/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS kernel
 * FILE:            ntoskrnl/ke/bug.c
 * PURPOSE:         Graceful system shutdown if a bug is detected
 * PROGRAMMER:      David Welch (welch@mcmail.com)
 * UPDATE HISTORY:
 *                  Created 22/05/98
 */

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


#include <ddk/ntddk.h>

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


#define TAG_LOCK			TAG('F','l','c','k')

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

NTSTATUS
STDCALL
  NtLockFileCompletionRoutine(
    IN PDEVICE_OBJECT  DeviceObject,
    IN PIRP  Irp,
    IN PVOID  Context
    )
{
	ExFreePool(Context);
	return STATUS_SUCCESS;
	//FIXME: should I call IoFreeIrp and return STATUS_MORE_PROCESSING_REQUIRED?
}

NTSTATUS
STDCALL
NtLockFile (
	IN	HANDLE			FileHandle,
	IN	HANDLE			EventHandle		OPTIONAL,
	IN	PIO_APC_ROUTINE		ApcRoutine	OPTIONAL,
	IN	PVOID			ApcContext	OPTIONAL,
	OUT	PIO_STATUS_BLOCK	UserIoStatusBlock,
	IN	PLARGE_INTEGER		ByteOffset,
	IN	PLARGE_INTEGER		Length,
	IN	PULONG			Key,
	IN	BOOLEAN			FailImmediatedly,
	IN	BOOLEAN			ExclusiveLock
	)
{
	NTSTATUS Status;
	PFILE_OBJECT FileObject = NULL;
	PLARGE_INTEGER	LocalLength = NULL;
	PKEVENT Event = NULL;
	PIRP Irp = NULL;
	PIO_STACK_LOCATION StackPtr;
	IO_STATUS_BLOCK		LocalIoStatusBlock;
	PIO_STATUS_BLOCK IoStatusBlock;
	PDEVICE_OBJECT	DeviceObject;

	//FIXME: instead of this, use SEH when available?
	if (!Length || !ByteOffset)	{
		Status = STATUS_INVALID_PARAMETER;
		goto fail;
	}

	/*
	BUGBUG: ObReferenceObjectByHandle fails if DesiredAccess=0 and mode=UserMode!
	It should ONLY fail if we desire an access that conflict with granted access!
	*/
	Status = ObReferenceObjectByHandle(
	  				 FileHandle,
				     FILE_READ_DATA,//BUGBUG: have to use something...but shouldn't have to!
				     IoFileObjectType,
				     ExGetPreviousMode(),
				     (PVOID*)&FileObject,
				     NULL);

	if (!NT_SUCCESS(Status)){
		goto fail;
	}

	DeviceObject = IoGetRelatedDeviceObject(FileObject);

	Irp = IoAllocateIrp(
			DeviceObject->StackSize,
			TRUE
			);

	if (Irp == NULL) {
		Status = STATUS_INSUFFICIENT_RESOURCES;
		goto fail;
	}

	if (EventHandle != NULL && !FailImmediatedly) {
		 Status = ObReferenceObjectByHandle(
		  			 EventHandle,
					 SYNCHRONIZE,
					 ExEventObjectType,
					 ExGetPreviousMode(),
					 (PVOID*)&Event,
					 NULL);

		if (!NT_SUCCESS(Status)) {
	  		goto fail;
		}

	}	
	else {
		Event = &FileObject->Event;
		KeResetEvent(Event);
	}

	if ((FileObject->Flags & FO_SYNCHRONOUS_IO) || FailImmediatedly)
		IoStatusBlock = &LocalIoStatusBlock;
	else
		IoStatusBlock = UserIoStatusBlock;

	Irp->Overlay.AsynchronousParameters.UserApcRoutine = ApcRoutine;
	Irp->Overlay.AsynchronousParameters.UserApcContext = ApcContext;

	Irp->UserEvent = Event;
	Irp->UserIosb = IoStatusBlock;
	Irp->Tail.Overlay.Thread = PsGetCurrentThread();

	StackPtr = IoGetNextIrpStackLocation(Irp);
	StackPtr->MajorFunction = IRP_MJ_LOCK_CONTROL;
	StackPtr->MinorFunction = IRP_MN_LOCK;
	StackPtr->DeviceObject = DeviceObject;
	StackPtr->FileObject = FileObject;
	
	if (ExclusiveLock) StackPtr->Flags |= SL_EXCLUSIVE_LOCK;
	if (FailImmediatedly) StackPtr->Flags |= SL_FAIL_IMMEDIATELY;

	LocalLength = ExAllocatePoolWithTag(
									NonPagedPool,
									sizeof(LARGE_INTEGER),
									TAG_LOCK
									);
	if (!LocalLength){
		Status = STATUS_INSUFFICIENT_RESOURCES;
		goto fail;
	}

	*LocalLength = *Length;

