bonding: Don't hold lock when calling rtnl_unlock

Change bond_mii_monitor to not hold any locks when calling rtnl_unlock,
as rtnl_unlock can sleep (when acquring another mutex in netdev_run_todo).

Bug reported by Makito SHIOKAWA <mshiokawa@miraclelinux.com>, who
included a different patch.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 2c6da4969382..49a198206e3d 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2386,7 +2386,9 @@ void bond_mii_monitor(struct work_struct *work)
                 rtnl_lock();
                 read_lock(&bond->lock);
                 __bond_mii_monitor(bond, 1);
-                rtnl_unlock();
+                read_unlock(&bond->lock);
+                rtnl_unlock();  /* might sleep, hold no other locks */
+                read_lock(&bond->lock);
         }
 
         delay = ((bond->params.miimon * HZ) / 1000) ? : 1;