Example #1
0
VOID
LfsWriteLfsRestart (
    IN PLFCB Lfcb,
    IN ULONG ThisRestartSize,
    IN BOOLEAN WaitForIo
    )

/*++

Routine Description:

    This routine puts the Lfs restart area on the queue of operations to
    write to the file.  We do this by allocating a second restart area
    and attaching it to the Lfcb.  We also allocate a buffer control
    block to use for this write.  We look at the WaitForIo boolean to
    determine whether this thread can perform the I/O.  This also indicates
    whether this thread gives up the Lfcb.

Arguments:

    Lfcb - A pointer to the log file control block for this operation.

    ThisRestartSize - This is the size to use for the restart area.

    WaitForIo - Indicates if this thread is to perform the work.

Return Value:

    None.

--*/

{
    PLBCB NewLbcb = NULL;
    PLFS_RESTART_AREA NewRestart = NULL;

    PAGED_CODE();

    LfsDebugTrace( +1, Dbg, "LfsWriteLfsRestart:  Entered\n", 0 );
    LfsDebugTrace(  0, Dbg, "Lfcb          -> %08lx\n", Lfcb );
    LfsDebugTrace(  0, Dbg, "Write Chkdsk  -> %04x\n", WriteChkdsk );
    LfsDebugTrace(  0, Dbg, "Restart Size  -> %08lx\n", ThisRestartSize );
    LfsDebugTrace(  0, Dbg, "WaitForIo     -> %08lx\n", WaitForIo );

    //
    //  Use a try-finally to facilitate cleanup.
    //

    __try {

        PLBCB ActiveLbcb;

        //
        //  We allocate another restart area and
        //  copy the current area into it.  Attach the new area to the Lfcb.
        //

        LfsAllocateRestartArea( &NewRestart, ThisRestartSize );

        //
        //  We allocate a Lbcb structure and update the values to
        //  reflect this restart area.
        //

        LfsAllocateLbcb( Lfcb, &NewLbcb );
        SetFlag( NewLbcb->LbcbFlags, LBCB_RESTART_LBCB );

        //
        //  If this is the second page, then add a system page to the offset.
        //

        if (!Lfcb->InitialRestartArea) {

            NewLbcb->FileOffset = Lfcb->SystemPageSize + NewLbcb->FileOffset;
        }

        (ULONG)NewLbcb->Length = ThisRestartSize;

        NewLbcb->PageHeader = (PVOID) Lfcb->RestartArea;

        //
        //  Lets put the current lsn in the Lbcb.
        //

        NewLbcb->LastEndLsn = NewLbcb->LastLsn = Lfcb->NextRestartLsn;
        Lfcb->NextRestartLsn.QuadPart = 1 + Lfcb->NextRestartLsn.QuadPart;

        //
        //  Copy the existing restart area into the new area.
        //

        RtlCopyMemory( NewRestart, Lfcb->RestartArea, ThisRestartSize );
        Lfcb->RestartArea = NewRestart;

        Lfcb->ClientArray = LfsAdd2Ptr( NewRestart, Lfcb->ClientArrayOffset, PLFS_CLIENT_RECORD );

        NewRestart = NULL;

        //
        //  Update the Lfcb to indicate that the other restart area
        //  on the disk is to be used.
        //

        Lfcb->InitialRestartArea = !Lfcb->InitialRestartArea;

        //
        //  Add this Lbcb to the end of the workque and flush to that point.
        //

        InsertTailList( &Lfcb->LbcbWorkque, &NewLbcb->WorkqueLinks );

        //
        //  If we don't support a packed log file then we need to make
        //  sure that all file records written out ahead of this
        //  restart area make it out to disk and we don't add anything
        //  to this page.
        //

        if (!FlagOn( Lfcb->Flags, LFCB_PACK_LOG )
            && !IsListEmpty( &Lfcb->LbcbActive )) {

            ActiveLbcb = CONTAINING_RECORD( Lfcb->LbcbActive.Flink,
                                            LBCB,
                                            ActiveLinks );

            if (FlagOn( ActiveLbcb->LbcbFlags, LBCB_NOT_EMPTY )) {

                RemoveEntryList( &ActiveLbcb->ActiveLinks );
                ClearFlag( ActiveLbcb->LbcbFlags, LBCB_ON_ACTIVE_QUEUE );
            }
        }

        if (WaitForIo) {

            LfsFlushLbcb( Lfcb, NewLbcb );
        }

    } __finally {

        DebugUnwind( LfsWriteLfsRestart );

        if (NewRestart != NULL) {

            ExFreePool( NewRestart );
        }

        LfsDebugTrace( -1, Dbg, "LfsWriteLfsRestart:  Exit\n", 0 );
    }

    return;
}
Example #2
0
PLBCB
LfsGetLbcb (
    IN PLFCB Lfcb
    )

/*++

Routine Description:

    This routine is called to add a Lbcb to the active queue.

Arguments:

    Lfcb - This is the file control block for the log file.

Return Value:

    PLBCB - Pointer to the Lbcb allocated.

