292 lines
6.9 KiB
C
292 lines
6.9 KiB
C
/*++ BUILD Version: 0000 // Increment this if a change has global effects
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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LfsDisk.h
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Abstract:
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This module defines the on-disk structures present in the log file.
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Author:
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Brian Andrew [BrianAn] 13-June-1991
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Revision History:
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IMPORTANT NOTE:
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The Log File Service will by used on systems that require that on-disk
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structures guarantee the natural alignment of all arithmetic quantities
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up to and including quad-word (64-bit) numbers. Therefore, all Lfs
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on-disk structures are quad-word aligned, etc.
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--*/
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#ifndef _LFSDISK_
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#define _LFSDISK_
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#define MINIMUM_LFS_PAGES 0x00000030
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#define MINIMUM_LFS_CLIENTS 1
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//
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// The following macros are used to set and query with respect to the
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// update sequence arrays.
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//
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#define UpdateSequenceStructureSize( MSH ) \
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((((PMULTI_SECTOR_HEADER) (MSH))->UpdateSequenceArraySize - 1) * SEQUENCE_NUMBER_STRIDE)
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#define UpdateSequenceArraySize( STRUCT_SIZE ) \
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((STRUCT_SIZE) / SEQUENCE_NUMBER_STRIDE + 1)
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#define FIRST_STRIDE \
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(SEQUENCE_NUMBER_STRIDE - sizeof( UPDATE_SEQUENCE_NUMBER ))
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//
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// Log client ID. This is used to uniquely identify a client for a
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// particular log file.
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//
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typedef struct _LFS_CLIENT_ID {
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USHORT SeqNumber;
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USHORT ClientIndex;
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} LFS_CLIENT_ID, *PLFS_CLIENT_ID;
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//
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// Log Record Header. This is the header that begins every Log Record in
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// the log file.
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//
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typedef struct _LFS_RECORD_HEADER {
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//
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// Log File Sequence Number of this log record.
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//
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LSN ThisLsn;
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//
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// The following fields are used to back link Lsn's. The ClientPrevious
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// and ClientUndoNextLsn fields are used by a client to link his log
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// records.
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//
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LSN ClientPreviousLsn;
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LSN ClientUndoNextLsn;
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//
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// The following field is the size of data area for this record. The
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// log record header will be padded if necessary to fill to a 64-bit
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// boundary, so the client data will begin on a 64-bit boundary to
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// insure that all of his data is 64-bit aligned. The below value
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// has not been padded to 64 bits however.
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//
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ULONG ClientDataLength;
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//
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// Client ID. This identifies the owner of this log record. The owner
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// is uniquely identified by his offset in the client array and the
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// sequence number associated with that client record.
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//
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LFS_CLIENT_ID ClientId;
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//
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// This the Log Record type. This could be a commit protocol record,
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// a client restart area or a client update record.
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//
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LFS_RECORD_TYPE RecordType;
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//
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// Transaction ID. This is used externally by a client (Transaction
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// Manager) to group log file entries.
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//
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TRANSACTION_ID TransactionId;
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//
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// Log record flags.
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//
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USHORT Flags;
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//
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// Alignment field.
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//
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USHORT AlignWord;
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} LFS_RECORD_HEADER, *PLFS_RECORD_HEADER;
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#define LOG_RECORD_MULTI_PAGE (0x0001)
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#define LFS_RECORD_HEADER_SIZE QuadAlign( sizeof( LFS_RECORD_HEADER ))
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//
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// Following are the version specific fields in the record page header.
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//
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typedef struct _LFS_UNPACKED_RECORD_PAGE {
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//
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// This gives us the offset of the free space in the page.
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//
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USHORT NextRecordOffset;
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USHORT WordAlign;
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//
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// Reserved. The following array is reserved for possible future use.
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//
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USHORT Reserved;
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//
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// Update Sequence Array. Used to protect the page block.
