From: Xin Long <lucien.xin@xxxxxxxxx> Date: Mon, 15 Oct 2018 19:58:29 +0800 > Other than asoc pmtu sync from all transports, sctp_assoc_sync_pmtu > is also processing transport pmtu_pending by icmp packets. But it's > meaningless to use sctp_dst_mtu(t->dst) as new pmtu for a transport. > > The right pmtu value should come from the icmp packet, and it would > be saved into transport->mtu_info in this patch and used later when > the pmtu sync happens in sctp_sendmsg_to_asoc or sctp_packet_config. > > Besides, without this patch, as pmtu can only be updated correctly > when receiving a icmp packet and no place is holding sock lock, it > will take long time if the sock is busy with sending packets. > > Note that it doesn't process transport->mtu_info in .release_cb(), > as there is no enough information for pmtu update, like for which > asoc or transport. It is not worth traversing all asocs to check > pmtu_pending. So unlike tcp, sctp does this in tx path, for which > mtu_info needs to be atomic_t. > > Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Applied.
