__drv_mustHoldCriticalRegion
NTSTATUS
CdQueryDirectory (
__inout PIRP_CONTEXT IrpContext,
__inout PIRP Irp,
__in PIO_STACK_LOCATION IrpSp,
__in PFCB Fcb,
__in PCCB Ccb
)
/*++
Routine Description:
This routine performs the query directory operation. It is responsible
for either completing of enqueuing the input Irp. We store the state of the
search in the Ccb.
Arguments:
Irp - Supplies the Irp to process
IrpSp - Stack location for this Irp.
Fcb - Fcb for this directory.
Ccb - Ccb for this directory open.
Return Value:
NTSTATUS - The return status for the operation
--*/
{
NTSTATUS Status = STATUS_SUCCESS;
ULONG Information = 0;
ULONG LastEntry = 0;
ULONG NextEntry = 0;
ULONG FileNameBytes;
ULONG SeparatorBytes;
ULONG VersionStringBytes;
FILE_ENUM_CONTEXT FileContext;
PDIRENT ThisDirent = NULL;
BOOLEAN InitialQuery;
BOOLEAN ReturnNextEntry = FALSE;
BOOLEAN ReturnSingleEntry;
BOOLEAN Found;
BOOLEAN DoCcbUpdate = FALSE;
PCHAR UserBuffer;
ULONG BytesRemainingInBuffer;
ULONG BaseLength;
PFILE_BOTH_DIR_INFORMATION DirInfo = NULL;
PFILE_NAMES_INFORMATION NamesInfo;
PFILE_ID_FULL_DIR_INFORMATION IdFullDirInfo;
PFILE_ID_BOTH_DIR_INFORMATION IdBothDirInfo;
PAGED_CODE();
//
// Check if we support this search mode. Also remember the size of the base part of
// each of these structures.
//
switch (IrpSp->Parameters.QueryDirectory.FileInformationClass) {
case FileDirectoryInformation:
BaseLength = FIELD_OFFSET( FILE_DIRECTORY_INFORMATION,
FileName[0] );
break;
case FileFullDirectoryInformation:
BaseLength = FIELD_OFFSET( FILE_FULL_DIR_INFORMATION,
FileName[0] );
break;
case FileIdFullDirectoryInformation:
BaseLength = FIELD_OFFSET( FILE_ID_FULL_DIR_INFORMATION,
FileName[0] );
break;
case FileNamesInformation:
BaseLength = FIELD_OFFSET( FILE_NAMES_INFORMATION,
FileName[0] );
break;
case FileBothDirectoryInformation:
BaseLength = FIELD_OFFSET( FILE_BOTH_DIR_INFORMATION,
FileName[0] );
break;
case FileIdBothDirectoryInformation:
BaseLength = FIELD_OFFSET( FILE_ID_BOTH_DIR_INFORMATION,
FileName[0] );
break;
default:
CdCompleteRequest( IrpContext, Irp, STATUS_INVALID_INFO_CLASS );
return STATUS_INVALID_INFO_CLASS;
}
//
// Get the user buffer.
//
CdMapUserBuffer( IrpContext, &UserBuffer);
//
// Initialize our search context.
//
CdInitializeFileContext( IrpContext, &FileContext );
//
// Acquire the directory.
//
CdAcquireFileShared( IrpContext, Fcb );
//
// Use a try-finally to facilitate cleanup.
//
try {
//
// Verify the Fcb is still good.
//
CdVerifyFcbOperation( IrpContext, Fcb );
//
// Start by getting the initial state for the enumeration. This will set up the Ccb with
// the initial search parameters and let us know the starting offset in the directory
// to search.
//
CdInitializeEnumeration( IrpContext,
IrpSp,
Fcb,
Ccb,
&FileContext,
&ReturnNextEntry,
&ReturnSingleEntry,
&InitialQuery );
//
// The current dirent is stored in the InitialDirent field. We capture
// this here so that we have a valid restart point even if we don't
// find a single entry.
