| Message ID | 20190612165233.109749-9-edumazet@google.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | net/packet: better behavior under DDOS | expand |
Hi, Eric Dumazet <edumazet@google.com> writes: > There are two places where we want to clear the pressure > if possible, add a helper to make it more obvious. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Suggested-by: Willem de Bruijn <willemb@google.com> > --- > net/packet/af_packet.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c > index d409e2fdaa7ee8ddf261354f91b682e403f40e9e..8c27e198268ab5148daa8e90aa2f53546623b9ed 100644 > --- a/net/packet/af_packet.c > +++ b/net/packet/af_packet.c > @@ -1271,6 +1271,13 @@ static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) > return ret; > } > > +static void packet_rcv_try_clear_pressure(struct packet_sock *po) > +{ > + if (READ_ONCE(po->pressure) && > + __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) > + WRITE_ONCE(po->pressure, 0); Just a couple of (microscopical?) nitpicks, double space here and on the commit message of patch 1/8. Series look good. Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cheers, -- Vinicius
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d409e2fdaa7ee8ddf261354f91b682e403f40e9e..8c27e198268ab5148daa8e90aa2f53546623b9ed 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1271,6 +1271,13 @@ static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) return ret; } +static void packet_rcv_try_clear_pressure(struct packet_sock *po) +{ + if (READ_ONCE(po->pressure) && + __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) + WRITE_ONCE(po->pressure, 0); +} + static void packet_sock_destruct(struct sock *sk) { skb_queue_purge(&sk->sk_error_queue); @@ -3308,8 +3315,7 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, if (skb == NULL) goto out; - if (READ_ONCE(pkt_sk(sk)->pressure)) - packet_rcv_has_room(pkt_sk(sk), NULL); + packet_rcv_try_clear_pressure(pkt_sk(sk)); if (pkt_sk(sk)->has_vnet_hdr) { err = packet_rcv_vnet(msg, skb, &len); @@ -4127,8 +4133,7 @@ static __poll_t packet_poll(struct file *file, struct socket *sock, TP_STATUS_KERNEL)) mask |= EPOLLIN | EPOLLRDNORM; } - if (READ_ONCE(po->pressure) && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) - WRITE_ONCE(po->pressure, 0); + packet_rcv_try_clear_pressure(po); spin_unlock_bh(&sk->sk_receive_queue.lock); spin_lock_bh(&sk->sk_write_queue.lock); if (po->tx_ring.pg_vec) {
There are two places where we want to clear the pressure if possible, add a helper to make it more obvious. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Willem de Bruijn <willemb@google.com> --- net/packet/af_packet.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)