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reactos/ntoskrnl/fsrtl/fastio.c
Art Yerkes c501d8112c Create a branch for network fixes. 
svn path=/branches/aicom-network-fixes/; revision=34994
2008-08-01 11:32:26 +00:00

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/*
* PROJECT: ReactOS Kernel
* LICENSE: GPL - See COPYING in the top level directory
* FILE: ntoskrnl/fsrtl/fastio.c
* PURPOSE: Provides Fast I/O entrypoints to the Cache Manager
* PROGRAMMERS: buzdelabuz2@gmail.com,alex.ionescu@reactos.org
*/
/* INCLUDES ******************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
/* PUBLIC FUNCTIONS **********************************************************/
/*
* @implemented
*/
VOID
NTAPI
FsRtlIncrementCcFastReadResourceMiss(VOID)
{
CcFastReadResourceMiss++;
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlIncrementCcFastReadNotPossible(VOID)
{
CcFastReadNotPossible++;
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlIncrementCcFastReadWait(VOID)
{
CcFastReadWait++;
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlIncrementCcFastReadNoWait(VOID)
{
CcFastReadNoWait++;
}
_SEH_FILTER(FsRtlCcCopyFilter)
{
LONG ExceptionDisposition;
/* Check if this was an expected exception */
ExceptionDisposition = FsRtlIsNtstatusExpected(_SEH_GetExceptionCode() ?
EXCEPTION_EXECUTE_HANDLER :
EXCEPTION_CONTINUE_SEARCH);
/* Continue execution if we expected it, otherwise fail the call */
return ExceptionDisposition;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlCopyRead(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN BOOLEAN Wait,
IN ULONG LockKey,
OUT PVOID Buffer,
OUT PIO_STATUS_BLOCK IoStatus,
IN PDEVICE_OBJECT DeviceObject)
{
PFSRTL_COMMON_FCB_HEADER FcbHeader;
LARGE_INTEGER Offset;
PFAST_IO_DISPATCH FastIoDispatch;
PDEVICE_OBJECT Device;
BOOLEAN Result = TRUE;
ULONG PageCount = COMPUTE_PAGES_SPANNED(FileOffset,Length);
PAGED_CODE();
ASSERT(FileObject);
ASSERT(FileObject->FsContext);
/* No actual read */
if (!Length)
{
/* Return success */
IoStatus->Status = STATUS_SUCCESS;
IoStatus->Information = 0;
return TRUE;
}
if (MAXLONGLONG < (LONGLONG) FileOffset->QuadPart + Length) {
IoStatus->Status = STATUS_INVALID_PARAMETER;
IoStatus->Information = 0;
return FALSE;
}
/* Get the offset and FCB header */
Offset.QuadPart = FileOffset->QuadPart + Length;
FcbHeader = (PFSRTL_COMMON_FCB_HEADER)FileObject->FsContext;
if (Wait) {
/* Use a Resource Acquire */
FsRtlEnterFileSystem();
CcFastReadWait++;
ExAcquireResourceSharedLite(FcbHeader->Resource, TRUE);
} else {
/* Acquire the resource without blocking */
/* Return false and the I/O manager will retry using the standard IRP method. */
/* Use a Resource Acquire */
FsRtlEnterFileSystem();
if (!ExAcquireResourceSharedLite(FcbHeader->Resource, FALSE)) {
FsRtlExitFileSystem();
FsRtlIncrementCcFastReadResourceMiss();
return FALSE;
}
}
/* Check if this is a fast I/O cached file */
if (!(FileObject->PrivateCacheMap) ||
(FcbHeader->IsFastIoPossible == FastIoIsNotPossible)) {
/* It's not, so fail */
Result = FALSE;
goto Cleanup;
}
/* Check if we need to find out if fast I/O is available */
if (FcbHeader->IsFastIoPossible == FastIoIsQuestionable)
{
/* Sanity check */
ASSERT(!KeIsExecutingDpc());
/* Get the Fast I/O table */
Device = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = Device->DriverObject->FastIoDispatch;
/* Sanity check */
ASSERT(FastIoDispatch != NULL);
ASSERT(FastIoDispatch->FastIoCheckIfPossible != NULL);
/* Ask the driver if we can do it */
if (!FastIoDispatch->FastIoCheckIfPossible(FileObject,
FileOffset,
Length,
TRUE,
LockKey,
TRUE,
IoStatus,
Device))
{
/* It's not, fail */
Result = FALSE;
goto Cleanup;
}
}
/* Check if we read too much */
if (Offset.QuadPart > FcbHeader->FileSize.QuadPart){
/* We did, check if the file offset is past the end */
if (FileOffset->QuadPart >= FcbHeader->FileSize.QuadPart){
/* Set end of file */
IoStatus->Status = STATUS_END_OF_FILE;
IoStatus->Information = 0;
goto Cleanup;
}
/* Otherwise, just normalize the length */
Length = (ULONG)(FcbHeader->FileSize.QuadPart - FileOffset->QuadPart);
}
/* Set this as top-level IRP */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
_SEH_TRY
{
/* Make sure the IO and file size is below 4GB */
if (Wait && !(Offset.HighPart | FcbHeader->FileSize.HighPart )) {
/* Call the cache controller */
