tipc: remove pre-allocated message header in link struct

Until now, we have kept a pre-allocated protocol message header
aggregated into struct tipc_link. Apart from adding unnecessary
footprint to the link instances, this requires extra code both to
initialize and re-initialize it.

We now remove this sub-optimization. This change also makes it
possible to clean up the function tipc_build_proto_msg() and remove
a couple of small functions that were accessing the mentioned header.
In particular, we can replace all occurrences of the local function
call link_own_addr(link) with the generic tipc_own_addr(net).

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 45 insertions, 77 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index e401108360a2..ae469b37d852 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -412,11 +412,6 @@ enomem:
         return -ENOMEM;
 }
 
-void tipc_bcast_reinit(struct net *net)
-{
-        tipc_link_reinit(tipc_bc_sndlink(net), tipc_own_addr(net));
-}
-
 void tipc_bcast_stop(struct net *net)
 {
         struct tipc_net *tn = net_generic(net, tipc_net_id);
diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h
index 1944c6c00bb9..d5e79b3767fd 100644
--- a/net/tipc/bcast.h
+++ b/net/tipc/bcast.h
@@ -46,7 +46,6 @@ struct tipc_node_map;
 extern const char tipc_bclink_name[];
 
 int tipc_bcast_init(struct net *net);
-void tipc_bcast_reinit(struct net *net);
 void tipc_bcast_stop(struct net *net);
 void tipc_bcast_add_peer(struct net *net, struct tipc_link *l,
                          struct sk_buff_head *xmitq);
diff --git a/net/tipc/link.c b/net/tipc/link.c
index e31d92f80572..fc2fa833749e 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/link.c: TIPC link code
  *
- * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
+ * Copyright (c) 1996-2007, 2012-2016, Ericsson AB
  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
  * All rights reserved.
  *
@@ -127,6 +127,7 @@ struct tipc_link {
 
         /* Management and link supervision data */
         u32 peer_session;
+        u32 session;
         u32 peer_bearer_id;
         u32 bearer_id;
         u32 tolerance;
@@ -136,11 +137,7 @@ struct tipc_link {
         u16 peer_caps;
         bool active;
         u32 silent_intv_cnt;
-        struct {
-                unchar hdr[INT_H_SIZE];
-                unchar body[TIPC_MAX_IF_NAME];
-        } proto_msg;
-        struct tipc_msg *pmsg;
+        char if_name[TIPC_MAX_IF_NAME];
         u32 priority;
         char net_plane;
 
@@ -215,10 +212,11 @@ enum {
  * Interval between NACKs when packets arrive out of order
  */
 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
-/*
- * Out-of-range value for link session numbers
+
+/* Wildcard value for link session numbers. When it is known that
+ * peer endpoint is down, any session number must be accepted.
  */
-#define WILDCARD_SESSION 0x10000
+#define ANY_SESSION 0x10000
 
 /* Link FSM states:
  */
@@ -398,16 +396,6 @@ char *tipc_link_name(struct tipc_link *l)
         return l->name;
 }
 
-static u32 link_own_addr(struct tipc_link *l)
-{
-        return msg_prevnode(l->pmsg);
-}
-
-void tipc_link_reinit(struct tipc_link *l, u32 addr)
-{
-        msg_set_prevnode(l->pmsg, addr);
-}
-
 /**
  * tipc_link_create - create a new link
  * @n: pointer to associated node
@@ -441,29 +429,22 @@ bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
                       struct tipc_link **link)
 {
         struct tipc_link *l;
-        struct tipc_msg *hdr;
 
         l = kzalloc(sizeof(*l), GFP_ATOMIC);
         if (!l)
                 return false;
         *link = l;
-        l->pmsg = (struct tipc_msg *)&l->proto_msg;
-        hdr = l->pmsg;
-        tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
-        msg_set_size(hdr, sizeof(l->proto_msg));
-        msg_set_session(hdr, session);
-        msg_set_bearer_id(hdr, l->bearer_id);
+        l->session = session;
 
