diskperf例子中IRP_MJ_READ/IRP_MJ_WRITE处理出错！

typedef struct {
LARGE_INTEGER dwSecBeg;
DWORD dwSecCnt;
}SPLIT_TAB,*PSPLIT_TAB;

NTSTATUS DispatchReadWrite(PDEVICE_OBJECT DeviceObject, PIRP Irp)
{
PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

DWORD TotalLen = Irp->MdlAddress ? MmGetMdlByteCount(Irp->MdlAddress) : 0;
if(TotalLen == 0)
{
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
return STATUS_SUCCESS;
}

PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
PIO_STACK_LOCATION nextstack = IoGetNextIrpStackLocation(Irp);

KIRQL oldirql;
KeAcquireSpinLock(&pdx->RWSpinLock, &oldirql); // RWSpinLock已经初始化

int MapNum = Split(pdx->pmtst,stack->Parameters.Read.ByteOffset,TotalLen);

KeReleaseSpinLock(&pdx->RWSpinLock, oldirql);

if(MapNum != 1)
{
KeBugCheckEx(0xffff0001,0,0,0,0);
}

KeAcquireSpinLock(&pdx->RWSpinLock, &oldirql);

LARGE_INTEGER dwBeg = pdx->pmtst[0].dwSecBeg;

KeReleaseSpinLock(&pdx->RWSpinLock, oldirql);

stack->Parameters.Read.ByteOffset = dwBeg;

*nextstack = *stack;

IoSetCompletionRoutine(Irp,DispatchIoCompletion,
NULL,TRUE,TRUE,TRUE);

return IoCallDriver(pdx->TargetDeviceObject,Irp);
}

NTSTATUS
DispatchIoCompletion(
IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp,
IN PVOID Context
)
{
if (Irp->PendingReturned) {
IoMarkIrpPending(Irp);
}
return STATUS_SUCCESS;
}

DWORD Split(PSPLIT_TAB pst,LARGE_INTEGER dwSecBeg ,DWORD dwSecCnt)
{
pst[0].dwSecBeg = dwSecBeg;
pst[0].dwSecCnt = dwSecCnt;
return 1;
}

粗体字部分不加上，一切正常！
粗体字部分加上后，发现数据读写错误，究竟是哪里错了？

Help me！

[编辑 -  9/6/04 by  Leopard]

我把RWSpinLock去掉，居然又一切正常！和RWSpinLock有什么关系吗？
Help Me！

你为什么要把stack->Parameters.Read.ByteOffset保存起来呢？
Split返回值一定是1
if(MapNum != 1)
{
        KeBugCheckEx(0xffff0001,0,0,0,0);
}
就没有什么作用的啊！
你把stack->Parameters.Read.ByteOffset的值修改了吧！
估计问题出在Split函数里面和stack->Parameters.Read.ByteOffset = dwBeg;
这一句话
你尝试一下把
DWORD Split(PSPLIT_TAB pst,PLARGE_INTEGER pSecBeg ,DWORD dwSecCnt)
{
pst[0].dwSecBeg.QuadPart  = pSecBeg->QuadPart ;
pst[0].dwSecCnt = dwSecCnt;
return 1;
}

LARGE_INTEGER dwBeg;
dwBeg.QuadPart    = pdx->pmtst[0].dwSecBeg.QuadPart;


stack->Parameters.Read.ByteOffset.QuadPart  = dwBeg.QuadPart ;

谢谢！
为何我把RWSpinLock去掉后，一切正常？
我主要是想切割请求，如何才能做到？
Help Me！

我试试吧，看是不是这个原因！
Thanks!

虽然你没有给出正确答案，我仍然感谢你，付分为证！

其实是Split使用pdx->pmtst有错，应该用局部变量pmtst！

你把以下的这些去掉就可以了啊！
KeReleaseSpinLock(&pdx->RWSpinLock, oldirql);

if(MapNum != 1)
{
KeBugCheckEx(0xffff0001,0,0,0,0);
}

KeAcquireSpinLock(&pdx->RWSpinLock, &oldirql);

我的意思是第一次SpinLock保护Split函数，第二次SpinLock保证
传给stack的数据的正确！

if(MapNum != 1)
{
KeBugCheckEx(0xffff0001,0,0,0,0);
}
是判断Split的返回值！

其实是Split使用pdx->pmtst有错，应该用局部变量pmtst！

换成局部变量问题就解决，这样对吗？

Thanks！

是的！因为你的
KIRQL oldirql;
KeAcquireSpinLock(&pdx->RWSpinLock, &oldirql); // RWSpinLock已经初始化

int MapNum = Split(pdx->pmtst,stack->Parameters.Read.ByteOffset,TotalLen);

KeReleaseSpinLock(&pdx->RWSpinLock, oldirql);
把pdx->pmtst修改了！假如有两个请求一前一后的到来，第一个从这部分代码过去了！到
KeAcquireSpinLock(&pdx->RWSpinLock, &oldirql);

LARGE_INTEGER dwBeg = pdx->pmtst[0].dwSecBeg;

KeReleaseSpinLock(&pdx->RWSpinLock, oldirql);

停住！第二个进入了上面的代码，把全局变量pdx->pmtst修改了！那么这个时候两个请求的pdx->pmtst都是一样的了

Thanks!

学习一下，顺便问一句，diskperf 是disk performance 吗，主要是干什么的？