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;
}
VOID
LfsDeallocateLfcb (
IN PLFCB Lfcb,
IN BOOLEAN CompleteTeardown
)
/*++
Routine Description:
This routine releases the resources associated with a log file control
block.
Arguments:
Lfcb - Supplies a pointer to the log file control block.
CompleteTeardown - Indicates if we are to completely remove this Lfcb.
Return Value:
None
--*/
{
PLBCB NextLbcb;
PAGED_CODE();
DebugTrace( +1, Dbg, "LfsDeallocateLfcb: Entered\n", 0 );
DebugTrace( 0, Dbg, "Lfcb -> %08lx\n", Lfcb );
//
// Check that there are no buffer blocks.
//
ASSERT( IsListEmpty( &Lfcb->LbcbActive ));
ASSERT( IsListEmpty( &Lfcb->LbcbWorkque ));
//
// Check that we have no clients.
//
ASSERT( IsListEmpty( &Lfcb->LchLinks ));
//
// If there is a restart area we deallocate it.
//
if (Lfcb->RestartArea != NULL) {
LfsDeallocateRestartArea( Lfcb->RestartArea );
}
//
// If there are any of the tail Lbcb's, deallocate them now.
//
if (Lfcb->ActiveTail != NULL) {
LfsDeallocateLbcb( Lfcb, Lfcb->ActiveTail );
Lfcb->ActiveTail = NULL;
}
if (Lfcb->PrevTail != NULL) {
LfsDeallocateLbcb( Lfcb, Lfcb->PrevTail );
Lfcb->PrevTail = NULL;
}
//
// Only do the following if we are to remove the Lfcb completely.
//
if (CompleteTeardown) {
//
// If there is a resource structure we deallocate it.
//
if (Lfcb->Sync != NULL) {
ExDeleteResource( &Lfcb->Sync->Resource );
ExFreePool( Lfcb->Sync );
}
}
//
// Deallocate all of the spare Lbcb's.
//
while (!IsListEmpty( &Lfcb->SpareLbcbList )) {
NextLbcb = (PLBCB) Lfcb->SpareLbcbList.Flink;
RemoveHeadList( &Lfcb->SpareLbcbList );
ExFreePool( NextLbcb );
}
//
// Discard the Lfcb structure.
//
ExFreePool( Lfcb );
DebugTrace( -1, Dbg, "LfsDeallocateLfcb: Exit\n", 0 );
return;
}
