tipc: define new functions to operate bc_lock

As we are going to do more jobs when bc_lock is released, the two
operations of holding/releasing the lock should be encapsulated with
functions. In addition, we move bc_lock spin lock into tipc_bclink
structure avoiding to define the global variable.

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

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 119a59b..9eceaa7 100644 (file)
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -71,7 +71,7 @@ struct tipc_bcbearer_pair {
  * Note: The fields labelled "temporary" are incorporated into the bearer
  * to avoid consuming potentially limited stack space through the use of
  * large local variables within multicast routines.  Concurrent access is
- * prevented through use of the spinlock "bc_lock".
+ * prevented through use of the spinlock "bclink_lock".
  */
 struct tipc_bcbearer {
        struct tipc_bearer bearer;
@@ -84,6 +84,7 @@ struct tipc_bcbearer {
 
 /**
  * struct tipc_bclink - link used for broadcast messages
+ * @lock: spinlock governing access to structure
  * @link: (non-standard) broadcast link structure
  * @node: (non-standard) node structure representing b'cast link's peer node
  * @bcast_nodes: map of broadcast-capable nodes
@@ -92,6 +93,7 @@ struct tipc_bcbearer {
  * Handles sequence numbering, fragmentation, bundling, etc.
  */
 struct tipc_bclink {
+       spinlock_t lock;
        struct tipc_link link;
        struct tipc_node node;
        struct tipc_node_map bcast_nodes;
@@ -105,8 +107,6 @@ static struct tipc_bcbearer *bcbearer = &bcast_bearer;
 static struct tipc_bclink *bclink = &bcast_link;
 static struct tipc_link *bcl = &bcast_link.link;
 
-static DEFINE_SPINLOCK(bc_lock);
-
 const char tipc_bclink_name[] = "broadcast-link";
 
 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
@@ -115,6 +115,16 @@ static void tipc_nmap_diff(struct tipc_node_map *nm_a,
 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node);
 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node);
 
+static void tipc_bclink_lock(void)
+{
+       spin_lock_bh(&bclink->lock);
+}
+
+static void tipc_bclink_unlock(void)
+{
+       spin_unlock_bh(&bclink->lock);
+}
+
 static u32 bcbuf_acks(struct sk_buff *buf)
 {
        return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
@@ -132,16 +142,16 @@ static void bcbuf_decr_acks(struct sk_buff *buf)
 
 void tipc_bclink_add_node(u32 addr)
 {
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
        tipc_nmap_add(&bclink->bcast_nodes, addr);
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 }
 
 void tipc_bclink_remove_node(u32 addr)
 {
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
        tipc_nmap_remove(&bclink->bcast_nodes, addr);
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 }
 
 static void bclink_set_last_sent(void)
@@ -167,7 +177,7 @@ static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
 /**
  * tipc_bclink_retransmit_to - get most recent node to request retransmission
  *
- * Called with bc_lock locked
+ * Called with bclink_lock locked
  */
 struct tipc_node *tipc_bclink_retransmit_to(void)
 {
@@ -179,7 +189,7 @@ struct tipc_node *tipc_bclink_retransmit_to(void)
  * @after: sequence number of last packet to *not* retransmit
  * @to: sequence number of last packet to retransmit
  *
- * Called with bc_lock locked
+ * Called with bclink_lock locked
  */
 static void bclink_retransmit_pkt(u32 after, u32 to)
 {
@@ -196,7 +206,7 @@ static void bclink_retransmit_pkt(u32 after, u32 to)
  * @n_ptr: node that sent acknowledgement info
  * @acked: broadcast sequence # that has been acknowledged
  *
- * Node is locked, bc_lock unlocked.
+ * Node is locked, bclink_lock unlocked.
  */
 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 {
@@ -204,8 +214,7 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
        struct sk_buff *next;
        unsigned int released = 0;
 
-       spin_lock_bh(&bc_lock);
-
+       tipc_bclink_lock();
        /* Bail out if tx queue is empty (no clean up is required) */
        crs = bcl->first_out;
        if (!crs)
@@ -269,7 +278,7 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
        if (unlikely(released && !list_empty(&bcl->waiting_ports)))
                tipc_link_wakeup_ports(bcl, 0);
 exit:
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 }
 
 /**
@@ -322,10 +331,10 @@ void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
                                 ? buf_seqno(n_ptr->bclink.deferred_head) - 1
                                 : n_ptr->bclink.last_sent);
 
-               spin_lock_bh(&bc_lock);
+               tipc_bclink_lock();
                tipc_bearer_send(MAX_BEARERS, buf, NULL);
                bcl->stats.sent_nacks++;
-               spin_unlock_bh(&bc_lock);
+               tipc_bclink_unlock();
                kfree_skb(buf);
 
                n_ptr->bclink.oos_state++;
@@ -362,7 +371,7 @@ int tipc_bclink_xmit(struct sk_buff *buf)
 {
        int res;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
 
        if (!bclink->bcast_nodes.count) {
                res = msg_data_sz(buf_msg(buf));
@@ -377,14 +386,14 @@ int tipc_bclink_xmit(struct sk_buff *buf)
                bcl->stats.accu_queue_sz += bcl->out_queue_size;
        }
 exit:
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
        return res;
 }
 
