Windows Driver Development | windows driver samples | cdfs file system driver | C++

Sample Code

windows driver samples/ cdfs file system driver/ C++/ volinfo.c/

/*++
 
Copyright (c) 1989-2000 Microsoft Corporation
 
Module Name:
 
    VolInfo.c
 
Abstract:
 
    This module implements the volume information routines for Cdfs called by
    the dispatch driver.
 
 
--*/
 
#include "CdProcs.h"
 
//
//  The Bug check file id for this module
//
 
#define BugCheckFileId                   (CDFS_BUG_CHECK_VOLINFO)
 
//
//  Local support routines
//
 
_Requires_lock_held_(_Global_critical_region_)
NTSTATUS
CdQueryFsVolumeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_VOLUME_INFORMATION Buffer,
    _Inout_ PULONG Length
    );
 
NTSTATUS
CdQueryFsSizeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_SIZE_INFORMATION Buffer,
    _Inout_ PULONG Length
    );
 
NTSTATUS
CdQueryFsDeviceInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_DEVICE_INFORMATION Buffer,
    _Inout_ PULONG Length
    );
 
NTSTATUS
CdQueryFsAttributeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_ATTRIBUTE_INFORMATION Buffer,
    _Inout_ PULONG Length
    );
 
NTSTATUS
CdQueryFsSectorSizeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_writes_bytes_(*Length) PFILE_FS_SECTOR_SIZE_INFORMATION Buffer,
    _Inout_ PULONG Length
    );
 
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, CdCommonQueryVolInfo)
#pragma alloc_text(PAGE, CdQueryFsAttributeInfo)
#pragma alloc_text(PAGE, CdQueryFsDeviceInfo)
#pragma alloc_text(PAGE, CdQueryFsSizeInfo)
#pragma alloc_text(PAGE, CdQueryFsVolumeInfo)
#pragma alloc_text(PAGE, CdQueryFsSectorSizeInfo)
#endif
 

_Requires_lock_held_(_Global_critical_region_)
NTSTATUS
CdCommonQueryVolInfo (
    _Inout_ PIRP_CONTEXT IrpContext,
    _Inout_ PIRP Irp
    )
 
/*++
 
Routine Description:
 
    This is the common routine for querying volume information called by both
    the fsd and fsp threads.
 
Arguments:
 
    Irp - Supplies the Irp being processed
 
Return Value:
 
    NTSTATUS - The return status for the operation
 
--*/
 
{
    NTSTATUS Status = STATUS_INVALID_PARAMETER;
    PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( Irp );
 
    ULONG Length;
 
    TYPE_OF_OPEN TypeOfOpen;
    PFCB Fcb;
    PCCB Ccb;
 
    PAGED_CODE();
 
    //
    //  Reference our input parameters to make things easier
    //
 
    Length = IrpSp->Parameters.QueryVolume.Length;
 
    //
    //  Decode the file object and fail if this an unopened file object.
    //
 
    TypeOfOpen = CdDecodeFileObject( IrpContext, IrpSp->FileObject, &Fcb, &Ccb );
 
    if (TypeOfOpen == UnopenedFileObject) {
 
        CdCompleteRequest( IrpContext, Irp, STATUS_INVALID_PARAMETER );
        return STATUS_INVALID_PARAMETER;
    }
 
    //
    //  Acquire the Vcb for this volume.
    //
 
    CdAcquireVcbShared( IrpContext, Fcb->Vcb, FALSE );
 
    //
    //  Use a try-finally to facilitate cleanup.
    //
 
    try {
 
        //
        //  Verify the Vcb.
        //
 
        CdVerifyVcb( IrpContext, Fcb->Vcb );
 
        //
        //  Based on the information class we'll do different actions.  Each
        //  of the procedures that we're calling fills up the output buffer
        //  if possible and returns true if it successfully filled the buffer
        //  and false if it couldn't wait for any I/O to complete.
        //
 
        switch (IrpSp->Parameters.QueryVolume.FsInformationClass) {
 
        case FileFsSizeInformation:
 
            Status = CdQueryFsSizeInfo( IrpContext, Fcb->Vcb, Irp->AssociatedIrp.SystemBuffer, &Length );
            break;
 
        case FileFsVolumeInformation:
 
            Status = CdQueryFsVolumeInfo( IrpContext, Fcb->Vcb, Irp->AssociatedIrp.SystemBuffer, &Length );
            break;
 
        case FileFsDeviceInformation:
 
            Status = CdQueryFsDeviceInfo( IrpContext, Fcb->Vcb, Irp->AssociatedIrp.SystemBuffer, &Length );
            break;
 
        case FileFsAttributeInformation:
 
            Status = CdQueryFsAttributeInfo( IrpContext, Fcb->Vcb, Irp->AssociatedIrp.SystemBuffer, &Length );
            break;
 
#if (NTDDI_VERSION >= NTDDI_WIN8)
        case FileFsSectorSizeInformation:
 
