fatstruc.h

winddk src目录下的文件系统驱动源码压缩!

/*++

Copyright (c) 1989-2000 Microsoft Corporation

Module Name:

    FatStruc.h

Abstract:

    This module defines the data structures that make up the major internal
    part of the Fat file system.


--*/

#ifndef _FATSTRUC_
#define _FATSTRUC_

typedef PVOID PBCB;     //**** Bcb's are now part of the cache module


//
//  The FAT_DATA record is the top record in the Fat file system in-memory
//  data structure.  This structure must be allocated from non-paged pool.
//

typedef struct _FAT_DATA {

    //
    //  The type and size of this record (must be FAT_NTC_DATA_HEADER)
    //

    NODE_TYPE_CODE NodeTypeCode;
    NODE_BYTE_SIZE NodeByteSize;


    PVOID LazyWriteThread;


    //
    //  A queue of all the devices that are mounted by the file system.
    //

    LIST_ENTRY VcbQueue;

    //
    //  A pointer to the Driver object we were initialized with
    //

    PDRIVER_OBJECT DriverObject;

    //
    //  A pointer to the filesystem device objects we created.
    //

    PVOID DiskFileSystemDeviceObject;
    PVOID CdromFileSystemDeviceObject;

    //
    //  A resource variable to control access to the global Fat data record
    //

    ERESOURCE Resource;

    //
    //  A pointer to our EPROCESS struct, which is a required input to the
    //  Cache Management subsystem.
    //

    PEPROCESS OurProcess;

    //
    //  The following tells us if we should use Chicago extensions.
    //

    BOOLEAN ChicagoMode:1;

    //
    //  The following field tells us if we are running on a Fujitsu
    //  FMR Series. These machines supports extra formats on the
    //  FAT file system.
    //

    BOOLEAN FujitsuFMR:1;

    //
    //  Inidicates that FspClose is currently processing closes.
    //

    BOOLEAN AsyncCloseActive:1;

    //
    //  The following BOOLEAN says shutdown has started on FAT.  It
    //  instructs FspClose to not keep the Vcb resources anymore.
    //

    BOOLEAN ShutdownStarted:1;

    //
    //  The following flag tells us if we are going to generate LFNs
    //  for valid 8.3 names with extended characters.
    //

    BOOLEAN CodePageInvariant:1;

    //
    //  The following flags tell us if we are in an aggresive push to lower
    //  the size of the deferred close queues.
    //

    BOOLEAN HighAsync:1;
    BOOLEAN HighDelayed:1;

    //
    //  The following list entry is used for performing closes that can't
    //  be done in the context of the original caller.
    //

    ULONG AsyncCloseCount;
    LIST_ENTRY AsyncCloseList;

    //
    //  The following two fields record if we are delaying a close.
    //

    ULONG DelayedCloseCount;
    LIST_ENTRY DelayedCloseList;

    //
    //  This is the ExWorkerItem that does both kinds of deferred closes.
    //

    PIO_WORKITEM FatCloseItem;

    //
    //  This spinlock protects several rapid-fire operations. NOTE: this is
    //  pretty horrible style.
    //

    KSPIN_LOCK GeneralSpinLock;

    //
    //  Cache manager call back structures, which must be passed on each call
    //  to CcInitializeCacheMap.
    //

    CACHE_MANAGER_CALLBACKS CacheManagerCallbacks;
    CACHE_MANAGER_CALLBACKS CacheManagerNoOpCallbacks;
} FAT_DATA;
typedef FAT_DATA *PFAT_DATA;

//
// An array of these structures will keep

typedef struct _FAT_WINDOW {
    
    ULONG FirstCluster;       // The first cluster in this window.
    ULONG LastCluster;        // The last cluster in this window.
    ULONG ClustersFree;       // The number of clusters free in this window.

} FAT_WINDOW;
typedef FAT_WINDOW *PFAT_WINDOW;

//
//  Forward reference some circular referenced structures.
//

typedef struct _VCB VCB;
typedef VCB *PVCB;

typedef struct _FCB FCB;
typedef FCB *PFCB;

//
//  This structure is used to keep track of information needed to do a
//  deferred close.  It is now embedded in a CCB so we don't have to
//  allocate one in the close path (with mustsucceed).
//

typedef struct {

    //
    //  Two sets of links, one for the global list and one for closes
    //  on a particular volume.
    //
    
    LIST_ENTRY GlobalLinks;
    LIST_ENTRY VcbLinks;

    PVCB Vcb;
    PFCB Fcb;
    enum _TYPE_OF_OPEN TypeOfOpen;
    BOOLEAN Free;

} CLOSE_CONTEXT;

typedef CLOSE_CONTEXT *PCLOSE_CONTEXT;

//
//  The Vcb (Volume control Block) record corresponds to every volume mounted
//  by the file system.  They are ordered in a queue off of FatData.VcbQueue.
//  This structure must be allocated from non-paged pool
//

typedef enum _VCB_CONDITION {
    VcbGood = 1,
    VcbNotMounted,
    VcbBad
} VCB_CONDITION;

typedef struct _VCB {

    //
    //  This is a common head for the FAT volume file
    //

    FSRTL_ADVANCED_FCB_HEADER VolumeFileHeader;

