static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
void sock_update_memcg(struct sock *sk)
{
- /* A socket spends its whole life in the same cgroup */
- if (sk->sk_cgrp) {
- WARN_ON(1);
- return;
- }
if (static_branch(&memcg_socket_limit_enabled)) {
struct mem_cgroup *memcg;
BUG_ON(!sk->sk_prot->proto_cgroup);
+ /* Socket cloning can throw us here with sk_cgrp already
+ * filled. It won't however, necessarily happen from
+ * process context. So the test for root memcg given
+ * the current task's memcg won't help us in this case.
+ *
+ * Respecting the original socket's memcg is a better
+ * decision in this case.
+ */
+ if (sk->sk_cgrp) {
+ BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
+ mem_cgroup_get(sk->sk_cgrp->memcg);
+ return;
+ }
+
rcu_read_lock();
memcg = mem_cgroup_from_task(current);
if (!mem_cgroup_is_root(memcg)) {