Sample Code
Windows Driver Samples/ CDFS File System Driver/ C++/ lockctrl.c/
/*++
Copyright (c) 1989-2000 Microsoft Corporation
Module Name:
LockCtrl.c
Abstract:
This module implements the Lock Control routines for Cdfs called
by the Fsd/Fsp dispatch driver.
--*/
#include "CdProcs.h"
//
// The Bug check file id for this module
//
#define BugCheckFileId (CDFS_BUG_CHECK_LOCKCTRL)
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, CdCommonLockControl)
#pragma alloc_text(PAGE, CdFastLock)
#pragma alloc_text(PAGE, CdFastUnlockAll)
#pragma alloc_text(PAGE, CdFastUnlockAllByKey)
#pragma alloc_text(PAGE, CdFastUnlockSingle)
#endif
NTSTATUS
CdCommonLockControl (
_Inout_ PIRP_CONTEXT IrpContext,
_Inout_ PIRP Irp
)
/*++
Routine Description:
This is the common routine for Lock Control called by both the fsd and fsp
threads.
Arguments:
Irp - Supplies the Irp to process
Return Value:
NTSTATUS - The return status for the operation
--*/
{
NTSTATUS Status;
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( Irp );
TYPE_OF_OPEN TypeOfOpen;
PFCB Fcb;
PCCB Ccb;
PAGED_CODE();
//
// Extract and decode the type of file object we're being asked to process
//
TypeOfOpen = CdDecodeFileObject( IrpContext, IrpSp->FileObject, &Fcb, &Ccb );
//
// If the file is not a user file open then we reject the request
// as an invalid parameter
//
if (TypeOfOpen != UserFileOpen) {
CdCompleteRequest( IrpContext, Irp, STATUS_INVALID_PARAMETER );
return STATUS_INVALID_PARAMETER;
}
//
// We check whether we can proceed based on the state of the file oplocks.
// This call might post the irp for us.
//
Status = FsRtlCheckOplock( CdGetFcbOplock(Fcb),
Irp,
IrpContext,
CdOplockComplete,
NULL );
//
// If we don't get success then the oplock package completed the request.
//
if (Status != STATUS_SUCCESS) {
return Status;
}
//
// Verify the Fcb.
//
CdVerifyFcbOperation( IrpContext, Fcb );
//
// If we don't have a file lock, then get one now.
//
if (Fcb->FileLock == NULL) { CdCreateFileLock( IrpContext, Fcb, TRUE ); }
//
// Now call the FsRtl routine to do the actual processing of the
// Lock request
//
Status = FsRtlProcessFileLock( Fcb->FileLock, Irp, NULL );
//
// Set the flag indicating if Fast I/O is possible
//
CdLockFcb( IrpContext, Fcb );
Fcb->IsFastIoPossible = CdIsFastIoPossible( Fcb );
CdUnlockFcb( IrpContext, Fcb );
//
// Complete the request.
//
CdCompleteRequest( IrpContext, NULL, Status );
return Status;
}
BOOLEAN
CdFastLock (
_In_ PFILE_OBJECT FileObject,
_In_ PLARGE_INTEGER FileOffset,
_In_ PLARGE_INTEGER Length,
_In_ PEPROCESS ProcessId,
_In_ ULONG Key,
_In_ BOOLEAN FailImmediately,
_In_ BOOLEAN ExclusiveLock,
_Out_ PIO_STATUS_BLOCK IoStatus,
_In_ PDEVICE_OBJECT DeviceObject
)
/*++
Routine Description:
This is a call back routine for doing the fast lock call.
Arguments:
FileObject - Supplies the file object used in this operation
FileOffset - Supplies the file offset used in this operation
Length - Supplies the length used in this operation
ProcessId - Supplies the process ID used in this operation
Key - Supplies the key used in this operation
FailImmediately - Indicates if the request should fail immediately
if the lock cannot be granted.
ExclusiveLock - Indicates if this is a request for an exclusive or
shared lock
IoStatus - Receives the Status if this operation is successful
Return Value:
BOOLEAN - TRUE if this operation completed and FALSE if caller
needs to take the long route.
--*/
{
BOOLEAN Results = FALSE;
PFCB Fcb;
TYPE_OF_OPEN TypeOfOpen;
PAGED_CODE();
UNREFERENCED_PARAMETER( DeviceObject );
ASSERT_FILE_OBJECT( FileObject );
IoStatus->Information = 0;
//
// Decode the type of file object we're being asked to process and
// make sure that is is only a user file open.
//
TypeOfOpen = CdFastDecodeFileObject( FileObject, &Fcb );
if (TypeOfOpen != UserFileOpen) {
IoStatus->Status = STATUS_INVALID_PARAMETER;
return TRUE;
}
//
// Only deal with 'good' Fcb's.
