On Fri, May 28, 2021 at 07:39:49PM +0800, Jia He wrote: > +/** > + * d_path_fast - fast return the full path of a dentry without taking > + * any seqlock/spinlock. This helper is typical for debugging purpose > + */ > +char *d_path_fast(const struct path *path, char *buf, int buflen) I'd suggest calling it d_path_unsafe(). Otherwise people will call it instead of d_path because who doesn't like fast? > +{ > + struct path root; > + struct mount *mnt = real_mount(path->mnt); > + DECLARE_BUFFER(b, buf, buflen); > + > + rcu_read_lock(); > + get_fs_root_rcu(current->fs, &root); > + > + prepend(&b, "", 1); > + __prepend_path(path->dentry, mnt, &root, &b); > + rcu_read_unlock(); > + > + return extract_string(&b); > +} > +EXPORT_SYMBOL(d_path_fast); Why export it? What module needs this?