CcFastCopyRead (FileObject,FileOffset->LowPart,Length,PageCount,Buffer,IoStatus);
/* File was accessed */
FileObject->Flags |= FO_FILE_FAST_IO_READ;
if (IoStatus->Status != STATUS_END_OF_FILE) {
ASSERT(( FcbHeader->FileSize.QuadPart) >= (FileOffset->QuadPart + IoStatus->Information));
}
} else {
/* Call the cache controller */
Result = CcCopyRead(FileObject, FileOffset, Length, Wait,Buffer, IoStatus);
/* File was accessed */
FileObject->Flags |= FO_FILE_FAST_IO_READ;
if (Result == TRUE) {
ASSERT( (IoStatus->Status == STATUS_END_OF_FILE) ||
((LONGLONG)(FileOffset->QuadPart + IoStatus->Information) <= FcbHeader->FileSize.QuadPart)
);
}
}
/* Update the current file offset */
if (Result == TRUE) {
FileObject->CurrentByteOffset.QuadPart += IoStatus->Information;
}
}
_SEH_EXCEPT(FsRtlCcCopyFilter)
{
Result = FALSE;
} _SEH_END;
PsGetCurrentThread()->TopLevelIrp = 0;
/* Return to caller */
Cleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
if (Result == FALSE) {
CcFastReadNotPossible += 1;
}
return Result;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlCopyWrite(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN BOOLEAN Wait,
IN ULONG LockKey,
OUT PVOID Buffer,
OUT PIO_STATUS_BLOCK IoStatus,
IN PDEVICE_OBJECT DeviceObject)
{
BOOLEAN Result = TRUE;
PFAST_IO_DISPATCH FastIoDispatch;
PDEVICE_OBJECT Device;
PFSRTL_COMMON_FCB_HEADER FcbHeader;
/* WDK doc. Offset=0xffffffffffffffff indicates append to the end of file */
BOOLEAN FileOffsetAppend = ((FileOffset->HighPart == 0xffffffff) && (FileOffset->LowPart == 0xffffffff));
BOOLEAN ResourceAquiredShared = FALSE;
BOOLEAN b_4GB = FALSE;
BOOLEAN FileSizeModified = FALSE;
LARGE_INTEGER OldFileSize;
LARGE_INTEGER OldValidDataLength;
LARGE_INTEGER NewSize;
LARGE_INTEGER Offset;
PAGED_CODE();
ASSERT(FileObject);
ASSERT(FileObject->FsContext);
/* Initialize some of the vars and pointers */
NewSize.QuadPart = 0;
Offset.QuadPart = FileOffset->QuadPart + Length;
FcbHeader = (PFSRTL_COMMON_FCB_HEADER)FileObject->FsContext;
/* Nagar p.544 -- Check with Cc if we can write and check if the IO > 64kB (WDK macro) */
if ( (CcCanIWrite(FileObject, Length,Wait, FALSE) == FALSE) ||
(CcCopyWriteWontFlush(FileObject,FileOffset,Length) == FALSE) ||
((FileObject->Flags & FO_WRITE_THROUGH )== TRUE)
)
{
return FALSE;
}
/* No actual read */
if (!Length)
{
IoStatus->Status = STATUS_SUCCESS;
IoStatus->Information = Length;
return TRUE;
}
FsRtlEnterFileSystem();
/* Nagar p.544/545 -- The CcFastCopyWrite doesn't deal with filesize beyond 4GB*/
if (Wait && (FcbHeader->AllocationSize.HighPart == 0))
{
/* If the file offset is not past the file size, then we can acquire the lock shared */
if ((FileOffsetAppend == FALSE) && (Offset.LowPart <= FcbHeader->ValidDataLength.LowPart)){
ExAcquireResourceSharedLite(FcbHeader->Resource,TRUE);
ResourceAquiredShared = TRUE;
} else {
ExAcquireResourceExclusiveLite(FcbHeader->Resource,TRUE);
}
/* Nagar p.544/545 -- If we append, use the file size as offset. Also, check that we aren't crossing the 4GB boundary */
if ((FileOffsetAppend == TRUE)) {
Offset.LowPart = FcbHeader->FileSize.LowPart;
NewSize.LowPart = FcbHeader->FileSize.LowPart + Length;
b_4GB = (NewSize.LowPart < FcbHeader->FileSize.LowPart);
} else {
Offset.LowPart = FileOffset->LowPart;
NewSize.LowPart = FileOffset->LowPart + Length;
b_4GB = ((NewSize.LowPart < FileOffset->LowPart) || (FileOffset->HighPart != 0));
}
/* Nagar p.544/545
Make sure that caching is initated.
That fast are allowed for this file stream.
That we are not extending past the allocated size
That we are not creating a hole bigger than 8k
That we are not crossing the 4GB boundary
*/
if ( (FileObject->PrivateCacheMap != NULL) &&
(FcbHeader->IsFastIoPossible != FastIoIsNotPossible) &&
(FcbHeader->AllocationSize.LowPart >= NewSize.LowPart) &&
(Offset.LowPart < (FcbHeader->ValidDataLength.LowPart + 0x2000) ) &&
!b_4GB
)
{
/* If we are extending past the file size, we need to release the lock and acquire it
exclusively, because we are going to need to update the FcbHeader */
if (ResourceAquiredShared && (NewSize.LowPart > (FcbHeader->ValidDataLength.LowPart + 0x2000))) {
/* Then we need to acquire the resource exclusive */
ExReleaseResourceLite(FcbHeader->Resource);
ExAcquireResourceExclusiveLite(FcbHeader->Resource,TRUE);
if (FileOffsetAppend == TRUE) {
Offset.LowPart = FcbHeader->FileSize.LowPart; // ??
