drivers/filesystems/fastfat_new/rw.c

   1 /*
   2  * PROJECT:         ReactOS FAT file system driver
   3  * LICENSE:         GNU GPLv3 as published by the Free Software Foundation
   4  * FILE:            drivers/filesystems/fastfat/rw.c
   5  * PURPOSE:         Read/write support
   6  * PROGRAMMERS:     Aleksey Bragin (aleksey@reactos.org)
   7  */
   8
   9 /* INCLUDES *****************************************************************/
  10
  11 #define NDEBUG
  12 #include "fastfat.h"
  13
  14 /* FUNCTIONS *****************************************************************/
  15
  16 NTSTATUS
  17 NTAPI
  18 FatiRead(PFAT_IRP_CONTEXT IrpContext)
  19 {
  20     ULONG NumberOfBytes;
  21     LARGE_INTEGER ByteOffset;
  22     PFILE_OBJECT FileObject;
  23     TYPE_OF_OPEN OpenType;
  24     PIO_STACK_LOCATION IrpSp = IrpContext->Stack;
  25     PFCB Fcb;
  26     PVCB Vcb;
  27     PCCB Ccb;
  28     PVOID Buffer;
  29     LONG BytesRead;
  30
  31     FileObject = IrpSp->FileObject;
  32     NumberOfBytes = IrpSp->Parameters.Read.Length;
  33     ByteOffset = IrpSp->Parameters.Read.ByteOffset;
  34     if (NumberOfBytes == 0)
  35     {
  36         FatCompleteRequest(IrpContext, IrpContext->Irp, STATUS_SUCCESS);
  37         return STATUS_SUCCESS;
  38     }
  39
  40     OpenType = FatDecodeFileObject(FileObject, &Vcb, &Fcb, &Ccb);
  41
  42     DPRINT("FatiRead() Fcb %p, Name %wZ, Offset %d, Length %d, Handle %p\n",
  43         Fcb, &FileObject->FileName, ByteOffset.LowPart, NumberOfBytes, Fcb->FatHandle);
  44
  45     /* Perform actual read */
  46
  47     if (IrpContext->MinorFunction & IRP_MN_MDL)
  48     {
  49         DPRINT1("MDL read\n");
  50     }
  51     else
  52     {
  53         Buffer = FatMapUserBuffer(IrpContext->Irp);
  54         DPRINT("Normal cached read, buffer %p\n");
  55
  56         /* Set offset */
  57         FF_Seek(Fcb->FatHandle, ByteOffset.LowPart, FF_SEEK_SET);
  58
  59         /* Read */
  60         BytesRead = FF_Read(Fcb->FatHandle, NumberOfBytes, 1, Buffer);
  61         DPRINT("Read %d bytes\n", BytesRead);
  62
  63         /* Indicate we read requested amount of bytes */
  64         IrpContext->Irp->IoStatus.Information = BytesRead;
  65         IrpContext->Irp->IoStatus.Status = STATUS_SUCCESS;
  66     }
  67
  68     /* Complete the request */
  69     FatCompleteRequest(IrpContext, IrpContext->Irp, STATUS_SUCCESS);
  70     return STATUS_SUCCESS;
  71 }
  72
  73 NTSTATUS
  74 NTAPI
  75 FatRead(PDEVICE_OBJECT DeviceObject, PIRP Irp)
  76 {
  77     NTSTATUS Status;
  78     BOOLEAN TopLevel, CanWait;
  79     PFAT_IRP_CONTEXT IrpContext;
  80
  81     CanWait = TRUE;
  82     TopLevel = FALSE;
  83     Status = STATUS_INVALID_DEVICE_REQUEST;
  84     /* Get CanWait flag */
  85     if (IoGetCurrentIrpStackLocation(Irp)->FileObject != NULL)
  86         CanWait = IoIsOperationSynchronous(Irp);
  87
  88     /* Enter FsRtl critical region */
  89     FsRtlEnterFileSystem();
  90
  91     if (DeviceObject != FatGlobalData.DiskDeviceObject)
  92     {
  93         /* Set Top Level IRP if not set */
  94         if (IoGetTopLevelIrp() == NULL)
  95         {
  96             IoSetTopLevelIrp(Irp);
  97             TopLevel = TRUE;
  98         }
  99
 100         /* Build an irp context */
 101         IrpContext = FatBuildIrpContext(Irp, CanWait);
 102
 103         /* Perform the actual read */
 104         Status = FatiRead(IrpContext);
 105
 106         /* Restore top level Irp */
 107         if (TopLevel)
 108             IoSetTopLevelIrp(NULL);
 109     }
 110     /* Leave FsRtl critical region */
 111     FsRtlExitFileSystem();
 112
 113     return Status;
 114 }
 115
 116 NTSTATUS
 117 NTAPI
 118 FatWrite(PDEVICE_OBJECT DeviceObject, PIRP Irp)
 119 {
 120     DPRINT1("FatWrite()\n");
 121     return STATUS_NOT_IMPLEMENTED;
 122 }
 123
 124