diff options
Diffstat (limited to 'net/core/sock_reuseport.c')
| -rw-r--r-- | net/core/sock_reuseport.c | 94 |
1 files changed, 89 insertions, 5 deletions
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c index fb90e1e00773..5a165286e4d8 100644 --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -37,6 +37,70 @@ void reuseport_has_conns_set(struct sock *sk) } EXPORT_SYMBOL(reuseport_has_conns_set); +static void __reuseport_get_incoming_cpu(struct sock_reuseport *reuse) +{ + /* Paired with READ_ONCE() in reuseport_select_sock_by_hash(). */ + WRITE_ONCE(reuse->incoming_cpu, reuse->incoming_cpu + 1); +} + +static void __reuseport_put_incoming_cpu(struct sock_reuseport *reuse) +{ + /* Paired with READ_ONCE() in reuseport_select_sock_by_hash(). */ + WRITE_ONCE(reuse->incoming_cpu, reuse->incoming_cpu - 1); +} + +static void reuseport_get_incoming_cpu(struct sock *sk, struct sock_reuseport *reuse) +{ + if (sk->sk_incoming_cpu >= 0) + __reuseport_get_incoming_cpu(reuse); +} + +static void reuseport_put_incoming_cpu(struct sock *sk, struct sock_reuseport *reuse) +{ + if (sk->sk_incoming_cpu >= 0) + __reuseport_put_incoming_cpu(reuse); +} + +void reuseport_update_incoming_cpu(struct sock *sk, int val) +{ + struct sock_reuseport *reuse; + int old_sk_incoming_cpu; + + if (unlikely(!rcu_access_pointer(sk->sk_reuseport_cb))) { + /* Paired with REAE_ONCE() in sk_incoming_cpu_update() + * and compute_score(). + */ + WRITE_ONCE(sk->sk_incoming_cpu, val); + return; + } + + spin_lock_bh(&reuseport_lock); + + /* This must be done under reuseport_lock to avoid a race with + * reuseport_grow(), which accesses sk->sk_incoming_cpu without + * lock_sock() when detaching a shutdown()ed sk. + * + * Paired with READ_ONCE() in reuseport_select_sock_by_hash(). + */ + old_sk_incoming_cpu = sk->sk_incoming_cpu; + WRITE_ONCE(sk->sk_incoming_cpu, val); + + reuse = rcu_dereference_protected(sk->sk_reuseport_cb, + lockdep_is_held(&reuseport_lock)); + + /* reuseport_grow() has detached a closed sk. */ + if (!reuse) + goto out; + + if (old_sk_incoming_cpu < 0 && val >= 0) + __reuseport_get_incoming_cpu(reuse); + else if (old_sk_incoming_cpu >= 0 && val < 0) + __reuseport_put_incoming_cpu(reuse); + +out: + spin_unlock_bh(&reuseport_lock); +} + static int reuseport_sock_index(struct sock *sk, const struct sock_reuseport *reuse, bool closed) @@ -64,6 +128,7 @@ static void __reuseport_add_sock(struct sock *sk, /* paired with smp_rmb() in reuseport_(select|migrate)_sock() */ smp_wmb(); reuse->num_socks++; + reuseport_get_incoming_cpu(sk, reuse); } static bool __reuseport_detach_sock(struct sock *sk, @@ -76,6 +141,7 @@ static bool __reuseport_detach_sock(struct sock *sk, reuse->socks[i] = reuse->socks[reuse->num_socks - 1]; reuse->num_socks--; + reuseport_put_incoming_cpu(sk, reuse); return true; } @@ -86,6 +152,7 @@ static void __reuseport_add_closed_sock(struct sock *sk, reuse->socks[reuse->max_socks - reuse->num_closed_socks - 1] = sk; /* paired with READ_ONCE() in inet_csk_bind_conflict() */ WRITE_ONCE(reuse->num_closed_socks, reuse->num_closed_socks + 1); + reuseport_get_incoming_cpu(sk, reuse); } static bool __reuseport_detach_closed_sock(struct sock *sk, @@ -99,6 +166,7 @@ static bool __reuseport_detach_closed_sock(struct sock *sk, reuse->socks[i] = reuse->socks[reuse->max_socks - reuse->num_closed_socks]; /* paired with READ_ONCE() in inet_csk_bind_conflict() */ WRITE_ONCE(reuse->num_closed_socks, reuse->num_closed_socks - 1); + reuseport_put_incoming_cpu(sk, reuse); return true; } @@ -166,6 +234,7 @@ int reuseport_alloc(struct sock *sk, bool bind_inany) reuse->bind_inany = bind_inany; reuse->socks[0] = sk; reuse->num_socks = 1; + reuseport_get_incoming_cpu(sk, reuse); rcu_assign_pointer(sk->sk_reuseport_cb, reuse); out: @@ -209,6 +278,7 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse) more_reuse->reuseport_id = reuse->reuseport_id; more_reuse->bind_inany = reuse->bind_inany; more_reuse->has_conns = reuse->has_conns; + more_reuse->incoming_cpu = reuse->incoming_cpu; memcpy(more_reuse->socks, reuse->socks, reuse->num_socks * sizeof(struct sock *)); @@ -458,18 +528,32 @@ static struct sock *run_bpf_filter(struct sock_reuseport *reuse, u16 socks, static struct sock *reuseport_select_sock_by_hash(struct sock_reuseport *reuse, u32 hash, u16 num_socks) { + struct sock *first_valid_sk = NULL; int i, j; i = j = reciprocal_scale(hash, num_socks); - while (reuse->socks[i]->sk_state == TCP_ESTABLISHED) { + do { + struct sock *sk = reuse->socks[i]; + + if (sk->sk_state != TCP_ESTABLISHED) { + /* Paired with WRITE_ONCE() in __reuseport_(get|put)_incoming_cpu(). */ + if (!READ_ONCE(reuse->incoming_cpu)) + return sk; + + /* Paired with WRITE_ONCE() in reuseport_update_incoming_cpu(). */ + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) + return sk; + + if (!first_valid_sk) + first_valid_sk = sk; + } + i++; if (i >= num_socks) i = 0; - if (i == j) - return NULL; - } + } while (i != j); - return reuse->socks[i]; + return first_valid_sk; } /** |