            Status = CdQueryFsSectorSizeInfo( IrpContext, Fcb->Vcb, Irp->AssociatedIrp.SystemBuffer, &Length );
            break;
#endif
        }
 
        //
        //  Set the information field to the number of bytes actually filled in
        //
 
        Irp->IoStatus.Information = IrpSp->Parameters.QueryVolume.Length - Length;
 
    } finally {
 
        //
        //  Release the Vcb.
        //
 
        CdReleaseVcb( IrpContext, Fcb->Vcb );
    }
 
    //
    //  Complete the request if we didn't raise.
    //
 
    CdCompleteRequest( IrpContext, Irp, Status );
 
    return Status;
}
 

//
//  Local support routine
//
 
_Requires_lock_held_(_Global_critical_region_)
NTSTATUS
CdQueryFsVolumeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_VOLUME_INFORMATION Buffer,
    _Inout_ PULONG Length
    )
 
/*++
 
Routine Description:
 
    This routine implements the query volume info call
 
Arguments:
 
    Vcb - Vcb for this volume.
 
    Buffer - Supplies a pointer to the output buffer where the information
        is to be returned
 
    Length - Supplies the length of the buffer in byte.  This variable
        upon return recieves the remaining bytes free in the buffer
 
Return Value:
 
    NTSTATUS - Returns the status for the query
 
--*/
 
{
    ULONG BytesToCopy;
 
    NTSTATUS Status = STATUS_SUCCESS;
 
    PAGED_CODE();
 
    UNREFERENCED_PARAMETER( IrpContext );
 
    //
    //  Fill in the data from the Vcb.
    //
 
    Buffer->VolumeCreationTime = *((PLARGE_INTEGER) &Vcb->VolumeDasdFcb->CreationTime);
    Buffer->VolumeSerialNumber = Vcb->Vpb->SerialNumber;
 
    Buffer->SupportsObjects = FALSE;
 
    *Length -= FIELD_OFFSET( FILE_FS_VOLUME_INFORMATION, VolumeLabel[0] );
 
    //
    //  Check if the buffer we're given is long enough
    //
 
    if (*Length >= (ULONG) Vcb->Vpb->VolumeLabelLength) {
 
        BytesToCopy = Vcb->Vpb->VolumeLabelLength;
 
    } else {
 
        BytesToCopy = *Length;
 
        Status = STATUS_BUFFER_OVERFLOW;
    }
 
    //
    //  Copy over what we can of the volume label, and adjust *Length
    //
 
    Buffer->VolumeLabelLength = BytesToCopy;
 
    if (BytesToCopy) {
 
        RtlCopyMemory( &Buffer->VolumeLabel[0],
                       &Vcb->Vpb->VolumeLabel[0],
                       BytesToCopy );
    }
 
    *Length -= BytesToCopy;
 
    //
    //  Set our status and return to our caller
    //
 
    return Status;
}
 

//
//  Local support routine
//
 
NTSTATUS
CdQueryFsSizeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_SIZE_INFORMATION Buffer,
    _Inout_ PULONG Length
    )
 
/*++
 
Routine Description:
 
    This routine implements the query volume size call.
 
Arguments:
 
    Vcb - Vcb for this volume.
 
    Buffer - Supplies a pointer to the output buffer where the information
        is to be returned
 
    Length - Supplies the length of the buffer in byte.  This variable
        upon return recieves the remaining bytes free in the buffer
 
Return Value:
 
    NTSTATUS - Returns the status for the query
 
--*/
 
{
    PAGED_CODE();
 
    UNREFERENCED_PARAMETER( IrpContext );
 
    //
    //  Fill in the output buffer.
    //
 
    Buffer->TotalAllocationUnits.QuadPart = LlSectorsFromBytes( Vcb->VolumeDasdFcb->AllocationSize.QuadPart );
 
    Buffer->AvailableAllocationUnits.QuadPart = 0;
    Buffer->SectorsPerAllocationUnit = 1;
    Buffer->BytesPerSector = SECTOR_SIZE;
 
    //
    //  Adjust the length variable
    //
 
    *Length -= sizeof( FILE_FS_SIZE_INFORMATION );
 
    //
    //  And return success to our caller
    //
 
    return STATUS_SUCCESS;
}
 

//
//  Local support routine
//
 
NTSTATUS
CdQueryFsDeviceInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_DEVICE_INFORMATION Buffer,
    _Inout_ PULONG Length
    )
 
/*++
 
Routine Description:
 
    This routine implements the query volume device call.
 
Arguments:
 
    Vcb - Vcb for this volume.
 
