytesPerSector);
+       memcpy(Buffer, (PVOID)FILESYSBUFFER, FatVolumeBootSector->SectorsPerCluster * FatVolumeBootSector->BytesPerSector);
 
        return TRUE;
 }
@@ -1000,12 +1005,12 @@ BOOL FatReadClusterChain(ULONG StartClusterNumber, ULONG NumberOfClusters, PVOID
                //
                // Read cluster into memory
                //
-               if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)DISKREADBUFFER))
+               if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)FILESYSBUFFER))
                {
                        return FALSE;
                }
 
-               memcpy(Buffer, (PVOID)DISKREADBUFFER, FatVolumeBootSector->SectorsPerCluster * FatVolumeBootSector->BytesPerSector);
+               memcpy(Buffer, (PVOID)FILESYSBUFFER, FatVolumeBootSector->SectorsPerCluster * FatVolumeBootSector->BytesPerSector);
 
                //
                // Decrement count of clusters left to read
@@ -1051,12 +1056,12 @@ BOOL FatReadPartialCluster(ULONG ClusterNumber, ULONG StartingOffset, ULONG Leng
 
        ClusterStartSector = ((ClusterNumber - 2) * FatVolumeBootSector->SectorsPerCluster) + DataSectorStart;
 
-       if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)DISKREADBUFFER))
+       if (!FatReadVolumeSectors(FatDriveNumber, ClusterStartSector, FatVolumeBootSector->SectorsPerCluster, (PVOID)FILESYSBUFFER))
        {
                return FALSE;
        }
 
-       memcpy(Buffer, (PVOID)(DISKREADBUFFER + StartingOffset), Length);
+       memcpy(Buffer, ((PVOID)FILESYSBUFFER + StartingOffset), Length);
 
        return TRUE;
 }