--*/

{
    PLBCB Lbcb = NULL;
    PVOID PageHeader;
    PBCB PageHeaderBcb = NULL;

    BOOLEAN WrappedOrUsaError;

    PAGED_CODE();

    LfsDebugTrace( +1, Dbg, "LfsGetLbcb:  Entered\n", 0 );
    LfsDebugTrace(  0, Dbg, "Lfcb      -> %08lx\n", Lfcb );

    //
    //  Use a try-finally to facilitate cleanup.
    //

    try {

        //
        //  Pin the desired record page.
        //

        LfsPreparePinWriteData( Lfcb,
                                Lfcb->NextLogPage,
                                (ULONG)Lfcb->LogPageSize,
                                &PageHeader,
                                &PageHeaderBcb );

        //
        //  Put our signature into the page so we won't fail if we
        //  see a previous 'BAAD' signature.
        //

        *((PULONG) PageHeader) = LFS_SIGNATURE_RECORD_PAGE_ULONG;

        //
        //  Now allocate an Lbcb.
        //

        LfsAllocateLbcb( Lfcb, &Lbcb );

        //
        //  If we are at the beginning of the file we test that the
        //  sequence number won't wrap to 0.
        //

        if (!FlagOn( Lfcb->Flags, LFCB_NO_LAST_LSN | LFCB_REUSE_TAIL )
            && ( Lfcb->NextLogPage == Lfcb->FirstLogPage )) {

            Lfcb->SeqNumber = Lfcb->SeqNumber + 1;

            //
            //  If the sequence number is going from 0 to 1, then
            //  this is the first time the log file has wrapped.  We want
            //  to remember this because it means that we can now do
            //  large spiral writes.
            //

            if (Int64ShllMod32( Lfcb->SeqNumber, Lfcb->FileDataBits ) == 0) {

                LfsDebugTrace( 0, Dbg, "Log sequence number about to wrap:  Lfcb -> %08lx\n", Lfcb );
                KeBugCheck( FILE_SYSTEM );
            }

            //
            //  If this number is greater or equal to  the wrap sequence number in
            //  the Lfcb, set the wrap flag in the Lbcb.
            //

            if (!FlagOn( Lfcb->Flags, LFCB_LOG_WRAPPED )
                && ( Lfcb->SeqNumber >= Lfcb->SeqNumberForWrap )) {

                SetFlag( Lbcb->LbcbFlags, LBCB_LOG_WRAPPED );
                SetFlag( Lfcb->Flags, LFCB_LOG_WRAPPED );
            }
        }

        //
        //  Now initialize the rest of the Lbcb fields.
        //

        Lbcb->FileOffset = Lfcb->NextLogPage;
        Lbcb->SeqNumber = Lfcb->SeqNumber;
        Lbcb->BufferOffset = Lfcb->LogPageDataOffset;

        //
        //  Store the next page in the Lfcb.
        //

        LfsNextLogPageOffset( Lfcb,
                              Lfcb->NextLogPage,
                              &Lfcb->NextLogPage,
                              &WrappedOrUsaError );

        Lbcb->Length = Lfcb->LogPageSize;
        Lbcb->PageHeader = PageHeader;
        Lbcb->LogPageBcb = PageHeaderBcb;

        Lbcb->ResourceThread = ExGetCurrentResourceThread();

        //
        //  If we are reusing a previous page then set a flag in
        //  the Lbcb to indicate that we should flush a copy
        //  first.
        //

        if (FlagOn( Lfcb->Flags, LFCB_REUSE_TAIL )) {

            SetFlag( Lbcb->LbcbFlags, LBCB_FLUSH_COPY );
            ClearFlag( Lfcb->Flags, LFCB_REUSE_TAIL );

            (ULONG)Lbcb->BufferOffset = Lfcb->ReusePageOffset;

            Lbcb->Flags = ((PLFS_RECORD_PAGE_HEADER) PageHeader)->Flags;
            Lbcb->LastLsn = ((PLFS_RECORD_PAGE_HEADER) PageHeader)->Copy.LastLsn;
            Lbcb->LastEndLsn = ((PLFS_RECORD_PAGE_HEADER) PageHeader)->Header.Packed.LastEndLsn;
        }

        //
        //  Put the Lbcb on the active queue
        //

        InsertTailList( &Lfcb->LbcbActive, &Lbcb->ActiveLinks );

        SetFlag( Lbcb->LbcbFlags, LBCB_ON_ACTIVE_QUEUE );

    } finally {

        DebugUnwind( LfsGetLbcb );

        //
        //  If an error occurred, we need to clean up any blocks which
        //  have not been added to the active queue.
        //

        if (AbnormalTermination()) {

            if (Lbcb != NULL) {

                LfsDeallocateLbcb( Lfcb, Lbcb );
                Lbcb = NULL;
            }

            //
            //  Unpin the system page if pinned.
            //

            if (PageHeaderBcb != NULL) {

                CcUnpinData( PageHeaderBcb );
            }
        }

        LfsDebugTrace( -1, Dbg, "LfsGetLbcb:  Exit\n", 0 );
    }

    return Lbcb;
}