mirror of
https://github.com/reactos/reactos.git
synced 2024-08-14 15:16:27 +00:00
577 lines
15 KiB
C
Executable file
577 lines
15 KiB
C
Executable file
/*++
|
||
|
||
Copyright (c) 1989-2000 Microsoft Corporation
|
||
|
||
Module Name:
|
||
|
||
Read.c
|
||
|
||
Abstract:
|
||
|
||
This module implements the File Read routine for Read called by the
|
||
Fsd/Fsp dispatch drivers.
|
||
|
||
|
||
--*/
|
||
|
||
#include "cdprocs.h"
|
||
|
||
//
|
||
// The Bug check file id for this module
|
||
//
|
||
|
||
#define BugCheckFileId (CDFS_BUG_CHECK_READ)
|
||
|
||
//
|
||
// VOID
|
||
// SafeZeroMemory (
|
||
// _Out_ PUCHAR At,
|
||
// _In_ ULONG ByteCount
|
||
// );
|
||
//
|
||
|
||
//
|
||
// This macro just puts a nice little try-except around RtlZeroMemory
|
||
//
|
||
|
||
#ifndef __REACTOS__
|
||
#define SafeZeroMemory(IC,AT,BYTE_COUNT) { \
|
||
_SEH2_TRY { \
|
||
RtlZeroMemory( (AT), (BYTE_COUNT) ); \
|
||
__pragma(warning(suppress: 6320)) \
|
||
} _SEH2_EXCEPT( EXCEPTION_EXECUTE_HANDLER ) { \
|
||
CdRaiseStatus( IC, STATUS_INVALID_USER_BUFFER ); \
|
||
} _SEH2_END; \
|
||
}
|
||
#else
|
||
#define SafeZeroMemory(IC,AT,BYTE_COUNT) { \
|
||
_SEH2_TRY { \
|
||
RtlZeroMemory( (AT), (BYTE_COUNT) ); \
|
||
} _SEH2_EXCEPT( EXCEPTION_EXECUTE_HANDLER ) { \
|
||
CdRaiseStatus( IC, STATUS_INVALID_USER_BUFFER ); \
|
||
} _SEH2_END; \
|
||
}
|
||
#endif
|
||
|
||
//
|
||
// Read ahead amount used for normal data files
|
||
//
|
||
|
||
#define READ_AHEAD_GRANULARITY (0x10000)
|
||
|
||
#ifdef ALLOC_PRAGMA
|
||
#pragma alloc_text(PAGE, CdCommonRead)
|
||
#endif
|
||
|
||
|
||
|
||
_Requires_lock_held_(_Global_critical_region_)
|
||
NTSTATUS
|
||
CdCommonRead (
|
||
_Inout_ PIRP_CONTEXT IrpContext,
|
||
_Inout_ PIRP Irp
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This is the common entry point for NtReadFile calls. For synchronous requests,
|
||
CommonRead will complete the request in the current thread. If not
|
||
synchronous the request will be passed to the Fsp if there is a need to
|
||
block.
|
||
|
||
Arguments:
|
||
|
||
Irp - Supplies the Irp to process
|
||
|
||
Return Value:
|
||
|
||
NTSTATUS - The result of this operation.
|
||
|
||
--*/
|
||
|
||
{
|
||
NTSTATUS Status = STATUS_SUCCESS;
|
||
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( Irp );
|
||
|
||
TYPE_OF_OPEN TypeOfOpen;
|
||
PFCB Fcb;
|
||
PCCB Ccb;
|
||
|
||
BOOLEAN Wait;
|
||
ULONG PagingIo;
|
||
ULONG SynchronousIo;
|
||
ULONG NonCachedIo;
|
||
PVOID UserBuffer;
|
||
|
||
LONGLONG StartingOffset;
|
||
LONGLONG ByteRange;
|
||
ULONG ByteCount;
|
||
ULONG ReadByteCount;
|
||
ULONG OriginalByteCount;
|
||
|
||
PVOID SystemBuffer;
|
||
|
||
BOOLEAN ReleaseFile = TRUE;
|
||
|
||
CD_IO_CONTEXT LocalIoContext;
|
||
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// If this is a zero length read then return SUCCESS immediately.
