tipc: remove implicit message delivery in node_unlock()

After the most recent changes, all access calls to a link which
may entail addition of messages to the link's input queue are
postpended by an explicit call to tipc_sk_rcv(), using a reference
to the correct queue.

This means that the potentially hazardous implicit delivery, using
tipc_node_unlock() in combination with a binary flag and a cached
queue pointer, now has become redundant.

This commit removes this implicit delivery mechanism both for regular
data messages and for binding table update messages.

Tested-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>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 3a92924..2aa19de 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -559,8 +559,6 @@ void link_prepare_wakeup(struct tipc_link *l)
                        break;
                skb_unlink(skb, &l->wakeupq);
                skb_queue_tail(l->inputq, skb);
-               l->owner->inputq = l->inputq;
-               l->owner->action_flags |= TIPC_MSG_EVT;
        }
 }
 
@@ -598,8 +596,6 @@ void tipc_link_purge_queues(struct tipc_link *l_ptr)
 
 void tipc_link_reset(struct tipc_link *l)
 {
-       struct tipc_node *owner = l->owner;
-
        tipc_link_fsm_evt(l, LINK_RESET_EVT);
 
        /* Link is down, accept any session */
@@ -611,14 +607,10 @@ void tipc_link_reset(struct tipc_link *l)
        /* Prepare for renewed mtu size negotiation */
        l->mtu = l->advertised_mtu;
 
-       /* Clean up all queues, except inputq: */
+       /* Clean up all queues: */
        __skb_queue_purge(&l->transmq);
        __skb_queue_purge(&l->deferdq);
-       if (!owner->inputq)
-               owner->inputq = l->inputq;
-       skb_queue_splice_init(&l->wakeupq, owner->inputq);
-       if (!skb_queue_empty(owner->inputq))
-               owner->action_flags |= TIPC_MSG_EVT;
+       skb_queue_splice_init(&l->wakeupq, l->inputq);
 
        tipc_link_purge_backlog(l);
        kfree_skb(l->reasm_buf);
@@ -972,7 +964,6 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
 {
        struct tipc_node *node = link->owner;
        struct tipc_msg *msg = buf_msg(skb);
-       u32 dport = msg_destport(msg);
 
        switch (msg_user(msg)) {
        case TIPC_LOW_IMPORTANCE:
@@ -980,17 +971,11 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
        case TIPC_HIGH_IMPORTANCE:
        case TIPC_CRITICAL_IMPORTANCE:
        case CONN_MANAGER:
-               if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
-                       node->inputq = link->inputq;
-                       node->action_flags |= TIPC_MSG_EVT;
-               }
+               skb_queue_tail(link->inputq, skb);
                return true;
        case NAME_DISTRIBUTOR:
                node->bclink.recv_permitted = true;
-               node->namedq = link->namedq;
                skb_queue_tail(link->namedq, skb);
-               if (skb_queue_len(link->namedq) == 1)
-                       node->action_flags |= TIPC_NAMED_MSG_EVT;
                return true;
        case MSG_BUNDLER:
        case TUNNEL_PROTOCOL:

diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 53d98ef..a82c584 100644 (file)
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -862,28 +862,6 @@ static inline struct sk_buff *tipc_skb_dequeue(struct sk_buff_head *list,
        return skb;
 }
 
-/* tipc_skb_queue_tail(): add buffer to tail of list;
- * @list: list to be appended to
- * @skb: buffer to append. Always appended
- * @dport: the destination port of the buffer
- * returns true if dport differs from previous destination
- */
-static inline bool tipc_skb_queue_tail(struct sk_buff_head *list,
-                                      struct sk_buff *skb, u32 dport)
-{
-       struct sk_buff *_skb = NULL;
-       bool rv = false;
-
-       spin_lock_bh(&list->lock);
-       _skb = skb_peek_tail(list);
-       if (!_skb || (msg_destport(buf_msg(_skb)) != dport) ||
-           (skb_queue_len(list) > 32))
-               rv = true;
-       __skb_queue_tail(list, skb);
-       spin_unlock_bh(&list->lock);
-       return rv;
-}
-
 /* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
  * @list: list to be appended to
  * @skb: buffer to add

