reactos/drivers/filesystems/udfs/dircntrl.cpp

////////////////////////////////////////////////////////////////////
// Copyright (C) Alexander Telyatnikov, Ivan Keliukh, Yegor Anchishkin, SKIF Software, 1999-2013. Kiev, Ukraine
// All rights reserved
// This file was released under the GPLv2 on June 2015.
////////////////////////////////////////////////////////////////////
/*************************************************************************
*
* File: DirCntrl.cpp
*
* Module: UDF File System Driver (Kernel mode execution only)
*
* Description:
*   Contains code to handle the "directory control" dispatch entry point.
*
*************************************************************************/

#include            "udffs.h"

// define the file specific bug-check id
#define         UDF_BUG_CHECK_ID                UDF_FILE_DIR_CONTROL

/*
// Local support routine(s):
*/

#define UDF_FNM_FLAG_CAN_BE_8D3    0x01
#define UDF_FNM_FLAG_IGNORE_CASE   0x02
#define UDF_FNM_FLAG_CONTAINS_WC   0x04

NTSTATUS UDFFindNextMatch(
    IN PVCB            Vcb,
    IN PDIR_INDEX_HDR  hDirIndex,
    IN PLONG           CurrentNumber,      // Must be modified
    IN PUNICODE_STRING PtrSearchPattern,
    IN UCHAR           FNM_Flags,
    IN PHASH_ENTRY     hashes,
   OUT PDIR_INDEX_ITEM* _DirNdx);

/*************************************************************************
*
* Function: UDFDirControl()
*
* Description:
*   The I/O Manager will invoke this routine to handle a directory control
*   request
*
* Expected Interrupt Level (for execution) :
*
*  IRQL_PASSIVE_LEVEL (invocation at higher IRQL will cause execution
*   to be deferred to a worker thread context)
*
* Return Value: STATUS_SUCCESS/Error
*
*************************************************************************/
NTSTATUS
NTAPI
UDFDirControl(
    PDEVICE_OBJECT      DeviceObject,       // the logical volume device object
    PIRP                Irp                 // I/O Request Packet
    )
{
    NTSTATUS            RC = STATUS_SUCCESS;
    PtrUDFIrpContext    PtrIrpContext = NULL;
    BOOLEAN             AreWeTopLevel = FALSE;

    TmPrint(("UDFDirControl: \n"));

    FsRtlEnterFileSystem();
    ASSERT(DeviceObject);
    ASSERT(Irp);

    // set the top level context
    AreWeTopLevel = UDFIsIrpTopLevel(Irp);
    ASSERT(!UDFIsFSDevObj(DeviceObject));

    _SEH2_TRY {

        // get an IRP context structure and issue the request
        PtrIrpContext = UDFAllocateIrpContext(Irp, DeviceObject);
        if(PtrIrpContext) {
            RC = UDFCommonDirControl(PtrIrpContext, Irp);
        } else {
            RC = STATUS_INSUFFICIENT_RESOURCES;
            Irp->IoStatus.Status = RC;
            Irp->IoStatus.Information = 0;
            // complete the IRP
            IoCompleteRequest(Irp, IO_DISK_INCREMENT);
        }

    } _SEH2_EXCEPT(UDFExceptionFilter(PtrIrpContext, _SEH2_GetExceptionInformation())) {

        RC = UDFExceptionHandler(PtrIrpContext, Irp);

        UDFLogEvent(UDF_ERROR_INTERNAL_ERROR, RC);
    } _SEH2_END;

    if (AreWeTopLevel) {
        IoSetTopLevelIrp(NULL);
    }

    FsRtlExitFileSystem();

    return(RC);
} // end UDFDirControl()



/*************************************************************************
*
* Function: UDFCommonDirControl()
*
* Description:
*   The actual work is performed here. This routine may be invoked in one'
*   of the two possible contexts:
*   (a) in the context of a system worker thread
*   (b) in the context of the original caller
*
* Expected Interrupt Level (for execution) :
*
*  IRQL_PASSIVE_LEVEL
*
* Return Value: STATUS_SUCCESS/Error
*
*************************************************************************/
NTSTATUS
NTAPI
UDFCommonDirControl(
   PtrUDFIrpContext  PtrIrpContext,
   PIRP              Irp
   )
{
    NTSTATUS                RC = STATUS_SUCCESS;
    PIO_STACK_LOCATION      IrpSp = NULL;
    PFILE_OBJECT            FileObject = NULL;
    PtrUDFFCB               Fcb = NULL;
    PtrUDFCCB               Ccb = NULL;
    PVCB                    Vcb = NULL;
    BOOLEAN                 AcquiredVcb = FALSE;

