Source code of Windows XP (NT5)
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/*++ BUILD Version: 0000 // Increment this if a change has global effects
Copyright (c) 1989 Microsoft Corporation
Module Name:
LfsStruc.h
Abstract:
This module defines the data structures that make up the major internal part of the Log File Service.
Author:
Brian Andrew [BrianAn] 13-June-1991
Revision History:
--*/
#ifndef _LFSSTRUC_
#define _LFSSTRUC_
typedef PVOID PBCB; //**** Bcb's are now part of the cache module
//
// Log Enumeration Block. A pointer to this structure is returned to the user
// when a client is reading a particular set of log records from the log
// file.
//
typedef struct _LEB {
//
// The type and size of this record (must be LFS_NTC_LEB)
//
NODE_TYPE_CODE NodeTypeCode; NODE_BYTE_SIZE NodeByteSize;
//
// Log record header. This is the mapped log record header and bcb
// for the record header of the current Lsn.
//
struct _LFS_RECORD_HEADER *RecordHeader; PBCB RecordHeaderBcb;
//
// Context Mode. This is the mode governing the log record lookup. We
// can look backwards via the ClientUndoNextLsn or ClientPreviousLsn.
// We can also look forwards by walking through all the log records and
// comparing ClientId fields.
//
LFS_CONTEXT_MODE ContextMode;
//
// Client Id. This is the client ID for the log records being returned.
//
LFS_CLIENT_ID ClientId;
//
// Log record pointer. This is the address returned to the user as the
// log record referred to by CurrentLsn. If we allocated a buffer to
// hold the record, we need to deallocate it as necessary.
//
// This field is either the actual mapped log record or a pointer to
// an auxilary buffer allocated by the Lfs.
//
PVOID CurrentLogRecord; BOOLEAN AuxilaryBuffer;
} LEB, *PLEB;
//
// Lfcb synchronization. This is the synchronization structure used by the Lfcb.
//
typedef struct _LFCB_SYNC {
//
// Principal Lfcb Resource.
//
ERESOURCE Resource;
//
// Notification Event. This event is set to the Signalled state when
// pages are flushed to the cache file. Any waiters will then check
// to see if the Lsn they're waiting for made it to disk.
//
KEVENT Event;
//
// User Count. Number of clients using this structure. We will deallocate
// when all clients are gone.
//
ULONG UserCount;
//
// Mutant to guard Leb spare list
//
FAST_MUTEX SpareListMutex;
} LFCB_SYNC, *PLFCB_SYNC;
//
// Log Client Structure. The Lfs allocates one of these for each active
// client. The address of this structure will be returned to the user
// as a log handle.
//
typedef struct _LCH {
//
// The type and size of this record (must be LFS_NTC_LCH)
//
NODE_TYPE_CODE NodeTypeCode; NODE_BYTE_SIZE NodeByteSize;
//
// Links for all the client handles on an Lfcb.
//
LIST_ENTRY LchLinks;
//
// Log File Control Block. This is the log file for this log handle.
//
struct _LFCB *Lfcb;
//
// Client Id. This refers to the client record for this client in the
// Lfs restart area.
//
LFS_CLIENT_ID ClientId;
//
// The following is the number of bytes this client has asked to
// have reserved in the log file. It includes the space
// for the log record headers.
//
LONGLONG ClientUndoCommitment;
//
// Byte offset in the client array.
//
ULONG ClientArrayByteOffset;
//
// Pointer to the resource in the Lfcb. We access the resource with
// this pointer for the times when the lfcb has been deleted.
//
PLFCB_SYNC Sync;
} LCH, *PLCH;
//
// Log Buffer Control Block. A buffer control block is associated with
// each of the log buffers. They are used to serialize access to the
// log file.
//
typedef struct _LBCB {
//
// The type and size of this record (must be LFS_NTC_LBCB)
//
NODE_TYPE_CODE NodeTypeCode; NODE_BYTE_SIZE NodeByteSize;
//
// Buffer Block Links. These fields are used to link the buffer blocks
// together.
