bonding: fix locking in sysfs primary/active selection
Fix the functions that store the primary and active slave
options via sysfs to hold the correct locks in the correct order.
The bond_change_active_slave and bond_select_active_slave
functions both require rtnl, bond->lock for read and curr_slave_lock for
write_bh, and no other locks. This is so that the lower level
mode-specific functions (notably for balance-alb mode) can release locks
down to just rtnl in order to call, e.g., dev_set_mac_address with the
locks it expects (rtnl only).
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 11b76b3..28a2d80 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -1075,7 +1075,10 @@
struct slave *slave;
struct bonding *bond = to_bond(d);
- write_lock_bh(&bond->lock);
+ rtnl_lock();
+ read_lock(&bond->lock);
+ write_lock_bh(&bond->curr_slave_lock);
+
if (!USES_PRIMARY(bond->params.mode)) {
printk(KERN_INFO DRV_NAME
": %s: Unable to set primary slave; %s is in mode %d\n",
@@ -1109,8 +1112,8 @@
}
}
out:
- write_unlock_bh(&bond->lock);
-
+ write_unlock_bh(&bond->curr_slave_lock);
+ read_unlock(&bond->lock);
rtnl_unlock();
return count;
@@ -1190,7 +1193,8 @@
struct bonding *bond = to_bond(d);
rtnl_lock();
- write_lock_bh(&bond->lock);
+ read_lock(&bond->lock);
+ write_lock_bh(&bond->curr_slave_lock);
if (!USES_PRIMARY(bond->params.mode)) {
printk(KERN_INFO DRV_NAME
@@ -1247,7 +1251,8 @@
}
}
out:
- write_unlock_bh(&bond->lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+ read_unlock(&bond->lock);
rtnl_unlock();
return count;
