bpf: support deferring bpf_link dealloc to after RCU grace period

[linux-2.6-block.git] / include / linux / bpf.h

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 4f20f62f9d63da87800af4ac21cbc7c92dae5fb9..890e152d553ea3cc8d16b2a058f2dfd657aba1f8 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1574,12 +1574,26 @@ struct bpf_link {
        enum bpf_link_type type;
        const struct bpf_link_ops *ops;
        struct bpf_prog *prog;
-       struct work_struct work;
+       /* rcu is used before freeing, work can be used to schedule that
+        * RCU-based freeing before that, so they never overlap
+        */
+       union {
+               struct rcu_head rcu;
+               struct work_struct work;
+       };
 };
 
 struct bpf_link_ops {
        void (*release)(struct bpf_link *link);
+       /* deallocate link resources callback, called without RCU grace period
+        * waiting
+        */
        void (*dealloc)(struct bpf_link *link);
+       /* deallocate link resources callback, called after RCU grace period;
+        * if underlying BPF program is sleepable we go through tasks trace
+        * RCU GP and then "classic" RCU GP
+        */
+       void (*dealloc_deferred)(struct bpf_link *link);
        int (*detach)(struct bpf_link *link);
        int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,
                           struct bpf_prog *old_prog);