OK. What do you have to say about this statement? Because fsnotify_nameremove() is called from d_delete() with negative or unhashed dentry, d_move() is not expected on this dentry, so it is safe to use d_parent/d_name without take_dentry_name_snapshot(). I assume it is not correct, but cannot figure out why. Under what circumstances is d_move() expected to move an unhashed dentry and hash it?

My other thought is why is fsnotify_nameremove() in d_delete() and not in vfs_unlink()/vfs_rmdir() under parent inode lock like the rest of the fsnotify_create/fsnotify_move hooks? In what case would we need the fsnotify event that is not coming from vfs_unlink()/vfs_rmdir()?