write.c

FSD file system driver

				{
					FFSBreakPoint();

					Status = STATUS_INVALID_USER_BUFFER;
					__leave;
				}

				if (!CcCopyWrite(Vcb->StreamObj,
							(PLARGE_INTEGER)(&ByteOffset),
							Length,
							TRUE,
							Buffer))
				{
					Status = STATUS_PENDING;
					__leave;
				}

				Status = Irp->IoStatus.Status;
				FFSAddMcbEntry(Vcb, ByteOffset.QuadPart, (LONGLONG)Length);
			}

			if (NT_SUCCESS(Status))
			{
				Irp->IoStatus.Information = Length;
			}
		}
		else
		{
			PFFS_BDL            ffs_bdl = NULL;
			ULONG               Blocks = 0;

			LONGLONG            DirtyStart;
			LONGLONG            DirtyLba;
			LONGLONG            DirtyLength;
			LONGLONG            RemainLength;

			if ((ByteOffset.QuadPart + Length) >
					Vcb->PartitionInformation.PartitionLength.QuadPart)
			{
				Length = (ULONG)(
						Vcb->PartitionInformation.PartitionLength.QuadPart -
						ByteOffset.QuadPart);

				Length &= ~((ULONG)SECTOR_SIZE - 1);
			}

			Status = FFSLockUserBuffer(
					IrpContext->Irp,
					Length,
					IoReadAccess);

			if (!NT_SUCCESS(Status))
			{
				__leave;
			}

			ffs_bdl = ExAllocatePool(PagedPool, 
					(Length / Vcb->BlockSize) *
					sizeof(FFS_BDL));

			if (!ffs_bdl)
			{
				Status = STATUS_INSUFFICIENT_RESOURCES;
				__leave;
			}

			DirtyLba = ByteOffset.QuadPart;
			RemainLength = (LONGLONG)Length;

			while (RemainLength > 0)
			{
				DirtyStart = DirtyLba;

				if (FFSLookupMcbEntry(Vcb, 
							DirtyStart,
							&DirtyLba,
							&DirtyLength,
							(PLONGLONG)NULL,
							(PLONGLONG)NULL,
							(PULONG)NULL))
				{

					if (DirtyLba == -1)
					{
						DirtyLba = DirtyStart + DirtyLength;

						RemainLength = ByteOffset.QuadPart + 
							(LONGLONG)Length -
							DirtyLba;
						continue;
					}

					ffs_bdl[Blocks].Irp = NULL;
					ffs_bdl[Blocks].Lba = DirtyLba;
					ffs_bdl[Blocks].Offset = (ULONG)((LONGLONG)Length +
							DirtyStart -
							RemainLength - 
							DirtyLba);

					if (DirtyLba + DirtyLength > DirtyStart + RemainLength)
					{
						ffs_bdl[Blocks].Length = (ULONG)(DirtyStart +
								RemainLength -
								DirtyLba);
						RemainLength = 0;
					}
					else
					{
						ffs_bdl[Blocks].Length = (ULONG)DirtyLength;
						RemainLength =  (DirtyStart + RemainLength) -
							(DirtyLba + DirtyLength);
					}

					DirtyLba = DirtyStart + DirtyLength;
					Blocks++;
				}
				else
				{
					if (Blocks == 0)
					{
						if (ffs_bdl)
							ExFreePool(ffs_bdl);

						//
						// Lookup fails at the first time, ie. 
						// no dirty blocks in the run
						//

						FFSBreakPoint();

						if (RemainLength == (LONGLONG)Length)
							Status = STATUS_SUCCESS;
						else
							Status = STATUS_UNSUCCESSFUL;

						__leave;
					}
					else
					{
						break;
					}
				}
			}

			if (Blocks > 0)
			{
				Status = FFSReadWriteBlocks(IrpContext,
							Vcb,
							ffs_bdl,
							Length,
							Blocks,
							FALSE);
				Irp = IrpContext->Irp;

				if (NT_SUCCESS(Status))
				{
					ULONG   i;

					for (i = 0; i < Blocks; i++)
					{
						FFSRemoveMcbEntry(Vcb,
								ffs_bdl[i].Lba,
								ffs_bdl[i].Length);
					}
				}

				if (ffs_bdl)
					ExFreePool(ffs_bdl);

				if (!Irp)
					__leave;

			}
			else
			{
				if (ffs_bdl)
					ExFreePool(ffs_bdl);

				Irp->IoStatus.Information = Length;

