axeld + bonefish:

* Unmount when uninitializing a partition.
* Finished the media checker implementation, i.e. we rescan when a media
  was inserted and uninitialize when ejected.
* Turned the disk device media checker from a kernel daemon into a thread.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22909 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/disk_device_manager/KDiskDeviceManager.h

@@ -99,8 +99,8 @@ public:
 	status_t RescanDiskSystems();
 
 private:
-	static void _CheckMediaStatusDaemon(void* self, int iteration);
-	void _CheckMediaStatus();
+	static status_t _CheckMediaStatusDaemon(void* self);
+	status_t _CheckMediaStatus();
 
 	status_t _RescanDiskSystems(bool fileSystems);
 
@@ -127,6 +127,8 @@ private:
 	PartitionMap				*fPartitions;
 	DiskSystemMap				*fDiskSystems;
 	PartitionSet				*fObsoletePartitions;
+	thread_id					fMediaChecker;
+	volatile bool				fTerminating;
 
 	static KDiskDeviceManager	*sDefaultManager;
 };

headers/private/kernel/disk_device_manager/KPartition.h

@@ -54,6 +54,7 @@ public:
 	bool IsBusy() const;
 	bool IsBusy(bool includeDescendants);
 	bool CheckAndMarkBusy(bool includeDescendants);
+	void MarkBusy(bool includeDescendants);
 	void UnmarkBusy(bool includeDescendants);
 
 	void SetOffset(off_t offset);