reactos/drivers/filesystems/fs_rec/reiserfs.c

   1 /*
   2  * COPYRIGHT:        See COPYING in the top level directory
   3  * PROJECT:          ReactOS File System Recognizer
   4  * FILE:             drivers/filesystems/fs_rec/btrfs.c
   5  * PURPOSE:          Btrfs Recognizer
   6  * PROGRAMMER:       Peter Hater
   7  *                   Pierre Schweitzer (pierre@reactos.org)
   8  */
   9
  10 /* INCLUDES *****************************************************************/
  11
  12 #include "fs_rec.h"
  13 #include "reiserfs.h"
  14
  15 #define NDEBUG
  16 #include <debug.h>
  17
  18 /* FUNCTIONS ****************************************************************/
  19
  20 BOOLEAN
  21 NTAPI
  22 FsRecIsReiserfsVolume(IN PRFSD_SUPER_BLOCK sb)
  23 {
  24     UCHAR sz_MagicKey[] = REISER2FS_SUPER_MAGIC_STRING;
  25     UCHAR currentChar;
  26     int   i;
  27
  28     // If any characters read from disk don't match the expected magic key, we don't have a ReiserFS volume.
  29     for (i = 0; i < MAGIC_KEY_LENGTH; i++)
  30     {
  31         currentChar = sb->s_magic[i];
  32         if (currentChar != sz_MagicKey[i])
  33         {
  34             return FALSE;
  35         }
  36     }
  37
  38     return TRUE;
  39 }
  40
  41 NTSTATUS
  42 NTAPI
  43 FsRecReiserfsFsControl(IN PDEVICE_OBJECT DeviceObject,
  44                     IN PIRP Irp)
  45 {
  46     PIO_STACK_LOCATION Stack;
  47     NTSTATUS Status;
  48     PDEVICE_OBJECT MountDevice;
  49     PRFSD_SUPER_BLOCK Spb = NULL;
  50     ULONG SectorSize;
  51     LARGE_INTEGER Offset;
  52     BOOLEAN DeviceError = FALSE;
  53     PAGED_CODE();
  54
  55     /* Get the I/O Stack and check the function type */
  56     Stack = IoGetCurrentIrpStackLocation(Irp);
  57     switch (Stack->MinorFunction)
  58     {
  59         case IRP_MN_MOUNT_VOLUME:
  60
  61             /* Assume failure */
  62             Status = STATUS_UNRECOGNIZED_VOLUME;
  63
  64             /* Get the device object and request the sector size */
  65             MountDevice = Stack->Parameters.MountVolume.DeviceObject;
  66             if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
  67             {
  68                 /* Try to read the superblock */
  69                 Offset.QuadPart = REISERFS_DISK_OFFSET_IN_BYTES;
  70                 if (FsRecReadBlock(MountDevice,
  71                                    &Offset,
  72                                    SectorSize,
  73                                    SectorSize,
  74                                    (PVOID)&Spb,
  75                                    &DeviceError))
  76                 {
  77                     /* Check if it's an actual BTRFS volume */
  78                     if (FsRecIsReiserfsVolume(Spb))
  79                     {
  80                         /* It is! */
  81                         Status = STATUS_FS_DRIVER_REQUIRED;
  82                     }
  83                 }
  84
  85                 /* Free the boot sector if we have one */
  86                 ExFreePool(Spb);
  87             }
  88             else
  89             {
  90                 /* We have some sort of failure in the storage stack */
  91                 DeviceError = TRUE;
  92             }
  93
  94             /* Check if we have an error on the stack */
  95             if (DeviceError)
  96             {
  97                 /* Was this because of a floppy? */
  98                 if (MountDevice->Characteristics & FILE_FLOPPY_DISKETTE)
  99                 {
 100                     /* Let the FS try anyway */
 101                     Status = STATUS_FS_DRIVER_REQUIRED;
 102                 }
 103             }
 104
 105             break;
 106
 107         case IRP_MN_LOAD_FILE_SYSTEM:
 108
 109             /* Load the file system */
 110             Status = FsRecLoadFileSystem(DeviceObject,
 111                                          L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\reiserfs");
 112             break;
 113
 114         default:
 115
 116             /* Invalid request */
 117             Status = STATUS_INVALID_DEVICE_REQUEST;
 118     }
 119
 120     /* Return Status */
 121     return Status;
 122 }