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701 lines
19 KiB
701 lines
19 KiB
/*++
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Copyright (c) 1990 Microsoft Corporation
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Module Name:
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LogRcSup.c
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Abstract:
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This module implements support for dealing with log records, both
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writing and recovering them.
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Author:
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Brian Andrew [BrianAn] 20-June-1991
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Revision History:
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--*/
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#include "lfsprocs.h"
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//
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// The debug trace level
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//
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#define Dbg (DEBUG_TRACE_LOG_RECORD_SUP)
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VOID
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LfsPrepareLfcbForLogRecord (
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IN OUT PLFCB Lfcb,
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IN ULONG RemainingLogBytes
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);
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VOID
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LfsTransferLogBytes (
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IN PLBCB Lbcb,
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IN OUT PLFS_WRITE_ENTRY *ThisWriteEntry,
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IN OUT PCHAR *CurrentBuffer,
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IN OUT PULONG CurrentByteCount,
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IN OUT PULONG PadBytes,
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IN OUT PULONG RemainingPageBytes,
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IN OUT PULONG RemainingLogBytes
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);
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, LfsPrepareLfcbForLogRecord)
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#pragma alloc_text(PAGE, LfsTransferLogBytes)
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#pragma alloc_text(PAGE, LfsWriteLogRecordIntoLogPage)
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#endif
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BOOLEAN
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LfsWriteLogRecordIntoLogPage (
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IN PLFCB Lfcb,
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IN PLCH Lch,
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IN ULONG NumberOfWriteEntries,
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IN PLFS_WRITE_ENTRY WriteEntries,
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IN LFS_RECORD_TYPE RecordType,
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IN TRANSACTION_ID *TransactionId OPTIONAL,
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IN LSN ClientUndoNextLsn OPTIONAL,
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IN LSN ClientPreviousLsn OPTIONAL,
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IN LONG UndoRequirement,
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IN BOOLEAN ForceToDisk,
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OUT PLSN Lsn
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)
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/*++
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Routine Description:
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This routine is called to write a log record into the log file
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using the cache manager. If there is room in the current log
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page it is added to that. Otherwise we allocate a new log page
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and write the log record header for this log page. We then
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write the log record into the remaining bytes of this page and
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into any subsequent pages if needed.
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Arguments:
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Lfcb - File control block for this log file.
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Lch - This is the client handle, we may update the undo space for this
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client.
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NumberOfWriteEntries - Number of components of the log record.
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WriteEntries - Pointer to an array of write entries.
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UndoRequirement - Signed value indicating the requirement to write
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an abort log record for this log record. A negative
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value indicates that this is the abort record.
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RecordType - The Lfs-defined type of this log record.
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TransactionId - Pointer to the transaction structure containing the
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Id for transaction containing this operation.
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ClientUndoNextLsn - This is the Lsn provided by the client for use
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in his restart. Will be the zero Lsn for
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a restart log record.
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ClientPreviousLsn - This is the Lsn provided by the client for use
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in his restart. Will the the zero Lsn for a
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restart log record.
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UndoRequirement - This is the data size for the undo record for
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this log record.
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ForceToDisk - Indicates if this log record will be flushed immediately
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to disk.
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Lsn - A pointer to store the Lsn for this log record.
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Return Value:
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BOOLEAN - Advisory, TRUE indicates that less than 1/4 of the log file is
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available.
