Implemented rescanning the device list. A few things, e.g. notifications and change counter updates, are still missing. Added a periodical rescan event.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2694 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/registrar/DiskDeviceManager.cpp

@@ -9,20 +9,29 @@
 #include "DiskDeviceManager.h"
 #include "Debug.h"
 #include "EventMaskWatcher.h"
+#include "EventQueue.h"
+#include "MessageEvent.h"
 #include "RDiskDevice.h"
 #include "RDiskDeviceList.h"
 #include "RPartition.h"
 #include "RSession.h"
 
+// priorities of the different message kinds
 enum {
 	REQUEST_PRIORITY			= 0,
+	RESCAN_PRIORITY				= 5,
 	NODE_MONITOR_PRIORITY		= 10,
 	WATCHING_REQUEST_PRIORITY	= 20,
 };
 
+// time interval between device rescans
+static const bigtime_t kRescanEventInterval = 5000000;
+
 // constructor
-DiskDeviceManager::DiskDeviceManager()
+DiskDeviceManager::DiskDeviceManager(EventQueue *eventQueue)
 	: BLooper("disk device manager"),
+	  fEventQueue(eventQueue),
+	  fRescanEvent(NULL),
 	  fDeviceListLock(),
 	  fWatchingService(),
 	  fVolumeList(BMessenger(this), fDeviceListLock),
@@ -45,11 +54,19 @@ DiskDeviceManager::DiskDeviceManager()
 		if (fWorker >= 0)
 			resume_thread(fWorker);
 	}
+	// set up the rescan event
+	fRescanEvent = new MessageEvent(system_time() + kRescanEventInterval,
+									this, B_REG_ROSTER_DEVICE_RESCAN);
+	fRescanEvent->SetAutoDelete(false);
+	fEventQueue->AddEvent(fRescanEvent);
 }
 
 // destructor
 DiskDeviceManager::~DiskDeviceManager()
 {
+	// remove the rescan event from the event queue
+	fEventQueue->RemoveEvent(fRescanEvent);
+	// terminate the worker thread
 	fTerminating = true;
 	delete_sem(fMessageCounter);
 	int32 dummy;
@@ -74,6 +91,11 @@ DiskDeviceManager::MessageReceived(BMessage *message)
 			if (!_PushMessage(message, WATCHING_REQUEST_PRIORITY))
 				delete message;
 			break;
+		case B_REG_ROSTER_DEVICE_RESCAN:
+			DetachCurrentMessage();
+			if (!_PushMessage(message, RESCAN_PRIORITY))
+				delete message;
+			break;
 		case B_NODE_MONITOR:
 			DetachCurrentMessage();
 			if (!_PushMessage(message, NODE_MONITOR_PRIORITY))
@@ -307,6 +329,12 @@ DiskDeviceManager::_Worker()
 				case B_REG_DEVICE_STOP_WATCHING:
 					_StopWatchingRequest(message);
 					break;
+				case B_REG_ROSTER_DEVICE_RESCAN:
+					fDeviceList.Rescan();
+					fRescanEvent->SetTime(system_time()
+										  + kRescanEventInterval);
+					fEventQueue->AddEvent(fRescanEvent);
+					break;
 				case B_NODE_MONITOR:
 				{
 					fVolumeList.HandleMessage(message);

src/servers/registrar/DiskDeviceManager.h

@@ -15,9 +15,12 @@
 #include "RVolumeList.h"
 #include "WatchingService.h"
 
+class EventQueue;
+class MessageEvent;
+
 class DiskDeviceManager : public BLooper {
 public:
-	DiskDeviceManager();
+	DiskDeviceManager(EventQueue *eventQueue);
 	virtual ~DiskDeviceManager();
 
 	virtual void MessageReceived(BMessage *message);
@@ -37,6 +40,11 @@ private:
 	int32 _Worker();
 
 private:
+	class RescanEvent;
+
+private:
+	EventQueue				*fEventQueue;
+	MessageEvent			*fRescanEvent;
 	BLocker					fDeviceListLock;
 	WatchingService			fWatchingService;
 	RVolumeList				fVolumeList;

