* Fixed a possible dead lock between the kernel daemon and the DDM; the media

status checker now only tries to lock the manager, it won't wait anymore.
* Added MediaChanged() and UpdateMediaStatusIfNeeded() methods to KDiskDevice.
* KDiskDeviceManager::_CheckMediaStatus() now uses these new methods; it should
  no longer detect removed media more than once :-)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22621 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/disk_device_manager/KDiskDevice.h

@@ -51,8 +51,9 @@ public:
 	bool IsWriteOnce() const;
 	bool IsRemovable() const;
 	bool HasMedia() const;
+	bool MediaChanged() const;
 
-	virtual status_t GetMediaStatus(status_t *mediaStatus);
+	void UpdateMediaStatusIfNeeded();
 
 	status_t SetPath(const char *path);
 		// TODO: Remove this method or make it private. Once initialized the
@@ -81,6 +82,7 @@ public:
 	virtual void Dump(bool deep = true, int32 level = 0);
 
 protected:
+	virtual status_t GetMediaStatus(status_t *mediaStatus);
 	virtual status_t GetGeometry(device_geometry *geometry);
 
 private:

src/system/kernel/disk_device_manager/KDiskDevice.cpp

@@ -239,9 +239,26 @@ KDiskDevice::IsRemovable() const
 bool
 KDiskDevice::HasMedia() const
 {
-	return (fMediaStatus == B_OK);
+	return fMediaStatus == B_OK || fMediaStatus == B_DEV_MEDIA_CHANGED;
 }
 
+
+bool
+KDiskDevice::MediaChanged() const
+{
+	return fMediaStatus == B_DEV_MEDIA_CHANGED;
+}
+
+
+void
+KDiskDevice::UpdateMediaStatusIfNeeded()
+{
+	// TODO: allow a device to notify us about its media status!
+	// This will then also need to clear any B_DEV_MEDIA_CHANGED
+	GetMediaStatus(&fMediaStatus);
+}
+
+
 // SetPath
 status_t
 KDiskDevice::SetPath(const char *path)

src/system/kernel/disk_device_manager/KDiskDeviceManager.cpp

@@ -1252,8 +1252,7 @@ KDiskDeviceManager::_ScanPartition(KPartition *partition, bool async)
 void
 KDiskDeviceManager::_CheckMediaStatus()
 {
-	ManagerLocker locker(this);
-	if (!locker.IsLocked())
+	if (fLock.LockWithTimeout(0) != B_OK)
 		return;
 
 	int32 cookie = 0;
@@ -1262,32 +1261,18 @@ KDiskDeviceManager::_CheckMediaStatus()
 		if (device == NULL)
 			break;
 
-		status_t mediaStatus;
-		if (device->GetMediaStatus(&mediaStatus) == B_OK) {
-			bool removed = false;
-			bool changed = false;
+		bool hadMedia = device->HasMedia();
+		device->UpdateMediaStatusIfNeeded();
 
-			switch (mediaStatus) {
-				case B_DEV_MEDIA_CHANGED:
-					changed = true;
-					break;
-				case B_DEV_NO_MEDIA:
-				case B_DEV_DOOR_OPEN:
-					removed = true;
-					break;
-				case B_DEV_MEDIA_CHANGE_REQUESTED:
-				case B_DEV_NOT_READY:
-				case B_OK:
-					break;
-			}
-
-			// TODO: propagate changes!
-			if (removed)
-				dprintf("Media removed from %s\n", device->Path());
-			if (changed)
+		// TODO: propagate changes!
+		if (device->MediaChanged()) {
 				dprintf("Media changed from %s\n", device->Path());
+		} else if (!device->HasMedia() && hadMedia) {
+			dprintf("Media removed from %s\n", device->Path());
 		}
 	}
+
+	fLock.Unlock();
 }