NewSize.LowPart = FcbHeader->FileSize.LowPart + Length;
/* Make sure we don't cross the 4GB boundary */
b_4GB = (NewSize.LowPart < Offset.LowPart);
}
/* Recheck some of the conditions since we let the lock go */
if ( (FileObject->PrivateCacheMap != NULL) &&
(FcbHeader->IsFastIoPossible != FastIoIsNotPossible) &&
(FcbHeader->AllocationSize.LowPart >= NewSize.LowPart) &&
(FcbHeader->AllocationSize.HighPart == 0) &&
!b_4GB
)
{
} else
{
goto FailAndCleanup;
}
}
}else
{
goto FailAndCleanup;
}
/* Check if we need to find out if fast I/O is available */
if (FcbHeader->IsFastIoPossible == FastIoIsQuestionable)
{
IO_STATUS_BLOCK FastIoCheckIfPossibleStatus;
/* Sanity check */
ASSERT(!KeIsExecutingDpc());
/* Get the Fast I/O table */
Device = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = Device->DriverObject->FastIoDispatch;
/* Sanity check */
ASSERT(FastIoDispatch != NULL);
ASSERT(FastIoDispatch->FastIoCheckIfPossible != NULL);
/* Ask the driver if we can do it */
if (!FastIoDispatch->FastIoCheckIfPossible(FileObject,
FileOffsetAppend? &FcbHeader->FileSize:FileOffset,
Length,
TRUE,
LockKey,
FALSE,
&FastIoCheckIfPossibleStatus,
Device))
{
/* It's not, fail */
goto FailAndCleanup;
}
}
/* If we are going to extend the file then save the old file size
in case the operation fails
*/
if (NewSize.LowPart > FcbHeader->FileSize.LowPart) {
FileSizeModified = TRUE;
OldFileSize.LowPart = FcbHeader->FileSize.LowPart;
OldValidDataLength.LowPart = FcbHeader->ValidDataLength.LowPart;
FcbHeader->FileSize.LowPart = NewSize.LowPart;
}
/* Set this as top-level IRP */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
_SEH_TRY
{
if (Offset.LowPart > FcbHeader->ValidDataLength.LowPart) {
LARGE_INTEGER OffsetVar;
OffsetVar.LowPart = Offset.LowPart;
OffsetVar.HighPart = 0;
CcZeroData(FileObject,&FcbHeader->ValidDataLength,&OffsetVar,TRUE);
}
/* Call the cache manager */
CcFastCopyWrite(FileObject,Offset.LowPart,Length,Buffer);
}
_SEH_EXCEPT(FsRtlCcCopyFilter)
{
Result = FALSE;
} _SEH_END;
/* Remove ourselves at the top level component after the IO is done */
PsGetCurrentThread()->TopLevelIrp = 0;
/* Did the operation succeed ? */
if (Result == TRUE) {
/* Update the valid file size if necessary */
if (NewSize.LowPart > FcbHeader->ValidDataLength.LowPart){
FcbHeader->ValidDataLength.LowPart = NewSize.LowPart ;
}
/* Flag the file as modified */
FileObject->Flags |= FO_FILE_MODIFIED;
/* Update the strucutres if the file size changed */
if (FileSizeModified) {
((SHARED_CACHE_MAP*) FileObject->SectionObjectPointer->SharedCacheMap)->FileSize.LowPart = NewSize.LowPart;
FileObject->Flags |= FO_FILE_SIZE_CHANGED;
}
/* Update the file object current file offset */
FileObject->CurrentByteOffset.QuadPart = NewSize.LowPart;
} else {
/* Result == FALSE if we get here. */
if (FileSizeModified) {
/* If the file size was modified then restore the old file size */
if(FcbHeader->PagingIoResource != NULL) {
// Nagar P.544 Restore the old file size if operation didn't succeed.
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource,TRUE);
FcbHeader->FileSize.LowPart = OldFileSize.LowPart;
FcbHeader->ValidDataLength.LowPart = OldValidDataLength.LowPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
} else {
/* If there is no lock and do it without */
FcbHeader->FileSize.LowPart = OldFileSize.LowPart;
FcbHeader->ValidDataLength.LowPart = OldValidDataLength.LowPart;
}
} else {
}
}
goto Cleanup;
} else {
LARGE_INTEGER OldFileSize;
/* Sanity check */
ASSERT(!KeIsExecutingDpc());
// Nagar P.544
/* Check if we need to acquire the resource exclusive */
if ( (FileOffsetAppend == FALSE) &&
( (FileOffset->QuadPart + Length) <= FcbHeader->ValidDataLength.QuadPart )
)
{
/* Acquire the resource shared */
if (!ExAcquireResourceSharedLite(FcbHeader->Resource,Wait)) {
goto LeaveCriticalAndFail;
}
ResourceAquiredShared =TRUE;
} else {
/* Acquire the resource exclusive */
if (!ExAcquireResourceExclusiveLite(FcbHeader->Resource,Wait)) {
goto LeaveCriticalAndFail;
}
}
/* Check if we are appending */
if (FileOffsetAppend == TRUE) {
Offset.QuadPart = FcbHeader->FileSize.QuadPart;
NewSize.QuadPart = FcbHeader->FileSize.QuadPart + Length;
} else {
Offset.QuadPart = FileOffset->QuadPart;
NewSize.QuadPart += FileOffset->QuadPart + Length;
}
/* Nagar p.544/545
Make sure that caching is initated.
That fast are allowed for this file stream.