src/servers/registrar/RDiskDevice.cpp

@@ -22,7 +22,7 @@ RDiskDevice::RDiskDevice()
 	: fSessions(10, true),
 	  fDeviceList(NULL),
 	  fID(-1),
-	  fChangeCounter(0),
+	  fChangeCounter(),
 	  fTouched(false),
 	  fPath(),
 	  fFD(-1),
@@ -45,7 +45,7 @@ PRINT(("RDiskDevice::SetTo()\n"));
 	Unset();
 	status_t error = B_OK;
 	fID = _NextID();
-	fChangeCounter = 0;
+	fChangeCounter.Reset();
 	fTouched = true;
 	fPath.SetTo(path);
 	fFD = fd;
@@ -68,28 +68,8 @@ PRINT(("RDiskDevice::SetTo()\n"));
 			error = fMediaStatus;
 			break;
 	}
-	// scan the device for sessions, if we have a media
+	// scan the device for sessions
-	if (fMediaStatus == B_OK) {
+	error = _RescanSessions(B_DEVICE_CAUSE_UNKNOWN);
-		session_info sessionInfo;
-		for (int32 i = 0; ; i++) {
-			// get the session info
-			status_t status = get_nth_session_info(fFD, i, &sessionInfo);
-			if (status != B_OK) {
-				if (status != B_ENTRY_NOT_FOUND)
-					error = status;
-				break;
-			}
-			// create and add a RSession
-			if (RSession *session = new(nothrow) RSession) {
-				error = session->SetTo(fFD, &sessionInfo);
-				if (error == B_OK)
-					AddSession(session);
-				else
-					delete session;
-			} else
-				error = B_NO_MEMORY;
-		}
-	}
 	// cleanup on error
 	if (error != B_OK)
 		Unset();
@@ -102,7 +82,7 @@ void
 RDiskDevice::Unset()
 {
 	for (int32 i = CountSessions() - 1; i >= 0; i--)
-		RemoveSession(i);
+		RemoveSession(i, B_DEVICE_CAUSE_UNKNOWN);
 	fID = -1;
 	fPath.SetTo("");
 	if (fFD >= 0) {
@@ -111,6 +91,51 @@ RDiskDevice::Unset()
 	}
 }
 
+// MediaChanged
+status_t
+RDiskDevice::MediaChanged()
+{
+PRINT(("RDiskDevice::MediaChanged()\n"));
+	status_t error = B_OK;
+	// get the new media status
+	status_t mediaStatus;
+	if (ioctl(fFD, B_GET_MEDIA_STATUS, &mediaStatus) == 0) {
+		fMediaStatus = mediaStatus;
+		// analyze the media status
+		switch (fMediaStatus) {
+			case B_NO_ERROR:
+			case B_DEV_NO_MEDIA:
+			case B_DEV_NOT_READY:
+			case B_DEV_MEDIA_CHANGE_REQUESTED:
+			case B_DEV_DOOR_OPEN:
+				break;
+			case B_DEV_MEDIA_CHANGED:
+				// Ignore changes between the our ioctl() and the one before;
+				// we rescan the sessions anyway.
+				fMediaStatus = B_OK;
+				break;
+			default:
+				error = fMediaStatus;
+				break;
+		}
+	}
+	// rescan sessions
+	error = _RescanSessions(B_DEVICE_CAUSE_PARENT_CHANGED);
+	// TODO: send notification
+	// ...
+	return error;
+}
+
+// SessionLayoutChanged
+status_t
+RDiskDevice::SessionLayoutChanged()
+{
+PRINT(("RDiskDevice::SessionLayoutChanged()\n"));
+	status_t error = B_OK;
+	error = _RescanSessions(B_DEVICE_CAUSE_UNKNOWN);
+	return error;
+}
+
 // Size
 off_t
 RDiskDevice::Size() const
@@ -119,9 +144,25 @@ RDiskDevice::Size() const
 			* fGeometry.cylinder_count * fGeometry.head_count;
 }
 
+// AddSession
+status_t
+RDiskDevice::AddSession(const session_info *sessionInfo, uint32 cause)
+{
+	status_t error = B_OK;
+	if (RSession *session = new(nothrow) RSession) {
+		error = session->SetTo(fFD, sessionInfo);
+		if (error == B_OK)
+			AddSession(session, cause);
+		else
+			delete session;
+	} else
+		error = B_NO_MEMORY;
+	return error;
+}
+
 // AddSession
 bool
-RDiskDevice::AddSession(RSession *session)
+RDiskDevice::AddSession(RSession *session, uint32 cause)
 {
 	bool success = false;
 	if (session) {
@@ -129,7 +170,7 @@ RDiskDevice::AddSession(RSession *session)
 		if (success) {
 			session->SetDevice(this);
 			if (RDiskDeviceList *deviceList = DeviceList())
-				deviceList->SessionAdded(session);
+				deviceList->SessionAdded(session, cause);
 		}
 	}
 	return success;
@@ -137,12 +178,12 @@ RDiskDevice::AddSession(RSession *session)
 
