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)
> +{
> + 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);
Umm... I'd suggest failing if __prepend_path() returns 3 (at least)...