That we are not extending past the allocated size
That we are not creating a hole bigger than 8k
*/
if ( (FileObject->PrivateCacheMap != NULL) &&
(FcbHeader->IsFastIoPossible != FastIoIsNotPossible) &&
((FcbHeader->ValidDataLength.QuadPart + 0x2000) > Offset.QuadPart) &&
(MAXLONGLONG > (Offset.QuadPart + Length)) &&
(FcbHeader->AllocationSize.QuadPart >= NewSize.QuadPart)
)
{
/* Check if we can keep the lock shared */
if (ResourceAquiredShared && (NewSize.QuadPart > FcbHeader->ValidDataLength.QuadPart) ) {
ExReleaseResourceLite(FcbHeader->Resource);
if(!ExAcquireResourceExclusiveLite(FcbHeader->Resource,Wait))
{
goto LeaveCriticalAndFail;
}
/* Compute the offset and the new filesize */
if (FileOffsetAppend) {
Offset.QuadPart = FcbHeader->FileSize.QuadPart;
NewSize.QuadPart = FcbHeader->FileSize.QuadPart + Length;
}
/* Recheck the above points since we released and reacquire the lock */
if ( (FileObject->PrivateCacheMap != NULL) &&
(FcbHeader->IsFastIoPossible != FastIoIsNotPossible) &&
(FcbHeader->AllocationSize.QuadPart > NewSize.QuadPart)
)
{
/* Do nothing */
} else {
goto FailAndCleanup;
}
}
/* Check if we need to find out if fast I/O is available */
if (FcbHeader->IsFastIoPossible == FastIoIsQuestionable)
{
IO_STATUS_BLOCK FastIoCheckIfPossibleStatus;
/* Sanity check */
ASSERT(!KeIsExecutingDpc());
/* Get the Fast I/O table */
Device = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = Device->DriverObject->FastIoDispatch;
/* Sanity check */
ASSERT(FastIoDispatch != NULL);
ASSERT(FastIoDispatch->FastIoCheckIfPossible != NULL);
/* Ask the driver if we can do it */
if (!FastIoDispatch->FastIoCheckIfPossible(FileObject,
FileOffsetAppend? &FcbHeader->FileSize:FileOffset,
Length,
TRUE,
LockKey,
FALSE,
&FastIoCheckIfPossibleStatus,
Device))
{
/* It's not, fail */
goto FailAndCleanup;
}
}
/* If we are going to modify the filesize, save the old fs in case the operation fails */
if (NewSize.QuadPart > FcbHeader->FileSize.QuadPart) {
FileSizeModified = TRUE;
OldFileSize.QuadPart = FcbHeader->FileSize.QuadPart;
OldValidDataLength.QuadPart = FcbHeader->ValidDataLength.QuadPart;
/* If the high part of the filesize is going to change, grab the Paging IoResouce */
if (NewSize.HighPart != FcbHeader->FileSize.HighPart && FcbHeader->PagingIoResource) {
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->FileSize.QuadPart = NewSize.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
} else {
FcbHeader->FileSize.QuadPart = NewSize.QuadPart;
}
}
/* Nagar p.544 */
/* Set ourselves as top component */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
_SEH_TRY
{
BOOLEAN CallCc = TRUE;
/* Check if there is a gap between the end of the file and the offset
If yes, then we have to zero the data
*/
if (Offset.QuadPart > FcbHeader->ValidDataLength.QuadPart) {
if (!(Result = CcZeroData(FileObject,&FcbHeader->ValidDataLength,&Offset,Wait))) {
/* If this operation fails, then we have to exit
We can jump outside the SEH, so I a using a variable to exit
normally
*/
CallCc = FALSE;
}
}
/* Unless the CcZeroData failed, call the cache manager */
if (CallCc) {
Result = CcCopyWrite(FileObject,&Offset,Length, Wait, Buffer);
}
}_SEH_EXCEPT(FsRtlCcCopyFilter)
{
Result = FALSE;
} _SEH_END;
/* Reset the top component */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
/* Did the operation suceeded */
if (Result) {
/* Check if we need to update the filesize */
if (NewSize.QuadPart > FcbHeader->ValidDataLength.QuadPart) {
if (NewSize.HighPart != FcbHeader->ValidDataLength.HighPart && FcbHeader->PagingIoResource) {
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->ValidDataLength.QuadPart = NewSize.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
} else {
FcbHeader->ValidDataLength.QuadPart = NewSize.QuadPart;
}
}
/* Flag the file as modified */
FileObject->Flags |= FO_FILE_MODIFIED;
/* Check if the filesize has changed */
if (FileSizeModified) {
/* Update the file sizes */
((SHARED_CACHE_MAP*) FileObject->SectionObjectPointer->SharedCacheMap)->FileSize.QuadPart = NewSize.QuadPart;
FileObject->Flags |= FO_FILE_SIZE_CHANGED;
}
/* Update the current FO byte offset */
FileObject->CurrentByteOffset.QuadPart = NewSize.QuadPart;
}
else
{
/* The operation did not succeed
Reset the file size to what it should be
*/
if (FileSizeModified) {
if (FcbHeader->PagingIoResource) {
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->FileSize.QuadPart = OldFileSize.QuadPart;