|
||
//
|
||
|
||
if (IrpSp->Parameters.Read.Length == 0) {
|
||
|
||
CdCompleteRequest( IrpContext, Irp, STATUS_SUCCESS );
|
||
return STATUS_SUCCESS;
|
||
}
|
||
|
||
//
|
||
// Decode the file object and verify we support read on this. It
|
||
// must be a user file, stream file or volume file (for a data disk).
|
||
//
|
||
|
||
TypeOfOpen = CdDecodeFileObject( IrpContext, IrpSp->FileObject, &Fcb, &Ccb );
|
||
|
||
// Internal lock object is acquired if return status is STATUS_PENDING
|
||
_Analysis_suppress_lock_checking_(Fcb->Resource);
|
||
|
||
if ((TypeOfOpen == UnopenedFileObject) ||
|
||
(TypeOfOpen == UserDirectoryOpen)) {
|
||
|
||
CdCompleteRequest( IrpContext, Irp, STATUS_INVALID_DEVICE_REQUEST );
|
||
return STATUS_INVALID_DEVICE_REQUEST;
|
||
}
|
||
|
||
//
|
||
// Examine our input parameters to determine if this is noncached and/or
|
||
// a paging io operation.
|
||
//
|
||
|
||
Wait = BooleanFlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT );
|
||
PagingIo = FlagOn( Irp->Flags, IRP_PAGING_IO );
|
||
NonCachedIo = FlagOn( Irp->Flags, IRP_NOCACHE );
|
||
SynchronousIo = FlagOn( IrpSp->FileObject->Flags, FO_SYNCHRONOUS_IO );
|
||
|
||
|
||
//
|
||
// Extract the range of the Io.
|
||
//
|
||
|
||
StartingOffset = IrpSp->Parameters.Read.ByteOffset.QuadPart;
|
||
OriginalByteCount = ByteCount = IrpSp->Parameters.Read.Length;
|
||
|
||
ByteRange = StartingOffset + ByteCount;
|
||
|
||
//
|
||
// Make sure that Dasd access is always non-cached.
|
||
//
|
||
|
||
if (TypeOfOpen == UserVolumeOpen) {
|
||
|
||
NonCachedIo = TRUE;
|
||
}
|
||
|
||
//
|
||
// Acquire the file shared to perform the read. If we are doing paging IO,
|
||
// it may be the case that we would have a deadlock imminent because we may
|
||
// block on shared access, so starve out any exclusive waiters. This requires
|
||
// a degree of caution - we believe that any paging IO bursts will recede and
|
||
// allow the exclusive waiter in.
|
||
//
|
||
|
||
if (PagingIo) {
|
||
|
||
CdAcquireFileSharedStarveExclusive( IrpContext, Fcb );
|
||
|
||
} else {
|
||
|
||
CdAcquireFileShared( IrpContext, Fcb );
|
||
}
|
||
|
||
//
|
||
// Use a try-finally to facilitate cleanup.
|
||
//
|
||
|
||
_SEH2_TRY {
|
||
|
||
//
|
||
// Verify the Fcb. Allow reads if this is a DASD handle that is
|
||
// dismounting the volume.
|
||
//
|
||
|
||
if ((TypeOfOpen != UserVolumeOpen) || (NULL == Ccb) ||
|
||
!FlagOn( Ccb->Flags, CCB_FLAG_DISMOUNT_ON_CLOSE)) {
|
||
|
||
CdVerifyFcbOperation( IrpContext, Fcb );
|
||
}
|
||
|
||
//
|
||
// If this is a non-cached then check whether we need to post this
|
||
// request if this thread can't block.