    TmPrint(("UDFCommonDirControl: \n"));
//    BrutePoint();

    _SEH2_TRY {
        // First, get a pointer to the current I/O stack location
        IrpSp = IoGetCurrentIrpStackLocation(Irp);
        ASSERT(IrpSp);
    
        FileObject = IrpSp->FileObject;
        ASSERT(FileObject);
    
        // Get the FCB and CCB pointers
        Ccb = (PtrUDFCCB)(FileObject->FsContext2);
        ASSERT(Ccb);
        Fcb = Ccb->Fcb;
        ASSERT(Fcb);
    
        Vcb = (PVCB)(PtrIrpContext->TargetDeviceObject->DeviceExtension);
        ASSERT(Vcb);
        ASSERT(Vcb->NodeIdentifier.NodeType == UDF_NODE_TYPE_VCB);
//        Vcb->VCBFlags |= UDF_VCB_SKIP_EJECT_CHECK;
    
        UDFFlushTryBreak(Vcb);
        UDFAcquireResourceShared(&(Vcb->VCBResource), TRUE);
        AcquiredVcb = TRUE;
        // Get some of the parameters supplied to us
        switch (IrpSp->MinorFunction) {
        case IRP_MN_QUERY_DIRECTORY:
            RC = UDFQueryDirectory(PtrIrpContext, Irp, IrpSp, FileObject, Fcb, Ccb);
            break;
        case IRP_MN_NOTIFY_CHANGE_DIRECTORY:
            RC = UDFNotifyChangeDirectory(PtrIrpContext, Irp, IrpSp, FileObject, Fcb, Ccb);
            break;
        default:
            // This should not happen.
            RC = STATUS_INVALID_DEVICE_REQUEST;
            Irp->IoStatus.Status = RC;
            Irp->IoStatus.Information = 0;
    
            // Free up the Irp Context
            UDFReleaseIrpContext(PtrIrpContext);
    
            // complete the IRP
            IoCompleteRequest(Irp, IO_NO_INCREMENT);
            break;
        }

//try_exit: NOTHING;

    } _SEH2_FINALLY {

        if(AcquiredVcb) {
            UDFReleaseResource(&(Vcb->VCBResource));
            AcquiredVcb = FALSE;
        }
    } _SEH2_END;
    return(RC);
} // end UDFCommonDirControl()


/*************************************************************************
*
* Function: UDFQueryDirectory()
*
* Description:
*   Query directory request.
*
* Expected Interrupt Level (for execution) :
*
*  IRQL_PASSIVE_LEVEL
*
* Return Value: STATUS_SUCCESS/Error
*
*************************************************************************/
NTSTATUS
NTAPI
UDFQueryDirectory(
    PtrUDFIrpContext            PtrIrpContext,
    PIRP                        Irp,
    PIO_STACK_LOCATION          IrpSp,
    PFILE_OBJECT                FileObject,
    PtrUDFFCB                   Fcb,
    PtrUDFCCB                   Ccb
    )
{
    NTSTATUS                    RC = STATUS_SUCCESS;
    BOOLEAN                     PostRequest = FALSE;
    PtrUDFNTRequiredFCB         NtReqFcb = NULL;
    BOOLEAN                     CanWait = FALSE;
    PVCB                        Vcb = NULL;
    BOOLEAN                     AcquiredFCB = FALSE;
    unsigned long               BufferLength = 0;
    UNICODE_STRING              SearchPattern;
    PUNICODE_STRING             PtrSearchPattern;
    FILE_INFORMATION_CLASS      FileInformationClass;
    BOOLEAN                     ReturnSingleEntry = FALSE;
    PUCHAR                      Buffer = NULL;
    BOOLEAN                     FirstTimeQuery = FALSE;
    LONG                        NextMatch;
    LONG                        PrevMatch = -1;
    ULONG                       CurrentOffset;
    ULONG                       BaseLength;
    ULONG                       FileNameBytes;
    ULONG                       Information = 0;
    ULONG                       LastOffset = 0;
    BOOLEAN                     AtLeastOneFound = FALSE;
    PEXTENDED_IO_STACK_LOCATION pStackLocation = (PEXTENDED_IO_STACK_LOCATION) IrpSp;
    PUDF_FILE_INFO              DirFileInfo = NULL;
    PDIR_INDEX_HDR              hDirIndex = NULL;
    PFILE_BOTH_DIR_INFORMATION  DirInformation = NULL;      // Returned from udf_info module
    PFILE_BOTH_DIR_INFORMATION  BothDirInformation = NULL;  // Pointer in callers buffer
    PFILE_NAMES_INFORMATION     NamesInfo;
    ULONG                       BytesRemainingInBuffer;
    UCHAR                       FNM_Flags = 0;
    PHASH_ENTRY                 cur_hashes = NULL;
    PDIR_INDEX_ITEM             DirNdx;
    // do some pre-init...
    SearchPattern.Buffer = NULL;

