net: sctp: migrate most recently used transport to ktime

Be more precise in transport path selection and use ktime
helpers instead of jiffies to compare and pick the better
primary and secondary recently used transports. This also
avoids any side-effects during a possible roll-over, and
could lead to better path decision-making.

Signed-off-by: Daniel Borkmann <dborkman@redhat.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 0dfcc92600e86cd3263a7378b613d8a3e81ff767..f38588bf3462d9e2374258bb6c383e38413507ed 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -838,10 +838,10 @@ struct sctp_transport {
        unsigned long sackdelay;
        __u32 sackfreq;
 
-       /* When was the last time (in jiffies) that we heard from this
-        * transport?  We use this to pick new active and retran paths.
+       /* When was the last time that we heard from this transport? We use
+        * this to pick new active and retran paths.
         */
-       unsigned long last_time_heard;
+       ktime_t last_time_heard;
 
        /* Last time(in jiffies) when cwnd is reduced due to the congestion
         * indication based on ECNE chunk.

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 9f1cc6f1535dd9cfaca5b8959272523854480911..620c99e19e7780209dad28dbb657e3db0a9281fb 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1036,7 +1036,7 @@ static void sctp_assoc_bh_rcv(struct work_struct *work)
                }
 
                if (chunk->transport)
-                       chunk->transport->last_time_heard = jiffies;
+                       chunk->transport->last_time_heard = ktime_get();
 
                /* Run through the state machine. */
                error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
@@ -1283,11 +1283,13 @@ static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
                    trans->state == SCTP_PF)
                        continue;
                if (trans_pri == NULL ||
-                   trans->last_time_heard > trans_pri->last_time_heard) {
+                   ktime_after(trans->last_time_heard,
+                               trans_pri->last_time_heard)) {
                        trans_sec = trans_pri;
                        trans_pri = trans;
                } else if (trans_sec == NULL ||
-                          trans->last_time_heard > trans_sec->last_time_heard) {
+                          ktime_after(trans->last_time_heard,
+                                      trans_sec->last_time_heard)) {
                        trans_sec = trans;
                }
        }

diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 3d9f429858dca24f6262996bbec03ca59491b0c0..9da76ba4d10fe316884973448c19e5b9b8310a79 100644 (file)
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -481,7 +481,7 @@ normal:
                }
 
                if (chunk->transport)
-                       chunk->transport->last_time_heard = jiffies;
+                       chunk->transport->last_time_heard = ktime_get();
 
                error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
                                   ep, asoc, chunk, GFP_ATOMIC);

diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 1d348d15b33de4c3b20f7f071442c05058e7dcc3..7dd672fa651f979ae6b93578fc678254a7317b6b 100644 (file)
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -72,7 +72,7 @@ static struct sctp_transport *sctp_transport_init(struct net *net,
         */
        peer->rto = msecs_to_jiffies(net->sctp.rto_initial);
 
-       peer->last_time_heard = jiffies;
+       peer->last_time_heard = ktime_get();
        peer->last_time_ecne_reduced = jiffies;
 
        peer->param_flags = SPP_HB_DISABLE |