    Buffer - Supplies a pointer to the output buffer where the information
        is to be returned
 
    Length - Supplies the length of the buffer in byte.  This variable
        upon return recieves the remaining bytes free in the buffer
 
Return Value:
 
    NTSTATUS - Returns the status for the query
 
--*/
 
{
    PAGED_CODE();
 
    UNREFERENCED_PARAMETER( IrpContext );
 
    //
    //  Update the output buffer.
    //
 
    Buffer->Characteristics = Vcb->TargetDeviceObject->Characteristics;
    Buffer->DeviceType = FILE_DEVICE_CD_ROM;
 
    //
    //  Adjust the length variable
    //
 
    *Length -= sizeof( FILE_FS_DEVICE_INFORMATION );
 
    //
    //  And return success to our caller
    //
 
    return STATUS_SUCCESS;
}
 

//
//  Local support routine
//
 
NTSTATUS
CdQueryFsAttributeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_ PFILE_FS_ATTRIBUTE_INFORMATION Buffer,
    _Inout_ PULONG Length
    )
 
/*++
 
Routine Description:
 
    This routine implements the query volume attribute call.
 
Arguments:
 
    Vcb - Vcb for this volume.
 
    Buffer - Supplies a pointer to the output buffer where the information
        is to be returned
 
    Length - Supplies the length of the buffer in byte.  This variable
        upon return recieves the remaining bytes free in the buffer
 
Return Value:
 
    NTSTATUS - Returns the status for the query
 
--*/
 
{
    ULONG BytesToCopy;
 
    NTSTATUS Status = STATUS_SUCCESS;
 
    PAGED_CODE();
 
    UNREFERENCED_PARAMETER( Vcb );
 
    //
    //  Fill out the fixed portion of the buffer.
    //
 
    Buffer->FileSystemAttributes = FILE_CASE_SENSITIVE_SEARCH |
                                   FILE_READ_ONLY_VOLUME |
                                   FILE_SUPPORTS_OPEN_BY_FILE_ID;
 
    if (FlagOn( IrpContext->Vcb->VcbState, VCB_STATE_JOLIET )) {
 
        SetFlag( Buffer->FileSystemAttributes, FILE_UNICODE_ON_DISK );
 
        Buffer->MaximumComponentNameLength = 110;
 
    } else {
 
        Buffer->MaximumComponentNameLength = 221;
    }
 
    *Length -= FIELD_OFFSET( FILE_FS_ATTRIBUTE_INFORMATION, FileSystemName );
 
    //
    //  Make sure we can copy full unicode characters.
    //
 
    ClearFlag( *Length, 1 );
 
    //
    //  Determine how much of the file system name will fit.
    //
 
    if (*Length >= 8) {
 
        BytesToCopy = 8;
 
    } else {
 
        BytesToCopy = *Length;
        Status = STATUS_BUFFER_OVERFLOW;
    }
 
    *Length -= BytesToCopy;
 
    //
    //  Do the file system name.
    //
 
    Buffer->FileSystemNameLength = BytesToCopy;
 
    RtlCopyMemory( &Buffer->FileSystemName[0], L"CDFS", BytesToCopy );
 
    //
    //  And return to our caller
    //
 
    return Status;
}
 
#if (NTDDI_VERSION >= NTDDI_WIN8)
 
NTSTATUS
CdQueryFsSectorSizeInfo (
    _In_ PIRP_CONTEXT IrpContext,
    _In_ PVCB Vcb,
    _Out_writes_bytes_(*Length) PFILE_FS_SECTOR_SIZE_INFORMATION Buffer,
    _Inout_ PULONG Length
    )
 
/*++
 
Routine Description:
 
    This routine implements the query sector size information call
    This operation will work on any handle and requires no privilege.
 
Arguments:
 
    Vcb - Supplies the Vcb being queried
 
    Buffer - Supplies a pointer to the output buffer where the information
        is to be returned
 
    Length - Supplies the length of the buffer in byte.  This variable
        upon return receives the remaining bytes free in the buffer
 
Return Value:
 
    NTSTATUS - Returns the status for the query
 
--*/
 
{
    NTSTATUS Status;
 
    PAGED_CODE();
    UNREFERENCED_PARAMETER( IrpContext );
 
    //
    //  Sufficient buffer size is guaranteed by the I/O manager or the
    //  originating kernel mode driver.
    //
 
    ASSERT( *Length >= sizeof( FILE_FS_SECTOR_SIZE_INFORMATION ));
    _Analysis_assume_( *Length >= sizeof( FILE_FS_SECTOR_SIZE_INFORMATION ));
 
    //
    //  Retrieve the sector size information
    //
 
    Status = FsRtlGetSectorSizeInformation( Vcb->Vpb->RealDevice,
                                            Buffer );
 
    //
    //  Adjust the length variable
    //
 
    if (NT_SUCCESS( Status )) {
 
        *Length -= sizeof( FILE_FS_SECTOR_SIZE_INFORMATION );
    }
 
    return Status;
}
 
#endif
Our Services

What our customers say about us?

Read our customer testimonials to find out why our clients keep returning for their projects.
View Testimonials
We Love Software

Sample Code

windows driver samples/ cdfs file system driver/ C++/ volinfo.c/

Our Services

What our customers say about us?

About Us

Sitemap

Explore