 // RemoveSession
 bool
-RDiskDevice::RemoveSession(int32 index)
+RDiskDevice::RemoveSession(int32 index, uint32 cause)
 {
 	RSession *session = SessionAt(index);
 	if (session) {
 		if (RDiskDeviceList *deviceList = DeviceList())
-			deviceList->SessionRemoved(session);
+			deviceList->SessionRemoved(session, cause);
 		session->SetDevice(NULL);
 		fSessions.RemoveItemAt(index);
 		delete session;
@@ -152,13 +193,13 @@ RDiskDevice::RemoveSession(int32 index)
 
 // RemoveSession
 bool
-RDiskDevice::RemoveSession(RSession *session)
+RDiskDevice::RemoveSession(RSession *session, uint32 cause)
 {
 	bool success = false;
 	if (session) {
 		int32 index = fSessions.IndexOf(session);
 		if (index >= 0)
-			success = RemoveSession(index);
+			success = RemoveSession(index, cause);
 	}
 	return success;
 }
@@ -167,7 +208,55 @@ RDiskDevice::RemoveSession(RSession *session)
 status_t
 RDiskDevice::Update()
 {
-	return B_ERROR;
+	status_t error = B_OK;
+	status_t mediaStatus = B_OK;
+	if (ioctl(fFD, B_GET_MEDIA_STATUS, &mediaStatus) == 0) {
+		if (mediaStatus == B_DEV_MEDIA_CHANGED
+			|| (mediaStatus == B_NO_ERROR) != (fMediaStatus == B_NO_ERROR)) {
+			// The media status is B_DEV_MEDIA_CHANGED or it changed from
+			// B_NO_ERROR to some error code or the other way around.
+			error = MediaChanged();
+		} else {
+			// TODO: notifications?
+			fMediaStatus = mediaStatus;
+			// The media has not been changed. If this is a read-only device,
+			// then we are safe, since nothing can have changed. Otherwise
+			// we check the sessions.
+			if (!IsReadOnly() && fMediaStatus == B_OK) {
+				session_info sessionInfo;
+				for (int32 i = 0; error == B_OK; i++) {
+					// get the session info
+					status_t status = get_nth_session_info(fFD, i,
+														   &sessionInfo);
+					if (status != B_OK) {
+						if (status == B_ENTRY_NOT_FOUND) {
+							// remove disappeared sessions
+							for (int32 k = CountSessions() - 1; k >= i; k--)
+								RemoveSession(k, B_DEVICE_CAUSE_UNKNOWN);
+						} else
+							error = status;
+						break;
+					}
+					// check the session
+					if (RSession *session = SessionAt(i)) {
+						if (session->Offset() == sessionInfo.offset
+							&& session->Size() == sessionInfo.size) {
+							session->Update(&sessionInfo);
+						} else {
+							// session layout changed
+							error = SessionLayoutChanged();
+							break;
+						}
+					} else {
+						// session added
+						error = AddSession(&sessionInfo,
+										   B_DEVICE_CAUSE_UNKNOWN);
+					}
+				}
+			}
+		}
+	}
+	return error;
 }
 
 // Archive
@@ -179,7 +268,7 @@ RDiskDevice::Archive(BMessage *archive) const
 	if (error == B_OK)
 		error = archive->AddInt32("id", fID);
 	if (error == B_OK)
-		error = archive->AddInt32("change_counter", fChangeCounter);
+		error = archive->AddInt32("change_counter", ChangeCounter());
 	// geometry
 	if (error == B_OK)
 		error = archive->AddInt64("size", Size());
@@ -219,6 +308,32 @@ RDiskDevice::Dump() const
 		session->Dump();
 }
 
+// _RescanSessions
+status_t
+RDiskDevice::_RescanSessions(uint32 cause)
+{
+	status_t error = B_OK;
+	// remove the current sessions
+	for (int32 i = CountSessions() - 1; i >= 0; i--)
+		RemoveSession(i, cause);
+	// scan the device for sessions, if we have a media
+	if (fMediaStatus == B_OK) {
+		session_info sessionInfo;
+		for (int32 i = 0; error == B_OK; i++) {
+			// get the session info
+			status_t status = get_nth_session_info(fFD, i, &sessionInfo);
+			if (status != B_OK) {
+				if (status != B_ENTRY_NOT_FOUND)
+					error = status;
+				break;
+			}
+			// create and add a RSession
+			error = AddSession(&sessionInfo, cause);
+		}
+	}
+	RETURN_ERROR(error);
+}
+
 // _NextID
 int32
 RDiskDevice::_NextID()

src/servers/registrar/RDiskDevice.h

@@ -10,6 +10,10 @@
 #include <ObjectList.h>
 #include <String.h>
 
+#include "RChangeCounter.h"
+
+struct session_info;
+
 class RDiskDeviceList;
 class RPartition;
 class RSession;
@@ -27,20 +31,31 @@ public:
 		{ fDeviceList = deviceList ;}
 	RDiskDeviceList *DeviceList() const { return fDeviceList; }
 