    UDFPrint(("UDFQueryDirectory: @=%#x\n", &PtrIrpContext));

#define CanBe8dot3    (FNM_Flags & UDF_FNM_FLAG_CAN_BE_8D3)
#define IgnoreCase    (FNM_Flags & UDF_FNM_FLAG_IGNORE_CASE)
#define ContainsWC    (FNM_Flags & UDF_FNM_FLAG_CONTAINS_WC)

    _SEH2_TRY
    {

        // Validate the sent-in FCB
        if ((Fcb->NodeIdentifier.NodeType == UDF_NODE_TYPE_VCB) || !(Fcb->FCBFlags & UDF_FCB_DIRECTORY)) {
            // We will only allow notify requests on directories.
            try_return(RC = STATUS_INVALID_PARAMETER);
        }

        // Obtain the callers parameters
        NtReqFcb = Fcb->NTRequiredFCB;
        CanWait = (PtrIrpContext->IrpContextFlags & UDF_IRP_CONTEXT_CAN_BLOCK) ? TRUE : FALSE;
        Vcb = Fcb->Vcb;
        //Vcb->VCBFlags |= UDF_VCB_SKIP_EJECT_CHECK;
        FNM_Flags |= (Ccb->CCBFlags & UDF_CCB_CASE_SENSETIVE) ? 0 : UDF_FNM_FLAG_IGNORE_CASE;
        DirFileInfo = Fcb->FileInfo;
        BufferLength = pStackLocation->Parameters.QueryDirectory.Length;

        // If the caller does not want to block, it would be easier to
        // simply post the request now.
        if (!CanWait) {
            PostRequest = TRUE;
            try_return(RC = STATUS_PENDING);
        }

        // Continue obtaining the callers parameters...
        if(IgnoreCase && pStackLocation->Parameters.QueryDirectory.FileName) {
            PtrSearchPattern = &SearchPattern;
            if(!NT_SUCCESS(RC = RtlUpcaseUnicodeString(PtrSearchPattern, (PUNICODE_STRING)(pStackLocation->Parameters.QueryDirectory.FileName), TRUE)))
                try_return(RC);
        } else {
            PtrSearchPattern = (PUNICODE_STRING)(pStackLocation->Parameters.QueryDirectory.FileName);
        }
        FileInformationClass = pStackLocation->Parameters.QueryDirectory.FileInformationClass;

        // Calculate baselength (without name) for each InfoClass
        switch (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 FileNamesInformation:
            BaseLength = FIELD_OFFSET( FILE_NAMES_INFORMATION,     FileName[0] );  
            break;
        case FileBothDirectoryInformation:
            BaseLength = FIELD_OFFSET( FILE_BOTH_DIR_INFORMATION,  FileName[0] );
            break;
        default:
            try_return(RC = STATUS_INVALID_INFO_CLASS);
        }
    
        // Some additional arguments that affect the FSD behavior
        ReturnSingleEntry = (IrpSp->Flags & SL_RETURN_SINGLE_ENTRY) ? TRUE : FALSE;

        UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
        UDFAcquireResourceShared(&(NtReqFcb->MainResource), TRUE);
        AcquiredFCB = TRUE;

        // We must determine the buffer pointer to be used. Since this
        // routine could either be invoked directly in the context of the
        // calling thread, or in the context of a worker thread, here is
        // a general way of determining what we should use.
        if(Irp->MdlAddress) {
            Buffer = (PUCHAR) MmGetSystemAddressForMdlSafer(Irp->MdlAddress);
            if(!Buffer)
                try_return(RC = STATUS_INSUFFICIENT_RESOURCES);
        } else {
            Buffer = (PUCHAR) Irp->UserBuffer;
            if(!Buffer)
                try_return(RC = STATUS_INVALID_USER_BUFFER);
        }

        // The method of determining where to look from and what to look for is
        // unfortunately extremely confusing. However, here is a methodology
        // we broadly adopt:
        // (a) We have to maintain a search buffer per CCB structure.
        // (b) This search buffer is initialized the very first time
        //       a query directory operation is performed using the file object.
        // (For the UDF FSD, the search buffer is stored in the
        //   DirectorySearchPattern field)
        // However, the caller still has the option of "overriding" this stored
        // search pattern by supplying a new one in a query directory operation.
        if(PtrSearchPattern &&
           PtrSearchPattern->Buffer &&
           !(PtrSearchPattern->Buffer[PtrSearchPattern->Length/sizeof(WCHAR) - 1])) {
            PtrSearchPattern->Length -= sizeof(WCHAR);
        }

        if(IrpSp->Flags & SL_INDEX_SPECIFIED) {
            // Good idea from M$: we should continue search from NEXT item
            // when FileIndex specified...
            // Strange idea from M$: we should do it with EMPTY pattern...
            PtrSearchPattern = NULL;
            Ccb->CCBFlags |= UDF_CCB_MATCH_ALL;
        } else if(PtrSearchPattern &&
                  PtrSearchPattern->Buffer &&
                  !UDFIsMatchAllMask(PtrSearchPattern, NULL) ) {

            Ccb->CCBFlags &= ~(UDF_CCB_MATCH_ALL |
                               UDF_CCB_WILDCARD_PRESENT |
                               UDF_CCB_CAN_BE_8_DOT_3);
            // Once we have validated the search pattern, we must
            // check whether we need to store this search pattern in
            // the CCB.
            if(Ccb->DirectorySearchPattern) {
                MyFreePool__(Ccb->DirectorySearchPattern->Buffer);
                MyFreePool__(Ccb->DirectorySearchPattern);
                Ccb->DirectorySearchPattern = NULL;
            }
            // This must be the very first query request.
            FirstTimeQuery = TRUE;

            // Now, allocate enough memory to contain the caller
            // supplied search pattern and fill in the DirectorySearchPattern
            // field in the CCB
            Ccb->DirectorySearchPattern = (PUNICODE_STRING)MyAllocatePool__(NonPagedPool,sizeof(UNICODE_STRING));
            if(!(Ccb->DirectorySearchPattern)) {
                try_return(RC = STATUS_INSUFFICIENT_RESOURCES);
            }
            Ccb->DirectorySearchPattern->Length = PtrSearchPattern->Length;
            Ccb->DirectorySearchPattern->MaximumLength = PtrSearchPattern->MaximumLength;
            Ccb->DirectorySearchPattern->Buffer = (PWCHAR)MyAllocatePool__(NonPagedPool,PtrSearchPattern->MaximumLength);
            if(!(Ccb->DirectorySearchPattern->Buffer)) {
                try_return(RC = STATUS_INSUFFICIENT_RESOURCES);
            }
            RtlCopyMemory(Ccb->DirectorySearchPattern->Buffer,PtrSearchPattern->Buffer,
                          PtrSearchPattern->MaximumLength);
            if(FsRtlDoesNameContainWildCards(PtrSearchPattern)) {
                Ccb->CCBFlags |= UDF_CCB_WILDCARD_PRESENT;
            } else {
                UDFBuildHashEntry(Vcb, PtrSearchPattern, cur_hashes = &(Ccb->hashes), HASH_POSIX | HASH_ULFN);
            }
            if(UDFCanNameBeA8dot3(PtrSearchPattern))
                Ccb->CCBFlags |= UDF_CCB_CAN_BE_8_DOT_3;