         /* Note: peer i/f name is completed by reset/activate message */
         sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
                 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
                 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
-        strcpy((char *)msg_data(hdr), if_name);
-
+        strcpy(l->if_name, if_name);
         l->addr = peer;
         l->peer_caps = peer_caps;
         l->net = net;
-        l->peer_session = WILDCARD_SESSION;
+        l->peer_session = ANY_SESSION;
         l->bearer_id = bearer_id;
         l->tolerance = tolerance;
         l->net_plane = net_plane;
@@ -790,7 +771,7 @@ static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
         struct tipc_msg *msg = buf_msg(skb_peek(list));
         int imp = msg_importance(msg);
         u32 oport = msg_origport(msg);
-        u32 addr = link_own_addr(link);
+        u32 addr = tipc_own_addr(link->net);
         struct sk_buff *skb;
 
         /* This really cannot happen...  */
@@ -839,16 +820,9 @@ void link_prepare_wakeup(struct tipc_link *l)
 
 void tipc_link_reset(struct tipc_link *l)
 {
-        /* Link is down, accept any session */
-        l->peer_session = WILDCARD_SESSION;
-
-        /* If peer is up, it only accepts an incremented session number */
-        msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
-
-        /* Prepare for renewed mtu size negotiation */
+        l->peer_session = ANY_SESSION;
+        l->session++;
         l->mtu = l->advertised_mtu;
-
-        /* Clean up all queues and counters: */
         __skb_queue_purge(&l->transmq);
         __skb_queue_purge(&l->deferdq);
         skb_queue_splice_init(&l->wakeupq, l->inputq);
@@ -1156,7 +1130,7 @@ int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
 
         /* Broadcast ACK must be sent via a unicast link => defer to caller */
         if (link_is_bc_rcvlink(l)) {
-                if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf)
+                if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
                         return 0;
                 l->rcv_unacked = 0;
                 return TIPC_LINK_SND_BC_ACK;
@@ -1268,15 +1242,30 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                       u16 rcvgap, int tolerance, int priority,
                                       struct sk_buff_head *xmitq)
 {
-        struct sk_buff *skb = NULL;
-        struct tipc_msg *hdr = l->pmsg;
+        struct sk_buff *skb;
+        struct tipc_msg *hdr;
+        struct sk_buff_head *dfq = &l->deferdq;
         bool node_up = link_is_up(l->bc_rcvlink);
 
         /* Don't send protocol message during reset or link failover */
         if (tipc_link_is_blocked(l))
                 return;
 
-        msg_set_type(hdr, mtyp);
+        if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
+                return;
+
+        if (!skb_queue_empty(dfq))
+                rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
+
+        skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
+                              TIPC_MAX_IF_NAME, l->addr,
+                              tipc_own_addr(l->net), 0, 0, 0);
+        if (!skb)
+                return;
+
+        hdr = buf_msg(skb);
+        msg_set_session(hdr, l->session);
+        msg_set_bearer_id(hdr, l->bearer_id);
         msg_set_net_plane(hdr, l->net_plane);
         msg_set_next_sent(hdr, l->snd_nxt);
         msg_set_ack(hdr, l->rcv_nxt - 1);
@@ -1286,36 +1275,23 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
         msg_set_linkprio(hdr, priority);
         msg_set_redundant_link(hdr, node_up);
         msg_set_seq_gap(hdr, 0);
-
-        /* Compatibility: created msg must not be in sequence with pkt flow */
         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
 