+	status_t MediaChanged();
+	status_t SessionLayoutChanged();
+
 	int32 ID() const { return fID; }
-	int32 ChangeCounter() const { return fChangeCounter; }
+	int32 ChangeCounter() const { return fChangeCounter.Count(); }
+	void Changed() { fChangeCounter.Increment(); }
 
 	void SetTouched(bool touched) { fTouched = touched; }
 	bool Touched() const { return fTouched; }
 
+	int FD() const { return fFD; }
 	off_t Size() const;
 	int32 BlockSize() const { return fGeometry.bytes_per_sector; }
+	bool IsReadOnly() { return fGeometry.read_only; }
 
 	const char *Path() const { return fPath.String(); }
 
-	bool AddSession(RSession *session);
+	status_t AddSession(const session_info *sessionInfo,
-	bool RemoveSession(int32 index);
+						uint32 cause/* = B_DEVICE_CAUSE_UNKNOWN*/);
-	bool RemoveSession(RSession *session);
+	bool AddSession(RSession *session,
+					uint32 cause/* = B_DEVICE_CAUSE_UNKNOWN*/);
+	bool RemoveSession(int32 index,
+					   uint32 cause/* = B_DEVICE_CAUSE_UNKNOWN*/);
+	bool RemoveSession(RSession *session,
+					   uint32 cause/* = B_DEVICE_CAUSE_UNKNOWN*/);
 	int32 CountSessions() const { return fSessions.CountItems(); }
 	RSession *SessionAt(int32 index) const { return fSessions.ItemAt(index); }
 	int32 IndexOfSession(const RSession *session) const
@@ -53,13 +68,15 @@ public:
 	void Dump() const;
 
 private:
+	status_t _RescanSessions(uint32 cause);
+
 	static int32 _NextID();
 
 private:
 	BObjectList<RSession>	fSessions;
 	RDiskDeviceList			*fDeviceList;
 	int32					fID;
-	int32					fChangeCounter;
+	RChangeCounter			fChangeCounter;
 	bool					fTouched;
 	BString					fPath;
 	int						fFD;

src/servers/registrar/RDiskDeviceList.cpp

@@ -186,6 +186,52 @@ RDiskDeviceList::MountPointMoved(const RVolume *volume,
 	Unlock();
 }
 
