Leaked source code of windows server 2003
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// Copyright (c) 1996-1999 Microsoft Corporation
//+============================================================================
//
// oidindex.cxx
//
// Implementation of CObjIdIndexChangeNotifier, which moniters the
// object ID index for changes. When a change is received, the
// CVolume is notified.
//
//+============================================================================
#include <pch.cxx>
#pragma hdrstop
#include "trkwks.hxx"
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::DoWork
//
// Called by the work manager - on the primary thread - when we've received
// a notification from the object ID index.
//
//+----------------------------------------------------------------------------
void
CObjIdIndexChangeNotifier::DoWork()
{
LPBYTE pbScan = _Buffer;
FILE_NOTIFY_INFORMATION * pNotifyInfo;
// Get the size and ntstatus of the notification.
DWORD dwNumberOfBytesTransfered = static_cast<DWORD>(_Overlapped.InternalHigh);
NTSTATUS status = static_cast<NTSTATUS>(_Overlapped.Internal);
_cs.Enter();
__try // __except
{
// Is this a good notification?
if( NT_SUCCESS(status) )
{
// Did we get data in this notification?
if( dwNumberOfBytesTransfered >= sizeof(FILE_NOTIFY_INFORMATION) )
{
// Yes. Loop through the entries, calling to special handlers
// for delete notifications and tunnelling-failure notifications.
do
{
pNotifyInfo = (FILE_NOTIFY_INFORMATION*)pbScan;
FILE_OBJECTID_INFORMATION *poi = (FILE_OBJECTID_INFORMATION*) pNotifyInfo->FileName;
TrkLog((TRKDBG_OBJID_DELETIONS,
TEXT("NTFS ObjId Index: %s"),
(const TCHAR*)CDebugString( _pVolume->GetVolIndex(),
pNotifyInfo) ));
// Check for adds/deletes
if (pNotifyInfo->Action == FILE_ACTION_REMOVED_BY_DELETE
||
pNotifyInfo->Action == FILE_ACTION_ADDED)
{
// Notify the general add/deletions handler
CDomainRelativeObjId droidBirth( *poi );
_pObjIdIndexChangedCallback->NotifyAddOrDelete( pNotifyInfo->Action, droidBirth );
}
// Check for tunnelling notifications
else
if (pNotifyInfo->Action == FILE_ACTION_ID_NOT_TUNNELLED)
{
// An attempt to tunnel an object ID failed because another file on the
// same volume was already using it.
_pVolume->FileActionIdNotTunnelled( (FILE_OBJECTID_INFORMATION*) pNotifyInfo->FileName );
}
} while ( pNotifyInfo->NextEntryOffset != 0 &&
( pbScan += pNotifyInfo->NextEntryOffset) );
} // if( dwNumberOfBytesTransfered >= sizeof(FILE_NOTIFY_INFORMATION) )
// We didn't get any data. Is this notification telling us that the IRP was
// cancelled?
else if( STATUS_NOTIFY_CLEANUP == status )
{
TrkLog(( TRKDBG_OBJID_DELETIONS, TEXT("OverlappedCompletionRoutine on %c: cleaning up"),
VolChar( _pVolume->GetIndex() ) ));
}
} // if( NT_SUCCESS(status) )
else if( STATUS_CANCELLED == status )
{
// The thread on which we made the ReadDirectoryChanges call terminated,
// thus terminating our IRP. We should now be running on an IO thread, since
// we register with WT_EXECUTEINIOTHREAD, so we just fall through and
// re-issue the IRP.
TrkLog(( TRKDBG_OBJID_DELETIONS,
TEXT("OverlappedCompletionRoutine on %c: ignoring status_cancelled"),
VolChar( _pVolume->GetIndex() ) ));
}
else
{
// If we failed for any other reason, there's something wrong. We don't
// want to call ReadDirectoryChanges again, because it might give us the
// same failure right away, and we'd thus be in an infinite loop.
TrkLog(( TRKDBG_ERROR, TEXT("OverlappedCompletionRoutine on %c: aborting due to %08x"),
status ));
CloseHandle( _hDir );
_hDir = INVALID_HANDLE_VALUE;
}
// When StopListeningAndClose is called, CancelIo is called, which triggers
// this DoWork routine. But we don't run until we get the critical section,
// after which time _hDir will be invalid.
if( INVALID_HANDLE_VALUE != _hDir )
{
StartListening();
}
}
__except( EXCEPTION_EXECUTE_HANDLER )
{
// We should never get any kind of an error here. If we do, the simplest
// recourse is just to reinit the volume.
