[PATCH v2] bonding: "primary_reselect" with "failure" is not working properly

[Mazhar Rana <ranamazharp@gmail.com>]

When "primary_reselect" is set to "failure", primary interface should
not become active until current active slave is up. But if we set first
member of bond device as a "primary" interface and "primary_reselect"
is set to "failure" then whenever primary interface's link get back(up)
it become active slave even if current active slave is still up.

With this patch, "bond_find_best_slave" will not traverse members if
primary interface is not candidate for failover/reselection and current
active slave is still up.

Signed-off-by: Mazhar Rana <mazhar.rana@cyberoam.com>
Reviewed-by: Sanket Shah <sanket.shah@cyberoam.com>
---
v2: return "curr" instead of "bond->curr_active_slave".

 drivers/net/bonding/bond_main.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 19eb990..ac71261 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -715,7 +715,7 @@ static bool bond_should_change_active(struct bonding *bond)
  */
 static struct slave *bond_find_best_slave(struct bonding *bond)
 {
-	struct slave *slave, *bestslave = NULL, *primary;
+	struct slave *slave, *bestslave = NULL, *primary, *curr;
 	struct list_head *iter;
 	int mintime = bond->params.updelay;
 
@@ -724,6 +724,14 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
 	    bond_should_change_active(bond))
 		return primary;
 
+	/* We are here means primary interface is not candidate for
+	 * reslection/failover. If currenet active slave is still up
+	 * then there is no meaning to traverse  members.
+	 */
+	curr = rtnl_dereference(bond->curr_active_slave);
+	if (curr && curr->link == BOND_LINK_UP)
+		return curr;
+
 	bond_for_each_slave(bond, slave, iter) {
 		if (slave->link == BOND_LINK_UP)
 			return slave;
-- 
1.9.1