Messages in this thread | | | Subject | Re: [Patch V2] bonding: fix potential deadlock in bond_uninit() | From | (Eric W. Biederman) | Date | Wed, 31 Mar 2010 23:12:22 -0700 |
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Amerigo Wang <amwang@redhat.com> writes:
> bond_uninit() is invoked with rtnl_lock held, when it does destroy_workqueue() > which will potentially flush all works in this workqueue, if we hold rtnl_lock > again in the work function, it will deadlock. > > So move destroy_workqueue() to destructor where rtnl_lock is not held any more, > suggested by Eric.
The error handling on creating a bond device needs to be updated as well.
Eric
> Signed-off-by: WANG Cong <amwang@redhat.com> > Cc: Jay Vosburgh <fubar@us.ibm.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Stephen Hemminger <shemminger@vyatta.com> > Cc: Jiri Pirko <jpirko@redhat.com> > Cc: "Eric W. Biederman" <ebiederm@xmission.com> > > --- > > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c > index 5b92fbf..9f0aaa2 100644 > --- a/drivers/net/bonding/bond_main.c > +++ b/drivers/net/bonding/bond_main.c > @@ -4450,6 +4450,14 @@ static const struct net_device_ops bond_netdev_ops = { > .ndo_vlan_rx_kill_vid = bond_vlan_rx_kill_vid, > }; > > +static void bond_destructor(struct net_device *bond_dev) > +{ > + struct bonding *bond = netdev_priv(bond_dev); > + if (bond->wq) > + destroy_workqueue(bond->wq); > + free_netdev(bond_dev); > +} > + > static void bond_setup(struct net_device *bond_dev) > { > struct bonding *bond = netdev_priv(bond_dev); > @@ -4470,7 +4478,7 @@ static void bond_setup(struct net_device *bond_dev) > bond_dev->ethtool_ops = &bond_ethtool_ops; > bond_set_mode_ops(bond, bond->params.mode); > > - bond_dev->destructor = free_netdev; > + bond_dev->destructor = bond_destructor; > > /* Initialize the device options */ > bond_dev->tx_queue_len = 0; > @@ -4542,9 +4550,6 @@ static void bond_uninit(struct net_device *bond_dev) > > bond_remove_proc_entry(bond); > > - if (bond->wq) > - destroy_workqueue(bond->wq); > - > netif_addr_lock_bh(bond_dev); > bond_mc_list_destroy(bond); > netif_addr_unlock_bh(bond_dev);
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