_pVolume->OnHandlesMustClose();
}
_cs.Leave();
return;
}
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::Initialize
//
// Initialize the critical section and register with the work manager.
//
//+----------------------------------------------------------------------------
void
CObjIdIndexChangeNotifier::Initialize(
TCHAR *ptszVolumeDeviceName,
PObjIdIndexChangedCallback * pObjIdIndexChangedCallback,
CVolume * pVolumeForTunnelNotification
)
{
TrkAssert( !_fInitialized );
_cs.Initialize();
_fInitialized = TRUE;
_ptszVolumeDeviceName = ptszVolumeDeviceName;
_pObjIdIndexChangedCallback = pObjIdIndexChangedCallback;
_hDir = INVALID_HANDLE_VALUE;
_pVolume = pVolumeForTunnelNotification;
TrkAssert( NULL == _hCompletionEvent );
_hCompletionEvent = CreateEvent( NULL, FALSE, FALSE, NULL ); // Auto-reset, not signaled
if( NULL == _hCompletionEvent )
{
TrkLog(( TRKDBG_ERROR, TEXT("Couldn't create completion event for objid index change notify (%lu)"),
GetLastError() ));
TrkRaiseLastError();
}
// Register the completion event with the thread pool.
_hRegisterWaitForSingleObjectEx
= TrkRegisterWaitForSingleObjectEx( _hCompletionEvent, ThreadPoolCallbackFunction,
static_cast<PWorkItem*>(this), INFINITE,
WT_EXECUTEINWAITTHREAD );
if( NULL == _hRegisterWaitForSingleObjectEx )
{
TrkLog(( TRKDBG_ERROR, TEXT("Failed RegisterWaitForSingleObjectEx in CObjIdIndexChangeNotifier (%lu) for %s"),
GetLastError(), ptszVolumeDeviceName ));
TrkRaiseLastError();
}
else
TrkLog(( TRKDBG_VOLUME, TEXT("Registered objid index change notification (%p)"),
_hRegisterWaitForSingleObjectEx ));
}
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::StartListening
//
// Call ReadDirectoryChangesW on the handle to the object ID index.
// This is an event-based async call, so it returns immediately, and
// NTFS signals the event when there's a notification ready.
//
//+----------------------------------------------------------------------------
void
CObjIdIndexChangeNotifier::StartListening()
{
// NTFS will write the notification into the _Overlapped structure.
memset(&_Overlapped, 0, sizeof(_Overlapped));
_Overlapped.hEvent = _hCompletionEvent;
_Overlapped.Internal = STATUS_INTERNAL_ERROR;
if (!ReadDirectoryChangesW( _hDir,
_Buffer, // pointer to the buffer to receive the read results
sizeof(_Buffer), // length of lpBuffer
FALSE, // flag for monitoring directory or directory tree
FILE_NOTIFY_CHANGE_FILE_NAME, // filter conditions to watch for
&_dwDummyBytesReturned, // number of bytes returned
&_Overlapped, // pointer to structure needed for overlapped I/O
NULL )) // pointer to completion routine
{
CloseHandle(_hDir);
_hDir = INVALID_HANDLE_VALUE;
TrkLog(( TRKDBG_OBJID_DELETIONS, TEXT("AsyncListen failed to ReadDirectoryChanges %d"),
GetLastError() ));
TrkRaiseLastError();
}
// Ordinarily, the previous call will leave an IO pending. If, however,
// it actually returns right away with data, set the event as if the data came
// back async.
if( GetOverlappedResult( _hDir, &_Overlapped, &_dwDummyBytesReturned, FALSE /*Don't Wait*/ ))
{
// There was data immediately available. Handle it in the normal way.
TrkVerify( SetEvent( _Overlapped.hEvent ));
}
else if( ERROR_IO_INCOMPLETE != GetLastError() ) // STATUS_PENDING
{
// This should never occur
TrkLog(( TRKDBG_ERROR, TEXT("GetOverlappedResult failed in CObjIdIndexChangeNotifier::AsyncListen (%lu)"),
GetLastError() ));
TrkRaiseLastError();
}
}
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::AsyncListen
//
// This method begins listening for changes to the NTFS object ID index
// directory. It does not block; when notifications are available an
// event is signaled and handled in DoWork.
