cachesup.c File Reference

#include "cdprocs.h"

Include dependency graph for cachesup.c:

Go to the source code of this file.

Macros
#define	BugCheckFileId   (CDFS_BUG_CHECK_CACHESUP)

Functions
VOID	CdCreateInternalStream (_In_ PIRP_CONTEXT IrpContext, _In_ PVCB Vcb, _Inout_ PFCB Fcb, _In_ PUNICODE_STRING Name)
VOID	CdDeleteInternalStream (_In_ PIRP_CONTEXT IrpContext, _Inout_ PFCB Fcb)
NTSTATUS	CdCompleteMdl (_In_ PIRP_CONTEXT IrpContext, _Inout_ PIRP Irp)
	_Requires_lock_held_ (_Global_critical_region_)

Macro Definition Documentation

BugCheckFileId

#define BugCheckFileId   (CDFS_BUG_CHECK_CACHESUP)

Definition at line 23 of file cachesup.c.

Function Documentation

_Requires_lock_held_()

_Requires_lock_held_

(

_Global_critical_region_

)

Definition at line 463 of file cachesup.c.

{
    NTSTATUS Status = STATUS_SUCCESS;

    PVOID RestartKey = NULL;
    PFCB ThisFcb = NULL;
    PFCB NextFcb;

    BOOLEAN RemovedFcb;

    PAGED_CODE();

    ASSERT_EXCLUSIVE_VCB( Vcb);

    //
    //  Force any remaining Fcb's in the delayed close queue to be closed.
    //

    CdFspClose( Vcb );

    //
    //  Acquire the global file resource.
    //

    CdAcquireAllFiles( IrpContext, Vcb );

    //
    //  Loop through each Fcb in the Fcb Table and perform the flush.
    //

    while (TRUE) {

        //
        //  Lock the Vcb to lookup the next Fcb.
        //

        CdLockVcb( IrpContext, Vcb );
        NextFcb = CdGetNextFcb( IrpContext, Vcb, &RestartKey );

        //
        //  Reference the NextFcb if present.
        //

        if (NextFcb != NULL) {

            NextFcb->FcbReference += 1;
        }

        //
        //  If the last Fcb is present then decrement reference count and call teardown
        //  to see if it should be removed.
        //

        if (ThisFcb != NULL) {

            ThisFcb->FcbReference -= 1;

            CdUnlockVcb( IrpContext, Vcb );

            CdTeardownStructures( IrpContext, ThisFcb, &RemovedFcb );

        } else {

            CdUnlockVcb( IrpContext, Vcb );
        }

        //
        //  Break out of the loop if no more Fcb's.
        //

        if (NextFcb == NULL) {

            break;
        }

        //
        //  Move to the next Fcb.
        //

        ThisFcb = NextFcb;

        //
        //  If there is a image section then see if that can be closed.
        //

        if (ThisFcb->FcbNonpaged->SegmentObject.ImageSectionObject != NULL) {

            MmFlushImageSection( &ThisFcb->FcbNonpaged->SegmentObject, MmFlushForWrite );
        }

        //
        //  If there is a data section then purge this.  If there is an image
        //  section then we won't be able to.  Remember this if it is our first
        //  error.
        //

        if ((ThisFcb->FcbNonpaged->SegmentObject.DataSectionObject != NULL) &&
            !CcPurgeCacheSection( &ThisFcb->FcbNonpaged->SegmentObject,
                                   NULL,
                                   0,
                                   FALSE ) &&
            (Status == STATUS_SUCCESS)) {

            Status = STATUS_UNABLE_TO_DELETE_SECTION;
        }

        //
        //  Dereference the internal stream if dismounting.
        //

        if (DismountUnderway &&
            (SafeNodeType( ThisFcb ) != CDFS_NTC_FCB_DATA) &&
            (ThisFcb->FileObject != NULL)) {