FcbHeader->ValidDataLength.QuadPart = OldValidDataLength.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
}else{
FcbHeader->FileSize.QuadPart = OldFileSize.QuadPart;
FcbHeader->ValidDataLength.QuadPart = OldValidDataLength.QuadPart;
}
}
}
goto Cleanup;
} else {
goto FailAndCleanup;
}
ASSERT(0);
}
LeaveCriticalAndFail:
FsRtlExitFileSystem();
return FALSE;
FailAndCleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
return FALSE;
Cleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
return Result;
}
/*
* @implemented
*/
NTSTATUS
NTAPI
FsRtlGetFileSize(IN PFILE_OBJECT FileObject,
IN OUT PLARGE_INTEGER FileSize)
{
FILE_STANDARD_INFORMATION Info;
NTSTATUS Status;
IO_STATUS_BLOCK IoStatus;
PDEVICE_OBJECT DeviceObject;
PFAST_IO_DISPATCH FastDispatch;
KEVENT Event;
PIO_STACK_LOCATION IoStackLocation;
PIRP Irp;
BOOLEAN OldHardError;
PAGED_CODE();
/* Get Device Object and Fast Calls */
DeviceObject = IoGetRelatedDeviceObject(FileObject);
FastDispatch = DeviceObject->DriverObject->FastIoDispatch;
/* Check if we support Fast Calls, and check FastIoQueryStandardInfo */
/* Call the function and see if it succeeds */
if ( !FastDispatch ||
!FastDispatch->FastIoQueryStandardInfo ||
!FastDispatch->FastIoQueryStandardInfo(FileObject,TRUE,
&Info,&IoStatus,DeviceObject))
{
/* If any of the above failed, then we are going to send an IRP to the device object */
/* Initialize the even for the IO */
KeInitializeEvent(&Event,NotificationEvent,FALSE);
/* Allocate the IRP */
Irp = IoAllocateIrp(DeviceObject->StackSize,FALSE);
if (Irp == NULL)
{
return STATUS_INSUFFICIENT_RESOURCES;
}
/* Don't process hard error */
OldHardError = IoSetThreadHardErrorMode(FALSE);
/* Setup the IRP */
Irp->UserIosb = &IoStatus;
Irp->UserEvent = &Event;
Irp->Tail.Overlay.Thread = PsGetCurrentThread();
Irp->Flags = IRP_SYNCHRONOUS_PAGING_IO | IRP_PAGING_IO;
Irp->RequestorMode = KernelMode;
Irp->Tail.Overlay.OriginalFileObject = FileObject;
Irp->AssociatedIrp.SystemBuffer = &Info;
/* Setup out stack location */
IoStackLocation = Irp->Tail.Overlay.CurrentStackLocation;
IoStackLocation--;
IoStackLocation->MajorFunction = IRP_MJ_QUERY_INFORMATION;
IoStackLocation->FileObject = FileObject;
IoStackLocation->DeviceObject = DeviceObject;
IoStackLocation->Parameters.QueryFile.Length = ALIGN_UP(sizeof(FILE_INFORMATION_CLASS),ULONG);
IoStackLocation->Parameters.QueryFile.FileInformationClass = FileStandardInformation;
/* Send the IRP to the related device object */
Status = IofCallDriver(DeviceObject,Irp);
/* Standard DDK IRP result processing */
if (Status == STATUS_PENDING)
{
KeWaitForSingleObject(&Event,Executive,KernelMode,FALSE,NULL);
}
/* If there was a synchronous error, signal it */
if (!NT_SUCCESS(Status))
{
IoStatus.Status = Status;
}
IoSetThreadHardErrorMode(OldHardError);
}
/* Check the sync/async IO result */
if (NT_SUCCESS(IoStatus.Status))
{
/* Was the request for a directory ? */
if (Info.Directory)
{
IoStatus.Status = STATUS_FILE_IS_A_DIRECTORY;
}
else
{
FileSize->QuadPart = Info.EndOfFile.QuadPart;
}
}
return IoStatus.Status;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlRead(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN ULONG LockKey,
OUT PMDL *MdlChain,
OUT PIO_STATUS_BLOCK IoStatus)
{
PDEVICE_OBJECT DeviceObject, BaseDeviceObject;
PFAST_IO_DISPATCH FastDispatch;
/* Get Device Object and Fast Calls */
DeviceObject = IoGetRelatedDeviceObject(FileObject);
FastDispatch = DeviceObject->DriverObject->FastIoDispatch;
/* Check if we support Fast Calls, and check this one */
if (FastDispatch && FastDispatch->MdlRead)
{
/* Use the fast path */
return FastDispatch->MdlRead(FileObject,
FileOffset,
Length,
LockKey,
MdlChain,
IoStatus,
DeviceObject);
}
/* Get the Base File System (Volume) and Fast Calls */
BaseDeviceObject = IoGetBaseFileSystemDeviceObject(FileObject);
FastDispatch = BaseDeviceObject->DriverObject->FastIoDispatch;
/* If the Base Device Object has its own FastDispatch Routine, fail */
if (FastDispatch && FastDispatch->MdlRead &&
BaseDeviceObject != DeviceObject)
{
return FALSE;
}
/* No fast path, use slow path */
return FsRtlMdlReadDev(FileObject,
FileOffset,
Length,
LockKey,
MdlChain,
IoStatus,
DeviceObject);
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlReadComplete(IN PFILE_OBJECT FileObject,
IN OUT PMDL MdlChain)
{
PDEVICE_OBJECT DeviceObject, BaseDeviceObject;
PFAST_IO_DISPATCH FastDispatch;