//
ThisDirent = &FileContext.InitialDirent->Dirent;
//
// At this point we are about to enter our query loop. We have
// determined the index into the directory file to begin the
// search. LastEntry and NextEntry are used to index into the user
// buffer. LastEntry is the last entry we've added, NextEntry is
// current one we're working on. If NextEntry is non-zero, then
// at least one entry was added.
//
while (TRUE) {
//
// If the user had requested only a single match and we have
// returned that, then we stop at this point. We update the Ccb with
// the status based on the last entry returned.
//
if ((NextEntry != 0) && ReturnSingleEntry) {
DoCcbUpdate = TRUE;
try_leave( Status );
}
//
// We try to locate the next matching dirent. Our search if based on a starting
// dirent offset, whether we should return the current or next entry, whether
// we should be doing a short name search and finally whether we should be
// checking for a version match.
//
Found = CdEnumerateIndex( IrpContext, Ccb, &FileContext, ReturnNextEntry );
//
// Initialize the value for the next search.
//
ReturnNextEntry = TRUE;
//
// If we didn't receive a dirent, then we are at the end of the
// directory. If we have returned any files, we exit with
// success, otherwise we return STATUS_NO_MORE_FILES.
//
if (!Found) {
if (NextEntry == 0) {
Status = STATUS_NO_MORE_FILES;
if (InitialQuery) {
Status = STATUS_NO_SUCH_FILE;
}
}
DoCcbUpdate = TRUE;
try_leave( Status );
}
//
// Remember the dirent for the file we just found.
//
ThisDirent = &FileContext.InitialDirent->Dirent;
//
// Here are the rules concerning filling up the buffer:
//
// 1. The Io system garentees that there will always be
// enough room for at least one base record.
//
// 2. If the full first record (including file name) cannot
// fit, as much of the name as possible is copied and
// STATUS_BUFFER_OVERFLOW is returned.
//
// 3. If a subsequent record cannot completely fit into the
// buffer, none of it (as in 0 bytes) is copied, and
// STATUS_SUCCESS is returned. A subsequent query will
// pick up with this record.
//
//
// Let's compute the number of bytes we need to transfer the current entry.
//
SeparatorBytes =
VersionStringBytes = 0;
//
// We can look directly at the dirent that we found.
//
FileNameBytes = ThisDirent->CdFileName.FileName.Length;
//
// Compute the number of bytes for the version string if
// we will return this. Allow directories with illegal ";".
//
if (((Ccb->SearchExpression.VersionString.Length != 0) ||
(FlagOn(ThisDirent->DirentFlags, CD_ATTRIBUTE_DIRECTORY))) &&
(ThisDirent->CdFileName.VersionString.Length != 0)) {
SeparatorBytes = 2;
VersionStringBytes = ThisDirent->CdFileName.VersionString.Length;
}
//
// If the slot for the next entry would be beyond the length of the
// user's buffer just exit (we know we've returned at least one entry
// already). This will happen when we align the pointer past the end.
//
if (NextEntry > IrpSp->Parameters.QueryDirectory.Length) {
ReturnNextEntry = FALSE;
DoCcbUpdate = TRUE;
try_leave( Status = STATUS_SUCCESS );
}
//
// Compute the number of bytes remaining in the buffer. Round this
// down to a WCHAR boundary so we can copy full characters.
//
BytesRemainingInBuffer = IrpSp->Parameters.QueryDirectory.Length - NextEntry;
ClearFlag( BytesRemainingInBuffer, 1 );
//
// If this won't fit and we have returned a previous entry then just
// return STATUS_SUCCESS.
//
if ((BaseLength + FileNameBytes + SeparatorBytes + VersionStringBytes) > BytesRemainingInBuffer) {
//
// If we already found an entry then just exit.
//
if (NextEntry != 0) {
ReturnNextEntry = FALSE;
DoCcbUpdate = TRUE;
try_leave( Status = STATUS_SUCCESS );
}
//
// Don't even try to return the version string if it doesn't all fit.
// Reduce the FileNameBytes to just fit in the buffer.
//
if ((BaseLength + FileNameBytes) > BytesRemainingInBuffer) {
FileNameBytes = BytesRemainingInBuffer - BaseLength;
}
//
// Don't return any version string bytes.