|
||
//
|
||
|
||
if (!Wait && NonCachedIo) {
|
||
|
||
//
|
||
// XA requests must always be waitable.
|
||
//
|
||
|
||
if (FlagOn( Fcb->FcbState, FCB_STATE_RAWSECTOR_MASK )) {
|
||
|
||
SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_FORCE_POST );
|
||
try_return( Status = STATUS_CANT_WAIT );
|
||
}
|
||
}
|
||
|
||
//
|
||
// If this is a user request then verify the oplock and filelock state.
|
||
//
|
||
|
||
if (TypeOfOpen == UserFileOpen) {
|
||
|
||
//
|
||
// We check whether we can proceed
|
||
// based on the state of the file oplocks.
|
||
//
|
||
|
||
Status = FsRtlCheckOplock( CdGetFcbOplock(Fcb),
|
||
Irp,
|
||
IrpContext,
|
||
(PVOID)CdOplockComplete,/* ReactOS Change: GCC "assignment from incompatible pointer type" */
|
||
(PVOID)CdPrePostIrp );/* ReactOS Change: GCC "assignment from incompatible pointer type" */
|
||
|
||
//
|
||
// If the result is not STATUS_SUCCESS then the Irp was completed
|
||
// elsewhere.
|
||
//
|
||
|
||
if (Status != STATUS_SUCCESS) {
|
||
|
||
Irp = NULL;
|
||
IrpContext = NULL;
|
||
|
||
try_return( NOTHING );
|
||
}
|
||
|
||
if (!PagingIo &&
|
||
(Fcb->FileLock != NULL) &&
|
||
!FsRtlCheckLockForReadAccess( Fcb->FileLock, Irp )) {
|
||
|
||
try_return( Status = STATUS_FILE_LOCK_CONFLICT );
|
||
}
|
||
}
|
||
|
||
//
|
||
// Check request beyond end of file if this is not a read on a volume
|
||
// handle marked for extended DASD IO.
|
||
//
|
||
|
||
if ((TypeOfOpen != UserVolumeOpen) ||
|
||
(!FlagOn( Ccb->Flags, CCB_FLAG_ALLOW_EXTENDED_DASD_IO ))) {
|
||
|
||
//
|
||
// Complete the request if it begins beyond the end of file.
|
||
//
|
||
|
||
if (StartingOffset >= Fcb->FileSize.QuadPart) {
|
||
|
||
try_return( Status = STATUS_END_OF_FILE );
|
||
}
|
||
|
||
//
|
||
// Truncate the read if it extends beyond the end of the file.
|
||
//
|
||
|
||
if (ByteRange > Fcb->FileSize.QuadPart) {
|
||
|
||
ByteCount = (ULONG) (Fcb->FileSize.QuadPart - StartingOffset);
|
||
ByteRange = Fcb->FileSize.QuadPart;
|
||
}
|
||
}
|
||
|
||
//
|
||
// Handle the non-cached read first.
|
||
//
|
||
|
||
if (NonCachedIo) {
|
||
|
||
//
|
||
// If we have an unaligned transfer then post this request if
|
||
// we can't wait. Unaligned means that the starting offset
|
||
// is not on a sector boundary or the read is not integral
|
||
// sectors.
|
||
//
|
||
|
||
ReadByteCount = BlockAlign( Fcb->Vcb, ByteCount );
|
||
|
||
if (SectorOffset( StartingOffset ) ||
|
||
SectorOffset( ReadByteCount ) ||
|
||
(ReadByteCount > OriginalByteCount)) {
|
||
|
||
if (!Wait) {
|
||
|
||
CdRaiseStatus( IrpContext, STATUS_CANT_WAIT );
|
||
}
|
||
|
||
//
|
||
// Make sure we don't overwrite the buffer.
|
||
//
|
||
|
||
ReadByteCount = ByteCount;
|
||
}
|
||
|
||
//
|
||
// Initialize the IoContext for the read.