+// DeviceAppeared
+void
+RDiskDeviceList::DeviceAppeared(const char *devicePath)
+{
+	status_t error = (devicePath ? B_OK : B_BAD_VALUE);
+	if (error == B_OK) {
+		int fd = open(devicePath, O_RDONLY);
+		if (fd >= 0) {
+			bool closeFile = true;
+			device_geometry geometry;
+			status_t mediaStatus = B_OK;
+			partition_info partitionInfo;
+			if (ioctl(fd, B_GET_MEDIA_STATUS, &mediaStatus) == 0
+				&& ioctl(fd, B_GET_GEOMETRY, &geometry) == 0
+				&& ioctl(fd, B_GET_PARTITION_INFO, &partitionInfo) < 0) {
+PRINT(("RDiskDeviceList::DeviceAppeared(`%s')\n", devicePath));
+				RDiskDevice *device = new(nothrow) RDiskDevice;
+				if (device) {
+					error = device->SetTo(devicePath, fd, &geometry,
+										  mediaStatus);
+					if (error == B_OK) {
+						closeFile = false;
+						device->SetTouched(true);
+						AddDevice(device);
+					} else
+						delete device;
+				} else
+					error = B_NO_MEMORY;
+			}
+			if (closeFile)
+				close(fd);
+		}
+	}
+}
+
+// DeviceDisappeared
+void
+RDiskDeviceList::DeviceDisappeared(const char *devicePath)
+{
+PRINT(("RDiskDeviceList::DeviceDisappeared(`%s')\n", devicePath));
+	if (devicePath) {
+		if (RDiskDevice *device = DeviceWithPath(devicePath))
+			RemoveDevice(device);
+	}
+}
+
 // AddDevice
 bool
 RDiskDeviceList::AddDevice(RDiskDevice *device)
@@ -280,6 +326,9 @@ status_t
 RDiskDeviceList::Rescan()
 {
 FUNCTION_START();
+// TODO: This method should be reworked, as soon as we react on events only
+// and don't need to poll anymore. This method will then do an initial
+// scan only.
 	status_t error = B_OK;
 	if (Lock()) {
 		// marked all devices untouched
@@ -292,8 +341,9 @@ FUNCTION_START();
 		}
 		// remove all untouched devices
 		for (int32 i = CountDevices() - 1; i >= 0; i--) {
-			if (!DeviceAt(i)->Touched())
+			RDiskDevice *device = DeviceAt(i);
-				RemoveDevice(i);
+			if (!device->Touched())
+				DeviceDisappeared(device->Path());
 		}
 		Unlock();
 	} else
@@ -410,17 +460,11 @@ RDiskDeviceList::Dump() const
 status_t
 RDiskDeviceList::_Scan(BDirectory &dir)
 {
-//BEntry dirEntry;
-//BPath dirPath;
-//dir.GetEntry(&dirEntry);
-//dirEntry.GetPath(&dirPath);
-//PRINT(("RDiskDeviceList::_Scan(`%s')\n", dirPath.Path()));
 	status_t error = B_OK;
 	BEntry entry;
 	while (dir.GetNextEntry(&entry) == B_OK) {
 		struct stat st;
 		if (entry.GetStat(&st) == B_OK) {
-//PRINT(("st.st_mode: 0x%x\n", st.st_mode & S_IFMT));
 			if (S_ISDIR(st.st_mode)) {
 				BDirectory subdir;
 				if (subdir.SetTo(&entry) == B_OK)
@@ -444,37 +488,13 @@ RDiskDeviceList::_ScanDevice(const char *path)
 	// search the list for a device with that path
 	if (RDiskDevice *device = DeviceWithPath(path)) {
 		// found: just update it
+		device->SetTouched(true);
 		error = device->Update();
 	} else {
 		// not found: check whether it is really a disk device and add it to
 		// the list
-		int fd = open(path, O_RDONLY);
+		// The event hook does the work anyway:
-		if (fd >= 0) {
+		DeviceAppeared(path);
-			bool closeFile = true;
-			device_geometry geometry;
-			status_t mediaStatus = B_OK;
-			partition_info partitionInfo;
-			if (ioctl(fd, B_GET_MEDIA_STATUS, &mediaStatus) == 0
-				&& ioctl(fd, B_GET_GEOMETRY, &geometry) == 0
-				&& ioctl(fd, B_GET_PARTITION_INFO, &partitionInfo) < 0) {
-//				int32 blockSize = geometry.bytes_per_sector;
-//				off_t deviceSize = (off_t)blockSize
-//					* geometry.sectors_per_track * geometry.cylinder_count
-//					* geometry.head_count;
-				RDiskDevice *device = new(nothrow) RDiskDevice;
-				if (device) {
-					error = device->SetTo(path, fd, &geometry, mediaStatus);
-					if (error == B_OK) {
-						closeFile = false;
-						AddDevice(device);
-					} else
-						delete device;
-				} else
-					error = B_NO_MEMORY;
-			}
-			if (closeFile)
-				close(fd);
-		}
 	}
 	return error;
 }

src/servers/registrar/RDiskDeviceList.h

@@ -43,11 +43,14 @@ public:
 
 	virtual void HandleMessage(BMessage *message);
 
+	// external event hooks
 	virtual void VolumeMounted(const RVolume *volume);
 	virtual void VolumeUnmounted(const RVolume *volume);
 	virtual void MountPointMoved(const RVolume *volume,
 								 const entry_ref *oldRoot,
 								 const entry_ref *newRoot);
+	virtual void DeviceAppeared(const char *devicePath);
+	virtual void DeviceDisappeared(const char *devicePath);
 
 	bool AddDevice(RDiskDevice *device);
 	bool RemoveDevice(int32 index);
@@ -74,6 +77,7 @@ public:
 	bool Lock();
 	void Unlock();
 
+	// internal event hooks
 	void DeviceAdded(RDiskDevice *device,
 					 uint32 cause = B_DEVICE_CAUSE_UNKNOWN);
 	void DeviceRemoved(RDiskDevice *device,

src/servers/registrar/RPartition.cpp

@@ -12,7 +12,7 @@
 RPartition::RPartition()
 	: fSession(NULL),
 	  fID(-1),
-	  fChangeCounter(0),
+	  fChangeCounter(),
 	  fVolume(NULL)
 {
 }
@@ -29,7 +29,7 @@ RPartition::SetTo(int fd, const extended_partition_info *partitionInfo)
 	Unset();
 	status_t error = B_OK;
 	fID = _NextID();
-	fChangeCounter = 0;
+	fChangeCounter.Reset();
 	fInfo = *partitionInfo;
 	return error;
 }
@@ -55,6 +55,14 @@ RPartition::Device() const
 	return (fSession ? fSession->Device() : NULL);
 }
 