 /**
  * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
  *
- * Called with both sending node's lock and bc_lock taken.
+ * Called with both sending node's lock and bclink_lock taken.
  */
 static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
 {
@@ -439,12 +448,12 @@ void tipc_bclink_rcv(struct sk_buff *buf)
                if (msg_destnode(msg) == tipc_own_addr) {
                        tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
                        tipc_node_unlock(node);
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bcl->stats.recv_nacks++;
                        bclink->retransmit_to = node;
                        bclink_retransmit_pkt(msg_bcgap_after(msg),
                                              msg_bcgap_to(msg));
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                } else {
                        tipc_node_unlock(node);
                        bclink_peek_nack(msg);
@@ -462,20 +471,20 @@ receive:
                /* Deliver message to destination */
 
                if (likely(msg_isdata(msg))) {
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bclink_accept_pkt(node, seqno);
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                        tipc_node_unlock(node);
                        if (likely(msg_mcast(msg)))
                                tipc_port_mcast_rcv(buf, NULL);
                        else
                                kfree_skb(buf);
                } else if (msg_user(msg) == MSG_BUNDLER) {
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bclink_accept_pkt(node, seqno);
                        bcl->stats.recv_bundles++;
                        bcl->stats.recv_bundled += msg_msgcnt(msg);
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                        tipc_node_unlock(node);
                        tipc_link_bundle_rcv(buf);
                } else if (msg_user(msg) == MSG_FRAGMENTER) {
@@ -485,28 +494,28 @@ receive:
                                                 &buf);
                        if (ret == LINK_REASM_ERROR)
                                goto unlock;
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bclink_accept_pkt(node, seqno);
                        bcl->stats.recv_fragments++;
                        if (ret == LINK_REASM_COMPLETE) {
                                bcl->stats.recv_fragmented++;
                                /* Point msg to inner header */
                                msg = buf_msg(buf);
-                               spin_unlock_bh(&bc_lock);
+                               tipc_bclink_unlock();
                                goto receive;
                        }
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                        tipc_node_unlock(node);
                } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bclink_accept_pkt(node, seqno);
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                        tipc_node_unlock(node);
                        tipc_named_rcv(buf);
                } else {
-                       spin_lock_bh(&bc_lock);
+                       tipc_bclink_lock();
                        bclink_accept_pkt(node, seqno);
-                       spin_unlock_bh(&bc_lock);
+                       tipc_bclink_unlock();
                        tipc_node_unlock(node);
                        kfree_skb(buf);
                }
@@ -552,14 +561,14 @@ receive:
        } else
                deferred = 0;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
 
        if (deferred)
                bcl->stats.deferred_recv++;
        else
                bcl->stats.duplicates++;
 
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 
 unlock:
        tipc_node_unlock(node);
@@ -663,7 +672,7 @@ void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
        int b_index;
        int pri;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
 
        if (action)
                tipc_nmap_add(nm_ptr, node);
@@ -710,7 +719,7 @@ void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
                bp_curr++;
        }
 
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 }
 
 
@@ -722,7 +731,7 @@ int tipc_bclink_stats(char *buf, const u32 buf_size)
        if (!bcl)
                return 0;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
 
        s = &bcl->stats;
 
@@ -751,7 +760,7 @@ int tipc_bclink_stats(char *buf, const u32 buf_size)
                             s->queue_sz_counts ?
                             (s->accu_queue_sz / s->queue_sz_counts) : 0);
 
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
        return ret;
 }
 
@@ -760,9 +769,9 @@ int tipc_bclink_reset_stats(void)
        if (!bcl)
                return -ENOPROTOOPT;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
        memset(&bcl->stats, 0, sizeof(bcl->stats));
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
        return 0;
 }
 
@@ -773,9 +782,9 @@ int tipc_bclink_set_queue_limits(u32 limit)
        if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
                return -EINVAL;
 
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
        tipc_link_set_queue_limits(bcl, limit);
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
        return 0;
 }
 
@@ -785,6 +794,7 @@ void tipc_bclink_init(void)
        bcbearer->media.send_msg = tipc_bcbearer_send;
        sprintf(bcbearer->media.name, "tipc-broadcast");
 
+       spin_lock_init(&bclink->lock);
        INIT_LIST_HEAD(&bcl->waiting_ports);
        bcl->next_out_no = 1;
        spin_lock_init(&bclink->node.lock);
@@ -799,9 +809,9 @@ void tipc_bclink_init(void)
 
 void tipc_bclink_stop(void)
 {
-       spin_lock_bh(&bc_lock);
+       tipc_bclink_lock();
        tipc_link_purge_queues(bcl);
-       spin_unlock_bh(&bc_lock);
+       tipc_bclink_unlock();
 
        RCU_INIT_POINTER(bearer_list[BCBEARER], NULL);
        memset(bclink, 0, sizeof(*bclink));