//
LIST_ENTRY WorkqueLinks; LIST_ENTRY ActiveLinks;
//
// Log file position and length. This is the location in the log file to write
// out this buffer.
//
LONGLONG FileOffset; LONGLONG Length;
//
// Sequence number. This is the sequence number for log records which
// begin on this page.
//
LONGLONG SeqNumber;
//
// Next Offset. This is the next offset to write a log record in the
// this log page. Stored as a large integer to facilitate large
// integer operations.
//
LONGLONG BufferOffset;
//
// Buffer. This field points to the buffer containing the log page
// for this block. For a log record page this is a pointer to
// a pinned cache buffer, for a log restart page, this is a pointer
// to an auxilary buffer.
//
PVOID PageHeader;
//
// Bcb for Log Page Block. This is the Bcb for the pinned data.
// If this buffer block describes an Lfs restart area, this field is NULL.
//
PBCB LogPageBcb;
//
// Last Lsn. This is the Lsn for the last log record on this page. We delay
// writing it until the page is flushed, storing it here instead.
//
LSN LastLsn;
//
// Last complete Lsn. This is the Lsn for the last log record which ends
// on this page.
//
LSN LastEndLsn;
//
// Page Flags. These are the flags associated with this log page.
// We store them in the Lbcb until the page is written. They flags
// to use are the same as in the log record page header.
//
// LOG_PAGE_LOG_RECORD_END - Page contains the end of a log record
// LOG_PAGE_PACKED - Page contains packed log records
// LOG_PAGE_TAIL_COPY - Page is a copy of the log file end
//
ULONG Flags;
//
// Lbcb flags. These are flags used to describe this Lbcb.
//
// LBCB_LOG_WRAPPED - Lbcb has wrapped the log file
// LBCB_ON_ACTIVE_QUEUE - Lbcb is on the active queue
// LBCB_NOT_EMPTY - Page has existing log record
// LBCB_FLUSH_COPY - Write copy of this page first
// LBCB_RESTART_LBCB - This Lbcb contains a restart page
//
ULONG LbcbFlags;
//
// This is the thread which has locked the log page.
//
ERESOURCE_THREAD ResourceThread;
} LBCB, *PLBCB;
#define LBCB_LOG_WRAPPED (0x00000001)
#define LBCB_ON_ACTIVE_QUEUE (0x00000002)
#define LBCB_NOT_EMPTY (0x00000004)
#define LBCB_FLUSH_COPY (0x00000008)
#define LBCB_RESTART_LBCB (0x00000020)
//
// Log file data. This data structure is used on a per-log file basis.
//
typedef enum _LFS_IO_STATE {
LfsNoIoInProgress = 0, LfsClientThreadIo
} LFS_IO_STATE;
typedef struct _LFCB {
//
// The type and size of this record (must be LFS_NTC_LFCB)
//
NODE_TYPE_CODE NodeTypeCode; NODE_BYTE_SIZE NodeByteSize;
//
// Lfcb Links. The following links the file control blocks to the
// global data structure.
//
LIST_ENTRY LfcbLinks;
//
// Lch Links. The following links all of the handles for the Lfcb.
//
LIST_ENTRY LchLinks;
//
//
// File Object. This is the file object for the log file.
//
PFILE_OBJECT FileObject;
//
// Log File Size. This is the size of the log file.
// The second value is the size proposed by this open.
//
LONGLONG FileSize;
//
// Log page size, masks and shift count to do multiplication and division
// of log pages.
//
LONGLONG LogPageSize; ULONG LogPageMask; LONG LogPageInverseMask; ULONG LogPageShift;
//
// First log page. This is the offset in the file of the first
// log page with log records.
//
LONGLONG FirstLogPage;
//
// Next log page offset. This is the offset of the next log page to use.
// If we are reusing this page we store the offset to begin with.
//
LONGLONG NextLogPage; ULONG ReusePageOffset;
//
// Data Offset. This is the offset within a log page of the data that
// appears on that page. This will be the actual restart data for
// an Lfs restart page, or the beginning of log record data for a log
// record page.