+// Changed
+void
+RPartition::Changed()
+{
+	if (fChangeCounter.Increment() && fSession)
+		fSession->Changed();
+}
+
 // Index
 int32
 RPartition::Index() const
@@ -76,6 +84,16 @@ RPartition::GetPath(char *path) const
 	}
 }
 
+// Update
+status_t
+RPartition::Update(const extended_partition_info *partitionInfo)
+{
+	status_t error = B_OK;
+	// TODO: Check the partition info for changes!
+	fInfo = *partitionInfo;
+	return error;
+}
+
 // Archive
 status_t
 RPartition::Archive(BMessage *archive) const
@@ -85,7 +103,7 @@ RPartition::Archive(BMessage *archive) const
 	if (error == B_OK)
 		error = archive->AddInt32("id", fID);
 	if (error == B_OK)
-		error = archive->AddInt32("change_counter", fChangeCounter);
+		error = archive->AddInt32("change_counter", ChangeCounter());
 	if (error == B_OK)
 		error = archive->AddInt32("index", Index());
 	// fInfo.info.*

src/servers/registrar/RPartition.h

@@ -9,6 +9,8 @@
 #include <disk_scanner.h>
 #include <SupportDefs.h>
 
+#include "RChangeCounter.h"
+
 class BMessage;
 
 class RDiskDevice;
@@ -30,18 +32,23 @@ public:
 	RSession *Session() const { return fSession; }
 
 	int32 ID() const { return fID; }
-	int32 ChangeCounter() const { return fChangeCounter; }
+	int32 ChangeCounter() const { return fChangeCounter.Count(); }
+	void Changed();
 
 	int32 Index() const;
 
 	const extended_partition_info *Info() const { return &fInfo; }
 	void GetPath(char *path) const;
+	off_t Offset() const { return fInfo.info.offset; }
+	off_t Size() const { return fInfo.info.size; }
 
 	void SetVolume(const RVolume *volume)	{ fVolume = volume; }
 	const RVolume *Volume() const			{ return fVolume; }
 
 	status_t Archive(BMessage *archive) const;
 
+	status_t Update(const extended_partition_info *partitionInfo);
+
 	void Dump() const;
 
 private:
@@ -50,7 +57,7 @@ private:
 private:
 	RSession				*fSession;
 	int32					fID;
-	int32					fChangeCounter;
+	RChangeCounter			fChangeCounter;
 	extended_partition_info	fInfo;
 	const RVolume			*fVolume;
 

src/servers/registrar/RSession.cpp

@@ -17,7 +17,7 @@ RSession::RSession()
 	: fPartitions(10, true),
 	  fDevice(NULL),
 	  fID(-1),
-	  fChangeCounter(0)
+	  fChangeCounter()
 {
 }
 
@@ -33,29 +33,10 @@ RSession::SetTo(int fd, const session_info *sessionInfo)
 	Unset();
 	status_t error = B_OK;
 	fID = _NextID();
-	fChangeCounter = 0;
+	fChangeCounter.Reset();
 	fInfo = *sessionInfo;
-	// iterate through the partitions
+	// scan for partitions
-	for (int32 i = 0; ; i++) {
+	error = _RescanPartitions(fd, B_DEVICE_CAUSE_UNKNOWN);
-		// get the partition info
-		extended_partition_info partitionInfo;
-		status_t status = get_nth_partition_info(fd, sessionInfo->index, i,
-			&partitionInfo, (i == 0 ? fPartitioningSystem : NULL));
-		if (status != B_OK) {
-			if (status != B_ENTRY_NOT_FOUND)
-				error = status;
-			break;
-		}
-		// create and add a RPartition
-		if (RPartition *partition = new(nothrow) RPartition) {
-			error = partition->SetTo(fd, &partitionInfo);
-			if (error == B_OK)
-				AddPartition(partition);
-			else
-				delete partition;
-		} else
-			error = B_NO_MEMORY;
-	}
 	// cleanup on error
 	if (error != B_OK)
 		Unset();
@@ -67,7 +48,7 @@ void
 RSession::Unset()
 {
 	for (int32 i = CountPartitions() - 1; i >= 0; i--)
-		RemovePartition(i);
+		RemovePartition(i, B_DEVICE_CAUSE_UNKNOWN);
 	fID = -1;
 }
 
@@ -78,6 +59,25 @@ RSession::DeviceList() const
 	return (fDevice ? fDevice->DeviceList() : NULL);
 }
 
