*** empty log message ***

1 files changed, 129 insertions, 0 deletions

diff --git a/libtreefs/trans-help.c b/libtreefs/trans-help.c
new file mode 100644
index 00000000..b28e93e1
--- /dev/null
+++ b/libtreefs/trans-help.c
@@ -0,0 +1,129 @@
+/* Helper routines for dealing with translators
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "trivfs.h"
+
+/* Return the active translator control port for NODE.  If there is no
+   translator, active or passive, MACH_PORT_NULL is returned in CONTROL_PORT.
+   If there is a translator, it is started if necessary, and returned in
+   CONTROL_PORT.  *DIR_PORT should be a port right to use as the new
+   translators parent directory.  If it is MACH_PORT_NULL, a port is created
+   from DIR and PARENT_PORT and stored in *DIR_PORT; otherwise DIR and
+   PARENT_PORT are not used.  Neither NODE or DIR should be locked when
+   calling this function.  */
+error_t
+treefs_node_get_active_trans (struct treefs_node *node,
+			      struct treefs_node *dir,
+			      mach_port_t parent_port,
+			      mach_port_t *control_port,
+			      mach_port_t *dir_port)
+{
+  /* Fill in dir_port */
+  void make_dir_port ()
+    {
+      mutex_lock (&dir->lock);
+      *dir_port = treefs_node_make_right (dir, 0, parent_port, 0);
+      mach_port_insert_right (mach_task_self (),
+			      *dir_port, *dir_port, MACH_MSG_TYPE_MAKE_SEND);
+      mutex_unlock (&dir->lock);
+    }
+
+  mutex_lock (&node->active_trans.lock);
+
+  if (node->active_trans.control != MACH_PORT_NULL)
+    {
+      mach_port_t control = node->active_trans.control;
+      mach_port_mod_refs (mach_task_self (), control, 
+			  MACH_PORT_RIGHT_SEND, 1);
+      mutex_unlock (&node->active_trans.lock);
+
+      /* Now we have a copy of the translator port that isn't
+	 dependent on the translator lock itself.  Relock
+	 the directory, make a port from it, and then call
+	 fsys_getroot. */
+
+      if (*dir_port == MACH_PORT_NULL)
+	make_dir_port ();
+	      
+      *control_port = control;
+
+      return 0;
+    }
+
+  mutex_unlock (&node->active_trans.lock);
+
+  /* If we get here, then we have no active control port.
+     Check to see if there is a passive translator, and if so
+     repeat the translator check. */
+  mutex_lock (&node->lock);
+  if (!node->istranslated)
+    {
+      *control_port = MACH_PORT_NULL;
+      return 0;
+    }
+
+  err = treefs_node_get_translator (node, trans, &trans_len);
+  if (err == E2BIG)
+    {
+      trans = alloca (trans_len);
+      err = treefs_node_get_translator (node, trans, &trans_len);
+    }
+  if (err)
+    {
+      mutex_unlock (&node->lock);
+      return err;
+    }
+
+  if (*dir_port == MACH_PORT_NULL)
+    {
+      mutex_unlock (&node->lock);
+      make_dir_port ();
+      mutex_lock (&node->lock);
+    }
+
+  /* Try starting the translator (this unlocks NODE).  */
+  err = treefs_start_translator (node, trans, trans_len, *dir_port);
+  if (err)
+    return err;
+
+  /* Try again now that we've started the translator...  This call
+     should be tail recursive.  */
+  return
+    treefs_node_get_active_trans (node, dir, parent_port,
+				  control_port, dir_port);
+}
+
+/* Drop the active translator CONTROL_PORT on NODE, unless it's no longer the
+   current active translator, in which case just drop a reference to it.  */
+void
+treefs_node_drop_active_trans (struct treefs_node *node,
+			       mach_port_t control_port)
+{
+  mutex_lock (&node->active_trans.lock);
+  /* Only zero the control port if it hasn't changed. */
+  if (node->active_trans.control == control)
+    fshelp_translator_drop (&node->active_trans);
+  mutex_unlock (&node->active_trans.lock);
+	      
+  /* And we're done with this port. */
+  mach_port_deallocate (mach_task_self (), control_port);
+}