bonding: rework rlb_next_rx_slave() to use bond_for_each_slave()

Currently, we're using bond_for_each_slave_from(), which is really hard to
implement under RCU and/or neighbour list.

Remove it and use bond_for_each_slave() instead, taking care of the last
used slave.

Also, rename next_rx_slave to rx_slave and store the current (last)
rx_slave.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 22 insertions, 23 deletions

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index f4929cee21a6..c5b85ad5554d 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -383,30 +383,31 @@ out:
 static struct slave *rlb_next_rx_slave(struct bonding *bond)
 {
         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
-        struct slave *rx_slave, *slave, *start_at;
-        int i = 0;
-
-        if (bond_info->next_rx_slave)
-                start_at = bond_info->next_rx_slave;
-        else
-                start_at = bond_first_slave(bond);
-
-        rx_slave = NULL;
+        struct slave *before = NULL, *rx_slave = NULL, *slave;
+        struct list_head *iter;
+        bool found = false;
 
-        bond_for_each_slave_from(bond, slave, i, start_at) {
-                if (SLAVE_IS_OK(slave)) {
-                        if (!rx_slave) {
-                                rx_slave = slave;
-                        } else if (slave->speed > rx_slave->speed) {
+        bond_for_each_slave(bond, slave, iter) {
+                if (!SLAVE_IS_OK(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;
 
-        if (rx_slave) {
-                slave = bond_next_slave(bond, rx_slave);
-                bond_info->next_rx_slave = slave;
-        }
+        if (rx_slave)
+                bond_info->rx_slave = rx_slave;
 
         return rx_slave;
 }
@@ -1611,7 +1612,7 @@ void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
         tlb_clear_slave(bond, slave, 0);
 
         if (bond->alb_info.rlb_enabled) {
-                bond->alb_info.next_rx_slave = NULL;
+                bond->alb_info.rx_slave = NULL;
                 rlb_clear_slave(bond, slave);
         }
 }
diff --git a/drivers/net/bonding/bond_alb.h b/drivers/net/bonding/bond_alb.h
index c5eff5dafdfe..4226044efd08 100644
--- a/drivers/net/bonding/bond_alb.h
+++ b/drivers/net/bonding/bond_alb.h
@@ -154,9 +154,7 @@ struct alb_bond_info {
         u8                      rx_ntt; /* flag - need to transmit
                                          * to all rx clients
                                          */
-        struct slave            *next_rx_slave;/* next slave to be assigned
-                                                * to a new rx client for
-                                                */
+        struct slave            *rx_slave;/* last slave to xmit from */
         u8                      primary_is_promisc;        /* boolean */
         u32                     rlb_promisc_timeout_counter;/* counts primary
                                                              * promiscuity time