+// PartitionLayoutChanged
+status_t
+RSession::PartitionLayoutChanged()
+{
+PRINT(("RSession::PartitionLayoutChanged()\n"));
+	status_t error = (fDevice ? B_OK : B_ERROR);
+	if (error == B_OK)
+		error = _RescanPartitions(fDevice->FD(), B_DEVICE_CAUSE_UNKNOWN);
+	return error;
+}
+
+// Changed
+void
+RSession::Changed()
+{
+	if (fChangeCounter.Increment() && fDevice)
+		fDevice->Changed();
+}
+
 // Index
 int32
 RSession::Index() const
@@ -87,9 +87,26 @@ RSession::Index() const
 	return -1;
 }
 
+// AddPartition
+status_t
+RSession::AddPartition(int fd, const extended_partition_info *partitionInfo,
+					   uint32 cause)
+{
+	status_t error = B_OK;
+	if (RPartition *partition = new(nothrow) RPartition) {
+		error = partition->SetTo(fd, partitionInfo);
+		if (error == B_OK)
+			AddPartition(partition, cause);
+		else
+			delete partition;
+	} else
+		error = B_NO_MEMORY;
+	return error;
+}
+
 // AddPartition
 bool
-RSession::AddPartition(RPartition *partition)
+RSession::AddPartition(RPartition *partition, uint32 cause)
 {
 	bool success = false;
 	if (partition) {
@@ -97,7 +114,7 @@ RSession::AddPartition(RPartition *partition)
 		if (success) {
 			partition->SetSession(this);
 			if (RDiskDeviceList *deviceList = DeviceList())
-				deviceList->PartitionAdded(partition);
+				deviceList->PartitionAdded(partition, cause);
 		}
 	}
 	return success;
@@ -105,12 +122,12 @@ RSession::AddPartition(RPartition *partition)
 
 // RemovePartition
 bool
-RSession::RemovePartition(int32 index)
+RSession::RemovePartition(int32 index, uint32 cause)
 {
 	RPartition *partition = PartitionAt(index);
 	if (partition) {
 		if (RDiskDeviceList *deviceList = DeviceList())
-			deviceList->PartitionRemoved(partition);
+			deviceList->PartitionRemoved(partition, cause);
 		partition->SetSession(NULL);
 		fPartitions.RemoveItemAt(index);
 		delete partition;
@@ -120,17 +137,66 @@ RSession::RemovePartition(int32 index)
 
 // RemovePartition
 bool
-RSession::RemovePartition(RPartition *partition)
+RSession::RemovePartition(RPartition *partition, uint32 cause)
 {
 	bool success = false;
 	if (partition) {
 		int32 index = fPartitions.IndexOf(partition);
 		if (index >= 0)
-			success = RemovePartition(index);
+			success = RemovePartition(index, cause);
 	}
 	return success;
 }
 
+// Update
+status_t
+RSession::Update(const session_info *sessionInfo)
+{
+	status_t error = (fDevice ? B_OK : B_ERROR);
+	// TODO: Check the session info for changes!
+	fInfo = *sessionInfo;
+	int fd = (fDevice ? fDevice->FD() : -1);
+	// check the partitions
+	for (int32 i = 0; error == B_OK; i++) {
+		// get the partition info
+		extended_partition_info partitionInfo;
+		char partitioningSystem[B_FILE_NAME_LENGTH];
+		status_t status = get_nth_partition_info(fd, sessionInfo->index, i,
+			&partitionInfo, (i == 0 ? partitioningSystem : NULL));
+		// check the partitioning system
+		if ((status == B_OK || status == B_ENTRY_NOT_FOUND) && i == 0
+			&& strcmp(partitioningSystem, fPartitioningSystem)) {
+			// partitioning system has changed
+			error = PartitionLayoutChanged();
+			break;
+		}
+		if (status != B_OK) {
+			if (status == B_ENTRY_NOT_FOUND) {
+				// remove disappeared partitions
+				for (int32 k = CountPartitions() - 1; k >= i; k--)
+					RemovePartition(k, B_DEVICE_CAUSE_UNKNOWN);
+			} else
+				error = status;
+			break;
+		}
+		// check the partition
+		if (RPartition *partition = PartitionAt(i)) {
+			if (partition->Offset() == partitionInfo.info.offset
+				&& partition->Size() == partitionInfo.info.size) {
+				partition->Update(&partitionInfo);
+			} else {
+				// partition layout changed
+				error = PartitionLayoutChanged();
+				break;
+			}
+		} else {
+			// partition added
+			error = AddPartition(fd, &partitionInfo, B_DEVICE_CAUSE_UNKNOWN);
+		}
+	}
+	return error;
+}
+
 // Archive
 status_t
 RSession::Archive(BMessage *archive) const
@@ -140,7 +206,7 @@ RSession::Archive(BMessage *archive) const
 	if (error == B_OK)
 		error = archive->AddInt32("id", fID);
 	if (error == B_OK)
-		error = archive->AddInt32("change_counter", fChangeCounter);
+		error = archive->AddInt32("change_counter", ChangeCounter());
 	if (error == B_OK)
 		error = archive->AddInt32("index", Index());
 	// fInfo.*
@@ -188,6 +254,31 @@ RSession::Dump() const
 		partition->Dump();
 }
 