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//
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UPDATE_SEQUENCE_ARRAY UpdateSequenceArray;
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} LFS_UNPACKED_RECORD_PAGE, *PLFS_UNPACKED_RECORD_PAGE;
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typedef struct _LFS_PACKED_RECORD_PAGE {
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//
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// This gives us the offset of the free space in the page.
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//
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USHORT NextRecordOffset;
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USHORT WordAlign;
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ULONG DWordAlign;
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//
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// The following is the Lsn for the last log record which ends on the page.
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//
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LSN LastEndLsn;
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//
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// Update Sequence Array. Used to protect the page block.
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//
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UPDATE_SEQUENCE_ARRAY UpdateSequenceArray;
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} LFS_PACKED_RECORD_PAGE, *PLFS_PACKED_RECORD_PAGE;
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//
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// Log Record Page Header. This structure is present at the beginning of each
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// log file page in the client record section.
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//
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typedef struct _LFS_RECORD_PAGE_HEADER {
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//
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// Cache multisector protection header.
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//
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MULTI_SECTOR_HEADER MultiSectorHeader;
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union {
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//
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// Highest Lsn in this log file page. This field is only for
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// regular log pages.
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//
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LSN LastLsn;
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//
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// Log file offset. This is for the tail copies and indicates the
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// location in the file where the original lays. In this case the
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// LastLsn field above can be obtained from the last ending Lsn
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// field in the PACKED_RECORD_PAGE structure.
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//
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LONGLONG FileOffset;
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} Copy;
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//
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// Page Header Flags. These are the same flags that are stored in the
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// Lbcb->Flags field.
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//
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// LOG_PAGE_LOG_RECORD_END - Page contains the end of a log record
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//
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ULONG Flags;
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//
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// I/O Page Position. The following fields are used to determine
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// where this log page resides within a Lfs I/O transfer.
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//
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USHORT PageCount;
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USHORT PagePosition;
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//
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// The following is the difference between version 1.1 and earlier.
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//
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union {
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LFS_UNPACKED_RECORD_PAGE Unpacked;
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LFS_PACKED_RECORD_PAGE Packed;
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} Header;
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} LFS_RECORD_PAGE_HEADER, *PLFS_RECORD_PAGE_HEADER;
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#define LOG_PAGE_LOG_RECORD_END (0x00000001)
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#define LFS_UNPACKED_RECORD_PAGE_HEADER_SIZE ( \
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FIELD_OFFSET( LFS_RECORD_PAGE_HEADER, Header.Unpacked.UpdateSequenceArray ) \
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)
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#define LFS_PACKED_RECORD_PAGE_HEADER_SIZE ( \
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FIELD_OFFSET( LFS_RECORD_PAGE_HEADER, Header.Packed.UpdateSequenceArray ) \
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)
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//
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// Id strings for the page headers.
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//
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#define LFS_SIGNATURE_RESTART_PAGE "RSTR"
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#define LFS_SIGNATURE_RESTART_PAGE_ULONG 0x52545352
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#define LFS_SIGNATURE_RECORD_PAGE "RCRD"
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#define LFS_SIGNATURE_RECORD_PAGE_ULONG 0x44524352
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#define LFS_SIGNATURE_BAD_USA "BAAD"
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#define LFS_SIGNATURE_BAD_USA_ULONG 0x44414142
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#define LFS_SIGNATURE_MODIFIED "CHKD"
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#define LFS_SIGNATURE_MODIFIED_ULONG 0x444b4843
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#define LFS_SIGNATURE_UNINITIALIZED "\377\377\377\377"
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#define LFS_SIGNATURE_UNINITIALIZED_ULONG 0xffffffff
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//
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// Log Client Record. A log client record exists for each client user of
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// the log file. One of these is in each Lfs restart area.
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//
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#define LFS_NO_CLIENT 0xffff
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#define LFS_CLIENT_NAME_MAX 64
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#define RESTART_SINGLE_PAGE_IO (0x0001)
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#define LFS_RESTART_AREA_SIZE (FIELD_OFFSET( LFS_RESTART_AREA, LogClientArray ))
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#endif // _LFSDISK_
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