|
||
// If there is a context pointer, we need to make sure it was
|
||
// allocated and not a stale stack pointer.
|
||
//
|
||
|
||
if (IrpContext->IoContext == NULL ||
|
||
!FlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO )) {
|
||
|
||
//
|
||
// If we can wait, use the context on the stack. Otherwise
|
||
// we need to allocate one.
|
||
//
|
||
|
||
if (Wait) {
|
||
|
||
IrpContext->IoContext = &LocalIoContext;
|
||
ClearFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
|
||
|
||
} else {
|
||
|
||
IrpContext->IoContext = CdAllocateIoContext();
|
||
SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
|
||
}
|
||
}
|
||
|
||
RtlZeroMemory( IrpContext->IoContext, sizeof( CD_IO_CONTEXT ));
|
||
|
||
//
|
||
// Store whether we allocated this context structure in the structure
|
||
// itself.
|
||
//
|
||
|
||
IrpContext->IoContext->AllocatedContext =
|
||
BooleanFlagOn( IrpContext->Flags, IRP_CONTEXT_FLAG_ALLOC_IO );
|
||
|
||
if (Wait) {
|
||
|
||
KeInitializeEvent( &IrpContext->IoContext->SyncEvent,
|
||
NotificationEvent,
|
||
FALSE );
|
||
|
||
} else {
|
||
|
||
IrpContext->IoContext->ResourceThreadId = ExGetCurrentResourceThread();
|
||
IrpContext->IoContext->Resource = Fcb->Resource;
|
||
IrpContext->IoContext->RequestedByteCount = ByteCount;
|
||
}
|
||
|
||
Irp->IoStatus.Information = ReadByteCount;
|
||
|
||
//
|
||
// Call one of the NonCacheIo routines to perform the actual
|
||
// read.
|
||
//
|
||
|
||
if (FlagOn( Fcb->FcbState, FCB_STATE_RAWSECTOR_MASK )) {
|
||
|
||
Status = CdNonCachedXARead( IrpContext, Fcb, StartingOffset, ReadByteCount );
|
||
|
||
} else {
|
||
|
||
Status = CdNonCachedRead( IrpContext, Fcb, StartingOffset, ReadByteCount );
|
||
}
|
||
|
||
//
|
||
// Don't complete this request now if STATUS_PENDING was returned.
|
||
//
|
||
|
||
if (Status == STATUS_PENDING) {
|
||
|
||
Irp = NULL;
|
||
ReleaseFile = FALSE;
|
||
|
||
//
|
||
// Test is we should zero part of the buffer or update the
|
||
// synchronous file position.
|
||
//
|
||
|
||
} else {
|
||
|
||
//
|
||
// Convert any unknown error code to IO_ERROR.
|
||
//
|
||
|
||
if (!NT_SUCCESS( Status )) {
|
||
|
||
//
|
||
// Set the information field to zero.
|
||
//
|
||
|
||
Irp->IoStatus.Information = 0;
|
||
|
||
//
|
||
// Raise if this is a user induced error.
|
||
//
|
||
|
||
if (IoIsErrorUserInduced( Status )) {
|
||
|
||
CdRaiseStatus( IrpContext, Status );
|
||
}
|
||
|
||
Status = FsRtlNormalizeNtstatus( Status, STATUS_UNEXPECTED_IO_ERROR );
|
||
|
||
//
|
||
// Check if there is any portion of the user's buffer to zero.
|
||
//
|
||
|
||
} else if (ReadByteCount != ByteCount) {
|
||
|
||
CdMapUserBuffer( IrpContext, &UserBuffer);
|
||
|
||
SafeZeroMemory( IrpContext,
|
||
Add2Ptr( UserBuffer,
|
||
ByteCount,
|
||
PVOID ),
|
||
ReadByteCount - ByteCount );
|
||
|
||
Irp->IoStatus.Information = ByteCount;
|
||
}
|
||
|
||
//
|
||
// Update the file position if this is a synchronous request.
