windows-nt/Source/XPSP1/NT/base/fs/fastfat/filobsup.c
2020-09-26 16:20:57 +08:00

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/*++
Copyright (c) 1989-2000 Microsoft Corporation
Module Name:
FilObSup.c
Abstract:
This module implements the Fat File object support routines.
// @@BEGIN_DDKSPLIT
Author:
Gary Kimura [GaryKi] 30-Aug-1990
Revision History:
// @@END_DDKSPLIT
--*/
#include "FatProcs.h"
//
// The Bug check file id for this module
//
#define BugCheckFileId (FAT_BUG_CHECK_FILOBSUP)
//
// The debug trace level
//
#define Dbg (DEBUG_TRACE_FILOBSUP)
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, FatForceCacheMiss)
#pragma alloc_text(PAGE, FatPurgeReferencedFileObjects)
#pragma alloc_text(PAGE, FatSetFileObject)
#pragma alloc_text(PAGE, FatDecodeFileObject)
#endif
VOID
FatSetFileObject (
IN PFILE_OBJECT FileObject OPTIONAL,
IN TYPE_OF_OPEN TypeOfOpen,
IN PVOID VcbOrFcbOrDcb,
IN PCCB Ccb OPTIONAL
)
/*++
Routine Description:
This routine sets the file system pointers within the file object
Arguments:
FileObject - Supplies a pointer to the file object being modified, and
can optionally be null.
TypeOfOpen - Supplies the type of open denoted by the file object.
This is only used by this procedure for sanity checking.
VcbOrFcbOrDcb - Supplies a pointer to either a vcb, fcb, or dcb
Ccb - Optionally supplies a pointer to a ccb
Return Value:
None.
--*/
{
DebugTrace(+1, Dbg, "FatSetFileObject, FileObject = %08lx\n", FileObject );
ASSERT((Ccb == NULL) || (NodeType(Ccb) == FAT_NTC_CCB));
ASSERT(((TypeOfOpen == UnopenedFileObject))
||
((TypeOfOpen == UserFileOpen) &&
(NodeType(VcbOrFcbOrDcb) == FAT_NTC_FCB) &&
(Ccb != NULL))
||
((TypeOfOpen == EaFile) &&
(NodeType(VcbOrFcbOrDcb) == FAT_NTC_FCB) &&
(Ccb == NULL))
||
((TypeOfOpen == UserDirectoryOpen) &&
((NodeType(VcbOrFcbOrDcb) == FAT_NTC_DCB) || (NodeType(VcbOrFcbOrDcb) == FAT_NTC_ROOT_DCB)) &&
(Ccb != NULL))
||
((TypeOfOpen == UserVolumeOpen) &&
(NodeType(VcbOrFcbOrDcb) == FAT_NTC_VCB) &&
(Ccb != NULL))
||
((TypeOfOpen == VirtualVolumeFile) &&
(NodeType(VcbOrFcbOrDcb) == FAT_NTC_VCB) &&
(Ccb == NULL))
||
((TypeOfOpen == DirectoryFile) &&
((NodeType(VcbOrFcbOrDcb) == FAT_NTC_DCB) || (NodeType(VcbOrFcbOrDcb) == FAT_NTC_ROOT_DCB)) &&
(Ccb == NULL)));
//
// If we were given an Fcb, Dcb, or Vcb, we have some processing to do.
//
ASSERT((Ccb == NULL) || (NodeType(Ccb) == FAT_NTC_CCB));
if ( VcbOrFcbOrDcb != NULL ) {
//
// Set the Vpb field in the file object, and if we were given an
// Fcb or Dcb move the field over to point to the nonpaged Fcb/Dcb
//
if (NodeType(VcbOrFcbOrDcb) == FAT_NTC_VCB) {
FileObject->Vpb = ((PVCB)VcbOrFcbOrDcb)->Vpb;
} else {
FileObject->Vpb = ((PFCB)VcbOrFcbOrDcb)->Vcb->Vpb;
//
// If this is a temporary file, note it in the FcbState
//
if (FlagOn(((PFCB)VcbOrFcbOrDcb)->FcbState, FCB_STATE_TEMPORARY)) {
SetFlag(FileObject->Flags, FO_TEMPORARY_FILE);
}
}
}
ASSERT((Ccb == NULL) || (NodeType(Ccb) == FAT_NTC_CCB));
//
// Now set the fscontext fields of the file object
//
if (ARGUMENT_PRESENT( FileObject )) {
FileObject->FsContext = VcbOrFcbOrDcb;
FileObject->FsContext2 = Ccb;
}
ASSERT((Ccb == NULL) || (NodeType(Ccb) == FAT_NTC_CCB));
//
// And return to our caller
//
DebugTrace(-1, Dbg, "FatSetFileObject -> VOID\n", 0);
return;
}
TYPE_OF_OPEN
FatDecodeFileObject (
IN PFILE_OBJECT FileObject,
OUT PVCB *Vcb,
OUT PFCB *FcbOrDcb,
OUT PCCB *Ccb
)
/*++
Routine Description:
This procedure takes a pointer to a file object, that has already been
opened by the Fat file system and figures out what really is opened.