				Status = STATUS_SUCCESS;
				__leave;
			}
		}
	}

	__finally
	{
		if (PagingIoResourceAcquired)
		{
			ExReleaseResourceForThreadLite(
					&Vcb->PagingIoResource,
					ExGetCurrentResourceThread());
		}

		if (MainResourceAcquired)
		{
			ExReleaseResourceForThreadLite(
					&Vcb->MainResource,
					ExGetCurrentResourceThread());
		}

		if (!IrpContext->ExceptionInProgress)
		{
			if (Irp)
			{
				if (Status == STATUS_PENDING)
				{
					if(!bDeferred)
					{
						Status = FFSLockUserBuffer(
								IrpContext->Irp,
								Length,
								IoReadAccess);

						if (NT_SUCCESS(Status))
						{
							Status = FFSQueueRequest(IrpContext);
						}
						else
						{
							FFSCompleteIrpContext(IrpContext, Status);
						}
					}
				}
				else
				{
					if (NT_SUCCESS(Status))
					{
						if (SynchronousIo && !PagingIo)
						{
							FileObject->CurrentByteOffset.QuadPart =
								ByteOffset.QuadPart + Irp->IoStatus.Information;
						}

						if (!PagingIo)
						{
							SetFlag(FileObject->Flags, FO_FILE_MODIFIED);
						}
					}

					FFSCompleteIrpContext(IrpContext, Status);
				}
			}
			else
			{
				FFSFreeIrpContext(IrpContext);
			}
		}
	}

	return Status;
}


NTSTATUS
FFSv1WriteInode(
	IN PFFS_IRP_CONTEXT     IrpContext,
	IN PFFS_VCB             Vcb,
	IN PFFSv1_INODE         dinode1,
	IN ULONGLONG            offset,
	IN PVOID                Buffer,
	IN ULONG                size,
	IN BOOLEAN              bWriteToDisk,
	OUT PULONG              dwRet)
{
	PFFS_BDL    ffs_bdl = NULL;
	ULONG       blocks, i;
	NTSTATUS    Status = STATUS_UNSUCCESSFUL;
	ULONG       Totalblocks;
	LONGLONG    AllocSize;

	if (dwRet)
	{
		*dwRet = 0;
	}

	Totalblocks = (dinode1->di_blocks);
	AllocSize = ((LONGLONG)(FFSDataBlocks(Vcb, Totalblocks)) << BLOCK_BITS);

	if ((LONGLONG)offset >= AllocSize)
	{
		FFSPrint((DBG_ERROR, "FFSv1WriteInode: beyond the file range.\n"));
		return STATUS_SUCCESS;
	}

	if ((LONGLONG)offset + size > AllocSize)
	{
		size = (ULONG)(AllocSize - offset);
	}

	blocks = FFSv1BuildBDL(IrpContext, Vcb, dinode1, offset, size, &ffs_bdl);

	if (blocks <= 0)
	{
		return STATUS_SUCCESS;
	}

#if DBG
	{
		ULONG   dwTotal = 0;
		FFSPrint((DBG_INFO, "FFSv1WriteInode: BDLCount = %xh Size=%xh Off=%xh\n",
					blocks, size, offset));
		for(i = 0; i < blocks; i++)
		{
			FFSPrint((DBG_INFO, "FFSv1WriteInode: Lba=%I64xh Len=%xh Off=%xh\n",
						ffs_bdl[i].Lba, ffs_bdl[i].Length, ffs_bdl[i].Offset));
			dwTotal += ffs_bdl[i].Length;
		}

		if (dwTotal != size)
		{
			FFSBreakPoint();
		}

		FFSPrint((DBG_INFO, "FFSv1WriteInode: Total = %xh (WriteToDisk=%x)\n",
					dwTotal, bWriteToDisk));
	}
#endif

	if (bWriteToDisk)
	{

#if 0
		for(i = 0; i < blocks; i++)
		{
			{
				CcFlushCache(&(Vcb->SectionObject),
						(PLARGE_INTEGER)&(ffs_bdl[i].Lba),
						ffs_bdl[i].Length,
						NULL);

				if (Vcb->SectionObject.DataSectionObject != NULL)
				{
					ExAcquireSharedStarveExclusive(&Vcb->PagingIoResource, TRUE);
					ExReleaseResource(&Vcb->PagingIoResource);

					CcPurgeCacheSection(&(Vcb->SectionObject),
							(PLARGE_INTEGER)&(ffs_bdl[i].Lba),
							ffs_bdl[i].Length,
							FALSE);
				}
			}
		}
#endif

		// assume offset is aligned.
		Status = FFSReadWriteBlocks(IrpContext, Vcb, ffs_bdl, size, blocks, FALSE);
	}
	else
	{
		for(i = 0; i < blocks; i++)
		{
			if(!FFSSaveBuffer(IrpContext, Vcb, ffs_bdl[i].Lba, ffs_bdl[i].Length, (PVOID)((PUCHAR)Buffer + ffs_bdl[i].Offset)))
				goto errorout;
		}

		if (IsFlagOn(Vcb->Flags, VCB_FLOPPY_DISK))
		{
			FFSPrint((DBG_USER, "FFSv1WriteInode is starting FlushingDpc...\n"));
			FFSStartFloppyFlushDpc(Vcb, NULL, NULL);
		}

