lib: Squash last use of GFile deltas_dir

I was having this thought today about making more of the OS readonly,
and ultimately if we got to the point where all ostree operations are
through the repo and sysroot dfds, we could have rpm-ostree be the
only process holding those fds open, and have a read-only bind mount
on top.

Anyways, we're not there, likely won't be soon, but this gets us
closer to being fully fd relative.

Closes: #628
Approved by: jlebon

src/libostree/ostree-repo-private.h

@@ -72,7 +72,6 @@ struct OstreeRepo {
   int    cache_dir_fd;
   char  *cache_dir;
   int objects_dir_fd;
-  GFile *deltas_dir;
   int uncompressed_objects_dir_fd;
   GFile *sysroot_dir;
   char *remotes_config_dir;

src/libostree/ostree-repo-static-delta-core.c

@@ -73,65 +73,73 @@ ostree_repo_list_static_delta_names (OstreeRepo                  *self,
                                      GCancellable                *cancellable,
                                      GError                     **error)
 {
-  gboolean ret = FALSE;
   g_autoptr(GPtrArray) ret_deltas = NULL;
-  g_autoptr(GFileEnumerator) dir_enum = NULL;
+  glnx_fd_close int dfd = -1;
 
   ret_deltas = g_ptr_array_new_with_free_func (g_free);
 
-  if (g_file_query_exists (self->deltas_dir, NULL))
+  dfd = glnx_opendirat_with_errno (self->repo_dir_fd, "deltas", TRUE);
+  if (dfd < 0)
     {
-      dir_enum = g_file_enumerate_children (self->deltas_dir, OSTREE_GIO_FAST_QUERYINFO,
-                                            G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
-                                            NULL, error);
-      if (!dir_enum)
-        goto out;
+      if (errno != ENOENT)
+        {
+          glnx_set_error_from_errno (error);
+          return FALSE;
+        }
+    }
+  else
+    {
+      g_auto(GLnxDirFdIterator) dfd_iter = { 0, };
+
+      if (!glnx_dirfd_iterator_init_take_fd (dfd, &dfd_iter, error))
+        return FALSE;
+      dfd = -1;
 
       while (TRUE)
         {
-          g_autoptr(GFileEnumerator) dir_enum2 = NULL;
-          GFileInfo *file_info;
-          GFile *child;
+          g_auto(GLnxDirFdIterator) sub_dfd_iter = { 0, };
+          struct dirent *dent;
 
-          if (!g_file_enumerator_iterate (dir_enum, &file_info, &child,
-                                          NULL, error))
-            goto out;
-          if (file_info == NULL)
+          if (!glnx_dirfd_iterator_next_dent_ensure_dtype (&dfd_iter, &dent, cancellable, error))
+            return FALSE;
+          if (dent == NULL)
             break;
-
-          if (g_file_info_get_file_type (file_info) != G_FILE_TYPE_DIRECTORY)
+          if (dent->d_type != DT_DIR)
             continue;
 
-
-          dir_enum2 = g_file_enumerate_children (child, OSTREE_GIO_FAST_QUERYINFO,
-                                                 G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
-                                                 NULL, error);
-          if (!dir_enum2)
-            goto out;
+          if (!glnx_dirfd_iterator_init_at (dfd_iter.fd, dent->d_name, FALSE,
+                                            &sub_dfd_iter, error))
+            return FALSE;
 
           while (TRUE)
             {
-              GFileInfo *file_info2;
-              GFile *child2;
+              struct dirent *sub_dent;
               const char *name1;
               const char *name2;
+              g_autofree char *superblock_subpath = NULL;
+              struct stat stbuf;
 
-              if (!g_file_enumerator_iterate (dir_enum2, &file_info2, &child2,
-                                              NULL, error))
-                goto out;
-              if (file_info2 == NULL)
+              if (!glnx_dirfd_iterator_next_dent_ensure_dtype (&sub_dfd_iter, &sub_dent,
+                                                               cancellable, error))
+                return FALSE;
+              if (sub_dent == NULL)
                 break;
-
-              if (g_file_info_get_file_type (file_info2) != G_FILE_TYPE_DIRECTORY)
+              if (dent->d_type != DT_DIR)
                 continue;
 
-              name1 = g_file_info_get_name (file_info);
-              name2 = g_file_info_get_name (file_info2);
+              name1 = dent->d_name;
+              name2 = sub_dent->d_name;
 
+              superblock_subpath = g_strconcat (name2, "/superblock", NULL);
+              if (fstatat (sub_dfd_iter.fd, superblock_subpath, &stbuf, 0) < 0)
                 {
-                g_autoptr(GFile) meta_path = g_file_get_child (child2, "superblock");
-
-                if (g_file_query_exists (meta_path, NULL))
+                  if (errno != ENOENT)
+                    {
+                      glnx_set_error_from_errno (error);
+                      return FALSE;
+                    }
+                }
+              else
                 {
                   g_autofree char *buf = g_strconcat (name1, name2, NULL);
                   GString *out = g_string_new ("");
@@ -155,13 +163,10 @@ ostree_repo_list_static_delta_names (OstreeRepo                  *self,
             }
         }
     }
-    }
 
-  ret = TRUE;
   if (out_deltas)
     *out_deltas = g_steal_pointer (&ret_deltas);
- out:
-  return ret;
+  return TRUE;
 }
 
 gboolean

src/libostree/ostree-repo.c

@@ -521,7 +521,6 @@ ostree_repo_finalize (GObject *object)
     (void) close (self->cache_dir_fd);
   if (self->objects_dir_fd != -1)
     (void) close (self->objects_dir_fd);
-  g_clear_object (&self->deltas_dir);
   if (self->uncompressed_objects_dir_fd != -1)
     (void) close (self->uncompressed_objects_dir_fd);
   g_clear_object (&self->sysroot_dir);
@@ -606,8 +605,6 @@ ostree_repo_constructed (GObject *object)
 
   self->tmp_dir = g_file_resolve_relative_path (self->repodir, "tmp");
 
-  self->deltas_dir = g_file_get_child (self->repodir, "deltas");
-
   /* Ensure the "sysroot-path" property is set. */
   if (self->sysroot_dir == NULL)
     self->sysroot_dir = g_object_ref (_ostree_get_default_sysroot_path ());