//
//+----------------------------------------------------------------------------
BOOL
CObjIdIndexChangeNotifier::AsyncListen( )
{
TCHAR tszDirPath[MAX_PATH];
BOOL fStartedListening = FALSE;
_cs.Enter();
__try // __finally
{
if( INVALID_HANDLE_VALUE != _hDir )
{
TrkLog(( TRKDBG_OBJID_DELETIONS, TEXT("CObjIdIndexChangeNotifier already listening to %s:"),
_ptszVolumeDeviceName ));
__leave;
}
_tcscpy( tszDirPath, _ptszVolumeDeviceName );
_tcscat( tszDirPath, TEXT("\\$Extend\\$ObjId:$O:$INDEX_ALLOCATION") );
//
// Should use TrkCreateFile and NtNotifyChangeDirectoryFile
// but NtNotifyChangeDirectoryFile means writing an APC routine
// so I'm punting for now.
// None of these Win32 error codess need to be raised to the user.
//
_hDir = CreateFile (
tszDirPath,
FILE_LIST_DIRECTORY,
FILE_SHARE_WRITE|FILE_SHARE_READ|FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
NULL );
if (_hDir == INVALID_HANDLE_VALUE)
{
TrkLog((TRKDBG_OBJID_DELETIONS,
TEXT("AsyncListen failed to open objid index %s %d"),
tszDirPath,
GetLastError()));
TrkRaiseLastError();
}
StartListening(); // Call ReadDirectoryChangesW
fStartedListening = TRUE;
TrkLog((TRKDBG_OBJID_DELETIONS,
TEXT("AsyncListen succeeded ReadDirectoryChanges on %c:"), VolChar(_pVolume->GetIndex()) ));
}
__finally
{
_cs.Leave();
}
return fStartedListening;
}
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::StopListeningAndClose
//
// Cancel the previous call to ReadDirectoryChangesW, and close the
// handle to the object ID index directory.
//
//+----------------------------------------------------------------------------
void
CObjIdIndexChangeNotifier::StopListeningAndClose()
{
if( !_fInitialized )
return;
_cs.Enter();
TrkLog((TRKDBG_OBJID_DELETIONS, TEXT("StopListeningAndClose() on %c:"),
VolChar(_pVolume->GetIndex())));
// Cancel the IO, which will trigger once last completion with
// STATUS_NOTIFY_CLEANUP (why isn't it STATUS_CANCELLED?)
// Note that this one last completion will see that _hDir
// has been closed, and won't attempt to re-use it.
InterlockedCloseHandle( &_hDir, INVALID_HANDLE_VALUE, TRUE );
_cs.Leave();
}
//+----------------------------------------------------------------------------
//
// CObjIdIndexChangeNotifier::UnInitialize
//
// Cancel the notification IRP and close the handle to the
// object ID index directory.
//
//+----------------------------------------------------------------------------
void
CObjIdIndexChangeNotifier::UnInitialize()
{
if( _fInitialized )
{
StopListeningAndClose();
// Unregister from the thread pool. This must be done before closing
// _hCompletionEvent, because that's the event on which the thread
// pool is waiting.
if( NULL != _hRegisterWaitForSingleObjectEx )
{
if( !TrkUnregisterWait( _hRegisterWaitForSingleObjectEx ))
{
TrkLog(( TRKDBG_ERROR, TEXT("Failed UnregisterWait for CObjIdIndexChangeNotifier (%lu)"),
GetLastError() ));
}
else
TrkLog(( TRKDBG_VOLUME, TEXT("Unregistered wait for CObjIdIndexChangeNotifier (%p)"),
_hRegisterWaitForSingleObjectEx ));
_hRegisterWaitForSingleObjectEx = NULL;
}
if( NULL != _hCompletionEvent )
{
CloseHandle( _hCompletionEvent );
_hCompletionEvent = NULL;
}
// Delete the critical section. This must be done after unregistering from
// the thread pool, because until that time we have to worry about a thread
// coming in to DoWork.
_cs.UnInitialize();
_fInitialized = FALSE;
}
}