From 47faa1e4c50ec26e6e75dcd1ce53f064bd45f729 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 22 Jan 2016 01:49:09 +0800 Subject: [PATCH] sctp: remove the dead field of sctp_transport After we use refcnt to check if transport is alive, the dead can be removed from sctp_transport. The traversal of transport_addr_list in procfs dump is using list_for_each_entry_rcu, no need to check if it has been freed. sctp_generate_t3_rtx_event and sctp_generate_heartbeat_event is protected by sock lock, it's not necessary to check dead, either. also, the timers are cancelled when sctp_transport_free() is called, that it doesn't wait for refcnt to reach 0 to cancel them. Signed-off-by: Xin Long Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/structs.h | 3 +-- net/sctp/proc.c | 4 ---- net/sctp/sm_sideeffect.c | 12 ------------ net/sctp/transport.c | 4 +--- 4 files changed, 2 insertions(+), 21 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 344da04e2e30..205630bb5010 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -756,7 +756,6 @@ struct sctp_transport { /* Reference counting. */ atomic_t refcnt; - __u32 dead:1, /* RTO-Pending : A flag used to track if one of the DATA * chunks sent to this address is currently being * used to compute a RTT. If this flag is 0, @@ -766,7 +765,7 @@ struct sctp_transport { * calculation completes (i.e. the DATA chunk * is SACK'd) clear this flag. */ - rto_pending:1, + __u32 rto_pending:1, /* * hb_sent : a flag that signals that we have a pending diff --git a/net/sctp/proc.c b/net/sctp/proc.c index c74a810150aa..ded7d931a6a5 100644 --- a/net/sctp/proc.c +++ b/net/sctp/proc.c @@ -165,8 +165,6 @@ static void sctp_seq_dump_remote_addrs(struct seq_file *seq, struct sctp_associa list_for_each_entry_rcu(transport, &assoc->peer.transport_addr_list, transports) { addr = &transport->ipaddr; - if (transport->dead) - continue; af = sctp_get_af_specific(addr->sa.sa_family); if (af->cmp_addr(addr, primary)) { @@ -499,8 +497,6 @@ static int sctp_remaddr_seq_show(struct seq_file *seq, void *v) list_for_each_entry_rcu(tsp, &assoc->peer.transport_addr_list, transports) { - if (tsp->dead) - continue; /* * The remote address (ADDR) */ diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 2e21384697c2..b5327bb77458 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -259,12 +259,6 @@ void sctp_generate_t3_rtx_event(unsigned long peer) goto out_unlock; } - /* Is this transport really dead and just waiting around for - * the timer to let go of the reference? - */ - if (transport->dead) - goto out_unlock; - /* Run through the state machine. */ error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX), @@ -380,12 +374,6 @@ void sctp_generate_heartbeat_event(unsigned long data) goto out_unlock; } - /* Is this structure just waiting around for us to actually - * get destroyed? - */ - if (transport->dead) - goto out_unlock; - error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT), asoc->state, asoc->ep, asoc, diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 69f3799570a7..a431c14044a4 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -132,8 +132,6 @@ struct sctp_transport *sctp_transport_new(struct net *net, */ void sctp_transport_free(struct sctp_transport *transport) { - transport->dead = 1; - /* Try to delete the heartbeat timer. */ if (del_timer(&transport->hb_timer)) sctp_transport_put(transport); @@ -169,7 +167,7 @@ static void sctp_transport_destroy_rcu(struct rcu_head *head) */ static void sctp_transport_destroy(struct sctp_transport *transport) { - if (unlikely(!transport->dead)) { + if (unlikely(atomic_read(&transport->refcnt))) { WARN(1, "Attempt to destroy undead transport %p!\n", transport); return; }