* Made the use of file devices more convenient and complete by adding

the methods IsFile() and GetFilePath() to BDiskDevice, and
  BDiskDeviceRoster::GetFileDeviceForPath().
* Added new syscalls to implement this functionality.
* Added new flag B_DISK_DEVICE_IS_FILE.
* Fixed wrong operator precedence assumption in the BDiskDevice class at
  several places.
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28052 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/storage/DiskDevice.h

@@ -37,6 +37,9 @@ public:
 									bool receiveCompleteProgressUpdates = true);
 			status_t			CancelModifications();
 
+			bool				IsFile() const;
+			status_t			GetFilePath(BPath* path) const;
+
 private:
 			friend class BDiskDeviceList;
 			friend class BDiskDeviceRoster;

headers/private/storage/DiskDeviceRoster.h

@@ -28,7 +28,7 @@ enum {
 	// Basic masks
 	B_DEVICE_REQUEST_MOUNT_POINT			= 0x0001,	// mount point changes
 	B_DEVICE_REQUEST_MOUNTING				= 0x0002,	// mounting/unmounting
-	B_DEVICE_REQUEST_PARTITION				= 0x0004,	// partition changes 
+	B_DEVICE_REQUEST_PARTITION				= 0x0004,	// partition changes
 	B_DEVICE_REQUEST_DEVICE					= 0x0008,	// device changes (media changes)
 	B_DEVICE_REQUEST_DEVICE_LIST			= 0x0010,	// device additions/removals
 	B_DEVICE_REQUEST_JOB_LIST				= 0x0020, 	// job addition/initiation/cancellation/completion
@@ -125,6 +125,8 @@ public:
 								BDiskDevice* device);
 			status_t		GetPartitionForPath(const char* filename,
 								BDiskDevice* device, BPartition** _partition);
+			status_t		GetFileDeviceForPath(const char* filename,
+								BDiskDevice* device);
 
 			status_t		StartWatching(BMessenger target,
 								uint32 eventMask = B_DEVICE_REQUEST_ALL);