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--*/
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{
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PLFS_WRITE_ENTRY ThisWriteEntry;
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ULONG RemainingLogBytes;
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ULONG OriginalLogBytes;
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ULONG RemainingPageBytes;
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ULONG HeaderAdjust;
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PLBCB ThisLbcb;
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LSN NextLsn;
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PLFS_RECORD_HEADER RecordHeader;
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PCHAR CurrentBuffer;
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ULONG CurrentByteCount;
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ULONG PadBytes;
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BOOLEAN LogFileFull = FALSE;
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PAGED_CODE();
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DebugTrace( +1, Dbg, "LfsWriteLogRecordIntoLogPage: Entered\n", 0 );
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DebugTrace( 0, Dbg, "Lfcb -> %08lx\n", Lfcb );
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DebugTrace( 0, Dbg, "Lch -> %08lx\n", Lch );
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DebugTrace( 0, Dbg, "Number of Write Entries -> %08lx\n", NumberOfWriteEntries );
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DebugTrace( 0, Dbg, "Write Entries -> %08lx\n", WriteEntries );
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DebugTrace( 0, Dbg, "Record Type -> %08lx\n", RecordType );
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DebugTrace( 0, Dbg, "Transaction Id -> %08lx\n", TransactionId );
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DebugTrace( 0, Dbg, "ClientUndoNextLsn (Low) -> %08lx\n", ClientUndoNextLsn.LowPart );
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DebugTrace( 0, Dbg, "ClientUndoNextLsn (High) -> %08lx\n", ClientUndoNextLsn.HighPart );
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DebugTrace( 0, Dbg, "ClientPreviousLsn (Low) -> %08lx\n", ClientPreviousLsn.LowPart );
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DebugTrace( 0, Dbg, "ClientPreviousLsn (High) -> %08lx\n", ClientPreviousLsn.HighPart );
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DebugTrace( 0, Dbg, "UndoRequirement -> %08lx\n", UndoRequirement );
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DebugTrace( 0, Dbg, "ForceToDisk -> %04x\n", ForceToDisk );
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//
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// We'd absolutely hate for this to happen on a read only volume.
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//
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ASSERT(!(FlagOn( Lfcb->Flags, LFCB_READ_ONLY )));
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//
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// We compute the size of this log record.
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//
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ThisWriteEntry = WriteEntries;
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RemainingLogBytes = 0;
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while (NumberOfWriteEntries--) {
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RemainingLogBytes += QuadAlign( ThisWriteEntry->ByteLength );
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ThisWriteEntry++;
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}
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OriginalLogBytes = RemainingLogBytes;
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ThisWriteEntry = WriteEntries;
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//
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// Loop until we have the Lbcb and we know it is not part of
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// a partial page transfer. We need to make sure we have
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// a Bcb for this page.
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//
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while (TRUE) {
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LogFileFull = LfsVerifyLogSpaceAvail( Lfcb,
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Lch,
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RemainingLogBytes,
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UndoRequirement,
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ForceToDisk );
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//
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// We update the Lfcb so that we can start putting the log record into
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// the top of the Lbcb active list.
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//
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LfsPrepareLfcbForLogRecord( Lfcb,
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RemainingLogBytes + Lfcb->RecordHeaderLength );
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ThisLbcb = CONTAINING_RECORD( Lfcb->LbcbActive.Flink,
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LBCB,
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ActiveLinks );
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#ifdef BENL_DBG
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ASSERT( ThisLbcb->BufferOffset < 0x1000 );
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#endif
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//
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// If there is a Bcb then we are golden.
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//
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if (ThisLbcb->LogPageBcb != NULL) { break; }
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//
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// Otherwise we want to drop the Lfcb and wait for the IO to complete.
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//
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Lfcb->Waiters += 1;
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LfsReleaseLfcb( Lfcb );
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KeWaitForSingleObject( &Lfcb->Sync->Event,
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Executive,
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KernelMode,
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FALSE,
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NULL );
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LfsAcquireLfcb( Lfcb );
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Lfcb->Waiters -= 1;
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}
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RemainingPageBytes = (ULONG)Lfcb->LogPageSize - (ULONG)ThisLbcb->BufferOffset;
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//
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// Compute the Lsn starting in the next log buffer.
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//
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NextLsn.QuadPart = LfsComputeLsnFromLbcb( Lfcb, ThisLbcb );
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//
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// We get a pointer to the log record header and the start of the
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// log record in the pinned buffer.
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//
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RecordHeader = Add2Ptr( ThisLbcb->PageHeader,
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(ULONG)ThisLbcb->BufferOffset,
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PLFS_RECORD_HEADER );
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//
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// We update the record header.
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//
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//
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// Zero out the structure initially.
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//
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RtlZeroMemory( RecordHeader, Lfcb->RecordHeaderLength );
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//
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// Update all the fields.
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//
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RecordHeader->ThisLsn = NextLsn;
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RecordHeader->ClientPreviousLsn = ClientPreviousLsn;
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RecordHeader->ClientUndoNextLsn = ClientUndoNextLsn;
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if (TransactionId != NULL) {
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RecordHeader->TransactionId = *TransactionId;
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}
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RecordHeader->ClientDataLength = RemainingLogBytes;
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RecordHeader->ClientId = Lch->ClientId;
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RecordHeader->RecordType = RecordType;
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//
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// Check if this is a multi-page record.
