bonding: "primary_reselect" with "failure" is not working properly

Upstream commit b5a983f3141239b5.

When "primary_reselect" is set to "failure", primary interface should
not become active until current active slave is down. 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 gets back(up)
it becomes 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.

Orabug: 24831739

Reviewed-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Mazhar Rana <mazhar.rana@cyberoam.com>
Signed-off-by: Jay Vosburgh <j.vosburgh@gmail.com>
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 16440d2e97fd70658c934598fd7aba9a63f2d777..75016ccc090c1a3945103d5b00b4351e046858da 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -709,40 +709,57 @@ out:
 
 }
 
-static bool bond_should_change_active(struct bonding *bond)
+static struct slave *bond_choose_primary_or_current(struct bonding *bond)
 {
        struct slave *prim = rtnl_dereference(bond->primary_slave);
        struct slave *curr = rtnl_dereference(bond->curr_active_slave);
 
-       if (!prim || !curr || curr->link != BOND_LINK_UP)
-               return true;
+       if (!prim || prim->link != BOND_LINK_UP) {
+               if (!curr || curr->link != BOND_LINK_UP)
+                       return NULL;
+               return curr;
+       }
+
        if (bond->force_primary) {
                bond->force_primary = false;
-               return true;
+               return prim;
+       }
+
+       if (!curr || curr->link != BOND_LINK_UP)
+               return prim;
+
+       /* At this point, prim and curr are both up */
+       switch (bond->params.primary_reselect) {
+       case BOND_PRI_RESELECT_ALWAYS:
+               return prim;
+       case BOND_PRI_RESELECT_BETTER:
+               if (prim->speed < curr->speed)
+                       return curr;
+               if (prim->speed == curr->speed && prim->duplex <= curr->duplex)
+                       return curr;
+               return prim;
+       case BOND_PRI_RESELECT_FAILURE:
+               return curr;
+       default:
+               netdev_err(bond->dev, "impossible primary_reselect %d\n",
+                          bond->params.primary_reselect);
+               return curr;
        }
-       if (bond->params.primary_reselect == BOND_PRI_RESELECT_BETTER &&
-           (prim->speed < curr->speed ||
-            (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
-               return false;
-       if (bond->params.primary_reselect == BOND_PRI_RESELECT_FAILURE)
-               return false;
-       return true;
 }
 
 /**
- * find_best_interface - select the best available slave to be the active one
+ * bond_find_best_slave - select the best available slave to be the active one
  * @bond: our bonding struct
  */
 static struct slave *bond_find_best_slave(struct bonding *bond)
 {
-       struct slave *slave, *bestslave = NULL, *primary;
+       struct slave *slave, *bestslave = NULL;
        struct list_head *iter;
        int mintime = bond->params.updelay;
 
-       primary = rtnl_dereference(bond->primary_slave);
-       if (primary && primary->link == BOND_LINK_UP &&
-           bond_should_change_active(bond))
-               return primary;
+       slave = bond_choose_primary_or_current(bond);
+       if (slave)
+               return slave;
 
        bond_for_each_slave(bond, slave, iter) {
                if (slave->link == BOND_LINK_UP)