	StackPtr->Parameters.LockControl.Length = LocalLength;
	StackPtr->Parameters.LockControl.ByteOffset = *ByteOffset;
	StackPtr->Parameters.LockControl.Key = Key ? *Key : 0;

	IoSetCompletionRoutine(  
					Irp,  
					NtLockFileCompletionRoutine,  
					LocalLength,  
					TRUE,   
					TRUE,  
					TRUE  );

  	Status = IofCallDriver(DeviceObject, Irp);

	if (Status == STATUS_PENDING && (FileObject->Flags & FO_SYNCHRONOUS_IO)) {

		Status = KeWaitForSingleObject(
							Event,
							Executive,
							ExGetPreviousMode() , 
							(FileObject->Flags & FO_ALERTABLE_IO) ? TRUE : FALSE,
							NULL
							);

		if (Status != STATUS_WAIT_0) {
			DPRINT1("NtLockFile -> KeWaitForSingleObject failed!\n");
			/*
			FIXME: should do some special processing here if alertable wait 
			was interupted by user apc or a thread alert (STATUS_ALERTED, STATUS_USER_APC)
			*/
			return Status;	 //set status to something else?
	 	}

		Status = LocalIoStatusBlock.Status;
	}

	if (FileObject->Flags & FO_SYNCHRONOUS_IO)
		*UserIoStatusBlock = LocalIoStatusBlock;

	return Status;

	fail:;

	if (LocalLength) ExFreePool(LocalLength);
	if (Irp) IoFreeIrp(Irp);
	if (Event) ObDereferenceObject(Event);
	if (FileObject) ObDereferenceObject(FileObject);

	return Status;

}




NTSTATUS
STDCALL
NtUnlockFile (
	IN	HANDLE			FileHandle,
	OUT	PIO_STATUS_BLOCK	UserIoStatusBlock,
	IN	PLARGE_INTEGER		ByteOffset,
	IN	PLARGE_INTEGER		Length,
	OUT	PULONG			Key		OPTIONAL
	)
{
	NTSTATUS Status;
	PFILE_OBJECT FileObject = NULL;
	PLARGE_INTEGER	LocalLength = NULL;
	PIRP Irp  = NULL;
	PIO_STACK_LOCATION StackPtr;
	IO_STATUS_BLOCK		LocalIoStatusBlock;
	PDEVICE_OBJECT	DeviceObject;

	//FIXME: instead of this, use SEH when available
	if (!Length || !ByteOffset)	{
		Status = STATUS_INVALID_PARAMETER;
		goto fail;
	}

	/*
	BUGBUG: ObReferenceObjectByHandle fails if DesiredAccess=0 and mode=UserMode
	It should ONLY fail if we desire an access that conflict with granted access!
	*/
	Status = ObReferenceObjectByHandle(
	  				 FileHandle,
				     FILE_READ_DATA,//BUGBUG: have to use something...but shouldn't have to!
				     IoFileObjectType,
				     ExGetPreviousMode(),
				     (PVOID*)&FileObject,
				     NULL);

	if (!NT_SUCCESS(Status)){
		goto fail;
	}

	DeviceObject = IoGetRelatedDeviceObject(FileObject);

	Irp = IoAllocateIrp(
			DeviceObject->StackSize,
			TRUE
			);

	if (Irp == NULL) {
		Status = STATUS_INSUFFICIENT_RESOURCES;
		goto fail;
	}

	Irp->UserIosb = &LocalIoStatusBlock;
	Irp->Tail.Overlay.Thread = PsGetCurrentThread();

	StackPtr = IoGetNextIrpStackLocation(Irp);
	StackPtr->MajorFunction = IRP_MJ_LOCK_CONTROL;
	StackPtr->MinorFunction = IRP_MN_UNLOCK_SINGLE;
	StackPtr->DeviceObject = DeviceObject;
	StackPtr->FileObject = FileObject;

	LocalLength = ExAllocatePoolWithTag(
									NonPagedPool,
									sizeof(LARGE_INTEGER),
									TAG_LOCK
									);
	if (!LocalLength){
		Status = STATUS_INSUFFICIENT_RESOURCES;
		goto fail;
	}

	*LocalLength = *Length;

	StackPtr->Parameters.LockControl.Length = LocalLength;
	StackPtr->Parameters.LockControl.ByteOffset = *ByteOffset;
	StackPtr->Parameters.LockControl.Key = Key ? *Key : 0;

	//allways syncronious
	Status = IofCallDriver(DeviceObject, Irp);

	*UserIoStatusBlock = LocalIoStatusBlock;

	ExFreePool(LocalLength);

	return Status;

	fail:;

	if (LocalLength) ExFreePool(LocalLength);
	if (Irp) IoFreeIrp(Irp);
	if (FileObject) ObDereferenceObject(FileObject);

	return Status;
}