blockdev.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/fs/ext2/blockdev.c
 * PURPOSE:          Temporary sector reading support
 * PROGRAMMER:       David Welch ([e-mail])
 * UPDATE HISTORY:
 */

/* INCLUDES *****************************************************************/

#include <ntddk.h>

//#define NDEBUG
#include <debug.h>

#include "ext2fs.h"

/* FUNCTIONS ***************************************************************/

BOOLEAN
Ext2ReadSectors(IN PDEVICE_OBJECT pDeviceObject,
		IN ULONG DiskSector,
		IN ULONG SectorCount,
		IN PVOID Buffer)
{
    LARGE_INTEGER   sectorNumber;
    PIRP            irp;
    IO_STATUS_BLOCK ioStatus;
    KEVENT          event;
    NTSTATUS        status;
    ULONG           sectorSize;
    int j;

    DPRINT("VFATReadSector(pDeviceObject %x, DiskSector %d, Buffer %x)\n",
           pDeviceObject,DiskSector,Buffer);

    sectorNumber.u.HighPart = 0;
    sectorNumber.u.LowPart = DiskSector * BLOCKSIZE;

    DPRINT("DiskSector:%ld BLKSZ:%ld sectorNumber:%ld:%ld\n",
           (unsigned long) DiskSector,
           (unsigned long) BLOCKSIZE,
           (unsigned long) sectorNumber.u.HighPart,
           (unsigned long) sectorNumber.u.LowPart);

    KeInitializeEvent(&event, NotificationEvent, FALSE);

    sectorSize = BLOCKSIZE*SectorCount;


    DPRINT("Building synchronous FSD Request...\n");
    irp = IoBuildSynchronousFsdRequest(IRP_MJ_READ,
                                       pDeviceObject,
                                       Buffer,
                                       sectorSize,
                                       &sectorNumber,
                                       &event,
                                       &ioStatus );

    if (!irp)
     {
        DbgPrint("READ failed!!!\n");
        return FALSE;
     }

    DPRINT("Calling IO Driver...\n");
    status = IoCallDriver(pDeviceObject, irp);

    DPRINT("Waiting for IO Operation...\n");
    if (status == STATUS_PENDING)
     {
        KeWaitForSingleObject(&event,
                              Suspended,
                              KernelMode,
                              FALSE,
                              NULL);
        DPRINT("Getting IO Status...\n");
        status = ioStatus.Status;
     }

   if (!NT_SUCCESS(status))
     {
        DbgPrint("IO failed!!! Error code: %d(%x)\n", status, status);
        return FALSE;
     }

   return TRUE;
}

BOOLEAN VFATWriteSectors(IN PDEVICE_OBJECT pDeviceObject,
		     	 IN ULONG	DiskSector,
                         IN ULONG       SectorCount,
			 IN UCHAR*	Buffer)
{
    LARGE_INTEGER   sectorNumber;
    PIRP            irp;
    IO_STATUS_BLOCK ioStatus;
    KEVENT          event;
    NTSTATUS        status;
    ULONG           sectorSize;
    PULONG          mbr;
    int j;

    DPRINT("VFATWriteSector(pDeviceObject %x, DiskSector %d, Buffer %x)\n",
           pDeviceObject,DiskSector,Buffer);

    sectorNumber.u.HighPart = 0;
    sectorNumber.u.LowPart = DiskSector * BLOCKSIZE;

    KeInitializeEvent(&event, NotificationEvent, FALSE);

    sectorSize = BLOCKSIZE*SectorCount;


    DPRINT("Building synchronous FSD Request...\n");
    irp = IoBuildSynchronousFsdRequest(IRP_MJ_WRITE,
                                       pDeviceObject,
                                       Buffer,
                                       sectorSize,
                                       &sectorNumber,
                                       &event,
                                       &ioStatus );

    if (!irp) {
        DbgPrint("WRITE failed!!!\n");
        return FALSE;
    }

    DPRINT("Calling IO Driver...\n");
    status = IoCallDriver(pDeviceObject,
                          irp);

    DPRINT("Waiting for IO Operation...\n");
    if (status == STATUS_PENDING) {
        KeWaitForSingleObject(&event,
                              Suspended,
                              KernelMode,
                              FALSE,
                              NULL);
        DPRINT("Getting IO Status...\n");
        status = ioStatus.Status;
    }

    if (!NT_SUCCESS(status)) {
        DbgPrint("IO failed!!! Error code: %d(%x)\n", status, status);
        return FALSE;
    }


    ExFreePool(mbr);
    DPRINT("Block request succeeded\n");
    return TRUE;
}