tipc: Simplify bearer shutdown logic

Optimize processing in TIPC's bearer shutdown code, including:

1. Remove an unnecessary check to see if TIPC bearer's can exist.
2. Don't release spinlocks before calling a media-specific disabling
routine, since the routine can't sleep.
3. Make bearer_disable() operate directly on a struct bearer, instead
of needlessly taking a name and then mapping that to the struct.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Reviewed-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/tipc/bearer.c

@@ -288,9 +288,6 @@ static struct bearer *bearer_find(const char *name)
 	struct bearer *b_ptr;
 	u32 i;
 
-	if (tipc_mode != TIPC_NET_MODE)
-		return NULL;
-
 	for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
 		if (b_ptr->active && (!strcmp(b_ptr->publ.name, name)))
 			return b_ptr;
@@ -630,30 +627,17 @@ int tipc_block_bearer(const char *name)
  * Note: This routine assumes caller holds tipc_net_lock.
  */
 
-static int bearer_disable(const char *name)
+static int bearer_disable(struct bearer *b_ptr)
 {
-	struct bearer *b_ptr;
 	struct link *l_ptr;
 	struct link *temp_l_ptr;
 
-	b_ptr = bearer_find(name);
-	if (!b_ptr) {
-		warn("Attempt to disable unknown bearer <%s>\n", name);
-		return -EINVAL;
-	}
-
-	info("Disabling bearer <%s>\n", name);
+	info("Disabling bearer <%s>\n", b_ptr->publ.name);
 	tipc_disc_stop_link_req(b_ptr->link_req);
 	spin_lock_bh(&b_ptr->publ.lock);
 	b_ptr->link_req = NULL;
 	b_ptr->publ.blocked = 1;
-	if (b_ptr->media->disable_bearer) {
-		spin_unlock_bh(&b_ptr->publ.lock);
-		write_unlock_bh(&tipc_net_lock);
-		b_ptr->media->disable_bearer(&b_ptr->publ);
-		write_lock_bh(&tipc_net_lock);
-		spin_lock_bh(&b_ptr->publ.lock);
-	}
+	b_ptr->media->disable_bearer(&b_ptr->publ);
 	list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
 		tipc_link_delete(l_ptr);
 	}
@@ -664,10 +648,16 @@ static int bearer_disable(const char *name)
 
 int tipc_disable_bearer(const char *name)
 {
+	struct bearer *b_ptr;
 	int res;
 
 	write_lock_bh(&tipc_net_lock);
-	res = bearer_disable(name);
+	b_ptr = bearer_find(name);
+	if (b_ptr == NULL) {
+		warn("Attempt to disable unknown bearer <%s>\n", name);
+		res = -EINVAL;
+	} else
+		res = bearer_disable(b_ptr);
 	write_unlock_bh(&tipc_net_lock);
 	return res;
 }
@@ -680,13 +670,7 @@ void tipc_bearer_stop(void)
 
 	for (i = 0; i < MAX_BEARERS; i++) {
 		if (tipc_bearers[i].active)
-			tipc_bearers[i].publ.blocked = 1;
-	}
-	for (i = 0; i < MAX_BEARERS; i++) {
-		if (tipc_bearers[i].active)
-			bearer_disable(tipc_bearers[i].publ.name);
+			bearer_disable(&tipc_bearers[i]);
 	}
 	media_count = 0;
 }
-
-