reactos/drivers/filesystems/fs_rec/btrfs.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 "btrfs.h"
  14
  15 #define NDEBUG
  16 #include <debug.h>
  17
  18 /* FUNCTIONS ****************************************************************/
  19
  20 BOOLEAN
  21 NTAPI
  22 FsRecIsBtrfsVolume(IN PBTRFS_SUPER_BLOCK SuperBlock)
  23 {
  24     /* Just check for magic */
  25     return (SuperBlock->magic == BTRFS_MAGIC);
  26 }
  27
  28 NTSTATUS
  29 NTAPI
  30 FsRecBtrfsFsControl(IN PDEVICE_OBJECT DeviceObject,
  31                     IN PIRP Irp)
  32 {
  33     PIO_STACK_LOCATION Stack;
  34     NTSTATUS Status;
  35     PDEVICE_OBJECT MountDevice;
  36     PBTRFS_SUPER_BLOCK Spb = NULL;
  37     ULONG SectorSize;
  38     LARGE_INTEGER Offset;
  39     BOOLEAN DeviceError = FALSE;
  40     PAGED_CODE();
  41
  42     /* Get the I/O Stack and check the function type */
  43     Stack = IoGetCurrentIrpStackLocation(Irp);
  44     switch (Stack->MinorFunction)
  45     {
  46         case IRP_MN_MOUNT_VOLUME:
  47
  48             /* Assume failure */
  49             Status = STATUS_UNRECOGNIZED_VOLUME;
  50
  51             /* Get the device object and request the sector size */
  52             MountDevice = Stack->Parameters.MountVolume.DeviceObject;
  53             if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
  54             {
  55                 /* Try to read the superblock */
  56                 Offset.QuadPart = BTRFS_SB_OFFSET;
  57                 if (FsRecReadBlock(MountDevice,
  58                                    &Offset,
  59                                    BTRFS_SB_SIZE,
  60                                    SectorSize,
  61                                    (PVOID)&Spb,
  62                                    &DeviceError))
  63                 {
  64                     /* Check if it's an actual BTRFS volume */
  65                     if (FsRecIsBtrfsVolume(Spb))
  66                     {
  67                         /* It is! */
  68                         Status = STATUS_FS_DRIVER_REQUIRED;
  69                     }
  70                 }
  71
  72                 /* Free the boot sector if we have one */
  73                 ExFreePool(Spb);
  74             }
  75             else
  76             {
  77                 /* We have some sort of failure in the storage stack */
  78                 DeviceError = TRUE;
  79             }
  80
  81             /* Check if we have an error on the stack */
  82             if (DeviceError)
  83             {
  84                 /* Was this because of a floppy? */
  85                 if (MountDevice->Characteristics & FILE_FLOPPY_DISKETTE)
  86                 {
  87                     /* Let the FS try anyway */
  88                     Status = STATUS_FS_DRIVER_REQUIRED;
  89                 }
  90             }
  91
  92             break;
  93
  94         case IRP_MN_LOAD_FILE_SYSTEM:
  95
  96             /* Load the file system */
  97             Status = FsRecLoadFileSystem(DeviceObject,
  98                                          L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\btrfs");
  99             break;
 100
 101         default:
 102
 103             /* Invalid request */
 104             Status = STATUS_INVALID_DEVICE_REQUEST;
 105     }
 106
 107     /* Return Status */
 108     return Status;
 109 }