    //
    //  The links for the device queue off of FatData.VcbQueue
    //

    LIST_ENTRY VcbLinks;

    //
    //  A pointer the device object passed in by the I/O system on a mount
    //  This is the target device object that the file system talks to when it
    //  needs to do any I/O (e.g., the disk stripper device object).
    //
    //

    PDEVICE_OBJECT TargetDeviceObject;

    //
    //  A pointer to the VPB for the volume passed in by the I/O system on
    //  a mount.
    //

    PVPB Vpb;

    //
    //  The internal state of the device.  This is a collection of fsd device
    //  state flags.
    //

    ULONG VcbState;
    VCB_CONDITION VcbCondition;

    //
    //  A pointer to the root DCB for this volume
    //

    struct _FCB *RootDcb;

    //
    //  If the FAT has so many entries that the free cluster bitmap would
    //  be too large, we split the FAT into buckets, and only one bucket's
    //  worth of bits are kept in the bitmap.
    //

    ULONG NumberOfWindows;
    PFAT_WINDOW Windows;
    PFAT_WINDOW CurrentWindow;

    //
    //  A count of the number of file objects that have opened the volume
    //  for direct access, and their share access state.
    //

    CLONG DirectAccessOpenCount;
    SHARE_ACCESS ShareAccess;

    //
    //  A count of the number of file objects that have any file/directory
    //  opened on this volume, not including direct access.  And also the
    //  count of the number of file objects that have a file opened for
    //  only read access (i.e., they cannot be modifying the disk).
    //

    CLONG OpenFileCount;
    CLONG ReadOnlyCount;

    //
    //  A count of the number of internal opens on this VCB.
    //

    ULONG InternalOpenCount;

    //
    //  A count of the number of residual opens on this volume.
    //  This is usually two or three.  One is for the virutal volume
    //  file.  One is for the root directory.  And one is for the
    //  EA file, if there is one.
    //

    ULONG ResidualOpenCount;

    //
    //  The bios parameter block field contains
    //  an unpacked copy of the bpb for the volume, it is initialized
    //  during mount time and can be read by everyone else after that.
    //

    BIOS_PARAMETER_BLOCK Bpb;

    PUCHAR First0x24BytesOfBootSector;

    //
    //  The following structure contains information useful to the
    //  allocation support routines.  Many of them are computed from
    //  elements of the Bpb, but are too involved to recompute every time
    //  they are needed.
    //

    struct {

        LBO RootDirectoryLbo;       // Lbo of beginning of root directory
        LBO FileAreaLbo;            // Lbo of beginning of file area
        ULONG RootDirectorySize;    // size of root directory in bytes

        ULONG NumberOfClusters;     // total number of clusters on the volume
        ULONG NumberOfFreeClusters; // number of free clusters on the volume

        UCHAR FatIndexBitSize;      // indicates if 12, 16, or 32 bit fat table

        UCHAR LogOfBytesPerSector;  // Log(Bios->BytesPerSector)
        UCHAR LogOfBytesPerCluster; // Log(Bios->SectorsPerCluster)

    } AllocationSupport;

    //
    //  The following Mcb is used to keep track of dirty sectors in the Fat.
    //  Runs of holes denote clean sectors while runs of LBO == VBO denote
    //  dirty sectors.  The VBOs are that of the volume file, starting at
    //  0.  The granuality of dirt is one sectors, and additions are only
    //  made in sector chunks to prevent problems with several simultaneous
    //  updaters.
    //

    LARGE_MCB DirtyFatMcb;

    //
    //  The FreeClusterBitMap keeps track of all the clusters in the fat.
    //  A 1 means occupied while a 0 means free.  It allows quick location
    //  of contiguous runs of free clusters.  It is initialized on mount
    //  or verify.
    //

    RTL_BITMAP FreeClusterBitMap;

    //
    //  The following fast mutex controls access to the free cluster bit map
    //  and the buckets.
    //

    FAST_MUTEX FreeClusterBitMapMutex;

    //
    //  A resource variable to control access to the volume specific data
    //  structures
    //

    ERESOURCE Resource;

    //
    //  A resource to make sure no one changes the volume bitmap while
    //  you're using it.  Only for volumes with NumberOfWindows > 1.
    //

    ERESOURCE ChangeBitMapResource;


    //
    //  The following field points to the file object used to do I/O to
    //  the virtual volume file.  The virtual volume file maps sectors
    //  0 through the end of fat and is of a fixed size (determined during
    //  mount)
    //

    PFILE_OBJECT VirtualVolumeFile;

    //
    //  The following field contains a record of special pointers used by
    //  MM and Cache to manipluate section objects.  Note that the values
    //  are set outside of the file system.  However the file system on an
    //  open/create will set the file object's SectionObject field to point
    //  to this field
    //

    SECTION_OBJECT_POINTERS SectionObjectPointers;

    //
    //  The following fields is a hint cluster index used by the file system
    //  when allocating a new cluster.
    //

    ULONG ClusterHint;

    //
    //  This field contains the "DeviceObject" that this volume is
    //  currently mounted on.  Note Vcb->Vpb->RealDevice is constant.
    //

    PDEVICE_OBJECT CurrentDevice;

    //
    //  This is a pointer to the file object and the Fcb which represent the ea data.
    //