4 files changed, 109 insertions, 3 deletions

diff --git a/engine/Makefile.am b/engine/Makefile.am
index b69c70c..8eda5f1 100644
--- a/engine/Makefile.am
+++ b/engine/Makefile.am
@@ -9,6 +9,7 @@ libdconf_engine_a_SOURCES = \
 	dconf-engine-source-private.h	\
 	dconf-engine-source.h		\
 	dconf-engine-source-user.c	\
+	dconf-engine-source-user-nfs.c	\
 	dconf-engine-source-system.c	\
 	dconf-engine-source.c		\
 	dconf-engine.h			\
diff --git a/engine/dconf-engine-source-private.h b/engine/dconf-engine-source-private.h
index 822354a..57840dc 100644
--- a/engine/dconf-engine-source-private.h
+++ b/engine/dconf-engine-source-private.h
@@ -26,6 +26,7 @@
 #include "dconf-engine-source.h"
 
 G_GNUC_INTERNAL extern const DConfEngineSourceVTable dconf_engine_source_user_vtable;
+G_GNUC_INTERNAL extern const DConfEngineSourceVTable dconf_engine_source_user_nfs_vtable;
 G_GNUC_INTERNAL extern const DConfEngineSourceVTable dconf_engine_source_system_vtable;
 
 #endif /* __dconf_engine_source_private_h__ */
diff --git a/engine/dconf-engine-source-user-nfs.c b/engine/dconf-engine-source-user-nfs.c
new file mode 100644
index 0000000..336fa04
--- /dev/null
+++ b/engine/dconf-engine-source-user-nfs.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright © 2010 Codethink Limited
+ * Copyright © 2012 Canonical Limited
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#include "dconf-engine-source-private.h"
+
+#include "../shm/dconf-shm.h"
+#include "dconf-engine.h"
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <errno.h>
+
+static void
+dconf_engine_source_user_nfs_init (DConfEngineSource *source)
+{
+  GError *error = NULL;
+  GVariant *reply;
+
+  source->bus_type = G_BUS_TYPE_SESSION;
+  source->bus_name = g_strdup ("ca.desrt.dconf");
+  source->object_path = g_strdup_printf ("/ca/desrt/dconf/Writer/%s", source->name);
+  source->writable = TRUE;
+
+  /* We need to get the dconf-service to come online and notice that
+   * we're on an NFS home directory.  In that case it will copy the
+   * given database into the XDG_RUNTIME_DIR which is where we will
+   * access it.
+   *
+   * This prevents us from doing mmap() on a file on NFS (which often
+   * results in us seeing SIGBUS).
+   */
+  reply = dconf_engine_dbus_call_sync_func (G_BUS_TYPE_SESSION, source->bus_name, source->object_path,
+                                            "ca.desrt.dconf.Writer", "Init", NULL, G_VARIANT_TYPE_UNIT, &error);
+
+  if (reply)
+    g_variant_unref (reply);
+  else
+    {
+      g_warning ("Trying to start the dconf service failed: %s.  Expect problems.", error->message);
+      g_error_free (error);
+    }
+}
+
+static gboolean
+dconf_engine_source_user_nfs_needs_reopen (DConfEngineSource *source)
+{
+  return !source->values || !gvdb_table_is_valid (source->values);
+}
+
+static GvdbTable *
+dconf_engine_source_user_nfs_reopen (DConfEngineSource *source)
+{
+  GvdbTable *table;
+  gchar *filename;
+
+  filename = g_build_filename (dconf_shm_get_shmdir (), source->name, NULL);
+  table = gvdb_table_new (filename, FALSE, NULL);
+  g_free (filename);
+
+  return table;
+}
+
+static void
+dconf_engine_source_user_nfs_finalize (DConfEngineSource *source)
+{
+}
+
+G_GNUC_INTERNAL
+const DConfEngineSourceVTable dconf_engine_source_user_nfs_vtable = {
+  .instance_size    = sizeof (DConfEngineSource),
+  .init             = dconf_engine_source_user_nfs_init,
+  .finalize         = dconf_engine_source_user_nfs_finalize,
+  .needs_reopen     = dconf_engine_source_user_nfs_needs_reopen,
+  .reopen           = dconf_engine_source_user_nfs_reopen
+};
diff --git a/engine/dconf-engine-source.c b/engine/dconf-engine-source.c
index 4eb7faa..68b10de 100644
--- a/engine/dconf-engine-source.c
+++ b/engine/dconf-engine-source.c
@@ -71,6 +71,15 @@ dconf_engine_source_refresh (DConfEngineSource *source)
   return FALSE;
 }
 
+static const DConfEngineSourceVTable *
+dconf_engine_source_get_user_vtable (void)
+{
+  if (dconf_shm_homedir_is_native ())
+    return &dconf_engine_source_user_vtable;
+  else
+    return &dconf_engine_source_user_nfs_vtable;
+}
+
 DConfEngineSource *
 dconf_engine_source_new (const gchar *description)
 {
@@ -94,7 +103,7 @@ dconf_engine_source_new (const gchar *description)
 
   /* Check if the part before the colon is "user-db"... */
   if ((colon == description + 7) && memcmp (description, "user-db", 7) == 0)
-    vtable = &dconf_engine_source_user_vtable;
+    vtable = dconf_engine_source_get_user_vtable ();
 
   /* ...or "system-db" */
   else if ((colon == description + 9) && memcmp (description, "system-db", 9) == 0)
@@ -122,10 +131,12 @@ dconf_engine_source_new (const gchar *description)
 DConfEngineSource *
 dconf_engine_source_new_default (void)
 {
+  const DConfEngineSourceVTable *vtable;
   DConfEngineSource *source;
 
-  source = g_malloc0 (dconf_engine_source_user_vtable.instance_size);
-  source->vtable = &dconf_engine_source_user_vtable;
+  vtable = dconf_engine_source_get_user_vtable ();
+  source = g_malloc0 (vtable->instance_size);
+  source->vtable = vtable;
   source->name = g_strdup ("user");
   source->vtable->init (source);