reactos/drivers/filesystems/fs_rec/ext2.c

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/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS File System Recognizer
* FILE: drivers/filesystems/fs_rec/ext2.c
* PURPOSE: EXT2 Recognizer
* PROGRAMMER: Eric Kohl
* Pierre Schweitzer (pierre@reactos.org)
*/
/* INCLUDES *****************************************************************/
#include "fs_rec.h"
#include "ext2.h"
#define NDEBUG
#include <debug.h>
/* FUNCTIONS ****************************************************************/
BOOLEAN
NTAPI
FsRecIsExt2Volume(IN PEXT2_SUPER_BLOCK SuperBlock)
{
/* Just check for magic */
return (SuperBlock->Magic == EXT2_SUPER_MAGIC);
}
NTSTATUS
NTAPI
FsRecExt2FsControl(IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp)
{
PIO_STACK_LOCATION Stack;
NTSTATUS Status;
PDEVICE_OBJECT MountDevice;
PEXT2_SUPER_BLOCK Spb = NULL;
ULONG SectorSize;
LARGE_INTEGER Offset;
BOOLEAN DeviceError = FALSE;
PAGED_CODE();
/* Get the I/O Stack and check the function type */
Stack = IoGetCurrentIrpStackLocation(Irp);
switch (Stack->MinorFunction)
{
case IRP_MN_MOUNT_VOLUME:
/* Assume failure */
Status = STATUS_UNRECOGNIZED_VOLUME;
/* Get the device object and request the sector size */
MountDevice = Stack->Parameters.MountVolume.DeviceObject;
if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
{
/* Try to read the superblock */
Offset.QuadPart = EXT2_SB_OFFSET;
if (FsRecReadBlock(MountDevice,
&Offset,
EXT2_SB_SIZE,
SectorSize,
(PVOID)&Spb,
&DeviceError))
{
/* Check if it's an actual EXT2 volume */
if (FsRecIsExt2Volume(Spb))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
/* Free the boot sector if we have one */
ExFreePool(Spb);
}
else
{
/* We have some sort of failure in the storage stack */
DeviceError = TRUE;
}
/* Check if we have an error on the stack */
if (DeviceError)
{
/* Was this because of a floppy? */
if (MountDevice->Characteristics & FILE_FLOPPY_DISKETTE)
{
/* Let the FS try anyway */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
break;
case IRP_MN_LOAD_FILE_SYSTEM:
/* Load the file system */
Status = FsRecLoadFileSystem(DeviceObject,
L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Ext2fs");
break;
default:
/* Invalid request */
Status = STATUS_INVALID_DEVICE_REQUEST;
}
/* Return Status */
return Status;
}
/* EOF */