            CdDeleteInternalStream( IrpContext, ThisFcb );
        }
    }

    //
    //  Now look at the path table and volume Dasd Fcb's.
    //

    if (DismountUnderway) {

        if (Vcb->PathTableFcb != NULL) {

            ThisFcb = Vcb->PathTableFcb;
            InterlockedIncrement( (LONG*)&Vcb->PathTableFcb->FcbReference );

            if ((ThisFcb->FcbNonpaged->SegmentObject.DataSectionObject != NULL) &&
                !CcPurgeCacheSection( &ThisFcb->FcbNonpaged->SegmentObject,
                                       NULL,
                                       0,
                                       FALSE ) &&
                (Status == STATUS_SUCCESS)) {

                Status = STATUS_UNABLE_TO_DELETE_SECTION;
            }

            CdDeleteInternalStream( IrpContext, ThisFcb );

            InterlockedDecrement( (LONG*)&ThisFcb->FcbReference );

            CdTeardownStructures( IrpContext, ThisFcb, &RemovedFcb );
        }

        if (Vcb->VolumeDasdFcb != NULL) {

            ThisFcb = Vcb->VolumeDasdFcb;
            InterlockedIncrement( (LONG*)&ThisFcb->FcbReference );

            if ((ThisFcb->FcbNonpaged->SegmentObject.DataSectionObject != NULL) &&
                !CcPurgeCacheSection( &ThisFcb->FcbNonpaged->SegmentObject,
                                       NULL,
                                       0,
                                       FALSE ) &&
                (Status == STATUS_SUCCESS)) {

                Status = STATUS_UNABLE_TO_DELETE_SECTION;
            }

            InterlockedDecrement( (LONG*)&ThisFcb->FcbReference );

            CdTeardownStructures( IrpContext, ThisFcb, &RemovedFcb );
        }
    }

    //
    //  Release all of the files.
    //

    CdReleaseAllFiles( IrpContext, Vcb );

    return Status;
}

CdCompleteMdl()

NTSTATUS CdCompleteMdl	(	_In_ PIRP_CONTEXT	IrpContext,
		_Inout_ PIRP	Irp
	)

Definition at line 411 of file cachesup.c.

{
    PFILE_OBJECT FileObject;

    PAGED_CODE();

    //
    // Do completion processing.
    //

    FileObject = IoGetCurrentIrpStackLocation( Irp )->FileObject;

    CcMdlReadComplete( FileObject, Irp->MdlAddress );

    //
    // Mdl is now deallocated.
    //

    Irp->MdlAddress = NULL;

    //
    // Complete the request and exit right away.
    //

    CdCompleteRequest( IrpContext, Irp, STATUS_SUCCESS );

    return STATUS_SUCCESS;
}

Referenced by _IRQL_requires_max_().

CdCreateInternalStream()

VOID CdCreateInternalStream	(	_In_ PIRP_CONTEXT	IrpContext,
		_In_ PVCB	Vcb,
		_Inout_ PFCB	Fcb,
		_In_ PUNICODE_STRING	Name
	)

Definition at line 38 of file cachesup.c.

{
    PFILE_OBJECT StreamFile = NULL;
    BOOLEAN DecrementReference = FALSE;

    BOOLEAN CleanupDirContext = FALSE;
    BOOLEAN UpdateFcbSizes = FALSE;

    DIRENT Dirent = {0};
    DIRENT_ENUM_CONTEXT DirContext = {0};

    PAGED_CODE();

    ASSERT_IRP_CONTEXT( IrpContext );
    ASSERT_FCB( Fcb );

    //
    //  We may only have the Fcb shared.  Lock the Fcb and do a
    //  safe test to see if we need to really create the file object.
    //

    CdLockFcb( IrpContext, Fcb );

    if (Fcb->FileObject != NULL) {

        CdUnlockFcb( IrpContext, Fcb );
        return;
    }

    //
    //  Use a try-finally to facilitate cleanup.
    //

    _SEH2_TRY {

        //
        //  Create the internal stream.  The Vpb should be pointing at our volume
        //  device object at this point.
        //