diff --git a/net/tipc/node.c b/net/tipc/node.c
index cdca57b..9e9b093 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -873,10 +873,8 @@ static void node_lost_contact(struct tipc_node *n_ptr,
                                      SHORT_H_SIZE, 0, tn->own_addr,
                                      conn->peer_node, conn->port,
                                      conn->peer_port, TIPC_ERR_NO_NODE);
-               if (likely(skb)) {
+               if (likely(skb))
                        skb_queue_tail(inputq, skb);
-                       n_ptr->action_flags |= TIPC_MSG_EVT;
-               }
                list_del(&conn->list);
                kfree(conn);
        }
@@ -923,27 +921,20 @@ void tipc_node_unlock(struct tipc_node *node)
        u32 flags = node->action_flags;
        u32 link_id = 0;
        struct list_head *publ_list;
-       struct sk_buff_head *inputq = node->inputq;
-       struct sk_buff_head *namedq;
 
-       if (likely(!flags || (flags == TIPC_MSG_EVT))) {
-               node->action_flags = 0;
+       if (likely(!flags)) {
                spin_unlock_bh(&node->lock);
-               if (flags == TIPC_MSG_EVT)
-                       tipc_sk_rcv(net, inputq);
                return;
        }
 
        addr = node->addr;
        link_id = node->link_id;
-       namedq = node->namedq;
        publ_list = &node->publ_list;
 
-       node->action_flags &= ~(TIPC_MSG_EVT |
-                               TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
+       node->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
                                TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP |
                                TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT |
-                               TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET);
+                               TIPC_BCAST_RESET);
 
        spin_unlock_bh(&node->lock);
 
@@ -964,12 +955,6 @@ void tipc_node_unlock(struct tipc_node *node)
                tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
                                      link_id, addr);
 
-       if (flags & TIPC_MSG_EVT)
-               tipc_sk_rcv(net, inputq);
-
-       if (flags & TIPC_NAMED_MSG_EVT)
-               tipc_named_rcv(net, namedq);
-
        if (flags & TIPC_BCAST_MSG_EVT)
                tipc_bclink_input(net);
 
@@ -1270,6 +1255,9 @@ unlock:
        if (unlikely(rc & TIPC_LINK_DOWN_EVT))
                tipc_node_link_down(n, bearer_id, false);
 
+       if (unlikely(!skb_queue_empty(&n->bclink.namedq)))
+               tipc_named_rcv(net, &n->bclink.namedq);
+
        if (!skb_queue_empty(&le->inputq))
                tipc_sk_rcv(net, &le->inputq);
 

diff --git a/net/tipc/node.h b/net/tipc/node.h
index 9a97746..344b3e7 100644 (file)
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -53,13 +53,11 @@
  * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
  */
 enum {
-       TIPC_MSG_EVT                    = 1,
        TIPC_NOTIFY_NODE_DOWN           = (1 << 3),
        TIPC_NOTIFY_NODE_UP             = (1 << 4),
        TIPC_WAKEUP_BCAST_USERS         = (1 << 5),
        TIPC_NOTIFY_LINK_UP             = (1 << 6),
        TIPC_NOTIFY_LINK_DOWN           = (1 << 7),
-       TIPC_NAMED_MSG_EVT              = (1 << 8),
        TIPC_BCAST_MSG_EVT              = (1 << 9),
        TIPC_BCAST_RESET                = (1 << 10)
 };
@@ -124,8 +122,6 @@ struct tipc_node {
        spinlock_t lock;
        struct net *net;
        struct hlist_node hash;
-       struct sk_buff_head *inputq;
-       struct sk_buff_head *namedq;
        int active_links[2];
        struct tipc_link_entry links[MAX_BEARERS];
        int action_flags;