|
||
//
|
||
|
||
if (SynchronousIo && !PagingIo && NT_SUCCESS( Status )) {
|
||
|
||
IrpSp->FileObject->CurrentByteOffset.QuadPart = ByteRange;
|
||
}
|
||
}
|
||
|
||
try_return( NOTHING );
|
||
}
|
||
|
||
//
|
||
// Handle the cached case. Start by initializing the private
|
||
// cache map.
|
||
//
|
||
|
||
if (IrpSp->FileObject->PrivateCacheMap == NULL) {
|
||
|
||
//
|
||
// Now initialize the cache map.
|
||
//
|
||
|
||
CcInitializeCacheMap( IrpSp->FileObject,
|
||
(PCC_FILE_SIZES) &Fcb->AllocationSize,
|
||
FALSE,
|
||
&CdData.CacheManagerCallbacks,
|
||
Fcb );
|
||
|
||
CcSetReadAheadGranularity( IrpSp->FileObject, READ_AHEAD_GRANULARITY );
|
||
}
|
||
|
||
//
|
||
// Read from the cache if this is not an Mdl read.
|
||
//
|
||
|
||
if (!FlagOn( IrpContext->MinorFunction, IRP_MN_MDL )) {
|
||
|
||
//
|
||
// If we are in the Fsp now because we had to wait earlier,
|
||
// we must map the user buffer, otherwise we can use the
|
||
// user's buffer directly.
|
||
//
|
||
|
||
CdMapUserBuffer( IrpContext, &SystemBuffer );
|
||
|
||
//
|
||
// Now try to do the copy.
|
||
//
|
||
|
||
if (!CcCopyRead( IrpSp->FileObject,
|
||
(PLARGE_INTEGER) &StartingOffset,
|
||
ByteCount,
|
||
Wait,
|
||
SystemBuffer,
|
||
&Irp->IoStatus )) {
|
||
|
||
try_return( Status = STATUS_CANT_WAIT );
|
||
}
|
||
|
||
//
|
||
// If the call didn't succeed, raise the error status
|
||
//
|
||
|
||
if (!NT_SUCCESS( Irp->IoStatus.Status )) {
|
||
|
||
CdNormalizeAndRaiseStatus( IrpContext, Irp->IoStatus.Status );
|
||
}
|
||
|
||
//
|
||
// Otherwise perform the MdlRead operation.
|
||
//
|
||
|
||
} else {
|
||
|
||
CcMdlRead( IrpSp->FileObject,
|
||
(PLARGE_INTEGER) &StartingOffset,
|
||
ByteCount,
|
||
&Irp->MdlAddress,
|
||
&Irp->IoStatus );
|
||
|
||
Status = Irp->IoStatus.Status;
|
||
}
|
||
|
||
//
|
||
// Update the current file position in the user file object.
|
||
//
|
||
|
||
if (SynchronousIo && !PagingIo && NT_SUCCESS( Status )) {
|
||
|
||
IrpSp->FileObject->CurrentByteOffset.QuadPart = ByteRange;
|
||
}
|
||
|
||
try_exit: NOTHING;
|
||
} _SEH2_FINALLY {
|
||
|
||
//
|
||
// Release the Fcb.
|
||
//
|
||
|
||
if (ReleaseFile) {
|
||
|
||
CdReleaseFile( IrpContext, Fcb );
|
||
}
|
||
} _SEH2_END;
|
||
|
||
//
|
||
// Post the request if we got CANT_WAIT.
|
||
//
|
||
|
||
if (Status == STATUS_CANT_WAIT) {
|
||
|
||
Status = CdFsdPostRequest( IrpContext, Irp );
|
||
|
||
//
|
||
// Otherwise complete the request.
|
||
//
|
||
|
||
} else {
|
||
|
||
CdCompleteRequest( IrpContext, Irp, Status );
|
||
}
|
||
|
||
return Status;
|
||
}
|
||
|
||
|
||
|