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>

1 files changed, 10 insertions, 28 deletions

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 85af961f1317..4efdeb67ab7c 100644
--- 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;
 }