NT4/private/ntos/fastfat/volinfo.c
2020-09-30 17:12:29 +02:00

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/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
VolInfo.c
Abstract:
This module implements the volume information routines for Fat called by
the dispatch driver.
Author:
Gary Kimura [GaryKi] 12-Apr-1990
Revision History:
--*/
#include "FatProcs.h"
//
// The local debug trace level
//
#define Dbg (DEBUG_TRACE_VOLINFO)
NTSTATUS
FatQueryFsVolumeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_VOLUME_INFORMATION Buffer,
IN OUT PULONG Length
);
NTSTATUS
FatQueryFsSizeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_SIZE_INFORMATION Buffer,
IN OUT PULONG Length
);
NTSTATUS
FatQueryFsDeviceInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_DEVICE_INFORMATION Buffer,
IN OUT PULONG Length
);
NTSTATUS
FatQueryFsAttributeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_ATTRIBUTE_INFORMATION Buffer,
IN OUT PULONG Length
);
NTSTATUS
FatSetFsLabelInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_LABEL_INFORMATION Buffer
);
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, FatCommonQueryVolumeInfo)
#pragma alloc_text(PAGE, FatCommonSetVolumeInfo)
#pragma alloc_text(PAGE, FatFsdQueryVolumeInformation)
#pragma alloc_text(PAGE, FatFsdSetVolumeInformation)
#pragma alloc_text(PAGE, FatQueryFsAttributeInfo)
#pragma alloc_text(PAGE, FatQueryFsDeviceInfo)
#pragma alloc_text(PAGE, FatQueryFsSizeInfo)
#pragma alloc_text(PAGE, FatQueryFsVolumeInfo)
#pragma alloc_text(PAGE, FatSetFsLabelInfo)
#endif
NTSTATUS
FatFsdQueryVolumeInformation (
IN PVOLUME_DEVICE_OBJECT VolumeDeviceObject,
IN PIRP Irp
)
/*++
Routine Description:
This routine implements the Fsd part of the NtQueryVolumeInformation API
call.
Arguments:
VolumeDeviceObject - Supplies the volume device object where the file
being queried exists.
Irp - Supplies the Irp being processed.
Return Value:
NTSTATUS - The FSD status for the Irp.
--*/
{
NTSTATUS Status;
PIRP_CONTEXT IrpContext = NULL;
BOOLEAN TopLevel;
DebugTrace(+1, Dbg, "FatFsdQueryVolumeInformation\n", 0);
//
// Call the common query routine, with blocking allowed if synchronous
//
FsRtlEnterFileSystem();
TopLevel = FatIsIrpTopLevel( Irp );
try {
IrpContext = FatCreateIrpContext( Irp, CanFsdWait( Irp ) );
Status = FatCommonQueryVolumeInfo( IrpContext, Irp );
} except(FatExceptionFilter( IrpContext, GetExceptionInformation() )) {
//
// We had some trouble trying to perform the requested
// operation, so we'll abort the I/O request with
// the error status that we get back from the
// execption code
//
Status = FatProcessException( IrpContext, Irp, GetExceptionCode() );
}
if (TopLevel) { IoSetTopLevelIrp( NULL ); }
FsRtlExitFileSystem();
//
// And return to our caller
//
DebugTrace(-1, Dbg, "FatFsdQueryVolumeInformation -> %08lx\n", Status);
UNREFERENCED_PARAMETER( VolumeDeviceObject );
return Status;
}
NTSTATUS
FatFsdSetVolumeInformation (
IN PVOLUME_DEVICE_OBJECT VolumeDeviceObject,
IN PIRP Irp
)
/*++
Routine Description:
This routine implements the FSD part of the NtSetVolumeInformation API
call.
Arguments:
VolumeDeviceObject - Supplies the volume device object where the file
being set exists.
Irp - Supplies the Irp being processed.
Return Value:
NTSTATUS - The FSD status for the Irp.
