Hello, On Fri, Jun 02, 2017 at 02:53:55PM -0700, Shaohua Li wrote: > @@ -630,7 +633,11 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, > if (!kn) > goto err_out1; > > - ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); > + idr_preload(GFP_KERNEL); > + spin_lock(&kernfs_idr_lock); > + ret = idr_alloc(&root->ino_idr, kn, 1, 0, GFP_ATOMIC); > + spin_unlock(&kernfs_idr_lock); > + idr_preload_end(); So, this ends up populating the idr w/ a kn which isn't fully initialized yet, which can lead to bugs which are difficult to hunt down as we're gonna allow kn's to be looked up through ino / gen. We probably should allocate with NULL here and populate the actual pointer with idr_replace() after the kn is fully initialized / online. Thanks. -- tejun
