diff --git a/src/libostree/ostree-repo.c b/src/libostree/ostree-repo.c
index f87bd33c..729f9d4b 100644
--- a/src/libostree/ostree-repo.c
+++ b/src/libostree/ostree-repo.c
@@ -574,25 +574,19 @@ write_gvariant_to_tmp (OstreeRepo  *self,
   GVariant *serialized = NULL;
   gboolean ret = FALSE;
   gsize bytes_written;
-  char *tmp_name = NULL;
-  char *dest_name = NULL;
-  int fd = -1;
-  GUnixOutputStream *stream = NULL;
+  GFile *tmp_f = NULL;
+  GOutputStream *stream = NULL;
   GChecksum *checksum = NULL;
+  GFile *ret_tmpname = NULL;
 
   serialized = ostree_wrap_metadata_variant (type, variant);
 
-  tmp_name = g_build_filename (ot_gfile_get_path_cached (priv->tmp_dir), "variant-tmp-XXXXXX", NULL);
-  fd = g_mkstemp (tmp_name);
-  if (fd < 0)
-    {
-      ot_util_set_error_from_errno (error, errno);
-      goto out;
-    }
+  if (!ot_gfile_create_tmp (priv->tmp_dir, "variant-tmp-", NULL, 0666,
+                            &tmp_f, &stream, NULL, error))
+    goto out;
 
   checksum = g_checksum_new (G_CHECKSUM_SHA256);
 
-  stream = (GUnixOutputStream*)g_unix_output_stream_new (fd, FALSE);
   if (!g_output_stream_write_all ((GOutputStream*)stream,
                                   g_variant_get_data (serialized),
                                   g_variant_get_size (serialized),
@@ -607,29 +601,27 @@ write_gvariant_to_tmp (OstreeRepo  *self,
                               NULL, error))
     goto out;
 
-  dest_name = g_build_filename (ot_gfile_get_path_cached (priv->tmp_dir), g_checksum_get_string (checksum), NULL);
-  if (rename (tmp_name, dest_name) < 0)
+  ret_tmpname = g_file_get_child (priv->tmp_dir, g_checksum_get_string (checksum));
+  if (rename (ot_gfile_get_path_cached (tmp_f), ot_gfile_get_path_cached (ret_tmpname)) < 0)
     {
       ot_util_set_error_from_errno (error, errno);
       goto out;
     }
-  g_free (tmp_name);
-  tmp_name = NULL;
+  g_clear_object (&tmp_f);
 
   ret = TRUE;
-  *out_tmpname = ot_gfile_new_for_path (dest_name);
+  *out_tmpname = ret_tmpname;
+  ret_tmpname = NULL;
   *out_checksum = checksum;
   checksum = NULL;
  out:
-  if (tmp_name)
-    (void) unlink (tmp_name);
-  g_free (tmp_name);
-  if (fd != -1)
-    close (fd);
+  if (tmp_f)
+    (void) g_file_delete (tmp_f, NULL, NULL);
+  g_clear_object (&tmp_f);
+  g_clear_object (&stream);
+  g_clear_object (&ret_tmpname);
   ot_clear_checksum (&checksum);
   ot_clear_gvariant (&serialized);
-  g_free (dest_name);
-  g_clear_object (&stream);
   return ret;
 }
 
@@ -817,6 +809,8 @@ link_object_trusted (OstreeRepo   *self,
           || rename (tmp_dest_path, dest_path) < 0)
         {
           ot_util_set_error_from_errno (error, errno);
+          g_prefix_error (error, "Storing file '%s': ",
+                          ot_gfile_get_path_cached (file));
           goto out;
         }
       g_free (tmp_dest_path);
diff --git a/src/libotutil/ot-gio-utils.c b/src/libotutil/ot-gio-utils.c
index 28fd79c0..0c4e0010 100644
--- a/src/libotutil/ot-gio-utils.c
+++ b/src/libotutil/ot-gio-utils.c
@@ -24,11 +24,16 @@
 
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
+#include <gio/gunixoutputstream.h>
 
 #include <string.h>
 
 #include "otutil.h"
 
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
 gboolean
 ot_gfile_ensure_directory (GFile     *dir,
                            gboolean   with_parents, 
@@ -133,6 +138,64 @@ ot_gfile_get_basename_cached (GFile *file)
   return name;
 }
 
+gboolean
+ot_gfile_create_tmp (GFile       *dir,
+                     const char  *prefix,
+                     const char  *suffix,
+                     int          mode,
+                     GFile      **out_file,
+                     GOutputStream **out_stream,
+                     GCancellable *cancellable,
+                     GError       **error)
+{
+  gboolean ret = FALSE;
+  GString *tmp_name = NULL;
+  int tmpfd = -1;
+  GFile *ret_file = NULL;
+  GOutputStream *ret_stream = NULL;
+
+  if (g_cancellable_set_error_if_cancelled (cancellable, error))
+    return FALSE;
+
+  if (!prefix)
+    prefix = "tmp-";
+  if (!suffix)
+    suffix = ".tmp";
+
+  tmp_name = g_string_new (ot_gfile_get_path_cached (dir));
+  g_string_append_c (tmp_name, '/');
+  g_string_append (tmp_name, prefix);
+  g_string_append (tmp_name, "XXXXXX");
+  g_string_append (tmp_name, suffix);
+  
+  tmpfd = g_mkstemp_full (tmp_name->str, O_WRONLY | O_BINARY, mode);
+  if (tmpfd == -1)
+    {
+      ot_util_set_error_from_errno (error, errno);
+      goto out;
+    }
+
+  ret_file = ot_gfile_new_for_path (tmp_name->str);
+  ret_stream = g_unix_output_stream_new (tmpfd, TRUE);
+  
+  ret = TRUE;
+  if (out_file)
+    {
+      *out_file = ret_file;
+      ret_file = NULL;
+    }
+  if (out_stream)
+    {
+      *out_stream = ret_stream;
+      ret_stream = NULL;
+    }
+ out:
+  g_clear_object (&ret_file);
+  g_clear_object (&ret_stream);
+  g_string_free (tmp_name, TRUE);
+  return ret;
+}
+
 gboolean
 ot_gfile_merge_dirs (GFile    *destination,
                      GFile    *src,
diff --git a/src/libotutil/ot-gio-utils.h b/src/libotutil/ot-gio-utils.h
index 819a8738..26da9adf 100644
--- a/src/libotutil/ot-gio-utils.h
+++ b/src/libotutil/ot-gio-utils.h
@@ -43,6 +43,14 @@ gboolean ot_gfile_load_contents_utf8 (GFile         *file,
                                       GCancellable  *cancellable,
                                       GError       **error);
 
+gboolean ot_gfile_create_tmp (GFile       *dir,
+                              const char  *prefix,
+                              const char  *suffix,
+                              int          mode,
+                              GFile      **out_file,
+                              GOutputStream **out_stream,
+                              GCancellable *cancellable,
+                              GError       **error);
 
 gboolean ot_gfile_merge_dirs (GFile    *destination,
                               GFile    *src,