--*/
{
NTSTATUS Status;
PIRP_CONTEXT IrpContext = NULL;
BOOLEAN TopLevel;
DebugTrace(+1, Dbg, "FatFsdSetVolumeInformation\n", 0);
//
// Call the common set routine
//
FsRtlEnterFileSystem();
TopLevel = FatIsIrpTopLevel( Irp );
try {
IrpContext = FatCreateIrpContext( Irp, CanFsdWait( Irp ) );
Status = FatCommonSetVolumeInfo( IrpContext, Irp );
} except(FatExceptionFilter( IrpContext, GetExceptionInformation() )) {
//
// We had some trouble trying to perform the requested
// operation, so we'll abort the I/O request with
// the error status that we get back from the
// execption code
//
Status = FatProcessException( IrpContext, Irp, GetExceptionCode() );
}
if (TopLevel) { IoSetTopLevelIrp( NULL ); }
FsRtlExitFileSystem();
//
// And return to our caller
//
DebugTrace(-1, Dbg, "FatFsdSetVolumeInformation -> %08lx\n", Status);
UNREFERENCED_PARAMETER( VolumeDeviceObject );
return Status;
}
NTSTATUS
FatCommonQueryVolumeInfo (
IN PIRP_CONTEXT IrpContext,
IN 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;
PIO_STACK_LOCATION IrpSp;
PVCB Vcb;
PFCB Fcb;
PCCB Ccb;
ULONG Length;
FS_INFORMATION_CLASS FsInformationClass;
PVOID Buffer;
BOOLEAN WeAcquiredVcb = FALSE;
//
// Get the current stack location
//
IrpSp = IoGetCurrentIrpStackLocation( Irp );
DebugTrace(+1, Dbg, "FatCommonQueryVolumeInfo...\n", 0);
DebugTrace( 0, Dbg, "Irp = %08lx\n", Irp );
DebugTrace( 0, Dbg, "->Length = %08lx\n", IrpSp->Parameters.QueryVolume.Length);
DebugTrace( 0, Dbg, "->FsInformationClass = %08lx\n", IrpSp->Parameters.QueryVolume.FsInformationClass);
DebugTrace( 0, Dbg, "->Buffer = %08lx\n", Irp->AssociatedIrp.SystemBuffer);
//
// Reference our input parameters to make things easier
//
Length = IrpSp->Parameters.QueryVolume.Length;
FsInformationClass = IrpSp->Parameters.QueryVolume.FsInformationClass;
Buffer = Irp->AssociatedIrp.SystemBuffer;
//
// Decode the file object to get the Vcb
//
(VOID) FatDecodeFileObject( IrpSp->FileObject, &Vcb, &Fcb, &Ccb );
try {
//
// Make sure the vcb is in a usable condition. This will raise
// and error condition if the volume is unusable
//
// Also verify the Root Dcb since we need info from there.
//
FatVerifyFcb( IrpContext, Vcb->RootDcb );
//
// 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 (FsInformationClass) {
case FileFsVolumeInformation:
//
// This is the only routine we need the Vcb shared because of
// copying the volume label. All other routines copy fields that
// cannot change or are just manifest constants.
//
if (!FatAcquireSharedVcb( IrpContext, Vcb )) {
DebugTrace(0, Dbg, "Cannot acquire Vcb\n", 0);
Status = FatFsdPostRequest( IrpContext, Irp );
} else {
Status = FatQueryFsVolumeInfo( IrpContext, Vcb, Buffer, &Length );
WeAcquiredVcb = TRUE;
}
break;
case FileFsSizeInformation:
Status = FatQueryFsSizeInfo( IrpContext, Vcb, Buffer, &Length );
break;
case FileFsDeviceInformation:
Status = FatQueryFsDeviceInfo( IrpContext, Vcb, Buffer, &Length );
break;
case FileFsAttributeInformation:
Status = FatQueryFsAttributeInfo( IrpContext, Vcb, Buffer, &Length );
break;
default:
Status = STATUS_INVALID_PARAMETER;
break;
}
//
// Set the information field to the number of bytes actually filled in
//
Irp->IoStatus.Information = IrpSp->Parameters.QueryVolume.Length - Length;
} finally {
DebugUnwind( FatCommonQueryVolumeInfo );
if ( WeAcquiredVcb ) { FatReleaseVcb( IrpContext, Vcb ); }
if (!AbnormalTermination()) {
