>An open issue is that lockless dentry lookup cannot happen on a directory which has extended attributes or when there is any sort of security module active. Nick acknowledged the problem, but had no immediate solution to offer; it is a matter of future work. Evidently supporting lockless lookup in such situations will require changes within the filesystems as well as at the VFS layer.
Does it apply to name-based security modules (AppArmor and TOMOYO)?