/* Get Device Object and Fast Calls */
DeviceObject = IoGetRelatedDeviceObject(FileObject);
FastDispatch = DeviceObject->DriverObject->FastIoDispatch;
/* Check if we support Fast Calls, and check this one */
if (FastDispatch && FastDispatch->MdlReadComplete)
{
/* Use the fast path */
return FastDispatch->MdlReadComplete(FileObject,
MdlChain,
DeviceObject);
}
/* Get the Base File System (Volume) and Fast Calls */
BaseDeviceObject = IoGetBaseFileSystemDeviceObject(FileObject);
FastDispatch = BaseDeviceObject->DriverObject->FastIoDispatch;
/* If the Base Device Object has its own FastDispatch Routine, fail */
if ((BaseDeviceObject != DeviceObject) && FastDispatch
&& FastDispatch->MdlReadComplete)
{
return FALSE;
}
/* No fast path, use slow path */
return FsRtlMdlReadCompleteDev(FileObject, MdlChain, DeviceObject);
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlReadCompleteDev(IN PFILE_OBJECT FileObject,
IN PMDL MemoryDescriptorList,
IN PDEVICE_OBJECT DeviceObject)
{
/* Call the Cache Manager */
CcMdlReadComplete2(MemoryDescriptorList, FileObject);
return TRUE;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlReadDev(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN ULONG LockKey,
OUT PMDL *MdlChain,
OUT PIO_STATUS_BLOCK IoStatus,
IN PDEVICE_OBJECT DeviceObject)
{
PFSRTL_COMMON_FCB_HEADER FcbHeader;
BOOLEAN Result = TRUE;
LARGE_INTEGER Offset;
PFAST_IO_DISPATCH FastIoDispatch;
PDEVICE_OBJECT Device;
PAGED_CODE();
/* No actual read */
if (!Length)
{
/* Return success */
IoStatus->Status = STATUS_SUCCESS;
IoStatus->Information = 0;
return TRUE;
}
/* Sanity check */
ASSERT(MAXLONGLONG - FileOffset->QuadPart >= (LONGLONG)Length);
/* Get the offset and FCB header */
Offset.QuadPart = FileOffset->QuadPart + Length;
FcbHeader = (PFSRTL_COMMON_FCB_HEADER)FileObject->FsContext;
/* Enter the FS */
FsRtlEnterFileSystem();
CcFastMdlReadWait++;
/* Lock the FCB */
ExAcquireResourceShared(FcbHeader->Resource, TRUE);
/* Check if this is a fast I/O cached file */
if (!(FileObject->PrivateCacheMap) ||
(FcbHeader->IsFastIoPossible == FastIoIsNotPossible))
{
/* It's not, so fail */
CcFastMdlReadNotPossible += 1;
Result = FALSE;
goto Cleanup;
}
/* Check if we need to find out if fast I/O is available */
if (FcbHeader->IsFastIoPossible == FastIoIsQuestionable)
{
/* Get the Fast I/O table */
Device = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = Device->DriverObject->FastIoDispatch;
/* Sanity check */
ASSERT(!KeIsExecutingDpc());
ASSERT(FastIoDispatch != NULL);
ASSERT(FastIoDispatch->FastIoCheckIfPossible != NULL);
/* Ask the driver if we can do it */
if (!FastIoDispatch->FastIoCheckIfPossible(FileObject,
FileOffset,
Length,
TRUE,
LockKey,
TRUE,
IoStatus,
Device))
{
/* It's not, fail */
CcFastMdlReadNotPossible += 1;
Result = FALSE;
goto Cleanup;
}
}
/* Check if we read too much */
if (Offset.QuadPart > FcbHeader->FileSize.QuadPart)
{
/* We did, check if the file offset is past the end */
if (FileOffset->QuadPart >= FcbHeader->FileSize.QuadPart)
{
/* Set end of file */
IoStatus->Status = STATUS_END_OF_FILE;
IoStatus->Information = 0;
goto Cleanup;
}
/* Otherwise, just normalize the length */
Length = (ULONG)(FcbHeader->FileSize.QuadPart - FileOffset->QuadPart);
}
/* Set this as top-level IRP */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
_SEH_TRY
{
/* Attempt a read */
CcMdlRead(FileObject, FileOffset, Length, MdlChain, IoStatus);
FileObject->Flags |= FO_FILE_FAST_IO_READ;
}
_SEH_EXCEPT(FsRtlCcCopyFilter)
{
Result = FALSE;
} _SEH_END;
/* Remove the top-level IRP flag */
PsGetCurrentThread()->TopLevelIrp = 0;
/* Return to caller */
Cleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
return Result;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlWriteComplete(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN PMDL MdlChain)
{
PDEVICE_OBJECT DeviceObject, BaseDeviceObject;
PFAST_IO_DISPATCH FastDispatch;
/* Get Device Object and Fast Calls */
DeviceObject = IoGetRelatedDeviceObject(FileObject);
FastDispatch = DeviceObject->DriverObject->FastIoDispatch;
/* Check if we support Fast Calls, and check this one */
if (FastDispatch && FastDispatch->MdlWriteComplete)
{
/* Use the fast path */
return FastDispatch->MdlWriteComplete(FileObject,
FileOffset,
MdlChain,
DeviceObject);
}
/* Get the Base File System (Volume) and Fast Calls */
BaseDeviceObject = IoGetBaseFileSystemDeviceObject(FileObject);