//
if (!CdVerifyFcbOperation( NULL, Fcb )) {
return FALSE;
}
FsRtlEnterFileSystem();
//
// Use a try-finally to facilitate cleanup.
//
try {
//
// We check whether we can proceed based on the state of the file oplocks.
//
if (!FsRtlOplockIsFastIoPossible( CdGetFcbOplock(Fcb) )) {
try_return( NOTHING );
}
//
// If we don't have a file lock, then get one now.
//
if ((Fcb->FileLock == NULL) && !CdCreateFileLock( NULL, Fcb, FALSE )) {
try_return( NOTHING );
}
//
// Now call the FsRtl routine to perform the lock request.
//
#pragma prefast(suppress: 28159, "prefast thinks this is an obsolete routine, but it is ok for CDFS to use it")
if ((Results = FsRtlFastLock( Fcb->FileLock,
FileObject,
FileOffset,
Length,
ProcessId,
Key,
FailImmediately,
ExclusiveLock,
IoStatus,
NULL,
FALSE )) != FALSE) {
//
// Set the flag indicating if Fast I/O is questionable. We
// only change this flag if the current state is possible.
// Retest again after synchronizing on the header.
//
if (Fcb->IsFastIoPossible == FastIoIsPossible) {
CdLockFcb( NULL, Fcb );
Fcb->IsFastIoPossible = CdIsFastIoPossible( Fcb );
CdUnlockFcb( NULL, Fcb );
}
}
try_exit: NOTHING;
} finally {
FsRtlExitFileSystem();
}
return Results;
}
BOOLEAN
CdFastUnlockSingle (
_In_ PFILE_OBJECT FileObject,
_In_ PLARGE_INTEGER FileOffset,
_In_ PLARGE_INTEGER Length,
_In_ PEPROCESS ProcessId,
_In_ ULONG Key,
_Out_ PIO_STATUS_BLOCK IoStatus,
_In_ PDEVICE_OBJECT DeviceObject
)
/*++
Routine Description:
This is a call back routine for doing the fast unlock single call.
Arguments:
FileObject - Supplies the file object used in this operation
FileOffset - Supplies the file offset used in this operation
Length - Supplies the length used in this operation
ProcessId - Supplies the process ID used in this operation
Key - Supplies the key used in this operation
Status - Receives the Status if this operation is successful
Return Value:
BOOLEAN - TRUE if this operation completed and FALSE if caller
needs to take the long route.
--*/
{
BOOLEAN Results = FALSE;
TYPE_OF_OPEN TypeOfOpen;
PFCB Fcb;
PAGED_CODE();
UNREFERENCED_PARAMETER( DeviceObject );
IoStatus->Information = 0;
//
// Decode the type of file object we're being asked to process and
// make sure that is is only a user file open.
//
TypeOfOpen = CdFastDecodeFileObject( FileObject, &Fcb );
if (TypeOfOpen != UserFileOpen) {
IoStatus->Status = STATUS_INVALID_PARAMETER;
return TRUE;
}
//
// Only deal with 'good' Fcb's.
//
if (!CdVerifyFcbOperation( NULL, Fcb )) {
return FALSE;
}
//
// If there is no lock then return immediately.
//
if (Fcb->FileLock == NULL) {
IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
return TRUE;
}
FsRtlEnterFileSystem();
try {
//
// We check whether we can proceed based on the state of the file oplocks.
//
if (!FsRtlOplockIsFastIoPossible( CdGetFcbOplock(Fcb) )) {
try_return( NOTHING );
}
//
// If we don't have a file lock, then get one now.
//
if ((Fcb->FileLock == NULL) && !CdCreateFileLock( NULL, Fcb, FALSE )) {
try_return( NOTHING );
}
//
// Now call the FsRtl routine to do the actual processing of the
// Lock request. The call will always succeed.
//
Results = TRUE;
IoStatus->Status = FsRtlFastUnlockSingle( Fcb->FileLock,
FileObject,
FileOffset,
Length,
ProcessId,
Key,
NULL,
FALSE );
//
// Set the flag indicating if Fast I/O is possible. We are
// only concerned if there are no longer any filelocks on this
// file.
//
if (!FsRtlAreThereCurrentFileLocks( Fcb->FileLock ) &&
(Fcb->IsFastIoPossible != FastIoIsPossible)) {
CdLockFcb( IrpContext, Fcb );
Fcb->IsFastIoPossible = CdIsFastIoPossible( Fcb );
CdUnlockFcb( IrpContext, Fcb );
}
try_exit: NOTHING;
} finally {
FsRtlExitFileSystem();
}
return Results;
}
BOOLEAN
CdFastUnlockAll (
_In_ PFILE_OBJECT FileObject,
_In_ PEPROCESS ProcessId,
_Out_ PIO_STATUS_BLOCK IoStatus,
_In_ PDEVICE_OBJECT DeviceObject
)
/*++
Routine Description:
This is a call back routine for doing the fast unlock all call.