        } else if(!Ccb->DirectorySearchPattern &&
                  !(Ccb->CCBFlags & UDF_CCB_MATCH_ALL) ) {

            // If the filename is not specified or is a single '*' then we will
            // match all names.
            FirstTimeQuery = TRUE;
            PtrSearchPattern = NULL;
            Ccb->CCBFlags |= UDF_CCB_MATCH_ALL;

        } else {
            // The caller has not supplied any search pattern that we are
            // forced to use. However, the caller had previously supplied
            // a pattern (or we must have invented one) and we will use it.
            // This is definitely not the first query operation on this
            // directory using this particular file object.
            if(Ccb->CCBFlags & UDF_CCB_MATCH_ALL) {
                PtrSearchPattern = NULL;
/*                if(Ccb->CurrentIndex)
                    Ccb->CurrentIndex++;*/
            } else {
                PtrSearchPattern = Ccb->DirectorySearchPattern;
                if(!(Ccb->CCBFlags & UDF_CCB_WILDCARD_PRESENT)) {
                    cur_hashes = &(Ccb->hashes);
                }
            }
        }

        if(IrpSp->Flags & SL_INDEX_SPECIFIED) {
            // Caller has told us wherefrom to begin.
            // We may need to round this to an appropriate directory entry
            // entry alignment value.
            NextMatch = pStackLocation->Parameters.QueryDirectory.FileIndex + 1;
        } else if(IrpSp->Flags & SL_RESTART_SCAN) {
            NextMatch = 0;
        } else {
            // Get the starting offset from the CCB.
            // Remember to update this value on our way out from this function.
            // But, do not update the CCB CurrentByteOffset field if our reach
            // the end of the directory (or get an error reading the directory)
            // while performing the search.
            NextMatch = Ccb->CurrentIndex + 1; // Last good index
        }

        FNM_Flags |= (Ccb->CCBFlags & UDF_CCB_WILDCARD_PRESENT) ? UDF_FNM_FLAG_CONTAINS_WC : 0;
        // this is used only when mask is supplied
        FNM_Flags |= (Ccb->CCBFlags & UDF_CCB_CAN_BE_8_DOT_3) ? UDF_FNM_FLAG_CAN_BE_8D3 : 0;

        // This is an additional verifying
        if(!UDFIsADirectory(DirFileInfo)) {
            try_return(RC = STATUS_INVALID_PARAMETER);
        }

        hDirIndex = DirFileInfo->Dloc->DirIndex;
        if(!hDirIndex) {
            try_return(RC = STATUS_INVALID_PARAMETER);
        }

        RC = STATUS_SUCCESS;
        // Allocate buffer enough to save both DirInformation and FileName
        DirInformation = (PFILE_BOTH_DIR_INFORMATION)MyAllocatePool__(NonPagedPool,
                            sizeof(FILE_BOTH_DIR_INFORMATION)+((ULONG)UDF_NAME_LEN*sizeof(WCHAR)) );
        if(!DirInformation) {
            try_return(RC = STATUS_INSUFFICIENT_RESOURCES);
        }
        CurrentOffset=0;
        BytesRemainingInBuffer = pStackLocation->Parameters.QueryDirectory.Length;
        RtlZeroMemory(Buffer,BytesRemainingInBuffer);

        if((!FirstTimeQuery) && !UDFDirIndex(hDirIndex, (uint_di)NextMatch) ) {
            try_return( RC = STATUS_NO_MORE_FILES);
        }

        // One final note though:
        // If we do not find a directory entry OR while searching we reach the
        // end of the directory, then the return code should be set as follows:

        // (a) If any files have been returned (i.e. ReturnSingleEntry was FALSE
        //       and we did find at least one match), then return STATUS_SUCCESS
        // (b) If no entry is being returned then:
        //       (i) If this is the first query i.e. FirstTimeQuery is TRUE
        //            then return STATUS_NO_SUCH_FILE
        //       (ii) Otherwise, return STATUS_NO_MORE_FILES

        while(TRUE) {
            // If the user had requested only a single match and we have
            // returned that, then we stop at this point.
            if(ReturnSingleEntry && AtLeastOneFound) {
                try_return(RC);
            }
            // We call UDFFindNextMatch to look down the next matching dirent.
            RC = UDFFindNextMatch(Vcb, hDirIndex,&NextMatch,PtrSearchPattern, FNM_Flags, cur_hashes, &DirNdx);
            // If we didn't receive next match, 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(!NT_SUCCESS(RC)) {
                RC = AtLeastOneFound ? STATUS_SUCCESS :
                                      (FirstTimeQuery ? STATUS_NO_SUCH_FILE : STATUS_NO_MORE_FILES);
                try_return(RC);
            }
            // We found at least one matching file entry
            AtLeastOneFound = TRUE;
            if(!NT_SUCCESS(RC = UDFFileDirInfoToNT(Vcb, DirNdx, DirInformation))) {
                // this happends when we can't allocate tmp buffers
                try_return(RC);
            }
            DirInformation->FileIndex = NextMatch;
            FileNameBytes = DirInformation->FileNameLength;

            if ((BaseLength + FileNameBytes) > BytesRemainingInBuffer) {
                // We haven't successfully transfered current data &
                // later NextMatch will be incremented. Thus we should
                // prevent loosing information in such a way:
                if(NextMatch) NextMatch --;
                // If this won't fit and we have returned a previous entry then just
                // return STATUS_SUCCESS. Otherwise
                // use a status code of STATUS_BUFFER_OVERFLOW.
                if(CurrentOffset) {
                    try_return(RC = STATUS_SUCCESS);
                }
                // strange policy...
                ReturnSingleEntry = TRUE;
                FileNameBytes = BaseLength + FileNameBytes - BytesRemainingInBuffer;
                RC = STATUS_BUFFER_OVERFLOW;
            }
            //  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 (FileInformationClass) {

            case FileBothDirectoryInformation:
            case FileFullDirectoryInformation:
            case FileDirectoryInformation:
                    
                BothDirInformation = (PFILE_BOTH_DIR_INFORMATION)(Buffer + CurrentOffset);
                RtlCopyMemory(BothDirInformation,DirInformation,BaseLength);
                BothDirInformation->FileIndex = NextMatch;
                BothDirInformation->FileNameLength = FileNameBytes;
                break;

            case FileNamesInformation:

                NamesInfo = (PFILE_NAMES_INFORMATION)(Buffer + CurrentOffset);
                NamesInfo->FileIndex = NextMatch;
                NamesInfo->FileNameLength = FileNameBytes;
                break;

            default:
                break;
            }
            if (FileNameBytes) {
                //  This is a Unicode name, we can copy the bytes directly.
                RtlCopyMemory( (PVOID)(Buffer + CurrentOffset + BaseLength),
                               DirInformation->FileName, FileNameBytes );
            }

            Information = CurrentOffset + BaseLength + FileNameBytes;

            //  ((..._INFORMATION)(PointerToPreviousEntryInBuffer))->NextEntryOffset = CurrentOffset - LastOffset;
            *((PULONG)(Buffer+LastOffset)) = CurrentOffset - LastOffset;
            //  Set up our variables for the next dirent.
            FirstTimeQuery = FALSE;

            LastOffset    = CurrentOffset;
            PrevMatch     = NextMatch;
            NextMatch++;
            CurrentOffset = UDFQuadAlign(Information);
            BytesRemainingInBuffer = BufferLength - CurrentOffset;
        }

try_exit:   NOTHING;


    } _SEH2_FINALLY {

        if (PostRequest) {

            if (AcquiredFCB) {
                UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
                UDFReleaseResource(&(NtReqFcb->MainResource));
            }
            // Map the users buffer and then post the request.
            RC = UDFLockCallersBuffer(PtrIrpContext, Irp, TRUE, BufferLength);
            ASSERT(NT_SUCCESS(RC));

            RC = UDFPostRequest(PtrIrpContext, Irp);

