From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH net-next 1/5] bonding: convert to list API and replace bond's custom list Date: Wed, 31 Jul 2013 20:44:49 +0200 Message-ID: <51F95B21.5020004@redhat.com> References: <1375283553-32070-1-git-send-email-nikolay@redhat.com> <1375283553-32070-2-git-send-email-nikolay@redhat.com> <20130731113717.32f48d71@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, andy@greyhouse.net, davem@davemloft.net, fubar@us.ibm.com To: Stephen Hemminger Return-path: Received: from mx1.redhat.com ([209.132.183.28]:63622 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757210Ab3GaSpA (ORCPT ); Wed, 31 Jul 2013 14:45:00 -0400 In-Reply-To: <20130731113717.32f48d71@nehalam.linuxnetplumber.net> Sender: netdev-owner@vger.kernel.org List-ID: On 07/31/2013 08:37 PM, Stephen Hemminger wrote: > On Wed, 31 Jul 2013 17:12:29 +0200 > Nikolay Aleksandrov wrote: > >> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >> index 390061d..80e288c 100644 >> --- a/drivers/net/bonding/bond_3ad.c >> +++ b/drivers/net/bonding/bond_3ad.c >> @@ -143,10 +143,13 @@ static inline struct bonding *__get_bond_by_port(struct port *port) >> */ >> static inline struct port *__get_first_port(struct bonding *bond) >> { >> + struct slave *first_slave; >> + >> if (bond->slave_cnt == 0) >> return NULL; >> + first_slave = bond_first_slave(bond); > > As Jay said, it would be be better to have bond_first_slave return > NULL (if no slaves), and eliminate slave_cnt. It would also fix > a race here between slave_cnt and all slave's being removed. > Hi Stephen, First off - thank you for the review. What do you mean by eliminate slave_cnt ? We need it for various calculations throughout the bonding. There's no race here because read_lock(&bond->lock) is held every time this is called and slave_cnt can change only under write_lock of the same lock, the 3ad code is not yet converted to RCU. Nik