         if (mtyp == STATE_MSG) {
-                if (!tipc_link_is_up(l))
-                        return;
-
-                /* Override rcvgap if there are packets in deferred queue */
-                if (!skb_queue_empty(&l->deferdq))
-                        rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
-                if (rcvgap) {
-                        msg_set_seq_gap(hdr, rcvgap);
-                        l->stats.sent_nacks++;
-                }
+                msg_set_seq_gap(hdr, rcvgap);
+                msg_set_size(hdr, INT_H_SIZE);
                 msg_set_probe(hdr, probe);
-                if (probe)
-                        l->stats.sent_probes++;
                 l->stats.sent_states++;
                 l->rcv_unacked = 0;
         } else {
                 /* RESET_MSG or ACTIVATE_MSG */
                 msg_set_max_pkt(hdr, l->advertised_mtu);
-                msg_set_ack(hdr, l->rcv_nxt - 1);
-                msg_set_next_sent(hdr, 1);
+                strcpy(msg_data(hdr), l->if_name);
         }
-        skb = tipc_buf_acquire(msg_size(hdr));
-        if (!skb)
-                return;
-        skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
+        if (probe)
+                l->stats.sent_probes++;
+        if (rcvgap)
+                l->stats.sent_nacks++;
         skb->priority = TC_PRIO_CONTROL;
         __skb_queue_tail(xmitq, skb);
 }
@@ -1340,7 +1316,7 @@ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
 
         /* At least one packet required for safe algorithm => add dummy */
         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
-                              BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
+                              BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
                               0, 0, TIPC_ERR_NO_PORT);
         if (!skb) {
                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
@@ -1351,7 +1327,7 @@ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
         __skb_queue_purge(&tmpxq);
 
         /* Initialize reusable tunnel packet header */
-        tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
+        tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
                       mtyp, INT_H_SIZE, l->addr);
         pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
         msg_set_msgcnt(&tnlhdr, pktcnt);
@@ -1410,7 +1386,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
         if (tipc_link_is_blocked(l) || !xmitq)
                 goto exit;
 
-        if (link_own_addr(l) > msg_prevnode(hdr))
+        if (tipc_own_addr(l->net) > msg_prevnode(hdr))
                 l->net_plane = msg_net_plane(hdr);
 
         switch (mtyp) {
@@ -1418,7 +1394,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 
                 /* Ignore duplicate RESET with old session number */
                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
-                    (l->peer_session != WILDCARD_SESSION))
+                    (l->peer_session != ANY_SESSION))
                         break;
                 /* fall thru' */
 
@@ -1515,7 +1491,7 @@ static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
         u16 gap_to = peers_snd_nxt - 1;
 
         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
-                              0, l->addr, link_own_addr(l), 0, 0, 0);
+                              0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
         if (!skb)
                 return false;
         hdr = buf_msg(skb);
@@ -1670,7 +1646,7 @@ int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
         if (mtyp != STATE_MSG)
                 return 0;
 
-        if (dnode == link_own_addr(l)) {
+        if (dnode == tipc_own_addr(l->net)) {
                 tipc_link_bc_ack_rcv(l, acked, xmitq);
                 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
                 l->stats.recv_nacks++;
diff --git a/net/tipc/link.h b/net/tipc/link.h
index b4ee9d6e181d..6a94175ee20a 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -86,7 +86,6 @@ bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
                          struct sk_buff_head *namedq,
                          struct tipc_link *bc_sndlink,
                          struct tipc_link **link);
-void tipc_link_reinit(struct tipc_link *l, u32 addr);
 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
                            int mtyp, struct sk_buff_head *xmitq);
 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
diff --git a/net/tipc/net.c b/net/tipc/net.c
index 77bf9113c7a7..86d68b352bd6 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -116,7 +116,6 @@ int tipc_net_start(struct net *net, u32 addr)
         tn->own_addr = addr;
         tipc_named_reinit(net);
         tipc_sk_reinit(net);
-        tipc_bcast_reinit(net);
 
         tipc_nametbl_publish(net, TIPC_CFG_SRV, tn->own_addr, tn->own_addr,
                              TIPC_ZONE_SCOPE, 0, tn->own_addr);