Remove Packet_ref from File_system::Packet_descriptor

The intention of Packet_ref was to allow clients to place opaque
references into the packet descriptor itself, which could be observed on
packet completion. Currently no component in our sources uses this
feature and beyond that it is questionable if it should be used at all:
If the server tampers with the ref the client may easily be confused
into observing an incorrect or invalid context. It seems better to
remove the opaque context from the descriptor and leave the actual
implementation to the client and its needs.

repos/os/include/file_system/util.h

@@ -121,7 +121,6 @@ namespace File_system {
 
 			Packet_descriptor
 				packet(source.alloc_packet(curr_packet_size),
-				       0,
 				       node_handle,
 				       File_system::Packet_descriptor::READ,
 				       curr_packet_size,
@@ -178,7 +177,6 @@ namespace File_system {
 
 			Packet_descriptor
 				packet(source.alloc_packet(curr_packet_size),
-				       0,
 				       node_handle,
 				       File_system::Packet_descriptor::WRITE,
 				       curr_packet_size,

repos/os/include/file_system_session/file_system_session.h

@@ -28,15 +28,6 @@ namespace File_system {
 	struct Dir_handle;
 	struct Symlink_handle;
 
-	/**
-	 * Type of client context embedded in each packet descriptor
-	 *
-	 * Using the opaque refererence, the client is able to attribute incoming
-	 * packet acknowledgements to a context that is meaningful for the client.
-	 * It has no meaning at the server side.
-	 */
-	struct Packet_ref;
-
 	typedef Genode::uint64_t seek_off_t;
 	typedef Genode::uint64_t file_size_t;
 
@@ -123,8 +114,6 @@ class File_system::Packet_descriptor : public Genode::Packet_descriptor
 		seek_off_t  _position; /* seek offset in bytes */
 		size_t      _length;   /* transaction length in bytes */
 		bool        _success;  /* indicates success of operation */
-		Packet_ref *_ref;      /* opaque reference used at the client side
-		                          for recognizing acknowledgements */
 
 	public:
 
@@ -141,14 +130,13 @@ class File_system::Packet_descriptor : public Genode::Packet_descriptor
 		 *
 		 * \param position  seek offset in bytes (by default, append)
 		 */
-		Packet_descriptor(Packet_descriptor p, Packet_ref *ref,
+		Packet_descriptor(Packet_descriptor p,
 		                  Node_handle handle, Opcode op, size_t length,
 		                  seek_off_t position = ~0)
 		:
 			Genode::Packet_descriptor(p.offset(), p.size()),
 			_handle(handle), _op(op),
-			_position(position), _length(length), _success(false),
-			_ref(ref)
+			_position(position), _length(length), _success(false)
 		{ }
 
 		Node_handle handle()    const { return _handle;   }
@@ -156,7 +144,6 @@ class File_system::Packet_descriptor : public Genode::Packet_descriptor
 		seek_off_t  position()  const { return _position; }
 		size_t      length()    const { return _length;   }
 		bool        succeeded() const { return _success;  }
-		Packet_ref *ref()       const { return _ref;      }
 
 		/*
 		 * Accessors called at the server side

repos/os/include/vfs/fs_file_system.h

@@ -100,7 +100,6 @@ class Vfs::Fs_file_system : public File_system
 
 			::File_system::Packet_descriptor const
 				packet_in(source.alloc_packet(clipped_count),
-				          0,
 				          node_handle,
 				          ::File_system::Packet_descriptor::READ,
 				          clipped_count,
@@ -137,7 +136,6 @@ class Vfs::Fs_file_system : public File_system
 
 			::File_system::Packet_descriptor
 				packet(source.alloc_packet(count),
-				       0,
 				       node_handle,
 				       ::File_system::Packet_descriptor::WRITE,
 				       count,
@@ -217,7 +215,6 @@ class Vfs::Fs_file_system : public File_system
 
 					::File_system::Packet_descriptor
 						packet(source.alloc_packet(count),
-							   0,
 							   file,
 							   ::File_system::Packet_descriptor::READ,
 							   count,
@@ -298,7 +295,6 @@ class Vfs::Fs_file_system : public File_system
 
 			::File_system::Packet_descriptor
 				packet(source.alloc_packet(DIRENT_SIZE),
-				       0,
 				       dir_handle,
 				       ::File_system::Packet_descriptor::READ,
 				       DIRENT_SIZE,

repos/os/src/server/fs_log/log_file.h

@@ -74,7 +74,6 @@ class Fs_log::Log_file : public List<Log_file>::Element
 
 			File_system::Packet_descriptor
 				packet(raw_packet,
-				       0, /* The result struct. */
 				       _handle, File_system::Packet_descriptor::WRITE,
 				       msg_len, _offset);
 
@@ -88,4 +87,4 @@ class Fs_log::Log_file : public List<Log_file>::Element
 		}
 };
 
-#endif
+#endif