libfshelp: fix the api of fshelp_set_active_translator

To detect if an active translator goes away, we need to register for
dead name notifications. Those notifications have to be sent to a port
known to the ports library, as the ports library handles the dead name
notifications. The most straight forward way is to use the port to the
underlying node for that. To that end, a reference to the port_info
struct is handed in and kept in the list of active translators.

This commit also moves the registration of dead name notifications to
libfshelp.

* libfshelp/fshelp.h (fshelp_set_active_translator): Add port_info argument.
* libfshelp/translator-list.c (struct translator): Add port_info pointer.
(translator_ihash_cleanup): Dereference port_info object.
(fshelp_set_active_translator): Register dead name notifications.
* libdiskfs/file-set-trans.c (diskfs_S_file_set_translator): Update
  accordingly.
* libnetfs/file-set-translator.c (netfs_S_file_set_translator): Likewise.

1 files changed, 4 insertions, 15 deletions

diff --git a/libnetfs/file-set-translator.c b/libnetfs/file-set-translator.c
index a9883a3a..b46eb029 100644
--- a/libnetfs/file-set-translator.c
+++ b/libnetfs/file-set-translator.c
@@ -1,5 +1,6 @@
 /*
-   Copyright (C) 1996, 1997, 1999, 2001, 2013 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1999, 2001, 2013, 2014
+     Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -175,20 +176,8 @@ netfs_S_file_set_translator (struct protid *user,
 	}
     }
 
-  if (! err && user->po->path)
-    err = fshelp_set_active_translator (user->po->path, active);
-
-  if (! err && active != MACH_PORT_NULL)
-    {
-      mach_port_t old;
-      err = mach_port_request_notification (mach_task_self (), active,
-					    MACH_NOTIFY_DEAD_NAME, 0,
-					    user->pi.port_right,
-					    MACH_MSG_TYPE_MAKE_SEND_ONCE,
-					    &old);
-      if (old != MACH_PORT_NULL)
-	mach_port_deallocate (mach_task_self (), old);
-    }
+  if (! err && user->po->path && active_flags & FS_TRANS_SET)
+    err = fshelp_set_active_translator (&user->pi, user->po->path, active);
 
  out:
   pthread_mutex_unlock (&np->lock);