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//
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if (RemainingLogBytes + Lfcb->RecordHeaderLength > RemainingPageBytes) {
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SetFlag( RecordHeader->Flags, LOG_RECORD_MULTI_PAGE );
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}
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RemainingPageBytes -= Lfcb->RecordHeaderLength;
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//
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// Update the buffer position in the Lbcb
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//
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(ULONG)ThisLbcb->BufferOffset += Lfcb->RecordHeaderLength;
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HeaderAdjust = Lfcb->RecordHeaderLength;
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//
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// Remember the values in the current write entry.
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//
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CurrentBuffer = ThisWriteEntry->Buffer;
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CurrentByteCount = ThisWriteEntry->ByteLength;
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PadBytes = (8 - (CurrentByteCount & ~(0xfffffff8))) & ~(0xfffffff8);
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//
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// Continue to transfer bytes until all the client's data has
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// been transferred.
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//
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while (RemainingLogBytes != 0) {
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PLFS_RECORD_PAGE_HEADER PageHeader;
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PageHeader = (PLFS_RECORD_PAGE_HEADER) ThisLbcb->PageHeader;
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//
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// If the Lbcb is empty and we are about to store data into it we
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// subtract the data size of the page from the available space.
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// Update all the information we want to put in the header.
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//
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if (!FlagOn( ThisLbcb->LbcbFlags, LBCB_NOT_EMPTY )) {
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//
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// We subtract this page from the available pages only if
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// we are at the beginning of the page. Otherwise this
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// could be a reuse page. In that case it has already
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// been subtracted.
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//
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if ((ULONG)ThisLbcb->BufferOffset - HeaderAdjust == (ULONG)Lfcb->LogPageDataOffset) {
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Lfcb->CurrentAvailable = Lfcb->CurrentAvailable - Lfcb->ReservedLogPageSize; //**** xxSub( Lfcb->CurrentAvailable, Lfcb->ReservedLogPageSize );
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}
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InsertTailList( &Lfcb->LbcbWorkque, &ThisLbcb->WorkqueLinks );
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SetFlag( ThisLbcb->LbcbFlags, LBCB_NOT_EMPTY );
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}
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HeaderAdjust = 0;
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//
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// Compute the number of transfer bytes. Update the remaining
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// page bytes, remaining log bytes and position in the write
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// buffer array. This routine also copies the bytes into the buffer.
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//
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LfsTransferLogBytes( ThisLbcb,
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&ThisWriteEntry,
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&CurrentBuffer,
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&CurrentByteCount,
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&PadBytes,
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&RemainingPageBytes,
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&RemainingLogBytes );
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//
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// This log record ends on this page. Update the fields for the
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// ending Lsn.
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//
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if (RemainingLogBytes == 0) {
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SetFlag( ThisLbcb->Flags, LOG_PAGE_LOG_RECORD_END );
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ThisLbcb->LastEndLsn = NextLsn;
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if (FlagOn( Lfcb->Flags, LFCB_PACK_LOG )) {
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PageHeader->Header.Packed.LastEndLsn = NextLsn;
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PageHeader->Header.Packed.NextRecordOffset = (USHORT)ThisLbcb->BufferOffset;
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}
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}
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//
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// We are done with this page, update the fields in the page header.
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//
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if (RemainingPageBytes == 0
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|| RemainingLogBytes == 0) {
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//
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// We are done with this page. Update the Lbcb and page header.
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//
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ThisLbcb->LastLsn = NextLsn;
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PageHeader->Copy.LastLsn = NextLsn;
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PageHeader->Flags = ThisLbcb->Flags;
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//
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// We can't put any more log records on this page. Remove
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// it from the active queue.
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//
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if (RemainingPageBytes < Lfcb->RecordHeaderLength) {
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RemoveHeadList( &Lfcb->LbcbActive );
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ClearFlag( ThisLbcb->LbcbFlags, LBCB_ON_ACTIVE_QUEUE );
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//
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// If there are more log bytes then get the next Lbcb.
