Creating a separate fs_init_finish() would perhaps have been clearner, but
it's a lot more work and usually isn't even necessary for most backends.
So I simply chose to use fs_get_properties() which is a fast call in all fs
backends and the few ones that actually care about the initialization finish
can then do their work in there.
ctx = p_new(list->pool, struct mailbox_list_fs_context, 1);
ctx->list = list;
MODULE_CONTEXT_SET(parent_fs, mailbox_list_fs_module, ctx);
+
+ /* a bit kludgy notification to the fs that we're now finished setting
+ up the module context. */
+ (void)fs_get_properties(*fs_r);
return 0;
}