//
VersionStringBytes =
SeparatorBytes = 0;
//
// Use a status code of STATUS_BUFFER_OVERFLOW. Also set
// ReturnSingleEntry so that we will exit the loop at the top.
//
Status = STATUS_BUFFER_OVERFLOW;
ReturnSingleEntry = TRUE;
}
//
// Protect access to the user buffer with an exception handler.
// Since (at our request) IO doesn't buffer these requests, we have
// to guard against a user messing with the page protection and other
// such trickery.
//
try {
//
// Zero and initialize the base part of the current entry.
//
RtlZeroMemory( Add2Ptr( UserBuffer, NextEntry, PVOID ),
BaseLength );
//
// Now we have an entry to return to our caller.
// We'll case on the type of information requested and fill up
// the user buffer if everything fits.
//
switch (IrpSp->Parameters.QueryDirectory.FileInformationClass) {
case FileBothDirectoryInformation:
case FileFullDirectoryInformation:
case FileIdBothDirectoryInformation:
case FileIdFullDirectoryInformation:
case FileDirectoryInformation:
DirInfo = Add2Ptr( UserBuffer, NextEntry, PFILE_BOTH_DIR_INFORMATION );
//
// Use the create time for all the time stamps.
//
CdConvertCdTimeToNtTime( IrpContext,
FileContext.InitialDirent->Dirent.CdTime,
&DirInfo->CreationTime );
DirInfo->LastWriteTime = DirInfo->ChangeTime = DirInfo->CreationTime;
//
// Set the attributes and sizes separately for directories and
// files.
//
if (FlagOn( ThisDirent->DirentFlags, CD_ATTRIBUTE_DIRECTORY )) {
DirInfo->EndOfFile.QuadPart = DirInfo->AllocationSize.QuadPart = 0;
SetFlag( DirInfo->FileAttributes, FILE_ATTRIBUTE_DIRECTORY);
} else {
DirInfo->EndOfFile.QuadPart = FileContext.FileSize;
DirInfo->AllocationSize.QuadPart = LlSectorAlign( FileContext.FileSize );
SetFlag( DirInfo->FileAttributes, FILE_ATTRIBUTE_READONLY);
}
if (FlagOn( ThisDirent->DirentFlags,
CD_ATTRIBUTE_HIDDEN )) {
SetFlag( DirInfo->FileAttributes, FILE_ATTRIBUTE_HIDDEN );
}
DirInfo->FileIndex = ThisDirent->DirentOffset;
DirInfo->FileNameLength = FileNameBytes + SeparatorBytes + VersionStringBytes;
break;
case FileNamesInformation:
NamesInfo = Add2Ptr( UserBuffer, NextEntry, PFILE_NAMES_INFORMATION );
NamesInfo->FileIndex = ThisDirent->DirentOffset;
NamesInfo->FileNameLength = FileNameBytes + SeparatorBytes + VersionStringBytes;
break;
}
//
// Fill in the FileId
//
switch (IrpSp->Parameters.QueryDirectory.FileInformationClass) {
case FileIdBothDirectoryInformation:
IdBothDirInfo = Add2Ptr( UserBuffer, NextEntry, PFILE_ID_BOTH_DIR_INFORMATION );
CdSetFidFromParentAndDirent( IdBothDirInfo->FileId, Fcb, ThisDirent );
break;
case FileIdFullDirectoryInformation:
IdFullDirInfo = Add2Ptr( UserBuffer, NextEntry, PFILE_ID_FULL_DIR_INFORMATION );
CdSetFidFromParentAndDirent( IdFullDirInfo->FileId, Fcb, ThisDirent );
break;
default:
break;
}
//
// Now copy as much of the name as possible. We also may have a version
// string to copy.
//
if (FileNameBytes != 0) {
//
// This is a Unicode name, we can copy the bytes directly.