Arguments:
FileObject - Supplies the file object pointer being interrogated
Vcb - Receives a pointer to the Vcb for the file object.
FcbOrDcb - Receives a pointer to the Fcb/Dcb for the file object, if
one exists.
Ccb - Receives a pointer to the Ccb for the file object, if one exists.
Return Value:
TYPE_OF_OPEN - returns the type of file denoted by the input file object.
UserFileOpen - The FO represents a user's opened data file.
Ccb, FcbOrDcb, and Vcb are set. FcbOrDcb points to an Fcb.
UserDirectoryOpen - The FO represents a user's opened directory.
Ccb, FcbOrDcb, and Vcb are set. FcbOrDcb points to a Dcb/RootDcb
UserVolumeOpen - The FO represents a user's opened volume.
Ccb and Vcb are set. FcbOrDcb is null.
VirtualVolumeFile - The FO represents the special virtual volume file.
Vcb is set, and Ccb and FcbOrDcb are null.
DirectoryFile - The FO represents a special directory file.
Vcb and FcbOrDcb are set. Ccb is null. FcbOrDcb points to a
Dcb/RootDcb.
EaFile - The FO represents an Ea Io stream file.
FcbOrDcb, and Vcb are set. FcbOrDcb points to an Fcb, and Ccb is
null.
--*/
{
TYPE_OF_OPEN TypeOfOpen;
PVOID FsContext;
PVOID FsContext2;
DebugTrace(+1, Dbg, "FatDecodeFileObject, FileObject = %08lx\n", FileObject);
//
// Reference the fs context fields of the file object, and zero out
// the out pointer parameters.
//
FsContext = FileObject->FsContext;
FsContext2 = FileObject->FsContext2;
//
// Special case the situation where FsContext is null
//
if (FsContext == NULL) {
*Ccb = NULL;
*FcbOrDcb = NULL;
*Vcb = NULL;
TypeOfOpen = UnopenedFileObject;
} else {
//
// Now we can case on the node type code of the fscontext pointer
// and set the appropriate out pointers
//
switch (NodeType(FsContext)) {
case FAT_NTC_VCB:
*Ccb = FsContext2;
*FcbOrDcb = NULL;
*Vcb = FsContext;
TypeOfOpen = ( *Ccb == NULL ? VirtualVolumeFile : UserVolumeOpen );
break;
case FAT_NTC_ROOT_DCB:
case FAT_NTC_DCB:
*Ccb = FsContext2;
*FcbOrDcb = FsContext;
*Vcb = (*FcbOrDcb)->Vcb;
TypeOfOpen = ( *Ccb == NULL ? DirectoryFile : UserDirectoryOpen );
DebugTrace(0, Dbg, "Referencing directory: %Z\n", &(*FcbOrDcb)->FullFileName);
break;
case FAT_NTC_FCB:
*Ccb = FsContext2;
*FcbOrDcb = FsContext;
*Vcb = (*FcbOrDcb)->Vcb;
TypeOfOpen = ( *Ccb == NULL ? EaFile : UserFileOpen );
DebugTrace(0, Dbg, "Referencing file: %Z\n", &(*FcbOrDcb)->FullFileName);
break;
default:
FatBugCheck( NodeType(FsContext), 0, 0 );
}
}
//
// and return to our caller
//
DebugTrace(-1, Dbg, "FatDecodeFileObject -> %08lx\n", TypeOfOpen);
return TypeOfOpen;
}
VOID
FatPurgeReferencedFileObjects (
IN PIRP_CONTEXT IrpContext,
IN PFCB Fcb,
IN FAT_FLUSH_TYPE FlushType
)
/*++
Routine Description:
This routine non-recursively walks from the given FcbOrDcb and trys
to force Cc or Mm to close any sections it may be holding on to.
Arguments:
Fcb - Supplies a pointer to either an fcb or a dcb
FlushType - Specifies the kind of flushing to perform
Return Value:
None.
--*/
{
PFCB OriginalFcb = Fcb;
PFCB NextFcb;
DebugTrace(+1, Dbg, "FatPurgeReferencedFileObjects, Fcb = %08lx\n", Fcb );
ASSERT( FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) );
//
// First, if we have a delayed close, force it closed.
//
FatFspClose(Fcb->Vcb);
//
// Walk the directory tree forcing sections closed.
//
// Note that it very important to get the next node to visit before
// acting on the current node. This is because acting on a node may
// make it, and an arbitrary number of direct ancestors, vanish.
// Since we never visit ancestors in our top-down enumeration scheme, we
// can safely continue the enumeration even when the tree is vanishing
// beneath us. This is way cool.
