diff --git a/gio/ChangeLog b/gio/ChangeLog
index c27397ea6..23f537935 100644
--- a/gio/ChangeLog
+++ b/gio/ChangeLog
@@ -1,3 +1,10 @@
+2009-02-16  Matthias Clasen  <mclasen@redhat.com>
+
+	* gmountoperation.[hc]: Add an "aborted" signal to abort a
+	mount operation from the backend side.
+
+	* gvolume.h: Add docs regarding the "aborted" signal.
+
 2009-02-13  Ryan Lortie  <desrt@desrt.ca>
 
 	Bug 505042 – add file attribute for actually used file size in bytes
diff --git a/gio/gmountoperation.c b/gio/gmountoperation.c
index 8234b8315..0635e7594 100644
--- a/gio/gmountoperation.c
+++ b/gio/gmountoperation.c
@@ -57,6 +57,7 @@ enum {
   ASK_PASSWORD,
   ASK_QUESTION,
   REPLY,
+  ABORTED,
   LAST_SIGNAL
 };
 
@@ -296,6 +297,26 @@ g_mount_operation_class_init (GMountOperationClass *klass)
 		  G_TYPE_NONE, 1,
 		  G_TYPE_MOUNT_OPERATION_RESULT);
 
+  /**
+   * GMountOperation::aborted:
+   *
+   * Emitted by the backend when e.g. a device becomes unavailable
+   * while a mount operation is in progress. 
+   *
+   * Implementations of GMountOperation should handle this signal
+   * by dismissing open password dialogs.
+   *
+   * Since: 2.20
+   */
+  signals[ABORTED] = 
+    g_signal_new (I_("aborted"),
+		  G_TYPE_FROM_CLASS (object_class),
+		  G_SIGNAL_RUN_LAST,
+		  G_STRUCT_OFFSET (GMountOperationClass, aborted),
+		  NULL, NULL,
+		  g_cclosure_marshal_VOID__VOID,
+		  G_TYPE_NONE, 0);
+
   /**
    * GMountOperation:username:
    *
diff --git a/gio/gmountoperation.h b/gio/gmountoperation.h
index 6c3029dc8..e6ba51a9c 100644
--- a/gio/gmountoperation.h
+++ b/gio/gmountoperation.h
@@ -73,6 +73,8 @@ struct _GMountOperationClass
   void (* reply)        (GMountOperation       *op,
 			 GMountOperationResult  result);
 
+  void (* aborted)      (GMountOperation       *op);
+
   /*< private >*/
   /* Padding for future expansion */
   void (*_g_reserved1) (void);
@@ -86,7 +88,6 @@ struct _GMountOperationClass
   void (*_g_reserved9) (void);
   void (*_g_reserved10) (void);
   void (*_g_reserved11) (void);
-  void (*_g_reserved12) (void);
 };
 
 GType             g_mount_operation_get_type      (void) G_GNUC_CONST;
diff --git a/gio/gvolume.h b/gio/gvolume.h
index 640c42fd0..f81faad2e 100644
--- a/gio/gvolume.h
+++ b/gio/gvolume.h
@@ -85,7 +85,10 @@ G_BEGIN_DECLS
  * @get_mount: Gets a #GMount representing the mounted volume. Returns %NULL if the #GVolume is not mounted.
  * @can_mount: Returns %TRUE if the #GVolume can be mounted.
  * @can_eject: Checks if a #GVolume can be ejected.
- * @mount_fn: Mounts a given #GVolume.
+ * @mount_fn: Mounts a given #GVolume. 
+ *     #GVolume implementations must emit the #GMountOperation::aborted 
+ *     signal before completing a mount operation that is aborted while 
+ *     awaiting input from the user through a #GMountOperation instance.
  * @mount_finish: Finishes a mount operation.
  * @eject: Ejects a given #GVolume.
  * @eject_finish: Finishes an eject operation.