Arguments:
FileObject - Supplies the file object used in this operation
ProcessId - Supplies the process ID used in this operation
Status - Receives the Status if this operation is successful
Return Value:
BOOLEAN - TRUE if this operation completed and FALSE if caller
needs to take the long route.
--*/
{
BOOLEAN Results = FALSE;
TYPE_OF_OPEN TypeOfOpen;
PFCB Fcb;
PAGED_CODE();
UNREFERENCED_PARAMETER( DeviceObject );
IoStatus->Information = 0;
//
// Decode the type of file object we're being asked to process and
// make sure that is is only a user file open.
//
TypeOfOpen = CdFastDecodeFileObject( FileObject, &Fcb );
if (TypeOfOpen != UserFileOpen) {
IoStatus->Status = STATUS_INVALID_PARAMETER;
return TRUE;
}
//
// Only deal with 'good' Fcb's.
//
if (!CdVerifyFcbOperation( NULL, Fcb )) {
return FALSE;
}
//
// If there is no lock then return immediately.
//
if (Fcb->FileLock == NULL) {
IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
return TRUE;
}
FsRtlEnterFileSystem();
try {
//
// We check whether we can proceed based on the state of the file oplocks.
//
if (!FsRtlOplockIsFastIoPossible( CdGetFcbOplock(Fcb) )) {
try_return( NOTHING );
}
//
// If we don't have a file lock, then get one now.
//
if ((Fcb->FileLock == NULL) && !CdCreateFileLock( NULL, Fcb, FALSE )) {
try_return( NOTHING );
}
//
// Now call the FsRtl routine to do the actual processing of the
// Lock request. The call will always succeed.
//
Results = TRUE;
IoStatus->Status = FsRtlFastUnlockAll( Fcb->FileLock,
FileObject,
ProcessId,
NULL );
//
// Set the flag indicating if Fast I/O is possible
//
CdLockFcb( IrpContext, Fcb );
Fcb->IsFastIoPossible = CdIsFastIoPossible( Fcb );
CdUnlockFcb( IrpContext, Fcb );
try_exit: NOTHING;
} finally {
FsRtlExitFileSystem();
}
return Results;
}
BOOLEAN
CdFastUnlockAllByKey (
_In_ PFILE_OBJECT FileObject,
_In_ PVOID ProcessId,
_In_ ULONG Key,
_Out_ PIO_STATUS_BLOCK IoStatus,
_In_ PDEVICE_OBJECT DeviceObject
)
/*++
Routine Description:
This is a call back routine for doing the fast unlock all by key call.
Arguments:
FileObject - Supplies the file object used in this operation
ProcessId - Supplies the process ID used in this operation
Key - Supplies the key used in this operation
Status - Receives the Status if this operation is successful
Return Value:
BOOLEAN - TRUE if this operation completed and FALSE if caller
needs to take the long route.
--*/
{
BOOLEAN Results = FALSE;
TYPE_OF_OPEN TypeOfOpen;
PFCB Fcb;
PAGED_CODE();
UNREFERENCED_PARAMETER( DeviceObject );
IoStatus->Information = 0;
//
// Decode the type of file object we're being asked to process and
// make sure that is is only a user file open.
//
TypeOfOpen = CdFastDecodeFileObject( FileObject, &Fcb );
if (TypeOfOpen != UserFileOpen) {
IoStatus->Status = STATUS_INVALID_PARAMETER;
return TRUE;
}
//
// Only deal with 'good' Fcb's.
//
if (!CdVerifyFcbOperation( NULL, Fcb )) {
return FALSE;
}
//
// If there is no lock then return immediately.
//
if (Fcb->FileLock == NULL) {
IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
return TRUE;
}
FsRtlEnterFileSystem();
try {
//
// We check whether we can proceed based on the state of the file oplocks.
//
if (!FsRtlOplockIsFastIoPossible( CdGetFcbOplock(Fcb) )) {
try_return( NOTHING );
}
//
// If we don't have a file lock, then get one now.
//
if ((Fcb->FileLock == NULL) && !CdCreateFileLock( NULL, Fcb, FALSE )) {
try_return( NOTHING );
}
//
// Now call the FsRtl routine to do the actual processing of the
// Lock request. The call will always succeed.
//
Results = TRUE;
IoStatus->Status = FsRtlFastUnlockAllByKey( Fcb->FileLock,
FileObject,
ProcessId,
Key,
NULL );
//
// Set the flag indicating if Fast I/O is possible
//
CdLockFcb( IrpContext, Fcb );
Fcb->IsFastIoPossible = CdIsFastIoPossible( Fcb );
CdUnlockFcb( IrpContext, Fcb );
try_exit: NOTHING;
} finally {
FsRtlExitFileSystem();
}
return Results;
}
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