FatCompleteRequest( IrpContext, Irp, Status );
}
DebugTrace(-1, Dbg, "FatCommonQueryVolumeInfo -> %08lx\n", Status);
}
return Status;
}
NTSTATUS
FatCommonSetVolumeInfo (
IN PIRP_CONTEXT IrpContext,
IN PIRP Irp
)
/*++
Routine Description:
This is the common routine for setting 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;
PIO_STACK_LOCATION IrpSp;
PVCB Vcb;
PFCB Fcb;
PCCB Ccb;
TYPE_OF_OPEN TypeOfOpen;
ULONG Length;
FS_INFORMATION_CLASS FsInformationClass;
PVOID Buffer;
//
// Get the current stack location
//
IrpSp = IoGetCurrentIrpStackLocation( Irp );
DebugTrace(+1, Dbg, "FatCommonSetVolumeInfo...\n", 0);
DebugTrace( 0, Dbg, "Irp = %08lx\n", Irp );
DebugTrace( 0, Dbg, "->Length = %08lx\n", IrpSp->Parameters.SetVolume.Length);
DebugTrace( 0, Dbg, "->FsInformationClass = %08lx\n", IrpSp->Parameters.SetVolume.FsInformationClass);
DebugTrace( 0, Dbg, "->Buffer = %08lx\n", Irp->AssociatedIrp.SystemBuffer);
//
// Reference our input parameters to make things easier
//
Length = IrpSp->Parameters.SetVolume.Length;
FsInformationClass = IrpSp->Parameters.SetVolume.FsInformationClass;
Buffer = Irp->AssociatedIrp.SystemBuffer;
//
// Decode the file object to get the Vcb
//
TypeOfOpen = FatDecodeFileObject( IrpSp->FileObject, &Vcb, &Fcb, &Ccb );
if (TypeOfOpen != UserVolumeOpen) {
FatCompleteRequest( IrpContext, Irp, STATUS_ACCESS_DENIED );
DebugTrace(-1, Dbg, "FatCommonSetVolumeInfo -> STATUS_ACCESS_DENIED\n", 0);
return STATUS_ACCESS_DENIED;
}
#ifndef DOUBLE_SPACE_WRITE
ASSERT(Vcb->Dscb == NULL);
#endif // DOUBLE_SPACE_WRITE
//
// Acquire exclusive access to the Vcb and enqueue the Irp if we didn't
// get access
//
if (!FatAcquireExclusiveVcb( IrpContext, Vcb )) {
DebugTrace(0, Dbg, "Cannot acquire Vcb\n", 0);
Status = FatFsdPostRequest( IrpContext, Irp );
DebugTrace(-1, Dbg, "FatCommonSetVolumeInfo -> %08lx\n", Status );
return Status;
}
try {
//
// Make sure the vcb is in a usable condition. This will raise
// and error condition if the volume is unusable
//
// Also verify the Root Dcb since we need info from there.
//
FatVerifyFcb( IrpContext, Vcb->RootDcb );
//
// Based on the information class we'll do different actions. Each
// of the procedures that we're calling performs the action if
// possible and returns true if it successful and false if it couldn't
// wait for any I/O to complete.
//
switch (FsInformationClass) {
case FileFsLabelInformation:
Status = FatSetFsLabelInfo( IrpContext, Vcb, Buffer );
break;
default:
Status = STATUS_INVALID_PARAMETER;
break;
}
FatUnpinRepinnedBcbs( IrpContext );
} finally {
DebugUnwind( FatCommonSetVolumeInfo );
FatReleaseVcb( IrpContext, Vcb );
if (!AbnormalTermination()) {
FatCompleteRequest( IrpContext, Irp, Status );
}
DebugTrace(-1, Dbg, "FatCommonSetVolumeInfo -> %08lx\n", Status);
}
return Status;
}
//
// Internal support routine
//
NTSTATUS
FatQueryFsVolumeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_VOLUME_INFORMATION Buffer,
IN OUT PULONG Length
)
/*++
Routine Description:
This routine implements the query volume info call
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 recieves the remaining bytes free in the buffer
Return Value:
NTSTATUS - Returns the status for the query
--*/
{
ULONG BytesToCopy;
NTSTATUS Status;
DebugTrace(0, Dbg, "FatQueryFsVolumeInfo...\n", 0);
//
// Zero out the buffer, then extract and fill up the non zero fields.
