mirror of
https://github.com/reactos/reactos.git
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252 lines
6.9 KiB
C
252 lines
6.9 KiB
C
/*
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* ReactOS kernel
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* Copyright (C) 2002, 2003 ReactOS Team
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/*
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* COPYRIGHT: See COPYING in the top level directory
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* PROJECT: ReactOS kernel
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* FILE: drivers/filesystems/cdfs/rw.c
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* PURPOSE: CDROM (ISO 9660) filesystem driver
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* PROGRAMMER: Art Yerkes
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* Eric Kohl
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*/
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/* INCLUDES *****************************************************************/
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#include "cdfs.h"
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#define NDEBUG
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#include <debug.h>
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/* FUNCTIONS ****************************************************************/
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#define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
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#define ROUND_DOWN(N, S) ((N) - ((N) % (S)))
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/* FUNCTIONS ****************************************************************/
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static NTSTATUS
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CdfsReadFile(PCDFS_IRP_CONTEXT IrpContext,
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PFILE_OBJECT FileObject,
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PUCHAR Buffer,
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ULONG Length,
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ULONG ReadOffset,
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ULONG IrpFlags,
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PULONG LengthRead)
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/*
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* FUNCTION: Reads data from a file
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*/
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{
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NTSTATUS Status = STATUS_SUCCESS;
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PDEVICE_EXTENSION DeviceExt;
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PFCB Fcb;
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ULONG ToRead = Length;
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DPRINT("CdfsReadFile(ReadOffset %lu Length %lu)\n", ReadOffset, Length);
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*LengthRead = 0;
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if (Length == 0)
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return(STATUS_SUCCESS);
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DeviceExt = IrpContext->DeviceObject->DeviceExtension;
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Fcb = (PFCB)FileObject->FsContext;
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if (ReadOffset >= Fcb->Entry.DataLengthL)
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return(STATUS_END_OF_FILE);
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if (ReadOffset + Length > Fcb->Entry.DataLengthL)
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ToRead = Fcb->Entry.DataLengthL - ReadOffset;
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if (!(IrpFlags & IRP_PAGING_IO) &&
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FsRtlAreThereCurrentFileLocks(&Fcb->FileLock))
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{
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if (!FsRtlCheckLockForReadAccess(&Fcb->FileLock, IrpContext->Irp))
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{
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return STATUS_FILE_LOCK_CONFLICT;
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}
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}
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DPRINT("Reading %u bytes at %u\n", Length, ReadOffset);
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if (!(IrpFlags & (IRP_NOCACHE|IRP_PAGING_IO)))
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{
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LARGE_INTEGER FileOffset;
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IO_STATUS_BLOCK IoStatus;
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CC_FILE_SIZES FileSizes;
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DPRINT("Using cache\n");
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if (FileObject->PrivateCacheMap == NULL)
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{
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FileSizes.AllocationSize = Fcb->RFCB.AllocationSize;
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FileSizes.FileSize = Fcb->RFCB.FileSize;
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FileSizes.ValidDataLength = Fcb->RFCB.ValidDataLength;
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DPRINT("Attach FCB to File: Size %08x%08x\n",
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Fcb->RFCB.ValidDataLength.HighPart,
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Fcb->RFCB.ValidDataLength.LowPart);
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_SEH2_TRY
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{
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CcInitializeCacheMap(FileObject,
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&FileSizes,
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FALSE,
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&(CdfsGlobalData->CacheMgrCallbacks),
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Fcb);
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}
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_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
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{
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return _SEH2_GetExceptionCode();
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}
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_SEH2_END;
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}
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FileOffset.QuadPart = (LONGLONG)ReadOffset;
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_SEH2_TRY
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{
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CcCopyRead(FileObject,
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&FileOffset,
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ToRead,
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TRUE,
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Buffer,
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&IoStatus);
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}
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_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
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{
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IoStatus.Information = 0;
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IoStatus.Status = _SEH2_GetExceptionCode();
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}
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_SEH2_END;
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*LengthRead = IoStatus.Information;
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Status = IoStatus.Status;
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}
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else
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{
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ULONG ActualReadOffset = ROUND_DOWN(ReadOffset, BLOCKSIZE);
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ULONG nBlocks = (ROUND_UP(ReadOffset + ToRead, BLOCKSIZE) - ActualReadOffset) / BLOCKSIZE;
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PUCHAR PageBuf;
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BOOLEAN bFreeBuffer = FALSE;
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if ((ReadOffset % BLOCKSIZE) != 0 || (ToRead % BLOCKSIZE) != 0)
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{
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PageBuf = ExAllocatePoolWithTag(NonPagedPool,
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nBlocks * BLOCKSIZE,
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CDFS_TAG);
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if (!PageBuf)
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{
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return STATUS_NO_MEMORY;
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}
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bFreeBuffer = TRUE;
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}
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else
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{
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PageBuf = Buffer;
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}
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Status = CdfsReadSectors(DeviceExt->StorageDevice,
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Fcb->Entry.ExtentLocationL + (ActualReadOffset / BLOCKSIZE),
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nBlocks,
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(PVOID)PageBuf,
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FALSE);
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if(NT_SUCCESS(Status))
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{
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*LengthRead = ToRead;
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if(bFreeBuffer)
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{
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/* Copy what we've got */
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RtlCopyMemory(Buffer, PageBuf + (ReadOffset - ActualReadOffset), ToRead);
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}
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/* Zero out the rest */
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if(ToRead != Length)
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RtlZeroMemory(Buffer + ToRead, Length - ToRead);
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}
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if(bFreeBuffer)
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ExFreePoolWithTag(PageBuf, CDFS_TAG);
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}
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return Status;
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}
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NTSTATUS NTAPI
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CdfsRead(
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PCDFS_IRP_CONTEXT IrpContext)
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{
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PIRP Irp;
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PIO_STACK_LOCATION Stack;
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PFILE_OBJECT FileObject;
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PVOID Buffer = NULL;
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ULONG ReadLength;
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LARGE_INTEGER ReadOffset;
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ULONG ReturnedReadLength = 0;
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NTSTATUS Status = STATUS_SUCCESS;
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DPRINT("CdfsRead(%p)\n", IrpContext);
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ASSERT(IrpContext);
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Irp = IrpContext->Irp;
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Stack = IrpContext->Stack;
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FileObject = Stack->FileObject;
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ReadLength = Stack->Parameters.Read.Length;
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ReadOffset = Stack->Parameters.Read.ByteOffset;
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if (ReadLength) Buffer = MmGetSystemAddressForMdl(Irp->MdlAddress);
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Status = CdfsReadFile(IrpContext,
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FileObject,
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Buffer,
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ReadLength,
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ReadOffset.u.LowPart,
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Irp->Flags,
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&ReturnedReadLength);
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if (NT_SUCCESS(Status))
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{
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if (FileObject->Flags & FO_SYNCHRONOUS_IO)
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{
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FileObject->CurrentByteOffset.QuadPart =
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ReadOffset.QuadPart + ReturnedReadLength;
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}
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Irp->IoStatus.Information = ReturnedReadLength;
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}
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else
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{
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Irp->IoStatus.Information = 0;
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}
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return(Status);
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}
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NTSTATUS NTAPI
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CdfsWrite(
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PCDFS_IRP_CONTEXT IrpContext)
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{
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DPRINT("CdfsWrite(%p)\n", IrpContext);
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ASSERT(IrpContext);
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IrpContext->Irp->IoStatus.Information = 0;
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return(STATUS_NOT_SUPPORTED);
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}
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/* EOF */
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