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//
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if (RemainingLogBytes != 0) {
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ThisLbcb = CONTAINING_RECORD( Lfcb->LbcbActive.Flink,
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LBCB,
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ActiveLinks );
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RemainingPageBytes = (ULONG)Lfcb->LogPageSize
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- (ULONG)ThisLbcb->BufferOffset;
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}
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}
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}
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}
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*Lsn = NextLsn;
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Lfcb->RestartArea->CurrentLsn = NextLsn;
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Lfcb->RestartArea->LastLsnDataLength = OriginalLogBytes;
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ClearFlag( Lfcb->Flags, LFCB_NO_LAST_LSN );
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DebugTrace( 0, Dbg, "Lsn (Low) -> %08lx\n", Lsn->LowPart );
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DebugTrace( 0, Dbg, "Lsn (High) -> %08lx\n", Lsn->HighPart );
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DebugTrace( -1, Dbg, "LfsWriteLogRecordIntoLogPage: Exit\n", 0 );
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return LogFileFull;
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}
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//
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// Local support routine.
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//
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VOID
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LfsPrepareLfcbForLogRecord (
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IN OUT PLFCB Lfcb,
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IN ULONG RemainingLogBytes
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)
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/*++
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Routine Description:
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This routine is called to insure that the Lfcb has a Lbcb in the
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active queue to perform the next log record transfer.
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This condition is met when there is a least one buffer block and
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the log record data will fit entirely on this page or this buffer
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block contains no other data in the unpacked case. For the packed
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case we just need to make sure that there are sufficient Lbcb's.
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Arguments:
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Lfcb - File control block for this log file.
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RemainingLogBytes - The number of bytes remaining for this log record.
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Return Value:
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None
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--*/
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{
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PLBCB ThisLbcb;
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ULONG RemainingPageBytes;
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PLIST_ENTRY LbcbLinks;
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PAGED_CODE();
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DebugTrace( +1, Dbg, "LfsPrepareLfcbForLogRecord: Entered\n", 0 );
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DebugTrace( 0, Dbg, "Lfcb -> %08lx\n", Lfcb );
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DebugTrace( 0, Dbg, "RemainingLogBytes -> %08lx\n", RemainingLogBytes );
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//
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// If there is no Lbcb in the active queue, we don't check it for size.
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//
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if (!IsListEmpty( &Lfcb->LbcbActive )) {
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//
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// If the log record won't fit in the remaining bytes of this page,
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// we queue this log buffer.
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//
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ThisLbcb = CONTAINING_RECORD( Lfcb->LbcbActive.Flink,
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LBCB,
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ActiveLinks );
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RemainingPageBytes = (ULONG)Lfcb->LogPageSize
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- (ULONG)ThisLbcb->BufferOffset;
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//
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// This log page won't do if the remaining bytes won't hold the data
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// unless this is the first log record in the page or we are packing
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// the log file.
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//
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if (RemainingLogBytes > RemainingPageBytes
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&& !FlagOn( Lfcb->Flags, LFCB_PACK_LOG )
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&& (ULONG)ThisLbcb->BufferOffset != (ULONG)Lfcb->LogPageDataOffset) {
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RemoveHeadList( &Lfcb->LbcbActive );
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ClearFlag( ThisLbcb->LbcbFlags, LBCB_ON_ACTIVE_QUEUE );
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}
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}
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//
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// We now make sure we can allocate enough Lbcb's for all of the log pages
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// we will need. We now include the bytes for the log record reader.
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//
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LbcbLinks = Lfcb->LbcbActive.Flink;
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while (TRUE) {
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//
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// If the Lbcb link we have is the head of the list, we will need another
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// Lbcb.
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//
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if (LbcbLinks == &Lfcb->LbcbActive) {
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ThisLbcb = LfsGetLbcb( Lfcb );
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} else {
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ThisLbcb = CONTAINING_RECORD( LbcbLinks,
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LBCB,
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ActiveLinks );
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}
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//
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// Remember the bytes remaining on this page. This will always be quad
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// aligned.
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//
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RemainingPageBytes = (ULONG)Lfcb->LogPageSize - (ULONG)ThisLbcb->BufferOffset;
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if (RemainingPageBytes >= RemainingLogBytes) {
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break;
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}
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//
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// Move to the next log record.
