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 <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 344da04..205630b 100644 (file)
--- 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 c74a810..ded7d93 100644 (file)
--- 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 2e21384..b5327bb 100644 (file)
--- 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 69f3799..a431c14 100644 (file)
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -132,8 +132,6 @@ fail:
  */
 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;
        }