FastDispatch = BaseDeviceObject->DriverObject->FastIoDispatch;
/* If the Base Device Object has its own FastDispatch Routine, fail */
if (FastDispatch && FastDispatch->MdlWriteComplete &&
BaseDeviceObject != DeviceObject)
{
return FALSE;
}
/* No fast path, use slow path */
return FsRtlMdlWriteCompleteDev(FileObject,
FileOffset,
MdlChain,
DeviceObject);
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlMdlWriteCompleteDev(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN PMDL MdlChain,
IN PDEVICE_OBJECT DeviceObject)
{
if (FileObject->Flags & FO_WRITE_THROUGH)
{
return FALSE;
}
/* Call the Cache Manager */
CcMdlWriteComplete2(FileObject,FileOffset,MdlChain);
return TRUE;
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlPrepareMdlWrite(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN ULONG LockKey,
OUT PMDL *MdlChain,
OUT PIO_STATUS_BLOCK IoStatus)
{
PDEVICE_OBJECT DeviceObject, BaseDeviceObject;
PFAST_IO_DISPATCH FastDispatch;
/* Get Device Object and Fast Calls */
DeviceObject = IoGetRelatedDeviceObject(FileObject);
FastDispatch = DeviceObject->DriverObject->FastIoDispatch;
/* Check if we support Fast Calls, and check this one */
if (FastDispatch && FastDispatch->PrepareMdlWrite)
{
/* Use the fast path */
return FastDispatch->PrepareMdlWrite(FileObject,
FileOffset,
Length,
LockKey,
MdlChain,
IoStatus,
DeviceObject);
}
/* Get the Base File System (Volume) and Fast Calls */
BaseDeviceObject = IoGetBaseFileSystemDeviceObject(FileObject);
FastDispatch = BaseDeviceObject->DriverObject->FastIoDispatch;
/* If the Base Device Object has its own FastDispatch Routine, fail */
if (FastDispatch && FastDispatch->PrepareMdlWrite &&
BaseDeviceObject != DeviceObject)
{
return FALSE;
}
/* No fast path, use slow path */
return FsRtlPrepareMdlWriteDev(FileObject,
FileOffset,
Length,
LockKey,
MdlChain,
IoStatus,
DeviceObject);
}
/*
* @implemented
*/
BOOLEAN
NTAPI
FsRtlPrepareMdlWriteDev(IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER FileOffset,
IN ULONG Length,
IN ULONG LockKey,
OUT PMDL *MdlChain,
OUT PIO_STATUS_BLOCK IoStatus,
IN PDEVICE_OBJECT DeviceObject)
{
BOOLEAN Result = TRUE;
PFAST_IO_DISPATCH FastIoDispatch;
PDEVICE_OBJECT Device;
PFSRTL_COMMON_FCB_HEADER FcbHeader;
LARGE_INTEGER OldFileSize;
LARGE_INTEGER OldValidDataLength;
LARGE_INTEGER NewSize;
LARGE_INTEGER Offset;
/* WDK doc. Offset=0xffffffffffffffff indicates append to the end of file */
BOOLEAN FileOffsetAppend = ((FileOffset->HighPart == 0xffffffff) && (FileOffset->LowPart == 0xffffffff));
BOOLEAN FileSizeModified = FALSE;
BOOLEAN ResourceAquiredShared = FALSE;
/* Initialize some of the vars and pointers */
OldFileSize.QuadPart = 0;
OldValidDataLength.QuadPart = 0;
PAGED_CODE();
Offset.QuadPart = FileOffset->QuadPart + Length;
/* Nagar p.544 -- Check with Cc if we can write */
if ( (!CcCanIWrite(FileObject, Length,TRUE,FALSE))||
(FileObject->Flags & FO_WRITE_THROUGH))
{
return FALSE;
}
IoStatus->Status = STATUS_SUCCESS;
/* No actual read */
if (!Length)
{
return TRUE;
}
FcbHeader = (PFSRTL_COMMON_FCB_HEADER)FileObject->FsContext;
FsRtlEnterFileSystem();
/* Check we are going to extend the file */
if ( (FileOffsetAppend == FALSE) &&
( (FileOffset->QuadPart + Length) <= FcbHeader->ValidDataLength.QuadPart )
)
{
/* Acquire the resource shared */
ExAcquireResourceSharedLite(FcbHeader->Resource,TRUE);
ResourceAquiredShared =TRUE;
} else
{
/* Acquire the resource exclusive */
ExAcquireResourceExclusiveLite(FcbHeader->Resource,TRUE);
}
/* Check if we are appending */
if (FileOffsetAppend == TRUE) {
Offset.QuadPart = FcbHeader->FileSize.QuadPart;
NewSize.QuadPart = FcbHeader->FileSize.QuadPart + Length;
} else
{
Offset.QuadPart = FileOffset->QuadPart;
NewSize.QuadPart = FileOffset->QuadPart + Length;
}
if ( (FileObject->PrivateCacheMap) &&
(FcbHeader->IsFastIoPossible) &&
(MAXLONGLONG >= (LONGLONG) FileOffset->QuadPart + Length) &&
(NewSize.QuadPart <= FcbHeader->AllocationSize.QuadPart) )
{
/* Check if we can keep the lock shared */
if (ResourceAquiredShared && (NewSize.QuadPart > FcbHeader->ValidDataLength.QuadPart) ) {
ExReleaseResourceLite(FcbHeader->Resource);
ExAcquireResourceExclusiveLite(FcbHeader->Resource,TRUE);
/* Compute the offset and the new filesize */
if (FileOffsetAppend) {
Offset.QuadPart = FcbHeader->FileSize.QuadPart;
NewSize.QuadPart = FcbHeader->FileSize.QuadPart + Length;
}
/* Recheck the above points since we released and reacquire the lock */