//
RtlZeroMemory( Buffer, sizeof(FILE_FS_VOLUME_INFORMATION) );
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;
Status = STATUS_SUCCESS;
} else {
BytesToCopy = *Length;
Status = STATUS_BUFFER_OVERFLOW;
}
//
// Copy over what we can of the volume label, and adjust *Length
//
Buffer->VolumeLabelLength = Vcb->Vpb->VolumeLabelLength;
RtlCopyMemory( &Buffer->VolumeLabel[0],
&Vcb->Vpb->VolumeLabel[0],
BytesToCopy );
*Length -= BytesToCopy;
//
// Set our status and return to our caller
//
UNREFERENCED_PARAMETER( IrpContext );
return Status;
}
//
// Internal support routine
//
NTSTATUS
FatQueryFsSizeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_SIZE_INFORMATION Buffer,
IN OUT PULONG Length
)
/*++
Routine Description:
This routine implements the query volume size call
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 recieves the remaining bytes free in the buffer
Return Value:
Status - Returns the status for the query
--*/
{
PDSCB Dscb = Vcb->Dscb;
DebugTrace(0, Dbg, "FatQueryFsSizeInfo...\n", 0);
RtlZeroMemory( Buffer, sizeof(FILE_FS_SIZE_INFORMATION) );
//
// Set the output buffer. If this is a double space volume, we have
// some additional work to do.
//
Dscb = Vcb->Dscb;
if (Dscb && (Dscb->SectorsAllocated != 0)) {
ULONG EstimatedClustersFree;
//
// Compute how many clusters we think we can represent on this
// disk. This is:
//
// (Total - Allocated) * (Represented / Allocated)
//
// which for computational reasons, we reduce to:
//
// (Total * Represented / Allocated) - Represented
//
EstimatedClustersFree =
(ULONG)
((((LONGLONG)(Dscb->CvfLayout.CvfHeap.Size / 512) *
(LONGLONG)(Dscb->SectorsRepresented)) /
Dscb->SectorsAllocated)
-
Dscb->SectorsRepresented)
/
Vcb->Bpb.SectorsPerCluster;
//
// Now, if this number is smaller than the remaining clusters in
// the FAT table, then use it.
//
Buffer->AvailableAllocationUnits.LowPart =
EstimatedClustersFree < Vcb->AllocationSupport.NumberOfFreeClusters ?
EstimatedClustersFree : Vcb->AllocationSupport.NumberOfFreeClusters;
//
// To get the total number of clusters, take how many FAT clusters
// we have used, and add the number returned above.
//
Buffer->TotalAllocationUnits.LowPart =
Vcb->AllocationSupport.NumberOfClusters -
Vcb->AllocationSupport.NumberOfFreeClusters +
Buffer->AvailableAllocationUnits.LowPart;
} else {
Buffer->TotalAllocationUnits.LowPart =
Vcb->AllocationSupport.NumberOfClusters;
Buffer->AvailableAllocationUnits.LowPart =
Vcb->AllocationSupport.NumberOfFreeClusters;
}
Buffer->SectorsPerAllocationUnit = Vcb->Bpb.SectorsPerCluster;
Buffer->BytesPerSector = Vcb->Bpb.BytesPerSector;
//
// Adjust the length variable
//
*Length -= sizeof(FILE_FS_SIZE_INFORMATION);
//
// And return success to our caller
//
UNREFERENCED_PARAMETER( IrpContext );
return STATUS_SUCCESS;
}
//
// Internal support routine
//
NTSTATUS
FatQueryFsDeviceInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_DEVICE_INFORMATION Buffer,
IN OUT PULONG Length
)
/*++
Routine Description:
This routine implements the query volume device call
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 recieves the remaining bytes free in the buffer
Return Value:
Status - Returns the status for the query
--*/
{
DebugTrace(0, Dbg, "FatQueryFsDeviceInfo...\n", 0);
RtlZeroMemory( Buffer, sizeof(FILE_FS_DEVICE_INFORMATION) );
//
// Set the output buffer
//
Buffer->DeviceType = FILE_DEVICE_DISK;
Buffer->Characteristics = Vcb->TargetDeviceObject->Characteristics;
if (Vcb->Dscb != NULL) {
SetFlag( Buffer->Characteristics, FILE_VIRTUAL_VOLUME );
}
//
// Adjust the length variable
//
*Length -= sizeof(FILE_FS_DEVICE_INFORMATION);
//
// And return success to our caller
//
UNREFERENCED_PARAMETER( IrpContext );
return STATUS_SUCCESS;
}
//
// Internal support routine
//
NTSTATUS
FatQueryFsAttributeInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_ATTRIBUTE_INFORMATION Buffer,
IN OUT PULONG Length
)
/*++
Routine Description:
This routine implements the query volume attribute call
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 recieves the remaining bytes free in the buffer
Return Value:
Status - Returns the status for the query
--*/
{
ULONG BytesToCopy;
NTSTATUS Status;
DebugTrace(0, Dbg, "FatQueryFsAttributeInfo...\n", 0);
//
// Determine how much of the file system name will fit.