//
while ( Fcb != NULL ) {
NextFcb = FatGetNextFcbTopDown(IrpContext, Fcb, OriginalFcb);
//
// Check for the EA file fcb
//
if ( !FlagOn(Fcb->DirentFatFlags, FAT_DIRENT_ATTR_VOLUME_ID) ) {
FatForceCacheMiss( IrpContext, Fcb, FlushType );
}
Fcb = NextFcb;
}
DebugTrace(-1, Dbg, "FatPurgeReferencedFileObjects (VOID)\n", 0 );
return;
}
VOID
FatForceCacheMiss (
IN PIRP_CONTEXT IrpContext,
IN PFCB Fcb,
IN FAT_FLUSH_TYPE FlushType
)
/*++
Routine Description:
The following routine asks either Cc or Mm to get rid of any cached
pages on a file. Note that this will fail if a user has mapped a file.
If there is a shared cache map, purge the cache section. Otherwise
we have to go and ask Mm to blow away the section.
NOTE: This caller MUST own the Vcb exclusive.
Arguments:
Fcb - Supplies a pointer to an fcb
FlushType - Specifies the kind of flushing to perform
Return Value:
None.
--*/
{
PVCB Vcb;
BOOLEAN ChildrenAcquired = FALSE;
//
// If we can't wait, bail.
//
ASSERT( FatVcbAcquiredExclusive( IrpContext, Fcb->Vcb ) ||
FlagOn( Fcb->Vcb->VcbState, VCB_STATE_FLAG_LOCKED ) );
if (!FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT)) {
FatRaiseStatus( IrpContext, STATUS_CANT_WAIT );
}
//
// If we are purging a directory file object, we must acquire all the
// FCBs exclusive so that the parent directory is not being pinned.
// Careful, we can collide with something acquiring up the tree like
// an unpin repinned flush (FsRtlAcquireFileForCcFlush ...) of a parent
// dir on extending writethrough of a child file (oops). So get things
// going up the tree, not down.
//
if ((NodeType(Fcb) != FAT_NTC_FCB) &&
!IsListEmpty(&Fcb->Specific.Dcb.ParentDcbQueue)) {
PLIST_ENTRY Links;
PFCB TempFcb;
ChildrenAcquired = TRUE;
for (Links = Fcb->Specific.Dcb.ParentDcbQueue.Flink;
Links != &Fcb->Specific.Dcb.ParentDcbQueue;
Links = Links->Flink) {
TempFcb = CONTAINING_RECORD( Links, FCB, ParentDcbLinks );
(VOID)FatAcquireExclusiveFcb( IrpContext, TempFcb );
}
}
(VOID)FatAcquireExclusiveFcb( IrpContext, Fcb );
//
// We use this flag to indicate to a close beneath us that
// the Fcb resource should be freed before deleting the Fcb.
//
Vcb = Fcb->Vcb;
SetFlag( Fcb->FcbState, FCB_STATE_FORCE_MISS_IN_PROGRESS );
ClearFlag( Vcb->VcbState, VCB_STATE_FLAG_DELETED_FCB );
try {
BOOLEAN DataSectionExists;
BOOLEAN ImageSectionExists;
PSECTION_OBJECT_POINTERS Section;
if ( FlushType ) {
(VOID)FatFlushFile( IrpContext, Fcb, FlushType );
}
//
// The Flush may have made the Fcb go away
//
if (!FlagOn(Vcb->VcbState, VCB_STATE_FLAG_DELETED_FCB)) {
Section = &Fcb->NonPaged->SectionObjectPointers;
DataSectionExists = (BOOLEAN)(Section->DataSectionObject != NULL);
ImageSectionExists = (BOOLEAN)(Section->ImageSectionObject != NULL);
//
// Note, it is critical to do the Image section first as the
// purge of the data section may cause the image section to go
// away, but the opposite is not true.
//
if (ImageSectionExists) {
(VOID)MmFlushImageSection( Section, MmFlushForWrite );
}
if (DataSectionExists) {
CcPurgeCacheSection( Section, NULL, 0, FALSE );
}
}
} finally {
//
// If we purging a directory file object, release all the Fcb
// resources that we acquired above. The Dcb cannot have vanished
// if there were Fcbs underneath it, and the Fcbs couldn't have gone
// away since I own the Vcb.
//
if (ChildrenAcquired) {
PLIST_ENTRY Links;
PFCB TempFcb;
for (Links = Fcb->Specific.Dcb.ParentDcbQueue.Flink;
Links != &Fcb->Specific.Dcb.ParentDcbQueue;
Links = Links->Flink) {
TempFcb = CONTAINING_RECORD( Links, FCB, ParentDcbLinks );
FatReleaseFcb( IrpContext, TempFcb );
}
}
//
// Since we have the Vcb exclusive we know that if any closes
// come in it is because the CcPurgeCacheSection caused the
// Fcb to go away. Also in close, the Fcb was released
// before being freed.
//
if ( !FlagOn(Vcb->VcbState, VCB_STATE_FLAG_DELETED_FCB) ) {
ClearFlag( Fcb->FcbState, FCB_STATE_FORCE_MISS_IN_PROGRESS );
FatReleaseFcb( (IRPCONTEXT), Fcb );
}
}
}