On Fri, Dec 13, 2024 at 12:03:42AM +0100, Christian Brauner wrote:
> +static inline void mnt_ns_tree_write_lock(void)
> +{
> + write_lock(&mnt_ns_tree_lock);
> + write_seqcount_begin(&mnt_ns_tree_seqcount);
> +}
> +
> +static inline void mnt_ns_tree_write_unlock(void)
> +{
> + write_seqcount_end(&mnt_ns_tree_seqcount);
> + write_unlock(&mnt_ns_tree_lock);
> }
> static void mnt_ns_tree_add(struct mnt_namespace *ns)
> {
> - guard(write_lock)(&mnt_ns_tree_lock);
> - rb_add(&ns->mnt_ns_tree_node, &mnt_ns_tree, mnt_ns_less);
> + struct rb_node *node;
> +
> + mnt_ns_tree_write_lock();
> + node = rb_find_add_rcu(&ns->mnt_ns_tree_node, &mnt_ns_tree, mnt_ns_cmp);
> + mnt_ns_tree_write_unlock();
> +
> + WARN_ON_ONCE(node);
> }
> static void mnt_ns_tree_remove(struct mnt_namespace *ns)
> {
> /* remove from global mount namespace list */
> if (!is_anon_ns(ns)) {
> - guard(write_lock)(&mnt_ns_tree_lock);
> + mnt_ns_tree_write_lock();
> rb_erase(&ns->mnt_ns_tree_node, &mnt_ns_tree);
> + mnt_ns_tree_write_unlock();
> }
>
> - mnt_ns_release(ns);
> + call_rcu(&ns->mnt_ns_rcu, mnt_ns_release_rcu);
> }
Its probably not worth the effort, but I figured I'd mention it anyway,
if you do:
DEFINE_LOCK_GUARD_0(mnt_ns_tree_lock, mnt_ns_tree_lock(), mnt_ns_tree_unlock())
You can use: guard(mnt_ns_tree_lock)();
But like said, probably not worth it, given the above are the only two
sites and they're utterly trivial.
Anyway, rest of the patches look good now.