        } else {
#ifdef UDF_DBG
            if(!NT_SUCCESS(RC)) {
               UDFPrint(("    Not found\n"));
            }
#endif // UDF_DBG
            // Remember to update the CurrentByteOffset field in the CCB if required.
            if(Ccb) Ccb->CurrentIndex = PrevMatch;

            if (AcquiredFCB) {
                UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
                UDFReleaseResource(&(NtReqFcb->MainResource));
            }
            if (!_SEH2_AbnormalTermination()) {
                // complete the IRP
                Irp->IoStatus.Status = RC;
                Irp->IoStatus.Information = Information;
                IoCompleteRequest(Irp, IO_DISK_INCREMENT);
                // Free up the Irp Context
                UDFReleaseIrpContext(PtrIrpContext);
            }
        }

        if(SearchPattern.Buffer) RtlFreeUnicodeString(&SearchPattern);
        if(DirInformation) MyFreePool__(DirInformation);
    } _SEH2_END;

    return(RC);
} // end UDFQueryDirectory()

/*
  Return: STATUS_NO_SUCH_FILE if no more files found
*/
NTSTATUS
UDFFindNextMatch(
    IN PVCB Vcb,
    IN PDIR_INDEX_HDR  hDirIndex,
    IN PLONG           CurrentNumber,      // Must be modified in case, when we found next match
    IN PUNICODE_STRING PtrSearchPattern,
    IN UCHAR           FNM_Flags,
    IN PHASH_ENTRY     hashes,
   OUT PDIR_INDEX_ITEM* _DirNdx
    )
{
    LONG    EntryNumber = (*CurrentNumber);
    PDIR_INDEX_ITEM DirNdx;

#define CanBe8dot3    (FNM_Flags & UDF_FNM_FLAG_CAN_BE_8D3)
#define IgnoreCase    (FNM_Flags & UDF_FNM_FLAG_IGNORE_CASE)
#define ContainsWC    (FNM_Flags & UDF_FNM_FLAG_CONTAINS_WC)

    for(;(DirNdx = UDFDirIndex(hDirIndex, EntryNumber));EntryNumber++) {
        if(!DirNdx->FName.Buffer ||
           UDFIsDeleted(DirNdx))
            continue;
        if(hashes &&
           (DirNdx->hashes.hLfn != hashes->hLfn) &&
           (DirNdx->hashes.hPosix != hashes->hPosix) &&
           (!CanBe8dot3 || ((DirNdx->hashes.hDos != hashes->hLfn) && (DirNdx->hashes.hDos != hashes->hPosix))) )
            continue;
        if(UDFIsNameInExpression(Vcb, &(DirNdx->FName),PtrSearchPattern, NULL,IgnoreCase,
                                ContainsWC, CanBe8dot3 && !(DirNdx->FI_Flags & UDF_FI_FLAG_DOS), 
                                EntryNumber < 2) &&
           !(DirNdx->FI_Flags & UDF_FI_FLAG_FI_INTERNAL))
            break;
    }

    if(DirNdx) {
        // Modify CurrentNumber to appropriate value
        *CurrentNumber = EntryNumber;
        *_DirNdx = DirNdx;
        return STATUS_SUCCESS;
    } else {
        // Do not modify CurrentNumber because we have not found next match entry
        return STATUS_NO_MORE_FILES;
    }
} // end UDFFindNextMatch()

/*************************************************************************
*
* Function: UDFNotifyChangeDirectory()
*
* Description:
*   Handle the notify request.
*
* Expected Interrupt Level (for execution) :
*
*  IRQL_PASSIVE_LEVEL
*
* Return Value: STATUS_SUCCESS/Error
*
*************************************************************************/
NTSTATUS
NTAPI
UDFNotifyChangeDirectory(
    PtrUDFIrpContext            PtrIrpContext,
    PIRP                        Irp,
    PIO_STACK_LOCATION          IrpSp,
    PFILE_OBJECT                FileObject,
    PtrUDFFCB                   Fcb,
    PtrUDFCCB                   Ccb
    )
{
    NTSTATUS                    RC = STATUS_SUCCESS;
    BOOLEAN                     CompleteRequest = FALSE;
    BOOLEAN                     PostRequest = FALSE;
    PtrUDFNTRequiredFCB         NtReqFcb = NULL;
    BOOLEAN                     CanWait = FALSE;
    ULONG                       CompletionFilter = 0;
    BOOLEAN                     WatchTree = FALSE;
    PVCB                        Vcb = NULL;
    BOOLEAN                     AcquiredFCB = FALSE;
    PEXTENDED_IO_STACK_LOCATION pStackLocation = (PEXTENDED_IO_STACK_LOCATION) IrpSp;