if ( (FileObject->PrivateCacheMap != NULL) &&
(FcbHeader->IsFastIoPossible != FastIoIsNotPossible) &&
(FcbHeader->AllocationSize.QuadPart > NewSize.QuadPart)
)
{
/* Do nothing */
} else {
goto FailAndCleanup;
}
}
/* Check if we need to find out if fast I/O is available */
if (FcbHeader->IsFastIoPossible == FastIoIsQuestionable)
{
/* Sanity check */
/* ASSERT(!KeIsExecutingDpc()); */
/* Get the Fast I/O table */
Device = IoGetRelatedDeviceObject(FileObject);
FastIoDispatch = Device->DriverObject->FastIoDispatch;
/* Sanity check */
ASSERT(FastIoDispatch != NULL);
ASSERT(FastIoDispatch->FastIoCheckIfPossible != NULL);
/* Ask the driver if we can do it */
if (!FastIoDispatch->FastIoCheckIfPossible(FileObject,
FileOffset,
Length,
TRUE,
LockKey,
FALSE,
IoStatus,
Device))
{
/* It's not, fail */
goto FailAndCleanup;
}
}
/* If we are going to modify the filesize, save the old fs in case the operation fails */
if (NewSize.QuadPart > FcbHeader->FileSize.QuadPart)
{
FileSizeModified = TRUE;
OldFileSize.QuadPart = FcbHeader->FileSize.QuadPart;
OldValidDataLength.QuadPart = FcbHeader->ValidDataLength.QuadPart;
/* If the high part of the filesize is going to change, grab the Paging IoResouce */
if (NewSize.HighPart != FcbHeader->FileSize.HighPart && FcbHeader->PagingIoResource)
{
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->FileSize.QuadPart = NewSize.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
} else {
FcbHeader->FileSize.QuadPart = NewSize.QuadPart;
}
}
/* Nagar p.544 */
/* Set ourselves as top component */
PsGetCurrentThread()->TopLevelIrp = FSRTL_FAST_IO_TOP_LEVEL_IRP;
_SEH_TRY
{
/* Check if there is a gap between the end of the file and the offset
If yes, then we have to zero the data
*/
if (Offset.QuadPart > FcbHeader->ValidDataLength.QuadPart) {
Result = CcZeroData(FileObject,&FcbHeader->ValidDataLength,&Offset,TRUE);
if (Result)
{
CcPrepareMdlWrite(FileObject,&Offset,Length,MdlChain,IoStatus);
}
} else {
CcPrepareMdlWrite(FileObject,&Offset,Length,MdlChain,IoStatus);
}
}_SEH_EXCEPT(FsRtlCcCopyFilter)
{
Result = FALSE;
} _SEH_END;
/* Reset the top component */
PsGetCurrentThread()->TopLevelIrp = 0;
/* Did the operation suceeded */
if (Result) {
/* Check if we need to update the filesize */
if (NewSize.QuadPart > FcbHeader->ValidDataLength.QuadPart) {
if (NewSize.HighPart != FcbHeader->ValidDataLength.HighPart && FcbHeader->PagingIoResource) {
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->ValidDataLength.QuadPart = NewSize.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
} else {
FcbHeader->ValidDataLength.QuadPart = NewSize.QuadPart;
}
}
/* Flag the file as modified */
FileObject->Flags |= FO_FILE_MODIFIED;
/* Check if the filesize has changed */
if (FileSizeModified) {
/* Update the file sizes */
((SHARED_CACHE_MAP*) FileObject->SectionObjectPointer->SharedCacheMap)->FileSize.QuadPart = NewSize.QuadPart;
FileObject->Flags |= FO_FILE_SIZE_CHANGED;
}
}
else
{
/* The operation did not succeed
Reset the file size to what it should be
*/
if (FileSizeModified) {
if (FcbHeader->PagingIoResource) {
ExAcquireResourceExclusiveLite(FcbHeader->PagingIoResource, TRUE);
FcbHeader->FileSize.QuadPart = OldFileSize.QuadPart;
FcbHeader->ValidDataLength.QuadPart = OldValidDataLength.QuadPart;
ExReleaseResourceLite(FcbHeader->PagingIoResource);
}else{
FcbHeader->FileSize.QuadPart = OldFileSize.QuadPart;
FcbHeader->ValidDataLength.QuadPart = OldValidDataLength.QuadPart;
}
}
}
goto Cleanup;
}
else
{
goto FailAndCleanup;
}
FailAndCleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
return FALSE;
Cleanup:
ExReleaseResourceLite(FcbHeader->Resource);
FsRtlExitFileSystem();
return Result;
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlAcquireFileExclusive(IN PFILE_OBJECT FileObject)
{
/*
PAGED_CODE();
FsRtlAcquireFileExclusiveCommon(FileObject,0,0);
*/
KEBUGCHECK(0);
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlReleaseFile(IN PFILE_OBJECT FileObject)
{
KEBUGCHECK(0);
}
/*++
* @name FsRtlRegisterFileSystemFilterCallbacks
* @unimplemented
*
* FILLME
*
* @param FilterDriverObject
* FILLME
*
* @param Callbacks
* FILLME
*
* @return None
*
* @remarks None
*
*--*/
NTSTATUS
NTAPI
FsRtlRegisterFileSystemFilterCallbacks(IN PDRIVER_OBJECT FilterDriverObject,
IN PFS_FILTER_CALLBACKS Callbacks)
{
UNIMPLEMENTED;
return STATUS_NOT_IMPLEMENTED;
}
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