		Status = STATUS_SUCCESS;
	}

errorout:

	if (ffs_bdl)
		ExFreePool(ffs_bdl);

	if (NT_SUCCESS(Status))
	{
		if (dwRet) *dwRet = size;
	}

	return Status;
}


NTSTATUS
FFSv2WriteInode(
	IN PFFS_IRP_CONTEXT     IrpContext,
	IN PFFS_VCB             Vcb,
	IN PFFSv2_INODE         dinode2,
	IN ULONGLONG            offset,
	IN PVOID                Buffer,
	IN ULONG                size,
	IN BOOLEAN              bWriteToDisk,
	OUT PULONG              dwRet)
{
	return STATUS_UNSUCCESSFUL;
}


NTSTATUS
FFSWriteFile(
	IN PFFS_IRP_CONTEXT IrpContext)
{
	NTSTATUS            Status = STATUS_UNSUCCESSFUL;

	PFFS_VCB            Vcb;
	PFFS_FCB            Fcb;
	PFFS_CCB            Ccb;
	PFILE_OBJECT        FileObject;
	PFILE_OBJECT        CacheObject;

	PDEVICE_OBJECT      DeviceObject;

	PIRP                Irp;
	PIO_STACK_LOCATION  IoStackLocation;

	ULONG               Length;
	ULONG               ReturnedLength;
	LARGE_INTEGER       ByteOffset;

	BOOLEAN             PagingIo;
	BOOLEAN             Nocache;
	BOOLEAN             SynchronousIo;
	BOOLEAN             MainResourceAcquired = FALSE;
	BOOLEAN             PagingIoResourceAcquired = FALSE;

	BOOLEAN             bNeedExtending = FALSE;
	BOOLEAN             bAppendFile = FALSE;

	BOOLEAN             bDeferred = FALSE;

	PUCHAR              Buffer;

	__try
	{
		ASSERT(IrpContext);

		ASSERT((IrpContext->Identifier.Type == FFSICX) &&
				(IrpContext->Identifier.Size == sizeof(FFS_IRP_CONTEXT)));

		DeviceObject = IrpContext->DeviceObject;

		Vcb = (PFFS_VCB)DeviceObject->DeviceExtension;

		ASSERT(Vcb != NULL);

		ASSERT((Vcb->Identifier.Type == FFSVCB) &&
				(Vcb->Identifier.Size == sizeof(FFS_VCB)));

		FileObject = IrpContext->FileObject;

		Fcb = (PFFS_FCB)FileObject->FsContext;

		ASSERT(Fcb);

		ASSERT((Fcb->Identifier.Type == FFSFCB) &&
				(Fcb->Identifier.Size == sizeof(FFS_FCB)));

		Ccb = (PFFS_CCB)FileObject->FsContext2;

		Irp = IrpContext->Irp;

		IoStackLocation = IoGetCurrentIrpStackLocation(Irp);

		Length = IoStackLocation->Parameters.Write.Length;
		ByteOffset = IoStackLocation->Parameters.Write.ByteOffset;

		PagingIo = (Irp->Flags & IRP_PAGING_IO ? TRUE : FALSE);
		Nocache = (Irp->Flags & IRP_NOCACHE ? TRUE : FALSE);
		SynchronousIo = (FileObject->Flags & FO_SYNCHRONOUS_IO ? TRUE : FALSE);

		FFSPrint((DBG_INFO, "FFSWriteFile: Off=%I64xh Len=%xh Paging=%xh Nocache=%xh\n",
					ByteOffset.QuadPart, Length, PagingIo, Nocache));

		/*
		if (IsFlagOn(Fcb->Flags, FCB_FILE_DELETED))
		{
			Status = STATUS_FILE_DELETED;
			__leave;
		}

		if (IsFlagOn(Fcb->Flags, FCB_DELETE_PENDING))
		{
			Status = STATUS_DELETE_PENDING;
			__leave;
		}
		*/

		if (Length == 0)
		{
			Irp->IoStatus.Information = 0;
			Status = STATUS_SUCCESS;
			__leave;
		}

		if (Nocache &&
				(ByteOffset.LowPart & (SECTOR_SIZE - 1) ||
				 Length & (SECTOR_SIZE - 1)))
		{
			Status = STATUS_INVALID_PARAMETER;
			__leave;
		}

		if (FlagOn(IrpContext->MinorFunction, IRP_MN_DPC))
		{
			ClearFlag(IrpContext->MinorFunction, IRP_MN_DPC);
			Status = STATUS_PENDING;
			__leave;
		}

#if FALSE
		if (!Nocache)
		{
			BOOLEAN bAgain = IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_DEFERRED);
			BOOLEAN bWait  = IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT);
			BOOLEAN bQueue = IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_REQUEUED);

			if (!CcCanIWrite(
						FileObject,
						Length,