        StreamFile = IoCreateStreamFileObjectLite( NULL, Vcb->Vpb->RealDevice );

        if (StreamFile == NULL) {

            CdRaiseStatus( IrpContext, STATUS_INSUFFICIENT_RESOURCES );
        }

        //
        //  Initialize the fields of the file object.
        //

        StreamFile->ReadAccess = TRUE;
        StreamFile->WriteAccess = FALSE;
        StreamFile->DeleteAccess = FALSE;

        StreamFile->SectionObjectPointer = &Fcb->FcbNonpaged->SegmentObject;

        //
        //  Set the file object type and increment the Vcb counts.
        //

        CdSetFileObject( IrpContext,
                         StreamFile,
                         StreamFileOpen,
                         Fcb,
                         NULL );
        
        //
        //  We'll give stream file objects a name to aid IO profiling etc. We 
        //  NULL this in CdDeleteInternalStream before OB deletes the file object,
        //  and before CdRemovePrefix is called (which frees Fcb names).
        //

        StreamFile->FileName = *Name;

        //
        //  We will reference the current Fcb twice to keep it from going
        //  away in the error path.  Otherwise if we dereference it
        //  below in the finally clause a close could cause the Fcb to
        //  be deallocated.
        //

        CdLockVcb( IrpContext, Vcb );
        CdIncrementReferenceCounts( IrpContext, Fcb, 2, 0 );
        CdUnlockVcb( IrpContext, Vcb );
        DecrementReference = TRUE;

        //
        //  Initialize the cache map for the file.
        //

        CcInitializeCacheMap( StreamFile,
                              (PCC_FILE_SIZES)&Fcb->AllocationSize,
                              TRUE,
                              &CdData.CacheManagerCallbacks,
                              Fcb );

        //
        //  Go ahead and store the stream file into the Fcb.
        //

        Fcb->FileObject = StreamFile;
        StreamFile = NULL;

        //
        //  If this is the first file object for a directory then we need to
        //  read the self entry for this directory and update the sizes
        //  in the Fcb.  We know that the Fcb has been initialized so
        //  that we have a least one sector available to read.
        //

        if (!FlagOn( Fcb->FcbState, FCB_STATE_INITIALIZED )) {

            ULONG NewDataLength;

            //
            //  Initialize the search structures.
            //

            CdInitializeDirContext( IrpContext, &DirContext );
            CdInitializeDirent( IrpContext, &Dirent );
            CleanupDirContext = TRUE;

            //
            //  Read the dirent from disk and transfer the data to the
            //  in-memory dirent.
            //

            CdLookupDirent( IrpContext,
                            Fcb,
                            Fcb->StreamOffset,
                            &DirContext );

            CdUpdateDirentFromRawDirent( IrpContext, Fcb, &DirContext, &Dirent );

            //
            //  Verify that this really for the self entry.  We do this by
            //  updating the name in the dirent and then checking that it matches
            //  one of the hard coded names.
            //

            CdUpdateDirentName( IrpContext, &Dirent, FALSE );

            if (Dirent.CdFileName.FileName.Buffer != CdUnicodeSelfArray) {

                CdRaiseStatus( IrpContext, STATUS_FILE_CORRUPT_ERROR );
            }

            //
            //  If the data sizes are different then update the header
            //  and Mcb for this Fcb.
            //

            NewDataLength = BlockAlign( Vcb, Dirent.DataLength + Fcb->StreamOffset );

            if (NewDataLength == 0) {

                CdRaiseStatus( IrpContext, STATUS_FILE_CORRUPT_ERROR );
            }

            if (NewDataLength != Fcb->FileSize.QuadPart) {

                Fcb->AllocationSize.QuadPart =
                Fcb->FileSize.QuadPart =
                Fcb->ValidDataLength.QuadPart = NewDataLength;

                CcSetFileSizes( Fcb->FileObject, (PCC_FILE_SIZES) &Fcb->AllocationSize );