//
if ( (*Length - FIELD_OFFSET( FILE_FS_ATTRIBUTE_INFORMATION,
FileSystemName[0] )) >= 6 ) {
BytesToCopy = 6;
*Length -= FIELD_OFFSET( FILE_FS_ATTRIBUTE_INFORMATION,
FileSystemName[0] ) + 6;
Status = STATUS_SUCCESS;
} else {
BytesToCopy = *Length - FIELD_OFFSET( FILE_FS_ATTRIBUTE_INFORMATION,
FileSystemName[0]);
*Length = 0;
Status = STATUS_BUFFER_OVERFLOW;
}
//
// Set the output buffer
//
Buffer->FileSystemAttributes = FILE_CASE_PRESERVED_NAMES |
FILE_UNICODE_ON_DISK;
#ifdef WE_WON_ON_APPEAL
if (FlagOn(Vcb->VcbState, VCB_STATE_FLAG_COMPRESSED_VOLUME)) {
SetFlag( Buffer->FileSystemAttributes, FILE_VOLUME_IS_COMPRESSED );
}
#endif // WE_WON_ON_APPEAL
Buffer->MaximumComponentNameLength = FatData.ChicagoMode ? 255 : 12;
Buffer->FileSystemNameLength = BytesToCopy;
RtlCopyMemory( &Buffer->FileSystemName[0], L"FAT", BytesToCopy );
//
// And return success to our caller
//
UNREFERENCED_PARAMETER( IrpContext );
UNREFERENCED_PARAMETER( Vcb );
return Status;
}
//
// Internal support routine
//
NTSTATUS
FatSetFsLabelInfo (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PFILE_FS_LABEL_INFORMATION Buffer
)
/*++
Routine Description:
This routine implements the set volume label call
Arguments:
Vcb - Supplies the Vcb being queried
Buffer - Supplies the input where the information is stored.
Return Value:
NTSTATUS - Returns the status for the operation
--*/
{
NTSTATUS Status;
PDIRENT Dirent;
PBCB DirentBcb = NULL;
ULONG ByteOffset;
WCHAR TmpBuffer[11];
UCHAR OemBuffer[11];
OEM_STRING OemLabel;
UNICODE_STRING UnicodeString;
UNICODE_STRING UpcasedLabel;
DebugTrace(+1, Dbg, "FatSetFsLabelInfo...\n", 0);
//
// Setup our local variable
//
UnicodeString.Length = (USHORT)Buffer->VolumeLabelLength;
UnicodeString.MaximumLength = UnicodeString.Length;
UnicodeString.Buffer = (PWSTR) &Buffer->VolumeLabel[0];
//
// Make sure the name can fit into the stack buffer
//
if ( UnicodeString.Length > 11*sizeof(WCHAR) ) {
return STATUS_INVALID_VOLUME_LABEL;
}
//
// Upcase the name and convert it to the Oem code page.
//
OemLabel.Buffer = &OemBuffer[0];
OemLabel.Length = 0;
OemLabel.MaximumLength = 11;
Status = FatUpcaseUnicodeStringToCountedOemString( &OemLabel,
&UnicodeString,
FALSE );
//
// Volume label that fits in 11 unicode character length limit
// is not necessary within 11 characters in OEM character set.
//
if (!NT_SUCCESS( Status )) {
DebugTrace(-1, Dbg, "FatSetFsLabelInfo: Label must be too long. %08lx\n", Status );
return STATUS_INVALID_VOLUME_LABEL;
}
//
// Get the Unicode upcased string to store in the VPB.