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//
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RemainingLogBytes -= RemainingPageBytes;
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LbcbLinks = ThisLbcb->ActiveLinks.Flink;
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}
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DebugTrace( -1, Dbg, "LfsPrepareLfcbForLogRecord: Exit\n", 0 );
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return;
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}
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VOID
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LfsTransferLogBytes (
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IN PLBCB Lbcb,
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IN OUT PLFS_WRITE_ENTRY *ThisWriteEntry,
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IN OUT PCHAR *CurrentBuffer,
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IN OUT PULONG CurrentByteCount,
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IN OUT PULONG PadBytes,
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IN OUT PULONG RemainingPageBytes,
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IN OUT PULONG RemainingLogBytes
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)
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/*++
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Routine Description:
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This routine is called to transfer the next block of bytes into
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a log page. It is given a pointer to the current position in the
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current Lfs write entry and the number of bytes remaining on that
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log page. It will transfer as many of the client's bytes from the
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current buffer that will fit and update various pointers.
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Arguments:
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Lbcb - This is the buffer block for this log page.
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ThisWriteEntry - This is a pointer to a pointer to the current Lfs
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write entry.
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CurrentBuffer - This is a pointer to a pointer to the current position
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in the current write entry buffer. If this points to a NULL
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value it means to put zero bytes into the log.
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CurrentByteCount - This is a pointer to the number of bytes remaining
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in the current buffer.
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PadBytes - This is a pointer to the number of padding byes for
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this write entry.
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RemainingPageBytes - This is pointer to the number of bytes remaining
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in this page.
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RemainingLogBytes - This is the number of bytes remaining to transfer
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for this log record.
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Return Value:
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None
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--*/
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{
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PCHAR CurrentLogPagePosition;
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PCHAR CurrentClientPosition;
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ULONG TransferBytes;
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ULONG ThisPadBytes;
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PAGED_CODE();
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DebugTrace( +1, Dbg, "LfsTransferLogBytes: Entered\n", 0 );
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DebugTrace( 0, Dbg, "Lbcb -> %08lx\n", Lbcb );
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DebugTrace( 0, Dbg, "ThisWriteEntry -> %08lx\n", *ThisWriteEntry );
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DebugTrace( 0, Dbg, "CurrentBuffer -> %08lx\n", *CurrentBuffer );
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DebugTrace( 0, Dbg, "CurrentByteCount -> %08lx\n", *CurrentByteCount );
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DebugTrace( 0, Dbg, "RemainingPageBytes -> %08lx\n", *RemainingPageBytes );
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DebugTrace( 0, Dbg, "RemainingLogBytes -> %08lx\n", *RemainingLogBytes );
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//
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// Remember the current client buffer position and current position
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// in log page.
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//
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CurrentLogPagePosition = Add2Ptr( Lbcb->PageHeader, (ULONG)Lbcb->BufferOffset, PCHAR );
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CurrentClientPosition = *CurrentBuffer;
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//
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// The limiting factor is either the number of bytes remaining in a
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// write entry or the number remaining in the log page.
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//
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if (*CurrentByteCount <= *RemainingPageBytes) {
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TransferBytes = *CurrentByteCount;
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ThisPadBytes = *PadBytes;
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if (*RemainingLogBytes != (*CurrentByteCount + *PadBytes) ) {
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(*ThisWriteEntry)++;
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*CurrentBuffer = (*ThisWriteEntry)->Buffer;
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*CurrentByteCount = (*ThisWriteEntry)->ByteLength;
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*PadBytes = (8 - (*CurrentByteCount & ~(0xfffffff8))) & ~(0xfffffff8);
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}
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} else {
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TransferBytes = *RemainingPageBytes;
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ThisPadBytes = 0;
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*CurrentByteCount -= TransferBytes;
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if (*CurrentBuffer != NULL) {
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*CurrentBuffer += TransferBytes;
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}
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}
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//
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// Transfer the requested bytes.
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//
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if (CurrentClientPosition != NULL) {
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RtlCopyMemory( CurrentLogPagePosition, CurrentClientPosition, TransferBytes );
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} else {
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RtlZeroMemory( CurrentLogPagePosition, TransferBytes );
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}
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//
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// Reduce the remaining page and log bytes by the transfer amount and
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// move forward in the log page.
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//
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*RemainingLogBytes -= (TransferBytes + ThisPadBytes);
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*RemainingPageBytes -= (TransferBytes + ThisPadBytes);
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(ULONG)Lbcb->BufferOffset += (TransferBytes + ThisPadBytes);
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DebugTrace( -1, Dbg, "LfsTransferLogBytes: Exit\n", 0 );
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return;
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}
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