                CdTruncateAllocation( IrpContext, Fcb, 0 );
                CdAddInitialAllocation( IrpContext,
                                        Fcb,
                                        Dirent.StartingOffset,
                                        NewDataLength );

                UpdateFcbSizes = TRUE;
            }

            //
            //  Check for the existence flag and transform to hidden.
            //

            if (FlagOn( Dirent.DirentFlags, CD_ATTRIBUTE_HIDDEN )) {

                SetFlag( Fcb->FileAttributes, FILE_ATTRIBUTE_HIDDEN );
            }

            //
            //  Convert the time to NT time.
            //

            CdConvertCdTimeToNtTime( IrpContext,
                                     Dirent.CdTime,
                                     (PLARGE_INTEGER) &Fcb->CreationTime );

            //
            //  Update the Fcb flags to indicate we have read the
            //  self entry.
            //

            SetFlag( Fcb->FcbState, FCB_STATE_INITIALIZED );

            //
            //  If we updated the sizes then we want to purge the file.  Go
            //  ahead and unpin and then purge the first page.
            //

            CdCleanupDirContext( IrpContext, &DirContext );
            CdCleanupDirent( IrpContext, &Dirent );
            CleanupDirContext = FALSE;

            if (UpdateFcbSizes) {

                CcPurgeCacheSection( &Fcb->FcbNonpaged->SegmentObject,
                                     NULL,
                                     0,
                                     FALSE );
            }
        }

    } _SEH2_FINALLY {

        //
        //  Cleanup any dirent structures we may have used.
        //

        if (CleanupDirContext) {

            CdCleanupDirContext( IrpContext, &DirContext );
            CdCleanupDirent( IrpContext, &Dirent );
        }

        //
        //  If we raised then we need to dereference the file object.
        //

        if (StreamFile != NULL) {

            //
            //  Null the name pointer, since the stream file object never actually
            //  'owns' the names, we just point it to existing ones.
            //

            StreamFile->FileName.Buffer = NULL;
            StreamFile->FileName.MaximumLength = StreamFile->FileName.Length = 0;

            ObDereferenceObject( StreamFile );
            Fcb->FileObject = NULL;
        }

        //
        //  Dereference and unlock the Fcb.
        //

        if (DecrementReference) {

            CdLockVcb( IrpContext, Vcb );
            CdDecrementReferenceCounts( IrpContext, Fcb, 1, 0 );
            CdUnlockVcb( IrpContext, Vcb );
        }

        CdUnlockFcb( IrpContext, Fcb );
    } _SEH2_END;

    return;
}

Referenced by CdUpdateVcbFromVolDescriptor(), and CdVerifyOrCreateDirStreamFile().

CdDeleteInternalStream()

VOID CdDeleteInternalStream	(	_In_ PIRP_CONTEXT	IrpContext,
		_Inout_ PFCB	Fcb
	)

Definition at line 333 of file cachesup.c.

{
    PFILE_OBJECT FileObject;

    PAGED_CODE();

    UNREFERENCED_PARAMETER( IrpContext );

    ASSERT_IRP_CONTEXT( IrpContext );
    ASSERT_FCB( Fcb );

    //
    //  Lock the Fcb.
    //

    CdLockFcb( IrpContext, Fcb );

    //
    //  Capture the file object.
    //

    FileObject = Fcb->FileObject;
    Fcb->FileObject = NULL;

    //
    //  It is now safe to unlock the Fcb.
    //

    CdUnlockFcb( IrpContext, Fcb );

    //
    //  Dereference the file object if present.
    //

    if (FileObject != NULL) {

        if (FileObject->PrivateCacheMap != NULL) {

            CcUninitializeCacheMap( FileObject, NULL, NULL );
        }

        //
        //  Null the name pointer, since the stream file object never actually
        //  'owns' the names, we just point it to existing ones.
        //
        
        FileObject->FileName.Buffer = NULL;
        FileObject->FileName.MaximumLength = FileObject->FileName.Length = 0;

        ObDereferenceObject( FileObject );
    }
}

Referenced by _Requires_lock_held_().