//
UpcasedLabel.Length = UnicodeString.Length;
UpcasedLabel.MaximumLength = 11*sizeof(WCHAR);
UpcasedLabel.Buffer = &TmpBuffer[0];
Status = RtlOemStringToCountedUnicodeString( &UpcasedLabel,
&OemLabel,
FALSE );
if (!NT_SUCCESS( Status )) {
DebugTrace(-1, Dbg, "FatSetFsLabelInfo: Label must be too long. %08lx\n", Status );
return STATUS_INVALID_VOLUME_LABEL;
}
DirentBcb = NULL;
//
// Make this look like a write through to disk. This is important to
// avoid a unpleasant window where it looks like we have the wrong volume.
//
SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_WRITE_THROUGH );
try {
//
// Check for a label length other than zero.
//
if (OemLabel.Length > 0) {
ULONG i;
//
// Check the label for illegal characters
//
for (i=0; i < (ULONG)OemLabel.Length; i += 1) {
if ( FsRtlIsLeadDbcsCharacter( OemLabel.Buffer[i] ) ) {
i += 1;
continue;
}
if (!FsRtlIsAnsiCharacterLegalFat(OemLabel.Buffer[i], FALSE) ||
(OemLabel.Buffer[i] == '.')) {
DebugTrace( 0, Dbg, "INVALID VOLUME LABEL\n", 0);
try_return( Status = STATUS_INVALID_VOLUME_LABEL );
}
}
//
// Locate the volume label if there already is one
//
FatLocateVolumeLabel( IrpContext,
Vcb,
&Dirent,
&DirentBcb,
&ByteOffset );
//
// Check that we really got one, if not then we need to create
// a new one. The procedure we call will raise an appropriate
// status if we are not able to allocate a new dirent
//
if (Dirent == NULL) {
ByteOffset = FatCreateNewDirent( IrpContext,
Vcb->RootDcb,
1 );
FatPrepareWriteDirectoryFile( IrpContext,
Vcb->RootDcb,
ByteOffset,
sizeof(DIRENT),
&DirentBcb,
&Dirent,
FALSE,
&Status );
ASSERT( NT_SUCCESS( Status ));
}
//
// Now reconstruct the volume label dirent and mark it dirty
//
FatConstructLabelDirent( IrpContext,
Dirent,
&OemLabel );
FatSetDirtyBcb( IrpContext, DirentBcb, Vcb );
//
// Unpin the Bcb here so that we will get any IO errors
// here before changing the VPB label.
//
FatUnpinBcb( IrpContext, DirentBcb );
FatUnpinRepinnedBcbs( IrpContext );
//
// Now set the upcased label in the VPB
//
RtlCopyMemory( &Vcb->Vpb->VolumeLabel[0],
&UpcasedLabel.Buffer[0],
Buffer->VolumeLabelLength );
Vcb->Vpb->VolumeLabelLength = (USHORT)Buffer->VolumeLabelLength;
} else {
//
// Otherwise we're trying to delete the label
// Locate the current volume label if there already is one
//
FatLocateVolumeLabel( IrpContext,
Vcb,
&Dirent,
&DirentBcb,
&ByteOffset );
//
// Check that we really got one
//
if (Dirent == NULL) {
try_return( Status = STATUS_SUCCESS );
}
//
// Now delete the current label.
//
Dirent->FileName[0] = FAT_DIRENT_DELETED;
ASSERT( (Vcb->RootDcb->Specific.Dcb.UnusedDirentVbo == 0xffffffff) ||
RtlAreBitsSet( &Vcb->RootDcb->Specific.Dcb.FreeDirentBitmap,
ByteOffset / sizeof(DIRENT),
1 ) );
RtlClearBits( &Vcb->RootDcb->Specific.Dcb.FreeDirentBitmap,
ByteOffset / sizeof(DIRENT),
1 );
FatSetDirtyBcb( IrpContext, DirentBcb, Vcb );
//
// Unpin the Bcb here so that we will get any IO errors
// here before changing the VPB label.
//
FatUnpinBcb( IrpContext, DirentBcb );
FatUnpinRepinnedBcbs( IrpContext );
//
// Now set the label in the VPB
//
Vcb->Vpb->VolumeLabelLength = 0;
}
Status = STATUS_SUCCESS;
try_exit: NOTHING;
} finally {
DebugUnwind( FatSetFsALabelInfo );
FatUnpinBcb( IrpContext, DirentBcb );
DebugTrace(-1, Dbg, "FatSetFsALabelInfo -> STATUS_SUCCESS\n", 0);
}
return Status;
}