//
RtlCopyMemory( Add2Ptr( UserBuffer, NextEntry + BaseLength, PVOID ),
ThisDirent->CdFileName.FileName.Buffer,
FileNameBytes );
if (SeparatorBytes != 0) {
*(Add2Ptr( UserBuffer,
NextEntry + BaseLength + FileNameBytes,
PWCHAR )) = L';';
if (VersionStringBytes != 0) {
RtlCopyMemory( Add2Ptr( UserBuffer,
NextEntry + BaseLength + FileNameBytes + sizeof( WCHAR ),
PVOID ),
ThisDirent->CdFileName.VersionString.Buffer,
VersionStringBytes );
}
}
}
//
// Fill in the short name if we got STATUS_SUCCESS. The short name
// may already be in the file context. Otherwise we will check
// whether the long name is 8.3. Special case the self and parent
// directory names.
//
if ((Status == STATUS_SUCCESS) &&
(IrpSp->Parameters.QueryDirectory.FileInformationClass == FileBothDirectoryInformation ||
IrpSp->Parameters.QueryDirectory.FileInformationClass == FileIdBothDirectoryInformation) &&
(Ccb->SearchExpression.VersionString.Length == 0) &&
!FlagOn( ThisDirent->Flags, DIRENT_FLAG_CONSTANT_ENTRY )) {
//
// If we already have the short name then copy into the user's buffer.
//
if (FileContext.ShortName.FileName.Length != 0) {
RtlCopyMemory( DirInfo->ShortName,
FileContext.ShortName.FileName.Buffer,
FileContext.ShortName.FileName.Length );
DirInfo->ShortNameLength = (CCHAR) FileContext.ShortName.FileName.Length;
//
// If the short name length is currently zero then check if
// the long name is not 8.3. We can copy the short name in
// unicode form directly into the caller's buffer.
//
} else {
if (!CdIs8dot3Name( IrpContext,
ThisDirent->CdFileName.FileName )) {
CdGenerate8dot3Name( IrpContext,
&ThisDirent->CdCaseFileName.FileName,
ThisDirent->DirentOffset,
DirInfo->ShortName,
&FileContext.ShortName.FileName.Length );
DirInfo->ShortNameLength = (CCHAR) FileContext.ShortName.FileName.Length;
}
}
}
//
// Sum the total number of bytes for the information field.
//
FileNameBytes += SeparatorBytes + VersionStringBytes;
//
// Update the information with the number of bytes stored in the
// buffer. We quad-align the existing buffer to add any necessary
// pad bytes.
//
Information = NextEntry + BaseLength + FileNameBytes;
//
// Go back to the previous entry and fill in the update to this entry.
//
*(Add2Ptr( UserBuffer, LastEntry, PULONG )) = NextEntry - LastEntry;
//
// Set up our variables for the next dirent.
//
InitialQuery = FALSE;
LastEntry = NextEntry;
NextEntry = QuadAlign( Information );
} except (EXCEPTION_EXECUTE_HANDLER) {
//
// We had a problem filling in the user's buffer, so stop and
// fail this request. This is the only reason any exception
// would have occured at this level.
//
Information = 0;
try_leave( Status = GetExceptionCode());
}
}
DoCcbUpdate = TRUE;
} finally {
//
// Cleanup our search context - *before* aquiring the FCB mutex exclusive,
// else can block on threads in cdcreateinternalstream/purge which
// hold the FCB but are waiting for all maps in this stream to be released.
//
CdCleanupFileContext( IrpContext, &FileContext );
//
// Now we can safely aqure the FCB mutex if we need to.
//
if (DoCcbUpdate && !NT_ERROR( Status )) {
//
// Update the Ccb to show the current state of the enumeration.
//
CdLockFcb( IrpContext, Fcb );
Ccb->CurrentDirentOffset = ThisDirent->DirentOffset;
ClearFlag( Ccb->Flags, CCB_FLAG_ENUM_RETURN_NEXT );
if (ReturnNextEntry) {
SetFlag( Ccb->Flags, CCB_FLAG_ENUM_RETURN_NEXT );
}
CdUnlockFcb( IrpContext, Fcb );
}
//
// Release the Fcb.
//
CdReleaseFile( IrpContext, Fcb );
}
//
// Complete the request here.