+// _RescanPartitions
+status_t
+RSession::_RescanPartitions(int fd, uint32 cause)
+{
+	status_t error = B_OK;
+	// remove the current partitions
+	for (int32 i = CountPartitions() - 1; i >= 0; i--)
+		RemovePartition(i, cause);
+	// scan for partitions
+	for (int32 i = 0; error == B_OK; i++) {
+		// get the partition info
+		extended_partition_info partitionInfo;
+		status_t status = get_nth_partition_info(fd, fInfo.index, i,
+			&partitionInfo, (i == 0 ? fPartitioningSystem : NULL));
+		if (status != B_OK) {
+			if (status != B_ENTRY_NOT_FOUND)
+				error = status;
+			break;
+		}
+		// create and add a RPartition
+		error = AddPartition(fd, &partitionInfo, cause);
+	}
+	return error;
+}
+
 // _NextID
 int32
 RSession::_NextID()

src/servers/registrar/RSession.h

@@ -9,6 +9,8 @@
 #include <disk_scanner.h>
 #include <ObjectList.h>
 
+#include "RChangeCounter.h"
+
 class RDiskDevice;
 class RDiskDeviceList;
 class RPartition;
@@ -25,14 +27,19 @@ public:
 	RDiskDeviceList *DeviceList() const;
 	RDiskDevice *Device() const { return fDevice; }
 
+	status_t PartitionLayoutChanged();
+
 	int32 ID() const { return fID; }
-	int32 ChangeCounter() const { return fChangeCounter; }
+	int32 ChangeCounter() const { return fChangeCounter.Count(); }
+	void Changed();
 
 	int32 Index() const;
 
-	bool AddPartition(RPartition *partition);
+	status_t AddPartition(int fd, const extended_partition_info *partitionInfo,
-	bool RemovePartition(int32 index);
+						  uint32 cause);
-	bool RemovePartition(RPartition *partition);
+	bool AddPartition(RPartition *partition, uint32 cause);
+	bool RemovePartition(int32 index, uint32 cause);
+	bool RemovePartition(RPartition *partition, uint32 cause);
 	int32 CountPartitions() const { return fPartitions.CountItems(); }
 	RPartition *PartitionAt(int32 index) const
 		{ return fPartitions.ItemAt(index); }
@@ -40,19 +47,25 @@ public:
 		{ return fPartitions.IndexOf(partition); }
 
 	const session_info *Info() const { return &fInfo; }
+	off_t Offset() const { return fInfo.offset; }
+	off_t Size() const { return fInfo.size; }
+
+	status_t Update(const session_info *sessionInfo);
 
 	status_t Archive(BMessage *archive) const;
 
 	void Dump() const;
 
 private:
+
+	status_t _RescanPartitions(int fd, uint32 cause);
 	static int32 _NextID();
 
 private:
 	BObjectList<RPartition>	fPartitions;
 	RDiskDevice				*fDevice;
 	int32					fID;
-	int32					fChangeCounter;
+	RChangeCounter			fChangeCounter;
 	session_info			fInfo;
 	char					fPartitioningSystem[B_FILE_NAME_LENGTH];
 

src/servers/registrar/Registrar.cpp

@@ -218,6 +218,8 @@ void
 Registrar::ReadyToRun()
 {
 	FUNCTION_START();
+	// create event queue
+	fEventQueue = new EventQueue(kEventQueueName);
 	// create roster
 	fRoster = new TRoster;
 	fRoster->Init();
@@ -228,10 +230,9 @@ Registrar::ReadyToRun()
 	fMIMEManager = new MIMEManager;
 	fMIMEManager->Run();
 	// create disk device manager
-	fDiskDeviceManager = new DiskDeviceManager;
+	fDiskDeviceManager = new DiskDeviceManager(fEventQueue);
 	fDiskDeviceManager->Run();
 	// create message runner manager
-	fEventQueue = new EventQueue(kEventQueueName);
 	fMessageRunnerManager = new MessageRunnerManager(fEventQueue);
 	// init the global be_roster
 	BRoster::Private().SetTo(be_app_messenger, BMessenger(NULL, fMIMEManager));