//
ULONG RestartDataOffset; LONGLONG LogPageDataOffset;
//
// Data Size. This is the amount of data that may be stored on a
// log page. It is included here because it is frequently used. It
// is simply the log page size minus the data offset.
//
ULONG RestartDataSize; LONGLONG LogPageDataSize;
//
// Record header size. This is the size to use for the record headers
// when reading the log file.
//
USHORT RecordHeaderLength;
//
// Sequence number. This is the number of times we have cycled through
// the log file. The wrap sequence number is used to confirm that we
// have gone through the entire file at least once. When we write a
// log record page for an Lsn with this sequence number, then we have
// cycled through the file.
//
LONGLONG SeqNumber; LONGLONG SeqNumberForWrap; ULONG SeqNumberBits; ULONG FileDataBits;
//
// Buffer Block Links. The following links the buffer blocks for this
// log file.
//
LIST_ENTRY LbcbWorkque; LIST_ENTRY LbcbActive;
PLBCB ActiveTail; PLBCB PrevTail;
//
// The enumerated type indicates if there is an active write for
// this log file and whether it is being done by an Lfs or
// client thread.
//
LFS_IO_STATE LfsIoState;
//
// Current Restart Area. The following is the in-memory image of the
// next restart area. We also store a pointer to the client data
// array in the restart area. The client array offset is from the start of
// the restart area.
//
PLFS_RESTART_AREA RestartArea; PLFS_CLIENT_RECORD ClientArray; USHORT ClientArrayOffset; USHORT ClientNameOffset;
//
// Restart Area size. This is the usable size of the restart area.
//
ULONG RestartAreaSize; USHORT LogClients;
//
// Initial Restart area. If true, then the in-memory restart area is to
// be written to the first position on the disk.
//
BOOLEAN InitialRestartArea;
//
// The following pseudo Lsn's are used to track when restart areas
// are flushed to the disk.
//
LSN NextRestartLsn; LSN LastFlushedRestartLsn;
//
// The following is the earliest Lsn we will guarantee is still in the
// log file.
//
LSN OldestLsn;
//
// The following is the file offset of the oldest Lsn in the system.
// We redundantly store it in this form since we will be constantly
// checking if a new log record will write over part of the file
// we are trying to maintain.
//
LONGLONG OldestLsnOffset;
//
// Last Flushed Lsn. The following is the last Lsn guaranteed to
// be flushed to the disk.
//
LSN LastFlushedLsn;
//
//
// The following fields are used to track current usage in the log file.
//
// TotalAvailable - is the total number of bytes available for
// log records. It is the number of log pages times the
// data size of each page.
//
// TotalAvailInPages - is the total number of bytes in the log
// pages for log records. This is TotalAvailable without
// subtracting the size of the page headers.
//
// TotalUndoCommitment - is the number of bytes reserved for
// possible abort operations. This includes space for
// log record headers as well.
//
// MaxCurrentAvail - is the maximum available in all pages
// subtracting the page header and any reserved tail.
//
// CurrentAvailable - is the total number of bytes available in
// unused pages in the log file.
//
// ReservedLogPageSize - is the number of bytes on a page available
// for reservation.
//
LONGLONG TotalAvailable; LONGLONG TotalAvailInPages; LONGLONG TotalUndoCommitment; LONGLONG MaxCurrentAvail; LONGLONG CurrentAvailable;
LONGLONG ReservedLogPageSize;
//
// The following fields are used to store information about the
// update sequence arrays.
//
USHORT RestartUsaOffset; USHORT UsaArraySize;
USHORT LogRecordUsaOffset;
//
// Major and minor version numbers.
//
SHORT MajorVersion; SHORT MinorVersion;
//
// Log File Flags.
//
// LFCB_LOG_WRAPPED - We found an Lbcb which wraps the log file
// LFCB_MULTIPLE_PAGE_IO - Write multiple pages if possible
// LFCB_NO_LAST_LSN - There are no log records to return
// LFCB_PACK_LOG - Pack the records into the pages
// LFCB_REUSE_TAIL - We will be reusing the tail of the log file after restart
// LFCB_NO_OLDEST_LSN - There is no oldest page being reserved
//
ULONG Flags;
//
// The following are the spare Lbcb's for the volume and a field with
// the count for these.