//
Irp->IoStatus.Information = Information;
CdCompleteRequest( IrpContext, Irp, Status );
return Status;
}
NTSTATUS
CdCommonWrite (
_Inout_ PIRP_CONTEXT IrpContext,
_Inout_ PIRP Irp
)
/*++
Routine Description:
This is the common entry point for NtWriteFile calls. For synchronous requests,
CommonWrite 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 SynchronousIo;
PVOID UserBuffer;
LONGLONG StartingOffset;
LONGLONG ByteRange;
ULONG ByteCount;
ULONG WriteByteCount;
ULONG OriginalByteCount;
BOOLEAN ReleaseFile = TRUE;
CD_IO_CONTEXT LocalIoContext;
PAGED_CODE();
//
// If this is a zero length write then return SUCCESS immediately.
//
if (IrpSp->Parameters.Write.Length == 0) {
CdCompleteRequest( IrpContext, Irp, STATUS_SUCCESS );
return STATUS_SUCCESS;
}
//
// Decode the file object and verify we support write on this. It
// must be a volume file.
//
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 != UserVolumeOpen) {
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 );
SynchronousIo = FlagOn( IrpSp->FileObject->Flags, FO_SYNCHRONOUS_IO );
//
// Extract the range of the Io.
//
StartingOffset = IrpSp->Parameters.Write.ByteOffset.QuadPart;
OriginalByteCount = ByteCount = IrpSp->Parameters.Write.Length;
ByteRange = StartingOffset + ByteCount;
//
// Acquire the file shared to perform the write.
//
CdAcquireFileShared( IrpContext, Fcb );
//
// Use a try-finally to facilitate cleanup.
//
try {
//
// Verify the Fcb. Allow writes if this is a DASD handle that is
// dismounting the volume.
//
if (!FlagOn( Ccb->Flags, CCB_FLAG_DISMOUNT_ON_CLOSE )) {
CdVerifyFcbOperation( IrpContext, Fcb );
}
if (!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 write if it extends beyond the end of the file.
//
if (ByteRange > Fcb->FileSize.QuadPart) {
ByteCount = (ULONG) (Fcb->FileSize.QuadPart - StartingOffset);
ByteRange = Fcb->FileSize.QuadPart;
}
}
//
// 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 write is not integral
// sectors.
//
WriteByteCount = BlockAlign( Fcb->Vcb, ByteCount );
if (SectorOffset( StartingOffset ) ||
SectorOffset( WriteByteCount ) ||
(WriteByteCount > OriginalByteCount)) {
if (!Wait) {
CdRaiseStatus( IrpContext, STATUS_CANT_WAIT );
}
//
// Make sure we don't overwrite the buffer.
//
WriteByteCount = ByteCount;
}
//
// Initialize the IoContext for the write.
// 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 = WriteByteCount;
//
// Set the FO_MODIFIED flag here to trigger a verify when this
// handle is closed. Note that we can err on the conservative
// side with no problem, i.e. if we accidently do an extra
// verify there is no problem.
//
SetFlag( IrpSp->FileObject->Flags, FO_FILE_MODIFIED );
//
// Dasd access is always non-cached. Call the Dasd write routine to
// perform the actual write.
//
Status = CdVolumeDasdWrite( IrpContext, Fcb, StartingOffset, WriteByteCount );
//
// 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 (WriteByteCount != ByteCount) {
CdMapUserBuffer( IrpContext, &UserBuffer );
SafeZeroMemory( IrpContext,
Add2Ptr( UserBuffer,
ByteCount,
PVOID ),
WriteByteCount - ByteCount );
Irp->IoStatus.Information = ByteCount;
}
//
// Update the file position if this is a synchronous request.
//
if (SynchronousIo && NT_SUCCESS( Status )) {
IrpSp->FileObject->CurrentByteOffset.QuadPart = ByteRange;
}
}
try_exit: NOTHING;
} finally {
//
// Release the Fcb.
//
if (ReleaseFile) {
CdReleaseFile( IrpContext, Fcb );
}
}
//
// 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;
}
