bonding: consolidate the two rlb_next_rx_slave functions into one

__rlb_next_rx_slave() is a copy of rlb_next_rx_slave() with the
difference that it uses rcu primitives to walk the slave list. We don't
need the two functions and can make rlb_next_rx_slave() a wrapper for
callers which hold RTNL.
So add a comment and ASSERT_RTNL() to make sure what is intended.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 85af961f13179f667f731421462607fed40edad8..4efdeb67ab7cc57543d25054e31728be3afa2a38 100644 (file)
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -334,14 +334,15 @@ out:
        return RX_HANDLER_ANOTHER;
 }
 
-static struct slave *rlb_next_rx_slave(struct bonding *bond)
+/* Caller must hold rcu_read_lock() */
+static struct slave *__rlb_next_rx_slave(struct bonding *bond)
 {
        struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
        struct slave *before = NULL, *rx_slave = NULL, *slave;
        struct list_head *iter;
        bool found = false;
 
-       bond_for_each_slave(bond, slave, iter) {
+       bond_for_each_slave_rcu(bond, slave, iter) {
                if (!bond_slave_can_tx(slave))
                        continue;
                if (!found) {
@@ -366,35 +367,16 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond)
        return rx_slave;
 }
 
-/* Caller must hold rcu_read_lock() */
-static struct slave *__rlb_next_rx_slave(struct bonding *bond)
+/* Caller must hold RTNL, rcu_read_lock is obtained only to silence checkers */
+static struct slave *rlb_next_rx_slave(struct bonding *bond)
 {
-       struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
-       struct slave *before = NULL, *rx_slave = NULL, *slave;
-       struct list_head *iter;
-       bool found = false;
+       struct slave *rx_slave;
 
-       bond_for_each_slave_rcu(bond, slave, iter) {
-               if (!bond_slave_can_tx(slave))
-                       continue;
-               if (!found) {
-                       if (!before || before->speed < slave->speed)
-                               before = slave;
-               } else {
-                       if (!rx_slave || rx_slave->speed < slave->speed)
-                               rx_slave = slave;
-               }
-               if (slave == bond_info->rx_slave)
-                       found = true;
-       }
-       /* we didn't find anything after the current or we have something
-        * better before and up to the current slave
-        */
-       if (!rx_slave || (before && rx_slave->speed < before->speed))
-               rx_slave = before;
+       ASSERT_RTNL();
 
-       if (rx_slave)
-               bond_info->rx_slave = rx_slave;
+       rcu_read_lock();
+       rx_slave = __rlb_next_rx_slave(bond);
+       rcu_read_unlock();
 
        return rx_slave;
 }