From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [1/4] bonding: don't call slave_xxx_netpoll under spinlocks Date: Sat, 20 Jul 2013 12:38:01 +0200 Message-ID: <20130720103800.GB9149@redhat.com> References: <51EA3B03.7010302@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Netdev To: dingtianhong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4148 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752467Ab3GTKix (ORCPT ); Sat, 20 Jul 2013 06:38:53 -0400 Content-Disposition: inline In-Reply-To: <51EA3B03.7010302@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, Jul 20, 2013 at 03:23:47PM +0800, dingtianhong wrote: >the slave_xxx_netpoll may sleep, so it should't be called under spinlocks. I don't really see how it may sleep, it was specifically changed to not sleep actually. However, see below... > >the slave point of the bonding will not be changed outside rtnl lock, >so rtnl lock is enough here. Yep, as far as I see there's really no need to take the lock, both the slave list and the netpoll part are always protected by rtnl lock, unless I'm missing something, and indeed .ndo_netpoll_setup() is always called under rtnl. BTW, bond_netpoll_cleanup() has the same problem - maybe you could check if we can remove the bond->lock from there also and update the patch? > >Signed-off-by: Ding Tianhong > >--- >drivers/net/bonding/bond_main.c | 15 +++------------ > 1 file changed, 3 insertions(+), 12 deletions(-) > >diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c >index 07f257d4..5eb75ef 100644 >--- a/drivers/net/bonding/bond_main.c >+++ b/drivers/net/bonding/bond_main.c >@@ -1249,8 +1249,9 @@ static void bond_poll_controller(struct net_device *bond_dev) > { > } > >-static void __bond_netpoll_cleanup(struct bonding *bond) >+static void bond_netpoll_cleanup(struct net_device *bond_dev) > { >+ struct bonding *bond = netdev_priv(bond_dev); > struct slave *slave; > int i; > >@@ -1258,14 +1259,6 @@ static void __bond_netpoll_cleanup(struct bonding *bond) > if (IS_UP(slave->dev)) > slave_disable_netpoll(slave); > } >-static void bond_netpoll_cleanup(struct net_device *bond_dev) >-{ >- struct bonding *bond = netdev_priv(bond_dev); >- >- read_lock(&bond->lock); >- __bond_netpoll_cleanup(bond); >- read_unlock(&bond->lock); >-} > > static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, gfp_t gfp) > { >@@ -1273,15 +1266,13 @@ static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, g > struct slave *slave; > int i, err = 0; > >- read_lock(&bond->lock); > bond_for_each_slave(bond, slave, i) { > err = slave_enable_netpoll(slave); > if (err) { >- __bond_netpoll_cleanup(bond); >+ bond_netpoll_cleanup(dev); > break; > } > } >- read_unlock(&bond->lock); > return err; > } >