//
ULONG SpareLbcbCount; LIST_ENTRY SpareLbcbList;
//
// The following are sparse LEB's to be used rather than having to allocate
// then when reading log records
//
ULONG SpareLebCount; LIST_ENTRY SpareLebList;
//
// The following structure synchronizes access to this structure.
//
PLFCB_SYNC Sync;
//
// Count of waiters wanting access to flush the Lfcb.
//
ULONG Waiters;
//
// On-disk value for OpenLogCount. This is the value we will stuff into
// the client handles.
//
ULONG CurrentOpenLogCount;
//
// Maintain the flush range for this file.
//
PLFS_WRITE_DATA UserWriteData;
ERESOURCE_THREAD LfsIoThread;
//
// Buffer and mdls which hold down the first 4 pages at the head of the log
// this includes the lfs restart areas and the ping pong pages. The partial mdl
// is used to pin pieces of the total buffer
//
PMDL LogHeadMdl; PMDL LogHeadPartialMdl; PVOID LogHeadBuffer;
//
// preallocated error log packet for use logging errors to the eventlog
//
PIO_ERROR_LOG_PACKET ErrorLogPacket;
#ifdef LFS_CLUSTER_CHECK
LSN LsnAtMount; ULONG LsnRangeIndex;#endif
//
// Embedded array with enough space for SYSTEM PAGE / LOG PAGE SIZE
// used to facilitate flushing partial system pages
//
PLBCB DirtyLbcb[0];
} LFCB, *PLFCB;
#define LFCB_LOG_WRAPPED (0x00000001)
#define LFCB_MULTIPLE_PAGE_IO (0x00000002)
#define LFCB_NO_LAST_LSN (0x00000004)
#define LFCB_PACK_LOG (0x00000008)
#define LFCB_REUSE_TAIL (0x00000010)
#define LFCB_NO_OLDEST_LSN (0x00000020)
#define LFCB_LOG_FILE_CORRUPT (0x00000040)
#define LFCB_FINAL_SHUTDOWN (0x00000080)
#define LFCB_READ_FIRST_RESTART (0x00000100)
#define LFCB_READ_SECOND_RESTART (0x00000200)
#define LFCB_READ_ONLY (0x00000400)
#ifdef LFS_CLUSTER_CHECK
#define LFCB_DEVICE_OFFLINE_SEEN (0x80000000)
#define LFCB_FLUSH_FAILED (0x40000000)
#endif
#define LFCB_RESERVE_LBCB_COUNT (5)
#define LFCB_MAX_LBCB_COUNT (25)
#define LFCB_RESERVE_LEB_COUNT (5)
#define LFCB_MAX_LEB_COUNT (25)
//
// Global Log Data. The following structure has only one instance and
// maintains global information for the entire logging service.
//
typedef struct _LFS_DATA {
//
// The type and size of this record (must be LFS_NTC_DATA)
//
NODE_TYPE_CODE NodeTypeCode; NODE_BYTE_SIZE NodeByteSize;
//
// The following field links all of the Log File Control Blocks for
// the logging system.
//
LIST_ENTRY LfcbLinks;
//
// Flag field.
//
ULONG Flags;
//
// The following mutex controls access to this structure.
//
FAST_MUTEX LfsDataLock;
//
// Allocated buffers for reading spanning log records in low memory case.
// Flags indicate which buffers owned.
// LFS_BUFFER1_OWNED
// LFS_BUFFER2_OWNED
//
PVOID Buffer1; PVOID Buffer2; ERESOURCE_THREAD BufferOwner; ULONG BufferFlags;
FAST_MUTEX BufferLock; KEVENT BufferNotification;
} LFS_DATA, *PLFS_DATA;
#define LFS_DATA_INIT_FAILED (0x00000001)
#define LFS_DATA_INITIALIZED (0x00000002)
#define LFS_BUFFER1_OWNED (0x00000001)
#define LFS_BUFFER2_OWNED (0x00000002)
#define LFS_BUFFER_SIZE (0x10000)
#endif // _LFSSTRUC_
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