246 lines
4.7 KiB
C
246 lines
4.7 KiB
C
/*++
|
||
|
||
Copyright (c) 1989-2000 Microsoft Corporation
|
||
|
||
Module Name:
|
||
|
||
FilObSup.c
|
||
|
||
Abstract:
|
||
|
||
This module implements the Udfs File object support routines.
|
||
|
||
// @@BEGIN_DDKSPLIT
|
||
|
||
Author:
|
||
|
||
Dan Lovinger [DanLo] 23-Sep-1996
|
||
|
||
Revision History:
|
||
|
||
// @@END_DDKSPLIT
|
||
|
||
--*/
|
||
|
||
#include "UdfProcs.h"
|
||
|
||
//
|
||
// The Bug check file id for this module
|
||
//
|
||
|
||
#define BugCheckFileId (UDFS_BUG_CHECK_FILOBSUP)
|
||
|
||
//
|
||
// The local debug trace level
|
||
//
|
||
|
||
#define Dbg (UDFS_DEBUG_LEVEL_FILOBSUP)
|
||
|
||
//
|
||
// Local constants.
|
||
//
|
||
|
||
#define TYPE_OF_OPEN_MASK (0x00000007)
|
||
|
||
#ifdef ALLOC_PRAGMA
|
||
#pragma alloc_text(PAGE, UdfDecodeFileObject)
|
||
#pragma alloc_text(PAGE, UdfFastDecodeFileObject)
|
||
#pragma alloc_text(PAGE, UdfSetFileObject)
|
||
#endif
|
||
|
||
|
||
VOID
|
||
UdfSetFileObject (
|
||
IN PIRP_CONTEXT IrpContext,
|
||
IN PFILE_OBJECT FileObject,
|
||
IN TYPE_OF_OPEN TypeOfOpen,
|
||
IN PFCB Fcb OPTIONAL,
|
||
IN PCCB Ccb OPTIONAL
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine will initialize the FileObject context fields based on the
|
||
input type and data structures.
|
||
|
||
Arguments:
|
||
|
||
FileObject - Supplies the file object pointer being initialized.
|
||
|
||
TypeOfOpen - Sets the type of open.
|
||
|
||
Fcb - Fcb for this file object. Ignored for UnopenedFileObject.
|
||
|
||
Ccb - Ccb for the handle corresponding to this file object. Will not
|
||
be present for stream file objects.
|
||
|
||
Return Value:
|
||
|
||
None.
|
||
|
||
--*/
|
||
|
||
{
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// We only have values 0 to 7 available so make sure we didn't
|
||
// inadvertantly add a new type.
|
||
//
|
||
|
||
ASSERTMSG( "FileObject types exceed available bits\n", BeyondValidType <= 8 );
|
||
|
||
//
|
||
// Setting a file object to type UnopenedFileObject means just
|
||
// clearing all of the context fields. All the other input
|
||
//
|
||
|
||
if (TypeOfOpen == UnopenedFileObject) {
|
||
|
||
FileObject->FsContext =
|
||
FileObject->FsContext2 = NULL;
|
||
|
||
return;
|
||
}
|
||
|
||
//
|
||
// Check that the 3 low-order bits of the Ccb are clear.
|
||
//
|
||
|
||
ASSERTMSG( "Ccb is not quad-aligned\n", !FlagOn( ((ULONG_PTR) Ccb), TYPE_OF_OPEN_MASK ));
|
||
|
||
//
|
||
// We will or the type of open into the low order bits of FsContext2
|
||
// along with the Ccb value.
|
||
// The Fcb is stored into the FsContext field.
|
||
//
|
||
|
||
FileObject->FsContext = Fcb;
|
||
FileObject->FsContext2 = Ccb;
|
||
|
||
SetFlag( ((ULONG_PTR) FileObject->FsContext2), TypeOfOpen );
|
||
|
||
//
|
||
// Set the Vpb field in the file object.
|
||
//
|
||
|
||
FileObject->Vpb = Fcb->Vcb->Vpb;
|
||
|
||
return;
|
||
}
|
||
|
||
|
||
|
||
TYPE_OF_OPEN
|
||
UdfDecodeFileObject (
|
||
IN PFILE_OBJECT FileObject,
|
||
OUT PFCB *Fcb,
|
||
OUT PCCB *Ccb
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine takes a file object and extracts the Fcb and Ccb (possibly NULL)
|
||
and returns the type of open.
|
||
|
||
Arguments:
|
||
|
||
FileObject - Supplies the file object pointer being initialized.
|
||
|
||
Fcb - Address to store the Fcb contained in the file object.
|
||
|
||
Ccb - Address to store the Ccb contained in the file object.
|
||
|
||
Return Value:
|
||
|
||
TYPE_OF_OPEN - Indicates the type of file object.
|
||
|
||
--*/
|
||
|
||
{
|
||
TYPE_OF_OPEN TypeOfOpen;
|
||
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// If this is an unopened file object then return NULL for the
|
||
// Fcb/Ccb. Don't trust any other values in the file object.
|
||
//
|
||
|
||
TypeOfOpen = (TYPE_OF_OPEN) FlagOn( (ULONG_PTR) FileObject->FsContext2,
|
||
TYPE_OF_OPEN_MASK );
|
||
|
||
if (TypeOfOpen == UnopenedFileObject) {
|
||
|
||
*Fcb = NULL;
|
||
*Ccb = NULL;
|
||
|
||
} else {
|
||
|
||
//
|
||
// The Fcb is pointed to by the FsContext field. The Ccb is in
|
||
// FsContext2 (after clearing the low three bits). The low three
|
||
// bits are the file object type.
|
||
//
|
||
|
||
*Fcb = FileObject->FsContext;
|
||
*Ccb = FileObject->FsContext2;
|
||
|
||
ClearFlag( (ULONG_PTR) *Ccb, TYPE_OF_OPEN_MASK );
|
||
}
|
||
|
||
//
|
||
// Now return the type of open.
|
||
//
|
||
|
||
return TypeOfOpen;
|
||
}
|
||
|
||
|
||
TYPE_OF_OPEN
|
||
UdfFastDecodeFileObject (
|
||
IN PFILE_OBJECT FileObject,
|
||
OUT PFCB *Fcb
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This procedure takes a pointer to a file object, that has already been
|
||
opened by Udfs and does a quick decode operation. It will only return
|
||
a non null value if the file object is a user file open
|
||
|
||
Arguments:
|
||
|
||
FileObject - Supplies the file object pointer being interrogated
|
||
|
||
Fcb - Address to store Fcb if this is a user file object. NULL
|
||
otherwise.
|
||
|
||
Return Value:
|
||
|
||
TYPE_OF_OPEN - type of open of this file object.
|
||
|
||
--*/
|
||
|
||
{
|
||
PAGED_CODE();
|
||
|
||
ASSERT_FILE_OBJECT( FileObject );
|
||
|
||
//
|
||
// The Fcb is in the FsContext field. The type of open is in the low
|
||
// bits of the Ccb.
|
||
//
|
||
|
||
*Fcb = FileObject->FsContext;
|
||
|
||
return (TYPE_OF_OPEN) FlagOn( (ULONG_PTR) FileObject->FsContext2, TYPE_OF_OPEN_MASK );
|
||
}
|
||
|