    UDFPrint(("UDFNotifyChangeDirectory\n"));

    _SEH2_TRY {

        // Validate the sent-in FCB
        if ( (Fcb->NodeIdentifier.NodeType == UDF_NODE_TYPE_VCB) ||
            !(Fcb->FCBFlags & UDF_FCB_DIRECTORY)) {

            CompleteRequest = TRUE;
            try_return(RC = STATUS_INVALID_PARAMETER);
        }

        NtReqFcb = Fcb->NTRequiredFCB;
        CanWait = (PtrIrpContext->IrpContextFlags & UDF_IRP_CONTEXT_CAN_BLOCK) ? TRUE : FALSE;
        Vcb = Fcb->Vcb;

        // Acquire the FCB resource shared
        UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
        if (!UDFAcquireResourceShared(&(NtReqFcb->MainResource), CanWait)) {
            PostRequest = TRUE;
            try_return(RC = STATUS_PENDING);
        }
        AcquiredFCB = TRUE;

        //  If the file is marked as DELETE_PENDING then complete this
        //  request immediately.
        if(Fcb->FCBFlags & UDF_FCB_DELETE_ON_CLOSE) {
            ASSERT(!(Fcb->FCBFlags & UDF_FCB_ROOT_DIRECTORY));
            try_return(RC = STATUS_DELETE_PENDING);
        }

        // Obtain some parameters sent by the caller
        CompletionFilter = pStackLocation ->Parameters.NotifyDirectory.CompletionFilter;
        WatchTree = (IrpSp->Flags & SL_WATCH_TREE) ? TRUE : FALSE;

        // If we wish to capture the subject context, we can do so as
        // follows:
        // {
        //      PSECURITY_SUBJECT_CONTEXT SubjectContext;
        //  SubjectContext = MyAllocatePool__(PagedPool,
        //                                  sizeof(SECURITY_SUBJECT_CONTEXT));
        //      SeCaptureSubjectContext(SubjectContext);
        //  }

        FsRtlNotifyFullChangeDirectory(Vcb->NotifyIRPMutex, &(Vcb->NextNotifyIRP), (PVOID)Ccb,
                            (Fcb->FileInfo->ParentFile) ? (PSTRING)&(Fcb->FCBName->ObjectName) : (PSTRING)&(UDFGlobalData.UnicodeStrRoot),
                            WatchTree, FALSE, CompletionFilter, Irp,
                            NULL,   // UDFTraverseAccessCheck(...) ?
                            NULL);  // SubjectContext ?

        RC = STATUS_PENDING;

        try_exit:   NOTHING;

    } _SEH2_FINALLY {

        if (PostRequest) {
            // Perform appropriate related post processing here
            if (AcquiredFCB) {
                UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
                UDFReleaseResource(&(NtReqFcb->MainResource));
                AcquiredFCB = FALSE;
            }
            RC = UDFPostRequest(PtrIrpContext, Irp);
        } else if (CompleteRequest) {

            if (!_SEH2_AbnormalTermination()) {
                Irp->IoStatus.Status = RC;
                Irp->IoStatus.Information = 0;
                // Free up the Irp Context
                UDFReleaseIrpContext(PtrIrpContext);
                // complete the IRP
                IoCompleteRequest(Irp, IO_DISK_INCREMENT);
            }

        } else {
            // Simply free up the IrpContext since the IRP has been queued
            if (!_SEH2_AbnormalTermination())
                UDFReleaseIrpContext(PtrIrpContext);
        }

        // Release the FCB resources if acquired.
        if (AcquiredFCB) {
            UDF_CHECK_PAGING_IO_RESOURCE(NtReqFcb);
            UDFReleaseResource(&(NtReqFcb->MainResource));
            AcquiredFCB = FALSE;
        }

    } _SEH2_END;

    return(RC);
} // end UDFNotifyChangeDirectory()