Re: [PATCH] kernfs: Drop kernfs_rwsem while invoking lookup_positive_unlocked().

Sebastian Andrzej Siewior
2025-02-21T07:50:01Z

On 2025-02-20 20:39:24 [+0000], Al Viro wrote:
> On Tue, Feb 18, 2025 at 05:39:38PM +0100, Sebastian Andrzej Siewior wrote:
>
> > + scoped_guard(rcu) {
> > + knparent = find_next_ancestor(kn, NULL);
> > + if (WARN_ON(!knparent)) {
> > + dput(dentry);
> > + return ERR_PTR(-EINVAL);
> > + }
>
> NAK. dput() is blocking; you *can't* do that under rcu_read_lock().

Thank you.
Since it got merged, let me do another one on top.

Sebastian