From 267074bb2e47cf1a38b7b5b167a2e4b469c73ef6 Mon Sep 17 00:00:00 2001
From: Hartmut Birr <osexpert@googlemail.com>
Date: Sat, 4 Jan 2003 02:07:18 +0000
Subject: [PATCH] Fixed handling of large FAT32 partitions.

svn path=/trunk/; revision=3928
---
 reactos/drivers/fs/vfat/fat.c  | 47 +++-------------------------------
 reactos/drivers/fs/vfat/rw.c   |  6 ++---
 reactos/drivers/fs/vfat/vfat.h | 11 +++-----
 3 files changed, 9 insertions(+), 55 deletions(-)

diff --git a/reactos/drivers/fs/vfat/fat.c b/reactos/drivers/fs/vfat/fat.c
index 0008a5d8acb..9dbbbe7215b 100644
--- a/reactos/drivers/fs/vfat/fat.c
+++ b/reactos/drivers/fs/vfat/fat.c
@@ -1,5 +1,5 @@
 /*
- * $Id: fat.c,v 1.40 2002/10/01 19:27:18 chorns Exp $
+ * $Id: fat.c,v 1.41 2003/01/04 02:07:18 hbirr Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -632,7 +632,7 @@ WriteCluster(PDEVICE_EXTENSION DeviceExt,
   return(Status);
 }
 
-ULONG
+ULONGLONG
 ClusterToSector(PDEVICE_EXTENSION DeviceExt,
 		ULONG Cluster)
 /*
@@ -641,7 +641,8 @@ ClusterToSector(PDEVICE_EXTENSION DeviceExt,
  */
 {
   return DeviceExt->FatInfo.dataStart +
-    ((Cluster - 2) * DeviceExt->FatInfo.SectorsPerCluster);
+    ((ULONGLONG)(Cluster - 2) * DeviceExt->FatInfo.SectorsPerCluster);
+
 }
 
 NTSTATUS
@@ -774,44 +775,4 @@ GetNextCluster(PDEVICE_EXTENSION DeviceExt,
   return(Status);
 }
 
-
-NTSTATUS
-GetNextSector(PDEVICE_EXTENSION DeviceExt,
-	      ULONG CurrentSector,
-	      PULONG NextSector,
-	      BOOLEAN Extend)
-/* Some functions don't have access to the cluster they're really reading from.
-   Maybe this is a dirty solution, but it will allow them to handle fragmentation. */
-{
-  NTSTATUS Status;
-
-  DPRINT("GetNextSector(DeviceExt %x, CurrentSector %x)\n",
-	 DeviceExt,
-	 CurrentSector);
-  if (CurrentSector<DeviceExt->FatInfo.dataStart || ((CurrentSector - DeviceExt->FatInfo.dataStart + 1) % DeviceExt->FatInfo.SectorsPerCluster))
-  /* Basically, if the next sequential sector would be on a cluster border, then we'll need to check in the FAT */
-    {
-      (*NextSector)=CurrentSector+1;
-      return (STATUS_SUCCESS);
-    }
-  else
-    {
-      CurrentSector = (CurrentSector - DeviceExt->FatInfo.dataStart) / DeviceExt->FatInfo.SectorsPerCluster + 2;
-
-      Status = GetNextCluster(DeviceExt, CurrentSector, NextSector, Extend);
-      if (!NT_SUCCESS(Status))
-	{
-	  return(Status);
-	}
-      if ((*NextSector) == 0 || (*NextSector) == 0xffffffff)
-	{
-	  /* The caller wants to know a sector. These FAT codes don't correspond to any sector. */
-	  return(STATUS_UNSUCCESSFUL);
-	}
-
-      (*NextSector) = ClusterToSector(DeviceExt,(*NextSector));
-      return(STATUS_SUCCESS);
-    }
-}
-
 /* EOF */
diff --git a/reactos/drivers/fs/vfat/rw.c b/reactos/drivers/fs/vfat/rw.c
index 566e978c778..7fb3b7f7ea1 100644
--- a/reactos/drivers/fs/vfat/rw.c
+++ b/reactos/drivers/fs/vfat/rw.c
@@ -1,5 +1,5 @@
 
-/* $Id: rw.c,v 1.51 2003/01/03 23:58:31 gvg Exp $
+/* $Id: rw.c,v 1.52 2003/01/04 02:07:18 hbirr Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -273,7 +273,6 @@ VfatReadFileData (PVFAT_IRP_CONTEXT IrpContext, PVOID Buffer,
   NTSTATUS Status;
   ULONG BytesDone;
   ULONG BytesPerSector;
-  LARGE_INTEGER BytesPerSectorLarge;
   ULONG BytesPerCluster;
 
   /* PRECONDITION */
@@ -293,7 +292,6 @@ VfatReadFileData (PVFAT_IRP_CONTEXT IrpContext, PVOID Buffer,
   Ccb = (PVFATCCB)IrpContext->FileObject->FsContext2;
   Fcb = Ccb->pFcb;
   BytesPerSector = DeviceExt->FatInfo.BytesPerSector;
-  BytesPerSectorLarge.QuadPart = BytesPerSector;
   BytesPerCluster = DeviceExt->FatInfo.BytesPerCluster;
 
   assert(ReadOffset.QuadPart + Length <= ROUND_UP(Fcb->RFCB.FileSize.QuadPart, BytesPerSector));
@@ -377,7 +375,7 @@ VfatReadFileData (PVFAT_IRP_CONTEXT IrpContext, PVOID Buffer,
   while (Length > 0 && CurrentCluster != 0xffffffff && NT_SUCCESS(Status))
   {
     StartCluster = CurrentCluster;
-    StartOffset.QuadPart = ClusterToSector(DeviceExt, StartCluster) * BytesPerSectorLarge.QuadPart;
+    StartOffset.QuadPart = ClusterToSector(DeviceExt, StartCluster) * BytesPerSector;
     BytesDone = 0;
     ClusterCount = 0;
 
diff --git a/reactos/drivers/fs/vfat/vfat.h b/reactos/drivers/fs/vfat/vfat.h
index 651f8768692..dddb7165e5a 100644
--- a/reactos/drivers/fs/vfat/vfat.h
+++ b/reactos/drivers/fs/vfat/vfat.h
@@ -1,4 +1,4 @@
-/* $Id: vfat.h,v 1.49 2002/12/03 01:14:49 hbirr Exp $ */
+/* $Id: vfat.h,v 1.50 2003/01/04 02:07:18 hbirr Exp $ */
 
 #include <ddk/ntifs.h>
 
@@ -397,19 +397,14 @@ NTSTATUS OffsetToCluster (PDEVICE_EXTENSION DeviceExt,
                           PULONG Cluster,
                           BOOLEAN Extend);
 
-ULONG ClusterToSector (PDEVICE_EXTENSION DeviceExt,
-                       ULONG Cluster);
+ULONGLONG ClusterToSector (PDEVICE_EXTENSION DeviceExt,
+			   ULONG Cluster);
 
 NTSTATUS GetNextCluster (PDEVICE_EXTENSION DeviceExt,
                          ULONG CurrentCluster,
                          PULONG NextCluster,
                          BOOLEAN Extend);
 
-NTSTATUS GetNextSector (PDEVICE_EXTENSION DeviceExt,
-                        ULONG CurrentSector,
-                        PULONG NextSector,
-                        BOOLEAN Extend);
-
 NTSTATUS CountAvailableClusters (PDEVICE_EXTENSION DeviceExt,
                                  PLARGE_INTEGER Clusters);